Mercury porosimetry investigation of plastic, integrated circuit packages

Abstract

Mercury porosimetry was used to characterize the pores and elastic properties of plastic IC packages. Three types of pores were identified: external gaps, epoxy-metal leadframe pores, and epoxy pores. When intrusion pressure was high enough to fill all pores, porosimetry data were used to calculate elastic constants. Highly accelerated stress test (HAST) and pressure cooker test failures were analyzed the mercury porosimetry techniques. Mercury porosimetry confirmed the existence of epoxy-leadframe pores that had caused failures during HAST testing, but was not effective in detecting die passivation crack failure mechanisms.<>