SOPM20-11-01印刷电路组件和元件板组件的修理

印刷电路组件和元件板组件的修理REPAIR OF PRINTED CIRCUIT ASSEMBLIES AND COMPONENT BOARD ASSEMBLIES

1. INTRODUCTION 介绍

A. The data in this subject comes from the Boeing Process Specifications identified in Paragraph 1.C.. Access to the Boeing Process Specifications is available.

本主题中的数据来自第 1.C 段中的波音工艺规范。可查阅波音工艺规范。

B. The data is general. It is not about all situations or specific installations. Use this data to help you write minimum requirements.

数据是通用的。它不涉及所有情况或特定安装。使用此数据可帮助您编写最低要求。

C. For more details, refer to these Boeing Process Specifications.

有关详细信息，请参阅这些波音工艺规范。

(1) BAC5162-60 — Assembly of BACC65-series connectors

BAC5162-60 — BACC65 系列连接器的装配

(2) BAC5128 — Requirements for Electrical/Electronic Assemblies, which replaces:

BAC5128 — 电气/电子装配要求，它取代了

(a) BAC5850 — Polyurethane Resin Conformal Coating

BAC5850 — 聚氨酯树脂保形涂料

(b) BAC5853 — Installation of Electronic Parts on Printed Circuit Boards

BAC5853 — 在印刷电路板上安装电子零件

(3) BAC5891 — Modification and Rework of Printed-Wiring Boards and Assemblies

BAC5891 — 印刷线路板和组件的修改和返工

D. This subject tells you how to repair printed circuits where components are mounted in holes through the board. For removal and replacement of surface mounted components, refer to SOPM 20-11-07. For removal and replacement of ball grid array components, refer to SOPM 20-11-10.

本主题将向您介绍如何修理元件安装在电路板孔中的印刷电路。有关拆卸和更换表面安装部件，请参阅 SOPM 20-11-07。有关球形网格阵列元件的拆卸和更换，请参阅 SOPM 20-11-10。

E. Refer to SOPM 20-00-00 for a list of all the vendor names and addresses.

有关所有供应商的名称和地址，请参阅 SOPM 20-00-00。

2. DEFINITIONS 定义

NOTE: BAC5035 is a glossary of many general electrical and electronic terms. Some of the terms used in this subject are given below.

注：BAC5035 是许多通用电气和电子术语的词汇表。本主题中使用的一些术语如下。

A. Circuit Pads — Areas along the metal circuit pattern which are shaped or drilled to permit connection to the leads of the components.

电路板 — 金属电路板上的区域，其形状或钻孔允许与元件引线连接。

B. Component Board Assembly — A board that has components installed on it, but the electrical connections are not made by the etch procedure.

元件板组件 — 已安装元件但未通过蚀刻程序进行电气连接的电路板。

C. Conformal Coating — See Encapsulant

保形涂料 — 参见封装剂

D. Dual in Line Flat Pack — An electronic component in a rectangular shape with two parallel rows of pins or leads that extend from opposite sides of the part and are then bent downwards.

双列平面包 — 一种长方形的电子部件，有两排平行的引脚或引线，从零件的相对两侧伸出，然后向下弯曲。

E. Encapsulant (coating) — A layer of acrylic, polyurethane, or other material applied to a circuit to give protection from abrasion, moisture, and help hold components in position.

封装剂（涂层） — 电路上的一层丙烯酸、聚氨酯或其他材料，用于防止磨损和受潮，并帮助固定元件位置。

F. Etched Circuit Board — A board with the metal circuit pattern made by a chemical procedure.

蚀刻电路板 — 通过化学程序制作金属电路图案的电路板。

G. Feed-Through or Interconnect — A wire or swaged hardware device through a circuit board to make electrical connection between the circuit on one side and the circuit on the other side.

馈通或互连 — 一种穿过电路板的导线或压接硬件装置，用于实现一侧电路与另一侧电路之间的电气连接。

H. Flat Pack — A configuration of electronic component with ribbon leads that extend from the edges.

平面包 — 一种电子元件结构，其带状引线从边缘延伸。

I. Icicle — A sharp cone-shaped point in the solder of a connection.

冰柱 — 连接处焊料中尖锐的锥形点。

J. Printed Circuit Assembly (PCA) — An etched circuit board with components installed.

印刷电路组件 (PCA) — 安装了元件的蚀刻电路板。

K. Printed Circuit Board (PCB) — An etched circuit board without the components installed.

印刷电路板 (PCB) — 没有安装元件的蚀刻电路板。

L. TO-Type Can — A configuration of electronic component which is a metal cylinder with wire leads that come out from the bottom (for commonly used low power transistors and integrated circuits).

TO型罐 — 一种电子元件结构，它是一个金属圆筒，导线从底部伸出（常用于低功率晶体管和集成电路）。

3. GENERAL 通用

CAUTION ：MANY OF THESE COMPONENTS CAN BE DAMAGED BY ELECTROSTATIC DISCHARGE. IF YOU SEE YELLOW, STATIC-SENSITIVE, CAUTION LABELS, REFER TO SOPM 20-12-02 FOR INSTRUCTIONS.

注意：这些部件中有许多会因静电放电而损坏。如果看到黄色的静电敏感警告标签，请参阅 SOPM 20-12-02 中的说明。

A. Be careful with all electronic components to prevent problems with lead stress, dents, scratches, twists, or cracks.

小心处理所有电子元件，防止出现引线应力、凹痕、划痕、扭曲或裂纹等问题。

B. Do not use a lead pencil or other conductive material which can leave a conductive residue to trace circuitry, or to touch any part of the board or any electronic part.

不要使用铅笔或其他会留下导电残留物的导电材料来勾勒电路，也不要接触电路板的任何部分或任何电子零件。

C. Compressed air, as in forced air dryers, must have a maximum of 3 ppm by weight of hydrocarbons at the work surface.

压缩空气，如强力空气干燥器中的压缩空气，在工作表面的碳氢化合物重量比不得超过 3 ppm。

D. Install all components to let you see part numbers and serialized labels. If the data comes off or cannot be seen after installation, you can mark or identify it again as necessary.

安装所有零件时要让您看到件号和序列化标签。如果安装后数据脱落或无法看到，可以根据需要重新标记或识别。

E. Always hold boards by their edges, but not by the electric contact edge.

始终握住电路板的边缘，但不要握住电链接边缘。

F. To help prevent damage to the units, use cushioning material on the work bench surface, such as a 1/8 inch or thicker rubber mat. BAC5485 gives recommended items.

为防止设备损坏，请在工作台表面使用缓冲材料，如 1/8 英寸或更厚的橡胶垫。BAC5485 提供了推荐项目。

G. Examine the electronic unit if it fell 6 inches or more onto a hard surface. Do tests as necessary.

如果电子单元跌落到 6 英寸或更高的硬表面上，则对其进行检查。必要时进行测试。

H. If damage occurs during overhaul, repair it the same as an original defect.

如果在大修过程中出现损坏，应按照原有缺陷进行修复。

I. Be careful not to damage adjacent components. If necessary, remove adjacent components that prevent removal of a bad component.

小心不要损坏邻近的部件。如有必要，拆下妨碍拆卸故障部件的相邻部件。

J. Remove as one unit the bad components mounted on heat sinks when the heat sink is attached to the board, unless the heat sink is riveted to the board. Then you can remove the component from the heat sink without removal of the heat sink from the board.

当散热片连接到电路板上时，将安装在散热片上的坏元件作为一个整体拆下，除非散热片是铆接到电路板上的。在这种情况下，可以将元件从散热片上拆下，而无需将散热片从电路板上拆下。

K. Printed circuit boards are serviceable if there is only a small change in color because of heat. A board is not serviceable if it is charred, blistered, if the laminations break apart, or if the epoxy coating is burned or melted because of too much heat.

如果电路板受热后颜色变化很小，则可以使用。如果电路板烧焦、起泡、层压板破裂或环氧树脂涂层因受热过多而烧焦或融化，则不能使用。

L. When you install bare conductors, keep a 0.10 inch minimum air gap from other bare metal conductors or parts.

安装裸露导体时，与其他裸露金属导体或零件保持最小 0.10 英寸的空气间隙。

M. Do not put tension or compression on leads in the finished assembly. Components with rigid leads mounted by threaded fasteners must have the fasteners fully tightened before soldering. Do not loosen or tighten mounting screws and nuts after soldering.

不要对成品组件中的导线施加拉力或压力。用螺纹紧固件安装刚性引线的元件必须在焊接前完全拧紧紧固件。焊接后不得松动或拧紧安装螺钉和螺母。

N. Do not try to move, pull or push a component or lead as a check of the mechanical strength of a solder joint. This will cause poor or broken solder connections and could tear the copper from the board.

不要试图移动、拉动或推动元件或引线来检查焊点的机械强度。这将导致焊接连接不良或断裂，并可能撕裂电路板上的铜。

O. If the overhaul instructions tell you to bond parts to the circuit board, but the adhesive is not specified, bond them with Type 69 or Type 52 as specified in SOPM 20-50-12 (Figure 1).

如果大修说明告诉您将零件粘接到电路板上，但没有规定粘接剂，则应按照 SOPM 20-50-12 （图 1）的规定使用 69 型或 52 型粘接剂进行粘接。

P. Do not bend a board to remove the warp. You could break the board or pull the components loose. The warp will be removed when the board is mounted.

切勿弯曲电路板以去除翘曲。否则可能会弄坏电路板或拉松元件。安装电路板时翘曲将被移除。

(1) When measured by this procedure, the warp or twist of the circuit board must not be more than 1.5 percent.

用此程序测量时，电路板的翘曲或扭曲不得超过 1.5%。

(a) Put the loose board by itself on a flat, horizontal surface with the convex surface up.

将松动的电路板，使其凸面向上单独放在一个平坦的水平面上。

(b) Measure the height of the convex upper surface. Subtract the thickness of the board. Divide by the length of the longest side and convert to a percent.

测量凸起上表面的高度。减去电路板的厚度。除以最长边的长度，换算成百分数。

(2) Measurement is not necessary if you can see that the circuit board does not have too much warp.

如果可以看到电路板没有太多翘曲，则无需测量。

Q. Do not put printed boards in a stack. Put them side by side on their edges.

不要将印刷电路板堆放在一起。将它们并排放在边缘上。

R. Clean contamination from the leads with gauze or swab and isopropyl alcohol.

用纱布或棉签和异丙醇清除引线上的污染物。

S. Tin leads as necessary, as specified in BAC5128.

根据 BAC5128 规定的要求，在必要时为引线镀锡。

T. Install all parts to prevent small spaces that could catch flux residues. Solder by hand the parts and wires that could catch flux.

安装所有零件时，防止出现可能接触助焊剂残留物的狭小空间。用手焊接可能接触助焊剂的零件和导线。

4. FAULT ISOLATION AND REPAIR QUALITY CHECKS 故障隔离和修理质量检查

A. Visually examine all electronic equipment before all tests and after all repairs. This inspection is to make sure you find obvious defects first, to make sure the repairs did not cause more damage, and to look for defects that could cause more damage if power is applied. Use 4X to 10X magnification if necessary. The board must not have these defects:

在所有测试之前和修理之后，对所有电子设备进行目视检查。检查的目的是确保首先发现明显的缺陷，确保修理没有造成更大的损坏，并查找通电后可能造成更大损坏的缺陷。必要时使用 4 倍至 10 倍放大镜。电路板不得有以下缺陷：

(1) Drops of solder

焊剂滴落

(2) Sharp points (icicles) on the solder surfaces

焊料表面有尖锐点（冰柱）

(3) Terminals, leads, or pad base metal areas without conformal coating

端子、引线或板基底金属区域无保形涂层

(4) Damage other than small concave empty spaces (indentations)

除了小凹陷空位（压痕）以外的损坏

(5) Rough holes 粗糙的孔

(6) Probe holes not repaired with conformal coating

未用保形涂料修复的探针孔

(7) Overheated electronic components

过热的电子元件

(8) Loose or missing mechanical hardware

机械硬件松动或丢失

(9) Defective operation of mechanical controls

机械控制操作有缺陷

(10) Frayed, burnt, pinched or broken wires

电线磨损、烧焦、挤压或断裂

(11) Loose components or circuit cards

元件或电路板松动

(12) Defects in mechanical, crimped or soldered connections

机械、压接或焊接连接有缺陷

(13) Missing, damaged, recessed or bent connector contacts

连接器插针缺失、损坏、凹陷或弯曲

(14) Defects in insulation around contacts

插针周围绝缘缺陷

(15) Defects in the case

外壳缺陷

(16) All defects (such as nicks, scratches, dents) in the conductor surface must not decrease the cross section area of the conductor more than 20 percent along no more than 0.80 inch of the conductor

导体表面的所有缺陷（如缺口、划痕、凹痕）不得使导体横截面积减少超过 20%，沿导体的长度不得超过 0.80 英寸。

B. Touch instrument probes to the solder joints or the component leads only.

仪器探针只能接触焊点或元件引线。

C. Use instrument probes with small, sharp points to go through the encapsulant. Hold the probe perpendicular to the encapsulant surface to make the hole as small as possible.

使用尖头小的仪器探针穿过封装材料。将探针垂直于封装表面，使孔尽可能小。

D. If you attach probe clips to component leads, be careful not to damage the leads.

如果在元件引线上安装探针夹，应小心不要损坏引线。

E. After the repair, do functional tests as necessary to be sure that the problem is gone.

修理后，根据需要进行功能测试，以确保问题已解决。

F. Clean and apply conformal coating to the probe holes and the repaired areas.

清洁探针孔和修理区域并涂上保形涂料。

G. Be sure to replace markings which were removed.

一定要更换被移除的标记。

5. REMOVAL OF CONFORMAL COATING (ENCAPSULANT)去除保形涂料（封装剂）

CAUTION ：WHEN YOU CLEAN CIRCUIT BOARDS OR REMOVE THE CONFORMAL COATING, FIRST TRY THE PROCEDURES FOR REMOVAL OF ACRYLIC COATING IN A SMALL TEST AREA BECAUSE ISOPROPYL ALCOHOL REMOVES ACRYLIC COATING.

注意：在清洁电路板或清除保形涂料时，由于异丙醇能清除丙烯酸涂层，因此应首先在小范围内尝试清除丙烯酸涂层的程序。

A. Apply a small quantity of isopropyl alcohol to a small test area. If the conformal coating becomes soft and removable, continue with this procedure to remove the conformal coating at the damaged area. If the coating stays hard, use the procedures for removal of polyurethane coatings or parylene as necessary. If the conformal coating is soft before you apply the alcohol, it could be a silicone coating that you can easily peel off. If it is, use the procedure for removal of silicone coatings.

在小测试区域涂抹少量异丙醇。如果保形涂料变软并可去除，则继续按此程序去除受损部位的保形涂料。如果涂层保持坚硬，则根据需要使用清除聚氨酯涂层或聚对二甲苯的程序。如果在使用异丙醇之前保形涂料是软的，那么它可能是硅树脂涂料，可以很容易地剥离。如果是，请使用去除硅树脂涂层的程序。

CAUTION ：BE CAREFUL NOT TO CUT OR CAUSE DAMAGE TO THE ADJACENT COMPONENTS OR THE FIRST FIBERGLASS LAYER OF THE BOARD.

注意：小心不要切割或损坏相邻元件或电路板的第一层玻璃纤维。

B. Break the bond between the encapsulant on the board and the component, with long nose pliers or a sharp cutting tool (scalpel). Push and pull in a direction perpendicular to the longitudinal axis of component.

用长嘴钳或锋利的切割工具（手术刀）破坏电路板上封装涂层与元件之间的粘合。沿垂直于元件纵轴的方向推拉。

NOTE: To help you remove the encapsulant coating, you can heat the board to 210°F. maximum for no more than 20 minutes.

注：为帮助去除封装涂层，可将电路板加热到 210°F 最高温度，时间不超过 20 分钟。

(1) As an alternative, apply a soldering iron with a component-removal tip. Be careful not to apply too much heat to adjacent electronic components during removal operations.

作为替代方法，使用带有元件拆卸尖头的烙铁。注意在拆卸过程中不要对邻近的电子元件加热过多。

(2) Use wire braid to soak up the melted encapsulant. Add a small quantity of solder flux to help soak up the melted encapsulant.

使用编织线吸收熔化的封装胶。加入少量焊剂，帮助浸透熔化的封装胶。

CAUTION ：BE VERY CAREFUL WHEN YOU REMOVE CONNECTORS WHICH HAVE CONFORMAL COATING. THE CIRCUIT BOARD CAN BE DAMAGED.

注意：拆卸有保形涂料的连接器时要非常小心。可能会损坏电路板。

C. Remove encapsulant from connector pin solder joints on the circuit side of the board and also on the screws which attach the connector. Refer to Paragraph 10. on how to remove connectors.

清除电路板电路侧边连接器引脚焊点上的封装胶，以及连接连接器的螺钉上的封装胶。有关如何拆卸连接器，请参阅第 10 段。

D. Mechanically remove encapsulant from the terminals and back 0.25 inch on all leads and jumper wires attached.

用机械方法清除端子上的封装胶，并将所有引线和跳线向后移 0.25 英寸。

E. Remove a sufficient amount of encapsulant around heat sinks and attaching hardware to make the bond weak for removal.

在散热片和连接硬件周围清除足够量的封装胶，使其粘合薄弱，以便拆卸。

F. Remove conformal coatings only in a clean work area. Cut and scrape carefully.

只能在清洁的工作区内清除保形涂料。小心切割和刮擦。

G. To remove polyurethane and epoxy coatings:

要清除聚氨酯和环氧树脂涂层，应采取以下步骤

(1) Soften the coating with heat. Heat the assembly to 210°F maximum for no more than 20 minutes.

加热软化涂层。将组件加热至最高 210°F，时间不超过 20 分钟。

(2) Remove the polyurethane from the part with a vacuum-solder removal device. Remove parts as specified in Paragraph 9. Do not burn or damage the adjacent encapsulant area.

用真空脱焊装置清除零件上的聚氨酯。按照第 9 段规定的方法拆卸零件。不要烧伤或损坏邻近的封装区域。

(3) Apply acetone or methyl ethyl ketone to a local area of the encapsulant for faster removal of the Humiseal 1A33 polyurethane coating. The assembly temperature can be at the usual air temperature or increased to 210°F maximum. Apply solvent with a rigid brush or a cotton swab with a strong movement to remove the encapsulant.

在封装材料的局部区域涂抹丙酮或甲乙酮，以便更快地去除 Humiseal 1A33 聚氨酯涂层。装配温度可以是通常的空气温度，也可以提高到最高 210°F。用硬质刷子或棉签用力涂抹溶剂，清除封装剂。

H. To locally remove acrylic coatings, use isopropyl alcohol or toluene and a clean cotton swab or pipe cleaner.

要局部去除丙烯酸涂层，可使用异丙醇或甲苯和干净的棉签或清管器。

I. To remove all acrylic coatings from the unit:

清除设备上的所有丙烯酸涂层：

(1) Put the part fully into isopropyl alcohol or toluene for 10 minutes maximum. Do not use toluene on parts without a hermetic seal.

将零件完全放入异丙醇或甲苯中最多 10 分钟。不要在没有密封的零件上使用甲苯。

(2) Or, as an alternative, put the part into 1,1,1 trichloroethane (vapor degreaser) gas for one minute maximum. Then spray each side one minute maximum with 1,1,1 trichloroethane.

或者，作为替代，将零件放入 1,1,1 三氯乙烷（蒸气脱脂剂）气体中最多 1 分钟。然后用 1,1,1-三氯乙烷喷洒每一面最多一分钟。

在封装材料的局部区域使用丙酮或甲乙酮，以便更快地去除 Humiseal 1A33 聚氨酯涂层。装配温度可以是通常的空气温度，也可以提高到最高 210°F。用硬质刷子或棉签用力涂抹溶剂，清除封装剂。

J. To remove Uralene 5750 coating:

清除 Uralene 5750 涂层：

(1) Apply Uralene 5750 thinner to the local area of the encapsulant for faster removal of the Uralene 5750 coating. Apply the solvent with a rigid brush or a cotton swab with a strong movement to remove the encapsulant.

