JP2007326341A - Manufacturing method for inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate a process for flattening grooves occurring on ink channel walls, when the ink channel walls are formed using an inorganic material. <P>SOLUTION: The manufacturing method for an inkjet recording head includes a process for forming a first mold material 16 which occupies the portion becoming a plurality of ink channels, on an Si substrate 11 provided with a plurality of heat generating elements 18. Furthermore, the method includes a process for forming the ink channel walls 34 for partitioning a plurality of ink channels from each other between the first mold material 16 on the Si substrate 11 and a process for forming the second mold material 36 which occupies the portion becoming the ejection ports communicating with the ink channels on the first mold material 16. The method also includes a process for forming an orifice plate 40 forming the ejection ports on the ink channel walls 34 and the first mold material 16 and a process for removing the first and the second mold materials 15, 36. The process for forming the ink channel walls 34 includes applying gold plating on the ink channel walls 34. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an ink jet recording head that performs recording by discharging ink.

  The ink jet recording method disclosed in Patent Document 1 or Patent Document 2 is capable of high-speed, high-density, high-precision, high-quality recording, and is suitable for colorization and compactness. A recording head using this ink jet recording system uses thermal energy to foam ink and discharge the ink onto a recording medium. In this recording head, a heating resistor for foaming ink and a wiring for electrical connection to the heating resistor are produced on the same substrate to form an ink jet recording head substrate, and ink is further ejected onto the substrate. A configuration in which a nozzle is formed is common.

  On the other hand, various methods have been proposed for the formation method and material of this nozzle. A typical one is a method in which an ink path, a discharge port, and a supply port are formed in advance by a resin mold and directly attached to the substrate. is there. The other is a method of forming an ink path, an ink path wall, and a discharge port by photolithography using a resin on the substrate so as to form a through hole in the substrate to be a supply port and communicate with the supply port. . The latter is the most common method at present, because it allows for a higher density of outlets than the former.

However, the method of forming by photolithography using a resin is simple in production, but causes the following reliability problem.
1. Since the linear expansion coefficients of the resin and the substrate, that is, the inorganic material are different, they are easily peeled off at the interface.
2. As the resin absorbs moisture and swells, the dimensional accuracy deteriorates.

  In order to overcome the above problems, a device for changing the resin material to an inorganic material has been made.

There is a method of forming an ink path, an ink path wall, and an ejection port by chemical vapor deposition (hereinafter abbreviated as “CVD”). That is, in order to form a plurality of ink paths, a plurality of mold materials that can be dissolved are formed on the substrate, and then ink path walls and orifice plates are formed of an inorganic material by a CVD method. Thereafter, an ejection port is formed in the orifice plate, and the mold material is dissolved and removed to complete the ink path.
U.S. Pat. No. 4,723,129 U.S. Pat. No. 4,740,796

  However, the CVD method has the following problems due to its properties. That is, since the film formed by the CVD method grows along the step between the substrate and the mold material, a groove is formed in a region that becomes each ink path wall separating the plurality of ink paths. The groove becomes deeper as the mold material is thicker, and ink adheres to the groove when ejecting ink or cleaning the ejection port of the head, which adversely affects ink ejection.

  The problem of growth along the step is also a problem in a semiconductor process in which the CVD method is generally used. That is, when an insulating film is formed by CVD after forming an Al wiring, the insulating film is formed along the wiring and between the wirings. It becomes lower than the height, and a groove is formed between the two. The groove becomes narrower and deeper as the insulating film becomes thicker. For this reason, in a multilayer wiring process employing an Al multilayer film, once the insulating film is formed to a certain thickness, the surface is ground and flattened by polishing, and the insulating film is grown again. A method of reducing the groove, that is, the step is generally used.

  However, in the case of the ink jet recording head, unlike the Al wiring having a thickness of about 0.5 μm used for the semiconductor multilayer wiring, the height of the mold material is about 5 μm to 20 μm, so that the groove becomes deep. Therefore, much trouble is required for polishing the groove, that is, the insulating film for reducing the level difference.

  Accordingly, the present invention provides a method for manufacturing a substrate for an ink jet recording head, which makes it possible to eliminate the step of flattening the grooves generated in the ink path wall when forming the ink path wall using an inorganic material. For the purpose.

