Abstract Scope |
1200V 200A SiC MOSFET power module for electric vehicle (EV) was developed with pressureless silver (Ag) sintering process which was 240 ℃, 75 min in vacuum and nitrogen gas. Ag finish Si3N4 active metal brazed (AMB) ceramic substrate and Ag paste were used. Also, we prepared Sn-3.0Ag-0.5Cu (SAC305) soldered power module to compare the Ag sintered module. As-sintered bonding strength, bonding layer thickness (BLT), void content and densification were 39-41 MPa, 70-80㎛, 2% under and 91-95 %, respectively. To compare the electrical performance for SAC305 soldered and Ag sintered power modules, we conducted power cycling tests (50~100 ℃ (△Tc=50℃), 50~150 ℃ (△Tc=100℃), 3000 cycles) and thermal cycling(-40~125 ℃, 30 min dwell time, 1100 cycles), and then, on resistance and switching efficiency were compared. We finally confirmed that the reliability and electrical performance degradation characteristics of the Ag sinter joint power module were superior to that of the solder-bonded module. |