Method for manufacturing an article having a plurality of through holes

Abstract

To provide a production method of an article having multiple open holes, in which the wall surface of an open hole is a mirror surface in the vertical direction, and even a thick article of several hundred μm or more can be produced.SOLUTION: A production method of an article 1 having multiple open holes comprises: a substrate forming step for forming a substrate 10 having multiple columnar protrusions 12; a photochromic layer forming step for forming a photochromic layer 20 whose special property is changed by a light irradiation having a specific wavelength region onto a surface having the columnar protrusion 12 of the substrate 10; a light irradiation step for changing the special property of the photochromic layer 20 at a position corresponding to the apex portion by irradiating a light beam to the inside of the columnar protrusion 12 from the opposite surface to the columnar protrusion 12 of the substrate 10, completely reflecting the light on the side surface of the columnar protrusion 12, and letting the light reach the apex portion of the columnar protrusion 12; an electrode layer forming step for forming an electrode layer 50 on the part excluding the apex portion 12a of the columnar protrusion 12; an electroforming step for forming an electroformed product between the columnar protrusions 12 by performing electroforming using the electrode layer 50; and a removal step for removing the substrate 10 out of the electroformed product.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an article having a plurality of through-holes.

Background Art

[0002] To produce a shaped article having a large number of through-holes such as a mesh, there are methods of forming through-holes by etching using a patterned resist or using electroforming.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the method using etching, since etching progresses faster in the portion closer to the surface, the diameter of the through-hole becomes larger in the portion closer to the surface, and it is difficult to form a cylindrical through-hole. Therefore, it is difficult to form a through-hole with a depth of several hundred μm or more. In addition, since the etched surface finishes as a rough surface, the wall surface of the through-hole does not become a mirror surface. In the method using electroforming, it is difficult to make the thickness of the resist several hundred μm or more or to pattern it, and similar to etching, patterning of the resist cannot be performed uniformly in the depth direction, and the rising surface cannot be made a vertical mirror surface.

[0005] An object of the present invention is to provide a method for manufacturing an article having a plurality of through-holes capable of making the wall surface of the through-hole a vertical mirror surface and also capable of manufacturing an article with a thickness of several hundred μm or more.

Means for Solving the Problems

[0006] The present invention solves the above problems by the following solution means. For ease of understanding, the description will be given with reference numerals corresponding to the embodiments of the present invention, but it is not limited thereto.

[0007] The first invention includes a substrate forming step of forming a substrate (10) having a plurality of columnar protrusions (12), a photochromic layer forming step of forming a photochromic layer (20) whose properties change by irradiation with light in a specific wavelength region on the surface of the substrate (10) having the columnar protrusions (12), an irradiation step of irradiating light from the surface of the substrate (10) opposite to the columnar protrusions (12) into the inside of the columnar protrusions (12), totally reflecting the light on the side surfaces (12b) of the columnar protrusions (12), and causing the light to reach the top portions (12a) of the columnar protrusions (12) to change the properties of the photochromic layer (20) at positions corresponding to the top portions (12a), an electrode layer forming step of forming electrode layers (50, 60) on portions of the columnar protrusions (12) excluding the top portions (12a), an electroforming step of performing electroforming using the electrode layers (50, 60) to form an electroformed product between the columnar protrusions (12), and a removing step of removing the substrate (10) from the electroformed product, and is a method for manufacturing an article (1) having a plurality of through holes (1a).

[0008] The second invention is a method for manufacturing an article (1) having a plurality of through-holes (1a) described in the first invention. In this method, the photochromic layer (20) is formed of a material whose properties change from hydrophilic to hydrophobic upon irradiation with light in a specific wavelength region. By the light irradiation step, the side surface (12b) and the bottom surface (12c) of the columnar protrusion (12) maintain hydrophilicity, and the top surface (12a) of the columnar protrusion (12) is changed to hydrophobicity. Between the light irradiation step and the electrode layer forming step, a catalytic material for electroless plating is applied to the photochromic layer (20), and an electroless plating catalyst layer (40) is formed on the photochromic layer (20) that maintains hydrophilicity. In the electrode layer forming step, an electroless plating layer is formed as the electrode layer (50) by performing an electroless plating treatment on the electroless plating catalyst layer (40). This is a method for manufacturing an article (1) having a plurality of through-holes (1a).

