US Patent 7528000 Method of fabricating optical device caps

A wafer having a plurality of through holes is provided, and a glass wafer is disposed on the wafer. A plate having a plurality of concave cavities is disposed on the glass wafer, wherein the concave cavities corresponding to the through holes of the wafer so that a part of the plate corresponding to the through holes is not in contact with the glass wafer. A voltage source is provided, and two electrodes thereof respectively have electrical connections to the wafer and the plate. The wafer and the glass wafer are bonded to each other by the anodic bonding method so that a plurality of optical device caps are formed.