Method for manufacturing pressure chamber member and method for manufacturing inkjet head

Abstract

This method for manufacturing a pressure chamber member includes the steps of: preparing a laminate in which a first electrode layer, a piezoelectric layer, a second electrode layer, and a metal wall part for a pressure chamber are laminated in this order on a substrate; and electrolytically polishing a surface of the wall part of the laminate. The step of electrolytic polishing is performed in a state where the first electrode layer and the second electrode layer are electrically connected.

Description

Method for manufacturing a pressure chamber component and method for manufacturing an inkjet head

[0001] The present invention relates to a method for manufacturing a pressure chamber member and a method for manufacturing an inkjet head.

[0002] In recent years, the demand for miniaturization and higher density of inkjet heads has led to further miniaturization and thinning of the constituent components, requiring high precision in the processing and assembly of components such as inkjet heads. Conventionally, as a method for manufacturing pressure chamber components for inkjet heads, a piezoelectric element and the pressure chamber wall portion have been formed separately, aligned, and then bonded together. However, in order to improve processing and assembly precision, a manufacturing method has been developed in which the pressure chamber wall portion is formed on the piezoelectric element. For example, Patent Document 1 states that a manufacturing method in which the piezoelectric element and the pressure chamber wall portion are formed as a single unit suppresses misalignment after bonding and excess adhesive.

[0003] Japanese Patent Publication No. 2009-45871

[0004] In a manufacturing method for pressure chamber members formed by integrating such piezoelectric elements with pressure chamber walls, polishing of the pressure chamber walls is performed for purposes such as adjusting the height and smoothing of each pressure chamber wall. Polishing methods for the pressure chamber walls include physical polishing using a scriber or electrolytic polishing, which dissolves the surface layer using an electrolytic reaction. Electrolytic polishing is often used because it does not generate burrs or polishing debris. However, there has been a problem in pressure chamber members manufactured using electrolytic polishing as the wall polishing method, where the piezoelectric properties of the piezoelectric elements deteriorate.

[0005] The present invention has been made in view of the above-mentioned problems, and aims to provide a method for manufacturing a pressure chamber member having good piezoelectric properties when electropolished, and a method for manufacturing an inkjet head.

[0006] One aspect of the present invention for solving the above problems relates to a method for manufacturing a pressure chamber member as described in [1] to

[14] below.

[0007] [1] A method for manufacturing a pressure chamber member, comprising the steps of: preparing a laminate in which a first electrode layer, a piezoelectric layer, a second electrode layer, and a metal wall portion for a pressure chamber are stacked on a substrate in this order; and electropolishing the surface of the wall portion of the laminate, wherein the electropolishing step is performed while the first electrode layer and the second electrode layer are electrically connected.

[0008] [2] The method for manufacturing a pressure chamber member according to [1], wherein the electrical connection is made by contact between the second electrode layer and the first electrode layer.

[0009] [3] The piezoelectric layer is patterned, and the second electrode layer is in contact with the first electrode layer in the patterned portion, the method for manufacturing a pressure chamber member according to [2].

[0010] [4] The method for manufacturing a pressure chamber member according to [2], wherein the first electrode layer and the piezoelectric layer are patterned, and the second electrode layer is in contact with the first electrode layer in the patterned portion.

[0011] [5] The method for manufacturing a pressure chamber member according to [1], wherein the electrical connection is made by contact between the wall portion and the first electrode layer and the second electrode layer, respectively.

[0012] [6] The piezoelectric layer and the second electrode layer are patterned, and in the patterned portion, the wall portion is in contact with the first electrode layer and the second electrode layer, respectively, the method for manufacturing a pressure chamber member according to [5].

[0013] [7] The method for manufacturing a pressure chamber member according to [5], wherein the first electrode layer, the piezoelectric layer, and the second electrode layer are patterned, and in the patterned portion, the wall portion is in contact with the first electrode layer and the second electrode layer, respectively.

[0014] [8] The method for manufacturing a pressure chamber member according to [1], wherein the electrical connection is made by contact between the energizing member and the first electrode layer and the second electrode layer, respectively.

[0015] [9] The method for manufacturing a pressure chamber member according to [8], wherein the current-carrying member is solder.

[0016]

[10] The method for manufacturing a pressure chamber member according to [2], wherein the second electrode layer is in contact with the side surface of the first electrode layer.

[0017]

[11] A method for manufacturing a pressure chamber member according to any one of [1] to

[10] , comprising the step of chipping the electropolished laminate, wherein in the chipping step, a region of the laminate in which the first electrode layer and the second electrode layer are electrically connected is removed.

[0018]

[12] The method for manufacturing a pressure chamber member according to any one of [1] to

[11] , wherein the laminate has an insulating resin layer between the second electrode layer and the pressure chamber member.

[0019]

[13] The piezoelectric layer contains lead zirconate titanate, a method for manufacturing a pressure chamber member according to any one of [1] to

[12] .

[0020]

[14] A method for manufacturing a pressure chamber member according to any one of [1] to

[13] , wherein both the first electrode layer and the second electrode layer contain a metal selected from the group consisting of Ti, Cu, Cr, Ni, and Ir.

[0021] One aspect of the present invention for solving the above problems relates to a method for manufacturing an inkjet head as described in

[15] below.

[0022]

[15] A method for manufacturing an inkjet head, comprising the method for manufacturing a pressure chamber member described in any of [1] to

[14] .

[0023] According to the present invention, it is possible to provide a method for manufacturing a pressure chamber member having good piezoelectric properties when electropolished, and a method for manufacturing an inkjet head.

[0024] This is a schematic diagram showing an electropolishing apparatus. Figure 2A is a cross-sectional view showing an example of a laminate in the electropolishing process. Figure 2B is a schematic diagram showing the relationship of potentials of a laminate in the electropolishing process when the first electrode layer and the second electrode layer are not electrically connected, as an equivalent circuit. Figure 2C is a schematic diagram showing the relationship of potentials of a laminate in the electropolishing process when the first electrode layer and the second electrode layer are electrically connected, as an equivalent circuit. Figure 3A is a cross-sectional view showing a laminate in the first form in which a patterned portion is formed in the in-plane center of the piezoelectric layer. Figure 3B is a cross-sectional view showing a laminate in the first form in which a patterned portion is formed at the in-plane edge of the piezoelectric layer. Figure 4A is a cross-sectional view showing a laminate in the second form in which patterned portions are formed in the in-plane center of the first electrode layer and the piezoelectric layer. Figure 4B is a cross-sectional view showing a laminate in the second form in which patterned portions are formed at the in-plane edges of the first electrode layer and the piezoelectric layer. Figure 5A is a cross-sectional view showing a laminate of the third form, in which a patterned portion is formed in the in-plane center of the piezoelectric layer and the second electrode layer. Figure 5B is a cross-sectional view showing a laminate of the third form, in which a patterned portion is formed at the in-plane edge of the piezoelectric layer and the second electrode layer. Figure 6A is a cross-sectional view showing a laminate of the fourth form, in which a patterned portion is formed in the in-plane center of the first electrode layer, the piezoelectric layer, and the second electrode layer. Figure 6B is a cross-sectional view showing a laminate of the fourth form, in which a patterned portion is formed at the in-plane edge of the first electrode layer, the piezoelectric layer, and the second electrode layer. A cross-sectional view showing a fifth form of the laminate. A cross-sectional view showing a sixth form of the laminate. Figures 9(a) to (e) are cross-sectional views showing an example of the manufacturing process of the laminate (1). Figure 9(a) shows a cross-sectional view when the substrate is prepared. Figure 9(b) shows a cross-sectional view when the first electrode layer and the piezoelectric layer are formed on the substrate. Figure 9(c) shows a cross-sectional view when the piezoelectric layer has been patterned and a patterned portion has been created. Figure 9(d) shows a cross-sectional view when the second electrode layer has been formed and a portion of the second electrode layer has been fitted into the patterned portion, forming a fitted portion. Figure 9(e) shows a cross-sectional view when the wall portion has been formed.Figures 10(a) to 10(e) are cross-sectional views showing modified examples of the manufacturing process of the laminate (1). Figure 10(a) shows a cross-sectional view when the substrate is prepared. Figure 10(b) shows a cross-sectional view when the first electrode layer, the piezoelectric layer, and the piezoelectric layer-side region of the second electrode layer are formed on the substrate. Figure 10(c) shows a cross-sectional view when the piezoelectric layer and the piezoelectric layer-side region of the second electrode layer are patterned and a patterned portion is provided. Figure 10(d) shows a cross-sectional view when the wall-side region of the second electrode layer is formed and a part of the second electrode layer is fitted into the patterned portion, forming a fitted portion. Figure 10(e) shows a cross-sectional view when the wall portion is formed. Figures 11(a) to 11(e) are cross-sectional views showing an example of the manufacturing process of the laminate (2). Figure 11(a) is a cross-sectional view when the substrate is prepared. Figure 11(b) is a cross-sectional view when the first electrode layer and the piezoelectric layer are formed on the substrate. Figure 11(c) is a cross-sectional view when the first electrode layer and the piezoelectric layer have been patterned and a patterned portion has been formed. Figure 11(d) is a cross-sectional view when the second electrode layer has been formed and a part of the second electrode layer has been fitted into the patterned portion, forming a fitted portion. Figure 11(e) is a cross-sectional view when the wall portion has been formed. Figures 12(a) to (e) are cross-sectional views showing modified examples of the manufacturing process of the laminate (2). Figure 12(a) is a cross-sectional view when the substrate has been prepared. Figure 12(b) is a cross-sectional view when the first electrode layer, the piezoelectric layer, and the piezoelectric layer side region of the second electrode layer have been formed on the substrate. Figure 12(c) is a cross-sectional view when the first electrode layer, the piezoelectric layer, and the piezoelectric layer side region of the second electrode layer have been patterned and a patterned portion has been formed. Figure 12(d) is a cross-sectional view when the wall side region of the second electrode layer has been formed and a part of the second electrode layer has been fitted into the patterned portion, forming a fitted portion. Figure 12(e) is a cross-sectional view when the wall portion is formed. Figures 13(a) to (d) are cross-sectional views showing an example of the manufacturing process of the laminate (3). Figure 13(a) is a cross-sectional view when the substrate is prepared. Figure 13(b) is a cross-sectional view when the first electrode layer, piezoelectric layer, and second electrode layer are formed on the substrate. Figure 13(c) is a cross-sectional view when the piezoelectric layer and the second electrode layer are patterned and a patterned portion is provided. Figure 13(d) is a cross-sectional view when the wall portion is formed and a part of the wall portion is fitted into the patterned portion, forming a fitted portion.Figures 14(a) to 14(d) are cross-sectional views showing an example of the manufacturing process of the laminate (4). Figure 14(a) is a cross-sectional view when the substrate is prepared. Figure 14(b) is a cross-sectional view when the first electrode layer, piezoelectric layer, and second electrode layer are formed on the substrate. Figure 14(c) is a cross-sectional view when the first electrode layer, piezoelectric layer, and second electrode layer are patterned and a patterned portion is provided. Figure 14(d) is a cross-sectional view when a wall portion is formed and a part of the wall portion is fitted into the patterned portion, forming a fitted portion. Figures 15(a) to 15(c) are cross-sectional views showing an example of the manufacturing process of the laminate (5). Figure 15(a) is a cross-sectional view when the substrate is prepared. Figure 15(b) is a cross-sectional view when the first electrode layer, piezoelectric layer, second electrode layer, and wall portion are formed on the substrate. Figure 15(c) is a cross-sectional view when an energizing member is provided to at least a part of the laminate. Figures 16(a) to 16(e) are cross-sectional views showing an example of the manufacturing process of the laminate (6). Figure 16(a) is a cross-sectional view when the substrate is prepared. Figure 16(b) is a cross-sectional view when the first electrode layer and the piezoelectric layer are formed on the substrate. Figure 16(c) is a cross-sectional view when a spacer having a thickness similar to that of the substrate is placed in contact with the end face of the substrate. Figure 16(d) is a cross-sectional view when an overhang is formed by forming the second electrode layer. Figure 16(e) is a cross-sectional view when the spacer is removed and a wall is formed. This is a schematic diagram showing a nickel electroplating apparatus for forming the wall. Figure 18A is a cross-sectional view showing an example of the laminate before electropolishing. Figure 18B is a cross-sectional view showing an example of the laminate after electropolishing. This is a cross-sectional view showing an example of the layer configuration when a holding substrate is bonded to the laminate with a thermal release sheet. Figure 20A is a cross-sectional view showing an example of a patterning method for the first electrode layer and the piezoelectric layer in a region corresponding to the inside of the pressure chamber of an inkjet head. Figure 20B is a cross-sectional view showing an example of a patterning method for the first electrode layer and the piezoelectric layer in a region corresponding to the cut portion for chipping the pressure chamber member. Figure 21A is a cross-sectional view showing an example of a method for forming a protective film in a region corresponding to the inside of the pressure chamber of the inkjet head. Figure 21B is a cross-sectional view showing an example of a method for forming a protective film in a region corresponding to the cut portion for chipping the pressure chamber member.This is a cross-sectional view showing an example of the layer structure when a cut portion is formed to chip the pressure chamber member. This is an example of a plan view of the pressure chamber member to which the holding substrate is attached, as seen from the protective film side.

