CN113322494B

CN113322494B - Method for producing electroformed product and electroformed product

Info

Publication number: CN113322494B
Application number: CN202110166411.8A
Authority: CN
Inventors: 佐佐木阳介
Original assignee: Citizen Watch Co Ltd
Current assignee: Citizen Watch Co Ltd
Priority date: 2020-02-28
Filing date: 2021-02-04
Publication date: 2023-06-30
Anticipated expiration: 2041-02-04
Also published as: CH717177A2; CN113322494A; CH717177B1

Abstract

In a method for manufacturing a multilayered electroformed product, the accuracy of the shape of an electroformed portion in the interface of layers is improved. A method for manufacturing an electroformed product in which electroformed portions (40, 80) of two layers are integrally formed by stacking electroformed portions (40, 80) formed by metal plating in the thickness direction, wherein a metal film (50) having good corrosion resistance is formed on a surface (41) of a side to be stacked of an electroformed portion (80) of a second layer of a first layer of electroformed portions (40) formed in advance; next, a resist layer (60) for the electroformed portion (80) is formed on the metal film (50); then, removing a portion (62) of the resist layer (60) corresponding to the electroformed portion (80) by exposure and development; electroformed portions (80) are formed in the removed unexposed areas (62) of the resist layer (60).

Description

Method for producing electroformed product and electroformed product

Technical Field

The present invention relates to a method for producing an electroformed article and an electroformed article.

Background

A structure having a minute shape, such as a component of a timepiece, is manufactured by electroforming. As electroformed products, products formed of a multi-layered (multi-stage) electroformed portion having different contour shapes according to positions in the thickness direction have been proposed (for example, refer to patent documents 1 and 2).

According to the technique described in patent document 1, an isolation (barrier) layer is provided on the surface (surface in contact with the electroformed portion of the second layer (second stage)) of the electroformed portion (portion formed by the electroforming (plating) step) of the first layer (first stage), a resist layer of the second layer is formed on the entire surface of the isolation layer and the resist layer (resistance) of the first layer, and after the resist layer of the second layer is exposed and developed, the isolation layer on the surface of the electroformed portion of the first layer is removed, thereby forming an electroformed portion of the second layer in contact with the surface of the electroformed portion of the first layer.

According to the technique described in patent document 2, a resist layer of the second layer is formed on the entire surface of an electroformed portion (portion formed by an electroforming (plating) process) of the first layer, and after exposing and developing the resist layer of the second layer, an electroformed portion of the second layer is formed to be in contact with the surface of the electroformed portion of the first layer.

(prior art literature)

(patent literature)

Patent document 1: japanese patent No. 6284144

Patent document 2: european patent application publication No. 2405301 (EP-A1-002405301)

Disclosure of Invention

(problem to be solved by the invention)

In the technique described in patent document 1, when the isolation layer on the surface of the electroformed portion of the first layer is removed, not only the isolation layer in the region in contact with the electroformed portion of the second layer but also the isolation layer in the region in contact with the resist layer of the second layer is removed from among the isolation layers formed on the surface of the electroformed portion of the first layer.

In this way, a void corresponding to the removed isolation layer is formed between the electroformed portion of the first layer and the resist layer of the second layer. As a result, the following problems occur: the electroformed portion of the second layer, which should be outlined by the resist layer of the second layer, is also formed in the void, and the electroformed portion of the second layer is formed to a void further outside than the resist layer of the second layer, resulting in a decrease in dimensional accuracy of the shape of the electroformed portion.

In the technique described in patent document 2, an oxide film is formed on the surface of the electroformed portion of the first layer formed by a reaction between the electroformed portion and oxygen in the air. The oxide film may decrease the degree of bonding of the electroformed portion of the second layer and the electroformed portion of the first layer. Therefore, after exposure and development of the resist layer of the second layer, it is necessary to remove the oxide film formed on the surface of the electroformed portion of the first layer with a strong acid or the like.

However, when this oxide film is removed, not only the oxide film in the range in contact with the electroformed portion of the second layer, but also the oxide film in the range in contact with the resist layer of the second layer among the oxide films formed on the surface of the electroformed portion of the first layer are removed.

As described above, as in the case of patent document 1, a void corresponding to the oxide film to be removed is formed between the electroformed portion of the first layer and the resist layer of the second layer. As a result, the following problems occur: the electroformed portion of the second layer is also formed in the void, and the electroformed portion of the second layer, which should be outlined by the resist layer of the second layer, is formed to a void further outside than the resist layer of the second layer, resulting in a decrease in dimensional accuracy of the shape of the electroformed portion.

In view of the above, an object of the present invention is to provide a method for producing an electroformed product and an electroformed product, which can prevent corrosion of an electroformed portion at an interface of layers and improve accuracy of shape while obtaining adhesion force between layers.

(measures taken to solve the problems)

A first aspect of the present invention is a method for manufacturing an electroformed article in which electroformed portions formed by metal plating are integrally formed by stacking the electroformed portions in a thickness direction, wherein a metal film having good corrosion resistance, which is less likely to form an oxide film, is formed on a surface of a side of a preceding electroformed portion on which a next electroformed portion is to be stacked; next, a resist layer for the next electroforming portion is formed over the metal film; next, a portion of the resist layer corresponding to the next electroformed portion is removed by exposure and development; the next electroformed portion is formed at the removed portion of the resist layer.

A second aspect of the present invention is an electroformed product in which a plurality of electroformed portions formed by metal plating are stacked in a thickness direction, and a metal film having good corrosion resistance and having no oxide film is formed at an interface of a step formed in the stacked electroformed portions.

(effects of the invention)

According to the method for producing an electroformed article and the electroformed article of the present invention, corrosion of the electroformed portion at the interface of the layers can be prevented and the accuracy of the shape can be improved, while the adhesion force between the layers can be obtained.

Drawings

Fig. 1A is a schematic cross-sectional view (one of them) showing a flow of a method for manufacturing a two-layer electroformed article according to an embodiment of the invention.

Fig. 1B is a schematic cross-sectional view (second) showing the flow of the manufacturing method of the two-layer electroformed article of the embodiment.

Fig. 1C is a schematic cross-sectional view (third) showing the flow of the manufacturing method of the two-layer electroformed article of the embodiment.

Fig. 1D is a schematic cross-sectional view (fourth) showing the flow of the manufacturing method of the two-layer electroformed article of the embodiment.

Fig. 1E is a schematic cross-sectional view showing the flow of the manufacturing method of the two-layer electroformed article of the embodiment (fifth).

Fig. 1F is a schematic cross-sectional view (sixth) showing the flow of the manufacturing method of the two-layer electroformed article of the embodiment.

Fig. 1G is a schematic cross-sectional view (seventh) showing the flow of the manufacturing method of the two-layer electroformed article of the embodiment.

Fig. 1H is a schematic cross-sectional view (eighth thereof) showing the flow of the manufacturing method of the two-layer electroformed article of the embodiment.

Fig. 1I is a schematic cross-sectional view (nine thereof) showing the flow of the method for manufacturing a two-layer electroformed article of an embodiment.

