WO2012133171A1

WO2012133171A1 - Method for manufacturing ink-jet head, and ink-jet head

Info

Publication number: WO2012133171A1
Application number: PCT/JP2012/057490
Authority: WO
Inventors: 有希穂苅; 雅章栗田; 徳子篠田
Original assignee: ブラザー工業株式会社
Priority date: 2011-03-31
Filing date: 2012-03-23
Publication date: 2012-10-04
Also published as: JP2012210757A

Abstract

Provided is a method for manufacturing an ink-jet head, wherein a residue of a sacrificial layer is prevented from being left in an ink chamber at the time of removing the sacrificial layer, and the volume of the ink chamber can be accurately maintained. Also provided is an ink-jet head. A board-like substrate (11), and a heater (13) formed on one surface of the substrate (11) are prepared. Then, one surface of the substrate (11) has formed thereon: a sacrificial layer (16), which is provided at a position that corresponds to an ink flow channel; a flow channel wall (15), which includes at least the sacrificial layer (16) and the heater (13), and which partitions an ink chamber (CH); and a nozzle layer (17), which is provided on the flow channel wall (15) and the sacrificial layer (16). Then, a jetting port (A), from which an ink is to be jetted, is formed in the nozzle layer (17). Then, the sacrificial layer (16) is removed by taking out the sacrificial layer (16) to the outside of the ink chamber (CH) through the jetting port (A). Then, an ink supply port (B) that penetrates the substrate (11) from the other surface thereof to the one surface is formed from the other surface by etching.

Description

Ink discharge head manufacturing method and ink discharge head

The present disclosure relates to a method of manufacturing an ink discharge head used for an ink jet printer or the like, and the 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. Ink droplets are ejected by the expansion force of the bubbles. The ink discharge head has an ink chamber in order to hold the discharged ink. A plurality of ink chambers are provided on one surface (for example, the upper surface) of the substrate. The ink chamber has an ink supply port that penetrates the substrate in the thickness direction. Ink is supplied to the ink chamber from the other surface (for example, the lower surface) of the substrate through the ink supply port.

As a method for manufacturing the ink discharge head, for example, there is a method of forming a sacrificial layer for securing a space of the ink flow path at a position corresponding to the ink flow path such as an ink chamber provided on the substrate. The flow path wall and the nozzle layer that define the ink flow path are formed on the substrate so as to be in contact with the sacrificial layer. After the flow path wall and the nozzle layer are formed, the sacrificial layer is removed from the substrate to form a space for the ink flow path. In Patent Document 1, an ink supply port is formed from the lower surface of a silicon substrate by wet etching or the like. The sacrificial layer is removed through the ink supply port.

US Pat. No. 7,285,226 (Claim 1 etc.)

In order to remove the sacrificial layer from the ink supply port, the ink supply port needs to be formed in a state where the sacrificial layer is present on the substrate. When the ink supply port is formed by wet etching, the sacrificial layer existing on the ink supply port is exposed to an etching solution for etching the silicon substrate. However, it has been discovered by the present inventors that the sacrificial layer is altered by exposing the sacrificial layer to the etching solution of the substrate. In order not to expose the sacrificial layer to the etching solution, a method of forming a protective layer having ink resistance and anisotropic etching resistance on the upper surface of the substrate is conceivable. However, in this case, dry etching or the like is required when removing the protective film formed on the ink supply port. Similarly, since the sacrificial layer is exposed to dry etching, the sacrificial layer may be altered. The altered sacrificial layer causes blackening or the like. The inventors have discovered that this altered sacrificial layer produces a residue for the solvent that dissolves the sacrificial layer. The sacrificial layer residue may remain in the ink chamber. The volume of the ink chamber changes due to the remaining residue. Since the volume change of the ink quality is not uniform, there is a possibility that the volume varies among individual ink chambers provided on the substrate. As a result, the amount of ink droplets ejected for each ink chamber may change.

