JP2005153124A - Method for manufacturing micro structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a micro structure having a plurality of cone shapes by using a powder blast process. <P>SOLUTION: The method for manufacturing the micro structure by the powder blast process is characterized in that mask material is formed of a polyurethane resin composition containing a metal particle dispersion liquid on a surface of material to be processed, a fine pattern comprised of recessed portions in accordance with a lattice-shaped fine pattern and a plurality of isolated island portions other than the concave portions is formed by irradiating laser beam to at least a part of the mask material in accordance with the lattice-shaped fine pattern, powder blasting is carried out in a condition that peripheries of the respective island portions are worn out with only almost central parts left, and the respective island portions are removed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a microstructure, and more particularly to a method for manufacturing a microstructure using a powder blast method.

  In recent years, in the manufacture of micromachine parts, microsensors, and the like, high-precision microfabrication techniques for substrates made of materials such as silicon, glass, and ceramics have been required. The powder blasting method is a method in which fine abrasive grains are ejected from a nozzle to a work material provided with a mask material and mechanically processed by high-speed and high-density collision. It has the feature of showing excellent processability with little occurrence. For this reason, it is expected as a technique for producing a micro structure on the order of several tens of micrometers including a rapid prototyping technique for a glass chip necessary for designing and prototyping a micro analysis chip. Patent Document 1 discloses a method for forming micropores in a slide glass for DNA analysis using a powder blasting method.

However, in the manufacturing method of the microstructure using the conventional powder blasting method, especially when the mask material has excellent wear resistance, the processing region is limited to the pattern of the mask material. Even if the microstructure such as the hole can be precisely processed, there is a problem that it is impossible to produce a microstructure having a conical shape or a stepped shape useful as a microneedle. Although it is possible to produce the shape by performing powder blasting a plurality of times using a plurality of different mask materials, there has been a problem that the cost is remarkably increased due to an increase in the number of mask materials and man-hours.
Japanese Patent Laid-Open No. 2003-266311

  The present invention has been made to solve such problems, and an object of the present invention is to provide a method for manufacturing a microstructure having a plurality of conical shapes using a powder blast method.

  The invention according to claim 1 of the present invention is a method of manufacturing a microstructure by a powder blasting method, wherein a mask material made of a polyurethane resin composition containing a metal fine particle dispersion is formed on a surface of a workpiece, and at least of the mask material By irradiating laser light to a part according to a lattice-like fine pattern, a fine pattern composed of a recess according to the lattice-like fine pattern and a plurality of isolated island-like portions other than the recess is formed, and each island-like portion The method for producing a microstructure is characterized in that powder blasting is performed under the condition that the peripheral part is worn away except for the substantially central part of the above, and the island-like parts are removed.

  The invention according to claim 2 is the method for producing a microstructure according to claim 1, wherein the metal fine particle dispersion is a gold fine particle dispersion.

  According to the invention described in each claim of the present application, a microstructure having a plurality of conical shapes can be easily manufactured by using the powder blast method.

  In the method for manufacturing a microstructure of the present invention, first, as shown in FIG. 2, a mask made of a polyurethane resin composition containing a metal fine particle dispersion on the surface of a workpiece 21 made of glass, silicon, ceramics or the like. The material 2 is formed.

  The metal fine particle dispersion is a dispersion of metal fine particles such as gold, silver, platinum, palladium or the like having a particle size of 100 nm or less in a solvent. By dispersing the metal fine particle dispersion in a matrix, the kind of metal The absorption by the plasmon resonance vibration corresponding to is shown.

  The metal fine particle dispersion is prepared by a gas evaporation method disclosed in Japanese Patent No. 2561537, a reduction precipitation method from a metal salt disclosed in Japanese Patent Application Laid-Open No. 11-319538, and the like. These metal fine particle dispersions can also increase the dispersion stability by using a dispersant such as an alkylamine, a carboxylic acid amide, and an aminocarboxylate as disclosed in JP-A No. 2002-121606. As the metal type, gold fine particles exhibiting absorption corresponding to the wavelength of a low-power green laser are most preferable.

