JP2012201069A - Method of manufacturing ink discharge head, and ink discharge head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an ink discharge head, and the ink discharge head having a water repellent layer which prevents performance from being deteriorated due to friction.SOLUTION: The ink discharge head includes: a plate-like substrate 11; a heater 12 formed on one surface of the substrate 11; a flow channel wall 14b for partitioning an ink chamber having at least the heater 12 and formed on the one surface of the substrate 11; a nozzle layer 14a formed on the flow channel wall 14b and having a discharge hole A for discharging ink; and the water repellent layer 15 formed on an upper surface of the nozzle layer 14a. The water repellent layer 15 is formed of a resin material containing at least polyamide resin which is curable by an ultraviolet ray, and a compound having fluorocarbon.

Description

  The present invention relates to a method for manufacturing an ink discharge head used in an ink jet printer or the like, and an ink discharge head.

  A heat source driving type ink discharge head used in an inkjet printer or the like generates bubbles in ink using a heat source and discharges ink droplets by the expansion force of the bubbles. The ink ejection head has ejection holes for ejecting ink in the nozzle layer. Here, when a liquid such as ink adheres to the periphery of the ejection hole, there is a problem that a deviation occurs in the ejection direction of the ejected ink droplet, and printing with high accuracy becomes impossible. Therefore, in Patent Document 1, a water repellent layer containing an epoxy resin and a fluorocarbon compound is formed around the discharge holes. This water-repellent layer can prevent ink from adhering to the periphery of the ejection holes.

Japanese Patent No. 3679668

  Generally, the surface of the nozzle layer of the ink discharge head is wiped with a resin wiper after ink discharge. This is to prevent ink adhering to the nozzle layer from being dried after ejection and causing clogging of the ejection holes. However, since the wiper rubs the surface of the nozzle layer, when the water repellent layer is formed on the surface of the nozzle layer, a load is applied to the water repellent layer. For this reason, the water repellent layer may be damaged or the water repellent layer may be peeled off. Such deterioration in performance is a problem because it shortens the life of the ink ejection head. In order to extend the life of the ink ejection head, a water repellent layer is required that is less likely to deteriorate in performance against friction caused by a wiper or the like.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide an ink discharge head manufacturing method and an ink discharge head having a water-repellent layer whose performance is not easily deteriorated against friction.

  In order to solve the above-described problems, one aspect of the present invention includes a plate-like substrate, and an energy generating element that is formed on one surface of the substrate and that gives the ink energy for discharging the ink. A preparatory step of preparing a substrate, and a flow passage wall forming step of forming, on the one surface, a flow passage wall that includes at least the energy generating element and defines an ink chamber that contains ink that is overheated by the energy generating element A water-repellent resin comprising at least a nozzle layer forming step of forming a nozzle layer having an ejection hole for ejecting ink on the flow path wall, a polyamide resin curable by ultraviolet rays, and a compound having a fluorocarbon A water repellent layer forming step for forming a water repellent layer on the upper surface of the nozzle layer by using a material, and an ultraviolet ray is applied to the water repellent layer while avoiding a region on the nozzle hole; Irradiation is performed to cure the water-repellent layer, and after the curing step, remove the non-cured region of the water-repellent layer using a solvent that is soluble in the resin material that has not been cured by ultraviolet rays. And a heat treatment step for heating the water-repellent layer after the removing step.

  According to this, the water repellent layer is constituted by a water repellent resin material containing a polyamide resin. The polyamide resin has a higher elastic modulus than, for example, the epoxy resin used in Patent Document 1 and the like. Therefore, it is possible to obtain a water repellent layer that is less likely to be scratched even when rubbed with a wiper or the like, that is, whose performance is hardly deteriorated due to friction.

  Furthermore, a polar group forming step of forming a polar group containing hydrogen atoms capable of hydrogen bonding on the upper surface of the nozzle layer may be further provided after the nozzle layer forming step and before the water repellent layer forming step. .

  According to this, a polar group containing a hydrogen atom capable of hydrogen bonding is formed on the upper surface of the nozzle layer. Since the water repellent layer contains a polyamide resin, it has a carbonyl group at the amide bond portion. Therefore, a hydrogen bond is generated between the hydrogen atom of the polar group formed on the upper surface of the nozzle layer and the oxygen atom of the carbonyl group. As a result, the bonding between the nozzle layer and the water repellent layer becomes stronger, and a water repellent layer that does not easily peel off due to friction can be obtained.

  Further, the compound having a fluorocarbon may contain an ultraviolet reactive group.