The present disclosure provides a method of manufacturing an ink discharge head that can prevent the residue of the sacrificial layer from remaining in the ink chamber when the sacrificial layer is removed, and can maintain the volume of the ink chamber with high accuracy, and the ink discharge head. The purpose is to do.

In order to solve the above-described problems, one aspect of the present invention provides a preparatory step of preparing a plate-like substrate and an energy generating element formed on one surface of the substrate, and an ink flow path including an ink chamber. A sacrificial layer provided at a position corresponding to the above, a flow path wall that includes at least the sacrificial layer and the energy generating element, and partitions the ink chamber, and a nozzle layer provided on the flow path wall and the sacrificial layer Forming an ink chamber on the one surface, forming a discharge hole penetrating the nozzle layer in the thickness direction, forming the discharge hole in the nozzle layer, and performing the sacrifice after the discharge hole forming step. A sacrificial layer removing step for removing the sacrificial layer by discharging the layer to the outside of the ink chamber through the ejection holes, and an ink supply penetrating the substrate in the thickness direction after the sacrificial layer removing step Mouth, said Square and an ink supply port forming step of forming by etching from the surface of a method of manufacturing an ink jet head comprising a.

According to this, the sacrificial layer is discharged from the ink chamber through the discharge hole provided in the nozzle layer. After the sacrificial layer is removed, an ink supply port is formed in the substrate by etching. Therefore, the sacrificial layer is removed without being affected by the etching that creates the ink supply port. As a result, the sacrificial layer does not change in quality, and the residue of the sacrificial layer is prevented from remaining in the ink chamber. Therefore, the volume of the ink chamber can be maintained with high accuracy.

Further, the ink chamber forming step includes a channel wall forming step of forming the channel wall on the one surface and a space formed by the channel wall after the channel wall forming step. A sacrificial layer forming step of forming a layer, a planarizing step of planarizing an upper surface of the sacrificial layer after the sacrificial layer forming step, and on the sacrificial layer and the flow path wall after the planarizing step. A nozzle layer forming step of forming the nozzle layer.

According to this, after the upper surface of the sacrificial layer is flattened, the nozzle layer is formed thereon. Accordingly, the surface of the nozzle layer on the ink chamber side can be formed with high accuracy, and the height of the ink chamber can be determined with high accuracy. As a result, the volume of the ink chamber is maintained with high accuracy.

Further, in the preparation step, a highly flat silicon substrate having a total thickness variation of 2 μm or less may be prepared as the substrate.

According to this, the ink discharge head is manufactured using the high flat silicon whose total thickness variation is 2 μm or less. Since the total thickness variation is 2 μm or less, the distance between the substrate and the nozzle layer is accurately determined regardless of the position on the substrate. As a result, the volume of the ink chamber is maintained with high accuracy.

Furthermore, the flattening step may include a cutting step of flattening the upper surface of the sacrificial layer by cutting from the upper surface of the sacrificial layer toward the substrate.

As the flattening process, various processing methods such as polishing and cutting can be used. When flattening is performed by polishing, the abrasive grains of the polishing tool adhere to the sacrificial layer, and there is a problem that the abrasive grains remain in the ink chamber after the sacrificial layer is removed. On the other hand, cutting is preferable to polishing because such a problem does not occur. However, in many cases, the machining height is defined by using the lower surface of the workpiece as a reference surface. If the thickness of the substrate varies greatly depending on the location, the bottom surface of the substrate and the top surface of the sacrificial layer after removal are made parallel, so the thickness of the sacrificial layer varies depending on the position on the substrate. This leads to fluctuations in the volume of the ink chamber. However, the use of highly flat silicon suppresses the substrate tilt sufficiently. Therefore, even if the sacrificial layer is flattened by cutting, the thickness of the sacrificial layer is kept constant regardless of the position on the substrate. As a result, the volume of the ink chamber is maintained with high accuracy.

