SMT 缺陷.pdf - 第22页
30 No Solder No Solder / / 无锡 No solder to the land or termination where solder is required. 焊点无锡
38
Countermeasure/ 对策
1. Wrong placement machine program : Check and correct the machine program.
贴片机程序错误: 检查和更正机器程序
2. Manual placement in reverse direction: 手工放置元件错误
a) Avoid manual placement components 避免手工放置元件
b) Need special inspection for the manual placement prior to reflow (document control).
炉前需要特别检查那些手工放置的元件 (文件控制)
3. Disordered orientation in the tray/reel of the incoming material:
卷装或盘装来料元件的不规则放置．
a) Inspect before loading it to SMT.
上料前检查来料
b) Feedback to vendor to take corrective actions.
反馈给供应商采取改善行动
Wrong Orientation/Polarity
Wrong Orientation/Polarity
反向
反向
,
,
极性反
极性反
30
No Solder
No Solder
/
/ 无锡
No solder to the land or termination where solder
is required.
焊点无锡
31
No Solder
No Solder
/
/ 无锡
Countermeasure/ 对策
1. Missing printing/ 漏印
Root cause: a) Stencil aperture was jammed./ 钢网堵孔
b) High viscosity of solder paste./ 锡膏粘性过高
Action: a) Clean stencil;/ 清洗钢网
b) Replace the recycled paste with fresh one./更换新锡膏
c) Printing machine parameter adjustment./校正丝印机参数
2. Poor solderability of component or pad./元件或焊盘可焊性太低
Root cause: a) Old date component or PCB. /陈旧元件或PCB板
b) Contamination on component or PCB. /元件或焊盘受污染
Action: Purge the material for further disposition. /清除来料
3. Insufficient flux volume: increase flux spray rate (wave solder).
助焊剂量不足: 增加助焊剂喷射量 (波峰焊接)
4. Preheat excess: lower preheat temperature properly (wave solder).
预热过度: 适当降低预热温度 (波峰焊)
5. Chip wave or solder wave height is low : proper height (wave solder).
波峰高度过低: 调整到适当高度 (波峰焊)