Both, the SMD component and the tin plated copper heat sink are soldered by reflow-soldering-process on the PCB within one production step. Due to this kind of assembly process a manual fixation of the semiconductor on or with the heat sink by screw, clip or gluing is not necessary anymore. Semiconductors in D-PAK sizes like MO-184, SO-10, TO-252, TO-263 do not get into direct contact with the heat sinks. This process of cooling is called indirect cooling system. In this case the heat will be transferred from the SMD semiconductor component through a copper drain pad to the heat sink for dissipation. The operating range of thermal resistance for those SMD heat sinks is between 24K/W and 11K/W. The reasons for this excellent Rth - values are first of all the geometry and secondly the best conductive Copper material itself, so called C1100. Neither Aluminium (99,5 %) nor Graphite achieved a thermal conductivity of 389 W/(mK). Therefore, a Copper heat sink has an obvious advantage in thermal conductivity compared with an aluminium heat sink. This series is only used as tin plated version with a material thickness of 0,6mm. All SMD parts are available in bulk or in tape & reel packing for manual, semi- or full automatic assembly processes.