JP2018165811A - Flat-plate mold matrix manufacturing method, molding die manufacturing method and roll mold manufacturing method - Google Patents

Abstract

A plate mold master manufacturing method, a molding mold manufacturing method, and a roll mold manufacturing method capable of forming a plurality of three-dimensional patterns with high accuracy are provided. A method for manufacturing a flat plate mold master disk is used for manufacturing a microlens array 10 as a lens molded body in which a plurality of convex lenses are arranged. A method for manufacturing a flat plate mold master disk for forming a plurality of three-dimensional patterns P having curvatures of lenses 13 includes an exposure step and a development step. In the exposure process, based on the profile R of the three-dimensional pattern P, which is the inverted shape of the microlens 13, the light intensity I of the exposure light 47 is different in the film surface direction of the resist film. In the developing process, a three-dimensional pattern P is formed by developing the resist film 43 that has undergone the exposure process. [Selection drawing] Fig. 3

Description

  The present invention relates to a flat plate mold master manufacturing method, a molding die manufacturing method, and a roll mold manufacturing method.

  A lens molded body in which a plurality of convex lenses are arranged, for example, a microlens array in which microlenses are arranged is known. In manufacturing a microlens array, a mold for forming a plurality of three-dimensional patterns having the curvature of a target microlens may be used on a curable resin that is a material of the microlens array.

  As a method for manufacturing a molding die, for example, the one described in Patent Document 1 is known. In this method, a molding die that duplicates a mold master is manufactured by performing an electroforming method using a mold master having a plurality of three-dimensional patterns formed on the surface, which is a reversed shape of a microlens. .

  In Patent Document 1, in manufacturing a mold master, a recess having a triangular cross section is formed in a resist film formed on a flat substrate such as a glass substrate, and the resist film and the substrate are formed by isotropic dry etching. Etching gradually. As a result, a three-dimensional pattern that is the inverted shape of the microlens is formed on the substrate at a portion corresponding to the recess of the resist film. This substrate is used as a mold master. Thus, according to Patent Document 1, a plate-shaped mold master is obtained.

  Further, as a mold master manufacturing method, there is a method of forming a plurality of three-dimensional patterns on a resist film by performing exposure and development. For example, in Patent Document 2, a resist film made of a photosensitive resin is exposed with laser light as exposure light and then developed. The resist film is formed by applying a photosensitive resin to the peripheral surface of the cylindrical roll. It is also described that a laser device that emits laser light also has a scanning device that sets the focal position and staying time of the laser light while controlling the integrated power of the laser light.

JP 2009-132010 A JP 2007-229996 A

  In the method for manufacturing a flat plate master described in Patent Document 1, it is difficult to accurately form a target three-dimensional pattern because the entire surface of the substrate is etched. In the mold master manufacturing method of Patent Document 2, since multiple exposure occurs at the boundary between three-dimensional patterns, it is difficult to control the dissolution rate of the resist film in the developer. Further, in Patent Document 2, since the resist film to be exposed is provided on the peripheral surface of the cylindrical roll, it is more difficult to control the dissolution rate. For this reason, it is impossible to accurately manufacture a mold master in which three-dimensional patterns are arranged.

  Therefore, an object of the present invention is to provide a flat plate mold master manufacturing method, a molding die manufacturing method, and a roll mold manufacturing method capable of accurately forming a plurality of three-dimensional patterns.

  The flat plate mold master manufacturing method of the present invention is used for manufacturing a lens molded body in which a plurality of convex lenses are arranged, and a plurality of three-dimensional patterns having a convex lens curvature are formed by developing after exposing a resist film. The flat plate mold master manufacturing method includes an exposure step and a development step. In the exposure step, exposure is performed in which the light intensity of the exposure light differs in the surface direction of the film surface of the resist film based on the profile of the three-dimensional pattern that is the inverted shape of the convex lens. In the development process, a three-dimensional pattern is formed by developing the resist film that has undergone the exposure process.

  In the exposure step, it is preferable to perform exposure for each exposure target area that partitions the resist film.

  The lens molded body is preferably a microlens array in which microlenses as convex lenses are arranged.

