JP2017179458A - Metallic porous structure body, manufacturing method thereof and imprint mold for manufacturing metallic porous structure body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for highly accurately manufacturing a metallic porous structure body having fine-sized through holes, a metallic porous structure body manufactured by the method, and an imprint mold used for manufacturing the metallic porous structure body.SOLUTION: In a manufacturing method of a metallic porous structure body 1, an imprint mold 30 having at least two step-like recesses 31 is used to perform an imprint process to a resist layer 20 on a base material 10, and a step-like projection 21 having at least two projections 211, 212 is formed on the base material 10. A metal layer 40 is then formed on the base material 10 where the step-like projection 21 is formed by electrical plating treatment so that part of the projection 212 located at the top of the step-like projection 21 is exposed, and the metal layer 40 is pulled away from the base material 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a metal perforated structure having a through hole, a method for manufacturing the same, and an imprint mold used for manufacturing the metal perforated structure.

  With the advancement of technology for handling fluids, proposals for nozzles for precisely controlling fluid ejection and spraying and high-performance filters for separating fine particles in fluids are required. For example, a nozzle for an ink jet head or the like needs to eject ink as fine droplets with good directivity. Further, in a filter or the like used for separating fine particles such as red blood cells and viruses in blood, it is necessary to form through holes having nano-level pore diameters.

  As such a nozzle or filter, a metal perforated structure having a through hole formed in the thickness direction is used. Such metal perforated structures are conventionally manufactured by electroforming or the like. Specifically, as shown in FIG. 7, a resist pattern 21 ′ having a circular shape in plan view is formed on a Cu substrate 10 ′, and electroplating film 40 ′ is formed by performing a thick electroplating process such as platinum. To do. The electroformed film 40 ′ is grown on the Cu substrate 10 ′ where the resist pattern 21 ′ is not present at the beginning of the electroplating process in a direction perpendicular to the surface of the Cu substrate 10 ′. When the thickness exceeds the thickness of the resist pattern 21 ′, the electroformed film 40 ′ grows isotropically and is also formed on the resist pattern 21 ′. Thereafter, the electroplating process is stopped before the resist pattern 21 'is completely covered with the electroformed film 40'. As a result, a metal perforated structure 1 ′ having fine through holes 2 ′ is manufactured (see Patent Document 1).

  When the metal perforated structure 1 ′ is manufactured by the electroforming method (electroplating method) as described above, the dimension (hole diameter) of the through hole 2 ′ is determined by the timing at which the electroplating process is stopped. However, since the growth rate of the electroformed film 40 ′ changes due to changes in the plating conditions such as the composition, temperature, stirring conditions, and current density of the electroplating bath, the dimension of the through hole 2 ′ must be precisely controlled. There is a problem that is difficult. Further, there is a problem that the dimension of the through hole 2 ′ varies in the plane due to the variation in the dimension of the resist pattern 21 ′ in the plane of the Cu substrate 10 ′ and the variation in the growth rate of the electroformed film 40 ′. is there.

  Therefore, conventionally, a step of forming a first resist pattern having a circular shape in plan view on a metal substrate, and a step of stacking and forming a second resist pattern having a circular shape in plan view smaller in diameter than the first resist pattern on the first resist pattern. And forming an electroformed film that contacts the side wall of the second resist pattern by electroplating, and stopping the electroplating process before the electroformed film exceeds the height of the second resist pattern, A method for manufacturing a metal perforated structure having a through hole has been proposed (see Patent Document 2).

JP-A-9-217191 JP 2014-140524 A

  According to the method described in Patent Document 2, the dimension of the through hole in the metal perforated structure is determined by the dimension of the second resist pattern. Therefore, if the second resist pattern is formed with high accuracy, the dimension of the through hole can be precisely controlled, and variation in the dimension in the plane can also be suppressed. However, even if the resolution, exposure / development conditions, etc. of the resist material constituting the second resist pattern are optimized, it is extremely difficult to uniformly control the dimension of the second resist pattern in the plane. There is a limit to suppressing variations in the dimension plane.

