JPH10228679A - Device and method for press-fixing for manufacturing optical information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a defect due to burrs stuck to a substrate surface and to improve quality by forming a surface of a pressing plate of a press-fixing device with material softer than the substrate surface of a recording medium and giving it a cushionlike role in manufacture of an optical information recording medium. SOLUTION: The surfaces of upper/lower two disk like pressing plates 11a, 11b of the press-fixing device 10 are formed by the material having hardness of 70-80% of the surface hardness of the substrates 41a, 41b of the optical information recording medium 40 at a hardness display according to a measuring method of a Rockwell or JIS-K-6301. For instance, when the substrate is polycarbonate, the material such as ABS resin and nylon, etc., is used. Thickness of surface layers 12a, 12b is made 0.5-10mm of an extent that projections due to the burrs occurring in a substrate circumferential part at a press-fixed time is buried in the surface layer, and the surfaces of the substrates 41a, 41b become an adhesive state with the surface of the pressing plates 11a, 11b. The matter that the substrate surface is injured due to the burrs is prevented, and two sheets of substrates are stuck to each other parallel and precisely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure bonding apparatus used for producing an optical information recording medium having a sandwich structure in which two disc-shaped substrates or a disc-shaped substrate and a disc-shaped protective substrate are bonded to each other. And a crimping method. In particular, the present invention relates to an improvement of a pressure plate provided in a pressure bonding device used when bonding these substrates.

[0002]

2. Description of the Related Art Recently, a DVD (Digital Video Disk) capable of achieving a large recording capacity has been actively studied as an optical information recording medium from which information can be read or written using a laser beam. DVDs are read-only (DVD-ROM) or write-once DVs depending on the application.
D (DVD-R) or rewritable DVD (DVD-R
AM) has been proposed. These optical information recording media are
Two disk-shaped substrates each provided with a layer from which information can be read or written by laser light, or a disk-shaped substrate provided with a layer from which information can be read or written by laser light, and a disk having the same shape as the substrate Each of the substrates has a sandwich type structure in which the respective substrates are overlapped with each other so that these layers are on the inner side, and both substrates are bonded together via an adhesive layer. For example, taking a write-once DVD as an example, the optical information recording medium 40 has a guide groove (pre-group) for tracking as shown in FIG. Disc-shaped substrates 41a and 41b having a recording layer 46b, dye recording layers (recording layers) 42a and 42b formed on the disc-shaped substrate, and reflection layers 43a and 43b and a protective layer 44a formed thereon.
In this structure, two disks 44b in order are bonded together with an adhesive layer 45 with the respective recording layers facing inward. Incidentally, these optical information recording media, for example,
"Nikkei Electronics" (Special Issue: Optical Disk, 199
5 years, no. 630) and “Nikkei New Media” (separate volume [DVD], published in 1995).

[0003]

SUMMARY OF THE INVENTION The present inventor has studied a crimping device conventionally used in manufacturing the above-mentioned optical information recording medium having a sandwich structure.
As the crimping device, for example, a device 30 provided with two disk-shaped pressing plates 31a and 31b as shown in FIG. 3 is generally used. An optical information recording medium having a sandwich structure is manufactured by the following steps using such a pressure bonding apparatus. The manufacturing method of the write-once type DVD described above will be briefly described. First, a recording layer is formed on one side of a disc-shaped substrate using a spin coater or the like, and a reflection layer is provided on the recording layer by masking or the like by vapor deposition or the like. Further, a protective layer made of a curable resin is provided on the reflective layer. Thus, two disk-shaped substrates having three layers stacked are prepared. Next, an adhesive is applied on the protective layer of one or both substrates, and these substrates are overlapped such that each layer is on the inside. After the two substrates are overlapped, the two substrates are sandwiched between two pressing plates 31a and 31b of the crimping device shown in FIG. 3 and pressed from outside the substrates, whereby the two substrates are bonded in parallel. An optical information recording medium having a sandwich type structure can be manufactured. The two pressing plates provided in the pressure bonding apparatus are usually made of stainless steel having a larger outer shape than the disk-shaped substrate as shown in the drawing so that a uniform pressing operation can be performed over the entire surface of the substrate.

