JP2008126481A - Method for manufacturing substrate for inkjet recording head and method for manufacturing inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form an ink feeding opening with a beam accurately in a short time. <P>SOLUTION: A method for manufacturing a substrate for an inkjet head includes the process of forming a face to be etched with an exposed silicon face on a part on the back face of a silicon substrate on which the ink feeding opening 10 is formed. In addition, the method includes the process of forming a first recessed part by laser processing in a region in which at least a region in which the beam 19 is formed in the face to be etched is excluded, and has the process of performing a first wet etching from the face to be etched to the silicon substrate. In addition, the method includes the process of a second recessed part 20b is formed by laser processing on a face to be etched of the silicon substrate etched by the first wet etching. Furthermore, the method includes the process of performing a second wet etching until the face to be etched penetrates through the silicon substrate and reaches a sacrifice layer to the silicon substrate to form an ink feeding opening 20 equipped with the beam 19. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an ink jet recording head substrate and a method for manufacturing an ink jet recording head.

  2. Description of the Related Art Conventionally, an ink jet recording head that obtains a driving force for droplet discharge by applying thermal energy to a liquid is known. According to this type of ink jet recording head, the liquid subjected to the action of thermal energy is superheated to generate bubbles, and droplets are formed from the orifices by the action force based on the generation of the bubbles, and the droplets are formed on the recording medium. The information is recorded by adhering. This type of ink jet recording head has an ink discharge port that discharges a liquid, and an ink flow path in which a discharge energy generating element that gives thermal energy to the liquid in communication with the discharge port is disposed. .

  4 (A) to 4 (F) are schematic cross-sectional views showing basic manufacturing steps of a conventional ink jet recording head.

On the substrate 1 shown in FIG. 4A, a plurality of ink discharge energy generating elements 11 such as heating resistors are arranged. The entire back surface of the substrate 1 is covered with the SiO ₂ film 18.

  First, as shown in FIG. 4B, a thermoplastic resin layer 13 and a thermoplastic resin layer 14 are respectively applied to the front and back surfaces of the substrate 1, and the thermoplastic resin layers 13 and 14 are baked and cured. . Then, in order to pattern the thermoplastic resin layer 13 on the surface side, a positive resist is applied on the thermoplastic resin layer 13 by spin coating or the like, exposed and developed, and the thermoplastic resin layer 13 is patterned by dry etching or the like. Then, the positive resist is removed. Further, in order to pattern the thermoplastic resin layer 14 on the back surface side, a positive resist is applied on the thermoplastic resin layer 14 by spin coating or the like, exposed and developed, and the thermoplastic resin layer 14 is patterned by dry etching or the like. Then, the positive resist is removed.

  Next, as shown in FIG. 4C, a positive resist (ODUR (trade name) 12 manufactured by Tokyo Ohka Kogyo Co., Ltd.), which is a mold material that becomes an ink flow path, is patterned on the surface side of the substrate 1.

  Next, as shown in FIG. 4D, a coated photosensitive resin (CR) 6 is formed on the mold material 12 by spin coating or the like. On the coated photosensitive resin (CR) 6, a water repellent material 15 is formed by laminating a dry film or the like. Then, the coated photosensitive resin (CR) 6 is patterned by exposure and development using ultraviolet rays, deep UV light, or the like to form the ink discharge ports 4.

  Next, as shown in FIG. 4E, the surface and side surfaces of the substrate 1 on which the mold material 12 and the coated photosensitive resin (CR) 6 are formed are covered with a protective material 16. The protective material 16 is applied by spin coating or the like.

The SiO ₂ film 18 on the back surface side of the substrate 1 has an exposed Si surface (surface to be etched) as a wet etching start surface using the resin layer 14 as a mask. Next, the ink supply port 10 is formed in the substrate 1. The ink supply port 10 is formed by subjecting the substrate 1 to chemical etching, for example, anisotropic etching with a strong alkaline solution such as TMAH.

  When anisotropic etching is performed from the back side of the substrate 1, the etched portion reaches the sacrificial layer 17 on the front side of the substrate 1, and the ink supply port 10 is formed as shown in FIG.

  Subsequently, the thermoplastic resin layer 14 and the protective material 16 on the back side of the substrate 1 are removed. Further, the mold material 12 is eluted from the ink discharge port 4 and the ink supply port 10 to form an ink flow path and a foaming chamber.

