JP2007021798A - Method for manufacturing substrate for inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that when the number of nozzles on a substrate for an inkjet head is increased, or the length of the substrate is increased or decreased, the deformation of the substrate in the tensile direction occurs by the influence of a photosensitive resin formed on the surface of the substrate, and then peeling of a nozzle or deformation of an ejection hole may occur, the ejection direction of ink is not stabilized, and adverse influence is applied to the printing. <P>SOLUTION: Two resin layers having different patterns are formed on a rear face in a process of forming a nozzle and an ink supply hole of an inkjet recording head, warpage of a wafer is prevented, and then cracking of a membrane at the upper portion of the substrate is prevented. Finally, one of the resin layers is removed in the halfway of the process so that one layer of the other resin layer is remained at the rear face of the substrate for an inkjet recording head. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an injection recording head substrate according to a manufacturing technique for manufacturing an inkjet recording head substrate at low cost.

  With regard to this type of ink jet recording head, for example, the ink jet recording method described in Patent Document 1 is different from other ink jet recording methods in that thermal energy is applied to a liquid to obtain a driving force for droplet ejection. It has characteristics.

  That is, in the recording method disclosed in the above-mentioned publication, the liquid that has been subjected to the action of thermal energy is superheated to generate bubbles, and droplets are discharged from the orifice at the tip of the recording head by the action force based on the generation of bubbles. It is characterized in that information is recorded by forming the droplets on the recording member. A recording head applied to this recording method generally includes an orifice provided for ejecting a liquid, and a heat acting portion that is a portion where heat energy for ejecting droplets communicated with the orifice acts on the liquid. A liquid discharge section having a liquid flow path having a liquid crystal structure as a part, a heating resistance layer as a heat conversion body that is a means for generating thermal energy, an upper protective layer that protects it from ink, and a lower layer for storing heat It has.

  Conventionally, Patent Document 2 discloses a method of manufacturing an ink jet recording head substrate. This forming method is a basic patent in which the ink discharge port is formed by anisotropic etching and the discharge port is formed of a photosensitive resin.

  With reference to FIG. 4, a description will be given of a process of forming a nozzle for ejecting ink and an ink supply port for supplying ink on the substrate. FIG. 4 is a cross-sectional view taken along the line BB in FIG.

4A to 4F are schematic cross-sectional views for illustrating basic manufacturing steps of a conventional inkjet recording head. On the substrate 1 shown in FIG. 4- (A), a plurality of ink discharge energy generating elements 3 such as heating resistors are arranged. A SiO ₂ film 2 is formed on the back surface of the substrate 1. In addition to the ink discharge energy generating element 3 on the substrate, a sacrificial layer 4 used when creating the ink supply port in the nozzle manufacturing process, and a wiring and a driving element (not shown) for driving the ink discharge energy generating element (not shown) Is formed.

  First, a resin layer 14 is applied to the back surface of the substrate 1, and in order to pattern the resin layer 14, a positive resist is applied by spin coating or the like, exposed, and developed, as shown in FIG. The resin layer 14 on the back surface of the substrate 1 is patterned by dry etching or the like, and the positive resist is peeled off. Then, a positive resist (ODUR: manufactured by Tokyo Ohka Kogyo Co.) 7, which is a mold material that becomes a nozzle flow path, is patterned on the surface.

  Next, as shown in FIG. 4C, a coating resin layer 8 (CR: coating resin) is formed on the mold material 7 by spin coating or the like. A water repellent layer 9 is formed on the coating resin layer 8 by laminating a dry film or the like. Since the coating resin layer 8 (CR) is a photosensitive resin layer, the ink discharge port 10 is formed by patterning by performing exposure and development using ultraviolet rays, deep UV light, or the like.

Next, as shown in FIG. 4D, the surface and side surfaces of the substrate 1 on which the mold material 7 and the coating resin layer 8 are patterned are applied by spin coating or the like and covered with a protective material 11. The SiO ₂ film 2 on the back surface of the substrate 1 is patterned by wet etching or the like using the resin layer 14 as a mask, and the Si surface is exposed to form an anisotropic etching start surface 12.

