JP2021139026A - Method for manufacturing electroformed article and electroformed article - Google Patents

Abstract

To provide a method for manufacturing an electroformed article which does not require a mask for forming a conductive layer, can surely separate the conductive layer on a step surface at an appropriate position, and does not form a cavity between a first electroformed part and a second electroformed part.SOLUTION: Provided is a method for manufacturing an electroformed article 200 in which a first electroformed part 40 and a second electroformed part 80 projecting in a width direction from the first electroformed part 40 are integrally formed. The second electroformed part 80 is formed by an electroplating process in a state in which conductive particles 120 are distributed and arranged on a step forming surface 25 of a first layer resist 20 where the second electroformed part 80 forms a step surface 210 projecting in a width direction W from the first electroformed part 40.SELECTED DRAWING: Figure 2I

Description

The present invention relates to a method for producing an electrocast product and an electrocast product.

For example, a structure having a minute shape such as a clock part is manufactured by electrocasting. Then, an electroplated product is manufactured in which a first electroplated portion close to the conductive substrate and a second electroplated portion far from the conductive substrate protruding in the width direction from the first electroplated portion are integrally formed. A method of doing so has also been proposed (see, for example, Patent Documents 1 and 2).

According to the techniques described in Patent Documents 1 and 2, the resist corresponding to the first electrocast portion (first layer electrocast portion) and the second electrocast portion (second layer electrocast portion) are supported. A conductive layer is formed on the upper surface of the step with the resist.

As a result, when the first electrocast portion reaches the step, the first electrocast portion is connected to the conductive layer formed on the upper surface of the step, and the upper surface of the step also becomes a conductive portion. As a result, it is possible to suppress a decrease in the growth rate of the electrocast portion on the upper surface of the step.

Japanese Patent No. 4550569 Japanese Patent No. 4840756

Here, according to the technique of Patent Document 1, after the exposure of the first layer of the resist, a conductive layer is formed on the entire surface including the exposed portion and the unexposed portion, the unexposed portion is removed by development, and the unexposed portion is removed. When the portion is removed, the conductive layer formed on the upper surface of the unexposed portion is torn off from the conductive layer formed on the upper surface of the exposed portion (remaining without being removed), but the conductive layer is removed. Is not properly torn, so that a part of the portion formed on the upper surface of the unexposed portion remains and is turned over, or the entire portion remains and the unexposed portion of the first layer cannot be removed.

Further, there is a difference in plating speed between the inner peripheral side and the outer peripheral side of the substrate, and there is a possibility that a cavity is formed between the first electrocast portion and the second electrocast portion on the slower side. ..

Further, after the second electrocast portion is completed, the upper surface (surface) of the second electrocast portion is ground flat with a grinder, but due to the grinding load, one conductive layer is formed on the stepped surface. The peripheral part of the surface of the second electrocast part is lifted due to peeling from the stepped surface of the resist of the eye, and when the surface is ground flat as it is, the second electrocast part is the peripheral part compared to the central part. There is a problem that the thickness of the material becomes thin.

Further, in the technique of Patent Document 2, after the exposure of the first layer resist, a conductive layer is formed on a portion to be a stepped surface with the second layer resist by using a mask. However, using a mask increases the cost.

Further, in the cavity of the first layer resist on which the first electrocast portion is formed, unevenness (difference) is likely to occur in the flow velocity of the plating solution, and the entire inside of the cavity is not uniformly plated and reaches a step quickly. When the formed portion is connected to the conductive layer on the stepped surface, plating is started between the stepped surface and the conductive layer, and a second electrocast portion is started to be formed. Then, when the second electrocast portion grows, a cavity is formed between the second electrocast portion and the first electrocast portion that has not reached the stepped surface.

Further, after the second electrocast portion is completed, the upper surface (surface) of the second electrocast portion is ground flat with a grinder or the like, but the conductive layer formed on the stepped surface is 1 due to the grinding load. The second layer of resist is peeled off from the stepped surface, and the peripheral edge of the surface of the second electrocast part is in a raised state. There is a problem that the thickness of the part becomes thin.

The present invention has been made in view of the above circumstances, does not require a mask for forming the conductive layer, and can reliably separate the conductive layer on the stepped surface at an appropriate position. It is an object of the present invention to provide a method for manufacturing an electrocast product in which a cavity is not formed between the electrocast portion 1 and the second electrocast portion, and an electrocast product.

The first of the present invention is an electroplating portion in which a first electroplated portion close to a conductive substrate and a second electroplated portion far from the conductive substrate protruding in the width direction from the first electroplated portion are integrally formed. A method for producing a cast product, in which a first mold layer serving as a first mold for forming the first electroplated portion is formed on the conductive substrate, and then the first mold layer is formed. Conductive particles are distributed and arranged on the upper surface, and then a second mold layer, which is a second mold for forming the second electroplated portion, is formed on the first mold layer. Next, among the upper surfaces of the first mold layer, the conductive particles arranged on the step forming surface on which the second electroplated portion forms a stepped surface protruding from the first electroplated portion in the width direction. This is a method for manufacturing an electrocast product in which the first electrocast portion and the second electrocast portion are integrally formed by an electroplating step in a state where the first electroplating portion and the second electrocast portion are integrally formed.

