JP2007307735A - Method for manufacturing liquid droplet delivering head and method for manufacturing liquid droplet delivering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a liquid droplet delivering head and the like with high reliability, which realizing good sealing of an inorganic film and perfect and intimate contacting of an actuator. <P>SOLUTION: The method for manufacturing the liquid droplet delivering head comprises processes of: forming a protective film 18 having an etching resistance on a surface of a glass substrate 1a after forming a gap step section 21a on the glass substrate 1a, and forming a plurality of electrodes to be discrete electrodes 17 by forming ITO films 17a on the surface of the protective film 18; carrying out anodic bonding between the glass substrate 1a and a silicon substrate 2a having formed thereon at least a plurality of recessed sections to be delivering chambers 13 by opposing the electrodes to parts to be diaphragms 12 of the delivering chambers 13 with gaps therebetween; applying wet etching to the silicon substrate 2a, and then applying dry etching to a part to be an electrode drawing section 27 to drill the silicon substrate 2a to form a through-hole; and sealing a sealing hole section 71 of the gap by using the through-hole on the silicon substrate 2a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a droplet discharge head and a method for manufacturing a droplet discharge device.

  The electrostatic drive type ink jet head has an electrostatic actuator, and by generating an electrostatic force between the diaphragm and the electrode, the volume of the actuator is changed to realize droplet discharge. Such an inkjet head manufacturing method is classified into two types. The first manufacturing method is a method in which a silicon substrate provided with a diaphragm and a glass substrate provided with an electrode are individually manufactured, and after anodic bonding thereof, the actuator is sealed. The second manufacturing method is a method in which, after anodically bonding a silicon substrate serving as a vibration plate and a glass substrate having electrodes, the vibration plate is processed, and then the actuator is sealed.

  In the manufacturing process of the ink jet head using the second manufacturing method, when the through hole of the electrode extraction portion is formed by dry etching, in order to prevent damage to the electrode and the substrate, at least on the electrode in advance. An etching cover film having high insulating properties and strong etching resistance is formed in advance, thereby preventing damage to the electrodes and the substrate (see, for example, Patent Document 1).

  In the above manufacturing method, it is necessary to seal the actuator after completely removing the moisture inside the actuator, so that the actuator is sealed. In addition, after sealing the actuator, it is necessary to reliably prevent moisture from entering the actuator from the outside. For this reason, after forming the through-hole of an electrode extraction part, sealing an electrode extraction part with an inorganic film is performed. Unlike the case of using an organic material, there is no need for thermosetting, and outgassing from the material can be prevented (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 2001-63072 (upper column on page 9, FIG. 4) JP 2002-248757 A (lower column of page 3, FIG. 1)

  In the method of manufacturing an ink jet head described in Patent Document 1, an etching cover film that is an insulating film is formed in advance when forming the electrode lead-out portion. Don't be. This is because if the insulating film is not removed, an unnecessary silicon thin film portion remains on the face of the individual electrode, and the individual electrode cannot be taken out. Since this removal process cannot be performed by wet etching, dry etching is required. However, when this method is used, not only the silicon thin film but also the glass surface is etched, and fine irregularities are formed on the glass surface. Cause surface roughness.

  In the ink jet head described in Patent Document 2, the sealing material is changed from an organic material to an inorganic material. However, it is not easy to ensure the airtightness of the electrostatic actuator only by changing the material. For example, after dry etching, when a fine uneven shape is formed on the glass surface and the surface becomes rough, even if it is sealed with an inorganic film, the adhesion by the inorganic film becomes insufficient, resulting in an actuator This is because the airtightness cannot be secured.

  The present invention has been made in order to solve the above-described problems. An inorganic film that does not require thermosetting and does not generate outgas is used for sealing the sealing hole portion of the electrode extraction portion, and the inorganic An object of the present invention is to provide a highly reliable droplet discharge head manufacturing method and a droplet discharge device manufacturing method in which film sealing is satisfactory and actuators can be completely adhered.

