A fluid cartridge having a plastic fluid body, a bottom wall having a fluid supply opening therein. A metal insert is adhesively attached to the bottom wall. The metal insert has a fluid supply slot therein corresponding to the fluid supply opening in the bottom wall, a die bond surface adjacent to the fluid supply slot for adhesively attaching an ejection head chip thereto, and a plurality of air vents adjacent to the die bond surface. An ejection head chip is adhesively attached to the die bond surface of the metal insert.

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.

A method of manufacturing a plurality of semiconductor chips for a liquid discharge head from a substrate includes forming trenches of a linear form through etching from the second surface along intended cutting portions, forming modified portions in the substrate by irradiating a laser beam from the first surface side along the intended cutting portions, and splitting the substrate into the plurality of semiconductor chips for a liquid discharge head, by cutting the substrate with stress applied to the modified portions. The intended cutting portions include inclined portions extending in a direction inclined with respect to a crystal orientation plane of the substrate and uninclined portions extending in a direction along the crystal orientation plane of the substrate, and the trenches are formed at least along the inclined portions.

A head chip, a liquid jet head, and a liquid jet recording device each capable of increasing pressure generated while achieving power saving are provided. The head chip according to an aspect of the present disclosure includes a flow channel member, an actuator plate, and drive electrodes. The drive electrodes include a first electrode disposed on a first surface of the actuator plate so as to overlap one of a pressure chamber and a partition wall when viewed from a first direction, a second electrode which is disposed on the first surface of the actuator plate so as to be adjacent to the first electrode, and which generates a potential difference from the first electrode, and a first opposed electrode which is individually disposed on a second surface of the actuator plate at a position opposed to the first electrode, and which generates a potential difference from the first electrode.

Provided are a barium titanate-based piezoelectric ceramics having satisfactory piezoelectric performance and a satisfactory mechanical quality factor (Q.sub.m), and a piezoelectric element using the same. Specifically provided are a piezoelectric ceramics, including: crystal particles; and a grain boundary between the crystal particles, in which the crystal particles each include barium titanate having a perovskite-type structure and manganese at 0.04% by mass or more and 0.20% by mass or less in terms of a metal with respect to the barium titanate, and the grain boundary includes at least one compound selected from the group consisting of Ba.sub.4Ti.sub.12O.sub.27 and Ba.sub.6Ti.sub.17O.sub.40, and a piezoelectric element using the same.

A piezoelectric actuator array includes a substrate plate with a number of signal leads and at least one common lead, and a number of piezoelectric bodies arranged in a row on one surface of the substrate plate and formed by dividing a common piezoelectric block. The piezoelectric bodies include a number of active bodies each of which has, on a first side of the row, a signal electrode in contact with one of the signal leads and, on an opposite second side of the row, a common electrode in contact with the common lead. The substrate plate has at least one connector lead disposed on the first side of the row and electrically connected to the common lead on the second side of the row. At least one piezoelectric body has a conductive outer surface layer that establishes an electrically conductive path from the connector lead to the common lead.

In order that the interior of a cap member, in a case where the cap member abuts to a cover member, is allowed to have improved airtightness so that the cap member can sufficiently function, a sealing member is used to seal between the cover member and first and second flow path members for retaining the cover member.

A liquid discharge head comprising a silicon substrate; an insulating layer A formed on a first surface of the silicon substrate, a protective layer A that includes metal oxide and is formed on the insulating layer A, the structure that is formed on the protective layer A by direct contact with the protective layer A, includes organic resin, and forms a part of a flow path for liquid, and an element that is formed on a second surface of the silicon substrate on a side opposite to the first surface, and is configured to generate energy used for discharging the liquid.

Various embodiments provide an ejection device for a fluid. The ejection device includes a first semiconductor wafer, housing, on a first side thereof, a piezoelectric actuator and an outlet channel for the fluid alongside the piezoelectric actuator; a second semiconductor wafer having, on a first side thereof, a recess and, on a second side thereof opposite to the first side, at least one inlet channel for said fluid fluidically coupled to the recess; and a dry-film coupled to a second side, opposite to the first side, of the first wafer. The first and the second wafers are coupled together so that the piezoelectric actuator and the outlet channel are set directly facing, and completely contained in, the recess that forms a reservoir for the fluid. The dry-film has an ejection nozzle.

A head includes the passageway member which is configured by a plurality of plates stacked through the adhesive and in which the ink passageways are configured by communication of the through holes individually formed in the plurality of plates to each other. The plurality of plates includes the resin plate and a plurality of metal plates. The resin plate does not have a relief groove for the adhesive. The plurality of metal plates include the eighth metal plate and/or ninth metal plate which is adhered to the resin plate and includes the relief groove for the adhesive on the resin plate side.