[0025] In this specification, numerical ranges expressed using "~" mean a range that includes the numbers written before and after "~" as the lower and upper limits, respectively.

[0026] 1. Method for Manufacturing a Pressure Chamber Member The method for manufacturing a pressure chamber member according to this embodiment comprises the steps of: preparing a laminate in which a first electrode layer, a piezoelectric layer, a second electrode layer, and a metal wall portion for a pressure chamber are laminated on a substrate in this order; and electropolishing the surface of the wall portion of the laminate, wherein the electropolishing step is performed while the first electrode layer and the second electrode layer are electrically connected.

[0027] In this specification, "pressure chamber member" refers to a laminate comprising at least a first electrode layer, a piezoelectric layer, a second electrode layer, and a metal wall portion for a pressure chamber.

[0028] First, the electrolytic polishing process will be explained using the schematic diagram of the electrolytic polishing apparatus shown in Figure 1, the cross-sectional view of the laminate shown in Figure 2A, and the schematic diagrams showing the equivalent circuit shown in Figures 2B and 2C.

[0029] In the electropolishing apparatus shown in Figure 1, the workpiece 101 and the counter electrode 103 are immersed in an electrolyte solution 102. The positive terminal of the voltage generator 104 is electrically connected to the workpiece 101, and the negative terminal of the voltage generator 104 is electrically connected to the counter electrode 103. Here, a laminate 200 is fixed as the workpiece 101, and voltage is applied by the voltage generator 104 to energize it, performing electropolishing of the wall surface for purposes such as smoothing (removal of burrs).

[0030] Figure 2A is a schematic cross-sectional view showing an example of a laminate 200 in the electropolishing process. The laminate 200 is a laminate in which at least a substrate 201, a first electrode layer 202, a piezoelectric layer 203, a second electrode layer 205, and a metal pressure chamber wall portion 208 (hereinafter also simply referred to as "wall portion") are laminated in this order, and these may be patterned. Also, as shown in Figure 2A, in the electropolishing process, the positive electrode terminal of the voltage generator 104 and the wall portion 208 are electrically connected so that the surface of the wall portion is electropolished, and the laminate 200 is immersed in the electrolyte solution 102.

[0031] As shown in Figure 2A, a resist member 209 may be provided on the side of the second electrode layer 205 opposite to the first electrode layer 202 such that a region without a wall portion 208 is created. The portion without a wall portion functions as the interior of a pressure chamber, and inkjet ink can be contained within the pressure chamber. In such a laminate 200, when an electric field is applied to the piezoelectric layer 203 by the first electrode layer 202 and the second electrode layer 205, the piezoelectric layer 203 deforms, and the force generated in the piezoelectric layer 203 is transmitted into the pressure chamber, causing the inkjet ink to be ejected.

[0032] As shown in Figure 2A, the laminate 200 may also include other layers, such as an insulating layer 204 for adjusting the electric field applied to the piezoelectric layer, an insulating resin layer 206 for preventing ink penetration or suppressing cracks in the piezoelectric layer, and a seed layer 207 for promoting the formation of walls.

[0033] While not entirely clear, the following factors are considered to be the causes of deterioration in the piezoelectric properties of the pressure chamber component, including the piezoelectric layer, during electropolishing of the wall surface.

[0034] As described above, when performing electrolytic polishing, the laminate 200 is immersed in the electrolyte solution 102. Since the potential of the electrolyte solution 102 is lower than that of the positive electrode, the potential of the substrate 201 immersed in the electrolyte solution 102 becomes relatively lower than that of the wall portion 208 electrically connected to the positive electrode side terminal of the voltage generator 104. Then, if there is an insulating layer such as an insulator or a dielectric (piezoelectric body) between the wall portion 208 and the substrate 201, an electric field is generated in the insulating layer. In FIG. 2A, this insulating layer corresponds to the piezoelectric layer 203 and the insulating resin layer 206.

[0035] FIG. 2B is a diagram showing a simplified equivalent circuit of the potential relationship when electrolytically polishing the laminate 200 shown in FIG. 2A. As described above, as shown in FIG. 2B, in the laminate 200, since the piezoelectric layer 203 and the insulating resin layer 206 form an insulating layer, an electric field is generated in these layers. Among these, it is considered that the piezoelectric characteristics of the piezoelectric layer deteriorate due to the electric field generated in the piezoelectric layer 203.

[0036] In the process of electrolytic polishing, the reason why the piezoelectric characteristics can be improved by performing electrolytic polishing on the surface of the wall portion of the laminate in which the first electrode layer 202 and the second electrode layer 205 are electrically connected is not necessarily clear, but it is considered as follows.

[0037] FIG. 2C is a diagram showing a simplified equivalent circuit of the potential relationship when electrolytically polishing the surface of the wall portion of the laminate 200 in which the first electrode layer 202 and the second electrode layer 205 are electrically connected. As shown in FIG. 2C, even when a potential difference occurs between the wall portion 208 and the substrate 200, if the first electrode layer 202 and the second electrode layer 205 are electrically connected, no electric field is generated in the piezoelectric layer 203. Thereby, it is considered that deterioration of the piezoelectric characteristics does not occur in the process of performing electrolytic polishing.

[0038] Hereinafter, the manufacturing method of the pressure chamber member according to the present embodiment will be described in detail.

[0039] 1-1. Process for preparing the laminate The process for preparing the laminate according to this embodiment involves preparing a laminate in which a first electrode layer, a piezoelectric layer, a second electrode layer, and a metal wall portion for a pressure chamber are laminated on a substrate in this order. However, it is preferable to prepare a laminate in which the first electrode layer and the second electrode layer are electrically connected.

[0040] The following describes a laminate according to this embodiment, showing several embodiments of a laminate in which the first electrode layer and the second electrode layer are electrically connected. Note that the figures showing each embodiment are simplified for illustrative purposes, and the layer configuration, shape, thickness, etc. of each embodiment are not limited by these figures.

[0041] The first to fourth embodiments of the laminate described below are laminates in which at least the piezoelectric layer is patterned and the second electrode layer is in contact with the first electrode layer, or the wall portion is in contact with the first electrode layer and the second electrode layer, respectively.

[0042] A first embodiment of the laminate (hereinafter also referred to as "laminated body (1)") is a laminate in which a piezoelectric layer is patterned, and a second electrode layer is in contact with a first electrode layer at the patterned portion of the piezoelectric layer.

