JP4167422B2 - Mold apparatus for manufacturing disk-shaped substrate material and method for manufacturing disk-shaped substrate material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mold apparatus and a manufacturing method for manufacturing a disk-shaped substrate material for an optical disk.
[0002]
[Prior art]
Generally, a disc-shaped optical recording medium (optical disc) such as a CD (Compact Disc) or a DVD (Digital Versatile Disc) is attached to a stamper formed in a mastering process in a mold installed in an injection molding machine. A resin-made disc-shaped substrate material is formed by injection molding the area that becomes the information recording surface, and a recording layer that can be recorded on this is formed, and a reflective layer that is provided so as to be reproducible is formed. In addition, a protective layer made of resin is provided thereon.
[0003]
These optical discs record and / or reproduce information by rotating while irradiating a predetermined laser beam through the disc-shaped substrate material.
[0004]
Conventionally, optical discs are manufactured by attaching a stamper in the cavity of a mold during substrate injection molding, and transferring the surface irregularities to the surface of the disc-shaped substrate material to form an area that becomes an information recording surface. Then, after forming the reflective film and the recording layer configured to be recordable, in the next step, a resin protective layer or the like is formed by, for example, a spin coating method to obtain a finished product.
[0005]
The CD or DVD usually has a central hole (15 mm in diameter here) for use in positioning of an optical disk at the center position during recording and / or reproduction.
[0006]
Further, the stamper provided in the mold as described above usually has a through hole larger than the center hole of the optical disc, and positioning or injecting a molten material in the mold using this through hole. It is used for the purpose of doing. This through hole has a diameter of 20 to 38 mm in the case of a CD or DVD.
[0007]
On the other hand, recently, for example, as disclosed in JP-A-8-235638, a support layer (protective layer) that does not require light transmission, that is, no optical thickness requirement, is used as a disk-shaped substrate material (substrate). As a thick film by injection molding, a reflective film provided to make information reproducible or a recording layer made recordable is formed on the information recording surface side of this substrate, and then recorded and reproduced on it. An optical disk manufactured by a manufacturing method in which a light transmission layer is formed by a transparent resin layer that can transmit a laser beam for industrial use has attracted attention.
[0008]
As shown in FIG. 5, the optical disk is manufactured by using a sprue runner 3 solidified in a gate at the time of injection molding together with the central portion of the substrate 2 in the mold apparatus 1 as shown in FIG. By separating and removing with the cut punch 5B, a circular center hole 2A is opened at the center, and further, after forming the reflective film and the recording layer configured to be recordable, in the next step, for example, by spin coating A finished product is formed by forming a protective layer made of resin or a light transmitting layer made of a light transmitting resin.
[0009]
In the mold apparatus 1, the substrate 2 is formed in the cavity 6 between the upper fixed mold 4 and the lower movable mold 5, and as a component of the fixed mold 4, The sprue bush 4A, the stamper holder 4B, and the mirror surface block 4C are arranged concentrically in order from the mold center. The stamper 7 is held on the fixed mold 4 via a stamper holder 4B, and molten resin is injected into the cavity 6 from the sprue bush 4A.
[0010]
Further, as the components of the movable mold 5, the projecting pin 5A, the cut punch 5B, the projecting sleeve 5C, the bush 5D, the mirror block 5E, and the outer ring 5F are similarly arranged concentrically in order from the mold center.
[0011]
On the information recording surface of the substrate 2, a concavo-convex pattern that becomes the information area 2 </ b> B is formed by a pattern previously formed on the stamper 7. The opposite side surface of the information area 2 </ b> B is a mirror surface of the movable mold 5. The mirror surface 5E is formed on a mirror surface, and the mirror surface block 5E constitutes an integral bulk so that no mold parting line or step is generated on the mirror surface side.
[0012]
Since this mirror surface corresponds to the side on which laser light is incident upon recording / reproduction in a conventional CD or DVD, at least an information recording area cannot be provided with a mold dividing line or a step.
[0013]
[Problems to be solved by the invention]
As described above, in order to satisfy the optical characteristics of an optical disc in a conventional mold, a uniform integrated mirror block is essential, and the mold on the side opposite to the information recording surface is divided into molds due to various restrictions. Since a line or a step is not provided and a cooling circuit cannot be provided in a part of the component part on the mold structure, problems such as a radial warp of an injection-molded substrate occur. This improvement in mechanical accuracy, such as warping, can be dealt with by dividing the cooling circuit of the mirror block or changing the cross-sectional area and the distance to the cavity. .
