JPWO2005098486A1 - Manufacturing method of fine structure, manufacturing method of stamper using the fine structure, and manufacturing method of resin-made fine structure using the stamper - Google Patents

Abstract

The manufacturing method of the fine structure having grooves on the surface of the present invention allows the parallel light from the light source to pass through the photomask (13) having a plurality of slits (13b) arranged at predetermined intervals. By irradiating the resist layer (12) formed on the substrate (11) while changing the angle continuously or stepwise from one direction to the other direction with respect to the vertical plane along the longitudinal direction, the resist layer Forming a substantially trapezoidal light irradiation part (12a) in (12) (step 100) and developing the resist layer (12), the light non-irradiation part (12b) of the resist layer (12) is removed. (Step 101).

Description

  The present invention relates to a method for manufacturing a fine structure suitable for forming an optical sheet, a method for manufacturing a stamper for obtaining a fine structure having the same shape as or reversed from the fine structure using the fine structure, and The present invention relates to a method for manufacturing a resin microstructure using the stamper.

  An optical sheet obtained by finely processing the surface of a transparent resin such as a methacrylic resin, a styrene resin, or a polycarbonate resin is used in a surface light source device for a backlight type liquid crystal display.

  The optical sheet having a V-shaped groove as a fine process is used to enhance the collection of light emitted from the light guide plate, and is called a prism sheet. Also, the optical sheet with fine irregularities on the surface is used not only to make the reflective dots inconspicuous by scattering the light, but also to collect the light in the front and increase the front brightness, and is called a diffusion sheet Yes.

  An optical sheet having such a V-shaped groove is generally manufactured by injection molding or transfer molding of a transparent resin using a mold (stamper). As a manufacturing method of this stamper, a direct metal mold is used. A method of cutting a V-shaped groove with a diamond tool or the like is common.

  On the other hand, an optical sheet having fine irregularities on the surface is a method of imparting irregularities with an embossing roller as described in JP-A No. 2001-129881 (reference document 1), JP-A No. 05-092529 (reference document). 2) A method for imparting irregularities due to inorganic powder to the transparent resin layer by blending the transparent resin layer with the inorganic fine powder and laminating with the transparent resin layer as described in 2), JP-A-11-227115 It is manufactured by a method of laminating resin-crosslinked particles having a specific particle diameter as described in the gazette (Reference Document 3) on the surface of a transparent resin substrate.

  Japanese Laid-Open Patent Publication No. 6-202341 (reference document 4) proposes a method for forming a fine structure using a photosensitive resin.

  In the proposal according to the reference document 1, as shown in FIG. 10A, a positive photosensitive resin such as polymethyl methacrylate is applied to the conductive substrate 1 to form the resist layer 2. Next, as shown in FIG. 10B, a mask 4 having slits 4a arranged at a predetermined interval is fixed to the resist layer 2 with a predetermined interval L1, and X-rays (hereinafter referred to as synchrotron radiation) First exposure is performed by inclining the conductive substrate 1 by an angle of + α with respect to a plane 6 perpendicular to SR light. As a result, a plate-like exposed portion 2 a having a thickness corresponding to the width of the slit is formed in the resist layer 2.

  Next, as shown in FIG. 10C, the second exposure is performed by inclining the conductive substrate 1 by an angle of −α with respect to the surface 6 perpendicular to the SR light. As a result, a plate-like exposed portion 2 b having a thickness corresponding to the width of the slit is formed in the resist layer 2.

  Next, when the obtained conductive substrate 1 is developed, the exposed portion 2a and the exposed portion 2b are removed, and the resist layer 2c between the exposed portion 2a and the exposed portion 2b is cut out, so that FIG. As shown in FIG. 2, a resist pattern 7 having a V-shaped groove 7a is formed on the conductive substrate 1 by the remaining resist layer 2d.

  The conductive substrate 1 having the obtained resist pattern 7 is immersed in a plating solution, and the entire conductive substrate 1 is used as an electrode, and electroplating is performed to deposit the metal structure 8 in the V-shaped groove 7a. ((A) of FIG. 11). Next, as shown in FIG. 11B, the resist material is dissolved with a solvent to form the metal mold 9 having the resist pattern 7 and the inverted pattern. By performing resin molding such as injection molding and transfer molding using the metal mold 9 as a mold (stamper), a microstructure 11 having a V-shaped groove as shown in FIG. 11C can be molded. it can.