  In recent years, in an inkjet nozzle or the like using such a metal perforated structure, in order to further reduce the size of ink droplets and improve the landing accuracy, the through holes can be further miniaturized and linearity can be improved. There is a growing demand for improvement. Furthermore, there is an increasing demand for proposals for metallic porous structures having fine through-holes that can capture ultrafine particles such as DNA (deoxyribonucleic acid) and influenza virus in blood.

  Under such circumstances, in order to form the through hole of the metal perforated structure with a fine size (for example, about φ3 μm) in the method described in Patent Document 2, the fineness corresponding to the size of the through hole is used. It is necessary to form a second resist pattern having a proper size. However, since both the first resist pattern and the second resist pattern are formed by a photolithography method, it is extremely difficult to form a second resist pattern with a fine dimension with high accuracy. There is a risk of variations. As a result, the method described in Patent Document 2 has a problem that it is difficult to form fine through holes with high accuracy.

  In addition, since the second resist pattern formed by the photolithography method in the method described in Patent Document 2 is not excellent in linearity (orthogonality with respect to the metal substrate), the linearity of the through hole in the metal perforated structure. There is a problem that is not improved.

  Furthermore, since the through hole is formed by stopping the electroplating process before the height of the second resist pattern is exceeded, in order to increase the length of the through hole, the height of the second resist pattern is increased. Must. However, in Patent Document 2, since the second resist pattern is formed by photolithography, the second resist pattern having a fine dimension and a large aspect ratio (for example, about 2) is formed with high accuracy. Is difficult.

  In view of such a problem, the present invention provides a method for manufacturing a metal perforated structure having through holes of fine dimensions with high accuracy, a metal perforated structure manufactured by the method, and the metal It aims at providing the imprint mold used in order to manufacture a perforated structure.

  In order to solve the above problems, the present invention provides a method for producing a metal perforated structure, wherein an imprint mold having at least two stepped recesses is used to imprint a resin layer on a substrate. A printing process is performed, and an imprint process for forming at least two stepped convex portions on the base material, and a metal layer is formed by electroplating on the base material on which the stepped convex portions are formed. An electroplating step, and a mold release step of separating the metal layer from the base material on which the metal layer is formed. In the electroplating step, a convex portion located at the uppermost stage of the stepped convex portion Provided is a method for manufacturing a metal porous structure, wherein the metal layer is formed so as to expose a part (Invention 1).

  According to the said invention (invention 1), the convex part located in the uppermost step of the step-like convex part which has a convex part of at least 2 steps | paragraphs by the imprint process using an imprint mold is highly accurate with a fine dimension. Since it can be formed, it is possible to manufacture a metal perforated structure having a through-hole with a minute dimension corresponding to it with high accuracy.

  In the said invention (invention 1), it is preferable that the convex part located in the uppermost step of the said step-like convex part is a substantially cylindrical shape which has a diameter of 0.5-10 micrometers (invention 2), and the said step-like convex part It is preferable that the aspect ratio of the convex portion located at the uppermost step of the first step is 1 to 5 (Invention 3), and the side wall angle of the convex portion located at the uppermost step of the stepped convex portion is 70 to 90 °. (Invention 4).

  Moreover, this invention is equipped with the metal base which has a 1st surface and the 2nd surface facing the said 1st surface, The metal perforated structure in which the through-hole is formed in the thickness direction of the said metal base The through hole is continuous with the straight portion having the same hole diameter from the first surface toward the second surface and the straight portion, and expands in a trumpet shape toward the second surface side. The present invention provides a metal perforated structure including a diameter-enlarged portion having a diameter of 0.5 to 10 μm (Invention 5).

  In the said invention (invention 5), it is preferable that the length of the said straight part in the thickness direction of the said metal base part is 1-25 micrometers (invention 6), and the side wall angle of the said straight part is 70-90 degrees. (Invention 7)

  Furthermore, the present invention is an imprint mold used for producing a metal perforated structure, wherein the substrate has a first surface and a second surface facing the first surface, Provided is an imprint mold for producing a metal porous structure, comprising at least two stepped recesses formed on a first surface (Invention 8).

  According to the present invention, a method for manufacturing a metal perforated structure having through holes of fine dimensions with high accuracy, a metal perforated structure manufactured by the method, and the metal perforated structure An imprint mold used for manufacturing can be provided.