In the second aspect of the present invention, the first electroplated portion and the second electroplated portion protruding in the width direction from the first electroplated portion are integrally formed, and the second electroplated portion is the first electroplated portion. It has a stepped surface that protrudes from the portion in the width direction, and conductive particles that serve as electrodes when the second electroplated portion is formed in the electroplating step are distributed and arranged on the stepped surface. It is an electroplated product.

According to the method for producing an electrocast product and the electrocast product according to the present invention, a mask for forming the conductive layer is not required, and the conductive layer on the stepped surface can be reliably separated at an appropriate position. Further, it is possible to prevent the formation of a cavity between the first electrocast portion and the second electrocast portion.

It is sectional drawing (the 1) which shows typically the flow of forming the conductive particle dispersion sheet in the flow of the manufacturing method of the electric casting article which is one Embodiment of this invention. It is sectional drawing (the 2) which shows typically the flow of forming the conductive particle dispersion sheet of an embodiment. It is sectional drawing (the 3) which shows typically the flow of forming the conductive particle dispersion sheet of an embodiment. It is sectional drawing (the 4) which shows typically the flow of forming the conductive particle dispersion sheet of an embodiment. It is sectional drawing (the 1) which shows typically the flow of the manufacturing method of the electric casting product of embodiment. It is sectional drawing (the 2) which shows typically the flow of the manufacturing method of the electric casting product of embodiment. It is sectional drawing (the 3) which shows typically the flow of the manufacturing method of the electric casting product of embodiment. It is sectional drawing (the 4) which shows typically the flow of the manufacturing method of the electric casting product of embodiment. FIG. 5 is a cross-sectional view (No. 5) schematically showing a flow of a method for manufacturing an electrocast product according to an embodiment. FIG. 6 is a cross-sectional view (No. 6) schematically showing a flow of a method for manufacturing an electrocast product according to an embodiment. It is sectional drawing (the 7) which shows typically the flow of the manufacturing method of the electric casting product of embodiment. It is sectional drawing (8) which shows typically the flow of the manufacturing method of the electric casting product of embodiment. It is sectional drawing (the 4) which shows typically the flow of the manufacturing method of the electric casting product of embodiment. FIG. 5 is a cross-sectional view (No. 5) schematically showing a flow of a method for manufacturing an electrocast product according to an embodiment. FIG. 6 is a cross-sectional view (No. 6) schematically showing a flow of a method for manufacturing an electrocast product according to an embodiment. It is sectional drawing (the 7) which shows typically the flow of the manufacturing method of the electric casting product of embodiment. It is sectional drawing (8) which shows typically the flow of the manufacturing method of the electric casting product of embodiment. FIG. 5 is a cross-sectional view showing a comparative example in which the conductive particle dispersion sheet is an integral conductive film 350, which is not an embodiment. It is sectional drawing which shows the case where the growth rate of electric casting in the cavity (unexposed area) corresponding to the 1st electric casting part becomes non-uniform partially. FIG. 1 is a cross-sectional view (No. 1) showing a modified example (Modified Example 1) of the embodiment in which the first mold layer in the embodiment is formed of a silicon substrate instead of a resist. It is sectional drawing (the 2) which shows the modification 1. FIG. It is sectional drawing (the 3) which shows the modification 1. FIG. It is sectional drawing (the 4) which shows the modification 1. FIG. FIG. 5 is a cross-sectional view (No. 5) showing a modification 1. FIG. 6 is a cross-sectional view (No. 6) showing a modification 1. It is sectional drawing (7) which shows the modification 1. FIG. It is sectional drawing (8) which shows the modification 1. FIG. It is sectional drawing (9) which shows the modification 1. FIG. It is sectional drawing (10) which shows the modification 1. FIG. It is sectional drawing (11) which shows the modification 1. FIG. It is sectional drawing (12) which shows the modification 1. FIG. It is sectional drawing (13) which shows the modification 1. FIG. FIG. 1 is a cross-sectional view (No. 1) showing a modified example (modified example 2) of the embodiment in which the conductive particles in the embodiment are made into conductive particles in which the conductive particles are changed into a shape that prevents the resist from coming off. It is sectional drawing (the 2) which shows the modification 2. FIG. 3 is a cross-sectional view (No. 3) showing a modification 2. It is sectional drawing (the 4) which shows the modification 2. FIG. 5 is a cross-sectional view (No. 5) showing a modification 2. FIG. 6 is a cross-sectional view (No. 6) showing a modification 2. FIG. 7 is a cross-sectional view (No. 7) showing a modification 2.