[0004] The disk-shaped substrate has a donut shape having a circular hole at the center thereof, and a substrate molded with a resin material such as polycarbonate is often used. For this reason, projections such as burrs are likely to occur at the peripheral portion of the substrate, particularly at the outer peripheral portion. According to the study by the present inventors, it has been found that the following problems are caused by the occurrence of such protrusions, for example. That is, while moving the molded substrate according to the process, burrs are peeled off from the peripheral portion, the fragments adhere to the substrate surface, and in that state, the substrate is sent into the pressure bonding apparatus, At the time of pressure bonding, the surface of the substrate is scratched by the stainless steel pressure plate, and the thickness of the substrate is uneven due to protrusions at the peripheral edge of the substrate, and it is difficult to apply pressure uniformly to the entire surface of the substrate. It has been found that problems such as difficulty in bonding in parallel with high accuracy occur. If the laser beam is prevented from entering the correct track due to scratches on the substrate surface, or if the parallelism between the two substrates is insufficient, the laser beam will not be able to scan a predetermined track accurately, and the output will decrease. Easy to cause. Although a process for removing burrs can be provided after molding the substrate, it is not a preferable method from the viewpoint of productivity because the number of manufacturing steps increases.

An object of the present invention is to provide a crimping apparatus and a method for crimping two disc-shaped substrates which are suitably used for manufacturing an optical information recording medium having a sandwich structure. In particular, according to the present invention, even if burrs are attached to the substrate surface, the surface of the substrate is not damaged, and the thickness of the peripheral portion of the substrate is uneven due to projections such as burrs. It is another object of the present invention to provide a crimping apparatus and a crimping method capable of bonding two disc-shaped substrates in parallel with high accuracy.

[0006]

The present inventor has found that the above problems can be solved by forming the surface of the pressure plate with a material softer than the substrate, instead of a hard material as in the prior art. The present invention has been reached. That is,
Even if there are burrs on the surface of the substrate, or if there are variations in the thickness due to burrs on the periphery of the substrate, the surface of the pressure plate is formed of a material softer than the substrate during crimping. Since it functions as a cushion, it can absorb irregularities on the substrate surface. Therefore, it is possible to suppress the generation of scratches on the substrate surface due to burrs and to perform a more uniform pressing operation on the substrate, and to bond two substrates in parallel with high accuracy. Become.
As a result, a higher quality optical information recording medium can be manufactured.

According to the present invention, there are provided two disk-shaped substrates each provided with a layer from which information can be read or written by a laser beam, or a disk-shaped substrate provided with a layer from which information can be read or written by a laser beam. A disk-shaped protective substrate having the same shape as the substrate, the substrates are overlapped with each other such that these layers are on the inside, and pressure is applied from the outside of each substrate,
An optical information recording medium manufacturing pressure bonding apparatus including at least one pressure plate having a surface formed of a material softer than the surface of the substrate for bonding the substrates together via an adhesive layer.

The present invention is also directed to two disk-shaped substrates each provided with a layer from which information can be read or written by laser light, or a disk-shaped substrate provided with a layer from which information can be read or written by laser light. And a disk-shaped protective substrate having the same shape as the substrate, the substrates are overlapped with each other such that these layers are on the inner side, and each of the substrates has a surface formed of a material softer than the surface of the substrate from the outside. There is also a pressure bonding method for manufacturing an optical information recording medium in which the substrates are bonded to each other via an adhesive layer by pressing with at least one pressing plate.

The preferred embodiments of the present invention are as follows. (1) The surface of the pressure plate is formed of a material having a hardness of 80% or less and 10% or more (more preferably, 80% or less, 40% or more) of the hardness of the substrate surface in Rockwell hardness display. ing. (2) When the surface of the pressure plate is 80% or less of the hardness of the surface of the substrate as indicated by hardness according to the measurement method of JIS-K-6301,
% Or more (more preferably, 80% or less, 30% or more). (3) The surface of the pressure plate is formed of a rubber material. (4) The surface of the pressure plate is made of silicone rubber or chloroprene rubber. (5) The substrate is formed from polycarbonate.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A crimping apparatus for manufacturing an optical information recording medium (hereinafter, may be simply referred to as a crimping apparatus) and a crimping method according to the present invention will be described with reference to the accompanying drawings. FIG.
FIG. 1 is a schematic cross-sectional view of a preferred example of a pressure bonding apparatus for manufacturing an optical information recording medium according to the present invention. In the figure, the write-once DVD described above as an optical information recording medium is shown sandwiched between two pressure plates of a crimping device. As shown in FIG. 1, the crimping device 10 includes two upper and lower disc-shaped pressure plates 11.
a and 11b. And the surface 12 of this pressure plate
a and 12b are formed of a material softer than the surface of the disk-shaped substrate of the optical information recording medium. Therefore, the material of the surface of the pressure plate is not particularly limited as long as the material meets such conditions.