  A method of manufacturing a droplet discharge head according to the present invention includes a nozzle hole that discharges a droplet, a discharge chamber that communicates with the nozzle hole and forms a part of a liquid channel, and supplies the liquid to the discharge chamber. A liquid supply unit; a diaphragm formed on a part of the wall surface of the discharge chamber; an individual electrode disposed opposite to the diaphragm; and an electrode extraction unit for taking out the individual electrode; and a plurality of substrates. A method of manufacturing a laminated droplet discharge head, wherein after forming a gap step portion on a glass substrate, a protective film having etching resistance is formed on the surface of the glass substrate, and an ITO film is further formed on the surface of the protective film Forming a plurality of electrodes to be the individual electrodes, forming the glass substrate on which the plurality of electrodes to be the individual electrodes are formed, and silicon having at least a plurality of recesses to be the discharge chambers A substrate, the electrode and the A step of anodic bonding the portion of the exit chamber that is to be a vibration plate facing through a gap, and a portion of the silicon substrate that is bonded to the glass substrate that is to be a liquid flow path including at least a recess and an electrode extraction portion. After etching using etching, a step of further dry-etching the portion that becomes the electrode extraction portion, and a step of sealing the gap sealing hole portion using the through hole of the silicon substrate Is included.

  Since the protective film having etching resistance is formed on the surface of the electrode substrate before the ITO film is formed, the glass surface is protected from being roughened by etching during the penetration of the through hole of the electrode extraction portion, thereby protecting the glass surface. be able to. Further, it is not necessary to remove the protective film after the etching is completed, and it is possible to perform post-processes such as sealing and mounting processes as they are. For this reason, the electrostatic actuator composed of the diaphragm and the individual electrodes can ensure stable airtightness over time and can prevent a short circuit between the diaphragm and the individual electrodes.

In the method for manufacturing a droplet discharge head according to the present invention, a protective film having etching resistance is formed on the entire surface of the electrode substrate.
Since the protective film having etching resistance is formed on the entire surface of the electrode substrate, the surface of the glass is not roughened by etching when the through hole of the electrode extraction portion is penetrated.

In the method of manufacturing a droplet discharge head according to the present invention, a protective film having etching resistance is formed only in the vicinity of a portion to be a sealing hole portion on the surface of the electrode substrate.
Since the protective film having etching resistance is formed only in the vicinity of the portion to be the sealing hole portion on the surface of the electrode substrate, the glass surface in the vicinity of the sealing hole portion is roughened by etching when the through hole of the electrode extraction portion is penetrated. Will not cause. Furthermore, since the protective film is selectively formed only in the vicinity of the sealing hole portion of the electrode substrate, it is possible to prevent the bonding strength from being lowered when the glass substrate and the silicon substrate are anodic bonded.

Further, in the method for manufacturing a droplet discharge head according to the present invention, a groove having a depth corresponding to the thickness of the protective film is formed in the electrode substrate before forming the protective film, and the protective film Is formed in the groove portion of the electrode substrate so as to have the same height as the surface of the electrode substrate.
In the selective film formation of the protective film, a groove having a depth corresponding to the film thickness of the protective film is formed in advance on the electrode substrate side, so that a step corresponding to the film thickness is newly formed by this protective film. Can be prevented.

In the method for manufacturing a droplet discharge head according to the present invention, the protective film is an insulator and has resistance to an etching gas used in the dry etching.
Since a protective film that is an insulator and is resistant to the etching gas used during dry etching is formed on the surface of the electrode substrate, this protective film allows the vicinity of the sealing hole portion to pass through the through hole of the electrode extraction portion. The glass surface is not roughened by the etching gas.

In the manufacturing method of the droplet discharge head according to the present invention, the etching gas used in the dry etching is made of CF ₄ or SF ₆ .
Since a protective film which is an insulator and is resistant to an etching gas made of CF ₄ or SF ₆ used for dry etching is formed on the surface of the electrode substrate, the protective film allows the through hole of the electrode extraction portion to be formed. During penetration, the glass surface near the sealing hole is not roughened by the etching gas.

In the method for manufacturing a droplet discharge head according to the present invention, the protective film is an insulator and has resistance to an etching solution used for etching the ITO film.
Since the protective film having etching resistance is formed on the surface of the electrode substrate, the glass surface is not etched by the protective film when the ITO film is etched, and the surface is not roughened.

In the method for manufacturing a droplet discharge head according to the present invention, the protective film is made of Al ₂ O ₃ .
Since a protective film made of Al ₂ O ₃ is formed on the surface of the electrode substrate, this protective film etches the glass surface in the vicinity of the sealing hole when etching the ITO film or when penetrating the through hole of the electrode extraction part. Does not cause surface roughness.

In the method for manufacturing a droplet discharge head according to the present invention, the sealing hole of the gap is sealed with an inorganic film.
Since the adhesion interface between the inorganic film for sealing and the glass substrate is flat, it is possible to prevent a decrease in the adhesion between the inorganic film and the glass substrate. Full sealing is possible.

