Glass-Based Micro-Hotplate With Low Power Consumption and TGV Structure Through Anodic Bonding and Glass Thermal Reflow

This study presents a novel microfabrication approach using anodic bonding and glass thermal reflow to fabricate glass-based micro-hotplates with low power consumption owing to the low thermal conductivity coefficient. The glass-film-suspended micro-hotplate, integrated with through glass via (TGV) structure, is achieved by anodic bonding a glass substrate with a patterned silicon (Si) wafer, followed by thermal reflow of the glass substrate around the patterned Si wafer. TGV structures, wherein conductive Si columns are inserted into the glass substrate, have the potential to replace wire-bonders for electrical interconnection with integrated circuit (IC) boards. The fabricated glass-film-suspended micro-hotplates with similar to 20 mu m thickness demonstrate significantly lower power consumption and higher heating efficiency, compared to equivalent dimensions in Si-based counterparts. It is noted that the thermal conductivity coefficient of Pyrex glass should be corrected after thermal reflow, due to water evaporation and glass substrate recrystallization. Furthermore, our microfabrication approach for precisely patterning glass-based microstructures can be applicable to other glass-based MEMS devices for three-dimensional (3D) integrated microsystems.