JP2007185833A - Method for manufacturing electrode substrate and method for manufacturing liquid droplet ejection head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an electrode substrate capable of preventing chipping due to processing of a through-hole when an electrode is formed on a glass substrate to make the electrode substrate after the through-hole such as an ink supply hole is processed to be formed on the glass substrate. <P>SOLUTION: This method for manufacturing the electrode substrate comprises a step of drilling the ink supply hole 23 on the glass substrate 2a, and then sequentially laminating an etching protection film 51 and a dry film resist 71 on one face of the glass substrate 2a having the ink supply hole 23, a step of carrying out patterning by photolithography in alignment with a groove shape for forming the etching protection film 51, a step of forming a groove 21 on the surface of the glass substrate 2a by dipping the glass substrate 2a with the ink supply hole 23 and the etching protection film 51 patterned thereon to an etching liquid, and a step of forming the electrode 22 in the groove 21 by forming a film of a conductive material on the glass substrate 2a. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an electrode substrate that can be used as a fixed electrode among a pair of electrodes constituting an electrostatic drive actuator, and a method for manufacturing a droplet discharge head using the same.

The electrostatic drive type ink jet head has a cavity substrate on which a discharge chamber (also referred to as a pressure chamber) for discharging liquid using pressure fluctuation caused by elastic displacement of the bottom surface, and a bottom surface (also referred to as a vibration plate) of the discharge chamber. ) And an electrode substrate on which an electrode for elastic displacement is formed, and the bottom surface of the discharge chamber and the electrode constitute an electrostatic drive actuator.
As a method of manufacturing such a droplet discharge head, after bonding a silicon substrate before flow path formation to a glass substrate on which a plurality of electrodes are formed, the silicon substrate is thinned, and a discharge chamber is formed in the thinned silicon substrate. A method of forming a flow path such as is proposed (see, for example, Patent Documents 1 and 2). By this method, a large-diameter silicon substrate can be used, and cracks in the silicon substrate during processing can be reduced.
JP 2004-306444 A Japanese Patent Laid-Open No. 11-993

  However, when a minute foreign matter is sandwiched between the interface between the cavity substrate and the electrode substrate constituting the actuator, the vibration plate constituting the bottom surface of the discharge chamber is easily damaged. In addition, defective bonding between the cavity substrate and the electrode substrate due to foreign matter is likely to occur. In particular, when the ink supply hole (through hole) of the electrode substrate is formed by machining, there are a large number of foreign matter generation sources such as processing residue and processing waste (hereinafter referred to as chipping) in the hole. There are many. Then, there is a high possibility that this chipping is detached from the inside of the hole during cleaning before anodic bonding and reattaches to the substrate surface to become a foreign substance.

  The present invention has been made in view of the above problems. When an electrode is formed on a glass substrate after processing and forming a through hole such as an ink supply hole, chipping caused by processing of the through hole is prevented. The present invention proposes a method of manufacturing an electrode substrate that does not remain, and a method of manufacturing a droplet discharge head using the method.

The electrode substrate manufacturing method of the present invention includes a step of forming a through hole in a glass substrate, then sequentially laminating an etching protective film and a dry film resist on one surface of the glass substrate, and a groove to be formed by photolithography. Patterning the etching protective film in accordance with the shape; immersing the glass substrate patterned with the etching protective film in an etching solution to form a groove on the surface of the glass substrate; and a conductive material on the glass substrate. And forming an electrode in the groove.
According to this method, the chipping in the through hole is simultaneously removed by etching in the groove forming etching step. Further, by using a dry film resist for patterning the etching protective film of the glass substrate, good patterning is possible even if the glass substrate has a through hole.