In the method of manufacturing a droplet discharge head according to the present invention, the inorganic film is a TEOS-SiO ₂ film.
Since the adhesion interface between the inorganic film made of TEOS-SiO ₂ for sealing and the glass substrate is flat, it is possible to prevent the adhesion of the inorganic film made of TEOS-SiO ₂ from being lowered.

A method for manufacturing a droplet discharge device according to the present invention is a method for manufacturing a droplet discharge device by applying any one of the above-described methods for manufacturing a droplet discharge head.
It is possible to obtain a high-performance liquid droplet ejection apparatus including a liquid droplet ejection head with good airtightness of the actuator.

Embodiment 1 FIG.
FIG. 1 is an exploded perspective view of a droplet discharge head according to Embodiment 1 of the present invention, and FIG. 2 is a longitudinal sectional view of a main part of FIG. The above-mentioned droplet discharge head is a face eject type liquid that discharges droplets from nozzle holes provided on the surface side of the nozzle substrate, as a representative of electrostatic drive type electrostatic actuators driven by electrostatic force. It is a droplet discharge head.

As shown in FIG. 1, a droplet discharge head 100 has a structure in which a cavity substrate 2 is sandwiched from above and below by an electrode substrate 1 and a nozzle substrate 3, and the electrode substrate 1, the cavity substrate 2, and the nozzle substrate 3 are stacked in this order. Are joined together.
The nozzle substrate 3 is made of silicon, and is provided with a plurality of nozzle holes 32. The nozzle holes 32 are formed in two stages so as to improve straightness when ejecting droplets. The nozzle substrate 3 is formed with one narrow groove-like orifice 31 for each discharge chamber (described later).

The cavity substrate 2 is formed of a silicon single crystal substrate (hereinafter simply referred to as a silicon substrate) having a (110) plane orientation. The cavity substrate 2 is formed with a plurality of discharge chambers 13 arranged in parallel from the front side to the back side of the paper, and each discharge chamber 13 is composed of a single recess for supplying droplets of ink or the like. A reservoir 14 is formed.
A diaphragm 12 is provided on the bottom wall of the discharge chamber 13 of the cavity substrate 2 and is formed of a high-concentration boron diffusion layer. The boron diffusion layer is formed because the diaphragm 12 can be formed to a desired thickness by using this boron diffusion layer as an etching stop layer and using wet etching.
An insulating film 16 is formed of alumina (Al ₂ O ₃ ), for example, on the surface of the cavity substrate 2 to which the electrode substrate 1 is bonded. This insulating film 16 prevents dielectric breakdown or short circuit from occurring when the droplet discharge head 100 is driven.

The electrode substrate 1 is formed from a glass substrate made of borosilicate glass, and is joined to the diaphragm 12 side of the cavity substrate 2. The electrode substrate 1 has a gap step portion 21a slightly larger than these shapes in a position elongated to a position facing each diaphragm 12 so that individual electrodes (described later) can be mounted. The pattern is formed to have a thickness. These gap step portions 21 a form a space portion 21 between the cavity substrate 2 and the diaphragm 12.
On the entire surface of the electrode substrate 1 including the gap stepped portion 21a (the surface on the side where the electrode substrate 1 is bonded to the cavity substrate 2), a thin protective film made of, for example, Al ₂ O ₃ having strong etching resistance as an etching mask. 18 is formed.

A plurality of individual electrodes 17 are formed on the protective film 18 in the gap step portion 21 a of the electrode substrate 1. The individual electrode 17 is made of ITO (Indium Tin Oxide) using an ECR sputtering apparatus, and is arranged to face the diaphragm 12 with a gap of a constant interval. 170 is formed.
An ink supply hole 19 communicating with the reservoir 14 is formed in the electrode substrate 1, and droplets such as ink are supplied from the outside to the reservoir 14 through the ink supply hole 19.

  An electrode extraction portion 27 is opened near the end portion of the lead portion 170 of the individual electrode 17, and a sealing hole for the space portion 21 formed between the cavity substrate 2 and the electrode substrate 1 in this opening portion. The portion 71 is sealed with a sealing film 70 made of an inorganic film, and the actuator is sealed.

  The droplet discharge head 100 is provided with a drive circuit (not shown) constituted by an integrated circuit such as a driver IC, and one end thereof is connected to the lead portion 170 of the individual electrode 17 provided on the electrode substrate 1. The other end is connected to the cavity substrate 2 and a drive signal is supplied from this drive circuit.