FIG. 1 is a process flow diagram showing each process (imprint process) of the method for manufacturing a metal porous structure according to an embodiment of the present invention in a cut end view. FIG. 2 is a process flow diagram showing each step (electroplating step and mold release step) of the method for manufacturing a metal porous structure according to one embodiment of the present invention in a cut end view. FIG. 3 is a cut end view showing a schematic configuration of the imprint mold in one embodiment of the present invention. FIG. 4 is a partially enlarged cut end view showing the configuration of the through hole of the metal porous structure in one embodiment of the present invention. FIG. 5 is a process flow diagram showing a manufacturing process of an imprint mold in one embodiment of the present invention in a cut end view. FIG. 6 is a cut end view showing a schematic configuration of another aspect of the imprint mold in one embodiment of the present invention. FIG. 7 is a process flow diagram showing each step of the conventional method for producing a metal perforated structure in a cut end view.

  Embodiments of the present invention will be described with reference to the drawings. 1 and 2 are process flow diagrams showing each step of the method for manufacturing a metal porous structure according to the present embodiment in a cut end view.

  The manufacturing method of the metal perforated structure according to the present embodiment includes an imprint process in which stepped convex portions are formed on a base material by imprint processing, and a metal layer is formed on the base material by electroplating processing. An electroplating step and a mold release step of separating the metal layer from the substrate.

[Imprint process]
First, the base material 10 which has the 1st surface 11 and the 2nd surface 12 facing it is prepared, and the resin film 20 is formed on the 1st surface 11 of the said base material 10 (refer FIG. 1 (A)).

  The base material 10 functions as a power feeding layer when performing an electroplating process in an electroplating process (see FIG. 2) described later. Therefore, as the base material 10, for example, a copper substrate, a silver substrate, a nickel substrate, or a metal substrate such as an alloy having a low sheet resistance, copper on at least one surface (the first surface 11 on which the resin film 20 is formed), An insulating substrate or the like on which a metal foil such as nickel, palladium, silver, gold, or aluminum, an electroless metal plating layer, a metal vapor deposition film, or the like can be used.

  The resin material constituting the resin film 20 is not particularly limited, and a conventionally known imprint resin material (for example, an ultraviolet curable resin or a thermosetting resin) can be used.

  Next, the imprint mold 30 formed with the two-step stepped recesses 31 is pressed against the resin film 20 on the substrate 10, and the resin film 20 (imprint resin material) is placed in the stepped recesses 31. The resin film 20 is cured in this state (see FIG. 1B).

  The method of curing the resin film 20 can be appropriately selected according to the curing characteristics of the imprint resin material. For example, if the imprint resin material is an ultraviolet curable resin, the resin is passed through the imprint mold 30. The film 20 may be cured by irradiating ultraviolet rays, and if the imprint resin material is a thermosetting resin, the resin film 20 may be cured by applying heat.

The stepped recess 31 of the imprint mold 30 in the present embodiment is configured by a first recess 311 having a substantially circular shape in plan view and a second recess 312 having a substantially circular shape in plan view located at a substantially center of the bottom surface of the first recess 311. (See FIG. 3). In the present embodiment, the dimension (diameter) D ₂₁₂ of the second convex portion 212 (see FIG. 1C) of the stepped convex portion 21 formed on the base material 10 is the second concave portion 312 of the imprint mold 30. The dimension (diameter) D _{312 is} determined. That is, the dimension (diameter) D ₃₁₂ of the second recess 312 of the stepped recess 31 of the imprint mold 30, the dimensions of the straight portion 2A of the through-holes 2 of the metal porous structure 1 (diameter) D _2A (FIG. 4 Reference) is determined. Therefore, the dimension (diameter) D ₃₁₂ of the second recess 312 is preferably 0.5 to 10 μm, and more preferably 1 to 6 μm.

