MASTER FORM AND METAL FORMING METHOD

Abstract

In a master mold and a method for producing a metal molded article, the master mold has: a product region having an electrodeposition surface on which a metal molded article is formed by electrodeposition, in which a product part that is cut out as a product from the metal molded article is formed on the electrodeposition surface; and a non-product region other than the product region. The master mold has: a product pattern which is formed in the product region and includes a depressed part and a projecting part; and a dummy pattern which is formed in at least a part of the non-product region and includes a plurality of depressed parts and a plurality of projecting parts, in which, when the surface area of the product pattern per unit area of the product region is defined as a first surface area and the surface area of the dummy pattern per unit area of a dummy region on which the dummy pattern is formed is defined as a second surface area, the second surface area is larger than the first surface area.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to methods for manufacturing electroforming masters and metal moldings. [Background technology]

[0002] A master matrix for producing a metal molded product having a texture by electroforming is known (see, for example, JP 2015-30881 A). Such a master matrix has an electrodeposited surface on which a metal molded product is formed by electrodeposition, and a textured pattern is formed on the electrodeposited surface using, for example, a resist. The electroforming procedure involves immersing the master matrix on which the textured pattern has been formed in a plating solution, and depositing metal on the electrodeposited surface to grow the metal molded product. The grown metal molded product is then peeled off from the master matrix. The metal molded product thus obtained has, for example, textured surfaces that are the inverse of the textured pattern of the master matrix.

[0003] Furthermore, Japanese Patent Application Laid-Open No. 2015-30881 lists, as metal molded articles, aperture plates having a plurality of apertures, such as nozzle plates for ejecting ink in inkjet printers and filter plates used for filtration.

[0004] Japanese Patent Application Laid-Open Publication No. 2015-30881 discloses the use of a master master on which a dummy resist pattern smaller than the concave-convex pattern for forming an aperture in an aperture plate is formed around the concave-convex pattern for the plate. According to the technology of Japanese Patent Application Laid-Open Publication No. 2015-30881, electroforming is performed using a master master with a dummy pattern around the concave-convex pattern for the plate, thereby making the current density distribution in and around the concave-convex pattern for the plate uniform. This makes it possible to make the thickness of the electrodeposited layer formed over the entire area of ​​the concave-convex pattern for the plate uniform. Summary of the Invention [Problem to be solved by the invention]

[0005] As described in JP 2015-30881 A, a metal molded product formed using a master is peeled from the master, and a portion of the product is cut out. The electroforming surface of such a master is provided with a product area where the product portion of the metal molded product to be cut out as the product is formed, and a non-product area other than the product area. In JP 2015-30881 A, the product area is an area where a product pattern, such as a concave-convex pattern for a plate, is formed. A dummy pattern is formed in at least a portion of the non-product area, such as around the product pattern.

[0006] In the master master of JP 2015-30881 A, for example, if the dimensions of the recesses or protrusions included in the product pattern are small or the density of the recesses or protrusions is low, the metal molding may peel off from the master master during electroforming.

[0007] The present disclosure has been made in consideration of the above circumstances, and aims to provide a master plate and a method for manufacturing a metal molded product that are capable of suppressing peeling of the metal molded product during growth in the electroforming process. [Means for solving the problem]

[0008] The master matrix of the present disclosure has an electrodeposited surface on which a metal molded product is formed by electrodeposition, and has, on the electrodeposited surface, a product region in which a product portion to be cut out of the metal molded product is formed, and a non-product region other than the product region, a product pattern formed in the product area and including recesses and protrusions; The master substrate includes a dummy pattern formed in at least a portion of a non-product area and including a plurality of recesses and protrusions, wherein the surface area of ​​the product pattern per unit area of ​​the product area is defined as a first surface area, and the surface area of ​​the dummy pattern per unit area of ​​the dummy area in which the dummy pattern is formed is defined as a second surface area, and the second surface area is defined as the surface area of ​​the dummy pattern per unit area of ​​the dummy area in which the dummy pattern is formed.

[0009] In the master disc of the present disclosure, the area of ​​the dummy region is preferably larger than the product region.

[0010] In the master disk of the present disclosure, it is preferable that a plurality of recesses or protrusions are regularly arranged in the dummy area.

[0011] In the master disk of the present disclosure, the product pattern includes a plurality of recesses or protrusions, and the recesses or protrusions are regularly arranged in the product pattern; It is preferable that the arrangement pitch of the plurality of recesses or protrusions of the dummy pattern is smaller than the arrangement pitch of the recesses or protrusions of the product pattern.

[0012] In the master disk of the present disclosure, it is preferable that the height of the convex portions of the dummy pattern is greater than the height of the convex portions of the product pattern.

[0013] In the master disk of the present disclosure, the aspect ratio of the convex portions or concave portions of the dummy pattern is preferably larger than the aspect ratio of the convex portions or concave portions of the product pattern.

[0014] In the master master of the present disclosure, the dummy pattern and the product pattern each have a bottom surface and a convex portion protruding from the bottom surface, and it is preferable that the angle formed between the side wall of the convex portion of the dummy pattern and the bottom surface is smaller than the angle formed between the side wall of the convex portion of the product pattern and the bottom surface.

[0015] In the master disk of the present disclosure, the dummy pattern has a bottom surface and the convex portion protruding from the bottom surface, and it is preferable that the angle formed between the sidewall of the convex portion of the dummy pattern and the bottom surface is 90° or less.

[0016] In the master master of the present disclosure, the planar shape of the electrodeposited surface is circular, and three product areas are provided with three-fold rotational symmetry about the center of the electrodeposited surface, and a dummy pattern may be provided within the area surrounded by the three product areas.

[0017] The master master of the present disclosure has a conductive substrate having an electrodeposited surface and a non-conductive mask formed on the electrodeposited surface to control the growth of the metal molding, and the convex portions of the product pattern and dummy pattern may be non-conductive masks.

[0018] In the master disk of the present disclosure, the material of the non-conductive mask that forms the convex portions of at least one of the product pattern and the dummy pattern may be a photosensitive resin.

[0019] In the master disk of the present disclosure, the material of the non-conductive mask that forms the convex portions of at least one of the product pattern and the dummy pattern may be an inorganic material.

[0020] In the master disk of the present disclosure, at least one of the convex portions of the product pattern and the convex portions of the dummy pattern may be formed from a conductive material, and the other may be formed from a non-conductive material.

[0021] The method for manufacturing a metal molded product of the present disclosure includes an electroforming process in which a master matrix of the present disclosure is immersed in an electroforming solution and a metal is deposited on the electrodeposited surface to grow a metal molded product, and a peeling process in which the metal molded product is peeled off from the master matrix.

