Piezoelectric Actuator, Liquid Discharge Head, and Manufacturing Method of Piezoelectric Actuator

A piezoelectric actuator, comprising:

• a piezoelectric element;
• a plurality of discrete electrodes, which is disposed on one side of the piezoelectric element in a thickness direction of the piezoelectric element;
• a common electrode, which is disposed on the other side of the piezoelectric element in the thickness direction and faces the plurality of discrete electrodes in the thickness direction with the piezoelectric element interposed therebetween;
• a plurality of discrete contacts, which are respectively connected to the plurality of discrete electrodes, and
• a common contact, which is connected to the common electrode,
• wherein the plurality of discrete electrodes include:
• a plurality of first discrete electrodes, which are arranged in a first direction along a surface direction of the piezoelectric element and form a first discrete electrode row;
• and
• a plurality of second discrete electrodes, which are arranged in the first direction, form a second discrete electrode row that is arranged beside the first discrete electrode row in a second direction perpendicular to the first direction and along the surface direction and which are disposed at positions away from each corresponding discrete contact among the plurality of discrete contacts in the second direction, as compared with the plurality of first discrete electrodes,
• wherein the common electrode includes:
• a first common electrode, which faces at least one of the plurality of first discrete electrodes in the thickness direction;
• and
• a second common electrode, which is separated from the first common electrode in the second direction and faces at least one of the plurality of second discrete electrodes in the thickness direction, wherein at least one of the first common electrode and the second common electrode is made to extend in the first direction, and
• wherein a connection wiring is further provided to connect e first common electrode with the second common electrode.

A manufacturing method of a piezoelectric actuator, comprising:

• forming a piezoelectric element;
• forming a plurality of discrete electrodes on one side of the piezoelectric element in a thickness direction of the piezoelectric element;
• forming a common electrode on the other side of the piezoelectric element in the thickness direction to face the plurality of discrete electrodes in the thickness direction with the piezoelectric element interposed therebetween;
• forming a plurality of discrete contacts to respectively connect the plurality of discrete electrodes;
• forming a common contact to connect the common electrode;
• and
• forming a plurality of discrete wirings to connect the plurality of discrete electrodes with the plurality of discrete contacts,
• wherein, in the forming of the plurality of discrete electrodes, the plurality of discrete electrodes is formed to include:
• a first discrete electrode;
• and
• a second discrete electrode, which is disposed at a position away from a corresponding discrete contact among the plurality of discrete contacts in a surface direction of the piezoelectric element, as compared with the first discrete electrode,
• wherein, in the forming of the common electrode, the common electrode is formed to include:
• a first common electrode, which faces the first discrete electrode in the thickness direction;
• and
• a second common electrode which is separated from the first common electrode in the surface direction and faces the second discrete electrode in the thickness direction is formed, wherein it is formed to satisfy at least one of a condition where the first common electrode faces a plurality of the first discrete electrodes in the thickness direction and a condition where the second common electrode faces a plurality of the second discrete electrodes in the thickness direction, and
• wherein, in the forming of the plurality of discrete wirings, a connection wiring which connects the first common electrode with the second common electrode is formed in the same process as the forming of the plurality of discrete wirings.

A manufacturing method of a piezoelectric actuator, comprising:

• forming a piezoelectric element;
• forming a plurality of discrete electrodes on one side of the piezoelectric element in a thickness direction of the piezoelectric element;
• forming a common electrode on the other side the piezoelectric element in the thickness direction to face the plurality of discrete electrodes in the thickness direction with the piezoelectric element interposed therebetween;
• forming a plurality of discrete contacts to respectively connect the plurality of discrete electrodes;
• forming a common contact to connect the common electrode;
• and
• forming a plurality of discrete wirings to connect the plurality of discrete electrodes with the plurality of discrete contacts,
• wherein, in the forming of the plurality of discrete electrodes, the plurality of discrete electrodes is formed to include:
• a plurality of first discrete electrodes, which are arranged in a first direction along a surface direction of the piezoelectric element and form a first discrete electrode row;
• and
• a plurality of second discrete electrodes, which are arranged in the first direction, form a second discrete electrode row that is arranged beside the first discrete electrode row in a second direction perpendicular to the first direction and along the surface direction and which are disposed at positions away from corresponding discrete contacts among the plurality of discrete contacts in the second direction, as compared with the plurality of first discrete electrodes,
• wherein, in the forming of the common electrode, the common electrode is formed to include:
• a first common electrode which faces at least one of the plurality of first discrete electrodes in the thickness direction;
• and
• a second common electrode which is separated from the first common electrode in the second direction and faces at least one of the plurality of second discrete electrodes in the thickness direction, wherein at least one of the first common electrode and the second common electrode is made to extend in the first direction, and
• wherein in the forming of the plurality of discrete wirings, a connection wiring which connects the first common electrode with the second common electrode is formed in the same process as the forming of the plurality of discrete wirings.