Provided are a liquid jetting structure and its applications. The liquid jetting structure includes: a nozzle substrate on which a nozzle for jetting a liquid is formed; and a flow passage substrate on which a liquid flow passage communicating with the nozzle is formed, in which a first layer, a second layer, and a liquid-repellent layer are provided in this order on a jetting surface of the nozzle substrate, the first layer and the second layer are provided in this order on an inner wall of the liquid flow passage, the first layer is a layer containing at least one selected from the group consisting of tantalum oxide, zirconium oxide, titanium oxide, and hafnium oxide, and the second layer is a layer containing at least one selected from the group consisting of SiO.sub.2, SiC, SiN, SiCN, and SiON.

A method for manufacturing a liquid discharge head comprising: a substrate, a protective layer covering at least a part of the substrate, and a laminate member formed on the protective layer, wherein the method comprises steps of: forming the protective layer on at least a part of the substrate; forming the laminate member on the protective layer with a part of the protective layer exposed, the protective layer comprises at least Si and C, a content of oxygen in a bulk of the protective layer is less than 20 atomic % in terms of an element composition ratio, a modified layer with a content of oxygen of 20 atomic % or more in terms of an element composition ratio is present on a surface of the protective layer, and a thickness of the modified layer between the protective layer and the laminate member is 3.40 nm or less.

A liquid ejection head comprises: a first print element substrate having an ejection port for ejecting a liquid; a support member supporting the first print element substrate; and an adhesive agent provided for adhering the first print element substrate to the support member, wherein the first print element substrate includes a supply port opposed to the support member and communicating with the ejection port, a first surface opposed to the support member and surrounding the supply port, and a second surface opposed to the support member and provided along at least a part of an outer edge of the first surface and retracted from the first surface relative to the support member, and the adhesive agent is filled in a first space between the first surface and the support member, and at least a part of a second space between the second surface and the support member.

There is provided a method of manufacturing a liquid ejection head. The liquid ejection head includes a recording device substrate, an electric wiring member configured to be connected to the recording device substrate at an electric connection portion, and a support member including a concave portion and a convex portion. The convex portion includes a first surface and a second surface. The method includes applying an adhesive to the surface of the concave portion on which the recording device substrate is to be placed and to the first surface, pressing the applied adhesive after the recording device substrate is placed on the surface of the concave portion on which the recording device substrate is to be placed, to fill, with the adhesive, a gap between the convex portion and the recording device substrate to a position higher than the first surface, and sealing the electric connection portion.

A method of manufacturing a liquid discharge head includes preparing a first substrate where a discharge port configured to discharge liquid is formed to face a first surface, a concave portion is formed on a side of a second surface opposite to the first surface, and a first liquid flow passage penetrating from the first surface to the second surface is opened inside the concave portion on the side of the second surface, preparing a second substrate including a second liquid flow passage opened on a third surface, and sticking the first substrate and the second substrate to communicate the first liquid flow passage with the second liquid flow passage by bonding a bottom face of the concave portion and the third surface with an adhesive agent.

An actuator includes a substrate, a diaphragm on the substrate, a lower electrode on the diaphragm, a piezoelectric body on the lower electrode, and an upper electrode on the piezoelectric body. A ratio of lead (Pb) and zirconium (Zr) in atomic percent (atm %) present at a grain boundary in the piezoelectric body satisfies a relation of Pb/Zr>1.7.

There is provided liquid discharging head including; channel member which includes plates stacked in a first direction and adhered to each other via adhesive, and in which individual channels each including nozzle and pressure chamber communicated with the nozzle is formed. The plates include first plate and second plate adhered to adhesion surface of the first plate via the adhesive. Hollows each construct one of the individual channels are opened in the adhesion surface. The hollows are arranged side by side in second direction orthogonal to the first direction in the adhesion surface, and three or more grooves are formed in the adhesion surface between two of the hollows adjacent to each other in the second direction, each of the three or more grooves extending in third direction which is orthogonal to the first direction and which crosses the second direction.

A substrate joined body including: a first substrate; a second substrate; an organic film that comprises silicon and carbon and joins the first substrate and the second substrate; and a protective film that comprises an inorganic element and is formed over the organic film from at least a part of the surface of the first substrate and at least a part of the surface of the second substrate, wherein the protective film comprises a region in which the ratio of carbon to silicon based on atomic percentage is from 0.0 to 5.0 in a region within 50 nm in a thickness direction from a surface of the organic film on the protective film side, when the surface is measured by X-ray photoelectron spectroscopy.

A liquid discharge head includes a flow passage member, a sealing member, and an actuator member. The flow passage member is formed with individual flow passages each including a nozzle and a pressure chamber and the flow passage member has a surface on which the pressure chamber is open. The sealing member is arranged on the surface and seals the pressure chamber. The actuator member has a piezoelectric layer, a driving electrode, and a high electric potential portion. The piezoelectric layer is adhered to a first surface of the sealing member on a side opposite to the flow passage member, via a first adhesive having an insulating property. The driving electrode is arranged on a side opposite to the sealing member with respect to the piezoelectric layer at a position overlapped with the pressure chamber in a first direction orthogonal to the surface.

an adhesive having a first amount exists on a side of the first piezoelectric element line, of a joint of the wiring substrate and the pressure chamber substrate or the vibration plate, an adhesive having a second amount that is larger than the first amount exists on a side of the second piezoelectric element line of the wiring substrate, of the joint, and a first discharging element related to the first piezoelectric element line is different from a second discharging element related to the second piezoelectric element line.