JP2014069420A - Method of producing ink discharging head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing an ink discharging head which can prevent dissolution of a sacrifice layer even when a nozzle layer is formed by applying a resin dissolved in a solvent.SOLUTION: A method of producing an ink discharging head comprises a step S2 of forming a sacrifice layer 204 composed of a negative resist on a substrate 201, a step S3 of forming a glass layer 203 on the sacrifice layer 204, a step S4 of applying a resin dissolved in a solvent onto the glass layer 203 to form a nozzle layer 207 and forming nozzle holes 110 in the nozzle layer 207, a step S5 of forming an ink supply port 120 in the substrate 201, a step S6 of removing the sacrifice layer 204 from the side of the formed ink supply port 120 by ashing and a step S7 of removing the glass layer 203 located under the nozzle holes 110 to communicate the nozzle holes 110 with an ink passage CH.

Description

  The present invention relates to a method for manufacturing an ink discharge head.

  Conventionally, various methods for manufacturing an ink discharge head have been proposed. For example, in the manufacturing method described in Patent Document 1, a mold material that becomes an ink flow path is formed on a silicon substrate, a coating photosensitive resin is applied to the peripheral surface of the mold material, exposure and development are performed, and nozzle holes are formed. Form. In this manufacturing method, when an ink flow path is formed, a positive resist serving as a mold material is applied onto a silicon substrate, and exposure and development are performed. Further, a negative resist is used as the coating photosensitive resin.

JP 2009-178906 A

  However, conventionally, when a coated photosensitive resin dissolved in a solvent is applied to the peripheral surface of a mold material formed of a positive resist, there is a problem that the mold material is dissolved by the solvent.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an ink ejection head capable of preventing the sacrificial layer from melting even when a nozzle layer is formed by applying a resin dissolved in a solvent. It is in providing the manufacturing method of.

  In order to achieve this object, a method of manufacturing an ink discharge head according to claim 1 includes a heater provided on a substrate for generating thermal energy for discharging ink, an ink flow path provided on the heater, and an ink. In a method of manufacturing an ink ejection head having a nozzle hole communicating with a flow path, a step of forming a sacrificial layer made of a negative resist on the substrate, a step of forming an inorganic film on the sacrificial layer, Applying a resin dissolved in a solvent on the inorganic film to form a nozzle layer; forming a nozzle hole in the nozzle layer; forming an ink supply port in the substrate; and the ink supply port Removing the sacrificial layer by ashing from the side on which the nozzle hole is formed, and removing the inorganic film located below the nozzle hole to allow the nozzle hole and the ink flow path to communicate with each other.

  According to the method for manufacturing an ink ejection head according to claim 1, even if the nozzle layer is formed by applying a resin dissolved in a solvent, the sacrificial layer is melted because the inorganic film is formed on the sacrificial layer. Can be prevented.

  3. The method of manufacturing an ink ejection head according to claim 2, wherein the step of forming the inorganic film forms a glass layer on the sacrificial layer.

  According to the method for manufacturing an ink discharge head according to claim 2, since the glass layer is formed on the sacrificial layer in the step of forming the inorganic film, the glass layer is heat resistant, and the nozzle layer and the nozzle hole are formed. The deformation of the inorganic film due to can be further suppressed.

  4. The method of manufacturing an ink ejection head according to claim 3, wherein in the step of forming the inorganic film, the glass layer is formed by P-TEOS.

  According to the method for manufacturing the ink discharge head of the third aspect, since the glass layer is formed by P-TEOS, a film without a pinhole can be formed in the glass layer.

  5. The method of manufacturing an ink ejection head according to claim 4, wherein in the step of forming the nozzle hole, the nozzle hole is formed in the nozzle layer by dry etching using hydrogen fluoride.

  According to the method for manufacturing an ink discharge head of the fourth aspect, since dry etching is performed using hydrogen fluoride when forming the nozzle hole, damage to the heater can be reduced even if hydrogen fluoride adheres to the heater.