[0043] Figures 3A and 3B are cross-sectional views showing an example of a laminate (1). In Figure 3A, a patterned portion 210 is formed in the in-plane center of the piezoelectric layer, and a part of the second electrode layer is fitted into the patterned portion 210 to form a fitted portion 211, and the second electrode layer 205 is in contact with the first electrode layer 202. In Figure 3B, a patterned portion 210 is formed at the in-plane end of the piezoelectric layer, and a part of the second electrode layer is fitted into the patterned portion 210 to form a fitted portion 211, and the second electrode layer 205 is in contact with the first electrode layer 202.

[0044] A second embodiment of the laminate (hereinafter also referred to as "laminated body (2)") is a laminate in which the piezoelectric layer and the first electrode layer are patterned, and the second electrode layer is in contact with the first electrode layer at the patterned portion of the piezoelectric layer and the first electrode layer.

[0045] Figures 4A and 4B are cross-sectional views showing an example of the laminate (2). In Figure 4A, a patterned portion 210 is formed in the in-plane center of the first electrode layer 202 and the piezoelectric layer 203, and a part of the second electrode layer is fitted into the patterned portion 210 to form a fitted portion 211, and the second electrode layer 205 is in contact with the first electrode layer 202. In Figure 4B, a patterned portion 210 is formed at the in-plane end of the first electrode layer 202 and the piezoelectric layer 203, and a part of the second electrode layer is fitted into the patterned portion 210 to form a fitted portion 211, and the second electrode layer 205 is in contact with the first electrode layer 202.

[0046] A third embodiment of the laminate (hereinafter also referred to as "laminated body (3)") is a laminate in which the piezoelectric layer and the second electrode layer are patterned, and the wall portion 208 in the patterned portion of the piezoelectric layer and the second electrode layer is in contact with the first electrode layer and the second electrode layer, respectively.

[0047] Figures 5A and 5B are cross-sectional views showing an example of the laminate (3). In Figure 5A, a patterned portion 210 is formed in the center of the in-plane area of ​​the piezoelectric layer 203 and the second electrode layer 205. In the patterned portion 210, a part of the wall is fitted in to form a fitted portion 211, and the wall portion 208 is in contact with the first electrode layer 202 and the second electrode layer 205, respectively. In Figure 5B, a patterned portion 210 is formed in the center of the in-plane area of ​​the piezoelectric layer 203 and the second electrode layer 205. In the patterned portion 210, a part of the wall is fitted in to form a fitted portion 211, and the wall portion 208 is in contact with the first electrode layer 202 and the second electrode layer 205, respectively.

[0048] A fourth embodiment of the laminate (hereinafter also referred to as "laminated (4)") is a laminate in which a first electrode layer, a piezoelectric layer, and a second electrode layer are patterned, and the walls of the patterned portions of the first electrode layer, piezoelectric layer, and second electrode layer are in contact with the first electrode layer and the second electrode layer, respectively.

[0049] Figures 6A and 6B are cross-sectional views showing an example of the laminate (4). In Figure 6A, a patterned portion 210 is formed in the in-plane center of the first electrode layer 202, the piezoelectric layer 203, and the second electrode layer 205. In the patterned portion 210, a part of the wall is fitted in to form a fitted portion 211, and the wall 208 is in contact with the first electrode layer 202 and the second electrode layer 205. In Figure 6B, a patterned portion 210 is formed at the in-plane end of the first electrode layer 202, the piezoelectric layer 203, and the second electrode layer 205. In the patterned portion 210, a part of the wall is fitted in to form a fitted portion 211, and the wall 208 is in contact with the first electrode layer 202 and the second electrode layer 205.

[0050] The fifth and sixth embodiments of the laminate described below are laminates in which the piezoelectric layer is not patterned and the first electrode layer and the second electrode layer are electrically connected.

[0051] A fifth embodiment of the laminate (hereinafter also referred to as "laminated body (5)") is a laminate in which electrical connections are made by contact between the conductive member and the first electrode layer and the second electrode layer, respectively.

[0052] Figure 7 is a cross-sectional view showing an example of the laminate (5). In Figure 7, the laminate 200 has an energizing member 212 at its end, and the energizing member 212 is in contact with the first electrode layer 202 and the second electrode layer 205, respectively.

[0053] A sixth embodiment of the laminate (hereinafter also referred to as "laminated body (6)") is a laminate in which a portion of the second electrode layer is in contact with the side surface of the first electrode layer.

[0054] Figure 8 is a cross-sectional view showing an example of the laminate (6). In Figure 8, an overhang portion 214 is formed so that a part of the second electrode layer protrudes from a part of the end face of the laminate, and the overhang portion 214 (part of the second electrode layer) is in contact with the side surface of the first electrode layer 202.

[0055] Among these, it is preferable to prepare a laminate (1) from the viewpoint of suppressing yield reduction. This is because, since only the piezoelectric layer is patterned, it can be patterned under relatively mild conditions (e.g., wet etching), and situations in which a voltage is applied to the piezoelectric layer, such as in plasma treatment of dry etching, are less likely to occur, and the piezoelectric properties tend to improve.

[0056] 1-1-1. Laminate (1): Structure and Formation Method of Patterned and Embedded Parts Below, we will first explain the structure and formation method of the patterned part 210 and the embedded part 211 of laminate (1). The structure and formation method of each layer other than the patterned part 210 and the embedded part 211 will be described together later as they overlap with other laminates.

[0057] Figures 9(a) to 9(e) are cross-sectional views showing an example of the manufacturing process of the laminate (1). In Figure 9(a), a substrate 201 is prepared, and in Figure 9(b), a first electrode layer 202 and a piezoelectric layer 203 are formed on the substrate 201. In Figure 9(c), the piezoelectric layer 203 is patterned to provide a patterned portion 210. In Figure 9(d), a second electrode layer 205 is formed, and a part of the second electrode layer is fitted into the patterned portion 210 to form a fitted portion 211. In Figure 9(e), a wall portion 208 is formed.

[0058] Figures 10(a) to 10(e) are cross-sectional views showing modified examples of the manufacturing process of the laminate (1). In Figures 10(a) to 10(e), the second electrode layer has a two-layer structure consisting of a piezoelectric layer-side region 205a of the second electrode layer and a wall-side region 205b of the second electrode layer. In this case, in Figure 10(a), a substrate 201 is prepared, and in Figure 10(b), the first electrode layer 202, the piezoelectric layer 203, and the piezoelectric layer-side region 205a of the second electrode layer are formed on the substrate 201. In Figure 10(c), the piezoelectric layer 203 and the piezoelectric layer-side region 205a of the second electrode layer are patterned to provide a patterned portion 210. In Figure 10(d), the wall-side region 205b of the second electrode layer is formed, and a part of the second electrode layer is fitted into the patterned portion 210, forming a fitted portion 211. In Figure 9(e), a wall portion 208 is formed.

[0059] (Patterning portion of laminate (1)) The patterning portion 210 is not particularly limited in terms of its formation position, shape, or size, as long as a portion of the second electrode layer is embedded in it and a portion of the second electrode layer is in contact with the first electrode layer 202.

[0060] From the viewpoint of minimizing damage to the product caused by the patterning process, the preferred location for forming the patterned area is the edge of the substrate.

[0061] The shape of the patterned area is preferably circular or rectangular, from the viewpoint of simplifying the manufacturing method.

[0062] The size of the patterned area is preferably 50 μm to 100 μm, from the viewpoint of simplifying the manufacturing method.

[0063] Furthermore, if the laminate 200 includes layers other than the piezoelectric layer 203 between the first electrode layer 202 and the second electrode layer 205, the layers other than the piezoelectric layer between the first electrode layer and the second electrode layer may be patterned. In this case, it is preferable that each layer, including the piezoelectric layer between the first electrode layer and the second electrode layer, has a patterned portion in at least the same in-plane region. This makes it easier for the first electrode layer 202 and the second electrode layer 205 to be electrically connected when a part of the second electrode layer is fitted into the patterned portion 210.

[0064] The method for forming the patterned area 210 is not particularly limited, but known patterning methods can be used. For example, a layer for providing the patterned area (piezoelectric layer 203) can be formed on the entire surface of the piezoelectric layer side of the first electrode layer, a resist member can be applied to the area where the patterned area is not provided, an etching process can be performed to provide the patterned area in the area where the resist member is not formed, and the resist member can be peeled off to form the patterned area.

[0065] As a method for etching the piezoelectric layer 203 as shown in Figure 9, or as a method for etching the piezoelectric layer 203 and a part of the second electrode layer as shown in Figure 10, dry etching or wet etching may be used.

[0066] Known methods can be used to form the resist member, but the resist member can also be formed by applying a resist solution, transferring a mask pattern by exposure, and developing.

[0067] When dry etching is used, examples of etching gases include argon, oxygen, chlorine, bromine, or trifluoromethane (CHF). ３ ) or a mixture of these gases are examples.

[0068] When wet etching is used, examples of etching solutions include a mixture of hydrofluoric acid aqueous solution and nitric acid aqueous solution (hydrofluoric acid-nitric acid), known alkaline solutions (sodium hydroxide aqueous solution, ammonium persulfate aqueous solution), etc.

[0069] In particular, when etching the piezoelectric layer 203, it is preferable to use wet etching.

[0070] Furthermore, when etching the piezoelectric layer 203 and a portion of the second electrode layer, it is preferable to employ dry etching.

[0071] (Insertion portion of laminate (1)) The insertion portion 211 is formed in a manner in which a part of the second electrode layer is inserted and a part of the second electrode layer is in contact with the first electrode layer 202, but its position, shape, and size are not particularly limited.

[0072] The preferred configuration of the formation position, shape, and size of the embedded portion 211 is the same as the preferred configuration of the formation position, shape, and size of the patterned portion.

[0073] The method for forming the embedded portion 211 is not particularly limited, but known electrode formation methods can be used. For example, sputtering can be used as a method for forming the embedded portion 211.

[0074] 1-1-2. Laminate (2): Structure and Formation Method of Patterned and Embedded Parts Below, the structure and formation method of the patterned part 210 and embedded part 211 of laminate (2) will be described. Similar to laminate (1), the structure of each layer other than the patterned part 210 and embedded part 211, and the formation method of each layer, will be described together later as they overlap with other laminates.

