Patent ID: 8541929

Claim:
A piezoelectric device, comprising: a piezoelectric vibrating piece; a package containing the piezoelectric vibrating piece, the package comprising (a) a package base comprised of glass, having first and second opposing surfaces, a cavity defined on the first surface, and at least one through-hole on the second surface, (b) at least one mounting electrode, formed having a hemispherical shape, wherein an electrically conductive adhesive is applied on the surface of the at least one mounting electrode to achieve bonding thereto of a respective connecting electrode of the piezoelectric vibrating piece, (c) a respective sealing electrode, formed having a conical shape, that electrically connects to the at least one mounting electrode and seals the through-hole, (d) at least one external electrode situated on the second surface and electrically connected to the respective sealing electrode, and (e) a package lid comprising glass or silicon, bonded to the package base, wherein the at least one mounting electrode, the at least one sealing electrode, and the at least one external electrode are integral with each other by a conductive glass paste having resistance to a temperature higher than a temperature at which the package lid is bonded to the package base, the conductive glass paste and package base having substantially equal respective coefficients of thermal expansion.