A liquid election head including a silicon substrate and an element for generating energy that is utilized for electing a liquid on the silicon substrate, wherein a protective layer A containing a metal oxide is disposed on a first surface of the silicon substrate, a structure containing an organic resin and constituting part of a liquid flow passage is disposed on the protective layer A, and an intermediate layer A containing a silicon compound is disposed between the protective layer A and the structure.

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.

A piezoelectric device includes a diaphragm, a piezoelectric actuator, and an orientation layer between the diaphragm and the piezoelectric layer. The piezoelectric actuator has a first electrode, a piezoelectric layer, and a second electrode, with the first electrode, a piezoelectric layer, and a second electrode on the diaphragm. The orientation layer is a stack of two or more tiers.

At least one embodiment of a liquid discharge head includes a liquid discharge substrate, a support substrate on which a back surface of the liquid discharge substrate is joined, and a wiring substrate. A second edge of the liquid discharge substrate and at least one third edge that forms a surface of the support substrate and is in contact with the back surface of the liquid discharge substrate, intersect at an intersecting point. A sealing agent for sealing an electric connection portion between the liquid discharge substrate and the wiring substrate extends over a portion of the second edge extending toward at least one second side surface of the liquid discharge substrate from a space on a lower side of the electric connection portion, to reach at least the intersecting point.

A planarization layer and method therefor. The planarization layer has a thickness ranging from about 2 to about 3 microns, and contains from about 8.0 to about 8.5 wt. % photoacid generator; from about 2 to about 3.6 wt. % photoinitiator; from about 0.35 to about 0.5 wt. % green dye; from about 35 to about 46 wt. % multifunctional epoxy compound; from about 35 to about 50 wt. % of one or more difunctional epoxy compounds; and from about 1 to about 2.6 wt. % silane adhesion promoter, wherein all weight percent is based on a total weight of the layer devoid of solvent.

A liquid ejection head includes a first substrate having a first surface and a second surface opposite the first surface, the first surface having a structure, a second substrate having a second surface facing the first surface of the first substrate, and a third substrate having a first surface facing the second surface of the first substrate. The first, second, and third substrates are joined together by an adhesive. The second surface of the first substrate has an opening located in a region on a rear side of the structure and having corners each having a curvature radius R2. The second surface of the second substrate has an opening in a region facing the structure and having corners each having a curvature radius R1. The curvature radii R1 and R2 satisfy R1<R2.

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 pressure chamber of each of channels of an inkjet head has a non-rotating body shape around an axis perpendicular to a support substrate on which the pressure chamber is formed. The direction of the pressure chamber corresponding to a rotation angle from a reference position around the axis passing through the pressure chamber is defined as the direction of the pressure chamber. A plurality of channels arranged in a same row in a direction parallel to the substrate includes channels and having the pressure chamber facing different directions. In a same row, channels (e.g. channel 21a.sub.1) driven by a same circuit element (e.g. circuit element) are arranged such that the pressure chambers face a same direction.

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.

A liquid discharge head including a first recording element substrate, a second recording element substrate, and a third recording element substrate successively arranged in a longer direction of the liquid discharge head, the first, second, and third recording element substrates each including a discharge port configured to discharge a liquid and an energy-generating element configured to generate energy used for discharging the liquid; a first support member supporting an end part of the first recording element substrate on a side of the second recording element substrate and an end part of the second recording element substrate on a side of the first recording element substrate; and a second support member supporting an end part of the second recording element substrate on a side of the third recording element substrate and an end part of the third recording element substrate on a side of the second recording element substrate.