表面安装设备的拆除和更换
REMOVAL AND REPLACEMENT OF SURFACE MOUNTED DEVICES
1. INTRODUCTION 介绍
A. The data in this subject comes from Boeing process specification BAC5128 (which supersedes BAC5214, BAC5215, BAC5216 and BAC5224) for removal and replacement of surface mounted devices.
本主题中的数据来自波音工艺规范 BAC5128（取代 BAC5214、BAC5215、BAC5216 和 BAC5224），用于拆卸和更换表面安装设备。
B. This data is general. It is not about all situations. Use this data as a guide to help you write minimum requirements.
本数据为通用数据。并非适用于所有情况。请将此数据作为指南，帮助您编写最低要求。
C. A surface mounted device (SMD) can be a small outline integrated circuit (SOIC) or a chip capacitor or resistor. SOICs are plastic packaged ICs which have leads that can be soldered to circuit pads on top of the printed circuit board. Chip capacitors and resistors are made of ceramic-like material and have metal caps on the two ends. These end caps are soldered to the circuit pads on the printed circuit board. Some of the SMDs have many leads, very near to each other, frequently 20 to 50 in one inch of component length. Examples are plastic leaded chip carriers (PLCC), plastic quad flat packs (PQFP).
表面安装设备 (SMD) 可以是小外形集成电路 (SOIC)，也可以是片式电容器或电阻器。SOIC 是塑料封装的集成电路，其引线可焊接到印刷电路板顶部的电路盘上。片式电容器和电阻器由类陶瓷材料制成，两端有金属帽。这些端盖焊接到印刷电路板上的电路盘上。有些 SMD 有很多引线，彼此非常接近，在一英寸的元件长度内经常有 20 至 50 根引线。例如塑料引线式芯片载体 (PLCC)、塑料四扁平封装 (PQFP)。
D. 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. EQUIPMENT 设备
NOTE: Equivalent substitutes can be used.
注：可使用等效替代品。
A. Solder systems
焊接系统
(1) Sta-Temp Solder System STSS-001, V47882
Sta-Temp 焊接系统 STSS-001，V47882
(a) Tips (required as a minimum) — SMTC-001 thru 005, STTC-026
焊头（至少需要）– SMTC-001 至 005、STTC-026
(b) Talon tweezer tool with tips
带吸头的 Talon 镊子工具
(2) Pace MBT-250 SMT rework/repair station, V17794
Pace MBT-250 SMT 返修/修理站，V17794
B. Tweezer tool — Pace Thermotweeze unit, V17794 (a component removal device equivalent to two soldering irons hinged together at the handles)
镊子工具–Pace Thermotweeze 装置，V17794（相当于两个手柄处铰接在一起的烙铁的元件拆除装置）
C. Special soldering iron tips
特殊烙铁头
(1) Slotted tips (with a groove that fits chip components)
开槽吸头（带有适合芯片元件的凹槽）
(2) Specialty tips (for removal of specified components, such as 44-lead PLCCs or 132-pin PQFP’s. Available from tool vendors, such as Pace, Inc. (V17794) and Metcal, Inc. (V47882), to fit their tools.
专用吸头（用于取出规定的元件，如 44 引线 PLCC 或 132 引脚 PQFP。可从 Pace, Inc. (V17794) 和 Metcal, Inc. (V47882) 等工具供应商处购买，以适合其工具。
D. Hot air wand — A hand-held device, in the shape of a soldering iron, to supply hot air at controlled temperature and flow rates for heating and soldering tools
热风棒 — 一种手持式设备，形状类似烙铁，用于为加热和焊接工具提供受控温度和流速的热风。
E. Tweezers, manual 手动镊子
F. Scraping tool 刮削工具
3. MATERIALS 材料
NOTE: Equivalent substitutes can be used.