The method for producing an electrode substrate according to the present invention includes a step of sequentially forming an etching protective film and a dry film resist on one surface of the glass substrate after forming the through holes in the glass substrate, and the through holes by photolithography. Removing the surrounding etching protective film, immersing the glass substrate in an etching solution to form a recess recessed around the through hole from other portions, and peeling the dry film from the glass substrate; Coating the inside of the substrate with a dry film resist, applying a resist to the glass substrate surface on the side where the recess is formed, and patterning the etching protective film in accordance with the groove shape to be formed by photolithography And a step in which the etching protective film is patterned. Comprising forming a groove on the surface of the glass substrate to scan the substrate is immersed in an etching solution, and forming an electrode in the groove by forming a conductive material on the glass substrate.
According to this method, the chipping in the through hole is simultaneously removed by etching in the etching process for forming the recess around the through hole. In addition, since the resist for patterning the etching protective film of the glass substrate is applied in a state where the through hole is closed with the dry film resist, high-precision patterning is possible even for the glass substrate having the through hole.

  The through hole may be formed by machining using a drill or sandblast. Even if chipping occurs due to the machining of the glass substrate, it is removed by the subsequent etching process.

The method for manufacturing a droplet discharge head according to the present invention includes joining the silicon substrate to the electrode substrate manufactured by any one of the above methods through a gap, etching the silicon substrate, and And a reservoir for supplying the liquid to the pressure chamber is formed, and the reservoir is communicated with the through hole.
Further, in the method for manufacturing a droplet discharge head of the present invention, a silicon substrate is bonded to the electrode substrate manufactured by any one of the above methods through a gap between the electrodes, and the silicon substrate is etched. A pressure chamber whose bottom surface corresponding to the electrode is elastically displaceable, a reservoir substrate on which a reservoir for supplying the liquid to the pressure chamber is formed is bonded to a silicon substrate on which the pressure chamber is formed, and the reservoir Is communicated with the through hole.

  According to these methods, since the generation of foreign matter from the electrode substrate is greatly reduced, the rate of occurrence of defective bonding between the electrode substrate and the silicon substrate and damage to the bottom surface of the discharge chamber is reduced, and the production yield of the droplet discharge head is reduced. It is possible to improve and stabilize the ejection characteristics of the droplet ejection head.

  FIGS. 1A, 1B and 1C are back views showing an example of an electrostatically driven droplet discharge head using an electrode substrate manufactured by the method of Embodiment 1 or 2 described below. 6A is a cross-sectional view taken along line bb in FIG. 5A, and a cross-sectional view taken along line cc in FIG. This droplet discharge head is formed by laminating three substrates: a cavity substrate 1, an electrode substrate 2, and a nozzle substrate.

The nozzle substrate 3 is made of, for example, a silicon substrate, and a large number of nozzle holes 32 are opened on the surface. An orifice 31 is also formed in the nozzle substrate 3.
The cavity substrate 1 covered with the nozzle substrate 3 has a plurality of discharge chambers 12 (also referred to as pressure chambers) 12 formed on the vibration plate 13 whose bottom surface is elastically displaceable and communicated with each nozzle hole 32, and an orifice 31. A common reservoir 11 is formed in each discharge chamber 12 for supplying a discharge liquid to the discharge chamber 12 through the discharge chamber 12.

The electrode substrate 2 is made of a glass substrate, and on the side of the joint surface with the cavity substrate 1, elongated grooves 21 having a constant depth are formed at positions facing the vibration plates 13. In this groove 21, an individual electrode 22 made of a conductive material (for example, ITO (Indium Tin Oxide)) is formed, and this individual electrode 22 faces the diaphragm 13 through a gap (an operating space of the diaphragm 13). ing. The individual electrode 22 is formed up to the rear end face 26 of the electrode substrate 2, and the rear end portion serves as an electrode extraction portion 27 for external wiring connection.
An ink supply hole 23 is passed through the electrode substrate 2, and a discharge liquid is supplied from the outside to the reservoir 11 through the ink supply hole 23.