  The mold manufacturing method of the present invention includes a flat plate mold master manufacturing process and a mold forming process. In the flat mold master manufacturing process, a flat mold master is manufactured by the flat mold master manufacturing method described above. In the mold forming step, a mold for forming a lens molded body is formed from a flat mold master by electroforming.

  In the mold forming step, it is preferable to form a replica mold that duplicates the three-dimensional pattern of the flat plate mold master as the molding mold by performing the electroforming method an even number of times.

  The roll mold manufacturing method of the present invention includes a mold manufacturing process and a roll mold forming process. In the mold manufacturing process, a molding mold is manufactured by the above-described mold manufacturing method. In the roll mold forming step, a roll mold is formed by winding a molding mold around a roll material.

  According to the present invention, a flat plate mold master, a mold for molding, and a roll mold in which a plurality of three-dimensional patterns are accurately formed are manufactured.

1 is a schematic diagram of a microlens array made by the practice of the present invention. FIG. It is a principal part schematic diagram of a film manufacturing apparatus. It is explanatory drawing explaining the flat plate metal mold | die master manufacturing method. It is explanatory drawing explaining exposure. It is explanatory drawing explaining the light intensity of exposure light. It is explanatory drawing explaining a metal mold | die manufacturing method. It is explanatory drawing explaining a metal mold | die manufacturing method. It is explanatory drawing explaining a roll metal mold manufacturing method.

  A microlens array 10 shown in FIG. 1 is an example of a lens molded body in which a plurality of convex lenses are arranged. The microlens array 10 is made by using a flat mold master 50 (see FIG. 3) manufactured by carrying out the present invention. The flat plate mold master 50 will be described later with reference to another drawing.

  The microlens array 10 includes a sheet portion 11 and a lens portion 12. The sheet part 11 and the lens part 12 are transparent. The boundary between the sheet portion 11 and the lens portion 12 is not visually recognized when both the sheet portion 11 and the lens portion 12 are transparent as in the present embodiment, but in FIG. is there.

  The thickness T1 of the sheet portion 11 is in the range of 50 μm or more and 300 μm or less, and is 135 μm in this embodiment.

  The lens unit 12 is provided on one sheet surface 11 a of the sheet unit 11. The lens unit 12 includes a microlens 13 as a convex lens. That is, the microlens array 10 is a lens molded body in which microlenses 13 as convex lenses are arranged. The microlenses 13 are arranged on the XY plane in FIG. The arrangement of the microlenses 13 is a zigzag arrangement in this example, but is not limited to this and may be a square arrangement.

  In the present embodiment, the microlens 13 is a convex lens whose lens surface 13a has a semicircular cross section, that is, a hemispherical lens. The microlens 13 is not limited to a hemispherical convex lens, and may be a convex lens in which the cross-sectional shape of the lens surface 13a is a curve such as an arc, a parabola, an elliptical arc, or the like.

  As shown in FIG. 2, the microlens array 10 is obtained by cutting a long optical film 16 manufactured by a film manufacturing apparatus 15 into a sheet shape. FIG. 2 is a schematic view showing a main part of the film manufacturing apparatus 15. The film manufacturing apparatus 15 includes a delivery machine 17, a coating machine 18, a shape imparting device 19, and the like.

  The sending machine 17 is for supplying a long transparent film base 20 to be the sheet portion 11 of the microlens array 10 to the shape imparting device 19. In this example, the film base 20 is wound in a roll shape, and the sending machine 17 is set with a film roll in which the film base 20 is wound in a roll shape, and sends out the film base 20 from the film roll. The film base 20 functions as a support for the coating film 22 formed by the coating machine 18. A driving roller 21 that rotates in the circumferential direction is disposed between the feeding machine 17 and the coating machine 18. The film base 20 is wound around the driving roller 21 and is conveyed toward the shape imparting device 19 by the rotation of the driving roller 21. The film base 20 is made of PET (polyethylene terephthalate), PC (polycarbonate), TAC (triacetyl cellulose), or the like.