[0022] In the method for producing a metal molded product according to the present disclosure, it is preferable that the surface of the convex portions of the product pattern on the master disk have a water contact angle of 20° or less. [Effects of the Invention]

[0023] According to the master matrix and metal molded product manufacturing method of the present disclosure, it is possible to prevent the metal molded product from peeling off during growth in the electroforming process. [Brief explanation of the drawings]

[0024] [Figure 1A] FIG. 2 is a plan view of a master matrix according to an embodiment. [Figure 1B] FIG. 10 is a plan view of a master disk according to a modified example of the design. [Figure 2]FIG. 2A is an enlarged plan view of a portion of a master disc according to one embodiment, and FIG. 2B is a cross-sectional view. [Figure 3] FIG. 3A is an enlarged plan view of a portion of a master disk having a concave-convex pattern, and FIG. 3B is a cross-sectional view. [Figure 4] FIG. 10 is an explanatory diagram of the heights of the convex portions of the product pattern and the convex portions of the dummy pattern. [Figure 5] 10 is an explanatory diagram of the angle formed between the sidewall and bottom surface of a convex portion of a product pattern and the angle formed between the sidewall and bottom surface of a convex portion of a dummy pattern. FIG. [Figure 6] 10 is an explanatory diagram of the angle formed between the sidewall and bottom surface of a convex portion of a dummy pattern; [Figure 7] FIG. 2 is a cross-sectional view showing a specific configuration example 20A of the master disk 20. [Figure 8] FIG. 2 is a cross-sectional view showing a specific configuration example 20B of the master disc 20. [Figure 9] 10 is a cross-sectional view showing a specific configuration example 20C of the master disc 20. FIG. [Figure 10] FIG. 10 is a cross-sectional view showing a specific configuration example 20D of the master disc 20. [Figure 11] 10 is a cross-sectional view showing a specific configuration example 20E of the master disk 20. FIG. [Figure 12] 10 is a cross-sectional view showing a specific configuration example 20F of the master disk 20. FIG. [Figure 13] 10 is a cross-sectional view showing a specific configuration example 20G of the master disk 20. FIG. [Figure 14] FIG. 2 is a perspective view showing a part of a nozzle plate. [Figure 15] 1A to 1C are diagrams illustrating a manufacturing process of a nozzle plate. [Figure 16] FIG. 1 is a diagram illustrating an example of an electroforming apparatus. [Figure 17] 1A to 1C are diagrams illustrating a process for producing a master disc. [Figure 18] FIG. [Figure 19] 1A to 1C are diagrams illustrating a manufacturing process of a mold. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0026] "Master master" FIG. 1A is a plan view of a master matrix 20 according to one embodiment, and FIG. 2 is an enlarged view of a portion of the master matrix 20, with FIG. 2A being a plan view and FIG. 2B being a cross-sectional view.

[0027] The master matrix 20 is used to manufacture metal molded products by electroforming. The master matrix 20 has an electrodeposited surface 20a on which the metal molded product is formed by electrodeposition. The electrodeposited surface 20a of the master matrix 20 has a product region 23 where a product portion of the metal molded product to be cut out as a product is formed, and a non-product region 24 outside the product region 23. The master matrix 20 further includes a product pattern 30 formed in the product region 23 and including recesses 32 and protrusions 34, and a dummy pattern 40 formed in at least a portion of the non-product region 24 and including a plurality of recesses 42 and protrusions 44. Here, the dummy pattern 40 is a pattern whose second surface area S2 is larger than the first surface area S1, where the surface area of ​​the product pattern 30 per unit area of ​​the product region 23 is defined as a first surface area S1 and the surface area of ​​the dummy pattern 40 per unit area of ​​the dummy region 25 in which the dummy pattern 40 is formed is defined as a second surface area S2.

[0028] The product area 23 is, for example, an area surrounded by a dashed line in the figure, and in this example, is defined by an alignment mark 31. In the master disk 20 of this example, the electrodeposited surface 20a has a circular planar shape, and three product areas 23 are provided around the center C of the electrodeposited surface 20a with three-fold rotational symmetry. On the electrodeposited surface 20a, all areas other than the product areas 23 are non-product areas 24. In this example, the dummy areas 25 are formed over almost the entire non-product areas 24.

[0029] Concave-convex patterns including concave and convex portions include concave-convex patterns formed by forming concave portions on a flat surface (hereinafter referred to as concave-type patterns), and concave-convex patterns formed by forming convex portions on a flat surface (hereinafter referred to as convex-type patterns). In the master matrix 20 shown in FIG. 2, both the concave-convex patterns of the product pattern 30 and the dummy pattern 40 are convex-type patterns. On the other hand, FIG. 3 shows a partially enlarged plan view (FIG. 3A) and a cross-sectional view (FIG. 3B) of the master matrix 20 in which both the concave-convex patterns of the product pattern 30 and the dummy pattern 40 of the master matrix 20 are concave-type patterns. Note that a single master matrix 20 may contain both a convex-type pattern and a concave-type pattern, such as when the product pattern 30 is a convex-type pattern and the dummy pattern 40 is a concave-type pattern. Whether the concave-convex pattern is a convex-type pattern or a concave-type pattern, the concave-convex pattern includes a bottom surface and convex portions 34, 44 protruding from the bottom surface. Here, the bottom surface corresponds to the inner bottom surface of the recesses 32 and 42 (see FIGS. 2 and 3).

[0030] The surface area of ​​the product pattern 30 is the sum of the area Sp of the product region 23 in a plan view and the area Ss1 of the side walls 32a of the recesses 32 or the side walls 34a of the protrusions 34 of the product pattern 30. Therefore, the surface area per unit area of ​​the product pattern 30 (first surface area S1) is expressed as S1 = (Sp + Ss1) / Sp.

[0031] As shown in FIG. 2, when the product pattern 30 is a convex pattern, the surface area of ​​the product pattern 30 is the sum of the area of ​​the product region 23 in a plan view and the area of ​​the side walls 34a of the convex portions 34 of the product pattern 30.

[0032] As shown in FIG. 3, when the product pattern 30 is a recessed pattern, the surface area of ​​the product pattern 30 is the sum of the area of ​​the product region 23 in a plan view and the area of ​​the sidewalls 32a of the recesses 32 of the product pattern 30.

[0033] When there are multiple product regions 23 as shown in FIG. 1A, the surface area per unit area of ​​the product pattern 30 is the average value of the surface area per unit area in each region.

[0034] The surface area of ​​the dummy pattern 40 is the sum of the area Sd of the dummy region 25 in a plan view and the area Ss2 of the side walls 42a of the recesses 42 or the side walls 44a of the protrusions 44 of the dummy pattern 40. Therefore, the surface area per unit area of ​​the dummy pattern 40 (second surface area S2) is expressed as S2 = (Sd + Ss2) / Sd.