注：可使用等效替代品。
A. Solvents (SOPM 20-60-01)
溶剂（SOPM 20-60-01）
(1) Ethyl alcohol
乙醇
(2) Isopropyl Alcohol, TT-I-735, Grade A
异丙醇，TT-I-735，A 级
(3) Aliphatic Naphtha, TT-N-95
脂肪族石脑油，TT-N-95
B. Cotton tipped applicators (SOPM 20-60-04)
棉签涂抹器（SOPM 20-60-04）
C. Solder — Non Activated Rosin Cored Wire, Sn60 WRP2 or P3 or Sn63 WRP2 or P3.
焊料 – 非活性松香芯线，Sn60 WRP2 或 P3 或 Sn63 WRP2 或 P3。
D. Adhesive
粘合剂
(1) Type 52 or 69 (SOPM 20-50-12)
(2) Type 625 VT (light weld) with activator 535, V1T842
E. Desoldering braid — Soder Wick, V34605
拆焊编织带 — Soder Wick, V34605
4. PREPARATION 准备工作
CAUTION :IF YOU USE THE STA-TEMP SYSTEM, TURN OFF THE POWER BEFORE YOU CHANGE THE TIP. IF THE POWER IS ON WITH NO TIP INSTALLED, THERMAL RUNAWAY AND POSSIBLE AUTOMATIC SHUTDOWN CAN OCCUR.
注意 :如果使用 sta-temp 系统，请在更换喷嘴前关闭电源。如果在未安装喷嘴的情况下接通电源，可能会发生热失控和自动关机。
A. Install the tip on the desoldering tool before you make it hot.
将焊头安装到脱焊工具上，然后再使其发热。
B. Make sure that leads and pads are clean and have no oxides or contaminants.
确保引线和盘干净，没有氧化物或污染物。
C. If bonded components are a problem, the adhesive can be made soft if you heat the assembly board for 20-40 minutes at 94°C (200°F).
如果粘合元件有问题，可在 94°C (200°F) 温度下加热装配板 20-40 分钟，使粘合剂变软。
5. REMOVAL OF SURFACE MOUNTED DEVICES 拆卸表面贴装设备
NOTE: Soldering iron temperatures can usually be lower for SMD work than for devices mounted on holes through the circuit board. A tip temperature of 550°F is sufficient.
注：对于 SMD 工作，烙铁温度通常比安装在电路板孔上的设备要低。烙铁头温度达到 550℉即可。
A. Chip components (capacitors, resistors, diodes, etc.)
片式元件（电容器、电阻器、二极管等）
(1) Soldering iron method
烙铁焊接法
(a) Hold the body of the part with tweezers. Heat one end of the component, then the other, until the two solder joints are melted at the same time.
用镊子夹住零件主体。先加热元件的一端，再加热另一端，直到两个焊点同时熔化。
(b) Twist the body of the part to break the adhesive bond and remove the part.
扭转零件主体，使粘合剂断开，然后取出零件。
(2) Slotted soldering iron tip method
开槽烙铁头法
(a) Get a slotted tip made for the size of the component to be removed. Install it on the iron and heat it up.
根据要拆卸元件的尺寸制作开槽烙铁头。将其安装在烙铁上并加热。
(b) Fill the tip with new solder.
将新焊料注入烙铁头。
(c) Apply the tip to the component. When the solder melts, twist to break the adhesive bond and remove the part.
将焊头插入元件。当焊料融化时，扭转以破坏粘合剂的粘合，然后取下零件。
(d) Remove the part from the tip.
将零件从吸头上取下。
(3) Hot tweezer tool method
热镊子工具法
(a) Heat up the tweezer tool and use it to hold the component until the solder melts.
加热镊子工具，用它夹住元件，直到焊料熔化。
(b) When the solder melts, twist to remove the part.
焊料熔化后，扭转取下零件。
(4) Hot air wand method
热风棒法
(a) Heat the component with hot air until the solder melts.
用热风加热元件，直至焊料熔化。
(b) Twist and remove the part with manual tweezers.
用手动镊子扭转并取出零件。
B. SMDs with leads (flat packs, PLCCs, PQFPs, etc.)
带引线的 SMD（扁平封装、PLCC、PQFP 等）
(1) Soldering iron method
电烙铁法
(a) Use desoldering braid to remove as much of the solder as you can.
使用拆焊编织带尽可能多地去除焊料。
(b) Heat and lift each lead from the circuit board with a dental pick or equivalent tool
加热并用牙签或类似工具从电路板上取下每根引线
(2) Special soldering iron tip method
专用烙铁头法
(a) Get and install on the iron the special tip made for the part to be removed.
