Comparison of the surface properties of power electronic substrates

This paper deals with thick film copper technology (TFC) and its comparison with other power electronic substrates such as a printed silver or direct bonded copper (DBC) on alumina substrates. The research activities were concentrated on surface properties of power substrates and its solderability. The solderability of thick film copper is comparable with other power electronic substrates such as DBC, but it is necessary to ensure proper firing condition or remove oxides from the surface after firing and use a proper flux. The main advantages of thick film copper in comparison with common power electronic substrates are a high resolution of conductive pattern, higher reliability at thermal cycling and a possibility to create a different local thickness of copper layer on substrate. Maximal thickness of copper layer can reach 300 µm.