Corrosion inhibition of Ga-based thermal interface materials with Ni coating on Cu substrate

Abstract

The gallium (Ga) base liquid metal (LM) with high thermal conductivity and deformability is applied widely in thermal management in electrical systems. However, Ga readily reacts with Cu to form intermetallic compounds (IMCs), which can cause failure in electronic devices. Herein, the thermal interface material (TIM) with Ga and diamond is prepared to analyze the reaction behavior of TIM and Cu/Ni-plated Cu under an aging test at 125 °C. The results show that Ga reacts with Cu substrate and forms CuGa2 bulk. Moreover, Ni coating can inhibit the corrosion of Ga and Cu. However, the as-volcano IMC structures were generated, also. The thermal resistance increased from 2.24 mm2·K·W−1 to 14.47 mm2·K·W−1 from initial time to 200 h. The interfacial corrosion behavior between TIM and Cu substrate is studied by first-principles molecular dynamics simulation. The diffusion coefficient in the z direction of Cu is 0.04 × 10−5 cm2/s. In a word, the work could provide the guidelines for the further design of high-performance corrosion resistance in the region where Ga was used for thermal management on electronic products.