  When manufacturing an optical sheet for use in a surface light source device for a large liquid crystal display, a stamper was used, such as injection molding or transfer molding, rather than extrusion molding that cuts a thin and large area extrusion plate into a desired shape. It is expected that cost reduction can be achieved by resin molding.

  Moreover, the surface of such an optical sheet has to be molded in a finer and more uniform shape due to an increase in size, which makes extrusion molding difficult. For this reason, there is an increasing need to shape the surface using a precise transfer method such as injection molding, hot pressing, or casting.

  Furthermore, in recent years, such optical sheets have been improved in functionality. For example, when an optical sheet having a large number of functions is used in a single device such as a prism sheet or a light diffusion sheet, an optical sheet having a mutual function has been proposed. For example, a prism sheet that can be used alone is proposed for two prism sheets having different prism directions. Attempts have also been made to incorporate the function of the prism sheet into the light diffusion sheet.

  Therefore, the method for producing a resin plate as described in the above-mentioned references 1 to 3 is not suitable for producing such an optical sheet. When cutting a die with a diamond tool, etc., it takes more time as the processing area increases, and due to the rough line caused by the deformation of the diamond tool during this time, processing such as depth accuracy and angle accuracy is performed. It becomes difficult to maintain the uniformity of accuracy, and when a homogeneous product is manufactured, the problem is that the price increases dramatically.

  In the method of forming a fine structure described in Reference 4, it is considered that a mold having a fine V-shaped groove can be manufactured, but the resist layer 2c shown in FIG. 10C is cut out. In this case, the mask pitch and the incident angle are limited, and at least the exposure part 2a and the exposure part 2b need to intersect or contact each other as shown in FIG.

  That is, when the exposed portion 2a and the exposed portion 2b do not cross, as shown in FIG. 12, it becomes difficult to cut out the resist layer 2c, and the exposed portion 2a and the exposed portion 2b cross each other in the middle. As shown in FIG. 13, although the resist layer 2c can be cut out, the shape of the remaining resist layer 2d becomes complicated or becomes a hung shape.

  Further, the fine structure forming method described in Reference 4 is a technique achieved by a combination of synchrotron radiation X-rays (SR light) and a positive resist. The X-ray of synchrotron radiation has a problem that the apparatus becomes large. There is also a problem that the photosensitive resin to be used is mainly limited to a positive resist.

  It is desired to provide a method for easily producing a fine structure capable of accurately forming fine V-shaped grooves so as to withstand the increase in size of the optical sheet. In addition to the function of the prism sheet, a method of manufacturing a fine structure suitable for manufacturing an optical sheet having other functions is also desired.

  One feature of the present invention is that a method for manufacturing a microstructure having a groove on a surface causes a parallel light beam from a light source to pass in the longitudinal direction of the slit via a photomask having a plurality of slits arranged at predetermined intervals. By irradiating the resist layer formed on the substrate by changing the angle continuously or stepwise from one direction to the other direction with respect to the vertical plane along, a substantially trapezoidal light irradiation part is applied to the resist layer. Forming a resist layer and developing the resist layer to remove the light non-irradiated portion of the resist layer.

FIG. 1 is a schematic diagram showing a manufacturing process of a master according to the present invention.
FIG. 2 is a schematic view showing a manufacturing process of a master according to the present invention.
FIG. 3 is a schematic diagram showing a cross section of an example of a master obtained by the present invention.
FIG. 4 is a schematic diagram showing a manufacturing process of a master according to the present invention.
FIG. 5 is a schematic diagram showing a manufacturing process of a master according to the present invention.
FIG. 6 is a schematic diagram showing an example of a master obtained by the present invention.
FIG. 7 is a schematic view showing an example of a master obtained by the present invention in cross section.
FIG. 8 is a view showing a photographing result obtained by photographing the surface of the master manufactured according to the present invention with an electron microscope.
[FIG. 9] is a diagram showing the measurement result of the arithmetic surface roughness of the stamper manufactured according to the present invention.
FIG. 10 is a schematic diagram showing a manufacturing process of a master according to a conventional example.
FIG. 11 is a schematic diagram showing a manufacturing process of a microstructure according to a conventional example.
FIG. 12 is a schematic diagram for explaining the problems in the manufacturing process of the master according to the conventional example.
FIG. 13 is a schematic diagram for explaining the problems in the manufacturing process of the master according to the conventional example.
FIG. 14 is a flowchart for explaining the manufacturing method of the fine structure according to the present invention and the manufacturing method of the stamper using the fine structure.