  In order to achieve the above object, the method of manufacturing an ink jet recording head according to the present invention occupies a portion serving as a plurality of ink paths on a substrate provided with a plurality of ink ejection energy generating elements that generate energy for ejecting ink. Forming a first mold material, forming an ink path wall for partitioning the plurality of ink paths between the first mold materials on the substrate, and on the first mold material Forming a second mold material that occupies a portion serving as an ejection port communicating with the ink path, and forming an orifice plate that forms the ejection port on the ink path wall and the first mold material. And a step of removing the first mold material and the second mold material, wherein the step of forming the ink path wall includes the step of forming the ink path wall. The characterized in that it consists of forming the gold plating.

  According to the present invention, it is possible to eliminate the step of flattening the grooves generated in the ink path wall when the ink path wall is formed using the inorganic material.

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

  FIG. 1 is a schematic perspective view showing a main part of an ink jet recording head according to an embodiment of the present invention. FIG. 2 is a schematic side sectional view of the ink jet recording head of FIG. 1 cut along the line XX.

  As shown in FIG. 1 and FIG. 2, the ink jet recording head of this embodiment is formed with heating resistors 18 as ink ejection energy generating elements that generate energy for ejecting ink arranged in two rows at a predetermined pitch. The Si substrate 11 is provided. In the Si substrate 11, a supply port 12 is opened between two rows of heating resistors 18. The nozzle forming member provided on the Si substrate 11 is formed with an ejection port 14 that opens above each heating resistor 18 and an ink path 15 that communicates from the supply port 12 to each ejection port 14. This ink jet recording head records ink by ejecting ink droplets 24 from the ejection ports 14 by applying pressure generated by the heating resistor 18 to the ink filled in the ink path 15 via the supply ports 12. I do.

  A method of manufacturing the ink jet recording head configured as described above will be described with reference to FIGS.

  First, as shown in FIG. 3A, the heating resistor 18 is formed on the Si substrate 11 with the <100> face exposed, and a thermal oxidation method, a sputtering method, a CVD method is formed on the uppermost layer of the Si substrate 11. A protective film and an anti-cavitation film (not shown) are formed by a method or the like. Thereafter, a first mold member 16 that can be eluted by a solvent is formed to a thickness of about 15 μm by sputtering using Al as a material.

  Next, as shown in FIG. 3B, a resist is formed (not shown) on the first mold material 16 by photolithography, and the first mold material 16 is wet using phosphoric acid using the resist as a mask. It is formed into a predetermined shape by an etching method, and then the resist is removed.

  Next, as shown in FIG. 3C, an adhesion improving layer 31 is formed on the Si substrate 11 and the first mold material 16 to a thickness of about 100 nm by sputtering using TiW as a material.

  Next, as shown in FIG. 4D, a gold plating base layer 32 described later is formed to a thickness of about 100 nm by sputtering using Au as a material.

  Next, as shown in FIGS. 4E and 4F, a resist 33 for plating formation is formed into a predetermined shape by photolithography. Then, using this as a mask for electroplating, a gold plating is formed to a thickness of 15 μm using a plating solution using gold sulfite to form the ink path wall 34.

  Next, as shown in FIG. 5G, the resist 33 is removed, and a part of the base layer 32 (the part above the first mold member 16) is removed using a mixed solution of iodine and potassium iodide. To do.

  Next, as shown in FIG. 5H, a resist 35 is formed in a predetermined shape by a photolithography method, and using the resist 35 as a mask, the adhesion improving layer 31 is predetermined by a wet etching method using hydrogen peroxide water. Form into shape.

  Next, after removing the resist 35 as shown in FIG. 5 (I), as shown in FIG. 6 (J), a second mold material 36 for forming the discharge ports 14 is formed by sputtering using Al as a material. It is formed to a thickness of 10 μm.

  Next, as shown in FIG. 6K, a resist (not shown) is formed by photolithography, and the second mold material 36 is formed into a predetermined shape by wet etching using phosphoric acid using the resist as a mask. Form.

