JP4873132B2 - Method for manufacturing actuator device - Google Patents

Description

The present invention, a portion of the pressure generating chamber is constituted by a diaphragm, to form a piezoelectric element on a surface of the vibration plate, relates to the production how the actuator device for deforming the vibration plate by displacement of the piezoelectric element.

  An actuator device including a piezoelectric element that is displaced by applying a voltage is used, for example, as a liquid ejecting unit of a liquid ejecting head mounted on a liquid ejecting apparatus that ejects droplets. As such a liquid ejecting apparatus, for example, a part of the pressure generation chamber communicating with the nozzle opening is configured by a vibration plate, and the vibration plate is deformed by a piezoelectric element so as to pressurize the ink in the pressure generation chamber and thereby the nozzle opening There is known an ink jet recording apparatus including an ink jet recording head for discharging ink droplets.

  Two types of ink jet recording heads have been put into practical use: those equipped with an actuator device in a longitudinal vibration mode that expands and contracts in the axial direction of the piezoelectric element, and those equipped with an actuator device in a flexural vibration mode. As a device using a flexural vibration mode actuator device, for example, a uniform piezoelectric film is formed by a film forming technique over the entire surface of the diaphragm, and the piezoelectric layer is formed by a lithography method. In some cases, piezoelectric elements are formed so as to be independent for each pressure generating chamber by cutting into shapes corresponding to the above.

  Such a piezoelectric element includes a lower electrode, a piezoelectric layer, and an upper electrode, and an end surface of the lower electrode is exposed on one side surface of the piezoelectric layer (see, for example, Patent Document 1). In such a configuration, the lead-out wiring drawn out from the upper electrode to the diaphragm is short-circuited with the lower electrode. Therefore, by forming the lead-out wiring through an insulating film having an insulating property, the lead-out wiring and the lower electrode are formed. Insulates the electrode.

  However, such an insulating film is preferably formed as thin as possible so as not to hinder the deformation of the piezoelectric element. However, if the insulating film is formed thinly, the covering to the side surface of the piezoelectric element becomes worse, and the lead-out wiring And the lower electrode film may be short-circuited, and there is a problem that reliability is low. In addition, in order to reliably insulate the lower electrode film from the lead-out wiring, it is necessary to form a thick film of the insulating film, which deteriorates the displacement characteristics of the piezoelectric element and increases the manufacturing cost. There is a problem.

  In addition, the piezoelectric element used in the actuator device is formed by forming a lower electrode on a substrate via a diaphragm film, forming a piezoelectric precursor film on the lower electrode, and firing it to crystallize the piezoelectric body. After the film is formed, the piezoelectric film and the lower electrode are patterned into a predetermined shape, and then a process of further forming and firing a piezoelectric precursor film on the piezoelectric film is repeated a plurality of times from the plurality of piezoelectric films. The piezoelectric layer is formed, and the upper electrode is formed on the piezoelectric layer (see, for example, Patent Document 2).

  In such a method of manufacturing a piezoelectric element, the first piezoelectric film and the lower electrode are patterned into a predetermined shape before forming the second and subsequent piezoelectric films. For this reason, when the second and subsequent piezoelectric films are formed, a region where the lower electrode is formed and a region where the lower electrode is not formed exist on the substrate. Then, after forming the piezoelectric precursor film over the formation region and the non-formation region of the lower electrode on such a substrate, the lower electrode is baked to crystallize the piezoelectric precursor film. Due to the difference in heat absorption between the formation region of the lower electrode and the non-formation region of the lower electrode (region where the diaphragm film is exposed), firing unevenness of the piezoelectric precursor film occurs. That is, the crystal growth of the piezoelectric film in the second and subsequent layers has a difference between the formation region and the non-formation region of the lower electrode, resulting in variations in crystallinity of the obtained piezoelectric layer. There is a problem that variations occur in the piezoelectric characteristics of the piezoelectric layer. In addition, when the crystallinity of the piezoelectric layer varies, the withstand voltage of the piezoelectric layer may decrease.

  In a piezoelectric element including a piezoelectric layer having such a problem, uniform piezoelectric characteristics cannot be obtained, and in some cases, a problem such as destruction when a voltage is applied occurs. In addition, an ink jet recording head provided with such a piezoelectric element as an ink droplet ejection means has a problem that ink ejection characteristics are poor and failure occurs due to destruction of the piezoelectric element, resulting in low reliability.

  Such a problem exists not only in an actuator device mounted on a liquid ejecting head such as an ink jet recording head but also in an actuator device mounted on another device.

JP 10-211701 A (11th page, FIGS. 24 to 25) JP 2002-314163 A (paragraph [0056] to paragraph [0057])

The present invention has been made in view of such circumstances, the production of an actuator device having a piezoelectric element of the piezoelectric characteristics and reduce manufacturing cost, excellent in and uniformly with the lead wiring and the lower electrode reliably insulated from improving reliability an object of the present invention is to provide an mETHODS.

According to a first aspect of the present invention for solving the above problems, a piezoelectric element comprising a lower electrode, a piezoelectric layer and an upper electrode is disposed on one surface of a substrate via a vibration plate, and the vibration plate from the upper electrode of the piezoelectric element. One side surface on which the lead-out wiring extended to the top is formed to be an inclined surface inclined with respect to a direction orthogonal to the surface direction of the diaphragm, and the end surface of the lower electrode is exposed on the inclined surface. A step of forming an insulating film having an insulating property at least in a region where the lead wiring is formed, and the inclined surface on the entire surface of the piezoelectric element and the insulating film on the flow path forming substrate. Forming an adhesion layer having a thin portion having a thickness smaller than the thickness on the diaphragm in at least a region opposite to the lower electrode, and a lead-out wiring led out from the upper electrode on the adhesion layer Forming process and Etching the adhesion layer using the lead wiring as a mask removes a region of the adhesion layer other than between the lead wiring and the insulating layer, and removes the thin portion by side etching to remove the insulating film. And a step of forming a hollow portion between the lead wire and the lead-out wiring.
In the first aspect, since the end surface of the lower electrode and the lead-out wiring are separated by the hollow portion, even if the covering on one side surface of the piezoelectric element is deteriorated by forming a thin insulating film, It is possible to reliably insulate the electrode and the lead-out wiring to prevent a short circuit between them and improve the reliability. In addition, when patterning is performed by etching the adhesion layer, the hollow portion can be formed by side etching at the same time, so that the hollow portion can be formed without increasing the number of manufacturing steps, and the manufacturing cost can be reduced. it can.

