JP7508993B2 - Roll mold manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a roll type.

Microlens array sheets, Fresnel lens sheets, diffractive optical sheets, and the like have fine patterns formed on their surfaces, and their production generally involves the use of a molding die.
In producing a sheet having a microstructure on its surface as described above, a method of forming a microstructure on the sheet surface by thermoforming, ultraviolet curing molding, or the like using a roll mold having an inverse shape of the microstructure on its surface is a highly productive method because it can form the microstructure continuously.
However, it is difficult to form many fine three-dimensional shapes, such as microlenses, on the micron or nano order on the surface of a cylindrical roll, and it has been extremely difficult to manufacture a highly accurate roll mold.

Patent Document 1 discloses a technique for drawing a submicron-sized pattern on a cylindrical mold using a laser drawing device. However, in the method of Patent Document 1, because the roll surface is cylindrical, the distance between the drawing device and the roll surface varies depending on the position on the roll, making it difficult to draw curved surfaces with high precision when forming a single shape. In addition, by rotating the roll, the distance between the drawing device and the roll surface also changes due to the influence of the roundness of the roll, etc., which creates problems such as making it difficult to form the same shape at different positions on the roll.

JP 2010-152253 A

The objective of the present invention is to provide a method for manufacturing a roll mold that can accurately and easily produce the desired mold shape.

The present invention solves the above problems by the following means. Note that, for ease of understanding, the following description will use symbols corresponding to the embodiments of the present invention, but the present invention is not limited to these.

The first invention is a method for manufacturing a roll mold, which includes a planarizing step of holding a part of a flexible cylindrical sleeve portion (10) on a flat surface, a mold shape forming step of forming a mold shape (11) in the area of the sleeve portion (10) held on the flat surface, and a fixing step of fitting and fixing the sleeve portion (10) with the mold shape (11) formed thereon to the outer periphery of a cylindrical cylinder portion (20).

The second invention is the method for manufacturing a roll mold described in the first invention, characterized in that the planarization process and the mold shape formation process are performed multiple times by changing the area to be held on the flat surface.

The third invention is the method for manufacturing a roll mold described in the second invention, characterized in that the mold shape forming process is performed so that the mold shape is continuously arranged at least in the circumferential direction of the sleeve portion (10).

The present invention provides a method for manufacturing a roll mold that can accurately and easily produce the desired mold shape.

1 is a diagram showing a roll mold 1 produced by a roll mold manufacturing method according to the present invention. FIG. 3 is a flowchart showing the flow of a method for manufacturing the roll mold 1 of the present embodiment. FIG. 4A to 4C are diagrams showing a process of fitting the sleeve portion 10 onto the outer periphery of the cylinder portion 20.

The best mode for carrying out the present invention will be described below with reference to the drawings.

First Embodiment
FIG. 1 is a diagram showing a roll mold 1 produced by a method for producing a roll mold according to the present invention.
Note that the figures shown below, including FIG. 1, are schematic diagrams, and the size and shape of each part are exaggerated or omitted as appropriate to facilitate understanding.
In the following description, specific numerical values, shapes, materials, etc. are given, but these can be changed as appropriate.

The roll mold 1 includes a sleeve portion 10 and a cylinder portion 20 .
The sleeve portion 10 is formed of a flexible tubular member. In the configuration of the roll mold 1 shown in Fig. 1, the sleeve portion 10 is fitted onto the cylindrical surface of the cylinder portion 20, and is therefore formed into a cylindrical shape.

The sleeve portion 10 has a mold-shaped portion 11 on its surface. The mold-shaped portion 11 has an inverted shape (mold shape) of the shape of the molded member molded by the roll mold 1. Examples of molded members molded by the mold-shaped portion 11 of the roll mold 1 include a microlens array sheet, a Fresnel lens sheet, and a diffractive optical sheet. In order to be used as a mold for molding these fine shapes, the mold-shaped portion 11 has a large number of fine uneven shapes on the order of microns or nanometers.

The molded portion 11 may be formed by providing an uneven surface on the metal surface that constitutes the sleeve portion, or may be formed by further laminating a resin layer and providing an uneven surface on this resin layer.

The sleeve portion 10 can be made of, for example, stainless steel having a thickness of 0.2 mm, and is configured without any gaps around the entire circumference. Note that the sleeve portion 10 is not limited to stainless steel, and may be made of, for example, copper, nickel, etc., and the thickness is preferably 0.1 mm or more and 0.5 mm or less.

The cylinder section 20 is the core of the roll mold 1 and is made of stainless steel or the like in a cylindrical shape.

FIG. 2 is a flowchart showing a flow of a method for manufacturing the roll mold 1 of this embodiment.
In step (hereinafter simply referred to as S) 10, a resist layer is formed on the surface of the sleeve portion 10. At this time, since the sleeve portion 10 has flexibility, the shape may not be stable. Therefore, if it is difficult to form a uniform resist layer, it is preferable to form the resist layer in a state where the sleeve portion 10 is temporarily fixed to a jig having a similar shape to the cylinder portion 20.

