Wiring connecting structure for piezoelectric actuator, piezoelectric actuator, and head suspension

A wiring connecting structure for a piezoelectric actuator having a piezoelectric element, the piezoelectric element being arranged on an object having a base part and a movable part, to minutely move the movable part relative to the base part according to deformation that occurs on the piezoelectric element in response to electric power applied thereto, the wiring connecting structure comprising:

• a terminal having an electric insulating layer that faces an electrode surface of the piezoelectric element and a wiring layer that is formed on a surface of the insulating layer not facing the electrode surface and is used to supply electric power to the electrode surface;
• a through hole formed in the terminal through at least the insulating layer;
• a first liquid stopper annularly arranged around the through hole in a gap between the electrode surface and the terminal so that an inside of the first liquid stopper communicates with the through hole in a layer direction of the terminal;
• a liquid trap arranged adjacent to the first liquid stopper;
• and
• a conductive adhesive filled in the through hole, the conductive adhesive being liquid when filled into the through hole, the conductive adhesive electrically connecting the electrode surface and the wiring layer to each other, and
• wherein the first liquid stopper narrows the gap between the electrode surface and the terminal to define a narrow gap that causes a capillary phenomenon when the conductive adhesive is injected into the through hole so that the conductive adhesive diffuses and is maintained in the narrow gap, thereby stopping the conductive adhesive from spreading out of the first liquid stopper, and
• wherein the liquid trap has a trapping space to accept an excess of the conductive adhesive that may develop when the conductive adhesive is filled into the through hole.