[0035] As shown in FIG. 2, when the dummy pattern 40 is a convex pattern, the surface area of ​​the dummy pattern 40 is the sum of the area of ​​the dummy region 25 in a plan view and the area of ​​the sidewalls 44a of the convex portions 44 of the dummy pattern 40.

[0036] As shown in FIG. 3, when the dummy pattern 40 is a recessed pattern, the surface area of ​​the dummy pattern 40 is the sum of the area of ​​the dummy region 25 in a plan view and the area of ​​the sidewall 42a of the recess 42 of the dummy pattern 40.

[0037] When there are a plurality of dummy regions 25, the surface area per unit area of ​​the dummy pattern 40 is the average value of the surface area per unit area of ​​each region.

[0038] The dummy area 25 refers to a closed area in the non-product area 24 where a dummy pattern 40 is formed. In the master master 20 shown in FIG. 1A, the dummy pattern 40 is formed throughout the entire non-product area 24, and the entire non-product area 24 corresponds to the dummy area 25. As in the master master 120 shown in FIG. 1B, the dummy area 25 may be formed partially in the non-product area 24. In FIG. 1B, components equivalent to those of the master master 20 shown in FIGS. 1A and 2 are denoted by the same reference numerals. The same applies to the following drawings. In the master master 120 shown in FIG. 1B, a dummy pattern 40 is formed within an area surrounded by three product areas 23, and the area in which this dummy pattern 40 is formed is the dummy area 25. When the dummy pattern 40 is a convex pattern and the dummy region 25 is partially formed in the non-product region 24, the dummy region 25 is a region surrounding the outer periphery of the outermost convex portion 44 of the multiple convex portions 44 formed in the non-product region 24. When the dummy pattern 40 is a concave pattern and the dummy region 25 is partially formed in the non-product region 24, the dummy region 25 is a region surrounding the outer periphery of the outermost concave portion 42 of the multiple concave portions 42 formed in the non-product region 24. Note that the dummy region 25 is not limited to being provided in one location in the center of the master as shown in FIG. 1B , but may be provided anywhere within the non-product region 24, and may be formed in multiple locations rather than in one location.

[0039] The size and density of the recesses or protrusions of the product pattern are determined by the product specifications and cannot be changed. If the surface area of ​​the recesses or protrusions of the product pattern is small, adhesion with the electrodeposited layer will be poor, raising concerns about peeling between the electrodeposited layer and the master during electroforming. In JP 2015-30881 A, a dummy pattern is provided around the product pattern, which is expected to provide an anchoring effect. However, the dummy pattern in JP 2015-30881 A has smaller recesses or protrusions than the product pattern. As a result, there was concern that the anchoring effect of the dummy pattern would be weaker than that of the product pattern, and the required anchoring effect would not be achieved. However, in the present master master 20, the surface area per unit area of ​​the dummy region is larger than the surface area per unit area of ​​the product region, thereby providing a strong anchoring effect, further improving adhesion, and fully suppressing peeling during electroforming.

[0040] In the master master 20, 120, the area of ​​the dummy region 25 is preferably larger than the product region 23. When comparing the area of ​​the dummy region 25 and the area of ​​the product region 23 in the master master 20, 120, the total area of ​​all dummy regions 25 formed in one master master 20, 120 is compared with the total area of ​​all product regions 23. For example, in the master master 120 shown in FIG. 1B, the area of ​​one dummy region 25 is preferably larger than the total area of ​​the three product regions 23. If the area of ​​the dummy region 25 is larger than the product region 23, the anchor effect during electroforming is enhanced, and the peeling suppression effect can be improved.

[0041] 1A and 2, the master disk 20 has a plurality of recesses 42 or protrusions 44 regularly arranged in the dummy area 25. However, the recesses 42 and protrusions 44 formed in the dummy area 25 are not limited to a regular arrangement, and may be irregularly arranged. Furthermore, the dummy pattern 40 may be a pattern in which irregular recesses or protrusions are formed by a surface roughening process such as matte.

[0042] In this embodiment, the product pattern 30 of the master disk 20 includes a plurality of recesses 32 or protrusions 34, and the recesses 32 or protrusions 34 are regularly arranged in the product pattern 30. The dummy pattern 40 also has a plurality of recesses 42 and protrusions 44 regularly arranged.

[0043] In such a case, it is preferable that the arrangement pitch of the recesses 42 or protrusions 44 of the dummy pattern 40 is smaller than the arrangement pitch of the recesses 32 or protrusions 34 of the product pattern 30. That is, it is preferable that the recesses 42 or protrusions 44 are formed at a higher density in the dummy region 25 than the arrangement density of the recesses 32 or protrusions 34 in the product region 23. If the arrangement pitch of the recesses 42 or protrusions 44 of the dummy pattern 40 is smaller than the arrangement pitch of the recesses 32 or protrusions 34 of the product pattern 30, it is possible to easily make the second surface area S2 larger than the first surface area S1.

[0044] 2, when the product pattern 30 is a convex pattern in which a plurality of convex portions 34 are arranged two-dimensionally and spaced apart from one another, the arrangement pitch of the convex portions 34 of the product pattern 30 is the average value of the arrangement pitches Psa and Psb in the directions of two orthogonal axes. When the product pattern 30 is a pattern in which a plurality of convex portions 34 are arranged in one direction and spaced apart from one another, the arrangement pitch of the convex portions 34 of the product pattern 30 is the arrangement pitch of the convex portions 34 in that one direction.

[0045] When the product pattern 30 is a recessed pattern, the arrangement pitch of the recessed portions 32 of the product pattern 30 is determined by replacing the convex portions 34 with the recessed portions 32 in the above description.

[0046] 2, when the dummy pattern 40 is a convex pattern in which a plurality of convex portions 44 are arranged two-dimensionally and spaced apart from one another, the arrangement pitch of the convex portions 44 of the dummy pattern 40 is the average value of the arrangement pitches Pda and Pdb in the directions of two orthogonal axes. When the dummy pattern 40 is a pattern in which a plurality of convex portions 44 are arranged in one direction and spaced apart from one another, the arrangement pitch of the convex portions 44 of the dummy pattern 40 is the arrangement pitch of the convex portions 44 in that one direction.

[0047] When the dummy pattern 40 is a concave pattern, the arrangement pitch of the concave portions 42 of the dummy pattern 40 is determined by replacing the convex portions 44 with the concave portions 42 in the above description.

[0048] 4, in the master matrix 20, it is desirable that the height Hd of the convex portions 44 of the dummy pattern 40 is greater than the height Hs of the convex portions 34 of the product pattern 30. By making Hd>Hs, it is possible to easily make the second surface area S2 greater than the first surface area S1.

