Ceramic mini-ball grid array package for high speed device

We have developed a Ceramic Mini Ball Grid Array (BGA) package for a high speed switch chip (200 MHz) application. In this paper, we describe the 0.5 mm pitch mini BGA package and the processes developed to fabricate this package. In addition, a matching ceramic socket that was developed to test the high speed switch chips is also briefly reviewed. The mini-BGA process enabled the packaging of the switch chip in a 21 mm ceramic substrate with 1521 solder ball connections. The main difference between the mini solder ball connections described here and conventional ceramic ball grid array (CBGA) packages is that 60/40 Pb/Sn eutectic solder is used in the mini-BGA package compared to 90/10 Pb/Sn solder balls used in CBGA packages.