The ink further includes a protective layer preparing step of preparing a protective layer having ink resistance and anisotropic etching resistance on the one surface before the ink chamber forming step and after the preparing step. The supply port forming step includes a substrate removal step of removing the substrate from the other surface toward the one surface by anisotropic etching at a position corresponding to the ink supply port of the substrate, and the substrate removal step. And a protective layer removing step of removing the protective layer formed at a position corresponding to the ink supply port from the other surface.

According to this, the protective layer functions as an etching stop layer when performing anisotropic etching on the substrate. Therefore, the etchant for anisotropic etching is prevented from flowing into the ink chamber.

Further, the sacrificial layer removing step may be performed after the substrate removing step, and the protective layer removing step may be performed after the sacrificial layer removing step.

According to this, the sacrificial layer is removed after the substrate is removed by anisotropic etching. Then, after the sacrificial layer is removed, the protective layer is removed. When the substrate is removed by anisotropic etching, the sacrificial layer is not exposed to the etchant for anisotropic etching because the protective layer functions as an etching stop layer. Further, the sacrificial layer is removed before the protective layer is removed by dry etching or the like. Therefore, the sacrificial layer is removed without being exposed to dry etching or the like for removing the protective layer. As a result, the sacrificial layer does not change in quality, and the residue of the sacrificial layer is prevented from remaining in the ink chamber. Therefore, the volume of the ink chamber can be maintained with high accuracy.

The discharge hole forming step further forms an additional discharge hole in the nozzle layer, and the sacrificial layer removal step discharges the sacrificial layer to the outside of the ink chamber through the discharge hole and the additional discharge hole. By doing so, the sacrificial layer may be removed.

According to this, the sacrificial layer is discharged from the ink chamber through the additional discharge hole in addition to the discharge hole. As a result, the sacrificial layer can be reliably removed from the ink chamber.

In order to solve the above problem, another aspect of the present disclosure includes a plate-shaped substrate, an energy generation element provided on one surface of the substrate, and a flow path that partitions an ink chamber including at least the energy generation element. And a nozzle layer provided on the flow path wall, wherein the substrate has an ink supply port penetrating the substrate in a thickness direction, and the nozzle layer is located at a position corresponding to the energy generating element. A discharge hole penetrating through the nozzle layer in the thickness direction; an additional hole penetrating the nozzle layer in the thickness direction; and the ink chamber of the nozzle layer. And a sealing member that covers the additional hole on the surface opposite to the ink discharge head.

According to this, the residue of the sacrificial layer is prevented from remaining in the ink chamber, and the ink ejection head in a state where the sacrificial layer is reliably removed from the ink chamber can be obtained.

According to the present disclosure, there is provided an ink discharge head manufacturing method capable of preventing a residue of a sacrificial layer from remaining in an ink chamber when the sacrificial layer is removed and maintaining the volume of the ink chamber with high accuracy, and an ink discharge head. can get.

FIG. 3 is a perspective view showing the ink discharge head 100. FIG. 3 is a cross-sectional view showing the ink discharge head 100. FIG. 3 is an explanatory diagram of a method for manufacturing the ink discharge head 100. Explanatory drawing of the manufacturing method of the ink discharge head 100 (continuation of FIG. 3).

Embodiments according to the present disclosure will be described below with reference to the drawings. Note that the drawings referred to are used to describe technical features that can be adopted by the present disclosure. The configuration described in the drawings is not intended to be limited to that, but merely an illustrative example. For example, in each configuration described below, a predetermined configuration may be omitted or replaced with another configuration. Moreover, you may make it include another structure. 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). In the ink chamber CH, heaters 13 (see FIG. 2) functioning as energy generating elements are respectively provided. 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 due to the heating of the heater 13. The ink in the ink chamber CH pushed out by the bubbles is ejected from the ejection hole A.

