A method of forming a through-substrate having a first surface and a second surface opposite to the first surface, the method causing the first surface to communicate with the second surface through the substrate, the method including: a first step that forms a first trench from the first surface side of the substrate using dry etching, the first trench having side surfaces on which protective film is formed; and a second step that forms a second trench from the second surface side using dry etching, the second trench communicating with the first trench having the side surfaces on which the protective film is formed.

A method for manufacturing a liquid ejection head includes the steps of: preparing a substrate including an energy-generating element disposed on a first surface of the substrate and a supply path for liquid; disposing a dry film on the first surface of the substrate in such a manner that the dry film partially enters the supply path; etching the dry film from a side of the dry film facing the first surface of the substrate so that the dry film has an etched surface substantially in parallel with the first surface and covers the supply path; forming a resin layer to be a flow path member on the dry film covering the supply path; and removing the dry film covering the supply path.

A conduction structure includes a device substrate (third substrate) including a conductive portion, an IC (second substrate) including an upper surface, an end surface inclined toward the upper surface, and a conductive portion (second conductive portion), a sealing plate (first substrate) including an upper surface, an end surface (first side wall portion) inclined toward the upper surface, and a conductive portion (first conductive portion), and plating layers that respectively form electrical connections between a conductive portion and a conductive portion and between a conductive portion and the conductive portion.

A liquid ejecting head includes a flow path substrate configuring a side face of a pressure chamber in communication with a nozzle through which a liquid is ejected, a diaphragm including a first face joined to the flow path substrate and a second face on an opposite side of the diaphragm to the first face, and a drive device provided on the second face and configured to change pressure in the pressure chamber. A corner of the side face of the pressure chamber includes a curved face having a center of curvature positioned in the pressure chamber in plan view, a recess is formed in the first face, and the pressure chamber is positioned inside the recess in plan view.

A microfluidic ejection chip includes a silicon substrate having a fluid passageway. The fluid passageway is defined by a silicon sidewall of the silicon substrate that is covered by a permanent passivation layer to protect the silicon sidewall from exposure to an acidic fluid. The permanent passivation layer is retained on the silicon sidewall at a conclusion of etching of the silicon substrate to form the fluid passageway.

An ink-jet recording head includes a plurality of recording element substrates each having an ejection pressure generating element configured to generate pressure for ejecting ink from an ink discharge port. The plurality of recording element substrates each include a first surface on which the corresponding ejection pressure generating element is disposed and a second surface, serving as an end surface intersecting with the first surface, being at least partially formed by etching.

A liquid discharge head includes a plurality of recording element substrates each having an energy generating element configured to generate energy for discharging liquid from a discharge port, and a sealing member with which a surround of each of the plurality of recording element substrates is filled. Each of the plurality of recording element substrates includes a recessed portion formed on an end surface facing a neighboring recording element substrate, and in the recessed portion, a gap between neighboring recording element substrates is wider than a gap between element surfaces on which the energy generating element is provided.

Aspects are directed to techniques for fabricating a microfluidic device on a substrate. In a particular example, a method of manufacturing a microfluidic device includes growing a thermal oxide layer on a substrate and depositing a dielectric layer, including doped a dielectric film, over the thermal oxide layer. Next, an aperture defined by a dielectric wall which forms part of the dielectric layer is formed in the dielectric layer by selectively removing the dielectric film. Finally, the aperture is sealed with a sealing film to prevent the dielectric film from being exposed to a fluid contained in the aperture. The sealing film may be of an electrically insulating material resistive to corrosive attributes of the fluid contained in the aperture.

The present disclosure includes a method of fabricating a thermal ink jet printhead including depositing a first metal layer having a thickness to form a power bus, deposing a first dielectric layer, forming a via in the first dielectric layer to connect the first metal layer to a second metal layer, depositing the second metal layer, depositing a resistive layer, forming a thermal resistor in the resistive layer, depositing a second dielectric layer, and removing a portion of the second dielectric layer.

A liquid discharge head provided with a member having discharge ports formed configured to discharge liquid thereon, wherein a discharge port surface of the member having discharge ports arrayed thereon includes fumed silica.