Patent ID: 7656070

Claim:
A surface wave sensor apparatus, comprising: a base substrate having first and second principal surfaces opposing each other; a first through-hole conductor arranged to penetrate the second principal surface of the base substrate from the first principal surface; a terminal electrode arranged on the second principal surface of the base substrate so as to be electrically connected to the first through-hole conductor; a thermo-compression anisotropic conductive sheet arranged on the first principal surface of the base substrate so as to be electrically connected to an end of the through-hole conductor; and a surface acoustic wave device bonded on the base substrate with the thermo-compression anisotropic conductive sheet; wherein the surface acoustic wave device includes a piezoelectric substrate having first and second principal surfaces opposing each other, at least one IDT disposed on the first principal surface of the piezoelectric substrate, an insulating protection film arranged to cover the IDT, and a second through-hole conductor electrically connected to the IDT and arranged to extend to the second principal surface of the piezoelectric substrate from the first principal surface; the first and second through-hole conductors overlap with each other via the thermo-compression anisotropic conductive sheet so that the second through-hole conductor is electrically connected to the first through-hole conductor of the base substrate with the thermo-compression anisotropic conductive sheet; the thermo-compression anisotropic conductive sheet includes conductive particles dispersed in a resin composition, the resin composition being made of a material that is softened when heated and has a bonding force when cooled; the dispersed conductive particles cohere to each other in a thickness direction of the thermo-compression anisotropic conductive sheet to provide a conductive track extending in the thickness direction of the thermo-compression anisotropic conductive sheet and arranged to provide an electrical connection between the first and second through-hole conductors; a detection film is disposed on the insulating protection film; and a mass of the detection film is increased by a reaction of the detection film with a specific substance so that the detection film applies a load corresponding to the increased mass to the piezoelectric substrate.