  According to this, the compound having a fluorocarbon contains an ultraviolet reactive group. That is, the reactive group which crosslinks with an ultraviolet-ray is also couple | bonded with the compound itself which has a fluorocarbon. Therefore, when the water repellent film is cured with ultraviolet rays, a crosslinking reaction also occurs between the polyamide resin and the compound having a fluorocarbon. As a result, a polyamide resin and a compound having a fluorocarbon are bonded more firmly, and a water repellent layer is obtained in which the water repellency is not easily impaired by friction.

  Furthermore, the water repellent resin material may contain 1 to 50 wt% of the compound having the fluorocarbon with respect to the polyamide resin.

  When the content of the compound having a fluorocarbon with respect to the polyamide resin is less than 1 wt%, the water repellency of the water repellent layer is lowered. On the other hand, when the content of the compound having a fluorocarbon with respect to the polyamide resin is larger than 50 wt%, the amount of the polyamide resin having a high elastic modulus is too small, so that the water repellent layer becomes weak against friction. Therefore, when the content of the compound having a fluorocarbon is 1 to 50 wt%, a water-repellent layer having sufficient water repellency and hardly deteriorated in performance against friction can be obtained.

  Further, in the water repellent layer forming step, the adhesive film in which the thin film of the water repellent resin material is formed on the resin film is arranged such that the one surface is in contact with the thin film of the water repellent resin material. You may have the sticking process affixed with respect to a surface, and the peeling process which peels the said resin film from the said sticking film after the said sticking process.

  According to this, a water repellent layer is formed using a sticking film. Since the water repellent layer is formed after the formation of the ejection holes, for example, when the water repellent layer is applied on the nozzle layer by spray coating or spin coating, the constituent material of the water repellent layer is ejected inside the ink chamber. Get into the hole. As a result, an ink chamber that should contain ink containing water may have water repellency. On the other hand, when the water-repellent layer is formed using the adhesive film, the constituent material of the water-repellent layer does not enter the ink chamber. Therefore, the ink chamber does not have water repellency.

  In order to solve the above-mentioned problems, another aspect of the present invention includes a plate-shaped substrate, an energy generating element that is formed on one surface of the substrate, and that imparts energy for discharging ink to the ink, and at least the Including an energy generating element, formed on one surface of the substrate and defining an ink chamber containing ink heated by the energy generating element; and formed on the channel wall; A nozzle layer having ejection holes to be ejected; and a water repellent layer formed of a resin material formed on the upper surface of the nozzle layer and including at least a polyamide resin curable by ultraviolet rays and a compound having a fluorocarbon. This is an ink discharge head.

  According to this, the water repellent layer is constituted by a water repellent resin material containing a polyamide resin. Therefore, it is possible to obtain an ink ejection head having a water-repellent layer that is less likely to be scratched even when rubbed with a wiper or the like, that is, whose performance is less likely to deteriorate due to friction.

  Further, the compound having a fluorocarbon may contain an ultraviolet reactive group.

  According to this, an ink ejection head having a water repellent layer in which the polyamide resin and the compound having a fluorocarbon are more firmly bonded by a crosslinking reaction and the water repellency is not easily impaired by friction can be obtained.

  Furthermore, the resin material may include 1 to 50 wt% of the compound having the fluorocarbon with respect to the polyamide resin.

  According to this, an ink ejection head having a water-repellent layer that has sufficient water repellency and hardly deteriorates in performance against friction can be obtained.

  According to the present invention, it is possible to obtain an ink discharge head manufacturing method and an ink discharge head having a water-repellent layer whose performance hardly deteriorates against friction.

FIG. 3 is a perspective view showing the ink ejection head 100 according to the first embodiment. FIG. 3 is a cross-sectional view illustrating the ink ejection head 100 according to the first embodiment. Explanatory drawing of the manufacturing method of the ink discharge head 100 based on 1st Embodiment. Explanatory drawing of the manufacturing method of the ink discharge head 100 based on 1st Embodiment (continuation of FIG. 3). The figure which shows typically the hydrogen bond between the nozzle layer 14a and the water-repellent layer 15. FIG. The figure explaining the external appearance of a water repellent layer in the case of changing a water repellent. The figure explaining the change of water repellency when the addition amount of a water repellent and the post-baking conditions of a water repellent layer are changed. FIG. 6 is a cross-sectional view illustrating an ink discharge head 200 according to a second embodiment. Explanatory drawing of the manufacturing method of the ink discharge head 200 based on 2nd Embodiment. Explanatory drawing of the manufacturing method of the ink discharge head 200 based on 2nd Embodiment (continuation of FIG. 9).

<First Embodiment>
A first embodiment according to the present invention will be described below with reference to the drawings. First, the configuration of the ink discharge head 100 will be described with reference to FIGS. 1 and 2.

