A study of bonding reliability for substrate to metal cavity of microwave module

The trend of most electronic products is toward higher operating frequencies. Recently the microwave modules have been used worldwide step by step in high frequency application. In this paper, the reliability of bonding between substrate and metal cavity of microwave module is studied. Two different kinds of bonding methods are introduced, which are bonding with adhesive or with solder paste respectively. The defects during two kinds of bonding process are investigated. The non-destructive bonding defects analysis techniques, such as X-ray inspection and scanning acoustic microscopy are presented. Furthermore, the effects of thermal cycling stress on bonding reliability for substrate to metal cavity of microwave module were investigated. The experimental results show that thermal cycling stress had limited influences on the adhesion between substrate and metal cavity which were bonded by solder. Finally several suggestions are given.