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

1A to 1D are cross-sectional views schematically showing a flow of forming a conductive particle dispersion film in the flow of a manufacturing method of an electrocast product 200 according to an embodiment of the present invention, and FIGS. 2A to 2M are cross-sectional views of the present invention. It is sectional drawing which shows typically the flow of the manufacturing method of the electric casting product 200 which is one Embodiment.

The illustrated electrocast product 200 is manufactured by a first electrocast portion 40 close to the conductive substrate 10 (hereinafter, simply referred to as a substrate 10) and a substrate protruding from the first electrocast portion 40 in the width direction W. This is a method for manufacturing an electrocast product 200 in which a second electrocast portion 80 far from 10 is integrally formed.

In this manufacturing method, first, as shown in FIGS. 1A to 1D, a conductive particle dispersion sheet 140 arranged on a stepped surface between the first electrocast portion 40 and the second electrocast portion 80 is formed. Specifically, first, as shown in FIG. 1A, the conductive film 121 is formed on one surface 110a of the substrate 110 having heat resistance and flexibility. Before forming the conductive film 121, a mold release agent may be applied to the surface 110a.

Examples of the substrate 110 include G-Leaf (registered trademark), which is a flexible glass manufactured by Nippon Electric Glass Co., Ltd., and high heat resistance manufactured by Xenomax Japan Co., Ltd. (a joint venture between Toyobo Co., Ltd. and Nagase Sangyo Co., Ltd.). Xenomax (registered trademark), which is a sex polyimide film, can be used. The substrate 110 is not limited to these examples.

For the conductive film 121, for example, gold (Au) can be used as the conductor, and in this case, the conductive film 121 is formed by forming a gold conductor to, for example, a thickness of 5 [nm]. The conductive film 121 is not limited to the one formed of a gold conductor, and the thickness is not limited to 5 [nm], and for example, a range of 1 to 10 [nm] can be applied. The thickness of the conductive film 121 may be 10 [nm] or more.

Next, the substrate 110 on which the conductive film 121 is formed is heated to form the conductive film 121 into conductive particles 120 distributed on the substrate 110, as shown in FIG. 1B. When the conductor is gold, it can be made into particles by heating at a temperature of 400 [° C.] for 1 [hour] under atmospheric pressure, for example. As shown in the plan view of FIG. 1C (plan view seen from the → direction in FIG. 1B), the conductive particles 120 are arranged so that the particles 120 are distributed apart from each other.

In the plan view of FIG. 1C, when the percentage of the area occupied by the particles 120 in the plan view with respect to the area of the surface 110a of the substrate 110 is defined as the filling rate [%], the filling rate is 30 [%] or more and 90 [%] or less. be. In this embodiment, the filling rate is preferably 50 [%] or more.

When the filling rate of the conductive particles 120 is lower than the above range, the conductive particles 120 are formed, and then the conductive particles 121 are added to the surface 110a of the substrate 110 to form the conductive film 121 at 400 [° C.]. The filling rate can be increased by repeating heating again for 1 [hour].

The conductive particles 120 preferably have a long side of 10 [μm] or less at the maximum, and the particles 120 become spherical by increasing the number of repetitions of the above-mentioned coating and heating steps of the conductive film 121. It is possible to approach and suppress the formation of long particles 120 in only one direction.

Next, as shown in FIG. 1D, the resist 130 is applied onto the surface 110a in which the conductive particles 120 are distributed and arranged, and then heated to remove the solvent in the resist 130. The thickness t2 of the resist 130 may be such that the conductive particles 120 are covered. The resist 130 is formed of, for example, a chemically amplified epoxy-based negative photoresist, but is not limited to the negative type, and may be, for example, a polymethylmethacrylate-based positive photoresist or the like.

By applying the resist 130, the plurality of conductive particles 120 distributed and arranged on the surface 110a are solidified by the resist 130, so that the plurality of conductive particles 120 are distributed at a predetermined filling rate. The arranged conductive particle dispersion sheet 140 can be generated.

As shown in FIG. 2A, the first layer resist 20 to be the first mold layer is applied onto the conductive substrate 10 in parallel with or before and after the formation of the conductive particle dispersion sheet 140. Then, it is heated to remove the solvent in the resist 20.

The conductive substrate 10 may be formed of a conductive metal, or a conductive film may be formed on a substrate body such as silicon which is a semiconductor or a substrate body such as a non-conductive resin to conduct conductivity. It may be one that exerts its sexuality. The conductive substrate 10 may be formed by laminating a plurality of types of metals.

The resist 20 must be of at least the same type as the resist 130 (when the resist 130 is a negative type, the resist 20 is also a negative type, and when the resist 130 is a positive type, the resist 20 is also a positive type). It is preferably the same material.

