Power module durability copper clad insulated metal substrates

Copper clad insulated metal substrate materials are used by manufacturers of a variety of power modules for industrial motor control, computer, and automotive engine control applications. Copper clad insulated metal designs allow high waste heat densities. Process chemical residuals and uncontrolled test procedures can reduce the product durability advantage associated with copper clad insulated metal´s thermal management advantage. Copper clad insulated metal designs rely on relatively thin (75-150 μm) ceramic filled electrical isolation to achieve minimum thermal resistance between waste heat generating components and the metal thermal management base layer. Product durability is often estimated by exposing an assembly to bias voltage at elevated temperature. This exposure is followed by dielectric stress testing to safety agency standards. Bias aging and dielectric testing is carried out at stress levels significantly higher than those used with normal printed wiring designs. Previously published data suggests that surface cleanliness levels better than 1 μm gm NaCl equivalent per cm² allow the production of assemblies resistant to the effects of aging at elevated temperature with or without voltage bias stress. This test program focuses on the sources of and analysis for assembly process related ionic contaminants. This test program used samples of industrial motor control panels, aged at elevated temperature