在封装剂的局部区域使用 Uralene 5750 稀释剂，以便更快地清除 Uralene 5750 涂层。用硬毛刷或棉签用力涂抹溶剂，以去除封装剂。

(2) Also, you can apply toluene or methyl ethyl ketone to a local area to remove Uralene 5750 coating. Apply the solvent with a rigid brush or a cotton swab with a strong movement to remove the encapsulant.

也可以在局部区域使用甲苯或甲乙酮去除 Uralene 5750 涂层。用硬毛刷或棉签用力涂抹溶剂，以去除封装剂。

K. To remove Parylene C conformal coating:

清除 Parylene C 保形涂料：

(1) Make a hole in the coating.

在涂层上开孔。

(2) Remove the coating with tweezers. A small strip (lip) of less than 5 mils of lifted coating is permitted.

用镊子去除涂层。允许隆起涂层有小于5英里的小带（唇）。

L. To remove silicone coatings such a Sylgard or Dow-Corning RTV 3140:

清除硅树脂涂层，如 Sylgard 或 Dow-Corning RTV 3140：

(1) These coatings are removable by hand, but old coatings could be hardened or without edges to pull on. Then you can use a scalpel or equivalent to carefully cut into the coating.

这些涂层可以手工去除，但旧涂层可能已经硬化或没有边缘，无法拉扯。然后可以使用手术刀或相似工具小心地切开涂层。

(2) Remove other coatings, such as polyurethane or acrylic conformal coatings, if necessary.

如有必要，可去除其他涂层，如聚氨酯或丙烯酸保形涂层。

(3) Replace components as necessary.

根据需要更换部件。

(4) Fully clean the surfaces with isopropyl alcohol. Let the surfaces air dry.

用异丙醇充分清洁表面。让表面风干。

6. REMOVAL OF CONDUCTORS AND EDGE CONTACTS 导体和边缘插针的拆除

A. Internal Conductors 内部导体

(1) At locations other than at plated-through holes:

除电镀通孔外的其他位置：

(a) Use a location on the conductor which has sufficient clearance from adjacent conductors.

在导体上选择与相邻导体有足够间隙的位置。

(b) Use the clearance hole procedures of Paragraph 6.C. to drill a hole through at this location to cut the conductor.

使用第 6.C. 段的间隙孔程序在该位置钻孔，以切割导体。

(c) Use a drill, a drill with an end mill cutter or bottom drill (180 degree point), an engraving burr or a ball mill. The drill, end mill, engraving burr or ball mill must not touch the circuit traces below the hole.

使用钻头、带立铣刀的钻头或底部钻头（180 度角）、雕刻锉或球磨机。钻头、立铣刀、雕刻锉或球磨机不得触及孔下方的电路线路。

(d) The hole must isolate the conductor ends by 0.010 inch minimum. More holes can be drilled to isolate the conductor ends.

孔必须至少将导体两端隔离 0.010 英寸。可钻更多的孔以隔离导体端部。

(e) Examine the sides and bottom of the hole with a 10X to 30X magnification lens for copper particle contamination. (See Figure 2).

用 10 倍至 30 倍放大镜检查孔的侧面和底部是否有铜粒污染。(见图 2）。

(f) Flush with isopropyl alcohol to remove copper particles. A rough wall is permitted. Gouges, pits or tearouts are not permitted.

用异丙醇冲洗，去除铜粒。允许铜壁粗糙。不允许有刮痕、凹坑或撕裂。

(g) For a conductor that is not above other conductors, drill a hole completely through the printed wiring board. Examine the hole, as above.

对于不在其他导体上方的导体，在印刷电路板上钻一个完全穿透的孔。如上所述检查孔。

(h) Fill the hole with epoxy resin BMS 5-72, Type 1, or Type 52 adhesive, or with Scotchcast 251. No bubbles are permitted in the filled hole.

用环氧树脂 BMS 5-72、1 型或 52 型粘合剂或 Scotchcast 251 填充孔。填充孔内不得有气泡。

(2) At plated-through hole locations: 在电镀通孔位置：

(a) Drill out a plated-through hole as specified in Paragraph 6.C.

按第 6.C 段规定的方法钻出电镀通孔。

(b) Drill the hole no larger than necessary to remove the through-plating.

钻孔不大于去除镀层所需的孔径。

按上述的规定用环氧树脂填孔。

(d) If a surface conductor is to be connected, drill a new hole for the lead.

如需连接表面导体，则为导线钻一个新孔。

(e) If the overhaul instructions do not specify the hole size, drill the hole diameter to 0.010-0.015 inch larger than the specified component or lead diameter to be installed in the hole.

如果大修说明书没有规定孔的尺寸，则钻孔直径应比规定的要安装在孔中的部件或导线直径大 0.010-0.015 英寸。

B. Surface Conductors

表面导体

(1) Carefully cut through the conductor with a sharp knife or scalpel. Do not damage adjacent conductors or circuit board base laminates below the first layer of glass fiber.

用锋利的小刀或手术刀小心割开导体。不要损坏第一层玻璃纤维以下的相邻导体或电路板基板层压板。

(2) Remove the piece of the conductor from the circuit board.

将导体从电路板上取下。

(3) Remove a minimum length of 0.01 inch of conductor where the circuit is to be stopped.

在电路要停止的地方移除最小长度为 0.01 英寸的导体。

(4) Remove all particles of the conductor.

清除导体上的所有颗粒。

(5) Apply a layer of Type 52 adhesive to the first layer of glass fiber.

在第一层玻璃纤维上涂上一层 52 型粘合剂。

C. Clearance Holes Through Thermal, Ground and Power Planes

穿过热、接地和电源平面的间隙孔

(1) Drilled holes must meet these requirements:

钻孔必须符合以下要求：

(a) When not specifically dimensioned, keep hole locations away from conductors on other layers whenever possible.

如无特殊尺寸，应尽可能使钻孔位置远离其他层的导体。

(b) Hold the assembly tightly to not let it move or bend during drilling operations.

在钻孔过程中，应紧紧抓住组件，防止其移动或弯曲。

只能使用硬质合金钻头。每个钻头最多钻 200 个孔。

(d) Examine each drill for damage before you use it again.

在再次使用之前，检查每个钻头是否损坏。

(e) Primary cutting edges must be sharp and free of chips and nicks. Nicks up to 0.002 inch are acceptable on margin cutting edges.

主切削刃必须锋利、无切屑和划痕。边缘切削刃上的划痕不超过 0.002 英寸是可以接受的。

(f) Drill the hole to be larger than the given lead size by 0.040 inch minimum unless a specific size is given.

除非指定了具体尺寸，否则钻出的孔应比给定的导线尺寸至少大 0.040 英寸。

(2) Clean the drilled holes to the requirements of step (4) below.

按以下步骤(4)的要求清理钻孔。

(a) For assemblies which have static sensitive parts installed, use a hand-held reamer or twist drill 0.001-0.005 inch larger than the drill used.

对于安装了静电敏感零件的组件，使用比所用钻头大 0.001-0.005 英寸的手持铰刀或麻花钻。

(b) For all other assemblies, clean the holes with a dry abrasive:

对于所有其他组件，使用干磨料清理孔：

NOTE: Do not apply the dry abrasive to the complete assembly.

注：不要在完成的组件上使用干磨料。

1) Use 27 micron aluminum oxide abrasive in an air or gas jet at 60-80 psi.

在 60-80 psi 的空气或气体喷射器中使用 27 微米的氧化铝磨料。

2) Hold the abrasive cleaning nozzle perpendicular to the surface of the board and at a distance to produce a spray pattern larger than the diameter of the hole.

将磨料清洁喷嘴垂直于电路板表面，并保持一定距离，以产生大于孔直径的喷型。

3) Clean the holes from each side of the board. Clean each hole for no more than 4 seconds.

清洁电路板两侧的孔。每个孔的清洁时间不超过 4 秒钟。

4) Blow loose particles from the holes with air.

用空气吹走孔中的松散颗粒。

(3) Flush abrasive from the assembly and the clean hole with isopropyl alcohol and let it dry in the air.

用异丙醇冲洗组件和清洁孔中的研磨剂，并让其在空气中干燥。

(4) Examine all of the hole wall at 10X to 30X magnification and light from the rear and at the surface.

用 10 倍至 30 倍的放大镜，在从背面和表面有灯光的状态下，检查所有孔壁。

(a) Copper annular rings must be completely visible. The hole must be uniform. Copper annular rings must be bright with continuous, sharp, distinct edges. Abrasion on the surface of the board is acceptable if it is not more than 0.030 inch from the edge of the hole and does not damage pads or circuitry. Exposed copper extending no more than 0.030 inch from the edge of the hole is acceptable.

铜环必须完全可见。孔必须均匀一致。铜环必须明亮，边缘需连续、锐利、清晰。如果电路板表面的磨损距离孔边缘不超过 0.030 英寸，且不会损坏电路板或电路，则可以接受。裸露的铜从孔边缘延伸不超过 0.030 英寸也是可以接受的。

(b) There must be no loose or rubbed-in copper particles or burrs.

不得有松动或摩擦产生的铜粒或毛刺。

不得有松动的环氧树脂颗粒或环氧树脂污迹。

(d) There must be no visually detectable inner layer nail heading.

内层钉头不得有肉眼可见的痕迹。

(e) There must be no torn out epoxy or fiberglass material from the hole wall, or gouging of copper layers where the bottom of the hole cannot be seen at a viewing angle of 45 degrees or less. (See Figure 3).

孔壁不得有撕裂的环氧树脂或玻璃纤维材料，或在45度或更小的视角下无法看到孔底的铜层刨痕。(见图 3）。

(5) Fill the hole with Scotchcast 251, BMS 5-72, Type 1 or Type 52 adhesive. There must be no bubbles or bare locations larger than 0.010 inch or which make an overlap between conductors.

用 Scotchcast 251、BMS 5-72、1 型或 52 型粘合剂填满孔洞。不得有大于 0.010 英寸的气泡或裸露位置，也不得使导体重叠。

(6) Visually examine all of each hole.

目视检查每个孔。

D. Removal of edge contacts which are not used.

拆除不使用的边缘插针。

(1) Do not remove more than 3 edge contacts from each side of a printed circuit board. Such contacts must not connect to any circuits and are to be removed because they are unwanted, damaged, are not plated correctly and for other faults. Do not damage the fiberglass.

不得从印刷电路板的任一面拆除超过 3 个边缘插针。这些插针不得与任何电路连接和因不需要、损坏、电镀不正确或其他故障而被移除。不要损坏玻璃纤维。

7. REPAIR OF CONDUCTOR FOILS 修理导体箔片

A. Use these procedures to repair lifted or damaged surface conductors. Because the bond between the conductor foil and the board is not strong, the conductor can be made unserviceable because of nicks, breaks, separation from the board, or damage to terminal pads and areas.

使用这些程序修理隆起或损坏的表面导体。由于导体箔片与电路板之间的结合不牢固，导体可能会因划痕、断裂、与电路板分离或端子板和区域损坏而无法使用。

B. Nicks and Scratches

划伤和划痕

(1) Clean the surface with isopropyl alcohol. Remove conformal coating.

用异丙醇清洁表面。清除保形涂料。

(2) Fill the nick or scratch with melted solder by hand-soldering.

手工焊接，用融化的焊料填满缺口或划痕。

(3) Make sure the repair did not decrease the distance to adjacent conductors.

确保修理不会减少与相邻导体的距离。

(4) Apply conformal coating to the area.

在该区域涂上保形涂料。

C. Broken Surface Conductors

表面破损的导体

(1) Scratches

划痕

(a) Remove conformal coating from an area along the conductor foil a minimum of 0.5 inch in each direction from the defect.

从导体箔片上沿缺陷方向各至少 0.5 英寸的区域去除保形涂料。

(b) Clean the foil with an eraser.

用橡皮擦清洁导体箔。

用牙科探针或类似工具将融化的焊料擦入缺陷处，直至该区域光滑。

(d) Add a small amount of flux.

加入少量助焊剂。

(e) Add a small amount of solder.

加入少量焊料。

(f) Tin over the defect.

在缺陷上镀锡。

(g) Let the solder cool. Then clean the area with isopropyl alcohol and apply conformal coating.

让焊料冷却。然后用异丙醇清洗该区域并涂上保形涂料。

(2) Cuts or Breaks

切割或断裂

(a) Remove conformal coating from an area along the conductor foil a minimum of 0.5 inch in each direction from the defect.

从导体箔片沿缺陷的每个方向至少 0.5 英寸的区域去除保形涂料。

(b) Clean the foil with an eraser.

用橡皮擦清洁导体箔。

(c) With a sharp blade held at a 45 degree angle from the vertical, cut out the damaged area a minimum of 0.06 inch from the defect, to put a 45 degree downwards slope from the good conductor surface to the cut ends.

用锋利的刀片从垂直方向 45 度角切下距离缺陷至少 0.06 英寸的受损区域，使良好导体表面与切口两端呈 45 度向下倾斜。

(d) Lightly tin the two cut ends.

在两个切口处轻轻镀锡。

(e) Get a scrapped circuit board. Cut and trim from it, a replacement piece of foil of the same width and thickness as the damaged conductor.

找一块报废的电路板。从电路板上切割和修剪一块与受损导体宽度和厚度相同的箔片。

NOTE: As an alternative, you can make and install a jumper wire, but this must not be smaller in cross-sectional area than that of the damaged foil or any wire attached to it.

注：作为替代方法，您可以制作并安装一条跳线，但其横截面积不得小于损坏的金属箔或连接在其上的任何导线的横截面积。

(f) Cut the replacement foil piece to extend a minimum of two times the width of the damaged foil over each cut end of the damaged foil. Cut the ends of the replacement foil at a 45-degree angle.

切割替换箔片，使其在受损箔片的每个切割端上至少延伸受损箔片宽度的两倍。将替换箔片的两端剪成 45 度角。

(g) Scrape off the adhesive from the bottom surface of the replacement foil which will touch the surfaces of the damaged foil. Then tin these cleaned surfaces.

从替换箔片的底面刮掉与受损箔片表面接触的粘合剂。然后在这些清洁过的表面镀锡。

(h) Apply a thin layer of Type 52 adhesive to the circuit board surface between the two cut ends of the damaged foil.

在受损铝箔的两个切口之间的电路板表面涂上一层薄薄的 52 型粘合剂。

(i) Put the replacement piece of foil into position on the damaged foil.

将替换箔片放在受损箔片上。

(j) Lap solder, with liquid flux only, one end of the replacement foil to the mating foil on the circuit board. Do not add solder, because the tinned surfaces will contain a sufficient amount of solder to make a serviceable joint.

仅用液态助焊剂将替换箔片的一端与电路板上的配对箔搭接焊接。不要添加焊料，因为镀锡表面将含有足够的焊料，可以形成可用的连接。

(k) Let this connection cool. Then lap solder by the same procedure at the other end of the replacement foil.

让此连接冷却。然后用同样的程序在替换箔片的另一端搭接焊料。

(l) Let the connection cool.

让连接处冷却。

(m) With a clamp, a piece of Teflon or plastic, and orange sticks, apply pressure to the repaired area.

用夹子、特氟龙或塑料片和桔黄色的棍子对修理过的地方施加压力。

(n) Cure the adhesive for 4 hours minimum at room temperature or 2 hours minimum at 140-160°F.

将粘合剂在室温下固化至少 4 小时，或在 140-160°F 下固化至少 2 小时。

(o) After the adhesive is cured, remove unwanted adhesive with an eraser.

粘合剂固化后，用橡皮擦去除不需要的粘合剂。

(p) Clean the repaired area with isopropyl alcohol. Apply conformal coating.

用异丙醇清洗修理部位。涂敷保形涂料。

D. Lifted Surface Conductors

表面隆起的导体

NOTE: Foils can come loose from the circuit board if too much heat was applied during soldering operations.

注意：如果在焊接操作过程中温度过高，箔片可能会从电路板上松脱。

(1) Clean the area under and around the lifted foil to remove conformal coating, adhesive, and burned material.

清洁隆起的金属箔片下方和周围区域，清除保形涂层、粘合剂和烧焦的材料。

(2) Carefully de-solder the lifted metal foil and make it smooth.

小心将隆起的金属箔片熔焊并使其平滑。

(3) Bond the lifted foil to the circuit board with Type 52 adhesive. Make sure this does not decrease the distance to adjacent conductors.

用 52 型粘合剂将隆起的金属箔片粘合到电路板上。确保不会减少与相邻导体的距离。

(4) Push the foil down into position.

将铝箔向下推入定位。

(5) With a clamp, a piece of Teflon or plastic, and orange sticks, apply pressure to the repaired area.

用夹子、特氟龙或塑料片和橙色棍子对修理部位施压。

(6) Cure the adhesive for 4 hours minimum at room temperature or 2 hours minimum at 140-160°F.

粘合剂在室温下至少固化 4 小时，或在 140-160°F 下至少固化 2 小时。

(7) After the adhesive is cured, remove unwanted adhesive with an eraser.

粘合剂固化后，用橡皮擦去除不需要的粘合剂。

(8) Clean the repaired area with isopropyl alcohol. Apply conformal coating.

用异丙醇清洁修理区。涂上保形涂料。

(9) If there are mounting holes in the area, clean or drill the holes to original size.

如有安装孔，清洁或钻孔至原始尺寸。

E. Damaged or Missing Terminal Areas

损坏或缺失的端子区域

(1) Remove the defective terminal area if it is there. Clean the area with isopropyl alcohol and let it dry.

如果端子区域有损坏，应将其移除。用异丙醇清洁该区域并晾干。

(2) Get a scrapped circuit board. Cut and trim from it a replacement piece of foil of the same shape and thickness as the damaged or missing terminal area. Make the piece larger to permit a 0.125 inch minimum overlap with the remaining good foil pattern for a good solder lap joint.

找一块报废的电路板。从电路板上切割和修剪一块与损坏或丢失的端子区域形状和厚度相同的替换箔片。将该片做大，使其与剩余的良好铝箔至少重叠 0.125 英寸，以实现良好的焊接搭接。

(3) With an electric eraser, clean the mating foil surfaces to remove all contamination and oxides.

用电橡皮擦清洁接合箔表面，清除所有污染物和氧化物。

(4) Clean the area with isopropyl alcohol.

用异丙醇清洁该区域。

(5) Solder the replacement foil piece to the existing circuit. Be sure to align the terminal area with the mating hole in the circuit board.

将替换箔片焊接到现有电路上。确保端子区域与电路板上的配对孔对齐。

(6) Bond the terminal area to the circuit board with Type 52 adhesive as specified in SOPM 20-50-12.

按照 SOPM 20-50-12 规定的 52 型粘合剂将端子区域粘合到电路板上。

(7) Install an eyelet in the hole.

在孔中安装孔眼。

(8) Clean the area with isopropyl alcohol.

用异丙醇清洁该区域。

(9) Install mating electrical items and apply conformal coating as applicable.

安装配套电气设备，并视情况涂上保形涂料。

F. Lifted or Missing Pads

隆起或缺失的板

(1) Clean under the lifted pad, and the adjacent area, with isopropyl alcohol. Dry with clean compressed air.

用异丙醇清洁隆起的板下方和邻近区域。用干净的压缩空气吹干。

(2) Prepare some Type 52 adhesive.

准备一些 52 型粘合剂。

(3) If the pad has a solder joint, fill the space under the pad and around the pad with the adhesive. If the pad has no solder joint, apply sufficient adhesive to fill only the bond line and push down on the pad to make it flat against the circuit board. Do not let adhesive get on the top surface of the pad.

如果板上有焊点，用粘合剂填满板下方和板周围的空间。如果板没有焊点，则涂上足够的粘合剂，只填满粘合线，然后向下按压板，使其与电路板平齐。不要让粘合剂沾到板的上表面。

(4) Cure the adhesive a minimum of 4 hours at room temperature or 2 hours minimum at 140-160°F.

在室温下至少固化粘合剂 4 小时，或在 140-160°F 下至少固化 2 小时。

(5) Solder as necessary.

必要时进行焊接。

(6) Apply Type 52 adhesive to the completed solder joint and the repaired pad. Make the adhesive smooth with the adjacent area.

