宇航用PCB组件的半水清洗工艺研究

PCB组件的清洗是宇航电子产品装联中的重要工序,清洗的质量对PCB组件的可靠性影响极大。针对焊丝手工焊接和免清洗焊膏的再流焊接两种焊接方式进行了全自动半水清洗工艺研究。结果显示随着清洗剂浓度增加清洗效果越好,对清洗后的PCB组件进行了表面离子污染测试,离子污染量仅为0.14μg/cm2;同时还对清洗过程对元器件的标识影响进行了分析,研制了新型的固定工装,防止在清洗过程中PCB组件移动,探索出采用聚酰亚胺胶带保护电连接器腔体,防止多余物进入。

Study on Semi-aqueous Cleaning of PCB Assembly in Aerospace Electronic Products

The cleaning of PCB assembly is very important in aerospace electronic products, which will influence the reliability of the PCB assembly greatly. The processes of automatic semi-aqueous cleaning were studied on manual filling wire and no-clean solder paste reflowing. Results show that with the concentration of cleaning agent increasing, the cleaning quality gets better. Ion contamination test on the surface of PCB assembly was performed, which indicated that the ion contamination extent is 0.14/lg/cm2. Moreover, the influence of cleaning process on the sign of PCB component was analyzed. A new fixture which can avoid the movement of PCB component during cleaning is developed. The kapton to protect the redundancy from entering into the electric coupler cavity is discovered.