Design of High-Temperature Packaging Insulation for Power Modules Using Grafted Nanostructured Silicone Elastomer Composites

Developing high-temperature and high-voltage SiC power modules requires packaging insulation with better thermal stability and electrical properties at high temperatures. This work studied the thermal and electrical properties of the proposed grafted silicone elastomer (SE) nanocomposites, and the electrical performance of the two packaging module prototypes (plane-plane and point-plane electrodes) using the grafted SE nanocomposites as the packaging material at 20 °C and 160 °C. It was found that the grafted SE nanocomposites exhibited higher thermal stability, lower electrical conductivity, higher breakdown strength, more deep charge traps, lower real permittivity, reduced dielectric loss, and higher ion hopping barrier than pure SE. Moreover, the packaging modules encapsulated with the grafted SE nanocomposite performed a lower leakage current, higher breakdown voltage, higher partial discharge inception voltage, and less carbonized electrical tree areas. Besides, the breakdown channels and electrical trees in the packaging modules appeared at the packaging material/ceramic substrate interface. The reported grafted SE nanocomposites are promising for high-temperature and high-voltage packaging insulation.