JPH0270412A - Manufacturing stamper for synthetic resin molded product - Google Patents

Abstract

PURPOSE:To manufacture an optical part.product having a micro-shape on the surface with high accuracy by using a stamper of light transmission properties, flexible and non-bending in the process similar to the 2P process. CONSTITUTION:A stamper 1 is a sheet-like material constituted of a non-bonding material of light transmission properties and flexibility, processed in an enlarged or contracted shape to compensate production shape and, if necessary, shape variation of contracting or expanding in a shaping section in the following process. A base 2 is a plate-shaped material having required characteristics of a product, and a plate- shaped material disposed with a light diffusion material with a near infrared rays flat plate-shaped on the rear surface in case of an optical disk, and a lenticular lens shaped thereon in case of a transmission type screen such as a projection type television is used. A photosetting fluidizing material 3 is applied on the end of the base 2, and the stamper 1 is pressed to the base 2 in the given position gradually from its end. Surplus photosetting fluidizing material 3 is pushed out and moved, and as the shape (depth) to be shaped is very small, it can be filled easily. When the stamper 1 is pressed on the whole surface of the base 2, a given quantity of light beam 4 is directed from a light irradiation device to set the photosetting material 3.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing a synthetic resin molded article.

In particular, the present invention relates to a manufacturing method suitable for efficiently manufacturing synthetic resin molded products for optical applications having fine surface shapes such as Fresnel lenses, diffraction gratings, optical disks, and focus plates.

[Conventional technology]

In addition to purely optical products such as cameras, movie projectors, and eyeglasses that have been commonly used since ancient times, there are also home electronic devices such as compact audio discs, optical video discs, and their players, projection televisions, and facsimiles, office supplies, and optical communications and information. Optical applied products have come to be widely used in equipment, etc. In addition, improvements have been made to conventional optical products, such as putting autofocus systems into practical use and improving operability. In order to meet these needs, 1
The technological development of optical components and products with fine shapes on their surfaces, such as diffraction gratings, Fresnel lenses, matte focusing plates, and optical disks, is being promoted.

Conventionally, typical examples of this type of parts and products have been optical discs and compact discs, but in the future, in order to improve the performance, miniaturize, lower cost, and mass produce products, it will be necessary to improve the surface shape of optical parts. Miniaturization, high precision, and increasing the size of single parts are continuing to grow.

Regarding conventional optical disk manufacturing methods, please refer to ``Key Points of Optical Disk Process Technology'' supervised by Yoshihiro Okino (published by Japan Industrial Technology Center, Electronics Essentials Nα5).
), injection molding/injection compression molding, 2
P process is adopted. In injection molding and injection compression molding, thin-walled and large parts cannot be injection-filled and the transfer accuracy is incomplete.As a result, optical parts with finer surface shapes and higher precision parts are becoming larger. As detailed in pages 108 to 128 of the above-mentioned document, the 2P process has excellent transfer accuracy, but since a nickel stamper is used for the stamper, it is difficult to release the mold. There are disadvantages such as it takes a long time to process, it is difficult to obtain parts with sufficient precision (m1 products) due to mold release deformation, and the nickel stamper is easily damaged and cannot be used for a long time, resulting in poor precision. It was expensive.

Furthermore, since the stamper is made of nickel, it is opaque, so when using photocurable 2P resin, only light-transmitting materials can be used for the substrate.

[Problems to be Solved by the Invention] The above-mentioned conventional technology has problems when transferring fine surface shapes with high precision.
Transfer accuracy: There is no consideration given to mold release time, mold release deformation, and stamper life, resulting in poor accuracy, time required for mold release, the need to prepare a large number of stampers, and short stamper life. There were drawbacks. Additionally, there were restrictions on the substrates that could be used.

An object of the present invention is to provide a method for manufacturing optical components and products having fine shapes on the surface, such as diffraction gratings, Fresnel lenses, matte focusing plates, and optical disks, with high precision and at low cost.

[Means to solve the problem]

The above object is achieved by using a light-transmissive, flexible and non-adhesive stamper in a method similar to the conventional 2P process.

[Effect]

The light-transparent, non-adhesive, flexible synthetic resin sheet stamper works as a shaping mold and is also light-transparent, so it is possible to irradiate light for curing the photocurable 2P resin from the stamper side. Yes, the substrate material is not limited to light transmittance, and since it is flexible, it is possible to spread the 2P resin in order from the periphery or the center and bring it into close contact, without bending the molded product when releasing the mold. The mold can be released sequentially from the periphery.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a diagram schematically showing a process of manufacturing an optical component using the stamper of the present invention.

In the figure, 1 is a stamper, 2 is a substrate, 3 is a photocurable fluid resin material, 4 is a light beam, and 5 is a completed molded product. The stamper 1 is made of a light-transmitting, flexible, and non-adhesive material, and the shaping part (lower surface in Figure 1) has a product (molded product) shape, which shrinks or expands in subsequent processing steps as necessary. It is a sheet-like material that has been processed into an expanded or contracted shape to compensate for changes in shape. The substrate 2 is a plate-like material that has the characteristics required for the product, and in the case of an optical disc, it has the characteristics required for the product.