获取并在烙铁上安装专为要移除的零件制作的特殊烙铁头。
(b) Heat the tip. Clean and tin it with new solder.
加热烙铁头。清洁并用新焊料上锡。
(c) Apply a large quantity of solder to make a bridge across all of the component leads and to let the heat flow easily from the iron to the component.
涂上大量焊料，在所有元件引线上搭桥，让热量容易从烙铁流向元件。
(d) Apply the tip to the component and push down lightly.
将烙铁头放在元件上，然后轻轻向下按。
(e) When the solder melts, carefully twist and remove the component.
当焊料融化时，小心扭转并取出元件。
(3) Cut-the-leads method
切断引线法
(a) Cut through the leads with a diagonal cutters or a razor knife. Remove the component body.
用对角线切割器或剃刀切断引线。取出元件本体。
(b) Remove the leads from the board surface with a soldering iron, desoldering braid or a vacuum tool.
用烙铁、脱焊编织带或真空工具从电路板表面去除引线。
(4) Hot tweezer tool method
热镊子工具法
(a) Get and install on the tool the tips made for the component to be removed.
获取并在工具上安装专为待拆元件制作的尖头。
(b) Apply a large quantity of solder to make a bridge across all of the component leads and to let the heat flow easily from the tool to the component.
涂上大量焊料，在所有元件引线上搭桥，使热量容易从工具流向元件。
(c) Apply the tweezer tool to the component.
用镊子工具夹住元件。
(d) When the solder melts, carefully twist and remove the part.
当焊料熔化后，小心扭转并取出零件。
(5) Hot air wand method
热风棒法
(a) Get and install the tip or nozzle good for the component to be removed.
获取并安装与待拆元件匹配的喷嘴。
(b) Heat the component leads and the circuit board pads. Be quick to remove the component immediately when the solder melts. Be careful not to let the circuit board get too hot. Too much heat will change the color of the board or burn it.
加热元件引线和电路板盘。当焊料融化时，应立即快速取下元件。注意不要让电路板太热。太热会使电路板变色或烧毁。
C. RF devices and other metal packages soldered directly to the circuit board surface
直接焊接到电路板表面的射频设备和其他金属封装
(1) Use the hot tweezer tool or a special soldering iron tip if you can.
尽可能使用热镊子工具或专用烙铁头。
(2) Remove as much solder as you can from leads, mounting tabs, etc. and move them away from their circuit board pads.
尽可能多地去除引线、安装片等上的焊料，并将它们从电路板盘上移开。
(3) Get and install tips on the tool that best fits the part to be removed. Heat the tip, clean and tin them.
获取并在工具上安装最适合要移除的零件的烙铁头。加热焊头，清洁并上锡。
(4) Use the highest temperature you can, up to 700°F.
尽可能使用最高温度，最高可达 700°F。
(5) Apply the tool to the component.
将工具用于元件。
(6) When the solder melts, remove the component.
当焊料融化时，取下元件。
6. PREPARATION FOR SURFACE MOUNTED DEVICE REPLACEMENT 更换表面安装设备的准备工作
A. Remove solder, flux residue, and coating material from the area of the circuit board where the component will be installed. Use desoldering braid or a vacuum tool to remove the solder. Use isopropyl alcohol to remove the flux. Use heat, a razor knife, or isopropyl alcohol to remove other coatings.
清除电路板上将要安装元件区域的焊料、助焊剂残留物和涂层材料。使用脱焊编织带或真空工具清除焊料。使用异丙醇清除助焊剂。使用热量、剃刀或异丙醇去除其他涂层。
7. ADHESIVE APPLICATION (OPTIONAL) 涂抹粘合剂（可选）
NOTE: This adhesive is not necessary when you solder surface-mounted components to printed circuit foils. You can hold the component in position with something mechanical, such as tweezers, while you apply the solder.
注意：将表面贴装元件焊接到印刷电路箔上时，无需使用这种粘合剂。在涂抹焊料时，可以用镊子等机械工具将元件固定到位。
A. Do not let the adhesive get on the circuit pads, or the solder will not bond correctly. See Figure 1 for adhesive placement recommendations.