  This droplet discharge head applies a voltage between the diaphragm 13 and the individual electrode 22, generates an electrostatic force, deforms the diaphragm 13 toward the individual electrode 22, and then removes the applied voltage. Ink droplets are ejected from the nozzle holes 32 by the pressure generated by the spring force of the diaphragm 13. Therefore, the diaphragm 13 and the individual electrode 22 are electrostatically driven actuators.

Embodiment 1 (Method 1 of manufacturing electrode substrate)
Next, the manufacturing method of the electrode substrate 2 which comprises the above electrostatic drive actuators is demonstrated. FIG. 2 is a process diagram for explaining the manufacturing method of the electrode substrate according to the first embodiment, and FIG. 3 shows the same process as FIG. 2 in a direction (C′− in FIG. It is process drawing seen from (C 'direction). Hereinafter, it demonstrates along (a)-(g) of FIG. 2, FIG.

(A) A glass substrate 2a made of borosilicate glass having a thickness of 1 mm is prepared, and ink supply holes 23 that are through holes are formed by mechanical processing such as drilling or sandblasting or laser processing.
After that, an etching protective film (here, referred to as Cr / Au film 51) is sputtered on one surface (the upper surface in FIG. 2) of the glass substrate 2a, and a dry film resist 71 is laminated thereon.
(B) The Cr / Au film 51 is patterned by photolithography in order to form the grooves 21 for forming the individual electrodes 22.
(C) Using the dry film resist 71 and the Cr / Au film 51 as an etching mask, the glass substrate 2a is immersed in a hydrofluoric acid aqueous solution and etched to form grooves 21 on the surface of the glass substrate 2a. At this time, innumerable chipping generated on the inner wall of the ink supply hole 23 due to drilling is also removed by etching.
(D) The dry film resist 71 is peeled off, and the Cr / Au film 51 is removed by etching. (E) An ITO film 22a is formed by sputtering on the surface of the glass substrate 2a on the side where the grooves 21 are formed.
(F) A dry film resist 71 is laminated on the ITO film 22a, the ITO film 22a is patterned by photolithography, and the ITO film 22a is left only in the groove 21 to form the individual electrodes 22.
(G) The dry film resist 71 is peeled off.

  The electrode substrate 2 can be manufactured by the above process. According to the method of the first embodiment, the chipping of the ink supply hole 23 is simultaneously removed by etching in the etching process of the groove 21. Further, patterning performed by applying a conventional resist is difficult and difficult because spin coating of the resin is difficult because of the ink supply holes 23, but patterning is performed using the dry film resist 71 as in this example. Thus, good patterning is possible even with the ink supply hole 23.

Second Embodiment (Method 2 for Manufacturing Electrode Substrate)
4 to 5 are process diagrams for explaining the method of manufacturing the electrode substrate according to the second embodiment, and show views seen from the same direction as FIG. Hereinafter, a description will be given along (a) to (l) of FIGS.

(A) A glass substrate 2a made of borosilicate glass having a thickness of 1 mm is prepared, and ink supply holes 23 that are through holes are formed by mechanical processing such as drilling or sandblasting or laser processing. Thereafter, an etching protective film (here, referred to as Cr / Au film 51) is sputtered on one surface (upper surface in FIG. 4) of the glass substrate 2a, and a dry film resist 71 is laminated thereon. Then, the Cr / Au film 51 around the ink supply hole 23 is patterned by photolithography.
(B) Using the dry film resist 71 and the Cr / Au film 51 as an etching mask, the glass substrate 2a is immersed in a hydrofluoric acid aqueous solution and etched to form a recess 23a around the ink supply hole 23 of the glass substrate 2a. At this time, innumerable chipping generated on the inner wall of the ink supply hole 23 due to the drilling process is also removed by etching.
(C) The dry film resist 71 is peeled off.
(D) The dry film resist 71 is laminated again on the upper surface of the glass substrate 2a, and the dry film resist 71 is left only in the recesses 23a around the ink supply holes 23 by photolithography.
(E) The resist 72 is coated by spin coating, and the Cr / Au film 51 is patterned in order to form the grooves 21 for the individual electrodes 22 by photolithography.
(F) Using the resist 72 and the Cr / Au film 51 as an etching mask, the glass substrate 2a is immersed in a hydrofluoric acid aqueous solution and etched to form the grooves 21 on the surface of the glass substrate 2a.
(G) The resist 72 and the dry film resist 71 in the recess 23a are removed, and the Cr / Au film 51 is removed by etching.
(H) An ITO film 22a is formed by sputtering on the surface of the glass substrate 2a on the side where the grooves 21 are formed.
(I) A dry film resist 71 is laminated on the ITO film 22a, and the dry film resist 71 is left only in the recesses 23a around the ink supply holes 23 by photolithography.
(J) A resist 72 is coated on the ITO film 22a and the dry film resist 71 by spin coating.
(K) The ITO film 22a is patterned by photolithography, leaving the ITO film 22a only in the groove 21, and forming the individual electrodes 22.
(L) The resist 72 and the dry film resist 71 in the recess 23a are peeled off.