According to a second aspect of the present invention, in the step of forming the piezoelectric element, the lower electrode, the piezoelectric layer, and the upper electrode are stacked on the substrate via the diaphragm, and the lower electrode , in the manufacturing method of the actuator device of the first aspect, characterized by comprising the step of continuously dry-etched through a mask of the piezoelectric layer and the upper electrode.
In the second aspect, one side surface of the piezoelectric element can be easily formed to be an inclined surface, the inclination angle of the inclined surface can be adjusted, and the thin portion of the adhesion layer is formed on the inclined surface. It can be formed easily.

According to a third aspect of the present invention, when the piezoelectric element including the lower electrode, the piezoelectric layer, and the upper electrode is formed over the entire surface of the one surface of the substrate via the diaphragm, and the piezoelectric element is patterned, By side-etching the lower electrode selectively by wet etching, the end of the lower electrode is formed inside the end of the piezoelectric layer, and then from the upper electrode of the piezoelectric element to the diaphragm. In the manufacturing method of the actuator device, the lead wire is formed to form a hollow portion between the lead wire and the end portion of the lower electrode.
In the third aspect, since the end portion of the lower electrode and the lead-out wiring are separated by the hollow portion, the lower electrode and the lead-out wiring can be reliably insulated to prevent a short circuit therebetween. Can be improved. In addition, by forming the piezoelectric element over the entire surface of the substrate and then patterning the piezoelectric element, when the piezoelectric layer is baked and formed, the crystallization of the piezoelectric layer due to the influence of the base becomes uneven. In addition to being able to prevent formation of a piezoelectric element having uniform piezoelectric characteristics, the manufacturing process can be simplified and the manufacturing cost can be reduced. Further, after patterning the piezoelectric element, only the lower electrode is selectively side-etched by wet etching, so that the hollow portion can be easily formed, and the manufacturing process can be simplified and the manufacturing cost can be reduced. .

According to a fourth aspect of the present invention, when the piezoelectric element is patterned, the piezoelectric layer and the upper electrode are continuously dry-etched and patterned through a mask, and then the lower electrode is passed through the mask. 4. The method of manufacturing an actuator device according to claim 3, wherein patterning is performed by wet etching, and side etching is simultaneously performed.
In the fourth aspect, by patterning the piezoelectric element, when the piezoelectric layer is baked and formed, the crystallization of the piezoelectric layer due to the influence of the base can be prevented from becoming non-uniform, A piezoelectric element having uniform piezoelectric characteristics can be formed, and the manufacturing process can be simplified to reduce the manufacturing cost. In addition, since the lower electrode can be reliably side-etched by wet etching the lower electrode through a mask, a hollow portion having a sufficient space between the lead-out wiring and the end portion of the lower electrode can be secured. .

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
FIG. 1 is an exploded perspective view showing a schematic configuration of an ink jet recording head according to Embodiment 1 of the present invention, and FIG. 2 is a plan view of FIG. 1, its AA ′ sectional view, and its main part enlarged sectional view. FIG.

  As shown in the drawing, the flow path forming substrate 10 is made of a silicon single crystal substrate in the present embodiment, and one surface thereof is made of silicon dioxide previously formed by thermal oxidation, and has an elastic film 50 having a thickness of 0.5 to 2 μm. Is formed.

  This flow path forming substrate 10 is provided with pressure generating chambers 12 partitioned by a plurality of partition walls 11 by anisotropic etching from the other side, and each pressure generating chamber 12 is disposed on the outer side in the longitudinal direction. A communication portion 13 constituting a part of the reservoir 100 serving as a common ink chamber is formed, and is communicated with one end portion in the longitudinal direction of each pressure generation chamber 12 via an ink supply path 14. The ink supply path 14 is formed with a narrower width than the pressure generation chamber 12, and maintains a constant flow path resistance of ink flowing into the pressure generation chamber 12 from the communication portion 13.

Further, a nozzle plate 20 having a nozzle opening 21 communicating with the side opposite to the ink supply path 14 of each pressure generating chamber 12 on the opening surface side of the flow path forming substrate 10 is an adhesive, a heat-welded film, or the like. It is fixed through. The nozzle plate 20 has a thickness of, for example, 0.01 to 1 mm and a linear expansion coefficient of 300 ° C. or lower, for example, 2.5 to 4.5 [× 10 ⁻⁶ / ° C.], or Made of non-rust steel. The nozzle plate 20 entirely covers one surface of the flow path forming substrate 10 on one surface, and also serves as a reinforcing plate that protects the silicon single crystal substrate from impact and external force. Further, the nozzle plate 20 may be formed of a material having substantially the same thermal expansion coefficient as that of the flow path forming substrate 10. In this case, since the deformation by heat of the flow path forming substrate 10 and the nozzle plate 20 is substantially the same, it can be easily joined using a thermosetting adhesive or the like.

On the other hand, an elastic film 50 made of silicon dioxide and having a thickness of, for example, about 1.0 μm is formed on the side opposite to the opening surface of the flow path forming substrate 10. An insulator film 55 made of zirconium oxide (ZrO ₂ ) or the like and having a thickness of, for example, about 0.4 μm is laminated. Further, on the insulator film 55, the lower electrode film 60 having a thickness of about 0.1 to 0.5 μm and lead zirconate titanate (PZT) or the like has a thickness of about 1.0 μm, for example. The piezoelectric layer 300 and an upper electrode film 80 made of gold, platinum, iridium, or the like and having a thickness of, for example, about 0.05 μm are laminated by a process described later to constitute the piezoelectric element 300.

Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80. In general, one electrode of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure generating chamber 12. In addition, here, a portion that is configured by any one of the patterned electrodes and the piezoelectric layer 70 and in which piezoelectric distortion is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. In this embodiment, the lower electrode film 60 is a common electrode of the piezoelectric element 300, and the upper electrode film 80 is an individual electrode of the piezoelectric element 300. However, there is no problem even if this is reversed for the convenience of the drive circuit and wiring. In any case, a piezoelectric active part is formed for each pressure generating chamber 12. In addition, here, the piezoelectric element 300 and a vibration plate that is displaced by driving the piezoelectric element 300 are collectively referred to as a piezoelectric actuator (an example of an “actuator device” described in the claims). In the example described above, the elastic film 50 and the insulator film 55 act as a diaphragm. However, in this embodiment, the lower electrode film 60 extends across the width direction of the plurality of piezoelectric elements 300 as shown in FIG. Since it is formed, part of the lower electrode film 60 also functions as a diaphragm. Of course, without providing the elastic film 50 and the insulator film 55, only the lower electrode film 60 may be left and the lower electrode film 60 may be used as a diaphragm.

