Reflow characteristics of Sn-Ag matrix in-situ composite solders

Abstract

With ever increasing packing density of electronic packages, mechanical properties and thermal stability of the solders are recognized as one of the critical factors that determine their reliability and lifetime 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. The increased heat release rate per unit volume of the device associated with the employment of smaller diameter solder balls in recent packages such as the chip scale packages (CSPs) makes those properties even more crucial.

One of the approaches attempted to improve the characteristics of the solders is to develop composite solders. The solders matrix reinforced with intermetallic or metallic particles have been reported to have superior mechanical properties compared with those of the eutectic solders 11, 12, 13, 14, 15, 16, 17. For the composite solders are applicable in actual packages, its reflow solderability should be also as good as that of eutectic solder. Thus, in this study, we report the reflow characteristics of the Sn-Ag matrix composite solders manufactured via an in-situ processing technique.