在已完成的焊点和修理过的板上涂抹 52 型粘合剂。使粘合剂与邻近区域平滑。

(7) Make sure this layer of adhesive is smooth and continuous, with no voids or bubbles larger than 0.01 inch in diameter, and with no wrinkles, foldovers, kinks or other defects.

确保这层粘合剂平滑、连续，无直径大于 0.01 英寸的空隙或气泡，无皱褶、折叠、扭结或其他缺陷。

(8) Cure the adhesive as specified in Paragraph 7.F.(4) above.

按照上文第 7.F.(4)段的规定固化粘合剂。

G. Defective Pads With a Preform

带预型件的有缺陷板

(1) Remove the mating part or feed through interconnect.

拆下配合零件或穿入互连件。

(2) Repair the lifted pad or circuit as specified in Paragraph 7.D. or Paragraph 7.F. above.

按上文第 7.D. 段或第 7.F. 段的规定修理被隆起的板或电路。

(3) Make a drilled preform, or get one from a repair kit, which will make an overlap of 0.125-0.250 inch with the defect.

制作一个钻孔预型件，或从修理包中获取一个预型件，使其与缺陷重叠 0.125-0.250 英寸。

(4) Put the preform in position over the defect and hand solder to the mating circuit and leads as applicable. Make sure the solder connections are smooth, with no blow holes, icicles or cold solder joints.

如适用将预型件放在缺陷位置上，用手工焊接到配对电路和引线上。确保焊点连接平滑，无气孔、冰柱或冷焊点。

(5) Apply conformal coating or a layer of Type 52 adhesive over the repaired area.

在修理区域涂上保形涂料或 52 型粘合剂。

8. REPAIR OF INTERNAL CONDUCTORS 修理内部导体

A. Use these procedures when you find problems with internal conductors on multilayer printed circuit boards. These procedures are for components mounted through the holes.

当发现多层印刷电路板上的内部导体出现问题时，请使用这些程序。这些程序适用于通过孔安装的元件。

B. Shorted Conductors

短路导体

(1) After you find the bad conductors, remove the components at each end of each conductor. Clean the areas with isopropyl alcohol.

找到不良导体后，拆下每个导体两端的元件。用异丙醇清洁这些区域。

(2) Drill out the through-hole pads for each end of the bad conductor. Be sure to give the assembly support to prevent movement or deflection while you drill.

钻出不良导体两端的通孔板。确保在钻孔时为组件提供支撑以防止移动或偏移。

(a) Make the initial hole a small amount larger than the pad size, but not sufficiently large to cut into adjacent pads.

初始钻孔要比板尺寸大一些，但不能大到足以切到相邻的板。

(b) Make the final hole size 0.040 inch larger than the part lead size.

最终钻孔尺寸比零件引线尺寸大 0.040 英寸。

(3) Clean the drilled holes with isopropyl alcohol and let them air dry.

用异丙醇清洗钻好的孔，并让其风干。

(4) Fill the hole with Type 52 adhesive or Scotchcast 251. Make sure there are no bubbles or voids larger than 0.010 inch.

用 52 型粘合剂或 Scotchcast 251 填充孔。确保没有大于 0.010 英寸的气泡或空隙。

(5) After the adhesive or Scotchcast 251 is cured, drill a new hole at each of these locations. Make the holes a maximum of 0.040 inch larger than the part lead size. There must be a minimum of 0.010 inch thickness of adhesive in the wall of the hole.

待粘合剂或 Scotchcast 251 固化后，在上述每个位置钻一个新孔。钻的孔最多比零件引线尺寸大 0.040 英寸。孔壁的粘合剂厚度至少要有 0.010 英寸。

(6) Install replacements for the components you removed in Paragraph 8.B.(1) above. Bond axial-leaded discrete parts (such as resistors or capacitors) in place with Type 69 adhesive. This is not necessary for parts with 3 or more leads, because their installation will be sufficiently strong after the other leads are soldered to the existing circuit board foils.

为上文第 8.B.(1)段中拆除的部件安装替换件。用 69 型粘合剂粘合轴向引线分立零件（如电阻器或电容器）。对于有 3 根或更多引线的零件不必这样做，因为在其他引线焊接到现有电路板箔片上后，它们的安装将足够牢固。

(7) Do not clip the leads that will be connected to conductors (jumper wires) in Paragraph 8.B.(8).

不要夹住将连接到第 8.B.(8)段中导线（跳线）的引线。

(8) Install conductors (jumper wires) on the non-component side of the circuit board, between the points that were connected by the bad internal conductor. Give the jumper wires the same routing as the old internal conductors they replace. Tack-bond them to the circuit board with Type 69 adhesive and solder their ends to the leads by hand.

将导线（跳线）安装在电路板的非元件侧，即由内部不良导线连接的点之间。跳线的走向应与所取代的旧内部导体的走向相同。用 69 型粘合剂将其粘合到电路板上，然后手工将其两端焊接到引线上。

(9) Clip unwanted lead lengths, as necessary, to be sure there will be no interference when the circuit board is installed.

必要时夹住不需要的导线长度，以确保安装电路板时不会产生干扰。

(10) Clean the area with isopropyl alcohol. Apply conformal coating as necessary.

用异丙醇清洁该区域。按需涂敷保形涂料。

C. Open Conductors

开路导体

(1) After you find the bad conductors, remove the conformal coating at each end of each conductor. Clean the areas with isopropyl alcohol.

找到不良导体后，清除每根导体两端的保形涂料。用异丙醇清洁这些区域。

(2) Install conductors (jumper wires) on the non-component side of the circuit board, between the points that were connected by the bad internal conductor. Give the jumper wires the same routing as the old internal conductors they replace. Tack-bond them to the circuit board with Type 69 adhesive and solder their ends to the leads by hand.

将导线（跳线）安装在电路板的非元件侧，与内部不良导线连接的点之间。跳线的走向应与所取代的旧内部导体相同。用 69 型粘合剂将其粘接到电路板上，然后手工将其两端焊接到引线上。

(3) Clean the area with isopropyl alcohol. Apply conformal coating as necessary.

用异丙醇清洁该区域。必要时涂敷保形涂料。

9. REMOVAL OF COMPONENTS 拆除元件

CAUTION ：BE CAREFUL NOT TO DAMAGE ADJACENT COMPONENTS.

注意：小心不要损坏邻近的元件。

CAUTION ：DO NOT USE ANY ELECTRIC COMPONENT AGAIN AFTER REMOVAL FROM THE CIRCUIT BOARD ASSEMBLY. IT COULD BE DAMAGED BY THE HEAT OR THE FORCE USED TO REMOVE IT.

注意：从电路板组件上拆下任何电气元件后，请勿再次使用。拆卸时的热量或力量可能会损坏元件。

CAUTION ：DO NOT REPAIR A PRINTED-CIRCUIT BOARD AREA SUCH AS A PLATED THROUGH HOLE MORE THAN TWO TIMES. THE CIRCUIT COULD BE DAMAGED.

注意：不要修理印刷电路板区域（如电镀通孔）两次以上。否则会损坏电路。

A. Remove the conformal coating (Ref Paragraph 5.) from the joint area. It is not necessary to remove parylene conformal coating.

清除接合处的保形涂料（参考第 5 段）。不必去除聚对二甲苯保形涂料。

B. For parts installed into plated-through holes, cut the leads of the parts to remove the parts.

对于安装在电镀通孔中的零件，应剪断零件的引线以取出零件。

C. To remove the leads from the plated-through holes:

从电镀通孔中去除引线：

(1) Procedure with two soldering irons.

用两个烙铁进行程序。

(a) Use one iron on each side of the board.

在电路板的两侧各使用一个烙铁。

(b) When the solder is melted, use one iron to push the lead and use the other to pull the lead out.

焊锡熔化后，用一个烙铁推引线，用另一个烙铁拉引线。

小心推拉，取出引线。

(d) Do not touch the board with the soldering iron for more than 3 seconds or the board or components could be damaged.

用烙铁接触电路板的时间不要超过 3 秒钟，否则会损坏电路板或元件。

(2) Or, as alternatives, use solder wick, a vacuum unsoldering device, or use one soldering iron and a pair of tweezers.

或作为替代，使用焊芯、真空脱焊装置，或使用一个烙铁和一把镊子。

D. Use rosin flux to help in part removal.

使用松香助焊剂帮助拆卸部件。

E. The large leads and the configuration of a DIP (dual inline package) can prevent removal of the leads. To remove solder from these parts, apply a soldering iron to the component side of the circuit board and apply the vacuum unsoldering tool to the other side of the board.

大引线和 DIP（双列直插式封装）的结构会妨碍引线的移除。要清除这些部件上的焊料，可在电路板的元件侧使用烙铁，在电路板的另一侧使用真空脱焊工具。

F. To remove the leads from holes which are not plated-through, use a vacuum unsoldering device, solder wick or a soldering iron and tweezers.

要从非电镀通孔中去除引线，可使用真空脱焊装置、焊芯或烙铁和镊子。

G. To remove parts that are bonded to the board, cut through the adhesive bond. Then carefully rock, pry, or twist to break the part loose from the board.

若要移除粘接在电路板上的部件，请割开粘接剂。然后小心地摇晃、撬动或扭转，使部件脱离电路板。

(1) Some procedures to help make the adhesive soft or weak:

使粘合剂变软或变弱的一些步骤：

(a) Heat the assembly in an oven to 210°F maximum for no more than 20 minutes.

在烤箱中将组件加热到最高 210 华氏度，时间不超过 20 分钟。

(b) Point a jet of hot air at the bond line while you carefully rock or pry the component.

在小心摇晃或撬动部件的同时，将热气喷射到粘合线处。

使用加热刀片（如安装在烙铁上的刀片）切去粘合剂。

(2) After removing the leads, remove solder from the circuit pads or plated-through holes with a device which melts and removes solder by vacuum as shown in Figure 4. As an option, you can use a soldering iron and wicking. Apply the solder iron on the solder for 3 seconds maximum, then wait for at least 30 seconds before you apply the iron to the same joint.

移除引线后，如图 4 所示，使用真空熔化和清除焊料的装置清除电路板或电镀通孔中的焊料。作为选择，也可以使用烙铁和吸锡器。将烙铁放在焊料上最多 3 秒钟，然后至少等待 30 秒钟，再将烙铁放在同一焊点上。

(3) Remove the flux residues from encapsulated units with isopropyl alcohol or with a bristle brush followed by an alcohol rinse.

用异丙醇或鬃毛刷清除封装单元上的助焊剂残留物，然后用异丙醇冲洗。

(4) Be sure to examine all replaced components and joints.

一定要检查所有已更换的部件和接头。

(5) Replace the conformal coating on the affected area as specified in Paragraph 17.

按照第 17 段的规定，更换受影响区域的保形涂料。

H. Transistors mounted on transistor pads must be removed as one unit with a tool which closes around the component and cuts parallel to the board. Gently rock the closed tool until the transistor and the pad breaks free of the board.

安装在晶体管盘上的晶体管必须作为一个整体用工具移除，工具应围绕元件闭合并与电路板平行切割。轻轻摇动闭合工具，直到晶体管和板脱离电路板。

NOTE: Thermal expansion of the transistor pads can strain solder joints. Do not install transistor pads unless specified by the instructions.

注：晶体管盘的热膨胀会拉伤焊点。除非有说明，否则不要安装晶体管板。

I. To remove parts with lap-soldered flat leads:

拆卸带有搭接焊接平引线的部件：

(1) Disconnect or cut the part leads from the attachment pads.

从连接盘上断开或切断零件引线

(2) On encapsulant coated units, remove the part with a tool that will cut the encapsulant fillet and pull up and cut from under the part body. Be careful not to damage the conductor or feed through below the part. Remove flux with a small bristle brush, cotton tipped applicator or wiper wet with isopropyl alcohol.

对于涂有封装材料的部件，使用能切割封装胶片的工具，并从零件下方拉起切割来移除部件。小心不要损坏导体或从零件下面穿透。用小鬃毛刷、棉尖涂抹器或异丙醇湿抹布清除助焊剂。

10. INSTALLATION OF NEW COMPONENTS 安装新部件

A. Preparation of the circuit board

电路板的准备工作

(1) Manually ream the lead holes with a twist drill bit of the same size to remove solder which could prevent installation of the new component. Hold the drill with fingers or a pin vise. Do not enlarge the hole more than 10% of its original size.

用同样大小的麻花钻头手动铰削引线孔，以去除可能妨碍安装新元件的焊料。用手指或针台钳夹住钻头。孔径不要超过原尺寸的 10%。

WARNING :WHEN YOU USE ISOPROPYL ALCOHOL, DO NOT BREATHE THE VAPOR OR MISTS. USE ONLY WITH APPROVED VENTILATION, AVOID PROLONGED OR REPEATED SKIN CONTACT. KEEP AWAY FROM HEAT, SPARKS, AND OPEN FLAME.

警告 :使用异丙醇时，切勿吸入蒸汽或雾气。只能在通风条件允许的情况下使用，避免长时间或反复接触皮肤。远离热源、火花和明火。

(2) Carefully scrape the area with isopropyl alcohol and soldering iron or a sharp edged tool to let you install the new component. Make a smooth edge to the encapsulant around this area.

用异丙醇和烙铁或锋利的工具小心刮擦该区域，以便安装新元件。使该区域周围的封装材料边缘光滑。

(3) Clean unwanted matter from the area with isopropyl alcohol. Do not use an abrasive. Remove solvent from cleaned areas with a clean cloth.

用异丙醇清洁该区域的杂质。不要使用研磨剂。用干净的布清除清洁区域的溶剂。

CAUTION :MANY OF THESE COMPONENTS ARE SUBJECT TO DAMAGE FROM ELECTROSTATIC DISCHARGE DURING HANDLING. IF YOU SEE YELLOW STATIC-SENSITIVE-CAUTION LABELS, REFER TO SOPM 20-12-02 FOR INSTRUCTIONS.

注意 :在处理过程中，这些部件中有许多会因静电放电而损坏。如果您看到黄色的静电敏感警告标签，请参阅 SOPM 20-12-02 的说明。

B. Preparation of the new components

准备新元件

(1) How to straighten component leads:

如何拉直元件引线：

(a) Do not use component parts that have cracks in the dielectric at the lead-part junction.

切勿使用引线与部件接合处电介质有裂纹的零件。

CAUTION :DO NOT STRESS THE LEAD-TO-PART BODY JUNCTION OR GIVE SHOCK TO THE PART.

注意 :不要对引线与零件主体交界处施加压力或对零件造成冲击。

(b) Leads can be straightened if misalignment is within the limits shown in Figure 5. Do not use component parts which have lead misalignment greater than that shown in Figure 5. Leads can be aligned 0.03 inch to agree with the mounting members.

如果偏差在图 5 所示的范围内，可以拉直引线。不要使用引线偏差大于图 5 所示的零件。引线可对齐 0.03 英寸，以便与安装部件一致。

只能按以下方法手工校直引线：

1) Wear clean, dry, lint-free cotton or equivalent gloves.

戴上干净、干燥、不起毛的棉质手套或类似手套。

2) Hold the lead between the point to be straightened and the part body with smooth, flat-jawed pliers.

用光滑的平口钳夹住要校直点和零件主体之间的引线。

(d) You can straighten rectangular flat pack leads which are not bent more than 30 degrees in a vertical plane at the seal and misaligned to more than one lead width in the horizontal plane. Reject the part if the leads are bent more than 30 degrees in a vertical plane at the part body junction.

您可以校直矩形扁平封装引线，这些引线在密封处的垂直面上弯曲不超过 30 度，在水平面上错位不超过一个引线宽度。如果引线在零件主体连接处的垂直面上弯曲超过 30 度，则报废该零件。

(e) You can straighten dual-in-line package leads which are bent 30 degrees or less from normal.

如果双列直插式封装引线的弯曲度小于或等于 30 度，则可将其拉直。

(f) To prevent work hardening and the risk of broken leads, do not bend leads more than one time at the same location.

为防止加工硬化和引线断裂的风险，请勿在同一位置多次弯曲引线。

(2) How to Bend Component Leads (Figure 5, Figure 6, Figure 7)

如何弯曲元件引线（图 5、图 6、图 7）

(a) If the leads must be bent before assembly to the circuit board, use these requirements. (Solder seals, glass bead seals, and other protrusions are to be included in the part body.)

如果必须在组装到电路板之前弯曲引线，请按照以下要求进行。(焊接密封件、玻璃珠密封件和其他突起物要包含在零件本体内）。

1) Bend rounded leads to a radius no smaller than one lead diameter. Bend flat-pack leads to a radius no smaller than one lead thickness. Measure the bend radius at the inside of the lead bend.

将圆形引线进行弯曲，使其弯曲半径不小于引线的直径。将扁平引线进行弯曲，使其弯曲半径不小于引线的厚度。测量引线弯曲内侧的半径。

2) For axial-leaded parts, make the bends agree with Figure 5. For flat packs, bend and cut the leads as specified in Figure 6 and overhaul instructions.

对于轴向引线零件，使弯曲度与图 5 一致。对于扁平封装，按照图 6 和大修说明规定的方法弯曲和切割引线。

3) For TO-type cans, CKO-5, -6 and CKRO-5, -6 capacitors, bend the leads when you put them into the circuit board holes, or into the lead-forming tool.

对于 TO 型罐、CKO-5、-6 和 CKRO-5、-6 电容器，在将引线放入电路板孔中或引线成型工具中时弯曲引线。

4) Before you bend the leads, make sure you hold the component body to keep the polarity identification visible after the part is installed.

在弯曲引线之前，请务必握住零件主体，以便在安装零件后保持极性标识清晰可见。

5) While you bend the leads, hold or support the lead between the part body end of component and the point of bend, for those leads to be manually put into the holes.

在弯曲引线时，在零件本体端部和弯曲点之间夹住或支撑引线，以便这些引线被手动放入孔中。

6) After you bend the leads, make sure the part has none of the defects listed in Paragraph 10.B.(2)(a)8).

弯曲引线后，确保零件没有第 10.B.(2)(a)8)段中列出的缺陷。

7) Clip or trim the leads with a tool which will not damage the seal, lead, part body or adjacent leads. The tool must cut smooth with the surface, with cutting edge faces toward the part body and perpendicular to the axis of the part lead. Hand trim leads before you solder them. Keep the tools and equipment in good condition to let the clipped end come off the lead in one operation.

用不会损坏密封件、引线、零件主体或相邻引线的工具夹住或修剪引线。工具必须与表面平滑切削，切削刃朝向零件本体并垂直于零件引线的轴线。焊接前手工修整引线。保持工具和设备处于良好状态，以便一次操作即可将剪切端从引线上取下。

8) Reject components with these defects:

报废有以下缺陷的部件

a) One or more leads with nicks or cuts which expose base metal in the area between the component body junction and the point at which lead will be soldered.

一条或多条引线上有划痕或切口，在元件本体接合处和引线焊接点之间的区域露出基底金属。

b) Exposed base metal on leads larger than one-tenth the lead diameter, or a total exposed area more than 10 percent of the lead.

引线上的基底金属裸露面积大于引线直径的十分之一，或裸露总面积超过引线的 10%。

c) Lead bends with cracks in the base metal when viewed up to 10X magnification.

在 10 倍放大镜下观察，引线弯曲处的基底金属有裂纹。

d) Damaged insulation, connector contacts, or cases.

绝缘层、连接器插针或外壳损坏。

e) Leaks in components that contain liquid dielectric.

含有液态电介质的元件泄漏。

9) Handle and store components after lead bending so they will not be damaged and the lead form will not be disturbed.

引线弯曲后，处理和存放元件时要确保元件不会损坏，引线的形态不会受到干扰。

C. Installation of the parts

零件的安装

(1) How to mount components with accessible leads (such as resistors)

如何安装带有引线的部件（如电阻器）

(a) Mount components with the leads down through the circuit board as shown in Figure 8, view A.

如图 8 视图 A 所示，安装元件时，引线应向下穿过电路板。

(b) The component must be parallel to, on the side opposite the circuitry, and down against the circuit board unless specified by the overhaul instructions or unless necessary for heat dissipation.

