JP5031428B2 - Method for manufacturing piezoelectric actuator - Google Patents

Description

The present invention relates to the production how the piezoelectric actuator having an addressing structure using a lower electrode on the substrate side as an individual electrode.

  2. Description of the Related Art Conventionally, a liquid discharge head mainly composed of a nozzle that discharges liquid, a pressure chamber that communicates with the nozzle, and a piezoelectric actuator that changes the volume of the pressure chamber is known. In general, a piezoelectric actuator is used in which a diaphragm constituting one wall surface of a pressure chamber is used as a substrate, and a lower electrode, a piezoelectric film, and an upper electrode are stacked on the substrate in this order.

  As an addressing structure for driving the piezoelectric actuator, a structure using the lower electrode on the substrate side as a common electrode and the upper electrode as an individual electrode (upper addressing structure) is generally used.

  On the other hand, a structure using a lower electrode on the substrate side as an individual electrode and an upper electrode as a common electrode (lower addressing structure) is also known (see, for example, Patent Document 1).

  Examples of the method for forming the piezoelectric film include an aerosol deposition method, a sputtering method, a CVD (Chemical Vapor Deposition) method, a sol-gel method, and the like (for example, see Patent Document 2).

As the substrate constituting the diaphragm, for example, a Si (silicon) substrate is used. In this case, a substrate whose surface is covered with a silicon dioxide (SiO ₂ ) film, silicon nitride (Si ₃ N ₄ ), silicon oxynitride (SiON), zirconium oxide (ZrO ₂ ), or the like is used (for example, (See Patent Document 3).
JP 2006-6096 A JP 2006-19718 A Japanese Patent Laid-Open No. 11-309858

  The piezoelectric film formed on the diaphragm by sputtering has a polarization state with high orientation, but has a polarization direction opposite to the polarization direction in a liquid discharge head having a normal upper addressing structure. Specifically, in the case of a piezoelectric film made of PZT (lead zirconate titanate) or modified PZT (PZT doped with other materials) formed under a temperature condition near 500 ° C., the film formation surface on the diaphragm The film is formed in a state of being polarized vertically upward (upward in the film thickness direction). As a method of using the piezoelectric film in such a polarization direction, minus driving is conceivable. However, minus driving generally has a problem that the driving system becomes complicated and the cost is increased. Although a method of reversing the polarization direction is also conceivable, there is a problem that the displacement obtained with the same voltage is reduced by 20 to 30%.

  Therefore, in order to maintain a low cost while maintaining a highly oriented polarization state obtained by sputtering, a lower addressing structure is unavoidable. That is, it is necessary to have a structure in which the lower electrode on the diaphragm side as a substrate is addressed as an individual electrode and the upper electrode is used as a common electrode.

  However, as shown in FIG. 26, in the piezoelectric actuator 900 having the lower addressing structure, not only the diaphragm 902 needs to be insulated so that the individual electrodes do not conduct through the diaphragm 902, but also the diaphragm 902. A step 910 is formed at the boundary between where the lower electrode 904 serving as the upper individual electrode is present and where the lower electrode 904 is absent, and the piezoelectric film 906 is formed on the step 910. As a result, irregularities are formed on the upper surface of the piezoelectric film 906, a crack 912 is generated in the upper electrode 908 on the piezoelectric film 906, and the upper electrode 908 as a common electrode is insulated at the position where the crack 912 is generated. There is a problem.

  Further, when the piezoelectric film 906 is fired and formed, the portion where the lower electrode 904 is present and the portion where the lower electrode 904 is present are heated at the same time, so that the growth of the piezoelectric film 906 and the substance from the vibration plate 902 to the piezoelectric film 906 are obtained. The diffusion state of the piezoelectric film 906 is different between the portion on the lower electrode 904 and the other portion of the piezoelectric film 906, and there is another problem that the piezoelectric film 906 is easily peeled off from the vibration plate 902. Specifically, the portion of the piezoelectric film 906 on the lower electrode 904 has a so-called columnar perovskite structure, but the portion of the piezoelectric film 906 that is not on the lower electrode 904 (that is, the portion on the diaphragm 902) has a so-called pyrochlore phase. Thus, the piezoelectric film 906 is peeled from the diaphragm 902 in the direction indicated by the arrow 914 in FIG.

  A part of a liquid discharge head provided with such a conventional piezoelectric actuator 900 is shown in a plan view of FIG. 27A, and a cross section taken along line 27b-27b is shown in FIG. In the liquid discharge head 950 shown in FIG. 27A, the piezoelectric actuator 900 includes a plurality of piezoelectric elements 920 including a lower electrode 904, a piezoelectric film 906, and an upper electrode 908. The upper electrodes 908 as common electrodes of the piezoelectric elements 920 are connected to each other at the common wiring portion 908a. The portion indicated by reference numeral 922 in FIG. 27B corresponds to the structural portion shown in FIG. Such a structure portion denoted by reference numeral 922 is absolutely necessary in the lower addressing structure (that is, the structure in which the lower electrode 904 is an individual electrode and the upper electrode 908 is a common electrode), and is caused by the step 910 as described above. A crack 912 will occur. Insulation occurs at the location where such a crack 912 occurs (that is, the narrow branch portion 908b of the upper electrode 908 in FIGS. 27A and 27B), and the connection reliability of the upper electrode 908 as a common electrode is generated. There has been a problem of lowering.

  Patent Documents 1 to 3 do not describe the above-described problem and the solution.

The present invention has been made in view of such circumstances, and is a piezoelectric actuator that can improve the reliability of electrical connection of a common electrode in a piezoelectric actuator having a lower addressing structure that uses a lower electrode on the substrate side as an individual electrode. an object of the present invention is to provide a manufacturing how.

In order to achieve the above object, the invention according to claim 1 is a manufacturing method of a piezoelectric actuator in which a lower electrode film, a piezoelectric film, and an upper electrode film are sequentially laminated on a substrate having an insulating layer formed on at least a surface thereof. A plurality of upper electrode films are individually drawn out on a surface different from the surface on which the upper electrode film is disposed and the surface on which the lower electrode film is disposed, and then connected to each other to form a common electrode , A step of forming a lower electrode film on the insulating layer; a step of patterning the lower electrode film into a predetermined shape; and the insulation on the lower electrode film and the lower electrode film left by the patterning. Forming the piezoelectric film on a layer, and patterning the piezoelectric film so that at least the piezoelectric film does not remain on the insulating layer, and the piezoelectric layer is formed on the surface of the insulating layer. body To provide a method for manufacturing a piezoelectric actuator, characterized in that not is formed.

