According to the present invention, it is possible to provide an element substrate and a print head with which a decrease in yield and an increase in cost in a manufacturing process can be suppressed. For that purpose, a VH wiring line and a GNDH wiring line are provided in parallel in the same layer.

One embodiment of the present invention is a liquid ejection apparatus having: a liquid ejection head including a heating element, a first protection layer that blocks contact between the heating element and liquid, a second protection layer that partially covers the first protection layer and functions as a first electrode, a second electrode that is electrically connected to the first electrode through the liquid, and an ejection port that ejects the liquid; and a control unit configured to perform control of setting a potential difference between the first electrode and the second electrode to a predetermined value in each of aging and printing by changing at least one of potentials of the first electrode and the second electrode, wherein ΔVa≠ΔVp is satisfied in the case where the potential difference in the aging is represented by ΔVa and the potential difference in the printing is represented by ΔVp.

A method of manufacturing a liquid discharge head substrate is provided. The method includes forming a first substrate that includes a semiconductor element and a first wiring structure; forming a second substrate that includes a liquid discharge element and a second wiring structure; and bonding the first wiring structure and the second wiring structure such that the semiconductor element and the liquid discharge element are electrically connected to each other after the forming the first substrate and the second substrate.

The present invention proposes a thermal inkjet printhead, as well as a printing assembly and printing apparatus comprising the same. The thermal inkjet printhead of the present invention comprises: a substrate; a nozzle layer, including a plurality of nozzles formed therethrough; a plurality of ink ejection chambers corresponding to the plurality of nozzles; a plurality of heater resistors formed on the substrate and corresponding to the plurality of ink ejection chambers, each of the heater resistors being located in a different one of the ink ejection chambers so that ink drop ejection through each of the nozzles is caused by heating of one of the heater resistors that is located in the corresponding ink ejection chamber; a plurality of separated cavitation islands formed on and corresponding to the plurality of heater resistors, each of the cavitation islands covering a different one of the heater resistors; and a dielectric layer interposed between the heater resistors and the cavitation islands. Using the present invention can help to enhance and substantially improve the printhead reliability, increasing in turn the yield of the manufacturing process.

An aspect of the present invention is a liquid ejection apparatus including: a liquid ejection head including a heating element, a first protection layer, a second protection layer that functions as a first electrode, a second electrode that is electrically connected to the first electrode, and an ejection port; and a control unit configured to perform control of setting a potential difference between potentials of the first and second electrodes to a predetermined value by changing at least one of the potentials of the first electrode and the second electrode, in which the control unit sets the potential difference to a first value in a case where printing is performed, and the control unit sets the potential difference to a second value different from the first value and feeds power to at least one of a plurality of the heating elements in a case where printing is not performed.

An element substrate of multi-layer structure, comprising an electrothermal transducing element formed in a first layer, a protective film covering the electrothermal transducing element, an anti-cavitation film formed on the protective film, a first electrical wire formed in the same layer as the anti-cavitation film, arranged to be separated from the electrothermal transducing element, and electrically connected to at least one end of the electrothermal transducing element, a second electrical wire on an opposite side, in relation to the electrothermal transducing element, to the protective film, and formed in a second layer, and a first connection member that extends between the first and second layers, and that electrically connects the first and second electrical wires.

An object is to provide a liquid ejection apparatus and a method of controlling a liquid ejection apparatus capable of preventing bubbles generated by kogation removal from interfering with the kogation removal. To this end, in a long liquid ejection head with a liquid circulated therethough, a pressure chamber is pressurized and a voltage is applied to a heat applying portion and an electrode to perform kogation removing cleaning.

A wafer structure is disclosed and includes a chip substrate and a plurality of inkjet chips. The chip substrate is a silicon substrate which is fabricated by a semiconductor process on a wafer of at least 12 inches. The plurality of inkjet chips include at least one first inkjet chip and at least one second inkjet chip. The plurality of inkjet chips are directly formed on the chip substrate by the semiconductor process, respectively, and diced into the at least one first inkjet chip and the at least one second inkjet chip, to be implemented for inkjet printing. Each of the first inkjet chip and the second inkjet chip includes a plurality of ink-drop generators produced by the semiconductor process and formed on the chip substrate.

In one example, a liquid ejection device. The device includes a first metal layer over a substrate, a dielectric layer over the first metal layer, and an orifice through the dielectric layer to the first metal layer. The device also includes a second metal layer over the dielectric layer and partially filling the orifice to form a via to electrical connect the two metal layers. The via has a depth-to-width ratio of at least 0.4. The device further includes a passivation stack covering the second metal layer including all interior surfaces of the via. The stack includes an ALD-deposited layer formed by atomic layer deposition.

A liquid discharge head substrate, comprising a discharging element configured to discharge a liquid, a driver configured to drive the discharging element, a conductive protection film covering the discharging element via an insulating film, and a controller connected to the protection film and configured to output a control signal that sets the driver in an inactive state when a change of a voltage of the protection film or a change in a current that flows to the protection film is detected.