Search Results (3)

With the growing need for high-power density, high-efficiency power electronics, wide band gap (WBG) semiconductors, such as silicon carbide (SiC) and gallium nitride (GaN), have been widely used in recent years. With high switching speed, stray inductance induced by packaging would cause voltage overshooting and oscillation during the switching transient, which should be mitigated at all costs. In this paper, a power module design based on a multilayer insulated metal substrate (MIMS) structure was proposed to effectively address the stray inductance concern based on the mutual-inductance cancelling effect. Fabrication process flow with high feasibility was also designed. Electrical and thermal simulations were conducted based on a power module with a nominal rating of 1200 V and 500 A. Compared to the planar module, the proposed design possessed much lower stray inductance (3.47 nH vs. 14.85 nH). In the transient thermal simulation, the proposed module exhibited a time constant 141.7% higher than that of the hybrid module with a ceramic substrate on the bottom but MIMS on the top, making it suitable for applications with high-constant power output requirements. Full article

In this article, thermal investigation methods for electrically insulating and thermally conductive substrate materials will be presented. The investigations were performed in their real-world application environment, i.e., in the form of IGBT (insulated gate bipolar transistor) module substrate plates. First, the overall thermal resistance and thermal structure function of the system in a multivariable parameter space were revealed using CFD (computational fluid dynamics) simulations. Afterwards, thermal transient testing was performed on real samples, with the help of which the thermal resistance values of the modules were determined using the thermal dual interface test method. The presented tests are not intended to determine material parameters, but to rank different substrate materials based on their thermal performance. Full article

In power semiconductor systems such as inverters, managing losses is critical for optimizing performance. Inverters, which convert DC to AC for applications such as renewable energy systems, motor drives, and power supplies, are significantly affected by the thermal performance of components such as metal-oxide-semiconductor field-effect transistors (MOSFETs). Efficient thermal management is critical for the longevity and performance of power electronic systems, especially in high-power applications. Designing effective thermal management strategies for inverters reduces losses, increases efficiency, and improves performance while considering space constraints and complex component interactions. In this study, power electronics simulations and computational fluid dynamics (CFD) thermal analysis were integrated to design the inverter. Using an integrated simulation, a thermal analysis was performed based on the inverter losses per module. A power electronics simulation was used to verify the validity of the loss values in the inverter design, and the CFD thermal analysis facilitated the visual analysis of the variables to be considered. The validity of the design was evaluated through experimental verification of the inverter system. A temperature saturation of 63.9 $\mathrm{℃}$ at 60$A_{rms}$ was recorded in the simulation, and a temperature saturation of 45 $\mathrm{℃}$ or less at 59$A_{rms}$ to 60$A_{rms}$ was obtained for each phase in the actual test. Considering the ambient temperature difference, it showed a difference of approximately 9.9 $\mathrm{℃}$. This conclusion allows us to reduce the high probability of risk derived by considering a small margin of safety for each variable in the design. This solution can be used to compactly design real inverters and solve complex thermal problems in power semiconductor-based systems. Finally, this study analyzes the similarities and differences between CFD simulations, power electronics simulations, and real-world experimental validation, highlighting the importance of thermal management in improving the efficiency of power electronic systems, particularly inverters. Full article