Electric current characteristic and mechanical properties of Si-glass-Al anodic bonding process

In this paper, a novel current-time model of two-step triple-stack anodic bonding was proposed, and Si-glass-Al was successfully bonded together. The results indicate that the current variation of two bonding process is similar, the currents increase rapidly to the maximum value and then decreases exponentially. The peak current of the second step bonding is always larger than the first step, which indicates resistance produced by incomplete contact between bonding materials has a significant effect on peak current. SEM was conducted to investigate the interfacial structure of the Si-glass-Al samples. At 450℃/800 V, the thickness of Na+ depletion layer at the glass-Al and glass-Si interfaces is 546 and 820 nm, respectively. The tensile strength of the sample increases with the increase of voltage. Whether Si or Al was bonded first, fracture always occurs near the second step bonding interface or the glass substrate.