  The substrate 1 on which the nozzle portion is formed by the above steps is cut and separated into chips by a dicing saw or the like, and electrical connection of wiring for driving the ejection energy generating element 11 is performed. Thereafter, when a chip tank member for supplying ink is connected, the ink jet recording head is completed.

  As the silicon substrate 1 of the ink jet recording head, a silicon substrate having a <100> plane of crystal orientation on the front and back surfaces is used. One ink supply port 10 is formed in the substrate 1 by anisotropic etching.

Thus, in the conventional manufacturing method, a step of forming a member (thermoplastic resin layer) serving as a mask for forming the ink supply port by anisotropic etching, and an anisotropic etching step using the mask member In this way, an ink supply port is formed (see Patent Document 1).
Japanese Patent Laid-Open No. 9-11479

  When wet etching is used when forming the ink supply port on the silicon substrate of the ink jet recording head, it takes a long time to open the silicon substrate, resulting in low production efficiency. In addition, the concentration of the etching solution may change due to the influence of silicon dissolved during wet etching, and as a result, the etching rate may fluctuate, which may affect the dimensional accuracy of the ink supply port.

  Further, since the portion of the silicon substrate where the ink supply port is formed has low strength, it is preferable to form a beam in the ink supply port in order to improve the strength of this portion.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing an ink jet recording head substrate that enables an ink supply port provided with a beam to be accurately formed in a short time.

In order to achieve the above object, a method for manufacturing an ink jet recording head substrate according to the present invention is a method for manufacturing an ink jet recording head substrate including forming an ink supply port provided with a beam on a silicon substrate,
Forming a sacrificial layer in a portion where the ink supply port is formed on the surface of the silicon substrate;
Forming a surface to be etched in which a silicon surface is exposed at a portion where the ink supply port is formed on the back surface of the silicon substrate;
Forming a first recess by laser processing in a region excluding at least a region for forming the beam in the etched surface;
Performing a first wet etching on the silicon substrate from the surface to be etched using an etchant;
Forming a second recess by laser processing on the etched surface of the silicon substrate etched by the first wet etching;
The ink supply port provided with the beam by performing second wet etching on the silicon substrate using the etching solution until the etched surface penetrates the silicon substrate and reaches the sacrificial layer. Forming the step.

  According to the present invention, the ink supply port provided with the beam can be accurately formed in a short time.

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

  FIG. 1 is a perspective view showing an ink jet recording head according to an embodiment of the present invention in a partially broken state. FIG. 2 is a cross-sectional view taken along the line AA of FIG.

The ink jet recording head of this embodiment has a silicon substrate 1 on which ink discharge energy generating elements 11 are arranged in two rows at a predetermined pitch. In the silicon substrate 1, an ink supply port 10 having a beam 19 formed by a combination of anisotropic etching of silicon using a SiO ₂ film as a mask and laser processing is provided with two ink ejection energy generating elements 11. Arranged between the columns. The beam 19 connects portions separated by the ink supply port 10 of the silicon substrate 1, and improves the strength of the portion of the silicon substrate 1 where the ink supply port 10 is formed. Since the ratio of the beam 19 occupying the ink supply port 10 is small, the beam 19 hardly affects the flow of ink supplied through the ink supply port 10 into the ink flow path 5.

  On the silicon substrate 1, an ink discharge port 4 that opens above each ink discharge energy generating element 11, and an ink flow channel 5 that connects the ink supply port 10 and each ink discharge port 4 by a flow path forming member 6. Is formed. This ink jet recording head is disposed so that the surface on which the ink supply port 10 is formed faces the recording surface of the recording medium. The ink jet recording head ejects ink droplets from the ink ejection port 4 by applying the pressure generated by the ink ejection energy generating element 11 to the ink filled in the ink flow path 5 via the ink supply 10. . The ink droplets ejected from the ink ejection port 4 adhere to the recording medium, thereby recording on the recording medium.

  The ink jet recording head can be mounted on an apparatus such as a printer, a copying machine, a facsimile having a communication system, a word processor having a printer unit, or an industrial recording apparatus combined with various processing apparatuses. By using this ink jet recording head, recording can be performed on various recording media such as paper, thread, fiber, leather, metal, plastic, glass, wood, and ceramic.

  Note that “recording” in the present specification and claims not only gives an image having a meaning such as a character or a figure to a recording medium but also gives an image having no meaning such as a pattern. It also means.

