There is provided a liquid discharge head including: a piezoelectric body, a common electrode, a bypass trace, and a plurality of individual electrodes. The piezoelectric body is provided with: a first through hole extending in a stacking direction between a conductive layer constructing the piezoelectric body and a first extending portion of the common electrode, and a second through hole extending in the stacking direction between the conductive layer and the first extending portion. The conductive layer and the first extending portion are electrically connected to each other by a conductive material arranged in the first and second through holes.

An ink jet head includes a nozzle plate substrate having a nozzle for ejecting ink toward a recording medium and an oil repellent film on a surface of the nozzle plate, the surface facing the recording medium. The oil repellent film comprises a terminal perfluoroalkyl group including a CF2 group, a CF3 group, and a CF3+ group.

A method for manufacturing a liquid ejection head includes forming a water-repellent layer containing a condensate of a first hydrolyzable silane compound and a second hydrolyzable silane compound, and irradiating the water-repellent layer with light including a light ray having a wavelength of less than 270 nm, wherein the first hydrolyzable silane compound contains a fluorine-containing group but no carbonyl group between the fluorine-containing group and a silicon atom, and the second hydrolyzable silane compound contains a fluorine-containing group and a carbonyl group between the fluorine-containing group and a silicon atom.

A fluid ejection die includes a substrate including an array of nozzles.

A liquid ejecting head includes a driving substrate including a driving element configured to, in response to a signal from an external controller, expand or contract so that a liquid is discharged from a pressure chamber through a nozzle, and a connection portion connecting the driving element to a wiring substrate connectable to the external controller; a sealing member that covers the connection portion and a part of the wiring substrate; and a mask plate partially covering a part of the driving substrate including the connection portion and contacting the sealing member.

A method of manufacturing an inkjet head substrate is provided. The inkjet head substrate includes an ink supply port having a through portion and a non-through portion, and the non-through portion is disposed at a position closer than the through portion to the energy generating element. The method includes disposing a mask having an opening that has a relatively large opening-width portion and a relatively small opening-width portion. The method also includes forming the through portion in the substrate at a position corresponding to the relatively large opening-width portion and the non-through portion in the substrate at a position corresponding to the relatively small opening-width portion by performing reactive ion etching on the substrate through the opening of the mask in one operation.

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.

Provided is a liquid ejection head substrate including: a substrate; a liquid ejection element that generates liquid ejection energy on the substrate; and an electrode pad that is electrically connected to the liquid ejection element, in which the electrode pad includes a barrier metal layer and a bonding layer on the barrier metal layer, and an end side surface of the barrier metal layer is covered with a silicon-based film containing carbon.

A head chip capable of suppressing the degradation of the reliability, and a liquid jet head and a liquid jet recording device using the head chip are provided. The head chip includes an actuator plate having a plurality of ejection channels respectively communicated with nozzle holes and electrodes disposed on inner walls of the respective ejection channels, a bonded plate to be bonded to the actuator plate, and having a liquid contact surface which liquid entered the ejection channels has contact with, an adhesive layer disposed between the bonded plate and the actuator plate, and adapted to bond the bonded plate and the actuator plate to each other, and a protective film adapted to cover continuously from inner walls of the respective ejection channels to at least a part of the liquid contact surface via an end surface of the adhesive layer exposed on the ejection channel side.

A liquid ejection apparatus is disclosed. One apparatus includes a piezoelectric element. The piezoelectric element includes an upper electrode and a lower electrode. The lower electrode has a partial overlapping portion and a non-overlapping portion. The partial overlapping portion at least partially overlaps the pressure chamber. The partial overlapping portion of the lower electrode has two ends in the transverse direction. The upper electrode has two ends in the transverse direction. A distance from the center of the pressure chamber in the transverse direction to one of the two ends of the upper electrode in the transverse direction is smaller than a distance from the center of the pressure chamber in the transverse direction to a corresponding one of the two ends of the partial overlapping portion in the transverse direction.