According to the present invention, a plurality of upper electrode films are respectively drawn out to a surface different from the surface on which they are disposed and the surface on which the lower electrode film is disposed, and then connected to each other to form a common electrode. The reliability of the electrical connection can be improved without being influenced by the level difference of the piezoelectric film constituting the surface on which the is disposed. In addition, since the piezoelectric film does not remain on the insulating layer, the piezoelectric film can be prevented from peeling off.

  The invention according to claim 2 is the method of manufacturing a piezoelectric actuator according to claim 1, wherein the plurality of lower electrode films are individually drawn out on the same surface as the surface from which the plurality of upper electrode films are drawn. Features.

  According to the aspect of the second aspect, by drawing out the lower electrode film serving as the individual electrode on the same surface as the surface from which the upper electrode film is drawn out, it is easy to secure an electric wiring space, and high-density wiring can be mounted. .

The invention according to claim 3 is the method for manufacturing the piezoelectric actuator according to claim 1 or 2 , wherein the piezoelectric film is formed by a sputtering method, a sol-gel method, or a CVD method. To do.

  In the present invention, a piezoelectric film formed by a sputtering method, a sol-gel method, or a CVD method is suitable, and high performance of a piezoelectric actuator having a lower addressing structure can be realized.

According to the present invention, a plurality of upper electrode films are respectively drawn out to a surface different from the surface on which they are disposed and the surface on which the lower electrode film is disposed, and then connected to each other to form a common electrode. The reliability of the electrical connection can be improved without being influenced by the level difference of the piezoelectric film constituting the surface on which the is disposed. In addition, since the piezoelectric film does not remain on the insulating layer, the piezoelectric film can be prevented from peeling off.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Liquid discharge head]
(First embodiment)
As an embodiment (first embodiment) of a liquid discharge head according to the present invention, the configuration of an ink jet head (hereinafter referred to as “recording head”) including a piezoelectric actuator to which the present invention is applied will be described. Next, a method for manufacturing the recording head will be described.

  FIG. 1 is a cross-sectional view illustrating a part of a configuration example of a recording head 10A as the first embodiment. FIG. 2 is a plan view showing a part of the piezoelectric actuator 16A provided in the recording head 10A. For convenience of explanation, in FIG. 2, the resin layer 38 and the wiring forming substrate 40 that constitute a part of the piezoelectric actuator 16A are not shown (see FIG. 1).

  As shown in FIG. 1, the recording head 10 </ b> A of the present embodiment includes a nozzle 12 serving as an ink ejection port, a pressure chamber 14 communicating with the nozzle 12, and a piezoelectric actuator 16 </ b> A that changes the volume in the pressure chamber 14. Mainly composed.

  Although not shown, a plurality of nozzles 12 are arranged two-dimensionally (matrix) on the ejection surface (nozzle surface) of the recording head 10A, and a plurality of pressure chambers 14 are arranged in the recording head 10A. It is provided for each. Each pressure chamber 14 is formed with an ink supply port 18, and a plurality of pressure chambers 14 communicate with the common flow path 20 via the ink supply port 18. The common flow path 20 is a liquid storage section for storing ink supplied from an ink tank (not shown) provided outside the recording head 10 </ b> A, and ink in the common flow path 20 is supplied to each pressure chamber 14. Is done.

  The wall surface of the pressure chamber 14 (upper surface in FIG. 1) is constituted by a diaphragm 22 that constitutes a part of the piezoelectric actuator 16A. The diaphragm 22 is a non-conductive material or a substrate having an insulating layer formed on at least the surface (the side opposite to the pressure chamber 14 side). In this embodiment, a silicon substrate 24 having a silicon oxide film (insulating layer) 26 formed on the front side and a silicon oxide film (etching stop layer) 28 formed on the back side (pressure chamber 14 side) is the diaphragm 22. Used as

  As shown in FIGS. 1 and 2, the piezoelectric actuator 16A of the present embodiment includes a diaphragm 22, a lower electrode film 30 made of a conductive material, a piezoelectric film 32 made of a piezoelectric material, and a conductive material. The lower electrode film 30, the piezoelectric film 32, and the upper electrode film 34 are sequentially stacked at positions corresponding to the pressure chambers 14 on the vibration plate 22. Thus, a piezoelectric element (pressure generating element) 36 including the lower electrode film 30, the piezoelectric film 32, and the upper electrode film 34 is provided for each pressure chamber 14. By applying an electric field to the piezoelectric film 32 of each piezoelectric element 36, the volume of the corresponding pressure chamber 14 can be changed, and ink droplets can be ejected from the nozzles 12 communicating with each pressure chamber 14, respectively. it can.

  In the piezoelectric actuator 16A of the present embodiment, a structure in which the lower electrode film 30 is an individual electrode and the upper electrode film 34 is a common electrode (hereinafter referred to as “lower addressing structure”) is employed. In the piezoelectric actuator employing the lower addressing structure (see FIG. 26), as described above, when the piezoelectric film is formed on the step formed between the individual electrodes on the diaphragm, the upper surface of the piezoelectric film is uneven, There is a problem that cracks are generated in the upper electrode film on the piezoelectric film, and insulation is generated in the upper electrode film as a common electrode at the crack generation position, thereby reducing the reliability of electrical connection.

  Therefore, in the present invention, in order to solve such a problem, the upper electrode films 34 are arranged on the same surface as the surface on which the upper electrode film 34 of each piezoelectric element 36 is arranged (that is, the upper surface of the piezoelectric film 32). Rather than connecting, the upper electrode films 34 are individually drawn out on a surface whose height direction (vertical direction in FIG. 1) is different from the surface on which the upper electrode film 34 of each piezoelectric element 36 is disposed, and then connected to each other. To do.

  In the piezoelectric actuator 16A of the present embodiment, through electrodes 42 and 44 corresponding to the respective piezoelectric elements 36 are formed in the resin layer 38 and the wiring formation substrate 40 that are stacked on the vibration plate 22, and these through electrodes The upper electrode film 34 and the lower electrode film 30 of each piezoelectric element 36 are individually drawn out to the surface of the wiring forming substrate 40 by 42 and 44. In FIG. 2, the connection position of the first through electrode 42 on the upper electrode film 34 is indicated by reference numeral 34a, and the connection position of the second through electrode 44 on the lower electrode film 30 is indicated by reference numeral 30a.

  FIG. 3 is a plan view showing a configuration example of an electric wiring pattern formed on the surface of the wiring forming substrate 40. As shown in FIG. 3, the first and second through electrodes 42, 44 connected to the upper electrode film 34 and the lower electrode film 30 of each piezoelectric element 36 are exposed on the surface of the wiring formation substrate 40. Yes. A plurality (four in this example) of first through electrodes 42 are connected to each other by a common wiring portion 46 and led out to a common terminal portion 48 formed at one end portion (lower end portion in FIG. 3) of the wiring forming substrate 40. . On the other hand, each second through electrode 44 is individually drawn out to an individual terminal portion 52 formed at one end portion of the wiring forming substrate 40 by an individual wiring portion 50 provided correspondingly. An external wiring member (flexible cable or the like) for transmitting a drive signal for each piezoelectric element 36 is connected to each terminal portion 48, 52.