  Next, as shown in FIG. 6L, an adhesion improving layer 37 made of TiW and an underlayer 38 made of Au are formed to a thickness of about 100 nm by sputtering.

  Next, as shown in FIGS. 7M and 7N, a resist 39 for plating is formed in a predetermined shape above the second mold member 36 by photolithography. Then, using this as a mask for electroplating, a gold plating is formed to a thickness of 10 μm using a plating solution using gold sulfite to constitute the orifice plate 40.

  Next, as shown in FIG. 7O, the resist 39 is removed, and a part of the base layer 38 (the part above the second mold member 36) is removed using a mixed solution of iodine and potassium iodide. To do.

  Next, as shown in FIG. 8 (P), a part of the adhesion improving layer 37 made of TiW is removed by a wet etching method using hydrogen peroxide solution, and the second mold member 36 for forming the discharge port is removed. Expose.

  Next, as shown in FIG. 8 (Q), the first mold material 16 that forms the ink path and the second mold material 36 that forms the ejection port 14 are eluted by a wet etching method using phosphoric acid. The ejection port 14 and the ink path 15 were formed.

Next, as shown in FIG. 9 (R) showing a cross section taken along line YY of FIG. 1, a resist 23 is formed in a predetermined shape on the back side of the Si substrate 11 by photolithography. Further, the silicon oxide 22 formed on the back surface side of the Si substrate 11 is etched by a dry etching method using CF ₄ to form a mask 25 for etching the supply port 12.

  Finally, as shown in FIG. 9S, wet etching is performed on the Si substrate 11 through the opening of the mask 25 using TMAH (tetramethylammonium hydroxide) as an etching solution. The Si substrate 11 is etched along the <111> plane, and the supply port 12 penetrates to the surface side. Finally, when the resist 23 is removed, the ink jet recording head is completed.

  As described above, according to the present embodiment, the ink path wall 34 is formed by gold plating instead of the CVD method. In the gold plating step, no groove is formed on the ink passage wall 34 as in the case of the CVD method, and therefore, the step of flattening the groove can be eliminated.

  Furthermore, the ink path wall 34 and the orifice plate 40 can be integrally formed by similarly forming the orifice plate 40 by gold plating.

FIG. 2 is a schematic perspective view showing a main part of an ink jet recording head according to an embodiment of the present invention. FIG. 2 is a schematic side cross-sectional view of the ink jet recording head of FIG. 1 cut along line XX. It is a figure which shows the manufacturing method of the inkjet recording head which concerns on one Embodiment of this invention. It is a figure which shows the manufacturing method of the inkjet recording head which concerns on one Embodiment of this invention. It is a figure which shows the manufacturing method of the inkjet recording head which concerns on one Embodiment of this invention. It is a figure which shows the manufacturing method of the inkjet recording head which concerns on one Embodiment of this invention. It is a figure which shows the manufacturing method of the inkjet recording head which concerns on one Embodiment of this invention. It is a figure which shows the manufacturing method of the inkjet recording head which concerns on one Embodiment of this invention. It is a figure which shows the manufacturing method of the inkjet recording head which concerns on one Embodiment of this invention.

Explanation of symbols

11 Si substrate 14 Discharge port 15 Ink path 16 First mold material 34 Ink path wall 36 Second mold material 40 Orifice plate

Claims (3)

Forming a first mold material that occupies a portion serving as a plurality of ink paths on a substrate provided with a plurality of ink ejection energy generating elements that generate energy for ejecting ink;
Forming an ink path wall that partitions the plurality of ink paths between the first mold members on the substrate;
Forming on the first mold material a second mold material that occupies a portion that becomes an ejection port communicating with the ink path;
Forming an orifice plate for forming the discharge port on the ink path wall and the first mold material;
Removing the first mold material and the second mold material;
In the manufacturing method of the inkjet recording head having
The method of manufacturing an ink jet recording head, wherein the step of forming the ink path wall includes forming the ink path wall by gold plating.   2. The method of manufacturing an ink jet recording head according to claim 1, wherein the step of forming the orifice plate includes forming the orifice plate integrally with the ink path wall by gold plating.   The method for manufacturing an ink jet recording head according to claim 1, comprising forming the first mold material and the second mold material with aluminum.

Images