[0049] In the master disk 20, it is preferable that the aspect ratio of the convex portions 44 or concave portions 42 of the dummy pattern 40 be larger than the aspect ratio of the convex portions 34 or concave portions 32 of the product pattern 30. By making the aspect ratio of the concave portions 42 or convex portions 44 of the dummy pattern 40 larger than the aspect ratio of the concave portions 32 or convex portions 34 of the product pattern 30, it is possible to easily make the second surface area S2 larger than the first surface area S1.

[0050] Here, the aspect ratio is the height of the convex portion / the diameter of the circle equivalent to the area of ​​the convex portion or the concave portion in a plan view. For example, when the product pattern 30 is a convex pattern, Aspect ratio = height Hs of the protrusion 34 / diameter Ds of the circle equivalent to the area of ​​the protrusion 34 in a plan view When the dummy pattern 40 is a recessed pattern, Aspect ratio = height Hs of the convex portion 34 / diameter Ds of the concave portion 32 in a plan view is.

[0051] Similarly, when the dummy pattern 40 is a convex pattern, Aspect ratio = height Hd of the protrusion 44 / diameter Dd of the circle equivalent to the area of ​​the protrusion 44 in a plan view Furthermore, when the dummy pattern 40 is a recessed pattern, Aspect ratio=height Hd of convex portion 44 / circle-equivalent diameter Dd of concave portion 42 in plan view.

[0052] The dummy region 25 preferably has recesses 42 or protrusions 44 that are larger in size than the recesses 32 or protrusions 34 in the product region 23. Larger in size than the recesses 32 or protrusions 34 in the product region 23 means that the product of the height Hd of the recesses 42 or protrusions 44 and the circle-equivalent diameter Dd of the area in a plan view is larger than the product of the height Hs of the recesses 32 or protrusions 34 and the circle-equivalent diameter Ds of the area in a plan view. Note that if the product region 23 includes recesses 32 or protrusions 34 of different sizes, the heights and the circle-equivalent diameters of the area in a plan view are their average values. The same applies when the dummy region 25 includes recesses 42 or protrusions 44 of different sizes.

[0053] 5, in the master plate 20, it is preferable that the angle θ2 formed between the sidewalls 44a of the convex portions 44 of the dummy pattern 40 and the bottom surfaces 42b of the concave portions 42 is smaller than the angle θ1 formed between the sidewalls 34a of the convex portions 34 of the product pattern 30 and the bottom surfaces 32b of the concave portions 32. When θ2<θ1, the adhesion of the dummy pattern 40 to the electrodeposited layer during electroforming can be made higher than that of the product pattern 30, and the anchor effect of the dummy pattern 40 can be further enhanced. This can improve the effect of suppressing peeling of the metal molded product during growth in the electroforming process.

[0054] 6, the angle θ2 formed between the sidewall 44a of the protrusion 44 of the dummy pattern 40 and the bottom surface 42b of the recess 42 is preferably 90° or less. By setting θ2 to 90° or less, more preferably less than 90°, the anchoring effect of the dummy pattern 40 during electrodeposition can be further enhanced. Therefore, the effect of suppressing peeling of the metal molded product during growth in the electroforming process can be further enhanced.

[0055] Configuration examples 20A to 20G of the master disc 20 will be described with reference to FIGS.

[0056] A method for manufacturing a metal molded product will be described later. When manufacturing a product with an opening, such as a nozzle plate, the master matrix 20 includes a conductive substrate 21 having an electrodeposited surface and a non-conductive mask formed on the substrate 21 to control the growth of the metal molded product. In this case, the master matrix 20 has a convex pattern, and the convex portions 34 of the product pattern 30 and the convex portions 44 of the dummy pattern 40 are formed using a non-conductive mask. That is, the convex portions 34 of the product pattern 30 and the convex portions 44 of the dummy pattern 40 are made of a non-conductive material, and the convex portions 34 and the convex portions 44 made of a non-conductive material function as a non-conductive mask to control the growth of the metal molded product. The non-conductive mask forming at least one of the convex portions 34 of the product pattern 30 and the convex portions 44 of the dummy pattern 40 may be made of a photosensitive resin. The non-conductive mask forming at least one of the convex portions 34 of the product pattern 30 and the convex portions 44 of the dummy pattern 40 may also be made of an inorganic material. The conductive substrate 21 is preferably a metal substrate such as stainless steel.

[0057] The master master 20A shown in FIG. 7 includes a conductive substrate 21 and convex portions 34 and 44 serving as a non-conductive mask on one surface of the substrate 21. The convex portions 34 and 44 serving as a non-conductive mask can be formed from a photosensitive resin. The master master 20A shown in FIG. 7 can be produced, for example, by forming a photosensitive resin layer on the substrate 21, exposing it to light in the shape of a mask, and developing it. If both the product pattern 30 and the dummy pattern 40 include convex portions 34 and 44 made from a photosensitive resin layer, there is an advantage in that the metal molded product formed by electroforming can be easily peeled from the master master 20A.

[0058] The master disk 20B shown in Figure 8 includes a non-conductive substrate 22, a metal film 22a formed on one surface of the non-conductive substrate 22, and convex portions 34, 44 serving as a non-conductive mask on the metal film 22a. As with the master disk 20A, the convex portions 34, 44 are formed from a photosensitive resin. The non-conductive substrate 22 may be a glass substrate or a silicon substrate. In this way, either a conductive substrate or a non-conductive substrate may be used as the flat substrate, without any restrictions.

[0059] The master master 20C shown in FIG. 9, like the master master 20A, includes a conductive substrate 21 and non-conductive masks, i.e., convex portions 34 and 44. The non-conductive mask convex portions 34 and 44 can be formed from an inorganic material instead of a photosensitive resin. Examples of inorganic materials include metal oxides, metal nitrides, and metal fluorides. The master master 20C shown in FIG. 9 is formed by, for example, sputtering a metal mask having an opening pattern corresponding to the desired convex portion pattern, facing one surface of the substrate 21. This allows the formation of convex portions 34 and 44 corresponding to the opening pattern. When both the product pattern 30 and the dummy pattern 40 include convex portions 34 and 44 made of inorganic materials, the convex and concave patterns of the master master 20C remain even when a metal molded product formed by electroforming is peeled from the master master 20C. Therefore, the master master 20C can be reused repeatedly, and multiple metal molded products can be produced using a single master master 20C.

[0060] The master matrix 20D shown in FIG. 10 includes a conductive substrate 21 and convex portions 34 and 44 serving as non-conductive masks. In the master matrix 20D, the convex portions 34 of the product pattern 30 are formed from a photosensitive resin, and the convex portions 44 of the dummy pattern 40 are formed from an inorganic material. Because the convex portions 34 of the product pattern 30 are made of a photosensitive resin, the metal molding can be peeled off without placing a large load on the product portion. On the other hand, because the convex portions 44 of the dummy pattern 40 are made from an inorganic material, they remain on the substrate 21 even after the metal molding is peeled off. Therefore, after the metal molding is peeled off, the master matrix 20D can be reproduced by re-forming only the convex portions 34 of the product pattern 30 on the substrate 21, and the master matrix 20D can be reused for electroforming of a metal molding.

