Comparison of delamination effects between temperature cycling test and highly accelerated stress test, in plastic packaged devices

Abstract

Two reliability stress tests were performed on, plastic packaged test chips consisting of a temperature cycle test (TCT) of 500 cycles and a highly accelerated stress test (HAST) of 300 h with bias voltage. Before and after the tests delamination of the die-mold interface was examined with scanning acoustic tomography. On these test chips bondwire failures, mechanical deformation, and corrosion test structures have also been measured. It appeared that 300 h of HAST nearly destroyed the adhesion between chip and mold whereas a 500 TCT caused delamination only to initiate from the die corners. The HAST caused a large number of corrosion failures, and the TCT a number of mechanical deformation failures.<>