  Next, the operation of the droplet discharge head 100 will be described. A pulse voltage is applied between the cavity substrate 2 and the individual electrode 17 by a drive circuit connected to the droplet discharge head 100. Then, a potential difference is generated between the cavity substrate 2 and the individual electrode 17, and an electrostatic force is generated. In this way, the vibration plate 12 bends toward the individual electrode 17, and droplets such as ink that have accumulated in the reservoir 14 flow into the ejection chamber 13. Thereafter, when the pulse voltage applied between the cavity substrate 2 and the individual electrode 17 disappears, the diaphragm 12 is restored to the original state position, the pressure inside the discharge chamber 13 is increased, and the nozzle hole 32 Ink droplets are ejected.

  A method of manufacturing the droplet discharge head 100 configured as described above will be described with reference to FIGS. 3 is a cross-sectional process diagram illustrating a manufacturing process until an insulating film is formed on a silicon substrate, FIG. 4 is a cross-sectional process diagram illustrating a glass substrate manufacturing process, and FIG. 5 illustrates a glass substrate manufacturing process subsequent to FIG. FIG. 6 is an enlarged plan view of the vicinity of the electrode extraction part of the glass substrate and its II cross-sectional view, FIG. 7 is a cross-sectional process diagram showing the bonding manufacturing process of the silicon substrate and the glass substrate, and FIG. FIG. 9 is a cross-sectional process diagram illustrating the bonding and manufacturing process of the silicon substrate and the glass substrate following FIG. 8, FIG. 9 is a cross-sectional process diagram illustrating the bonding and manufacturing process of the silicon substrate and the glass substrate. FIG. 11 is a sectional process diagram showing a bonding manufacturing process for bonding a nozzle substrate to a bonded body of a cavity substrate and a glass substrate.

First, a manufacturing process until the insulating film 16 is formed on the silicon substrate 2a will be described with reference to FIG.
(A) A silicon substrate 2a having one surface to be a cavity substrate 2 polished is prepared. Then, as shown in FIG. 3A, boron is diffused at a high concentration on the polished surface of the silicon substrate 2a. As a result, a boron diffusion layer 12a and a SiB ₆ layer 40 due to thermal diffusion of boron are generated on the surface of the silicon substrate 2a.
(B) As shown in FIG. 3B, the SiB ₆ layer 40 is oxidized to form a B ₂ O ₃ layer 41.
(C) As shown in FIG. 3C, the B ₂ O ₃ layer 41 is removed by wet etching.
(D) As shown in FIG. 3D, an insulating film 16 made of alumina (Al ₂ O ₃ ) is formed on the boron diffusion layer 12a by a plasma CVD apparatus.

Next, the manufacturing process of the glass substrate 1a is demonstrated using FIGS.
(A) As shown in FIG. 4 (a), a Cr / Au film (chromium / gold alloy film) is formed on the upper surface (front surface) of a glass substrate 1a made of borosilicate glass to be the electrode substrate 1 of the droplet discharge head 100. ) 51 is formed by an ECR sputtering apparatus.
(B) The Cr / Au film 51 is patterned into a shape corresponding to the gap stepped portion 21a by photolithography (stepper, mask aligner, etc.), and thereafter, by etching, as shown in FIG. A portion corresponding to the gap step portion 21a of the Au film 51 is removed.

(C) Using the Cr / Au film 51 as an etching mask, the glass substrate 1a is etched with a hydrofluoric acid aqueous solution to form a gap stepped portion 21a as shown in FIG.
(D) As shown in FIG. 4D, the Cr / Au film 51 is removed by etching.
FIGS. 6D1 and 6D2 are an enlarged plan view and an II cross-sectional view of the vicinity of the electrode extraction portion 27 (A portion in FIG. 1) of the glass substrate 1a at this time.