  The applicator 18 is for forming the coating film 22 on the film base 20. The coating film 22 is made into the microlens 13 by the shape imparting device 19. The coating machine 18 continuously flows out the supplied coating liquid 26. When the coating liquid 26 flows out toward the film base 20 traveling in the longitudinal direction, the coating film 22 is formed on one film surface of the film base 20. The film base 20 on which the coating film 22 is formed is guided to the shape imparting device 19. The coating liquid 26 includes a transparent photocurable polymer in this embodiment. As the photocurable polymer, for example, Unidic (registered trademark) manufactured by DIC Corporation and Aika Eyetron manufactured by Aika Industry Co., Ltd. are used.

  The shape imparting device 19 includes a support roller 31, a roll mold 32, and a light source 33.

  The support roller 31 is disposed on the side opposite to the coating film 22 in the conveyance path of the film base 20 and supports the film base 20 on the peripheral surface. The support roller 31 has a rotation axis arranged in parallel with the rotation axis of the drive roller 21. The support roller 31 is rotated by the motor 35 in synchronization with the conveyance of the film base 20. The rotation direction of the support roller 31 is a direction in which the film base 20 is conveyed (clockwise direction in the drawing). The support roller 31 may be driven to rotate as the film base 20 is conveyed.

  The roll mold 32 is provided on the coating film 22 side in the conveyance path of the film base 20, and forms the microlens 13 on the coating film 22 in cooperation with the support roller 31.

  The roll mold 32 includes a roll material 37 and a molding mold 38. The roll material 37 has a rotation axis arranged in parallel with the rotation axis of the drive roller 21. The roll material 37 is rotated by the motor 40 in synchronization with the conveyance of the film base 20. The rotation direction of the roll material 37 is a direction in which the film base 20 is conveyed (a counterclockwise direction in the drawing).

  The molding die 38 is for forming the microlens 13 on the coating film 22. A plurality of three-dimensional patterns P that are the inverted shapes of the microlenses 13 are formed on the surface of the molding die 38. The inverted shape of the microlens 13 is a concave shape. The molding die 38 is wound around the peripheral surface of the roll material 37 with the surface on which the three-dimensional pattern P is formed facing outward. The molding die 38 is manufactured using a flat plate master 50 described later. A method for manufacturing the molding die 38 will be described later with reference to another drawing.

  The roll mold 32 having the above configuration is rotated by the motor 40 with the film base 20 and the coating film 22 sandwiched between the support roller 31. The roll mold 32 presses the coating film 22 on the support roller 31 and transfers the three-dimensional pattern P to the coating film 22, thereby continuously forming a plurality of microlenses 13.

  The roll mold 32 is provided with a pressure adjuster 39. The pressure adjuster 39 adjusts the pressing force when the three-dimensional pattern P of the molding die 38 is transferred to the coating film 22. By adjusting the pressing force, the microlens 13 is more reliably formed on the coating film 22.

  The light source 33 is provided downstream from the roll mold 32 in the film manufacturing apparatus 15. In the present embodiment, the light source 33 is disposed on the roll mold 32 side. The light source 33 cures the coating film 22 by emitting ultraviolet rays, and the film base 20 and the coating film 22 become the optical film 16. The light source 33 is connected to the controller 33a, and an output for emitting light is controlled by the controller 33a. Note that the type of light emitted from the light source 33 and the output from which light is emitted depend on the type of photocurable polymer.

  A light source 33 and / or another light source (not shown) may be provided. When another light source is used in addition to the light source 33, the other light source includes a position facing the support roller 31 upstream of the roll mold 32, a position on the coating film 22 side facing the roll mold 32, and It can be provided at a position facing the support roller 31 downstream of the roll mold 32. When another light source is provided upstream of the roll mold 32, the coating film 22 is cured so as to be in a gel state in which fluidity is lost. Thereby, the microlens 13 is more reliably formed on the coating film 22.

  A method for manufacturing the flat plate mold master 50 will be described with reference to FIG. The flat plate mold master 50 is manufactured by exposing the resist film 43 formed on the substrate 42 and developing it. That is, the flat plate master 50 is manufactured by an exposure process and a development process. The exposure is performed by an exposure device 45 described later.

