A novel methodology for thermal characterization of power packages in high current applications

This article describes the thermal characterization of semiconductor packages that include MOSFET solutions for high current capability applications. MOSFETs have three kinds of electrical characteristic parameters in regards to the heat generation of the silicon die, such as linear, saturation and parasitic diode mode. This paper shows the results of a study on thermal characterization according to those electrical characteristics and parameters. The thermal resistance is defined by the function of the temperature difference between junction to referenced temperature and the power dissipation between them. Therefore, the thermal resistance has a different value due to different heating characteristics such as linear mode, saturation mode and diode mode heating respectively. For this paper, thermal simulation and measurement were conducted using CFD simulation and experimentation. In the results illustrated various thermal characteristics depending on the different structure of packages having either Al bonding directly to the substrate or Al bonding to the lead frame with DBC substrate.