The electrode substrate 2 can be manufactured by the above process. According to the method of the embodiment, the chipping of the ink supply hole 23 is simultaneously removed by etching in the etching process of the recess 23a. Further, the ink supply hole 23 is closed with a dry film resist 71, thereby making it possible to use a resist coating and to perform highly accurate patterning by the resist coating. In addition, by using a resist coating, a stepper with high patterning accuracy can be used.
Furthermore, by first forming the recess 23a around the ink supply hole, the ITO electrode is not formed on the upper surface of the glass substrate 2a, that is, the anodic bonding interface, and anodic bonding can be performed without any problem. It also has the advantage that it can.

Embodiment 3 (Manufacturing method 1 of a droplet discharge head)
Next, a method for manufacturing a droplet discharge head using the electrode substrate 2 will be described. 6 to 7 are cross-sectional process diagrams illustrating a method for manufacturing a droplet discharge head according to the third embodiment. In the following, description will be made along (a) to (k) of FIGS.

(A) A Si (silicon) substrate 1a having a thickness of, for example, 525 μm with a polished bottom surface is prepared, and boron is diffused at a high concentration on the bottom surface to form a boron diffusion layer 13a. Further, an insulating film 43 of SiO ₂ film is formed on the surface of the boron diffusion layer 13a by plasma CVD. Moreover, the electrode substrate 2 manufactured by the method of Embodiment 1 or 2 described above is prepared.
(B) The Si substrate 1a and the electrode substrate 2 are anodically bonded. At this time, a gap 16 caused by the groove 21 is formed between the insulating film 43 of the Si substrate 1 a and the individual electrode 22 of the electrode substrate 2. Note that a substrate in which the Si substrate 1 a and the electrode substrate 2 are bonded is referred to as a bonded substrate 61. (C) The upper surface of the Si substrate 1a is ground with a grinder to a thickness of about 150 μm. At this time, the grinding trace which draws a parabola from the center remains on the surface of the Si substrate 1a, and the surface roughness (Rmax) is about 0.1 μm. Thereafter, the entire surface of the Si substrate 1a is etched with a 32 wt% potassium hydroxide aqueous solution at 80 ° C. to remove a work-affected layer generated by grinding. Although the surface of the Si substrate 1a is roughened by this etching, the surface roughness (Rmax) of the Si substrate 1a is 1 μm or less, and there is no problem in nozzle plate adhesion in the subsequent process.
(D) An SiO ₂ film 62 is formed with a thickness of 1 μm on the upper surface of the bonding substrate 61 by plasma CVD.
(E) The SiO 2 film 62 of the portion 12a that becomes the discharge chamber 12, the portion 11a that becomes the reservoir 11, and the portion 27a that becomes the electrode extraction portion is patterned by photolithography. Note that the SiO ₂ film 62 in the portion 11a to be the reservoir 11 is half-etched without being completely removed.
(F) The bonding substrate 61 is immersed in a 35 wt%, 80 ° C. potassium hydroxide aqueous solution, and the discharge chamber 12 and the electrode extraction portion 27 are etched halfway. Then, the SiO ₂ film 62 left in the reservoir portion 11a is removed with a hydrofluoric acid aqueous solution, and then the bonding substrate 61 is continuously etched with a 35 wt% potassium hydroxide aqueous solution at 80 ° C. When the etching proceeds to the boron diffusion layer 13a, the etching rate decreases, and the etching is performed up to that point. As a result, the boron diffusion layer 13 a on the bottom surface of the discharge chamber 12 becomes the diaphragm 13 that faces the individual electrode 22. On the other hand, in the reservoir portion 11a in which the start of etching is delayed, the etching does not proceed to the boron diffusion layer 13a, and as a result, the bottom portion of the reservoir 11 can be made thicker than the other portions.