  According to the present invention, even if a nozzle layer is formed by applying a resin dissolved in a solvent, the sacrificial layer can be prevented from melting because the inorganic film is formed on the sacrificial layer. As a result, the nozzle hole can be formed in the shape as designed.

FIG. 2 is a schematic perspective view illustrating an example of an ink discharge head according to an embodiment of the present invention. It is a typical sectional view showing each manufacturing process of the ink discharge head concerning this embodiment. It is sectional drawing which shows the typical sectional drawing in heater formation process S1 shown to Fig.2 (a) in detail.

  Exemplary embodiments of an ink discharge head manufacturing method according to the present invention will be described below in detail with reference to the accompanying drawings.

(Embodiment)
(Configuration of ink ejection head)
The configuration of the ink ejection head according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic perspective view showing an example of an ink discharge head according to an embodiment of the present invention. In FIG. 1, in the ink discharge head 100, a plurality of nozzle holes 110 are formed in the nozzle layer 207 in an aligned state. The plurality of nozzle holes 110 communicate with a plurality of individually provided ink channels CH, which will be described later with reference to FIG. FIG. 2G is a schematic cross-sectional view of the ink ejection head taken along line AA shown in FIG. The ink discharge head shown in FIG. 2G is in a completed state after the manufacturing process of the ink discharge head has been completed. 2A to 2G are schematic cross-sectional views showing the respective steps of the method of manufacturing the ink ejection head according to the present embodiment. The manufacturing method of the ink discharge head is executed by sequentially executing the seven steps shown in FIGS. The cross section along the line AA is a cross section from the upper vertical direction in the figure, and is a cross section seen from the direction of the arrow A, and an example of a cross section that cuts two nozzle holes 110 among the plurality of nozzle holes 110. Show.

  In FIG. 2G, the ink channel CH is defined by a glass layer 203 and a nozzle layer 207 formed on a plurality of layers formed on the substrate 201. A heating resistor 202 that generates thermal energy for ejecting ink is provided in each ink channel CH. The ink supply port 120 is connected from the lower surface of the ink discharge head 100 to the ink flow channel CH. Ink is supplied from an ink tank (not shown) that supplies ink to the ink supply port 120 to the ink channel CH. A part of the ink supplied to the ink flow channel CH becomes bubbles due to the heating of the heating resistor 202. The ink in the ink channel CH pushed out by the bubbles is ejected from the nozzle hole 110.

(Ink discharge head manufacturing method)
A method for manufacturing the ink ejection head according to the present embodiment will be described with reference to FIGS. FIG. 2A is a schematic cross-sectional view showing the heater forming step S1 of the ink discharge head according to the present embodiment. FIG. 3 is a cross-sectional view showing in detail a schematic cross-sectional view in the heater forming step S1 shown in FIG. FIG. 2A is a schematic diagram of FIG. 3 in which a known heater for discharging ink to the substrate 201 is formed. 2B to 2G are schematic cross-sectional views illustrating the schematic configuration of each layer in each step, as in FIG. 2A.

  As shown in FIG. 3, in the heater forming step S1, a heater is formed by a known forming method. A heat storage layer 302 is formed with a film thickness of about 10,000 mm on a silicon substrate 201, and a heating resistor 202 and an electrode layer 303 are formed on the formed heat storage layer 302. An oxide insulating film 301 such as SiO 2 or SiN is formed on the lower surface of the substrate 201 with a film thickness of about 1000 to 10,000 mm. The heating resistor 202 is formed, for example, by forming a film of TaN or TaAl or the like at a position where the heating resistor 202 is formed by a sputtering method so as to have a thickness within a range of 200 to 1000 mm.

