BGA package integration of electrical, optical, and capacitive interconnects

We present a novel optically-enabled ball grid array (OBGA) package that integrates conventional electrical I/O, proximity communication (PxC), and optical communication in one industry-compatible BGA package for the first time. The key enabling technologies for such a packaging solution, including the precision alignment needed to combine multiple CMOS chips and compact opto-electronic (OE) subassemblies, are detailed here. We designed and fabricated a 45 mm times 45 mm times 5.2 mm organic cavity-down BGA package with up to 600 solder balls for electrical I/O. Its cavity holds three CMOS chips, with PxC interfaces and optical driver/receiver circuits, as well as two multi-channel optical subassemblies with standard optical fiber connections. We report preliminary testing results.