电子封装用硅铝合金镀金黑点分析

Analysis on black pits appearing on gold-coated Si–Al alloy for electronic packaging

针对某硅铝合金微波组件表面镀金黑点问题,采用扫描电镜、能谱和金相显微镜分析了缺陷区域基材和镀层的微观形貌与元素组成。其原因是前处理后基材中弥散分布的硅颗粒脱落,附着于表面而难于除净,在电镀Au后才脱落,留下了坑洞。通过调整粗化液组分和缩短粗化时间,延长超声清洗时间,问题得到解决。

As for the black pits appearing on the surface of a gold-coated microwave module made of Si–Al alloy, the micromorphologies and elemental compositions of the substrate and coating at the defective area were analyzed by scanning electron microscopy(SEM), energy-dispersive spectroscopy(EDS), and optical microscopy(OM). It was found that some silicon particles distributed dispersively in the substrate fell off and adhered to its surface during pretreatment, which were hard to be removed, but peeled after gold plating, resulting in the formation of some pits. The problem was solved by modifying the composition of roughening solution, shortening the roughening time, and extending the ultrasonic cleaning time.