  The substrate 42 has a flat plate shape. The substrate 42 is a glass substrate in the present embodiment, but is not limited thereto, and may be a silicon substrate or the like. The resist film 43 is formed flat on one surface of the flat substrate 42 by applying a photosensitive resin by spin coating or the like. In this embodiment, a positive resist is used as the photosensitive resin.

  As shown in FIG. 3A, in the exposure process, based on the profile R (see FIG. 5B) of the three-dimensional pattern P which is the inverted shape of the microlens 13, the light intensity I of the exposure light 47 is changed to a resist film. Different exposures are performed in the plane direction of the film surface 43. In this example, by performing scanning exposure while increasing or decreasing the light intensity I of the exposure light 47, the dissolution rate of the resist film 43 in the developer is changed in the scanning direction. In FIG. 3A, the dissolution rate of the resist film 43 in the developing solution is indicated by a dotted line, and the dissolution rate is faster as the distance from the film surface of the resist film 43 is larger.

  In FIG. 3A, the scanning direction is the X direction which is the right direction of the paper along the film surface of the resist film 43, and the magnitude of the light intensity I is represented by the size of the arrow indicating the exposure light 47. is there. The larger the arrow indicating the exposure light 47, the greater the light intensity I. Further, among the arrows indicating the exposure light 47, those indicated by solid lines indicate that irradiation is being performed, and those indicated by two-dot chain lines indicate that irradiation has been performed.

  In this embodiment, by performing scanning exposure, the dissolution rate of the resist film 43 in the developer is changed in the scanning direction. However, the present invention is not limited to this, and the exposure depth of the resist film 43 is changed in the scanning direction. Also good. The exposure depth is the distance that the exposure light 47 reaches in the thickness direction of the resist film 43 from the film surface of the resist film 43 opposite to the substrate 42. The exposure depth is controlled by increasing or decreasing the light intensity I of the exposure light 47, making the light intensity constant, and increasing the height from the film surface opposite to the substrate 42 of the resist film 43 to the tip of the light source unit 45a. There is a method for controlling the thickness.

  As shown in FIG. 3B, in the development process, a three-dimensional pattern P is formed by developing the resist film 43 that has undergone the exposure process. The dissolution rate of the resist film 43 in the developer varies depending on the light intensity I of the exposure light 47, and the greater the light intensity I of the exposure light 47, the greater the amount of removal of the resist film 43 in the same development time. A three-dimensional pattern P that is the inverted shape of the microlens 13 is formed on the resist film 43 after development. The developed resist film 43 and the substrate 42 constitute a flat mold master 50.

  The exposure device 45 includes a light source unit 45a and emits exposure light 47 from the light source unit 45a. The exposure light 47 is, for example, laser light. Further, the exposure device 45 is connected to a moving mechanism 46, and can be moved in each of the XYZ directions (X, Y, and Z directions are orthogonal to each other) in FIG. Yes. In the present embodiment, the moving mechanism 46 does not move the exposure device 45 in the Z direction, but moves it on the XY plane.

  The exposure process will be described more specifically with reference to FIG. In the exposure step, exposure is performed for each exposure target area that partitions the resist film 43. Each exposure target area is partitioned by a boundary line. The boundary line is set so as to pass through the boundary portion between the three-dimensional patterns P. Thus, the boundary line is a conceptual line. In FIG. 4, only the first exposure target region R1 and the second exposure target region R2 are shown for simplification of the drawing. Hereinafter, the first exposure target region R1 and the second exposure target region R2 will be described. In the actual exposure process, three or more exposure target areas may be formed. The first exposure target region R1 is a region between the boundary line L1 and the boundary line L2. The second exposure target region R2 is a region between the boundary line L2 and the boundary line L3. Scanning exposure is performed for each of the first exposure target region R1 and the second exposure target region R2. That is, the exposure process includes a first scanning exposure process for scanning exposure of the first exposure target area R1 of the resist film 43 and a second scanning exposure process for scanning exposure of the second exposure target area R2 in contact with the first exposure target area R1. And have.

