A method for manufacturing a bonded substrate, the method includes: bonding a first mother substrate including a first substrate and a second mother substrate including a second substrate to form a bonded mother substrate; cutting off a part of the first mother substrate along a dividing line of the bonded mother substrate to form a cutoff portion; dividing the bonded mother substrate along the dividing line; separating a bonded substrate from the bonded mother substrate, the bonded substrate including the first substrate and the second substrate bonded to the first substrate; forming a contact terminal on an end portion of the first mother substrate, the contact terminal contactable with an external terminal; forming a communication path between the first mother substrate and the second mother substrate along the dividing line.

In one example, a printhead structure includes an ejector element, a multi-layer insulator covering the ejector element, and an amorphous metal on the insulator.

A piezoelectric actuator is disclosed that may include a insulating layer, individual electrodes, a common electrode, and a piezoelectric layer. The common electrode may include divisional electrodes that are connected with one another. The individual electrodes may be disposed between the insulating layer and the piezoelectric layer while the piezoelectric layer may be disposed between the individual electrodes and the common electrode. Further, the divisional electrodes may be configured to face the individual electrodes.

A piezoelectric film includes a plurality of laminated main baking unit PZT layers. A first seed layer is present at a lower surface side of a lowermost main baking unit PZT layer. A second seed layer is interposed between two adjacent main baking unit PZT layers at an intermediate position between the lowermost main baking unit PZT layer and an uppermost main baking unit PZT layer.

An actuator includes a deformable thin-film member having an opening, an electromechanical conversion element disposed at a periphery of the opening of the deformable thin-film member, an insulating film covering the electromechanical conversion element, a protective film over a surface of the insulating film, the protective film covering the surface of the insulating film and a surface of an electrode wiring connected to the electromechanical conversion element, and an adhesion improving film disposed between the electrode wiring and the protective film.

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.

An electric current based on electric charge produced on the piezoelectric body changes by going through a first path, a second path, a third path, and a fourth path in this order. On the first path, the electric current becomes larger as the voltage becomes higher. On the second path, the electric current becomes smaller as the voltage becomes higher. On the third path, the electric current becomes larger as the voltage becomes higher. On the fourth path, the electric current becomes smaller as the voltage becomes higher.

In order to provide an inkjet head using an adhesive containing an epoxy resin as a main agent and an imidazole-based curing agent as a curing agent, capable of securing a time for joining work before curing, and having excellent long-term reliability, and a production method for the inkjet head, constituent members are bonded to each other by an adhesive containing at least an epoxy resin as a main agent, a microencapsulated imidazole-based curing agent as a curing agent, and an alcohol that dissolves the microcapsules at a low temperature, and preferably, a residue of the microcapsules dissolved by the alcohol is dispersed in the cured epoxy resin.

Provided are a liquid jetting structure and its applications. The liquid jetting structure includes: a nozzle substrate on which a nozzle for jetting a liquid is formed; and a flow passage substrate on which a liquid flow passage communicating with the nozzle is formed, in which a first layer, a second layer, and a liquid-repellent layer are provided in this order on a jetting surface of the nozzle substrate, the first layer and the second layer are provided in this order on an inner wall of the liquid flow passage, the first layer is a layer containing at least one selected from the group consisting of tantalum oxide, zirconium oxide, titanium oxide, and hafnium oxide, and the second layer is a layer containing at least one selected from the group consisting of SiO.sub.2, SiC, SiN, SiCN, and SiON.

A method for manufacturing a liquid discharge head comprising: a substrate, a protective layer covering at least a part of the substrate, and a laminate member formed on the protective layer, wherein the method comprises steps of: forming the protective layer on at least a part of the substrate; forming the laminate member on the protective layer with a part of the protective layer exposed, the protective layer comprises at least Si and C, a content of oxygen in a bulk of the protective layer is less than 20 atomic % in terms of an element composition ratio, a modified layer with a content of oxygen of 20 atomic % or more in terms of an element composition ratio is present on a surface of the protective layer, and a thickness of the modified layer between the protective layer and the laminate member is 3.40 nm or less.