Design and Characterizations of a Planar Multichip Half-Bridge Power Module by Pressureless Sintering of Nanosilver Paste

Abstract

A planar phase-leg 650-V/240-A insulated-gate bipolar transistor (IGBT) module with 16 IGBT chips and 16 free-wheeling diodes has been demonstrated by pressureless sintering nanosilver paste to achieve extremely high power density and low parasitic inductance. Nanosilver paste was chosen as the die-attach material to increase the operation temperature as well as the power density and heat dissipation. The thermal coupling effect of so many power chips in parallel and the thermal performance of the planar IGBT module have been discussed. The electrical performance has also been characterized to verify the feasibility of the packaging process. The I-V curves between the two bridge arms were in good consistency, resulting from the symmetrical architecture. The low switching loss of the multichip planar IGBT module can be attributed to its low parasitic inductance since the removal of bonding wires and compact architecture. Thermomechanical reliability has also been investigated by the passive thermal shocking test of the module from -55 °C to 150 °C. In addition, the increment of VCE(sat) of the modules reached the failure standard until 900 cycles.