(G) The bonding substrate 61 is immersed in a hydrofluoric acid aqueous solution to remove the SiO ₂ film 62 remaining on the surface of the Si substrate 1a. In addition, since the gap 16 between the cavity substrate 1 and the electrode substrate 2 is completely sealed from the bonding of the Si substrate 1a and the electrode substrate 2 to this process, the processing liquid in the intermediate process enters the gap 16. There is no.
(H) A metal mask having an opening corresponding to the electrode lead-out portion 27 is overlapped, and the boron diffusion layer 13a and the thin film of the insulating film 43 remaining on the electrode lead-out portion 27 are removed by dry etching. The Si substrate 1a that has been completed up to this step is referred to as a cavity substrate 1.
(I) The sealing material 28 is applied from the opening of the electrode extraction portion 27 so as to close the gap 16 formed between the cavity substrate 1 and the electrode substrate 2, and the gap 16 is sealed.
(J) The nozzle substrate 3 is bonded to the cavity substrate 1.
(K) The laminated substrate in which the cavity substrate 1, the electrode substrate 2, and the nozzle substrate 3 are joined in order is diced for each head to form a droplet discharge head.

  According to this method, since the chipping due to the processing of the through holes such as the ink supply holes 23 is removed from the electrode substrate 2, the silicon substrate 1a bonded to the electrode substrate 2 is processed to form the droplet discharge head. When forming, problems due to chipping can be avoided. This also improves the quality of the manufactured droplet discharge head and stabilizes the characteristics.

Embodiment 4 (Manufacturing method 2 of a droplet discharge head)
FIG. 8 is an exploded perspective view showing a schematic configuration of a droplet discharge head manufactured by the method of Embodiment 4 of the present invention. This droplet discharge head is formed by laminating four substrates: a nozzle substrate 101, a reservoir substrate 102, a cavity substrate 103, and an electrode substrate 104. This configuration is a structure suitable for increasing the volume of the reservoir.

  The nozzle substrate 101 is made of, for example, a silicon substrate having a thickness of about 50 μm. The nozzle substrate 101 is provided with a large number of nozzle holes 111 at a predetermined pitch. Each nozzle hole 111 has two hole diameters, the nozzle front end side has a smaller hole diameter, and the nozzle rear end side has a larger hole diameter than the nozzle front end side. Each nozzle hole 111 corresponds to a plurality of discharge chambers (also referred to as pressure chambers) 131 described later.

  The reservoir substrate 102 is made of, for example, a silicon substrate having a thickness of about 180 μm and a surface orientation of (100) on the front and back surfaces. The reservoir substrate 102 is provided with a plurality of nozzle communication holes 121 that vertically penetrate the reservoir substrate 102 and communicate with the nozzle holes 111 independently. Further, a common reservoir (common ink chamber) 123 is formed by wet etching with respect to a plurality of discharge chambers 131 to be described later, and the inner wall surface thereof has a surface orientation of (111).