  Next, an ink supply port 13 is provided in the substrate 1. The ink supply port 13 is formed by chemically etching the substrate. For example, it is formed by anisotropic etching with a strong alkali solution such as TMAH. Then, as shown in FIG. 4E, when anisotropic etching is performed from the back surface, the sacrificial layer 4 on the front surface is reached, and the ink supply port 13 is formed.

  Next, the resin layer 14 and the protective material 11 are removed. Further, the mold material 7 is eluted from the ink discharge port 10 and the ink supply port 13 to form an ink flow path and a foaming chamber.

  After the ink jet recording head substrate 16 in which the ink flow path and the like are formed by the above steps is electrically joined to drive the ink ejection energy generating element 3, a chip tank member for supplying ink is connected. Thus, the ink jet recording head is completed.

  FIG. 5A shows an ink jet recording head substrate 16 on which ink flow paths and the like manufactured in such a process are formed.

  The silicon substrate 1 of the substrate of the ink jet head is a silicon substrate having a crystal orientation of 100, and the ink supply port 13 is formed by anisotropic etching. Reference numeral 8 denotes a CR material, and a water repellent layer 9 is formed thereon. An ink flow path 17 and an orifice 10 are formed. Reference numeral 18 denotes a bonding pad.

As shown in the BB cross-sectional view of FIG. 5B, an oxide film 2 is formed on the back surface of the substrate.
JP 54-51837 A Japanese Patent Laid-Open No. 9-11479

  However, when an inkjet head is manufactured using the above-described inkjet head substrate, there are the following problems.

  1. As the number of nozzles on the inkjet head substrate increases, the photosensitive resin formed on the surface of the substrate loses its rigidity because anisotropic etching holes are greatly opened in the nozzle row direction. As a result, the substrate is deformed in the pulling direction, the nozzle is peeled off, the ejection port is deformed, and the ink ejection direction is not determined, which adversely affects printing.

  2. In order to reduce the cost of the inkjet head substrate, if the substrate is made smaller, the stiffness of the substrate will be lost, as in the case of increasing the number of nozzles, and the tensile resin will be pulled by the influence of the photosensitive resin formed on the surface of the substrate. The substrate was deformed in the direction, and the nozzles were peeled off, the ejection ports were deformed, and further, the ink ejection direction was not determined, and the printing was adversely affected.

  As described above, the ink-jet substrate is increased, the number of ink supply ports is increased, and the number of nozzles is increased, so that the ink supply port is increased, the rigidity of the substrate is lost, and the printing yield is reduced. Problems such as peeling may occur.

  The present invention has been made in view of the above, and an object of the present invention is to increase the rigidity of an inkjet substrate and to prevent deformation of the substrate. An object of the present invention is to provide a method of manufacturing an ink jet recording head that can perform good printing even when scaled and has high quality. The present invention particularly relates to a manufacturing method, and an object thereof is to prevent warpage during the process and suppress defects such as nozzle peeling due to warpage.

In the present invention, in order to solve the above-mentioned problems, a step of preparing a Si substrate having a first surface that is an element formation surface and a second surface that is a back surface of the first surface, and the second of the Si substrate is provided. Forming a SiO ₂ film on a surface; forming a sacrificial layer on the first surface of the Si substrate; and generating liquid discharge energy for generating energy for discharging a liquid onto the first surface of the Si substrate. A step of forming an element, a step of patterning a first resin layer on the SiO ₂ film formed on the second surface, and a _second resin layer on the second surface from the opening width of the first resin layer Patterning the mold material that becomes the ink flow path, patterning the photosensitive resin that becomes the ejection port and orifice plate material, forming the water repellent layer, and protecting the substrate with the protective material Cover anisotropic etching An ink jet process comprising: a step of removing a second resin layer formed on the second surface to leave the first resin layer formed on the second surface; and a step of removing the protective material and the mold material. A method of manufacturing a recording head substrate is proposed.