除非大修说明有规定，或为散热所必需，否则元件必须与电路平行，在与电路相对的一侧，并向下紧贴电路板。

(c) Remove unwanted lead lengths to prevent stress to the lead-to-component body junction to send no mechanical shock to the part. Hold the component lead between component body junction and the cut. Do not swage.

去除不需要的引线长度，以防止引线与部件本体接合处受力，使零件不受到机械冲击。将元件引线夹在元件本体与切口之间。切勿压接。

(2) Mounting components with Inaccessible leads (such as transistors)

安装不带引线的元件（如晶体管）

(a) Mount components that have leads extending from bottom of components as shown in Figure 8, views B, C, D and E, with one of these procedures to let you clean between the component and the circuit board after soldering.

如图 8 视图 B、C、D 和 E 所示，安装引线从元件底部伸出的元件时，可采用以下程序之一，以便在焊接后元件与电路板之间进行清理。

CAUTION ：USE SEPARATE OR INTEGRAL STANDOFF PADS OR STRIPS ONLY WHEN REQUIRED BY THE OVERHAUL INSTRUCTIONS. TRANSISTOR PADS UNDER TO-TYPE CANS COULD DAMAGE SOLDER JOINTS BECAUSE OF THERMAL EXPANSION OF THE PAD.

(b) Mount transistors without pads with a clearance from the board as shown in Figure 7.

如图 7 所示，安装不带板的晶体管，与电路板留有间隙。

如图 8，视图 B 所示，安装有板的晶体管。

(d) Bond a piece of nylon strip (Polymer type 101, 0.031 inch thick), cut to a width to fit under the center of the component and between the leads as shown in Figure 8, view D, or bond a piece under each end of the component as shown in Figure 8, view E. Bond these pieces with a soluble maskant or Type R flux as a temporary adhesive. Do not let the nylon strips extend out from the edges of the component, or let them be nearer than shown to the component leads. Removable spacer strips (Dissopads) or permanent standoffs can be used.

如图 8，视图 D 所示，在元件中心下方和引线之间粘接一片尼龙条（101 型聚合物，0.031 英寸厚），或如图 8，视图 E 所示，在元件两端各粘接一片。不要让尼龙条伸出元件边缘，也不要让它们比图中所示更靠近元件引线。可使用可拆卸的间隔条（Dissopads）或永久性支座。

(3) How to Clinch Component Leads (Figure 9)

如何夹紧元件引线（图 9）

(a) If the overhaul instructions tell you to clinch the leads, bend them in the direction of, parallel to, and against the circuit pattern, as shown. These leads must extend through the board a minimum of the pad radius and a maximum of the pad diameter. A spring back of 15 degrees maximum is permitted.

如果大修说明中要求夹紧引线，则应按图示将引线弯曲，弯曲方向应与电路图案平行，并与电路图案相对。这些引线必须穿过电路板，最小为板半径，最大为板直径。允许最大回弹 15 度。

(b) Component leads can be formed or swaged before you clip them, to keep components tightly against the circuit board.

元件引线在夹住之前可以成型或压接，以使元件紧贴电路板。

(4) How to Install Heat-Shrink Tubing (Figure 10)

如何安装热缩管（图 10）

(a) Install and shrink heat-shrink tubing on all parts with metal or conductive cases if the parts will be mounted over printed conductor wiring. These parts must not be mounted over solder connections.

如果零件将安装在印刷导线上方，则在所有带金属或导电外壳的零件上安装和收缩热缩管。这些零件不得安装在焊接连接处。

(b) Install and shrink heat-shrinkable tubing on all parts with glass or ceramic cases if the parts are to be bonded to the circuit board.

如果要将玻璃或陶瓷外壳的所有零件粘接到电路板上，则在这些零件上安装和收缩热缩管。

管道必须完全覆盖零件主体。它最多可延伸到引线上 0.06 英寸。

(d) Shrink the tubing on the part as specified in SOPM 20-11-03 before you install the part on the circuit board.

在将零件安装到电路板上之前，按照 SOPM 20-11-03 规定的方法收缩零件上的热缩管。

(5) How to Mount Components to Terminal Posts or Lugs

如何将部件安装到接线柱或接线片上

(a) Give sufficient stress relief to unsupported components attached to terminals or lugs. To do this, put a gradual bend in one lead. If the component body is rigidly held in a component holder or if it is encapsulated, put the stress relief in the two leads (Figure 11).

为连接到端子或接线片上的无支撑部件提供足够的应力消除。为此，应在一根引线上逐渐弯曲。如果元件本体被固定在元件支架上或被封装，则在两条引线上施加应力（图 11）。

(b) Wrap component leads around terminals 3/4 to 1-1/4 turns.

将元件引线绕端子 3/4 至 1-1/4 圈。

(c) Do not wrap component leads around slotted terminals. Make the lead parallel to the sides and the bottom of slot and extend the lead beyond terminal as shown (Figure 12).

不要将元件引线缠绕在有槽的端子上。使引线与槽的侧面和底部平行，并将引线延伸至端子之外，如图 12 所示。

(d) Put the component leads through the eye of terminal lugs and wrap the lead 3/4 to 1-1/4 turns around one side of the eye.

将元件引线穿过端子接线片的孔眼，并将引线绕孔眼一侧 3/4 至 1-1/4 圈。

(e) As applicable, remove unwanted lead lengths as specified in Paragraph 10.C.(1)(c) above.

根据上述第 10.C.(1)(c)段的规定，按规定去除不需要的引线长度。

(f) Refer to SOPM 20-12-01 to solder between the components and the terminal posts or lugs.

参考 SOPM 20-12-01，在元件和接线柱或接线片之间进行焊接。

(g) If the leads are more than 1 inch long, refer to Paragraph 12. for instructions.

如果引线长度超过 1 英寸，请参阅第 12 段的说明。

(6) How to Install Parts With No Printed Circuit Pads

如何安装无印制电路板的零件

(a) For parts with lead ends on the side opposite to the component side of the board:

对于引线端头位于电路板与零件相反一侧的零件：

1) To make clearance holes in boards that have a ground or power plane, refer to Paragraph 6.C.

在有接地或电源平面的电路板上打间隙孔，请参阅第 6.C 段。

2) Drill holes for mounting parts.

为安装零件钻孔。

a) If the overhaul instructions do not specify the hole locations, put the new holes in positions away from conductors on other layers, if possible.

如果大修说明没有规定孔的位置，尽可能将新孔放于远离其他层导体的位置。

b) Hold the assembly to help prevent movement or deflection while you drill the holes.

在钻孔时，固定住组件以防止移动或变形。

c) Drill new holes 0.035-0.060 inch larger than the diameter of the leads of the part.

新钻的孔要比零件引线直径大 0.035-0.060 英寸。

d) Clean the new holes with a hand-held reamer or a twist drill 0.001-0.005 inch larger than the drill you used to make the holes.

用比钻孔用的钻头大 0.001-0.005 英寸的手持铰刀或麻花钻清理新孔。

e) Clean the holes with isopropyl alcohol. Let the holes air dry.

用异丙醇清洗孔。让孔晾干。

f) Fill the new holes with Type 52 adhesive or Scotchcast 251. Make sure there are no bubbles or voids larger than 0.010 inch, or which fill the space between conductors.

用 52 型粘合剂或 Scotchcast 251 填充新孔。确保没有大于 0.010 英寸的气泡或空隙，或填满导体之间的空间。

g) Drill the final hole through the adhesive, but make the hole size a maximum of 0.040 inch larger than the diameter of the leads of the part. There must be a minimum of 0.010 inch of adhesive between the hole wall and the original circuit board material.

在粘合剂上钻最后一个孔，但孔径最多比零件引线直径大 0.040 英寸。孔壁与原电路板材料之间必须至少有 0.010 英寸的粘合剂。

3) Install the new part. Parts which are not mechanically fastened must be bonded with adhesive. Use Type 69 adhesive as specified in SOPM 20-50-12.

安装新零件。非机械固定的零件必须用粘合剂粘合。使用 SOPM 20-50-12 规定的 69 型粘合剂。

4) Cut the lead to 0.03-0.06 inch length.

将引线剪成 0.03-0.06 英寸长。

5) Add jumper wires to the component leads as shown in Figure 13.

如图 13 所示，在元件引线上添加跳线。

6) Hand solder the connections.

手工焊接连接点。

7) Be careful not to attach component leads together.

注意不要将元件引线连接在一起。

8) When component leads are soldered directly to the conductor, there must be a minimum clearance of 0.05 inch from terminal area.

当元件引线直接焊接到导体上时，必须与端子区域保持至少 0.05 英寸的间隙。

(b) For parts with lead ends on the component side of the boards:

对于引线端在电路板元件侧的零件：

1) Install part in its specified location. If it is not mechanically fastened, bond it to the board. Use Type 69 adhesive as specified in SOPM 20-50-12.

将零件安装在规定的位置。如果没有机械固定，则将其粘接到电路板上。使用 SOPM 20-50-12 规定的 69 型粘合剂。

2) Connect leads to existing part leads with 180 degrees minimum wrap as shown in Figure 14.

如图 14 所示，将引线与现有零件引线连接，最小缠绕 180 度。

3) Hand solder the connections.

手工焊接连接点。

4) If the bare lead is too short to get to its attachment point or it must go nearer than 0.025 inch to another bare lead or other bare metal surface, prepare it as follows:

如果裸引线太短，无法到达连接点，或必须靠近另一条裸引线或其他裸金属表面超过 0.025 英寸，则按以下方法准备：

a) Cut the lead to 0.25-0.50 inch long.

将引线剪成 0.25-0.50 英寸长。

b) Prepare the required length of magnet wire (AWG26 or AWG28 coated wire).

准备好所需长度的磁导线（AWG26 或 AWG28 涂层导线）。

c) Wrap one of the prepared ends of the coated wire around the shortened part lead 3/4 to 1-1/4 turns. If the access is too tight, make a hook in the end of both the lead and the wire and connect them as shown in Figure 15.

将涂层导线的一端绕在缩短的零件引线上 3/4 至 1-1/4 圈。如果接得太紧，可在引线和导线的末端做一个钩，然后如图 15 所示将它们连接起来。

d) Solder the connection. Solder the other end of coated wire to the attachment point.

焊接连接点。将涂层导线的另一端焊接到连接点上。

5) Make sure you examine each joint.

确保检查每个结合点。

11. REMOVAL AND REPLACEMENT OF CONNECTORS 拆除和更换连接器

A. Unpotted Connector

非封装连接器

(1) Use the procedures for removal and installation of parts given in Paragraph 9., Paragraph 10.

使用第 9 段、第 10 段中给出的拆卸和安装零件程序。

(2) Clipping of connector pins is optional.

连接器针脚可选择剪断。

(3) Remove mounting screws and rivets. To remove rivets, drill or machine off the heads and punch out the body.

卸下安装螺钉和铆钉。拆卸铆钉时，用钻头或机器将铆钉头钻掉，然后冲出铆钉体。

(4) Remove all metallic particles. Light scratches or burnishing are permitted. No delamination or machining damage to circuit board surfaces or mounting holes are permitted.

清除所有金属颗粒。允许轻微划痕或抛光。不允许对电路板表面或安装孔造成分层或机加工损坏。

B. Potted Connector

封装连接器

CAUTION ：BE VERY CAREFUL WHEN YOU REMOVE CONNECTORS WHICH HAVE CONFORMAL COATING. THE CIRCUIT BOARD CAN BE DAMAGED.

注意：拆卸有保形涂料的连接器时要非常小心。否则会损坏电路板。

(1) Remove mounting screws.

拧下安装螺钉。

(2) Machine off a large piece of the connector. Be careful not to damage the circuit board.

用机器切下一大块连接器。小心不要损坏电路板。

(3) Light scratches or burnishing are permitted. No delamination or machining damage to circuit board or components is permitted.

允许轻微划痕或抛光。不允许对电路板或元件造成分层或机加工损坏。

(4) Remove the remaining conformal coating and potting material, remove the solder, remove the connector pins, clean the assembly and install a new connector as specified in Paragraph 9. and Paragraph 10.

按照第 9.段和第 10.段的规定，清除剩余的保形涂料和灌封材料，去除焊料，拆下连接器插针，清洁组件并安装新的连接器。

C. Removal of BACC65K-series Connectors

拆卸 BACC65K 系列连接器

CAUTION ：BE VERY CAREFUL WHEN YOU REMOVE CONNECTORS WHICH HAVE CONFORMAL COATING. THE CIRCUIT BOARD CAN BE DAMAGED.

注意：拆卸有保形涂层的连接器时要非常小心。可能会损坏电路板。

(1) Remove the solder and encapsulant from the connector pin solder joint on the circuit side of the board as specified in Paragraph 5.

按照第 5 段的规定，清除电路板电路侧连接器引脚焊点上的焊料和封装胶。

(2) Remove the connector mounting screws. Cut the encapsulant if necessary.

卸下连接器的安装螺钉。必要时切断封装胶。

(3) Cut and remove as much encapsulant as possible from around the connector.

从连接器周围剪切并去除尽可能多的封装胶。

(4) Carefully pry the connector from the board. Start the separation at one end of the connector and go along to the other end. Do not bend the board more than 0.25 inch over the span of the board.

小心撬开电路板上的连接器。从连接器的一端开始分离，一直到另一端。在整个电路板的跨度上，弯曲不要超过 0.25 英寸。

D. Installation of BACC65K-series Connectors

安装 BACC65K 系列连接器

CAUTION ：REMOVE THE KEYING PINS BEFORE YOU MOUNT THE CONNECTOR TO THE CIRCUIT CARD. THE CONNECTOR IS NOT SERVICEABLE IF THE ADJACENT PINS ON THE CONNECTOR FACE ARE BENT OR DAMAGED.

注意：在将连接器安装到电路卡上之前，请卸下键针。如果连接器面上的相邻插针弯曲或损坏，则连接器无法维修。

(1) When you install new connectors, do not straighten the connector pins which mate with plugs. Straighten the pins that are soldered to a printed circuit card only if misalignment is not more than the diameter of the pin. Use tools which will not damage the finish of the pins or contacts.

安装新连接器时，不要拉直与插头配接的连接器插针。只有在偏差不超过插针直径的情况下，才可拉直焊接到印刷电路板上的插针。使用不会损坏插针或插针表面的工具。

(a) Remove the unwanted keying pins of BACC65K-series connectors as specified by the overhaul instructions. Cut the pins off with tool ST2351B or break the pins off with tool ST2351C. Then make sure the depth is 0.260 inch minimum to permit correct engagement of the mating connector (Figure 16).

按照大修说明的规定，拆除 BACC65K 系列连接器不需要的键控引脚。用工具 ST2351B 切断插针或用工具 ST2351C 折断插针。然后确保最小深度为 0.260 英寸，以便正确啮合配接连接器（图 16）。

(b) Remove contamination from the mating surface between the printed circuit assembly and the connector. Use isopropyl alcohol, cleaning solvent, or 1,1,1 trichloroethane with a bristle brush within one hour after the solder is solid. Dry with compressed air or let the solvent evaporate.

清除印刷电路组件和连接器之间配合表面的污染物。在焊料凝固后一小时内，使用异丙醇、清洁溶剂或 1,1,1 三氯乙烷，并用鬃刷刷洗。用压缩空气吹干或让溶剂挥发。

(c) Adjust the position of the mating assembly with the connector solder pins to make the hole position numbers in the assembly agree with the same pin numbers on the connector. Do not use too much force.

调整配接组件与连接器焊针的位置，使组件上的孔位置编号与连接器上的相同焊针编号一致。不要用力过猛。

(d) Apply two drops of thread locking compound on the screw threads. Make the drop cover a minimum of two threads. Install the connector on the assembly with the screws.

在螺纹上滴两滴螺纹锁固剂。至少覆盖两个螺纹。用螺钉将连接器安装到组件上。

(e) Tighten the screws equally to prevent too much load on one screw.

均匀拧紧螺丝，以防一个螺丝承受过大的负荷。

(f) Tighten the screws to 4-6 pound-inches.

将螺丝拧紧至 4-6 磅英寸。

CAUTION ：DO NOT TIGHTEN OR REPLACE FASTENERS AFTER YOU SOLDER UNLESS YOU REFLOW THE SOLDER.

注意：除非回流焊，否则不要在焊接后拧紧或更换紧固件。

(g) Solder the connector to the board.

将连接器焊接到电路板上。

(h) If the assembly will not be coated with encapsulant within 24 hours:

如果组件在 24 小时内没有涂上封装胶，则应采取以下措施

1) If the assembly is not static sensitive, put it in a clean, dry polyethylene bag, seal the bag, and store it in an area where the relative humidity is no higher than 50 percent. If the unit is static sensitive, give it protection as specified in SOPM 20-12-02.

如果组件对静电不敏感，将其装入干净、干燥的聚乙烯袋中，密封袋口，并存放在相对湿度不高于 50% 的地方。如果组件对静电敏感，则应按照 SOPM 20-12-02 规定的要求给予保护。

2) As an alternative, you can clean the assembly again to prepare for the conformal coating.

作为替代方法，可以再次清洁组件，为涂敷保形涂料做好准备。

(i) Apply the conformal coat to the repaired areas as specified in Paragraph 17.

按照第 17 段的规定，在修理过的地方涂上保形涂料。

(j) Then apply the same coating to the slot between the connector and the board. Be sure to cover all of the conductors and leads.

然后在连接器和电路板之间的槽内涂上同样的涂层。确保覆盖所有导线和引线。

12. REMOVAL AND REPLACEMENT OF JUMPER WIRES拆除和更换跳线

A.Removal of a Jumper Wire

拆除跳线

(1)Cut the jumper wire at a location 0.05 inch or more from the termination point.

在距离端接点0.05 英寸或以上的位置剪断跳线。

(2)Unsolder and remove the jumper wire terminations. Full removal of the jumper wire is optional.

熔断并拆除跳接线终端。可选择完全拆除跳线。

(3)If the remaining part of the jumper wire will stay, make sure the cut ends of the jumper are a minimum of 0.02 inch from other conductors.

如果要保留跳接线的剩余零件，应确保跳接线的切割端与其他导体的距离至少为 0.02 英寸。

(4)Bond the cut ends of the jumper wire to the printed circuit board with Type 52 or BMS 5-72, Type 1 adhesive, or the conformal coating specified by the overhaul instructions.

用 52 型或 BMS 5-72,1 型粘合剂或大修说明规定的保形涂料将跳线的切端粘合到印刷电路板上。

B.Installing Solid Conductor Jumper Wires

安装实芯跳线

(1)Do not use sleeving as insulation for jumper wires. Use AWG 26 or 28 polyurethane-nylon coated magnet wire, J-W-1177/9 (which has coatings such as Nylac, Nyleze, Nysol,Poly-Nylon, Soderon) unless otherwise specified by overhaul instructions.Wires of less than 0.5-inch length can be without insulation.

不要使用套管作为跳线的绝缘层。除非大修说明另有规定，否则请使用 AWG 26 或 28 的聚氨酯尼龙涂层电磁线 J-W-1177/9（其涂层包括 Nylac、Nyleze、Nysol、Poly-Nylon、Soderon）。长度小于 0.5 英寸的导线可以不带绝缘层。

(2) Do the steps that follow to strip coated wires in areas to be soldered:

按以下步骤剥去待焊区域的涂层导线：

NOTE: Unless specified differently, you can use the procedures for J-W-1177/4, J-W-1177/9, and J-W-1170/10 magnet wire in Paragraph 12.B.(2)(a), Paragraph 12.B.(2)(b) and Paragraph 12.B.(2)(c). You can also use these procedures for equivalent magnet wires as specified in cancelled MIL-W-583.

注：除非另有规定，否则可以使用第 12.B.(2)(a)段、第 12.B.(2)(b)段和第 12.B.(2)(c)段中有关 J-W-1177/4、J-W-1177/9 和 J-W-1170/10 磁导线的程序。您也可以将这些程序用于废除的 MIL-W-583 规定的同等电磁线。

(a) Solder Stripping

剥焊

WARNING：DO NOT BREATHE THE FUMES. USE ONLY WITH APPROVED VENTILATION.