[0009] The third invention is a method for manufacturing an article (1) having a plurality of through-holes (1a) described in the first invention. In this method, the photochromic layer (20) is formed of a material whose state changes from a state where metal deposition is possible to a state where metal deposition is impossible upon irradiation with light in a specific wavelength region. By the light irradiation step, the side surface (12b) and the bottom surface (12c) of the columnar protrusion (12) maintain a state where metal deposition is possible, and the top surface (12a) of the columnar protrusion (12) is changed to a state where metal deposition is impossible. In the electrode layer forming step, a metal to be the electrode layer (50, 60) is deposited on the side of the columnar protrusion (12) to form the electrode layer (60) on the side surface (12b) and the bottom surface (12c) of the columnar protrusion (12). This is a method for manufacturing an article (1) having a plurality of through-holes (1a).

[0010] The fourth invention is a method for manufacturing an article (1) having a plurality of through-holes (1a) described in any one of the first to third inventions, characterized in that it includes a low refractive index layer forming step of forming a low refractive index layer having a lower refractive index than the columnar convex portion (12) between the columnar convex portion (12) and the photochromic layer (20). It is a method for manufacturing an article (1) having a plurality of through-holes (1a).

[0011] The fifth invention is a method for manufacturing an article (1) having a plurality of through-holes (1a) described in any one of the first to fourth inventions, characterized in that it includes an initial irradiation step of irradiating the entire photochromic layer (20) with light in a wavelength region different from the light irradiation in the specific wavelength region before the light irradiation step. It is a method for manufacturing an article (1) having a plurality of through-holes (1a).

[0012] The sixth invention is a method for manufacturing an article (1) having a plurality of through-holes (1a) described in any one of the first to fifth inventions, characterized in that it includes a light shielding layer forming step of forming a light shielding layer (30) that partially shields the light irradiated in the light irradiation step on the surface of the base material (10) opposite to the columnar convex portion (12) before the light irradiation step. It is a method for manufacturing an article (1) having a plurality of through-holes (1a).

Advantages of the Invention

[0013] According to the present invention, it is possible to provide a method for manufacturing an article having a plurality of through-holes, in which the wall surface of the through-hole can be made into a perpendicular mirror surface, and an article with a thickness of several hundred μm or more can also be produced.

Brief Description of the Drawings

[0014]

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Mode for Carrying Out the Invention

[0015] Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings and the like.

[0016] (First Embodiment) FIG. 1 is a perspective view showing an article 1 having a plurality of through holes manufactured by a method for manufacturing an article having a plurality of through holes according to the present invention. Note that each of the drawings shown below, including FIG. 1, is a schematic diagram, and the size and shape of each part are exaggerated or omitted as appropriate for easy understanding. In the following description, specific numerical values, shapes, materials, etc. are shown for explanation, but these can be changed as appropriate. In this specification, with regard to terms specifying shapes and geometric conditions, such as terms like parallel and orthogonal, in addition to their strict meanings, states having errors to the extent that they can perform similar functions and can be regarded as parallel or orthogonal are also included.

[0017] In this embodiment, an example of manufacturing a plate-shaped article 1 having a plurality of through-holes 1a as shown in FIG. 1 will be described. Here, an example where the through-hole 1a is a quadrangular prism-shaped hole will be described, but the shape of the through-hole 1a may be a cylindrical shape or another polygonal shape. In this embodiment, the material of the article 1 is copper, but any material may be used as long as it is a material capable of electroforming described later. For example, it may be aluminum, magnesium, molybdenum, titanium, nickel, or the like.

[0018] Next, a method for manufacturing an article having a plurality of through-holes according to this embodiment will be described. First, a base material 10 having a plurality of columnar protrusions 12 is manufactured (base material forming step). FIG. 2 is a view showing a negative mold (resin mold) base material 10 used for manufacturing the article 1 shown in FIG. 1. FIG. 2(a) shows a cross-sectional view orthogonal to the sheet surface of the base material 10, and FIG. 2(b) shows a perspective view. The base material 10 includes a base material sheet 11 and columnar protrusions 12.