Similarly, the length L _2A of the straight portion 2A of the through hole 2 of the metal perforated structure 1 is determined by the depth T ₃₁₂ of the second recess 312 of the stepped recess 31 of the imprint mold 30 and the side wall angle θ _312. The side wall angle θ _2A (see FIG. 4) is determined. Therefore, the depth T ₃₁₂ of the second recess 312 is preferably 1 to 25 μm, and more preferably 2 to 15 μm. The aspect ratio (depth / dimension) of the second recess 312 is preferably 1 to 5, and more preferably 1 to 3. Further, sidewall angle theta ₃₁₂ of the second recess 312 is preferably from 70 to 90 °, and more preferably 80-90 °.

  In addition, the dimension (diameter) of the 1st recessed part 311 of the step-shaped recessed part 31 of the imprint mold 30 is although it does not specifically limit, It can set to about 10-50 micrometers. When the 2nd convex part 212 for forming the through-hole 2 of the metal porous structure 1 is directly formed on the base material 10 (1st surface 11), when the imprint mold 30 peels, for example (FIG.1 (C )), The second convex portion 212 may fall. However, the first convex portion 211 corresponding to the first concave portion 311 is formed on the base material 10 (first surface 11), so that the second hole for forming the through hole 2 of the metal porous structure 1 is formed. The convex portion 212 can be stably formed on the base material 10 (first surface 11). Further, the pitch of the stepped recesses 31 is the use of the metal perforated structure 1 manufactured according to this embodiment (the pitch of the through holes 2 required for the metal perforated structure 1 based on the use, etc.) ) Is set as appropriate.

  Subsequently, the imprint mold 30 is peeled from the cured resin film 20 (see FIG. 1C). Thereby, the step-like convex portion 21 (first convex portion 211 and second convex portion 212) corresponding to the step-like concave portion 31 (first concave portion 311 and second concave portion 312) of the imprint mold 30 is formed on the base material 10 (first 1 surface 11) (see FIG. 1C).

[Electroplating process]
As shown in FIG. 2, a metal (for example, gold, silver, platinum, palladium, nickel, iron) is formed on the base material 10 (first surface 11) having the step-like convex portion 21 manufactured as described above. , Chrome, etc.) is formed by electroplating. At the beginning of the electroplating process, the first surface 11 of the base material 10 that is not covered with the stepped convex portion 21 functions as a power feeding layer, and the electroformed layer 40 is deposited on the first surface 11 (FIG. 2A). )reference). At this time, the electroformed layer 40 grows only in the direction orthogonal to the first surface 11 of the substrate 10 (see the arrow shown in FIG. 2A). When the thickness of the electroformed layer 40 reaches the thickness of the first convex portion 211, the electroformed layer 40 grows in an in-plane direction of the first surface 11 of the substrate 10 (FIG. 2B). )reference). Thereafter, the electroformed layer 40 comes into contact with the side wall of the second convex portion 212, and the electroplating process 40 is stopped before the thickness of the second convex portion 212 is exceeded, whereby the electroformed layer 40 is formed (FIG. 2 (C)).

[Release process]
Then, the base material 10 and the step-like convex part 21 are peeled from the electroformed layer 40 (see FIG. 2D). Thereby, the metal base 3 having the first surface 3A and the second surface 3B opposite to the first surface 3A is provided, and substantially in the thickness direction of the metal base 3 from the first surface 3A to the second surface 3B. Metal perforated structure 1 in which a through hole 2 having a straight portion 2A having the same hole diameter and a diameter-enlarged portion 2B that is continuous with the straight portion 2A and expands in a trumpet shape toward the second surface 3B side is formed. Can be produced.

The dimension (hole diameter) D _2A , length L _2A and side wall angle θ _2A (see FIG. 4) of the through hole 2 (straight portion 2A) in the metal perforated structure 1 are the same as those on the first surface 11 of the substrate 10. It is determined by the dimension (diameter), height and side wall angle of the step-like convex portion 21 (second convex portion 212) formed in the above. Then, the dimension, depth, and side wall angle of the stepped concave portion 31 (second concave portion 312) of the imprint mold are highly accurate as the size, height, and side wall angle of the stepped convex portion 21 (second convex portion 212). Transcribed. Therefore, the dimension D _2A of the through hole 2 (the straight portion 2A) of the metal porous structure 1, 0.5 to 10 [mu] m, preferably a 1 to 6 m, the length L _2A is, 1 to 25 m, preferably 2 to 15 μm, and the side wall angle θ _2A is 70 to 90 °, preferably 80 to 90 °. The side wall angle θ _2A of the through hole 2 (straight portion 2A) can be measured using an electron microscope (product name: SU-5000, manufactured by Hitachi High-Technologies Corporation).

