JP5499418B2 - Etching apparatus and mold manufacturing method - Google Patents

Description

  The present invention relates to an etching apparatus that etches a base material for a mold that molds a product that exhibits an antiglare effect by an uneven shape formed on the surface, and a method for manufacturing the mold.

  In order to manufacture a product having an antiglare effect, it is known that it is effective to form a fine uneven shape on the surface of the product. An example of an antiglare film having such a configuration is described in Japanese Patent Application Laid-Open No. 2006-53371 (Patent Document 1). In this document, in order to obtain an anti-glare film, it is supposed that a concavo-convex shape is provided in advance by causing fine particles to collide with the surface of a mold for forming the film.

  On the other hand, various techniques related to etching have been proposed. For example, in Japanese Patent Application Laid-Open No. 10-36981 (Patent Document 2), the substrate to be etched is irradiated with light from a light source, and the control unit advances the etching based on the change in the light amount or the spectral pattern detected by the detection unit. A spin etching method has been proposed in which the situation is monitored and the spraying of the etchant is stopped when it is determined that the etching is completed.

  In JP-A-2002-151462 (Patent Document 3), a substrate is irradiated with a light beam from a light source, its specular reflection light is detected by a photodetector, and the circuit amplifies the output of the photodetector. A wet etching method has been proposed in which an etching end point is detected by comparing with a reference voltage, and the etching is stopped after a set time has elapsed since the etching end point was detected.

  In Japanese Patent Laid-Open No. 2002-99074 (Patent Document 4), an optical fiber is installed on the back surface of a transparent substrate set in a chamber of a dry etching apparatus, and is transmitted through the transparent substrate from a light source and incident on the optical fiber. The amount of light was measured with a light meter, and the etching amount of the transparent substrate became the required depth using the relationship diagram of the transmittance with respect to the thickness of the transparent substrate prepared in advance and the etching depth of the dry etching. There has been proposed a dry etching method that sometimes stops dry etching.

JP 2006-53371 A Japanese Patent Laid-Open No. 10-36981 JP 2002-151462 A JP 2002-99074 A

  If the uneven surface of the mold for forming a product that exhibits an antiglare effect is uneven due to the uneven shape formed on the surface, and unevenness of the uneven shape occurs, the unevenness of the surface of the product transferred from the mold Unevenness occurs in the shape. When forming a mold by a manufacturing method in which fine particles collide with the surface of the mold proposed in Patent Document 1 to provide an uneven shape, it is difficult to form the surface uneven shape in a precisely controlled state. If the uneven surface shape of the mold cannot be controlled uniformly, the degree of light scattering on the product surface to which the uneven surface shape has been transferred will be different. Therefore, it has been difficult to manufacture a product that exhibits a certain antiglare effect.

  A photosensitive substance is applied to the surface of the mold base material in order to accurately form a fine uneven shape on the mold surface and to produce a mold useful for manufacturing a product exhibiting a high anti-glare function. Then, it is conceivable that the surface is exposed in a pattern using a photolithography method, and an etching process is performed. In order to control the depth at which the surface of the substrate is processed by the etching process, it is conceivable to manage the etching process time.

  However, time management alone is not sufficient to keep the etching amount constant. Even if the etching process time is constant, it is difficult to keep the etching concentration constant because it is difficult to keep the concentration and temperature of the etching solution constant. As a result, there is a problem that the uneven shape on the mold surface cannot be processed with good reproducibility so that equivalent anti-glare treatment characteristics are exhibited.

  Regarding the management of the end point of etching, there are known documents such as Patent Documents 2 to 4. However, since the mold does not transmit light, it is impossible to detect a change in the thickness of the layer to be etched by measuring transmittance as in Patent Document 3.

  Furthermore, in the processing of the mold for anti-glare treatment, the target depth of the recess formed by etching is not always constant, and is adjusted according to the desired anti-glare treatment characteristics. For this reason, there is no underlying layer exposed as the etching process ends as in Patent Documents 2 and 4. Therefore, a sharp change in the amount of reflected light or the reflected spectrum does not occur in the just-etched state. In processing by etching an anti-glare mold, two factors, light absorption by the corrosive liquid used (etching solution) and an increase in light scattering due to the formation of irregularities, affect light reflection. The variation in the amount of reflected light resulting from the variation in the amount of etching solution adhering to the surface is larger than the change in the amount of reflected light caused by the uneven shape. For this reason, the end point of the etching process cannot be detected by a conventionally known technique in the processing of the anti-glare mold that cannot expect a sharp change in the amount of reflected light or the reflection spectrum in the just-etched state.

  The present invention has been made in view of the above problems, and its main purpose is to etch the surface to be treated of a mold base for molding a product that exhibits an antiglare effect by the uneven shape formed on the surface. An etching apparatus that can stabilize an etching amount and can etch a surface to be processed with high reproducibility.

  An etching apparatus according to the present invention is an etching apparatus that etches a base material for a mold that molds a product that exhibits an antiglare effect by means of a concavo-convex shape formed on a surface, the surface to be processed of the base material, an etching solution, A reaction vessel that contacts the surface to be processed, a light projecting fiber that projects light toward the surface to be processed, a light receiving fiber that receives reflected light from the surface to be processed, and a detection unit that detects the intensity of light received by the light receiving fiber. Prepare.

In one aspect of the etching apparatus , a light receiving fiber bundle including a plurality of light receiving fibers that receive reflected light from the surface to be processed is provided, and the light receiving fiber bundle includes a first light receiving fiber located at the center and a first light receiving fiber. A plurality of second light-receiving fibers surrounding the periphery of the light-receiving fiber so that the first light-receiving fiber is positioned on the extension of the light path when the light emitted from the light projecting fiber is regularly reflected by the surface to be processed A bunch is placed.

In another aspect of the etching apparatus , a plurality of light receiving fibers that receive reflected light from the surface to be processed are provided, and the plurality of light receiving fibers are disposed so as to surround the light projecting fibers . The light projecting fiber and the plurality of light receiving fibers constitute an optical fiber bundle. The optical fiber bundle has a first state in which any one of the plurality of light receiving fibers is positioned on the extension of the light path when the light emitted from the light projecting fiber is regularly reflected by the surface to be processed, and the surface to be processed. It is configured to be able to take at least two ways of the vertical second state.

  Preferably, the diameter of the opening for receiving light from the outside in the light receiving fiber is the same or smaller than the diameter of the opening for emitting light to the outside in the light projecting fiber.

  Preferably, the light projected toward the surface to be processed has a peak wavelength of 490 nm to 510 nm.

A mold manufacturing method according to the present invention is a mold manufacturing method for molding a product that exhibits an antiglare effect by means of a concavo-convex shape formed on a surface, and a base material for a mold having a surface to be processed is prepared. And a step of etching the surface to be processed of the substrate. The etching step includes a step of projecting light from the projection fiber toward the surface to be processed, a step of receiving reflected light from the surface to be processed by the light receiving fiber, and a step of detecting the intensity of light received by the light receiving fiber. , and a step of determining whether or not to end the error etching process, the. The step of receiving light includes a step of receiving light mainly composed of specularly reflected light and a step of receiving light mainly composed of scattered light when the surface to be processed is irradiated with light. The step of detecting includes a step of detecting the intensity M1 of light mainly composed of specularly reflected light and a step of detecting the intensity m1 of light mainly composed of scattered light. The step of determining is performed based on the intensity M1 and the intensity m1.

Preferably, the light projecting step uses an optical fiber bundle arranged so as to surround the light projecting fiber with a plurality of light receiving fibers. In the light projecting step, the optical fiber bundle is set so that one of the plurality of light receiving fibers is positioned on the extension of the light path when the light emitted from the light projecting fiber is regularly reflected on the surface to be processed. A first step of irradiating light from the light projecting fiber, and irradiating light from the light projecting fiber by arranging the optical fiber bundle so as to be in a second state perpendicular to the surface to be processed. A second step to be performed. The step of receiving light includes a third step of receiving light while performing the first step, and a fourth step of receiving light while performing the second step. In the detecting step, the intensity M1 of light mainly composed of specularly reflected light received by the light receiving fiber positioned on the extension of the light path when regularly reflected on the surface to be processed among the plurality of light receiving fibers in the third step. And a step of detecting the intensity m1 of light mainly composed of scattered light received by the plurality of light receiving fibers in the fourth step.

Preferably, the light projecting step projects light in a direction not perpendicular to the surface to be processed. In the light receiving step, the light emitted from the light projecting fiber is regularly reflected on the surface to be processed by using the light receiving fiber bundle arranged so that the plurality of second light receiving fibers surround the first light receiving fiber located at the center. In this case, the light receiving fiber bundle is arranged so that the first light receiving fiber is positioned on the extension of the light path, and the reflected light from the surface to be processed is received. The detecting step includes the step of detecting the intensity M1 of light mainly composed of specularly reflected light received by the first light receiving fiber, and the intensity m1 of light mainly comprising scattered light received by the plurality of second light receiving fibers. Detecting.

Preferably, the step of determining, using the strength M1 and strength m1, including the step of obtaining m1 / a (M1 + m1) as an interim haze.

Preferably, the step of determining, using the strength M1 and strength m1, (M1-m1) / (M1 + m1) a step of including obtaining an interim reflection image sharpness.

