JP4415175B2 - Electroforming mold manufacturing method - Google Patents

Description

The present invention, electroforming die in respect to the production how, particularly to those for producing the light diffusion plate.

  In recent years, overhead projectors and slide projectors have been widely used as methods for presenting materials by speakers in meetings and the like. In general households, video projectors and moving picture film projectors using liquid crystals are becoming popular. The projection method of these projectors modulates the light output from the light source by, for example, a transmissive liquid crystal panel to form image light, and the image light is emitted through an optical system such as a lens and projected onto the screen. To do.

  For example, a projector device capable of forming a color image on a screen separates light rays emitted from a light source into red (R), green (G), and blue (B) colors and converges them on a predetermined optical path. An illumination optical system, a liquid crystal panel (light valve) that optically modulates the RGB light beams separated by the illumination optical system, and a light combining unit that combines the RGB light beams light-modulated by the liquid crystal panel, The color image synthesized by the light synthesizing unit is enlarged and projected on a screen by a projection lens.

  Recently, a projector device of a type that uses a narrow-band three-primary-color light source as a light source and spatially modulates luminous fluxes of RGB colors using a grating light valve (GLV) instead of a liquid crystal panel has been developed. Yes.

  In the projector apparatus described above, a projector screen is used to view a projected image. This projector screen is roughly divided into a front projector screen for irradiating projection light from the front side of the screen to see the reflected light on the screen, and a projection light from the back side of the screen for transmission through the screen. There is a rear projector screen for viewing light from the front side of the screen. Any type of screen is required to have a wide viewing angle with good visibility.

  For this reason, a light diffusing plate that scatters light is generally provided on the screen surface in any of the methods, and image light is diffused and emitted to the entire effective area of the screen by the light diffusing plate.

  As a method for producing this light diffusing plate, there are conventionally a method of applying a dispersion of resin particles in a resin binder to a transparent substrate, a method of transferring a shape using a UV curable resin or the like from a mold in which minute irregularities are machined, and the like. there were.

  In addition, a method of forming a speckle pattern generated when a rough surface is irradiated with a coherent light beam on a photosensitive material has been conventionally used (see, for example, Patent Documents 1 and 2). In particular, this method not only provides effective light diffusion by considering individual speckle patterns as microlenses, but also has an advantage that moire patterns and coloring due to light interference do not occur because the shapes are randomly arranged. It is.

  The manufacture of a light diffusing plate using a method for forming a speckle pattern on a photosensitive material is performed by the following process.

(S91) A photosensitive substrate provided with a photosensitive medium such as heavy chromium oxide gelatin (DCG) as a photosensitive agent layer on the substrate was prepared, and the photosensitive agent layer was exposed to laser light modulated into a speckle pattern. Develop and fix later. In addition, since the area of one exposure area is 1 to several tens of cm ² , in the exposure process, the entire surface of the photosensitive agent layer is repeatedly exposed while shifting the exposure target portion of the photosensitive agent layer. When a positive photoresist is used, the exposed area is removed when developed, and the non-exposed area remains as it is. As a result, a photosensitive substrate having a concavo-convex fine engraving surface corresponding to the speckle pattern formed on the surface is obtained.

(S92) For example, an ultraviolet curable epoxy resin is applied to the surface of the photosensitive substrate manufactured in step s91 and cured to prepare a resin mold in which unevenness on the surface of the photosensitive substrate is transferred.

(S93) Next, a conductive layer is formed on the surface of the resin mold to form a conductive layer, and electroforming is performed using the conductive layer as a cathode to produce a master mold. At this time, a conductive layer made of metal or the like is formed by silver mirror treatment, electroless plating treatment, vacuum deposition treatment, sputtering treatment or the like as the conductive treatment. Further, as electroforming, for example, nickel is electrodeposited to a predetermined thickness, and a resin die is removed from the electrodeposited nickel layer to obtain a metal electroforming master die.
Alternatively, the process of step s92 may be omitted, and the master mold may be directly formed by performing the process of step s93 on the photosensitive substrate manufactured in step s91.

(S94) Based on the master mold produced in step s93, a light diffusing plate is manufactured by, for example, embossing on a thermoformed plastic film.