[0019] The base material sheet 11 is formed of, for example, a polyester resin such as PET (polyethylene terephthalate) having high light transmittance, an acrylic resin, a styrene resin, an acrylic styrene resin, a PC (polycarbonate) resin, an alicyclic polyolefin resin, a TAC (triacetyl cellulose) resin, or the like. The layer thickness of the base material sheet 11 can be, for example, 50 μm or more and 300 μm or less.

[0020] The columnar protrusions 12 are arranged in a plurality protruding from one surface of the base sheet 11. In the present embodiment, in order to make the shape of the through-hole 1a of the article 1 a quadrangular prism shape, the columnar protrusions 12 have a quadrangular prism shape. In FIG. 2, the arrangement of the columnar protrusions 12 is exemplified as a regularly arranged form at equal intervals, but it may be a random arrangement or may be arranged in a staggered grid pattern, and is not particularly limited. The width of the columnar protrusion 12 can be, for example, 20 μm or more and 1000 μm or less, and the amount of protrusion from the base sheet 11 can be, for example, 50 μm or more and 2000 μm or less. The columnar protrusions 12 are formed of an ultraviolet curable resin such as a urethane acrylate-based, polyester acrylate-based, epoxy acrylate-based, polyether acrylate-based, polythiol-based, butadiene acrylate-based resin with high light transmittance. The columnar protrusions 12 are formed by applying an uncured ultraviolet curable resin to one surface of the base sheet 11 and irradiating with ultraviolet rays in a state of being pressed together with the base sheet 11 against a separately prepared mold. Also, the columnar protrusions 12 may be formed by mask exposure of the ultraviolet curable resin. In the present embodiment, although the ultraviolet curable resin is exemplified as the resin constituting the columnar protrusions 12, it is not limited thereto, and for example, other ionizing radiation curable resins such as electron beam curable resins, thermoplastic resins, and thermosetting resins may also be used.

[0021] After producing the base material 10, next, a photochromic layer 20 whose characteristics change by light irradiation in a specific wavelength region is formed on the surface of the base material 10 having the columnar protrusions 12 (photochromic layer forming step). FIG. 3 is a diagram showing a state in which the photochromic layer 20 is formed on the base material 10 by the photochromic layer forming step. The photochromic layer 20 is a layer whose properties change upon irradiation with light in a specific wavelength range. More specifically, the photochromic layer 20 in the present embodiment is formed by applying and drying 1,2-diarylethene, and is hydrophilic immediately after drying. The photochromic layer 20 can be formed, for example, by a vapor deposition method, a spin coating method, a slit coating method, or the like. Further, the photochromic layer 20 in the present embodiment has the property of becoming hydrophobic when irradiated with ultraviolet light (wavelength: 100 to 400 nm) and becoming hydrophilic when irradiated with visible light (wavelength: 400 to 750 nm). The layer thickness of the photochromic layer 20 is desirably 1 μm or more and 50 μm or less.

[0022] In this specification, the term "photochromic" represents that some properties change upon light irradiation, and it is not necessary for a color change (change in transmission spectrum) to occur upon light irradiation. Further, in the example of the photochromic layer 20 described above, it has reversible photochromic properties, but it may also have irreversible photochromic properties. As a technique in which the wettability changes upon light irradiation, there is "Photochromism" edited by the Polymer Society, published by Kyoritsu Shuppan, p. 28 (2012). This document describes the properties of diarylethene that change from hydrophilic to hydrophobic upon light irradiation.

[0023] Note that the photochromic layer 20 is hydrophilic immediately after drying, but depending on the storage conditions after drying, it is assumed that the photochromic layer 20 may be irradiated with ultraviolet light. In such a case, before proceeding to the next step, it is advisable to sufficiently irradiate the photochromic layer 20 with visible light (wavelength: 400 to 750 nm) (initial irradiation step) to ensure a hydrophilic state.