  Preferably, the diameter of the opening for receiving light from the outside in the light receiving fiber is the same or smaller than the diameter of the opening for emitting light to the outside in the light projecting fiber.

  Preferably, the light projected toward the surface to be processed has a peak wavelength of 490 nm to 510 nm.

  According to the etching apparatus of the present invention, the etching amount of the surface to be processed of the mold base can be stabilized, and the surface to be processed can be etched with good reproducibility.

It is a figure which shows typically a preferable example of the first half part of the manufacturing method of the metal mold | die of this invention. It is a figure which shows typically a preferable example of the second half part of the manufacturing method of the metal mold | die of this invention. It is a figure which shows typically the state which side etching advances in a 1st etching process. It is a figure which shows typically the state by which the 2nd surface uneven | corrugated shape which has gentle surface inclination was formed by the 2nd etching process. It is a flowchart which shows the detail of an etching process. It is a conceptual diagram of an example of the concrete structure of an etching apparatus. It is a schematic diagram which shows the outline | summary of the internal structure of the collimating lens unit by the side of a projection fiber. It is an enlarged view of the edge part of the optical fiber bundle containing a light projection fiber. It is a schematic diagram which shows the outline | summary of the internal structure of the collimating lens unit by the side of a light reception fiber. It is an enlarged view of the edge part of a light reception fiber bundle. It is a conceptual diagram of the test | inspection apparatus contained in the etching apparatus shown in FIG. It is explanatory drawing corresponding to the state in which reflected light injects into the 1st light reception fiber. It is a conceptual diagram of the inspection apparatus contained in the etching apparatus of a modification. It is an enlarged view of the edge part of the optical fiber bundle of the inspection apparatus of a modification. It is a figure which shows the course of the light in a 1st state. It is a figure which shows the course of the light in a 2nd state. It is a flowchart which shows an example of the first half part of the process which test | inspects the to-be-processed surface of the base material for metal mold | dies. It is a flowchart which shows a preferable example of the first half part of the process which test | inspects a to-be-processed surface. It is a flowchart which shows the other preferable example of the first half part of the process which test | inspects a to-be-processed surface.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

  The mold targeted by the present invention is a mold for forming a product having an uneven shape of about several μm to several mm on the surface and exhibiting an anti-glare effect by the uneven shape formed on the surface. It is called a mold for use. As one type of anti-glare product, an anti-glare film (also referred to as “AG (Anti-Glare) film”) can be given.

  The mold is usually used for transfer to a film by a UV embossing method or a molding process, and forms an anti-glare surface on a workpiece. As the mold for anti-glare treatment, a mold in which the surface of a base material such as copper is etched and then given scratch resistance by hard chrome plating is used. Examples of the shape of the die include a plate shape and a roll shape die used in a roll-to-roll process.

  FIG. 1 is a diagram schematically showing a preferred example of the first half of the mold manufacturing method of the present invention. FIG. 1 schematically shows a cross section of a mold in each step. The mold manufacturing method of the present invention includes: [1] a first plating step, [2] a polishing step, [3] a photosensitive resin film coating step, [4] an exposure step, and [5] a development step. [6] Basically includes a first etching step, [7] a photosensitive resin film peeling step, and [8] a second plating step. Hereafter, each process of the manufacturing method of the metal mold | die of this invention is demonstrated in detail, referring FIG.

[1] First Plating Step In the mold manufacturing method of the present invention, first, copper plating or nickel plating is applied to the surface of the substrate used for the mold. Thus, by performing copper plating or nickel plating on the surface of the mold base, it is possible to improve the adhesion and gloss of chromium plating in the subsequent second plating step.

  That is, when chrome plating is applied to the surface of iron, etc., or when chrome plating is applied again after forming irregularities on the chrome plating surface, the surface tends to be rough and fine cracks occur, resulting in a mold surface It becomes difficult to control the uneven shape. On the other hand, such inconvenience can be eliminated by first performing copper plating or nickel plating on the substrate surface. This is because copper plating or nickel plating has a high covering property and a strong smoothing action, so that a flat and glossy surface is formed by filling minute irregularities and voids of the mold base. is there.

  Due to these copper plating or nickel plating characteristics, even if chromium plating is applied in the second plating step described later, the rough surface of the chromium plating that seems to be caused by minute irregularities and voids that existed on the substrate is eliminated. In addition, the occurrence of fine cracks is reduced due to the high coverage of copper plating or nickel plating.

  The copper or nickel used in the first plating step can be each pure metal, or an alloy mainly composed of copper or an alloy mainly composed of nickel. Accordingly, “copper” as used herein is meant to include copper and copper alloys, and “nickel” is meant to include nickel and nickel alloys. Copper plating and nickel plating may be performed by electrolytic plating or electroless plating, respectively, but electrolytic plating is usually employed.

  When copper plating or nickel plating is performed, if the plating layer is too thin, the influence of the underlying surface cannot be completely eliminated. Therefore, the thickness is preferably 50 μm or more. Although the upper limit of the plating layer thickness is not critical, it is generally preferable that the upper limit of the plating layer thickness is about 500 μm in view of cost and the like.

  In the metal mold manufacturing method of the present invention, examples of the metal material suitably used for forming the metal mold substrate include aluminum and iron from the viewpoint of cost. From the viewpoint of handling convenience, it is more preferable to use lightweight aluminum. The aluminum and iron here may be pure metals, respectively, or may be an alloy mainly composed of aluminum or iron.

  In addition, the shape of the mold base is not particularly limited as long as it is an appropriate shape conventionally employed in the field, and may be, for example, a flat plate or a columnar or cylindrical roll. May be. If a die is produced using a roll-shaped substrate, there is an advantage that an antiglare treatment can be continuously performed and an antiglare film can be continuously produced.

[2] Polishing Step In the subsequent polishing step, the surface of the substrate that has been subjected to copper plating or nickel plating in the first plating step described above is polished. It is preferable that the base material surface is grind | polished in the state close | similar to a mirror surface through the said process. This is because metal plates and metal rolls that serve as base materials are often subjected to machining such as cutting and grinding in order to achieve the desired accuracy, and as a result, machine marks remain on the base material surface. This is because even if copper plating or nickel plating is applied, those processed marks may remain, and the surface may not be completely smooth in the plated state. That is, even if a process described later is performed on the surface where such deep processed marks remain, unevenness such as processed marks may be deeper than the unevenness formed after each process is performed. Such effects may remain, and when an antiglare treatment is performed using such a mold or an antiglare film is produced, the optical characteristics may be unexpectedly affected.

  In FIG. 1 (a), a plate-shaped die base material 107 is subjected to copper plating or nickel plating on the surface in the first plating step (the copper plating or nickel plating formed in the first plating step). A layer is not shown), and a state in which the surface 108 is further mirror-polished by a polishing process is schematically shown.

  There is no particular limitation on the method for polishing the surface of the substrate on which copper plating or nickel plating has been applied, and any of mechanical polishing, electrolytic polishing, and chemical polishing can be used. Examples of the mechanical polishing method include super finishing, lapping, fluid polishing, and buff polishing. As for the surface roughness after polishing, the center line average roughness Ra in accordance with the provisions of JIS B 0601 is preferably 0.1 μm or less, and more preferably 0.05 μm or less. If the center line average roughness Ra after polishing is greater than 0.1 μm, the final unevenness of the mold surface may be affected by the surface roughness after polishing, which is not preferable. In addition, the lower limit of the center line average roughness Ra is not particularly limited, and there is no limit in particular because there is a natural limit from the viewpoint of processing time and processing cost.

[3] Photosensitive resin film coating step In the subsequent photosensitive resin film coating step, the photosensitive resin is applied as a solution in which the photosensitive resin is dissolved in a solvent to the polished surface 108 of the substrate 107 that has been mirror-polished by the above-described polishing step. Then, a photosensitive resin film is formed by heating and drying. FIG. 1B schematically shows a state where the photosensitive resin film 109 is formed on the surface 108 of the base material 107.

  A conventionally known photosensitive resin can be used as the photosensitive resin. Examples of the negative photosensitive resin having a property of curing the photosensitive part include, for example, a monomer or prepolymer of an acrylate ester having an acrylic group or a methacrylic group in the molecule, a mixture of bisazide and a diene rubber, polyvinyl Cinnamate compounds and the like can be used. Further, as a positive photosensitive resin having such a property that a photosensitive part is eluted by development and only an unexposed part remains, for example, a phenol resin type or a novolac resin type can be used. Moreover, you may mix | blend various additives, such as a sensitizer, a development accelerator, an adhesiveness modifier, and a coating property improving agent, with a photosensitive resin as needed.

  When these photosensitive resins are applied to the polished surface 108 of the mold base 107, it is preferable to dilute and apply them in an appropriate solvent in order to form a good coating film. As the solvent, cellosolve solvents, propylene glycol solvents, ester solvents, alcohol solvents, ketone solvents, highly polar solvents, and the like can be used.

  As a method for applying the photosensitive resin solution, known methods such as meniscus coating, fountain coating, dip coating, spin coating, roll coating, wire bar coating, air knife coating, blade coating, and curtain coating may be used. it can. The thickness of the coating film is preferably in the range of 1 to 6 μm after drying.