A step of preparing a Si substrate having a first surface that is an element forming surface and a second surface that is a back surface of the first surface; a step of forming a SiO ₂ film on the second surface of the Si substrate; Forming a sacrificial layer on the first surface of the Si substrate; forming a liquid discharge energy generating element for generating energy for discharging liquid on the first surface of the Si substrate; and the second surface. A step of patterning a first resin layer on the SiO ₂ film formed on the substrate, a step of patterning a second resin layer on the second surface wider than the opening width of the first resin layer, and an ink channel. A step of patterning a mold material to be formed, a step of patterning a photosensitive resin to be a discharge port or an orifice plate material, a step of forming a water repellent layer, a step of covering the substrate with a protective material and performing anisotropic etching, The second formed on two sides The present invention proposes a method of manufacturing a substrate for an ink jet recording head, comprising a step of removing the oil layer and leaving the first resin layer formed on the second surface, and a step of removing the protective material and the mold material. .

  As described above, according to the present invention, the photosensitive layer formed on the substrate surface can be obtained by adopting a manufacturing method in which a resin is provided on the back surface of the ink supply port in order to lengthen and reduce the size of the inkjet recording head substrate. It is possible to suppress the tensile stress caused by the adhesive resin, prevent warpage in the nozzle process, and improve the nozzle yield and the printing yield.

  Furthermore, since the warpage of the IJ substrate, which is a component of the head, is suppressed, the reliability of the ink jet recording head is improved.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 3A is a perspective view of an ink jet recording head substrate manufactured in this embodiment. FIG. 3A is a perspective view showing a part of the ink jet recording apparatus.

This ink jet recording head (liquid discharge head) has a Si substrate 1 on which ink discharge energy generating elements (liquid discharge energy generating elements) 3 are formed in two rows at a predetermined pitch. In the Si substrate 1, an ink supply port (liquid supply port) 13 formed by anisotropic etching of Si using a SiO ₂ film as a mask is opened between two rows of ink ejection energy generating elements 3. . On the Si substrate 1, an ink ejection port (liquid ejection port) 10 opened above each ink ejection energy generating element 3 and an ink communicating from the ink supply port 13 to each ink ejection port 10 by an orifice plate material 8. A flow path (liquid flow path) 17 is formed.

  This ink jet recording head is arranged so that the surface on which the ink supply port 13 is formed faces the recording surface of the recording medium. The ink jet recording head applies ink pressure generated by the ink discharge energy generating element 3 to the ink (liquid) filled in the ink flow path via the ink supply port 13, thereby causing the ink liquid from the ink discharge port 10. Recording is performed by discharging droplets and attaching them to a recording medium.

  The present invention relates to the formation of an inkjet recording head that performs recording by ejecting liquid to form flying droplets, an ejection port (hereinafter also referred to as an orifice) that ejects liquid, and an ink supply port that supplies the liquid. .

  The present invention also includes a printer, a copier, a facsimile having a communication system, and a printer unit that perform recording on a recording medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, and ceramics. The present invention can be applied to an apparatus such as a word processor or an industrial recording apparatus combined with various processing apparatuses.

  In the present invention, “recording” means not only giving an image having a meaning such as a character or a figure to a recording medium but also giving an image having no meaning such as a pattern. .

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view for producing an ink jet recording head substrate according to the present invention, and is a diagram illustrating the order of steps.

  1- (A) to (F) are cross-sectional views taken along the line BB of FIG. 3 (A), and are schematic cross-sectional views for illustrating a basic manufacturing process of the ink jet recording head of the present invention. The different sectional views were used to explain this patent in an easy-to-understand manner. First, the manufacturing process of the BB cross-sectional view will be described with reference to FIG.

A plurality of ink discharge energy generating elements 3 such as heating resistors are arranged on the substrate 1 shown in FIG. Although the crystal orientation of the substrate used this time is 100, it is needless to say that the same results can be obtained with 110. A SiO ₂ film 2 is formed on the back surface of the substrate 1. And when forming an ink supply port with an alkaline solution, the sacrificial layer 4 for processing the surface dimension with high accuracy is provided on the substrate 1. The wiring of the heater 3 and the semiconductor element for driving the heater are not shown. The sacrificial layer may be any material that can be etched with an alkaline solution, and is formed of polysilicon or aluminum. Preferably, aluminum, aluminum silicon, aluminum copper, aluminum silicon copper, or the like having a high etching rate with respect to the alkaline solution is used.