Next, in the manufacturing method of the present embodiment, as shown in FIG. 2B, the conductive particle dispersion sheet 140 is attached to the surface 20a of the resist 20 on the side far from the substrate 10. Specifically, the surface 20a of the resist 20 is brought into close contact with the surface 140a of the conductive particle dispersion sheet 140 shown in FIG. 1D, which is opposite to the substrate 110.

At this time, in order to prevent air bubbles from entering between the surface 20a of the resist 20 and the surface 140a of the conductive particle dispersion sheet 140, the above-mentioned operation of close contact between the two is performed in the following (1), (2),. This can be done by any of the methods (3).

(1) Heat the resist 20 and the resist 130 to a temperature below the glass transition point (2) After heating the resist 20 and the resist 130 to a temperature below the glass transition point and performing an adhesion operation, the resist 20 and the resist Warm to a temperature above the glass transition point of 130 to improve the bonding force at the interface between the two (3) Warm to a temperature above the glass transition point of the resist 20 and resist 130 (however, the thickness is controlled). Therefore, it is necessary to precisely control the pressurization conditions)

Then, as shown in FIG. 2C, the substrate 110 is peeled off from the conductive particle dispersion sheet 140. Here, since the adhesiveness between the conductive particles 120 and the resist 130 of the conductive particle dispersion sheet 140 and the substrate 110 is low, the substrate 110 can be peeled off relatively easily, but the substrate 110 is previously released from the surface 110a of the substrate 110. When the mold agent is applied, the substrate 110 can be peeled off more easily.

When the substrate 110 transmits ultraviolet rays, the substrate 110 may be peeled off after the next exposure step.

Next, as shown in FIG. 2D, the resist 20 is irradiated (exposed) with UV light (ultraviolet rays) L through the conductive particle dispersion sheet 140 via the photomask 30 in which the opening 31 and the shielding portion 32 are formed. .. Since the filling rate of the particles 120 in the conductive particle dispersion sheet 140 is smaller than 100, the region in which the resist 20 is irradiated with UV light L through the opening 31 through the region of the resist 130 in which the particles 120 do not exist. A (exposed region) 21 and a region (unexposed region) 22 not irradiated with UV light L by the shielding portion 32 are formed.

The unexposed area 22 becomes hollow by the subsequent development process, and becomes a mold (first mold) for forming the first electrocast portion 40 close to the substrate 10.

Next, as shown in FIG. 2E, a second-layer resist 60 to be a second mold layer is formed on the first-layer resist 20 with the conductive particle dispersion sheet 140 interposed therebetween. The resist 60 corresponds to the second electrocast portion 80 on the side farther from the substrate 10 than the first electrocast portion 40 closer to the substrate 10.

Next, as shown in FIG. 2F, the resist 60 of the second layer is irradiated (exposed) with UV light (ultraviolet rays) L via the photomask 70 in which the opening 71 and the shielding portion 72 are formed. As a result, the resist 60 is formed with a region (exposed region) 61 that is irradiated with UV light L through the opening 71 and a region (unexposed region) 62 that is not irradiated with UV light L by the shielding portion 72. NS. The unexposed area 62 becomes hollow by the subsequent development process, and becomes a mold (second mold) for forming the second electrocast portion 80 far from the substrate 10.

Here, the width W2 of the unexposed region 62 of the second layer resist 60 along the width direction W orthogonal to the thickness direction t is wider than the width W1 of the unexposed region 22 of the first layer resist 20. .. As a result, as shown in FIG. 2G, when the unexposed region 22 of the first layer resist 20 and the unexposed region 62 of the second layer resist 60 are removed by the development process, the first layer resist 20 is subjected to. A step forming surface 25 is formed in which the first electrocast portion 40 to the second electrocast portion 80 project from the width direction W to form a step surface.

Further, when the resists 20 and 60 are removed by development, the portion 142 of the conductive particle dispersion sheet 140 corresponding to the unexposed region 22 of the resist 20 is also removed, but the conductive particle dispersion corresponding to the step forming surface 25 is also removed. Since the conductors are not connected as an integral film but only the resist 130 in which the particles 120 are distributed and arranged, the portions 141 and 142 of the sheet 140 are connected at an appropriate boundary by development. Easy to tear.

When the particles 120 are not exposed on the surface of the conductive particle dispersion sheet 140 on the step forming surface 25, the surface of the conductive particle dispersion sheet 140 is ashed with oxygen plasma prior to electrocasting by metal plating described later. The treatment is performed to expose the particles 120 to the step forming surface 25.

Next, by electroplating with the substrate 10 using nickel (Ni), first, as shown in FIG. 2H, the first cavity corresponding to the unexposed region 22 of the first layer resist 20 is used as a mold. The electroplated portion 40 is formed. The electroformed material is not limited to nickel, and all electroformed materials such as copper (Cu), tin (Sn), and cobalt (Co) can be applied.