  Among the conductive treatments in step s93, the silver mirror treatment includes a method of spraying a silver nitrate aqueous solution and a reducing agent aqueous solution with a two-cylinder nozzle gun, an immersion method of immersing in the same mixed solution, and both methods have a large area. The processing does not require a large-scale equipment such as vacuum deposition or sputtering, and is a very simple and effective technique and is generally widely used.

JP-A-53-51755 Japanese Patent Laid-Open No. 2001-1000062

  However, in the above silver mirror treatment, silver deposition has a thickness of several μm, and therefore, the uneven surface with a height of about several tens of μm formed by a method using a speckle pattern is buried by adhesion of the silver layer. For this reason, if the electrodeposition of the next step is performed in this state, the buried shape is transferred to the electroformed surface instead of the original uneven shape.

  Further, after the electroforming (first generation electroforming) in step s93 is finished, the resin mold is peeled off, and the electrodeposition (second generation electroforming) is performed again without removing the silver layer. However, since the silver layer produced by the silver mirror reaction is weak in strength, it is peeled nonuniformly in the silver layer during the resin mold peeling process, and faithful shape reproduction is impossible.

The present invention is more has been made in view of the problems in the prior art, that the uneven shape of the speckle pattern formed on the photosensitive substrate to provide a manufacturing how accurately transcribed electroforming die Objective.

The present invention provided to solve the above-mentioned problems is a method for producing an electroforming mold using a photosensitive substrate in which a substrate, a release layer, and a photosensitive agent layer are sequentially formed, the photosensitive agent for the photosensitive substrate A pattern forming step for forming a predetermined pattern on the layer by exposure and development; a conductive treatment step for forming a conductive layer on the pattern; and a first electroformed product on the conductive layer using the conductive layer as a cathode. A first electroforming step of depositing the substrate, separating the substrate in the release layer, removing the photosensitive agent layer and the release layer from the first electroformed product having a surface made of a conductive layer, and forming a first electroforming mold. And a second electroforming step of forming a second electroforming mold by depositing a second electroformed product on the conductive layer using the first electroforming mold as a cathode. This is a method for producing an electroformed mold characterized by the following.

The pattern is preferably a speckle pattern generated from coherent light.
Further, the release layer is made of a heat-meltable material. In the step of forming the first electroforming mold, it is preferable that the substrate is separated by the release layer by heating.
In particular, the electroforming mold is preferably used for manufacturing a light diffusion plate.

Further, in order to solve the above-mentioned problem, a photosensitive substrate used for forming a photosensitive layer having a predetermined pattern, wherein the substrate, the release layer, and the photosensitive layer are sequentially formed. A characteristic photosensitive substrate may be used.

Here, the pattern is preferably a speckle pattern generated from coherent light.
The release layer is preferably made of a heat-meltable material.

  According to the present invention, for example, a photosensitive substrate on which a speckle pattern is exposed and developed to form a concavo-convex pattern has a release layer between the substrate and the photosensitive agent layer, so that it remains in the conductive layer after the first generation electrodeposition. It is possible to remove the photosensitive agent layer without breaking the shape, and it is possible to obtain an electroformed mold faithful to the original mold (uneven pattern of the photosensitive substrate) by the second generation electrodeposition that is subsequently performed. If this electroformed mold is used, a resin molded product having a desired shape, for example, a light diffusing plate having a desired diffusion effect can be obtained.

Embodiments of the present invention will be described below.
FIG. 1 is a sectional view of a photosensitive substrate used in the present invention.
A photosensitive substrate 10 used for electroforming mold production has a configuration in which a substrate 1, a release layer 2, and a photosensitive agent layer 3 are sequentially formed.

  The substrate 1 is made of a light-transmitting material so that the light transmitted through the photosensitive agent layer 3 and the release layer 2 is reflected when the photosensitive agent layer 3 is exposed to light and does not adversely affect the photosensitive agent layer 3. preferable. For example, polyester (polyethylene terephthalate, polybutylene terephthalate, etc.), polyethylene, polycarbonate, PMMA, glass or the like may be used, and there is no particular limitation as long as the material has optical transparency.

