Thermal interface material and heat sink configuration

Thermal interface materials (TIMs) are critical to protect active semiconductor devices, such as microprocessors, from exceeding the operational temperature limit. They enable bonding of the heat generating device (e.g., a silicon semiconductor) to a heat sink or a heat spreader (e.g, copper and/or aluminum components) without creating an excessive thermal barrier. The TIM may also be used in the assembly of other components of the heat sink or the heat spreader stack that comprise the overall thermal impedance path. A thermal interface material for use in electronic packaging, the thermal interface material comprises a solder with relatively high heat flow characteristics and a CTE modifying component to reduce or prevent damage due to thermal cycling. The thermal interface material comprises an active solder that contains indium and an intrinsic oxygen getter selected from the group consisting of alkali metals, alkaline-earth metals, refractory metals, rare earth metals and zinc and mixtures and alloys thereof. Lastly, damage due to an electronic package due to thermal cycling stress is reduced by using an insert in a lid of an electronic device package wherein the insert has a coefficient of thermal expansion that is between about that of the lid and about that of a semiconductor substrate.