(E) As shown in FIG. 5E, a protective film 18 made of, for example, Al ₂ O ₃ having a high etching resistance is formed on the entire upper surface of the glass substrate 1a by sputtering as an etching mask.
6 (e1) and 6 (e2) are an enlarged plan view and an II cross-sectional view of the vicinity of the electrode extraction portion 27 (A portion in FIG. 1) of the glass substrate 1a at this time.
The material of the protective film 18 is resistant to an etching gas such as CF ₄ or SF ₆ used when forming a sealing through-hole (described later) in the electrode extraction portion 27 and is an insulator. Is used. Further, the protective film 18 has resistance to an ITO etching solution (water: hydrochloric acid: nitric acid = 1.3: 1.3: 0.12) during etching (described later) of the ITO film serving as the individual electrode 17. Is desirable. In addition, if it is a material which can take the etching selection ratio with an ITO film | membrane, it is also possible to adjust with the film-forming film thickness.
As described above, by using an insulating material such as Al ₂ O ₃ as the material of the protective film 18, the glass surface of the glass substrate 1 a is etched and roughened during the through dry etching of the electrode extraction portion 27. And the entire glass surface can be protected. Furthermore, it is possible to prevent a short circuit between the diaphragm 12 and the individual electrode 17 formed of an electrode material such as ITO.

(F) After forming the protective film 18 as described above, as shown in FIG. 5F, an ITO film 17a as an electrode material is formed on the entire upper surface of the protective film 18 by an ECR sputtering apparatus.
6 (f1) and 6 (f2) are an enlarged plan view and an II cross-sectional view of the vicinity of the electrode extraction portion 27 (A portion in FIG. 1) of the glass substrate 1a at this time.
A protective film 18 as an etching mask is formed under the ITO film 17a. However, the protective film 18 does not need to be removed, and remains in the subsequent process (sealing and mounting process). It can be performed.

(G) Next, the ITO film 17a is patterned into a shape corresponding to the individual electrode 17, and the ITO film 17a other than the portion to be the individual electrode 17 is removed by etching. Specifically, the ITO film 17a is patterned along the wiring pattern of the droplet discharge head 100, and ITO at an unnecessary portion is formed with an ITO etching solution (water: hydrochloric acid: nitric acid = 1.3: 1.3: 0.12). The film 17a is removed. In this way, the individual electrode 17 is formed as shown in FIG.
6 (g1) and 6 (g2) are an enlarged plan view of the vicinity of the electrode extraction portion 27 (portion A in FIG. 1) of the glass substrate 1a and a Y sectional view thereof.
(H) Finally, as shown in FIG. 5 (h), the ink supply port 19 is processed by the sandblast method.

Next, the bonding manufacturing process of the silicon substrate 2a and the glass substrate 1a will be described with reference to FIGS.
(A) As shown in FIG. 7A, a silicon substrate 2a (see FIG. 3) on which a boron diffusion layer 12a and an insulating film 16 are formed, and a glass substrate 1a (see FIG. 5) on which an ink supply hole 19 is formed. prepare.
(B) As shown in FIG. 7B, a voltage is applied between the silicon substrate 2a and the glass substrate 1a to anodic bond them to manufacture a bonded substrate 61.

(C) As shown in FIG. 7C, the upper surface (front surface) of the silicon substrate 2a is ground and thinned by a grinder. At this time, a grinding mark that draws a parabola from the center remains on the surface of the substrate. Subsequently, the entire upper surface of the silicon substrate 2a is etched with a 32 wt% potassium hydroxide aqueous solution at 80 ° C., and the work-affected layer generated by grinding with a grinder is removed. Although the surface of the silicon substrate 2a is roughened by this etching, there is no problem in the adhesion (described later) of the nozzle substrate 3 in a later step.
(D) As shown in FIG. 7D, an SiO ₂ film (silicon oxide film) 62 is formed on the surface of the silicon substrate 2a of the bonding substrate 61 by a CVD apparatus.

(E) As shown in FIG. 8E, a portion 13a of the SiO ₂ film 62 corresponding to the discharge chamber 13, a portion 14a corresponding to the reservoir 14, and a portion 27a corresponding to the electrode extraction portion 27 are formed by photolithography (stepper or Patterning is performed using a mask aligner or the like, and the SiO ₂ film 62 in these portions is removed by etching. Note that half etching is performed so that the SiO ₂ film 62 in the portion 14a to be the reservoir 14 is not completely removed.

(F) As shown in FIG. 8F, the bonding substrate 61 is immersed in a 35 wt% potassium hydroxide aqueous solution at 80 ° C., and the discharge chamber 13 and the electrode extraction portion 27 are etched halfway. Then, the SiO ₂ film 62 is removed with the hydrofluoric acid aqueous solution left in the reservoir 14, and the etching is continued with a 35 wt% potassium hydroxide aqueous solution at 80 ° C. Thus, the boron diffusion layer 12 a remains without being etched, and the boron diffusion layer 12 a on the bottom surface of the discharge chamber 13 becomes the diaphragm 12.
On the other hand, the reservoir 14 that has delayed the start of etching does not proceed to the boron diffusion layer 12a, and can leave the silicon at the bottom thick.