  In such a piezoelectric element 300, lead electrodes 90 are formed as lead wirings that are drawn from the upper electrode film 80 via one side surface of the piezoelectric element 300. Examples of the lead electrode 90 include gold (Au) and aluminum (Al). In addition, a connection wiring 120 such as a bonding wire connected to a drive circuit 110 described later in detail is connected to the end of the lead electrode 90.

  In addition, one side surface from which the lead electrode 90 of the piezoelectric element 300 is drawn out is an inclined surface 301 that is inclined with respect to a direction orthogonal to the surface direction of the insulator film 55. In the present embodiment, the lead electrode 90 is drawn out from one end side in the longitudinal direction of the piezoelectric element 300 so that the longitudinal section of the piezoelectric element 300 has a trapezoidal shape. Further, the end surface of the lower electrode film 60 is exposed to the inclined surface 301 of the piezoelectric element 300 to form the inclined surface 301. That is, in this embodiment, the end surfaces of the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80 are formed so as to be flush with the side surface of the piezoelectric element 300.

  Although the piezoelectric element 300 will be described in detail later, the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80 are sequentially stacked on the flow path forming substrate 10 to form the upper electrode film 80 and the piezoelectric body. By subjecting the layer 70 to dry etching such as ion milling continuously, the inclined surface 301 can be formed and patterned at a desired inclination angle.

  The lead electrode 90 is provided via an insulating film 91 having an insulating property and an adhesive layer 92 having a conductivity for improving the adhesiveness between the insulating film 91 and the insulating film 91.

The insulating film 91 is provided at least between the lead electrode 90 and the piezoelectric element 300, so that the end surface of the lower electrode film 60 and the lead electrode 90 (adhesion layer 92) are not short-circuited by the inclined surface 301 of the piezoelectric element 300. Both are insulated. In the present embodiment, the insulating film 91 is formed only in the region where the lead electrode 90 is formed. However, if the insulating film 91 is formed so as to cover the entire piezoelectric element 300, the moisture should be retained from the outside by any chance. The piezoelectric element 300 can be protected from the moisture even if it enters the inside. The details of the process of forming the hollow portion 93 will be described later, but when the hollow portion 93 is formed by side etching by wet etching, the piezoelectric element 300 is also prevented from coming into contact with the etching solution. Examples of such an insulating film 91 include an insulating inorganic material such as aluminum oxide (AlO _X ) and tantalum oxide (TaO _X ), but an inorganic amorphous material such as aluminum oxide ( Al ₂ O ₃ ) or the like is preferably used.

  The insulating film 91 is provided with a contact hole 91 a penetrating in the thickness direction on the upper electrode film 80, and the lead electrode 90 (adhesion layer 92) is formed through the contact hole 91 a of the insulating film 91. The electrode film 80 is electrically connected.

  The adhesion layer 92 is provided between the insulating film 91 and the lead electrode 90, and is formed to ensure adhesion between the insulating film 91 and the lead electrode 90. In the present embodiment, the adhesion layer 92 is provided in a region other than the region facing the inclined surface 301 of the piezoelectric element 300 between the lead electrode 90 and the insulating film 91. That is, the adhesion layer 92 is provided with a hollow portion 93 defined by the insulating film 91 and the lead electrode 90 by removing a region facing the inclined surface 301 of the piezoelectric element 300. That is, the hollow portion 93 is formed by removing a part of the layer formed between the portion where the end surface of the lower electrode film 60 is exposed to the inclined surface 301 of the piezoelectric element 300 and the lead electrode 90.

  The adhesion layer 92 may be made of a conductive material. For example, when aluminum (Al) is used for the lead electrode 90, for example, titanium tungsten (TiW) can be used. For example, when gold (Au) is used for the lead electrode 90, titanium tungsten (TiW), nickel chrome (NiCr), or the like can be used.

  In addition, as will be described later in detail, the hollow portion 93 of the present embodiment is opposed to the inclined surface 301 when wet etching is performed using the lead electrode 90 as a mask after the adhesion layer 92 is formed on the entire surface of the flow path forming substrate 10. The adhesion layer 92 in the region to be formed can be formed by removing by side etching. The side etching of the adhesion layer 92 formed on the inclined surface 301 in this way can be performed by making the thickness of the adhesion layer 92 on the inclined surface 301 thinner than that on the insulator film 55. That is, the hollow portion 93 formed in this way is formed thinner than the thickness of the adhesion layer 92 on the insulator film 55. Further, the thickness of the adhesion layer 92 to be removed on the inclined surface 301 can be appropriately adjusted according to the inclination angle of the inclined surface 301 of the piezoelectric element 300.

  Thus, by forming the hollow portion 93 between the end face of the lower electrode film 60 and the lead electrode 90, the lower electrode film 60 and the lead electrode 90 are surely insulated, and short circuit between them is reliably prevented. be able to. In addition, the thickness of the insulating film 91 can be reduced to prevent the deformation of the piezoelectric element 300 from being disturbed, and the lower electrode film can be formed even if the covering of the inclined surface 301 is poor due to the thin insulating film 91. Since 60 and the lead electrode 90 can be reliably insulated, reliability can be improved.

  Further, on the flow path forming substrate 10 on which such a piezoelectric element 300 is formed, that is, on the lower electrode film 60, the elastic film 50, and the lead electrode 90, a reservoir unit 31 constituting at least a part of the reservoir 100 is provided. A protective substrate 30 having the same is bonded through an adhesive 34. In the present embodiment, the reservoir portion 31 is formed through the protective substrate 30 in the thickness direction and across the width direction of the pressure generation chamber 12. As described above, the communication portion 13 of the flow path forming substrate 10. The reservoir 100 is configured as a common ink chamber for the pressure generation chambers 12.

  A piezoelectric element holding portion 32 having a space that does not hinder the movement of the piezoelectric element 300 is provided in a region of the protective substrate 30 that faces the piezoelectric element 300. The protective substrate 30 only needs to have a space that does not hinder the movement of the piezoelectric element 300, and the space may be sealed or unsealed.

  As such a protective substrate 30, it is preferable to use substantially the same material as the coefficient of thermal expansion of the flow path forming substrate 10, for example, glass, ceramic material, etc. In this embodiment, the same material as the flow path forming substrate 10 is used. The silicon single crystal substrate was used.

