JP2010125639A - Liquid-droplet ejecting head, liquid-droplet ejecting apparatus, method of manufacturing the liquid-droplet ejecting head, and method of manufacturing the liquid-droplet ejecting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid-droplet ejecting head or the like excellent in dielectric strength. <P>SOLUTION: The liquid droplet ejecting head has at least a second substrate 2 in which electrodes A are formed on a plurality of gap steps 20, respectively, and a first substrate 1 which has a plurality of ejection chambers 13 the wall surfaces of which are partly comprised of diaphragms 12 and in which insulating films 15 are formed on a surface of a side opposite to the ejection chambers of the diaphragms 12. The diaphragm 12 and the insulating film 15 are opposed via a gap G to the electrodes A. The liquid droplet ejecting head has electrode extraction portions 29 which extract the electrodes A from the gap steps 20. An insulating protecting film 25 with a tolerance to etching is formed in the vicinity of the electrode extraction portion 29 of the gap step 20. The insulating protecting film 25 is formed in the vicinity of an end of a lead 22 of the electrode A. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  In the opening etching process of the electrode extraction part of the conventional droplet discharge head, when forming the through hole, an insulating film having high insulation and strong etching resistance is formed in advance as an etching cover film, Damage to the electrode part and the substrate due to dry etching was prevented (for example, see Patent Document 1).

JP 2001-63072 A (page 4, FIG. 1)

  According to the technique described in Patent Document 1, since an insulating film is formed in advance as an etching cover film, damage to the electrode portion and the substrate due to dry etching can be prevented. There is a case where discharge occurs at the time of driving the ink jet in a portion not covered with the insulating film. For this reason, the dielectric strength and durability against long-term driving were not sufficient.

  The present invention has been made to solve the above-described problems, and is a droplet ejection head that has excellent withstand voltage and durability against long-term driving and has high reliability, a method for producing the same, and a droplet ejection device and the production thereof. It aims to provide a method.

The droplet discharge head according to the present invention includes a second substrate having electrode portions formed on a plurality of gap stepped portions, and a plurality of discharge chambers each having a part of a wall surface made of a vibration plate. At least a first substrate on which an insulating film is formed on a surface opposite to the chamber, with the diaphragm and the insulating film opposed to the electrode portion through the gap, and taking out the electrode portion from the gap stepped portion A droplet discharge head comprising a portion,
An insulating protective film having etching resistance is formed in the vicinity of the electrode extraction portion of the gap step portion.
Since the insulating protective film is formed in the vicinity of the electrode extraction portion of the gap step portion of the second substrate, the insulating film becomes thick in the vicinity of the electrode extraction portion together with the insulating film formed on the first substrate, Excellent withstand voltage.

In the droplet discharge head according to the present invention, an insulating protective film is formed in the vicinity of the end portion of the lead portion of the electrode portion.
Since the insulating protective film is formed in the vicinity of the end portion of the lead portion of the electrode portion of the second substrate, the insulating film becomes thick in the vicinity of the end portion of the lead portion together with the insulating film formed on the first substrate. Excellent in withstand voltage.

In the droplet discharge head according to the present invention, an insulating protective film is formed at a height substantially equal to the depth of the gap step portion.
The insulating film becomes thick at almost the same height as the gap stepped portion at the end portion of the lead portion of the electrode portion, and the withstand voltage is very excellent.

In the droplet discharge head according to the present invention, the insulating protective film is a film made of any one of a SiO ₂ film, a Si ₃ N ₄ film, and an Al ₂ O ₃ film.
Since the insulating protective film is formed from any one of the SiO ₂ film, the Si ₃ N ₄ film, and the Al ₂ O ₃ film, the withstand voltage is very excellent.

A droplet discharge apparatus according to the present invention is equipped with any of the droplet discharge heads described above.
It is possible to provide a droplet discharge device that has excellent durability with respect to long-term driving and high reliability.