[0061] The master matrix 20E shown in Figure 11 includes a conductive substrate 21 and convex portions 34, 44 serving as a non-conductive mask. In the master matrix 20E, the convex portions 34 of the product pattern 30 are formed from an inorganic material, and the convex portions 44 of the dummy pattern 40 are formed from a photosensitive resin. Because the convex portions 34 of the product pattern 30 are formed from an inorganic material, they remain on the substrate 21 even after the metal molding is peeled off. Therefore, after the metal molding is peeled off, the master matrix 20E can be reproduced by re-forming only the convex portions 44 of the dummy pattern 40 on the substrate 21, and can be used again for electroforming of a metal molding.

[0062] Furthermore, in the master matrix 20, at least one of the convex portions 34 of the product pattern 30 and the convex portions 44 of the dummy pattern 40 may be made of a conductive material, and the other may be made of a non-conductive material. Specific examples are shown in FIGS. 12 and 13.

[0063] The master master 20F shown in FIG. 12 is used when manufacturing products having openings such as nozzle plates, similar to the master masters 20A to 20E shown in FIGS. 7 to 11. The master master 20F includes a metal substrate 28 on which the convex portions 44 of the dummy pattern 40 are integrally formed, and convex portions 34 of the product pattern 30 as a non-conductive mask. In the master master 20F, the convex portions 44 of the dummy pattern 40 are formed as part of the metal substrate 28. The convex portions 34 of the product pattern 30 are formed from a non-conductive material. The non-conductive material can be a photosensitive resin or an inorganic material. As with the above, the inorganic material can be a metal oxide, metal nitride, or metal fluoride.

[0064] On the other hand, if the product is a mold such as a stamper for imprinting, the recessed portions 32 and protruding portions 34 that form the product pattern 30 in the product region 23 must all be conductive during electroforming. The master matrix 20G shown in FIG. 13 includes a metal substrate 29 on which the protruding portions 34 of the product pattern 30 are integrally formed, and protruding portions 44 of a dummy pattern 40 that serves as a non-conductive mask. In the master matrix 20G, the protruding portions 34 of the product pattern 30 are formed as part of the metal substrate 29. In this example, the protruding portions 44 of the dummy pattern 40 are formed from a non-conductive material. As with the above, a photosensitive resin or an inorganic material can be used as the non-conductive material.

[0065] In the case of a master for a mold, as described above, both the recesses 32 and protrusions 34 that form the product pattern 30 in the product region 23 must be conductive during electroforming. However, the master may have a non-conductive surface for both the product pattern and the dummy pattern. In this case, conductivity can be imparted to the non-conductive electrodeposited surface of the master by forming a metal film by sputtering or the like before electroforming. In other words, the electrodeposited surface of the master in this disclosure includes a non-conductive surface before conductivity is imparted.

[0066] "Metal molding manufacturing method" Next, a method for manufacturing a metal molded product using the master matrix of the present disclosure will be described. The method for manufacturing a metal molded product of the present disclosure includes an electroforming step using the master matrix. In the electroforming step, the master matrix is ​​immersed in an electrolyte, and a metal is deposited on the electroformed surface of the master matrix to grow the metal molded product. The method for manufacturing a metal molded product further includes a peeling step in which the metal molded product is peeled off from the master matrix. The metal molded product is manufactured by performing the electroforming step and the peeling step.

[0067] A method for manufacturing a metal molded product according to the first embodiment will be described below. Here, a method for manufacturing a nozzle plate 100 having a plurality of nozzles 102 as the metal molded product will be described.

[0068] FIG. 14 is a perspective view showing a part of a nozzle plate 100 used in a recording head of an inkjet printer, which is an example of a metal molded product manufactured by the method for manufacturing a metal molded product according to the first embodiment.

[0069] The nozzle plate 100 is a plate-like member formed of electroformed metal such as nickel (Ni) and having a rectangular planar shape. The nozzle plate 100 has a plurality of substantially circular openings 102 (hereinafter referred to as nozzles 102) arranged two-dimensionally and functioning as nozzles. The nozzles 102 are formed in a substantially circular shape, and their diameter is, for example, 100 μm or less, preferably 20 μm to 50 μm. In the recording head, the nozzle plate 100 is disposed in an orientation in which its long dimension corresponds to the main scanning direction X of the inkjet printer and its short dimension corresponds to the sub-scanning direction Y. The length of the nozzle plate 100 in the main scanning direction X is, for example, 100 mm, and the length in the sub-scanning direction Y is, for example, 40 mm.

[0070] As an example of the master master 20, a master master 20A (see FIG. 7) having convex portions 34, 44 made of a mask formed of a non-conductive material on a conductive substrate 21 is used. In the master master 20, the bottom surfaces of the concave portions 32, 42 of the product pattern 30 and the dummy pattern 40 are the surface of the substrate 21, and a metal layer 101 that will become the nozzle plate 100 grows from this portion. Growth of the metal layer 101 is suppressed in the mask portions made of a non-conductive material (convex portions 34, 44). As a result, openings are formed in the mask portions. These openings become the nozzles 102 in the nozzle plate 100. In this example, four rows of convex portions 34 are formed in a 100 mm × 40 mm area of ​​the master master 20, corresponding to the arrangement pitch and number of the nozzles 102 of the nozzle plate 100 described above. The diameter DM of the convex portions 34 is larger than the diameter D of the nozzles 102, and is, for example, 150 μm to 200 μm. The thickness of the protrusion 34 is, for example, 2 μm.

[0071] Figure 15 is a diagram showing the manufacturing process of the nozzle plate 100. Figure 15 shows a partial cross section (S0) including only three convex portions 34 of the product pattern 30 of the master matrix 20 shown in Figure 1A. First, in the electroforming step S1, with the master matrix 20 immersed in an electrolyte, a metal layer 101 is grown as an electrodeposited layer on the electrodeposited surface 20a by metal precipitated from the electrolyte.

