遥控器印制线路板腐蚀失效原因

Corrosion Failure Causes of Printed Circuit Board of Remote Controller

某遥控器印制线路板发生腐蚀失效,采用宏观分析、扫描电镜分析、能谱分析及红外分析等方法对线路板腐蚀失效的原因进行了分析。结果表明:该遥控器线路板在制造过程中某些地方的镀锡层漏镀,对基材失去了保护作用,基材发生氧化腐蚀;某些地方的镀锡层杂质含量高,在大气中的水汽、氧、二氧化碳、酸雾等参与下,锡作为薄液膜下腐蚀原电池中的负极失去电子发生电化学腐蚀。在两种腐蚀的综合作用下,最终造成遥控器线路板腐蚀失效。

A printed circuit board of remote controller occurred corrosion failure.The corrosion failure causes of the circuit board were analyzed by means of macroscopic analysis,scanning electron microscopy analysis,energy spectrum analysis and infrared analysis.The results show that the tin coating in some places of the circuit board of remote controller were missing in the manufacturing process,which lost the protective effect on the substrate,and the substrate occurred oxidation corrosion.The tin coating in some places had high impurity content.With the participation of water vapor,oxygen,carbon dioxide and acid mist in the atmosphere,tin,as the negative electrode of galvanic cell corroded under thin liquid film,lost electrons and occurred electrochemical corrosion.Under the combined action of two kinds of corrosion,the circuit board of remote controller corrosion failure was eventually caused.