Patent ID: 8737021

Claim:
A terminal structure having a metal layer, an insulating layer formed on the metal layer, and a wiring layer formed on the insulating layer, the metal layer facing an electrode of a piezoelectric element, the wiring layer being electrically connected through a conductive bonding part to the electrode of the piezoelectric element, the terminal structure comprising: an insulating layer hole being formed through the insulating layer in a layered direction of the terminal structure and having, when viewed in cross-section, a first opening portion proximal to the metal layer and a second opening portion proximal to the wiring layer, the first opening portion being in contact with a portion of the metal layer adjacent the first opening portion so that said first opening portion is terminated by said contact; a back face of the metal layer facing the first opening portion and having the insulating layer formed on said back face: a conducting part extending from the wiring layer and through the insulating layer hole to the back face of the metal layer so as to be connected at the back face of the metal layer, and electrically connecting the wiring layer and metal layer to each other; and a terminal face defined on a surface of the metal layer opposite the back face, and bonded through the conductive bonding part to the electrode of the piezoelectric element.