[4] Exposure Step In the subsequent exposure step, a predetermined pattern is exposed on the photosensitive resin film 109 formed in the photosensitive resin film application step described above. The light source used in the exposure process may be appropriately selected according to the photosensitive wavelength and sensitivity of the coated photosensitive resin. For example, the g-line (wavelength: 436 nm) of the high-pressure mercury lamp, the h-line (wavelength: 405 nm) of the high-pressure mercury lamp. ), High-pressure mercury lamp i-line (wavelength: 365 nm), semiconductor laser (wavelength: 830 nm, 532 nm, 488 nm, 405 nm, etc.), YAG laser (wavelength: 1064 nm), KrF excimer laser (wavelength: 248 nm), ArF excimer laser (wavelength) 193 nm), F2 excimer laser (wavelength: 157 nm), semiconductor laser, or the like.

  In order to form the surface unevenness shape with high accuracy in the mold manufacturing method of the present invention, it is preferable to expose a predetermined pattern on the photosensitive resin film in a precisely controlled manner in the exposure step. In the mold manufacturing method of the present invention, in order to accurately expose a predetermined pattern on the photosensitive resin film, it is based on a two-dimensional array of image data or discretized information created as a pattern on a computer. Thus, it is preferable to draw a pattern on the photosensitive resin film by laser light emitted from a computer-controlled laser head. When performing such laser drawing, a laser drawing apparatus for making a printing plate can be used. Examples of such a laser drawing apparatus include Laser Stream FX (manufactured by Sink Laboratories).

  FIG. 1C schematically shows a state in which a pattern is exposed on the photosensitive resin film 109. In the case where the photosensitive resin film is formed of a negative photosensitive resin, the exposed region 111 undergoes a crosslinking reaction of the resin by exposure, and the solubility in a developing solution described later is lowered. Therefore, the unexposed area 110 in the development process is dissolved by the developer, and only the exposed area 111 remains on the substrate surface as a mask. On the other hand, in the case where the photosensitive resin film is formed of a positive photosensitive resin, the exposed region 111 is cut by the bond of the resin by the exposure, and the solubility in the developer described later increases. Therefore, the area 111 exposed in the development process is dissolved by the developer, and only the unexposed area 110 remains on the substrate surface as a mask.

  The shape of the pattern drawn by exposure is not particularly limited, and a pattern in which circular, square, hexagonal patterns, etc. are arranged may be drawn, a continuous pattern may be drawn, or these You may draw what combined. Alternatively, a pattern in which patterns of different sizes such as a circle, a rectangle, and a hexagon are arranged may be drawn. Also, the pattern to be drawn may be regularly arranged or irregularly arranged, but is preferably irregularly arranged.

[5] Development Step In the subsequent development step, when a negative photosensitive resin is used for the photosensitive resin film 109, the unexposed area 110 is dissolved by the developer, and only the exposed area 111 is gold. It remains on the mold substrate and acts as a mask in the subsequent first etching step. On the other hand, when a positive photosensitive resin is used for the photosensitive resin film 109, only the exposed region 111 is dissolved by the developer, and the unexposed region 110 remains on the mold base. It acts as a mask in the subsequent first etching step.

  A conventionally well-known thing can be used about the developing solution used for a image development process. For example, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, di-n-butylamine and the like Secondary amines, tertiary amines such as triethylamine, methyldiethylamine, alcohol amines such as dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylhydroxyethylammonium hydroxide, etc. Examples include alkaline aqueous solutions such as quaternary ammonium salts, cyclic amines such as pyrrole and piperidine, and organic solvents such as xylene and toluene.

  The development method in the development step is not particularly limited, and methods such as immersion development, spray development, brush development, and ultrasonic development can be used.

  FIG. 1D schematically shows a state where development processing is performed using a negative photosensitive resin for the photosensitive resin film 109. In FIG. 1C, the unexposed area 110 is dissolved by the developer, and only the exposed area 111 remains on the surface of the base material to become a mask 112. FIG. 1E schematically shows a state where development processing is performed using a positive photosensitive resin for the photosensitive resin film 109. In FIG. 1C, the exposed area 111 is dissolved by the developer, and only the unexposed area 110 remains on the substrate surface to become a mask 112.

[6] First Etching Step In the subsequent first etching step, the mold base is mainly used in a portion where there is no mask, using the photosensitive resin film remaining on the mold base surface after the development step as a mask. The material is etched to form irregularities on the polished plated surface. FIG. 2 is a diagram schematically showing a preferred example of the latter half of the method for producing a mold of the present invention. FIG. 2A schematically shows a state in which the mold base 107 in the portion 113 without the mask is etched mainly by the first etching process.

  Although the base material 107 under the mask 112 is not etched from the mold base material surface, the etching from the portion 113 without the mask proceeds with the progress of the etching. Therefore, the base material 107 under the mask 112 is also etched in the vicinity of the boundary between the mask 112 and the portion 113 without the mask. The etching of the base material 107 below the mask 112 in the vicinity of the boundary between the mask 112 and the portion 113 without the mask is hereinafter referred to as side etching. FIG. 3 schematically shows the progress of side etching. A dotted line 114 in FIG. 3 shows the surface of the mold base 107 that changes with the progress of etching in stages.

The etching process in the first etching step is usually performed by using a ferric chloride (FeCl ₃ ) solution, a cupric chloride (CuCl ₂ ) solution, an alkaline etching solution (Cu (NH ₃ ) ₄ Cl ₂ ), etc. Although it is performed by corroding the surface, a strong acid such as hydrochloric acid or sulfuric acid can be used, or reverse electrolytic etching by applying a potential opposite to that at the time of electrolytic plating can also be used. The concave shape formed on the mold base material when the etching process is performed differs depending on the type of the base metal, the type of the photosensitive resin film, the etching technique, and the like. In the following cases, the etching is performed isotropically from the metal surface in contact with the etching solution. The etching amount here is the thickness of the base material to be cut by etching.

  The etching amount in the first etching step is preferably 1 to 50 μm. When the etching amount is less than 1 μm, the unevenness shape is hardly formed on the metal surface, and the die is almost flat, so that the antiglare property is not exhibited. In addition, when the etching amount exceeds 50 μm, the height difference of the concavo-convex shape formed on the metal surface becomes large, and in the image display device to which the antiglare film produced using the obtained mold is applied, it is white. This is not preferable because there is a risk of injury. The etching process in the first etching step may be performed by one etching process, or the etching process may be performed twice or more. Here, when the etching process is performed twice or more, the total etching amount in the two or more etching processes is preferably 1 to 50 μm.

[7] Photosensitive resin film peeling step In the subsequent photosensitive resin film peeling step, the remaining photosensitive resin film used as a mask in the first etching step is completely dissolved and removed. In the photosensitive resin film peeling step, the photosensitive resin film is dissolved using a peeling solution. As the remover, the same developer as described above can be used, and exposure is performed when a negative photosensitive resin film is used by changing pH, temperature, concentration, immersion time, and the like. When the positive photosensitive resin film of the part is used, the photosensitive resin film of the non-exposed part is completely dissolved and removed. There is no particular limitation on the peeling method in the photosensitive resin film peeling step, and methods such as immersion development, spray development, brush development, and ultrasonic development can be used.

  FIG. 2B schematically shows a state in which the photosensitive resin film used as the mask 112 in the first etching process is completely dissolved and removed by the photosensitive resin film peeling process. By etching using a mask 112 made of a photosensitive resin film, a first surface uneven shape 115 is formed on the surface of the mold base.

[8] Second plating step Subsequently, the uneven surface is blunted by performing chromium plating on the formed uneven surface (first surface uneven shape 115). In FIG. 2C, the chromium plating layer 116 is formed on the first uneven surface 115 formed by the etching process in the first etching step as described above, so that the first uneven surface 115 is formed. A state is shown in which a surface with unevenness (a surface 117 of chrome plating) is formed.

In the present invention, chrome plating is employed which has a glossy surface, a high hardness, a low coefficient of friction, and good release properties on the surface of a flat plate or a roll. The type of chrome plating is not particularly limited, but it is preferable to use a chrome plating that expresses a good gloss, so-called gloss chrome plating or decorative chrome plating. Chromium plating is usually performed by electrolysis, and an aqueous solution containing chromic anhydride (CrO ₃ ) and a small amount of sulfuric acid is used as the plating bath. By adjusting the current density and electrolysis time, the thickness of the chromium plating can be controlled.

  Depending on the base of the mold before plating and the type of chrome plating, the surface is often roughened after plating, or many fine cracks are generated by chrome plating, and as a result, the mold is produced. The optical characteristics of the transparent base material (including the antiglare film) having a concavo-convex shape formed on the surface proceeds in a direction in which it is not preferable. A mold having a rough plated surface is not suitable for antiglare treatment of a transparent substrate and production of an antiglare film. This is because the plating surface is generally polished after chromium plating in order to eliminate roughness, but as described later, polishing of the surface after plating is not preferable in the present invention. In the present invention, by applying copper plating or nickel plating to the base metal, such an inconvenience easily caused by chromium plating is solved.