  One object of the present invention is to provide a method for manufacturing a fine structure suitable for manufacturing an optical sheet such as a prism sheet.

  Another object of the present invention is to provide a method for manufacturing a fine structure suitable for manufacturing an optical sheet having a function of a diffusion sheet in addition to the function of an optical sheet such as a prism sheet.

  One feature of the present invention is that, as shown in the flowchart of FIG. 14, a method for manufacturing a microstructure having grooves on the surface is obtained from a light source through a photomask having a plurality of slits arranged at predetermined intervals. By irradiating the resist layer formed on the substrate while changing the angle continuously or stepwise from one direction to the other direction with respect to a vertical plane along the longitudinal direction of the slit, the resist is formed. Forming a substantially trapezoidal light-irradiated portion on the layer (step 100), and developing the resist layer to remove the light-irradiated portion of the resist layer (step 101). It is that you are.

  Here, a positive type resist can be used as the resist, but a fine structure having a V-shaped groove can be easily manufactured by using a negative type resist. Further, the predetermined interval between the slits does not have to be the same between the adjacent slits. For example, the predetermined interval can be appropriately changed according to the use of a light sheet to be manufactured later.

  In this case, if fine particles are dispersed in the above-described negative resist layer, the fine particles are exposed to the inclined surface in the step of removing the light non-irradiated portion by development, and the fine particles remain or are removed. As a result, fine concave portions or convex portions are formed on the inclined surface.

  Here, if a positive resist is used as the fine particles, the positive resist is exposed on the inclined surface in the step of removing the non-irradiated portion by development, but the positive resist is also dissolved and removed in the step, A fine structure having fine concave portions on the inclined surface can be manufactured.

The step of forming the light irradiation part adjusts the incident angle of the parallel rays, the size of each part of the photomask, and / or the thickness of the resist layer to thereby adjust the bottom of the adjacent substantially trapezoidal light irradiation part. When including or overlapping, the microstructure can include a V-shaped groove toward the substrate surface.
The step of forming the light irradiating unit adjusts the incident angle of the parallel light beam, the size of each part of the photomask and / or the thickness of the resist layer to thereby adjust the bottom of the substantially trapezoidal light irradiating unit adjacent thereto. In this case, the microstructure can include a groove having a substantially trapezoidal cross section whose width gradually decreases toward the substrate surface.

  Further, the microstructure manufactured as described above can be used as it is or as a stamper by the following method to manufacture a microstructure such as an optical sheet having a V-shaped groove by resin molding. That is, as shown in FIG. 14, using the manufactured microstructure, a metal mold having an inverted shape or a pattern of the same shape is formed on the surface of the microstructure (step 110). In addition, a molding stamper can be manufactured by a method including manufacturing a molding stamper having a groove having the same shape as or inverted from the surface of the microstructure using the metal mold (step 111). . Alternatively, a conductive film is formed on the surface of the microstructure (step 120), an electroforming metal is electroformed on the conductive film to form an electroformed layer (step 121), and The molding stamper can also be manufactured by a method including manufacturing the molding stamper by removing the fine structure from the conductive film (step 122).

  Furthermore, it is possible to easily manufacture a resin microstructure having a fine unevenness on the surface by transferring the fine unevenness to the resin using any of the molding stampers.

  According to one feature of the present invention, a method for manufacturing a fine structure suitable for manufacturing an optical sheet such as a prism sheet can be provided by a simple technique using a resist. In addition, one feature of this manufacturing method is that it can be applied to a manufacturing method of a fine structure suitable for manufacturing an optical sheet having a function of a diffusion sheet in addition to the function of an optical sheet such as a prism sheet. is there.

  The best mode for carrying out the present invention will be described with reference to the drawings. In the following drawings, for convenience of explanation, the vertical and horizontal scales of each part are illustrated by schematic diagrams that are randomly changed.

  First, FIGS. 1 and 2 are schematic views showing a manufacturing process of a master for manufacturing an optical sheet having a V-shaped groove according to an embodiment of the present invention, and FIG. 3 shows a fine pattern obtained by the process. It is a figure explaining the shape of a structure (original recording). The present invention will be described below with reference to these drawings.