FIG. 2A 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 aa in FIG. 1). The layer structure of the ink discharge head 100 is mainly composed of a substrate 11, insulating

layers

12 a and 12 b, a protective layer 14, a flow path wall 15, and a nozzle layer 17. The substrate 11 has an ink supply port B that penetrates the substrate 11 in the thickness direction (vertical direction in FIG. 2). The ink moves from the lower surface of the substrate 11 to the upper surface of the substrate 11 through the ink supply port B. Thereafter, the ink passes through the ink flow path partitioned by the flow path wall 15 and flows into the ink chamber CH defined by the nozzle layer 17 and the flow path wall 15. Hereinafter, each layer structure will be described.

An insulating layer 12 a is formed on one surface (for example, the upper surface) of the substrate 11. A heater 13 is formed on the insulating layer 12a. The term “formed on the upper surface (one surface) of the substrate 11 is formed in direct contact with the upper surface of the substrate 11, and is formed on the upper surface side of the substrate 11 with some configuration in between. It also means that. Of course, the term “formed on the lower surface (the other surface)” should be interpreted in the same manner.

The protective layer 14 is provided so as to cover the upper surface of the substrate 11. That is, the protective layer 14 is formed on the insulating layer 12 a and the heater 13.

The flow path wall 15 is erected upward from the upper surface of the substrate 11. The flow path wall 15 surrounds the heater 13 and the ink supply port B. The flow path wall 15 may be either in a state of surrounding the heater 13 and the ink supply port B over the entire circumference or in a state of being surrounded with a part or one side opened.

The nozzle layer 17 extends laterally from the upper end of the flow path wall 15. The nozzle layer 17 and the flow path wall 15 define an ink flow path through which ink flows on the upper surface of the substrate 11. A discharge hole A penetrating the nozzle layer 17 in the thickness direction is formed at a position facing the heater 13 of the nozzle layer 17. A sealing member 18 is provided at a position facing the ink supply port B of the nozzle layer 17. The sealing member 18 prevents the ink in the ink chamber CH from being ejected upward from other than the ejection holes A by closing the through holes penetrating the nozzle layer 17 in the thickness direction.

[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 silicon substrate 11 having an insulating layer 12a and an insulating layer 12b is prepared. In the present embodiment, as the substrate 11, a highly flat silicon substrate having a total thickness variation (TTV) of 2 μm or less is used. As a result, the distance between the substrate 11 and the nozzle layer 17 is accurately determined regardless of the position on the substrate 11. As a result, the volume of the ink chamber CH is maintained with high accuracy. The insulating layer 12a and the insulating layer 12b are made of, for example, silicon oxide. The insulating layer 12a and the insulating layer 12b are formed, for example, by thermally oxidizing a silicon substrate 11. Alternatively, the insulating layer 12a and the insulating layer 12b may be prepared by using a ready-made substrate in which silicon oxide films are provided on both surfaces in advance. In the present embodiment, as an example, the thickness of the substrate 11 is about 625 μm. The thickness of the insulating layer 12a and the insulating layer 12b is, for example, about 1 to 5 μm. Silicon oxide has ink resistance and anisotropic etching resistance. Therefore, the insulating layer 12a alone functions as a protective layer.

Next, as shown in FIG. 3B, the heater 13 is formed on the insulating layer 12a. The heater 13 is formed, for example, by depositing a resistance heating element such as tantalum nitride (TaN) or tantalum aluminum (TaAl) at a position where the heater 13 is formed by a sputtering method so as to have a thickness of about 200 to 1000 mm. Is done.

Next, as shown in FIG. 3C, a protective layer 14 having ink resistance and anisotropic etching resistance is formed so as to cover the upper surface of the substrate 11. In the present embodiment, the protective layer 14 is formed so as to cover the heater 13 and the insulating layer 12a. The protective layer 14 can be obtained by depositing silicon nitride on the heater 13 and the insulating layer 12a by, for example, chemical vapor deposition (plasma CVD) using plasma or sputtering. In addition, the thickness of the protective layer 14 is about 0.4 μm, for example.