  In the present embodiment, as shown in FIG. 1, the upper electrode film 34 and the lower electrode film 30 are individually drawn out on the same surface (the surface of the wiring forming substrate 38). Without being limited thereto, the upper electrode film 34 and the lower electrode film 30 may be individually drawn out on different surfaces. In this case, the wiring density can be improved because of the multilayer wiring.

  Although not shown, there is a mode in which only the upper electrode film 34 of each piezoelectric element 36 is individually drawn out on the surface of the wiring forming substrate 40 and connected to each other.

  Further, in the piezoelectric actuator 16A of this embodiment, the piezoelectric film 32 is not formed on the insulating layer (silicon oxide film) 26 of the diaphragm 22 (that is, formed only on the lower electrode film 30). ), The peeling of the piezoelectric film 32 is prevented.

  Next, as an embodiment of the manufacturing method of the piezoelectric actuator according to the present invention, an example of the manufacturing method (first to fourth manufacturing methods) of the recording head 10A of the first embodiment will be described.

  4 to 6 are process diagrams showing an example (first manufacturing method) of a method of manufacturing the recording head 10A according to the first embodiment.

First, the SOI substrate 100 having the insulating layer 108 formed on the surface is prepared (FIG. 4A). The SOI substrate 100 includes a support 102 constituted by a silicon substrate (Si substrate), a Box layer 104 constituted by a silicon oxide film (SiO ₂ film), and an active layer 106 constituted by a silicon substrate (Si substrate). A multilayer substrate. The insulating layer 108 is, for example, a silicon oxide film (SiO ₂ film), and can be formed by a method such as a thermal oxidation method, a sputtering method, or a CVD method. The insulating layer 108 may be made of an oxide such as ZrO ₂ or Al ₂ O ₃ , a nitride such as SiCN, TiAlN, Si ₃ N ₄ , or TiAlCrN, an oxynitride such as SiON, or a resin.

  Next, the lower electrode film 110 is formed on the entire surface of the insulating layer 108 (FIG. 4B). Examples of the material of the lower electrode film 110 include electrode materials such as Ir, Pt, and Ti. Examples of a method for forming the lower electrode film 110 include a sputtering method, a vapor deposition method, and a CVD method. The thickness of the lower electrode film 110 is, for example, 100 to 300 nm. Subsequently, the lower electrode film 110 is patterned by etching (FIG. 4C). Specifically, the lower electrode film 110 is individualized for each pressure chamber 14 by dry etching (RIE). The lower electrode film 110 may be formed at a position corresponding to each pressure chamber 14 by lift-off film formation using a resist instead of the step of forming the lower electrode film 110 on the insulating layer 108 and etching it. .

  Next, a piezoelectric film 112 is formed on the upper surface side of the SOI substrate 100 so as to cover the lower electrode film 110 on the insulating layer 108 (FIG. 4D). Examples of the material of the piezoelectric film 112 include piezoelectric materials such as lead zirconate titanate (PZT) and barium titanate. Examples of a method for forming the piezoelectric film 112 include a sputtering method, a CVD (MOCVD) method, and a sol-gel method. The thickness of the piezoelectric film 112 is, for example, 1 to 5 μm.

  Next, the upper electrode film 114 is formed on the entire surface of the piezoelectric film 112 (FIG. 4E). Examples of the material of the upper electrode film 114 include electrode materials such as Ir, Pt, Ti, and Au. A method for forming the upper electrode film 114 includes a sputtering method, a vapor deposition method, a CVD method, and the like. The thickness of the upper electrode film 114 is, for example, 100 to 300 nm. Subsequently, the upper electrode film 114 is patterned by etching (FIG. 4F). Specifically, the upper electrode film 114 is patterned by dry etching (RIE) using a fluorine-based gas or a chlorine-based gas. The upper electrode film 110 may be formed on the piezoelectric film 112 by lift-off film formation using a resist, instead of the process of forming the upper electrode film 114 on the piezoelectric film 112 and etching it.

  Next, the piezoelectric film 112 is patterned by etching (FIG. 4G). Specifically, similarly to the upper electrode film 114, the upper electrode film 114 is patterned by dry etching (RIE) using a fluorine-based gas or a chlorine-based gas. At this time, the piezoelectric film 112 is removed by etching so as not to remain on the insulating layer 108. Thereby, peeling of the piezoelectric film 112 can be prevented. Etching of the upper electrode film 114 and the piezoelectric film 112 may be performed simultaneously.

  Next, an opening 116 serving as the pressure chamber 14 is formed by etching or the like on the support body (silicon substrate) 102 constituting the lower surface side of the SOI substrate 100 (FIG. 2H). Subsequently, the flow path forming substrate 117 on which the nozzles 12 and the common flow path 20 are formed is bonded to the lower surface side of the SOI substrate 100 (FIG. 5A).

  Next, a resin layer 118 is formed on the upper surface side of the SOI substrate 100 so as to cover the lower electrode film 110, the piezoelectric film 112, and the upper electrode film 114 stacked on the insulating layer 108 (FIG. 5B). )). Examples of the material of the resin layer 118 include resin materials such as photosensitive epoxy, photosensitive polyimide, epoxy, and polyimide. Subsequently, the resin layer 118 is patterned by exposure or etching (FIG. 5C). Specifically, the resin layer 118 is patterned so that the recesses 118a and 118b constituting the lower portions of the through electrodes 42 and 44 and the recesses 118c constituting the space portions formed on the surface of the upper electrode film 114 are formed. .

  Next, the wiring formation substrate 120 is bonded onto the resin layer 118 (FIG. 5D). As the wiring formation substrate 120, for example, an insulating substrate such as a silicon substrate or glass having an insulating layer (silicon oxide film or the like) formed on the surface thereof is used. In the wiring formation substrate 120, through holes 120a and 120b constituting the upper portions of the through electrodes 42 and 44 are formed in advance, and the wiring is formed while aligning with the recesses 118a and 118b formed in the resin layer 118. The formation substrate 120 is bonded. As a result, the vias 122 and 124 that form the through electrodes 42 and 44 are formed.