  At the bottom of the reservoir 123, there are provided a plurality of supply ports 122 that communicate the reservoir 123 with each discharge chamber 131 described later, and an ink supply hole 127 for supplying discharge liquid to the reservoir 123 from the outside. . Further, the reservoir substrate 102 has an IC accommodating port 151 as a space for accommodating an IC driver 105 to be described later at the center, and a wiring that opens the wiring end of the electrode substrate 104 extending from the IC driver at the end. A take-out port 152 is opened.

  Since the nozzle communication hole 121 penetrating the reservoir substrate 102 is provided coaxially with the nozzle hole 111 of the nozzle substrate 101, it is possible to obtain straightness of ink droplet ejection, and thus the ejection characteristics are remarkably improved. Become. In particular, since minute ink droplets can be landed as intended, it is possible to faithfully reproduce subtle gradation changes without causing color misregistration, etc., and to realize clearer and higher quality image quality. it can.

  The cavity substrate 103 is made of, for example, a silicon substrate having a thickness of about 50 μm. The cavity substrate 103 is provided with a discharge chamber 131 that communicates independently with each of the nozzle communication holes 121. Further, the bottom wall constituting the discharge chamber 131 is configured as a flexible diaphragm 132 (see FIGS. 9 and 10) that is flexible and elastically deformable. The diaphragm 132 is preferably constituted by a boron diffusion layer formed by diffusing high-concentration boron in silicon. This is because, by using the boron diffusion layer, the etching stop can be sufficiently exerted, so that the thickness and surface roughness of the diaphragm 132 can be adjusted with high accuracy.

On at least the lower surface of the cavity substrate 103, an insulating film made of, for example, a SiO ₂ film by plasma CVD using TEOS (tetraethoxysilane) as a raw material is formed. This insulating film is provided in order to prevent dielectric breakdown and short circuit when the ink jet head is driven. The cavity substrate 103 is provided with an ink supply hole 135 that communicates with the ink supply hole 127 of the reservoir substrate 102.
Further, the cavity board 103 also has an IC accommodating port 151A as a space for accommodating an IC driver 105, which will be described later, at the center, and a wiring connection that opens the wiring end of the electrode substrate 104 extending from the IC driver at the end. The outlet 152A is opened. The cavity substrate 103 is also provided with a common electrode 136 that electrically connects the cavity substrate 103 to other devices such as a power source.

  The electrode substrate 104 is made of a glass substrate having a thickness of about 1 mm, for example. In particular, it is suitable to use a borosilicate heat-resistant hard glass having a thermal expansion coefficient close to that of the silicon substrate as the cavity substrate 103. By using borosilicate heat-resistant hard glass, when the electrode substrate 104 and the cavity substrate 103 are anodically bonded, the thermal expansion coefficients of both the substrates are close, so that the stress generated between the electrode substrate 104 and the cavity substrate 103 is reduced. This is because the electrode substrate 104 and the silicon substrate to be the cavity substrate 103 can be firmly bonded without causing problems such as peeling.

  The electrode substrate 104 is provided with a groove 142 at a position facing each diaphragm 132 of the cavity substrate 103. Each groove 142 is formed to a depth of, for example, about 0.2 μm by etching. In each groove 142, an individual electrode 141 made of ITO is formed by sputtering, for example, with a thickness of 0.1 μm. Therefore, the gap formed between the diaphragm 132 and the individual electrode 141 is 0.1 μm in this embodiment. The open end of the gap is hermetically sealed with a sealing material made of an epoxy adhesive or the like, and foreign matter and moisture are prevented from entering the gap 116.

In addition, the electrode terminal portion 141a of the individual electrode 141 extends to a region corresponding to the IC accommodating ports 151 and 151A of the reservoir substrate 102 and the cavity substrate 103, and is connected to the driver IC 105 for operation control there.
Further, signal lines and power supply lines for the driver IC 105 are exposed and wired in the areas of the wiring outlets 152 and 152A of the reservoir substrate 102 and the cavity substrate 103, and the exposed portions are used for connection with external devices. A cable connecting portion 144 is provided. For example, an FPC (Flexible Printed Circuit) is connected to the cable connection unit 144, and the driver IC 105 is connected to an external device such as a power source via the FPC.