  The protective substrate 30 is provided with a through hole 33 that penetrates the protective substrate 30 in the thickness direction. The vicinity of the end portion of the lead electrode 90 drawn from each piezoelectric element 300 is provided so as to be exposed in the through hole 33.

  A driving circuit 110 for driving the piezoelectric elements 300 arranged in parallel is fixed on the protective substrate 30. As the drive circuit 110, for example, a circuit board, a semiconductor integrated circuit (IC), or the like can be used. The drive circuit 110 and the lead electrode 90 are electrically connected via a connection wiring 120 made of a conductive wire such as a bonding wire.

  In addition, a compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the protective substrate 30. Here, the sealing film 41 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm), and the sealing film 41 seals one surface of the reservoir portion 31. It has been stopped. The fixing plate 42 is made of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 μm). Since the region of the fixing plate 42 facing the reservoir 100 is an opening 43 that is completely removed in the thickness direction, one surface of the reservoir 100 is sealed only with a flexible sealing film 41. Has been.

  An ink introduction port 44 for supplying ink to the reservoir 100 is formed on the compliance substrate 40 on the outer side of the central portion of the reservoir 100 in the longitudinal direction. Further, the protective substrate 30 is provided with an ink introduction path 35 that allows the ink introduction port 44 and the side wall of the reservoir 100 to communicate with each other.

  In such an ink jet recording head of this embodiment, ink is taken in from an ink introduction port 44 connected to an external ink supply means (not shown), and the interior is filled with ink from the reservoir 100 to the nozzle opening 21. In accordance with the recording signal from, a voltage is applied between each of the lower electrode film 60 and the upper electrode film 80 corresponding to the pressure generating chamber 12, and the elastic film 50, the lower electrode film 60, and the piezoelectric layer 70 are bent and deformed. As a result, the pressure in each pressure generating chamber 12 increases and ink droplets are ejected from the nozzle openings 21.

Hereinafter, a method for manufacturing such an ink jet recording head will be described with reference to FIGS. 3 to 5 are cross-sectional views of the pressure generating chamber 12 in the longitudinal direction. First, as shown in FIG. 3A, a flow path forming substrate 10 made of a silicon single crystal substrate is thermally oxidized in a diffusion furnace at about 1100 ° C., and a silicon dioxide film serving as an elastic film 50 and a protective film 51 is formed on the surface. 52 is formed. Next, as shown in FIG. 3B, a zirconium (Zr) layer is formed on the elastic film 50 (silicon dioxide film 52), and then thermally oxidized in, for example, a diffusion furnace at 500 to 1200 ° C. to form zirconium oxide ( An insulator film 55 made of ZrO ₂ ) is formed.

  Next, as shown in FIG. 3C, a lower electrode film 60 such as iridium or platinum, a piezoelectric layer 70 made of lead zirconate titanate (PZT), and iridium ( The upper electrode film 80 made of Ir) is sequentially stacked.

  Here, in the present embodiment, a so-called sol-gel is obtained in which a so-called sol in which a metal organic material is dissolved and dispersed in a catalyst is applied, dried, gelled, and further fired at a high temperature to obtain a piezoelectric layer 70 made of a metal oxide. The piezoelectric layer 70 is formed using the method. The method for manufacturing the piezoelectric layer 70 is not limited to the sol-gel method, and for example, a MOD (Metal-Organic Decomposition) method or the like may be used.

  Next, as shown in FIG. 3 (d), the lower electrode film 60, the piezoelectric layer 70 and the upper electrode film 80 are continuously dry-etched, so that the piezoelectric element 300 is placed in a region facing each pressure generating chamber 12. Form. Note that dry milling for forming the piezoelectric element 300 includes ion milling.

  In the present embodiment, the piezoelectric element 300 has a trapezoidal cross section in the longitudinal direction, and one end surface in the longitudinal direction is formed as an inclined surface 301 that is inclined with respect to a direction orthogonal to the surface direction of the insulator film 55. did. Although the inclination angle of the inclined surface 301 will be described later in detail, it may be determined as appropriate so that the adhesion layer 92 having a desired thickness is formed on the inclined surface 301. The inclined surface 301 of the piezoelectric element 300 is formed by inclining an ion beam irradiation angle when the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80 are continuously dry-etched, or by a mask such as a photoresist. It can be formed by inclining the end face shape of the material and then post baking using a mask material.

Next, as shown in FIG. 4A, an insulating film 91 made of, for example, aluminum oxide (Al ₂ O ₃ ) is formed over the entire surface of the flow path forming substrate 10 and then patterned into a predetermined shape. At the same time, a contact hole 91 a is formed in the insulating film 91.

  Next, as shown in FIG. 4B, an adhesion layer 92 made of, for example, titanium tungsten (TiW) is formed over the entire surface of the flow path forming substrate 10. The adhesion layer 92 can be formed by, for example, a sputtering method. At this time, in the adhesion layer 92, a thin portion 92 a that is thinner than the thickness on the insulator film 55 is formed in a region facing the inclined surface 301 of the piezoelectric element 300. Such a thin-walled portion 92a is formed thin only by forming the adhesion layer 92 by a sputtering method because one side surface of the piezoelectric element 300 is the inclined surface 301. That is, the thin portion 92 a can be formed with a desired thickness depending on the inclination angle of the inclined surface 301.

  Next, as shown in FIG. 4C, a lead electrode 90 made of aluminum (Al) is formed over the entire surface of the flow path forming substrate 10, and then patterned for each piezoelectric element 300.

  Next, as shown in FIG. 4D, the adhesion layer 92 is patterned by wet etching using the lead electrode 90 as a mask. At this time, the region other than the lead electrode 90 of the adhesion layer 92 is removed by wet etching, and the thin portion 92a on the inclined surface 301 formed thinner than the thickness on the insulator film 55 is removed by side etching. The As a result, a hollow portion 93 defined between the insulating film 91 and the lead electrode 90 is formed in a region facing the inclined surface 301 of the piezoelectric element 300.

