JP2004206837A - Disk, and method for manufacturing disk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a disk of good appearance by preventing an adhesive from flowing into the inner circumferential side or the grooves when disk base boards are stuck together. <P>SOLUTION: A disk substrate B is molded to form a concave part B4 on the boundary part between an inner circumferential side signal non-transfer area B3 and a signal transfer area B2 on the surface B1 of the side where the disk substrate B has the signal transfer area; a disk substrate A is molded to form a convex part A4 approximately at the same position as the convex part B4 on one surface A3 of the disk substrate A having no signal transfer area; thereafter, an adhesive C is supplied to the outer circumferential area from the concave part B4 of the disk substrate B having the signal transfer area or from the convex part A4 of the disk substrate A4 having no signal transfer area; and thus the disk substrates are stuck together so that the convex part A4 is fitted in the concave part B4. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a disk for bonding a disk substrate having a signal transfer region, such as a DVD-ROM, a DVD-RAM, and a DVD-R, to a disk substrate having no signal transfer region, and a method of manufacturing the disk.
[0002]
[Prior art]
As a conventional method of manufacturing a disk in which a disk substrate having a signal transfer region and a disk substrate having no signal transfer region are bonded, a method described in Patent Document 1 is known. In this document, an adhesive is applied onto a disk substrate, and the adhesive is spread by centrifugal force by a spin coating method, and then two disk substrates are bonded. However, when the disk substrates are stacked, the adhesive is also spread on the inner peripheral side, and thus the adhesive flowing into the inner peripheral side portion has a problem that the appearance of the bonded disks is deteriorated. If a large amount of the adhesive flows on the inner peripheral side, the interval between the disk substrates cannot be maintained at a predetermined interval, and a problem may occur in the accuracy in the thickness direction of the manufactured disk. Furthermore, since air flows from the inner peripheral side to the adhesive layer between the disk substrates, there is a problem that the reflection film made of aluminum or the like coated on the surface of the disk substrate having the signal transfer area is deteriorated. In FIG. 2 of Patent Document 1, a circumferential groove is formed by a stamper retainer. However, since the adhesive flows into the circumferential groove, the same problem as described above occurs.
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 8-315430 (Claims 1, 2, and 5)
[0004]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an object of the present invention is to prevent the adhesive from flowing into the inner peripheral side and into the concave groove portion, and to produce a beautiful-looking disk. Further, by preventing the adhesive from flowing into the inner peripheral side or into the concave groove portion, the disk substrates to be bonded are bonded at a predetermined interval to improve the accuracy in the thickness direction of the disk. I do. Furthermore, the object is to prevent the problem that air is circulated from the inner peripheral side to the adhesive layer between the disk substrates and the reflective film such as aluminum coated on the surface of the disk substrate having the signal transfer area is deteriorated. I do.
[0005]
[Means for Solving the Problems]
The method of manufacturing a disk according to claim 1 of the present invention is a method of manufacturing a disk in which a disk substrate having a signal transfer region is bonded to a disk substrate having no signal transfer region. Formed so that a concave portion is formed at the boundary between the inner peripheral side signal non-transfer area and the outer peripheral side signal transfer area on the side having the signal transfer area, and on one surface of the disc substrate having no signal transfer area After forming such that the convex portion is formed at substantially the same position in the radial direction as the concave portion, the outer peripheral region from the concave portion of the disk substrate having the signal transfer region or the outer peripheral region than the convex portion of the disk substrate having no signal transfer region. An adhesive is supplied to the side region, and the disk substrates are overlapped with each other so that the convex portions are fitted into the concave portions, and are bonded together.
[0006]
According to a second aspect of the present invention, there is provided a method of manufacturing a disk according to the first aspect, wherein the height of the convex portion of the disk substrate having no signal transfer region is higher than the depth of the concave portion of the disk substrate having the signal transfer region. It is characterized in that it is formed so as to have a high height, and when the disk substrates are overlapped with each other, the disk substrates are fitted so that the upper surface of the convex portion comes into contact with the bottom surface of the concave portion.