[0075] Figures 11(a) to 11(e) are cross-sectional views showing an example of the manufacturing process of the laminate (2). In Figure 11(a), a substrate 201 is prepared, and in Figure 11(b), a first electrode layer 202 and a piezoelectric layer 203 are formed on the substrate 201. In Figure 11(c), the first electrode layer 202 and the piezoelectric layer 203 are patterned to provide a patterned portion 210. In Figure 11(d), a second electrode layer 205 is formed, and a part of the second electrode layer is fitted into the patterned portion 210 to form a fitted portion 211. In Figure 11(e), a wall portion 208 is formed.

[0076] Figures 12(a) to 12(e) are cross-sectional views showing modified examples of the manufacturing process of the laminate (2). In Figure 12, the second electrode layer has a two-layer structure consisting of a piezoelectric layer-side region 205a and a wall-side region 205b of the second electrode layer. In Figure 12(a), a substrate 201 is prepared, and in Figure 12(b), the first electrode layer 202, the piezoelectric layer 203, and the piezoelectric layer-side region 205a of the second electrode layer are formed on the substrate 201. In Figure 12(c), the first electrode layer 202, the piezoelectric layer 203, and the piezoelectric layer-side region 205a of the second electrode layer are patterned to form a patterned portion 210. In Figure 12(d), the wall-side region 205b of the second electrode layer is formed, and a part of the second electrode layer is fitted into the patterned portion 210, forming a fitted portion 211. In Figure 12(e), a wall portion 208 is formed.

[0077] (Patterning portion of laminate (2)) The patterning portion 210 is not particularly limited in terms of its formation position, shape, or size, as long as a portion of the second electrode layer is embedded in it and a portion of the second electrode layer is in contact with the first electrode layer 202.

[0078] The preferred embodiment of the patterned portion in the laminate (2) is the same as the preferred embodiment in the laminate (1).

[0079] It is preferable that the first electrode layer 202 and the piezoelectric layer 203 have patterned areas in at least the same in-plane region. This makes it easier for the first electrode layer 202 and the second electrode layer 205 to be electrically connected when a part of the second electrode layer is fitted into the patterned area 210. Alternatively, the patterned area may be a part of the substrate that is patterned, and even in this case, the first electrode layer 202 and the second electrode layer 205 can still be electrically connected.

[0080] Furthermore, if the laminate 200 includes layers other than the piezoelectric layer 203 between the first electrode layer 202 and the second electrode layer 205, the layers other than the piezoelectric layer between the first electrode layer and the second electrode layer may be patterned. In this case, it is preferable that each layer, including the piezoelectric layer between the first electrode layer and the second electrode layer, has a patterned portion in at least the same in-plane region. This makes it easier for the first electrode layer 202 and the second electrode layer 205 to be electrically connected when a part of the second electrode layer is fitted into the patterned portion 210.

[0081] The method for forming the patterned area 210 is not particularly limited, but known patterning methods can be used. For example, the layer for providing the patterned area (first electrode layer 202 and piezoelectric layer 203) can be formed on the entire surface of the substrate on the first electrode layer side, a resist member can be applied to the area where the patterned area is not provided, an etching process can be performed to provide the patterned area in the area where the resist member is not formed, and the resist member can be peeled off to form the patterned area.

[0082] As for the etching method of the first electrode layer 202 and the piezoelectric layer 203 as shown in Figure 11, or the etching method of the first electrode layer 202, the piezoelectric layer 203 and a part of the second electrode layer as shown in Figure 12, the same method as the example method in the laminate (1) can be used.

[0083] In particular, when etching the first electrode layer 202 and the piezoelectric layer 203, it is preferable to use a combination of wet etching and dry etching.

[0084] Furthermore, when etching the first electrode layer 202, the piezoelectric layer 203, and a portion of the second electrode layer, it is preferable to use a combination of wet etching and dry etching.

[0085] (Insertion portion of laminate (2)) The insertion portion 211 is formed in a manner in which a part of the second electrode layer is inserted and the second electrode layer 205 is in contact with the first electrode layer 202, but its position, shape, and size are not particularly limited.

[0086] The preferred configuration of the formation position, shape, and size of the embedded portion 211 is the same as the preferred configuration of the formation position, shape, and size of the patterned portion.

[0087] The method for forming the embedded portion 211 is not particularly limited, but known electrode formation methods can be used. For example, sputtering can be used as a method for forming the embedded portion 211.

[0088] 1-1-3. Laminate (3): Structure and Formation Method of Patterned and Embedded Parts Below, the structure and formation method of the patterned part 210 and embedded part 211 of laminate (3) will be described. Similar to laminate (1), the structure of each layer other than the patterned part 210 and embedded part 211, and the formation method of each layer, will be described together later as they overlap with other laminates.

[0089] Figures 13(a) to 13(d) are cross-sectional views showing an example of the manufacturing process of the laminate (3). In Figure 13(a), a substrate 201 is prepared, and in Figure 13(b), a first electrode layer 202, a piezoelectric layer 203, and a second electrode layer 205 are formed on the substrate 201. In Figure 13(c), the piezoelectric layer 203 and the second electrode layer 205 are patterned to provide a patterned portion 210. At this time, the patterning is performed so that a part of the wall portion fits into the patterned portion 210 and comes into contact with the first electrode layer and the second electrode layer. In Figure 13(d), a wall portion 208 is formed, and a part of the wall portion fits into the patterned portion 210, forming an embedded portion 211.

[0090] (Patterning portion of laminate (3)) The patterning portion 210 is not particularly limited in terms of its formation position, shape, or size, as long as a part of the wall portion is fitted in and a part of the wall portion is in contact with the first electrode layer 202 and the second electrode layer 205.

[0091] The preferred embodiment of the patterned portion in the laminate (3) is the same as the embodiment in the laminate (1).

[0092] It is preferable that the piezoelectric layer 203 and the second electrode layer 205 have patterned portions in at least the same in-plane region. This makes it easier for the first electrode layer 202 and the second electrode layer 205 to be electrically connected when a part of the second electrode layer is fitted into the patterned portion 210.

[0093] Furthermore, if the laminate 200 includes layers other than the second electrode layer 205 and the piezoelectric layer 203 between the first electrode layer 202 and the wall portion 208, the layers other than the second electrode layer 205 and the piezoelectric layer 203 between the first electrode layer 202 and the wall portion 208 may be patterned. In this case, it is preferable that each layer, including the piezoelectric layer between the first electrode layer and the wall portion, has a patterned portion in at least the same region in the plane. This makes it easier for the first electrode layer 202 and the second electrode layer 205 to be electrically connected when a part of the wall portion is fitted into the patterned portion 210.

[0094] The method for forming the patterned area 210 is not particularly limited, but known patterning methods can be used. For example, the layer for providing the patterned area (piezoelectric layer 203 and second electrode layer 205) can be formed on the entire surface of the piezoelectric layer side of the first electrode layer, a resist member can be applied to the area where the patterned area is not provided, an etching process can be performed to provide the patterned area in the area where the resist member is not formed, and the resist member can be peeled off to form the patterned area.

[0095] As a method for etching the piezoelectric layer 203 and the second electrode layer 205 as shown in Figure 13, a method similar to the example method in the laminate (1) can be used.

[0096] In particular, when etching the piezoelectric layer 203 and the second electrode layer 205, it is preferable to use a combination of dry etching and wet etching.

[0097] (Insertion portion of laminate (3)) The insertion portion 211 is formed in a manner in which a part of the wall portion is inserted and the wall portion 208 is in contact with the first electrode layer 202 and the second electrode layer 205, respectively, but the position, shape, and size of the insertion portion 211 are not particularly limited.

[0098] The preferred configuration of the formation position, shape, and size of the embedded portion 211 is the same as the preferred configuration of the formation position, shape, and size of the patterned portion.

[0099] The method for forming the embedded portion 211 is not particularly limited, but known methods for forming metal layers can be used. One method for forming the embedded portion 211 is electroforming.

[0100] 1-1-4. Laminate (4): Structure and Formation Method of Patterned and Embedded Parts Below, the structure and formation method of the patterned part 210 and embedded part 211 of laminate (4) will be described. Similar to laminate (1), the structure of each layer other than the patterned part 210 and embedded part 211, and the formation method of each layer will be described together later as they overlap with other laminates.

[0101] Figures 14(a) to 14(d) are cross-sectional views showing an example of the manufacturing process of the laminate (4). In Figure 14(a), a substrate 201 is prepared, and in Figure 14(b), a first electrode layer 202, a piezoelectric layer 203, and a second electrode layer 205 are formed on the substrate 201. In Figure 14(c), the first electrode layer 202, the piezoelectric layer 203, and the second electrode layer 205 are patterned to form a patterned portion 210. In Figure 14(d), a wall portion 208 is formed, and a part of the wall portion is fitted into the patterned portion 210 to form a fitted portion 211.

[0102] (Patterning portion of laminate (4)) The patterning portion 210 is not particularly limited in terms of its formation position, shape, or size, as long as a part of the wall portion is fitted in such a way that the wall portion 208 is in contact with the first electrode layer 202 and the second electrode layer 205, respectively.

[0103] The preferred configuration of the patterned portion in the laminate (4) is the same as that in the laminate (1).

[0104] It is preferable that the first electrode layer 202, the piezoelectric layer 203, and the second electrode layer 205 have patterned areas in at least the same region in their plane. This makes it easier for the first electrode layer 202 and the second electrode layer 205 to be electrically connected when a part of the second electrode layer is fitted into the patterned area 210. Alternatively, the patterned area may be a part of the substrate that is patterned, and even in this case, the first electrode layer 202 and the second electrode layer 205 can still be electrically connected.

