Mounting Considerations for Power Transistors used on AC-DC Converter for UPS Applications

This This study investigates the assembly of power transistors on heat sinks for use in DC/AC converters, focusing on two different mounting techniques that vary depending on the type of encapsulation used. For devices with TO-220 encapsulation, the study compared mountings with and without the use of self-tapping screws. The findings revealed that screws with pre-defined threads require less torque and result in less deformation in the thermal paste. For TO-247 encapsulation, the study evaluated the pressure applied by the clip on the device's encapsulation, considering factors such as temperature variation, assembly tools (manual or electric screwdriver), and the quality of the clip manufacturing process.