  The electrode layer 303 includes Al or an Al alloy, and is formed on the heating resistor 202 so as to have a thickness of about 500 nm, for example. An electrode pad 304 having a known configuration is formed connected to the electrode layer 303. A driver IC unit 306 is embedded in the substrate 201 in a state of being connected to the electrode 305. A protective film 307 for protecting the electrode layer 303 from ink is formed on the electrode layer 303. On the protective film 307, an anti-cavitation film 308 for protecting from cavitation damage is formed at a position where ink is ejected. An electric signal is transmitted from the control unit (not shown) to the driver IC unit 306 via the electrode pad 304, and the driver IC unit 306 is driven. A voltage is applied to the heating resistor 202 via the electrode layer 303 from a power supply unit (not shown). By driving the driver IC unit 306, a current flows through the heating resistor 202 under the nozzle hole 110, and the heating resistor 202 generates heat. Due to this heat generation, ink bubbles are generated. The ink is ejected from the nozzle hole 110 by pushing out the ink by the bubbles. The heating resistor 202 and the electrode layer 303 in the present embodiment correspond to an example of a heater in the present invention.

  FIG. 2B is a schematic cross-sectional view showing a sacrificial layer forming step S2 of the ink ejection head according to the present embodiment. In the sacrificial layer forming step S2, a negative resist is applied on the protective film 307 by a spin coater, and the applied negative resist is exposed by a photolithography method and then developed. By these processes, the ink flow channel CH is patterned into a negative resist, and the sacrificial layer 204 is formed. The thickness of the sacrificial layer 204 is about 10 μm to 20 μm. The negative resist used as the sacrificial layer 204 includes an epoxy resin or the like. In addition, polyimide resin or the like is used. The negative resist can be hardened more than the positive resist because the portion exposed to light is not dissolved by the solvent. Therefore, it is more stable against heat or chemicals than the sacrificial layer 204 is formed with a positive resist. In addition, since the negative resist uses a general photosensitizer that does not contain antimony as a photosensitizer, a residue containing metal antimony that is a compound of antimony hardly remains, and the residue is the oxide insulating film 301 or the anti-cavitation film 308. Therefore, it is possible to form an ink channel CH that is less affected by the residue.

  FIG. 2C is a schematic cross-sectional view showing the inorganic film forming step S3 of the ink ejection head according to the present embodiment. In the inorganic film forming step S3, the glass layer 203 is formed by P-TEOS from the sacrificial layer 204 on which the ink flow channel CH is patterned. P-TEOS is a method of forming a silicon oxide film by plasma CVD using tetraethyl orthosilicate (TEOS) as a source. P-TEOS is a film forming method with good coverage (coverability), and the glass layer 203 can be uniformly formed on the side surface portion of the sacrificial layer 204 with the same thickness as the upper surface portion of the sacrificial layer 204. . P-TEOS can be formed even at a low temperature from 150 ° C. to 300 ° C., and can therefore be formed on the sacrificial layer 204 formed of a resin that deforms at a high temperature. The film thickness of the glass layer 203 is about 0.3 μm to 1 μm. Since the sacrificial layer 204 is a negative resist, even if the sacrificial layer 204 is heated from 150 ° C. to about 300 ° C., which is the temperature at which the glass layer 203 is formed by P-TEOS, the sacrificial layer 204 does not need to be deformed. When the sacrificial layer 204 is a positive resist, the sacrificial layer 204 is distorted by the temperature at which the glass layer 203 is formed, and a good ink channel CH shape cannot be obtained. The glass layer 203 is resistant to ashing by oxygen plasma described later.

  FIG. 2D is a schematic cross-sectional view showing the nozzle layer forming step S4 of the ink ejection head according to the present embodiment. In the nozzle layer forming step S4, a negative resist dissolved in a solvent mainly composed of PGMA (propylene glycol monomethyl ether acetate) or ethyl cellosolve (2-ethoxyethanol) is applied on the glass layer 203 by a spin coater. The The applied negative resist is exposed by a photolithography method. Thereafter, baking after exposure and development are sequentially performed to form nozzle holes 110 (see FIG. 2E) in the negative resist. The baking is performed at a temperature of 90 ° C. for 10 minutes. In the development, the nozzle hole portion 207 a is removed, and the nozzle hole 110 is formed in the nozzle layer 207. Specifically, for example, by immersing the nozzle layer 207 in a developing solution such as xylene, PGMA, or ethyl cellosolve, the ultraviolet ray is not irradiated by exposure, and the uncured nozzle hole 207a is removed. In other words, development is a portion that is soluble in the developer and not cured, leaving a cured portion of the nozzle layer 207 made of an ultraviolet thermosetting resin that is insoluble in the developer. This is a step of removing the nozzle hole portion 207a. The negative resist used as the nozzle layer 207 includes, for example, an epoxy resin or a polyimide resin.