  In FIG. 4, the arrow indicates the locus of the central portion of the light source unit 45a in the exposure process. In the first exposure target region R1, for example, the light source unit 45a is moved in the X direction from the point A on the boundary line L1, and after reaching the point B on the boundary line L2, the light source unit 45a is opposite to the Y direction. It moves in the direction with the component. In this example, the light source unit 45a is moved from the point B to the point C along the boundary line L2. Then, the light source unit 45a is moved from the point C in the direction opposite to the X direction, and after reaching the point D on the boundary line L1, the light source unit 45a is moved in a direction having a component opposite to the Y direction. In this example, the light source unit 45a is moved from the point D to the point E along the boundary line L1. In this way, by repeatedly performing scanning exposure between the boundary line L1 and the boundary line L2, the entire area of the first exposure target region R1 is exposed. Thereafter, the exposure of the second exposure target region R2 is performed. Similarly to the first exposure target region R1, the second exposure target region R2 is also exposed to the entire second exposure target region R2 by repeatedly performing scanning exposure between the boundary line L2 and the boundary line L3. In this embodiment, the exposure is performed while turning back between the boundary line L1 and the boundary line L2. However, the present invention is not limited to this, and the exposure is performed when the light source unit 45a is moved in one direction, and the exposure is moved in the other direction. In this case, the exposure may not be performed.

  The light intensity I of the exposure light 47 is set based on the design value of the curvature of the target lens surface 13a. The light intensity I will be described with reference to FIG. In FIG. 5A, the symbol Q is a profile of the three-dimensional pattern P that is a replica shape of the microlens 13, and corresponds to the design value of the curvature of the target lens surface 13a. In FIG. 5B, the symbol R is a profile of the three-dimensional pattern P that is the inverted shape of the microlens 13. Profile R is obtained from profile Q. In FIG. 5 (c), the symbol S is a profile of the light intensity I obtained from the profile R. Based on this profile S, the light intensity I of the exposure light 47 is set. The profile S may be obtained from the profile Q.

  The light intensity I of the exposure light 47 has a linear relationship with the exposure amount. Further, the greater the exposure amount, the better the controllability of the removal amount of the resist film 43. For this reason, the greater the light intensity I of the exposure light 47, the better the controllability of the three-dimensional pattern P. In the present embodiment, since the light intensity I of the exposure light 47 is maximized at a position corresponding to the vertex of the target lens surface 13a on the XY plane shown in FIG. 5C, the vicinity of the vertex of the lens surface 13a. Excellent lens shape controllability.

  In the above-described flat plate mold master manufacturing method, in the exposure process, the light intensity I of the exposure light 47 at the boundary between the three-dimensional patterns P is reduced, so that the influence of multiple exposure such as double exposure occurs at this boundary. It is suppressed. In particular, in the case where scanning exposure is performed for each exposure target area, the boundary between the exposure target areas is a part where the influence of double exposure is prominent, but this influence is more reliably suppressed. As a result, a flat plate master 50 on which a plurality of three-dimensional patterns P are accurately formed is manufactured.

  Further, in the microlens array 10 made using the flat mold master 50, the variation in the thickness T1 of the portion of the sheet portion 11 corresponding to the boundary between the microlenses 13 is suppressed. For this reason, the microlens array 10 is excellent in strength against deformation such as bending even if the thickness T1 of the sheet portion 11 is in the range of 50 μm or more and 300 μm or less.

  A method for manufacturing the molding die 38 will be described. The molding die 38 is manufactured by a flat plate mold master manufacturing process and a mold forming process. The flat mold master manufacturing process is a process of manufacturing the flat mold master 50 by the above flat mold master manufacturing method. The mold forming step is a step of forming the molding die 38 from the flat plate master 50 by electroforming. A plurality of three-dimensional patterns P are accurately formed on the molding die 38 manufactured by this mold manufacturing method. Description of the flat plate mold master manufacturing process is omitted, and only the mold forming process is described.

  The mold forming process is a process of forming a replica mold that duplicates the three-dimensional pattern P of the flat mold master 50 as the molding mold 38 by performing the electroforming method an even number of times. In this embodiment, the electroforming method is performed twice.