  Next, an electrode film (wiring metal) 126 is formed on the surface of the wiring forming substrate 120 and the inner wall surfaces of the vias 122 and 124 (FIG. 5E). Examples of the material of the electrode film 126 include electrode materials such as Au, Al, Pt, and Ir. Examples of a method for forming the electrode film 126 include a sputtering method and a CVD method. Subsequently, electrodes (through electrodes) 128 and 129 are formed inside the vias 122 and 124 by a method such as vacuum screen printing or plating (FIG. 5F).

  Finally, the electrode film 126 on the surface of the wiring formation substrate 120 is patterned by etching (FIG. 6). Specifically, patterning is performed so that electric wiring patterns such as the common wiring portion 46 and the individual wiring portion 50 shown in FIG. 3 are formed on the surface of the wiring forming substrate 120. In this way, the recording head 10A of the present embodiment can be obtained.

  7 and 8 are process diagrams illustrating another example (second manufacturing method) of the method of manufacturing the recording head 10 according to the first embodiment. In FIG. 7 and FIG. 8, the same reference numerals are given to portions common to FIG. 4 to FIG. 6. In the second manufacturing method, before the lower electrode film 110, the piezoelectric film 112, and the upper electrode film 114 are sequentially formed, the opening 116 that becomes the pressure chamber 14 is formed in advance on the support 102 of the SOI substrate 100. Is the same as the first manufacturing method. Hereinafter, description of points common to the first manufacturing method will be omitted or simplified.

  First, an opening 116 serving as the pressure chamber 14 is formed in the support 102 of the SOI substrate 100 having the insulating layer 108 formed on the surface, and a separately formed flow path forming substrate 117 is bonded to the lower surface side of the SOI substrate 100. (FIG. 7A).

  Next, the lower electrode film 110 is formed on the entire surface of the insulating layer 108 (FIG. 7B), and the lower electrode film 110 is patterned for each pressure chamber 14 by dry etching (RIE) (FIG. 7C). . Subsequently, a piezoelectric film 112 is formed on the upper surface side of the SOI substrate 100 so as to cover the lower electrode film 110 on the insulating layer 108 (FIG. 7D). Further, an upper electrode film 114 is formed on the piezoelectric film 112 (FIG. 7E), and the upper electrode film 114 is patterned by etching. The upper electrode film 114 may be formed directly on the piezoelectric film 112 by lift-off film formation using a resist, instead of the process of forming the upper electrode film 114 on the piezoelectric film 112 and etching it.

  Next, the piezoelectric film 112 is patterned by etching (FIG. 7G). At this time, similarly to the first manufacturing method, the piezoelectric film 112 is removed by etching so as not to remain on the insulating layer 108. Etching of the upper electrode film 114 and the piezoelectric film 112 may be performed simultaneously. The subsequent steps (FIG. 7 (h) and FIGS. 8 (a) to 8 (e)) are the same as those in the first manufacturing method, and thus description thereof is omitted.

  9 to 11 are process diagrams showing another example (third manufacturing method) of the method for manufacturing the recording head 10 of the first embodiment. In FIGS. 9 to 11, the same reference numerals are given to portions common to FIGS. 4 to 6. The third manufacturing method is the same as the first manufacturing method except that the patterning of the lower electrode film 110 by etching is performed after the piezoelectric film 112 and the upper electrode film 114 are formed. Hereinafter, description of points common to the first manufacturing method will be omitted or simplified.

  First, an SOI substrate 100 having an insulating layer 108 formed on the surface is prepared (FIG. 9A), and a lower electrode film 110, a piezoelectric film 112, and an upper electrode film 114 are sequentially stacked on the insulating layer 108 (FIG. 9). 9 (b)-(d)). Subsequently, the upper electrode film 114 and the piezoelectric film 112 are sequentially patterned by etching (FIGS. 9E and 9F). The upper electrode film 114 and the piezoelectric film 112 may be etched simultaneously. Thereafter, the lower electrode film 110 is patterned by etching (FIG. 9G). The subsequent steps (FIG. 9H, FIGS. 10A to 10F, and FIG. 11) are the same as those in the first manufacturing method, and thus the description thereof is omitted.

  12 and 13 are process diagrams showing another example (fourth manufacturing method) of the method of manufacturing the recording head 10 according to the first embodiment. In FIG. 12 and FIG. 13, the same reference numerals are given to portions common to FIG. 4 to FIG. 6. The fourth manufacturing method is the same as the second manufacturing method except that the patterning of the lower electrode film 110 by etching is performed after the piezoelectric film 112 and the upper electrode film 114 are formed. Hereinafter, description of points common to the second manufacturing method will be omitted or simplified.

  First, an opening 116 serving as the pressure chamber 14 is formed in the support 102 of the SOI substrate 100 having the insulating layer 108 formed on the surface, and a flow path forming substrate 117 is bonded to the lower surface side of the SOI substrate 100 (FIG. 12 (a)). Subsequently, the lower electrode film 110, the piezoelectric film 112, and the upper electrode film 114 are sequentially stacked on the insulating layer 108 (FIGS. 12B to 12D). Subsequently, the upper electrode film 114 and the piezoelectric film 112 are sequentially patterned by etching (FIGS. 12E and 12F). The upper electrode film 114 and the piezoelectric film 112 may be etched simultaneously. Thereafter, the lower electrode film 110 is patterned by etching (FIG. 12G). The subsequent steps (FIG. 12 (h) and FIGS. 13 (a) to (e)) are the same as those in the first manufacturing method, and thus the description thereof is omitted.

  According to each of the manufacturing methods (first to fourth manufacturing methods) described above, the upper electrode film 114 serving as the common electrode of each piezoelectric element 36 has a surface (the piezoelectric film 112 of the piezoelectric film 112) on which each upper electrode film 114 is disposed. Without being connected to each other on the same surface as the front surface, they are individually drawn out to surfaces (surfaces of the wiring forming substrate 120) having different height directions (vertical directions in the figure) and then connected to each other. Therefore, the reliability of electrical connection can be improved without being influenced by the level difference (unevenness) of the surface on which each upper electrode film 114 is disposed. In addition, since the piezoelectric film 112 does not remain on the insulating layer 108 in the end, the piezoelectric film 112 does not become a picroa phase, and peeling of the piezoelectric film 112 can be prevented.

  In particular, according to the third and fourth manufacturing methods, the lower electrode film 110 is processed later, so that the entire portion including the removed portion of the piezoelectric film 112 finally removed is formed on the lower electrode film 110. Since the film is formed, peeling of the piezoelectric film 112 during the process can be surely prevented.

(Second Embodiment)
As another embodiment (second embodiment) of the liquid discharge head according to the present invention, a recording head including a piezoelectric actuator to which the present invention is applied and a method for manufacturing the same will be described.

  FIG. 14 is a cross-sectional view showing a part of a configuration example of the recording head 10B as the second embodiment. In FIG. 14, the same reference numerals are given to portions common to FIG. 1.