[0007]
According to a third aspect of the present invention, there is provided a disk manufactured by the method for manufacturing a disk according to the first or second aspect.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a main part of a cavity for molding a disk substrate having no signal transfer area in a disk substrate molding die used in the disk manufacturing method of the present invention. FIG. 2 is an explanatory view of the present invention when the disk substrates are bonded together, and is a view showing a cross section of the disk substrate.
[0009]
With reference to FIG. 1, a description will be given of a disk substrate molding die and disk substrate molding used in the present invention. A movable mold 2 is disposed opposite to the fixed mold 1, and a cavity 3 is formed between the two molds when the movable mold 2 is closed. In this embodiment, although not shown, when the fixed mold 1 and the movable mold 2 are combined, two cavities are formed, and at the same time, the disk substrate A having no signal transfer area and the signal transfer area Can be formed on the disk substrate B.
[0010]
As shown in FIG. 1, a blank stamper 5 having no pits in the transfer area is provided on the cavity forming surface 4 of the movable mold 2 on the side of the cavity 3 for molding the disk substrate A having no signal transfer area. It is attached by a stamper inner peripheral pressing member 6 and a stamper outer peripheral pressing member (not shown). The stamper pressing portion 6a of the stamper inner peripheral pressing member 6 is formed in a brim shape so as to project toward the fixed mold 1 side from the inner peripheral surface 6b of the stamper inner peripheral pressing member 6 and the stamper surface 5a. Also, on the surface side of the center bush 8 constituting the cavity forming surface 7 of the fixed mold 1, it faces the stamper holding portion 6 a of the stamper inner circumference holding member 6 of the movable mold 2, and is located at substantially the same position in the radial direction. A concentric groove 10 is formed around the gate 9. The depth 10a of the concave groove portion 10 is formed to be at least deeper than the height of the stamper holding portion of the stamper holding member on the side of the cavity for forming the disk substrate B having the signal transfer area described later with respect to the stamper surface or the like.
[0011]
The cavity side for molding the disk substrate B having the signal transfer area is the same as the cavity side for molding the disk substrate A without the signal transfer area except for a part thereof. An information stamper having a signal pit in a transfer area is mounted on the cavity forming surface on the mold side by a stamper inner peripheral pressing member and a stamper outer pressing member. The stamper holding portion of the cavity on the side where the disk substrate B having the signal transfer region is formed has the same diameter and the same shape as the stamper holding portion of the disk substrate A having no signal transfer region. It protrudes toward the mold side. Further, a recess for forming a stack rib is formed on the disk substrate B having a signal transfer area in the fixed mold.
[0012]
The molten resin is injected and filled into the cavity 3 and the like via the gate portion 9 and the like provided continuously with the cavity 3 and the like of the molding die of the disk substrate, and the disk substrate A having no signal transfer area is formed. The disc substrate B having the signal transfer area is simultaneously formed one by one.
[0013]
The disk substrate A having no signal transfer area is formed by a stamper pressing portion 6a of the stamper inner peripheral pressing member 6 of the movable mold 2, and a radius from the center to a surface A1 which is the front surface side when the disk substrate is bonded. It is formed so as to form a concentric concave portion A2 of about 22 mm. Also, the concave groove portion 10 of the center bush 8 of the fixed mold 1 allows the surface A3 to be bonded when the disk substrates are bonded to each other to be located at a position having substantially the same diameter as the concave portion A2 of the surface A1 which is the front surface side. Concentric convex portions A4 are formed. As for the height of the convex portion A4, since the concave groove portion 10 of the center bush 8 is formed deeper than the height of the stamper pressing portion 6a of the stamper inner peripheral pressing member 6, it is formed higher than the depth of the concave portion A2. Is done.
[0014]
Also, in molding the disk substrate B having the signal transfer area, the surface B1 on the side having the signal transfer area is provided with a movable mold that serves as a boundary between the signal transfer area B2 formed by the information stamper and the inner peripheral signal non-transfer area B3. Since the stamper holding portion protrudes toward the fixed mold, the stamper holding portion is formed so that the concave portion B4 is formed concentrically. A stack rib B6 is formed on the surface B5 on the side having no signal transfer area. The depth B7 of the recess B4 is formed so as to be shallower than the height A5 of the projection A4 of the disk substrate A having no signal transfer area. In other words, the height A5 of the protrusion A4 of the disk substrate A having no signal transfer area is formed so as to be higher than the depth B7 of the recess B4.
