Wafer-level glass-caps for advanced optical applications

A novel process flow to manufacture miniaturized optical windows on wafer-level is presented. Those windows can be used for miniaturized optical products like high-brightness LEDs (HB-LED) and digital projection (DLP) as well as more complex optical data-communication, since integrated optical functions can be implemented with low tolerances. We explain the fabrication of cap-wafers having a shallow cavity with a depth of typically 10 μm used in photo sensors and a unique manufacturing process for cap-wafers with a deep cavity of e.g. 300 μm used in LED packaging. Those cap-wafers are used in wafer-level integration of advanced, miniaturized optical products. We discuss two options for wafer bonding i.e. bonding using adhesive as well as anodic bonding. As an example on product level a miniaturized photo sensor package, a pressure sensor package as well as a LED package is discussed.