Piezoelectric devices and methods for manufacturing same

A tuning-fork type piezoelectric vibrating piece, comprising:

• a base having a proximal edge, a distal edge, and opposing side edges;
• a pair of vibrating arms extending in a longitudinal direction from the distal edge;
• respective excitation electrodes situated on the vibrating arms;
• a respective supporting arm extending, outboard of each vibrating arm, from each side edge of the base;
• an outer frame surrounding the base, vibrating arms, and supporting arms, wherein the supporting arms being connected to the outer frame;
• and
• extraction electrodes situated on the base, the supporting arms, and the outer frame, the excitation electrodes and extraction electrodes comprising (i) a first metal layer consisting of a metal selected from the group consisting of Cr, Ni, Ti, Al, and W, (ii) an oxide layer of an oxidized form of the metal of the first metal layer, (iii) a foundation layer consisting of a metal selected from the group consisting of Cr, Ni, Ti, Al, and W formed on the oxide layer, and (iv) a second metal layer consisting of a metal selected from the group consisting of Au and Ag formed on the foundation layer, wherein the second metal layer is removed at designated loci on the extraction electrodes.

A tuning-fork type piezoelectric vibrating piece, comprising:

• a base having a proximal edge, a distal edge, and opposing side edges;
• a pair of vibrating arms extending in a longitudinal direction from the distal edge;
• respective excitation electrodes situated on the vibrating arms;
• a respective supporting arm extending, outboard of each vibrating arm, from each side edge of the base;
• an outer frame surrounding the base, vibrating arms, and supporting arms, wherein the supporting arms being connected to the outer frame;
• and
• extraction electrodes situated on the base, the supporting arms, and the outer frame, the excitation electrodes and extraction electrodes comprising (i) a first metal layer consisting of a metal selected from the group consisting of Cr, Ni, Ti, Al, and W, (ii) an oxide layer of an oxidized form of the metal of the first metal layer, (iii) a foundation layer consisting of a metal selected from the group consisting of Cr, Ni, Ti, Al, and W formed on the oxide layer, and (iv) a second metal layer consisting of a metal selected from the group consisting of Au and Ag formed on the foundation layer, wherein the second metal layer is removed at the connecting terminals and at loci on the extraction electrodes adjacent the connecting terminals.