In the method for manufacturing a droplet discharge head according to the present invention, a plurality of gap step portions are formed on a second substrate, an electrode portion is formed on each gap step portion, and a portion serving as an electrode extraction portion of the gap step portion is formed. A step of forming an insulating protective film having etching resistance in the vicinity, a step of forming a portion to be a vibration plate on the first substrate and forming an insulating film thereon, a second substrate and a first substrate; Bonding the electrode part, the part to be the diaphragm and the insulating film so as to face each other with a gap therebetween, and disposing the insulating protective film and the insulating film opposite to each other; The bonding substrate is etched by wet etching to form a liquid flow path including a discharge chamber having the diaphragm as a part of the wall surface and an electrode extraction through hole portion on the first substrate, and the electrode extraction through hole portion is formed. Furthermore, dry etching is performed to penetrate the electrode. It is intended to include the step of forming the out unit.
Since an insulating protective film is formed in the vicinity of the electrode extraction portion of the gap step portion of the second substrate, more specifically, in the vicinity of the end portion of the lead portion of the electrode portion, etching is performed in the opening etching process of the electrode extraction through hole portion. Even if the insulating film is slightly etched due to the gas flowing in, sufficient withstand voltage can be ensured.

A method for manufacturing a droplet discharge device according to the present invention is a method for manufacturing a droplet discharge device by applying the method for manufacturing a droplet discharge head described above.
It is possible to provide a droplet discharge device that has excellent durability with respect to long-term driving and high reliability.

Embodiment 1 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 the assembled droplet discharge head of FIG. The first embodiment shows a case of a face-type droplet discharge head that discharges droplets from nozzle holes provided in the surface portion of the substrate.
As shown in FIGS. 1 and 2, the droplet discharge head has a cavity substrate (first substrate) 1 having a vibration plate, a glass substrate (second substrate) 2 having an electrode portion, and a nozzle hole. It has a three-layer structure in which a nozzle substrate (third substrate) 3 is laminated.

  The cavity substrate 1 located in the middle of the three-layer structure is formed of, for example, a silicon (Si) single crystal substrate (hereinafter also referred to as a silicon substrate) having a surface orientation of (110) having a thickness of about 50 μm. The cavity substrate 1 is formed by performing anisotropic wet etching on a silicon substrate, and stores a liquid for discharging in common to the discharge chamber 13 whose bottom wall is the diaphragm 12 and each nozzle hole 30. It has a reservoir 14 to keep.

The diaphragm 12 has a thickness of, for example, about 0.8 μm and is formed of a high-concentration boron-doped layer having the same thickness. When anisotropic wet etching of a silicon substrate is performed with an alkaline aqueous solution, when boron is used as a dopant, the etching rate becomes extremely small in a high concentration region (about 5 × 10 ¹⁹ atoms · cm ⁻³ or more). Therefore, the thickness of the diaphragm 12 and the volume of the discharge chamber 13 are accurately formed by using a so-called etching stop technique utilizing this.

On the lower surface of the cavity substrate 1 (the lower surface of the boron doped layer serving as the vibration plate 12), a TEOS (Tetraethyl orthosilicate Tetraethoxysilane) film 0.1 μm serving as the insulating film 15 is formed by plasma CVD (Chemical Vapor Deposition). Is formed. This is to prevent breakdown and short circuit of the insulating film when the droplet discharge head is driven.
A droplet supply hole 16 is formed in the reservoir 14, and a common electrode terminal portion 17 is formed on the cavity substrate 1.

  The glass substrate 2 to be anodically bonded to the lower surface of the cavity substrate 1 has a thickness of about 1 mm, for example, and is made of borosilicate heat-resistant hard glass. The glass substrate 2 is provided with an electrode recess (gap step portion) 20 having a depth of about 0.2 μm by etching in accordance with each discharge chamber 13 formed in the cavity substrate 1. Since the individual electrode 21, the lead portion 22, and the terminal portion 23 (hereinafter collectively referred to as the electrode portion A) are provided, the pattern shape of the electrode recess 20 is made slightly larger than the shape of the electrode portion A. .

