A method of manufacturing a liquid ejection head includes forming a resist film on a first surface of a light-transmitting support having the first surface and a second surface being a back surface of the first surface; bonding a back side of the surface of the resist film to the support side on a substrate having a through hole so as to block the through hole; exposing the resist film with light transmitted from the second surface to the first surface of the support and forming a portion which is removable with a dissolving liquid and a portion which remains against the dissolving liquid on the resist film; immersing the substrate and the exposed resist film in the dissolving liquid, allowing the dissolving liquid to enter the through hole, and removing the removable portion; and peeling the support from the resist film from which the removable portion has been removed.

A hydrophilic coating material including an alginic acid compound and a resin, in which the alginic acid compound is granulated and dispersed in the resin. In a coating film using the material, it is preferred that the granulated alginic acid compound is exposed on the surface. Such a hydrophilic coating film is suitable as a hydrophilization treatment film of a nozzle face surface of an inkjet recording head.

An actuator device includes: an actuator including a first element contact; and a wire member including (a) a first contact connected to the first element contact and (b) a first wire configured to conduct with the first contact. A first wide portion is formed at a distal end portion of the first wire at an edge portion of the wire member. The first wide portion is disposed beyond the first element contact in a wire direction of the first wire. The first contact is disposed at a basal end portion of the first wire. The basal end portion is located further from the edge portion of the wire member than the first wide portion. The first contact is connected to the first element contact.

A microfluidic device for continuous ejection of fluids includes: a semiconductor body that laterally delimits chambers; an intermediate structure which forms membranes each delimiting a top of a corresponding chamber; and a nozzle body which overlies the intermediate structure. The device includes, for each chamber: a corresponding piezoelectric actuator; a supply channel which traverses the intermediate structure and communicates with the chamber; and a nozzle which traverses the nozzle body and communicates with the supply channel. Each actuator is configured to operate i) in a resting condition such that the pressure of a fluid within the corresponding chamber causes the fluid to pass through the supply channel and become ejected from the nozzle as a continuous stream, and ii) in an active condition, where it causes a deformation of the corresponding membrane and a consequent variation of the pressure of the fluid, causing a temporary interruption of the continuous stream.

An ink jet head includes a head substrate, a printed board, and a plurality of flexible substrates connected in parallel to each other between the head substrate and the printed board. The head substrate includes a plurality of ink jet elements, and a common wire extending from an edge of the head substrate and electrically connected to the ink jet elements in common. The printed board includes a reference potential wire through which a reference potential is set to the ink jet head. A first one of the flexible substrates at a first end of an arrangement of the flexible substrates and a second one of the flexible substrates at a second end of the arrangement of the flexible substrates opposite to the first end each has a common connection wire electrically connected between the common wire and the reference potential wire.

A liquid discharge head that can prevent occurrence of cracks generated by a connection between an electrode pad and a wiring while reducing a manufacturing cost is provided. A bonding portion and a non-bonding portion are disposed at positions where the bonding portion and the non-bonding portion overlap an electrode and a coating film but do not overlap a through hole in a planar view of a liquid discharge head substrate.

A liquid ejection head 4 includes a substrate 1 provided with an energy-generating element 5, an ejection orifice forming member 2 that is formed on the substrate 1 and includes an ejection orifice 3 from which liquid is ejected, a reinforcing rib 10 provided in the ejection orifice forming member 2, and a recess 6 that is formed in the substrate 1 and forms a part of a flow path of liquid, wherein the reinforcing rib 10 is disposed in the inside of the recess 6.

A liquid-discharge-head substrate includes a first covering portion covering a first heating resistance element and having electrical conductivity, a second covering portion covering a second heating resistance element and having electrical conductivity, a fuse, and a common wiring line for electrically connecting the first and second covering portions. The common wiring line is electrically connected with the first covering portion via the fuse. The common wiring line and the fuse each have a multilayer structure including a stack of a plurality of conductive layers including a first conductive layer and a second conductive layer that is less oxidizable than the first conductive layer.

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.

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.