Next, as shown in FIG. 3D, the flow path wall 15 is formed on the protective layer 14 so as to include the heater 13 on the substrate 11. In the present embodiment, the flow path wall 15 is formed of a completely cured epoxy resin. Note that the flow path wall 15 may be either in a state in which the heater 13 is surrounded over the entire circumference or in a state in which a part or one side is open. Further, the film thickness of the flow path wall 15 may be adjusted to be, for example, about 10-30 μm.

Next, as shown in FIG. 3E, the sacrificial layer 16 is formed. The sacrificial layer 16 is also formed in a region covering the upper surface of the flow path wall 15. For example, the sacrificial layer 16 is formed by injecting a semi-cured resin into the space formed by the flow path wall 15 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 15 is completely cured by heat or light before the sacrificial layer 16 is injected. The epoxy resin constituting the flow path wall 15 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 15 and the sacrificial layer 16. Further, a novolac resin may be used as the sacrificial layer 16. As an example of the novolak resin, EP4080G, EP4050G manufactured by Asahi Organic Materials Co., Ltd. dissolved in an organic solvent such as propylene glycol monomethyl ether acetate (PGMEA) can be used. 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 15 is completely cured, it is insoluble in the organic solvent. Therefore, even when novolac resin is used, no cross-mixing occurs between the flow path wall 15 and the sacrificial layer 16.

Next, as shown in FIG. 3F, the sacrificial layer 16 is removed from the upper surface so that the upper surface of the sacrificial layer 16 becomes flat. Here, if the sacrificial layer 16 remains on the flow path wall 15, there is a possibility that the adjacent ink chambers CH communicate with each other. Therefore, it is desirable that the sacrificial layer 16 be flattened until the sacrificial layer 16 and the flow path wall 15 are located on the same plane, in other words, until the upper surface of the flow path wall 15 is exposed. At this time, the upper surface of the flow path wall 15 may be slightly removed. Since the upper surface of the sacrificial layer 16 is flattened, the surface of the nozzle layer 17 on the ink chamber CH side can be formed with high accuracy, and the height of the ink chamber CH can be determined with high accuracy. As a result, the volume of the ink chamber CH is maintained with high accuracy.

For the planarization, various processing methods such as polishing and cutting can be used. In the present embodiment, as an example, the planarization of the sacrificial layer 16 is performed by cutting. As a result, the abrasive grains do not remain in the sacrificial layer 16 as in polishing, and the residue is prevented from remaining in the ink chamber CH when the sacrificial layer 16 is removed. At the time of cutting, the substrate 11 is placed on a processing table of a cutting device. In general, the cutting height is defined by using the lower surface of the substrate 11 as a reference surface. If the thickness of the substrate 11 varies greatly depending on the location, the lower surface of the substrate 11 and the upper surface of the sacrificial layer 16 after removal are made parallel, so that the thickness of the sacrificial layer 16 varies depending on the position on the substrate 11. However, in this embodiment, since the substrate 11 is made of highly flat silicon, the tilt of the substrate is sufficiently suppressed. Therefore, even if the sacrificial layer 16 is planarized by cutting, the thickness of the sacrificial layer 16 is kept constant regardless of the position on the substrate 11. For this reason, the volume of the ink chamber CH is maintained with high accuracy. Note that the sacrificial layer 16 may be slightly dissolved from the upper surface by dipping the ink discharge head 100 in an alkaline solution after the flattening by cutting. Thereby, the upper surface of the sacrificial layer 16 becomes flatter.

