The electrical insulation characteristics of a glass adhesive process for the silicon MEMS element of a pressure sensor

Abstract

Recently, the electrical performance requirements of the sensor elements used in electric vehicles have been strengthened. Automotive pressure sensors are manufactured by bonding metal diaphragms and MEMS sensing elements. The withstand voltage of the pressure sensor is greatly affected by the electrical characteristics of the adhesive material between the metal diaphragm and the MEMS sensing element connected to the vehicle body. In this study, the withstand voltage of the sensor element was analyzed using glass paste as the bonding material for the glass paste process. As a result, it was found that this voltage was greatly influenced by the remaining glass paste porosity remaining following the glass paste process, and also by the area and thickness of the glass paste. Therefore, it was found that the thickness and area of the glass paste should be optimized and that the internal porosity should be minimized to obtain excellent withstand voltage characteristics in the sensing device.