  First, the first resin layer 5 is applied to the back surface of the substrate 1, and in order to pattern the first resin layer 5, a positive resist is applied, exposed, and developed by spin coating or the like, and the back surface of the substrate 1 is then applied. The first resin layer 5 is patterned by dry etching or the like, and the positive resist is peeled off. Thereafter, a second resin layer 6 is applied, and in order to pattern the second resin layer 6, a positive resist is applied by spin coating or the like, exposed and developed, and the second resin on the back surface of the substrate 1 is applied. The layer 6 is patterned by dry etching or the like, and the positive resist is removed. Needless to say, when patterning the back surface of the substrate in this way, the surface may be protected. Then, a positive resist (ODUR: manufactured by Tokyo Ohka Kogyo Co.) 7, which is a mold material that becomes a nozzle flow path, is patterned on the surface. The relationship between the first resin layer 5 and the second resin layer 6 thus formed is that the opening width of the second resin layer is narrower and the opening of the first resin layer is more open as shown in FIG. The shape is wide.

  Next, as shown in FIG. 1- (C), a coating resin layer 8 (CR) is formed on the mold material 4 by spin coating or the like. A water repellent layer 9 is formed on the coating resin layer 8 by laminating a dry film or the like. Since the coating resin layer 6 (CR) is a photosensitive resin layer, the ink discharge port 13 is formed by performing exposure and development using ultraviolet rays, deep UV light, or the like, and patterning.

Next, as shown in FIG. 1- (D), the surface and side surfaces of the substrate 1 on which the mold material 7 and the coating resin layer 6 are patterned are applied by spin coating or the like and covered with a protective material 11. The protective material 11 is a material that can sufficiently withstand a strong alkaline solution used when performing anisotropic etching, and therefore, it is possible to prevent deterioration of the water repellent layer 9 and the like due to anisotropic etching. Become. The SiO ₂ film 2 on the back surface of the substrate 1 is patterned by wet etching or the like using the second resin layer 6 as a mask, and becomes a starting surface 12 for anisotropic etching to expose the Si surface. Next, an ink supply port is provided in the substrate 1. The ink supply port is formed by chemically etching the substrate, for example, anisotropic etching with a strong alkaline solution such as TMAH. FIG. 1- (E) shows an intermediate process of anisotropic etching. After the silicon is etched by anisotropic etching, the sacrificial layer 4 is reached, and the sacrificial layer that is quickly etched proceeds in the lateral direction. As shown in FIG. 1- (F), first, burrs of the oxide film 2 generated during anisotropic etching are etched by wet etching. Thereafter, the second resin layer is etched from the back surface so that the first resin layer remains, and the first resin layer 5 remains to prevent warpage of the entire wafer. In the conventional process, when the resin is removed, stress is applied in the pulling direction by the photosensitive resin formed on the surface, and the wafer is warped, and is formed between the nozzle flow path 17 and the ink supply port 13 (not shown). As a result, the membrane film was cracked and the yield was reduced.

  Next, after removing the protective material 11, the mold material 7 is eluted from the ink discharge port 10 and the ink supply port 13, thereby forming an ink flow path and a foaming chamber. The mold material 7 may be removed by performing development and drying after performing the entire surface exposure with Deep UV light, and it is sufficient to ultrasonically immerse it when necessary.

  The ink jet recording head substrate 19 on which the nozzle portion is formed by the above steps is separated and cut into chips by a dicing saw or the like, and after electrical joining is performed to drive the ink ejection energy generating element 3, ink supply is performed. Therefore, the ink jet recording head is completed.

  Since this inkjet recording head is a process in which the resin is left on the back surface in the process of forming the nozzle and the ink supply port, the membrane is formed by suppressing the tensile stress of the photosensitive resin formed on the front surface and suppressing the warpage. The occurrence of defects such as cracks can be prevented.

  Hereinafter, other embodiments of the present invention will be described with reference to the drawings.

  FIG. 2 is a schematic cross-sectional view for producing the ink jet recording head substrate of the present invention, and is a diagram illustrating the order of steps.