警告：切勿吸入烟雾。只能在经过批准的通风条件下使用。

1)Apply rosin-based flux to the end of the wire to be stripped and put the end of the wire in a solder pot of solder QQ-S-571 Type SN60BS, SN60WS, SN63BS, or SN63WS, heated to 700-705°F.

在待剥线端涂抹松香助焊剂，然后将线端放入 QQ-S-571 SN60BS、SN60WS、SN63BS 或 SN63WS 型焊料罐中，加热至 700-705°F。

WARNING：DO NOT BREATHE ISOPROPYL ALCOHOL VAPOR OR MISTS. USE ONLY WITH APPROVED VENTILATION. AVOID LONG OR REPEATED SKIN CONTRACT. KEEP AWAY FROM HEAT, SPARKS AND OPEN FLAME.

警告：切勿吸入异丙醇蒸汽或雾气。仅在经过批准的通风条件下使用。避免长时间或反复接触皮肤。远离热源、火花和明火。

2)After the coating is removed, remove flux residues with isopropyl alcohol and a wiper.

去除涂层后，用异丙醇和擦拭布清除助焊剂残留物。

(b)Chemical Stripping

化学剥离

1)Neutralize the surface of the insulation for a minimum of two times the strip length. To do this, clean with isopropyl alcohol and rinse with water. Wipe dry with alcohol and rinse with water. Wipe dry with a wiper.

中和绝缘层表面的长度至少为带材长度的两倍。为此，用异丙醇清洗并用水冲洗。用异丙醇擦干，再用水冲洗。用手帕擦干。

WARNING：KEEP THE STRIPPING SOLUTION AWAY FROM OTHER PORTIONS OF THE WIRE OR MAGNETIC DEVICES.

警告：使剥线液远离导线的其他部分或磁性装置

2) Put the end of the wire in chemical stripping solution only to the depth of the insulation to be removed. When it is not easy to put the wire into the solution, you can apply the solution to the insulation.

将电线末端放入化学剥线溶液中，深度仅为需要剥除的绝缘层深度。如果不方便将电线放入溶液中，可以将溶液涂在绝缘层上。

3) If this is the higher temperature class wire with a hard surface glaze, pull the length to be stripped through pieces of 320 to 400 grit abrasive cloth put between two sponges. Apply finger pressure and pull slowly. Pull the wire through the adhesive two times.

如果是温度较高、表面釉质较硬的金属丝，则用两块海绵夹住 320 至 400 粗细度的砂布，拉出需要剥离的长度。用手指施压，慢慢拉。将电线穿过粘合剂拉两次。

4) Remove the soft insulation from the wire with a swab.

用棉签去除电线上的软绝缘层。

5) Wash the stripped surfaces and the adjacent insulation with clean water. Dry, then wipe with a wiper wet with solvent, isopropyl alcohol, or naphtha.

用清水清洗剥离表面和邻近的绝缘层。擦干后，用溶剂、异丙醇或石脑油浸湿的抹布擦拭。

机械剥离

1) Adjust the tool to completely remove the insulation from the conductor. Do not adjust the tool smaller than necessary to completely remove the insulation.

调整工具，以完全去除导体上的绝缘层。不要将工具调整到小于完全清除绝缘层所需的程度。

2) Do not let the tool twist the conductor during insulation removal.

剥除绝缘层时，不要让工具扭曲导体。

3) Do not make nicks or gouges on the conductor. But machining marks are acceptable on AWG 29 and larger wire.

不要在导体上留下划痕或沟痕。但在 AWG 29 及更大的导线上可以留下加工痕迹。

4) Power sanders with 150 to 200 grit material can be used to strip rectangular magnet wire insulation.

可以使用 150 至 200 粗细度的动力打磨机来剥除矩形电磁线的绝缘层。

5) Clean the stripped area and the adjacent insulation with isopropyl alcohol or naphtha.

用异丙醇或石脑油清洁剥离区域和邻近绝缘层。

(d) Laser Stripping (not applicable to J-W-1177/4 or J-T-1177/10 wires)

激光剥线（不适用于 J-W-1177/4 或 J-T-1177/10 导线）

1) Do not bend the wire to a radius smaller than half the wire diameter.

弯曲导线的半径不得小于导线直径的一半。

2) Clean the stripped surfaces and the adjacent insulation with isopropyl alcohol or naphtha.

用异丙醇或石脑油清洁剥线表面和邻近绝缘层。

(3) Use the procedures of SOPM 20-12-01 to apply a tinned surface of solder to the ends of the connection points of the jumpers.

使用 SOPM 20-12-01 的程序在跳线连接点的两端涂上一层镀锡的焊料表面。

(4) Put the wire ends through the holes in the terminals as shown in Figure 17.

如图 17 所示，将导线末端穿过端子上的孔。

(5) Connect jumper wires to turret-type terminals as follows (Figure 18):

按以下步骤将跳线连接到转塔型端子上（图 18）：

(a) Put the wires and the component lead ends in sequence from the base of the terminal post toward the top.

从接线柱底部向顶部依次穿入导线和元件引线端头。

(b) Put the larger diameter wires around the base of the terminal post with the smaller diameter wires attached above.

将直径较大的导线绕在接线柱底部，直径较小的导线连接在上面。

将导线和元件引线端头弯曲，绕接线柱转半圈。确保它们接触到接线柱。

(d) Solder the connections. When more than one wire is connected to a terminal, solder all the wires at the same time.

焊接连接处。当多根导线连接到一个端子时，应同时焊接所有导线。

(6) Solder the wires to pin-type terminals with the same procedure as for turret terminals, but tin and bend the stranded wires before you attach them to the terminals. Put the stranded wires no closer than 0.06 inch from the top of the pin.

按照与转塔接线端子相同的程序将导线焊接到针型接线端子上，但在将绞合导线连接到接线端子之前要先将其镀锡并弯曲。将绞合导线放在距插针顶部不超过 0.06 英寸的地方。

(7) Where necessary, make connections between the opposite sides of the board with swaged wires (Figure 19). On plated-through holes, swage the wire on the two sides of the board. On holes without plating, swage the wire on the part side of the board, so it will not fall through the holes. Then wire and clinch on the opposite side of the board. Clinch the wire in the direction of, parallel to, and to touch the circuit pattern. A 15 degree maximum spring back is permitted.

必要时，用压接导线连接电路板的两侧（图 19）。在电镀通孔上，将导线压接在电路板的两侧。在没有电镀的孔上，将导线压接在电路板的零件侧，这样导线就不会从孔中掉落。然后在电路板的反面接线并夹紧。夹线方向应与电路图案平行，并与电路图案接触。允许最大回弹 15 度。

(8) If permitted by the configuration, unless the overhaul instructions are different, make the leads from terminals or lugs of electronic parts go out from the part terminal as shown before they go down to the surface of the board. If the connection is too close for this, make a loop in the wire, as shown (Figure 20). Do not let the wire touch itself at the loop. This will let the loop stay flexible after the encapsulant is applied.

如果结构允许，除非大修说明有所不同，否则应使电子零件的端子或接线片的引线在下到电路板表面之前，如图所示从零件端子引出。如果连接太近，可在导线上打一个环，如图所示（图 20）。不要让导线在线圈处接触到自己。这将使线圈在涂上封装剂后保持柔性。

(9) On boards which will use acrylic conformal coating or which have no coating, bond the jumper to the board. Use Type 69 adhesive as specified in SOPM 20-50-12 to bond the jumpers at one-inch intervals.

在将使用丙烯酸保形涂料或没有涂料的电路板上，将跳线粘合到电路板上。使用 SOPM 20-50-12 规定的 69 型粘合剂，以一英寸的间距粘合跳线。

(10) Solder the jumper connections as specified in SOPM 20-12-01.

按照 SOPM 20-12-01 的规定焊接跳线连接。

C. Installing Stranded Conductor Jumper Wires

安装绞合导体跳线

(1) Use the procedures for solid jumper wires unless shown differently below.

除非以下显示不同，否则使用实心跳线的程序。

(2) Make a Z or C bend or helical loop in the wire and bond it to the circuit board to prevent movement when the joint is soldered and to prevent stress in the solder joint (Figure 21). Bond the wire with an adhesive that will not contaminate the board, or be a problem during later procedures. We recommend Type 52 or Type 69 adhesives (SOPM 20-50-12).

在导线上做一个 Z 形或 C 形弯曲或螺旋环，并将其粘合到电路板上，以防止焊接时发生移动，并防止焊点受力（图 21）。使用不会污染电路板或在以后程序中造成问题的粘合剂粘合导线。我们建议使用 52 型或 69 型粘合剂（SOPM 20-50-12）。

13. REMOVAL AND REPLACEMENT OF LEADS AND WIRES FROM TERMINALS 拆除和更换接线端子上的引线和导线

A. Cut the lead or wire from the terminal.

从接线端子上剪断引线或导线。

B. Remove conformal coating from the terminal solder joint as specified in Paragraph 5.

按第 5 段规定的方法清除端子焊点上的保形涂料。

C. Remove unwanted solder and wire or lead pieces from the terminal with a soldering iron and wick.

用烙铁和烙芯清除端子上多余的焊料、导线或引线碎片。

D. Clean the terminal with isopropyl alcohol.

用异丙醇清洁接线端子。

E. Install the new wires or leads and hand solder them.

安装新导线或引线并手工焊接。

F. Examine the joint carefully before you apply encapsulant or other coating.

在涂抹封装剂或其他涂层之前，仔细检查接头。

14. REMOVAL AND REPLACEMENT OF TERMINALS 拆除和更换端子

A. Remove the conformal coating as necessary. Refer to Paragraph 5.

根据需要清除保形涂料。参见第 5 段。

B. Remove leads or wires as specified in Paragraph 13.

按第 13 段规定的拆除引线或导线。

C. To remove the terminals, drill or clip them from the hole. Try not to enlarge the hole more than 10 percent.

拆卸接线端子时，将其从孔中钻出或夹出。尽量不要将孔扩大 10%以上。

D. If the hole is enlarged more than 10 percent, fill the hole with Type 52 epoxy adhesive as specified in SOPM 20-50-12. Drill a new hole to the correct hole size.

如果孔扩大超过 10%，则按照 SOPM 20-50-12 规定的 52 型环氧树脂粘合剂填充孔。按照正确的孔尺寸钻一个新孔。

E. Install the new terminal.

安装新端子。

F. Connect all part leads and jumper wires and hand solder the connections.

连接所有零件引线和跳线，并手工焊接连接。

G. Encapsulate the area as specified in Paragraph 17.

按照第 17 段规定的要求封装该区域。

15. PLATED THROUGH HOLE PROCEDURES 电镀通孔程序

A. Removal of Unwanted Solder

清除多余焊料

NOTE: Limit the removal of solder to 3 times for each hole.

注：每个孔的拆焊次数不得超过 3 次。

(1) Fill the holes with solder.

用焊料填满孔洞。

(2) Let the board cool a minimum of 30 seconds.

让电路板冷却至少 30 秒。

(3) Remove unwanted solder with a vacuum device or with a soldering iron and wick.

用真空装置或烙铁和烙芯去除多余的焊料。

B. Removal of Adhesive from Plated-Through Holes and Pads

清除电镀通孔和板上的粘合剂

NOTE: This procedure is applicable to adhesives Type 52 and BMS 5-72 only.

注：本程序仅适用于 52 型和 BMS 5-72 型粘合剂。

(1) Melt the solder with a soldering iron.

用烙铁熔化焊料。

(2) Wait until the solder is cool. Remove the adhesive manually.

等到焊料冷却。手工清除粘合剂。

(3) Clean the area with isopropyl alcohol.

用异丙醇清洁该区域。

(4) Examine for complete removal at a magnification of 4X.

用 4 倍放大镜检查是否完全清除。

C. Removal of Nodules From Plated-Through Holes

清除电镀通孔中的结节

(1) Drill through the holes with an ST1255 drill. The diameter of the drill must be 0.0005-0.0010 inch smaller than that of the drill used to make the hole.

用 ST1255 钻头钻孔。钻头的直径必须比用来钻孔的钻头小 0.0005-0.0010 英寸。

(2) Examine for complete removal at a magnification of 7X to 15X.

用 7 倍至 15 倍的放大镜检查是否完全清除。

D. Removal of a Plated-Through Hole

清除电镀穿孔

(1) Drill the hole out to completely remove the plating.

将孔钻出，完全去除镀层。

(2) Fill the hole with epoxy (Ref Paragraph 6.).

用环氧树脂填充孔洞（参考第 6 段）。

16. REPAIR OF PRINTED CIRCUIT BOARD BASE MATERIAL 修理印刷电路板基材

注意：在清洁电路板或去除保形涂料时，由于异丙醇能去除丙烯酸涂层，因此应先在小范围内试用去除丙烯酸涂层的程序。

A. Use these procedures to repair damage to the base material of the circuit board. Typical defects that can be repaired include cracks, nicks, holes, breaks, burns and delaminations.

使用这些程序修理电路板基材的损坏处。可修理的典型缺陷包括裂纹、划痕、孔洞、断裂、烧伤和脱层。

B. Holes and Voids

孔洞和空隙

(1) Put a small amount of Type 52 adhesive in the hole or void. Use an amount sufficient to fill the hole flush with, or a small distance above, the original board surface.

在孔洞或空隙中涂抹少量 52 型粘合剂。粘合剂的用量应足以填满孔洞，要求与原板表面齐平或高出原板表面一小段距离。

(2) Cure the adhesive 4 hours minimum at room temperature, or 2 hours minimum at 140-160°F.

在室温下至少固化 4 小时，或在 140-160°F 下至少固化 2 小时。

(3) With a small piece of 400-grit wet-or-dry sandpaper on the end of your finger, sand the repaired area smooth with the adjacent surfaces. Use light pressure and a cross-hatch pattern.

用手指末端夹一小块 400 号干湿砂纸，将修理区域与相邻表面打磨平整。使用轻微的压力和交叉打磨。

(4) Polish the repaired area with a soft rotary brush and light constant pressure.

用柔软的旋转刷和轻微的持续压力抛光修理区域。

(5) Clean the area with isopropyl alcohol. Let this air dry.

用异丙醇清洁该区域。让其风干。

(6) Replace removed conductors and components as necessary.

根据需要更换拆下的导体和元件。

(7) Apply conformal coating as necessary.

根据需要涂上保形涂料。

C. Cracks

裂缝

(1) Remove conformal coating, components, and foil pattern from the area around the crack.

清除裂缝周围的保形涂料、元件和箔片。

(2) Drill a small hole at each end of the crack to stop the crack.

在裂缝两端各钻一个小孔，以阻止裂缝。

(3) Open the crack on each side of the circuit board with a V-shaped cut to a depth equal to one-half the thickness of the base material.

在电路板两侧用 V 形切口打开裂缝，深度相当于基材厚度的二分之一。

(4) Clean the broken surfaces and the adjacent area with isopropyl alcohol.

用异丙醇清洁破损表面和邻近区域。

(5) Fill the crack and the drilled holes with Type 52 adhesive. Be careful not to let air bubbles or voids stay in the adhesive. Use an amount of adhesive sufficient to fill the area a small distance above the original board surface.

用 52 型粘合剂填满裂缝和钻孔。注意不要让气泡或空隙留在粘合剂中。粘合剂的用量应足以填满此区域，并且应高出原板表面一小段距离。

(6) Put a smooth piece of Teflon or plastic over the repaired area. Put orange sticks on each side of the repair area and hold lightly with clamps.

在修理区域铺上一块光滑的特氟龙或塑料布。在修理区域的两侧各放上一根橙色的粘条，用夹子轻轻夹住。

(7) Cure the adhesive 4 hours minimum at room temperature or 2 hours minimum at 140-160°F.

在室温下至少固化粘合剂 4 小时，或在 140-160°F 下至少固化 2 小时。

(8) Remove the clamps, orange sticks, and the Teflon or plastic.

取下夹子、橙色粘条和聚四氟乙烯或塑料。

(9) Remove unwanted adhesive.

去除不需要的粘合剂。

(10) Clean the area with isopropyl alcohol.

用异丙醇清洁该区域。

(11) Install replacement foil patterns, holes, eyelets and components.

安装替换的箔片、孔、孔眼和元件。

(12) Apply conformal coating as necessary.

必要时涂敷保形涂料。

D. Surface Defects

表面缺陷

(1) Remove components and conductors as necessary to permit access to the defects.

根据需要拆除元件和导体，以便接近缺陷。

(2) File away the damaged area with a rotary file. Remove all burnt material. If necessary, remove material to make a hole with a V-shaped taper from front to back. To make the repair stronger, you can do this also on the back side to permit a two-sided repair.

用旋转锉锉掉受损区域。清除所有烧焦的材料。如有必要，可将材料锉成一个前后呈 V 形的锥孔。为了使修理更牢固，可以在背面也这样做，以实现双面修理。

(3) Clean the repair area with isopropyl alcohol to remove loose material.

用异丙醇清洁修理区域，清除松动的材料。

(4) Fill the area with Type 52 adhesive to a small distance above the original board surface. Make sure there are no air bubbles or voids.

用 52 型粘合剂填满该区域，使其高出原板表面一小段距离。确保没有气泡或空隙。

(5) Cover the repair area with a smooth piece of Teflon or plastic. Make sure the piece does not move.

用一块光滑的特氟龙或塑料覆盖修理区域。确保该片不会移动。

(6) If applicable, fill the area on the back of the circuit board as specified in Paragraph 16.D.(4).

如适用，按第 16.D.(4)段规定的方法填充电路板背面的区域。

(7) Put the repaired circuit board in a screw press or equivalent device to apply pressure.

将修理好的电路板放入螺旋压力机或等效装置中施压。

(8) Cure the adhesive for 4 hours minimum at room temperature or 2 hours minimum at 140-160°F.

将粘合剂在室温下固化至少 4 小时，或在 140-160°F 下固化至少 2 小时。

(9) Remove the pressure, clamps, Teflon or plastic.

移除压力、夹具、特氟龙或塑料。

(10) Remove unwanted adhesive. Clean the area with isopropyl alcohol.

去除不需要的粘合剂。用异丙醇清洁该区域。

(11) Install replacement conductors and components.

安装替换导体和元件。

(12) Apply conformal coating as necessary.

根据需要涂敷保形涂料。

E. Damage That Goes Through The Board

贯穿电路板的损坏

(1) Remove components and conductors as necessary to permit access to the damaged area.

根据需要拆除元件和导体，以便接近受损区域。

(2) Remove all damaged or discolored board material with an abrasive.

用研磨剂清除所有损坏或变色的电路板材料。

(3) Bevel and undercut the edge of the area to help hold in the repair material.

对损坏区域的边缘进行斜切和下切，以帮助固定修理材料。

(4) Clean all unwanted matter and loose particles from the area.

清理区域内所有不需要的物质和松散颗粒。

(5) Attach a smooth Teflon or plastic surface against one side of the repaired area.

在修理区域的一侧贴上光滑的特氟龙或塑料表面。

(6) From the side opposite the attached surface, fill the repaired area with Type 52 adhesive to a small distance above the original board surface. Make sure there are no air bubbles or voids.

从与附着表面相对的一侧，用 52 型粘合剂填满修理区域，使其高出原板表面一小段距离。确保没有气泡或空隙。

(7) Cover the repaired area with a smooth piece of Teflon or plastic, then install clamps to hold the piece down. Make sure the piece does not move after it touches the adhesive.

用一块光滑的聚四氟乙烯或塑料覆盖修理区域，然后安装夹子将其夹住。确保板块接触粘合剂后不会移动。

(8) Cure the adhesive 4 hours minimum at room temperature or 2 hours minimum at 140-160°F.

在室温下至少固化粘合剂 4 小时，或在 140-160°F 下至少固化 2 小时。

(9) Remove the clamps and the pieces of Teflon or plastic.

取下夹子和特氟龙或塑料片。

(10) Remove unwanted adhesive. Clean the area with isopropyl alcohol.

去除不需要的粘合剂。用异丙醇清洁该区域。

(11) Install replacement conductors and components.

安装替换导线和元件。

(12) Apply conformal coating as necessary.

必要时涂敷保形涂料。

F. Edge Delamination

边缘分层

(1) Completely fill with Type 52 adhesive the area where the circuit board edges have separations.

