Evaluation and Characterization of Titanium to Glass Anodic Bonding

In this paper, Ti-Glass anodic bonding is investigated on both chip and wafer level. In concern of coefficients of thermal expansion (CTE) match, three different types of ion-containing glasses are evaluated: Pyrex 7740, D-263T and soda lime glass. By applying a potential between the two chips and heating them beyond 350°C, soda lime glass samples are successfully bonded with titanium. The influence of the bonding temperature on the bonding strength is revealed. For the first time, wafer level Ti-Glass bond is carried out, a 157-μm-thick titanium wafer is successfully bonded to a 1000-μm-thick soda glass wafer at 450°C and applying a voltage of 800V and a force of 1000N for 30min, over 60% of the surface are joined. The results are helpful to define potential applications in certain field of microsystems.