(G) The bonding substrate 61 is immersed in a hydrofluoric acid aqueous solution, and the SiO ₂ film 62 remaining on the surface of the silicon substrate 2a is completely removed as shown in FIG.
In the steps so far, the space portion 21 formed between the cavity substrate 2 and the electrode substrate 1 is completely sealed, so that the processing liquid does not enter the space portion 21 in the intermediate step.

(H) The opening portion of the metal mask (not shown) is overlapped with the portion to be the through hole of the electrode extraction portion 27 of the silicon substrate 2a, and the diaphragm (boron diffusion layer) 12 and the insulating film remaining in the portion to be the through hole 16 (see FIG. 8G) is removed by dry etching using the reaction gas CF ₄ or SF ₆ , and as shown in FIG. That is, the sealed space portion 21 and the lead portion 170 of the individual electrode 17 are communicated with each other through the through hole of the electrode extraction portion 27 and the sealing hole portion 71. At this time, since the protective film 18 made of Al ₂ O ₃ was formed on the entire surface of the glass substrate 1a before the formation of the ITO film 17a to be the individual electrodes 17 (see FIG. 5 (e)), the electrode extraction portion At the time of dry etching for forming the 27 through holes, the glass surface in the vicinity of the sealing hole 71 of the electrode extraction part 27 is not roughened.

(I) A sealing film 70 is applied from the through hole of the electrode extraction portion 27 so as to close the sealing hole portion 71 of the space portion 21 formed between the silicon substrate 2a and the glass substrate 1a. The actuator is sealed as shown in 9 (i). When sealing the sealing hole 71, after penetrating the electrode extraction portion 27 (see FIG. 8H), a sealing silicon mask (not shown) is aligned with a positioning pin, and a TEOS-CVD apparatus is used. Then, a TEOS-SiO ₂ film, which is a sealing film, is formed in the sealing hole portion 71 using the through hole of the electrode extraction portion 27 to form the sealing film 70.
10 is a longitudinal sectional view of the bonding substrate 61 at this time, FIG. 10 (i1) is a roll sectional view of the corresponding portion of FIG. 1, and FIG. 10 (i2) is a sectional view of the corresponding portion of FIG. -It is C sectional drawing.

As described above, the protective film 18 made of Al ₂ O ₃ is formed on the entire surface of the glass substrate 1 a before the formation of the ITO film 17 a to be the individual electrode 17, thereby roughening the surface of the electrode extraction portion 27 during the through etching. Therefore, the adhesion interface between the sealing film 70 and the glass substrate 1a is flat, so that there is no actuator leak after the sealing hole 71 is sealed by the sealing film 70, and the actuator It becomes possible to ensure the airtightness of the.
Further, since an insulating material such as Al ₂ O _{3 is} used as the material of the protective film 18 that protects the glass surface, it is possible to prevent a short circuit of the ITO wiring, and it is not necessary to remove the protective film 18. .

Next, a bonding manufacturing process for bonding the nozzle substrate 3 to the bonded body 61 of the silicon substrate 2a and the glass substrate 1a will be described with reference to FIG.
(A) As shown in FIG. 11A, the nozzle substrate 3 is bonded to the upper surface (front surface) of the silicon substrate 2a of the bonded body 61 made of the silicon substrate 2a and the glass substrate 1a with a bonding agent.
(B) Unnecessary portions are removed by dicing, and the droplet discharge head 100 is completed as shown in FIG.

Embodiment 2
FIG. 12 shows a manufacturing process of the droplet discharge head 100 according to the second embodiment, and is an enlarged plan view of the vicinity of the electrode extraction portion 27 (A portion in FIG. 1) of the glass substrate 1a. FIG. FIGS. 14A and 14B are a perspective view and a cross-sectional view of a corresponding portion of FIG.
In the first embodiment, when the droplet discharge head 100 is manufactured, the protective film 18 made of Al ₂ O ₃ is formed on the entire surface of the glass substrate 1a. In the second embodiment, FIG. As described above, the protective film 18 is selectively formed only on a part of the glass substrate 1 a. Specifically, the protective film 18 is selectively formed only in the vicinity of the sealing hole 71 of the electrode extraction part 27.
The means for forming the film varies depending on the film forming method using the etching mask or the material. For example, when forming the Al ₂ O ₃ film by sputtering or CVD, a silicon mask as shown in FIG. 80 can be performed by attaching to the glass substrate 1a before film formation.
In the manufacturing process, when the protective film 18 made of Al ₂ O ₃ is formed at a position near the sealing hole 71 of the electrode extraction portion 27 of the glass substrate 1a, as shown in FIG. Further, before the film formation, the silicon mask 80 is placed on the glass substrate 1a so that the opening 81 (see FIG. 13) of the silicon mask 80 comes to a position near the sealing hole 71 of the electrode extraction portion 27 of the glass substrate 1a. Attach to.