  In the second plating step, it is not preferable to perform plating other than chromium plating. This is because plating other than chromium has low hardness and wear resistance, so that the durability as a mold is lowered, and unevenness is worn away during use or the mold is damaged. Anti-glare treatment using such a mold and anti-glare film obtained from the mold are likely to be difficult to obtain sufficient anti-glare function, and defects on transparent substrates such as transparent resin films There is also a high possibility that this will occur.

  Further, polishing the surface after plating is also not preferable in the present invention. That is, it is preferable to use the concavo-convex surface subjected to chromium plating as the concavo-convex surface of the mold transferred onto the transparent substrate without providing a step of polishing the surface after the second plating step. By polishing, a flat part is generated on the outermost surface, which may lead to deterioration of optical characteristics, and since shape control factors increase, shape control with good reproducibility becomes difficult. Depending on the reason.

  In this way, in the mold manufacturing method of the present invention, a chrome plating is applied to the surface on which the fine surface irregularities are formed, whereby a mold having an irregular surface and a higher surface hardness can be obtained. . The bluntness of the irregularities at this time varies depending on the type of the base metal, the size and depth of the irregularities obtained from the first etching process, and the type and thickness of the plating. The greatest factor in controlling is the plating thickness. If the thickness of the chrome plating is thin, the effect of dulling the surface shape of the unevenness obtained before the chrome plating process is insufficient, and the antiglare treatment obtained by transferring the uneven shape to a transparent substrate such as a transparent film. The optical properties of a transparent substrate (such as an antiglare film) to which is applied are not so good. On the other hand, when the plating thickness is too thick, productivity is deteriorated and a projection-like plating defect called a nodule is generated, which is not preferable. Therefore, the thickness of the chrome plating is preferably in the range of 1 to 10 μm, and more preferably in the range of 3 to 6 μm.

  The chromium plating layer formed in the second plating step is preferably formed to have a Vickers hardness of 800 or more, and more preferably 1000 or more. When the Vickers hardness of the chrome plating layer is less than 800, the durability when using the mold is reduced, and the decrease in hardness due to chrome plating is due to abnormalities in the plating bath composition, electrolysis conditions, etc. during the plating process. This is because the possibility of occurrence is high, and the possibility of undesirably affecting the occurrence of defects is also high.

  Moreover, in the manufacturing method of the metal mold | die of this invention, the uneven | corrugated surface formed by the 1st etching process is etched between the above-mentioned [7] photosensitive resin film peeling process and [8] 2nd plating process. It is preferable to include the 2nd etching process blunted by.

  In the second etching process, the first surface irregularities 115 formed by the first etching process using the photosensitive resin film as a mask are blunted by an etching process. By this second etching process, there is no portion with a steep surface slope in the first surface irregularities 115 formed by the first etching process, and an anti-glare film such as an anti-glare film manufactured using the obtained mold. The optical properties of the transparent substrate subjected to the treatment change in a preferable direction. In FIG. 4, the first surface uneven shape 115 of the base material 107 is blunted by the second etching process, the portion having a steep surface inclination is blunted, and the second surface uneven shape 118 having a gentle surface inclination is formed. The formed state is shown.

Similarly to the first etching process, the etching process of the second etching process is usually ferric chloride (FeCl ₃ ) liquid, cupric chloride (CuCl ₂ ) liquid, alkaline etching liquid (Cu (NH ₃ ) ₄ Cl ₂ ) or the like, and by corroding the surface, strong acid such as hydrochloric acid or sulfuric acid can be used, or reverse electrolytic etching by applying a potential opposite to that during electrolytic plating can also be used. The bluntness of the unevenness after the etching process varies depending on the type of the underlying metal, the etching technique, and the size and depth of the unevenness obtained by the first etching process. The largest factor in controlling the amount is the etching amount. The etching amount here is also the thickness of the base material to be cut by etching, as in the first etching step.

  If the etching amount is small, the effect of dulling the surface shape of the unevenness obtained by the first etching step is insufficient, and the antiglare treatment obtained by transferring the uneven shape onto a transparent substrate such as a transparent film The optical properties of the applied transparent substrate (such as an antiglare film) are not so good. On the other hand, when the etching amount is too large, the uneven shape is almost lost and the die is almost flat, so that the antiglare property is not exhibited. Therefore, the etching amount is preferably in the range of 1 to 50 μm, and more preferably in the range of 4 to 20 μm.

  Similarly to the first etching process, the etching process in the second etching process may be performed by one etching process, or the etching process may be performed twice or more. When the etching process is performed twice or more, the total etching amount in the two or more etching processes is preferably 1 to 50 μm.

  Hereinafter, preferred embodiments of an etching process which is one process of the etching apparatus of the present invention and the above-described mold manufacturing method will be described in detail.

  Etching is a technique for processing a surface to be processed by the corrosive action of chemicals or the like, and is widely used for processing metals and semiconductors. In the case of dry etching using a corrosive gas or reactive ions, wet etching using a corrosive liquid, or metal, the surface to be treated is brought into contact with the electrolytic solution, and a potential opposite to that during electrolytic plating is applied. There is reverse electrolytic etching by applying. Any method can be used in the present invention, but wet etching or reverse electrolytic etching can be preferably used from the viewpoint of easy handling.

  An apparatus for carrying out such etching has a reaction tank for bringing a corrosive gas or a corrosive liquid into contact with the surface to be treated, and in addition to this, a temperature adjusting device for controlling the temperature of the corrosive substance, and the corrosive substance for covering. In general, a device having all or a part of a means for controlling the length of time of contact with the treatment surface and a means for removing a corrosive substance from the treatment surface.

The means for contacting the corrosive liquid on the treated surface within the reaction tank, a method of immersing an object to be processed in a corrosive liquid, there is a method such as spraying the corrosive liquid to be processed, using any of the methods I can do it. The depth at which the corrosive material invades the surface to be treated is often controlled by the length of time that the corrosive material is in contact with the surface to be treated. At this time, the speed at which the corrosive substance invades the surface to be treated needs to be constant.

  The rate at which corrosive substances attack the surface to be processed generally depends on the concentration and temperature of the corrosive substance and the temperature of the surface to be processed. For this reason, it is common to have a means for controlling the temperature of the corrosive substance. In a more precisely controlled apparatus, the temperature of the surface to be processed may be controlled. However, in practice, it is extremely difficult to keep the temperature and concentration of the corrosive substance and the temperature to be treated constant, and to keep the speed at which the corrosive substance invades the surface to be treated.

  The means for controlling the length of time that the corrosive substance is brought into contact is generally realized by instructing a control device represented by a programmable logic controller (PLC) to perform a specified operation after a specified time has elapsed. The As a method for terminating the contact, if the object to be treated is immersed in the corrosive liquid by wet etching, it is realized by lowering the corrosion tank filled with the corrosive liquid or pulling up the object to be treated. Is done. When the method of spraying the corrosive liquid onto the object to be treated is taken, the operation of spraying may be terminated.

  In order to control the processing depth by etching more precisely, it is preferable to stop the contact of the corrosive liquid with the object to be processed and simultaneously remove the corrosive substance. Generally, a method of washing away corrosive substances using water is used.

  FIG. 5 is a flowchart showing details of the etching process. In the first etching step and / or the second etching step in the above-described mold manufacturing method, the die base material 107 is etched according to the steps shown in FIG.

  First, in step S1, a mold base 107 is prepared. In the case of the first etching step, a base material 107 with a mask 112 formed on the surface to be processed shown in FIG. 1D or FIG. 1E is prepared. In the case of the second etching step, the base material 107 is prepared in a state where the surface irregularities 115 are formed by the first etching step and the mask 112 is removed as shown in FIG. The prepared mold base 107 is placed in a reaction tank in which the surface to be processed of the base is brought into contact with the etching solution.

  Subsequently, in step S <b> 2, the supply of the etching solution is started toward the surface to be processed of the base material 107, and the etching process for the surface to be processed is started. Subsequently, in step S3, the surface state of the surface to be processed is inspected while performing the etching process on the surface to be processed (that is, while supplying the etching solution). Subsequently, in step S4, it is determined whether the surface state of the surface to be processed has reached a predetermined state based on the inspection result in step S3.

  As a result of the determination in step S4, if it is determined that the surface state of the surface to be processed has not reached the predetermined state and the etching process is not terminated, the etching process is continued and the process returns to step S3 again. As a result of the determination in step S4, if it is determined that the surface state of the surface to be processed has reached a predetermined state and the etching process is to be terminated, then in step S5, the supply of the etching solution is stopped, and then step S6. Then, the etching solution is washed away from the surface to be treated with a cleaning solution such as water. In this way, the etching process is completed.

  The step of inspecting the surface to be processed shown in FIG. 5 (step S3) and the step of determining the surface state of the surface to be processed (step S4) will be described in more detail. FIG. 6 is a conceptual diagram illustrating an example of a specific configuration of the etching apparatus. As shown in FIG. 6, the etching apparatus includes a reaction tank 120. The reaction tank 120 has a shower nozzle 121 for supplying an etching solution 122 therein. The mold base 107 is installed inside the reaction tank 120. The shower nozzle 121 is disposed above the installation position of the base material 107. As a result, the etching liquid 122 ejected from the shower nozzle 121 is moved downward due to the action of gravity, and the etching liquid 122 contacts the surface 107 a to be processed of the base material 107 inside the reaction tank 120. It is said that.

