Novel and low cost through silicon via solution for wafer scale packaging of image sensors

Solid state CMOS image sensor are being incorporated in an every increasing diversity of products. This paper presents a new TSV solution suitable for both single die and stacked die wafer-scale packages. So- called 'via-through-pad' interconnects are a novel form of interconnect that superficially resemble a TSV but the differences are important and have profound implications for the product cost and reliability. Unusually, the materials of the package construction are sourced from outside the semiconductor industry. This is done to keep costs as low as possible. The process technology is wholly scaleable so the same tool set can be used irrespective of the wafer diameter. Data will be presented showing via-through-pad interconnects are able to surpass by a wide margin, the exacting reliability requirements of the automotive industry, both at the package and board level.