Análise do comportamento térmico de semicondutores de potência

Abstract

IGBT power semiconductor modules are widely used in various industries, these transistors are present in industrial control system, electrical systems for the solar and wind power industry, industrial machines, railway traction, engine’s activation, hybrid electric vehicles, power inverters and other high-power switching devices. IGBT power modules generate an undesirable amount of heat from the dissipation of electric power. The reliability of semiconductor device modules is tightly linked to the operating junction temperatures of the device chips. Clearly, simulation tools are required to compute the instantaneous temperature of the devices under different load conditions of the converter. This contribution presents a transient 3D heat transfer analysis based on Finite Element Method using ANSYS software, for an IGBT power device with many layers of varying cross-sectional areas, different materials and heat sources. Two different cases were investigated, namely electric conduction and switching, which is characterized by strongly time-dependent heat source. A method for smooth out this energy signal during switching was used to make the numerical code more optimized. Calculated results are validated against experiments, where the experimental temperature data were obtained via thermography with a research-grade infrared camera, which provides a large amount of non-intrusive measurements of the entire external surface of the IGBT module. A good agreement regarding numerical and experimental results was observed.