Reliability Evaluation of Multichip Phase-Leg IGBT Modules Using Pressureless Sintering of Nanosilver Paste by Power Cycling Tests

Nanosilver paste has become a promising lead-free die-attach material for power electronic packaging. This development solves the challenges faced by power device manufacturers to replace the lead-based or lead-free solders for high-temperature applications. This paper proposes the reliability of a 1200-V/150-A multichip insulated-gate bipolar transistor (IGBT) module using pressureless sintering of nanosilver paste as die attachment. The degradation in harsh environment was compared between the proposed IGBT module using pressureless sintered nanosilver and the commercial one using Sn5Pb92.5Ag2.5 solder by power cycling with two different test conditions. The device junction-to-case thermal resistance, I-V characteristics, and switching performance were measured at various numbers of cycles. The results show that the pressureless sintered nanosilver, which was used as the die attachment of the multichip phase-leg IGBT modules, has superior reliability rather than the commercial one.