As the material of the electrode part A provided in the electrode recess 20, transparent ITO (Indium Tin Oxide) doped with tin oxide as an impurity is used, and the film is formed by sputtering, for example, to a thickness of 0.1 μm. To do.
Therefore, the gap G formed between the diaphragm 12 and the individual electrode 21 is determined by the depth of the electrode recess 20 and the thickness of the individual electrode 21. This gap G greatly affects the ejection characteristics.
Here, the material of the electrode part A is not limited to ITO, but a metal such as chrome may be used as the material, but in the first embodiment, since it is transparent, it is confirmed whether or not it has been discharged. ITO is used for reasons such as ease.

An insulating protective film 25 is formed in the vicinity of the electrode take-out portion 29 of the electrode recess 20, more specifically, in the vicinity of the end portion of the lead portion 22 of the electrode portion A. Is preventing. For example, the insulating protective film 25 is formed at a height substantially equal to the depth of the electrode recess 20. The material constituting the insulating protective film 25 is a highly insulating material such as SiO _2, Si ₃ N ₄ , or Al ₂ O ₃ . This is because when forming the electrode extraction portion 29, the silicon thin film remaining in the portion (through hole portion for electrode extraction) 29a (see FIG. 13 (h)) that becomes a through hole of the silicon substrate (cavity substrate 1) and This is because when the TEOS insulating film is removed by dry etching, an etching gas is introduced to prevent the insulating film 15 located in the vicinity of the end portion of the lead portion 22 of the electrode portion A from being thinned and lowering the withstand voltage.

  The glass substrate 2 is provided with a droplet supply hole 24, which is formed by sandblasting or cutting, and communicates with the droplet supply hole 16 provided in the reservoir 14 of the cavity substrate 1.

The nozzle substrate 3 bonded to the upper surface (the upper side surface in FIG. 2) of the cavity substrate 1 is made of, for example, a silicon substrate having a thickness of about 180 μm, and is bonded to the cavity substrate 1 on the surface opposite to the glass substrate 2. A nozzle hole 30 that communicates with the discharge chamber 13 is formed in the nozzle substrate 3, and an orifice 31 is provided on the lower surface to communicate the discharge chamber 13 and the reservoir 14. A diaphragm 32 is formed in a portion in contact with the reservoir 14 in order to increase the compliance of the reservoir 14 and absorb crosstalk when the droplet discharge head is driven.
Here, the nozzle substrate 3 having the nozzle holes 30 is described as the upper surface, and the glass substrate 2 is described as the lower surface. However, when actually used, the nozzle substrate 3 is often the lower surface.

In the above droplet discharge head, the actuator composed of the diaphragm 12 and the fixed electrode 21 is sealed for each individual electrode 21 by a sealing material 50. Thereby, sticking between the individual electrode 21 and the diaphragm 12 when the actuator is driven can be prevented.
The terminal part 23 of the electrode part A formed on the glass substrate 2 is connected to the oscillation circuit 40 together with the terminal part 17 of the common electrode formed on the cavity substrate 1.

The operation of the droplet discharge head configured as described above will be described.
As shown in FIG. 2, the discharge liquid discharged from the nozzle hole 30 is stored in the discharge chamber 13. Then, the diaphragm 12 which is the bottom wall of the discharge chamber 13 is bent, the pressure in the discharge chamber 13 is increased, and droplets are discharged from the nozzle holes 30.

At this time, the oscillation circuit 40 controls the supply and stop of charge to the individual electrode 21. For example, it oscillates at 24 kHz, and charges are supplied by applying pulse potentials of 0 V and 30 V to the individual electrodes 21.
When an electric charge is supplied to the individual electrode 21 to be positively charged, the diaphragm 12 is negatively charged and is attracted to the individual electrode 21 by an electrostatic force to bend. As a result, the volume of the discharge chamber 13 increases. When the charge supply to the individual electrode 21 is stopped, the vibration plate 12 returns to its original state, but the volume of the discharge chamber 13 at that time also returns to its original size and is reduced. For example, when the droplet is ink, the recording is performed by landing on the recording paper to be recorded.
Such a method is called pulling, but there is also a method called pushing that discharges droplets using a spring or the like.