[0105] Furthermore, if the laminate 200 includes layers other than the second electrode layer 205 and the piezoelectric layer 203 between the first electrode layer 202 and the wall portion 208, the layers other than the second electrode layer 205 and the piezoelectric layer 203 between the first electrode layer 202 and the wall portion 208 may be patterned. In this case, it is preferable that each layer, including the piezoelectric layer between the first electrode layer and the wall portion, has a patterned portion in at least the same region in the plane. This makes it easier for the first electrode layer 202 and the second electrode layer 205 to be electrically connected when a part of the wall portion is fitted into the patterned portion 210.

[0106] The method for forming the patterned area 210 is not particularly limited, but known patterning methods can be used. For example, the layer for providing the patterned area (first electrode layer 202, piezoelectric layer 203, and second electrode layer 205) can be formed on the entire surface of the substrate on the first electrode layer side, a resist member can be applied to the area where the patterned area is not provided, an etching process can be performed to provide the patterned area in the area where the resist member is not formed, and the resist member can be peeled off to form the patterned area.

[0107] As a method for etching the first electrode layer 202, the piezoelectric layer 203, and the second electrode layer 205 as shown in Figure 14, a method similar to the example method in the laminate (1) can be used.

[0108] (Insertion portion of laminate (4)) The insertion portion 211 is formed in a position, shape, and size that is not particularly limited, as long as a part of the wall portion is inserted and the wall portion 208 is in contact with the first electrode layer 202 and the second electrode layer 205.

[0109] The preferred configuration of the formation position, shape, and size of the embedded portion 211 is the same as the preferred configuration of the formation position, shape, and size of the patterned portion.

[0110] The method for forming the embedded portion 211 is not particularly limited, but known methods for forming metal layers can be used. One method for forming the embedded portion 211 is electroforming.

[0111] 1-1-5. Laminate (5): Configuration and Formation Method of Conductive Members The configuration and formation method of the conductive member 212 of laminate (5) will be described below. The configuration and formation method of each layer other than the conductive member 212 will be described together later as they overlap with those of other laminates.

[0112] Figures 15(a) to 15(c) are cross-sectional views showing an example of the manufacturing process of the laminate (5). In Figure 15(a), a substrate 201 is prepared, and in Figure 15(b), a first electrode layer 202, a piezoelectric layer 203, a second electrode layer 205, and a wall portion 208 are formed on the substrate 201. In Figure 15(c), an energizing member 212 is attached to at least a part of the laminate.

[0113] The laminate (5) shown in Figure 15(c) is a laminate 200 having an electrically conductive member 212 on its end face, with a portion of the electrically conductive member in contact with the first electrode layer 202 and the second electrode layer 205. The electrically conductive member 212 only needs to electrically connect the first electrode layer 202 and the second electrode layer 205, and the material, shape, size, and position used can be anything.

[0114] A known conductive material may be used for the conductive member 212. From the viewpoint of ease of formation, solder is preferred for the conductive member 212, but it is not limited to this, and it may be a conductive material containing metals such as copper, silver, gold, or aluminum, or a conductive material containing organic substances such as conductive rubber or adhesive. Examples of solder include solder containing metals such as copper, silver, gold, tin, and bismuth, and may also be silver-copper solder, tin-copper solder, tin-bismuth solder, etc., containing multiple metals from among these.

[0115] The electrical conductivity of the conductive material is 50 × 10 ６ S / m ~ 100 x 10 ６ It is preferable that the member has an S / m ratio.

[0116] From the viewpoint of ease of manufacturing and ease of improving conductivity, it is preferable to form the conductive element on the outer periphery of the substrate.

[0117] From the viewpoint of ease of manufacturing and ease of improving conductivity, the size of the conductive element is preferably formed to a length of several tens of micrometers to several millimeters on the outer periphery of the substrate, but it may also be formed around the entire circumference of the outer periphery of the substrate.

[0118] The method for forming the conductive member 212 is not particularly limited, as long as it is done after the second electrode layer 205 has been formed. For example, as shown in Figure 15, the conductive member 212 may be formed after the wall portion 208 has been formed. The conductive member 212 can be formed, for example, using a soldering iron or the like.

[0119] 1-1-6. Laminate (6): Structure and Formation Method of the Overhang The structure and formation method of the overhang 214 of laminate (6) will be described below. The structure and formation method of each layer other than the overhang 214 will be described together later as they overlap with those of other laminates.

[0120] Figures 16(a) to 16(e) are cross-sectional views showing an example of the manufacturing process of the laminate (6). In Figure 16(a), a substrate 201 is prepared, and in Figure 16(b), a first electrode layer 202 and a piezoelectric layer 203 are formed on the substrate 201. In Figure 16(c), a spacer 213 having a thickness similar to that of the substrate 201 is placed in contact with the end face of the substrate 201, and a second electrode layer 205 is formed as shown in Figure 16(d), thereby forming an overhang 214. As shown in Figure 16(e), the spacer 213 is removed, and a wall portion 208 is formed.

[0121] The laminate (6) shown in Figure 16(e) has an overhang portion 214 formed such that a part of the second electrode layer 205 protrudes from a part of the end face of the laminate, and the overhang portion 214 is in contact with the first electrode layer 202. The overhang portion 214 only needs to electrically connect the first electrode layer 202 and the second electrode layer 205, and its shape, size, and position can be anything.

[0122] From the viewpoint of ease of fabrication and improved conductivity, it is preferable to form the protruding portion on the outer periphery of the substrate.

[0123] From the viewpoint of ease of fabrication and ease of improving conductivity, the size of the protruding portion is preferably several tens of micrometers to several millimeters in length on the outer periphery of the substrate, but it may also be formed around the entire circumference of the outer periphery of the substrate.

[0124] As described above, one method for forming the protruding portion is to use a spacer 213 to form the second electrode layer 205. By placing the spacer 213 in contact with the end face of the substrate 201 and forming the second electrode layer 205 as shown in Figure 17(d), the protruding portion 214 can be formed.

[0125] The height of the spacer used in the above manufacturing method is not particularly limited as long as the formed protruding portion 214 comes into contact with the first electrode layer 202, but it is preferable that the spacer is the same as or thicker than the thickness of the substrate and thinner than the sum of the thickness of the substrate and the thickness of the first electrode layer.

[0126] 1-1-7. Common Structure and Formation Method of Each Laminate The following describes the common structure of each laminate (1) to (6) and the formation method for forming the common structure.

[0127] (Substrate 201) Any known substrate can be used for substrate 201, but a silicon substrate is preferred. The size is not particularly limited, but a diameter φ of 6 to 12 inches is preferred.

[0128] (Adhesion layer (1)) The laminate (1) may have an adhesion layer (1) between the substrate 201 and the first electrode layer 202 to improve the adhesion between the substrate 201 and the first electrode layer (not shown). Examples of materials used for the adhesion layer (1) include titanium, tantalum, iron, cobalt, nickel, or chromium or compounds thereof, and the thickness of the adhesion layer (1) is preferably in the range of 0.005 μm to 0.2 μm.

[0129] When forming the adhesion layer (1), the adhesion layer (1) can be formed, for example, by heating the substrate 201 to 400°C, applying a high-frequency power of 500W to a target material placed opposite it, and sputtering for 1 minute in argon gas at a gas pressure of 1 Pa during sputtering.

[0130] (First electrode layer 202) Examples of materials used for the first electrode layer 202 include platinum, iridium, palladium, titanium, or ruthenium, or compounds thereof. The thickness of the first electrode layer 202 is preferably in the range of 0.005 μm to 2 μm.

[0131] When forming the first electrode layer 202, the first electrode layer 202 is formed on one surface of the substrate 201 (or, if the adhesion layer (1) is formed, on the side opposite to the substrate of the adhesion layer (1)). An example of a formation method is sputtering. For example, a method is exemplified in which the substrate is heated to 600°C and sputtered for 12 minutes with a high-frequency power of 500W in an argon gas with a gas pressure of 1 Pa during sputtering onto a target material placed opposite it.

[0132] (Piezoelectric layer 203) An example of a material used in the piezoelectric layer 203 is PZT(Pb(Zr,Ti)O ３ : Lead zirconate titanate), PMN(Pb(Mg,Nb)O ３ : Lead niobate magnesiumate or PZN (Pb(Zn,Nb)O ３ Examples include lead niobate zincate or those containing additives such as La, Sr, Nb, and Al. Among these, PZT(Pb(Zr,Ti)O) is used to easily enhance piezoelectric properties. ３ It is preferable that lead zirconate titanate is used, and among these, it is more preferable that PZT with a Zr / Ti composition of Zr / Ti = 30 / 70 to 70 / 30 be used. The piezoelectric properties are measured, for example, by the laser Doppler method. In this application, the piezoelectric properties refer to the values ​​measured by the same method.

[0133] Furthermore, the thickness of the piezoelectric layer 203 is preferably 1 μm to 10 μm.

[0134] When forming the piezoelectric layer 203, the piezoelectric layer 203 is formed on the side of the first electrode layer 202 opposite to the substrate 201. An example of a formation method is the sputtering method. When forming the piezoelectric layer 203 by the sputtering method, it is preferable to control the temperature and plasma distribution to be concentrically uniform on the substrate. For example, by arranging inner and outer heaters concentrically to heat a heat-sensing plate (susceptor), and independently controlling the inner and outer heaters, the temperature distribution can be controlled to be concentrically uniform on the substrate. Alternatively, by arranging magnets in a concentric direction or rotating a mold unit with embedded magnets to make the applied magnetic field distribution uniform, the plasma distribution can be controlled to be concentrically uniform on the substrate.

[0135] (Insulator film 204) The laminate (1) preferably has a patterned insulating film 204 between the piezoelectric layer 203 and the second electrode layer 205.

[0136] When forming the insulating film 204, it can be formed, for example, by applying a photosensitive polyimide resin by a spin coating method. The insulating film 204 is formed in areas where lead wiring or electrode pad portions are formed, and is mainly used to prevent short circuits.