  The release layer 2 can be laminated with the photosensitive agent layer 3, and can be made the weakest in the composition of the photosensitive substrate 10 when the photosensitive agent layer 3 and the substrate 1 are separated. It suffices if so-called delamination that causes peeling is possible. Therefore, the material constituting the release layer 2 is preferably a heat-meltable material, and examples thereof include thermoplastic resins such as acrylic resins, hydrocarbon resins, and vinyl chloride resins, and may be resins having similar performance. There are no particular restrictions. The release layer 2 may be formed by uniformly applying these resins to the substrate 1 by a general coating method such as a gravure coating method or a spin coating method.

  The photosensitive agent layer 3 may be a general photoresist that is polymerized by a photochemical reaction, and includes, for example, a photopolymerization type photosensitive resin, and so on. Any of the eluting negative types can be used. The photoresist may be liquid or dry film type.

  The manufacturing method of the electroforming mold that forms the basis of the present invention includes a pattern forming step of forming a predetermined pattern on the photosensitive agent layer 3 of the photosensitive substrate 10 by exposure and development, and a conductive process for forming a conductive layer on the pattern. And a first electroforming process in which the electroconductive layer is used as a cathode and a first electroformed product is deposited on the electroconductive layer, and a substrate is separated from the release layer 2 and the surface is formed of a electroconductive layer. And removing the photosensitive agent layer and the release layer 2 from the electroformed product to form a first electroformed mold. In addition, after the step of forming the first electroformed mold, the first electroformed mold is used as a cathode, and a second electroformed mold is deposited on the conductive layer to form a second electroformed mold. 2 electroforming steps.

Hereinafter, each process will be described with reference to FIGS. 2 to 4 on the premise that the electroforming mold is used for manufacturing a light diffusion plate.
FIG. 2 is a block diagram of an exposure mechanism in an exposure process for manufacturing an electroformed mold for a light diffusing plate. FIGS. 3 and 4 are diagrams for producing an electroformed mold using a photosensitive substrate after exposure and development. It is the schematic which shows the process until.

(S1) Pattern Forming Step In the present invention, when producing an electroformed mold, first, exposure / development processing is performed using the photosensitive substrate 10 to form a predetermined uneven pattern on the surface of the photosensitive agent layer 3.
Specifically, in the exposure process shown in FIG. 2, the laser light emitted from the laser 20 passes through the objective lens 30 and then passes through a master diffuser 40 such as ground glass to generate interference light (coherent light modulated into a speckle pattern). And the photosensitive substrate 10 is exposed.
Next, a predetermined development process is performed on the photosensitive layer 3 of the photosensitive substrate 10 exposed in the above process. For example, when the photosensitive layer 3 is a negative type, only the exposed portion remains and a predetermined pattern is formed on the surface thereof. It is formed. This pattern is a speckle pattern generated from coherent light, and the photosensitive agent layer 3 has a fine engraving surface having an uneven shape on the surface. Moreover, this uneven | corrugated shape becomes a prototype of the surface shape of the light diffusing plate which is a final product.

In the exposure mechanism shown in FIG. 2, the laser 20 used is not particularly limited, but its wavelength is set so that the sensitivity of the photosensitive agent layer 3 is as high as possible, and at the same time, it is sufficiently large to shorten the exposure time. It is preferable that the output is secured.
The objective lens 30 may be a conventionally known lens.

  The master diffuser 40 is for modulating laser light into a speckle pattern, and may be, for example, a conventionally known ground glass, lenticular diffuser, acetate diffuser, or the like.

(S2) Conductive Treatment Step Using the photosensitive substrate (FIG. 3A) produced in step s1, a conductive layer 5 is formed on the concavo-convex pattern of the photosensitive agent layer 3 (FIG. 3B). This conductive treatment may be a conductive layer made of Ag by a conventionally known silver mirror treatment.

(S3) First Electroforming Step First electroforming layer 7 is formed by electroforming on conductive layer 5 using conductive layer 5 formed in step s2 as a cathode.
For example, Ni is electrodeposited by using the conductive layer 5 as a cathode to form an electrodeposited layer 6 (FIG. 3C), and its end face is polished and removed (dotted line portion in FIG. 3C) to obtain the first electrode. A first electroformed layer 7 made of a casting is formed. At this time, electrodeposition of Ni may be performed by a conventionally known method.