Next, as shown in FIG. 3G, the nozzle layer 17 is formed so as to cover the flow path wall 15 and the sacrificial layer 16. The nozzle layer 17 is formed so as not to dissolve the sacrificial layer 16. For this purpose, for example, spin coating or spray coating using a solvent that does not dissolve the resin of the sacrificial layer 16 is performed. For the formation of the nozzle layer 17, for example, a mixture of an epoxy resin dissolved in a solvent such as xylene or toluene, a silane coupling agent, and a photopolymerization initiator is used. Since xylene and toluene do not dissolve semi-cured polyimide or novolak resin, they are convenient as a solvent for the resin forming the nozzle layer 17. After application of the resin constituting the nozzle layer 17, the resin constituting the nozzle layer 17 is dried in order to improve the adhesion with the flow path wall 16 and drive out the solvent remaining in the nozzle layer 17. This drying may be performed, for example, by a method such as heating the ink ejection head 100 or exposing it to a vacuum. In the case of drying by heating, the ink ejection head 100 is exposed to an environment of 70 ° C. for about 30 minutes, for example. In the case of drying by vacuum exposure, the ink ejection head 100 is exposed to an environment of 10 Torr or less for about 8 hours, for example. The film thickness of the nozzle layer 17 is adjusted to 20-50 μm.

Next, as shown in FIG. 4A, nozzle holes A and additional discharge holes C penetrating the nozzle layer 17 in the vertical direction are formed in the nozzle layer 17. The discharge hole A is provided at a position facing the heater 13. The additional discharge hole C is provided at a position away from the nozzle hole A. The size of the additional discharge hole C is arbitrary. As an example, the size of the additional discharge hole C is larger than the size of the discharge hole A so that the dissolved sacrificial layer 16 can easily pass through. Alternatively, a plurality of additional discharge holes C having a size smaller than the size of the discharge holes A may be provided in the nozzle layer 17 for each ink chamber CH. Of course, a plurality of additional discharge holes C larger than the size of the discharge holes A may be provided in the nozzle layer 17. The discharge hole A and the additional discharge hole C are formed by photolithography. Specifically, a photomask is placed at a position corresponding to the discharge hole A and the additional discharge hole C on the upper surface of the nozzle layer 17. The nozzle layer 17 is irradiated with ultraviolet rays from above the photomask. The nozzle layer 17 is cured except for the positions of the discharge holes A and the additional discharge holes C by the ultraviolet irradiation. Then, by immersing the ink discharge head 100 in the developer, the uncured resin at the positions of the discharge holes A and the additional discharge holes C is dissolved, and the discharge holes A and the additional discharge holes C are developed. In developing the discharge holes A and the additional discharge holes C, a solvent that does not dissolve the sacrificial layer 16 such as xylene or toluene is used as a developer. However, the sacrificial layer 16 such as PGMEA, acetone, or an alkaline aqueous solution may be removed to a part of the sacrificial layer 16 in the vicinity of the discharge hole A and the additional discharge hole C using a solvent that can dissolve the sacrificial layer 16. .

Next, as shown in FIG. 4B, the substrate 11 is anisotropically etched from the lower surface. Specifically, first, an etching mask is formed on the lower surface of the substrate 11. In the present embodiment, the insulating layer 12b is used as an etching mask. That is, an opening is formed in the insulating layer 12b at a position facing the additional discharge hole C, whereby an etching mask is formed. The opening is formed by removing a part of the insulating layer 12b by dry etching using a gas such as tetrafluoromethane (CF4) or wet etching using a hydrofluoric acid solution. Then, the substrate 11 is immersed in an etching solution for anisotropic wet etching. In this embodiment, an alkaline aqueous solution such as an aqueous potassium hydroxide (KOH) solution or an aqueous tetramethylammonium hydroxide (TMAH) solution is used as the etching solution. The etching rate of the silicon oxide film constituting the insulating layer 12a is sufficiently slower than the etching rate of silicon constituting the substrate 11 with respect to the alkaline aqueous solution that is the etching solution. Therefore, anisotropic etching that proceeds from the lower surface of the substrate 11 toward the upper surface stops at the lower surface of the insulating layer 12a. That is, the insulating layer 12a functions as an etching stop layer. Therefore, the sacrificial layer 16 does not come into contact with the alkaline aqueous solution that is an etching solution. Therefore, alteration of the sacrificial layer 16 is prevented.