[0015]
The information stamper and the blank stamper 5 may be attached to the fixed mold 1 in the cavity 3 and the like of the molding die for the disk substrate. In this case, the concave groove portion 10 formed at a position facing the stamper holding portion 6a of the stamper inner peripheral holding member 6 on the side of the cavity 3 for molding the disk substrate A having no signal transfer area is provided on the movable mold 2 side. Is formed. Further, the disk substrate A having no signal transfer area and the disk substrate B having the signal transfer area may be molded by using a molding die for another disk substrate attached to another injection molding machine. Good. Further, a molding die for a disk substrate having only one cavity may be attached to one injection molding machine, and the information stamper and the blank stamper 5 may be replaced to form both disk substrates A and B. In this case, a convex portion formed by the concave groove portion of the center bush is formed on the surface B5 of the disk substrate B having the signal transfer region to be formed without the signal transfer region, and the stack rib is formed by the convex portion. Is formed.
[0016]
Next, the bonding of the disk substrate A having no signal transfer region and the disk substrate B having the signal transfer region, which is formed by the disk substrate forming die, will be described with reference to FIG. The signal transfer area B2 of the disk substrate B having the signal transfer area is coated with a reflective film and a protective film of aluminum or the like. The disk substrates A and B are bonded by a spin coating method using a bonding device (not shown). The disk substrate B having the signal transfer area on which the coating is applied is placed on the turntable of the bonding apparatus with the surface B1 on the side having the signal transfer area facing up. Then, a nozzle (not shown) is bonded to the signal transfer area B2, which is an area on the outer peripheral side of the recess B4 formed at the boundary between the signal transfer area B2 of the disk substrate B having the signal transfer area and the inner peripheral signal non-transfer area B3. Supply agent C. As the adhesive C, a UV-curable adhesive is used. The disk substrate B having the signal transfer area after or after the application of the adhesive C is rotated by a rotary table, and the adhesive C is spread to the outer peripheral side by centrifugal force.
[0017]
Next, on the disk substrate B having the signal transfer area on which the adhesive C is spread, the one side of the disk substrate A having no signal transfer area and the surface A3 on the side to be bonded, which is one side, is positioned at the same position. Layer on top. A surface A3 of the disc substrate A having no signal transfer area on the side to which the signal transfer area is adhered is protruded concentrically from the center at substantially the same position in the radial direction as the recess B4 formed on the disc substrate B having the signal transfer area. Since the portion A4 is formed, the portions are overlapped so that the protrusion A4 is fitted to the recess B4. At this time, as described above, since the height A5 of the protrusion A4 is formed higher than the depth B7 of the recess B4, the protrusion surface A6 of the protrusion A4 comes into contact with the bottom surface B8 of the recess B4. Is fitted to. As for the fitting, as long as the adhesive C can be prevented from entering, the fitting does not have to be completely fitted without any gap. In this case, the thickness of the disc is defined by the thickness of the adhesive C. You. Further, the shape may be such that the slope of the convex portion A4 abuts on the edge of the concave portion B4.
[0018]
The height A5 of the protrusion A4 is provided between the disc substrate B having the signal transfer region and the disc substrate A having no signal transfer region by fitting the protrusion A4 into the recess B4. Is calculated by subtracting the depth B7 of the concave portion B4 from the above (without taking into account the thickness of the reflection film of aluminum or the like), and a desired predetermined interval D is formed. it can. Then, by laminating the disk substrate A having no signal transfer area on the disk substrate B having the signal transfer area in which the adhesive C is spread, a part of the adhesive C is pressed and flows toward the inner peripheral side. However, since the concave portion B4 and the convex portion A4 are fitted, the adhesive C does not enter the concave portion B4. The fitting of the concave portion B4 and the convex portion A4 prevents entry of air from the inner peripheral side of the manufactured disc.
