Thermal performance evaluation of Power QFN package with stacked and side by side die configuration

Currently available Quad Flat No-lead package with 8 mils thick die pad, fails to meet the high power dissipation requirements of automotive, industrial, and commercial applications. The use of 20 mils thick die pad and heavy gauge aluminum bond wires in the Power Quad Flat No-lead package helps transfer heat from package while providing low electrical resistance. Side by side die configuration limits the capability to reduce the package size. A stacked die configuration eliminates the extra space for control die and flag. Thermal performance of both configurations was evaluated by using simulation tool under three different conditions, i.e. JEDEC thermal resistance measure for steady state operating condition, thermal impedance for transient switching operating condition, and thermal interaction of multiple independent heat sources in the package.