[0072] During electroforming, the metal layer 101 grows from the bottom of the recess 32, while no metal is deposited on the surface of the protrusion 34, which serves as a non-conductive mask, and the metal layer 101 does not grow. The metal layer 101 gradually grows on the bottom of the recess 32. After that, when the thickness of the grown metal layer 101 exceeds the thickness of the protrusion 34, the metal layer 101 grows from the surface of the previously grown metal layer 101 toward the protrusion 34 so as to cover the edges of the protrusion 34. As the metal layer 101 grows from the edges of the protrusion 34 toward the center, an opening is formed in the metal layer 101 with its center located approximately at the center of the protrusion 34. This opening becomes the nozzle 102. As the thickness of the metal layer 101 increases, the metal layer 101 grows toward the center of the protrusion 34, and the opening diameter of the nozzle 102 gradually decreases. The diameter of the protrusion 34 is determined so that the nozzle 102 has a desired opening diameter when the metal layer 101 is grown to a desired thickness. On the protrusion 34, the growth of the metal layer 101 progresses more rapidly as it approaches the bottom surface 32b of the recess 32. Therefore, as shown in FIG. 15 , the opening diameter of the nozzle 102 becomes smaller as it approaches the bottom surface 32b and becomes larger as it moves away from the bottom surface 32b, and the cross section of the metal layer 101 constituting the inner wall surface of the nozzle 102 has an arc shape. For example, the reference for the opening diameter of the target nozzle 102 is set to the opening diameter of the nozzle 102 closer to the bottom surface 32b. Then, the diameter of the protrusion 34 is determined so that the reference opening diameter of the nozzle 102 becomes the target opening diameter. The thickness of the metal layer 101 is, for example, approximately 50 μm.

[0073] After the electroforming step, the metal layer 101 is peeled off from the master master 20 (peeling step S2). At this time, the convex portions 34 made of photosensitive resin are peeled off together with the metal layer 101 from the master master 20 (here, the substrate 21).

[0074] Thereafter, the protrusions 34 attached to the metal layer 101 are removed (mask removal step S3). Furthermore, the nozzle plate 100 can be obtained by punching out the product area 23 using the alignment marks 31 as guides.

[0075] The electroforming step S1 will now be described in detail. Fig. 16 shows an example of an electroforming apparatus 130 used in the electroforming step S1. The electroforming apparatus 130 includes an electroforming tank 132, a master holding mechanism 135, an anode 139, and a circulation mechanism 140 for the electrolyte 134.

[0076] The electroforming tank 132 stores an electrolyte 134. An anode 139 is disposed on a portion of the inner wall surface of the electroforming tank 132. During electroforming, the master master 20 is immersed in the electrolyte 134 in the electroforming tank 132. In the electrolyte 134, the master master 20 is disposed with the electrodeposited surface 20a facing the anode 139. The anode 139 contains an electroforming metal such as a nickel pellet, and has a size that allows it to face the entire area of ​​the electrodeposited surface 20a on the master master 20. Electroforming is performed on the master master 20 with the electrodeposited surface 20a of the master master 20 facing the anode 139.

[0077] In this example, the electroforming tank 132 has a portion of its sidewall that is inclined. The inclination of the sidewall causes the upper opening of the electroforming tank 132 to be wider than the bottom surface thereof, and the inclination angle of the sidewall is, for example, approximately 40° to 50° with respect to the horizontal direction. The anode 139 is disposed along the inner wall surface of the inclined sidewall, in a position inclined with respect to the horizontal direction.

[0078] The master holding mechanism 135 includes a holding unit 136, a rotation shaft 137, and a rotation device 138. The holding unit 136 holds the master master 20 from the side opposite the electrodeposited surface 20a of the master master 20. The rotation shaft 137 is attached to the back surface of the holding unit 136 and extends in the normal direction to the back surface of the holding unit 136. The rotation device 138 rotates the holding unit 136 via the rotation shaft 137. The holding unit 136 holds the master master 20 in the electroforming tank 132 so that the electrodeposited surface 20a of the master master 20 faces an anode 139. In other words, the master master 20 is placed in an orientation where the electrodeposited surface 20a is tilted from the horizontal.

[0079] The master master 20 is held by the holder 136 so that its center coincides with the rotation axis 137. When the rotation device 138 is driven, the master master 20 rotates integrally with the holder 136 via the rotation axis 137, with the center coincident with the rotation axis 137 as the center of rotation. The master master 20 is set in the holder 136 outside the electroforming tank 132, and is immersed in the electroforming tank 132 while being held by the holder 136. Then, electroforming is performed while the master master 20 is rotated around an axis extending in the normal direction from the center position within the plane of the electrodeposited surface 20a.

[0080] During electroforming, the electrodeposition surface 20a of the master disk 20 is used as a cathode, and electricity is passed between the electrodeposition surface 20a, which serves as the cathode, and an anode 139 containing electroformed metal. This causes the electroformed metal of the anode 139 to electrolyze and dissolve as electric ions into the electrolytic solution 134. The metal precipitated from the electrolytic solution 134 is then electrodeposited on the electrodeposition surface 20a, which serves as the cathode, to form a metal layer 101.

[0081] The circulation mechanism 140 includes a storage tank 141, a discharge pipe 142, a valve 143, a pump 144, a filter 146, a supply pipe 147, and a nozzle 148. The circulation mechanism 140 circulates the electrolyte 134 stored in the electroforming tank 132 between the electroforming tank 132 and a storage tank 141 disposed outside the electroforming tank 132. This circulation causes the electrolyte 134 to flow between the electrodeposited surface 20a and the anode 139.

[0082] The discharge pipe 142 and the supply pipe 147 constitute a circulation path for the electrolytic solution 134 between the electroforming tank 132 and the storage tank 141. The discharge pipe 142 constitutes a return pipe in the circulation path that discharges the electrolytic solution 134 from the electroforming tank 132 and returns the discharged electrolytic solution 134 to the storage tank 141. The supply pipe 147 constitutes a supply pipe in the circulation path that supplies the electrolytic solution 134 from the storage tank 141 to the electroforming tank 132.

[0083] One end of the discharge pipe 142 is disposed in the electroforming tank 132, and the other end is connected to the storage tank 141. The discharge pipe 142 returns the electrolyte 134 in the electroforming tank 132 that exceeds a predetermined amount to the storage tank 141. Therefore, one end of the discharge pipe 142 is disposed with its opening facing upward, at approximately the same height as the liquid level of the predetermined amount of electrolyte 134. As a result, the electrolyte 134 that exceeds the predetermined amount in the electroforming tank 132 flows into the discharge pipe 142 and is returned to the storage tank 141 through the discharge pipe 142.

[0084] The supply pipe 147 also has one end disposed within the electroforming tank 132 and the other end connected to the storage tank 141. A nozzle 148 that sprays the electrolytic solution 134 into the electroforming tank 132 is connected to one end of the supply pipe 147. The other end of the supply pipe 147 is connected to the bottom of the storage tank 141. A valve 143, a pump 144, and a filter 146 are arranged along the supply pipe formed by the supply pipe 147, in this order from the storage tank 141 side, which is the upstream side in the supply direction of the electrolytic solution 134. The valve 143 opens and closes the supply path. When the valve 143 opens the supply path while the pump 144 is operating, the supply of the electrolytic solution 134 from the storage tank 141 to the electroforming tank 132 begins. The filter 146 filters the electrolytic solution 134. The electrolytic solution 134 that has passed through the filter 146 is supplied into the electroforming tank 132 through the supply pipe 147. The nozzle 148 sprays the electrolyte 134 toward the gap between the electrodeposition surface 20 a of the master disc 20 and the anode 139 .