  The etching apparatus also includes an inspection apparatus for inspecting the processing target surface 107a of the base material 107 for the mold. The inspection apparatus includes a light projecting fiber 11 for projecting light toward the surface 107a to be processed of the base material 107 (also referred to as the surface 107a to be inspected when the inspection apparatus is described), A plurality of light receiving fibers 12f and 12g for receiving reflected light from the surface 107a and a detection unit 20 for detecting the intensity of light received by the light receiving fibers 12f and 12g are provided. The inspection apparatus detects the intensity of the reflected light transmitted by the light receiving fibers 12f and 12g, and based on the intensity of the reflected light, it is possible to analyze the surface shape of the processing target surface 107a of the mold base 107. Has been.

  The light projecting fiber 11 is an optical fiber that guides light emitted by a light emitter described later and irradiates light from one point toward the surface 107a to be inspected. The light projecting fiber 11 may be a single-mode or multimode optical fiber, and a configuration in which a plurality of optical fibers are bundled is also conceivable.

  The light receiving fibers 12f and 12g are optical fibers that play a role of guiding light reflected from the surface 107a to be inspected from the inside of the reaction tank 120 filled with a corrosive substance to a photodiode described later. The light receiving fibers 12f and 12g may be single wires of single mode or multimode optical fibers, and a configuration in which a plurality of optical fibers are bundled is also conceivable.

  When the light projecting fiber 11 or the light receiving fibers 12f and 12g are constituted by a bundle of a plurality of optical fibers, the cross-sectional shape of the bundle may be a circle or an ellipse, and may be a quadrangle, a polygon, a ring, or a line. It may be. In order to facilitate the positioning of the optical fiber, the cross-sectional shape of the optical fiber bundle as a whole is preferably a shape having rotational symmetry, and particularly preferably a circular shape. In the case where the surface 107a to be inspected is a curved surface having some curvature, as in the case where the mold base 107 which is an inspection object is cylindrical, the reflected light obtained is in accordance with the curvature of the curved surface. It is preferable to use a bundle of optical fibers bundled in an elliptical shape so as to be close to a circle. When the mold base 107 has a cylindrical shape, the reflected light obtained by irradiating light on an elliptical region having the major axis in the diameter direction of the cylindrical shape and the minor axis in the central axis direction of the cylindrical shape. Becomes close to a circle.

  The diameter of the optical fiber to be used is not particularly limited, but a preferable optical fiber range in which good correlation with sharpness is expected is 0.125 mm to 4 mm, and a more preferable range is 0.125 mm to 2 mm. An optical fiber is mentioned. Further, it is preferable that the light projecting fiber and the light receiving fiber are arranged close to each other at a distance equal to or smaller than the diameter of the light receiving fiber so as not to cause a level of crosstalk that hinders measurement. Further, in a configuration in which the light projecting fiber is disposed at the center and the light receiving fiber is disposed at the periphery, a light receiving fiber smaller than the diameter of the light projecting fiber can be preferably used. Particularly preferably, the diameter of the light receiving fiber is about ½ of the diameter of the light projecting fiber.

  The inspection apparatus includes collimating lens units 10 and 10 i inside the reaction tank 120. In FIG. 6, the collimating lens unit 10 faces obliquely upward and the collimating lens unit 10i faces obliquely downward. However, the orientation is not limited to this, and any orientation may be used. A projecting fiber 11 is connected to the collimating lens unit 10. Light receiving fibers 12f and 12g are connected to the collimating lens unit 10i.

  FIG. 7 is a schematic diagram showing an outline of the internal structure of the collimating lens unit 10 on the light projecting fiber 11 side. As shown in FIG. 7, the collimating lens unit 10 has a container-like housing 15. An optical fiber bundle 13 composed of a plurality of optical fibers including the light projecting fiber 11 is connected to a housing 15. An end portion of the optical fiber bundle 13 is disposed inside the housing 15, and a collimator lens 14 is disposed at a position where the end portion is in focus. The collimating lens 14 is held by a housing 15.

  FIG. 8 is an enlarged view of the end of the optical fiber bundle 13 including the light projecting fiber 11. The optical fiber bundle 13 includes a plurality of optical fibers, and the light projecting fiber 11 that emits light is disposed at the center of the optical fiber bundle 13. The optical fiber 18 arranged in an annular shape so as to surround the projection fiber 11 is not used for projecting light onto the surface 107a to be inspected. In FIG. 6, a part of the optical fibers connected to the collimating lens unit 10 extends downward and is marked with an X mark, which means that these optical fibers are not used. Of the plurality of optical fibers held by the collimating lens unit 10, only the light projecting fiber 11 disposed at the center of the optical fiber bundle 13 is used for projecting light onto the surface 107a to be inspected. The optical fiber bundle 13 includes optical fibers other than the light projecting fiber 11.

FIG. 9 is a schematic diagram showing an outline of the internal structure of the collimating lens unit 10i on the light receiving fibers 12f and 12g side. As shown in FIG. 9, the collimating lens unit 10 i has a container-like housing 15. A light receiving fiber bundle 17 composed of a plurality of optical fibers for receiving reflected light from the surface 107 a to be inspected is connected to the housing 15. An end portion of the light receiving fiber bundle 17 is disposed inside the housing 15, and the collimator lens 14 is disposed at a position where the end portion is in focus. The collimating lens 14 is held by a housing 15.

  FIG. 10 is an enlarged view of the end portion of the light receiving fiber bundle 17. The light receiving fiber bundle 17 includes a plurality of optical fibers. In the example shown in FIG. 10, one first light receiving fiber 12f is located at the center of the light receiving fiber bundle 17, and six second light receiving fibers 12g are arranged so as to surround the first light receiving fiber 12f. ing. The number of the second light receiving fibers 12g is not limited to six and may be other numbers.

  Returning to FIG. 6, the inspection apparatus includes a light source (light emitter) that generates light, and an aspheric condenser lens 31 that collects light from the light emitter and enters the light projecting fiber 11. One end of the light projecting fiber 11 is connected to the collimating lens unit 10, and the other end is connected to the aspheric condenser lens 31. A collimating lens unit 10 is installed at the tip of the light projecting fiber 11. Light emitted from the LED 30, which is an example of a light source (light emitter), enters the light projecting fiber 11 through the aspheric condenser lens 31.

  As the light source, various light sources such as a halogen lamp, a tungsten lamp, a light bulb typified by a mercury lamp, a light emitting diode (LED), and a laser element can be used. As the light source, it is particularly preferable to use a solid light source such as an LED, a semiconductor laser element, or a semiconductor excitation laser element that can be easily modulated as necessary for noise removal.

The wavelength of the light source is preferably selected from a corrosive substance such as the etchant 122 that fills the reaction tank 120 and a wavelength at which light absorption of the resist is weak. A cupric chloride (CuCl ₂ ) solution widely used as a corrosive substance when etching copper strongly absorbs light other than around 500 nm. For this reason, a light source having a light emission peak in the wavelength range of 490 nm to 510 nm is used so that the light projected toward the surface 107a to be processed has a peak wavelength in the range of 490 nm to 510 nm. However, it is particularly preferable from the viewpoint of reducing the influence of light absorption by the etching solution 122. Such a light source may be realized by selecting an LED having a light emission peak in a corresponding wavelength band, or may be realized by combining a filter with a white light source.

  When a light bulb or LED is used as a light source, the light emitted from the light projecting fiber 11 travels while spreading. However, in the present invention, the light emitted from the light projecting fiber 11 needs to be substantially parallel light before reaching the surface 107a to be inspected. For this reason, when the light emitted from the light projecting fiber 11 is light that travels while spreading, it is only necessary to appropriately combine lenses so as to make the light close to parallel light. Such an operation can be generally realized by a convex lens (for example, a collimating lens 14 shown in FIG. 7) or a concave mirror.

  In addition, a lens that can make light emitted from the optical fiber almost parallel is commercially available from fiber sensor manufacturers. An example of such a lens is model F-3HA manufactured by Keyence Corporation. By combining this lens with a dedicated optical fiber (such as FU-35FZ manufactured by Keyence Corporation), substantially parallel light can be realized within a range of approximately 20 mm to 40 mm from the lens.

  The collimating lens unit F-3HA is composed of a convex lens having an aperture diameter of about 4.3 mm, and is designed to be approximately parallel light having a spot diameter of about 4 mm at a distance of 0 to 20 mm from the lens tip.

  In FU-35FZ, an optical fiber bundle in which a large number of optical fibers having a diameter of about 0.05 mm are bundled in a circle having a diameter of 0.5 mm is arranged at the center of a circular region having a diameter of about 1.1 mm, and the circumference thereof is 0.265 mm in diameter. The eight optical fibers are surrounded. That is, the diameter of the peripheral optical fiber is smaller than the diameter of the optical fiber bundle arranged at the center, and has a diameter about half that of the optical fiber bundle arranged at the center. Further, the gap between the central optical fiber bundle and the peripheral optical fiber calculated from the above information is 0.035 mm or less.

  The inspection apparatus includes photodiodes 32f and 32g for detecting reflected light from the processing surface 107a received by the light receiving fibers 12f and 12g. The light emitted from the collimating lens unit 10 and reflected by the surface 107a to be inspected enters the collimating lens unit 10i. Of the light receiving fiber bundle 17 connected to the tip of the collimating lens unit 10i, the first light receiving fiber 12f transmits light to the photodiode 32f. The second light receiving fiber 12g transmits light to the photodiode 32g.

