Simultaneous fabrication of a through-glass interconnect via and bumps using dry filling process of submicron gold particles

We propose a technique for the simultaneous fabrication of a through-glass interconnect via (TGV) and Au bumps using dry filling process of submicron Au particles. First, dry film resist holes were fabricated over glass through holes by photolithography. Next, submicron Au particles were filled into both the glass and resist holes, and sintered. We define a TGV sandwiched between two Au bumps as I-structure TGV. Cross-sectional SEM images showed that the proposed I-structure TGV was successfully fabricated without significant voids. Furthermore, the glass substrate covered with thin Au film and the Au bumps were well sealed because the Au particles shrank during a sintering. Four-probe method using daisy chain revealed that the resistance of the single I-structure TGV was 0.11 Ω. These results indicate that the proposed fabrication method will be very useful for various applications of glass interposers or glass IC chips.