In S20, the sleeve portion 10 is aligned with the suction plate 100.
The suction plate 100 has a flat suction surface 100a, and is inserted into the inner periphery of the sleeve portion 10 to suction a part of the inner wall of the sleeve portion 10 (see FIG. 3 described later).
In S20, the back surface of the area to be exposed is aligned so that it faces the suction surface 100a. In the alignment before the second and subsequent exposures, the areas are aligned so that there is no gap at the boundary between adjacent exposed areas and that they do not overlap. This results in the exposed areas being continuous, and the mold shapes to be formed later being continuously arranged. Note that in Figures 1 and 4, the continuous arrangement of the mold shape portions 11 is shown by dashed lines for each exposed area, but in reality, the boundaries of such areas are completely invisible or can only be seen by observing under magnification, and there are essentially no boundaries.

In S30, the sleeve portion 10 is adsorbed by the suction plate 100 to hold a portion of the sleeve portion 10 flat (flattening process).

In S40, a mask M is placed over the area held on the flat surface of the sleeve portion 10, and the resist layer is exposed to light.
FIG. 3 is a diagram showing an exposure process.
The resist layer may be directly exposed by laser writing without using the mask M. During exposure, areas other than those to be exposed are shielded from light so that they are not exposed to the light used for exposure.

In S50, it is determined whether or not to expose other areas. If it is determined that the other areas are to be exposed,
If exposure of other areas is not to be performed, the process proceeds to S60.

In S60, the exposed resist layer is developed to remove either the exposed or unexposed portions.
In S60, if necessary, the metal surface of the sleeve portion 10 is etched to form an uneven shape on the metal surface.

By carrying out steps S40 to S60 above, a mold shape is formed in the area of the sleeve portion 10 that is held on a flat surface (mold shape forming process). This mold shape forming process is carried out while a portion of the sleeve portion 10 is held on a flat surface. Therefore, there is no decrease in machining accuracy depending on the position, as occurs when machining on a cylindrical surface, and machining can be performed with high accuracy at all positions.

In S70, the sleeve portion 10 having the die shape formed thereon is fitted onto the outer periphery of the cylinder portion 20 and fixed thereto (fixing step).
FIG. 4 is a diagram showing a process of fitting the sleeve portion 10 onto the outer periphery of the cylinder portion 20. As shown in FIG.
At this time, it is advisable to use a cold fitting method in which the cylinder portion 20 is cooled to reduce its outer circumference, and then the sleeve portion 10 at room temperature is fitted into the cylinder portion 20, and then the sleeve portion 10 is fixed to the cylinder portion 20 as the cylinder portion 20 returns to room temperature.

As described above, the manufacturing method of the roll mold of this embodiment includes a planarization process for holding a part of the sleeve portion 10 flat, and a mold shape formation process for forming a mold shape in the area of the sleeve portion 10 held flat. Therefore, the desired mold shape can be produced accurately and easily.

(Modifications)
The present invention is not limited to the above-described embodiment, and various modifications and variations are possible, and these are also within the scope of the present invention.

(1) In the embodiment, an example of exposing a resist layer to light as described above has been described as the mold shape forming process for forming the mold shape. However, the present invention is not limited to this. For example, the mold shape forming process may be performed by using laser ablation, in which the surface of the sleeve portion 10 is directly processed with laser light without providing a resist layer.

(2) In the embodiment, the manufacturing method of the roll mold has been described using a roll mold used for molding optical components such as a microlens array sheet, a Fresnel lens sheet, and a diffractive optical sheet as an example. However, the present invention is not limited to this, and any component may be molded as long as the roll mold has a fine mold shape.

(3) In the embodiment, an example has been described in which the mold-shaped portion 11 is continuous around the entire circumference and in the axial direction of the roll. However, this is not limiting, and for example, the mold-shaped portion 11 may be provided in multiple regions with intervals between them.

The embodiments and variations may be used in any suitable combination, but detailed explanations will be omitted. Furthermore, the present invention is not limited to the embodiments described above.

1 Roll mold 10 Sleeve portion 11 Mold shape portion 20 Cylinder portion 100 Suction plate 100a Suction surface

Claims (5)

a planarizing step of adsorbing a portion of the flexible cylindrical sleeve portion with an adsorption plate having a planar adsorption surface to hold the portion flat;
a die shape forming step of forming a die shape in an area held on the plane of the sleeve portion;
a fixing step of fitting and fixing the sleeve portion having the mold shape to an outer periphery of a cylindrical cylinder portion;
A method for manufacturing a roll mold comprising the steps of: The method for producing a roll mold according to claim 1,
the die shape forming step includes forming a resist layer in an area held on the flat surface of the sleeve portion, exposing the resist layer, developing the exposed resist layer, and removing the exposed portion or the unexposed portion to form a die shape;
A roll mold manufacturing method comprising the steps of: The method for producing a roll mold according to claim 1,
The mold shape forming step forms a mold shape by utilizing laser ablation that directly processes an area held on the flat surface of the sleeve portion;
A roll mold manufacturing method comprising the steps of: The method for producing a roll mold according to any one of claims 1 to 3 ,
The planarizing step and the mold shape forming step are performed multiple times by changing the area to be held on the flat surface;
A roll mold manufacturing method characterized by the above. The method for producing a roll mold according to claim 4 ,
the die shape forming step is performed such that the die shapes are continuously arranged at least in a circumferential direction of the sleeve portion;
A roll mold manufacturing method comprising the steps of:

Images