  The detection unit 20 that detects the intensity of light received by the light receiving fibers 12 f and 12 g includes an LED driver 33 and an A / D converter 34. The LED driver 33 sends an instruction to the LED 30, and the A / D converter 34 converts the amount of light detected by the photodiodes 32f and 32g into a signal. In FIG. 6, the LED 30 and the photodiodes 32 f and 32 g are illustrated as being outside the detection unit 20, but some or all of the LED 30 and the photodiodes 32 f and 32 g are provided as a part of the detection unit 20. It may be.

  FIG. 11 is a conceptual diagram of the inspection apparatus 101 included in the etching apparatus shown in FIG. An inspection apparatus 101 illustrated in FIG. 11 includes a detection unit 20, and the detection unit 20 includes a fiber sensor amplifier unit 21 and a microcontroller 22. The light projecting fiber 11 and the light receiving fibers 12f and 12g, which are a plurality of light receiving fibers, are both connected to the fiber sensor amplifier unit 21. The fiber sensor amplifier unit 21 is connected to the microcontroller 22.

  The collimating lens units 10 and 10i are arranged such that the first light receiving fiber 12f is positioned on the extension of the light path when the light 71 emitted from the light projecting fiber 11 is regularly reflected by the surface 107a to be inspected. . The reflected light 72, which is a component of the light 71 emitted from the light projecting fiber 11 and regularly reflected by the surface 107 a to be inspected, enters the first light receiving fiber 12 f of the light receiving fiber bundle 17. A part of the scattered light 73, which is a component of the light 71 emitted from the light projecting fiber 11 and diffusely reflected by the surface 107a to be inspected, enters the second light receiving fiber 12g of the light receiving fiber bundle 17. The light 71, the reflected light 72, and the scattered light 73 actually travel as a light beam having a constant cross-sectional area, but in FIG. 11, the center line of the light beam is indicated by an arrow.

  FIG. 12 is an explanatory diagram corresponding to a state in which the reflected light 72 is incident on the first light receiving fiber 12f. As shown in FIG. 12, the reflected light 72, which is the regular reflection of the light 71 emitted from the light projecting fiber 11 by the surface 107a to be inspected, is collected by the collimator lens 14 on the end surface of the first light receiving fiber 12f, and the first light receiving fiber 12f. Is incident. The first light receiving fiber 12f has a mirror surface on which the light of the light projecting fiber 11 is irradiated, and when the light is reflected as substantially parallel light from the irradiation surface, the first light receiving fiber 12f is at a position where the parallel light is condensed by the lens. It is installed so that the end is located. On the other hand, the scattered light 73 diffused by the light 71 emitted from the light projecting fiber 11 at the surface 107a to be inspected reaches other than the end face of the first light receiving fiber 12f by the collimator lens 14. For this reason, when the scattered light 73 increases, the amount of light incident on the second light receiving fiber 12g located around the first light receiving fiber 12f increases.

  As a result, by using this inspection apparatus 101, the first light receiving fiber 12f receives the component of the light 71 emitted from the light projecting fiber 11 that is regularly reflected by the surface 107a to be inspected. The intensity of the component that is regularly reflected by the surface 107a to be inspected can be grasped. In addition, the component of the light 71 emitted from the light projecting fiber 11 that is diffusely reflected by the inspection surface 107a is received by the second light receiving fiber 12g, so that the intensity of the component of the light 71 that is irregularly reflected by the inspection surface 107a is grasped. can do. Therefore, in the inspection apparatus 101 of the present embodiment, the intensity of the component that is regularly reflected on the surface of the surface 107a to be inspected of the base material 107 and the intensity of the component that is irregularly reflected are separately detected in one measurement. Can do.

  FIG. 13 is a conceptual diagram of an inspection apparatus 102 included in an etching apparatus according to a modification. The inspection apparatus 102 shown in FIG. 13 includes a plurality of light receiving fibers 12 for receiving reflected light from the surface 107a to be inspected of the base material 107. The plurality of light receiving fibers 12 are arranged so as to surround the light projecting fiber 11.

  The optical fiber bundle 13 in which the light projecting fiber 11 and the plurality of light receiving fibers 12 are combined has a plurality of light receiving fibers on the extension of the light path when the light emitted from the light projecting fiber 11 is regularly reflected by the surface 107a to be inspected. The first state where any one of 12 is located and the second state perpendicular to the surface 107a to be inspected can be taken in at least two ways. In the inspection apparatus 102, the single collimating lens unit 10 serves to both irradiate the surface 107a to be inspected of the mold base 107 and receive reflected light reflected by the surface 107a to be inspected.

  FIG. 14 is an enlarged view of an end portion of the optical fiber bundle 13 of the inspection apparatus 102 according to the modification. The optical fiber bundle 13 includes a plurality of optical fibers. In the optical fiber bundle 13 shown in FIG. 14, one light projecting fiber 11 is located at the center of the optical fiber bundle 13, and six light receiving fibers 12 are arranged so as to surround the light projecting fiber 11. Yes. The number of light receiving fibers 12 is not limited to six and may be other numbers. For example, the number is FU-35FZ manufactured by Keyence Corporation.

  In FIG. 13, the second state is shown as apparent from the fact that the optical fiber bundle 13 is perpendicular to the surface 107a to be inspected. The inspection apparatus 102 includes a switching unit 16 for switching between the first state and the second state of the optical fiber bundle 13. The switching unit 16 can switch the direction of the optical fiber bundle 13 by a known technique. The switching unit 16 may switch the state of the optical fiber bundle 13 by manipulating the direction of the collimating lens unit 10 as shown in FIG. 13 and is connected so as to directly operate the optical fiber bundle 13. May be.

  FIG. 15 is a diagram illustrating a light path in the first state. As shown in FIG. 15, in the first state, the optical fiber bundle 13 is slightly inclined with respect to the surface 107a to be inspected. Therefore, the component of the light 71 emitted from the light projecting fiber 11 that is regularly reflected by the surface 107 a to be inspected becomes the reflected light 72 and enters one of the plurality of light receiving fibers 12. The reflected light 72 regularly reflected by the surface 107 a to be inspected is collected on the end face of the light receiving fiber 12 by the collimating lens 14 and is incident on the light receiving fiber 12.

  FIG. 16 is a diagram illustrating a light path in the second state. As shown in FIG. 16, in the second state, the optical fiber bundle 13 is perpendicular to the surface 107a to be inspected, so that the light 71 emitted from the light projecting fiber 11 is regularly reflected by the surface 107a to be inspected. The resulting component becomes reflected light 72 and is incident on the light projecting fiber 11 again. Also in the first state and the second state, as a result of the light 71 entering the surface 107a to be inspected, the scattered light 73 is generated at an angle different from the reflected light 72 in addition to the reflected light 72. In the second state shown in FIG. 16, it is mainly scattered light 73 that enters the light receiving fiber 12. The reflected light 72 specularly reflected by the surface 107 a to be inspected is collected on the end face of the projection fiber 11 by the collimating lens 14. Scattered light 73 traveling around the reflected light 72 is incident on the light receiving fiber 12.

  The light 71 and the reflected light 72 actually travel as a light beam having a constant cross-sectional area, but in FIGS. 15 and 16, the center line of the light beam is indicated by an arrow. Since each light beam has a constant cross-sectional area, even in the first state in which the reflected light 72 is incident on any of the plurality of light receiving fibers 12, the component incident on the light projecting fiber 11 of the reflected light 72 is completely absent. Not necessarily. Similarly, even in the second state in which the reflected light 72 is incident on the light projecting fiber 11, the component that is incident on any one of the plurality of light receiving fibers 12 in the reflected light 72 is not necessarily completely absent.

  In FIG. 15 and FIG. 16, the refraction by the collimating lens 14 is omitted for convenience of explanation, but the refraction angle is very small even if the reflected light 72 is refracted by the collimating lens 14. Therefore, the two states as described above can be distinguished by the difference in the inclination of the optical fiber bundle 13.

  Thereby, by using this inspection apparatus 102, the intensity of light incident on the light receiving fiber 12 in each of the first state and the second state can be detected. That is, in the first state, the intensity of the component specularly reflected by the surface 107a to be inspected among the light 71 emitted from the light projecting fiber 11 can be grasped. In the second state, the light 71 emitted from the light projecting fiber 11 is obtained. It is possible to grasp the intensity of some components of the scattered light 73 caused by the above. Therefore, in the inspection apparatus 102, the intensity of the component that is regularly reflected by the surface 107a to be inspected of the base material 107 and the intensity of the component that is irregularly reflected can be detected separately.

  In the inspection apparatuses 101 and 102 described above, compared to the diameter of the opening for emitting the light 71 to the outside in the light projecting fiber 11, the opening for receiving the light from the outside in the light receiving fibers 12, 12f, and 12g. The diameters are preferably the same or smaller. By adopting this configuration, the light receiving fibers 12, 12f, and 12g can easily receive only desired light components, and the probability of receiving unwanted light components can be reduced. In addition, by adopting this configuration, the amount of light incident on the light receiving fibers 12, 12f, and 12g greatly fluctuates due to a slight change in angle, so that a change in light intensity is sensitively detected. It becomes possible.