Fig. 1J is a schematic cross-sectional view (ten thereof) showing the flow of the manufacturing method of the two-layer electroformed article of the embodiment.

Fig. 1K is a schematic cross-sectional view (eleventh thereof) showing a flow of a method of manufacturing a two-layer electroformed article of an embodiment.

Fig. 1L is a schematic cross-sectional view (twelve of them) showing the flow of the manufacturing method of the two-layer electroformed article of the embodiment.

Fig. 1M is a schematic cross-sectional view (one) of an electroformed article in a process in a method for manufacturing a variation 1 of an electroformed article in which the size of an electroformed portion of the second layer is larger than that of an electroformed portion of the first layer, corresponding to the process shown in fig. 1E.

Fig. 1N is a schematic cross-sectional view (second) of an electroformed product at a step in the manufacturing method of modification 1, corresponding to the step shown in fig. 1H.

Fig. 1O is a schematic cross-sectional view (third) of an electroformed product at a step in the manufacturing method of modification 1, corresponding to the step shown in fig. 1L.

Fig. 1P is a schematic cross-sectional view of an electroformed product in a step of forming a resist layer of a first layer on an eave-forming layer in a manufacturing method of modification 2 of manufacturing an electroformed product in which a metal film is formed on a side surface of an electroformed portion of the first layer, corresponding to the step shown in fig. 1A.

Fig. 1Q is a schematic cross-sectional view of an electroformed product in a process of removing a resist layer of a first layer after forming an electroformed portion of the first layer in the manufacturing method of modification 2.

Fig. 1R is a schematic cross-sectional view of an electroformed product in a step of removing a part of the eave-forming layer in the manufacturing method of modification 2.

Fig. 1S is a schematic cross-sectional view of an electroformed product in a step of forming a metal film on the surface, side surface, and upper surface of a substrate of an electroformed portion of a first layer in the manufacturing method of modification 2.

Fig. 1T is a schematic cross-sectional view of an electroformed product in a step of forming a resist layer of a second layer in the manufacturing method of modification 2.

Fig. 1U is a schematic cross-sectional view of an electroformed product in a process of removing a resist layer after forming an electroformed portion of a second layer in the manufacturing method of modification 2.

Fig. 1V is a schematic cross-sectional view of an electroformed product in the process of integrating the electroformed portion of the first layer and the electroformed portion of the second layer to form an electroformed product in which a metal film is also formed on the side surface of the electroformed portion of the first layer in the manufacturing method of modification 2.

Fig. 1W is a schematic cross-sectional view of an electroformed article in a process of removing a portion of the metal film other than a portion directly below the electroformed portion of the first layer by etching.

Fig. 2A is a schematic cross-sectional view (one of them) showing the flow of the method for producing a two-layer electroformed article according to modification 3.

Fig. 2B is a schematic cross-sectional view (second) showing the flow of the method for producing the two-layer electroformed article of modification 3.

Fig. 2C is a schematic cross-sectional view (third) showing the flow of the method for producing the two-layer electroformed article of modification 3.

Fig. 2D is a schematic cross-sectional view (fourth) showing the flow of the method for producing the two-layer electroformed article of modification 3.

Fig. 2E is a schematic cross-sectional view (fifth) showing the flow of the method for producing the two-layer electroformed article of modification 3.

Fig. 2F is a schematic cross-sectional view (sixth) showing the flow of the method for producing the two-layer electroformed article of modification 3.

Fig. 2G is a schematic cross-sectional view (seventh) showing the flow of the method for producing the two-layer electroformed article of modification 3.

Fig. 2H is a schematic cross-sectional view (eighth) showing the flow of the method for producing the two-layer electroformed article of modification 3.

Fig. 3A is a schematic cross-sectional view (one of them) showing the flow of the method for producing the two-layer electroformed product of modification 4.

Fig. 3B is a schematic cross-sectional view (second) showing the flow of the method for producing the two-layer electroformed article of modification 4.

Fig. 3C is a schematic cross-sectional view (third) showing the flow of the method for producing the two-layer electroformed article of modification 4.

Fig. 3D is a schematic cross-sectional view (fourth) showing the flow of the method for producing the two-layer electroformed article of modification 4.

Fig. 3E is a schematic cross-sectional view (fifth) showing the flow of the method for producing the two-layer electroformed article of modification 4.

Fig. 3F is a schematic cross-sectional view (sixth) showing the flow of the method for producing the two-layer electroformed article of modification 4.

Fig. 3G is a schematic cross-sectional view (seventh) showing the flow of the method for producing the two-layer electroformed article of modification 4.

Fig. 3H is a schematic cross-sectional view (eighth) showing the flow of the method for producing the two-layer electroformed article of modification 4.

Fig. 4A is a schematic cross-sectional view (one of them) showing the flow of the method for producing a two-layer electroformed article of modification 5.

Fig. 4B is a schematic cross-sectional view (second) showing the flow of the method for producing the two-layer electroformed article of modification 5.

Fig. 4C is a schematic cross-sectional view (third) showing the flow of the method for producing the two-layer electroformed article of modification 5.

Fig. 4D is a schematic cross-sectional view (fourth) showing the flow of the method for producing the two-layer electroformed article of modification 5.

Fig. 4E is a schematic cross-sectional view (fifth) showing the flow of the method for producing the two-layer electroformed article of modification 5.

Fig. 4F is a schematic cross-sectional view (sixth) showing the flow of the method for producing the two-layer electroformed article of modification 5.

Fig. 4G is a schematic cross-sectional view (seventh) showing the flow of the method for producing the two-layer electroformed article of modification 5.

Detailed Description

Hereinafter, a method for producing an electroformed product and an embodiment of the electroformed product according to the present invention will be described with reference to the drawings.

Fig. 1A to 1L are schematic cross-sectional views showing the flow of a method for manufacturing an electroformed article 100 according to an embodiment of the invention. The illustrated manufacturing method of the electroformed article 100 is a manufacturing method of the electroformed article 100 in which the

electroformed portions

40, 80 of two layers are integrally formed by stacking the

electroformed portions

40, 80 formed by metal plating in the thickness direction.

In this manufacturing method, first, as shown in fig. 1A, a resist layer 20 of a first layer is coated on a conductive substrate 10.

The conductive substrate 10 may be formed of a conductive metal, or may be formed by forming conductive films on a substrate body such as silicon, which is a semiconductor, or a substrate body such as a nonconductive resin, respectively, to exert conductivity. The conductive substrate 10 may be formed by stacking a plurality of metals.

The resist layer 20 is formed of, for example, a chemically amplified epoxy resin negative photoresist, but is not limited to negative, and may be, for example, a polymethyl methacrylate positive photoresist or the like.

In the manufacturing method of the present embodiment, next, as shown in fig. 1B, UV light (ultraviolet light) L is irradiated (exposed) to the resist layer 20 through a photomask (photomask) 30 in which an opening 31 and a shielding portion 32 are formed. Thus, a region (exposed region) 21 irradiated with UV light L through the opening 31 and a region (unexposed region) 22 not irradiated with UV light L due to the shielding portion 32 are formed in the resist layer 20.