  In the piezoelectric actuator 16B of the present embodiment, as shown in FIG. 14, the upper electrode film 34 of each piezoelectric element 36 is individually drawn out to the surface (the surface of the insulating layer 26) on which the lower electrode film 30 is disposed. Connected to each other. Specifically, an insulating film 60 is provided on one side surface (left side surface in FIG. 14) of each piezoelectric element 36, and one end is connected to the upper electrode film 34 so as to cover the surface of the insulating film 60 and the other. A surface electrode film 62 whose end is connected to a common wiring portion 64 provided on the surface of the insulating layer 26 is provided. Since other structures are the same as those in the first embodiment, description thereof will be omitted.

  According to the present embodiment, the same effects as those of the first embodiment can be obtained, and it is necessary to newly prepare a substrate (such as a wiring formation substrate) for individually pulling out the upper electrode film 34 of each piezoelectric element 36. The cost can be reduced.

  Next, as another embodiment of the method for manufacturing a piezoelectric actuator according to the present invention, an example of the method for manufacturing the recording head 10B according to the second embodiment (fifth to eighth manufacturing methods) will be described.

  15 and 16 are process diagrams showing an example (fifth manufacturing method) of a method for manufacturing the recording head 10B of the second embodiment. In FIG. 15 and FIG. 16, the same reference numerals are given to portions common to FIG. 4 to FIG. 6. The fifth manufacturing method is a method corresponding to the first manufacturing method. Hereinafter, description of points common to the first manufacturing method will be omitted or simplified.

  First, after preparing the SOI substrate 100 having the insulating layer 108 formed on the surface (FIG. 15A), the lower electrode film 110 is formed on the entire surface of the insulating layer 108 (FIG. 15B), and etching is performed. The lower electrode film 110 is patterned (FIG. 15C). Subsequently, a piezoelectric film 112 is formed on the upper surface side of the SOI substrate 100 so as to cover the lower electrode film 110 (FIG. 15D), and further, an upper electrode film 114 is formed on the piezoelectric film 112. (FIG. 15E), the upper electrode film 114 and the piezoelectric film 112 are patterned sequentially or simultaneously by etching (FIGS. 15F and 15G). About the process so far, it is the same as that of the 1st manufacturing method.

  In this manufacturing method, a part 110a of the lower electrode film 110 patterned as described above functions as an individual electrode of the piezoelectric element 36, and another part 110b functions as a common wiring part 130. The upper electrode film 114 serving as a common electrode of the element 36 is connected to the common wiring part 130. Therefore, in the next step, as a pretreatment step for electrically connecting the upper electrode film 114 and the common wiring part 130 (lower electrode film 110b), the individual electrodes (lower electrode film 110a) of the piezoelectric element 36 and Insulating film 132 is formed in order to ensure the insulating property (FIG. 15H). Examples of the material of the insulating film 132 include polyimide, epoxy, and inorganic materials. The insulating film 132 can be formed by forming a solid film made of these materials on the upper surface side of the SOI substrate 100 and patterning it by etching. Moreover, it can also form without using a resist by using material (photosensitive polyimide, photosensitive epoxy, etc.) which has photosensitivity for material itself.

  Next, a surface electrode film 134 having one end connected to the upper electrode film 114 and the other end connected to the common wiring portion 130 is formed so as to cover the surface of the insulating film 132 (FIG. 16A). Examples of the material of the surface electrode film 134 include electrode materials such as Au, Al, Pt, and Ir. As a method for forming the surface electrode film 134, there is a method in which an electrode material such as Au, Al, Pt, or Ir is formed on the upper surface side of the SOI substrate 100 and patterned by etching.

  Thereafter, in the same manner as in the first manufacturing method, an opening 116 serving as the pressure chamber 14 is formed by etching on the support 102 of the SOI substrate 100 (FIG. 16B), and a separately manufactured flow path forming substrate 117 is formed. It joins to the lower surface side of the SOI substrate 100 (FIG. 16C). Thus, the recording head 10B of the present embodiment can be obtained.

  17 and 18 are process diagrams showing another example (sixth manufacturing method) of the method of manufacturing the recording head 10B of the second embodiment. In FIG. 17 and FIG. 18, the same reference numerals are given to portions common to FIG. 4 to FIG. 6. The sixth manufacturing method is a method corresponding to the second manufacturing method. Hereinafter, description of points common to the second manufacturing method will be omitted or simplified.

  First, an opening 116 serving as the pressure chamber 14 is formed in the support 102 of the SOI substrate 100 having the insulating layer 108 formed on the surface, and then a separately formed flow path forming substrate 117 is bonded to the lower surface side of the SOI substrate 100. (FIG. 17 (a)). Subsequently, a lower electrode film 110 is formed on the insulating layer 108 (FIG. 17B), and after patterning the lower electrode film 110 by etching (FIG. 17C), the lower electrode film 110 is further formed. A piezoelectric film 112 is formed on the upper surface side of the SOI substrate 100 so as to cover it (FIG. 17D). Subsequently, an upper electrode film 114 is formed on the piezoelectric film 112 (FIG. 17E), and the upper electrode film 114 and the piezoelectric film 112 are sequentially or simultaneously patterned by etching (FIGS. 17F and 17G). )). About the process so far, it is the same as that of the 2nd manufacturing method.

  Next, in order to individually connect the upper electrode film 114 serving as a common electrode of each piezoelectric element 36 to the common wiring portion 130 (lower electrode film 110b), an insulating film is formed on one side surface of each piezoelectric element 36 as a pretreatment step. 132 is formed (FIG. 17H), and a surface electrode film 134 having one end connected to the upper electrode film 114 and the other end connected to the common wiring portion 130 is formed so as to cover the surface of the insulating film 132. (FIG. 18). Thus, the recording head 10B of the present embodiment can be obtained.

  19 and 20 are process diagrams illustrating another example (seventh manufacturing method) of the method of manufacturing the recording head 10B of the second embodiment. In FIG. 17 and FIG. 18, the same reference numerals are given to portions common to FIG. 4 to FIG. 6. The seventh manufacturing method is a method corresponding to the third manufacturing method. Hereinafter, description of points common to the third manufacturing method will be omitted or simplified.

  First, the SOI substrate 100 having the insulating layer 108 formed on the surface is prepared (FIG. 19A), and the lower electrode film 110, the piezoelectric film 112, and the upper electrode film 114 are sequentially stacked on the insulating layer 108 ( FIG. 19 (b) to (d)). Subsequently, the upper electrode film 114 and the piezoelectric film 112 are patterned sequentially or simultaneously by etching (FIGS. 19E and 19F). Thereafter, the lower electrode film 110 is patterned by etching (FIG. 9G). The steps up to here are the same as in the third manufacturing method.