  The electrode substrate 104 is provided with an ink supply hole 145 connected to an ink cartridge (not shown). The ink supply hole 145 communicates with the reservoir 123 through the ink supply hole 135 provided in the cavity substrate 103 and the ink supply hole 127 provided in the reservoir substrate 102.

  9 and 10 are process diagrams of a method according to the fourth embodiment showing a manufacturing method of the droplet discharge head of FIG. Hereinafter, the manufacturing method of the droplet discharge head of FIG. 8 will be described with reference to (1) to (8) of FIGS.

(1) The electrode substrate 104 is manufactured using the method of the first embodiment or the second embodiment.
(2) A substrate having a thickness of 220 μm is prepared by mirror-polishing one surface of a silicon substrate 300 having a low oxygen concentration with a plane orientation of (110). A high-concentration boron diffusion layer equivalent to the thickness of the diaphragm 131 is formed on the mirror surface side of the silicon substrate 300 (not shown). Then, a TEOS insulating film is formed to a thickness of 0.1 μm on the surface of the boron diffusion layer (not shown).
Next, after the silicon substrate 300 and the electrode substrate 104 are heated to 360 ° C., a negative electrode is connected to the electrode substrate 104 and a positive electrode is connected to the silicon substrate 300, and anodic bonding is performed by applying a voltage of 800V.

(3) After anodic bonding, the surface of the silicon substrate 300 is ground until its thickness is about 60 μm. Thereafter, in order to remove the work-affected layer, the silicon substrate 300 is etched by about 10 μm with a potassium hydroxide solution having a concentration of 32 w%. As a result, the thickness of the silicon substrate 300 is about 50 μm.
(4) The bonded substrate of the electrode substrate 104 and the silicon substrate 300 is etched using an aqueous potassium hydroxide solution to form a discharge chamber 131 in the silicon substrate 300. In this etching process, the etching is stopped by utilizing the etching rate reduction in the boron diffusion layer. As a result, the bottom surface of the discharge chamber 131 becomes the diaphragm 132 of the boron diffusion layer.
At the same time, the silicon substrate 300 is formed with a through-hole or an open portion such as an IC accommodating port 151 A, a wiring outlet 152 A, a sealing hole 153, and an ink supply port 135, thereby forming the cavity substrate 103. These through portions or open portions are formed by first forming a corresponding portion into a thin film by wet etching, attaching a silicon mask having an opening corresponding to the through portion or open portion, performing RIE dry etching, and then performing these portions. This is done by removing the thin film.

(5) After the bonded substrate is dried and moisture in the gap 116 is removed, an epoxy resin is poured into the sealing hole 153 to seal the gap 116. As a result, the gap 116 is hermetically sealed.
(6) The reservoir substrate 102 in which the reservoir 123, the supply port 122, and the nozzle communication hole 121 are formed is bonded to the cavity substrate 103 with an epoxy adhesive.
(7) The driver IC 105 is mounted on the electrode terminal portion 141a of the individual electrode 141 of the electrode substrate 104.
(8) The nozzle substrate 101 is bonded to the reservoir substrate 102 with an epoxy adhesive. Then, dicing is performed, and each head is cut to obtain an ink jet head.

  According to the method of the fourth embodiment, since chipping due to the processing of the through holes such as the ink supply holes 145 is removed from the electrode substrate 104, the silicon substrate 300 bonded to the electrode substrate 104 is processed to produce droplets. When forming the ejection head, problems due to chipping can be avoided. This also improves the quality of the manufactured droplet discharge head.