Next, as shown in fig. 1C, the unexposed region 22 in the resist layer 20 is removed by development, and a cavity 23 corresponding to the portion where the unexposed region 22 was present is formed.

Next, as shown in fig. 1D, nickel plating (Ni) is performed using the substrate 10 as a cathode, whereby the electroformed portion 40 (electroformed portion formed first) of the first layer of nickel filling the cavity 23 is formed using the exposure region 21 and the substrate 10 as a mold.

The electroforming material is not limited to nickel, and any electroformable material such as copper (Cu), tin (Sn), cobalt (Co) or the like may be used. Here, the surface 41 of the electroformed portion 40 of the first layer and the surface of the resist layer 20 (exposure region 21) of the first layer may be ground and polished as necessary to be planarized.

Next, the oxide film formed on the surface 41 of the electroformed portion 40 of the first layer (the surface (upper surface in fig. 1E) on the side where the next electroformed portion (electroformed portion 80 of the second layer) is to be laminated) is removed, and the metal film 50 is formed as a layer of a noble metal such as gold (Au), silver (Ag), or a platinum group element or an alloy of a noble metal such as: in the case of gold, gold-silver alloy which is an alloy of gold and silver, gold-platinum alloy which is an alloy of gold and platinum, and the like may be any alloy which is difficult to form an oxide film.

The metal film 50 may have a layer of titanium (Ti) or chromium (Cr) on the lower layer side, but it is required to form a noble metal or an alloy of noble metals on the upper layer side (exposed side).

In addition, the metal film 50 may also be formed on the surface of the exposed region 21 of the resist layer 20 other than the surface 41 of the electroformed portion 40, but since the metal film 50 on the surface of the exposed region 21 is eventually removed, it is unnecessary for the electroformed article 100.

The metal film 50 formed only on the surface 41 of the electroforming portion 40 may be formed by wet plating, or may be formed by dry plating such as sputtering (sputtering), vapor deposition, ion plating, or the like by adhering a stencil mask (plating mask) having an opening portion corresponding to the surface 41 of the electroforming portion 40 to the surface. Further, the metal film 50 may be formed on all surfaces including the surface 41 of the electroformed portion 40 by any of the methods described above on the basis of the exposed region 21 of the resist layer 20 from which the first layer is removed.

After the metal film 50 is formed on the surface 41 of the electroformed portion 40, as shown in fig. 1F, a second layer of resist layer 60 (resist layer for the next electroformed portion) is formed over the electroformed portion 40 of the first layer and the exposed region 21 of the resist layer 20.

Next, as shown in fig. 1G, UV light L is irradiated (exposed) to the resist layer 60 through the photomask 70 formed with the opening 71 and the shielding portion 72. Thus, a region (exposed region) 61 where the UV light L is irradiated through the opening 71 and a region (unexposed region) 62 where the UV light L is not irradiated due to the shielding portion 72 are formed in the resist layer 60 of the second layer. The unexposed region 62 is formed so that at least a part overlaps with the electroformed portion 40 of the first layer.

Next, as shown in fig. 1H, development is performed to remove the unexposed region 62 in the resist layer 60, and a cavity 63 (a portion corresponding to the next electroformed portion) corresponding to the unexposed region 62 is formed. Further, a part of the exposed region 61 of the resist layer 60, which is not removed, remains over the metal film 50.

Here, the surface 41 of the electroformed portion 40 of the first layer is covered with the metal film 50, and therefore in the region facing the cavity 63, the metal film 50 covering the electroformed portion 40 is exposed instead of the electroformed portion 40 being exposed to the cavity 63.

In the article different from the present embodiment in which the surface of the electroformed portion 40 is not covered with the metal film 50, since the surface of the electroformed portion 40 is exposed to air at a stage before the formation of the resist layer 60 of the second layer, the surface of the electroformed portion 40 is oxidized to form an oxide film. The oxide film is also formed by developing the unexposed region 62 and exposing it to the cavity 63.

Since the oxide film may deteriorate the adhesion force of the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer formed over the electroformed portion 40 of the first layer, the oxide film must be removed. For removing the oxide film, for example, a strong acid such as hydrochloric acid may be used, but when the oxide film facing the region of the cavity 63 is removed by using the strong acid, the strong acid is impregnated into the interface 65 between the surface 41 of the electroformed portion 40 and the remaining resist layer 60 (exposed region 61) of the second layer, and the oxide film formed at the interface 65 is also removed.

If the oxide film of the interface 65 is removed, gaps are generated at the interface 65, and errors are generated in the contour shape of the electroformed portion 80 of the second layer, which will be described later. Further, since the interface 65 is narrow, a corrosive oxide film removing solution and plating solution tend to remain, and the surface of the electroformed portion 40 may be corroded.

In contrast, in the manufacturing method of the present embodiment, as shown in fig. 1H, the surface 41 of the electroformed portion 40 of the first layer is covered with the metal film 50, and the metal film 50 is made of an element that is difficult to oxidize and is hardly oxidized, so that the surface 41 of the electroformed portion 40 of the first layer has a good affinity with the electroformed portion 80 of the second layer and a high adhesion force, compared to an oxide film. Therefore, in the manufacturing method of the present embodiment, since the metal film 50 is already present at the stage of forming the cavity 63 shown in fig. 1H, it is not necessary to perform a step of removing the oxide film using a strong acid.

In the case where the resist layer 60 remains on the surface of the metal film 50 after development, the residues may be removed by Plasma ashing (Plasma ashing), which does not generate gaps at the interface 65.

Next, as shown in fig. 1I, nickel plating is performed using the substrate 10 as a cathode, whereby the electroformed portion 80 of the second layer made of nickel filling the cavity 63 is formed using the exposure region 61 and the electroformed portion 40 of the first layer as a mold.

The electroforming material is not limited to nickel, and any electroformable material such as copper, tin, cobalt, or the like may be used. Here, the surface of the electroformed portion 80 of the second layer and the surface of the resist layer 60 (exposure region 61) of the second layer may be ground and polished as necessary to be planarized.

Next, as shown in fig. 1J, the resist layer 20 (exposure region 21) of the first layer and the resist layer 60 (exposure region 61) of the second layer are removed, thereby forming an electroformed article 100 in which the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer having a different shape from the first layer are integrated.

Next, as shown in fig. 1K, the metal film 50 formed at the interface 65 of the electroformed product 100 is removed by etching as needed (there are cases where the metal film 50 is divided into a removed metal film 51 and a metal film 52 that remains without being removed as needed). In the case where the metal film 50 is gold, for example, an iodine-based etching solution can be used as the etching solution.

Finally, as shown in fig. 1L, the electroformed product 100 is removed from the substrate 10, whereby the electroformed product 100 in which the shapes of the two layers are integrated can be obtained.

As such, according to the method of manufacturing the electroformed article 100 of the present embodiment, the surface of the electroformed portion 40 of the first layer does not have an oxide film, and therefore no gap is generated at the interface 65 between the surface of the electroformed portion 40 of the first layer and the resist layer 60 of the second layer.

