Munich-based Wacker Chemie AG has unveiled a gap filler developed specifically for use in electric vehicle (EV) power electronics. The silicone-based compound consists of a two-component system that cures at room temperature through an addition reaction. The gap filler is said to have good electrical insulation properties and to achieve a thermal conductivity of around four watts per meter and Kelvin.
Robust at extreme temperatures
According to the company, the material has proven to be particularly robust in thermal resistance tests. It can withstand temperatures of up to 150 degrees Celsius without any significant change in its thermal conductivity or other material properties. WACKER claims that even thermal shocks with rapid temperature changes between minus 40 degrees and 150 degrees Celsius are unproblematic. Measurements of thermal resistance have shown that a composite between power electronics and cooling systems manufactured with the gap filler remains intact even under such conditions and retains its thermal conductivity almost unchanged.
Easy processing
Before curing, the gap filler marketed as “SEMICOSIL® 9649 TC” is a stable mass that becomes more fluid with increasing shear, for example during mixing and dosing. The shear-thinning property is adjusted so that the mass can be easily conveyed by machine and applied in the form of a bead. According to the company, this enables processors to achieve high dosing speeds and extremely high dosing accuracy.
Silicones for safe electric vehicles
Silicones can prevent thermal runaway and protect adjacent components. In addition to gap fillers, WACKER supplies many other specialty silicones to increase battery safety, such as pottings. These are used to encapsulate battery components such as battery cells, the cell contact system, and battery vent slots. Silicones also play an important role in the thermal management of power electronics.
Source:
Press release via e-mail
