Through-Silicon Isolation Based on Dry Filling and Reflow of Micron Glass Powders

This paper, for the first time, introduces glass powders into through-silicon isolation, and fabricates a monolayered combs-angle-sensor-integrated biaxial gimbal with 250μm-thickness and 1cm-diameter. Micron dry glass powders are filled into through holes by a silica-gel scraper, which is followed by surface cleaning to wipe off residual powders and reflow to turn these incompact glass powders into solidified glass liners respectively. These glass liners electrically insulate combs angle sensors from the main body of gimbal while maintaining robust mechanical connections. This gimbal is applied to development of magnetically-driven and closed-loop controlled mirror with millimeter-level size. Experimental results reveal that the insulation resistance value of each glass liner reaches TΩ-level. Furthermore, the glass liner is proved to be tolerant to mechanical impact and vibration in the process of assembling magnetic actuator and mirror onto this gimbal.