Next, as shown in FIG. 4C, the sacrificial layer 16 is removed. In the case where the sacrificial layer 16 is made of semi-cured polyimide, the ink ejection head 100 is immersed in a 2.38% TMAH alkaline aqueous solution. When the sacrificial layer 16 is composed of a novolac resin, the ink ejection head 100 is immersed in an organic solvent such as acetone or PGMEA. As the sacrificial layer 16 dissolved in the solvent flows out from the discharge hole A and the additional discharge hole C, the sacrificial layer 16 is removed. Since the sacrificial layer 16 is removed before the ink supply port B penetrates, the sacrificial layer 16 is not altered, and the residue of the sacrificial layer 16 is prevented from remaining in the ink chamber CH. Further, since the additional discharge hole C is provided, the sacrificial layer 16 can be reliably removed from the ink chamber.

Next, as shown in FIG. 4D, the insulating film 12a and the protective layer 14 formed at the position corresponding to the ink supply port B are removed. In the present embodiment, the insulating layer 12a and the protective layer 14 are removed from the lower surface of the substrate 11, for example, by dry etching using CF4. The sacrificial layer 16 is removed before the insulating film 12a and the protective layer 14 are removed by dry etching. Therefore, the sacrificial layer 16 is removed without being exposed to dry etching or the like for removing the insulating film 12a and the protective layer 14. As a result, the sacrificial layer 16 does not change in quality, and the residue of the sacrificial layer 16 is prevented from remaining in the ink chamber. Therefore, the volume of the ink chamber CH is kept with high accuracy.

Next, as shown in FIG. 4E, the sealing member 18 is formed in the nozzle layer 17 so as to cover the additional discharge hole C. Specifically, the adhesive film is attached to the position of the additional discharge hole C on the upper surface of the nozzle layer 17. The adhesive film is obtained by spin coating or spray coating a resin material constituting the sealing member 18 on a resin film 19 such as polyethylene terephthalate (PET) or polyimide. The resin material constituting the sealing member 18 is a mixture of an epoxy resin dissolved in a solvent such as xylene or toluene, a silane coupling agent, and a photopolymerization initiator, as with the nozzle layer 17. Used.

Finally, after the resin film 19 of the adhesive film is peeled off, the sealing member 18 is cured. The sealing member 18 is cured by irradiation with ultraviolet rays. The ink ejection head 100 is manufactured by the process described above.

The present disclosure is not limited to the embodiments described so far, and various modifications and changes can be made without departing from the spirit of the present disclosure. An example is described below.

In the above-described embodiment, the nozzle layer 17 is formed by applying and drying a resin dissolved in a solvent. However, as with the formation of the sealing member 18, the nozzle layer 17 may be formed by placing a film-like photocurable resin or a film-like resin having discharge holes formed thereon.

In the above-described embodiment, the sacrificial layer 16 was eluted from the discharge port A and the additional discharge port C (FIG. 4C). However, the sacrificial layer 16 may be eluted only from the discharge port A without forming the additional discharge port C. The ejection holes A are always provided in the ink ejection head 100. Therefore, when the sacrificial layer 16 is eluted only from the discharge hole A without providing the additional discharge port C, it is not necessary to form a special configuration for removing the sacrificial layer 16. Therefore, it leads to simplification of the manufacturing process.

In the above-described embodiment, the insulating layer 12 a provided under the heater 13 and the protective layer 14 provided on the heater 13 are formed on the upper surface of the substrate 11. Both the insulating layer 12a and the protective layer 14 have ink resistance and etching resistance against wet etching with an alkaline solution. However, any one of the layers may be omitted. In short, a protective film that functions as an etching stop layer may be provided on the upper surface of the substrate 11 when the substrate 11 is wet-etched.

