Provided are a vibrating plate, a first electrode provided over the vibrating plate, a piezoelectric layer provided over the first electrode, and a second electrode provided over the piezoelectric layer are provided. The piezoelectric layer is interposed between the first electrode and the second electrode. The piezoelectric layer includes an active portion of which at least one end portion is defined by the first electrode, and a non-active portion provided on an outside of the end portion of the first electrode for defining the active portion. The vibrating plate includes a first vibration portion under the non-active portion and a second vibration portion on an outside of the first vibration portion. The second vibration portion includes a taper part having the thickness which is increased toward the first vibration portion.

There is provided a liquid jet apparatus including a channel substrate having a plurality of pressure chambers and a film covering the plurality of pressure chambers, a piezoelectric layer, a plurality of individual electrodes, a common electrode, and a trace extending from one of the plurality of individual electrodes to pass through between two adjacent individual electrodes of the plurality of individual electrodes. An opening of the piezoelectric layer is provided between the two adjacent individual electrodes, and a metallic film is formed to cover the trace in such an area of the trace as to overlap with the opening positioned between the two adjacent individual electrodes.

A liquid ejection head having a channel member which includes an ejection hole surface and a pressurization chamber surface opposite thereto. An actuator substrate overlaps the pressurization chamber surface. The channel member includes a plurality of ejection holes opening in the ejection hole surface, a plurality of pressurization chambers individually communicating with the plurality of ejection holes and arranged in plan view of the pressurization chamber surface, and a plurality of dummy pressurization chambers positioned outside of the predetermined region in plan view of the pressurization chamber surface. The actuator substrate includes a plurality of pressurization portions that individually pressurize the pressurization chambers, and a plurality of dummy pressurization portions that individually pressurize the dummy pressurization chambers. The dummy pressurization chambers communicate with each other via a plurality of communication paths. A closed space including the plurality of dummy pressurization chambers and the plurality of communication paths is hermetically closed.

An improved photoimageable dry film formulation, a fluidic ejection head containing a thick film layer derived from the improved photoimageable dry film formulation, and a method for making a fluidic ejection head. The improved photoimageable dry film formulation includes a multifunctional epoxy compound, a photoinitiator capable of generating a cation, a non-photoreactive solvent, and from about 0.5 to about 5% by weight a silane oligomer adhesion enhancer based on a total weight of the photoimageable dry film formulation before drying.

A liquid ejection head having a channel member which includes an ejection hole surface and a pressurization chamber surface opposite thereto. An actuator substrate overlaps the pressurization chamber surface. The channel member includes a plurality of ejection holes opening in the ejection hole surface, a plurality of pressurization chambers individually communicating with the plurality of ejection holes and arranged in plan view of the pressurization chamber surface, and a plurality of dummy pressurization chambers positioned outside of the predetermined region in plan view of the pressurization chamber surface. The actuator substrate includes a plurality of pressurization portions that individually pressurize the pressurization chambers, and a plurality of dummy pressurization portions that individually pressurize the dummy pressurization chambers. The dummy pressurization chambers communicate with each other via a plurality of communication paths. A closed space including the plurality of dummy pressurization chambers and the plurality of communication paths is hermetically closed.

An improved photoimageable dry film formulation, a fluidic ejection head containing a thick film layer derived from the improved photoimageable dry film formulation, and a method for making a fluidic ejection head. The improved photoimageable dry film formulation includes a multifunctional epoxy compound, a photoinitiator capable of generating a cation, a non-photoreactive solvent, and from about 0.5 to about 5% by weight a silane oligomer adhesion enhancer based on a total weight of the photoimageable dry film formulation before drying.

There is provided a liquid jet apparatus including a channel substrate having a plurality of pressure chambers and a film covering the plurality of pressure chambers, a piezoelectric layer, a plurality of individual electrodes, a common electrode, and a trace extending from one of the plurality of individual electrodes to pass through between two adjacent individual electrodes of the plurality of individual electrodes. An opening of the piezoelectric layer is provided between the two adjacent individual electrodes, and a metallic film is formed to cover the trace in such an area of the trace as to overlap with the opening positioned between the two adjacent individual electrodes.

A MEMS device includes a first substrate; a second substrate that is disposed laminated on the first substrate; and a functional element that is disposed between the first substrate and the second substrate, in which the second substrate is smaller than the first substrate, and in planar view, an end portion of the second substrate is disposed inside an end portion of the first substrate.

There is provided a liquid jet apparatus including a channel substrate having a plurality of pressure chambers and a film covering the plurality of pressure chambers, a piezoelectric layer, a plurality of individual electrodes, a common electrode, and a trace extending from one of the plurality of individual electrodes to pass through between two adjacent individual electrodes of the plurality of individual electrodes. An opening of the piezoelectric layer is provided between the two adjacent individual electrodes, and a metallic film is formed to cover the trace in such an area of the trace as to overlap with the opening positioned between the two adjacent individual electrodes.

A liquid ejecting head and a method of manufacturing the liquid ejecting head are provided. The liquid ejecting head has a pressure-chamber-forming substrate that includes a plurality of piezoelectric elements and that is connected to a first surface of a sealing plate, a driver IC that outputs signals that drive the piezoelectric elements and that is provided on a second surface of the sealing plate that is on the opposite side to the first surface, and a power supply wire that supplies electrical power to the piezoelectric elements, that is formed in the second surface of the sealing plate, and that has at least one portion thereof embedded in the sealing plate and a surface thereof exposed on the second surface side.