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 piezoelectric device includes an active portion of a piezoelectric layer interposed between a first electrode and a second electrode is provided independently for each of a first recessed portions, the first electrode forms an individual electrode provided independently for each of the active portions, the second electrode forms a common electrode commonly provided to a plurality of the active portions, in the piezoelectric layer, a second recessed portion which is provided outside the active portion and opens on a side opposite to a substrate is provided, and in a lamination direction of the substrate and the piezoelectric element, a vibration plate has a nitride film as an uppermost layer on the second electrode side at least in a region overlapping a bottom surface of the second recessed portion.

A liquid jet head chip capable of exerting an excellent ejection performance while having a compact configuration is provided. The liquid jet head chip is provided with an actuator plate, a common electrode, a common electrode pad for external connection, a cover plate, and a sealing plate. The actuator plate has an obverse surface, a reverse surface, and an ejection channel penetrating in a thickness direction and extending in a first direction perpendicular to the thickness direction. The common electrode is disposed on an inner surface of the ejection channel. The common electrode pad is disposed in an end part region in the first direction out of the reverse surface, and is coupled to the common electrode. The cover plate is disposed so as to be opposed to the obverse surface of the actuator plate, and has a liquid flow hole opposed to the ejection channel. The sealing plate is disposed so as to be opposed to a channel formation region other than the end part region out of the reverse surface of the actuator plate, and closes the ejection channel.

In a substrate of a liquid ejection head, there are formed a first through hole which constitutes a liquid supply path, and a second through hole in which a through-hole electrode electrically connected to a wiring layer is formed on the inner surface. The first through hole has a first hole having a first opening and a second hole having a second opening, and the second through hole has a third hole having a third opening and a fourth hole having a fourth opening. When the minimum width of the first opening is represented by D1, the minimum width of the second opening is represented by D2, the minimum width of the third opening is represented by D3, and the minimum width of the fourth opening is represented by D4, the first to fourth openings satisfy a relation of

D1>D3>D4>D2.

A method for forming a pattern in which a plating layer is selectively formed on a base material using a resin layer as a mask, includes resin layer-forming in which the resin layer is formed on the base material; and patterning in which the resin layer is selectively removed, in which in the patterning, a part of the resin layer is sublimed by heating to be removed.

A liquid discharge head including: a flow path formation part in which pressure generation chambers are arranged; and a pressure generation unit configured to apply pressure to the pressure generation chambers, wherein the pressure generation unit is formed by joining a vibration unit to the flow path formation part with a resin layer, and wherein the resin layer includes a curable resin composition including (A) an epoxy resin, (B) a polythiol compound, (C) at least one adhesiveness-imparting agent selected from the group consisting of a compound represented by General Formula (1), a titanium compound represented by General Formula (2-1), and a titanium compound represented by General Formula (2-2), and (D) a curing accelerator. ##STR00001##

A nozzle member includes a base, a metal oxide film, and a water-repellent film. The base includes a first surface having a plurality of through-holes as ejection orifices. The metal oxide film is located on the first surface. The water-repellent film is located on the metal oxide film. The metal oxide film has a greater thickness in a first area than in a second area. The first area is an area surrounding each ejection orifice. The second area is an area between adjacent first areas.

A method for manufacturing a perforated substrate includes forming a through-hole extending through a substrate from a first surface to a second surface opposite the first surface; forming a film on the first surface, a sidewall of the through-hole, and the second surface; forming a resist on the first surface; patterning the resist such that the resist closes an opening of the through-hole in the first surface; etching the film on the first surface using the resist as a mask; before the etching step, forming an inspection member on the second surface such that the inspection member closes an opening of the through-hole in the second surface; and determining whether there is a film patterning defect or a flaw that causes a film patterning defect.

According to an embodiment, an ink jet head (liquid ejecting head) includes an actuator plate and a cover plate (see FIG. 8). As illustrated in FIG. 1, channel grooves for a discharge channel (ejection channel) and a non-discharge channel (non-ejection channel) in a Z-direction are formed on a front surface of the actuator plate, so as to be alternately arranged in an X-direction, by cutting with a dicing blade or the like. The discharge channel and the non-discharge channel are formed to have a groove width W of smaller than 70 m, in order to correspond to high density of nozzles. In the embodiment, the discharge channel and the non-discharge channel are formed to have a groove width of 55 m, 50 m, or 40 m, for example.

According to an embodiment, an ink jet head includes a pair of actuator plates, a return plate, and a flow passage plate. The pair of actuator plates are disposed to face each other in a Y-direction. In the actuator plate, a plurality of channels which extend in a Z-direction are arranged at a distance in an X-direction. The return plate is disposed on an opening end side of the channels in the pair of actuator plates. A circulation passage which communicates with the channels is formed in the return plate. The flow passage plate is disposed between the pair of actuator plates. An inlet flow passage into which an ink flows and an outlet flow passage which communicates with the circulation passage are arranged in the Z-direction.