  According to the present invention, since the insulating protective film 25 is formed in the vicinity of the electrode extraction portion 29 of the electrode recess 20 of the glass substrate 2, specifically, in the vicinity of the end portion of the lead portion 22 of the electrode portion A, In addition to the insulating film 15 formed in the above, the insulating film is thickened at the end portion of the lead portion 22, and a droplet discharge head having an excellent withstand voltage can be obtained.

A method of manufacturing the glass substrate 2 of the droplet discharge head configured as described above will be described with reference to manufacturing process diagrams of FIGS. 3 to 8 are cross-sectional views of the glass substrate 2, and FIGS. 9 to 11 are top views.
In addition, the numerical value described in the following description shows the example, and is not limited to this.

(A) As shown in FIG. 3A, a Cr film (chromium film) 201 serving as an etching mask is formed on one surface of a glass substrate 2 having a thickness of about 1 mm to a thickness of 0.1 μm.

(B) As shown in FIG. 3B, a resist 202 is applied to the surface of the formed Cr film 201, and resist patterning for forming the recess B is performed.

(C) As shown in FIG. 3C, the Cr film 201 is patterned by etching with an aqueous cerium ammonium nitrate solution.

(D) As shown in FIG. 3D, the glass substrate 2 is immersed in an aqueous ammonium fluoride solution with the resist 202 attached, and the recess (groove) B is etched to a depth of 0.2 μm.

(E) As shown in FIG. 4E, the resist 202 is stripped, and then the Cr film 201 is stripped. As shown in FIG. 9, the formed recess B includes an electrode recess (gap step portion) 20 as well as a gas phase processing recess 20 a communicating with the electrode recess (gap step portion) 20. The gas phase treatment recess 20a is used for performing a hydrophobic treatment after removing moisture in the gap G. The gas phase processing recess 20a is located outside the dicing line indicated by dotted lines a and b (upper side and right side in the figure) and does not remain in the completed droplet discharge head.
In the liquid droplet ejection head of FIG. 9, only five electrode recesses 20 are shown, but in reality there are many electrode recesses 20 (the same applies to FIGS. 10 and 11 below).

(F) As shown in FIG. 5F, a member a to be the electrode portion A having a thickness of 0.1 μm is formed on the entire surface of the patterning surface by using, for example, a sputtering method. For example, ITO is used as the member a to be the electrode part A.

(G) A resist 203 is applied to the patterning surface, and resist patterning is performed so that ITO remains in the electrode recess 20 as shown in FIG.

(H) As shown in FIG. 6 (h), the electrode part A is formed by etching the member a made of ITO using a mixed solution of nitric acid and hydrochloric acid. Thereafter, the resist 203 is peeled off.
As shown in FIG. 10, the electrode portions A communicate with each other on the end portion side of the terminal portion 23, and the communicating portions are diced, so that they do not remain in the completed droplet discharge head. .

(I) A resist 204 is applied to the patterning surface, and as shown in FIG. 7 (i), only the portion where the insulating protective film 25 (see FIG. 2) of the electrode portion A is formed, that is, the vicinity of the end portion of the lead portion 22. The resist patterning is performed so that the openings are opened.

(J) As shown in FIG. 7 (j), an insulating protective member 250 (a member such as SiO ₂ , Si ₃ N ₄ , Al ₂ O ₃ ) having a thickness of 0.1 μm is patterned using, for example, a sputtering method. A film is formed on the entire surface.

(K) The resist 204 underlying the insulating protection member 250 is removed. Thereby, as shown in FIG. 7 (k), the insulation protection member 250, that is, the insulation protection film 25 remains only in the vicinity of the end portion of the lead portion 22 of the electrode portion A.