  The polyurethane resin composition is produced by a polyaddition reaction of a polyol and an isocyanate. Examples of the polyol include acrylic, polyester, polyether, and fluorine.

  The acrylic polyol is, for example, a (meth) acrylic monomer having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate or 4-hydroxybutyl (meth) acrylate, and a carboxyl group such as (meth) acrylic acid. (Meth) acrylic monomers having an ester group such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, lauryl (meth) acrylate It is obtained by copolymerizing a (meth) acrylic monomer having

  The polyester-based polyol includes, for example, one or more dicarboxylic acids selected from the group consisting of adipic acid, hexamethylene dicarboxylic acid, isophthalic acid, and orthophthalic acid, 1,6-hexanediol, ethylene glycol, propylene glycol, In addition, the main chain includes a polyester unit formed from one or two or more diols selected from the group consisting of tetramethylene glycol and caprolactone diol, and those having hydroxyl groups at least at both ends of the main chain can be used.

  As the type of isocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, m-phenylene diisocyanate, xylylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, 1,4 -Cyclohexylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-dichloro -4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, isophorone diisocyanate, etc. are used. But the present invention is not particularly limited.

  A paste is prepared by mixing the metal fine particle dispersion, polyol, and isocyanate in a solvent such as toluene or p-xylene. The compounding amount of the metal fine particle dispersion is not particularly limited, but is preferably 5 wt% to 20 wt% in consideration of uniform dispersion in the polyurethane matrix. This paste is applied onto a workpiece using a spin coater, an applicator, or the like, and after application, is heated and dried to form a mask material on the workpiece. The film thickness of the mask material is preferably about 30 μm to 100 μm.

  In the polyurethane resin composition, the metal fine particles exhibit absorption due to plasmon resonance vibration specific to the type of metal, for example, in the case of gold fine particles, absorption having a maximum in the vicinity of 530 nm. If the green laser beam having a wavelength of 532 nm is condensed and irradiated from the side of the substrate according to a predetermined lattice-shaped fine pattern, the light energy absorbed by the gold fine particles is converted into thermal energy, and a recess is formed in the mask material 2 according to the lattice-shaped fine pattern. The

  Here, for example, the lattice-shaped fine pattern shown in FIG. 3 is used. By condensing and irradiating laser light according to a grid pattern having a width g, a recess having a width g and a plurality of isolated islands having a width w are formed. Here, the width g is set to 30 μm to 100 μm, and the width w is set to 300 μm to 1 mm. As will be described later, these values are finally related to the material and film thickness of the mask material and the blasting conditions. Is set.

  For example, an apparatus shown in FIG. 4 is used for producing a fine pattern on a mask material. As the laser light source 11, a green laser having an output of about several tens milliwatts, for example, a wavelength of 532 nm is preferably used. The laser beam 12 is guided through the plurality of mirrors 13 and the half mirror 14 into the optical microscope 15 on which the mask material 2 is placed. The surface of the mask material 2 on the substrate 1 placed on an XYZ stage 16 that can be moved in a three-dimensional direction by driving a motor is a TV monitor 19 through an objective lens 17 and a CCD camera 18 directly above, or an eyepiece (not shown). Observed with the naked eye. After confirming the state of the surface of the mask material 2 with the laser beam 12 blocked, the laser beam 12 is introduced into the mask material 2. The laser beam 12 is narrowed down to about 1 μm on the mask material 2 by the objective lens 17. While observing the surface of the mask material 2 on the TV monitor 19, the XYZ stage 16 is driven in the XY direction according to a predetermined fine lattice pattern, and a concave portion and an island-like portion according to the fine lattice pattern are formed on the mask material 2. Is done.

Following the formation of the lattice-like fine pattern on the mask material 2, a micro structure is manufactured on the workpiece by powder blasting. FIG. 5 shows a schematic diagram of the manufacturing process of the microstructure. As shown to Fig.5 (a), from the nozzle 24 with a diameter of 5-10 mm of a powder blast apparatus toward the mask material 2 which consists of the to-be-processed material 21, the recessed part 22 formed in the surface, and the island-shaped part 23, The blast material 25 is ejected at a blast pressure of 0.5 to 5 kg / cm ² by the action of a carrier gas such as compressed air.