在电路板边缘分层的地方完全涂满 52 型粘合剂。

(2) Use clamps to hold the damaged area tightly between two flat surfaces.

用夹子将受损区域紧紧夹在两个平面之间。

(3) Cure the adhesive 4 hours minimum at room temperature or 2 hours minimum at 140-160°F.

在室温下至少固化粘合剂 4 小时，或在 140-160°F 下至少固化 2 小时。

(4) Remove the clamps.

取下夹子。

(5) If necessary, make the repaired area smooth with 400-grit wet-or-dry sandpaper.

如有必要，用 400 级干湿砂纸将修理区域打磨光滑。

(6) Clean the area with isopropyl alcohol.

用异丙醇清洁该区域。

17. REPLACEMENT OF CONFORMAL COATING (ENCAPSULANT) 更换保形涂料（封装剂）

NOTE: We recommend that you use acrylic, polyurethane or silicone conformal coatings, not epoxy, to make it easier to replace components on the board.

注：我们建议您使用丙烯酸、聚氨酯或硅树脂保形涂料，而不是环氧树脂，以便于更换电路板上的元件。

A. For a complete PCA or for a large area coating, refer to the detailed paragraphs for Cleaning and for Conformal Coating preparations. For small areas, as when only two or three components are to be replaced, use these procedures:

对于整个 PCA 或大面积涂层，请参阅清洁和保形涂料准备的详细段落。对于小面积，如只需更换两三个元件，可使用以下程序：

(1) Apply a small quantity of isopropyl alcohol to a small test area. If the conformal coating becomes soft and removable, continue with this procedure to remove the conformal coating at the damaged area. If the coating stays hard, use the procedures for removing polyurethane coatings or parylene as necessary. If the conformal coating is soft before you apply the alcohol, it could be a silicone coating that you can easily peel off. Then use the procedure for removal of silicone coatings.

在小面积测试区域涂抹少量异丙醇。如果保形涂料变软并可清除，则继续使用此程序清除受损部位的保形涂料。如果涂层保持坚硬，则根据需要使用清除聚氨酯涂层或聚对二甲苯的程序。如果在使用异丙醇之前保形涂料是软的，那么它可能是硅树脂涂层，可以很容易地剥离。那就使用去除硅树脂涂层的程序。

(2) After a repair is complete, for all coatings but parylene, clean with a small brush or a cotton swab and isopropyl alcohol and then apply a coating to the repaired area. Use a brush to apply the coating to small areas. Cover all circuits for a minimum 0.03 inch overlap over the end of the repaired area unless an area is identified to be kept bare.

修理完成后，对于除对二甲苯以外的所有涂层，用小刷子或棉签和异丙醇进行清洁，然后在修理区域涂上一层涂层。使用刷子在小区域涂抹涂层。覆盖所有电路，在修理区域的末端至少重叠 0.03 英寸，除非确定某个区域要保持裸露。

(3) To add a new coating to units with a parylene coating:

在有聚对二甲苯涂层的设备上添加新涂层：

(a) Clean the area with isopropyl alcohol.

用异丙醇清洗该区域。

(b) Dry the assembly at 150-200°F for a minimum of 15 minutes.

在 150-200°F 下烘干组件至少 15 分钟。

(c) Apply a polyurethane conformal coating around the component. Make an overlap of the adjacent parylene coating of 0.03 inch minimum.

在元件周围涂上聚氨酯保形涂料。相邻聚对二甲苯涂层的重叠部分至少为 0.03 英寸。

(d) Cure the coating as specified in Paragraph 17.C.(5) below.

按照下文第 17.C.(5)段的规定固化涂层。

(4) To repair a Sylgard coating

修理 Sylgard 涂层

(a) Remove the Sylgard coating from the defective area.

清除缺陷部位的 Sylgard 涂层。

(b) Remove polyurethane or acrylic coating, as necessary, from the area of the components to be replaced.

根据需要，清除待更换部件区域的聚氨酯或丙烯酸涂层。

视需要更换部件。

(d) Clean the areas with isopropyl alcohol. Let them air dry.

用异丙醇清洁这些区域。让其风干。

(e) Do not apply acrylic coatings to areas where the base coating was removed.

不要在已除去底层涂料的区域涂上丙烯酸涂料。

(f) (Optional) Apply DC 1204 primer to the area. This primer is not necessary for the coating to bond to the surface. If you apply the primer, let it cure for one hour at room temperature before you apply conformal coating.

（可选）在该区域涂上 DC 1204 底漆。涂料与表面的粘合并不需要这种底漆。如果使用底漆，则应在室温下固化一小时后再涂敷保形涂料。

(g) Apply a continuous layer of RTV3140 coating. Be sure there are no bare surfaces (components, leads, etc.).

连续涂上一层 RTV3140 涂层。确保没有裸露表面（元件、导线等）。

(h) Let the coating cure for a minimum of 48 hours at room temperature. The cure is complete after 7 days.

让涂层在室温下固化至少 48 小时。7 天后固化完成。

B. Acrylic Conformal Coating

丙烯酸保形涂料

CAUTION：THESE PROCEDURES WILL REMOVE ALL OF THE ACRYLIC COATING FROM THE ASSEMBLY.

注意：这些程序将清除组件上的所有丙烯酸涂层。

(1) Clean the PCA

清洁 PCA

NOTE: You can use any of these 3 procedures to clean the PCA if all the circuit components have hermetic seals. If some components do not have a hermetic seal, use only the isopropyl alcohol wash procedure.

注意：如果所有电路元件都有密封圈，则可以使用上述 3 个程序中的任何一个来清洁 PCA。如果某些元件没有密封，则只能使用异丙醇清洗程序。

(a) Isopropyl Alcohol Wash

异丙醇清洗

1) Get three trays or other containers of a size to contain the assembly. Fill each one with isopropyl alcohol. Put them in a row. When the alcohol in the first container becomes dirty, discard that alcohol and put in it the alcohol from the second container. Put the alcohol from the third container into the second container and fill the third container with clean, new alcohol.

准备三个托盘或其他容器，大小应能容纳组件。在每个容器中注入异丙醇。将它们排成一排。当第一个容器中的异丙醇变脏时，将其丢弃，然后放入第二个容器中的异丙醇。将第三个容器中的异丙醇倒入第二个容器中，然后在第三个容器中注入干净的新异丙醇。

2) Rinse the assembly with tap water for 30 seconds minimum.

用自来水冲洗组件至少 30 秒钟。

3) Put the assembly fully in the first container of isopropyl alcohol and brush with a bristle brush until all visible contaminants are removed.

将组件完全放入第一个装有异丙醇的容器中，用鬃毛刷刷洗，直至清除所有可见污染物。

4) Move the assembly to the second container and clean as before.

将组件移到第二个容器中，按之前的方法清洁。

5) Move the assembly to the third container and clean as before.

将组件移到第三个容器中，按之前的方法清洁。

6) Rinse with new isopr异丙醇l alcohol from the bottle.

用瓶中的新异丙醇冲洗。

NOTE: A maximum total exposure time to alcohol of 15 minutes is recommended.

注：建议异丙醇暴露总时间不超过 15 分钟。

7) Let the part dry at room temperature.

让零件在室温下干燥。

(b) Freon TES fluorinated solvent in a vapor degreaser.

蒸汽脱脂剂中的氟利昂 TES 含氟溶剂。

1) The rate of travel into and out of the degreaser must be a maximum of 12 feet/minute. Adjust the speed such that parts dry as they exit the vapor.

进入和离开脱脂器的速度最多不得超过 12 英尺/分钟。调整速度，使零件在排出蒸汽时干燥。

2) Place parts in racks to prevent part damage and to permit the vapor to circulate around all part surfaces and the condensate to drain off.

将零件放在架子上，以防止零件损坏，并使蒸汽在所有零件表面循环和冷凝水排出。

3) Do not move parts or assemblies down into the boiling sump.

不要将零件或组件移到沸腾槽中。

4) Hold the parts or subassemblies in the vapor for a minimum of 60 seconds.

将零件或子组件在蒸汽中保持至少 60 秒。

5) If necessary to remove heavy dirt or flux, flush with clean liquid solvent. Do not use solvent from the degreaser boiling sump. If the degreaser has a vapor phase only, the parts must be removed, cooled and put through again until they are clean.

如有必要清除严重污垢或助焊剂，可用清洁的液体溶剂冲洗。不要使用脱脂剂沸腾槽中的溶剂。如果脱脂剂只有气相，则必须将零件取出、冷却并再次通入，直到清洁为止。

6) Keep the nozzle and the parts at least 6 inches below the vapor level. Point the nozzle downward. Again hold parts or subassemblies in the vapor for a minimum of 60 seconds.

将喷嘴和零件保持在蒸汽水平面以下至少 6 英寸处。将喷嘴朝下。再次将零件或组件置于蒸汽中至少 60 秒。

NOTE: With automated vapor degreasing equipment, you can put the subassemblies into the condensate sump for a minimum of 6 seconds and a maximum of 120 seconds, after the equipment sprays the subassemblies.

注：使用自动蒸汽脱脂设备时，可在设备喷洒组件后将子组件放入冷凝液槽中至少 6 秒钟，最多 120 秒钟。

7) Slowly remove the work from the degreaser. Let the liquid drain from the parts.

从脱脂剂中缓慢移除工件。让液体从零件中排出。

8) If you can see flux residue, do the cleaning cycle again after the subassemblies are cool to the touch.

如果可以看到助焊剂残留物，请在组件触感冷却后再次进行清洁循环。

丁基纤维素清洗（之后用异丙醇清洗）。

1) To make the butyl cellosolve solution, mix together 1-2 gallons Pluronic L-62F and 45-55 gallons butyl cellosolve. Then make up a 0.45 to 1.00 percent by volume solution of this in water.

配制丁基纤维素溶液时，将 1-2 加仑 Pluronic L-62F 和 45-55 加仑丁基纤维素溶液混合在一起。然后按体积将其配成 0.45-1.00% 的水溶液。

2) Put the items through a modified nonrecirculating water rinse at 145-175°F for 3 minutes minimum for parts and printed-wiring boards, and 10 minutes minimum for printed-wiring assemblies.

在 145-175°F 的温度下，用改良的非循环水冲洗零件和印刷线路板至少 3 分钟，印刷线路组件至少 10 分钟。

3) Put the items through a recirculating bath of the butyl cellosolve cleaning solution for 5 minutes minimum.

将物品放入丁基纤维素溶液的循环清洗槽中至少 5 分钟。

4) Put the items through a modified nonrecirculating water rinse at 145-175°F for 10 minutes minimum for parts, 15 minutes minimum for printed-wiring boards, and 20 minutes minimum for printed-wiring assemblies.

将物品放入 145-175°F 的改良非循环水冲洗槽中，零件至少冲洗 10 分钟，印刷线路板至少冲洗 15 分钟，印刷线路组件至少冲洗 20 分钟。

5) Wash the items in isopropyl alcohol as specified in Paragraph 17.B.(1)(a) above.

按照上文第 17.B.(1)(a)段的规定，用异丙醇清洗物品。

(2) Apply Maskants

涂抹掩蔽剂

(a) Apply a mask to the connectors, test points, trim pots, adjustable capacitors, and areas of the assembly not to get the conformal coating. The adjustable portion of adjustable components can be outside of the conformal coating. Use tape masks (Scotch 218) or strippable maskants (TC-533), or both.

在连接器、测试点、微调电位器、可调电容器和组件中不需要保形涂料的区域涂抹遮蔽剂。可调元件的可调部分可以在保形涂料之外。使用胶带遮蔽剂 (Scotch 218) 或可剥离遮蔽剂 (TC-533)，或两者兼用。

(b) If TC-533 strippable maskant is used, prepare and apply as follows:

如果使用 TC-533 可剥离遮蔽剂，请按以下步骤制备和涂抹：

1) Mix the maskant fully before you use it.

使用前充分混合遮蔽剂。

2) If necessary, dilute with water up to a maximum of 3 ounces per gallon of maskant.

如有必要，用水稀释，每加仑遮蔽剂最多稀释 3 盎司。

3) Pour on, dip or use a brush to apply a layer sufficiently thick for easy removal (0.004 inch is adequate). Apply more than one layer if necessary. No thickness inspection is necessary.

浇上、浸上或用刷子涂上一层足够厚的涂料，以便于清除（0.004 英寸即可）。如有必要，可多涂一层。无需检查厚度。

4) Cure the coating for 2 hours minimum at room temperature (full tensile strength will occur in 12 hours), or 30-90 minutes at 140-160°F.

涂层在室温下至少固化 2 小时（12 小时后可达到完全拉伸强度），或在 140-160°F 下固化 30-90 分钟。

(3) Prepare Acrylic Coating

准备丙烯酸涂层

(a) General

通用

1) Let the conformal coating material get to room temperature before you open the container.

打开容器前，让保形涂料达到室温。

2) Make sure the material is clean, transparent and has no coarse particles, lumps, or unwanted matter. Strain it if necessary.

确保材料干净、透明，没有粗颗粒、块状物或不需要的物质。必要时过滤一下。

3) Fully stir the material in the container, but do not mix in air bubbles.

充分搅拌容器中的材料，但不要混入气泡。

4) Do not let the coating mixture get a surface film, or cured particles. If it does, discard it and mix up some new coating.

不要让涂料混合物表面形成薄膜或固化颗粒。如果出现这种情况，应将其丢弃并混合一些新的涂料。

(b) Coatings to be applied by spray or brush

喷涂或刷涂涂料

1) Before you use the material, thin it with xylene to a viscosity of 18-20 seconds when measured with a number 2 Zahn cup.

使用涂料前，用二甲苯稀释至用 2 号Zahn杯测量时的粘度为 18-20 秒。

2) As you use the material, you can add more coating material (Humiseal 1B31) or xylene to the coating mixture, but the viscosity must be kept in the above range.

在使用涂料时，可以向涂料混合物中添加更多的涂料（Humiseal 1B31）或二甲苯，但粘度必须保持在上述范围内。

作为浸渍的涂层

1) Before you use the material, thin it with xylene or toluene to get a viscosity of 40-60 seconds when meassured with a number 2 Zahn cup.

在使用涂料之前，用二甲苯或甲苯稀释涂料，用 2 号Zahn杯测量粘度为 40-60 秒。

2) As you use the material, you can add more coating material or solvent to the coating mixture, but the viscosity must be kept in the above range.

在使用材料的过程中，可以向涂料混合物中添加更多的涂料或溶剂，但粘度必须保持在上述范围内。

(4) Apply Acrylic Coating

涂抹丙烯酸涂料

(a) General

通用

1) Break bubbles that occur during application with a clean swab wet with toluene or isopropyl alcohol.

用蘸有甲苯或异丙醇的干净棉签弄破涂抹过程中产生的气泡。

2) As quickly as possible after application, remove coating from areas not to get the coating. Use toluene or isopropyl alcohol on a clean swab, cotton-tip applicator or wiper.

涂装后尽快清除未涂装区域的涂层。用甲苯或异丙醇沾在干净的棉签、棉签涂抹器或抹布上。

(b) Spray Coating — Set up, adjust, and operate the equipment by the usual equipment operating procedure.

喷涂 — 按照通常的设备操作程序设置、调整和操作设备。

浸涂

1) Put the assembly fully into the dip coating mixture then remove it. Control the rate in to prevent air pockets. Control the rate out to control the coating thickness.

将组件完全放入浸涂混合物中，然后取出。控制进入速度，防止出现气穴。控制流出速度以控制涂层厚度。

2) Drain the coated assembly in a vertical position. You can use forced air, or other procedures to adjust the material on the assembly to smooth out local buildups or remove bridges.

垂直沥干涂层组件。可以使用强力空气或其他程序来调整组件上的材料，以平整局部堆积或去除桥接。

3) Keep covers on the containers of coating to prevent evaporation of solvent from the coating mixture.

保持涂料容器上有盖子，以防止涂料混合物中的溶剂蒸发。

(d) Brush Coating — Use a brush to apply the coating in small areas or if a spray or dip coating is not easily applied.

刷涂 — 在小面积区域或喷涂或浸涂不易涂抹时，使用刷子涂抹涂层。

(5) Thickness Control

厚度控制

(a) If large areas are coated, the thickness must be measured. Apply the coating to test panels and measure the coating thickness.

如果大面积涂装，必须测量厚度。在测试板上涂抹涂层并测量涂层厚度。

(b) For spray coating and brush coatings, use one set of panels for each side of the assemblies.

对于喷涂和刷涂，组件的每一面都使用一组面板。

(c) Measure and make a note of the thickness of the test panels before coating them and after the coating is fully cured.

在涂层前和涂层完全固化后，测量并记录测试板的厚度。

(d) If the coating did not get to the minimum thickness necessary, you can apply more layers of coating, but you must let the first layers fully cure.

如果涂层没有达到所需的最小厚度，可以多涂几层，但必须让第一层完全固化。

(6) Cure of Coating

涂层固化

(a) Let the coated assembly dry for a minimum of 10 minutes at room temperature.

让涂层组件在室温下干燥至少 10 分钟。

(b) Then give the unit one of these cure cycles.

然后给其一个固化周期。

1) 24 hours minimum at room temperature.

在室温下至少 24 小时。

2) 2 hours minimum at 140-160°F.

在 140-160°F 温度下至少 2 小时。

3) 30 minutes minimum at 160-180°F.

在 160-180 °F下至少 30 分钟。

(7) Removal of Masks

移除遮蔽物

(a) Cool the cured conformal coated assembly to room temperature before you remove the masks.

将固化的保形涂料组件冷却至室温后再去除遮蔽物。

(b) To remove the masking tape from static sensitive assemblies, pull the tape slowly in an ionized air stream to prevent static build-up.

从静电敏感组件上撕下遮蔽胶带时，应在离子气流中缓慢拉动胶带，以防止静电积聚。

可使用甲乙酮清除遮蔽剂残留物。

(8) Coating Touch-Up

涂层修补

(a) Do not try to touch up the coating until the cure is completed.

在固化完成之前，不要尝试修补涂层。

(b) Remove bubbles or unwanted matter with a clean cotton swab wet with toluene, or isopropyl alcohol. Clean cavities with methyl ethyl ketone or isopropyl alcohol. Let them dry in air. Be careful when you use these solvents to keep them away from other coating surfaces.

用沾有甲苯或异丙醇的干净棉签清除气泡或不需要的物质。用甲乙酮或异丙醇清洁空腔。让它们在空气中干燥。使用这些溶剂时要小心，使其远离其他涂层表面。

根据需要用刷子或等效工具涂抹更多的涂层材料。

(d) Cure the coating again.

再次固化涂层。

(9) Requirements

要求

(a) The assembly must be completely coated unless specified. The end of the leads can be outside the conformal coating unless specified differenty. Do not probe the coating to see if the layer is continuous. Sharp corners, part leads, tight areas between components, or other such irregular configurations are acceptable if the areas look wet. Use ultraviolet light to help see if a layer is continuous.

除非有规定的要求，否则组件必须完全涂敷。除非有不同的规定，否则引线末端可以在保形涂层之外。不要探查涂层是否连续。如果尖角、零件引线、元件之间的狭小区域或其他类似的不规则结构看起来是湿的，则可以接受。使用紫外线灯帮助查看涂层是否连续。

(b) Thickness limits are not applicable to sharp corners, part leads, tight areas between components, or equivalent configurations.

厚度限制不适用于尖角、零件引线、元件之间的紧密区域或同等配置。

1) To find the dry film (final) thickness of the coating, measure the average thickness on the surface of the test panels.

要找出涂层的干膜（最终）厚度，应测量测试板表面的平均厚度。

2) Measure and average to the nearest 0.0005 inch.

测量并平均到最接近的 0.0005 英寸。

3) Cured coating thickness must be 0.001-0.003 inch. Local edge buildup to 0.004 inch is acceptable.

固化涂层厚度必须为 0.001-0.003 英寸。可接受局部边缘增厚至 0.004 英寸。

(c) On or between printed conductors, some bubbles no larger than 0.025 inch in diameter are acceptable, if they are not between printed conductors 0.025 inch or less apart. No bare areas are permitted.