In the present invention, the surface of the pressure plate is
(I) 80 of the hardness of the surface of the substrate in Rockwell hardness display
% Or less, 10% or more (more preferably, 40% to 80%).
%). Also, the surface of the pressure plate is (II) JIS-K-630
In the hardness display according to the measurement method 1 (the method for measuring the hardness of the rubber material: measurement by a JIS spring hardness tester), 80% or less of the hardness of the surface of the substrate and 10% or more (more preferably 3%)
(0% to 80%). However, as a material for the disc-shaped substrate of the optical information recording medium, generally, polycarbonate is preferably used as described above, and as a preferable resin material other than polycarbonate, for example, acrylic resin, polyvinyl chloride resin, and vinyl chloride are used. Copolymers with other polymers,
Resin materials such as epoxy resins, amorphous polyolefin resins, and polyester resins are also used.
For this reason, the surface of the pressure plate according to the present invention, specifically,
What is necessary is just to be formed of a soft material with respect to these resin materials, and preferably, a material that meets the conditions shown in the above (I) and (II) is selected and used.

In the case where the disc-shaped substrate of the optical information recording medium is formed of polycarbonate, representative examples of the material suitable for the surface of the pressure plate according to the present invention are given below. (I) A material having a hardness of 80% or less and 10% or more of the hardness of the surface of the polycarbonate substrate in Rockwell hardness display. The values in parentheses are representative values of Rockwell hardness display. The hardness of a polycarbonate substrate for a normal optical information recording medium by Rockwell hardness display is 120. (1) ABS (acrylonitrile-butadiene-styrene) resin Extrusion, high impact (95) 20-40% glass-filled (83) (2) Nylon (linear aliphatic polyamide resin) Nylon 6 (elastomer, (95) (3) polypropylene (PP) filled (95), unfilled (95), copolymer (73),
Rubber modification, impact resistance (68) (4) Cellulose resin Ethyl cellulose (83) Cellulose acetate (80) Butyric acid / cellulose acetate (for molding) (74) Butyric acid / cellulose acetate (for sheet) (73) Cellulose propionate (Molding) (66) (5) Fluororesin Polyethylene trifluoride chloride (ethylene-modified (E-CTF
E)) (95) Polyethylene trifluorochloride (CTFE) (85) Polyfluoroethylene (modified with ethylene, filled with glass) (7)
4) Polyfluorinated ethylene (ethylene modified, ETFE) (6)
0) (6) Polyurethane (PU) resin Polyurethane (thermoplastic) (50)

(II) A material having a hardness of not more than 80% and not less than 10% of the hardness of the substrate surface in terms of hardness according to the measuring method of JIS-K-6301 (the measuring method of rubber material hardness). The values in parentheses are representative values of hardness display according to the measurement method of JIS-K-6301. Also JIS-K-63
The hardness of the polycarbonate substrate in the hardness display according to the measurement method of No. 01 is 100. (1) Urethane rubber Pure rubber compound (78) (2) Epichlorohydrin rubber (CHR) Carbon compound (75), silicate compound (65), carbon / oil compound (62) (3) Fluoro rubber Carbon compound (73, 70), pure rubber compound (60) (4) chlorinated polyethylene (CPE) carbon compound (73, 70), clay / oil compound (66) (5) chlorsulfonated polyethylene (CSM) Carbon blend (73) (6) Chloroprene rubber (CR) Carbon blend (72), clay / oil blend (6)
8), pure rubber compound (40) (7) acrylonitrile-butadiene rubber (NBR) carbon compound (72, 62, 58, 56), clay compound (64) (8) ethylene-propylene rubber (EPDM) Carbon blend (70), clay blend (64) (9) Acrylic rubber (ACM) Carbon blend (68), calcium carbonate blend (6
7) (10) Styrene-butadiene rubber (SBR) clay compound (67), carbon compound (50)