不要让粘合剂沾到电路盘上，否则焊料将无法正确粘合。有关粘合剂位置的建议，请参见图 1。
B. Remove the cotton tip from an applicator. Use the stick part as an adhesive applicator. Apply a quantity of 625 adhesive that will fill most of the space between the SMD and the board when the SMD is in position. Apply a thin layer of activator 535 on the side of the SMD which will touch the adhesive.
从涂胶器上取下棉签。将棒状零件用作涂胶器。在 SMD 就位时，涂抹一定量的 625 粘合剂，以填满 SMD 和电路板之间的大部分空间。在 SMD 接触粘合剂的一面涂上一层薄薄的活化剂 535。
C. Put the SMD in position within 1 minute of adhesive application. Then wait 60 seconds before soldering.
在涂抹粘合剂后 1 分钟内将 SMD 就位。然后等待 60 秒钟再进行焊接。
D. If adhesive gets on the circuit pads:
如果粘合剂沾到电路盘上：
(1) Remove the component (if it was in position) with tweezers or some other tool.
用镊子或其他工具取出元件（如果元件已就位）。
(2) Remove adhesive with cotton tipped applicators wet with solvent.
用沾有溶剂的棉签清除粘合剂。
(3) Let the cleaned area air dry
让清洁区域风干
8. INSTALLATION OF THE SURFACE MOUNTED DEVICE 表面安装设备的安装
NOTE: Repair of a surface mounted solder termination is limited to no more than 10 times.
注： 表面安装焊接终端的修理次数不得超过 10 次。
A. Be careful not to mix parts that have the same shape, size and color, because many of these small chip components have no part identification and could have different functions or values.
注意不要混用形状、尺寸和颜色相同的零件，因为这些小型芯片元件中有许多没有零件标识，可能具有不同的功能或数值。
B. Do not put too much tension or compression on devices during installation.
安装时不要对设备施加过大的拉力或压力。
C. Put the part in position within 1 minute of adhesive/activator application.
在涂抹粘合剂/活化剂后 1 分钟内将零件放好。
D. Install film chip resistors with the colored, protective glass film up (away from the board).
安装薄膜片式电阻器时，应将彩色玻璃保护膜朝上（远离电路板）。
E. Ceramic chip capacitors can be installed with either side down.
陶瓷片式电容器可以任一面朝下安装。
F. Tantalum chip capacitors can be installed either side down unless the epoxy coating covers one side of the negative termination. Then this side must be up. Polarity is indicated by a small stub on the positive end.
钽片式电容器可任一面朝下安装，除非环氧树脂涂层覆盖了负极终端的一面。那么这一面必须向上。极性由正极上的一个小突起表示。
G. Carefully hold the SMD in position above the circuit pads before you move it down to touch the pads. Tweezers can be used to help.
在向下移动 SMD 接触焊盘之前，要小心地将其固定在电路焊盘上方的位置。可用镊子帮忙。
H. Use a minimum amount of pressure to move the component down to touch the pads. Do not damage the board or the pads with tools or restraining devices. Be sure the leads touch the circuit pads.
使用最小的压力向下移动元件以接触焊盘。不要用工具或限制装置损坏电路板或焊盘。确保引线接触电路盘。
I. Do not move components laterally after they are in position on the board, or adhesive could be pushed on the circuit pads and prevent soldering.
元件在电路板上就位后，请勿横向移动元件，否则会将粘合剂推到电路焊盘上，导致无法焊接。
J. Examine the circuit board for the following (Figure 2, Figure 3, Figure 4):
检查电路板是否存在以下问题（图 2、图 3、图 4）：
(1) The circuit board or pads must not be damaged. Reject a damaged or melted board that exposes glass fibers and reduces the spacing between conductors to less than 0.010 inch (Figure 2). Reject a board with lifted circuit pads.
电路板或盘不得损坏。如果电路板损坏或熔化，玻璃纤维外露，导体间距小于 0.010 英寸（图 2），则报废该电路板。报废电路板上的电路盘。
(2) Parts must not be turned horizontally more than 25% of the part width.