  First, as shown in FIG. 1, a resist layer 12 is formed on an appropriate substrate 11, and a photomask 13 is brought into close contact with or close to the upper surface of the resist layer 12. The photomask 13 has a thin plate shape, and includes a light shielding portion 13a that reflects or absorbs light and shields light, and a plurality of slits (openings) 13b that are opened with a width W13b provided between the light shielding portions 13. Have. The plurality of slits 13b are arranged substantially parallel to each other.

  Next, as shown in FIG. 2, parallel light such as ultraviolet light (UV light) is irradiated from the photomask 13 side. Here, in the present invention, the parallel light beam is irradiated at an irradiation angle from one direction (angle θ1 in FIG. 2) to another direction (angle θ2 in FIG. 2) with respect to the vertical plane along the longitudinal direction of the slit. Is incident continuously or stepwise.

  As a result, the resist layer 12 is exposed at the portion indicated by reference numeral 12a by the parallel light irradiated from the slit 13b to form the exposed portion 12a, and the portion indicated by reference symbol 12b is not exposed to form the light non-exposed portion 12b. To do. Thereby, the cross-sectional shape of the exposure part 12a becomes a trapezoidal shape that gradually decreases toward the incident light side with the surface in contact with the slit 13b as the upper base, and the light non-exposure part 12b is located between the adjacent exposure parts 12a and 12a. Is formed in an inverted triangle shape.

  Here, since this resist is a negative resist, the photomask is peeled off and developed after exposure, whereby the light non-exposed portion 12b is removed and only the exposed portion 12a remains as shown in FIG. The master 14 as a fine structure can be obtained.

The master 14 has a cross section having an upper base 15 having the same width W15 as the width W13b of the slit 13, an inclined surface 16a having the same angle as the inclination angle θ1, and an inclined surface 16b having the same angle as the inclination angle θ2. It is almost trapezoidal. Further, in this embodiment, the bottoms of the substantially trapezoidal light exposure parts 12a (in FIG. 2 and FIG. 3, one bottom part of one light exposure part 12a is indicated by reference numeral 12c) overlap each other. As a result, due to the removal of the non-exposed portion 12a, a V-shaped groove 18 having an apex angle θ17 regulated by θ1 and θ2 is formed by the opposed inclined surfaces 16a and 16b.
[Modification 1]
4 to 6 are schematic views showing a manufacturing process of a master for manufacturing an optical sheet having a V-shaped groove of an embodiment according to the modification of FIGS. 1 to 3, and of the master manufactured thereby. It is a schematic diagram explaining an example with a cross section. The same or equivalent part members as those in FIGS. 1 to 3 are denoted by the same reference numerals and detailed description thereof is omitted.

  In Modification 1, as shown in FIG. 4, the thickness t12 of the resist layer 12 is made thin. As a result, as shown in FIG. 5, when parallel light rays (UV light) are irradiated from the photomask 13 side, the thickness t <b> 12 of the resist layer 12 is adjusted so that the exposed portions 12 a and 12 a adjacent to each other are adjusted. The bottom portions 12c of the two are separated from each other. That is, a gap 11a indicated by a width W11a is formed between adjacent exposed portions 12a. As a result, when the light non-exposed portion 12b is removed after development, as shown in FIG. 6, the master 14 having the substrate surface 17 exposed by separating the exposed portions 12a and 12a from each other can be obtained.

  The master 14 has a substantially trapezoidal shape having an upper base 15 having the same width W15 as the width W13b of the slit 13, an inclined surface 16a having the same angle as that of θ1, and an inclined surface 16b having the same angle as that of θ2. . A groove having an apex angle θ17 regulated by θ1 and θ2 is formed by the opposed inclined surface 16a and inclined surface 16b, and a part of the substrate 11 having a width W17 equal to the width W11a is exposed in this groove. Thus, a substantially trapezoidal groove 19 having an upper base 17 is formed.

  Such a substantially trapezoidal groove 19 can be obtained by appropriately changing the light irradiation angles θ1 and θ2, the width W13a of the shielding portion 13a, and the thickness t12 of the resist layer 12.

  Next, each material for producing such a master 14 will be described.