  Hereinafter, the mold forming process will be described with reference to FIGS. 6 and 7. The mold forming step includes a first conductive layer forming step, a first electroforming step, a mold intermediate forming step, a mold release treatment step, a second conductive layer forming step, a second electroforming step, And a peeling step.

  As shown in FIG. 6A, the first conductive layer forming step is a step of forming the first conductive layer 52 on the surface of the flat plate mold master 50 on which the three-dimensional pattern P is formed. The material of the first conductive layer 52 is not particularly limited, but is preferably a material suitable for the electroforming method performed in the first electroforming process. Examples of the method for forming the first conductive layer 52 include a sputtering method, a metal vapor deposition method, an EB vapor deposition method, a silver mirror reaction method, and an electroless plating method. In the present embodiment, the material of the first conductive layer 52 is nickel, and the first conductive layer 52 is formed by a sputtering method.

  As shown in FIG. 6B, the first electroforming step is a step of forming the first metal film 53 on the surface of the first conductive layer 52 by electroforming. As the material of the first metal film 53, either nickel or an alloy or a compound thereof is preferable. In the present embodiment, nickel is used. In addition, the material of the first metal film 53 includes a metal made of any one of copper, silver, gold, chromium, titanium, iron, and zinc, an alloy made of two or more of these, and at least Examples thereof include compounds containing one kind. If the first conductive layer 52 and the first metal film 53 are made of the same material as in the present embodiment, the boundary between the first conductive layer 52 and the first metal film 53 may not be visually recognized. However, in the following drawings, for convenience of explanation, they are shown by broken lines.

  As shown in FIG. 6C, in the mold intermediate forming step, the mold intermediate 54 is formed by peeling the flat plate master 50 from the first conductive layer 52 and the first metal film 53. It is. In the mold intermediate 54, a three-dimensional pattern P that is a replica shape of the microlens 13 is formed on the surface of the first conductive layer 52 side. Here, the peeling was performed by putting a wedge (wedge) between the flat plate mold master 50 and the first conductive layer 52 and mechanically peeling it. The wedge is preferably a metal such as stainless steel (SUS, Special Use Stainless) and iron.

  As shown in FIG. 7A, in the mold release process, the mold release layer 55 is formed on the first conductive layer 52 by performing the mold release process on the first conductive layer 52 of the mold intermediate 54. It is a process. The release layer 55 is for facilitating separation of the first conductive layer 52 and the second conductive layer 56 described later. Examples of the material of the release layer 55 include a fluorine-based release agent and PDMS (polydimethylsiloxane). Examples of the method for forming the release layer 55 include a spin coating method and a dip method. In this embodiment, the material of the release layer 55 is OPTOOL HD manufactured by Daikin Industries, Ltd., and the release layer 55 is formed by a dipping method.

  As shown in FIG. 7B, the second conductive layer forming step is a step of forming the second conductive layer 56 on the surface of the release layer 55. The material of the second conductive layer 56 is not particularly limited, but is preferably a material suitable for the electroforming method performed in the second electroforming process. Examples of the method for forming the second conductive layer 56 include a sputtering method, a metal vapor deposition method, an EB vapor deposition method, a silver mirror reaction method, and an electroless plating method. In the present embodiment, the material of the second conductive layer 56 is nickel, and the second conductive layer 56 is formed by a sputtering method.

  As shown in FIG. 7C, the second electroforming step is a step of forming the second metal film 57 on the surface of the second conductive layer 56 by electroforming. The material of the second metal film 57 is preferably either nickel or an alloy or compound thereof. In this embodiment, nickel is used. In addition, the material of the second metal film 57 includes a metal made of any one of copper, silver, gold, chromium, titanium, iron, and zinc, an alloy made of these two or more, and at least one of these. Examples thereof include compounds containing one kind. When the second conductive layer 56 and the second metal film 57 are made of the same material as in this embodiment, the boundary between the second conductive layer 56 and the second metal film 57 may not be visually recognized. However, in the following drawings, for convenience of explanation, they are shown by broken lines.