Therefore, errors in the contour shape, shape defects, and corrosion of the electroformed portion 80 of the second layer due to the occurrence of gaps at the interface 65 can be prevented, and the dimensional accuracy of the manufactured electroformed product 100 can be improved.

Furthermore, removal of the oxide film based on, for example, a corrosive liquid (strong acid or the like) is not required before the plating of the second layer.

In the electroformed product 100 manufactured by the manufacturing method of the present embodiment, although the metal film 50 is formed at the interface where the step is formed between the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer, the adhesion of the metal film 50 to the

electroformed portions

40, 80 is good, and therefore the strength of the integration of the electroformed portion 40 and the electroformed portion 80 can be ensured.

In addition, in the electroformed product 100 of the present embodiment, since the oxide film is not present at the interface between the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer, discoloration and strength decrease due to corrosion caused by the residual corrosive oxide film removing solution and plating solution can be prevented.

< modification 1>

In the method for manufacturing the electroformed article 100 and the electroformed article 100 of the above-described embodiment, the size of the electroformed portion 80 of the second layer to be formed later is smaller than the size of the electroformed portion 40 of the first layer to be formed earlier, and as shown in fig. 1E, the electroformed portion 80 of the second layer is formed in a size corresponding to a portion of the area of the metal film 50, which is formed only on the surface of the electroformed portion 40 of the first layer, but not on the surface of the exposed area 21 of the resist 20 of the first layer.

However, the manufacturing method of the electroformed article and the electroformed article of the present invention are not limited to the second layer having the electroformed portion with a smaller size than the first layer, but the second layer may have the electroformed portion with a larger size than the first layer, and the second layer may have the electroformed portion with a size equal to the first layer.

For example, modification 1 of the method for producing the electroformed product 100 in which the size of the electroformed portion 80 of the second layer is larger than the size of the electroformed portion 40 of the first layer is specifically described.

Fig. 1M is a schematic cross-sectional view (one) of an electroformed article in a process in a method of manufacturing variation 1 of an electroformed article in which the size of the electroformed portion 80 of the second layer is larger than the size of the electroformed portion 40 of the first layer, corresponding to the process shown in fig. 1E.

In the step shown in fig. 1E, the metal film 50 may be formed only on the surface 41 of the electroformed portion 40. On the other hand, in the process shown in fig. 1M, the metal film 50 is formed not only on the surface 41 of the electroformed portion 40 of the first layer, but also by including the surface of the exposed region 21 of the resist layer 20 adjacent to the electroformed portion 40.

Further, even in the case where the electroformed portion 80 of the second layer is larger than the electroformed portion 40 of the first layer, the metal film 50 can be formed only on the surface 41 of the electroformed portion 40, without forming the metal film 50 on the surface of the exposed region 21 of the adjacent resist layer 20.

However, if the metal film 50 is also formed on the surface of the exposure region 21 of the adjacent resist layer 20, the metal film 50 is preferably also formed on the surface of the exposure region 21 of the adjacent resist layer 20 because the growth of plating in the region protruding from the electroformed portion 40 of the first layer in the width direction in the electroformed portion 80 of the second layer can be promoted.

Further, the metal film 50 may also be formed in conformity with the shape of the electroformed portion 80 of the second layer. In this case, the metal film 50 matching the shape of the electroformed portion 80 of the second layer can be formed by etching using a stencil mask, photolithography.

After forming (fig. 1M) the metal film 50 on the surface 41 of the electroformed portion 40 of the first layer and the surface of the exposed region 21 of the resist layer 20, a second layer of resist layer 60 is formed on top of the metal film 50 in the same manner as in fig. 1F, and UV light L is irradiated (exposed) to the resist layer 60 using the same photomask 70 as in fig. 1G.

The shielding portion 72 of the photomask 70 is formed in a size corresponding to the electroformed portion 80 of the second layer, that is, a size larger than the electroformed portion 40 of the first layer.

Fig. 1N is a schematic cross-sectional view (second) of an electroformed product at a step in the manufacturing method of modification 1, corresponding to the step shown in fig. 1H of the above embodiment.

As shown in fig. 1N (corresponding drawing to fig. 1H), the unexposed region 62 of the resist layer 60 of the second layer, which is blocked by the photomask 70, is removed by subsequent development. At this time, the metal film 50 remains and is exposed on the entire surface of the bottom of the cavity 63 formed by removing the unexposed region 62.

Next, as in the step of fig. 1I, nickel plating is performed using the substrate 10 as a cathode, whereby the electroformed portion 80 of the second layer made of nickel filling the cavity 63 is formed. Thereby, the electroformed portion 80 of the second layer having a larger size than the electroformed portion 40 of the first layer is formed.

Thereafter, as in the process of fig. 1J, the remaining portions of the resist layer 60 of the second layer and the remaining portions of the resist layer 20 of the first layer are removed except for the electroformed portion 80 of the second layer and the electroformed portion 40 of the first layer.

At this time, unlike the above-described embodiment, the metal film 50 is formed on the surface of the resist layer 20 of the first layer, and therefore the resist layer 60 of the second layer covering the first layer is removed. However, since the resist layer 20 of the first layer is covered with the metal film 50, the resist layer 20 of the first layer may not be removed at the same time in the process of removing the resist layer 60 of the second layer.

Therefore, in the case where the resist layer 20 of the first layer cannot be removed simultaneously in the step of removing the resist layer 60 of the second layer, the metal film 50 covering the region protruding from the electroformed portion 40 of the first layer out of the metal film 50 on the surface of the resist layer 20 of the first layer can be removed by etching after the resist layer 60 of the second layer is removed, and the resist layer 20 of the first layer can be removed after the metal film 50 is removed.

Fig. 1O is a schematic cross-sectional view (third) of an electroformed product at a step in the manufacturing method of modification 1 corresponding to the step shown in fig. 1L of the above embodiment.

Finally, as shown in FIG. 1O, the electroformed product 100 is removed from the substrate 10, whereby the electroformed product 100 in which the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer having a larger size than the first layer, which are different in shape from the first layer, are integrated can be obtained.

Further, the metal film 50 of the portion of the metal film 50 of the bottom surface of the electroformed portion 80 of the second layer protruding from the region sandwiched by the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer may be removed by etching as needed.

In this way, according to the method of manufacturing the electroformed article 100 in which the electroformed portion 80 of the second layer is formed to be larger in size than the electroformed portion 40 of the first layer, the dimensional accuracy of the manufactured electroformed article 100 can also be improved without generating a gap at the interface 65 (refer to fig. 1N) between the surface of the electroformed portion 40 of the first layer and the resist layer 60 of the second layer.

Thus, the same operation and effect as those of the method for manufacturing the electroformed product 100 in which the electroformed portion 80 of the second layer is formed to a smaller size than the electroformed portion 40 of the first layer can be obtained.

< modification example 2>

In the method for producing the electroformed product 100 and the electroformed product 100 according to the above-described embodiments, the metal film 50 is not formed on the side surface of the electroformed product 100 (the surface along the lamination direction in which the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer are laminated).