  First, as the substrate 11, any material can be used as long as it supports a photoresist and can be used in a subsequent master manufacturing process, or if there is no problem. For example, a planar material such as a glass substrate or a metal plate can be exemplified.

  Here, if a substrate having fine irregularities (surface roughness) is used as the substrate 11, the master 14 formed in FIG. 6 has an upper base 17 formed by exposing a part of the substrate 11. Since it has a trapezoidal groove 19, a molded product molded using this master 14 or a mold (stamper) manufactured using this master 14 reproduces fine irregularities (surface roughness) of the upper base 17. It becomes a molded body or stamper.

  Next, a resist material for forming the resist layer 12 will be described. As the resist material, either a resist material such as a positive resist or a negative resist can be used. By using a negative resist, a fine structure having a V-shaped groove can be easily manufactured as described above. it can. In the case of a positive resist, it can be applied only when the thickness of the resist layer 12 is reduced as in the first modification, and the resulting shape is undercut.

  Such application of the resist layer 12 can be applied by an appropriate method such as spin coating, spray coating, dip coating, or the like. When the viscosity of the resist is moderately high, for example, 50 to 400 cps, the thickness of the resist layer 12 can be uniformly maintained within a range of 1 μm to 100 μm. In general, if it is 100 cps or more, the resist layer 12 having a film thickness of about 5 μm or more can be held uniformly. Such a thick film is preferably obtained by spin coating. However, for example, in order to apply by spray coating, a recoating method may be used.

  Note that the thickness of the resist layer 12 is determined as desired, and the V-shaped groove pattern can be changed by reducing the thickness of the resist layer 12 as described above.

  In the present invention, the fine particles 20 may be dispersed in the resist material. As a result, as shown in FIG. 7, the fine particles 20 are exposed on the inclined surface of the exposed portion (light irradiating portion) 12a after development to form fine convex portions 20a. Further, if the fine particles 20 are removed by a method such as dissolution in the development stage or other methods, a fine concave portion 21 corresponding to the diameter of the fine particles 20 is formed on the inclined surface 16a (or 16b) where the fine particles 20 are exposed. Is done.

  The uneven shape may be appropriately controlled by adjusting the particle diameter of the fine particles, the concentration of the fine particles, the uniformity of the fine particles, and the like. In order to improve the light diffusion performance, it is preferable that the fine particles have a spherical shape or a shape closer to a spherical shape. The concentration of the fine particles can be adjusted by the ratio (mixing ratio) of components that become fine particles.

  In this way, for example, the arithmetic average roughness of the inclined surface can be about 0.1 to 10 μm. Moreover, the unevenness | corrugation excellent in the uniformity whose arithmetic average roughness is in the range of 0.1-5 micrometers, and also arithmetic average roughness in the range of 0.2-2 micrometers can also be formed.

  The shape of the irregularities thus formed is generally about half or less of the diameter of the fine particles 20. Thereby, for example, by setting the particle diameter of the fine particles 20 within a range of 1 μm to 50 μm, preferably 1 μm to 15 μm, particularly preferably 1 μm to 10 μm, the unevenness formed by removing the fine particles can be reduced to 0.1 to 10 μm. The desired arithmetic average roughness can be set within a range of about 10 μm. Thereby, the spreading | diffusion performance of inclined surface 16a, 16b can be increased.

  In the present invention, it is preferable that fine particles of the dispersion are uniformly dispersed in the dispersion. Due to the uniform dispersion, it is easy to obtain an evenly dispersed surface of the resulting master. In order to uniformly disperse the fine particles in the dispersion, it can be dispersed by stirring using a homogenizer, a mixer or the like, but is not necessarily limited thereto, and can be appropriately selected.

  One simple technique for removing the fine particles 20 is to disperse the fine particles of the positive resist using a negative resist as a sea component. Since the positive resist as fine particles is decomposed by exposure, the positive resist exposed on the inclined surface is removed in the development step, thereby producing a fine structure having fine concave portions 21 on the inclined surface. can do.

  Such a dispersion is a conventional method for forming an emulsion, such as selecting a positive photoresist and a negative photoresist that are not compatible with each other, and ejecting a small amount of components vigorously using a predetermined small-diameter nozzle. Can be formed according to

  In this case, the obtained dispersion liquid is preferably dispersed as uniformly as possible through a defoaming step such as defoaming.