[0024] Next, a light shielding layer 30 that partially shields the light irradiated in the light irradiation step, which is the next step, is formed on the surface of the base material 10 opposite to the columnar convex portions 12 (light shielding layer forming step). FIG. 4 is a diagram showing a state in which a light-shielding layer 30 is formed on a substrate 10 in the light-shielding layer forming step. FIG. 4(a) shows a cross-sectional view orthogonal to the sheet surface of the substrate 10, and FIG. 4(b) shows a perspective view. The light-shielding layer 30 of the present embodiment is mainly formed in a region facing a region where the columnar protrusions 12 are not formed on the surface of the substrate 10 opposite to the columnar protrusions 12. Therefore, the light-shielding layer 30 has an opening 31 at a position facing the columnar protrusions 12 where the light-shielding layer 30 is not formed and light can pass through. It is desirable that the opening width W31 of the opening 31 is the same as or slightly narrower than the width W12 of the columnar protrusions 12. This is because light incident from an oblique direction can be appropriately blocked in the next light irradiation step. As the light-shielding layer 30, for example, chromium black, a resin in which a black pigment is dispersed, or the like can be used.

[0025] Next, only the photochromic layer 20 provided on the top of the columnar protrusions 12 is irradiated with ultraviolet light (wavelength: 100 to 400 nm) (light irradiation step). FIGS. 5 and 6 are diagrams showing the light irradiation step. FIGS. 5(a) and 6(a) show cross-sectional views orthogonal to the sheet surface of the substrate 10, and FIGS. 5(b) and 6(b) show perspective views.

[0026] Here, in the light irradiation step of the present embodiment, in order to irradiate only the photochromic layer 20 provided on the top of the columnar protrusions 12 with ultraviolet light, a phenomenon of total internal reflection of ultraviolet light on the side surface 12b of the columnar protrusions 12 is utilized. In the light irradiation step, ultraviolet light is irradiated into the columnar protrusions 12 through the opening 31 from the surface of the substrate 10 opposite to the columnar protrusions. At this time, the ultraviolet light to be irradiated is preferably parallel light, and is irradiated from an oblique direction having a slight angle with respect to the normal direction of the sheet surface of the substrate 10 (for example, a direction having an angle within 5° with respect to the normal direction of the substrate 10). This ultraviolet light is blocked by the light-shielding layer 30 and does not reach the portion where the columnar protrusions 12 are not provided (hereinafter, also referred to as the bottom surface 12c). Although the ultraviolet light is preferably parallel light, it may be diffused light as long as the purpose in the light irradiation step can be achieved.

[0027] The light that has entered the columnar convex portion 12 travels obliquely and reaches the side surface 12b. Here, the refractive index n20 of the photochromic layer 20 is lower than the refractive index n12 of the columnar convex portion 12. Specifically, in this embodiment, the columnar convex portion 12 is formed of a urethane acrylate resin with a refractive index n12 = 1.6, and the photochromic layer 20 is formed of 1,2-diarylethene with a refractive index n20 = 1.57. Therefore, when ultraviolet light reaches at an angle that satisfies the total reflection condition (the incident angle (critical angle) at the side surface 12b is 79° or more), total reflection occurs at the side surface 12b, and the ultraviolet light does not reach the photochromic layer 20 at the side surface 12b. Thus, even when irradiated with ultraviolet light, the photochromic layer 20 on the side surface 12b maintains its hydrophilicity.

[0028] The ultraviolet light that has undergone total reflection at the side surface 12b reaches the top portion 12a. However, at this site, since the ultraviolet light enters the top portion 12a at an incident angle smaller than the critical angle, the total reflection condition is not satisfied, and the ultraviolet light reaches the photochromic layer 20 and exits as it is. Thus, at the top portion 12a, the photochromic layer 20 is exposed to ultraviolet light and changes to hydrophobicity.

[0029] As shown in FIGS. 5 and 6, it is desirable to perform the light irradiation step a plurality of times while changing the irradiation angle and direction of the ultraviolet light to sufficiently expose the top portion 12a. However, depending on the shape of the columnar convex portion 12, only one ultraviolet light irradiation may be sufficient. By performing the light irradiation step, the photochromic layer 20 on the top portion 12a of the columnar convex portion 12 changes to hydrophobicity, and the photochromic layers 20 on the bottom surface 12c and the side surface 12b maintain their hydrophilic states.

