US 2006/0214536 A1Published application

Piezoelectric actuator, liquid transporting apparatus, and method of producing piezoelectric actuator

AssigneeBrother Kogyo Kabushiki Kaisha

InventorHiroto Sugahara

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Abstract

A piezoelectric actuator includes a vibration plate covering pressure chambers and serving also as a common electrode, a piezoelectric layer arranged entirely on the upper surface of the vibration plate, an insulating layer formed entirely on upper surfaces of individual electrodes and the piezoelectric layer, and wirings formed on the upper surface of the insulating layer. A through hole is formed in the insulating layer at an area facing both one of the individual electrodes and one of the wirings, and the individual electrode and the wiring are connected by an electroconductive material filled in the through hole. With this, both the simplification of structure of electric contact and the improvement in reliability of electric connection can be realized, and a piezoelectric actuator is capable of suppressing the generation of excessive electrostatic capacitance during the application of drive voltage can be provided.

Claims22

Dependent claims

A piezoelectric actuator for a liquid transporting apparatus, which is arranged on one surface of a channel unit in which a liquid channel including a plurality of pressure chambers arranged along a plane is formed, and which selectively changes volume of the pressure chambers, the piezoelectric actuator comprising:

a vibration plate which covers the pressure chambers;
a common electrode which is formed on a surface of the vibration plate on a side opposite to the pressure chambers;
a piezoelectric layer which is arranged continuously on a surface of the common electrode on a side opposite to the pressure chambers, so that the piezoelectric layer wholly covers the pressure chambers thereover;
an insulating layer which is formed entirely on a surface of the piezoelectric layer on a side opposite to the pressure chambers;
and
wirings which are formed, on a surface of the insulating layer on a side opposite to the pressure chambers, corresponding to the pressure chambers respectively, wherein:
a first through hole is formed in the insulating layer at an area facing one of the wirings;
and
the first through hole is filled with an electroconductive material which is connected to one of the wirings.

6 more elements

A liquid transporting apparatus comprising:

a channel unit in which a liquid channel including a plurality of pressure chambers arranged along a plane is formed;
and
a piezoelectric actuator which is provided on one surface of the channel unit, and which selectively changes volume of the pressure chambers,
wherein the piezoelectric actuator includes:
a vibration plate which covers the pressure chambers;
a common electrode which is formed on a surface of the vibration plate on a side opposite to the pressure chambers;
a piezoelectric layer which is arranged continuously on a surface of the common electrode on a side opposite to the pressure chambers, so that the piezoelectric layer wholly covers the pressure chambers thereover;
an insulating layer which is formed entirely on a surface of the piezoelectric layer on a side opposite to the pressure chambers;
and
wirings which are formed, on a surface of the insulating layer on a side opposite to the pressure chambers, corresponding to the pressure chambers respectively;
wherein:
a first through hole is formed in the insulating layer at an area facing one of the wirings;
and
the first through hole is filled with an electromagnetic material which is connected to one of the wirings.

11 more elements

Dependencies are inferred from the claim text.