  Note that the etching rate of the adhesion layer 92 that is removed by side etching on the inclined surface 301 is determined by the potential difference between the material of the lead electrode 90 and the material of the adhesion layer 92, and thus the material of the lead electrode 90 and the material of the adhesion layer 92. Thus, the thickness of the adhesion layer 92 on the inclined surface 301 may be appropriately determined. For example, as in this embodiment, when aluminum (Al) is used as the lead electrode 90 and titanium tungsten (TiW) is used as the adhesion layer 92, the thickness of the thin portion 92a on the inclined surface 301 is insulated. The thickness may be 1/10 or less of the thickness of the adhesion layer 92 on the body film 55. Thus, in order to set the thin portion 92a on the inclined surface 301 to a predetermined thickness, the inclination angle of the inclined surface 301 may be set to 70 degrees or more and less than 90 degrees with respect to the surface of the insulator film 55. Further, for example, when gold (Au) is used as the lead electrode 90 and titanium tungsten (TiW) or nickel chrome (NiCr) is used as the adhesion layer 92, the thickness of the thin portion 92a on the inclined surface 301 is What is necessary is just to make it 1/2 or less of the thickness of the contact | adherence layer 92 on the insulator film 55. In this case, the inclination angle of the inclined surface 301 can be set to 70 degrees or less with respect to the surface of the insulator film 55.

  Thus, in this embodiment, since the adhesion layer 92 is wet-etched using the lead electrode 90 as a mask, the thin-walled portion 92a is simultaneously removed by side etching to form the hollow portion 93. Therefore, the hollow portion 93 is formed. There is no need to provide a separate process, and the manufacturing cost can be reduced. Further, by forming the hollow portion 93, the lower electrode film 60 and the lead electrode 90 can be reliably insulated to prevent a short circuit therebetween. In addition, the thickness of the insulating film 91 can be reduced to prevent the deformation of the piezoelectric element 300 from being disturbed, and the lower electrode film can be formed even if the covering of the inclined surface 301 is poor due to the thin insulating film 91. Since 60 and the lead electrode 90 can be reliably insulated, reliability can be improved.

  Next, as shown in FIG. 5A, the protective substrate 30 that holds the plurality of patterned piezoelectric elements 300 is bonded onto the flow path forming substrate 10 with, for example, an adhesive 34. The protective substrate 30 is preliminarily formed with a reservoir portion 31, a piezoelectric element holding portion 32, and the like. Further, the protective substrate 30 is made of, for example, a silicon single crystal substrate having a thickness of about 400 μm, and the rigidity of the flow path forming substrate 10 is remarkably improved by bonding the protective substrate 30.

  Next, as shown in FIG. 5B, the protective film 51 is formed by patterning the silicon dioxide film 52 on the side opposite to the surface on which the piezoelectric element 300 of the flow path forming substrate 10 is formed into a predetermined shape. Then, the flow path forming substrate 10 is anisotropically etched (wet etching) using an alkaline solution such as KOH by using the protective film 51 as a mask, whereby the pressure generating chamber 12, the communication portion 13, and the ink supply are supplied to the flow path forming substrate 10. A path 14 and the like are formed.

  Thereafter, the nozzle plate 20 having the nozzle openings 21 formed on the surface of the flow path forming substrate 10 opposite to the protective substrate 30 is bonded, and the compliance substrate 40 is bonded to the protective substrate 30, so that FIG. An ink jet recording head as shown in FIG.

  In practice, a large number of chips are simultaneously formed on a single wafer by the above-described series of film formation and anisotropic etching, and after the process is completed, a single chip-sized flow path is formed as shown in FIG. An ink jet recording head is formed by dividing each substrate 10.

(Embodiment 2)
FIG. 6 is a cross-sectional view and an enlarged cross-sectional view of a main part of an ink jet recording head according to Embodiment 2 of the present invention. In addition, the same code | symbol is attached | subjected to the member similar to Embodiment 1 mentioned above, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 6, in the ink jet recording head of this embodiment, the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80 are disposed on the flow path forming substrate 10 via the elastic film 50 and the insulator film 55. A piezoelectric element 300 is formed. Further, the end portion of the lower electrode film 60 of the piezoelectric element 300 is formed inside the end portion of the piezoelectric layer 70. Thereby, a hollow portion 93 </ b> A is formed between the end portion of the lower electrode film 60 and the lead electrode 90.

  Here, the distance between the lower electrode film 60 and the lead electrode 90, that is, the width of the hollow portion 93 </ b> A is preferably 1 nm / V or more with respect to the voltage applied to the piezoelectric element 300. For example, when the voltage applied to the piezoelectric element 300 is 30 V, the width of the hollow portion 93A is 30 nm or more. As described above, by setting the width of the hollow portion 93 </ b> A to 1 nm / V or more with respect to the voltage applied to the piezoelectric element 300, a short circuit between the lead electrode 90 and the lower electrode film 60 can be reliably prevented.

  As will be described in detail later, the lower electrode film 60 is a refractory metal that can withstand the firing temperature at which the piezoelectric layer 70 is fired, is a material that is side-etched by wet etching, and has excellent conductivity. The material is preferable, and examples thereof include tungsten (W).

  In the present embodiment, the side surface of the piezoelectric element 300 is not inclined. However, the present invention is not particularly limited thereto, and the side surface of the piezoelectric element 300 may be inclined as in the first embodiment.

  Furthermore, in the present embodiment, the lead electrode 90 is provided so as to be electrically connected directly to one end of the upper electrode film 80 of the piezoelectric element 300. That is, in the present embodiment, the insulating film 91 and the adhesion layer 92 of Embodiment 1 described above are not provided.

  Even in an ink jet recording head having such an actuator device having the piezoelectric element 300 and the lead electrode 90, the lower electrode film 60 and the lead electrode 90 can be reliably insulated to prevent short circuit between them. Reliability can be improved.

  Here, the manufacturing method of the ink jet recording head of this embodiment will be described with reference to FIGS. 7 and 8 are cross-sectional views of the pressure generation chamber 12 in the longitudinal direction.

  First, similarly to the first embodiment described above, the elastic film 50 and the protective film 51 are formed on the flow path forming substrate 10 made of a silicon single crystal substrate, and the insulator film 55 is formed on the elastic film 50. Then, the lower electrode film 60 is formed over the entire surface of the insulator film 55 on the flow path forming substrate 10. As will be described in detail later, the lower electrode film 60 is a refractory metal that can withstand the firing temperature at which the piezoelectric layer 70 is fired, is a material that is side-etched by wet etching, and has excellent conductivity. The material is preferable, and examples thereof include tungsten (W).

  Next, a piezoelectric layer 70 made of lead zirconate titanate (PZT) is formed. Here, in the present embodiment, a so-called sol-gel is obtained in which a so-called sol in which a metal organic material is dissolved and dispersed in a catalyst is applied, dried, gelled, and further fired at a high temperature to obtain a piezoelectric layer 70 made of a metal oxide. The piezoelectric layer 70 is formed using the method. The material of the piezoelectric layer 70 is not limited to lead zirconate titanate, and other piezoelectric materials such as relaxor ferroelectrics (for example, PMN-PT, PZN-PT, PNN-PT, etc.) are used. May be. The method for manufacturing the piezoelectric layer 70 is not limited to the sol-gel method, and for example, a MOD (Metal-Organic Decomposition) method or the like may be used.