  As the blast material 25, a fine powder having a diameter of 5 μm to 20 μm, such as silica, alumina, zirconia, or silicon carbide, is preferably used. While the blast material 25 is ejected from the fixed nozzle 24, the stage on which the work material 21 is placed is scanned in one direction, and the blast material 25 is projected on the entire surface of the fine lattice pattern.

  As shown in FIG. 5 (b), by the action of the blast material 25, the work material 21 directly under the concave portion 22 is blasted, and each island-like portion 23 is left with only its substantially central portion worn away. Then, the workpiece 21 immediately below the periphery of each worn island portion 23 is blasted. Here, since there is a difference in the action of the blast material 25 between the workpiece 21 immediately below the recess 22 and the workpiece 21 directly below the periphery of each island-shaped portion 23, depending on the degree of the difference. Thus, the degree of blasting for the workpiece 21 is different, and as a result, the conical microstructure 26 is produced.

  In order to produce a desired conical microstructure 26, the material and film thickness of the mask material 2, the width g of the recess 22, the width w of the island 23, the material and particle size of the blast material 25, the blast pressure, The optimum condition is determined by adjusting at least one of the conditions of the number of scans.

  After the blasting process, the remaining island-like portion 23 is removed, whereby the conical microstructure 26 shown in FIG. 5C is obtained. The remaining island-like portion 23 is removed by applying a tape to the surface and peeling it off. Alternatively, the workpiece 21 may be immersed in a solvent in which the mask material 2 is dissolved.

  An acrylic polyol / isocyanate dissolved in toluene (Acridic manufactured by Dainippon Ink & Chemicals, Inc.) and a fine gold particle dispersion (vacuum metallurgy Perfect) with a concentration of about 20 wt% so that the concentration with respect to polyol / isocyanate is 17 wt%. Gold) was mixed to prepare a paste.

  The paste was spread on a glass substrate as a workpiece using an applicator, heated at 80 ° C. for 30 minutes and dried to form a mask material having a thickness of 50 μm.

  Subsequently, a concave portion and an island-shaped portion were formed on the mask material by condensing and irradiating the mask material with green laser light having an output of 23 mW according to a fine lattice pattern having a width g of 60 μm and a width w of 500 μm.

  The glass substrate together with the mask material is set in a powder blasting device (micro blasting device MB1 type manufactured by Shinto Blator Co., Ltd.), and silicon carbide having a diameter of 20 μm is used as the blasting material, and the number of projections is 43 times (Example 1) and 45 times (Example 1). Powder blasting was performed in Example 2). After powder blasting, the mask material was removed by attaching a tape to the surface of the mask material and peeling it off. Scanning electron microscope (SEM) photographs of the conical microstructures of each example are shown in FIGS. Due to the difference in the number of times of powder blasting, the degree of wear around the mask material was different, resulting in different cone-shaped microstructures.

It is a SEM photograph of each conical microstructure of (a) Example 1 and (b) Example 2. It is a side view of a workpiece and a mask material. It is a top view of the lattice-like fine pattern formed in a mask material. It is the schematic of the optical system for forming a lattice-shaped fine pattern in a mask material. (A)-(c) is the schematic of the manufacturing process of a conical microstructure.

Explanation of symbols

2 Mask material 21 Work material 22 Recess 23 Island-like portion 24 Nozzle 25 Blast material 26 Micro structure

Claims (2)

In the manufacturing method of the microstructure by the powder blast method,
A mask material made of a polyurethane resin composition containing a metal fine particle dispersion is formed on the surface of the workpiece,
By irradiating at least a part of the mask material with laser light according to a lattice-like fine pattern, a fine pattern composed of a concave portion according to the lattice-like fine pattern and a plurality of isolated island-like portions other than the concave portion is formed,
Powder blasting under the condition that the peripheral part is worn away leaving only the substantially central part of each island-shaped part,
A method for manufacturing a microstructure, wherein each of the islands is removed. The method for producing a microstructure according to claim 1, wherein the metal fine particle dispersion is a gold fine particle dispersion.

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