[0137] An example of a patterning method for the insulating film 204 is a method in which a mask pattern is transferred by exposure and then developed. After patterning, the film is cured by firing at, for example, 300°C. An example of an exposure apparatus is an apparatus corresponding to the size of the substrate, such as the UX-4438SC aligner manufactured by Ushio Inc. (Hereafter, the same apparatus may be used for exposure in this application.)

[0138] Furthermore, the insulating film 204 is not coated with a photosensitive polyimide resin, but rather SiO ２ These can also be formed by depositing inorganic materials such as these using the sputtering method.

[0139] The pattern of the insulating film 204 can be determined by the pattern that forms the wall portion.

[0140] (Second electrode layer 205) Examples of materials used for the second electrode layer 205 include copper, chromium, nickel, aluminum, tantalum, tungsten, or silicon or its oxides or nitrides (e.g., silicon dioxide, aluminum oxide, zirconium oxide, silicon nitride).

[0141] Furthermore, the film thickness of the second electrode 205 is preferably 1 to 10 μm.

[0142] The second electrode layer 205 may have a multilayer structure, and each layer may be made of a different type of metal. Furthermore, when the second electrode layer 205 has a two-layer structure, it is preferable to use a material with a lower Young's modulus in the piezoelectric layer side region 205a of the second electrode layer than the material used in the wall side region 205b of the second electrode layer. This reduces stress concentration in the piezoelectric layer 203 during the fabrication of the laminate 200, enabling the construction of a stable process. In addition, since the displacement surface of the piezoelectric layer 203 is set further outward, the force generated in the piezoelectric layer is more efficiently transmitted to the pressure chamber.

[0143] When forming the second electrode layer 205, the second electrode layer 205 is formed on the side of the first electrode layer 203 opposite to the substrate 201. An example of a formation method is the sputtering method.

[0144] For example, when forming a second electrode layer consisting of two layers, a 1.5 μm metal film is formed by using a metal for the first layer (e.g., copper) and applying a high-frequency power of 500 W in argon gas at a gas pressure of 1 Pa during sputtering at room temperature for 170 minutes. A 2.0 μm metal film is then formed by using a metal for the second layer (e.g., chromium) and applying a high-frequency power of 500 W in argon gas at a gas pressure of 1 Pa during sputtering at room temperature for 220 minutes.

[0145] (Resin layer 206) The laminate (1) may have a resin layer 206 between the second electrode layer 205 and the wall portion 208.

[0146] The resin layer 206 prevents ink penetration and prevents cracking of the piezoelectric layer. It also functions as a stress relaxation layer. The thickness of the resin layer 206 is preferably 1.0 μm to 1.5 μm.

[0147] Examples of materials used for the resin layer 206 include polyimide resin or a resin composition thereof. Alternatively, the material used for the resin layer 206 may be a photosensitive resin or resin composition, and the resin layer 206 may be patterned.

[0148] When forming the resin layer 206, for example, a photosensitive polyimide resin can be applied by spin coating and fired at 200°C. When patterning the resin layer 206, the resin layer 206 can be patterned by developing the photosensitive polyimide resin by exposure to a mask pattern before firing.

[0149] (Adhesion layer (2)) If the laminate (1) has a resin layer 206 and a seed layer 207, it may have an adhesion layer (2) between them to improve the adhesion between the resin layer 206 and the seed layer 207 (not shown).

[0150] Examples of materials used for the adhesion layer (2) include those selected considering their affinity with the resin layer 206, such as chromium, titanium, or molybdenum.

[0151] (Seed layer 207) The laminate (1) may have a seed layer 207 in contact with the second electrode layer 205 side of the wall portion 208.

[0152] As an example of the material used for the seed layer 207, it is preferable that it contains the same metal as the material used for the wall portion 208, which will be described later. The thickness of the seed layer 207 is preferably about 0.5 μm.

[0153] When forming the seed layer 207, it is preferable that the seed layer 207 be formed over the entire surface of the substrate, and this can be done by sputtering.

[0154] (Wall portion 208) Examples of materials used for the wall portion 208 include copper, nickel, or iron, or these metals containing small amounts of other metals such as cobalt, molybdenum, or ruthenium. Among these, nickel or nickel containing small amounts of other metals is preferred.

[0155] Furthermore, the thickness of the wall portion 208 is preferably 100 μm to 200 μm.

[0156] The hardness of the wall portion 208 is preferably 400 Hv to 700 Hv from the viewpoint of processability and processing accuracy in the subsequent polishing process. The hardness can be measured using the ENT110a ultra-micro indentation hardness tester manufactured by Elionix Corporation.

[0157] (Method for forming the wall portion 208) When forming the wall portion 208, the wall portion 208 is formed on the side of the second electrode layer 205 opposite to the piezoelectric layer 203. Electroforming is an example of a formation method. Electroforming can be carried out by known methods, but below, a method of forming the wall portion 208 using nickel electroforming will be described in particular.

[0158] Degreasing may be performed before nickel electroforming, and the following methods can be used. For example, a surfactant (World Metal L505-B) can be mixed with pure water in a 1:5 ratio and treated at a liquid temperature of 40°C for 1 minute. After degreasing, it is advisable to rinse and wash with pure water, and then perform acid washing. Acid washing can be performed using 10% hydrochloric acid and treated at a liquid temperature of 40°C for 30 seconds. After acid washing, rinse and wash with pure water again.

[0159] Nickel electroforming can be performed using a nickel electroplating apparatus as shown in Figure 17. In the apparatus shown in Figure 17, a workpiece 301 and a counter electrode 303 are immersed in a plating solution 302, the negative terminal of a voltage generator 304 is electrically connected to the workpiece 301, and the positive terminal of the voltage generator 304 is electrically connected to the counter electrode 303. The nickel electroplating apparatus may also have a pump, filter, reserve tank, etc. (not shown) for circulating the plating solution 302.

[0160] As the plating solution 302, for example, in a chemical solution ratio of 100 L of liquid volume, 56 L of nickel sulfamate at 60%, 1.0 kg of nickel chloride, 3.0 kg of boric acid, 0.3 L of a stress reliever (NSF-H-4 manufactured by Nippon Chemical Industry Co., Ltd.), and 1.0 L of a pitting inhibitor (Pitless S manufactured by Nippon Chemical Industry Co., Ltd.) are added, and pure water is added to make a total of 100 L to prepare a plating solution that can be used. Also, in order to adjust the hardness, gloss, etc. after electroforming, additives containing a small amount of other metals such as cobalt, molybdenum, ruthenium, etc. can be added. These metals are deposited in a small amount on the workpiece 301 together with nickel during electroforming.

[0161] As the device conditions for forming the wall portion 208, for example, with the electrode distance being 85 mm, the liquid temperature being 40°C, and the pH being maintained in the range of 4.0 to 4.5, the current density applied between the electrodes is set to 8 A / dm ２ and electroplating is performed for 3 hours, so that a 180-μm wall portion is deposited.

[0162] (Resist member 209) The laminate (1) may have a patterned resist member 209.

[0163] The resist member 209 is formed in a portion corresponding to the inside of the pressure chamber of the inkjet head or the cutting portion when chip-forming, etc. When depositing the wall portion 208 by the above-described electroforming method, if there is the resist member 209, the wall portion 208 can be prevented from being deposited on that portion.

[0164] As the resist member 209, a known resist member can be used, but a dry film resist may also be used. Examples of commercially available dry film resists include ORDYL MP108 manufactured by Tokyo Ohka Kogyo Co., Ltd. Note that the "dry film resist" refers to a film-like resist material that is pasted on a wiring board when manufacturing a printed wiring board, etc. and is used to form a circuit.

[0165] When forming the resist member 209, the resist member 209 can be formed by a known method. Degreasing treatment may be performed before forming the resist member 209. The degreasing treatment can use the same conditions as those used when forming the wall portion 208.

[0166] For example, when forming a dry film resist layer, the dry film resist is applied to the entire surface, and then pattern exposure and development are performed so that the dry film resist layer remains in areas corresponding to the inside of the pressure chamber of the inkjet head or the cut areas when chipping. This ensures that the dry film resist layer remains in the areas that will become the inside of the pressure chamber of the inkjet head.

[0167] By increasing the exposure time and development time, the shape of the dry film resist layer can be adjusted so that the width on the side of the second electrode layer 205 is narrowed, thereby adjusting the wall portion 208 so that the width on the side opposite to the second electrode layer 205 is narrowed. For example, exposure can be performed for 40 seconds at 500W using a UX-4438SC aligner manufactured by Ushio Inc., and development can be performed for 1 minute in a 0.1% sodium carbonate aqueous solution at 30°C, thereby adjusting the wall portion 208 so that the width on the side opposite to the second electrode layer 205 is narrowed.

[0168] By changing the exposure and development conditions, when the height of the dry film resist is 160 μm, the difference in width between the top and bottom of the dry film resist layer can be adjusted within the range of 0 μm to 30 μm.

[0169] 1-2. Process of electrolytically polishing the surface of the wall portion The process of electrolytically polishing the surface of the wall portion according to this embodiment is not particularly limited as long as the electrolytic polishing is performed while the first electrode layer 202 and the second electrode layer 205 are electrically connected.

[0170] Figure 18A is a cross-sectional view showing an example of a laminate 200 using laminate (1) before electropolishing. On the other hand, Figure 18B is a cross-sectional view showing an example of a laminate 200 using laminate (1) after electropolishing. As described above, the laminates (1) to (6) described above are preferably used as the laminate 200 in which the first electrode layer 202 and the second electrode layer 205 are electrically connected.

[0171] Before electropolishing, one side of the wall portion 208 opposite to the second electrode layer 205 of the laminate 200 may be physically polished. If the laminate 200 has a resist member 209, both the wall portion 208 and the resist member 209 may be physically polished. The method of physical polishing is not particularly limited, but for example, it may be physically polished using a DAG810 grinding machine manufactured by Disco Corporation, with a resin grinding wheel #320, at a grinding wheel rotation speed of 4000 rpm, a table rotation speed of 300 rpm, and a surface area of ​​15 μm / min.

