3D WL MEMS with TSV last technology's mechanical analysis

The through-silicon-via (TSV) technology is one of the most effective approaches to fulfill the form factor, profile, performance, and 3D interconnect demand of next generation handheld and wearable electronics. This paper introduces two structures of TSV LAST technology, standard flow and short flow. The standard flow TSV LAST structure shows better warpage control performance. The short flow TSV LAST structure can shorten manufacture procedures up to 20% and reduce the cost. This paper reports two warpage control solutions: (1) low modulus and low CTE passivation material, and (2) a balance layer design that the warpage issue can be improved more than 30% and 20%, respectively.