  Embodiments of the present invention will be described below with reference to the drawings. Here, a basic process for producing the ink jet recording head shown in FIG. 1 will be described with reference to FIGS. 3A to 3C. Each of FIGS. 3A (A) to 3C (I) is a cross-sectional view of a portion along line AA in FIG. 3A (B), 3B (F) and (G), and FIG. 3C (H), FIG. (I) shows a cross-sectional view and FIG. (Ii) shows a bottom view. 3B (G) (iii) shows a cross section along the line BB 'in FIG. 3 (i), and FIGS. 3C (H) (iii) show the line CC' in FIG. 3 (i). A cross section along is shown.

As shown in FIG. 3A (A), a plurality of ink discharge energy generating elements (heaters) 11 such as heating resistors are arranged on the silicon substrate 1. The entire back surface of the silicon substrate 1 is covered with a SiO ₂ film 18. A sacrificial layer 17 is provided on the surface of the silicon substrate 1 in order to accurately process the dimensions of the surface of the silicon substrate 1 when the ink supply port 10 is formed in the silicon substrate 1 with an alkaline solution. The sacrificial layer 17 is made of a material whose etching rate by an etching solution used for anisotropic etching for forming the ink supply port 10 in the silicon substrate 1 is faster than the etching rate of the silicon substrate 1. The sacrificial layer 17 is made of, for example, polysilicon or aluminum which is a metal that can be dissolved in an alkaline solution. Furthermore, the sacrificial layer 17 is preferably made of a material mainly composed of aluminum, including any one of aluminum, aluminum silicon, aluminum copper, and aluminum silicon copper.

A protective film 3 that covers the entire surface of the silicon substrate 1 is formed. The protective film 3 is made of, for example, a SiN film or a SiO ₂ film. The protective film 3 covers the surface of the silicon substrate 1, the heater 11 and the sacrificial layer 17.

  3A (A) to 3C (I), the wiring connected to the heater 11 and the semiconductor element for driving the heater are not shown. Further, the silicon substrate 1 has a crystal orientation plane of <100> plane on the front surface and the back surface.

  First, as shown in FIG. 3A (B), a thermoplastic resin layer 13 and a thermoplastic resin layer 14 are respectively applied to the front and back surfaces of the silicon substrate 1 by spin coating or the like, and these thermoplastic resin layers 13 and 14 are applied. Bake and cure. Then, in order to pattern the thermoplastic resin layer 13 on the surface side, a positive resist (not shown) is applied on the thermoplastic resin layer 13 by spin coating or the like, exposed and developed, and the thermoplastic resin layer 13 is dry-etched. The positive resist is peeled off by patterning with the above.

  Next, in order to pattern an opening for forming the ink supply port 10 in the thermoplastic resin layer 14 on the back surface side of the silicon substrate 1, a positive resist (not shown) is spin coated on the thermoplastic resin layer 14 or the like. Apply by. Then, the positive resist is exposed and developed, the thermoplastic resin layer 14 is patterned by dry etching or the like, and the positive resist is peeled off. Note that when the back surface side of the silicon substrate 1 is patterned, the front surface side of the substrate 1 may be covered with a protective material for protection.

  Next, as shown in FIG. 3A (C), a positive resist (ODUR (trade name) manufactured by Tokyo Ohka Kogyo Co., Ltd.), which is a mold material 12 for forming the ink flow path 5, is patterned on the surface side of the substrate 1.

  Next, as shown in FIG. 3A (D), a coated photosensitive resin (CR) 6 forming a flow path forming member is applied to the surface side of the silicon substrate 1 by spin coating or the like. Further, a water repellent material 15 is formed on the coated photosensitive resin 6 by laminating a dry film. Then, the coated photosensitive resin (CR) 6 is patterned by exposure and development using ultraviolet rays, deep UV light, or the like to form the ink discharge ports 4.

  Next, as shown in FIG. 3A (E), the surface and side surfaces of the silicon substrate 1 on which the mold material 12 and the coated photosensitive resin (CR) 6 are formed are covered with a protective material 16. The protective material 16 is applied by spin coating or the like. The protective material 16 prevents the silicon substrate 1 from being damaged by carrying the apparatus when laser processing is performed. The protective material 16 is made of a material that can sufficiently withstand a strong alkaline solution used when anisotropic etching is performed on the substrate 1. Therefore, the protective material 16 prevents the mold material 12, the coated photosensitive resin 6, the water repellent material 15, and the like from being deteriorated by the strong alkaline solution when performing anisotropic etching. In addition, as a material of the protective material 16, for example, a cyclized rubber-based cyclized polyisoprene rubber can be used.