(L) As shown in FIGS. 8 (l) and 11, the ink supply hole 24 and the air release hole 26 are formed by a sandblasting method or a cutting process. The air opening hole 26 is formed in the gas phase processing groove 20 a and communicates with the electrode recess 20 of the glass substrate 2.

  Next, a method of joining the glass substrate 2 manufactured by the steps shown in FIGS. 3 to 11 to a silicon substrate (cavity substrate 1) to form a liquid flow path including the discharge chamber 13 will be described. 12-A description will be given using the manufacturing process diagram of FIG.

(A) As shown to Fig.12 (a), the glass substrate 2 processed by the method shown in FIGS. 3-7 is prepared.

(B) One side of a cavity substrate 1 made of silicon with a low oxygen concentration and having a plane orientation of (110) is mirror-polished to produce a substrate having a thickness of 220 μm.
Next, the surface on which the boron dope layer 120 (vibrating plate 12) is formed on the cavity substrate 1 is set on a quartz boat so as to face a solid diffusion source containing B ₂ O ₃ as a main component. A quartz boat is set in a vertical furnace, the inside of the furnace is put into a nitrogen atmosphere, the temperature is raised to 1050 ° C., and the temperature is maintained as it is for 7 hours, and boron is diffused into the cavity substrate 1 to form the boron dope layer 120. In the boron doping process, the input temperature of the cavity substrate 1 is set to 800 ° C., and the extraction temperature of the cavity substrate 1 is also set to 800 ° C. Accordingly, it is possible to quickly pass through a region (600 ° C. to 800 ° C.) where the growth rate of oxygen defects is high, so that the generation of oxygen defects can be suppressed. The surface of the boron-doped layer 120 is a boron compound is formed (not shown), in an oxygen and steam atmosphere, 600 to oxidize 1 hour 30 minutes at ℃ conditions, which can be etched by hydrofluoric acid aqueous solution B ₂ It can be chemically changed to O ₃ + SiO ₂ . B ₂ O ₃ + SiO ₂ is removed by etching with a hydrofluoric acid aqueous solution in a state where it is chemically changed to B ₂ O ₃ + SiO ₂ . Thus, a boron doped layer 120 is formed on the surface of the cavity substrate 1 as shown in FIG.
Further, the TEOS insulating film 15 is formed on the surface on which the boron doped layer 120 is formed by plasma CVD, the processing temperature during film formation is 360 ° C., the high frequency output is 250 W, and the pressure is 66.7 Pa (0.5 Torr). The film thickness of 0.1 μm is formed under the conditions of a gas flow rate of TEOS flow rate of 100 cm ³ / min (100 sccm) and oxygen flow rate of 1000 cm ³ / min (1000 sccm).

(C) After the cavity substrate 1 and the patterned glass substrate 2 are heated to 360 ° C., the negative electrode is connected to the glass substrate 2, the positive electrode is connected to the cavity substrate 1, and a voltage of 800 V is applied, so that FIG. Anodic bonding as shown in FIG.
At the time of anodic bonding, glass is electrochemically decomposed at the interface between the cavity substrate 1 and the glass substrate 2 to generate oxygen. In addition, gas adsorbed on the surface may be generated by heating. At this time, the air opening hole 26 is connected to the electrode recess 20 (see FIG. 11), and these gases escape from the air opening hole 26, so that there is no positive pressure in the gap G and is formed after anodic bonding. The formed gap G is sealed to prevent the gap G from being pressurized by oxygen or the like generated during anodic bonding.

(D) After the anodic bonding, as shown in FIG. 12D, the surface of the cavity substrate 1 is ground until the thickness of the cavity substrate 1 becomes about 60 μm. Thereafter, in order to remove the work-affected layer, the cavity substrate 1 is polished by about 10 μm using CMP (Chemical Mechanical Polishing). Thereby, the thickness of the cavity substrate 1 becomes about 50 μm.
In the grinding step and the work-affected layer removal step, the air release hole 26 is protected using a single-sided protective jig, tape, or the like so that liquid does not enter the gap G from the air release hole 26 (see FIG. 11). ).