  As shown in FIG. 7D, the peeling process is a process of peeling the first conductive layer 52 from the second conductive layer 56. Here, the peeling was performed by putting the wedge between the first conductive layer 52 and the second conductive layer 56, that is, in the release layer 55 and mechanically peeling it. The wedge is preferably a metal such as stainless steel and iron. On the surface of the second conductive layer 56 after peeling, the three-dimensional pattern of the flat plate master 50, that is, the three-dimensional pattern P which is the inverted shape of the microlens 13, is duplicated. Therefore, the second conductive layer 56 and the second metal film 57 are used as a replica mold of the flat plate mold master 50 and used as the molding mold 38.

  The thickness T2 of the thinnest part of the molding die 38 is preferably in the range of 20 μm to 500 μm. Compared with the case where the thickness T2 is 20 μm or more and less than 20 μm, the strength against deformation such as bending of the molding die 38 is high, and when the thickness T2 is 500 μm or less, it is larger than 500 μm. Further, deformation such as bending of the molding die 38 is facilitated. For this reason, the molding die 38 is easily wound around the roll material 37 without being damaged due to cracks or the like when wound around the roll material 37. The thickness T2 is more preferably in the range of 100 μm or more and 400 μm or less, and further preferably in the range of 150 μm or more and 300 μm or less. In the present embodiment, the thickness T2 is 200 μm.

  Note that the mold intermediate 54 produced in the mold intermediate forming step may be used as a mold for molding. A plurality of three-dimensional patterns P are accurately formed on the mold intermediate 54 as a molding mold. When the mold intermediate 54 is used as a molding mold, a lens molded body in which a plurality of concave lenses are arranged is manufactured.

  In the mold manufacturing method, the electroforming method is performed an even number of times in the mold forming step. However, the electroforming method may be performed an odd number of times. In this case, the reversal mold of the flat mold master 50 is manufactured. A plurality of three-dimensional patterns P are accurately formed on the reversal mold of the flat mold master 50. The three-dimensional pattern P of the reversal mold is a replica shape of the microlens 13 as a convex lens. For this reason, when the said inversion metal mold | die is used as a metal mold | die for a shaping | molding, the lens molded object with which the several concave lens was distribute | arranged is manufactured.

  A method for manufacturing the roll mold 32 will be described. The roll mold 32 is manufactured by a mold manufacturing process and a roll mold forming process. The mold manufacturing process is a process for manufacturing the molding die 38 by the above-described mold manufacturing method. Description of this mold manufacturing process is omitted.

  The roll mold forming process is a process of forming the roll mold 32 by winding the molding mold 38 around the roll material 37. The roll mold forming process includes an adhesive layer forming process and a winding process.

  As shown in FIG. 8A, the adhesive layer forming step is a step of forming the adhesive layer 60 on the surface opposite to the surface on which the three-dimensional pattern P of the molding die 38 is formed. As a material of the adhesive layer 60, for example, an acrylic pressure-sensitive adhesive is used. In the present embodiment, the material of the adhesive layer 60 is a double-sided adhesive tape LA-50 (thickness: 50 μm) manufactured by Nitto Denko Corporation.

  As shown in FIG. 8B, the winding process is a process of winding the molding die 38 around the peripheral surface of the roll material 37. The molding die 38 is wound around the roll material 37 with the surface on which the three-dimensional pattern P is formed facing outward. Thereby, the roll mold 32 is obtained. In this example, the roll material 37 and the molding die 38 are bonded together by the adhesive layer 60. A plurality of three-dimensional patterns P are accurately formed on the roll mold 32 manufactured by this roll mold manufacturing method. In addition, by fixing the end portions of the molding die 38 in a cylindrical shape so that the surface on which the three-dimensional pattern P is formed is outside, the end portions are fixed by welding, so that the cylindrical molding die is preliminarily formed. 38 may be prepared, and the cylindrical molding die 38 may be fitted into the roll material 37.

  In addition, you may perform the mold release process process which forms a mold release layer by performing a mold release process to the surrounding surface of the roll metal mold | die 32 after a winding process. By performing the mold release process on the roll mold 32, the accuracy of forming the plurality of microlenses 13 on the coating film 22 is further improved.

