Electrode structure of piezoelectric element for head suspension
An electrode structure of a piezoelectric element is provided. The piezoelectric element 23 a ( 23 b ) constitutes a piezoelectric actuator 19 attached to an attaching part 30 of an object, to minutely move a movable part 15 of the object relative to a base part 13 of the object according to deformation occurring on the piezoelectric element in response to a power applied state of the piezoelectric element. The electrode structure includes an electrode 41 a formed on one of a pair of electrode forming faces 31 a and 31 b of the piezoelectric element on an inner side of a peripheral zone 31 a 1 , the peripheral zone being defined along the periphery of the electrode forming face 31 a on which the electrode is formed. The electrode structure also includes a non-electrode part 51 formed in the peripheral zone. Even if the peripheral zone 31 a 1 of the electrode forming face 31 a having a short-circuit causing possibility touches the attaching part 30 , no short circuit occurs.
1. A head suspension comprising:
a base plate;
a load beam;
a hinge member through which the load beam is longitudinally attached to the base plate along a longitudinal direction of the base plate;
a flexure attached to the load beam to support a magnetic head;
an opening formed through the base plate between a base part and a front part of the base plate in the longitudinal direction of the load beam,
the hinge member longitudinally protruding into the opening and forming front and rear supports at respective front and rear ends of the opening that extend throughout a bottom portion of the opening;
a piezoelectric element disposed in the opening and having front and rear portions thereof respectively attached to the front and rear supports at the respective front and rear ends of the opening by a nonconductive adhesive so that the piezoelectric element minutely moves the magnetic head relative to and in a widthwise direction of the head suspension according to deformation occurring on the piezoelectric element in response to power being applied to the piezoelectric element,
the piezoelectric element comprising upper and lower electrodes for applying the power at respective upper and lower surfaces of the piezoelectric element,
the lower electrode of the piezoelectric element comprising a peripheral edge disposed inwardly and away from a peripheral edge of the piezoelectric element so as to define a non-electrode portion along the peripheral edge of the lower surface of the piezoelectric element,
the lower electrode being connected to a terminal of the flexure, and
the peripheral edge of the lower electrode and the non-electrode portion being fixed to the front and rear supports through the nonconductive adhesive at the front and rear portions of the piezoelectric element.