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 substrate with an electrical connection section or a substrate for liquid ejection head comprises a wiring layer, a diffusion prevention layer laid on the wiring layer and a connection member laid on the diffusion prevention layer for establishing an electrical connection to an outside. An insulation layer having a wiring-layer-exposing opening is arranged on the wiring layer and the diffusion prevention layer is arranged in the opening, while the connection member is arranged on the diffusion prevention layer so as to cover an outer peripheral edge of the diffusion prevention layer.

A wiring substrate includes a first substrate having a first surface and a second surface at an opposite side to the first surface, a first interconnection disposed on the first surface, a second interconnection disposed on the second surface, and a through interconnection electrically coupling the first interconnection and the second interconnection to each other, and penetrating the first substrate, wherein the through interconnection includes a first through interconnection coupled to the first interconnection, and a second through interconnection coupled to the second interconnection, and the first through interconnection and the second through interconnection partially overlap each other in a plan view from a thickness direction of the first substrate.

Provided herein are a jet hole plate, a liquid jet head, a liquid jet recording apparatus, and a method for manufacturing a jet hole plate that can achieve a long life. A jet hole plate according to an embodiment of the present disclosure is a jet hole plate for use in a liquid jet head. The jet hole plate includes a metal substrate having provided therein a plurality of jet holes. The metal substrate has a principal surface having outlets for the jet holes. The principal surface has a surface roughness (arithmetic mean roughness Ra) that is smaller in outlet edge regions of the jet holes than in surrounding regions around the outlet edge regions.

An actuator device includes: an actuator including a first contact; and a wire member including a second contact connected to the first contact with a conductive adhesive including a conductive particle. One of the first contact and the second contact is a particular contact. The other of the first contact and the second contact is a specific contact. At least two protrusions and at least one recess are formed on and in the particular contact. The at least two protrusions are arranged in a first direction. The at least one recess is interposed between the at least two protrusions. The particular contact is joined to the specific contact with the conductive adhesive provided in the at least one recess, in a state in which each of the at least two protrusions is in contact with the specific contact.

A liquid discharge head includes an actuator base, a case member, and a nozzle plate. The actuator base includes a plurality of grooves space from each other in a first direction. Each of the grooves extends in a second direction. The actuator base is formed of a piezoelectric ceramic material. The case member includes a frame portion spaced from the actuator base in the second direction. The frame portion has an end surface in the third direction that is level with an end surface of the actuator base in the third direction. The frame portion is formed of a ceramic material having aluminum titanate as a main component. The nozzle plate is contacting the end surface of the frame portion and the end surface of the actuator base.

Provided are a liquid jet head with which the size-reduction can be achieved, while the resistance of wiring formed on a wiring plate such as a sealing plate is lowered, and a method for manufacturing the liquid jet head. The liquid jet head includes: a sealing plate having a first surface to which a pressure chamber-forming plate including multiple piezoelectric elements is joined and a second surface which is on a side opposite from the first surface and to which a drive IC that outputs signals for driving the piezoelectric elements is joined, wherein a lower surface-side embedded wire connected to a common wire common to the driving elements are formed on the first surface of the sealing plate, and the lower surface-side embedded wire is at least partially embedded in the sealing plate.

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 bonded substrate includes a first substrate, a second substrate bonded to the first substrate with adhesive applied to the second substrate, and a checking structure disposed on the first substrate and facing the second substrate. The checking structure includes a bonding surface portion to be adhered to the second substrate with the adhesive and an insufficiency detection surface to detect insufficient adhesion, a height of the insufficiency detection surface being lower than a height of the bonding surface portion. The adhesive does not contact the insufficiency detection surface when an adhesion state of the bonding surface portion to the second substrate with the adhesive is insufficient, and the adhesive contacts the insufficiency detection surface when the adhesion state of the bonding surface portion to the second substrate with the adhesive is sufficient.

An actuator device includes: an actuator including a first contact; and a wire member including a second contact connected to the first contact with a conductive adhesive including a conductive particle. One of the first contact and the second contact is a particular contact. The other of the first contact and the second contact is a specific contact. At least two protrusions and at least one recess are formed on and in the particular contact. The at least two protrusions are arranged in a first direction. The at least one recess is interposed between the at least two protrusions. The particular contact is joined to the specific contact with the conductive adhesive provided in the at least one recess, in a state in which each of the at least two protrusions is in contact with the specific contact.