Thermally conductive polymer overmold for a disc drive actuator assembly

A thermally conducting and electrically insulating overmold (120) encapsulates and supports an actuator coil (118) in a disc drive actuator assembly (110). The overmold is made from a base resin mixed with a ceramic filler compound such as boron nitride, alumina, aluminum nitride, magnesium oxide, zinc oxide, silicon carbide, beryllium oxide, chromium oxide or some combination thereof. The base resin is preferably polypheneline sulfide. Glass filler and/or a coupling agent are also preferably added. The overmold reduces off track position errors in a read/write head (116) supported by the actuator assembly by reducing popping forces caused by the sudden expansion and contraction of the actuator coil during operation.