[0085] In this way, in the electroforming step S1, the circulation mechanism 140 is used to circulate the electrolyte 134 between the electroforming tank 132 and the storage tank 141. Then, in the electroforming tank 132, the nozzle 148 sprays the electrolyte 134 toward between the electrodeposited surface 20a and the anode 139, causing the electrolyte 134 to flow in a direction in which the fluid pressure of the electrolyte 134 is applied toward the electrodeposited surface 20a. The electroforming step S1 is preferably performed while the electrolyte 134 is flowing in this way. In this manner, electroforming is performed on the electrodeposited surface 20a of the master disk 20.

[0086] In the master master 20 used in the above manufacturing method, the surface area per unit area of ​​the dummy region 25 is larger than the surface area per unit area of ​​the product region 23. Therefore, in the electroforming process, a high anchor effect can be exerted on the metal layer deposited and formed on the electrodeposition surface 20a of the master master 20, and the adhesion between the metal layer and the master master 20 can be further improved. Therefore, the effect of suppressing peeling of the metal layer from the master master 20 during electroforming can be fully exerted.

[0087] In the above manufacturing method, it is preferable that the surface of the convex portions 34 of the product pattern 30 of the master matrix 20 have a water contact angle of 20° or less.

[0088] In the above manufacturing method, if the water contact angle of the surface of the protrusions 34 is large, air bubbles may adhere to the surface of the protrusions 34, causing defects in the formation of the openings. The inventors speculate that the mechanism of defective formation of the openings due to air bubbles is as follows: When air bubbles adhere to the mask, i.e., the protrusions 34, the metal layer that grows to cover the edges of the mask grows while incorporating the air bubbles. When the metal layer incorporates air bubbles, the metal layer containing the bubbles is formed to bulge larger than other parts. When the metal layer bulges at the edges of the mask in this way, the metal layer bulges from the edges toward the center of the mask. As the metal layer bulges toward the center of the mask, the size of the opening becomes smaller, or the shape of the opening that should be circular becomes crescent-shaped, resulting in defective formation of the opening.

[0089] That is, defective formation of the openings can be suppressed if no air bubbles adhere to the surfaces of the protrusions 34. Here, by setting the water contact angle of the surfaces of the protrusions 34 to 20° or less, it is possible to suppress the adhesion of air bubbles to the surfaces of the protrusions 34 during electroforming. Therefore, by setting the water contact angle of the surfaces of the protrusions 34 to 20° or less, it is possible to suppress defective formation of the openings.

[0090] When the convex portions 34 are made of a photosensitive resin as in this example, the water contact angle of a typical photosensitive resin layer is very large, for example, exceeding 80°. In order to reduce the water contact angle of the photosensitive resin layer to 20° or less, the surface of the master matrix 20 may be subjected to a hydrophilic treatment.

[0091] The method of hydrophilization is not particularly limited, but oxygen plasma ashing or ultraviolet ozone treatment is preferred.

[0092] Here, an example of a method for producing a master disc will be described with reference to FIG. First, in the coating step S11, a photosensitive resin film 33 is formed on the surface of the substrate 21 by coating.

[0093] Next, in the exposure step S12, a mask 36 for pattern formation is placed on the photosensitive resin film 33, and the photosensitive resin film 33 is exposed to light to form a pattern.

[0094] Then, in the development step S13, the exposed photosensitive resin film 33 is developed and washed to obtain convex portions 34 made of photosensitive resin on the surface of the substrate 21, i.e., a master master 20 equipped with a non-conductive mask.

[0095] Then, prior to the electroforming process, the electrodeposited surface 20a is subjected to a hydrophilic treatment S14. The hydrophilic treatment is carried out by oxygen plasma ashing or ultraviolet ozone treatment. This makes it possible to obtain a master disk 20 in which the water contact angle of the surface of the convex portions 34 is 20° or less. The water contact angle is measured using a contact angle meter, and the value is the average of 10 points.

[0096] As described above, by hydrophilizing the electrodeposited surface 20a of the master master 20 and reducing the water contact angle of the surface of the convex portions 34 to 20° or less, air bubbles can be removed and the occurrence of the aforementioned crescent defects can be suppressed. On the other hand, the inventors discovered that using oxygen plasma ashing as a hydrophilizing treatment can easily cause the electrodeposited layer to peel off from the electrodeposited surface during electroforming. In contrast, providing a dummy pattern separate from the product pattern, as in the master master 20 of the present disclosure, can prevent the metal layer deposited during electroforming from peeling off from the master master 20. Furthermore, since the surface area per unit area of ​​the dummy region of the master master 20 is larger than the surface area per unit area of ​​the product region, a strong anchoring effect can be achieved, further improving adhesion. Therefore, this is particularly effective when using a master master 20 in which the electrodeposited surface 20a has been hydrophilized by oxygen plasma ashing to prevent air bubbles from adhering.

[0097] Next, a method for manufacturing a metal molded product according to a second embodiment will be described. Here, a method for manufacturing a metal molded product, ie, a die 110 having a plurality of protrusions, will be described.

[0098] FIG. 18 is a perspective view showing a part of a mold 110, which is an example of a metal molded product produced by the method for producing a metal molded product according to the second embodiment.

[0099] The mold 110 is made of electroformed metal such as Ni, etc. The mold 110 has a plurality of protrusions 112 formed in a two-dimensional array.

[0100] Figure 19 is a diagram showing the manufacturing process of the mold 110. As shown in Figures 1A and 2, the master master 20 has a product pattern and a dummy pattern, but Figure 19 shows a partial cross section including three convex portions 34 of the product pattern 30 of the master master 20. The master master 20 used in this example has a circular outer shape, but the outer shape is not limited to a circular shape.

[0101] 19 is made of a non-conductive substrate having a concave-convex pattern formed on its surface. As a pretreatment S21 for the electroforming process, a metal film 111a is formed on the electrodeposited surface 20a of the master substrate 20. This provides electrical conductivity to the electrodeposited surface 20a.

[0102] Next, in the electroforming step S22, the master master 20 is immersed in an electrolyte, and a metal layer 111b is grown on the metal film 111a using metal precipitated from the electrolyte. In this example, the metal film 111a is formed over the entire concave-convex pattern on the surface of the master master 20, so the metal layer 111b grows over the entire bottom surfaces of the recesses 32 and 42 and the surfaces of the protrusions 34 and 44. If the metal material of the metal film 111a and the metal layer 111b is the same, the boundary between them becomes indistinguishable, forming an integrated metal layer 111.