[Configuration of Ink Ejection Head 100]
As shown in FIG. 1, the ink discharge head 100 has a plurality of discharge holes A aligned in one direction. Each of the ejection holes A communicates with an individually provided ink chamber CH (see FIG. 2). Each ink chamber CH includes a heater 12 (see FIG. 2) that functions as an energy generating element for ejecting ink. Ink is supplied to the ink chamber CH through the ink supply port B connected from the lower surface of the ink discharge head 100 to the ink chamber CH. A part of the ink supplied to the ink chamber CH becomes bubbles by the heating of the heater 12. The ink in the ink chamber CH pushed out by the bubbles is ejected from the ejection hole A.

  FIG. 2 is a cross-sectional view of the ink discharge head 100 cut in a direction orthogonal to the alignment direction of the plurality of discharge holes A (that is, a cross section along line aa in FIG. 1). The layer structure of the ink ejection head 100 is mainly composed of a substrate 11, a heater 12, an ink chamber wall 14, and a water repellent layer 15. An ink supply port B is opened in the substrate 11. Ink is supplied from the lower surface of the substrate 11 to the ink chamber CH through the ink supply port B. Hereinafter, each layer structure will be described.

  The ink chamber wall 14 is formed on one surface (for example, the upper surface) of the substrate 11. The ink chamber wall portion 14 is composed of a flow path wall 14b erected upward from the substrate 11 and a nozzle layer 14a extending laterally from the upper end of the flow path wall 14b. The flow path wall 14b includes the heater 12 and the ink supply port B, and partitions the ink chamber CH. The flow path wall 14b may be either in a state of surrounding the heater 12 and the ink supply port B over the entire circumference or in a state of being surrounded with a part or one side opened. A discharge hole A is formed at a position facing the heater 12 of the nozzle layer 14a. The nozzle layer 14a and the flow path wall 14b are integrally formed.

  The water repellent layer 15 is formed on the upper surface of the nozzle layer 14a. The water repellent layer 15 is made of a water repellent resin material containing at least a polyamide resin curable by ultraviolet rays and a compound having a fluorocarbon. Around the discharge hole A is a hydrophilic portion S where the water repellent layer 15 is not formed. Here, the content of the compound having a fluorocarbon is desirably 1 to 50 wt% with respect to the polyamide resin. If the content of the compound having a fluorocarbon is less than 1 wt%, the water repellency of the water repellent layer 15 is lowered. On the other hand, when the content of the compound having a fluorocarbon is larger than 50 wt%, the water repellent layer 15 becomes weak against friction.

[Method for Manufacturing Ink Discharge Head 100]
Hereinafter, the manufacturing process of the ink ejection head 100 will be described with reference to FIGS. 3 and 4.

  First, as shown in FIG. 3A, a heater 12 is formed on a silicon substrate 11. For example, the heater 12 is formed by depositing a resistance heating element such as tantalum nitride (TaN) or tantalum aluminum (TaAl) at a position where the heater 12 is formed by a reactive sputtering method so as to have a thickness of about 200 to 1000 mm. Formed with. Although not shown in the present embodiment, a wiring layer made of titanium / aluminum on the heater 12 or a chromium oxide / silicon nitride protective film may be formed on the wiring layer.

Next, as shown in FIG. 3B, a positive resist 13 is formed at a position corresponding to the ink chamber CH (see FIG. 2) and including at least the heater 12. The positive resist 13 is composed of, for example, an alcohol-based or ketone-based organic solvent, a resist soluble in a weak alkaline aqueous solution, or the like. Specifically, for example, AZP4903 manufactured by AZ Electronic Materials Co., Ltd., PMER or OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd. can be used as the positive resist 13. As an example, after AZ4903 is applied on the substrate 11 by spin coating, it is annealed at 120 ° C. for 5 minutes. Thereafter, in order to obtain good patterning properties, the substrate 11 is immersed in water for 20 minutes. And after the board | substrate 11 is exposed with the intensity | strength of 2000 mJ / cm < ² >, the pattern of the positive resist 13 is formed by developing with weakly alkaline aqueous solution. The film thickness of the positive resist 13 is about 25 μm as an example.