As described above, according to the method for manufacturing a metal porous structure according to the present embodiment, the size of the second convex portion 212 for forming the through hole 2 can be formed with high accuracy. A metal perforated structure 1 having through holes 2 of various dimensions can be manufactured with high accuracy. Moreover, in this embodiment, since the 2nd convex part 212 can be formed with high aspect ratio by forming the step-shaped convex part 21 using the imprint mold 30, it is the straight of desired length. The through hole 2 having the portion 2A can be formed with high accuracy. Further, since the second convex portion 212 is formed with a substantially 90 ° sidewall angle, the sidewall angle θ _2A of the through hole 2 (straight portion 2A) can be substantially 90 °, and the straight portion 2A. it can be substantially the same over a dimension (hole diameter) D _2A in the longitudinal direction.

[Method for producing imprint mold]
A method for producing the imprint mold 30 used when producing the metal perforated structure 1 will be described. FIG. 5 is a process flow diagram showing a manufacturing process of an imprint mold used in the present embodiment in a cut end view.

  First, an imprint mold substrate 50 having a first surface 51 and a second surface 52 and having a hard mask layer 60 provided on the first surface 51 is prepared, and the hard mask of the imprint mold substrate 50 is prepared. A resist film 70 is formed over the layer 60 (see FIG. 5A).

  As the imprint mold substrate 50, a substrate generally used when manufacturing an imprint mold (for example, glass such as quartz glass, soda glass, fluorite, calcium fluoride substrate, magnesium fluoride substrate, acrylic glass, etc.) Transparent substrates such as a substrate, a polycarbonate substrate, a polypropylene substrate, a resin substrate such as a polyethylene substrate, a laminated substrate formed by laminating two or more substrates selected arbitrarily from these; a nickel substrate, a titanium substrate, an aluminum substrate, etc. A metal substrate; a silicon substrate, a semiconductor substrate such as a gallium nitride substrate, or the like) can be used.

  The thickness of the imprint mold substrate 50 can be appropriately set in the range of, for example, about 300 μm to 10 mm in consideration of the strength of the substrate, the handling suitability, and the like. In the present embodiment, “transparent” means that the transmittance of light having a wavelength of 300 to 450 nm is 85% or more, and preferably 90% or more.

  The material constituting the hard mask layer 60 is not particularly limited, and examples thereof include metals such as chromium, titanium, tantalum, silicon, and aluminum; chromium-based compounds such as chromium nitride, chromium oxide, and chromium oxynitride; Tantalum compounds such as tantalum, tantalum oxynitride, tantalum boride, and tantalum oxynitride, titanium nitride, silicon nitride, silicon oxynitride, and the like can be used alone or in combination of two or more selected arbitrarily. However, it is preferable that the material has a high etching selectivity with respect to the imprint mold substrate 50. For example, when quartz glass is used as the imprint mold substrate 50, it is preferable to use a chromium-based compound such as metal chromium, chromium oxide, or chromium nitride as a material constituting the hard mask layer 60.

  The thickness of the hard mask layer 60 is appropriately set in consideration of an etching selection ratio corresponding to the type of the imprint mold substrate 50. For example, when the imprint mold substrate 50 is made of quartz glass and the hard mask layer 60 is made of metal chromium, the thickness of the hard mask layer 60 is about 50 to 500 nm.

  The resist material constituting the resist film 70 is not particularly limited, and a conventionally known energy beam curable resin material (electron beam curable resin material, ultraviolet curable resin material, etc.) or the like can be used.

  Next, the resist film 70 is patterned by an electron beam lithography method, a photolithography method, or the like to form a resist pattern 71 having an opening corresponding to the second recess 312 on the hard mask layer 60 (see FIG. 5B). ).