[0172] Electropolishing can be performed using the electropolishing apparatus shown in Figure 1 above. As shown in Figure 1, the workpiece 101 and the counter electrode 103 are immersed in the electrolyte solution 102, the positive terminal of the voltage generator 104 is electrically connected to the workpiece 101, and the negative terminal of the voltage generator 104 is electrically connected to the counter electrode 103. Here, electropolishing can be performed by using a laminate 200 as the workpiece 101.

[0173] Examples of electrolyte solutions include commonly used electrolytes such as phosphoric acid. Examples of counter electrodes include stainless steel. The distance between counter electrodes is preferably in the range of 1 cm to 100 cm, and more preferably in the range of 5 cm to 50 cm. The current density during electropolishing is 10 A / m ２ ~1000 A / m ２ It is preferable that the range be 50 A / m ２ ~500 A / m ２ This is preferable.

[0174] 2. Method for Manufacturing an Inkjet Head The method for manufacturing an inkjet head according to this embodiment is not particularly limited as long as it includes the above-described method for manufacturing the pressure chamber member. The method for manufacturing an inkjet head according to this embodiment preferably includes a step of bonding the nozzle plate, and more preferably includes a step of bonding the ink flow channel member.

[0175] The following describes an example of an inkjet head manufacturing method, specifically the method using the laminated body (1), with reference to the figures. Note that the figures illustrating the manufacturing method are simplified for illustrative purposes, and the layer configuration, shape, thickness, etc., of each embodiment are not limited to these figures.

[0176] (Removal of resist member 209) The resist member 209 is removed to form a portion corresponding to the inside of the pressure chamber of the inkjet head.

[0177] Known methods for removing resists may be used. For example, when using a dry film resist, the resist member 209 can be removed by immersing it in MP2, a release agent manufactured by Tokyo Ohka Co., Ltd., at a liquid temperature of 60°C to 70°C for 3 hours. Brush cleaning may be performed in conjunction with immersion in the release agent, and the release agent may be washed and dried after the release agent treatment.

[0178] (Transfer to holding substrate 216 and removal of substrate 201) As shown in Figure 19, the holding substrate 216 is bonded to the side of the wall portion 208 opposite to the second electrode layer using a heat release sheet 215. The material of the holding substrate 216 is not particularly limited, and a glass substrate or the like may be used. The size of the holding substrate 216 is not particularly limited, but it is preferable that it be approximately the same size as the substrate 201.

[0179] The surface of the heat release sheet 215 facing the wall portion 208 is preferably heat release. The adhesion between the holding substrate 216 and the heat release sheet 215 may be heat release, or a non-heat release adhesive such as UV resin may be used. For example, the heat release sheet 215 can be one manufactured by Nitto Denko Corporation.

[0180] Furthermore, considering the process load, reinforcing adhesive may be applied to the edges of the substrate as needed.

[0181] After bonding the holding substrate 216, the substrate 201 is removed. Removal of the substrate 201 can be performed by dry etching, but prior to dry etching, the substrate may be removed by grinding or other processes until its thickness reaches 20 μm to 100 μm. The etching gas is sulfur hexafluoride (SF6). ６It is preferable to use ), which helps to suppress physical influence on the piezoelectric layer.

[0182] If an adhesion layer 1 is formed between the substrate 201 and the first electrode 202, this adhesion layer 1 may be removed in the same way as the substrate 201, but it does not have to be removed.

[0183] (Patterning of the first electrode layer 202 and piezoelectric layer 203) As shown in Figures 20A and 20B, the first electrode 202 and the piezoelectric layer 203 are patterned by photolithography.

[0184] Figure 20A shows an example of a patterning method when the area where the wall portion was not deposited by the resist member 209 becomes the interior of the pressure chamber of the inkjet head. It is preferable that the first electrode layer 202 remains in part or all of the area corresponding to the interior of the pressure chamber of the inkjet head, from the viewpoint of facilitating the transmission of the force generated by the piezoelectric layer to the pressure chamber.

[0185] Figure 20B shows an example of a patterning method when the area where the wall portion was not deposited is used as a cut portion 218 for chipping the pressure chamber member 219. Preferably, the cut portion 218 is patterned in such a way that the first electrode layer 202 is removed.

[0186] The patterning method for the first electrode 202 is not particularly limited, but can be performed by forming a resist member, dry etching, and peeling off the resist member. The etching gas can be argon, oxygen, or trifluoromethane (CHF). ３ ) or a mixture of these gases may be used. The resist member is formed by coating the resist, transferring the mask pattern by exposure, and developing.

[0187] Furthermore, as shown in Figure 20A, when patterning the first electrode 202, lead wiring and electrode pad portions may be formed extending from the first electrode layer.

[0188] Next, as shown in Figures 20A and 20B, the piezoelectric layer 203 is patterned by photolithography.

[0189] As shown in Figure 20A, it is preferable that the piezoelectric layer 203 is patterned so that it is removed in a portion of the region corresponding to the inside of the pressure chamber of the inkjet head.

[0190] Furthermore, as shown in Figure 20B, it is preferable that the piezoelectric layer 203 be removed in the region corresponding to the cut portion 218 for chipping the pressure chamber member.

[0191] Patterning of the piezoelectric layer 203 can be performed by forming a resist member, etching it away, or stripping the resist member. Etching can be either dry etching or wet etching. In the case of dry etching, an example of an etching gas is a mixed gas of chlorine and bromine. In the case of wet etching, an example of an etching solution is a mixed solution of hydrofluoric acid aqueous solution and nitric acid aqueous solution (hydrofluoric acid-nitric acid).

[0192] (Formation of protective film 217) If necessary, a protective film 217 may be formed on the side of the first electrode layer 202 opposite to the piezoelectric layer 203, as shown in Figures 21A and 21B, and may be patterned as necessary to form a pressure chamber member 219 including the piezoelectric layer 203.

[0193] Figure 21A shows an example of a method for forming a protective film 217 in a region corresponding to the inside of the pressure chamber of the inkjet head. Figure 21B also shows an example of a method for forming a protective film 217 in a region corresponding to the cut portion 218 for chipping the pressure chamber member 219. As shown in Figure 21B, it is preferable that the protective film 218 be removed from part or all of the region corresponding to the cut portion 218 for chipping the pressure chamber member 219 through patterning.

[0194] Examples of materials for the protective film 217 include photosensitive polyimide resin, and for example, the protective film 217 can be formed by a spin coating method. When forming a patterned protective film 217, it is preferable that after coating the entire surface, the protective film 217 corresponding to the cut portion 218 is removed during the chipping process described later.

[0195] (Formation of the cut portion 218) Figure 22 shows an example of a method for removing the second electrode layer 205, the resin layer 206, and the seed layer 207 in the region corresponding to the cut portion 218 for chipping the pressure chamber member 219. As shown in Figure 22, it is preferable that the second electrode layer 205, the resin layer 206, and the seed layer 207 are removed in the region corresponding to the cut portion 218 for chipping the pressure chamber member 219.

[0196] The cut portion 218 is formed by removing the second electrode layer 205, the resin layer 206, and the seed layer 207. The removal of the second electrode layer 205, the resin layer 206, and the seed layer 207 is preferably performed by laser processing, from the viewpoint of minimizing damage to the piezoelectric layer.

[0197] Furthermore, if there is no resin layer 206 in the region corresponding to the cut portion 218, the removal of the second electrode layer 205 and the seed layer 207 may be performed by laser processing or by photolithography.

[0198] For laser removal, UV (ultraviolet) lasers can be used.

[0199] Removal by photolithography can be performed by forming a resist member, etching it away, and then peeling off the resist member. After peeling off the resist member, rinsing and washing are preferably performed.

[0200] If the material of the second electrode layer 205 is chromium, it can be etched using an etching solution prepared by mixing, for example, 1000 parts by mass of pure water, 200 parts by mass of potassium ferricyanide, and 60 parts by mass of sodium hydroxide.

[0201] If the material of the second electrode layer 205 is copper, it can be etched using an etching solution prepared by mixing, for example, 1000 parts by mass of pure water, 90 parts by mass of ammonium persulfate, and 6 parts by mass of ammonium chloride.

[0202] Furthermore, when using such an alkaline etching solution, it is preferable to use an alkali-resistant rubber-based resist as the resist material; for example, OMR resist manufactured by Tokyo Ohka Chemical Industries can be used.

[0203] Examples of etching gases used to etch away the seed layer include argon, oxygen, or CHF. ３ Or, a mixture of these gases may be used.

[0204] (Chip Formation) Figure 23 is a plan view of the pressure chamber member 219 to which the holding substrate 216 is attached, as seen from the protective film 217 side. From this, the area to be incorporated into the inkjet head (inkjet head integration area 401) is extracted according to the shape of the inkjet head, etc., and chip formation is performed. At this time, as shown in Figure 23, it is preferable that a cut portion 218 is provided on the outer edge of the inkjet head integration area 401.

[0205] Furthermore, as shown in Figure 23, the area of ​​the cut portion 218 opposite to the inkjet head mounting area 401 (the separated area 402) may be an area that is not incorporated into the inkjet head. When forming such a separated area 402, it is preferable that the area in which the first electrode layer and the second electrode layer are electrically connected is included in the separated area 402. Also, in the pressure chamber member 219 from which the separated area 402 has been removed, it is preferable that the first electrode layer and the second electrode layer are not electrically connected.

[0206] Chip formation is performed by removing the retaining substrate 216 from the pressure chamber member 219. If the retaining substrate 216 is bonded with a heat release sheet 212, it can be removed by heating it to a temperature above the foaming temperature of the heat release sheet using a hot plate or heating furnace.

[0207] (Bonding to nozzle plate) The pressure chamber member 219, which has been chipped by removing the holding substrate 216, can be bonded to the nozzle plate to manufacture an inkjet head. A known nozzle plate can be used.