  Next, as shown in FIG. 3C, an ink chamber wall portion 14 having a nozzle layer 14 a and a flow path wall 14 b is formed so as to cover the positive resist 13. A region of the ink chamber wall portion 14 that protrudes from the positive resist 13 to the left and right and is located beside the positive resist 13 becomes a flow path wall 14b. That is, the process shown in FIG. 3C corresponds to both the flow path wall forming process for forming the flow path wall 14b and the nozzle layer forming process for forming the nozzle layer 14a. Here, the ink chamber wall 14 is made of, for example, an epoxy resin. In this embodiment, for example, Nippon Kayaku Co., Ltd. photo-curing epoxy resin SU-8 is used. The resin solvent is, for example, an organic solvent such as cyclohexane. The epoxy resin applied on the positive resist 13 is heated in order to improve the adhesion with the substrate 11 and evaporate the solvent in the epoxy resin. The ejection holes A are formed by, for example, photolithography. Specifically, a photomask is placed at a position corresponding to the ejection hole A on the ultraviolet curable resin applied on the positive resist 13. Thereafter, ultraviolet rays are irradiated to cure the ultraviolet curable resin at positions other than the discharge holes A. Then, the ink discharge head 100 is immersed in an organic solvent. The cured portion of the ultraviolet curable resin is insoluble in the organic solvent. Therefore, only the ultraviolet curable resin at the position corresponding to the discharge hole A that is not exposed to the ultraviolet rays by the photomask is dissolved. Thereby, the discharge hole A is formed. In the present embodiment, the flow path wall 14b and the substrate 11 are in direct contact. However, in order to improve the adhesion between the flow path wall 14b and the substrate 11, an adhesion layer made of polyimide or the like may be formed between them.

  Next, as shown in FIG. 3D, the positive resist 13 is removed. The positive resist 13 is removed by immersing the ink discharge head 100 in an organic solvent such as acetone or propylene glycol monomethyl ether acetate (PGMEA). The positive resist 13 dissolved in the organic solvent flows out from the discharge hole A, whereby the positive resist 13 is removed.

  Next, as shown in FIG. 3E, an ink supply port B penetrating the substrate 11 is formed by removing a part of the substrate 11 by anisotropic etching. Specifically, for example, a thin film made of silicon oxide or the like is formed on the lower surface of the substrate 11. This thin film has an opening formed by dry etching using a gas such as tetrafluoromethane (CF 4) or wet etching using hydrofluoric acid, and serves as an etching mask. Etching proceeds from the opening formed in the etching mask toward the upper surface of the substrate 11 by wet etching using an alkaline solution such as an aqueous potassium hydroxide (KOH) solution or an aqueous tetramethylammonium hydroxide (TMAH) solution. . Thereby, the ink supply port B is formed.

  Next, as shown in FIG. 3F, a polar group containing a hydrogen atom capable of hydrogen bonding is formed on the upper surface of the nozzle layer 14a. This step is performed, for example, by spraying hydrogen and oxygen plasma on the upper surface of the nozzle layer 14a. Thereby, as shown in FIG. 5, OH groups are formed on the upper surface of the nozzle layer 14a. The water repellent layer 15 of this embodiment contains a polyamide resin. Therefore, a carbonyl group exists in the amide bond portion of the water repellent layer 15. The oxygen atoms constituting the carbonyl group are hydrogen bonded to the hydrogen atoms of the OH group formed on the upper surface of the nozzle layer 14a. Similarly, hydrogen atoms contained in the polyamide resin form hydrogen bonds with oxygen atoms of OH groups formed on the upper surface of the nozzle layer 14a. By this hydrogen bonding, the nozzle layer 14a and the water repellent layer 15 are bonded more firmly.

  Next, as shown in FIG. 4A, a water repellent layer 15 is formed on the upper surface of the nozzle layer 14a. In the present embodiment, KI-1000T5WL manufactured by Hitachi Chemical Co., Ltd. is used as the polyamide resin contained in the water repellent resin material constituting the water repellent layer 15. KI-1000T5WL contains 22-32 wt% of modified amide resin, 22-32 wt% of three kinds of photocrosslinking agents, and 45-55 wt% of N, N-dimethylacetamide (DMAC). In addition, the tensile elasticity modulus at the time of hardening is 2.8 GPa. On the other hand, in the case of an epoxy resin used in Patent Document 1 or the like, the tensile elastic modulus is lower than this. For example, as an example of epoxy resin, in the case of SU-83000 manufactured by Nippon Kayaku Co., Ltd., the tensile elastic modulus is 2.0 Gpa, which is about 30% lower than that of polyamide resin. Therefore, in this embodiment, the water repellent layer 15 is obtained that is less likely to be scratched even when rubbed with a wiper or the like, and whose performance is less likely to deteriorate due to friction. In addition, as a compound having a fluorocarbon, for example, Megafac series manufactured by DIC Corporation is used. These compounds having a fluorocarbon are fluorine-based surfactants composed of oligomers containing UV-reactive groups. Therefore, when the water repellent layer 15 is cured with ultraviolet rays, a crosslinking reaction also occurs with the polyamide resin. As a result, the water-repellent layer 15 is obtained in which the polyamide resin and the compound having a fluorocarbon are more firmly bonded, and the water repellency is not easily impaired even by friction. The water repellent layer 15 is formed by applying a water repellent resin material containing a polyamide resin and a compound having a fluorocarbon to the upper surface of the nozzle layer 14a by spin coating. At this time, the water-repellent resin material enters the ink chamber CH from the discharge hole A (see the water-repellent resin material 15a on the heater 12).

