SMT 缺陷.pdf - 第25页
33 Insufficient Solder Insufficient Solder / / 少 少锡 Countermeasure / 对策 1. Stencil apertu re clogging caus e incomplete solder printing): Automatic or manual clean the stencil. 钢网孔堵塞导致锡膏不完全印刷 : 自动或者手工清洗钢网 2. No enough so…
32
Insufficient Solder
Insufficient Solder
/
/
少
少锡
Insufficient
Insufficient solder
焊
焊锡不足
33
Insufficient Solder
Insufficient Solder
/
/
少
少锡
Countermeasure /对策
1. Stencil apertu re clogging cause incomplete solder printing):
Automatic or manual clean the stencil.
钢网孔堵塞导致锡膏不完全印刷: 自动或者手工清洗钢网
2. No enough solder paste volume (Paste height under LCL) :
Visual inspection and Cpk control.
锡膏量不足(锡膏高度在LCL以下): 目检和Cpk控制
3. Solder paste print misalignment: Fine tune printing
machine
锡膏印刷偏位:校正丝印机使之最优
4. Poor solderability of component or PCB pad: 元件或PCB焊盘可焊性差
a) Optimize reflow profile.优化回流曲线
b) Exchange the poor solderability component. 更换掉低可焊性元件
5. Excess glue or glue misalignment: Fine tune screen print (wave solder). 点胶
过多或点胶偏位:优化丝印参数
6. Less flux : Increase the flux spray on board before it pass wave soldering
(wave solder).助焊剂不足: 增加助焊剂的喷射量
¾ 定位对齐（REGISTRATION）
¾ 塌落（SLUMP）
¾ 厚度（THICKNESS）
¾ 挖空（SCOOP）
¾ 圆顶（DOME）
¾ 斜度（SLOPE）
¾ 锡桥（PASTE BRIDGE）
¾ 边缘模糊（NOT CLEAR EDGES
STENCIL对SMT工艺的影响
2-3、常见SMT锡膏印刷缺陷分析: