Fischer elektronik extruded aluminium heat sink 6 5 deg c w to 220 sot 23 to 3p fischer elektronik sk129 38 1 sts a pcb screw mounting heat sink that is constructed from black anodised extruded aluminium the configuration of this heat sink makes it suitable for use with device packages to 220 sot 32 and to 3p a thermal resistance of 6 5 deg c w together with the aluminium construction for optimum device contact and black anodised finish to increase radiative heat loss maximises the therma