  In addition, as a polymer used for the coating liquid 26, it is not restricted to a transparent photocurable polymer like the said embodiment, A transparent thermosetting polymer may be sufficient. When the polymer used for the coating liquid 26 is a thermosetting polymer, a heat source such as a heater is provided instead of the light source 33.

  The photosensitive resin used for forming the resist film 43 is a positive resist in this embodiment, but may be a negative resist. In some cases, the negative resist absorbs the developer in the development process and expands. Therefore, from the viewpoint of the formation accuracy of the three-dimensional pattern P, the photosensitive resin used for forming the resist film 43 is preferably a positive resist.

  In the above-described embodiment, scanning exposure is performed while increasing or decreasing the light intensity I of the exposure light 47 emitted from the light source unit 45a in the exposure process, but the light intensity I of the exposure light 47 emitted from the light source unit 45a is changed. Exposure may be performed while moving the exposure target area for each exposure area using a gray scale mask. The distribution of light transmittance of the gray scale mask is designed based on the profile R of the three-dimensional pattern P that is the inverted shape of the microlens 13. As a result, in the exposure step, exposure is performed in which the light intensity I of the exposure light 47 differs in the surface direction of the film surface of the resist film 43 in accordance with the light transmittance distribution of the gray scale mask. The dissolution rate with respect to is changed in the plane direction.

DESCRIPTION OF SYMBOLS 10 Microlens array 11 Sheet | seat part 11a Sheet | seat surface 12 Lens part 13 Microlens 13a Lens surface 15 Film manufacturing apparatus 16 Optical film 17 Delivery machine 18 Coating machine 19 Shape imparting apparatus 20 Film base 21 Driving roller 22 Coating film 26 Coating liquid 31 Support Roller 32 Roll mold 33 Light source 33a Controller 35 Motor 37 Roll material 38 Molding mold 39 Pressure regulator 40 Motor 42 Substrate 43 Resist film 45 Exposure device 45a Light source section 46 Moving mechanism 47 Exposure light 50 Flat mold master 52 First 1 conductive layer 53 first metal film 54 mold intermediate 55 release layer 56 second conductive layer 57 second metal film 60 adhesive layer I light intensity L1 boundary line L2 boundary line L3 boundary line P three-dimensional pattern Q of microlens Of the three-dimensional pattern that is a duplicate shape Thinnest portion thickness of profile R microlens reverse shape in which three-dimensional pattern thickness T2 mold of the profile S light intensity profile R1 of the first exposure area R2 second exposure area T1 seat

Claims (6)

In the manufacturing method of a lens mold body in which a plurality of convex lenses are arranged, and a plurality of three-dimensional patterns having the curvature of the convex lens are formed by developing after exposing a resist film,
Based on the profile of the three-dimensional pattern that is the inverted shape of the convex lens, an exposure step of performing the exposure in which the light intensity of exposure light is different in the surface direction of the film surface of the resist film;
A developing step of forming the three-dimensional pattern by developing the resist film that has undergone the exposure step;
A method for producing a flat plate mold master.   The flat plate mold master manufacturing method according to claim 1, wherein in the exposure step, the exposure is performed for each exposure target region partitioning the resist film.   The flat plate mold master manufacturing method according to claim 1, wherein the lens molded body is a microlens array in which microlenses as the convex lenses are arranged. A flat mold master manufacturing process for manufacturing a flat mold master by the flat mold master manufacturing method according to any one of claims 1 to 3,
A mold forming step of forming a molding mold for the lens molded body by electroforming from the flat plate mold master; and
A mold manufacturing method comprising:   The said metal mold | die formation process forms the replication metal mold | die which replicated the said three-dimensional pattern of the said flat plate-shaped metal mold | die master as the said metal mold | die by performing the said electroforming method even number of times. Mold manufacturing method. A mold manufacturing process for manufacturing a mold for molding by the mold manufacturing method according to claim 4 or 5,
A roll mold forming step of forming a roll mold by winding the molding mold around a roll material;
A roll mold manufacturing method comprising:

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