Method of manufacturing actuator and ink jet head

#1. Field of the Invention

#The present invention relates to a manufacturing method of an actuator and an ink jet head comprising the steps of bonding a piezoelectric film formed on a single crystal substrate to a diaphragm structure member and removing the single crystal substrate therefrom to manufacture the actuator and ink jet head. Particularly, the present invention relates to a manufacturing method useful for forming the actuator and ink jet head with a large area. Also, the manufacturing method can produce actuators and ink jet heads with large areas.

#For example, the method can be suitably employed for manufacturing a piezoelectric/electrostrictive film type element, such as an ink jet print head, microphone, an articulator (loud speaker, etc.), various oscillators and radiators, as well as a piezoelectric/electrostrictive film type element which generates bending displacement of unimorph or bimorph type used for sensors, etc. Besides, so-called “element” herein means an element for transducing electric energy into mechanical energy, that is to say, mechanical displacement, stress, or oscillation, as well as an element for transducing reversely.

#FIGS. 1A, 1B, 1C and 1D are schematic diagrams showing a manufacturing process of the present invention.

#FIGS. 2A, 2B and 2C are schematic diagrams showing a formation process of a substrate of the present invention.

#FIGS. 3A, 3B and 3C are schematic diagrams showing a formation process of an ink jet head of the present invention.

#A manufacturing method of the present invention comprises the step of bonding a piezoelectric film formed on a single crystal substrate consisting of a plurality of bonded layers to a diaphragm structure body and the step of removing the single crystal substrate therefrom. The manufacturing method of the present invention comprises a step of forming the piezoelectric film on the single crystal substrate, a step of bonding the piezoelectric film to the diaphragm structure member, and a step of removing the substrate therefrom.

#FIGS. 1A to 1D are schematic diagrams showing a manufacturing process of the present invention. FIG. 1A shows a state where a piezoelectric film 2 is formed on a substrate 1. FIG. 1B shows a state where a piezoelectric film is patterned after requirements for a device. The step is not essential, but a preferable embodiment for making an ink jet head device. FIG. 1C shows a state where the patterned piezoelectric film is bonded to a diaphragm structure member 3. The reference numeral 4 refers to a bond layer made mainly of metallic material. FIG. 1D shows a state where the substrate is removed after bonding.

#The substrate 1 for use in the present invention is a single crystal substrate such as, for example, an MgO substrate, an STO(SrTiO3) substrate, a BaTiO3 substrate, or a ZrO2 substrate which may be doped with Y or a rare earth element. Examples of the rare earth element include Pr, Nd, Eu, Tb, Dy, Ho, Yb, Sm, Gd, Er and La. A preferable crystal face is (100), (111) or (101). A preferable substrate is the MgO substrate, the STO substrate, the BaTiO3 substrate, or the doped ZrO2 substrate. Further, the substrate for use in the present invention is such that plural substrates are bonded together. Therefore, in a rocking curve measured by XRD measurement, one or more peaks a few degrees apart from the main peak will be observed.