  Next, as illustrated in FIG. 4B, the water repellent layer 15 is cured by exposing the top surface of the water repellent layer 15 to ultraviolet rays. At this time, the mask M is placed on the ejection hole A. Thereby, ultraviolet rays can be shielded against the water-repellent resin material 15a that has entered the ink chamber CH. At this time, by setting the size of the mask M larger than the size of the discharge hole A, the formation of the water repellent layer 15 around the discharge hole A can be inhibited. The periphery of the discharge hole A where the water repellent layer 15 is not formed functions as a hydrophilic portion S. Since the hydrophilic portion S is only slightly larger than the ejection hole A, it does not affect ink ejection.

  Finally, the water repellent layer 15 is developed. That is, by immersing the ink discharge head 100 in an organic solvent such as PGMEA, the uncured resin mixture is dissolved and removed. That is, the hydrophilic portion S around the ejection hole A that is not exposed to ultraviolet rays and the water repellent resin material 15a in the ink chamber CH are removed. Thereafter, the water repellent layer 15 is heated (post-baked) by placing the ink ejection head 100 at a predetermined atmospheric temperature. Thus, the ink discharge head 100 is manufactured.

[Examination of water repellent layer 15]
The consideration regarding the kind of the compound which has a fluorocarbon utilized for the water repellent layer 15, the addition amount, and post-baking conditions is demonstrated using FIG.6 and FIG.7.

  FIG. 6 shows an overview of the water-repellent film 15 when the product numbers RS-72-K, RS-75, and exp-TF1630 are used in the Megafac series manufactured by DIC Corporation as a compound having a fluorocarbon. It is a figure explaining. RS-72-K is obtained by dissolving a solid corresponding to an active ingredient of fluorocarbon in propylene glycol monomethyl ether (PGME) and contains 30 wt% of the active ingredient. RS-75 is obtained by dissolving a solid corresponding to an active ingredient of fluorocarbon in a mixed solvent (MEK / MIBK) of methyl ethyl ketone and methyl isobutyl ketone, and contains 40 wt% of the active ingredient. Since exp-TF1630 consists only of the solid substance corresponding to the active ingredient of fluorocarbon, it experimented by using PGMEA as a solvent and content of an active ingredient 50 wt%.

  The compatibility of the compound having each fluorocarbon with the polyamide resin will be described. As the polyamide resin, KI-1000T5WL manufactured by Hitachi Chemical Co., Ltd. is used. The compatibility was confirmed by mixing the compound having each fluorocarbon described above with the polyamide resin. Specifically, the compound having each fluorocarbon was mixed so as to be 5 wt% with respect to the polyamide resin. RS-72-K was incompatible with the polyamide resin. RS-75 was compatible with the polyamide resin. exp-TF1630 became translucent with respect to the polyamide resin, and a part thereof was compatible.

  An overview of the water-repellent film 15 when the water-repellent film 15 is formed using a mixed solution of a compound having each fluorocarbon and a polyamide resin will be described. In the photograph shown in the “Overview” column in FIG. 6, the area surrounded by the broken line is the discharge hole A. In RS-72-K, which is incompatible with the polyamide resin, components incompatible with the polyamide resin were confirmed as fine spots on the surface of the water-repellent film 15 (black dots in the “Overview” column in FIG. 6). The surface of the water-repellent film 15 of the RS-75 compatible with the polyamide resin was uniformly clean, and no flaws could be confirmed. Exp-TF1630, which is partially compatible with the polyamide resin, has been confirmed to have a component that remains partially incompatible as a fine piece of about 10-20 μm on the surface of the water-repellent film 15.

  Sufficient water repellency has been confirmed in mixed solutions of all fluorocarbon-containing compounds and polyamide resins. Therefore, the object of the present invention is achieved regardless of which mixed solution is used. However, it is desirable that the surface of the water-repellent film 15 is clean in view of friction when rubbed with a wiper. The compounds having each fluorocarbon differ in the type of solvent. The polyamide resin is compatible with MEK / MIBK which is a solvent for RS-75. Therefore, when a solvent compatible with the polyamide resin is used as a solvent for a compound having a fluorocarbon, the compound having the fluorocarbon and the polyamide resin become compatible, and a water-repellent film 15 having a clean surface can be obtained. it is conceivable that. In addition, it was considered that the incompatible parts were confirmed in exp-TF1630 dissolved in the same PGMEA as the polyamide resin because the original exp-TF1630 was a solid and was not completely dissolved in PGMEA.