[0030] In addition, when the refractive index n20 of the photochromic layer 20 is higher than the refractive index n12 of the columnar convex portion 12, it is preferable to provide a low refractive index layer having a refractive index lower than the refractive index n12 of the columnar convex portion 12 between the columnar convex portion 12 and the photochromic layer 20. The low refractive index layer forming step for providing this low refractive index layer may be performed before the photochromic layer 20 is provided. As the low refractive index layer, for example, an amorphous fluoropolymer, hollow silica nanoparticles, a urethane acrylate resin in which porous silica nanoparticles are dispersed, an epoxy acrylate resin, or the like can be used.

[0031] Next, a catalytic material for electroless plating is applied to the photochromic layer 20, and an electroless plating catalyst layer 40 is formed on the photochromic layer 20 that maintains hydrophilicity (electroless plating catalyst layer forming step). FIG. 7 is a diagram showing a state in which the electroless plating catalyst layer 40 is formed by the electroless plating catalyst layer forming step. Here, since the photochromic layer 20 on the top 12a of the columnar convex portion 12 has changed to hydrophobicity by the previous light irradiation step, even if the catalytic material for electroless plating is applied, it is repelled and the catalytic material for electroless plating does not adhere to the top 12a. Therefore, as shown in FIG. 7, the electroless plating catalyst layer 40 is not formed on the top 12a of the columnar convex portion 12, and the electroless plating catalyst layer 40 is formed only on the bottom surface 12c and the side surface 12b. In the electroless plating catalyst layer forming step, for example, the photochromic layer 20 may be immersed in the catalytic material for electroless plating, or the catalytic material for electroless plating may be applied onto the photochromic layer 20 by slit coating, spin coating, or the like. As the electroless plating catalyst layer 40, for example, a palladium chloride catalyst, a palladium / tin colloid catalyst, a silver nanoparticle catalyst, or the like can be used.

[0032] Next, an electrode layer 50 is formed on the portion excluding the top 12a of the columnar convex portion 12 (electrode layer forming step). Specifically, electroless copper plating is performed. In addition to copper, nickel can also be used as the electrode layer 50. FIG. 8 is a diagram showing a state in which the electrode layer 50 is formed by the electrode layer forming step. In the electrode layer forming step, the substrate 10 formed with the electroless plating catalyst layer 40 is immersed in an electroless copper plating solution. As the electroless copper plating solution, a mixed solution of formalin and an aqueous copper sulfate solution is preferable. As shown in FIG. 8, an electroless copper plating layer of copper is formed as the electrode layer 50 only on the surface where the electroless plating catalyst layer 40 is formed.

[0033] Next, using the electrode layer 50 formed on the substrate 10 by the electrode layer forming step as a mold, electroforming is performed using the electrode layer 50 to form an electroformed product between the columnar convex portions 12 (electroforming step). FIG. 9 is a diagram showing a state in which the article 1 is formed by the electroforming step. In the electroforming step, the gap between the columnar convex portions 12 is filled with copper to form an article 1 having a plurality of through holes 1a as an electroformed product. The portion of the columnar convex portion 12 has a shape corresponding to the through hole 1a.

[0034] Finally, the substrate 10 is removed from the electroformed product, which is the article 1 (removing step). In this removing step, the substrate 10 may be peeled off from the article 1, or the substrate 10 may be melted and removed by a chemical agent. By finishing this removing step, an article 1 having a plurality of through holes 1a as shown in FIG. 1 can be obtained as an electroformed product.

[0035] As described above, according to the manufacturing method of the first embodiment, the inner wall surface of the through hole 1a of the manufactured article 1 can be a vertical mirror surface. Also, an article having a thickness of several hundred μm or more to about several mm can be manufactured.

[0036] (Second Embodiment) The second embodiment utilizes the fact that the photochromic layer 20 changes characteristics different from those of the first embodiment by light irradiation, and is common to the first embodiment in many points. Therefore, parts that perform the same functions as those of the first embodiment described above are denoted by the same reference numerals, and overlapping descriptions are omitted as appropriate.

