Methods of Improving the Reliability of Power Transistor Modules in Electric Energy Converters at the Stage of Completion

Abstract

Providing high reliability of electric energy converters based on power semiconductor devices (PSDs) is the main goal of designers, manufacturers and users of such devices. There are many factors affecting reliability—namely, the PSD heat dissipation regime determined by the electric and thermal parameters of the devices, magnitude and type of load, and operating environment conditions. In most cases, an increase in the converters’ power is achieved by combining parallel connected semiconductor devices into modules, which gives rise to additional reliability problems for the devises. We propose several solutions to those problems that guarantee safe thermal operation regime of PSDs (transistors) in the modules by choosing proper transistors and discarding potentially unreliable ones according to criteria based on the devices’ thermal properties. A new method is proposed for the rapid assessment of thermal resistance of transistors when integrating them in the power modules.