  Next, the photomask 13 is not particularly limited as long as it has a slit 13b having a desired shape, but in general, the photomask 13 is preferably thin. If the thickness is large, reflection of light on the side surface of the slit 13b may be a problem. In this respect, the side surface of the slit 13b is preferably made of at least a light-absorbing material. Moreover, it is preferable that the side in contact with the resist layer 12 has an appropriate release property or an appropriate release agent. Thereby, peeling with the resist layer 12 after exposure becomes easy. Moreover, it is preferable that the some slit 13b is substantially parallel depending on a use. If the plurality of slits 13b are substantially parallel, the plurality of light non-irradiation portions formed when the parallel rays are irradiated have substantially the same cross-sectional shape. For this reason, a more uniform groove can be formed on the surface of the microstructure after development.

  Next, a light source corresponding to the resist material to be used may be used as the light source. When a photoresist is used, a normal ultraviolet light source can be used as it is. The adjustment of the incident angle is achieved by moving the light source (including changing the irradiation angle) or changing the angle of the substrate 11.

  In the present invention, one of the features is that the resist layer is irradiated with parallel rays through the slits 13b while changing the angle continuously or stepwise. In a preferred embodiment, UV light is used as the parallel rays. Thereby, it is possible to obtain a desired shape while suppressing the amount of deformation without being affected by heat or temperature. Further, since the master can be manufactured with a simple device compared to SR light, the cost can be reduced.

  The fine structure obtained as described above can be used as a master as it is or after appropriate post-processing. An example of such post-processing is a moderate heat treatment. The shape of the pointed tip can be made smooth by appropriately heating. Further, the trapezoidal repeating pattern can be formed into a continuous dome-shaped repeating pattern by dropping the corners of the trapezoidal shape.

  In addition, after the photomask exposure, the photomask is removed, and a relief pattern with a specific shape can be formed by laser drawing or grayscale mask exposure. The light diffusion sheet has a complicated and complicated pattern due to a three-dimensional relief pattern. You can also get

  The master disc obtained in this way can be used as a mold (stamper) by a conventional method. For example, a conductive film is formed on the surface of the master, an electroforming metal is electroformed on the conductive film to form an electroformed layer, and the fine structure is peeled off from the conductive film, dissolved, etc. A stamper for molding can be manufactured by removing by a method.

  Of course, when a conductive substrate is used as the substrate, electroplating can be performed by immersing the conductive substrate in a plating solution and using the entire conductive substrate as an electrode.

  As the conductive film in this case, for example, any one of nickel, gold, silver, and copper, or any two or more alloys of gold, silver, copper, and nickel can be used. In addition, for example, any of copper, zinc, or nickel, or any two or more alloys of copper, zinc, and nickel can be used for electroforming.

  Moreover, a desired optical sheet can be manufactured at low cost by transferring fine irregularities to the resin using this molding stamper (mold).

  In addition to the method of transferring the fine irregularities formed on the surface of the molding stamper to the resin sheet, this transfer can be performed by injection molding, hot pressing, casting method, transfer molding, etc., but is not necessarily limited to these. It is not a thing and can be selected suitably.

  Hereinafter, the present invention will be described by way of examples.

  Using clean glass as a substrate, a negative photoresist (PMER N-H600) manufactured by Tokyo Ohka Co., Ltd. was applied by spin coating so that the film thickness of the photosensitive resin was about 30 μm, and 2 on a hot plate at 70 ° C. After pre-baking by warming for minutes, it was cooled to room temperature.

  A photomask in which slits having a width Wb13 of about 6 μm were formed at a pitch of 70 to 90 μm was adhered as shown in FIG.

  Next, irradiation was performed by sweeping UV light of 620 mj irradiation light over 64 seconds using a UV irradiation apparatus capable of rotating in the range of θ1: +45 degrees and θ2: −45 degrees.

  After peeling off the photomask, it was heated on a hot plate at 115 ° C. for 25 minutes, baked, cooled to room temperature, and immersed in a developer (PMER DEVELOPER N-A5) manufactured by Tokyo Ohka Co., Ltd. for 105 seconds for development.

  A nickel electroconductive film was formed on the surface of the obtained master according to a conventional method, and nickel as an electroforming metal was electroformed on the nickel electroconductive film to form a nickel electroformed layer. Further, the master was peeled from the nickel conductive film to obtain a molding stamper.