Next, as shown in FIG. 12 (e), Al ₂ O serving as an etching cover film is formed by sputtering at a position in the vicinity of the opening 81 of the silicon mask 80 that becomes the sealing hole 71 of the electrode extraction portion 27. the _third insulating protective film 18, a material selectively deposited. Note that, in the selective film formation, a step is formed by the thickness of the protective film 18, so that the depth corresponding to the film thickness to be formed is prevented in order to prevent the formation of the step corresponding to the film thickness. Are formed in advance on the glass substrate 1a side.

  Next, the silicon mask 80 is removed, and as shown in FIG. 12F, an ITO film 17a as an electrode material is formed on the entire upper surface of the glass substrate 1a including the protective film 18 by an ECR sputtering apparatus.

Next, as shown in FIG. 12G, a shape corresponding to the individual electrode 17 is patterned on the ITO film 17a, and the ITO film 17a other than the portion to be the individual electrode 17 is removed by etching.
The other manufacturing steps are substantially the same as those shown in the first embodiment, and a description thereof will be omitted.
FIG. 14 is a longitudinal sectional view of the bonded substrate 61 manufactured through the manufacturing process as described above, cut at different positions, and FIG. 14A is a sectional view taken along the line corresponding to FIG. FIG. 14B is a cross-sectional view of the corresponding portion in FIG.

According to the second embodiment, in addition to the effects shown in the first embodiment, since the protective film 18 made of Al ₂ O ₃ is selectively formed only in the vicinity of the sealing hole portion 17, At this time, a decrease in strength of anodic bonding is prevented. That is, when there is a concern about a decrease in the anodic bonding strength due to the formation of the etching mask on the entire surface of the glass substrate 1a, the protective film 18 is selectively formed only in the vicinity of the sealing hole 71, whereby the anode A decrease in bonding strength can be avoided.

Embodiment 3 FIG.
FIG. 15 is a perspective view showing an example of a droplet discharge device 150 on which the droplet discharge head 100 manufactured in the first and second embodiments is mounted. The droplet discharge device 150 is a general ink jet printer. As described above, the droplet discharge head 100 mounted on the droplet discharge device 150 has a flat contact interface between the sealing film 70 and the glass substrate 1a. The actuator leak portion after sealing is eliminated, and the airtightness of the actuator can be ensured. Therefore, it is possible to obtain the droplet discharge device 150 on which the highly reliable droplet discharge head 100 is mounted.

In addition to the inkjet printer shown in FIG. 15, the droplet discharge apparatus obtained by the method for manufacturing a droplet discharge head according to the present invention can manufacture color filters for liquid crystal displays by changing the droplets in various ways. Further, the present invention can be applied to formation of a light emitting portion of an organic EL display device, discharge of a biological liquid, and the like.
Further, the manufacturing method of the droplet discharge head according to the embodiment of the present invention is not limited to the above-described embodiment, and can be modified within the scope of the present invention. For example, the present invention can also be applied to the manufacture of MEMS (Micro Electro Mechanical Systems) devices such as micro pumps and mirror devices using electrostatic actuators. Furthermore, although the case where the droplet discharge head 100 manufactured by the method of manufacturing a droplet discharge head according to the embodiment of the present invention has a three-layer structure has been described as an example, the present invention is not limited to this, and four layers are provided. It may be a structure.

