Heat sink and package surface design

The present invention relates to an electronic assembly that includes a thermal interface material sandwiched between a heat sink and an integrated circuit package. An electronic assembly that includes a heat sink, a thermal interface material, integrated circuit, and a package connected to the integrated circuit. The thermal interface material is positioned between a first surface on the package and a second surface on the heat sink to improve thermal conductivity between the package and heat sink. At least one of the first and second surfaces includes either a cavity that traps excess thermal interface material when the heat sink is compressed against the package, or a protrusion that maintains bond line thickness between the heat sink and package.