Study on IMC Growth Behavior during Multiple Reflowing and Thermal Shock Tests of IGBT Module

Abstract:
The formation and growth of intermetallic compound (IMC) layer at the soldering interface during multiple reflowing and thermal shock tests were investigated. Results showed that the average thickness of Die/Solder A/DBC interfacial IMC layers increased after second reflowing. After thermal shocking, the IMC’s morphologies changed and the IMC average thickness on the all four kinds of interface increased except the (Ni, Cu)3Sn IMC unchanged. For one time reflowing solder joints, the Solder A/Cu interfacial IMC layer was increased faster with 1000 cycles. For twice reflowing solder joints, the Cu/ Solder B interfacial IMC layer was increased faster with 1000 cycles.