A near-infrared transparent flat plate such as a plastic plate such as polymethyl methacrylate or polycarbonate or a glass plate is
In the case of transmissive screens used in projection televisions, etc.
A polymethyl methacrylate plate is used, in which a lenticular lens is formed on the back surface (lower surface in FIG. 1) and a light diffusing material (such as quartz powder) is mixed therein.

To explain the manufacturing process of optical components using the stamper of the present invention, (1) a stamper 1 and a substrate 2 are prepared according to the order of (1) to (5) in FIG. 2 by a known method.

(2) Place the stamper 1 in a predetermined position and place the stamper 1 on the substrate 2 sequentially starting from the edge.
to press. The excess photocurable flowable material 3 sequentially moves to the right on the diagram so as to be pushed out. The shaped shape (depth) is minute (usually on the μm order or less, sub-μm-several nanometers for optical disks, diffraction gratings, etc.), so it is easily filled.

(3) Once the stamper 1 is pressed against the entire surface of the substrate 2, a predetermined amount of light 4 is irradiated by a known method using a light irradiation device (not shown) to harden the photocurable material 3. From the viewpoints of reaction speed (curing time), cost of light irradiation equipment, ease of handling of photocurable materials, and physical safety of light, it is preferable to cure ultraviolet curable resins with ultraviolet rays, but gamma rays, visible light, infrared rays, etc. It is not particularly limited, and may be a light beam of

(4) After the photocurable material is cured, it is sequentially released from the mold starting from the ends. Since the stamper 1 is non-adhesive and flexible, the molded product 5 can be easily released from the mold without bending.

(5) Once the mold release is completed, stamper 1 to obtain product 5
is returned to step (1) again and used repeatedly.

Next, the material of the stamper 1 will be described. As mentioned above,
In consideration of reaction rate, handling properties, etc., ultraviolet curing is preferred. In that case, the stamper forming material is
It is necessary that the ultraviolet transmittance is sufficiently large. As a result of various studies, polymethylpentene almost completely transmits ultraviolet rays with a wavelength of 300 nm or more, and is non-adhesive.
It has been found that ultraviolet curing resins such as acrylic, silicone, acrylic urethane, and epoxy resins can be easily released from the mold. A sheet-like material with a thickness of 10 μm to 5+ m, preferably 1 to 3 I, is good for handling. Average particle size 1-100μ
By blending crystal, quartz, and glass powder that does not contain iron ions, a matte surface can be easily formed and used while suppressing a decrease in ultraviolet transmittance.

The stiffness of the stamper can be adjusted by filling it with spherical quartz, crystal, or glass.

Next, a method for manufacturing the stamper will be explained. Machining may be performed by known methods, but when polymethylpentene or its compound is used as a stamper material, its hardness is lower than that of metal or ceramic, making it difficult to precisely machine minute shapes. It is. Preferably metal (eg free-cutting brass).

It is best to machine a matrix (mask) of ceramic (eg, free-cutting ceramic, McCormick: trade name) and transfer it to the stamper material. The manufacturing process will be explained using FIG. 2. Figure 2 (1) shows a mask made of metal or separately heated ceramic.
is pressed (Fig. 2 (2)) and cooled and solidified to obtain master 1.

Another embodiment will be explained using FIG. 2. FIG. 3 is a diagram schematically showing the main parts of the manufacturing process using the stamper of the present invention, and the same numbers as in FIG. 1 indicate the same parts. 7 and 7' are pressure rolls, and 8 is a light irradiation device. The roll 7.7' is moving to the right in the figure, filling the photopolymerizable material 3,
The stamper 1 is continuously press-cured and released from the mold to obtain a product 5 (FIG. 3 (2)). The roll 7' serves to maintain the flatness of the stamper 1 during photo-curing.

〔Effect of the invention〕

As described in detail above, according to the present invention, it has become possible to manufacture optical components with minute surface shapes with high precision and at low cost.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view schematically showing the process of one embodiment of the present invention, FIG. 2 is a cross-sectional view showing the manufacturing process of a stamper of the present invention, and FIG. 3 is a process showing another embodiment. FIG. 1... Stamper, 1'... Stamper material, 2...
・Substrate, 3... Photocurable material, 4... Light beam, 5...
・Optical component molded product, 8...Light irradiation device. Shiba! Figure (5) sth

Claims (1)

[Claims] 1. A light-transmissive, non-adhesive, flexible synthetic resin sheet stamper whose surface is processed into a product shape or a shape modified to compensate for dimensional changes that occur in subsequent processing steps. , characterized in that a light-curable resin material in a fluid state is filled between a plate-shaped substrate, and a light beam is irradiated while pressing the stamper onto the substrate to cure the light-curable resin material. Stamper for manufacturing synthetic resin molded products.