Modeling and fabrication of the redistribution layer on the 2.5D Si interposer

The hybrid material of PI (with SiC whisker, SiC particle, AlN particle, and diamond particle) is proposed to satisfy the requirement of higher thermal conductivity for the high density package system. The thermal conductivity of the proposed hybrid materials with a moderate amount of doping can be improved to about 6-12 times. The hybrid films are fabricated by mechanical ball-milling process, high speed mechanical stirring and spin-coating process. When the redistribution layer with the improved thermal conductivity (from 0.15 W/m.K to 1.5 W/m.K), the maximal temperature of the Si interposer reduced by 0.89 °C- 3.47 °C (2.50%-4.41%) and maximal thermal gradient decreased by 84.36% when the power density of the chip is among 2 W/m.K-8 W/m.K. And the tensile stress of sy was reduced from -201 MPa to 189 MPa.