Synthesis And Properties Study Of Thermal Interface Materials For Chip Testing

Thermal interface materials(TIMs) which consist of metal foil and polymer materials are applied in Intel for chip testing. It is the thermal conduction materials between PPV(Process Platform Validation)system and chip. In the actual process, the yield rate often decreases owing to the fact that thermal interface materials short lifespan and pollut io n phenomenon. Authorized by Intel, novel TIMs are needed to be re-designed and evaluated in the part of thermal conductivity, pollution phenomenon and production cost for chip testing.In this paper, the finite element model of PPV system is built based on the detection construction to analysis the stress and strain of TIMs so as to determine the reason of surface pollution. SEM and XRD are used to characterize the morphologies and compositions of the original TIMs and found it consist of nano-sized graphite sheets. And the novel TIMs are re-designed and fabricated from two parts, the one is metal foil, and the other is soft cushion. Finally obtain the appropriate substitute material Cu foil instead of Al, polymer TIMs added copper and silver flakes instead of original materials, and evaluate its performance.To increase the thermal conductivity of TIMs, the coupling agents KH550, KH570 are used to modify the surface. And the optimum types and amount of agents is respectively KH550, and 2.0%. Also the effects of the type, content, particle size and ratio of thermal conductive fil ers on the thermal conductivity and production cost are studied systemic. The variation of thermal conductivity is that it increases with the increasing fillers contents initially and decline with further contents exceeding the certain value; Thermal conductivit y of TIMs by adding the mix size particles is bigger than the single one; When the metal fillers copper and sliver content is 80wt%, the thermal conductivity of materials is increasing with the ratio of sliver flakes raise. Through the cost-thermal conductivity curves, The optimum TIMs has been obtained, and the appropriate contents of fil ers is 56.0% copper and 44.0% sliver flakes, its conductivity is 5.06 W/(m·K) and has the suitable price, satisfying the requirements of PPV tests.