Abstract: A thermal interface composition undergoes a viscoelastic change at microprocessor operating temperatures to transfer heat generated by a heat source, such as a microprocessor to a heat sink. The composition includes a low melting alloy dispersed in a matrix. The matrix comprises a viscoelastic composition which softens at about the operating temperature of the heat source. The viscoelastic composition may include a thermoplastic elastomer, a compatible hydrocarbon oil, and a tackifying resin. In use, the thermal interface composition flows under pressure between the heat source and the heat sink to make thermal contact between the two. When the heat source is operated and reaches operating temperature, the viscoelastic composition softens and the low melting alloy melts at around the operating temperature to form a highly thermally conductive, generally homogeneous mixture which readily transfers heat to the heat sink.

Abstract: A thermal interface composition undergoes a viscoelastic change at microprocessor operating temperatures to transfer heat generated by a heat source, such as a microprocessor to a heat sink. The composition includes a low melting alloy dispersed in a matrix. The matrix comprises a viscoelastic composition which softens at about the operating temperature of the heat source. The viscoelastic composition may include a thermoplastic elastomer, a compatible hydrocarbon oil, and a tackifying resin. In use, the thermal interface composition flows under pressure between the heat source and the heat sink to make thermal contact between the two. When the heat source is operated and reaches operating temperature, the viscoelastic composition softens and the low melting alloy melts at around the operating temperature to form a highly thermally conductive, generally homogeneous mixture which readily transfers heat to the heat sink.