  The change in water repellency when the addition amount of the compound having a fluorocarbon to the polyamide resin and the post-baking conditions are changed will be described with reference to FIG.

As shown in FIG. 7A, the water repellency was measured for the water repellent film 15 prepared under the following five conditions. In addition, as the compound having a fluorocarbon, the above-mentioned Megafac RS-75 was used.
・ Condition A: No addition of RS-75, 120 minutes at 120 ° C., 30 minutes at 150 ° C., 1 hour at 220 ° C. for 2 hours in total, Condition B: RS-75 against KI-1000T5WL 5 wt% addition, 30 minutes at 120 ° C, 30 minutes at 150 ° C, 1 hour at 220 ° C, 2 hours in total Post-bake Condition C: RS-75 added to KI-1000T5WL at 5 wt%, at 120 ° C 30 minutes post-baking and condition D: RS-75 added to KI-1000T5WL 10wt%, 120 ° C for 30 minutes, 150 ° C for 30 minutes, 220 ° C for 1 hour in sequence, total 2 hours post-baking and condition E : RS-75 added to KI-1000T5WL at 10 wt%, post-baked at 120 ° C. for 30 minutes. Condition A does not include a compound having a fluorocarbon. It is a water-repellent film.

  FIG. 7B is a diagram showing a result of measuring the contact angle after dropping ethylene glycol on the water-repellent film 15. FIG. 7C is a diagram showing a result of measuring a contact angle obtained by dropping a liquid obtained by mixing ethylene glycol and pure water at a weight ratio of 1: 1 onto the water-repellent film 15. FIG. 7D is a diagram showing a result of dropping pure water onto the water-repellent film 15 and measuring a contact angle thereof. 7B to 7D, the vertical axis indicates the contact angle. As apparent from FIGS. 7B to 7D, the conditions B to E including the compound having a fluorocarbon have a larger contact angle than the conditions A not including the compound having the fluorocarbon. Further, when the weight ratio of the compounds having a fluorocarbon is compared, the conditions D and E of 10 wt% have a larger contact angle than the conditions B and C of 5 wt%. Furthermore, when the difference in post-baking conditions is compared under the same weight ratio of the compound having a fluorocarbon, the temperature is gradually increased from 120 ° C. than the conditions C and E in which post-baking is performed at 120 ° C. for 30 minutes. In the case where the temperature was raised, specifically, conditions B and D in which post-baking was performed for 2 hours in total in order of 30 minutes at 120 ° C., 30 minutes at 150 ° C., and 1 hour at 220 ° C. Is big. These tendencies were the same regardless of the droplets dropped (ethylene glycol, pure water, or a mixture thereof). The larger the contact angle, the better the repelled droplet, that is, the higher the water repellency. From the above results, it was found that the mixing amount of the compound having a fluorocarbon is 10 wt%, and the post-baking conditions are preferably increased with time.

Second Embodiment
The configuration of the ink ejection head 200 according to the second embodiment of the present invention will be described with reference to FIG. The appearance of the ink discharge head 200 is the same as that of the ink discharge head 100 shown in FIG. The ink discharge head 200 is different from the ink discharge head 100 in its cross-sectional structure and manufacturing process.

[Configuration of Ink Ejection Head 200]
As shown in FIG. 8, the layer structure of the ink ejection head 200 is mainly composed of a substrate 21, a flow path wall 23, a nozzle layer 25, and a water repellent film 26. The cross-sectional structure of the ink discharge head 200 is different from the cross-sectional structure of the ink discharge head 100 shown in FIG. 2 in that the flow path wall 26 and the nozzle layer 28 are formed separately. Regarding other configurations, the ink discharge head 200 and the ink discharge head 100 are the same, and thus the description thereof is omitted.

[Method for Manufacturing Ink Discharge Head 200]
Hereinafter, the manufacturing process of the ink ejection head 200 will be described with reference to FIGS. 9 and 10.

  The process shown in FIG. 9A is the same as the process shown in FIG. 3A in the above-described embodiment. Therefore, detailed description is omitted.

