Techniques are provided for making a funnel-shaped nozzle in a substrate. The process can include forming a first opening having a first width in a top layer of a substrate, forming a patterned layer of photoresist on the top surface of the substrate, the patterned layer of photoresist including a second opening, the second opening having a second width larger than the first width, reflowing the patterned layer of photoresist to form curved side surfaces terminating on the top surface of the substrate, etching a second layer of the substrate through the first opening in the top layer of the substrate to form a straight-walled recess, the straight-walled recess having the first width and a side surface substantially perpendicular to the top surface of the semiconductor substrate.

A liquid injection head improving electric reliability includes: a substrate including: energy generating elements configured to apply energy for ejection to a liquid, and a substrate upper surface on which terminals respectively connected to electric wirings are provided, an ejection port forming member having: an ejection port forming surface in which the ejection ports for ejecting a liquid are formed, and a back surface on a side opposite to the ejection port forming surface, which is arranged so as to opposite to the substrate upper surface, and a sealant configured to cover connecting portions between the electric wirings and the terminals.

There is provided a flow channel member in which a flow channel of a liquid is formed by a plurality of flow channel forming members, the flow channel member including: a first flow channel forming member that includes a light absorbing member having absorbing properties with respect to laser light; a second flow channel forming member that includes a light transmitting member having transmitting properties with respect to the laser light and is welded to a first surface of the first flow channel forming member; and a third flow channel forming member that includes a light transmitting member having transmitting properties with respect to the laser light and is welded to a second surface of the first flow channel forming member. The first surface and the second surface are provided at positions where planes along the both surfaces intersect with each other.

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 liquid discharge head includes a channel forming member made of silicon, the channel forming member including a plurality of liquid channels, a natural oxide film having a film thickness of 2 nm or more on an outermost surface of the plurality of liquid channels of the channel forming member, and a surface treatment film on the natural oxide film to contact the natural oxide film. Each of a carbon content and a fluorine content in an interface between the natural oxide film and the surface treatment film is 5 atomic % or less.

A method for manufacturing a liquid ejection head includes selectively exposing a first photosensitive resin layer to light, thereby curing the portion of the first photosensitive resin layer defining a flow channel member; forming a second photosensitive resin layer on the first photosensitive resin layer; selectively exposing the second photosensitive resin layer to light, thereby curing the portion of the second photosensitive resin layer defining an ejection opening member; and removing the unexposed portions of the first and the second photosensitive resin layer at one time with a developer. Before removal with the developer, the water absorption W of the intermediate layer, the water absorption W1 of the exposed portion of the first photosensitive resin layer, and the water absorption W2 of the exposed portion of the second photosensitive resin layer satisfy the relationship WW1>W2.

A method for creating at least one recess, in particular an aperture, in a transparent or transmissive material, includes: selectively modifying the material along a beam axis by electromagnetic radiation; and creating the at least one recess by one or more etching steps, using different etching rates in a modified region and in non-modified regions. The electromagnetic radiation produces modifications having different characteristics in the material along the beam axis such that the etching process in the material is heterogeneous and the etching rates differ from one another in regions modified with different characteristics under unchanged etching conditions.

A liquid ejection head is equipped with a substrate having therethrough a supply path to be supplied with a liquid, a top plate placed opposite to the substrate, having an ejection orifice for ejecting the liquid and constituting, between the top plate and the substrate, a flow path communicated with the supply path and the ejection orifice and a columnar member extending from the top plate to the inside of the supply path through the flow path. An end surface of the columnar member positioned in the supply path is tilted relative to the top plate in a direction away from the ejection orifice.

A method of manufacturing a liquid ejecting head has a first molding step, a step of performing positioning and a second molding step. In the first molding step, a first member, a second member, and a third member are molded by injecting a resin at different locations inside of a set of a fixed mold, an intermediate movable mold, and a movable mold. In the step of performing positioning, the set is detached in a first direction and the intermediate movable mold and the movable mold are moved in a second direction. In the second molding step, a resin is injected to the inside of the set that is clamped to bond. During a period from the first molding step to completion of the second molding step, the first member, the second member, and the third member are held by insert mold pieces used for molding the members, respectively, in the first molding step.

A flow path formation substrate to which a nozzle plate is mounted includes a pressure chamber per nozzle, an individual supply path leading to the pressure chamber, an individual recovery path communicating with a flow channel near the nozzle. A conduction unit electrically coupled through a lead electrode to a pressure generator causing a pressure of the pressure chamber to vary is located at a position where the conduction unit overlaps with a flow path area of at least one individual flow path of the individual supply path or the individual recovery path in a plan view from a lamination direction in which the nozzle plate and the flow path formation substrate are laminated.