  Subsequently, using the resist pattern 71 as a mask, the hard mask layer 60 is etched to form a hard mask pattern 61 (see FIG. 5C). Then, using the hard mask pattern 61 as a mask, the imprint mold substrate 50 is dry-etched to form a second recess 312 (see FIG. 5D).

  Next, a resist film 72 that covers the hard mask pattern 61 and the second recess 312 is formed on the first surface 51 of the imprint mold substrate 50 in which the second recess 312 is formed (see FIG. 5E). ), The resist film 72 is patterned by an electron beam lithography method, a photolithography method or the like to form a resist pattern 73 having an opening corresponding to the first recess 311 (see FIG. 5F).

  Subsequently, using the resist pattern 73 as a mask, the hard mask pattern 61 is etched to form a hard mask pattern 62 (see FIG. 5G). Then, using the hard mask pattern 62 as a mask, the imprint mold substrate 50 is dry-etched to form a first recess 311 (see FIG. 5H). In this way, a stepped recess including the base having the first surface 30A and the second surface 30B opposite to the first surface, and the first recess 311 and the second recess 312 formed on the first surface 30A of the base. The imprint mold 30 according to this embodiment is manufactured.

In the imprint mold 30, the dimension (diameter) D ₃₁₂ of the second recess 312 is preferably 0.5 to 10 μm, and more preferably 1 to 6 μm. The depth T ₃₁₂ of the second recess 312 is preferably from 1 to 25 m, and more preferably 2 to 15 [mu] m. That is, the aspect ratio (depth / dimension) of the second recess 312 is preferably 1 to 5, and more preferably 1 to 3. Further, sidewall angle theta ₃₁₂ of the second recess 312 is preferably from 70 to 90 °, and more preferably 80-90 °.

  In the imprint mold 30 manufactured as described above, the stepped recesses 31 (the first recess 311 and the second recess) are highly accurate due to the high etching selectivity between the imprint mold substrate 50 and the hard mask layer 60. 312), the stepped convex portions 21 (the first convex portions 211 and the second convex portions 212) corresponding to the stepped concave portions 31 (the first concave portion 311 and the second concave portion 312) are formed on the substrate 10. It can be formed on the first surface 11 with high accuracy. As a result, the metal perforated structure 1 having the through holes 2 with fine dimensions can be manufactured with high accuracy by the electroplating process using the base material 10 having the stepped convex portions 21.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  In the above embodiment, the two-step stepped convex portion 21 is formed on the base material 10 and the electroformed layer 40 is formed by electroplating. However, the present invention is limited to such an embodiment. Instead, for example, the number of steps of the stepped convex portion 21 may be three or more.

  In the above embodiment, when forming the stepped convex portion 21, the imprint mold 30 in which the light shielding film 32 is provided in a region other than the region where the stepped concave portion 31 is formed on the first surface 30A (see FIG. 6) may be used. In general, in the imprint process using the imprint mold 30, the imprint resin is cured without bringing the first surface 30 </ b> A of the imprint mold 30 into contact with the first surface 11 of the substrate 10. Therefore, a residual film is formed on the first surface 11 of the base material 10 along with the stepped convex portion 21. Therefore, after the imprint mold 30 is peeled off, the remaining film needs to be removed by ashing or the like. At this time, the stepped convex portion 21 is also affected by ashing, and its dimensions and the like may change. However, according to the above aspect, when the ultraviolet ray curable resin is used as the imprint resin material constituting the resin film 20 formed on the first surface 11 of the substrate 10, the stepped concave portion of the imprint mold 30 is used. Since only the resin filled in 31 is cured, and the resin immediately below the light shielding film 32 is not cured, the stepped convex portion 21 is more accurately formed on the first surface 11 of the base material 10 by performing development processing. Can be formed.

  In the above embodiment, a release agent layer may be provided on the first surface 30 </ b> A of the imprint mold 30, or a material containing a release agent may be used as the imprint resin material constituting the resin film 20. Good. Thereby, the step-like convex portion 21 can be formed on the first surface 11 of the substrate 10 with high accuracy.

  In the above embodiment, at least the imprint process may be performed in an inert gas atmosphere such as helium. When the imprint mold 30 is pressed against the resin film 20, if a gas in the atmosphere is sandwiched between the imprint mold 30 and the resin film 20, a transfer defect may occur. By performing the imprint process at, generation of the transfer defect can be suppressed.