As the growth of the first electrocast portion 40 progresses, the tip portion of the grown first electrocast portion 40 eventually reaches the conductive particle dispersion sheet 140, as shown in FIG. 2I. Since the first electrocast portion 40 naturally has conductivity, the particles 120 of the conductive particle dispersion sheet 140 connected to the first electrocast portion 40 also conduct with the substrate 10, and the electroplating electrode is similar to the substrate 10. It becomes. Then, as shown in FIG. 2J, the second electrocast portion 80 is formed by using the cavity corresponding to the unexposed region 62 of the second layer resist 60 as a mold.

Here, since the particles 120 of the conductive particle dispersion sheet 140 also serve as electrodes for electroplating, the second electrocast portion 80 grows from the step forming surface 25 that protrudes in the width direction W from the first electrocast portion 40. To go.

At this time, the growth rate in the width direction W depends on the filling rate of the particles 120. For example, when the filling rate of the particles 120 is 50 [%], the growth rate is such that the filling rate of the particles 120 is 0 [%]. It is about twice the growth rate of the case.

Then, after the second electrocast portion 80 has grown to a desired thickness, the upper surface 60a of the resist 60 and the upper surface 80a of the second electrocast portion 80 are ground and polished flat as shown in FIG. 2K.

After that, by removing the resists 20, 60, and 130 and also removing the substrate 10, as shown in FIG. 2L, the first electrocast portion 40 and the second projecting from the first electrocast portion 40 in the width direction W. An electrocast product 200 in which the electrocast portion 80 is integrally formed is manufactured. The surface of the first electrocast portion 40 protruding in the width direction W of the second electrocast portion 80 becomes a step surface 210 formed by the step forming surface 25.

The conductive particles 120 contained in the conductive particle dispersion sheet 140 remain on the stepped surface 210 of the electrocast product 200. When the original conductive film 121 is gold, the particles 120 take on a color such as red or yellow due to surface plasmon resonance, so that a decorative effect due to the color can be obtained. Therefore, for the purpose of obtaining such a decorative effect, the particles 120 may be intentionally left on the stepped surface 210, or the particles 120 may be removed from the stepped surface 210 as shown in FIG. 2M.

As described above, according to the method for producing the electrocast product 200 of the present embodiment, the conductive particle dispersion sheet 140 is the first layer because the conductive particles 120 are separated from each other and are connected only by the resist 130. When the unexposed region 22 of the resist 20 is removed, the portion 142 of the conductive particle dispersion sheet 140 arranged on the upper surface of the unexposed region 22 and the portion 141 of the conductive particle dispersion sheet 140 of the step forming surface 25. Is easily cut off.

Therefore, as shown in FIG. 3A, at the boundary between the portion 352 corresponding to the unexposed region 22 and the portion 351 corresponding to the step forming surface 25, as compared with the case where the conductive particle dispersion sheet 140 is an integral conductive film 350. The remaining portion of the conductive film 350 is not easily peeled off without being cut accurately.

Further, the conductive particle dispersion sheet 140 is accurately cut at the boundary between the unexposed region 22 of the first layer resist 20 and the step forming surface 25, and the conductive particles 120 are completely separated at appropriate positions. Therefore, it is not necessary to prepare a mask for forming a conductive film formed in a shape that matches each shape of the step forming surface 25. Therefore, the manufacturing method of the electrocast product 200 of the present embodiment can reduce the manufacturing cost as compared with the manufacturing method in which such a mask is prepared each time.

Further, in the method for manufacturing the electric casting product 200 of the present embodiment, the growth rate of the electric casting in the cavity (unexposed region 22) corresponding to the first electric casting portion 40 of the first layer resist 20 is assumed to be partial. Even when only a part of the first electrocast portion 40 reaches the conductive particle dispersion sheet 140 prior to the other portion, as shown in FIG. 3B, for example, the first electrocast The portion of the conductive particle dispersion sheet 140 to which the portion 40 has not reached does not conduct with the substrate 10.

Therefore, the second electrocast portion 80 does not start to grow from the portion of the conductive particle dispersion sheet 140 that the first electrocast portion 40 has not reached before the first electrocast portion 40 arrives.

Therefore, a cavity is generated between the first electrocast portion 40 and the second electrocast portion 80, which may be formed when the second electrocast portion starts to grow before the first electrocast portion 40 arrives. There is nothing.

Further, in the method for manufacturing the electrocast product 200 of the present embodiment, the surface area of the step forming surface 25 is large because the particles 120 of the conductive particle dispersion sheet 140 are mainly spherical, and therefore the step of the second electrocast portion 80. Since the area of the surface 210 in contact with the particles 120 is larger than the area in contact with the flat conductive film, the bonding force between the second electrocast portion 80 and the particles 120 is large.