(S4) First Electroforming Mold Formation Step Next, the release layer 2 on the photosensitive substrate 10 is delaminated to separate the substrate 1, and then the surface of the first electroformed layer 7 including the conductive layer 5 to the photosensitive agent layer 3 is separated. And the remaining release layer 2 are removed to obtain a first electroformed mold comprising the first electroformed layer 7 and the conductive layer 5. Specifically, the following procedure may be performed.

  The strength of the release layer 2 is lowered while heating the substrate 1 to a predetermined temperature (FIG. 3D). The heating temperature may be set in consideration of the heat resistant temperature of the substrate 1 and the photosensitive agent layer 3 and the release layer 2, or the relationship between the glass transition temperature and the heat distortion temperature. That is, it is higher than the glass transition temperature Tg of the release layer 2 and lower than the heat resistance temperature of the substrate 1 and the reflow temperature of the photosensitive agent layer 3, and the strength of the substrate 1 and the photosensitive agent layer 3 at the heating temperature is higher than that of the release layer 2. Just make it higher. For example, when the release layer 2 is an acrylic resin (Tg 100 to 120 ° C.) and the heat resistant temperature of the substrate 1 and the reflow temperature of the photosensitive agent layer 3 are 200 ° C. or higher, the temperature may be set to 120 to 200 ° C.

Next, delamination is performed with the release layer 2, and the substrate 1 is separated and removed from the photosensitive agent layer 3, the conductive layer 5, and the first electroformed layer 7 (FIG. 4E).
Thereafter, the photosensitive agent layer 3 is swelled and removed with an alkaline solution for the combination of the photosensitive agent layer 3, the conductive layer 5, and the first electroformed layer 7. At this time, since the residue of the release layer 2 is removed together with the photosensitive agent layer 3, the conductive layer 5 and the conductive layer 5 having a concavo-convex pattern shape that is a mirror image of the concavo-convex pattern on the photosensitive substrate formed in step s 1 on the surface. A first electroforming mold comprising one electroforming layer 7 is obtained (FIG. 4 (f)).

(S5) Second Electroforming Process The second electroforming layer 8 is formed by electroforming on the conductive layer 5 using the first electroforming mold obtained in step s4 as a cathode. At this time, Ni electrodeposition similar to step s3 may be used.

(S6) Second Electroformed Mold Formation Step Next, the conductive layer 5 is delaminated to separate the second electroformed layer 8 from the first electroformed layer 7, and then the conductive material remaining on the second electroformed layer 8 is left. The layer is removed to obtain a second electroforming mold 9. As described above, if the conductive layer 5 is a layer made of Ag and the second electroformed layer 8 is a layer made of Ni, it is possible to cause peeling in the conductive layer 5 using the difference in strength. is there. Further, the residue of the conductive layer 5 on the second electroformed layer 8 side may be removed by chemical treatment.

Thus, the uneven shape of the speckle pattern formed on the photosensitive substrate can be accurately transferred to the first electroforming mold and further transferred to the second electroforming mold 9.
A resin molded product may be produced directly from the second electroformed mold obtained in step s6. However, this electroformed mold is further used as a master, and a sub master is produced from electroforming treatment or ultraviolet curable resin. Also good. A desired light diffusing plate can be obtained by applying and curing an ultraviolet curable resin to the sub-master and removing the mold. Moreover, what has optical transparency is preferable for the ultraviolet curable resin used here. For example, various resins such as acrylic resin, polyester resin, polyvinyl chloride, polyurethane, and silicone resin may be used, but are not particularly limited.

  In addition, when there is no release layer on the photosensitive substrate, a crack occurs inside the conductive layer when the substrate is mechanically peeled off from the first electroformed layer, so the uneven shape formed on the conductive layer after peeling is This is completely different from the originally recorded shape. Therefore, even if the second electroformed layer is formed therefrom, the desired performance cannot be obtained with the light diffusion plate obtained therefrom. Moreover, even if it is immersed in an alkaline solution without peeling off the substrate, the solution does not sufficiently penetrate from the end face, so that it cannot be peeled off or takes a long time, so that efficient production cannot be performed.