[0103] After the electroforming step, the metal layer 111 is peeled off from the master master 20 (peeling step S23). The metal layer 111 has a concave-convex pattern to which the product pattern and dummy patterns formed on the electrodeposited surface of the master master 20 are transferred, and a mold 110 having convex portions 112 shown in FIG. 19 is obtained.

[0104] In this example, the master matrix 20 also has a larger surface area per unit area in the dummy region than in the product region, so it can exert a strong anchoring effect and suppress peeling of the metal layer 111 during electroforming. In particular, in the case of a microchannel or the like in which the density of the concave-convex pattern in the product pattern is sparse, the adhesion between the master matrix and the electrodeposited layer in the product pattern is low, so by providing a dummy pattern with a large surface area per unit area, it is possible to obtain a strong effect of suppressing peeling.

[0105] The disclosure of Japanese Patent Application No. 2021-008220, filed on January 21, 2021, is incorporated herein by reference in its entirety. All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A master master disk having a metal molded product having an electrodeposited surface formed by electrodeposition, the electrodeposited surface having a product area in which a product portion to be cut out of the metal molded product is to be formed, and a non-product area other than the product area, a product pattern formed in the product area and including recesses and protrusions; a dummy pattern formed in at least a part of the non-product region and including a plurality of recesses and protrusions, wherein, when a surface area of ​​the product pattern per unit area of ​​the product region is defined as a first surface area and a surface area of ​​the dummy pattern per unit area of ​​the dummy region in which the dummy pattern is formed is defined as a second surface area, the second surface area is larger than the first surface area; The height of the convex portions of the dummy pattern is greater than the height of the convex portions of the product pattern.

2. A master master having an electrodeposited surface formed by electrodeposition on a metal molded product, the electrodeposited surface having a product area in which a product portion to be cut out of the metal molded product is formed, and a non-product area other than the product area, a product pattern formed in the product area and including recesses and protrusions; a dummy pattern formed in at least a part of the non-product region and including a plurality of recesses and protrusions, wherein, when a surface area of ​​the product pattern per unit area of ​​the product region is defined as a first surface area and a surface area of ​​the dummy pattern per unit area of ​​the dummy region in which the dummy pattern is formed is defined as a second surface area, the second surface area is larger than the first surface area; the dummy pattern and the product pattern each have a bottom surface and the convex portion protruding from the bottom surface, a master master, wherein an angle formed between the sidewalls and the bottom surface of the convex portions of the dummy pattern is smaller than an angle formed between the sidewalls and the bottom surface of the convex portions of the product pattern;

3. A master master having an electrodeposited surface formed by electrodeposition on a metal molding, and having, on the electrodeposited surface, a product area in which a product portion to be cut out of the metal molding as a product is formed, and a non-product area other than the product area, a product pattern formed in the product area and including recesses and protrusions; a dummy pattern formed in at least a part of the non-product region and including a plurality of recesses and protrusions, wherein, when a surface area of ​​the product pattern per unit area of ​​the product region is defined as a first surface area and a surface area of ​​the dummy pattern per unit area of ​​the dummy region in which the dummy pattern is formed is defined as a second surface area, the second surface area is larger than the first surface area; the dummy pattern has a bottom surface and the protrusion protruding from the bottom surface, The master disk, wherein the angle formed between the sidewall and the bottom surface of the convex portion of the dummy pattern is 90° or less.

4. A master master having an electrodeposited surface formed by electrodeposition on a metal molding, and having, on the electrodeposited surface, a product area in which a product portion to be cut out of the metal molding as a product is formed, and a non-product area other than the product area, a product pattern formed in the product area and including recesses and protrusions; a dummy pattern formed in at least a part of the non-product region and including a plurality of recesses and protrusions, wherein, when a surface area of ​​the product pattern per unit area of ​​the product region is defined as a first surface area and a surface area of ​​the dummy pattern per unit area of ​​the dummy region in which the dummy pattern is formed is defined as a second surface area, the second surface area is larger than the first surface area; The planar shape of the electrodeposited surface is circular, The master disk has three product areas arranged in three-fold rotational symmetry with respect to the center of the electrodeposited surface, and the dummy pattern is provided within an area surrounded by the three product areas.

5. A master master disk having an electrodeposited surface formed by electrodeposition on a metal molding, and having, on the electrodeposited surface, a product area in which a product portion to be cut out of the metal molding as a product is formed, and a non-product area other than the product area, a product pattern formed in the product area and including recesses and protrusions; a dummy pattern formed in at least a part of the non-product region and including a plurality of recesses and protrusions, wherein, when a surface area of ​​the product pattern per unit area of ​​the product region is defined as a first surface area and a surface area of ​​the dummy pattern per unit area of ​​the dummy region in which the dummy pattern is formed is defined as a second surface area, the second surface area is larger than the first surface area; At least one of the convex portions of the product pattern and the convex portions of the dummy pattern is made of a conductive material, and the other is made of a non-conductive material.

6. The master disc according to claim 1 , wherein the dummy region has an area larger than that of the product region.

7. The master disc according to claim 1 , wherein the plurality of recesses or protrusions are regularly arranged in the dummy area.

8. the product pattern includes a plurality of at least one of the recessed portions and the protruding portions, and the plurality of recessed portions or the protruding portions are regularly arranged in the product pattern; 8. The master disk according to claim 7, wherein an arrangement pitch of the plurality of recesses or protrusions of the dummy pattern is smaller than an arrangement pitch of the recesses or protrusions of the product pattern.

9. The master disk according to claim 1 , wherein the aspect ratio of the convex portions or the concave portions of the dummy pattern is larger than the aspect ratio of the convex portions or the concave portions of the product pattern.

10. a conductive substrate having the electrodeposited surface; and a non-conductive mask formed on the electrodeposited surface to control the growth of the metal molding; 10. The master disk according to claim 1, wherein the convex portions of the product pattern and the dummy pattern are formed by the non-conductive mask.

11. 11. The master disk according to claim 10, wherein the material of the non-conductive mask that forms at least one of the convex portions of the product pattern and the dummy pattern is a photosensitive resin.

12. 11. The master disk according to claim 10, wherein the material of the non-conductive mask that forms at least one of the convex portions of the product pattern and the dummy pattern is an inorganic material.

13. 5. The master disk according to claim 1, wherein at least one of the convex portions of the product pattern and the convex portions of the dummy pattern is formed from a conductive material, and the other is formed from a non-conductive material.

14. 14. A method for manufacturing a metal molded product, comprising: an electroforming step of growing the metal molded product by depositing metal on the electrodeposited surface of the master matrix according to claim 1 while the master matrix is ​​immersed in an electroforming solution; and a peeling step of peeling the metal molded product from the master matrix.

15. The method for manufacturing a metal molded product according to claim 14 , wherein the surface of the convex portion of the product pattern of the master matrix has a water contact angle of 20° or less.

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