Therefore, in the method for manufacturing the electrocast product 200 of the present embodiment, the upper surface 80a of the second electrocast portion 80 is ground and polished with a grinder (see FIG. 2K) to have a strong resistance to a load, and the stepped surface 210 has a stepped surface. It becomes difficult to peel off from the forming surface 25, and it is possible to prevent or suppress the periphery of the second electrocast portion 80 from rising.

Since the periphery of the second electrocast portion 80 does not rise with respect to the central portion, when the upper surface 80a of the second electrocast portion 80 is ground and polished as shown in FIG. 2K, for example, the second electrocast portion The thickness of the peripheral portion of 80 is not thinner than the thickness of the central portion, and the thickness can be made uniform.

In the conductive particle dispersion sheet 140 used in the method for producing the electroplated product 200 of the present embodiment, the filling rate of the particles 120 is 30 [%] or more and 90 [%] or less, but the filling rate is less than 30 [%]. As an electrode for growing the second electrocast portion 80 by electroplating, a sufficient growth rate cannot be obtained, and when the filling rate exceeds 90 [%], the conductive particle dispersion sheet 140 is covered. The resist 20 of the lower layer (first layer) that has been broken cannot be sufficiently exposed.

When the filling rate is 50 [%] or more, the growth rate of the second electrocast portion 80 can be sufficiently accelerated, which is preferable.

<Modification example 1>
In the electrocast product 200 of the embodiment, the first layer portion (mold layer) to be the mold of the first electrocast portion 40 is formed by the resist 20. Here, the resist 20 is generally formed on the substrate 10 by a spin coater.

Since the spin coater is rotated, centrifugal force acts on it, and the resist on the outer peripheral side tends to be thicker than the resist on the inner peripheral side near the center of rotation, and the accuracy of the thickness of the first electrocast portion 40 is adjusted. Is difficult. Further, even if an attempt is made to grind a resist, it is costly to grind a resist that reacts with ultraviolet rays in an environment that does not receive ultraviolet rays.

4A to 4M are cross-sectional views showing a modified example (modified example 1) of the embodiment in which the first mold layer in the embodiment is formed of a silicon substrate 321 instead of the resist 20.

In the method for manufacturing the electrocast product 200 of the first modification, first, a silicon substrate 321 as a first mold layer to be a mold of the first electrocast portion 40 is prepared, and as shown in FIG. 4A, one surface is provided. A silicon oxide layer 321c is formed on the 321a by plasma CVD, thermal oxidation treatment, or the like.

Next, as shown in FIG. 4B, the opposite surface 321b on which the silicon oxide 321c of the silicon substrate 321 is formed is ground and polished to obtain a uniform thickness t3.

Here, in the example of FIG. 4A, the silicon oxide layer 321c is formed only on one surface 321a of the silicon substrate 321. However, the silicon oxide layer 321c may be formed on both surfaces. In that case, only one of the two surfaces of the silicon substrate 321 is ground and polished.

Next, as shown in FIG. 4C, a conductive layer 322 is formed on the ground and polished surface (321b) by, for example, sputtering.

Next, as shown in FIG. 4D, the conductive layer 322 shown in FIG. 4C is attached to the support substrate 324 made of silicon or glass with an adhesive 323.

Next, as shown in FIG. 4E, a resist 325 is applied to the silicon oxide layer 321c, and the area corresponding to the cavity forming the first electrocast portion 40 is exposed by masking as an unexposed area 325a. A development process is performed to remove the unexposed region 325a. Next, of the silicon oxide layer 321c, the region 321d corresponding to the unexposed region 325a is removed by oxidative etching, and then the resist 325 is also removed.

Next, as shown in FIG. 4F, using the silicon oxide layer 321c as a mask, the region 321e corresponding to the removed region 321d was removed by deep-drill reactive ion etching, and this region 321e was transferred to the first electrocast portion 40. Form in the corresponding cavity. This region 321e is a mold (first mold) for forming the first electrocast portion 40 close to the conductive layer 322.

Next, as shown in FIG. 4G, the conductive particle dispersion sheet 140 shown in FIG. 2C is attached to the silicon oxide layer 321c. The conductive particle dispersion sheet 140 can be attached in the same process as the embodiment described with reference to FIGS. 2B and 2C. Then, the exposure is performed by masking so that the range corresponding to the cavity forming the first electrocast portion 40 is the unexposed region 142.

Next, as shown in FIG. 4H, a second resist 60, which is a second mold layer, is formed on the conductive particle dispersion sheet 140. Next, as in FIG. 2F, the second layer resist 60 is irradiated (exposed) with UV light (ultraviolet rays) L via the photomask 70, and the second electrocast portion 80 is formed by development (second). The unexposed area 62 that becomes the mold) is removed. At this time, the portion of the conductive particle dispersion sheet 140 corresponding to the region 321e is also removed.

