A complex reinforced polymer interposer with ordered Ni grid and SiC nano-whiskers polyimide composite based on micromachining technology

Abstract

A complex reinforced polymer interposer comprised with conductive Ni cylinders, ordered Ni grid and SiC nano-whiskers/Polyimide (PI) composite was proposed. The conductive Ni cylinders distributing in the middle of each Ni grid unite designed as the supporting structure were used as electric connecting component for the interposer and were insulated by the SiC nano-whiskers/PI composite. The comprehensive properties of the complex reinforced polymer interposer were improved by a complex reinforced mechanism: the improved thermal conductivity and mechanical strength by the Ni supporting structure and the reduced metal/polymer interfacial mismatch due to the SiC nano-whiskers/PI composite with the optimized mixture ratio. The above complex reinforced polymer interposer and a traditional reinforced polymer interposer only with Ni grid were fabricated using micro-machining technology for comparative analysis. The comprehensive properties of these two polymer interposers were analyzed respectively. Compared with the traditional design, the comprehensive properties of the proposed complex reinforced polymer interposer were improved further, such as, 21.3% increase for the Young modulus, 10.1% decrease for the coefficient of thermal expansion (CTE) and 54.9% increase for the thermal conductivity. Such complex reinforced mechanism based on the metal ordered grid and random nano-whiskers has potential to expand the applications of the polymer interposer.