There is provided a liquid jetting apparatus, including: a first pressure chamber and a second pressure chamber arranged in a first direction; a first insulating film covering the first and second pressure chambers; a first piezoelectric element arranged to face the first pressure chamber with the first insulating film being intervened therebetween; a second piezoelectric element arranged to face the second pressure chamber with the first insulating film being intervened therebetween; a trace arranged between the first and the second piezoelectric elements adjacent to each other in the first direction; and a second insulating film covering the trace. An end, in the first direction, of a part of the second insulating film covering the trace between the first piezoelectric element and the second piezoelectric element is positioned inside an end of a partition wall partitioning the first pressure chamber and the second pressure chamber.

A method is provided for manufacturing a piezoelectric device including a piezoelectric element that is disposed above a diaphragm and that has a multilayer structure including a first electrode disposed above the diaphragm, a piezoelectric layer disposed on the first electrode, and a second electrode disposed on the piezoelectric layer. The method includes forming the multilayer structure including the first electrode, the piezoelectric layer, and the second electrode above the diaphragm, forming a voltage application electrode extending outwardly from an end of the second electrode to cover a region located above the piezoelectric layer in an inactive section having no second electrode, applying a voltage between the first electrode and the second electrode, and removing the voltage application electrode.

The head has a passage member having a nozzle and a pressurizing chamber which is communicated with the nozzle and is positioned on the side opposite to the side where the nozzle is opened, a piezoelectric actuator substrate which is superimposed on the passage member so as to cover the pressurizing chamber, and a flexible printed circuit which faces the piezoelectric actuator substrate from the opposite side to the passage member. The piezoelectric actuator substrate has a piezoelectric body which is exposed on the flexible printed circuit side. The piezoelectric body has a via hole opened toward the flexible printed circuit and has a projection portion at the edge part of the via hole which projects to the flexible printed circuit side.

A liquid discharge head includes an actuator base, a case member, and a nozzle plate. The actuator base includes a plurality of grooves space from each other in a first direction. Each of the grooves extends in a second direction. The actuator base is formed of a piezoelectric ceramic material. The case member includes a frame portion spaced from the actuator base in the second direction. The frame portion has an end surface in the third direction that is level with an end surface of the actuator base in the third direction. The frame portion is formed of a ceramic material having aluminum titanate as a main component. The nozzle plate is contacting the end surface of the frame portion and the end surface of the actuator base.

In order to provide a liquid ejection device capable of ejecting a minute liquid droplet with stability, an end surface of a first partition portion is fixed to a plate with a first adhesive layer, an end surface of a second partition portion is fixed to the plate with a second adhesive layer, and an elastic coefficient of the first adhesive layer is smaller than an elastic coefficient of the second adhesive layer.

An inkjet head manufacturing method for an inkjet head that includes a head chip including: a nozzle ejecting ink; and a flow path substrate including an ink flow path which communicates with the nozzle and through which the ink flows, the method including: composite substrate manufacturing that is manufacturing a composite substrate including a plurality of regions which forms flow path substrates by being split; first protective film forming that is forming a first protective film on a surface of the composite substrate and an inner wall surface of the ink flow path; splitting that is splitting the composite substrate into the flow path substrates; and second protective film forming that is forming a second protective film on at least an exposed face in a split face of the flow path substrate generated in the splitting, the exposed face being exposed in a surface of the head chip.

The present invention may provide an inkjet head including a pressure chamber in which an aspect ratio of a partition wall is higher, the inkjet head less likely to be broken at the time of fabrication. An inkjet head of the present invention may include a diaphragm that vibrates by actuation of a piezoelectric body, and a pressure chamber a volume of which fluctuates by vibration of the diaphragm. In the pressure chamber, a region in contact with the diaphragm is divided from an adjacent pressure chamber or flow path by a partition wall formed of metal, and the partition wall has an aspect ratio of 1.3 or higher.

A liquid discharge head includes a nozzle to discharge a liquid, an individual chamber communicating with the nozzle, a supply channel communicating with the individual chamber to supply the liquid to the individual chamber, and a discharge channel communicating with the individual chamber to discharge the liquid in the individual chamber. A fluid resistance of the supply channel is greater than a fluid resistance of the discharge channel.

A liquid discharge head configured to discharge a liquid, the liquid discharge head includes a thin film member including a first layer, a second layer bonded with the first layer, and a through hole penetrating through the first layer and the second layer. The through hole includes the first opening in the first layer and the second opening in the second layer.

There are provided a head chip, a liquid jet head, and a liquid jet recording device each capable of ensuring an electrical reliability, and enhancing the durability. The head chip according to an aspect of the present disclosure includes an actuator plate having ejection channels and non-ejection channels extending in a Z direction and arranged alternately in an X direction, and a nozzle plate which has nozzle holes respectively communicated with the ejection channels, and faces the actuator plate. The non-ejection channels are terminated at positions separated from a lower end surface of the actuator plate. The ejection channels open on a lower end surface of the actuator plate.