[0019]
In bonding the disk substrates to each other, a disk substrate A having no signal transfer region is placed, and an adhesive C is applied to a region A7 on the outer peripheral side of the protrusion A4, and a disk substrate B having a signal transfer region is provided. May be overlapped. Note that, in the present invention, it is not assumed that the disk substrates B having the signal transfer area are bonded to each other. Because, in the case of the disc substrate B having the signal transfer area, the recess B4 is always formed by the stamper holding portion between the signal transfer area B2 and the inner peripheral side signal non-transfer area B3, so that the signal transfer area is not provided. This is because the protrusion A4 cannot be formed at that position unlike the disk substrate A.
[0020]
【The invention's effect】
The method of manufacturing a disk according to the present invention is a method of manufacturing a disk in which a disk substrate having a signal transfer region and a disk substrate having no signal transfer region are bonded to each other. Is formed so that a concave portion is formed at the boundary portion between the inner peripheral side signal non-transfer region and the outer peripheral side signal transfer region on the surface of the disk substrate. After molding so that a convex portion is formed at the same position, an adhesive is applied to an outer peripheral region from a concave portion of a disk substrate having a signal transfer region or an outer peripheral region from a convex portion of a disk substrate having no signal transfer region. The disc substrates are supplied and overlapped so that the protrusions fit into the recesses, and the disc substrates are bonded together. This prevents the adhesive from flowing into the recesses and provides a beautiful looking disk. It is possible to produce a click. In addition, the disk substrates to be bonded are adhered while maintaining a predetermined interval, and the accuracy in the thickness direction of the disk can be improved. Further, it is possible to prevent the problem that air is circulated from the inner peripheral side to the adhesive layer between the disk substrates and the reflective film such as aluminum coated on the surface of the disk substrate having the signal transfer area is deteriorated.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part of a cavity for molding a disk substrate having no signal transfer region in a disk substrate molding die used in the disk manufacturing method of the present invention.
FIG. 2 is an explanatory view of the present invention when the disk substrates are bonded together, and is a view showing a cross section of the disk substrate.
[Explanation of symbols]
1 ... fixed mold 2 ... movable mold 3 ... cavity 4, 7 ... cavity forming surface 5 ... blank stamper 5a ... surface 6 ... stamper inner circumference pressing member 6a ... stamper Holding portion 6b Inner peripheral surface 8 Center bush 9 Gate portion 10 Groove portion 10a Depth A Depth A Disk substrate A1 having no signal transfer area Surface A2 ... concave portion A3 ... Surface on the side to be bonded (one surface)
A4 Projection A5 Height A6 Projection surface A7 Outer peripheral area B Disk substrate B1 having signal transfer area Surface B2 having signal transfer area B2 Signal transfer area B3 Inner peripheral side signal non-transfer area B4 Concave part B5 Surface B6 having no signal transfer area Stack rib B7 Depth B8 Bottom surface C Adhesive D Predetermined interval

Claims (3)

In a method of manufacturing a disk for bonding a disk substrate having a signal transfer region and a disk substrate having no signal transfer region,
Molded such that a recess is formed at the boundary between the inner peripheral signal non-transfer area and the outer peripheral signal transfer area on the side of the disk substrate having the signal transfer area having the signal transfer area,
Molded such that a convex portion is formed at substantially the same position in the radial direction as the concave portion on one surface of the disc substrate not having the signal transfer region,
The adhesive is supplied to the outer peripheral region from the concave portion of the disk substrate having the signal transfer region or the outer peripheral region from the convex portion of the disk substrate having no signal transfer region,
The disk substrates are overlapped with each other so as to fit the convex portion to the concave portion,
A method for manufacturing a disc, characterized by laminating. With respect to the depth of the concave portion of the disk substrate having the signal transfer region,
Molded so that the height of the convex portion of the disk substrate having no signal transfer area is formed high,
2. The method of manufacturing a disk according to claim 1, wherein when the disk substrates are overlapped with each other, the upper surface of the projection is fitted to the lower surface of the recess. A disk manufactured by the method for manufacturing a disk according to claim 1 or 2.

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