However, since the surface on which the metal film 50 is formed can improve wear resistance, corrosion resistance, and decoration, when the manufactured electroformed product 100 is applied to a member (for example, a gear, a timepiece dial, a timepiece scale (index)) in which the wear resistance, corrosion resistance, and decoration of the side face need to be improved, it is preferable to form the metal film 50 on the side face of the electroformed product 100.

Therefore, for example, a description will be given of a manufacturing method of modification 2 for manufacturing the electroformed product 100 in which the metal film 50 is formed on the side surface of the electroformed portion 40 of the first layer, showing points different from the above-described embodiment.

Fig. 1P is a schematic cross-sectional view of an electroformed article under a step of forming a first resist layer 20 on an eave forming layer 11 in a manufacturing method of modification 2 of manufacturing an electroformed article 100 having a metal film 50 formed on a side surface 40a of an electroformed portion 40 of the first layer, corresponding to the step shown in fig. 1A.

In the step shown in fig. 1A, the resist layer 20 of the first layer may be directly laminated on the substrate 10. On the other hand, in the process shown in fig. 1P, before the first resist layer 20 is formed on the substrate 10, the eave-forming layer 11 is formed on the substrate 10, and the first resist layer 20 is formed on the eave-forming layer 11.

Here, the eave forming layer 11 is a layer that forms a gap between the substrate 10 and the electroformed portion 40 of the first layer, and is configured such that an edge portion of a bottom portion of the electroformed portion 40 of the first layer, which will be described later, is formed in a shape overhanging (overhanging) the substrate 10 in an eave shape. The eave forming layer 11 is formed of a material having conductivity different from that of the metal forming the metal film 50.

Fig. 1Q is a schematic cross-sectional view of an electroformed article 100 in the process of removing the resist layer 20 of the first layer after forming the electroformed portion 40 of the first layer in the manufacturing method of modification 2. As shown in fig. 1P, a resist layer 20 of a first layer is formed on the eave forming layer 11, and thereafter, an electroformed portion 40 of the first layer is formed in the same manner as in the steps of fig. 1B to 1D. Then, as shown in fig. 1Q, the resist layer 20 of the first layer is removed, and a part of the eave-forming layer 11 on the substrate 10 is removed by etching.

Fig. 1R is a schematic cross-sectional view of an electroformed product 100 in the process of manufacturing method of modification 2, in which a part of the eave-forming layer 11 is removed. In the case of removing the eave-forming layer 11 by etching, in general, only the eave-forming layer 11 facing the resist layer 20 in the eave-forming layer 11 is removed by etching, but in modification 2, the etching time or the like is prolonged and a part of the eave-forming layer 11 between the electroformed portion 40 of the first layer and the substrate 10 is also removed as shown in fig. 1R.

Specifically, a portion of the eave-forming layer 11 between the electroformed portion 40 of the first layer and the substrate 10 is removed such that the side 11a of the eave-forming layer 11 between the electroformed portion 40 of the first layer and the substrate 10 is located at a position recessed inward from the side 40a of the electroformed portion 40.

Thereby, the gap 12 from which the eave-forming layer 11 is removed is formed below the edge of the electroformed portion 40 adjacent to the side surface 40a of the electroformed portion 40 of the first layer between the electroformed portion 40 of the first layer and the substrate 10, and in this gap 12, the edge of the electroformed portion 40 adjacent to the side surface 40a of the electroformed portion 40 becomes eave-shaped with respect to the substrate 10.

Fig. 1S is a schematic cross-sectional view of an electroformed product 100 in the process of forming a metal film 50 on the surface 41, side surface 40a, and upper surface of the substrate 10 of the electroformed portion 40 of the first layer in the manufacturing method of modification 2. In the state shown in fig. 1R, the metal film 50 is formed by sputtering or vapor deposition as in fig. 1E. Thereby, as shown in fig. 1S, the metal film 50 is formed on the surface 41 and the side surface 40a corresponding to the upper surface of the electroformed portion 40 of the first layer and the upper surface of the substrate 10, respectively.

Further, since the gap 12 is formed below the edge portion of the electroformed portion 40 adjacent to the side surface 40a of the electroformed portion 40 of the first layer, the metal film 50 formed on the side surface 40a of the electroformed portion 40 and the metal film 50 formed on the upper surface of the substrate 10 are not connected, but formed with a gap.

Fig. 1T is a schematic cross-sectional view of an electroformed product 100 in the process of forming a second resist layer 60 in the manufacturing method of modification 2. As shown in fig. 1T, the resist layer 60 of the second layer is formed entirely covering the electroformed portion 40 of the first layer and over the electroformed portion 40 of the first layer up to a height range where the electroformed portion 80 of the second layer can be formed.

Fig. 1U is a schematic cross-sectional view of an electroformed article 100 in the process of modification 2 in which the resist layer 60 is removed after the electroformed portion 80 of the second layer is formed, and fig. 1V is a schematic cross-sectional view of the electroformed article 100 in the process of modification 2 in which the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer are integrated to form the electroformed article 100 in which the metal film 50 is also formed on the side 40a of the electroformed portion 40 of the first layer.

As in the steps of fig. 1G to 1I, the second electroformed portion 80 is formed on the first electroformed portion 40 with the metal film 50 interposed therebetween, the resist layer 60 is removed as in fig. 1J, and finally the eave forming layer 11 is removed by etching as in fig. 1U. Thus, the electroformed product 100 shown in fig. 1V in which the metal film 50 is formed on the side surface 40a of the electroformed portion 40 of the first layer can be manufactured.

Further, as shown in fig. 1U, a gap is formed between the metal film 50 formed on the side surface 40a of the electroformed portion 40 of the first layer and the metal film 50 formed on the substrate 10, so that the etching liquid for removing the eave forming layer 11 can be immersed between the electroformed portion 40 of the first layer and the substrate 10 through the gap.

Thus, the article shown in fig. 1U can easily remove the eave-forming layer 11 formed between the electroformed portion 40 of the first layer and the substrate 10 by using the etching liquid, compared to an article having no slits (an article in which the electroformed portion 40 of the first layer is directly formed on the substrate 10 without via the eave-forming layer 11).

Further, the product shown in fig. 1Q is formed so as to be in contact with the electroformed portion 40 over the eave-forming layer 11, but the electroformed portion 40 may be formed over the metal film 50 after the metal film 50 is formed on the upper face of the eave-forming layer 11.

Fig. 1W is a schematic cross-sectional view of the electroformed article 100 in a process of removing a portion of the metal film 50 other than a portion directly below the electroformed portion 40 of the first layer by etching the metal film 50. Before the gap 12 is formed by removing a portion of the eave-forming layer 11 between the electroformed portion 40 of the first layer and the substrate 10 as shown in fig. 1R, the metal film 50 other than the portion directly under the electroformed portion 40 of the first layer is removed by etching out of the metal films 50 formed on the eave-forming layer 11 as shown in fig. 1W.