  As a specific procedure for forming the piezoelectric layer 70, first, as shown in FIG. 7A, a piezoelectric precursor film 71 that is a PZT precursor film is formed on the lower electrode film 60. That is, a sol (solution) containing a metal organic compound is applied onto the flow path forming substrate 10 on which the lower electrode film 60 is formed (application process). Next, the piezoelectric precursor film 71 is heated to a predetermined temperature and dried for a predetermined time (drying step). For example, in the present embodiment, the piezoelectric precursor film 71 can be dried by holding at 170 to 180 ° C. for 8 to 30 minutes. Moreover, 0.5-1.5 degreeC / sec is suitable for the temperature increase rate in a drying process. The “temperature increase rate” referred to here is the time from the temperature at which the temperature difference between the temperature at the start of heating (room temperature) and the attained temperature increases by 20% to the temperature at which the temperature difference reaches 80%. It is defined as the rate of change. For example, when the temperature is raised from room temperature 25 ° C. to 100 ° C. in 50 seconds, the rate of temperature rise is (100−25) × (0.8−0.2) /50=0.9 [° C./sec]. Become.

  Next, the dried piezoelectric precursor film 71 is degreased by heating it to a predetermined temperature and holding it for a predetermined time (degreasing step). For example, in this embodiment, the piezoelectric precursor film 71 is degreased by heating to a temperature of about 300 to 400 ° C. and holding for about 10 to 30 minutes. In addition, degreasing said here is desorbing the organic component contained in the piezoelectric precursor film | membrane 71 as NO2, CO2, H2O etc., for example. In the degreasing step, it is preferable that the temperature rising rate is 0.5 to 1.5 ° C./sec.

  Then, by repeating such coating, drying, and degreasing processes a predetermined number of times, for example, twice in the present embodiment, the piezoelectric precursor film 71 has a predetermined thickness as shown in FIG. 7B. Form. In this embodiment, the piezoelectric precursor film 71 having a predetermined thickness is formed by repeating the coating step, the drying step, and the degreasing step twice. Of course, the number of times of repetition is not limited to two, and the number of repetitions may be only once. It may be three times or more.

  After that, as shown in FIG. 7B, the piezoelectric precursor film 71 is crystallized by being heated to a predetermined temperature and held for a predetermined time to form a piezoelectric film 72 (firing process). In the firing step, it is preferable to heat the piezoelectric precursor film 71 to 680 to 900 ° C. In this embodiment, the piezoelectric precursor film 71 is fired by heating at 680 ° C. for 5 to 30 minutes. A film 72 was formed. Here, the heating method in the firing step is not particularly limited, but it is preferable to use a RTA (Rapid Thermal Annealing) method or the like, for example, to relatively increase the temperature rising rate. For example, in the present embodiment, the piezoelectric film is heated at a relatively high rate of temperature rise using an RTP (Rapid Thermal Processing) apparatus that is heated by irradiation with an infrared lamp. Note that the rate of temperature increase when firing the piezoelectric film is preferably 50 ° C./sec or more. Moreover, as a heating apparatus used at a drying process and a degreasing process, a hot plate, an RTP apparatus, etc. can be used, for example.

  And the predetermined thickness which consists of the piezoelectric material film 72 of multiple layers as shown in FIG.7 (c) by repeating the piezoelectric material film formation process which consists of an application | coating process, a drying process, a degreasing process, and a baking process mentioned above several times. The piezoelectric layer 70 is formed. For example, when the film thickness per sol is about 0.1 μm, the entire film thickness of the piezoelectric layer 70 composed of ten piezoelectric films 72 is about 1.1 μm, for example. Thus, when forming the piezoelectric layer 70, the lower electrode film 60 is also heated to about 680 ° C. at the same time in the firing step. Therefore, the lower electrode film 60 needs to be a refractory metal that can withstand the firing temperature at which the piezoelectric layer 70 is fired. In this embodiment, since tungsten (W) is used as the lower electrode film 60, the lower electrode film 60 can sufficiently withstand the firing process of the piezoelectric layer 70.

After the piezoelectric layer 70 is formed by the steps shown in FIGS. 7A to 7C, the upper electrode film 80 made of, for example, iridium (Ir) is formed as shown in FIG. 8A. It is formed on the entire surface of the flow path forming substrate 10, and the upper electrode film 80 and the piezoelectric layer 70 are continuously dry etched to pattern each pressure generating chamber 12. At this time, the lower electrode film 60 is not patterned at the same time. The patterning of the upper electrode film 80 and the piezoelectric layer 70 can be performed, for example, by ion milling through a mask having a predetermined shape. In the present embodiment, the side surfaces of the upper electrode film 80 and the piezoelectric layer 70 are formed to be vertical. However, the present invention is not particularly limited thereto. For example, as in the first embodiment described above, the upper electrode film 80 is formed. In addition, patterning may be performed so that the side surface of the piezoelectric layer 70 is inclined. Then, as shown in FIG. 8B, a resist 400 is formed on the patterned upper electrode film 80 and on a region corresponding to the region where the pressure generating chambers 12 on the lower electrode film 60 are arranged in parallel. Then, the lower electrode film 60 is patterned by selective wet etching to form the piezoelectric element 300 in a region facing each pressure generating chamber 12. In the patterning of the lower electrode film 60 by wet etching, the lower electrode film 60 is selectively side-etched by wet etching so that the end portion of the lower electrode film 60 is located inside the end portion of the piezoelectric layer 70. To do. An example of an etchant that can selectively wet-etch only the lower electrode film 60 is an aqueous hydrogen peroxide (H ₂ O ₂ ) solution. Further, the position of the etched end portion of the lower electrode film 60 can be appropriately changed by adjusting the etching time.

