Environmental reliability of nano-structured polymer-metal composite thermal interface material

Heat dissipation has become a `bottleneck´ for the properties of electronics products and photoelectronic devices. Thermal interface material (TIM) plays a key role in heat dissipation, and must have flexibility and high thermal conductivity in order to decrease the thermal resistance of the interface between the device and heat sink or cooler. We developed a new type of nano-TIM based electrospun technology. Metal with low melting point was injected into the polymer nanofiber scaffold fabricated by electrospun. The heat of the electronic devices dispersed through the metal, resulting in high thermal conductivity of the nano-TIM. Environmental reliability of nano-structured polymer-metal composite thermal interface material was studied by thermal cycling test. A sandwich structure was used to get shear strength of pull test. The shear strength of the samples dropped to about 50% after 500 cycles. SEM and EDS results indicate that overflow of alloy during thermal cycling test leads to decreasing shear strength.