At this time, it is not necessary to remove the metal film 50 directly under the electroformed portion 40 to a position recessed inward from the side surface 40a of the electroformed portion 40 as in the case of the above-described eave forming layer 11, and then, as in fig. 1R, the eave forming layer 11 between (the metal film 50 remaining directly under) the electroformed portion 40 of the first layer and the substrate 10 may be removed to a position recessed inward from the side surface 40a of the electroformed portion 40.

In this way, according to the method for manufacturing the electroformed product 100 of modification 2 in which the metal film 50 remains on the side surface 40a of the electroformed portion 40 of the first layer, no gap is generated between the surface of the electroformed portion 40 of the first layer and the interface 65 (see fig. 1T) of the resist layer 60 of the second layer, and the dimensional accuracy of the manufactured electroformed product 100 can be improved.

Thus, the same operation and effect as those of the method of manufacturing the electroformed product 100 in which the electroformed portion 80 of the second layer is formed to a smaller size than the electroformed portion 40 of the first layer can be obtained, and at the same time, the wear resistance, corrosion resistance, and decorative properties of the side surface 40a of the electroformed portion 40 of the first layer can be improved.

< modification example 3>

The electroformed article 100 of the embodiment is an article that is integrated in a state in which the electroformed portion 80 of the second layer is placed on the surface 41 of the electroformed portion 40 of the first layer, but if it is an article that is integrated in a state in which a part (anchor portion) of the electroformed portion 80 of the second layer is inserted into the electroformed portion 40 of the first layer, the shearing resistance strength at the interface of the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer can be improved.

Fig. 2A to 2H are schematic cross-sectional views showing the flow of a method for manufacturing a two-layer electroformed article 100 as a modification (modification 3) of the embodiment shown in fig. 1A to 1L. In the manufacturing method of modification 3 shown in the drawing, first, as shown in fig. 2A, a resist layer 20 of a first layer is coated on a conductive substrate 10, and as in the above-described embodiment, an exposed region 21 and an unexposed region 22 are formed on the resist layer 20 under irradiation of UV light L using a photomask 30, and the unexposed region 22 is removed to form an electroformed portion 40.

At this time, the exposure region 21 between the two unexposed regions 22 (corresponding to the electroformed portion 40 in the drawing) corresponds to a void to be formed later by the anchor portion 81 formed in the electroformed portion 80 of the second layer.

With the plating after development, electroformed portions 40 of the first layer are formed at portions corresponding to the two unexposed areas 22.

Next, as shown in fig. 2B, if the exposed regions 21 of the resist layer 20 of the first layer are removed entirely, a cavity 24 is formed between the two electroformed portions 40. Thereafter, all surfaces including the surfaces 41 of the two electroformed portions 40 are subjected to dry plating or wet plating, whereby a metal film 50 is formed on the surfaces 41 of the electroformed portions 40 as shown in fig. 2C. The formation of the metal film 50 is performed after removing the oxide film on the surface of the electroformed portion 40 in advance.

After forming the metal film 50 on the surface 41 of the electroformed portion 40, as shown in fig. 2D, a second layer of resist layer 60 is formed on the substrate 10 so as to cover the electroformed portion 40 of the first layer.

Next, as shown in fig. 2E, UV light L is irradiated to the resist layer 60 by using a photomask 90 having an opening 91 and a shielding portion 92 formed therein. Thus, a region (exposed region) 61 to which UV light L is irradiated through the opening 91 and a region (unexposed region) 62 to which UV light L is not irradiated due to the shielding portion 92 are formed in the resist layer 60. The unexposed areas 62 are formed in such a way that at least a portion thereof spans both electroformed portions 40 of the first layer, i.e., contains voids 24.

Next, as shown in fig. 2F, the unexposed region 62 in the resist layer 60 is removed by development, and a cavity 63 corresponding to a portion where the unexposed region 62 was present is formed. The void 63 includes the void 24 between the two electroformed portions 40 of the first layer.

Here, the surface 41 of the electroformed portion 40 of the first layer is covered with the metal film 50, and in the region facing the cavity 63, the metal film 50 covering the electroformed portion 40 is exposed, instead of the electroformed portion 40 being exposed to the cavity 63. Further, a part of the exposed region 61 of the resist layer 60, which is not removed, remains over the metal film 50.

Next, as shown in fig. 2G, nickel plating is performed with the substrate 10 as a cathode, whereby the exposure region 61, the electroformed portion 40 of the first layer, and the substrate 10 are used as a mold to form an electroformed portion 80 of the second layer made of nickel filling the cavity 63. Wherein a portion of the electroformed portion 80 of the second layer forms an anchor 81 of the void 24 interposed between the two electroformed portions 40 of the first layer.

The electroforming material is not limited to nickel, and any electroformable material such as copper, tin, cobalt, or the like may be used.

Next, the surface of the electroformed portion 80 of the second layer and the surface of the resist layer 60 (exposure region 61) of the second layer are ground and polished as necessary to be leveled, and the resist layer 60 (exposure region 61) of the second layer is removed, thereby forming an electroformed article 100 in which the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer having a different shape from the first layer are integrated.

The metal film 50 formed on the interface 65 (see fig. 2F) of the electroformed product 100 may be removed by etching as needed, and finally, as shown in fig. 2H, the electroformed product 100 may be removed from the substrate 10, whereby the electroformed product 100 having a two-layer shape integrated may be obtained.

As described above, with respect to the electroformed product 100 manufactured by the manufacturing method of modification 3, in addition to the same effects as those of the electroformed product 100 of the embodiment, a part of the electroformed portion 80 of the second layer is integrated in a state of being inserted as the anchor portion 81 into the cavity 24 of the electroformed portion 40 of the first layer, so that the shearing strength at the interface of the step formed by the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer can be improved.

< modification 4>

In the method for producing the electroformed product 100 according to modification 3, the resist layer 20 (the exposure region 21) of the first layer is removed after the first layer of the electroformed product 100 is formed (see fig. 2A) and before the metal film 50 is formed (see fig. 2C).

Fig. 3A to 3H are schematic cross-sectional views showing the flow of a method for manufacturing the two-layer electroformed article 100 of modification 4.

The method of manufacturing the electroformed product 100 according to modification 4 is another modification of the embodiment shown in fig. 1A to 1L, and is the same as modification 3 except for a part of the steps. In the manufacturing method of modification 4, after forming the electroformed portion 40 of the first layer (see fig. 3A), the metal film 50 is formed on the surface 41 of the electroformed portion 40 of the first layer as shown in fig. 3B, and then the resist layer 20 (the exposure region 21) of the first layer is removed as shown in fig. 3C.

Here, the formation of the metal film 50 on the surface 41 of the electroformed portion 40 of the first layer is performed by dry plating using a stencil mask 110 having an opening 111 corresponding to the surface 41 of the electroformed portion 40, as shown in fig. 3B. Note that, the metal film 50 may be formed by wet plating, but it is noted that, when the oxide film on the surface of the electroformed portion 40 is removed, a removal liquid that has entered the gap between the electroformed portion 40 and the resist layer 21 may remain, resulting in corrosion.