1 is an exploded perspective view of a droplet discharge head according to Embodiment 1 of the present invention. The longitudinal cross-sectional view of the principal part of FIG. Sectional process drawing which shows a manufacturing process until it forms an insulating film in a silicon substrate. Sectional process drawing which shows the manufacturing process of a glass substrate. Sectional process drawing which shows the manufacturing process of the glass substrate following FIG. The top view which expanded the electrode extraction part vicinity of the glass substrate, and its II sectional drawing. Sectional process drawing which shows the joint manufacturing process of a silicon substrate and a glass substrate. Sectional process drawing which shows the joint manufacturing process of the silicon substrate and glass substrate following FIG. Sectional process drawing which shows the joint manufacturing process of the silicon substrate and glass substrate following FIG. FIG. 2 is a cross-sectional view of a corresponding portion of FIG. Sectional process drawing which shows the joining manufacturing process which joins a nozzle substrate to the joined body of a cavity substrate and a glass substrate. The top view to which the electrode extraction part vicinity of the glass substrate which concerns on Embodiment 2 of this invention was expanded. The perspective view which shows the attachment state of a silicon mask. FIG. 2 is a cross-sectional view of a corresponding portion of FIG. The perspective view which showed an example of the droplet discharge apparatus carrying a droplet discharge head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrode substrate, 1a Glass substrate, 2 Cavity substrate, 2a Silicon substrate, 3 Nozzle substrate, 12 Vibration plate, 12a Boron diffusion layer, 13 Discharge chamber, 13a Portion corresponding to discharge chamber, 14 Reservoir, Portion corresponding to 14a reservoir , 16 Insulating film, 17 Individual electrode, 17a ITO film, 18 Protective film, 19 Ink supply hole, 21 Space part, 21a Gap step part, 27 Electrode extraction part, 27a Part corresponding to electrode extraction part, 31 Orifice, 32 Nozzle Hole, 61 Bonded substrate, 70 Sealing film, 71 Sealing hole, 80 Silicon mask, 100 Droplet ejection head, 150 Droplet ejection device, 170 Lead part of individual electrode.

Claims (11)

A nozzle hole for discharging droplets, a discharge chamber communicating with the nozzle hole and forming a part of a liquid flow path, a liquid supply unit for supplying liquid to the discharge chamber, and a part of a wall surface of the discharge chamber A droplet discharge head comprising at least a diaphragm formed on the substrate, an individual electrode disposed opposite to the diaphragm, and an electrode extraction portion for taking out the individual electrode, and a plurality of substrates laminated. And
After forming a gap step on the glass substrate, a protective film having etching resistance is formed on the surface of the glass substrate, and an ITO film is further formed on the surface of the protective film to form a plurality of electrodes to be the individual electrodes And a process of
The glass substrate on which the plurality of electrodes to be the individual electrodes are formed and the silicon substrate on which at least the plurality of recesses to be the discharge chambers are formed are separated from each other by a gap between the electrodes and the portions to be the vibration plates of the discharge chambers. A process of anodic bonding facing each other,
Etching the liquid substrate including at least a recess and a portion to be an electrode extraction portion on the silicon substrate bonded to the glass substrate using wet etching, and further dry etching the portion to be the electrode extraction portion A step of penetrating;
And a step of sealing the gap sealing hole using the through hole of the silicon substrate.   2. The method of manufacturing a droplet discharge head according to claim 1, wherein a protective film having etching resistance is formed on the entire surface of the electrode substrate.   2. The method of manufacturing a droplet discharge head according to claim 1, wherein a protective film having etching resistance is formed only in the vicinity of a portion that becomes a sealing hole portion on the surface of the electrode substrate.   Before forming the protective film, a groove having a depth corresponding to the thickness of the protective film is formed in the electrode substrate, and the protective film is formed in the groove of the electrode substrate in the same manner as the surface of the electrode substrate. 4. The method of manufacturing a droplet discharge head according to claim 3, wherein the film is formed to have a height.   The method for manufacturing a droplet discharge head according to claim 1, wherein the protective film is an insulator and has resistance to an etching gas used in the dry etching. 6. The method of manufacturing a droplet discharge head according to claim 5, wherein an etching gas used in the dry etching is made of CF ₄ or SF ₆ .   5. The method of manufacturing a droplet discharge head according to claim 1, wherein the protective film is an insulator and has resistance to an etching solution used for etching the ITO film. The method for manufacturing a droplet discharge head according to claim 1, wherein the protective film is made of Al ₂ O ₃ .   The method for manufacturing a droplet discharge head according to claim 1, wherein a sealing hole portion of the gap is sealed with an inorganic film. The method for manufacturing a droplet discharge head according to claim 9, wherein the inorganic film is a TEOS-SiO ₂ film. A method for manufacturing a droplet discharge device, wherein the droplet discharge device is manufactured by applying the method for manufacturing a droplet discharge head according to claim 1.

Images