  Thus, in this embodiment, after forming the lower electrode film 60 over the entire surface of the flow path forming substrate 10, the piezoelectric layer 70 and the upper electrode film 80 are formed on the lower electrode film 60, and the upper electrode is formed. Since the film 80 and the piezoelectric layer 70 are first patterned continuously, a resist 400 covering a predetermined region is formed, and the lower electrode film 60 is patterned by wet etching, so that the piezoelectric layer 70 is formed. The lower electrode film 60 is formed over the entire surface of the flow path forming substrate 10 which is the base of the piezoelectric layer 70. The base when the piezoelectric layer 70 is formed is the same, and the piezoelectric body Uneven firing of the layer 70 is eliminated, and the piezoelectric layer 70 having uniform piezoelectric characteristics can be obtained. That is, for example, when the piezoelectric layer 70 is formed over the entire surface of the flow path forming substrate 10 after patterning the lower electrode film 60, the lower electrode forming region and the lower electrode The difference in heat absorption from the non-formation region (region where the diaphragm film is exposed), more specifically, the difference in infrared absorption becomes large, causing uneven firing of the piezoelectric precursor film 71, and the piezoelectric layer 70. Variation in the crystallinity of the film will occur. As a result, the piezoelectric characteristics of the piezoelectric layer 70 vary and the withstand voltage decreases.

  Also, patterning of the lower electrode film 60 and a hollow portion are performed by side etching by wet etching for patterning the lower electrode film 60 so that the end portion of the lower electrode film 60 is located inside the end portion of the piezoelectric layer 70. Since the space to be 93A can be formed, the manufacturing process can be simplified and the manufacturing cost can be reduced.

  Next, as shown in FIG. 8C, a lead electrode 90 made of gold (Au) is formed over the entire surface of the flow path forming substrate 10 and then patterned for each piezoelectric element 300. The lead electrode 90 can be formed by, for example, a sputtering method. By forming the lead electrode 90 by the sputtering method in this manner, the lead electrode 90 is not formed on the end portion of the lower electrode film 60, and the end portion of the lower electrode film 60 and the lead electrode 90 are not formed. A hollow portion 93A is formed therebetween.

  Thus, after forming the piezoelectric element 300, only the lower electrode film 60 is selectively side-etched by wet etching, and then the lead electrode 90 is formed, thereby forming the hollow portion 93A easily and with high accuracy. be able to. Further, by forming the hollow portion 93A in this way, it is possible to reliably prevent a short circuit between the lower electrode film 60 and the lead electrode 90.

  Thereafter, similarly to the first embodiment described above, the protective substrate 30 is bonded to the flow path forming substrate 10, and the flow path forming substrate 10 is anisotropically etched (wet etching) from the side opposite to the piezoelectric element 300. The pressure generation chamber 12, the communication portion 13, and the ink supply path 14 are formed.

(Embodiment 3)
FIG. 9 is a cross-sectional view and an enlarged cross-sectional view of a main part of an ink jet recording head according to Embodiment 3 of the present invention. In addition, the same code | symbol is attached | subjected to the member similar to Embodiment 1 and 2 mentioned above, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 9, in the ink jet recording head of this embodiment, the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80 are disposed on the flow path forming substrate 10 via the elastic film 50 and the insulator film 55. A piezoelectric element 300 is formed. Further, the end portion of the lower electrode film 60 of the piezoelectric element 300 is formed inside the end portion of the piezoelectric layer 70. Such an end portion of the lower electrode film 60 can be formed by patterning the piezoelectric element 300 and then selectively side-etching the lower electrode film 60 by wet etching, as in the first embodiment. it can.

An insulating film 91A having an insulating property is provided on the surface of the flow path forming substrate 10 on the piezoelectric element 300 side so as to cover the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80 constituting the piezoelectric element 300. It has been. Thus, by covering the piezoelectric element 300 with the insulating film 91A, it is possible to prevent the piezoelectric element 300 from being damaged due to moisture in the atmosphere. Here, as the material of the insulating film 91A, a material having moisture resistance is preferable. For example, an inorganic insulating material such as silicon oxide (SiO _x ), tantalum oxide (TaO _x ), and aluminum oxide (AlO _x ) is used. It is preferable to use aluminum oxide (AlO _x ) that is an inorganic amorphous material, for example, alumina (Al ₂ O ₃ ). When aluminum oxide is used as the material of the insulating film 91A, moisture permeation in a high humidity environment can be sufficiently prevented even if the film thickness of the insulating film 91A is relatively thin, such as about 100 nm. In the present embodiment, alumina (Al ₂ O ₃ ) is used as the insulating film 91A. In the present embodiment, the insulating film 91A that covers the piezoelectric element 300 is provided. However, the present invention is not particularly limited thereto. For example, the lead electrode 90 of the piezoelectric element 300 is provided as in the first embodiment described above. It may be formed only in the region.

  Such an insulating film 91 </ b> A is not formed on the end portion of the lower electrode film 60, but is formed so that a hollow portion 93 </ b> B is defined between the end portion of the lower electrode film 60. The insulating film 91A is not formed on the end portion of the lower electrode film 60 provided on the inner side of the end portion of the piezoelectric layer 70 by being formed on the flow path forming substrate 10 by the sputtering method. A portion 93B is formed.

  Further, a lead electrode 90 electrically connected to the upper electrode film 80 is provided on the insulating film 91A through a contact hole 91a penetrating in the thickness direction.

  Even with such a configuration, the hollow portion 93 </ b> B can reliably prevent a short circuit between the lower electrode film 60 and the lead electrode 90. That is, when the insulating film 91A is formed, the end of the lower electrode film 60 and the insulating film 91A are not covered even if the area (corner) facing the end of the lower electrode film 60 of the insulating film 91A is poorly covered. Since the hollow portion 93B exists between the lower electrode film 60 and the lead electrode 90, the reliability can be improved.

  Similarly to the first embodiment described above, even when the side surface of the piezoelectric element 300 is inclined, there is a possibility that the covering of the region facing the end portion of the lower electrode film 60 of the insulating film 91A may be deteriorated. Therefore, the lower electrode film 60 and the lead electrode 90 can be reliably insulated by forming the hollow portion 93 </ b> B with the end portion of the lower electrode film 60 inside the piezoelectric layer 70.

  Note that the ink jet recording head of the present embodiment can be formed by the same manufacturing method as that of the second embodiment described above. Thereby, the piezoelectric element 300 with a uniform piezoelectric characteristic can be formed similarly to Embodiment 2 mentioned above.

  In the present embodiment, the hollow portion 93B is provided between the end portion of the lower electrode film 60 and the insulating film 91A by making the end portion of the lower electrode film 60 inside the end portion of the piezoelectric layer 70. However, the present invention is not particularly limited to this, and for example, a hollow portion 93 similar to that of the first embodiment may be further provided.