In the above-described embodiment, the sealing member 18 seals the additional discharge hole C using a sticking film (see FIG. 4E). However, the sealing member 18 may seal the additional discharge hole C by covering the upper surface of the nozzle layer 17 by, for example, spray coating or spin coating. In this case, a mask is placed on the discharge hole A before the resin material constituting the sealing member 18 is applied to the upper surface of the nozzle layer 17 so as not to block the discharge hole A. The additional discharge hole C is formed of a plurality of fine holes so that the sealing member 18 does not flow into the ink chamber CH through the additional discharge hole C. In this case, the size of the additional discharge hole C is determined depending on the viscosity of the sealing member 18.

100 Ink Discharge Head 11

Substrate

12a, 12b Insulating Layer 13 Heater 14 Protective Layer 15 Channel Wall 16 Sacrificial Layer 17 Nozzle Layer 18 Sealing Member A Discharge Hole B Ink Supply Port C Additional Discharge Hole

Claims

A preparation step of preparing a plate-shaped substrate and an energy generating element formed on one surface of the substrate;
A sacrificial layer provided at a position corresponding to an ink flow path including an ink chamber; a flow path wall including at least the sacrificial layer and the energy generating element; and defining the ink chamber; and An ink chamber forming step of forming a nozzle layer provided on the one surface;
A discharge hole forming step of forming a discharge hole penetrating the nozzle layer in the thickness direction in the nozzle layer;
A sacrificial layer removing step of removing the sacrificial layer by discharging the sacrificial layer through the ejection holes to the outside of the ink chamber after the ejection hole forming step;
An ink supply port forming step of forming an ink supply port penetrating the substrate in the thickness direction by etching from the other surface after the sacrificial layer removing step;
An ink discharge head manufacturing method comprising:
The ink chamber forming step includes
A flow path wall forming step of forming the flow path wall on the one surface;
A sacrificial layer forming step of forming the sacrificial layer in the space formed by the flow channel wall after the flow channel wall forming step;
A planarization step of planarizing the upper surface of the sacrificial layer after the sacrificial layer formation step;
A nozzle layer forming step of forming the nozzle layer on the sacrificial layer and the flow path wall after the planarization step;
The method for manufacturing an ink ejection head according to claim 1, comprising:
In the preparation step, as the substrate, a highly flat silicon substrate having a total thickness variation of 2 μm or less is prepared.
A method for manufacturing the ink ejection head according to claim 2.
The planarization step includes a cutting step of planarizing the upper surface of the sacrificial layer by cutting from the upper surface of the sacrificial layer toward the substrate.
A method for manufacturing the ink ejection head according to claim 3.
A protective layer preparation step of preparing a protective layer having ink resistance and anisotropic etching resistance on the one surface before the ink chamber formation step and after the preparation step;
The ink supply port forming step includes
A substrate removing step of deleting the substrate from the other surface toward the one surface by anisotropic etching at a position corresponding to the ink supply port of the substrate;
A protective layer removing step of removing the protective layer formed at a position corresponding to the ink supply port from the other surface after the substrate removing step;
The method for manufacturing an ink ejection head according to claim 1.
The sacrificial layer removal step is performed after the substrate removal step,
The protective layer removing step is performed after the sacrificial layer removing step.
A method for manufacturing the ink ejection head according to claim 5.
The discharge hole forming step further forms an additional discharge hole in the nozzle layer,
The sacrificial layer removing step removes the sacrificial layer by discharging the sacrificial layer to the outside of the ink chamber through the ejection hole and the additional discharge hole,
A sealing step of sealing the additional discharge hole after the sacrificial layer removal step;
The method for manufacturing an ink ejection head according to claim 1.
A plate-like substrate;
An energy generating element provided on one surface of the substrate;
A flow path wall defining an ink chamber including at least the energy generating element;
A nozzle layer provided on the flow path wall,
The substrate has an ink supply port that penetrates the substrate in the thickness direction;
The nozzle layer is
A discharge hole provided at a position corresponding to the energy generating element and penetrating the nozzle layer in the thickness direction;
An additional hole provided at a position away from the discharge hole and penetrating the nozzle layer in the thickness direction;
A sealing member that covers the additional hole on the surface of the nozzle layer opposite to the ink chamber;
An ink discharge head.