Micro metal injection moulding for thermal management applications using ultrafine powders

There is an increasing interest in using tiny parts made of special metallic materials for new applications. In this new approach active cooled heat sinks with a microstructured surface are produced by micro-MIM (micro-metal injection moulding). In contrast to conventional heat sinks made of copper, in this case the parts are made of copper-tungsten and copper-molybdenum due to their combination of low CTE (coefficient of thermal expansion) and reasonable thermal conductivity. In this paper the current status of production of micro parts and parts with microstructured surfaces by micro-MIM for thermal management applications are presented. The scope and limitations are outlined with special concern to the materials and the minimal structure size. The implication and advantages of using ultrafine powders are pointed out. Therefore sintering behaviour, microstructure of sintered parts and characteristic properties as density, CTE and thermal conductivity are shown.