  Next, as shown in FIG. 9B, the flow path wall 26 is formed on the substrate 21 so as to include the heater 22 on the substrate 21. The flow path wall 23 is made of a photocured epoxy resin SU-8 manufactured by Nippon Kayaku Co., Ltd., as in the above-described embodiment. Note that the flow path wall 23 may be in either a state in which the heater 22 is surrounded over the entire circumference or a state in which a part or one side is open. Further, the film thickness of the flow path wall 23 may be adjusted to be, for example, about 10-30 μm.

  Next, as shown in FIG. 9C, a sacrificial layer 24 is formed. The sacrificial layer 24 is also formed in a region that covers the upper surface of the flow path wall 23. For example, the sacrificial layer 24 is formed by injecting a semi-cured resin into the space formed by the flow path wall 23 and drying it. In this embodiment, a polyimide material and photo nice of Toray Industries, Inc. are used in a semi-cured state as the semi-cured resin. Photo Nice is soluble in an alkaline solution, but insoluble in an organic solvent. The epoxy resin constituting the flow path wall 23 is completely cured before the sacrificial layer 24 is injected by heat or light. The epoxy resin constituting the flow path wall 23 is soluble in an organic solvent when not cured, but is insoluble in an organic solvent when cured. Therefore, cross mixing does not occur between the flow path wall 23 and the sacrificial layer 24. A novolac resin may be used as the sacrificial layer 24. Specific examples include EP4080G and EP4050G manufactured by Asahi Organic Materials Co., Ltd., such as PGMEA. The novolak resin has extremely low solubility in xylene and toluene, but dissolves in an alkaline aqueous solution and acetone. Since the epoxy resin constituting the flow path wall 23 is completely cured, it is insoluble in the organic solvent. Therefore, even when novolac resin is used, cross mixing does not occur between the flow path wall 23 and the sacrificial layer 24.

  Next, as shown in FIG. 9D, the sacrificial layer 24 is removed from the upper surface so that the upper surface of the sacrificial layer 24 becomes flat. Here, if the sacrificial layer 24 remains on the flow path wall 23, there is a possibility that the adjacent ink chambers communicate with each other. Therefore, it is desirable that the sacrificial layer 24 be flattened until the sacrificial layer 24 and the flow path wall 23 are located on the same plane, in other words, until the upper surface of the flow path wall 23 is exposed. At this time, the upper surface of the flow path wall 23 may be slightly removed. Note that the sacrificial layer 24 is planarized by, for example, machining such as polishing, grinding, or cutting. Alternatively, after the rough planarization by machining, fine planarization such as dissolving the sacrificial layer 24 from the upper surface by immersing the ink discharge head 200 in an alkaline solution may be performed.

  Next, as illustrated in FIG. 9E, the nozzle layer 25 is formed so as to cover the flow path wall 23 and the sacrificial layer 24. The nozzle layer 25 is provided with a nozzle hole C for ejecting ink at a position facing the heater 22. The nozzle layer 25 is composed of a photocured epoxy resin SU-8 manufactured by Nippon Kayaku Co., Ltd., similar to the flow path wall 23. An epoxy resin is applied so as to cover the flow path wall 23 and the sacrificial layer 24 by spin coating or spray coating. Then, the applied epoxy resin is heated to improve the adhesion with the flow path wall 23 and to evaporate the solvent remaining in the nozzle layer 25. The ejection hole C is formed by performing photolithography on the nozzle layer 25 thus formed. When developing the discharge hole C, a solvent that does not dissolve the sacrificial layer 24 such as xylene or toluene is used. However, the sacrificial layer 24 in the vicinity of the discharge hole C may be partially removed using PGMEA, acetone, an alkaline aqueous solution, or the like.

Next, as shown in FIG. 9F, the sacrificial layer 24 is removed. When the sacrificial layer 24 is made of semi-cured polyimide, the sacrificial layer 24 is removed by immersing the ink discharge head 200 in an alkaline aqueous solution of TMAH 2.38%. When the sacrificial layer 24 is composed of a novolac resin, the sacrificial layer 24 dissolved in the organic solvent flows out of the ejection holes C by immersing the ink ejection head 200 in an organic solvent such as acetone or PGMEA. Removed.
The sacrificial layer 24 is removed.

  Next, as shown in FIG. 9G, an ink supply port D penetrating from the lower surface to the upper surface of the substrate 21 is formed. Since this step is the same as the step shown in FIG. 3D, detailed description is omitted.

  Next, as shown in FIG. 10A, a polar group containing hydrogen atoms capable of hydrogen bonding is formed on the upper surface of the nozzle layer 25. This step is the same as the step shown in FIG. Therefore, detailed description is omitted.