(E) As shown in FIG. 13 (e), plasma CVD is used on the polished surface, the processing temperature during film formation is 360 ° C., the high frequency output is 700 W, the pressure is 33.3 Pa (0.25 Torr), and the gas The TEOS etching mask 101 is formed to a thickness of 1.0 μm under the conditions of a TEOS flow rate of 100 cm ³ / min (100 sccm) and an oxygen flow rate of 1000 cm ³ / min (1000 sccm).
Next, an epoxy adhesive is poured into the air opening hole 26 (see FIG. 11) to seal the hole. Thereby, the gap G is hermetically sealed, and the liquid does not enter from the atmosphere opening hole 26 in the subsequent processes. This step is preferably performed after the TEOS etching mask 101 is formed. If the air opening hole 26 is sealed before the film formation, the gas in the confined gap G may thermally expand during the film formation and push up the thinned cavity substrate 1 to break the cavity substrate 1. .

(F) The TEOS etching mask 101 is subjected to resist patterning and etched with a hydrofluoric acid aqueous solution, and a portion corresponding to a discharge chamber 13 and a second sealing portion (not shown) to be described later is patterned. Then, the resist is peeled off.
Further, resist patterning is performed on the TEOS etching mask 101, and etching is performed by 0.7 μm with a hydrofluoric acid aqueous solution. As shown in FIG. 13 (f), a reservoir 14 and a portion to be described later (through-hole portion for extracting an electrode) ) Pattern the portion corresponding to 29a. The remainder of the TEOS etching mask 101 corresponding to the reservoir 14 and the portion 29a to be the through hole is 0.3 μm. This is to increase the rigidity by giving the reservoir 14 and the portion 29a which finally becomes the through hole thick. Then, the resist is peeled off.

(G) The bonded substrate is immersed in a 35 wt% potassium hydroxide aqueous solution, and etching is performed until the thickness of the discharge chamber 13 becomes about 5 μm, as shown in FIG. At this time, the etching of the reservoir 14 and the portion 29a to be the through hole has not started yet.

(H) In order to remove the TEOS etching mask 101 in the portion corresponding to the reservoir 14 and the portion 29a to be the through hole, the bonding substrate is immersed in a hydrofluoric acid aqueous solution. Then, the bonding substrate is immersed in a 3 wt% potassium hydroxide aqueous solution for about 20 minutes to stop etching due to a decrease in the etching rate in the boron doped layer 120. By performing etching using the two types of potassium hydroxide aqueous solutions having different concentrations, as shown in FIG. 13 (h), the surface roughness of the diaphragm 12 formed from the boron dope layer 120 is suppressed, and the diaphragm 12 The thickness accuracy can be 0.80 ± 0.05 μm or less, and the discharge performance of the droplet discharge head can be stabilized.
The depth of the reservoir 14 and the portion 29a serving as the through hole is about 30 μm. Accordingly, the thickness of the reservoir 14 and the portion 29a serving as the through hole is about 20 μm. Therefore, the strength is improved, and the reservoir 14 having a large area and the portion 29a serving as the through hole are not broken during the etching of the cavity substrate 1, and the yield can be improved.