  The subsequent steps are the same as in the fifth manufacturing method. That is, an insulating film 132 is formed on one side surface of each piezoelectric element 36 (FIG. 19H), one end is connected to the upper electrode film 114 so as to cover the surface of the insulating film 132, and the other end is a common wiring. A surface electrode film 134 connected to the portion 130 is formed (FIG. 20A). Thereafter, an opening 116 serving as the pressure chamber 14 is formed by etching in the support 102 of the SOI substrate 100 (FIG. 20B), and a separately formed flow path forming substrate 117 is bonded to the lower surface side of the SOI substrate 100 ( FIG. 20 (c)). Thus, the recording head 10B of the present embodiment can be obtained.

  21 and 22 are process diagrams showing another example (eighth manufacturing method) of the method for manufacturing the recording head 10B of the second embodiment. In FIG. 21 and FIG. 22, parts that are the same as those in FIG. 4 to FIG. The eighth manufacturing method is a method corresponding to the fourth manufacturing method. Hereinafter, description of points common to the fourth manufacturing method will be omitted or simplified.

  First, an opening 116 serving as the pressure chamber 14 is formed in the support 102 of the SOI substrate 100 having the insulating layer 108 formed on the surface, and a separately formed flow path forming substrate 117 is bonded to the lower surface side of the SOI substrate 100. After that (FIG. 21A), the lower electrode film 110, the piezoelectric film 112, and the upper electrode film 114 are sequentially stacked on the insulating layer 108 (FIGS. 21B to 21D). Subsequently, the upper electrode film 114 and the piezoelectric film 112 are patterned sequentially or simultaneously by etching (FIGS. 21E and 21F), and further, the lower electrode film 110 is patterned by etching. The steps so far are the same as in the fourth manufacturing method.

  The subsequent steps are the same as in the sixth manufacturing method. That is, an insulating film 132 is formed on one side surface of each piezoelectric element 36 (FIG. 21H), one end is connected to the upper electrode film 114 so as to cover the surface of the insulating film 132, and the other end is a common wiring. A surface electrode film 134 connected to the portion 130 is formed (FIG. 22). Thus, the recording head 10B of the present embodiment can be obtained.

  According to each of the manufacturing methods (fifth to eighth manufacturing methods) described above, the same effects as those of the first to fourth manufacturing methods can be obtained, and the upper electrode film 114 serving as a common electrode of each piezoelectric element 36 can be obtained. Since the individual electrodes are individually drawn on the surface on which the lower electrode film 110 is disposed (that is, on the insulating layer 108), members for individually drawing the upper electrodes 34 of the respective piezoelectric elements 36 (wiring forming substrate, resin layer, etc.) The step of arranging the film becomes unnecessary, and the cost can be reduced.

  In particular, according to the seventh and eighth manufacturing methods, the lower electrode film 110 is processed on the lower electrode film 110 later, so that the entire portion including the removed portion of the piezoelectric film 112 that is finally removed is formed on the lower electrode film 110. Since the film is formed, peeling of the piezoelectric film 112 during the process can be surely prevented.

[Image forming apparatus]
Next, an ink jet recording apparatus as an embodiment of the image forming apparatus according to the present invention will be described.

  FIG. 23 is an overall configuration diagram showing an outline of the ink jet recording apparatus. As shown in FIG. 23, the inkjet recording apparatus 200 includes a printing unit 212 having a plurality of recording heads 212K, 212C, 212M, and 212Y provided for each ink color, and each recording head 212K, 212C, 212M, and 212Y. An ink storage / loading unit 214 for storing ink to be supplied to the printer, a paper feeding unit 218 for supplying the recording paper 216, a decurling unit 220 for removing curl of the recording paper 216, and a nozzle surface of the printing unit 212. The suction belt conveyance unit 222 that is arranged opposite to the (ink ejection surface) and conveys the recording paper 216 while maintaining the flatness of the recording paper 216, the print detection unit 224 that reads the printing result by the printing unit 212, and the printing And a paper discharge unit 226 that discharges printed recording paper (printed matter) to the outside. The recording heads 212K, 212C, 212M, and 212Y correspond to the recording heads 10A and 10B of the first or second embodiment, respectively.

  In FIG. 23, a magazine for rolled paper (continuous paper) is shown as an example of the paper supply unit 218, but a plurality of magazines having different paper widths, paper quality, and the like may be provided. Further, instead of the roll paper magazine or in combination therewith, the paper may be supplied by a cassette in which cut papers are stacked and loaded.

  In the case of an apparatus configuration that uses roll paper, a cutter 228 is provided as shown in FIG. 23, and the roll paper is cut into a desired size by the cutter 228. The cutter 228 includes a fixed blade 228A having a length equal to or larger than the conveyance path width of the recording paper 216 and a round blade 228B that moves along the fixed blade 228A. The fixed blade 228A is provided on the back side of the print. The round blade 228B is disposed on the printing surface side with the conveyance path interposed therebetween. Note that the cutter 228 is not necessary when cut paper is used.

  When multiple types of recording paper are used, an information recording body such as a barcode or wireless tag that records paper type information is attached to the magazine, and the information on the information recording body is read by a predetermined reader. Therefore, it is preferable to automatically determine the type of paper to be used and perform ink ejection control so as to realize appropriate ink ejection according to the type of paper.

  The recording paper 216 delivered from the paper supply unit 218 retains curl due to having been loaded in the magazine. In order to remove the curl, heat is applied to the recording paper 216 by the heating drum 230 in the direction opposite to the curl direction of the magazine in the decurling unit 220. At this time, it is more preferable to control the heating temperature so that the printed surface is slightly curled outward.

  After the decurling process, the cut recording paper 216 is sent to the suction belt conveyance unit 222. The suction belt conveyance unit 222 has a structure in which an endless belt 233 is wound between rollers 231 and 232, and at least portions facing the nozzle surface of the printing unit 212 and the sensor surface of the printing detection unit 224 are flat. It is configured to make.

  The belt 233 has a width that is greater than the width of the recording paper 216, and a plurality of suction holes (not shown) are formed on the belt surface. As shown in FIG. 23, an adsorption chamber 234 is provided at a position facing the nozzle surface of the print unit 212 and the sensor surface of the print detection unit 224 inside the belt 233 spanned between the rollers 231 and 232. Then, the suction chamber 234 is sucked by the fan 235 to be a negative pressure, whereby the recording paper 216 on the belt 233 is sucked and held.

  The power of a motor (not shown) is transmitted to at least one of the rollers 231 and 232 around which the belt 233 is wound, whereby the belt 233 is driven in the clockwise direction in FIG. 23 and held on the belt 233. The recording paper 216 is conveyed from left to right in FIG.