  In the above embodiment, an imprint mold 30 (replica mold) having a stepped recess 31 is produced by an imprint process using an imprint mold having a stepped protrusion as a master mold, and the imprint using the replica mold is used. You may form the step-shaped convex part 21 on the base material 10 by a printing process.

  EXAMPLES Hereinafter, although an Example etc. are given and this invention is demonstrated further in detail, this invention is not limited to the following Example etc. at all.

[Example 1]
[Production of imprint mold]
A quartz substrate is prepared as an imprint mold substrate 50 in which a hard mask layer 60 made of Cr having a thickness of 100 nm is provided on the first surface 51, and an electron beam sensitive resist (Merck Corp.) is formed on the hard mask layer 60. And a resist pattern 71 having an opening corresponding to the second recess 312 (opening dimension: 3 μm) was formed using an electron beam lithography apparatus (see FIG. 5B).

Next, using the resist pattern 71 as a mask, the hard mask layer 60 was dry-etched (etching gas: chlorine gas) to form a hard mask pattern 61 (see FIG. 5C). Then, using the hard mask pattern 61 as a mask, the imprint mold substrate 50 is dry-etched to form a second recess 312 (dimension D ₃₁₂ : 3 μm, depth T ₃₁₂ : 18 μm, sidewall angle θ ₃₁₂ : 88 °). (See FIG. 5D).

  Subsequently, an electron beam sensitive resist (Merck, MiR700) is applied on the first surface 51 of the imprint mold substrate 50 in which the second recess 312 is formed, and the first recess is formed using an electron beam drawing apparatus. A resist pattern 73 (opening size: φ30 μm) having an opening corresponding to 311 was formed (see FIG. 5F).

  Then, using the resist pattern 73 as a mask, the hard mask pattern 61 was dry-etched (etching gas: chlorine gas) to form a hard mask pattern 62 (see FIG. 5G). Finally, using the hard mask pattern 62 as a mask, the imprint mold substrate 50 is dry-etched to form a first recess 311 (dimension: φ30 μm, depth: 10 μm), and the hard mask pattern 32 is removed. An imprint mold 30 was produced (see FIG. 5H).

[Manufacture of metal perforated structures]
A resin film 20 made of an ultraviolet curable resin (SU-8 3000, manufactured by Nippon Kayaku Co., Ltd.) is formed on the first surface 11 of a rolled copper substrate (thickness: 300 μm) as the base material 10 by spin coating ( 1A), the imprint mold 30 is pressed against the resin film 20, and the resin film 20 (imprint resin material) is filled in the stepped recess 31, and the resin film 20 is filled in this state. It was cured by irradiation with ultraviolet rays (see FIG. 1B).

  Next, the imprint mold 30 was peeled from the cured resin film 20 (see FIG. 1C). Thereby, the step-shaped convex part 21 (the 1st convex part 211 and the 2nd convex part 212) was formed on the 1st surface 11 of the base material 10. FIG.

  Subsequently, on the base material 10 having the stepped convex portion 21, nickel is deposited by electroplating to form the electroformed layer 40, and the electroformed layer 40 contacts the side wall of the second convex portion 212, Before the thickness of the second convex portion 212 was exceeded, the electroplating process was stopped (see FIGS. 2A to 2C). In this way, the electroformed layer 40 was formed on the substrate 10.

Finally, the metal porous structure 1 was manufactured by peeling the base material 10 and the step-like convex portion 21 from the electroformed layer 40. The dimension D _2A of the straight portion 2A of the through hole 2 in the metal perforated structure 1 was 3 μm, the length L _2A of the straight portion 2A was 10 μm, and the side wall angle θ _2A of the straight portion _2A was 75 to 85 °. .

[Comparative Example 1]
[Manufacture of metal perforated structures]
A resin film (film thickness: 10 μm) made of an ultraviolet curable resin (SU-8 3000, manufactured by Nippon Kayaku Co., Ltd.) is formed on one surface of a copper substrate (thickness: 300 μm) by a spin coating method, and a predetermined opening is formed. Exposure / development processing was performed using a photomask having a first resin pattern (dimension: φ30 μm) on a copper substrate.