Then, the SiO ₂ film 18 on the back surface side of the silicon substrate 1 is patterned by wet etching using the thermoplastic resin layer 14 as a mask, and the Si surface (surface to be etched) that becomes the starting surface of anisotropic etching of the silicon substrate 1 is formed. Expose.

  Next, as shown in FIG. 3B (F), the first concave portion is formed by laser processing on the Si exposed surface on the back surface side of the silicon substrate 1 except for the region to be the beam 19 formed in the ink supply port 10. 20a is formed. The depth of the first recess 20 a is about 1/3 to 1/2 of the thickness of the silicon substrate 1. For this laser processing, laser light having a wavelength of 300 nm to 400 nm, for example, ultraviolet laser light having a wavelength of 355 nm can be used. Needless to say, the pulse width, output value, number of shots, and the like of the laser light should be adjusted as appropriate in order to obtain optimum processing conditions.

  Next, as shown in FIG. 3B (G), chemical etching, for example, wet etching with a strong alkali solution such as TMAH (tetramethylammonium solution) is performed for a short time on the Si exposed surface on the back side of the silicon substrate 1. Do. Since the Si exposed surface on the back side of the silicon substrate 1 is a <100> crystal orientation plane, the etching proceeds along the <111> plane forming an angle of 54.74 ° with respect to the Si exposed surface.

  Next, as shown in FIG. 3C (H), a second recess 20b is formed on the etching opening surface of the silicon substrate 1 by laser processing. At this time, the laser beam is irradiated obliquely to at least partially remove the back side of the beam 19 (see FIGS. 3C (H) (iii)). Thereafter, when the chemical etching is performed again in the same manner as in the step shown in FIG. 3B (G), the etching opening surface reaches the sacrificial layer 17 and the ink supply port 10 is formed. A beam 19 is formed.

  Subsequently, the thermoplastic resin 14 on the back side of the silicon substrate 1 is removed. Further, the mold material 12 is eluted from the ink supply port 10 and the ink discharge port 4, whereby the ink flow path 5 and the foaming chamber are formed in the coated photosensitive resin 6 (FIG. 3C (I)). The removal of the mold material 12 made of a positive resist may be performed by developing and drying the entire surface with deep UV light, and may be subjected to ultrasonic immersion during development as necessary.

  The silicon substrate 1 on which the nozzle portion is formed by the above steps is cut and separated by a dicing saw or the like into chips. Furthermore, after the electrical connection of the wiring for driving the ink ejection energy generating element 11 is performed, the chip tank member for supplying ink is connected, and the ink jet recording head is completed.

  According to the manufacturing process of the present embodiment, the ink supply port 10 is formed by combining the silicon anisotropic etching process and the laser processing process. Therefore, the formation time of the ink supply port 10 can be shortened compared with the case where the ink supply port 10 is formed using only the silicon anisotropic etching process. Furthermore, since the etching process time is shorter than when only the silicon anisotropic etching process is used, the influence of the etching rate variation due to the change in the concentration of the etchant due to the dissolution of silicon during wet etching. It becomes difficult to receive.

  Furthermore, by forming the ink supply port 10 by combining the silicon anisotropic etching process and the laser processing step, the beam 19 can be easily formed in the ink supply port 10 in the process of forming the ink supply port 10. It is.

  In the present embodiment, an example in which the ink supply port 10 provided with the beam 19 is formed in the silicon substrate 1 in the process of manufacturing the ink jet recording head is shown. However, the beam 19 is attached to the silicon substrate 1 before the ink jet recording head is manufactured. The provided ink supply port 10 may be formed in the silicon substrate 1.

In that case, first, as shown in FIG. 3A (A), the SiO ₂ film 18 on the back surface side of the silicon substrate 1 on which the sacrificial layer 17 is formed is formed on the thermoplastic resin layer as shown in FIG. 3A (E). Patterning is performed by wet etching using 14 as a mask. As a result, the Si surface that is the starting surface for anisotropic etching of the silicon substrate 1 is exposed. Thereafter, by performing the steps described with reference to FIGS. 3B (F) to 3C (H), the silicon substrate 1 having the ink supply port 10 provided with the beam 19 and serving as an inkjet recording head substrate is manufactured. be able to.

  By separately preparing a flow path forming member 6 in which the ink flow path 5 and the ink discharge port 4 are formed, the flow path forming member 6 is bonded onto the ink jet recording head substrate manufactured as described above. The ink jet recording head having the configuration shown in FIG. 1 can be manufactured.

