German company CeramTec has developed a ceramic cooling solution for power modules in electric vehicle drive inverters.

High-performance ceramics are especially suitable for cooling silicon carbide field effect transistors (MOSFETs) due to their high thermal conductivity, electrical insulation, and resistance to corrosion and wear. Liquid coolers use water or glycol mixtures and can achieve particularly high power densities for higher cooling capacity.

To ensure efficient heat dissipation, the new generation of ceramic cooling systems uses chip-on-heatsink technology, which connects the chip directly to the metallized ceramic heatsink, making it particularly close to the coolant. To do this, structured copper plates are mounted directly in front of and behind the ceramic cooler, so that both sides can act as circuit carriers for simultaneous cooling. 

The ceramic internal cooling structure is designed as a pin-fin structure, which significantly increases the heat transfer surface of the heat sink and enables ideal circulation around the surface. In this way, heat is optimally dissipated, while the structure increases mechanical strength and can absorb pressure, torsion and bending forces well. 

The thermal resistance of the direct chip heat sink is reduced by half compared to conventionally constructed systems.

The cooler is only 48x36mm, 3.6mm thick (including metallization), and weighs 10 grams. Based on thermal characteristics, the thermal resistance of a power module with a ceramic cooler 0.15 K*cm²/W from the chip to the design point of the cooling water.