[0015]
The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide a mold apparatus and a manufacturing method capable of manufacturing a disk-shaped substrate material for an optical disk with high warpage accuracy.
[0016]
[Means for Solving the Problems]
As a result of earnest research, the present inventor is a surface opposite to the information recording surface of the disk-shaped substrate material in the mold apparatus for injection molding which is one of the optical disk manufacturing processes, and corresponds to the information area. At least one mold parting line is provided at a position so that the mold can be divided, and a cooling circuit for the divided molds can be freely set, so that the disk-shaped substrate material formed by injection molding can be used. to improve the accuracy of warpage was to solve the above problems.
[0017]
That is, the above problems can be solved by the following invention.
[0018]
(1) A mold , a stamper disposed in a cavity of the mold, and a cooling circuit for cooling the mold , various functional layers are formed on a predetermined area on the information recording surface side, and A mold apparatus for producing a disk-shaped substrate material, which is an optical disk configured to be capable of recording and / or reproducing information, by injection molding, wherein the various information is provided on the information recording surface side of the disk-shaped substrate material. An information area in which information can be recorded and / or reproduced by forming a functional layer is provided, and the mold has a mirror block in contact with the stamper on the side opposite to the pattern for forming an information recording surface, said disk-like substrate material, at least one of the mold parting lines in the information area and the area corresponding to the mirror block on the opposite side to the information recording surface, said cooling circuit , The mold parting line by a separation disk-shaped substrate material manufacturing die apparatus, characterized in that is provided independently for each of the plurality of mold components corresponding to the cavity surface.
[0019]
(2) The disk-shaped substrate material according to (1) for an optical disk, wherein the mold parting lines are two mold parting lines formed by radial ends of a nested bush in the mold. Manufacturing mold equipment.
[0020]
(3) pre-Kikin type, in the disc-shaped substrate material, characterized by having at least visually recognizable processing pattern in a region corresponding to the information area on the opposite side to the information recording surface (1) Or the die apparatus for disk-shaped board | substrate material manufacture as described in (2) .
[0021]
(4) In the mold apparatus for manufacturing a disk-shaped substrate material according to (1), while cooling a plurality of mold components corresponding to the cavity surfaces separated by the mold dividing line independently, A method for producing a disc-shaped substrate material for an optical disc, wherein a resin is injected into the disc.
[0022]
(5) The nested bush separated by the mold parting line in the disk-shaped substrate material manufacturing mold apparatus of (2), and the mold adjacent to the nested bush through the mold separating line. A method for producing a disc-shaped substrate material for an optical disc, wherein a resin is injected into the cavity while cooling and controlling mold components independently.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings.
[0024]
First, referring to FIG. 1, a disk-shaped substrate material for a disk-shaped optical recording medium (hereinafter referred to as an optical disk) manufactured by a mold apparatus 30 (see FIG. 2) according to a first example of an embodiment of the present invention. explain. Here, the diameter of the center hole of the optical disk obtained from the disk-shaped substrate material is 15 mm.
[0025]
In the method of manufacturing the optical disc 20, first, the stamper 10 (see FIG. 1A) on which the information recording surface forming pattern 15 is formed is set in the mold apparatus 30, and the cavity 31 of the mold apparatus 30 is set. The molten synthetic resin is injected into the disc-shaped substrate material 12.
[0026]
The pattern 15 is formed on the surface of the stamper 10 on the cavity 31 side when attached to a fixed mold 32 (described later), and forms a region that becomes the information recording surface 12A of the disk-shaped substrate material 12. is there. This pattern 15 is provided in accordance with the format of the obtained optical disk 20.
[0027]
During the injection molding process, the central portion of the disc-shaped substrate material 12 is removed by a cut punch while the sprue runner 14 is attached integrally to form a central hole 28. The disk-shaped substrate material 12 is taken out from the mold apparatus 30 (see FIG. 1B), subjected to a sputtering process (see FIG. 1C), a spin coating process (see FIG. 1D), etc. It becomes.
[0028]
As shown in FIG. 2, the mold apparatus 30 has an upper fixed mold 32 and a lower movable mold 34, and the stamper 10 is disposed on the fixed mold 32 side and is melt-synthesized. It is arranged on the same side as the gate 33 for injecting resin.