  Next, as shown in FIG. 10 (B), the adhesive film in which the water-repellent resin material constituting the water-repellent layer 26 is formed on the resin film 27 has an upper surface of the nozzle layer 25 and the water-repellent layer 26. It is affixed with respect to the upper surface of the nozzle layer 25 so that it may contact. Here, the adhesive film is obtained by coating a water-repellent resin material on a resin film 27 such as polyethylene terephthalate (PET) or polyimide. As the water repellent resin material, a material obtained by mixing KI-1000T5WL manufactured by Hitachi Chemical Co., Ltd. and MegaFac series manufactured by DIC Co., Ltd. may be used as in the above-described embodiment. Here, since the water repellent layer 26 is formed on the resin film 27, unlike the above-described embodiment, when the adhesive film is laminated on the nozzle layer 25, the water repellent resin material is placed in the ink chamber CH. Does not invade. Therefore, the ink chamber CH does not have water repellency.

  Next, as shown in FIG. 10C, the resin film 27 is peeled from the adhesive film. After the resin film 27 is peeled off, the water repellent layer 26 is cured by exposing the top surface of the water repellent layer 26 to ultraviolet rays. At this time, the mask M is placed on the ejection hole C. Thereby, ultraviolet rays can be shielded against the water-repellent resin material present on the ejection holes C.

  Finally, as shown in FIG. 10D, the water repellent layer 26 is developed and post-baked. This step is the same as the step shown in FIG. Thus, the ink discharge head 200 is manufactured.

  Although the present invention has been described above in connection with the most practical and preferred embodiments at the present time, the present invention is not limited to the embodiments disclosed herein. The invention can be changed as appropriate without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and a method for manufacturing an ink discharge head with such a change is also included in the technical scope. Must be understood.

100, 200 Ink discharge heads 11, 21 Substrate 12, 22 Heater 13 Positive resist 14 Ink chamber wall 14b, 23 Channel wall 14a, 25 Nozzle layer 15, 26 Water repellent layer 24 Sacrificial layer 27 Resin film A, C Discharge hole B, D Ink supply port

Claims (8)

A preparation step of preparing a substrate comprising a plate-like substrate and an energy generation element that is formed on one surface of the substrate and that gives the ink energy for discharging ink;
A flow path wall forming step for forming, on the one surface, a flow path wall that includes at least the energy generating element and defines an ink chamber that contains ink that is superheated by the energy generating element;
A nozzle layer forming step of forming a nozzle layer having a discharge hole for discharging ink on the flow path wall;
A water repellent layer forming step of forming a water repellent layer on the upper surface of the nozzle layer using a water repellent resin material comprising at least a polyamide resin curable by ultraviolet rays and a compound having a fluorocarbon;
A curing step of curing the water-repellent layer by irradiating the water-repellent layer with ultraviolet rays while avoiding the region on the nozzle hole,
After the curing step, a removal step of removing the non-cured region of the water-repellent layer using a soluble solvent for the resin material that has not been cured by ultraviolet rays;
After the removing step, a heat treatment step for heating the water-repellent layer;
An ink discharge head manufacturing method comprising: A polar group forming step of forming a polar group containing hydrogen atoms capable of hydrogen bonding on the upper surface of the nozzle layer after the nozzle layer forming step and before the water repellent layer forming step;
The method for manufacturing an ink ejection head according to claim 1. The compound having the fluorocarbon contains an ultraviolet reactive group,
The method for manufacturing an ink ejection head according to claim 1. The water repellent resin material contains 1 to 50 wt% of the compound having the fluorocarbon with respect to the polyamide resin.
The manufacturing method of the ink discharge head of any one of Claims 1-3. The water repellent layer forming step includes
Affixing step of adhering the adhesive film in which the thin film of the water repellent resin material is formed on the resin film to the one surface so that the one surface and the thin film of the water repellent resin material are in contact with each other;
A peeling step of peeling the resin film from the sticking film after the sticking step;
The manufacturing method of the ink discharge head of any one of Claims 1-4. A plate-like substrate;
An energy generating element that is formed on one surface of the substrate and gives the ink energy for discharging the ink;
A flow path wall that includes at least the energy generating element, is formed on one surface of the substrate, and defines an ink chamber that contains ink that is overheated by the energy generating element;
A nozzle layer formed on the flow path wall and having discharge holes for discharging ink;
A water repellent layer formed of a resin material which is formed on an upper surface of the nozzle layer and includes at least a polyamide resin curable by ultraviolet rays and a compound having a fluorocarbon;
An ink ejection head comprising: The compound having the fluorocarbon contains an ultraviolet reactive group,
The ink discharge head according to claim 6. The resin material contains 1 to 50 wt% of the compound having the fluorocarbon with respect to the polyamide resin.
The ink ejection head according to claim 6 or 7.