  Examples of the present invention will be described below. In addition, a present Example is an illustration and this invention is not limited to this Example.

Example 1
The structure of the photosensitive substrate used is shown below.
(1) Photosensitive substrate:
i) Substrate: PET film (thickness 0.125 mm)
ii) Release layer: Acrylic resin (application thickness: 1-2 μm)
iii) Photosensitizer layer: negative type dry film (FMA6E series manufactured by DuPont MRC Dry Film Co., thickness 38 μm)

  Here, after applying and drying an acrylic resin as a release layer on the PET film of the substrate with a gravure coater, the dry film was laminated on the surface as a photosensitive agent layer at about 100 ° C. to obtain a photosensitive substrate.

Next, using this photosensitive substrate, a predetermined speckle pattern was exposed by the exposure mechanism shown in FIG. 2, and then a 1.0% sodium carbonate solution having a liquid temperature of 28 ° C. was sprayed at a spray pressure of 1.5 × 10 ⁵ Pa. And developed. Then, after sufficiently washing with water, it was dried with warm air to obtain a photosensitive substrate having irregularities corresponding to the speckle pattern.
Next, since this photosensitive substrate has a thickness of about 0.160 mm and lacks rigidity, an acrylic substrate having a thickness of 2 mm is adhered to the back surface of the photosensitive substrate using an ultraviolet curable adhesive to increase the rigidity, and the convenience of subsequent processing is improved. It was.

A silver nitrate aqueous solution and a reducing agent aqueous solution were applied to the surface of the photosensitive substrate thus prepared by a two-cylinder spray method, and a conductive treatment was performed by a silver mirror reaction to form an Ag layer as a conductive layer.
In the electroforming process, in a nickel sulfamate aqueous solution bath, a direct current was passed between the conductive layer as a cathode and a nickel electrode to electrodeposit a Ni layer having a thickness of 5 mm as an electrodeposition layer.

  After the electrodeposition, the first electroformed layer was obtained through an end face polishing step, and the acrylic substrate was heated to 120 ° C. to melt and peel the release layer to separate the substrate. Next, the remaining photosensitive agent layer and release layer were swelled and peeled off at 60 ° C. with a 5% aqueous sodium hydroxide solution.

Next, without removing the conductive layer adhering to the surface of the first electroformed layer, a Ni layer was formed as the second electrodeposited layer by the same procedure as in the case of the first electroformed layer.
Subsequently, the second electroformed layer was separated from the first electroformed layer by delamination of the conductive layer, and the remaining conductive layer adhering to the second electroformed layer was removed.

  Using the second electroformed layer thus obtained as a master electroforming mold, a sub-master electroforming mold was prepared, and after applying an acrylic UV curable resin to this, it was cured by UV irradiation to produce a light diffusion plate product. Got.

As a comparative example, a light diffusing plate was produced in the same manner as in the example using a photosensitive substrate having a structure having no release layer as shown below.
(2) Photosensitive substrate:
i) Substrate: PET film (thickness 0.125 mm)
ii) Photosensitizer layer: negative type dry film (FMA6E series manufactured by DuPont MRC Dry Film Co., thickness 38 μm)
In the first separation step, the substrate was separated by applying a peeling stress by a mechanical method.

The surface diffusion parameters and the diffusion angle were evaluated for the light diffusing plate thus produced.
As surface shape parameters, Ra (arithmetic mean roughness), Ry (maximum height), Rz (ten-point mean roughness), Sm (unevenness of roughness) using a stylus type shape measuring instrument ET4000A (manufactured by Kosaka Laboratory). The average interval was measured. For reference, the parameters on the surface of the photosensitive agent layer after exposure and development were also measured.

