Global energy consumption and the shift to more environmentally friendly power sources and uses demand an increasing number of power electronic components.1 Efficiency and reliability of power electronic components strongly rely on a maximum temperature. As they generate a certain amount of heat this thermal energy has to be deduced from the source into the environment. The mostly used passive coolers are manufactured by extrusion and are made of highly thermal conductive metals. By using extrusion technology, the shapes are limited to, in one direction, uniform shapes. These mostly finned heat exchangers are easy and cheap to produce. One of the biggest disadvantages is the limited design and that the heat exchanger needs a coupling to the source surface. This is mostly done by a thermal conductive paste which also can act as a glue. These pastes need a second step for applying and the life span is limited. The heat transfer from the source goes into the paste and from the paste into the heat exchanger and limits therefore the possible amount of transferred heat. Using polymer processing technologies, the shapes can vary much more and additional freedom comes into design, by using additive manufacturing. The biggest draw back is the limited heat conductivity,2 were metals like aluminium has values of up to 230, Copper 390 and unfilled polymers as Polyamides have lower than 0.3 W·(m·K)-1. With different shapes and fillers, compounds were produced and the heat conductivity was measured. One of the challenges with highly filled systems
is the stiffness of these compounds, which hinders the use of a filament for extrusion based additive manufacturing. Therefore, we added a thermoplastic elastomer into the compound to soften the material so that we can process it into filaments. Different polymer compounds were pressed into plates and the most promising candidates were extruded into filament and used on a Material Extrusion Printer. The heat exchanger was directly printed on a power resistor, which is used for testing the heat transfer into a measuring device.