在印刷导体上或印刷导体之间，如果不在相距 0.025 英寸或更小的印刷导体之间，则可以接受直径不大于 0.025 英寸的气泡。不允许有裸露区域。

(d) On component seams and lead seals, some bubbles no larger than 0.025 inch in diameter are acceptable. Component seal leaks (frothy bubbles) are not unacceptable.

在元件接缝和引线密封处，可接受一些直径不大于 0.025 英寸的气泡。元件密封泄漏（泡沫状气泡）并非不可接受。

(e) On areas without circuitry or electronic parts, and on or near nuts, bolts, and screws,bubbles no larger than 0.20 inch in diameter or groups of bubbles no larger than 0.10 square inch are acceptable if the area affected is not more than one percent of the assembly surface area.

在没有电路或电子零件的区域，以及在螺母、螺栓和螺钉上或附近，如果受影响的面积不超过装配表面积的百分之一，直径不大于 0.20 英寸的气泡或不大于 0.10 平方英寸的气泡群是可以接受的。

(f) The coating layer must be smooth and continuous over the areas specified to get the coating.

涂层必须在规定的区域内光滑、连续。

C. Polyurethane Conformal Coating

聚氨酯保形涂料

(1) Clean the PCA

清洁 PCA

(a) Use the procedures of Paragraph 17.B.(1).

使用第 17.B.(1)段的程序。

(b) Do not use water on printed-circuit-board assembles that have unsealed components.

不要用水清洗有未密封元件的印刷电路板组件。

(c) Dry the assemblies for 75 minutes minimum in an air-circulating oven at 145-155°F. Cool to room temperature before you apply the conformal coating.

在 145-155°F 的空气循环烘箱中干燥组件至少 75 分钟。冷却至室温后再涂敷保形涂料。

(d) If the dried assemblies cannot be coated within 24 hours, put them in an area where the relative humidity is not higher than 60 percent. If assemblies must wait more than 6 months, clean them again.

如果干燥后的组件不能在 24 小时内涂敷，则将其放在相对湿度不高于 60% 的地方。如果组件必须等待 6 个月以上，则应再次清洁。

(2) Apply maskants as specified in Paragraph 17.B.(2).

按照第 17.B.(2)段的规定涂抹遮蔽剂。

(3) Prepare Polyurethane Coating

准备聚氨酯涂层

(a) General

通用

1) Let the conformal coating materials get to room temperature before you open the container.

打开容器前，让保形涂料达到室温。

2) Make sure the material is clean, transparent and has no coarse particles, lumps, or unwanted matter. Strain it if necessary. Remove unwanted bubbles by vacuum degassing.

确保材料干净、透明，没有粗颗粒、块状物或多余物质。必要时进行过滤。通过真空脱气法去除不需要的气泡。

(b) Dip Coatings and Flow Coatings

浸涂和流涂

1) Thin encapsulant PC 18M as necessary with cellosolve acetate to get a viscosity of 25-32 seconds, as measured with a No. 2 Zahn cup. Keep the thinned encapsulant in a closed container when not in actual use.

根据需要用乙酸纤维素溶液稀释封装剂 PC 18M，使其粘度达到 25-32 秒（用 2 号Zahn杯测量）。不使用时，将稀释后的封装剂保存在密闭容器中。

2) As you use the material, you can add more encapsulant and solvent within 8 hours after you first thinned it. But the viscosity must be kept in the specified range. Discard encapsulant if it get a surface film.

使用材料时，可在首次稀释后 8 小时内添加更多的封装剂和溶剂。但粘度必须保持在规定的范围内。如果封装剂在表面上形成薄膜，则应将其丢弃。

喷涂

1) Thin each part of Humiseal 1A33 with 0.9-1.1 part by volume of xylene to get a viscosity of 25-30 seconds as measured by a No. 1 Zahn cup. Keep the thinned encapsulant in a closed container when not in actual use.

用 0.9-1.1 份二甲苯（体积分数）稀释每份 Humiseal 1A33，使其粘度达到 25-30 秒（用 1 号Zahn杯测量）。不使用时，将稀释后的封装剂保存在密闭容器中。

2) As you use the material, you can add more encapsulant and solvent within 8 hours after you first thinned it. But the viscosity must be kept in the specified range. Discard the encapsulant if it gets a surface film or cured particles.

在使用该材料时，可在首次稀释后的 8 小时内添加更多的封装剂和溶剂。但粘度必须保持在规定的范围内。如果封装剂表面出现薄膜或固化颗粒，则应丢弃。

(4) Apply Polyurethane Coating

涂上聚氨酯涂层

(a) General

通用

1) Break bubbles that occur during application with a clean swab wet with cellosolve acetate.

用乙酸纤维素溶液浸湿的干净棉签弄破涂抹过程中产生的气泡。

2) As quickly as possible after application, remove coating from areas not to get the coating. Use acetone or methyl ethyl ketone on a clean swab or wiper.

涂装后，尽快清除未涂装区域的涂层。用丙酮或甲乙酮沾在干净的棉签或抹布上。

(b) Dip Coating

浸涂

1) Carefully stir the coating material before you start to dip, and then at regular intervals. Keep the volume of the coating material as full as possible. Move the coating material from large size to smaller size containers, to decrease the deterioration because of mixed-in air and water. Tightly cover the tank or can at the end of the procedure.

开始浸涂前仔细搅拌涂层材料，然后每隔一段时间搅拌一次。尽量保持涂层材料的体积饱满。将涂层材料从大容器移到小容器中，以减少因混入空气和水而导致的变质。程序结束后，盖紧罐子。

2) Completely put the circuit-board assembly in the coating material, then pull it out vertically. Control the rate in, to avoid air pockets. Control the rate out at 3-5 inches per minute. Let the coated assemblies drain in the vertical position. Use forced air and move the units around to smooth out local buildups and remove bridges.

将电路板组件完全放入涂层材料中，然后垂直拉出。控制进料速度，避免出现气穴。取出速度控制在每分钟 3-5 英寸。让涂层组件在垂直位置排出。使用强制空气并移动设备，以清除局部积聚物和桥接。

流涂

1) Fully stir the material before application, but do not mix air into it.

喷涂前充分搅拌涂料，但不要混入空气。

2) Flow the material over the assembly, with the flow in one direction as much as possible.

将材料流过组件，尽可能朝一个方向流动。

(d) Spray Coating

喷涂

1) Set up, adjust, and operate the spray coating machine by the usual instructions.

按照常规说明设置、调整和操作喷涂机。

2) Send the circuit board assemblies through the spray coating machine. Send them through again as necessary to get the specified thickness on each side.

将电路板组件送入喷涂机。必要时再送一遍，使每一面都达到规定的厚度。

3) Include test panels with the production parts to monitor the coating thickness and make necessary machine adjustments. Be sure to include a test panel or coupon each time the automatic spray coating machine is adjusted when large surfaces are repaired.

在生产零件时附上测试板，以监控涂层厚度并对机器进行必要的调整。在大面积修理时，每次调整自动喷涂机时一定要附上测试板或测试单。

(5) Coating Cure

涂层固化

(a) Dip Coatings, Flow Coating — Use one of these cure cycles:

浸涂、流涂 — 使用以下固化周期之一

1) Air dry for 12 hours minimum, then humidity cure at 145-155°F and 35-55 percent relative humidity for 4 hours minimum.

至少风干 12 小时，然后在 145-155 °F和 35-55%相对湿度下湿气固化至少 4 小时。

2) Cure at room temperature for 80 hours minimum. After 18 hours of cure, the assemblies can be moved to the clean room for tests and assembly procedures.

在室温下固化至少 80 小时。固化 18 小时后，可将组件移至无尘室进行测试和组装程序。

3) Air dry for 60 minutes minimum, oven cure at 140-160°F for 60 minutes minimum, then immediately humidity cure at 145-155°F and 35-55 percent relative humidity for 4 hours minimum.

至少风干 60 分钟，在 140-160°F 下烘箱固化至少 60 分钟，然后立即在 145-155°F 和 35-55% 相对湿度下湿度固化至少 4 小时。

(b) Spray Coatings — Cure the coating for ten days (240 hours) in ambient air or for a minimum of 15 hours in an air circulating oven at 140-160°F.

喷涂涂层 — 在环境空气中固化十天（240 小时），或在 140-160 °F的空气循环烘箱中固化至少 15 小时。

(6) Removal of Masks

去除遮蔽物

(a) From Dip or Flow Coatings

从浸涂或流涂上

1) Strip the mask after the conformal coating air dried at least 18 hours (8 hours for boards with plated edge contacts) or after one hour of oven cure. To remove the mask, make an edge loose and hand peel. If you use a tool to do this, be careful not to damage assemblies. Clean maskant from all uncoated surfaces with acetone or methyl ethyl ketone on a wiper.

待保形涂层风干至少 18 小时（边缘有电镀触点的电路板风干 8 小时）或烘箱固化 1 小时后，剥去遮盖物。要剥离遮盖物，可将边缘弄松，然后用手剥离。如果使用工具，应小心不要损坏组件。用丙酮或甲乙酮在抹布上清洁所有未涂层表面的遮盖物。

(b) From Spray Coatings

从喷涂涂层上

1) The mask can be removed immediately after spray coating, or after the coating is cured. Use the same removal procedure as for dip and flow coatings.

可在喷涂后立即或在涂层固化后去除遮盖物。使用与浸涂和流涂相同的去除程序。

(7) Coating Repair

涂层修理

(a) Dip or Flow Coating Surfaces

浸涂或流涂表面

1) Break all unacceptable bubbles and cut out unwanted particles with a sharp or hot (450-650°F) tool.

用锋利或高温（450-650°F）工具打碎所有不可接受的气泡并切掉不需要的颗粒。

2) Clean cavities with acetone, methyl ethyl ketone, or isopropyl alcohol. Then apply more polyurethane coating.

用丙酮、甲乙酮或异丙醇清洗空腔。然后涂上更多的聚氨酯涂层。

3) On coatings thinner than the minimum thickness or on uncoated areas, you can apply more coats of the same material. On local areas, the polyurethane coating can be applied with a brush.

对于厚度小于最小厚度的涂层或未涂层区域，可以多涂几层相同的材料。在局部区域，可用刷子涂刷聚氨酯涂层。

4) Cure the added coats of polyurethane.

固化添加的聚氨酯涂层。

(b) Spray Coating Surfaces 喷涂表面

1) Method 1

方法 1

a) Break all unacceptable bubbles and cut out unwanted particles with a sharp or hot (450-650°F) tool.

用锋利或高温（450-650°F）的工具打碎所有不能接受的气泡，切掉不需要的颗粒。

b) Make sure you do not damage leads and parts. Remove loose flakes.

确保不损坏引线和零件。清除松散的薄片。

c) Clean cavities with acetone, methyl ethyl ketone, or isopropyl alcohol. Then apply more PC 18M or Humiseal 1A33.

用丙酮、甲乙酮或异丙醇清洁空腔。然后涂上更多的 PC 18M 或 Humiseal 1A33。

d) On coatings thinner than the minimum thickness, you can apply more coats of the same material. On local areas, PC 18M or Humiseal 1A33 coating can be applied with a brush.

对于比最小厚度薄的涂层，可以多涂几层相同的材料。在局部区域，可用刷子涂抹 PC 18M 或 Humiseal 1A33。

e) Cure the added coats of PC 18M. Dry the brushed-on Humiseal 1A33 coating for 1 hour at room temperature or for 5 minutes at 140-160°F first.

固化添加的 PC 18M 涂层。先将刷涂的 Humiseal 1A33 涂料在室温下干燥 1 小时，或在 140-160°F 下干燥 5 分钟。

2) Method 2

方法 2

a) If necessary, remove Humiseal coating from the area as above.

如有必要，按上述方法清除该区域的 Humiseal 涂层。

b) Clean the area with acetone, methyl ethyl ketone isopropyl alcohol. Air dry.

用丙酮、甲基乙基酮异丙醇清洗该区域。晾干。

c) Apply a brush coat of blended CE-1155 to the cleaned areas.

在清洁过的区域刷上一层混合的 CE-1155。

d) If more coats are necessary, let the material cure for 2 hours minimum at room temperature or 30 minutes minimum at 140-160°F between coats.

如果需要涂更多层，则让材料在室温下固化至少 2 小时，或在 140-160°F 温度下固化至少 30 分钟。

e) Cure for 3 hours minimum at 140-160°F or 1 hour minimum at 190-210°F. Do not seal coated assemblies from air or environmentally test them until the coating is cured.

在 140-160°F 下至少固化 3 小时，或在 190-210°F 下至少固化 1 小时。在涂层固化之前，不要将涂有涂层的组件与空气隔绝或对其进行环境测试。

(8) Requirements

要求

(a) The assembly must be continuously coated, but the ends of the leads can be outside the conformal coating. Do not probe the coating to see if it is continuous. Sharp corners, part leads, or similar irregular configurations are acceptable if they look wet. Use ultraviolet light to help see if a coating is continuous.

组件必须连续喷涂，但引线的末端可以在保形涂层之外。不要探查涂层是否连续。如果尖角、零件引线或类似的不规则结构看起来是湿的，则可以接受。使用紫外线灯帮助查看涂层是否连续。

(b) Make sure the electronic part identification can be read through the conformal coating.

确保可以透过保形涂层读取电子零件标识。

(c) To find the dry film (final) thickness of the coating, measure the average thickness on the surface of the test panels. Measure and average to the nearest 0.0005 inch. Cured coating thickness must be 0.001-0.003 inch. Local edge buildup to 0.004 inch is acceptable.

要找出涂层的干膜（最终）厚度，应测量测试板表面的平均厚度。测量和平均值精确到 0.0005 英寸。固化涂层厚度必须为 0.001-0.003 英寸。局部边缘厚度达到 0.004 英寸是可以接受的。

(d) Thickness limits are not applicable to sharp corners, part leads or equivalent configurations.

厚度限制不适用于尖角、零件引线或同等结构。

(e) On and between printed conductors, in dip and flow coatings, bubbles and voids no larger than 0.005 inch in diameter are acceptable. In spray coatings, bubbles no larger than 0.025 inch in diameter are acceptable, if they are not between printed conductors 0.025 inch or less apart. No voids are permitted.

在浸渍和流涂中，在印刷导体上和导体之间，直径不大于 0.005 英寸的气泡和空隙是可以接受的。在喷涂涂层中，如果气泡不在相距 0.025 英寸或更小的印刷导体之间，则可接受直径不大于 0.025 英寸的气泡。不允许有空隙。

(f) On component seams and lead seals, bubbles no larger than 0.025 inch in diameter are acceptable. Component seal leaks (frothy bubbles) are unacceptable.

在元件接缝和引线密封处，可接受直径不大于 0.025 英寸的气泡。元件密封泄漏（泡沫）是不可接受的。

(g) On areas without circuitry or electronic parts, or on or near nuts, bolts and screws,bubbles no larger than 0.2 inch in diameter or groups of bubbles no larger than 0.1 square inch are acceptable if the area affected is not more than one percent of the assembly surface area.

在没有电路或电子零件的区域，或在螺母、螺栓和螺钉上或附近，如果受影响的面积不超过组件表面积的百分之一，则可接受直径不大于 0.2 英寸的气泡或不大于 0.1 平方英寸的气泡群。

(h) The coating layer must be smooth and continuous over the areas specified to get the coating.

涂层必须在规定的区域内光滑、连续。

D. Silicone Conformal Coating

硅树脂保形涂料

(1) Clean the PCA

清洁 PCA

(a) Use the procedures of Paragraph 17.B.(1).

使用第 17.B.(1)段的程序。

(b) Do not use water on printed-circuit-board assemblies that have unsealed components.

不要用水清洗有未密封部件的印刷电路板组件。

(c) Dry the assemblies for 75 minutes minimum in an air-circulating oven at 145-155°F. Cool to room temperature before you apply the conformal coating.

在 145-155°F 的空气循环烘箱中干燥组件至少 75 分钟。冷却至室温后再涂敷保形涂料。

如果干燥后的组件不能在 24 小时内涂敷，则将其放在相对湿度不高于 60% 的地方。如果组件必须等待 6 个月以上，则应再次清洁。

(2) Apply maskants as specified in Paragraph 17.B.(2).

按照第 17.B.(2)段的规定涂抹遮蔽剂。

(3) Prepare Silicone Coating

准备有机硅涂层

(a) General

通用

1) Let the conformal coating materials get to room temperature before you open the container.

打开容器前，让保形涂料达到室温。

2) Make sure the material is clean, transparent and has no coarse particles, lumps, or unwanted matter. Strain it if necessary. Remove unwanted bubbles by vacuum degassing.

确保材料干净、透明，没有粗颗粒、块状物或多余物质。必要时进行过滤。用真空脱气法去除不需要的气泡。

(b) Use the coating as supplied by the vendor. Do not use a thinner.

使用供应商提供的涂层。不要使用稀释剂。

(4) Apply Silicone Coating

涂上硅树脂涂层

(a) Clean the areas to be coated with a cotton tip applicator or BMS 15-5 wipers wet with isopropyl alcohol.

用棉头涂抹器或 BMS 15-5 抹布沾异丙醇清洁待涂抹部位。

(b) Apply RTV3140 material to all areas specified by the overhaul instructions. As a minimum, apply the material to component leads and lead ends. Material can go onto adjacent areas such as component leads or bodies, solder pads or connections.

在大修说明规定的所有区域涂抹 RTV3140 材料。至少要在部件引线和引线端部涂抹材料。材料可涂到邻近区域，如元件引线或本体、焊板或连接处。

(c) Cure the RTV3140 material for a minimum of 48 hours at room temperature. After the material is tack free (approximately 1-2 hours), assemblies can be handled for examination and touchup.

在室温下固化 RTV3140 材料至少 48 小时。材料无粘性后（约 1-2 小时），可对组件进行检查和修整。

(d) If necessary, touch up the layer with more RTV3140 material, but cleaning is not necessary.

如有必要，可使用更多的 RTV3140 材料修补涂层，但不必进行清洁。

(5) Removal of Masks

去除遮蔽物

(a) Cool the cured conformal coated assembly to room temperature before you remove the masks.

将已固化的保形涂料组件冷却至室温后再去除遮蔽物。

(b) To remove the masking tape from static sensitive assemblies, pull the tape slowly in an ionized air stream to prevent static build-up.

从静电敏感组件上撕下遮蔽胶带时，应在离子气流中缓慢拉动胶带，以防止静电积聚。

可使用异丙醇清除遮蔽剂残留物。

(6) Coating Touch-Up

涂层修补

(a) Do not try to touch up the coating until the cure is completed.

在固化完成之前，不要尝试修补涂层。

(b) Remove bubbles or unwanted matter with a clean cotton swab wet with isopropyl alcohol. Clean cavities with isopropyl alcohol. Let them dry in air. Be careful when you use these solvents to keep them away from other coating surfaces.

用沾有异丙醇的干净棉签清除气泡或多余物质。用异丙醇清洁空腔。让它们在空气中干燥。使用这些溶剂时要小心，使其远离其他涂层表面。

根据需要用刷子或等效工具涂抹更多的涂层材料。

(d) Cure the coating again.

再次固化涂层。

18. ASSEMBLY OF SWAGED HARDWARE (EYELET, STANDOFF TERMINALS, ETC.) 组装压接硬件（吊环、支座端子等）

A. The terminal or eyelet shank must be pressed through the board and the terminal aligned as shown in Figure 22.

如图 22 所示，接线端子或孔眼柄必须穿过电路板并对准接线端子。

B. A V-type funnel swage must be used on printed circuit boards where the swaged end ends in a circuit pad or pattern. It must be soldered after swaging. A roll-type swage can be used only where the swaged end comes down only on the circuit board base material. The swaged V-type flare must not be split and must not damage the circuit pattern. Cracks in the rolled type swage are permitted if they are no longer than 40% of the length of the radius of the swage.

在印刷电路板上，必须使用 V 型漏斗压接器，压接端在电路板或图案中结束。压接后必须焊接。卷式压接钳只能用于压接端仅落在电路板基材上的情况。压接后的 V 型扩口不得裂开，也不得损坏电路图案。允许在卷式压接中出现裂缝，但裂缝长度不得超过压接半径的 40%。

C. Hardware which ends in a circuit pad or pattern to which it is to make electrical contact must be soldered after swaging.