  Since ink adheres to the belt 233 when a borderless print or the like is printed, the belt cleaning unit 236 is provided at a predetermined position outside the belt 233 (an appropriate position other than the print area). Although details of the configuration of the belt cleaning unit 236 are not illustrated, for example, there are a method of niping a brush roll, a water absorption roll, etc., an air blow method of blowing clean air, or a combination thereof. In the case where the cleaning roll is nipped, the cleaning effect is great if the belt linear velocity and the roller linear velocity are changed.

  Although a mode using a roller / nip conveyance mechanism may be used instead of the suction belt conveyance unit 222, if the roller / nip conveyance is performed in the printing area, the roller comes into contact with the printing surface of the paper immediately after printing, so that the image blurs. There is a problem that it is easy. Therefore, as in this example, suction belt conveyance that does not contact the image surface in the printing region is preferable.

  A heating fan 240 is provided on the upstream side of the printing unit 212 on the paper conveyance path formed by the suction belt conveyance unit 222. The heating fan 240 heats the recording paper 216 by blowing heated air onto the recording paper 216 before printing. Heating the recording paper 216 immediately before printing makes it easier for the ink to dry after landing.

  The printing unit 212 is a so-called full-line type head in which a line-type head having a length corresponding to the maximum paper width is arranged in a direction (main scanning direction) orthogonal to the paper transport direction (sub-scanning direction). Each of the recording heads 212K, 212C, 212M, and 212Y constituting the printing unit 212 has a plurality of ink discharge ports (nozzles) arranged over a length that exceeds at least one side of the maximum size recording paper 216 targeted by the inkjet recording apparatus 200. The line type head is constructed (see FIG. 24).

  Recording corresponding to each color ink in the order of black (K), cyan (C), magenta (M), and yellow (Y) from the upstream side (left side in FIG. 23) along the conveyance direction (paper conveyance direction) of the recording paper 216. Heads 212K, 212C, 212M, and 212Y are arranged. A color image can be formed on the recording paper 216 by ejecting the color inks from the recording heads 212K, 212C, 212M, and 212Y while conveying the recording paper 216, respectively.

  As described above, according to the printing unit 212 in which the full line head covering the entire width of the paper is provided for each ink color, the recording paper 216 and the printing unit 212 are relatively moved in the paper transport direction (sub-scanning direction). The image can be recorded on the entire surface of the recording paper 216 by performing the operation once (that is, by one sub-scanning). Thereby, high-speed printing is possible and productivity can be improved as compared with the shuttle type head in which the recording head reciprocates in the direction (main scanning direction) orthogonal to the paper transport direction.

  In this example, the configuration of KCMY standard colors (four colors) is illustrated, but the combination of ink colors and the number of colors is not limited to this embodiment, and light ink and dark ink are added as necessary. May be. For example, it is possible to add a recording head that discharges light ink such as light cyan and light magenta.

  As shown in FIG. 23, the ink storage / loading unit 214 has tanks that store inks of colors corresponding to the recording heads 212K, 212C, 212M, and 212Y, and each tank has a pipe line that is not shown. Via the recording heads 212K, 212C, 212M, and 212Y. Further, the ink storage / loading unit 214 includes notifying means (display means, warning sound generating means, etc.) for notifying when the ink remaining amount is low, and has a mechanism for preventing erroneous loading between colors. is doing.

  The print detection unit 224 includes an image sensor (line sensor or the like) for imaging the droplet ejection result of the print unit 212, and means for checking nozzle clogging and other ejection defects from the droplet ejection image read by the image sensor. Function as.

  The print detection unit 224 of this example is configured by a line sensor having a light receiving element array that is wider than at least the ink ejection width (image recording width) by the recording heads 212K, 212C, 212M, and 212Y. The line sensor includes an R sensor row in which photoelectric conversion elements (pixels) provided with red (R) color filters are arranged in a line, a G sensor row provided with green (G) color filters, The color separation line CCD sensor includes a B sensor array provided with a blue (B) color filter. Instead of the line sensor, an area sensor in which the light receiving elements are two-dimensionally arranged can be used.

  The print detection unit 224 reads the test patterns printed by the recording heads 212K, 212C, 212M, and 212Y for each color, and detects the ejection of each head. The ejection determination includes the presence / absence of ejection, measurement of dot size, measurement of dot landing position, and the like.

  A post-drying unit 242 is provided following the print detection unit 224. The post-drying unit 242 is means for drying the printed image surface, and for example, a heating fan is used. Since it is preferable to avoid contact with the printing surface until the ink after printing is dried, a method of blowing hot air is preferred.

  When printing on porous paper with dye-based ink, the weather resistance of the image is improved by preventing contact with ozone or other things that cause dye molecules to break by blocking the paper holes by pressurization. There is an effect to.

  A heating / pressurizing unit 244 is provided following the post-drying unit 242. The heating / pressurizing unit 244 is a means for controlling the glossiness of the image surface, and pressurizes with a pressure roller 245 having a predetermined uneven surface shape while heating the image surface, and transfers the uneven shape to the image surface. To do.

  The printed matter generated in this manner is outputted from the paper output unit 226. It is preferable that the original image to be printed (printed target image) and the test print are discharged separately. The ink jet recording apparatus 200 is provided with sorting means (not shown) for switching the paper discharge path in order to select the print product of the main image and the print product of the test print and send them to the discharge units 226A and 226B. ing. When the main image and the test print are simultaneously formed in parallel on a large sheet, the test print portion is separated by the cutter (second cutter) 248. The cutter 248 is provided immediately before the paper discharge unit 226, and cuts the main image and the test print unit when the test print is performed on the image margin. The structure of the cutter 248 is the same as that of the first cutter 228 described above, and includes a fixed blade 248A and a round blade 248B. Although not shown, the paper output unit 226A for the target prints is provided with a sorter for collecting prints according to print orders.

  FIG. 25 is a principal block diagram showing a control system of the inkjet recording apparatus 200. The ink jet recording apparatus 200 includes a communication interface 270, a system controller 272, an image memory 274, a motor driver 276, a heater driver 278, a print control unit 280, an image buffer memory 282, a head driver 284, and the like.

  The communication interface 270 is an interface unit that receives image data sent from the host computer 286. A serial interface or a parallel interface can be applied to the communication interface 270. In this part, a buffer memory (not shown) for speeding up communication may be mounted.

  Image data sent from the host computer 286 is taken into the inkjet recording apparatus 200 via the communication interface 270 and temporarily stored in the image memory 274. The image memory 274 is a storage unit that temporarily stores an image input via the communication interface 270, and data is read and written through the system controller 272. The image memory 274 is not limited to a memory composed of semiconductor elements, and a magnetic medium such as a hard disk may be used.