零件的水平翻转不得超过零件宽度的 25%。
(3) Parts must not be turned vertically (raised at one end).
零件不得垂直翻转（一端翘起）。
(4) When examined at 3X magnification, circuit and part terminations must have no adhesive. If you find adhesive on these areas, remove it with cotton-tipped applicators wet with solvent. Then let the cleaned area dry.
用 3 倍放大镜检查时，电路和零件端点不得有粘合剂。如果发现这些区域有粘合剂，请用棉签沾溶剂清除。然后让清洁区域干燥。
(5) SMDs with leads must have no more than 25% of the lead width off the solder pad (Figure 4).
带引线的 SMD 必须有不超过 25% 的引线宽度偏离焊盘（图 4）。
9. SOLDERING 焊接
A. Chip components (capacitors, resistors, diodes, etc.)
芯片元件（电容器、电阻器、二极管等）
NOTE: Ceramic parts could crack if heated too quickly. We recommend you preheat such components to 200-300°F in an oven, with a hot plate, or with a hot air gun.
注意：如果加热过快，陶瓷零件可能会破裂。建议用烤箱、热板或热风枪将此类元件预热到 200-300°F。
(1) Soldering iron method
烙铁法
(a) Apply new solder to one circuit pad. Let it become solid.
将新焊料涂在一个电路盘上。让其凝固。
(b) Apply flux to the component.
在元件上涂抹助焊剂。
(c) Heat the solder on the circuit pad until it is melted and immediately install the component, straight and level. Let it cool for 30 seconds.
将电路盘上的焊料加热至融化，然后立即安装元件，安装要平直。让其冷却 30 秒钟。
(d) Solder the other end of the component.
焊接元件的另一端。
(2) Hot air wand method
热风棒法
(a) Apply new solder to the two circuit pads. Let it become solid.
在两个电路盘上涂抹新焊料。让其凝固。
(b) Apply flux to the component.
在元件上涂抹助焊剂。
(c) Hold the component with tweezers. Heat the component and the circuit pads with a flow of hot air.
用镊子夹住元件。用热气流加热元件和电路盘。
(d) When the solder melts again, put the component on the board in the correct position, remove the heat, and hold the component in position until the solder becomes solid.
当焊料再次融化时，将元件放到电路板上的正确位置，移开热气，并保持元件的位置，直到焊料凝固。
B. SMDs with leads (flat packs, PLCCs, PQFPs, etc.)
带引线的 SMD（扁平封装、PLCC、PQFP 等）
NOTE: It is not easy to manually solder devices that have many leads very near to each other. We recommend drag soldering as the fastest, easiest method to solder these devices.
注意：手动焊接引线彼此非常接近的设备并不容易。我们建议将拖焊作为焊接这些设备的最快、最简单的方法。
(1) Individual point soldering method
单点焊接法
(a) Align the component with the circuit pads.
将元件与电路盘对齐。
(b) Solder opposite corners with a very small amount of solder to hold the device in the correct position.
用极少量的焊料焊接对角，将设备固定在正确位置。
(c) Individually solder each lead to the circuit pads.
将每根引线单独焊接到电路焊盘上。
(2) Drag soldering method
拖焊法
(a) Align the component with the circuit pads.
将元件与电路焊盘对齐。
(b) Solder opposite corners with a very small amount of solder to hold the device in the correct position.
用极少量的焊料焊接对角，将设备固定在正确位置。
(c) Apply flux to all leads of the component and their circuit pads.
在元件的所有引线及其电路盘上涂抹助焊剂。
(d) With a round, semi-chisel tip in the soldering iron, heat the tip and apply solder to the flat surface of the tip.
用烙铁的半圆形烙铁头加热烙铁头，并在烙铁头的平面上涂抹焊料。
(e) Apply the edge of the tip to the circuit pads with the flat side of the tip away from the body of the component. Touch the tip to the pad and the end of the lead at the same time, and lightly drag the tip along each component lead and pad location in sequence. Solder will flow from the tip to each pad and make a fillet joint with the lead.