(11) Solution-polymerized styrene-butadiene rubber (solution-SBR) carbon / oil blend (62) (12) polysulfide rubber carbon blend (67) (13) Propylene oxide rubber (POR) carbon / oil Compound (66), pure rubber compound (4
7) (14) Natural rubber (NR) Silicate / oil compound (65), pure rubber compound (42) (15) Silicone rubber For high strength (65), for general molding (55) (16) Butadiene rubber (BR) Carbon / oil blend (65), carbon blend (4
0) (17) Isoprene rubber (IR) Carbon blend (57), calcium carbonate blend (5
2), pure rubber compound (40) (18) isobutene-isoprene rubber (IIR) talc compound (53), carbon compound (50) Rockwell hardness of the above resin materials and JIS spring hardness test of rubber materials The hardness data from the machine is described in “Plastic, Rubber,
Handbook for the Optimal Selection Criteria for Adhesives "(Compiled by the Overseas Technical Data Institute Compilation Committee, published March 31, 1977)
It is described in.

[0015] The surface of the pressure plate according to the present invention is preferably formed of a rubber material because of its high elasticity among the above materials, and among the rubber materials, is formed of silicone rubber or chloroprene rubber. Is preferred.

The surface of the pressure plate according to the present invention may be formed of any of the above-mentioned materials, and the method of processing the surface of the pressure plate is not limited. For example, a method of pasting a sheet made of the above-mentioned material prepared in advance on the surface of a conventional pressing plate (pressing plate main body) or a method of applying a material in a solution state particularly in the case of a rubber material may be used. it can. There is no particular limitation on the thickness of the layer formed of a soft material, but a protrusion formed by burrs formed on the peripheral edge of the substrate at the time of pressure bonding is embedded in the layer, and the substrate surface and the pressure plate surface are brought into close contact with each other. Preferably. Usually, the thickness of this layer is preferably provided in the range of 0.5 to 10 mm, and more preferably in the range of 1 to 5 mm. When attaching a sheet to the surface of the pressure plate,
There is no problem even if an appropriate hole is formed in this sheet as long as sufficient parallelism between the substrates is maintained during pressure bonding.

In the pressure bonding apparatus of the present invention, as described above, it is preferable that both surfaces of the two disk-shaped pressing plates are formed of a material softer than the surface of the disk-shaped substrate. Alternatively, only the surface may be formed of a material softer than the surface of the disk-shaped substrate. Further, the pressure bonding apparatus of the present invention is characterized by the material of the surface of the pressure plate as described above, and other requirements (for example, the size of the pressure plate, the material of the pressure plate body, etc.) are particularly limited. Not done. Therefore, other requirements can be configured in the same manner as the conventional one. For example, as the material of the pressing plate body, a material such as stainless steel or glass is used.

Next, a brief description will be given of a pressure bonding method for manufacturing the optical information recording medium according to the present invention using the above-described pressure bonding apparatus. The pressure bonding method of the present invention is advantageously used in the final step of bonding two disc-shaped substrates when manufacturing an optical information recording medium having a so-called sandwich structure. An optical information recording medium having a sandwich structure is a read-only DVD-R as described above.
OM, write-once DVD-R, and rewritable DVD-RAM are included. Hereinafter, a write-once DVD-R will be described as an example.

