Characterization of a Bare-Die SiC-Based, Wirebond-Less, Integrated Half-Bridge With Multi-Functional Bus-Bars

Abstract

This article presents detailed analysis and charact- erization results of a bare-die silicon carbide (SiC) MOSFET-based, half-bridge switch module with integrated decoupling capacitors and gate-driver circuitry, suitable for high-performance power electronics in applications such as next-generation automotive systems. The module structure enables wirebond-less integration in an entirely PCB-based assembly, featuring compact vertical power and gate loops with low parasitic elements. The assembly uses thermoelectrically multi-functional components, which simultaneously serves as busbars and heat sinks, thereby obviating the need for thermal interface material, and also allows quasi-double-sided cooling. This article starts with a comprehensive review of integrated power modules followed by a description of the module structure under consideration and its various practical design aspects. Thereafter, a detailed discussion is presented on electrical parasitic modeling, conducted using 3-D finite element analysis simulations in Ansys Q3D. Results indicate that the module can achieve extremely low values of loop inductances ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$L_{\mathrm{ loop,power}}$ </tex-math></inline-formula> = 1.35 nH and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$L_{\mathrm{ loop,gate}}$ </tex-math></inline-formula> = 5.1 nH at an oscillation frequency of 100 MHz) without entailing high parasitic capacitances, which can provide enhanced switching performance compared with state-of-the-art solutions. Experiments performed on a proof-of-concept half-bridge prototype, operated up to 600 V, 30 A demonstrate close adherence of the measured electrical parameters with theoretical predictions and acceptable preliminary thermal performance.