1 is a perspective view showing an ink jet recording head according to an embodiment of the present invention in a partially broken state. It is sectional drawing along the AA line of FIG. It is a figure which shows the basic process of producing the inkjet recording head shown in FIG. It is a figure which shows the basic process of producing the inkjet recording head shown in FIG. It is a figure which shows the basic process of producing the inkjet recording head shown in FIG. It is the cross-sectional schematic diagram which showed the basic manufacturing process of the conventional inkjet recording head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Silicon substrate 4 Ink discharge port 5 Ink flow path 6 Flow path formation member (coating photosensitive resin)
10 Ink supply light 11 Ink discharge energy generating element 12 Mold material 17 Sacrificial layer 19 Beam

Claims (10)

An ink jet recording head substrate manufacturing method comprising forming an ink supply port with a beam on a silicon substrate,
Forming a sacrificial layer in a portion where the ink supply port is formed on the surface of the silicon substrate;
Forming a surface to be etched in which a silicon surface is exposed at a portion where the ink supply port is formed on the back surface of the silicon substrate;
Forming a first recess by laser processing in a region excluding at least a region for forming the beam in the etched surface;
Performing a first wet etching on the silicon substrate from the surface to be etched using an etchant;
Forming a second recess by laser processing on the etched surface of the silicon substrate etched by the first wet etching;
The ink supply port provided with the beam by performing second wet etching on the silicon substrate using the etching solution until the etched surface penetrates the silicon substrate and reaches the sacrificial layer. Forming a step;
A method for manufacturing an ink jet recording head substrate comprising:   The step of forming the second recess includes irradiating a laser beam obliquely with respect to the surface to be etched of the silicon substrate and removing at least a part of the back side portion of the region where the beam is to be formed. A method for manufacturing an ink jet recording head substrate according to claim 1.   The method for manufacturing a substrate for an ink jet recording head according to claim 1, wherein the sacrificial layer is made of a metal that can be dissolved by the etching solution.   The method of manufacturing a substrate for an ink jet recording head according to claim 3, wherein the metal is made of a material mainly composed of aluminum.   The method for manufacturing a substrate for an inkjet recording head according to claim 4, wherein the material containing aluminum as a main component includes any one of aluminum, aluminum silicon, and aluminum copper.   The method for manufacturing a substrate for an ink jet recording head according to any one of claims 1 to 5, wherein a front surface and a back surface of the silicon substrate are <100> planes.   The method for producing a substrate for an ink jet recording head according to any one of claims 1 to 6, wherein the wavelength of the laser light is 300 nm or more and 400 or less nm.   The method for manufacturing a substrate for an inkjet recording head according to claim 1, wherein the etching solution is a tetramethylammonium solution. A silicon substrate having a plurality of ejection energy generating elements that generate energy for ejecting ink droplets, and an ink supply port including a beam that includes a through-hole extending along an arrangement direction of the ejection energy generating elements;
A plurality of ink discharge ports provided on the silicon substrate and corresponding to the plurality of discharge energy generating elements, and a plurality of ink discharge ports including the discharge energy generating elements and communicating the ink supply ports and the ink discharge ports. A flow path forming member for forming the ink flow path,
In the manufacturing method of the inkjet recording head having
Forming a sacrificial layer in a portion where the ink supply port is formed on a surface of the silicon substrate where the ejection energy generating element is formed;
Forming a mold that occupies a portion to be the ink flow path on the silicon substrate;
Forming a flow path forming member having the discharge port on the substrate and the mold material;
Forming a surface to be etched in which a silicon surface is exposed in a portion where the ink supply port is formed on a surface opposite to the surface of the silicon substrate;
Forming a first concave portion by laser processing in a region excluding at least the region where the beam is formed in the etched surface;
Performing a first wet etching on the silicon substrate from the surface to be etched using an etchant;
Forming a second recess by laser processing on the etched surface of the silicon substrate etched by the first wet etching;
The ink supply port provided with the beam by performing second wet etching on the silicon substrate using the etching solution until the etched surface penetrates the silicon substrate and reaches the sacrificial layer. Forming a step;
Removing the mold material;
A method of manufacturing an ink jet recording head, comprising:   The step of forming the second recess includes irradiating a laser beam obliquely with respect to the surface to be etched of the silicon substrate and removing at least a part of the back side portion of the region where the beam is to be formed. A method for manufacturing an ink jet recording head according to claim 9.

Images