Patent ID: 7651879

Claim:
A method of simultaneously producing a plurality of SAW sensors, the method comprising the steps of: providing a SAW wafer, the SAW wafer including a plurality of SAW transducers disposed thereon; providing a cover wafer; providing a protective wall proximate a periphery of the cover wafer and inbetween the SAW wafer and the cover wafer; securing the cover wafer relative to the SAW wafer such that the protective wall, the SAW wafer, and cover wafer collectively define a chamber that surrounds the plurality of SAW transducers; after securing the cover wafer to the SAW wafer, forming a patterned metal layer on the SAW wafer and a protective metal layer on the cover wafer; etching one or more of the SAW wafer and cover wafer with an etchant; wherein the protective wall helps prevent the etchant from entering the chamber.