(I) When the etching of the cavity substrate 1 is completed, the cavity substrate 1 is immersed in a hydrofluoric acid aqueous solution, and the TEOS etching mask 101 on the surface of the cavity substrate 1 is peeled off.
In order to remove the silicon thin film (see FIG. 13 (h)) remaining in the portion (not shown) to be the second sealing portion and the portion 29a to be the through hole, an Si mask opened only in the through hole portion is used. Attach to the surface of the cavity substrate 1, perform RIE dry etching for 1 hour under the conditions of RF power 200W, pressure 40Pa (0.3 Torr), SF ₆ flow rate 30cm ³ / min (30sccm), and apply plasma only to the through hole . Next, since only the TEOS insulating film 15 remains, RIE dry etching is performed for 10 minutes under the conditions of an RF power of 200 W, a pressure of 40 Pa (0.3 Torr), and a CF ₄ flow rate of 30 cm ³ / min (30 sccm). In this way, a portion (not shown) that becomes the second sealing portion and a portion 29a that becomes the through hole penetrate, a second sealing portion (not shown) and the through hole are formed, and the gap G is opened to the atmosphere. The As shown in FIG. 14 (i), a portion 29 a that becomes a through hole penetrates to form an electrode extraction portion 29.
In this opening etching process, the TEOS insulating film 15 located near the end of the cavity substrate 1 (corresponding to the upper side near the end of the lead portion 22 of the glass substrate 2) and the insulating protective film 25 of the glass substrate 2 are also applied. Etching gas goes around. However, since the insulating protective film 25 is formed in advance as shown in FIG. 14 (i), a sufficient withstand voltage is ensured even if the TEOS insulating film 15 and the insulating protective film 25 are slightly etched. Can do.

(J) An Si mask having an opening only for the individual electrode sealing portion is attached to the surface of the cavity substrate 1, and an inorganic material is deposited from the rear surface of the glass using plasma CVD, and the gap G is sealed as shown in FIG. Sealing is performed with a stopper 50. As the inorganic material used for the sealing material 50, for example, a TEOS film is used.

(K) After the bonding substrate is placed in the vacuum chamber, as shown in FIG. 14 (k), a vacuum is drawn at a high temperature of 360 ° C. to remove moisture in the gap G. Then, by filling and curing the epoxy resin in the second sealing portion (not shown), the gap G is again sealed.

  Next, a method of manufacturing the droplet discharge head by bonding the nozzle substrate 3 to the bonded substrate of the glass substrate 2 and the cavity substrate 1 manufactured by the steps shown in FIGS. This will be described with reference to process drawings.

(A) As shown in FIG. 15A, the nozzle substrate 3 is bonded to the cavity substrate 1 side of the bonding substrate with an epoxy adhesive.

(B) As shown in FIG. 15 (b), dicing is performed along dicing lines A and B, and the head is cut into individual heads. At this time, the electrode portion A of ITO that was short-circuited at the time of anodic bonding is divided for each ink cavity. Further, the air sealing hole 26 and the gas phase processing recess 20a communicating therewith are also cut.
Thus, a droplet discharge head in which the glass substrate 2, the cavity substrate 1, and the nozzle substrate 3 are laminated is completed.

  According to the present invention, since the insulating protective film 25 is formed in the vicinity of the electrode extraction portion 29 of the electrode recess 20 of the glass substrate 2, more specifically, in the vicinity of the end portion of the lead portion 22 of the electrode portion A, it becomes a through hole. Even if the insulating film 15 is slightly etched by the etching gas flowing in the opening etching process of the portion 29a, a sufficient withstand voltage can be secured.

Embodiment 2. FIG.
FIG. 16 is a perspective view showing a droplet discharge device equipped with the droplet discharge head according to the first embodiment. The droplet discharge device shown in FIG. 16 is a general ink jet printer.
In the droplet discharge head shown in the first embodiment, an insulating protective film 25 is formed in the vicinity of the electrode extraction portion 29 of the electrode recess 20 of the glass substrate 2, specifically, in the vicinity of the end portion of the lead portion 22 of the electrode portion A. Therefore, in addition to the insulating film 15 formed on the cavity substrate 1, the insulating film is thick in the vicinity of the end portion of the lead portion 22 and has an excellent withstand voltage, so it has excellent durability against long-term driving, high accuracy and reliability. A droplet discharge device having a high droplet discharge head can be obtained.
In addition to the ink jet printer shown in FIG. 16, the droplet discharge head according to Embodiment 1 can be used to manufacture liquid crystal color filters and to form light emitting portions of organic EL display devices by variously changing droplets. It can also be applied to the discharge of biological liquids.