  FIG. 17 is a flowchart showing an example of the first half of the step (step S3) of inspecting the surface 107a to be processed of the mold base 107. As shown in FIG. 17, in step S <b> 11, light is projected from the light projecting fiber 11 toward the inspection surface 107 a of the mold base material 107. In step S12, the reflected light 72 from the surface 107a to be inspected is received by the light receiving fiber (the light receiving fiber 12, or the first light receiving fiber 12f and the second light receiving fiber 12g). In step S13, the detection unit 20 detects the intensity of light received by the light receiving fiber. Steps S11 to S13 do not mean that step S12 is performed after step S11 is completed, and step S12 may be performed in parallel while performing step S11. The same applies to step S12 and step S13 as well as step S11 and step S13.

  FIG. 18 is a flowchart showing a preferred example of the first half of the step (step S3) of inspecting the surface 107a to be processed, which can be performed using the inspection apparatus 101 described above. In the example shown in FIG. 18, in the light projecting step S11, light is projected in a direction that is not perpendicular to the surface 107a to be inspected.

  In the light receiving step S12, the light emitted from the light projecting fiber 11 is received by using the light receiving fiber bundle 17 arranged so that the plurality of second light receiving fibers 12g surround the first light receiving fiber 12f located at the center. The light receiving fiber bundle 17 is disposed so that the first light receiving fiber 12f is positioned on the extension of the light path when the light is regularly reflected by the inspection surface 107a, and the reflected light from the surface 107a to be inspected is received.

  The detecting step S13 includes a step S21 for detecting the intensity M1 of the light received by the first light receiving fiber 12f and a step S22 for detecting the intensity m1 of the light received by the second light receiving fiber 12g. Steps S11 and S12 are displayed as if they are related to each other on the flowchart of FIG. 18, but since they are actually light irradiation and light reception, they may be performed almost simultaneously. Moreover, the time slot | zone when process S11 and process S12 are performed may overlap.

  As a result, when the surface 107a of the mold base 107 is irradiated with light, M1 corresponding to the intensity of light mainly composed of specularly reflected light and the intensity of light mainly composed of scattered light. The corresponding m1 can be obtained. Based on the light intensities M1 and m1 thus obtained, it is possible to estimate the optical characteristics that will be obtained in the product.

  FIG. 19 is a flowchart showing another preferred example of the first half of the step (step S3) of inspecting the surface 107a to be processed, which can be performed using the inspection apparatus 102 described above. In the example illustrated in FIG. 19, in the light projecting step S <b> 11, the optical fiber bundle 13 disposed so as to surround the light projecting fiber 11 with the plurality of light receiving fibers 12 is used. The light projecting step S11 is in a first state in which any one of the plurality of light receiving fibers 12 is positioned on the extension of the light path when the light emitted from the light projecting fiber 11 is regularly reflected by the surface 107a to be inspected. The optical fiber bundle 13 is arranged in the first step S31 for irradiating light from the projection fiber 11, and the optical fiber bundle 13 is arranged so as to be in a second state perpendicular to the surface 107a to be inspected. A second step S32 of irradiating light from the light projecting fiber 11.

  The light receiving step S12 includes a third step S33 for receiving light while performing the first step S31, and a fourth step S34 for receiving light while performing the second step S32.

  The detecting step S13 includes a step of detecting the intensity M1 of the light received in the third step S33 and a step of detecting the intensity m1 of the light received in the fourth step S34. Either the first step S31 performed in the first state or the second step S32 performed in the second state may be performed first. Steps S11 and S12 are displayed as if they were related to each other on the flowchart of FIG. 19, but since they are actually light irradiation and light reception, they may be performed almost simultaneously. Moreover, the time slot | zone when process S11 and process S12 are performed may overlap.

  As a result, when the surface 107a of the mold base 107 is irradiated with light, M1 corresponding to the intensity of light mainly composed of specularly reflected light and the intensity of light mainly composed of scattered light. The corresponding m1 can be obtained. Based on the light intensities M1 and m1 thus obtained, it is possible to estimate the optical characteristics that will be obtained in the product.

  In the latter half of the step (step S3) of inspecting the processing target surface 107a of the mold base 107, m1 / (M1 + m1) may be obtained as a temporary haze using the strength M1 and the strength m1. In this way, “temporary haze” can be obtained as a parameter having a meaning close to “haze”, which is a parameter that can be obtained by a predetermined method using a product manufactured from a mold. Moreover, the provisional haze is advantageous because it can be obtained based on the optical characteristics of the surface 107a to be processed of the mold base 107 without actually making a trial product from the mold.

  In the latter half of the step (step S3) of inspecting the surface 107a to be processed of the mold base 107, the intensity M1 and the intensity m1 are used, and (M1-m1) / (M1 + m1) is used as the provisional reflected image definition. You may ask for it. In this way, “temporary reflected image definition” is a parameter expected to be proportional to “reflected image definition”, which is a parameter that can be obtained by a predetermined method using a product manufactured from a mold. Can be requested. Moreover, the provisional reflected image definition is advantageous because it can be obtained based on the optical characteristics of the surface 107a to be processed of the mold base 107 without actually making a prototype from the mold.

  “Temporary haze” and “temporary reflected image definition” are parameters that reflect the magnitude of light scattering caused by unevenness formed on the mold surface. That is, these parameters include information on unevenness formed by etching. On the other hand, these parameters are expected to be less susceptible to light absorption fluctuations due to the amount of etching solution by incorporating (M1 + m1) corresponding to the total reflected light amount into the denominator.

  As described above, the present invention includes the light receiving fibers 12f and 12g, or the plurality of light receiving fibers 12, so that the intensity of the component that is regularly reflected on the surface of the surface 107a to be inspected and the intensity of the component that is irregularly reflected are separately provided. Can be estimated. Due to this feature, the present invention can be preferably used for the management of the etching end point in the anti-glare mold processing.

  In the step of determining the etching amount (step S4), the surface state of the surface 107a to be processed of the mold base 107 is analyzed using the provisional haze or provisional reflected image definition obtained as described above. Then, the etching amount of the surface 107a to be processed is determined by determining whether the surface state of the surface 107a to be processed has reached a predetermined state. For a plurality of different base materials 107, the provisional haze or provisional reflected image definition during the etching process is obtained, and the etching operation is performed so that the etching is stopped when the provisional haze or provisional reflected image definition reaches a predetermined value. be able to.

  In this way, the etching operation can be performed for each of the different base materials 107 while inspecting the surface state of the surface 107a to be processed during the etching process. be able to. Therefore, the etching amount of the surface 107a to be processed of the mold base 107 can be stabilized, and the surface 107a to be processed can be etched with good reproducibility.

  The manufacturing method of the anti-glare film using the metal mold | die obtained with the manufacturing method of the metal mold | die of this invention mentioned above is demonstrated. The method for producing an antiglare film includes a step of transferring a concavo-convex surface of a mold produced by the method of producing a mold of the present invention to a transparent resin film, and a transparent resin film having the concavo-convex surface of the mold transferred to the mold. Removing from the substrate. By such a method for producing an antiglare film of the present invention, an antiglare film exhibiting preferable optical properties is suitably produced.

  The transfer to the mold-shaped film is preferably performed by embossing. Examples of the embossing include a UV embossing method using a photocurable resin and a hot embossing method using a thermoplastic resin. Among these, the UV embossing method is preferable from the viewpoint of productivity.

  The UV embossing method forms a photocurable resin layer on the surface of a transparent resin film, and cures the photocurable resin layer while pressing the photocurable resin layer against the uneven surface of the mold. It is a method of transferring to a layer. Specifically, an ultraviolet curable resin is applied onto the transparent resin film, and the ultraviolet curable resin is irradiated with ultraviolet rays from the transparent resin film side in a state where the applied ultraviolet curable resin is in close contact with the uneven surface of the mold. The mold resin is cured, and then the transparent resin film on which the cured ultraviolet curable resin layer is formed is peeled from the mold, thereby transferring the shape of the mold to the ultraviolet curable resin.

  When the UV embossing method is used, the transparent resin film may be a substantially optically transparent film. For example, a triacetyl cellulose film, a polyethylene terephthalate film, a polymethyl methacrylate film, a polycarbonate film, or a norbornene compound is used as a monomer. And a resin film such as a solvent cast film of thermoplastic resin such as amorphous cyclic polyolefin and an extruded film.

  Further, the type of the ultraviolet curable resin in the case of using the UV embossing method is not particularly limited, but a commercially available appropriate one can be used. It is also possible to use a resin that can be cured by visible light having a wavelength longer than that of ultraviolet rays by combining an ultraviolet curable resin with an appropriately selected photoinitiator. Specifically, polyfunctional acrylates such as trimethylolpropane triacrylate and pentaerythritol tetraacrylate are used alone or in admixture of two or more thereof, and Irgacure 907 (manufactured by Ciba Specialty Chemicals) ), Irgacure 184 (manufactured by Ciba Specialty Chemicals), and a photopolymerization initiator such as Lucillin TPO (manufactured by BASF) can be suitably used.

