A hybrid wafer level packaging technique for multi-chip interconnect using low loss organic layers

This paper presents a new wafer level packaging (WLP) technique that combines thin, low cost organic layers with high performance MMICs. More specifically, we present a GaAs-based single stage amplifier covered with layers of a low loss liquid crystal polymer organic material. It was observed that the RF performance of the MMIC is virtually unaffected by this technique unlike conventional packaging processes that degrade the RF performance due to the overlay of the dielectric material on the MMIC. The insertion loss for the laser ablated 50 micron vias was minimal up to 20 GHz. These results show that the hybrid WLP can be successfully implemented with virtually no performance degradation.