  Next, a resin film (film thickness: 15 μm) made of an ultraviolet curable resin (SU-8 3000 series, manufactured by Nippon Kayaku Co., Ltd.) is coated on the copper substrate so as to cover the resin pattern by spin coating. Then, exposure and development are performed using a photomask having a predetermined opening, and a second resin pattern (dimension: φ3 μm) smaller in size than the first resin pattern is formed on the first resin pattern. did.

  Subsequently, on the copper substrate, nickel is deposited by electroplating to form an electroformed layer, the electroformed layer is in contact with the side wall of the second resin pattern, and the thickness of the second resin pattern is reduced. The electroplating process was stopped before exceeding. In this way, an electroformed layer was formed on the copper substrate.

  Finally, the metal perforated structure was manufactured by peeling the copper substrate, the first resin pattern, and the second resin pattern from the electroformed layer. In such a metal perforated structure, the size of the through hole was 3 μm, the length of the through hole (straight portion) was 3 μm, and the side wall angle of the through hole was 65 to 80 °.

  From the results of Example 1 and Comparative Example 1, using the imprint mold 30 having at least two steps of the stepped recesses 31 (the first recess 311 and the second recess 312), at least two steps of the stepped protrusions 21. Since the (first convex part 211 and the second convex part 212) can be formed on the base material 10 with fine dimensions and high accuracy, the metal perforated holes having the through holes 2 with minute dimensions corresponding thereto. It was confirmed that the structure 1 can be manufactured with high accuracy.

  The present invention is useful in technical fields such as an ink jet nozzle and a filter that handle fluid.

DESCRIPTION OF SYMBOLS 1 ... Metal perforated structure 2 ... Through-hole 2A ... Straight part 2B ... Diameter expansion part 3 ... Metal base part 3A ... 1st surface 3B ... 2nd surface 10 ... Base material 20 ... Resin layer 21 ... Stair-like convex part 211 ... 1st convex part 212 ... 2nd convex part 30 ... Imprint mold 31 ... Stair-like recessed part 311 ... 1st recessed part 312 ... 2nd recessed part 40 ... Electroformed layer (metal layer)

Claims (8)

A method for producing a metal perforated structure, comprising:
Using an imprint mold having at least two steps of stepped recesses, imprinting the resin layer on the substrate, and forming at least two steps of stepped protrusions on the substrate;
An electroplating step of forming a metal layer by electroplating on the base material on which the step-like convex portions are formed;
A mold release step of separating the metal layer from the base material on which the metal layer is formed,
In the electroplating step, the metal layer is formed so as to expose a part of the convex portion located at the uppermost stage of the stepped convex portion.   The method for producing a metal perforated structure according to claim 1, wherein the convex portion located at the uppermost step of the step-like convex portion has a substantially cylindrical shape having a diameter of 0.5 to 10 μm.   The method for producing a metal perforated structure according to claim 1 or 2, wherein an aspect ratio of the convex portion located at the uppermost step of the step-like convex portion is 1 to 5.   The method for producing a metal perforated structure according to any one of claims 1 to 3, wherein a side wall angle of the convex portion located at the uppermost step of the step-like convex portion is 70 to 90 °. A metal perforated structure comprising a metal base having a first surface and a second surface facing the first surface, wherein a through hole is formed in the thickness direction of the metal base,
The through hole has a straight portion having substantially the same hole diameter from the first surface toward the second surface, and a diameter expansion that is continuous with the straight portion and expands in a trumpet shape toward the second surface side. Including
The hole structure of the said straight part is 0.5-10 micrometers, The metal porous structure characterized by the above-mentioned.   The metal perforated structure according to claim 5, wherein a length of the straight portion in a thickness direction of the metal base is 1 to 25 μm.   The metal perforated structure according to claim 5 or 6, wherein a side wall angle of the straight portion is 70 to 90 °. An imprint mold used for manufacturing a metal perforated structure,
A base material having a first surface and a second surface facing the first surface;
An imprint mold for producing a metal perforated structure, comprising: at least two stepped recesses formed on the first surface of the substrate.

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