Thus, the metal film 50 is formed only on the surface 41 of the electroformed portion 40, and the metal film 50 is not formed on the surface of the resist layer 20 corresponding to the shielded portion other than the opening 111. Thus, the metal film 50 can be formed using a smaller amount than in modification 3, and the amount of expensive noble metal used to form the metal film 50 can be suppressed.

After forming the metal film 50 on the surface 41 of the electroformed portion 40 (fig. 3B), the exposed regions 21 of the resist layer 20 of the first layer are all removed as shown in fig. 3C, and then, the resist layer 60 of the second layer is formed on the substrate 10 so as to cover over the electroformed portion 40 of the first layer (fig. 3D).

Next, as shown in fig. 3E, UV light L is irradiated to the resist layer 60 by using the photomask 90 having the opening 91 and the shielding portion 92 formed therein. Thus, a region (exposed region) 61 irradiated with UV light L through the opening 91 and a region (unexposed region) 62 not irradiated with UV light L due to the shielding portion 92 are formed in the resist layer 60. The unexposed region 62 is formed in such a manner that at least a portion thereof spans the two electroformed portions 40 of the first layer, i.e., the cavity 24 containing the electroformed portion 40 of the first layer.

Next, as shown in fig. 3F, the unexposed region 62 in the resist layer 60 is removed by development, and a cavity 63 corresponding to the portion where the unexposed region 62 was present is formed. The void 63 includes the void 24 between the two electroformed portions 40 of the first layer.

Here, since the surface 41 of the electroformed portion 40 of the first layer is covered with the metal film 50, the electroformed portion 40 is exposed to the cavity 63 in a region other than the surface 41 that faces the cavity 63.

Therefore, before the next plating, the oxide film on the side surface of the electroformed portion 40 on the side opposite to the cavity 63 needs to be removed. At this time, since the metal film 50 is present at the interface 65 of the resist layer 60 (exposure region 61) and the electroforming portion 40, no void is generated at the interface 65. Further, a part of the exposed region 61 of the resist layer 60, which is not removed, remains over the metal film 50.

Next, as shown in fig. 3G, nickel plating is performed with the substrate 10 as a cathode, whereby the exposure region 61, the electroformed portion 40 of the first layer, and the substrate 10 are used as a mold to form an electroformed portion 80 of the second layer made of nickel filling the cavity 63. Here, a part of the electroformed portion 80 of the second layer forms an anchor 81 of the cavity 24 interposed between the two electroformed portions 40 of the first layer.

The metal film 50 formed at the interface 65 (see fig. 3F) of the electroformed product 100 can be removed by etching, and finally, as shown in fig. 3H, the electroformed product 100 is removed from the substrate 10, whereby the electroformed product 100 in which the shapes of the two layers are integrated can be obtained.

As described above, with respect to the electroformed product 100 manufactured by the manufacturing method of modification 4, in addition to the same effects as those of the electroformed product 100 of the embodiment, a part of the electroformed portion 80 of the second layer is integrated in a state of being inserted as the anchor 81 into the cavity 24 of the electroformed portion 40 of the first layer, so that the shearing strength at the interface of the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer can be improved.

Further, the amount of the metal film 50 used can be further suppressed and the manufacturing cost can be further reduced as compared with the manufacturing method of modification 3.

Further, since the interface (peripheral surface) between the anchor 81 in the electroformed portion 80 of the second layer and the electroformed portion 40 of the first layer is not sandwiched by the metal film 50, but is configured such that the same kind of metal (for example, nickel) directly contacts, the affinity is improved, the adhesion is further improved, and the strength of integration of the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer can be further improved, as compared with the structure sandwiching the metal film 50.

< modification 5>

In the electroformed article 100 of modification 3, 4, the anchor portion 81 of the electroformed portion 80 of the second layer is inserted in the electroformed portion 40 of the first layer, so that the strength against shearing at the interface of the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer can be improved, but the electroformed portion 40 of the first layer is made to have a necked portion, and the front end portion of the anchor portion 81 is formed to be larger than the necked portion, whereby the strength against stretching in the lamination direction of the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer can be made to be higher than the electroformed article 100 of modification 3, 4.

Therefore, in the method of manufacturing the electroformed product 100 of modification 5, the necked portion 24b having a finer thickness than the distal end portion 24a, which is a portion on the side away from the electroformed portion 80 of the second layer, is formed in the portion of the cavity 24 of the electroformed portion 40 of the first layer on the side of the electroformed portion 80 of the second layer in the electroformed product 100 of modification 3, 4, and the distal end portion 81a of the anchor portion 81 of the electroformed portion 80 of the second layer is formed to have a coarser thickness than the base end portion 81 b.

Fig. 4A to 4G are schematic cross-sectional views showing the flow of the method for manufacturing the two-layer electroformed article 100 of modification 5.

In the method for manufacturing the electroformed product 100 of modification 5, first, as shown in fig. 4A, a cavity forming member 120, for example, formed of copper, corresponding to the distal end portion 81a of the anchor portion 81 of the electroformed portion 80 of the second layer is formed on the conductive substrate 10. The cavity forming member 120 is subsequently used for forming the front end portion 24a of the cavity 24. At this time, since the cavity forming member 120 needs to be selectively removed later, the cavity forming member 120 needs to be composed of an element different from the electroformed portion 40.

The resist layer 20 is coated so as to cover the cavity forming member 120, and as shown in fig. 4B, UV light L is irradiated to the resist layer 20 through the photomask 30 formed with the opening 31 and the shielding portion 32 so that a portion of the resist layer 20 corresponding to the central portion of the cavity forming member 120 (a portion having a smaller thickness than the cavity forming member 120: a portion for forming the neck portion 24B later) becomes an exposure region 21 and portions of the resist layer 20 corresponding to both sides and outer portions of the cavity forming member 120 become an unexposed region 22.

Next, as shown in fig. 4C, the unexposed region 22 of the resist layer 20 is removed by development, and voids 23 are formed in portions corresponding to both sides and the outer portions of the cavity forming member 120.

Next, as shown in fig. 4D, the exposed region 21 where the resist layer 20 remains and the substrate 10 are used as a mold, and nickel plating is performed to form an electroformed portion 40 of the first layer made of nickel filling the cavity 23. Here, since the cavity forming member 120 remains on the substrate 10 and the exposure region 21 of the resist layer 20 remains on the cavity forming member 120, the electroformed portion 40 of the first layer has a shape in which the central portion does not exist.

Next, the surface of the electroformed portion 40 of the first layer and the surface of the resist layer 20 (exposure region 21) of the first layer are ground and polished as necessary to be planarized.

Next, the metal film 50 is formed on the surface 41 of the electroformed portion 40 of the first layer by dry plating or wet plating using the stencil mask 110 formed with the opening 111 corresponding to the surface 41 of the electroformed portion 40 of the first layer, and then, as shown in fig. 4D, the exposed region 21 of the resist layer 20 is removed.

Next, as shown in fig. 4E, the cavity forming member 120 is removed by etching. For example, in the case where the cavity forming member 120 is formed of copper, an ammonium persulfate (ammonium persulfate) -based etching solution is used to selectively remove the cavity forming member 120.

