3-D analysis of the breakdown localised defects of ACS (TM) through a triac study

The reliability tests of triac and ACS(TM) present similarities. In this pa per, we propose to analyse the origin of the defects observed by using meas urements and 3D simulation with the ISE tools. We are interested in the ope ration of the triac or ACS(TM) in quadrant 2. The results presented here re late to the discrete triac only for reasons of confidentiality. Thermal sim ulation of the triac shows a strong thermal gradient (thermal shock) in the silicon at turn-on. Stresses and strains in the material created micro cra ckings that increase the temperature until the fusion of silicon (hot spot) . (C) 2000 Elsevier Science Ltd. All rights reserved.