  The diffusion angle was obtained from the state of the luminance distribution of the reflected light using the light diffusion plate as a reflective screen. That is, for each of the light diffusing plates of the example and the comparative example, a reflection type in which a reflective layer is provided on the back surface where the uneven pattern shape is not transferred by aluminum vapor deposition is attached to a surface (side wall of the room) perpendicular to the floor. The screen. In the measurement, a liquid crystal projector with a light output of 2000 ANSI lumen (SONY VPL-CX5) is placed facing the front surface at a position 2 m away from the surface where the light diffusion plate is attached, and a white screen is projected. The projection lens position was set to 0 degree, and the luminance measurement was performed by scanning a luminance meter (BM-9 manufactured by Topcon Corporation) on an arc having a radius of 2 m with the light diffusion plate as the center. At this time, the measurable angle region is limited to a range where the projector and the luminance meter do not interfere with each other, and is −2.5 to −85 degrees and +2.5 to 85 degrees when the counterclockwise direction is positive. The angle when the luminance was half of the value of ± 2.5 degrees (peak gain) (half width) was determined as the diffusion angle.

Table 1 shows the measurement results.
As for the surface shape parameter, in any of the parameters, the example is closer to the surface of the photosensitive layer after exposure. In the comparative example, since the substrate was mechanically peeled off without providing the peeling layer, peeling occurred inside the conductive layer, and the uneven pattern (prototype) based on the speckle pattern could not be maintained, and the surface roughness was considered to be small. .
The result regarding the diffusion angle corresponds to the result of the surface shape parameter, and the practical example was 85.2 °, which was 85.2 °, compared with 13.1 ° of the comparative example.

(Example 2)
A light diffusion plate was produced under the following conditions.
(1) Photosensitive substrate:
i) Substrate: PET film (thickness 125 μm) size Diagonal length 80 inches
ii) Release layer: Acrylic resin (application thickness: 1-2 μm)
iii) Photosensitive agent layer: negative type dry film (FMA107 manufactured by DuPont MRC Dry Film Co., thickness 25 μm)

  Here, after applying and drying an acrylic resin as a release layer on the PET film of the substrate with a gravure coater, the dry film was laminated on the surface as a photosensitive layer at about 100 ° C. to obtain a photosensitive substrate.

Next, this photosensitive substrate was used for exposure with the configuration of the exposure mechanism shown in FIG. In FIG. 5, the laser beam emitted from the laser 14 passes through the objective lens 15 and the cylindrical lens 16 and then passes through the master diffuser 17 to become interference light (coherent light modulated into a speckle pattern). The substrate 10 is exposed.
At that time, as shown in FIG. 6, exposure was performed by bending the surface of the photosensitive agent layer 12 of the photosensitive substrate 10 toward the master diffuser 17 side. That is, the photosensitive agent layer 12 is installed in a substantially arc shape with respect to the center of the master diffuser 17 by bending the substrate 1, and the distance z from the master diffuser 17 is set within the plane of the photosensitive agent layer 12 as much as possible. Constant.
The exposure conditions are shown below.

(2) Exposure conditions i) Light source: Argon ion laser (Spectraphysics STABILITE 2017, wavelength 488 nm, output 1 W)
ii) Master diffusion plate: ground glass (half-value width of transmitted light 20 °)
iii) Distance between master diffuser and photosensitive substrate: 600 mm
iv) Projection shape on the master diffuser (adjusted with a mask): horizontal x vertical = 60 mm x 10 mm oval
v) Photosensitive substrate bending shape: curved to R600mm with respect to the center of the lateral master diffuser
vi) Exposure time: 10 seconds

After exposure under the above exposure conditions, development was performed by spraying a 1.0% sodium carbonate solution having a liquid temperature of 28 ° C. at a spray pressure of 1.5 × 10 ⁵ Pa. Then, after sufficiently washing with water, it was dried with warm air to obtain a photosensitive substrate having a concave and convex fine engraving surface corresponding to the speckle pattern.
Next, since this photosensitive substrate has a thickness of about 0.160 mm and lacks rigidity, an acrylic substrate having a thickness of 2 mm is adhered to the back surface thereof using an ultraviolet curable adhesive to increase the rigidity, and the convenience of subsequent processing is improved. It was.

