Assessing Circuit Hermeticity By Electrolysis

 William J. Roesch, Shawn Peterson, Amy Poe, Steve Brockett, Steve Mahon, Jim Bruckner
TriQuint Semiconductor, Inc., 2300 N.E. Brookwood Parkway, Hillsboro, Oregon  97124-5300

This work describes a corrective action project to improve circuit hermeticity.  The objective was to provide quick feedback on experiments to improve performance in biased humidity environments.  The ultimate goal was to improve hermeticity to the point that enhanced circuits could withstand an accelerated biased humidity qualification test in plastic encapsulated packages.  Hermeticity was evaluated quickly by using current flow (electrolysis) in water applied directly to the surface of the devices.  Weaknesses in device construction were discovered, and effective solutions were evaluated by using the electrolysis technique.