Thereby, the cavity 24 is formed in the electroformed portion 40 of the first layer, which has the constricted portion 24b having a finer thickness in a portion near the electroformed portion 80 side of the stacked second layer than the tip portion 24a as a portion far from the electroformed portion 80 side of the second layer.

Next, a second resist layer 60 is formed on the substrate 10 so as to cover the electroformed portion 40 of the first layer.

Next, as shown in fig. 4F, UV light L is irradiated to the resist layer 60 through a photomask 90 formed with an opening 91 and a shielding portion 92. Thereby, an exposed region 61 irradiated with UV light L through the opening 91 and an unexposed region 62 not irradiated with UV light L due to the shielding portion 92 are formed in the resist layer 60. The unexposed areas 62 are formed at least partially across the two electroformed portions 40 of the first layer, i.e., the necked portion 24b including the void 24.

Next, as shown in fig. 4G, the unexposed region 62 in the resist layer 60 is removed by development, the cavity 24 corresponding to the portion where the unexposed region 62 was present is formed, and, for example, the exposed region 61, the electroformed portion 40 of the first layer, and the substrate 10 are used as a mold to perform nickel plating, thereby forming an electroformed portion 80 of the second layer made of nickel filling the cavity 24.

Here, a part of the electroformed portion 80 of the second layer is formed as an anchor 81 of the cavity 24 interposed between the two electroformed portions 40 of the first layer. The anchor portion 81 is formed such that a distal end portion 81a formed to correspond to the distal end portion 24a of the cavity 24 is thicker than a proximal end portion 81b formed to correspond to the constricted portion 24b of the cavity 24. That is, the distal end 81a of the anchor portion 81 is formed thicker than the constricted portion 24b of the cavity 24.

Next, the resist layer 60 (exposure region 61) of the second layer is removed to form an electroformed product 100 in which the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer having a different shape from the first layer are integrated.

As shown in fig. 4G, the electroformed product 100 can be removed from the substrate 10 to obtain a two-layer electroformed product 100 having an integrated shape.

As described above, with respect to the electroformed product 100 manufactured by the manufacturing method of modification 5, in addition to the same effects as those of the electroformed product 100 of the embodiment, a part of the electroformed portion 80 of the second layer is integrated in a state of being inserted into the electroformed portion 40 of the first layer as the anchor portion 81, so that the shearing strength at the interface between the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer can be improved.

Further, with the electroformed product 100 manufactured by the manufacturing method of modification 5, the electroformed portion 40 of the first layer has the tapered portion 24b, and the tip end portion 81a of the anchor portion 81 of the electroformed portion 80 of the second layer is formed thicker than the tapered portion 24b, so that the situation of coming off due to stretching in the lamination direction of the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer can be prevented, and the strength against stretching can be made stronger than that of the electroformed product 100 of modification 3, 4.

The distal end portion 81a and the proximal end portion 81b of the anchor portion 81 shown in modification 5 are connected by a portion extending in the stacking direction of the electroformed portion 40 of the first layer and the electroformed portion 80 of the second layer, but may be connected by a tapered portion extending from the proximal end portion 81b toward the distal end portion 81a instead of being connected by a portion extending in the stacking direction.

The electroformed product 100 according to the above embodiment and each modification is, for example, a tip member (a portion in which the electroformed portion 40 of the first layer is a lever and the electroformed portion 80 of the second layer is a shaft pressed into the pallet) fixed by being pressed into the pallet (Anchor) of the mechanical timepiece, but the method for manufacturing the electroformed product 100 according to the embodiment and each modification and the electroformed product 100 are not limited to the tip member, and may be applied to various members (gears, etc.) used in the timepiece, and may be applied to various articles other than the timepiece.

In particular, the method for producing an electroformed article and the electroformed article of the invention are preferably applied to integral members having different profile shapes of the first layer and the second layer.

The present invention is applicable to an integrated electroformed product having a plurality of layers of two or more layers having different contour shapes between layers, and is not limited to a two-layer electroformed product.

(description of the reference numerals)

40: an electroformed portion of the first layer; 41: a surface; 50: a metal film; 60: a resist layer;

62: unexposed area 80: an electroformed portion of the second layer; 100: electroforming the article; l: UV light

Claims

1. A method for producing an electroformed product in which electroformed portions formed by metal plating are integrally formed by stacking the electroformed portions of a plurality of layers in the thickness direction, characterized in that,

forming a metal film which is not easy to form an oxide film and has good corrosion resistance on the surface of the electroformed part formed in advance on the side where the next electroformed part is to be laminated;

next, a resist layer for the next electroforming portion is formed over the metal film;

next, a portion of the resist layer corresponding to the next electroformed portion is removed by exposure and development;

forming the next electroformed portion on the removed portion of the resist layer,

the metal film is a noble metal or an alloy of noble metals.

2. The method for producing an electroformed article according to claim 1, wherein,

at least a part of the other portion of the resist layer, which is not removed for forming the next electroformed portion, remains over the metal film before the next electroformed portion is formed.

3. The method for producing an electroformed article according to claim 1, wherein,

before forming the metal film, an oxide film is removed from the surface of the electroformed portion formed in advance.

4. The method for producing an electroformed article according to claim 1, wherein,

forming a cavity in a layer corresponding to the electroformed portion formed in advance,

in the cavity, an anchor portion inserted into the cavity is formed on the next electroformed portion.

5. The method for producing an electroformed article according to claim 4, wherein,

a constricted portion having a smaller thickness than a portion of the hollow on a side away from the next electroformed portion is formed on a portion of the hollow on a side closer to the next electroformed portion,

an insertion portion of the anchor portion, which is inserted into a portion of the cavity on a side away from the next electroformed portion, is formed thicker than the constricted portion.

6. The method for producing an electroformed article according to any one of claims 1 to 5, wherein,

an eave forming layer of a material having a conductivity different from that of the metal film is formed over the substrate,

forming the electroformed portion formed in advance over the eave-forming layer,

the eave forming layer is removed to a position recessed inward from the side surface of the electroformed portion formed in advance,

Forming the metal film on the substrate and the electroforming portion formed in advance,

removing the eave forming layer to the recessed position, thereby forming a gap between the metal film formed on the substrate and the metal film formed on the side surface of the electroformed portion formed in advance,

after the next electroformed portion is formed over the electroformed portion formed in advance with the metal film interposed therebetween, the eave forming layer remaining between the electroformed portion formed in advance and the substrate is removed via the gap by etching.

7. The method for producing an electroformed article according to claim 6, wherein,

forming the metal film on the eave forming layer before forming the electroforming portion formed in advance on the eave forming layer,

the electroformed portion formed in advance is formed over the metal film.

8. An electroformed product, characterized in that,

the electroforming portion formed by metal plating is formed by stacking a plurality of electroforming portions in the thickness direction,

a metal film having good corrosion resistance and no oxide film is formed at the interface of the laminated electroformed portion where the step is formed,

the metal film is a noble metal or an alloy of noble metals.