Sintered Silver-Based Direct-Cooled IGBTs With High Output Power and Thermal Reliability

The heat generated by IGBT modules during DC/AC power conversion requires the development of highly efficient direct-cooled thermal dissipation structures. Herein, direct-cooled IGBTs are realized using sintered silver (Ag) as the thermal interface materials (TIMs) between DBC substrate and heat sink. The high thermal homogeneity of Sintered Ag-IGBTs is first confirmed by the thermal performance differences derived from finite element simulations. The heat transfer advantage of sintered Ag enables fast thermal conduction from chip to heat sink, thus reducing the dynamic switching losses of Sintered Ag-IGBTs by 26%. Compared to SAC 305-IGBTs, the output current of Sintered Ag-IGBTs increased from 812 A to 848 A under the same driving conditions. Due to the low interfacial thermal resistance of sintered silver, the average thermal resistance reduction of 11.9% and the average chip junction temperature reduction of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5.5~^{\circ }$ </tex-math></inline-formula>C are realized in Sintered Ag-IGBTs. The high output power and thermal reliability of direct-cooled IGBTs are expected to facilitate their high-power density applications.