New energy vehicles (NEV) are powered by electricity with power generally between 100kW-300kW and motor controlled by multiple control modules. For example, IGBT power module, the core power device of electric vehicle’s inverter, provides power to the vehicle by controlling main motor of the vehicle; other modules also include motor drive circuit module, current conversion module, and etc. Among these core control modules, insulation substrate is one of the most important components. With high power electrical devices designed to cope with higher voltage, more current and higher power density, insulation substrate materials of electrical modules will bear more thermal stress. Silicon nitride, thanks to its excellent dynamic and heat conduction performance, will become the main material for the 3rd generation high heat conductive ceramic substrate, and it will see a more extensive development in semiconductor and hybrid electric vehicle (HEV) areas.