Evaluation of a thermally enhanced mold compound, containing SCAN TM silica coated aluminum nitride filler, for SO-8 packaged power MOSFETs

The performance of a new thermally conductive mold compound containing SCAN^TM Silica Coated Aluminum Nitride filler has been investigated for use with power MOSFET devices in the SO-8 package. Thermal performance was determined through measurement of junction-to-ambient thermal resistance (Rθja), both in still air and in a wind tunnel environment. Additionally, the devices were evaluated for shifts in electrical characteristics and extensive reliability testing was performed. It was found that the SCAN filler material reduced the Rθja by 8 to 13% (compared to the standard angular silica filler material) while causing no shifts in electrical characteristics and no degradation in device reliability. It was concluded that the while our version of the SO-8 package (with fused leadframe) would not realize the maximum potential benefit from a thermally enhanced mold compound, the mold compound containing SCAN filler would provide a measurable increase in thermal performance which allows for an increased current rating of the device and lower typical junction temperatures