  2A to 2F are cross-sectional views taken along the line BB in FIG. 3A, and are schematic cross-sectional views illustrating the basic manufacturing process of the ink jet recording head of the present invention. The different sectional views were used to explain this patent in an easy-to-understand manner. First, the manufacturing process of the BB sectional view will be described with reference to FIG.

A plurality of ink ejection energy generating elements 3 such as heating resistors are arranged on the substrate 1 shown in FIG. Although the crystal orientation of the substrate used this time is 100, it is needless to say that the same results can be obtained with 110. A SiO ₂ film 2 is formed on the back surface of the substrate 1. And when forming an ink supply port with an alkaline solution, the sacrificial layer 4 for processing the surface dimension with high accuracy is provided on the substrate 1. The wiring of the heater 3 and the semiconductor element for driving the heater are not shown. The sacrificial layer may be any material that can be etched with an alkaline solution, and is formed of polysilicon or aluminum. Preferably, aluminum, aluminum silicon, aluminum copper, aluminum silicon copper, or the like having a high etching rate with respect to the alkaline solution is used.

  First, a first resin layer 14 is applied to the back surface of the substrate 1, and a positive resist is applied, exposed, and developed by spin coating or the like in order to pattern the first resin layer 14. The first resin layer 14 is patterned by dry etching or the like, and the positive resist is peeled off. Thereafter, the second resin layer 15 is applied in the same manner, and in order to pattern the second resin layer 15, a positive resist is applied, exposed and developed by spin coating or the like, and the second resin layer 15 on the back surface of the substrate 1 is applied. The resin layer 15 is patterned by dry etching or the like, and the positive resist is peeled off. Needless to say, when patterning the back surface of the substrate in this way, the surface may be protected. Then, a positive resist (ODUR: manufactured by Tokyo Ohka Kogyo Co.) 7, which is a mold material that becomes a nozzle flow path, is patterned on the surface. The relationship between the first resin layer 14 and the second resin layer 15 thus formed is that the second resin layer has a wider opening width as shown in FIG. Has a narrower opening width.

  Next, as shown in FIG. 2C, a coating resin layer 8 (CR) is formed on the mold material 4 by spin coating or the like. A water repellent layer 9 is formed on the coating resin layer 8 by laminating a dry film or the like. Since the covering resin layer 15 (CR) is a photosensitive resin layer, the ink discharge port 13 is formed by patterning by performing exposure and development using ultraviolet light, deep UV light, or the like.

Next, as shown in FIG. 2D, the surface and side surfaces of the substrate 1 on which the mold material 7 and the coating resin layer 15 are patterned are applied by spin coating or the like and covered with the protective material 11. The protective material 11 is a material that can sufficiently withstand a strong alkaline solution used when performing anisotropic etching, and therefore, it is possible to prevent deterioration of the water repellent layer 9 and the like due to anisotropic etching. Become. The SiO ₂ film 2 on the back surface of the substrate 1 is patterned by wet etching or the like using the second resin layer 14 as a mask, and becomes a starting surface 12 for anisotropic etching to expose the Si surface. Next, an ink supply port is provided in the substrate 1. The ink supply port is formed by chemically etching the substrate, for example, anisotropic etching with a strong alkaline solution such as TMAH. FIG. 2- (E) shows an intermediate process of anisotropic etching. After the silicon is etched by anisotropic etching, the sacrificial layer 4 is reached, and the sacrificial layer that is quickly etched proceeds in the lateral direction. As shown in FIG. 2- (F), first, burrs of the oxide film 2 generated during anisotropic etching are etched by wet etching. Thereafter, the second resin layer is etched from the back surface so that the first resin layer remains, and the first resin layer 14 remains to prevent warpage of the entire wafer. In the conventional process, when the resin is removed, stress is applied in the pulling direction by the photosensitive resin formed on the surface, and the wafer is warped, and is formed between the nozzle flow path 17 and the ink supply port 13 (not shown). As a result, the membrane film was cracked and the yield was reduced.

  Next, after removing the protective material 11, the mold material 7 is eluted from the ink discharge port 10 and the ink supply port 13, thereby forming an ink flow path and a foaming chamber. The mold material 7 may be removed by performing development and drying after performing the entire surface exposure with deep UV light, and it is sufficient to perform ultrasonic dipping when developing.

