Full Low Temperature Solder BGA Development for Large size BGA Package

摘要

Fujitsu Limited (Fujitsu) has been adopting various compositive solders in developments of CPU packages used for high performance computers since 1990's. At first, SnPb solders were used in an age of MCM, while switched to SnAg and SnBiAg later for improving their manufacturability. After that, in the age of SCM, though SAC solders were used at the beginning, corresponding to tremendously increased performance as well as power consumption, size of the CPU packages are becoming larger year by year, in according some serious issues must be evaluated and worked out comprehensively. Regarding to the issues of BGA mounting yields due to their thermal warpage behaviors, managements of thermal resistance and temperatures, and failures of the 1st level connections, innovative manufacturing processes and mounting structures of all low-temperature solders are improved with applying SnBiAg for all BGA and pre-solders, the featured SPARC64™ XIfx packages were confirmed and shipped from 2014.