末端与电路板或电路图案有电气接触的五金件必须在压接后焊接。

D. The roll swage must be too tight to be moved by finger pressure. There must be no more than 0.050 inch of delamination of the base material beyond the flange and there must be a minimum of 0.030 inch of nondelaminated base material between the swaged hardware and other conductors. This includes delamination caused by installation or subsequent soldering operations.

卷式压接必须非常紧密，手指按压无法移动。法兰外的基底材料分层不得超过 0.050 英寸，在压接硬件和其他导体之间必须有至少 0.030 英寸的无分层基底材料。这包括安装或后续焊接操作造成的分层。

(1) Scalloped or roller hardware must not have splits which extend to the midpoint between the crown of the roll and the tangent point of the barrel (Figure 23).

扇形或卷形五金件不得有延伸至卷冠与桶切点之间中点的裂缝（图 23）。

(2) The scallops must be made to let solder flow under them.

扇形头必须能让焊料在扇形头下流动。

(3) If the overhaul instructions specify that the swaged terminals to be attached to circuitry must make an electrical connection, they must have a scalloped head. On single-sided cards, the scallop must be on the etched circuit side. These must be soldered.

如果大修说明规定的连接电路的压接端子必须有电气连接，则必须有扇形头。在单面卡上，扇形头必须位于蚀刻电路的一面。这些端子必须焊接。

(4) The scalloped or rolled flanges can have hairline cracks around their edges of roll.

扇形或卷制法兰的轧制边缘可能会出现毛细裂纹。

19. STRIP BONDING 带状粘接

A. Sand the faying surfaces (Ref. Figure 24) with 240 grit or finer garnet or aluminum oxide abrasive. Remove grit and sanding debris with a blast of clean, dry, oil-free air.

用 240 号或更细的石榴石或氧化铝磨料打磨粘合表面（参考图 24）。用清洁、干燥、无油的空气吹走砂粒和打磨的碎屑。

WARNING:WHEN YOU USE ISOPROPYL ALCOHOL, DO NOT BREATHE THE VAPOR OR MISTS. USE ONLY WITH APPROVED VENTILATION, AVOID PROLONGED OR REPEATED SKIN CONTACT. KEEP AWAY FROM HEAT, SPARKS, AND OPEN FLAME.

警告：使用异丙醇时，不要吸入其蒸气或雾气。只能在通风条件许可的情况下使用，避免长时间或反复接触皮肤。远离热源、火花和明火。

B. Fully clean all faying surfaces with isopropyl alcohol.

用异丙醇彻底清洁所有涂层表面。

C. Dry the strip and the circuit board in 140-160°F circulating air for 30-60 minutes.

在 140-160°F 的循环空气中干燥带材和电路板 30-60 分钟。

D. Cool to room temperature and bond within 2 hours.

冷却至室温并在 2 小时内粘合。

E. Mask across the etched contacts and pattern with Permacel P29 tape or Turco 522 Maskant.

用 Permacel P29 胶带或 Turco 522 遮蔽剂遮蔽蚀刻触点和图案。

F. Prepare BMS 5-72, Type 1 or Armstrong A31 adhesive by the manufacturers’ instructions.

按照制造商的说明配制 BMS 5-72、1 型或 Armstrong A31 粘合剂。

G. Apply the adhesive smoothly to one or both faying surfaces. Press the strip in position on the circuit board with up to 5 psi pressure (Figure 24).

将粘合剂平滑地涂在一个或两个粘合面上。用最大 5 磅 / 平方英寸的压力将条带按在电路板上（图 24）。

WARNING :WHEN YOU USE SOLVENTS, DO NOT BREATHE THE VAPOR OR MISTS. USE ONLY WITH APPROVED VENTILATION. AVOID PROLONGED OR REPEATED SKIN CONTACT. KEEP AWAY FROM HEAT, SPARKS, AND OPEN FLAME.

警告 :使用溶剂时，不要吸入蒸汽或雾气。只能在经过批准的通风条件下使用。避免长时间或反复接触皮肤。远离热源、火花和明火。

H. Before the adhesive cures, remove masking and wipe off unwanted adhesive with a clean cloth wet with methyl ethyl ketone or isopropyl alcohol.

在粘合剂固化前，取下遮蔽物，用沾有甲乙酮或异丙醇的干净布擦掉不需要的粘合剂。

I. Cure BMS 5-72, Type 1 adhesive for 8 hrs at 75°F or 1 hr at 160°F.

将 BMS 5-72 1 型粘合剂在 75°F 温度下固化 8 小时，或在 160°F 温度下固化 1 小时。

J. Cure Armstrong A31 adhesive for 24 hrs at 75°F or 2 hrs at 160°F.

Armstrong A31 胶粘剂在75°F下固化 24 小时或在160°F下固化 2 小时。

K. Apply conformal coat (encapsulant) to the repaired area as specified in Paragraph 17.

按第 17 段的规定在修理部位涂敷保形涂料（封装剂）。

20. REPAIR OF FLEXIBLE PRINTED WIRING 修理柔性印刷线路

NOTE: Military Specification MIL-P-50884 does not permit the repair of flexible printed wiring used in military equipment.

注：军标 MIL-P-50884 不允许修理军事装备中使用的柔性印刷线路。

A. Precautions

预防措施

(1) Flexible printed wiring can be damaged if dropped, bent or folded. Lift the units by their larger components, not by the flexible circuit sections.

如果掉落、弯曲或折叠，柔性印刷线路可能会损坏。请用较大的部件而不是柔性电路部分抬起设备。

(2) Do not put stresses at inside edge corners that could cause cracks and progressive tears.

不要在内侧边角施加可能导致裂缝和逐渐撕裂的应力。

(3) During tests, apply instrument probes to component leads or solder joint fillets. Apply test clips to component leads. Do not put stress on leads or flexible circuit.

在测试过程中，将仪器探针放在元件引线或焊点圆角上。在元件引线上使用测试夹。不要在引线或柔性电路上施加应力。

B. General

通用

(1) Holes can be punched with a leather punch or equivalent, or drilled with a hand-held motor drill. Use a drill board below and Plexiglas above when you drill. Holes must not have ragged edges that could grow into tears.

可用皮革打孔器或等效工具打孔，或用手持电动机钻孔。钻孔时，下面用钻孔板，上面用有机玻璃。孔的边缘不能粗糙，否则会造成撕裂。

(2) To keep the wiring flexible, Humiseal 1A33 polyurethane coating can be used as an alternative to polyimide tape or Metre Grip 303 adhesive in a fold area. Long lengths of wire can be sent over a fold area.

为保持布线的柔韧性，可在折叠区使用 Humiseal 1A33 聚氨酯涂层，以替代聚酰亚胺胶带或 Metre Grip 303 胶。长导线可穿过折叠区。

(3) Pin-to-pin connection by wire is an acceptable alternative to repair of a bad flex circuit conductor. The conductor can be cut, drilled or punched out and replaced with pin-to-pin wire.

用导线进行针对针连接是修理不良柔性电路导体的一种可接受的替代方法。导体可以切割、钻孔或打孔，然后用针对针导线代替。

(4) All corner areas must have a radius sufficiently large to decrease the risk of tears or cracks. Punch or drill at corner areas as necessary to get this radius.

所有转角区域的半径必须足够大，以减少撕裂或裂缝的风险。根据需要在拐角处打孔或钻孔，以获得这一半径。

(5) Use Humiseal 1A33 polyurethane coating to give protection to plated-through holes which do not have solder leads or polyimide covering.

使用 Humiseal 1A33 聚氨酯涂层保护没有焊接引线或聚酰亚胺覆盖层的电镀通孔。

(6) Remove solder with standard wick or vacuum procedures. Use heat for as short a time as possible to prevent delamination.

使用标准焊芯或真空程序去除焊料。加热时间越短越好，以防分层。

C. Removal and Replacement of Components or Wires

拆卸和更换元件或导线

(1) To remove the polyurethane coating, use a stiff bristle brush or a cotton swab and acetone or methyl ethyl ketone.

用硬毛刷或棉签和丙酮或丁酮去除聚氨酯涂层。

(2) Use usual wick or vacuum solder procedures.

使用通常的焊芯或真空焊接程序。

(3) Do not use too much heat, to reduce the risk of delamination.

不要过热，以减少分层的风险。

(4) Do not use too much force during component removal, to reduce the risk of damage to the flexible circuit.

拆卸元件时不要用力过猛，以减少损坏柔性电路的风险。

(5) Install the new component, solder it, and cut off the unwanted leads as required.

安装新元件，进行焊接，并按要求切断不需要的引线。

D. Repair of Circuitry (Figure 25)

修理电路（图 25）

(1) Use visual magnification as necessary.

必要时使用目视放大镜。

(2) Uncover the circuit conductor for a minimum of 1/8 inch on both sides of the defect. Cut through the insulating cover of the conductor with the point of a scalpel or other sharp instrument. Push or scrape with a scalpel to remove the cover and get at the conductor. When you use the scalpel, be careful to keep to a minimum any damage to the base metal. Small scratches are permitted.

剥开电路导体，在缺陷两侧至少露出 1/8 英寸。用手术刀或其他锋利的工具切开导体的绝缘层。用手术刀推动或刮擦，以去除外层并接触导体。使用手术刀时要小心，尽量减少对基底金属的损坏。小的划痕是允许的。

(3) Tin the exposed conductor with solder on both sides of the piece.

用焊锡在裸露导体的两面镀锡。

(4) Tin with solder a minimum of 1/4 inch at the ends of a length of AWG 26 or AWG 28 solid strand copper wire that will go across the defect.

在将穿过缺陷的 AWG 26 或 AWG 28 实芯铜线的两端至少 1/4 英寸处镀锡。

(5) Hold the wire segment in position over the break with the edge of a scalpel. Flux can be used. Solder the wire in place. Remove unwanted flux with a swab and isopropyl alcohol.

用手术刀的边缘将线段固定在断裂处。可以使用助焊剂。将导线焊接到位。用棉签和异丙醇清除不需要的助焊剂。

(6) Apply Metre Grip 303 adhesive or Humiseal 1A33 polyurethane coating over the repaired area for insulation and support.

在修理部位涂上 Metre Grip 303 粘合剂或 Humiseal 1A33 聚氨酯涂层，以起到绝缘和支撑作用。

E. Removal of Conductors (Figure 25)

拆除导线（图 25）

(1) Find a point on the conductor that has sufficient clearance from adjacent conductors.

在导体上找到一个与相邻导体有足够间隙的点。

(2) Drill or punch a circular hole through the flexible circuit. Make this hole only of a size to break the conductor. If the circuit is two-sided, and the hole cuts a circuit on the far side, repair the conductor on the far side as if it were a damaged conductor.

在柔性电路上钻孔或打孔。孔的大小应足以断开导体。如果电路是双面的，而该孔切断了远侧的电路，则应像修理损坏的导体一样修理远侧的导体。

(3) Cover the hole on each side with Scotch No. 92 tape. Put the tape over the cut area with a minimum of 1/4 inch beyond the hole area.

用 Scotch 92 号胶带覆盖两侧的孔。将胶带贴在切割区域上，至少超出孔洞区域 1/4 英寸。

(4) To remove a circuit at a pad location (for example, a electrical contact at a terminal post), you can punch or drill it out. Overcoat the hole with polyurethane. Be sure to include the walls. Tape is not necessary. If you must solder a wire to a terminal post that goes through such a hole, make sure that the solder fillet does not extend into the flexible circuit.

若要移除板位置的电路（例如接线柱上的电气触点），可以打孔或钻孔。在孔上涂一层聚氨酯。确保包括墙壁。不必使用胶带。如果必须将导线焊接到穿过这种孔的接线柱上，应确保焊丝不会延伸到柔性电路中。

F. Addition of Conductors

添加导线

(1) Get some coated copper wire, quadruple Formvar wire, or copper wire as specified in QQ-W-343 Type S or BMS 13-46.

找一些涂覆铜线、四氟线或 QQ-W-343 S 型或 BMS 13-46 规定的铜线。

(2) Remove insulation by the usual procedures.

按照常规程序拆除绝缘层。

(3) If the added wire is to end on a component lead, remove the solder fillet from the affected circuit side only.

如果添加的导线末端在元件引线上，则仅去除受影响电路一侧的焊料。

(4) Bend the wire end around the component lead and solder it.

将导线末端绕元件引线弯曲并焊接。

(5) If the wire is to end on a conductor pattern, remove the covering, tin the conductor pattern and wire, and solder the wire in position as specified in Paragraph 20.D. Remove unwanted flux with a swab and isopropyl alcohol.

如果导线的末端在导体图形上，则移除覆盖物，在导体图形和导线上镀锡，然后按照第 20.D 段规定的位置焊接导线。

(6) Bond the wire with Metre Grip 303 adhesive or Humiseal 1A33 polyurethane coating as necessary to give protection to the wire insulation.

必要时用 Metre Grip 303 胶或 Humiseal 1A33 聚氨酯涂层粘合导线，以保护导线绝缘层。

G. Repair of Cuts, Tears, Nicks, and Creases

修理割伤、撕裂、划痕和折痕

(1) Cuts or tears which do not go through a conductor (Figure 25)

不穿过导体的切割或撕裂（图 25）

(a) Drill or punch a circular hole at the end of the defect. Make sure that the hole removes the end of the crack, or the defect will continue to grow. If this hole goes into a far side circuit, repair the far side circuit as specified in Paragraph 20.D. above.

在缺陷末端钻孔或打孔。确保该孔消除了裂纹的末端，否则缺陷会继续扩大。如果该孔进入远侧电路，则按照上文第 20.D. 段规定的方法修理远侧电路。

(b) Cover the hole on both sides with Scotch No. 92 tape. Center the tape over the hole area with a minimum of 1/4 inch extension beyond the hole area.

用 Scotch 92 号胶带覆盖孔的两侧。将胶带对准孔洞区域的中心，并在孔洞区域外至少延伸 1/4 英寸。

(2) Cut or tear that goes through a conductor (Figure 25).

穿过导体的切割或撕裂（图 25）。

(a) Drill or punch a circular hole at the end of the defect. Make sure that the hole removes the end of the defect, or the defect will continue to grow.

在缺陷末端钻孔或打孔。确保该孔消除了缺陷的末端，否则缺陷会继续扩大。

(b) Repair broken circuits as specified in Paragraph 20.D. above. If no circuit is broken on one side, cover the hole there with Scotch No. 92 tape.

按照上文第 20.D. 段的规定修理断裂的电路。如果一侧没有断路，则用Scotch 92 号胶带盖住此处的孔。

(3) Badly Creased Sections

严重褶皱的部分

(a) If the conductor is not damaged, apply Scotch No. 92 tape to the two sides of the creased area to add strength to the area.

如果导体未损坏，在折痕区域的两侧粘贴Scotch 92 号胶带，以增加该区域的强度。

(b) If the conductor is damaged, repair as specified in Paragraph 20.D. above. Give strength to the area of the crease with Type 69 adhesive, or polyurethane coating, applied over the repaired side, and with Scotch No. 92 tape over the other side.

如果导体已损坏，则按照上文第 20.D. 段规定的方法修理。用 69 型粘合剂或聚氨酯涂层涂在修理过的一面，并用Scotch 92 号胶带涂在另一面，以增加折痕区域的强度。

(4) Nicks 缺口

(a) Bend the area of the nick into an arc with sufficient radius to help it not become worse and change into a crack or tear.

将缺口处弯成半径足够大的弧形，以免缺口恶化，变成裂缝或撕裂。

(b) If necessary, apply Scotch No. 92 tape to give strength to the area.

如有必要，可贴上Scotch 92 号胶带，以增强该区域的强度。

21. MATERIALS AND TOOLS 材料和工具

NOTE: Equivalent substitutes can be used.

注：可使用同等替代品。

A. Materials

材料

(1) Abrasives

(a) Aluminum oxide, 27 grit

(b) Aluminum oxide or garnet, 240 grit or finer

(2) Adhesives

(a) Armstrong A31, V98911

(b) BAC5010 Type 52 (BMS 5-60)

(d) BAC5010 Type 69 (BMS 5-72, Type 4, which replaces Type 2) (Metre Grip 303, V18604)

(3) Cleaners and Solvents (SOPM 20-60-01)

(a) Acetone, technical — O-A-51

(b) Alcohol, Ethyl

(d) Butyl Cellosolve — TT-E-776

(e) Cellosolve Acetate — 2, Ethoxy Ethyl Acetate, 99%, Polyurethane Grade, V80524

(f) Isopropyl Alcohol — TT-I-735, Grade A Technical

(g) Methyl Ethyl Ketone (MEK) — TT-M-261

(h) Thinner for Uralane 5750 — 75% Toluene, 25% MEK (by volume)

(i) Toluene — TT-T-548

(j) 1,1,1-Trichloroethane — MIL-T-81533

(k) Xylene — ASTM D 846

(4) Coatings, Conformal (Encapsulants)

(a) Acrylic — Humiseal 1B31, MIL-I-46058 Type AR

(b) Polyurethane — Humiseal 1A33, V99109

(d) Polyurethane — MIL-I-46058, Type UR

(e) Silicone — RTV3140, V71984

(5) Epoxy — Scotchcast 251, V76381

(6) Epoxy Resin — Scotchcast No. 8, V76381

(7) Flux

(a) Kester 135, V75297 (ANSI or IPC J–STD–004, Types RO–L0 or RE–L0)

(b) Kester 197, V75297 (ANSI or IPC J–STD–004, Types RO–L1 or RE–L1)

(d) Alpha NR310, Alpha Metals Inc., V28175

(8) Joint Compound, Thermal — Wakefield Type 152 (Type 120 optional), V92218

(9) Locking Compound, Glyptal — No. 1201 (Red Enamel), V34700

(10) Masking Materials

(a) Scotch No. 218, V76381

(b) Scotch No. 250, 1 inch width, V76381

(d) Tech Form Laboratories TC-533, V52700

(e) TEC-660-2W, V25227 or V8E724

(f) Turco 522, V61102

(11) Nylon Strip — Polymer No. 101, 0.031 inch thick, V83616

(12) Phosphor-Bronze — QQ-B-750, Composition A Annealed, 0.010 inch thick

(13) Pipe cleaners — U.S. Tobacco Co., V4V681

(14) Solder — QQ-S-571 (SOPM 20-12-01)

(15) Spacer Strips, Removable — Dissopads, V32559

(16) Strippers

(a) ES1, V26348

(b) Strip Jel 990, V75554

(17) Swabs, cotton (SOPM 20-60-04)

(18) Tape

(a) Flame resistant — Permacel P29, V99742

(b) Polyethylene — Polyken No. 822, V97327

(d) Protective — Scotch Y9017, V76381

(e) TFE Fluorocarbon — Permacel No. 422, V99742

(f) TFE Fluorocarbon — Scotch No. 65, V76381

(19) Tubing, Heat-Shrinkable, Clear

(a) Raychem DWP-125 (Replaces Raychem RNF-100), V06090

(b) Scotchtite 3028, V76381

(d) SAE-AMS-DTL-23053/8 (Replaces MIL-I-23053/8)

(20) Wipers — BMS 15-5, Class A or B (SOPM 20-60-04)

(21) Wire

(a) Bare, Copper, Tinned, Single Conductor, Soft Drawn or Annealed — QQ-W-343, Type S

(b) BMS 13-46

(22) Wire Braid — A-A-59569 (Replaces QQ-B-575)

B. Tools and Equipment

(1) Soldering iron with built-in suction device — Enterprise Model 300, V18885

(2) Cutting tool — Scalpel or knife

(3) Long-nose pliers

(4) Test jig for board assembly

(5) Lead cutting tool — Utica 262-5-1/2, V30106

(6) Smooth flat jawed pliers

(7) Pin cutter tool — ST2351B or ST2351C

(8) Brush, stiff bristle

(9) Drill board — Tempered hardboard, approx. 1/8 inch thick, finished, Georgia Pacific, V00284

(10) Drills, carbide

(a) ST 1255

(b) Carbet Series 2000, Carbet Division, Chicago Circuit Drilling Co.

(d) Catalog No. 5738, Union Card Div., UTD Corp.

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