  FIG. 2E is a schematic cross-sectional view showing the ink supply port forming step S5 of the ink ejection head according to the present embodiment. In the ink supply port forming step S5, the ink supply port 120 is formed from the lower side of the substrate 201 toward the sacrificial layer 204 side by removing a part of the substrate 201 by wet etching. In this embodiment, for example, wet etching is performed using a potassium hydroxide (KOH) aqueous solution or a tetramethylammonium hydroxide (TMAH) aqueous solution. Specifically, for example, a photoresist is applied on the oxide insulating film 301 on the lower side of the substrate 201, and then the photoresist corresponding to the ink supply port 120 is removed by a photolithography method. Next, wet etching is performed on the oxide insulating film 301 corresponding to the ink supply port 120. Thereafter, after the photoresist is removed by a stripping solution or the like, the substrate 201 is dissolved and removed by using the remaining oxide insulating film 301 other than the position corresponding to the ink supply port 120 as an etching mask.

  FIG. 2F is a schematic cross-sectional view showing a sacrificial layer removing step S6 of the ink ejection head according to the present embodiment. In the sacrificial layer removal step S6, the sacrificial layer 204 is removed by ashing from the ink supply port 120 side. Ashing refers to removal of a resist using dry etching, and isotropic etching using a radical reaction by oxygen plasma. Since the sacrificial layer 204 is made of a resin, carbon, hydrogen, nitrogen, sulfur, and the like, which are main components of the resin, are oxidized by ashing using an oxygen plasma gas, and are discharged from the ink supply port 120 as a gas. In addition, the sacrificial layer 204 contains a slight amount of components such as metal impurities remaining as a residue, but can be easily removed with an organic solvent, an acid, an alkaline cleaning solution, or the like after the ashing process. When ashing is performed in the absence of the glass layer 203, the nozzle layer 207 is removed by ashing, which affects ink ejection.

  FIG. 2G is a schematic cross-sectional view showing the hole forming step S7 of the glass layer 203 of the ink ejection head according to the present embodiment. In the hole forming step S7 of the glass layer 203, holes are formed in the glass layer 203 at the position where the nozzle holes 110 of the nozzle layer 207 are formed by etching using hydrogen fluoride. Through the hole forming step S7 of the glass layer 203, a hole is formed in the glass layer 203, and the nozzle hole 110 and the ink flow channel CH communicate with each other.

  In addition, if each process in this invention is demonstrated and linked | related with each process of this embodiment, the process of the process of forming the sacrificial layer of this invention will be performed by sacrificial layer formation process S2 shown in FIG.2 (b). Is done. By the inorganic film forming step S3 shown in FIG. 2C, the process of the step of forming the inorganic film of the present invention is performed. By the nozzle layer forming step S4 shown in FIG. 2D, the process of forming the nozzle layer of the present invention and the process of forming the nozzle holes are executed. In the ink supply port forming step S5 shown in FIG. 2E, the process of the step of forming the ink supply port of the present invention is executed. In the sacrificial layer removal step S6 shown in FIG. 2F, the process of the step of removing the sacrificial layer of the present invention by ashing is performed. By the hole forming step S7 of the glass layer 203 shown in FIG. 2G, the process of the step of communicating the nozzle hole and the ink flow path of the present invention is executed.