[0037] The article 1 created in the second embodiment has the same configuration as that of the first embodiment. Hereinafter, the manufacturing method of the article 1 in the second embodiment will be described. Up to the base material formation step and the photochromic layer formation step, it is the same as the first embodiment. The photochromic layer 20 is the same as that in the first embodiment, which is formed by applying 1,2-diarylethene and drying it, but the characteristics used are different from those in the first embodiment. In the second embodiment, when the 1,2-diarylethene is irradiated with light having a wavelength of 300 to 400 nm, it becomes a state in which the metal to be vapor-deposited can adhere (a state in which metal vapor deposition is possible), and when irradiated with light having a wavelength of 500 to 600 nm, it becomes a state in which the metal to be vapor-deposited does not adhere (a state in which metal vapor deposition is impossible). The characteristics are utilized.

[0038] After forming the photochromic layer 20, the photochromic layer 20 is sufficiently irradiated with light having a wavelength of 300 to 400 nm (initial irradiation step), so that the entire photochromic layer 20 is in a state where the metal to be vapor-deposited can adhere.

[0039] Next, a light-shielding layer formation step is performed in the same manner as in the first embodiment. Next, only the photochromic layer 20 provided on the top of the columnar convex portion 12 is irradiated with light having a wavelength of 500 to 600 nm (light irradiation step). This light irradiation step is the same as the first embodiment except that the wavelength of the irradiated light is different from that in the first embodiment. By performing the light irradiation step, the photochromic layer 20 on the top 12a of the columnar convex portion 12 changes to a state where the metal to be vapor-deposited does not adhere, and the photochromic layers 20 on the bottom surface 12c and the side surface 12b maintain a state where the metal to be vapor-deposited can adhere.

[0040] Next, copper serving as the electrode layer 60 is vapor-deposited on the photochromic layer 20 toward the columnar convex portion 12 side, and the electrode layer is formed on the side surface 12b and the bottom surface 12c of the columnar convex portion 12 (electrode layer formation step). FIG. 10 is a diagram showing a state in which the electrode layer 60 is formed by the electrode layer formation step of the second embodiment. Here, since the photochromic layer 20 on the top 12a of the columnar convex portion 12 has changed to a state where the metal to be vapor-deposited does not adhere, copper does not adhere.

[0041] Next, using the base material 10 on which the electrode layer 60 has been formed by the electrode layer forming step as a mold, electroforming is performed using the electrode layer 60 to form an electroformed product between the columnar convex portions 12 (electroforming step). FIG. 11 is a diagram showing a state in which the article 1 is formed by the electroforming step of the second embodiment. In the electroforming step, the gap between the columnar convex portions 12 is filled with copper, and the article 1 having a plurality of through holes 1a is formed as an electroformed product. The portion of the columnar convex portion 12 has a shape corresponding to the through hole 1a.

[0042] Finally, in the same manner as in the first embodiment, the base material 10 is removed from the article 1 which is an electroformed product (removing step). By finishing this removing step, the article 1 having a plurality of through holes 1a as shown in FIG. 1 can be obtained as an electroformed product.

[0043] As described above, according to the manufacturing method of the second embodiment, an article 1 similar to that of the first embodiment can be produced using vapor deposition.

[0044] (Modification) Without being limited to the embodiments described above, various modifications and changes are possible, and these are also within the scope of the present invention.

[0045] (1) In the first embodiment, the electrode layer forming step and the electroforming step were described as separate steps. However, this is not the only case. For example, when the material of the electrode layer 50 and the material of the article 1 are the same, these may be combined and performed as one step.

[0046] (2) In each embodiment, the material of the electrode layer 50 and the material of the article 1 may be changed. For example, silver may be used as the material of the electrode layer 50 and nickel may be used as the material of the article 1.

[0047] (3) In each embodiment, an example was described in which the light-shielding layer 30 is formed after the creation of the columnar protrusions 12. However, it may be difficult to align and form the light-shielding layer 30 corresponding to the arrangement of the columnar protrusions 12 when the thickness of the base sheet 11 is thick. In such a case, the light-shielding layer 30 may be formed on the base sheet 11 in advance before forming the columnar protrusions 12 on the base sheet 11. After forming the light-shielding layer 30, an ultraviolet curable resin is applied as the material for the columnar protrusions 12. Further, ultraviolet rays are irradiated from the side of the base sheet 11 where the light-shielding layer 30 is formed. In this case, ultraviolet rays are irradiated from the opening 31 where the light-shielding layer 30 is not provided to the ultraviolet curable resin, and the ultraviolet curable resin is cured, so that the shape of the columnar protrusions 12 can be formed. The columnar protrusions 12 may be formed by such a process, and this process is sometimes generally called a self-alignment process.