将烙铁头边缘贴在电路焊盘上，烙铁头的平面远离元件主体。同时将焊头触碰焊盘和引线末端，并依次沿着每个元件引线和焊盘位置轻轻拖动焊头。焊锡将从针尖流向每个焊盘，并与引线形成圆角焊点。
(f) As necessary, stop to put more solder on the tip.
必要时，停下来在焊头上涂抹更多焊料。
(3) Hot air wand method
热风棒法
(a) Align the component with the circuit pads.
将元件与电路盘对齐。
(b) Solder opposite corners with a very small amount of solder to hold the device in the correct position.
用极少量的焊料焊接对角，以将设备固定在正确位置。
(c) Apply a continuous bead of solder paste across the area of the component leads that touches the circuit pads.
在元件引线与电路盘接触的区域连续涂抹焊膏。
(d) Point a low-pressure flow of hot air at the solder paste from approximately 2-4 inches. Let the solder dry to a dull gray color.
在约 2-4 英寸处将低压热气流对准焊膏。让焊锡干燥成暗灰色。
(e) Hold the air tool to make the hot air come down at the part in a direction perpendicular to the circuit board surface. Be very careful to keep the flow vertical, or it could blow solder under the component and cause a short circuit. Move the airflow nearer to the component until the solder paste starts to melt and make solder joints. Move the air tool around the component until all leads are soldered.
握紧气动工具，使热气沿垂直于电路板表面的方向向零件喷射。要非常小心地保持气流垂直，否则会将焊料吹到元件下面，造成短路。将气流靠近元件，直到焊膏开始熔化并形成焊点。在元件周围移动气动工具，直到所有引线都焊接完毕。
(f) If solder bridges occur, remove them with increased airflow to make the solder melt and flow into the adjacent joints.
如果出现焊桥，用增加的气流清除焊桥，使焊料熔化并流入邻近的焊点。
10. INSTALLATION OF JUMPER WIRES 跳线的安装
A. If the area has conformal coating (encapsulant), remove the coating a minimum of 0.10 inch around the terminal areas and along the routing of the jumper.
如果该区域有保形涂层（封装剂），则应在端子区域周围和跳线路线上清除至少 0.10 英寸的涂层。
B. If the circuit board does not have conformal coating (encapsulant), apply a layer of Type 52 or 69 adhesive to the circuitry which the jumper wire will go across. Cure the adhesive layer (SOPM 20-50-12).
如果电路板上没有保形涂层（封装剂），则在跳线要穿过的电路上涂一层 52 型或 69 型粘合剂。固化粘合剂层（SOPM 20-50-12）。
C. If the jumper wire will go to a soldered component connection, remove the solder fillet from the side adjacent to the jumper wire routing. Use vacuum or desoldering braid.
如果跳线将连接到已焊接的元件连接上，则应去除跳接线布线邻近一侧的焊缝。使用真空或脱焊编织带。
D. Bend and put the jumper wire in the location specified by the overhaul instructions. Use a routing that does not let jumper wires touch solder joints other than the ones where they terminate. Be careful not to damage wire insulation. Use the minimum wire length possible.
将跳线弯曲并放在大修说明规定的位置。在布线时不要让跳线接触到焊点（跳线的终端位置除外）。小心不要损坏电线绝缘层。尽可能使用最短的导线长度。
E. Bond or mechanically hold the jumper wire in position to prevent relative movement between parts and joints during the soldering operation. To bond the wire, clean the area with isopropyl alcohol and bond the wire with Type 52 or 69 adhesive (SOPM 20-50-12).
将跳线粘合或机械固定在适当位置，以防止在焊接操作过程中零件和焊点之间发生相对移动。粘合导线时，用异丙醇清洁该区域，然后用 52 型或 69 型粘合剂 （SOPM 20-50-12）粘合导线。
F. Hand solder the jumper wires to the terminal areas (SOPM 20-12-01). Remove flux residues with isopropyl alcohol.
手工将跳线焊接到端子区域（SOPM 20-12-01）。用异丙醇清除助焊剂残留物。
G. If applicable, apply conformal coating (encapsulant) to the area.
如果适用，在该区域涂上保形涂料（封装剂）。