  On the other hand, the hot embossing method is a method in which a transparent resin film formed of a thermoplastic resin is pressed against a mold in a heated state, and the surface shape of the mold is transferred to the transparent resin film. The transparent resin film used in the hot embossing method may be any material as long as it is substantially transparent. For example, polymethyl methacrylate, polycarbonate, polyethylene terephthalate, triacetyl cellulose, norbornene compounds are used as monomers. A solvent cast film or an extruded film of a thermoplastic resin such as amorphous cyclic polyolefin can be used. These transparent resin films can also be suitably used as a base film for applying the ultraviolet curable resin in the UV embossing method described above.

  A transparent substrate subjected to an antiglare treatment, such as an antiglare film obtained by the above method for producing an antiglare film, is formed with its fine uneven surface shape controlled with high accuracy. Therefore, sufficient anti-glare properties are exhibited, whitishness does not occur, glare does not occur even when it is arranged on the surface of the image display device, and high contrast is exhibited.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

An example of an apparatus that uses a cupric chloride (CuCl ₂ ) solution as the etchant 122 and sprays the etchant 122 from the shower nozzle 121 to etch the surface 107a of the copper mold base 107 is performed. explain.

  First, as a light projecting fiber 11, Keyence Co., Ltd., Model F-3HA, and Keyence Co., Ltd. FU-35FZ are connected and sealed in a fluororesin tube for chemical resistance. It installs in the position in the reaction tank 120 which can project light. The light projecting fiber 11 is an optical fiber bundle having an opening at the center of the tip of the FU-35FZ.

  At this time, the position where the light to be projected strikes is a place where the etchant 122 sprayed from the shower nozzle 121 is not directly applied.

  Next, as the first light receiving fiber 12f and the second light receiving fiber 12g, Keyence Corporation, Model F-3HA, and Keyence Corporation FU-35FZ are connected, and a fiber bundle having an opening at the center is first. The light receiving fiber 12f is used, and a fiber bundle having an opening in the peripheral portion is called a second light receiving fiber 12g. Similarly, the first light receiving fiber 12f and the second light receiving fiber 12g are sealed in a fluorine tube so as to have chemical resistance, and then the light projected by the light projecting fiber 11 in the reaction tank 120 is treated. It is installed at a position where the reflected light reflected by 107a can be received. At this time, the distance between the F-3HA and the surface 107a to be processed is set to about 20 mm.

  As a light source, a light emitting diode LXHL-LE3C manufactured by Philips Lumileds Lighting Company was used, and a product code 43987-K (aspheric condenser lens Outer Diameter = 27 mm Effective Focal 13 mm) sold by Edmond Optics Japan Co., Ltd. Two pieces are used to introduce light into the light projecting fiber 11.

  Next, the base material 107 on which the mask 112 with the developed photosensitive resin film is attached is introduced into the etching apparatus, and the etching liquid 122 is sprayed onto the surface 107a to be processed. At this time, light is projected from the light projecting fiber 11, and the intensity of the light transmitted by the first light receiving fiber 12f and the second light receiving fiber 12g is detected by the photodiode SFH-213 made by Osram Opto Semiconductors Inc.

  When the intensity of the light transmitted to the detection unit 20 by the first light receiving fiber 12f is M1, the intensity of the light transmitted to the detection unit 20 by the second light receiving fiber 12g is m1, and the value of m1 / (M1 + m1) becomes a predetermined value. Then, spraying of the etching liquid 122 onto the surface to be processed 107a is stopped, and the etching liquid 122 is washed away from the surface to be processed 107a with water.

  By the above operation, an etching process with excellent optical property reproducibility can be realized.

  10, 10i collimating lens unit, 11 projecting fiber, 12, 12f, 12g receiving fiber, 13 optical fiber bundle, 14 collimating lens, 15 housing, 16 switching unit, 17 receiving fiber bundle, 20 detecting unit, 71 light, 72 Reflected light, 73 scattered light, 101, 102 inspection device, 107 base material, 107a surface to be treated, 120 reaction tank, 121 shower nozzle, 122 etching solution.

Claims (11)

An etching apparatus that etches a base material for a mold that molds a product that exhibits an antiglare effect by an uneven shape formed on a surface,
A reaction vessel in which the surface to be treated of the substrate and the etching solution are brought into contact;
A projecting fiber for projecting toward the surface to be treated;
A light receiving fiber bundle by a plurality of light receiving fibers that receive reflected light from the surface to be processed;
A detector that detects the intensity of light received by the light receiving fiber ;
The light receiving fiber bundle includes a first light receiving fiber located in the center and a plurality of second light receiving fibers surrounding the first light receiving fiber,
The so that light emitted from the light projecting fiber positioned the first light receiving fiber on the extension of the travel path of light when specularly reflected by the surface to be processed, said that have been receiving fiber bundle placement, an etching apparatus. An etching apparatus that etches a base material for a mold that molds a product that exhibits an antiglare effect by an uneven shape formed on a surface,
A reaction vessel in which the surface to be treated of the substrate and the etching solution are brought into contact;
A projecting fiber for projecting toward the surface to be treated;
A plurality of light receiving fibers for receiving reflected light from the surface to be processed ;
A detector that detects the intensity of light received by the light receiving fiber;
The plurality of light receiving fibers are arranged so as to surround the light projecting fiber, and the light projecting fiber and the plurality of light receiving fibers constitute an optical fiber bundle,
The optical fiber bundle includes a first state in which any one of the plurality of light receiving fibers is positioned on an extension of a light path when the light emitted from the light projecting fiber is regularly reflected by the surface to be processed. a second state perpendicular to the processing surface is configured as a can take at least two ways, et etching apparatus. Compared to the diameter of the opening for emitting light to the outside in the light projecting fiber, the diameter of the opening for receiving light from outside in the receiving fiber is made the same or smaller, according to claim 1 or The etching apparatus according to claim 2 . The etching apparatus according to any one of claims 1 to 3 , wherein the light projected toward the surface to be processed has a peak wavelength of 490 nm or more and 510 nm or less. A method of manufacturing a mold for molding a product that exhibits an antiglare effect due to the uneven shape formed on the surface,
Preparing a substrate for the mold having a surface to be treated;
Etching the treated surface of the substrate;
The etching step includes a step of projecting light from a light projecting fiber toward the surface to be processed.
Receiving light reflected from the surface to be processed by a light receiving fiber;
Detecting the intensity of light received by the light receiving fiber;
And the step of determining whether or not to terminate a picture etching process, only including,
The step of receiving light includes a step of receiving light mainly composed of specularly reflected light when irradiating the surface to be processed, and a step of receiving light mainly composed of scattered light,
The step of detecting includes a step of detecting an intensity M1 of light mainly composed of the specularly reflected light, and a step of detecting an intensity m1 of light mainly composed of the scattered light,
The determining step is a method for manufacturing a mold , which is performed based on the strength M1 and the strength m1 . The light projecting step uses an optical fiber bundle arranged so as to surround the light projecting fiber with a plurality of light receiving fibers,
The step of projecting includes
The optical fiber bundle is arranged so that one of the plurality of light receiving fibers is positioned on an extension of a light path when light emitted from the light projecting fiber is regularly reflected on the surface to be processed. A first step of irradiating light from the light projecting fiber;
A second step of irradiating light from the light projecting fiber by arranging the optical fiber bundle so as to be in a second state perpendicular to the surface to be processed,
The step of receiving light includes a third step of receiving light while performing the first step, and a fourth step of receiving light while performing the second step,
The detecting step includes, as a main component, the specularly reflected light received by a light receiving fiber located on an extension of a light path when regularly reflected by the processing surface among the plurality of light receiving fibers in the third step. to include a step of detecting the light intensity M1, and a step in which the plurality of light receiving fibers at the fourth step detects the intensity m1 of light mainly containing the scattered light received, according to claim 5 Mold manufacturing method. The step of projecting light projects in a direction not perpendicular to the surface to be processed,
The light receiving step uses a light receiving fiber bundle disposed so that a plurality of second light receiving fibers surround the first light receiving fiber located at the center, and the light emitted from the light projecting fiber is the surface to be processed. Receiving the reflected light from the surface to be processed by arranging the light receiving fiber bundle so that the first light receiving fiber is located on the extension of the light path when regularly reflected by
The detecting step includes a step of detecting intensity M1 of light mainly composed of the specularly reflected light received by the first light receiving fiber, and the scattered light received by the plurality of second light receiving fibers as a main component. The method of manufacturing the metal mold | die of Claim 5 including the process of detecting the intensity | strength m1 of the light to perform. Said step of determining, using the intensity M1 and the strength m1, m1 / (M1 + m1 ) the including the step of obtaining a provisional haze method of a mold according to claims 5 to claim 7 . Said step of determining, using the intensity M1 and the strength m1, (M1-m1) / the step of obtaining (M1 + m1) as provisional reflected image clarity including, in any one of claims 7 to claim 5 The manufacturing method of the metal mold | die of description. Compared to the diameter of the opening for emitting light to the outside in the light projecting fiber, the diameter of the opening for receiving light from outside in the receiving fiber is made the same or smaller, claim 5 The manufacturing method of the metal mold | die in any one of Claim 9 . The light projected toward a processing surface, with a peak wavelength of 490nm or more 510 nm, the mold manufacturing method according to claim 10 claim 5.

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