A revolutionary new copper clip in the ATPAK replaces the wire bonds of the DPAK - this new technology brings several substantial benefits. With Copper being an excellent thermal conductor, the clip facilitates much improved heat transfer between the semiconductor junction and the pins. Through reducing the thermal resistance of the package (R THJ+A), far greater densities become possible in power-related designs, especially in automotive applications.
Also, the copper clip has substantially greater cross-sectional area than the 70um wire bonds. This minimizes the R DSON of an ATPAK-based MOSFET, increasing efficiency and reducing power losses and heat generation. Additionally, the greater cross-sectional area of the clip increases the current carrying capability to 100A – a figure previously only achieved by the D2PAK, which has 7.5 times the volume of the new ATPAK.
On Semiconductor conducted benchmark tests to compare the thermal performance of the DPAK with the new ATPAK package and to demonstrate the advantages of the new technology. DPAK and ATPAK devices were placed on separate, yet identical, PCBs and controlled to dissipate 1.44 W each.
A thermograph was used to perform non-intrusive measurements of the surface temperatures. These measurements revealed a case temperature of 80℃ for the DPAK and 74.8℃ for the ATPAK. The junction temperatures for each device were calculated by using the thermal resistance for each package, resulting in junction temperatures of 76.0℃ and 82.2℃ for the ATPAK and DPAK respectively.