A silver nitrate aqueous solution and a reducing agent aqueous solution were applied to the surface of the photosensitive substrate thus prepared by a two-cylinder spray method, and a conductive treatment was performed by a silver mirror reaction to form an Ag layer as a conductive layer.
In the electroforming process, in a nickel sulfamate aqueous solution bath, a direct current was passed between the conductive layer as a cathode and a nickel electrode to electrodeposit a Ni layer having a thickness of 5 mm as an electrodeposition layer.

  After the electrodeposition, the first electroformed layer was obtained through an end face polishing step, and the acrylic substrate was heated to 120 ° C. to melt and peel the release layer, thereby separating the substrate. Next, the remaining photosensitizer layer and intermediate layer were swollen and peeled off at 60 ° C. with a 5% aqueous sodium hydroxide solution.

Next, without removing the conductive layer adhering to the surface of the first electroformed layer, a Ni layer was formed as the second electrodeposited layer by the same procedure as in the case of the first electroformed layer.
Next, the second electroformed layer was separated from the first electroformed layer by delamination of the conductive layer, and the remaining conductive layer adhering to the second electroformed layer was removed.

  The second electroformed layer thus obtained was used as a master electroforming mold to prepare a submaster electroforming mold, and an acrylic ultraviolet curable resin was applied thereto, followed by curing by ultraviolet irradiation to obtain a diagonal length of 80 An inch light diffuser product was obtained.

  As described above, since the exposure to the photosensitive agent layer having a large area can be performed in a short time, it is possible to produce a high-quality light diffusing plate with a large screen, and the first generation electric power is produced when the electroforming mold is produced. The photosensitive layer can be removed without destroying the shape remaining in the conductive layer after deposition, and an electroformed mold faithful to the original pattern (uneven pattern of the photosensitive substrate) is obtained by second-generation electrodeposition that is subsequently performed. It was possible. For this reason, it was possible to obtain a light diffusing plate having high and uniform brightness and gain that was controlled so that light emitted from any place of the light diffusing plate was directed into the target visual field.

1 is a cross-sectional configuration diagram of a photosensitive substrate according to the present invention. It is a block diagram of the exposure state in an exposure process among the manufacturing methods of the electroforming metal mold | die which concerns on this invention. It is a manufacturing-process figure (1) in the manufacturing method of the electroforming metal mold | die which concerns on this invention. It is a manufacturing process figure (2) in the manufacturing method of the electroforming metal mold | die which concerns on this invention. 6 is a configuration diagram of an exposure mechanism in an exposure process of Embodiment 2. FIG. FIG. 6 is an enlarged configuration diagram of FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 2 ... Release layer, 3,12 ... Photosensitive agent layer, 5 ... Conductive layer, 6 ... Electrodeposition layer, 7 ... 1st electroforming layer, 8 ... 2nd electroforming layer, 9 ... Electroforming mold, DESCRIPTION OF SYMBOLS 10 ... Photosensitive substrate, 14, 20 ... Laser, 15, 30 ... Objective lens, 16 ... Cylindrical lens, 17, 40 ... Master diffuser

Claims (4)

A method for producing an electroforming mold using a photosensitive substrate in which a substrate, a release layer, and a photosensitive agent layer are sequentially formed,
A pattern forming step of forming a predetermined pattern on the photosensitive layer of the photosensitive substrate by exposure and development; and
A conductive treatment step of forming a conductive layer on the pattern;
A first electroforming step in which the conductive layer is a cathode, and a first electroformed product is deposited on the conductive layer;
Separating the substrate in the release layer, removing the photosensitive agent layer and the release layer from the first electroformed product having a surface made of a conductive layer, and forming a first electroforming mold;
A second electroforming step in which the first electroforming mold is used as a cathode, and a second electroforming mold is formed by depositing a second electroformed product on the conductive layer;
A method for producing an electroformed mold, comprising:   The method for manufacturing an electroforming mold according to claim 1, wherein the pattern is a speckle pattern generated from coherent light.   2. The electrode according to claim 1, wherein the release layer is made of a heat-meltable material, and in the step of forming the first electroforming mold, the substrate is separated by the release layer by heating. Manufacturing method of casting mold.   The method of manufacturing an electroforming mold according to claim 1, wherein the electroforming mold is used for manufacturing a light diffusion plate.

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