High-density probe substrate for testing optical interconnects

The design, fabrication, and demonstration of a high-density probe substrate (100 /spl mu/m pitch) for testing chips with electrical and optical input/output (I/O) interconnects are presented. The primary purpose of this substrate is to provide nondamaging, temporary interconnections between the device-under-test (DUT) and the automated test equipment (ATE) during wafer probing - an essential step in the system-on-chip (SOC) manufacturing process. Optical probing of an array of polymer pillar-based optical I/O interconnects is demonstrated for the first time, to the authors' knowledge.