[0029]
The fixed mold 32 is configured by concentrically arranging a sprue bush 36, a stamper holder 38, and a mirror block 40, which are mold components thereof, in the radial direction from the center side.
[0030]
Further, the movable die 34 has a protruding pin 42, a cut punch 44, a protruding sleeve 46, a first bush 48, a second bush 50, and an outer peripheral ring 52 as concentric circles in order from the center in the radial direction. Arranged in a shape. The surfaces of the first bush 48 and the second bush 50 are formed with a concavo-convex pattern forming surface 54 that is visible, such as textured processing, fine steps such as letters and patterns.
[0031]
A mold parting line 49 between the first bush 48 and the second bush 50 is located in an area on the opposite side surface corresponding to the pattern 15 in the stamper 10.
[0032]
That is, the information area 13 is formed on the information recording surface 12A side of the disk-shaped substrate material 12 by the pattern 15, but the disk-shaped substrate material 12 is positioned at a position corresponding to the surface on the opposite side of the information area 13. A mold parting line 49 is arranged.
[0033]
Accordingly, the temperature of the first bush 48 and the second bush 50 can be appropriately controlled by providing the cooling circuits 48A and 50A separately. Furthermore, the radial position of the mold parting line 49 can also be set arbitrarily. Thereby, the dimensional accuracy of the disk-shaped board | substrate material 12 by which injection molding was carried out, especially the precision of curvature can be improved.
[0034]
The disc-shaped substrate material 12 solidified or semi-solidified in the mold apparatus 30 is first pushed out together with the sprue runner 14 by the cut punch 44 to form the center hole 28.
[0035]
Next, after the movable mold 34 is separated from the fixed mold 32, the sprue runner 14 and the disc-shaped substrate material 12 are separated from the movable mold 34 by the protruding pins 42 and the protruding sleeve 46.
[0036]
A disk-side mold parting line 12B corresponding to the mold parting line 49 is formed on the surface of the disc-shaped substrate material 12 taken out from the mold unit 30 on the side opposite to the information area 13 on the information recording surface 12A. ing.
[0037]
Further, as described above, the first bush 48 and the second bush 50 are separated by the mold parting line 49 and can be independently controlled by the cooling circuits 48A and 50A. Since the radial position can also be set arbitrarily, the warpage accuracy of the disk-shaped substrate material 12 taken out can be increased.
[0038]
In addition, since a visible concavo-convex pattern forming surface 54 is formed on the surfaces of the first bush 48 and the second bush 50, this is transferred to the side surface of the disc-shaped substrate material 12 opposite to the information recording surface 12A. Various uneven patterns 12C are formed by molding.
[0039]
As shown in FIG. 1C, for example, the disk-shaped substrate material 12 released from the mold apparatus 30 is sputtered with an inorganic material 16 to form a thin film 17 on the information recording surface 12A. Reference numerals 16A and 16B in FIG. 1C respectively indicate an outer peripheral mask and an inner peripheral mask used for the spack ring.
[0040]
As shown in FIG. 1D, a resin material for forming the light transmissive resin layer 19 is applied to the disk-shaped substrate material 12 on which the thin film 17 has been formed by sputtering, for example, by spin coating. Here, an ultraviolet curable resin is used, and after application, it is cured by irradiating ultraviolet rays. If necessary, the optical disc 20 is completed through a process such as hard coating.
[0041]
In the mold apparatus 30 according to the first example of the above-described embodiment, one mold parting line 12B is formed on the side of the information recording surface 12A of the disc-shaped substrate material 12 opposite to the information area 13. However, the present invention is not limited to this, and the first bush 62, the second bush 64, the second bush 64, the second bushing 64, and the like, for example, like the mold device 60 of the second example of the embodiment of the present invention shown in FIG. 3 bushing 66 is provided, and a mold parting line 65 is provided between the second bushing 64 and the third bushing 66, and a disc side mold parting line is provided on the opposite side of the information area 73 of the disc-like substrate material 72. 72B may be formed, and cooling circuits 62A, 64A, and 66A may be provided independently for each bush so that the temperature control of each bush can be made finer.