[0048] In addition, each embodiment and modified form can be used in appropriate combination, but detailed description thereof is omitted. Further, the present invention is not limited by each of the embodiments described above.

Explanation of Reference Numerals

[0049] 1 Article 1a Through-hole 10 Substrate 11 Base Sheet 12 Columnar Protrusion 12a Top 12b Side Surface 12c Bottom Surface 20 Photochromic Layer 30 Light-Shielding Layer 31 Opening 40 Electroless Plating Catalyst Layer 50 Electrode Layer 60 Electrode Layer

Claims

1. A substrate forming step of forming a substrate having a plurality of columnar protrusions; A photochromic layer forming step of forming a photochromic layer whose properties change by light irradiation in a specific wavelength region on the surface of the substrate having the columnar protrusions; A light irradiation step of irradiating light from the surface of the substrate opposite to the columnar protrusions into the interior of the columnar protrusions, totally reflecting the light on the side surfaces of the columnar protrusions, and causing the light to reach the top of the columnar protrusions to change the properties of the photochromic layer at the position corresponding to the top; An electrode layer forming step of forming an electrode layer on a portion of the columnar protrusions excluding the top; An electroforming step of performing electroforming using the electrode layer to form an electroformed product between the columnar protrusions; A removing step of removing the substrate from the electroformed product; A method for manufacturing an article having a plurality of through holes comprising the above steps.

2. In the method for manufacturing an article having a plurality of through holes according to Claim 1, the photochromic layer is formed of a material whose properties change from hydrophilic to hydrophobic by light irradiation in a specific wavelength region, the side surfaces and the bottom surface of the columnar protrusions maintain hydrophilicity, and the top of the columnar protrusions is changed to hydrophobicity by the light irradiation step, between the light irradiation step and the electrode layer forming step, a electroless plating catalyst layer forming step of applying a catalyst material for electroless plating to the photochromic layer and forming an electroless plating catalyst layer on the photochromic layer maintaining hydrophilicity is provided, in the electrode layer forming step, an electroless plating layer is formed as the electrode layer by performing an electroless plating treatment on the electroless plating catalyst layer; A method for manufacturing an article having a plurality of through holes, characterized by the above.

3. In the method for manufacturing an article having a plurality of through holes according to Claim 1, the photochromic layer is formed of a material whose state changes from a state where metal deposition is possible to a state where metal deposition is impossible by light irradiation in a specific wavelength region, the side surfaces and the bottom surface of the columnar protrusions maintain a state where metal deposition is possible, and the top of the columnar protrusions is changed to a state where metal deposition is impossible by the light irradiation step, in the electrode layer forming step, the metal to be the electrode layer is deposited on the columnar protrusion side to form the electrode layer on the side surfaces and the bottom surface of the columnar protrusions; A method for manufacturing an article having a plurality of through holes, characterized by the above.

4. In the method for manufacturing an article having a plurality of through holes according to any one of Claims 1 to 3, A low refractive index layer forming step of forming a low refractive index layer having a refractive index lower than that of the columnar convex portion between the columnar convex portion and the photochromic layer is provided. A method for manufacturing an article having a plurality of through holes, characterized thereby. **Claim 5** In the method for manufacturing an article having a plurality of through holes according to any one of Claims 1 to 4, before the light irradiation step, an initial irradiation step of irradiating the entire photochromic layer with light in a wavelength region different from the light irradiation in the specific wavelength region is provided. A method for manufacturing an article having a plurality of through holes, characterized thereby. **Claim 6** In the method for manufacturing an article having a plurality of through holes according to any one of Claims 1 to 5, before the light irradiation step, a light shielding layer forming step of forming a light shielding layer for partially shielding the light irradiated in the light irradiation step on the surface of the base material opposite to the columnar convex portion is provided. A method for manufacturing an article having a plurality of through holes, characterized thereby.

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