FIG. 2 is a diagram schematically showing a state in which two disk-shaped substrates are overlapped and pressed by using the pressing device of FIG. First, two disc-shaped substrates in an overlapping state are prepared. The disc-shaped substrates 41a and 41b are molded with resin in the same manner as in the related art, and burrs 47a and 47b are formed on the outer peripheral portions as shown in the figure. On one surface of the disc-shaped substrate, a recording layer, a reflective layer, and a protective layer are sequentially formed in a laminated state according to a conventional method. Two substrates having such three layers stacked are prepared. And apply an adhesive on the protective layer of one or both substrates,
The two substrates are overlaid such that these layers are on the inside. Next, the two substrates 41a, 4
1b is placed on the lower surface 12a of the upper pressing plate 11a, 11b while adjusting the center so that its center is at a predetermined position. Then, pressure is applied to both pressurizing plates to bond the substrates together. The surface of the pressure plate according to the present invention,
Since it is formed of a material softer than the surface of the substrate, even if burrs are present on the outer peripheral portion of the substrate as shown in the figure, the unevenness due to the burrs is almost completely absorbed by this layer. Therefore,
Irregularities due to burrs are not transmitted to the pressure plate main body, and the pressure applied to the pressure plate is uniformly applied to the substrate. This makes it possible to bond the two substrates in parallel with high accuracy. The above optical information recording medium is an example manufactured using a substrate having a structure in which a recording layer, a reflective layer, and a protective layer are sequentially provided on both of two substrates. Similarly, when a substrate provided with these layers is used and the other substrate is configured as a disc-shaped protective substrate, it is also possible to bond two substrates in parallel with high accuracy.

[0020]

According to the present invention, the use of the pressure bonding apparatus provided with the pressing plate according to the present invention prevents the substrate surface from being damaged even if burrs are adhered to the substrate surface, and the peripheral portion is not damaged. Even when a disk-shaped substrate having projections such as burrs is used, two substrates can be bonded in parallel with high accuracy.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a preferred example of a pressure bonding apparatus for producing an optical information recording medium according to the present invention.

FIG. 2 is a diagram schematically showing a state in which two disk-shaped substrates are pressed by using the pressing device of FIG. 1;

FIG. 3 is a schematic cross-sectional view of an example of a conventional pressure bonding apparatus for manufacturing an optical information recording medium.

FIG. 4 is a schematic partial sectional view of a conventional optical information recording medium.

[Explanation of symbols]

 10, 30 Crimping device for manufacturing optical information recording medium 11a, 11b, 31a, 31b Disc-shaped pressing plate 12a, 12b Surface of disc-shaped pressing plate 40 Optical information recording medium 41a, 41b Disc-shaped substrate 42a, 42b Recording layer 43a, 43b Reflective layer 44a, 44b Protective layer 45 Adhesive layer 46a, 46b Circular hole of disc-shaped substrate

Claims (7)

[Claims] 1. A disc-shaped substrate provided with a layer on which information can be read or written by laser light, or a disc-shaped substrate provided with a layer on which information can be read or written by laser light, and the substrate A disk-shaped protective substrate having the same shape as the above, the substrates are overlapped such that these layers are on the inside, and pressure is applied from the outside of each substrate, and the substrates are bonded to each other via an adhesive layer. A pressure bonding apparatus for producing an optical information recording medium, comprising at least one pressure plate having a surface formed of a material softer than the surface of the substrate. 2. The crimping apparatus according to claim 1, wherein the surface of the pressure plate is formed of a material having a hardness of 80% or less and 10% or more of the hardness of the surface of the substrate in Rockwell hardness. 3. The surface of the pressure plate is JIS-K-6301.
2. The crimping apparatus according to claim 1, wherein the crimping apparatus is formed of a material having a hardness of 80% or less and 10% or more of the hardness of the surface of the substrate in the hardness display according to the measurement method described above. 4. The pressure bonding apparatus according to claim 1, wherein the surface of the pressure plate is formed of a rubber material. 5. The pressure bonding apparatus according to claim 1, wherein the surface of the pressure plate is made of silicone rubber or chloroprene rubber. 6. The pressure bonding apparatus according to claim 1, wherein the substrate is formed of polycarbonate. 7. Two disc-shaped substrates each provided with a layer from which information can be read or written by laser light, or a disc-shaped substrate provided with a layer from which information can be read or written by laser light, and said substrate And a disk-shaped protective substrate having the same shape, the substrates are overlapped with each other such that these layers are on the inside, and at least one having a surface formed of a material softer than the surface of the substrate from the outside of each substrate. A pressure bonding method for manufacturing an optical information recording medium in which the substrates are bonded to each other via an adhesive layer by pressing with a pressing plate.