Next, by electroplating with the conductive layer 322 using nickel (Ni), as shown in FIG. 4I, the first electrocast portion 40 is formed in the cavity corresponding to the region 321e of the first layer silicon substrate 321. The second electroplated portion 80 is formed in the cavity corresponding to the unexposed region 62 of the second layer resist 60, and the first electroplated portion 40 and the second electroplated portion 80 are integrally electroplated. 200 is formed. The electroformed material is not limited to nickel, and all electroformed materials such as copper, tin, and cobalt can be applied.

The upper surface 60a of the second layer resist 60 and the upper surface 80a of the second electrocast portion 80 are ground and polished to make the thickness t4 of the second electrocast portion 80 uniform.

Next, as shown in FIG. 4J, the adhesive 323 is peeled off to separate the support substrate 324 and the conductive layer 322 side, and the conductive layer 322 side is turned upside down to turn the second electrocast portion 80 and the second layer resist. 60 is attached to the support substrate 324 with the adhesive 323.

Next, as shown in FIG. 4K, the conductive layer 322, the silicon substrate 321 and the silicon oxide layer 321c are removed by etching. For example, when the conductive layer is gold (Au), the conductive layer is removed by an iodine-based etching solution, silicon is removed by potassium hydroxide, and silicon oxide is removed by plasma etching using CHF3 gas.

Next, as shown in FIG. 4L, the conductive particle dispersion sheets 140 and the resists 60 and 130 are removed, and the adhesive 323 is dissolved to remove the electroformed product 200 from the support substrate 324. As a result, the electrocast product 200 in which the conductive particles 120 contained in the conductive particle dispersion sheet 140 remain is formed on the stepped surface 210.

In this electrocast component 200, the conductive particles 120 remain on the stepped surface 210, but the particles 120 may be intentionally left for the purpose of obtaining the same decorative effect as in the embodiment, or FIG. 4M. As shown in, the conductive particles 120 may be removed.

As described above, according to the method for manufacturing the electric cast product 200 according to the first modification, in addition to being able to obtain the same effect as that of the embodiment, without using a resist which may have a non-uniform thickness. By forming the first electrocast portion 40 using the silicon substrate 321 capable of uniformly producing the thickness, the thickness t3 of the first layer of the electrocast product 200 can be made uniform. can.

The first modification is a method of manufacturing an electrocast product 200 in which two layers of electrocast portions 40 and 80 are integrally formed, but the method is one in which three or more layers of electrocast portions are integrally formed. May be good. In this case, only the mold layer of the electrocast portion of the uppermost layer may be used as the resist 60, and the mold layers of all the other electrocast portions except the uppermost layer may be formed by either the resist 60 or the silicon substrate 321.

<Modification 2>
In the electrocast product 200 of the example, the conductive particles 120 are close to spherical, but the shape of the particles 120 is changed to increase the bonding force between the resist 130 and the conductive particles 120 in the conductive particle dispersion sheet 140. May be good.

5A to 5F are cross-sectional views showing a modified example (modified example 2) of the embodiment in which the conductive particles 120 in the embodiment are changed to conductive particles 129 in which the conductive particles 120 are changed into a shape that prevents the resist from coming off. be.

In the method of manufacturing the electrocast product 200 of the second modification, first, the conductive particle dispersion sheet 240 is formed instead of the conductive particle dispersion sheet 140 of the embodiment.

Specifically, as shown in FIG. 5A, the heat release sheet 115 is attached on one surface 110a of the substrate 110, and the conductive film 121 is formed on the heat release sheet 115.

Next, as shown in FIG. 5B, a resist 130 is formed on the conductive film 121, and an unexposed region 132 for forming conductive particles 129 corresponding to the particles 120 is formed on the resist 130 later. Form. The unexposed region 132 can be formed by exposure using a mask having a light-shielding portion having a width W5. As a result, the unexposed region 132 having a width W5 is formed, and the resist 130 in the unexposed region 132 is removed by development to form a cavity having a width W5.

Next, as shown in FIG. 5C, conductive particles 129 are formed in the cavities of the unexposed region 132 by wet plating using the conductive film 121 as an electrode. When the conductive particles 129 grow from the cavity of the resist 130 to the outside of the resist 130, the conductive particles 129 grow to a width W6 (> W5) wider than the width W5 of the cavity. As a result, the conductive particle 129 is formed by integrally forming a particle portion 127 having the same width W5 as the cavity and a particle portion 128 having a width W6 wider than the cavity.

Next, as shown in FIG. 5D, the resist 138 is further applied and heated on the resist 130 in which the conductive particles 129 are distributed and arranged to remove the solvent in the resist 138. The resist 138 may be thick enough to cover the conductive particles 129. The resist 138 may be the same as the resist 130.

By applying the resist 138, the particle portion 128 having a width wider than the particle portion 127 having a width W5 can be embedded in the resist 138, whereby a plurality of electrically distributed particles arranged in a distributed manner can be obtained. It is possible to generate a conductive particle dispersion sheet 240 in which 129 is integrally formed by resists 130 and 138.

