Reliability analysis of sintered Cu joints under power cycle condition

A Cu particles paste was developed as a candidate of die attach materials for next generation power devices. The evaluation including thermal shock and power cycling test were performed on SiC-DBC die-attach structure to test the reliability of sintered Cu joints. The thermal shock reliability of SiC die-attached on a DBC substrate was carried out from -50 °C to 250 °C in the ambient atmosphere. SiC MOSFETs bonded by the Cu paste were evaluated by power cycle test from 25 °C to 200 °C. In both test condition, the sintered Cu joints showed good stability. The shear strength increased with the thermal shock cycles increased, which can be attributed to Cu oxidation during test. The power cycle test also showed no obvious deterioration occurred.