Fischer elektronik clip on heat sinks for d pakdsup2 pakdsup3 pak fischer elektronik fk 244 13 d3 pak the fischer elektronik aluminium heat sink mount clip on 195cw d3 pak is a versatile heat sink especially suitable for cooling semiconductors in a d pak type package the devices are manufactured from 06mm copper for very high thermal conductivity and have a solderable surface meaning they can be directly mounted on a pcb fischer elektronik fk 244 13 d3 pak aluminium heat sin