[0208] Furthermore, in addition to the nozzle plate, ink flow path members including a common liquid chamber, supply port, and ink flow path may be bonded to the pressure chamber member 219. For example, in the pressure chamber member 219, adhesive may be applied to the side of the wall opposite to the seed layer, and a nozzle plate manufactured by a known method may be bonded to it after alignment adjustment.

[0209] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the examples, the units "parts" or "%" are used, and unless otherwise specified, they refer to "parts by mass" or "mass%".

[0210] In each process, a multi-channel sputtering system was used for sputtering. Furthermore, a UX-4438SC aligner manufactured by Ushio Inc. was used as the exposure system.

[0211] (Fabrication of the laminate in Example 1) [Formation of adhesion layer 1] An adhesion layer 1 of 0.02 μm was formed on an 8-inch silicon substrate by sputtering using a Ti target. The sputtering conditions were a temperature of 400°C, a high-frequency power of 500 W, and an argon gas atmosphere with a gas pressure of 1 Pa during sputtering, with a sputtering time of 1 minute.

[0212] [Formation of the first electrode layer] A 0.2 μm first electrode layer was formed using a sputtering method with a Pt target. The sputtering conditions were a temperature of 600°C, a high-frequency power of 500 W, and an argon gas atmosphere with a gas pressure of 1 Pa during sputtering, with a sputtering time of 12 minutes.

[0213] [Formation of Piezoelectric Layer] A 3 μm piezoelectric layer was formed by sputtering using a PZT. The sputtering conditions were: temperature 580°C, high-frequency power 500 W, and a mixed atmosphere of argon and oxygen with a gas pressure of 0.3 Pa during sputtering (gas volume ratio Ar:O ２ The ratio was 20:2, and the sputtering time was 180 minutes. For the PZT, a sintered body with a higher Pb content than the stoichiometric composition (Zr / Ti = 53 / 47, 20 mol% excess Pb) was used.

[0214] [Formation of patterned areas in the piezoelectric layer] The piezoelectric film is removed by wet etching. A mixture of aqueous fluorine solution and aqueous nitric acid solution (fluorinated nitric acid) is prepared and used as the etching solution.

[0215] [Formation of the second electrode layer] A second electrode layer consisting of a 1.5 μm copper film and a 2.0 μm chromium film was formed by sputtering. The sputtering conditions for the copper film were room temperature, high-frequency power of 500 W, an argon gas atmosphere with a gas pressure of 1 Pa during sputtering, and a sputtering time of 170 minutes. The sputtering conditions for the chromium film were room temperature, high-frequency power of 500 W, an argon gas atmosphere with a gas pressure of 1 Pa during sputtering, and a sputtering time of 120 minutes. As a result, a portion of the second electrode layer was embedded in the patterned area of ​​the piezoelectric layer, electrically connecting the first electrode layer and the second electrode layer.

[0216] [Formation of an insulating resin layer] A photosensitive polyimide resin was applied by spin coating and cured by firing at 200°C to obtain an insulating resin layer with a thickness of 1 μm.

[0217] [Formation of Seed Layer] A 0.5 μm nickel seed layer was formed by sputtering. The sputtering conditions were a high-frequency power of 500 W, an argon gas atmosphere with a gas pressure of 1 Pa during sputtering, and a sputtering time of 15 minutes.

[0218] [Formation of Resist Material] A 160 μm dry film resist layer was formed by laminating two layers of 80 μm thick dry film resist, ORDYL MP108, manufactured by Tokyo Ohka Co., Ltd. The resist layer was patterned by exposure and development so that the resist remained in the areas corresponding to the pressure chamber and the cut surface. Exposure was performed by processing at 500 W for 40 seconds, and development was performed by processing in a 0.1% sodium carbonate aqueous solution at 30°C for 1 minute.

[0219] [Wall Formation] The walls were formed using a nickel electroplating apparatus. The plating solution used was prepared by adding 5.6 L of 60% nickel sulfamate, 0.1 kg of nickel chloride, 0.3 kg of boric acid, 0.03 L of stress relaxation agent (NSF-H-4, manufactured by Nippon Chemical Industries Co., Ltd.), and 0.1 L of pitting prevention agent (Pitless S, manufactured by Nippon Chemical Industries Co., Ltd.) to 10 L of chemical solution, and then adding pure water to make a total volume of 10 L. The apparatus conditions were: electrode distance of 85 mm, liquid temperature of 40°C, pH in the range of 4.0 to 4.5, and current density applied between electrodes of 8 A / dm２ By setting the temperature to [value] and performing electroplating for 3 hours, a wall portion of 180 μm was formed, and the laminate of Example 1 was created.

[0220] (Fabrication of the laminate of Comparative Example 1) The laminate of Comparative Example 1 was formed in the same manner except that patterned areas were not formed in the piezoelectric layer. As a result, a laminate was formed in which the first electrode layer and the second electrode layer were not electrically connected.

[0221] (Electropolishing of Laminates) The laminate of Example 1 and the laminate of Comparative Example 1, prepared as described above, were electropolished under the following conditions to produce the pressure chamber members of Example 1 and Comparative Example 1. Phosphoric acid was used as the electrolyte for electropolishing. Stainless steel was used for the counter electrode, and the distance to the workpiece was adjusted to 10 cm. The current density during electropolishing was 20 A / m ２ Amperes per square meter were used. (Evaluation) [Piezoelectric properties of pressure chamber members] A sinusoidal AC voltage was applied between the first electrode layer and the second electrode layer, and the amount of displacement was measured using a laser Doppler displacement meter. The AC voltage was applied by gradually increasing the voltage from 1V to 50V using an AC voltage from 100Hz to 100kHz. At this time, the frequency was determined so as to avoid the resonance frequency of the actuator. For each laminate of Example 1 and Comparative Example 1, the amount of displacement was measured using a laser Doppler displacement meter, and the piezoelectric properties were evaluated using the displacement of the laminate of Comparative Example 1 as the reference and its magnification.

[0222]

[0223] As can be seen from Table 1, in the electrolytic polishing process of the wall portion, the pressure chamber member in the embodiment in which the first electrode layer and the second electrode layer were electrically connected exhibited better piezoelectric properties than the pressure chamber member in the comparative example.

[0224] This application claims priority under Japanese Patent Application No. 2024-221601, filed on 18 December 2024. All provisions of the said application are incorporated herein by reference.

[0225] The present invention's method for manufacturing an inkjet head can enhance piezoelectric properties. Therefore, the present invention is useful in the field of image formation.

[0226] 101 Workpiece 102 Electrolyte solution 103 Counter electrode 104 Voltage generator 200 Laminate 201 Substrate 202 First electrode layer 203 Piezoelectric layer 204 Insulator layer 205 Second electrode layer 205a Piezoelectric layer side region of the second electrode layer 205b Wall side region of the second electrode layer 206 Resin layer 207 Seed layer 208 Wall portion 209 Resist member 210 Patterning area 211 Insertion portion 212 Conductive member 213 Spacer 214 Overhang portion 215 Thermal release sheet 216 Holding substrate 217 Protective film 218 Cut portion 219 Pressure chamber member 301 Workpiece 302 Plating solution 303 Counter electrode 304 Voltage generator 401 Inkjet head mounting area 402 Separation area

Claims

1. A method for manufacturing a pressure chamber member, comprising the steps of: preparing a laminate in which a first electrode layer, a piezoelectric layer, a second electrode layer, and a metal wall portion for a pressure chamber are stacked on a substrate in this order; and electropolishing the surface of the wall portion of the laminate, wherein the electropolishing step is performed while the first electrode layer and the second electrode layer are electrically connected.

2. The method for manufacturing a pressure chamber member according to claim 1, wherein the electrical connection is made by contact between the second electrode layer and the first electrode layer.

3. The method for manufacturing a pressure chamber member according to claim 2, wherein the piezoelectric layer is patterned, and the second electrode layer is in contact with the first electrode layer in the patterned portion.

4. The method for manufacturing a pressure chamber member according to claim 2, wherein the first electrode layer and the piezoelectric layer are patterned, and the second electrode layer is in contact with the first electrode layer in the patterned portion.

5. The method for manufacturing a pressure chamber member according to claim 1, wherein the electrical connection is made by contact between the wall portion and the first electrode layer and the second electrode layer, respectively.

6. The method for manufacturing a pressure chamber member according to claim 5, wherein the piezoelectric layer and the second electrode layer are patterned, and in the patterned portion, the wall portion is in contact with the first electrode layer and the second electrode layer, respectively.

7. The method for manufacturing a pressure chamber member according to claim 5, wherein the first electrode layer, the piezoelectric layer, and the second electrode layer are patterned, and in the patterned portion, the wall portion is in contact with the first electrode layer and the second electrode layer, respectively.

8. The method for manufacturing a pressure chamber member according to claim 1, wherein the electrical connection is made by contact between the energizing member and each of the first electrode layer and the second electrode layer.

9. The method for manufacturing a pressure chamber member according to claim 8, wherein the energizing member is solder.

10. The method for manufacturing a pressure chamber member according to claim 2, wherein the second electrode layer is in contact with the side surface of the first electrode layer.

11. A method for manufacturing a pressure chamber member according to claim 1, comprising the step of chipping the electropolished laminate, wherein in the chipping step, a region of the laminate in which the first electrode layer and the second electrode layer are electrically connected is removed.

12. The method for manufacturing a pressure chamber member according to claim 1, wherein the laminate has an insulating resin layer between the second electrode layer and the pressure chamber member.

13. The method for manufacturing a pressure chamber member according to claim 1, wherein the piezoelectric layer contains lead zirconate titanate.

14. The method for manufacturing a pressure chamber member according to claim 1, wherein both the first electrode layer and the second electrode layer contain a metal selected from the group consisting of Ti, Cu, Cr, Ni, and Ir.

15. A method for manufacturing an inkjet head, comprising a method for manufacturing a pressure chamber member according to any one of claims 1 to 14.

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