Design and Optimization of Glass Frit Package Structure for Micro Pressure Switch

A novel packaging structure is designed and the packaging process is optimized for micro pressure sensors with glass frit bonding technology in this paper. The packaging structure with inner-outer reference walls, metal lead break, and thermal stress release break is designed. The height of the reference walls can precisely control the thickness of glass frit layer. The technological parameters of screen printing across metal lead steps are also explored in this article originally. By optimizing the presintering atmosphere, peak temperature and holding time, the covering issue of frit on the metal lead surface is solved. The micro holes in the glass frit are effectively removed by optimizing the bonding temperature. The results of experiments show that when the peak temperature of presintering is 400 °C and the presintering atmosphere is 30 minutes in vacuum and in air respectively, the coverage rate of glass frit on the metal leads reaches 85%, which meets the packaging requirements. When the bonding temperature is 500 °C, the micro holes in the interlayer of glass frit are completely removed and the bonding strength of the pressure sensor is 12.52 MPa.