  The transparent resin sheet molded using this molding stamper has a flat portion of about 6 μm at the top portion with a thickness of 8 mm, a prismatic pattern with a top angle of about 90 degrees and a pitch of 70 to 90 μm. It was.

  In 200 ml of the photoresist of Example 1, 35 g of silicone resin fine particles (Tospearl (manufactured by GE Toshiba Silicone)) having a particle diameter of 2 μm were mixed. This mixing was carried out for 10 minutes using a mixer-type stirrer, followed by pressure defoaming after mixing to obtain a dispersion in which silicone resin fine particles were uniformly dispersed.

  A master was obtained in the same manner as in Example 1 except that this dispersion was used, and a stamper was prepared in the same manner as in Example 1.

  The inclined surface 16a (or 16b) was cut out from this master, and the reflection image of the surface of the master was measured using a digital microscope VH-6100 (Keyence Corporation). The enlarged image is shown in FIG.

  Moreover, the arithmetic surface roughness (Ra) of the surface of the obtained stamper was measured using a surface roughness measuring machine (Surfcom200B (Tokyo Seimitsu)) under the condition of 1 MPa, and the measurement results are shown in FIG.

According to this, it was found that the arithmetic surface roughness of the slope of the master was approximately 0.23 to 0.25 μm, and fine and uniform irregularities were formed. Thereby, it is understood that this unevenness can impart diffusibility to the slope.
(Sign)
DESCRIPTION OF SYMBOLS 11: Board | substrate, 12: Resist layer, 12a: Light irradiation part (light exposure part), 12b: Light non-irradiation part (light non-exposure part), 12c: Bottom part, 13: Photomask, 13a: Shielding part, 13b: Slit , 14: master, 15: upper base, 16a, 16b: inclined surface, 17: upper base, 18: V-shaped groove, 19: substantially trapezoidal groove, 20: fine particles, 20a: convex portion, 21: concave portion

  According to the present invention, a master having a V-shaped groove having a mirror surface can be easily manufactured. Further, the surface of the master can be roughened by dispersing fine particles or using a roughened substrate. Also, the shape of the V-shaped groove can be freely controlled.

  Thereby, the manufacturing method of the fine structure of the present invention is not only for optical sheets having a V-shaped groove (for example, prism sheet), but also optical sheets having other functions such as diffusibility, or other It is expected to be applied to the production of various parts such as semiconductors and optical devices.

Claims (22)