Next, as shown in FIG. 5E, as shown in FIG. 2B of the embodiment, the conductivity shown in FIG. 2A was generated in parallel with or before and after the generation of the conductive particle dispersion sheet 240. The conductive particle dispersion sheet 240 is attached to the first layer resist 20 coated on the property substrate 10. The bonding of 240 of the conductive sheets is the same as that of the embodiment.

Next, as shown in FIG. 5F, the substrate 110 is removed by applying heat to reduce the adhesive strength of the heat release sheet 115, and further, the conductive film 121 is removed to disperse the conductive particles according to the first embodiment. Similar to the sheet 140, the conductive particle dispersion sheet 240 in which the particles 129 are distributed and arranged can be formed on the first layer resist 20.

Then, in the particles 129 distributed on the conductive particle dispersion sheet 240 formed in this way, the upper particle portion 127 exposed on the surface of the conductive particle dispersion sheet 140 has a width W5, and the lower side is buried in the resists 130 and 138. The particle portion 128 of the above has a width W6 wider than that of the particle portion 127.

As shown in FIG. 5G, the upper particle portion 127 serves as an electrode when forming the second electrocast portion 80, and thus is coupled to the second electrocast portion 80. Here, even if the surface of the second electrocast portion 80 is ground and a load is applied such that the periphery of the second electrocast portion 80 is lifted upward, the particle portion 128 buried in the resists 130 and 138 remains. Since the width is formed wider than the particle portion 127 bonded to the second electrocast portion 80, even if the particles 129 try to float together with the second electrocast portion 80, the particle portion 128 is formed from the resists 130 and 138. Demonstrates the function of preventing the particles from coming off.

As described above, according to the method for producing the electrocast product 200 according to the second modification, in addition to being able to obtain the same effect as that of the embodiment, the bonding between the particles 129 of the conductive particle dispersion sheet 240 and the resists 130 and 138 is obtained. Since the force is stronger than that of the conductive particle dispersion sheet 140 of the embodiment, the floating of the second electrocast portion 80 can be prevented more firmly.

10 Conductive Substrate 20, 60 Resist 25 Step Forming Surface 40 First Electroplated Part 80 Second Electroplated Part 120 Particles 140 Conductive Particle Dispersion Sheet 200 Electroplated Product 210 Step Surface L UV Light W Width Direction W1, W2 Width t Thickness Direction

Claims (6)

It is a method for manufacturing an electroplated product in which a first electroplated portion close to a conductive substrate and a second electroplated portion far from the conductive substrate protruding in the width direction from the first electroplated portion are integrally formed. hand,
On the conductive substrate, a first mold layer to be a first mold for forming the first electrocast portion is formed.
Next, conductive particles are distributed and arranged on the upper surface of the first mold layer.
Next, on the first mold layer, a second mold layer to be a second mold for forming the second electrocast portion is formed.
Next, among the upper surfaces of the first mold layer, the conductive particles arranged on the step forming surface on which the second electroplated portion forms a stepped surface protruding from the first electroplated portion in the width direction. A method for manufacturing an electrocast product in which the first electrocast portion and the second electrocast portion are integrally formed by an electroplating step in a state where the first electroplated portion and the second electrocast portion are integrally formed. A conductive film is formed on a flexible substrate having heat resistance,
The substrate on which the conductive film is formed is heated to atomize the conductive film into conductive particles distributed on the substrate.
A resist is applied onto a substrate on which the conductive particles are distributed, and then heated to form a large number of the distributed conductive particles into a conductive particle dispersion sheet integrated with the resist.
The upper surface side of the resist of the conductive particle dispersion sheet is attached to the upper surface of the first mold layer.
The method for producing an electrocast product according to claim 1, wherein the conductive particles are distributed and arranged on the upper surface of the first mold layer by peeling off the substrate. The width of the particle portion embedded in the resist is wider than the width of the particle portion bonded to the second electrocast portion, and the particle portion embedded in the resist forms a retaining material. The method for manufacturing an electrocast product according to claim 2. Prior to forming the second mold layer, the conductive particles are distributed and arranged on the upper surface of the first mold layer, and the first mold layer is covered with the first mold layer. The method for manufacturing an electrocast product according to any one of claims 1 to 3, wherein a cavity corresponding to the electrocast portion is formed. In the arrangement of the conductive particles distributed on the upper surface of the first mold layer, the filling rate defined by the ratio of the area of the conductive particles to the area of the upper surface is 30 to 90 [%]. The method for manufacturing an electrocast product according to any one of claims 1 to 4, wherein the arrangement is as follows. The first electrocast portion and the second electrocast portion protruding in the width direction from the first electrocast portion are integrally formed.
The second electrocast portion has a stepped surface protruding from the first electrocast portion in the width direction.
An electrocast product in which conductive particles that serve as electrodes when the second electroplating portion is formed in the electroplating step are distributed and arranged on the stepped surface.

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