  As described above, according to this embodiment, even if the negative resist dissolved in the solvent is applied to form the nozzle layer 207, the glass layer 203 is formed on the sacrificial layer 204. It is possible to prevent the layer 204 from melting. Conventionally, in order to solve the problem that the sacrificial layer 204 is melted, a method has been used such as using a solvent that dissolves the nozzle layer 207 well and does not dissolve the sacrificial layer 204. The interface between the sacrificial layer 204 and the nozzle layer 207 is compatible with each other and reacts with each other, so that a residue remains and affects ink ejection. According to this embodiment, since the sacrificial layer 204 and the nozzle layer 207 are not in contact with each other, the mutual interface does not dissolve, and the problem that the residue cannot be solved does not occur. Therefore, it is possible to discharge ink favorably without being affected by the residue.

(Modification)
The present invention is not limited to the embodiments described with reference to the above description and the drawings, and for example, the following various aspects are also included in the technical scope of the present invention.

  In the present embodiment, the glass layer 203 is formed by P-TEOS in the inorganic film forming step S3, but a metal film may be formed by a sputtering method. Further, not only a metal but also an inorganic target such as SiO 2 or SiN may be formed on the sacrifice layer 204 with a film thickness of about 0.1 μm to 1.5 μm by sputtering. In this case, since the film can be formed at room temperature, damage to the sacrificial layer 204 can be further reduced.

  In addition, in the inorganic film forming step S3, a glass liquid may be applied by a spin coater. This glass liquid includes a polysilazane solution. In this case, for example, it is applied to the sacrificial layer 204 using perhydropolysilazane (trade name Aquamica (registered trademark) NP-110AZ of AZ Electronic Materials), and then heated at a low temperature of about 70 ° C. to 100 ° C. Make it. Since this film forming method has a temperature lower than the film forming temperature of P-TEOS, damage to the sacrificial layer 204 can be reduced, and coverage is good because the glass liquid is liquid.

  In this embodiment, the nozzle hole 110 is formed in the nozzle layer forming step S4. However, the present invention is not limited to this, and the nozzle hole 110 may be formed after the ink supply port forming step S5. In addition, the nozzle hole 110 may be formed after the sacrificial layer removal step S6.

  In the above description, the embodiment and some modified examples have been described as separate examples, but the present invention is not limited to this. That is, as a configuration in which the components are combined, the embodiment and some of the modifications may be combined as appropriate.

DESCRIPTION OF SYMBOLS 100 Ink discharge head 110 Nozzle hole 120 Ink supply port CH Ink flow path 201 Substrate 202 Heating resistor 203 Glass layer 204 Sacrificial layer 207 Nozzle layer 207a Nozzle hole part 302 Thermal storage layer 307 Protective film S1 Heater formation process S2 Sacrificial layer formation process S3 Inorganic film forming step S4 Nozzle layer forming step S5 Ink supply port forming step S6 Sacrificial layer removing step S7 Hole forming step

Claims (4)

In a method for manufacturing an ink discharge head, which is provided on a substrate and has a heater that generates thermal energy for discharging ink, an ink flow path provided on the heater, and a nozzle hole that communicates with the ink flow path.
Forming a sacrificial layer composed of a negative resist on the substrate;
Forming an inorganic film on the sacrificial layer;
Forming a nozzle layer by applying a resin dissolved in a solvent on the inorganic film;
Forming nozzle holes in the nozzle layer;
Forming an ink supply port in the substrate;
Removing the sacrificial layer from the side where the ink supply port is formed by ashing;
Removing the inorganic film located below the nozzle hole to allow the nozzle hole and the ink flow path to communicate with each other. In the manufacturing method of the ink discharge head according to claim 1,
The method of forming an inorganic film comprises forming a glass layer on the sacrificial layer. In the manufacturing method of the ink discharge head according to claim 2,
The method of forming an inorganic film includes forming the glass layer by P-TEOS. In the manufacturing method of the ink discharge head according to any one of claims 1 to 3,
The step of forming the nozzle hole includes forming the nozzle hole in the nozzle layer by dry etching using hydrogen fluoride.

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