A method for producing a microstructure having a groove on a surface,
Through a photomask having a plurality of slits arranged at predetermined intervals, the angle of the parallel rays from the light source is directed from one direction to the other with respect to a vertical plane along the longitudinal direction of the slits in a continuous or stepwise manner. By irradiating the resist layer formed on the substrate by changing to the above, forming a substantially trapezoidal light irradiation portion on the resist layer, and developing the resist layer, the light non-irradiation of the resist layer A method for manufacturing a fine structure including the step of removing the portion. The method for manufacturing a microstructure according to claim 1, wherein the resist layer is formed of a negative resist. The method for producing a microstructure according to claim 2, wherein the negative resist has dispersed fine particles. The fine particles are formed from a positive resist,
The method of manufacturing a microstructure according to claim 3, wherein the step of removing the non-irradiated portion includes dissolving and removing the positive resist exposed on the inclined surface. The step of forming the light irradiation part adjusts the incident angle of the parallel rays, the size of each part of the photomask, and / or the thickness of the resist layer to thereby adjust the bottom of the adjacent substantially trapezoidal light irradiation part. The manufacturing method of the microstructure of Claim 2 including making it contact or make it overlap. The step of forming the light irradiation part adjusts the incident angle of the parallel rays, the size of each part of the photomask, and / or the thickness of the resist layer to thereby adjust the bottom of the adjacent substantially trapezoidal light irradiation part. The manufacturing method of the fine structure according to claim 2, comprising separating them from each other. A method for producing a molding stamper having a groove on its surface,
Through a photomask having a plurality of slits arranged at predetermined intervals, the angle of the parallel rays from the light source is directed from one direction to the other with respect to a vertical plane along the longitudinal direction of the slits in a continuous or stepwise manner. Irradiating the resist layer formed on the substrate by changing to a substantially trapezoidal light irradiation portion on the resist layer,
Developing the resist layer to remove the light non-irradiated portion of the resist layer to produce a microstructure having a groove on the surface;
Using the manufactured microstructure, forming a metal mold having a reversed shape or a pattern having the same shape, and forming a groove having the same shape or reversed shape as the microstructure by the metal mold. The manufacturing method of the stamper for shaping | molding including the process of manufacturing the stamper for glass. The method for manufacturing a molding stamper according to claim 7, wherein the resist layer is formed of a negative resist. The method for manufacturing a molding stamper according to claim 8, wherein the negative resist has dispersed fine particles. The fine particles are formed from a positive resist,
The method for manufacturing a molding stamper according to claim 9, wherein the step of removing the light non-irradiated portion includes dissolving and removing the positive resist exposed on the inclined surface. A method for producing a molding stamper having a groove on its surface,
Through a photomask having a plurality of slits arranged at predetermined intervals, the angle of the parallel rays from the light source is directed from one direction to the other with respect to a vertical plane along the longitudinal direction of the slits in a continuous or stepwise manner. Irradiating the resist layer formed on the substrate by changing to a substantially trapezoidal light irradiation portion on the resist layer,
Developing the resist layer to remove the light non-irradiated portion of the resist layer to produce a microstructure having a groove on the surface;
Forming a conductive film on the surface of the microstructure;
A stamper comprising the steps of: electroforming a metal for electroforming on the conductive film to form an electroformed layer; and producing a molding stamper by removing the microstructure from the conductive film. Production method. The method for manufacturing a molding stamper according to claim 11, wherein the resist layer is formed of a negative resist. The method for producing a molding stamper according to claim 12, wherein the negative resist has fine particles dispersed therein. The fine particles are formed from a positive resist,
The method for manufacturing a molding stamper according to claim 13, wherein the step of removing the non-irradiated portion includes dissolving and removing the positive resist exposed on the inclined surface. A method for producing a resin-made microstructure comprising fine irregularities on the surface,
Through a photomask having a plurality of slits arranged at predetermined intervals, the angle of the parallel rays from the light source is directed from one direction to the other with respect to a vertical plane along the longitudinal direction of the slits in a continuous or stepwise manner. Irradiating the resist layer formed on the substrate by changing to a substantially trapezoidal light irradiation portion on the resist layer,
Developing the resist layer to remove the light non-irradiated portion of the resist layer to produce a microstructure having a groove on the surface;
Forming a metal mold having an inverted shape or a pattern of the same shape using the manufactured microstructure;
The steps of manufacturing a molding stamper having grooves having the same shape as or inverted from the microstructure using the metal mold, and transferring fine irregularities to the resin using the molding stamper. The manufacturing method of the resin-made fine structure containing. The method for producing a resin microstructure according to claim 15, wherein the resist layer is formed of a negative resist. The method of manufacturing a resin microstructure according to claim 16, wherein the negative resist has dispersed fine particles. The fine particles are formed from a positive resist,
The method of manufacturing a resin microstructure according to claim 17, wherein the step of removing the light non-irradiation part includes dissolving and removing the positive resist exposed on the inclined surface. A method for producing a resin-made microstructure comprising fine irregularities on the surface,
Through a photomask having a plurality of slits arranged at predetermined intervals, the angle of the parallel rays from the light source is directed from one direction to the other with respect to a vertical plane along the longitudinal direction of the slits in a continuous or stepwise manner. Irradiating the resist layer formed on the substrate by changing to a substantially trapezoidal light irradiation portion on the resist layer,
Developing the resist layer to remove the light non-irradiated portion of the resist layer to produce a microstructure having a groove on the surface;
Forming a conductive film on the surface of the microstructure;
Electroforming a metal for electroforming on the conductive film to form an electroformed layer;
A resin-made microstructure comprising the steps of: producing a molding stamper by removing the microstructure from the conductive film; and transferring fine irregularities to the resin using the molding stamper. Production method. The method for manufacturing a resin microstructure according to claim 19, wherein the resist layer is formed of a negative resist. 21. The method for producing a resin microstructure according to claim 20, wherein the negative resist has dispersed fine particles. The fine particles are formed from a positive resist,
The method for manufacturing a resin microstructure according to claim 21, wherein the step of removing the light non-irradiation part includes dissolving and removing the positive resist exposed on the inclined surface.

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