(Other embodiments)
As mentioned above, although Embodiment 1-3 of this invention was demonstrated, the basic composition of an ink jet type recording head is not limited to what was mentioned above. For example, in Embodiment 1 described above, the region opposite to the inclined surface 301 of the piezoelectric element 300 of the adhesion layer 92 is removed to form the hollow portion 93. However, the present invention is not particularly limited thereto. A hollow portion may be formed by removing the adhesion layer 92 in a region facing the end face of the lower electrode film 60.

  Further, for example, in Embodiment 1 described above, when wet-etching the adhesion layer 92, the thin portion provided on the inclined surface 301 is removed by side etching to form the hollow portion 93. For example, before forming the adhesion layer 92, a sacrificial layer is formed in a region where the hollow portion 93 is formed, and after forming the lead electrode 90, the sacrificial layer is removed to form the hollow portion. You may make it form. That is, the removal of the adhesion layer of the present invention includes not forming the adhesion layer in advance.

  Furthermore, in Embodiment 1 described above, the insulating film 91 is formed on the inclined surface 301 of the piezoelectric element 300. However, in order to prevent a short circuit between the lead electrode 90 and the lower electrode film 60, the lower electrode film 60 of the piezoelectric element 300 is formed. If the hollow part 93 is formed in the exposed part, the insulating film 91 may not be provided. In this case, as a method for forming the hollow portion 93, the adhesion layer 92 is formed after the piezoelectric element 300 is formed, and the thin electrode portion 92a is simultaneously removed by side etching by wet etching using the lead electrode 90 as a mask. The part 93 can be formed.

  In addition, the ink jet recording heads of these embodiments constitute a part of a recording head unit having an ink flow path communicating with an ink cartridge or the like, and are mounted on the ink jet recording apparatus. FIG. 10 is a diagram showing a schematic configuration showing an example of the ink jet recording apparatus.

  As shown in FIG. 10, in the recording head units 1A and 1B having the ink jet recording head, cartridges 2A and 2B constituting ink supply means are detachably provided, and a carriage 3 on which the recording head units 1A and 1B are mounted. Is provided on a carriage shaft 5 attached to the apparatus body 4 so as to be movable in the axial direction. The recording head units 1A and 1B, for example, are configured to eject a black ink composition and a color ink composition, respectively.

  The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and timing belt 7 (not shown), so that the carriage 3 on which the recording head units 1A and 1B are mounted is moved along the carriage shaft 5. The On the other hand, the apparatus body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S, which is a recording medium such as paper fed by a paper feed roller (not shown), is conveyed on the platen 8. It is like that.

  In the first embodiment described above, an ink jet recording head has been described as an example of a liquid ejecting head. However, the present invention is widely intended for all liquid ejecting heads, and is a liquid ejecting a liquid other than ink. Of course, the present invention can also be applied to an ejection head. Other liquid ejecting heads include, for example, various recording heads used in image recording apparatuses such as printers, color material ejecting heads used in the manufacture of color filters such as liquid crystal displays, organic EL displays, and FEDs (surface emitting displays). Examples thereof include an electrode material ejection head used for electrode formation, a bioorganic matter ejection head used for biochip production, and the like.

FIG. 2 is an exploded perspective view illustrating a schematic configuration of the recording head according to the first embodiment. 2A and 2B are a plan view and a cross-sectional view of the recording head according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 6 is a cross-sectional view and a main part enlarged cross-sectional view of a recording head according to a second embodiment. 5 is a cross-sectional view illustrating a method for manufacturing a recording head according to Embodiment 2. FIG. 5 is a cross-sectional view illustrating a method for manufacturing a recording head according to Embodiment 2. FIG. FIG. 10 is a cross-sectional view and a main part enlarged cross-sectional view of a recording head according to a third embodiment. 1 is a diagram illustrating a schematic configuration of a recording apparatus according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Flow path formation board | substrate, 12 Pressure generation chamber, 13 Communication part, 14 Ink supply path, 20 Nozzle plate, 21 Nozzle opening, 30 Protection board, 31 Reservoir part, 32 Piezoelectric element holding part, 40 Compliance board, 50 Elastic film, 55 Insulator film, 60 Lower electrode film, 70 Piezoelectric layer, 80 Upper electrode film, 90 Lead electrode, 91, 91A Insulating film, 92 Adhesion layer, 93, 93A, 93B Hollow part, 100 Reservoir, 110 Drive circuit, 120 Connection wiring, 300 piezoelectric element, 301 inclined surface

Claims (4)

  A side surface on which a piezoelectric element composed of a lower electrode, a piezoelectric layer and an upper electrode is formed on one surface of a substrate via a vibration plate and a lead-out wiring that is led out from the upper electrode of the piezoelectric element to the vibration plate is formed on the side surface. Forming an inclined surface that is inclined with respect to a direction orthogonal to the surface direction of the diaphragm and exposing the end surface of the lower electrode on the inclined surface; and at least the extraction wiring is formed. A step of forming an insulating film having an insulating property in the region, and the vibration on at least a region of the inclined surface opposite to the lower electrode on the piezoelectric element and the entire surface of the insulating film on the flow path forming substrate. Forming a contact layer having a thin portion with a thickness smaller than the thickness on the plate; forming a lead-out line drawn from the upper electrode on the close-contact layer; and using the lead-out line as a mask, the contact Etching is performed to remove a region of the adhesion layer other than between the lead-out wiring and the insulating layer, and the thin portion is removed by side etching to form a hollow space between the insulating film and the lead-out wiring. And a step of forming a section. A method for manufacturing an actuator device. In the step of forming the piezoelectric element, the step of forming the lower electrode, the piezoelectric layer and the upper electrode on the substrate via the diaphragm, and the lower electrode, the piezoelectric layer and the upper electrode method of manufacturing an actuator device according to claim 1, characterized in that the and a step of continuously dry-etched through a mask.   A piezoelectric element including a lower electrode, a piezoelectric layer, and an upper electrode is formed over the entire surface of one surface of the substrate via a diaphragm, and the lower electrode is selectively etched by wet etching when patterning the piezoelectric element. By side etching, the end portion of the lower electrode is formed inside the end portion of the piezoelectric layer, and then a lead-out wiring that is drawn from the upper electrode of the piezoelectric element to the diaphragm is formed. A method for manufacturing an actuator device, comprising: forming a hollow portion between the lead-out wiring and the end portion of the lower electrode. When patterning the piezoelectric element, the piezoelectric layer and the upper electrode are continuously dry-etched and patterned through a mask, and then the lower electrode is patterned by wet-etching through a mask and at the same time side The method of manufacturing an actuator device according to claim 3 , wherein etching is performed.

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