  The system controller 272 is a control unit that controls each unit such as the communication interface 270, the image memory 274, the motor driver 276, and the heater driver 278. The system controller 272 includes a central processing unit (CPU) and its peripheral circuits, and performs communication control with the host computer 286, read / write control of the image memory 274, etc., and a transport motor 288 and heater 289. A control signal for controlling is generated.

  The motor driver 276 is a driver (drive circuit) that drives the motor 288 in accordance with an instruction from the system controller 272. The heater driver 278 is a driver that drives the heaters 289 of the post-drying unit 242 and other units in accordance with instructions from the system controller 272.

  The print control unit 280 has a signal processing function for performing various processes and corrections for generating a print control signal from the image data in the image memory 274 according to the control of the system controller 272, and the generated print A control unit that supplies a control signal (dot data) to the head driver 284. The print control unit 280 performs necessary signal processing, and controls the ejection amount and ejection timing of the ink droplets of the recording heads 212K, 212C, 212M, and 212Y via the head driver 284 based on the image data. Thereby, a desired dot size and dot arrangement are realized.

  The print control unit 280 includes an image buffer memory 282, and image data, parameters, and other data are temporarily stored in the image buffer memory 282 when image data is processed in the print control unit 280. In FIG. 25, the image buffer memory 282 is shown in a mode associated with the print control unit 280, but it can also be used as the image memory 274. Also possible is an aspect in which the print control unit 280 and the system controller 272 are integrated to form a single processor.

  The head driver 284 generates a drive signal for driving the piezoelectric elements 36 (see FIG. 1) of the recording heads 212K, 212C, 212M, and 212Y of the respective colors based on the dot data given from the print control unit 280, and the piezoelectric elements The generated drive signal is supplied to 36. The head driver 284 may include a feedback control system for keeping the driving conditions of the recording heads 212K, 212C, 212M, and 212Y constant.

  As described with reference to FIG. 23, the print detection unit 224 is a block including a line sensor. The print detection unit 224 reads an image printed on the recording paper 216, performs necessary signal processing, and the like to perform a print status (whether ejection is performed, droplet ejection And the detection result is provided to the print control unit 280.

  The print control unit 280 performs various corrections on the recording heads 212K, 212C, 212M, and 212Y based on information obtained from the print detection unit 224 as necessary.

Has been described in detail with the production how the piezoelectric actuator of the present invention, the present invention is not limited to the above examples, without departing from the scope of the present invention, it performs various improvements and modifications Of course it is also good.

Sectional drawing which showed a part of example of a structure of the recording head as 1st Embodiment Plan view showing a part of a piezoelectric actuator The top view which showed the example of composition of the electric wiring pattern formed in the surface of a wiring formation board Process drawing which showed the 1st manufacturing method of the recording head based on 1st Embodiment. Process drawing which showed the 1st manufacturing method of the recording head based on 1st Embodiment. Process drawing which showed the 1st manufacturing method of the recording head based on 1st Embodiment. Process drawing which showed the 2nd manufacturing method of the recording head concerning 1st Embodiment. Process drawing which showed the 2nd manufacturing method of the recording head concerning 1st Embodiment. Process drawing showing the third manufacturing method of the recording head according to the first embodiment Process drawing showing the third manufacturing method of the recording head according to the first embodiment Process drawing showing the third manufacturing method of the recording head according to the first embodiment Process drawing which showed the 4th manufacturing method of the recording head concerning a 1st embodiment. Process drawing which showed the 4th manufacturing method of the recording head concerning a 1st embodiment. Sectional drawing which showed a part of example of a structure of the recording head as 2nd Embodiment Process drawing which showed the 5th manufacturing method of the recording head based on 2nd Embodiment. Process drawing which showed the 5th manufacturing method of the recording head based on 2nd Embodiment. Process drawing showing a sixth manufacturing method of a recording head according to the second embodiment Process drawing showing a sixth manufacturing method of a recording head according to the second embodiment Process drawing showing a seventh manufacturing method of a recording head according to the second embodiment Process drawing showing a seventh manufacturing method of a recording head according to the second embodiment Process drawing which showed the 8th manufacturing method of the recording head concerning 2nd Embodiment. Process drawing which showed the 8th manufacturing method of the recording head concerning 2nd Embodiment. Overall configuration diagram showing outline of inkjet recording apparatus Main part plan view showing the periphery of the printing unit of the ink jet recording apparatus Main block diagram showing the control system of the ink jet recording apparatus Sectional view of relevant parts showing part of a conventional piezoelectric actuator Configuration diagram showing a liquid discharge head equipped with a conventional piezoelectric actuator

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10A, 10B ... Recording head, 12 ... Nozzle, 14 ... Pressure chamber, 16A, 16B ... Piezoelectric actuator, 20 ... Common flow path, 22 ... Diaphragm, 30 ... Lower electrode film, 32 ... Piezoelectric film, 34 ... Upper electrode Membrane, 36 ... piezoelectric element, 38 ... resin layer, 40 ... wiring forming substrate, 42, 44 ... through electrode, 46 ... common wiring portion, 50 ... individual wiring portion, 100 ... SOI substrate, 108 ... insulating layer, 110 ... lower Electrode film, 112... Piezoelectric film, 114... Upper electrode film, 116 .. Opening, 118... Resin layer, 120 .. Wiring forming substrate, 126, 128. ... Surface electrode film, 200 ... Inkjet recording apparatus

Claims (3)

A method of manufacturing a piezoelectric actuator in which a lower electrode film, a piezoelectric film, and an upper electrode film are sequentially laminated on a substrate having an insulating layer formed on at least a surface,
A plurality of upper electrode films are individually drawn out on a surface different from the surface on which the upper electrode film is disposed and the surface on which the lower electrode film is disposed, and then connected to each other as a common electrode,
Forming a lower electrode film on the insulating layer;
Patterning the lower electrode film into a predetermined shape;
Depositing the piezoelectric film on the lower electrode film left by the patterning and on the insulating layer from which the lower electrode film has been removed;
It is seen containing a step of patterning the piezoelectric film so as not to leave the piezoelectric film on at least the insulating layer, and
Method for producing a pressure electrostatic actuator you wherein said piezoelectric film on the surface of the insulating layer is not formed.   2. The method of manufacturing a piezoelectric actuator according to claim 1, wherein the plurality of lower electrode films are individually drawn out on the same surface as the surface from which the plurality of upper electrode films are drawn out.   The method for manufacturing a piezoelectric actuator according to claim 1, wherein the piezoelectric film is formed by a sputtering method, a sol-gel method, or a CVD method.

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