The electrode substrate manufactured by the method of the present invention is not limited to application to a droplet discharge head, and can be applied to various devices as one electrode of an electrostatic drive actuator.
In addition, the droplet discharge head manufactured by the method of the present invention is not limited to ink discharge, and can discharge various liquids. For example, a liquid containing a dye or a pigment, a liquid containing a compound serving as a light-emitting element in an application for discharging to a display substrate such as an organic EL, and a liquid containing a conductive metal in an application for wiring on the substrate. Etc.

FIG. 5B is a rear view showing an example of an electrostatically driven droplet discharge head using an electrode substrate manufactured by the method of the first or second embodiment, and a cross-sectional view taken along the line bb in FIG. ) And (c) is a cross-sectional view taken along line cc of (a). FIG. 3 is a process diagram showing a method for manufacturing an electrode substrate according to the first embodiment. FIG. 2 showing the same process as FIG. 2 is a process diagram viewed from a direction in which the direction is changed by 90 degrees. Process drawing seen from the same direction as FIG. 3 which shows the manufacturing method of the electrode substrate which concerns on Embodiment 2. FIG. Process drawing following FIG. FIG. 9 is a process diagram showing a method for manufacturing the droplet discharge head of FIG. 1 according to the third embodiment. Process drawing following FIG. FIG. 9 is an exploded perspective view showing a droplet discharge head made by the method of Embodiment 4. FIG. 9 is a process diagram illustrating a method for manufacturing the droplet discharge head of FIG. 8 according to the fourth embodiment. Process drawing following FIG.

Explanation of symbols

1 cavity substrate, 2 electrode substrate, 3 nozzle substrate, 11 reservoir, 12 discharge chamber (pressure chamber), 13 diaphragm, 16 gap, 21 groove, 22 individual electrode, 22a ITO film, 23 ink supply hole, 23a recess, 27 Electrode extraction part, 31 orifice, 32 nozzle hole, 51 Cr / Au film, 71 dry film resist, 72 spin coat resist.

Claims (5)

After forming a through hole in the glass substrate, laminating an etching protective film and a dry film resist in order on one side of the glass substrate;
Patterning the etching protection film in accordance with a groove shape to be formed by photolithography;
Immersing the glass substrate patterned with the etching protection film in an etching solution to form a groove on the surface of the glass substrate;
Forming a conductive material on the glass substrate and forming an electrode in the groove;
A method of manufacturing an electrode substrate comprising: After forming a through hole in the glass substrate, laminating an etching protective film and a dry film resist in order on one side of the glass substrate;
Removing the etching protective film around the through hole by photolithography and immersing the glass substrate in an etching solution to form a recess recessed from the other part around the through hole;
After peeling the dry film from the glass substrate, coating the inside of the recess with a dry film resist;
Applying a resist to the surface of the glass substrate on the side where the recesses are formed;
Patterning the etching protection film in accordance with a groove shape to be formed by photolithography;
Immersing the glass substrate patterned with the etching protection film in an etching solution to form a groove on the surface of the glass substrate;
Forming a conductive material on the glass substrate and forming an electrode in the groove;
A method of manufacturing an electrode substrate comprising:   The electrode substrate manufacturing method according to claim 1, wherein the through hole is formed by machining. A silicon substrate is bonded to the electrode substrate manufactured by the method according to claim 1 through a gap between the electrode substrate and the electrode substrate,
The silicon substrate is etched to form a pressure chamber whose bottom surface corresponding to the electrode can be elastically displaced, and a reservoir for supplying the liquid to the pressure chamber, and the reservoir communicates with the through hole. A method for manufacturing a droplet discharge head. A silicon substrate is bonded to the electrode substrate manufactured by the method according to claim 1 through a gap between the electrode substrate and the electrode substrate,
Etching the silicon substrate to form a pressure chamber whose bottom surface corresponding to the electrode can be elastically displaced,
A droplet discharge head comprising: a silicon substrate on which the pressure chamber is formed; a reservoir substrate on which a reservoir for supplying the liquid to the pressure chamber is formed; and the reservoir is connected to the through hole. Production method.

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