A Multichip Phase-Leg IGBT Module Bonded by Pressureless Sintering of Nanosilver Paste

This paper presents the design, development, and optimization of large-area die attachment by pressureless sintering of nanosilver paste. With the proposed die attachment, a high power 1200 V/150 A insulated-gate-bipolar-transistor (IGBT) module is fabricated using large-area IGBT (12.56 × 12.56 mm
²
) and diode (6.3 × 6.3 mm
²
) chips. The average die-shear strength of higher than 30 MPa can be obtained with the low void ratio of 1.8%. The electrical characteristics of the IGBT module using pressureless sintered nanosilver paste have been measured and compared with the commercial one using soldered Sn5Pb92.5Ag2.5. Test result shows that this IGBT module has identical static and dynamic characteristics as the commercial one. Therefore, the pressureless sintered nanosilver could be used as an alternative to high-lead solder in power module manufacturing, especially in assembling SiC or GaN-based devices for high temperature applications.