Electric feed-through for vacuum package using double-side anodic bonding of silicon-on-insulator wafer

It is not easy to hermetically seal using anodic bonding on both sides of silicon-on-insulator (SOI) wafer. Taking this into consideration, we suggest an electrical feed-through method for anodic bonding on the both sides of SOI wafer. The suggested method is illustrated on the basis of vacuum package of a conventional two-dimensional (2-D) micro-scanner. Electric feed-through for anodic bonding and electrical interconnection through the glass/silicon interface to the 2-D micro-scanner in the package are presented. The proposed electrical feed-through method is investigated by characterizing bonding current. The bonding current characteristics show that the electric feed-through has formed electric field distribution required for double-side anodic bonding. The operation characteristics of packaged 2-D micro-scanner are also investigated, which show successfully performed electric interconnection between inside and outside of the package. The proposed method is an effective technique for double-side anodic bonding based package not only for micro-scanner but also for different mechanical oscillators such as accelerometer, gyroscope and etc.

► A method for double-side anodic bonding of SOI wafer was suggested.
► The suggested method was based on electric feed-through.
► Bonding current characteristics were investigated.
► Electric field distribution was formed for double-side anodic bonding.
► The method is an effective technique for packaging MEMS devices in vacuum.