  The ink jet recording head substrate 19 on which the nozzle portion is formed by the above steps is separated and cut into chips by a dicing saw or the like, and after electrical joining is performed to drive the ink ejection energy generating element 3, ink supply is performed. Therefore, the ink jet recording head is completed.

  Since this inkjet recording head is a process that leaves the resin on the back side in the process of forming the nozzles and ink supply ports, it suppresses the tensile stress of the photosensitive resin formed on the surface and suppresses the warp, thereby The occurrence of defects such as these can be prevented.

It is typical sectional drawing of 1st Example of this invention. It is typical sectional drawing of 2nd Example of this invention. FIG. 2A is a schematic perspective view illustrating a part of a substrate for a liquid discharge head according to an embodiment of the present invention. (B) is BB sectional drawing of (A). It is typical sectional drawing for demonstrating each manufacturing process of the conventional board | substrate for inkjet recording heads. (A) is a schematic perspective view showing a part of a conventional substrate for an ink jet recording head. (B) is BB sectional drawing of (A).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Silicon substrate 2 Oxide film 3 Ink discharge energy generating element 4 Sacrificial layer 5 1st resin layer 6 2nd resin layer 7 Mold material 8 Photosensitive resin (flow path and orifice formation member)
DESCRIPTION OF SYMBOLS 9 Water repellent layer 10 Ejection port 11 Protective material 12 Etching start surface 13 Ink supply port 14 First resin layer 15 Second resin layer 16 Ink-jet printhead substrate 17 on which a conventional ink channel is formed 17 Ink channel 18 Bonding pad 19 Inkjet recording head substrate on which ink flow path, back surface resin layer, etc. are formed

Claims (5)

Preparing a Si substrate having a first surface that is an element formation surface and a second surface that is a back surface of the first surface; forming a SiO ₂ film on the second surface of the Si substrate; and Forming a sacrificial layer on the first surface of the substrate; forming a liquid discharge energy generating element for generating energy for discharging liquid on the first surface of the Si substrate; and forming on the second surface. Patterning the first resin layer on the SiO ₂ film, patterning the second resin layer narrower than the opening width of the first resin layer on the second surface, and a mold material that becomes an ink flow path A step of patterning a photosensitive resin to be a discharge port or an orifice plate material, a step of forming a water repellent layer, a step of covering the substrate with a protective material and performing anisotropic etching, a second surface Second resin layer formed on Removing first the step of leaving the resin layer, the protective material and the mold material manufacturing method for a substrate for an ink jet recording head which comprises a step of removing the formed on the second surface. Preparing a Si substrate having a first surface that is an element formation surface and a second surface that is a back surface of the first surface; forming a SiO ₂ film on the second surface of the Si substrate; and Forming a sacrificial layer on the first surface of the substrate; forming a liquid discharge energy generating element for generating energy for discharging liquid on the first surface of the Si substrate; and forming on the second surface. Patterning the first resin layer on the SiO ₂ film, patterning the second resin layer on the second surface wider than the opening width of the first resin layer, and a mold material that becomes an ink flow path A step of patterning a photosensitive resin to be a discharge port or an orifice plate material, a step of forming a water repellent layer, a step of covering the substrate with a protective material and performing anisotropic etching, a second surface Second resin layer formed on Removing first the step of leaving the resin layer, the protective material and the mold material manufacturing method for a substrate for an ink jet printhead which comprises a step of removing the formed on the second surface.   3. The method of manufacturing an ink jet recording head substrate according to claim 1, wherein the first resin layer and the second resin layer are the same resin, an organic film, and a thermoplastic resin.   4. The method of manufacturing an ink jet recording head substrate according to claim 1, wherein the crystal orientation of the Si substrate is 100 or 110.   2. The first resin layer, the second resin layer, a mold material, a photosensitive resin, a water repellent layer, and a protective material are formed on a substrate by spin coating, roll coating, or direct coating. The manufacturing method of the board | substrate for inkjet recording heads in any one of thru | or 4.

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