1 is an exploded perspective view of a droplet discharge head according to Embodiment 1 of the present invention. FIG. 2 is a longitudinal sectional view of a state in which the droplet discharge head of FIG. 1 is assembled. FIG. 4 is a cross-sectional view showing a manufacturing process of the glass substrate of the droplet discharge head according to the first embodiment. Sectional drawing which shows the manufacturing process of the glass substrate of the droplet discharge head following FIG. Sectional drawing which shows the manufacturing process of the glass substrate of the droplet discharge head following FIG. Sectional drawing which shows the manufacturing process of the glass substrate of the droplet discharge head following FIG. Sectional drawing which shows the manufacturing process of the glass substrate of the droplet discharge head following FIG. Sectional drawing which shows the manufacturing process of the glass substrate of the droplet discharge head following FIG. FIG. 5 is a top view of FIG. 4. FIG. 7 is a top view of FIG. 6. FIG. 9 is a top view of FIG. 8. FIG. 6 is a cross-sectional view showing a manufacturing process of the droplet discharge head according to the first embodiment. FIG. 13 is a cross-sectional view illustrating a manufacturing process of the droplet discharge head following FIG. 12. FIG. 14 is a cross-sectional view illustrating a manufacturing process of the droplet discharge head following FIG. 13. FIG. 6 is a cross-sectional view showing a manufacturing process of the droplet discharge head according to the first embodiment. The perspective view of the droplet discharge device which concerns on Embodiment 2 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Cavity substrate (1st substrate), 2 Glass substrate (2nd substrate), 3 Nozzle substrate (3rd substrate), 12 Vibration plate, 13 Discharge chamber, 14 Reservoir, 15 Insulating film, 20 Electrode recessed part (gap) Step part), 21 Individual electrode, 22 Lead part, 23 Terminal part, 25 Insulating protective film, 29 Electrode extraction part, 29a Part to be a through hole (through hole part for electrode extraction), 30 Nozzle hole, A electrode part, G gap.

Claims (7)

A second substrate in which electrode portions are respectively formed in a plurality of gap stepped portions;
A plurality of discharge chambers each having a wall surface made of a diaphragm, and at least a first substrate having an insulating film formed on a surface of the diaphragm opposite to the discharge chamber;
A liquid droplet ejection head comprising an electrode take-out portion that makes the diaphragm and the insulating film face the electrode portion via a gap and takes out the electrode portion from the gap stepped portion;
A droplet discharge head, wherein an insulating protective film having etching resistance is formed in the vicinity of the electrode extraction portion of the gap step portion.   The droplet discharge head according to claim 1, wherein the insulating protective film is formed in the vicinity of an end portion of the lead portion of the electrode portion.   The droplet discharge head according to claim 1, wherein the insulating protective film is formed at a height substantially equal to a depth of the gap step portion. 4. The droplet discharge head according to claim 1, wherein the insulating protective film is a film made of any one of a SiO ₂ film, a Si ₃ N ₄ film, and an Al ₂ O ₃ film. .   A droplet discharge apparatus comprising the droplet discharge head according to claim 1. A plurality of gap stepped portions are formed on the second substrate, electrode portions are formed on the respective gap stepped portions, and an insulating protective film having etching resistance is formed in the vicinity of the portion of the gap stepped portion serving as the electrode extraction portion. Process,
Forming a portion to be a vibration plate on the first substrate and forming an insulating film thereon;
The second substrate and the first substrate are joined such that the electrode portion, the portion serving as the diaphragm and the insulating film face each other with a gap therebetween, and the insulating protective film and the insulating film A step of arranging the film opposite to each other;
The first and second bonded substrates are etched by wet etching to form a liquid flow path including a discharge chamber having a vibration plate as a part of a wall surface and an electrode extraction through hole in the first substrate. The step of forming the electrode lead-out part by further dry etching the through-hole part for taking out the electrode and penetrating the through-hole part.
A method for manufacturing a droplet discharge head, comprising:   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 6.

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