[0042]
Furthermore, like the mold apparatus 80 of the third example of the embodiment of the present invention shown in FIG. 4, the third nested shape is formed at a position corresponding to the opposite side surface of the information area 83 of the disk-shaped substrate material 82. A bush 86 may be provided so that two mold parting lines 82 </ b> B and 82 </ b> C are formed on the opposite side of the information area 83.
[0043]
4, reference numeral 84 denotes a first bush, 85 denotes a second bush, 86B and 86C denote mold parting lines, and the nested third bush 86 is attached to the surface side of the second bush 85. The first to third bushes 84, 85, 86 are provided with cooling circuits 84A, 85A, 86A, respectively.
[0044]
In the mold apparatus 80, the design can be easily changed by applying a texture, a character, a pattern, or the like to the nested third bush 86.
[0045]
In FIG. 3 and FIG. 4, the mold components and the like are omitted by attaching the same reference numerals as those in FIG. 2 to the same parts as those in the mold apparatus 30. And
[0046]
【The invention's effect】
The present invention has an excellent effect that can be produced configured as hereinbefore, the disk-shaped substrate material warping accuracy is not high, as described above.
[Brief description of the drawings]
FIG. 1 is a perspective view schematically showing a disk-shaped substrate material manufactured by a mold apparatus of the present invention and a process of manufacturing an optical disk therefrom. FIG. 2 is a disk-shaped substrate according to a first example of an embodiment of the present invention. FIG. 3 is a sectional view showing a mold apparatus for manufacturing a disk-shaped substrate material according to a second example of an embodiment of the present invention. FIG. 4 is a sectional view showing a mold apparatus for manufacturing a material. Sectional view showing a mold apparatus for manufacturing a disk-shaped substrate material according to a third example. FIG. 5 is a cross-sectional view showing a conventional mold apparatus for manufacturing a disk-shaped substrate material.
DESCRIPTION OF SYMBOLS 10 ... Stamper 12, 72, 82 ... Disc-shaped board | substrate material 12B, 72B, 82B, 82C ... Disc side mold parting line 12C ... Uneven pattern 13, 73, 83 ... Information area 14 ... Sprue runner 15 ... Pattern 20 ... Optical disc 28 ... Center hole 30, 60, 80 ... Mold device 32 ... Fixed die 34 ... Movable die 48, 62, 84 ... First bush 48A, 50A, 62A, 66A, 84A, 85A, 86A ... Cooling circuit 49, 65, 86B, 86C ... mold parting lines 50, 64, 85 ... second bush 54 ... concavo-convex pattern forming surfaces 66, 86 ... third bush

Claims (5)

It has a mold , a stamper disposed in the cavity of the mold, and a cooling circuit for cooling the mold , various functional layers are formed on a predetermined area on the information recording surface side, and information recording And / or a mold apparatus for producing a disc-shaped substrate material to be an optical disc configured to be reproducible by injection molding, on the information recording surface side of the disc-shaped substrate material, the various functional layers. An information area in which information can be recorded and / or reproduced by formation is provided, and the mold has a mirror surface block in contact with the side opposite to the information recording surface forming pattern of the stamper, and the disk shape of the substrate material, at least one of the mold parting lines in an area corresponding to the information area and the mirror block on the opposite side to the information recording surface, said cooling circuit, before Mold parting line by a separation disk-shaped substrate material manufacturing die apparatus, characterized in that is provided independently for each of the plurality of mold components corresponding to the cavity surface. 2. The mold apparatus for manufacturing an optical disc-like substrate material according to claim 1, wherein the mold parting line is two mold parting lines formed by radial ends of a nested bush in the mold. . 3. The metal mold according to claim 1, wherein the mold has at least a visually recognizable processing pattern in a region corresponding to the information area on the side surface opposite to the information recording surface of the disk-shaped substrate material. Mold device for manufacturing disc-shaped substrate materials. In the mold apparatus for manufacturing a disk-shaped substrate material according to claim 1, a plurality of mold components corresponding to the cavity surfaces separated by the mold parting lines are independently cooled and controlled while resin is contained in the cavity. A method for producing a disk-shaped substrate material for an optical disk, wherein the method is characterized in that: 3. The nested bush separated by the mold parting line in the mold apparatus for manufacturing a disk-shaped substrate material according to claim 2, and a mold component adjacent to the nested bush via the mold separating line. And injecting resin into the cavity while controlling cooling independently.

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