JPH0423244A - Production of substrate for optical disk and optical disk - Google Patents

Abstract

PURPOSE:To prevent the splashing of a radiation curing type resin at the time of peeling a substrate by developing the resin on a stamper of the outside diameter smaller than the outside diameter of the substrate and pressurizing the resin by the substrate, then irradiating the resin with radiations in a specific quantity of an oxygen atmosphere to cure the resin. CONSTITUTION:A lining member 21 adhered with the stamper 25 of the outside diameter smaller than the outside diameter of the substrate 3 is imposed on a mounting base 1 and is fixed by a clamp 11. The anaerobic radiation curing type resin 40 is then developed between the substrate 3 and the stamper 25 and the stamper 25 is pressurized by the substrate 3. The resin 40 is irradiated with the radiations in the atmosphere contg. 0 to 5vol.% oxygen and is thereby cured. The resin 40 in the outer peripheral part of the substrate 3 exposed to the outdoor air is sufficiently cured by regulating the oxygen concn. The splashing of the resin in the outer peripheral part of the substrate and the filling of the grooves and pits at the time of peeling of the stamper from the substrate are prevented in this way.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is applicable to rewritable optical recording disks such as magneto-optical recording disks, write-once optical recording disks such as bit-forming optical recording disks, optical video disks, etc. The present invention relates to a method of manufacturing a substrate for an optical disc, such as a read-only optical disc, and the optical disc.

<Prior Art> Patterns such as tracking groups, bits, or recording bits are formed on the surface of an optical disc substrate.

When using a thermoplastic resin substrate, such a pattern can be formed directly during injection molding of the substrate.

When using a glass substrate or thermosetting resin substrate,
The so-called 2P method is often used.

In the 2P method, first, a radiation-curable resin is spread on the surface of a stamper having a master pattern of the pattern described above, and a disk-shaped substrate is pressed onto the radiation-curable resin. Next, after curing the resin with radiation, the stamper and the resin are separated. As a result, a resin layer to which the master pattern has been transferred can be formed on the substrate.

The 2P method has the advantage that the outer periphery of the board can be held with a jig.
Although it is advantageous to use a stamper with an outer diameter smaller than the substrate, when the substrate is pressed against the resin spread on the stamper, the resin protrudes from the stamper and flows onto the surface of the stamper.

Furthermore, in order to separate the stamper from the resin, as shown in FIG. 8, a jig having a raised portion 71 is usually used to push up the inner peripheral portion of the substrate 3.

However, when the inner circumferential portion of the substrate 3 is pushed up and peeled off, the substrate 3 is warped as shown in the figure, and when the outer circumferential portion of the substrate and the resin are separated, the outer circumferential portion of the substrate 3 springs up.

For this reason, the resin dripping from the outer periphery of the substrate onto the outer surface of the stamper 4 scatters, adheres to the formed resin layer 4, and buries groups, bits, etc., resulting in omission of groups etc. when used as an optical disc. .

In particular, in the 2P method, the narrow clearance between the stamper and the substrate (
It is advantageous to use an ultraviolet curable resin with anaerobic curability because the resin is filled between 10 and 100 Q) and radiation is irradiated through the substrate, but the resin on the outer periphery of the substrate is exposed to air. Therefore, when using an anaerobic resin, the resin on the outer periphery of the substrate is difficult to harden even when irradiated with radiation.

Therefore, when an anaerobic resin is used, if the resin on the outer periphery of the substrate is blown off, the adhesion of the blown off resin is even more noticeable.

<Problems to be Solved by the Invention> The purpose of the present invention is to provide a method for manufacturing an optical disc substrate in which the resin does not fly off and there are fewer defects such as group removal when the substrate is peeled off from a stamper in the 2P method, and An object of the present invention is to provide an optical disc using an optical disc substrate manufactured by such a method.

Means for Solving the Problems> Such objects are achieved by the following inventions (1) to (5).

(1) A method of forming a resin layer having a matrix pattern on the surface of the stamper on a substrate using a stamper having an outer diameter smaller than that of the substrate, the method comprising a radiation curing type having anaerobic curing properties between the substrate and the stamper. 1. A method for manufacturing an optical disc substrate, which comprises spreading a resin, pressurizing the substrate, and then irradiating the resin with radiation in an atmosphere containing 0 to 5% by volume of oxygen to cure the resin.

(2) A method of forming a resin layer having a matrix pattern on the surface of the stamper on a substrate using a stamper having an outer diameter smaller than that of the substrate, the method comprising: spreading a radiation-curable resin between the substrate and the stamper; After pressurizing, the resin is cured by irradiation with radiation, and then when peeling the substrate together with the resin layer from the stamper, press the outer or inner circumference of the substrate toward the stamper while pressing the substrate. 1. A method for manufacturing an optical disc substrate, which comprises pushing up and peeling off an inner peripheral portion or an outer peripheral portion of the substrate.

(3) A method of forming a resin layer having a matrix pattern on the surface of the stamper on a substrate using a stamper having an outer diameter smaller than that of the substrate, the method comprising a radiation curing type having anaerobic curing properties between the substrate and the stamper. After the resin is developed and the substrate is pressurized, the resin is cured by irradiation with radiation in an atmosphere containing 0 to 5% by volume of oxygen.

Next, when peeling the substrate together with the resin layer from the stamper, the substrate is peeled off by pushing up the inner or outer circumference of the substrate while pressing the outer or inner circumference of the substrate toward the stamper. A method for manufacturing an optical disc substrate.

(4) The method for manufacturing an optical disc substrate according to any one of (1) to 3) above, wherein radiation is irradiated through the substrate, the radiation is reflected, and the outer peripheral portion of the substrate is irradiated with radiation.

(5) An optical disc characterized by having an optical disc substrate manufactured by the method described in any one of (1) to 4) above.

<Function> In the first aspect of the present invention, an anaerobic resin is cured by irradiating radiation in an atmosphere containing 0 to 5% by volume of oxygen.

Therefore, the resin on the outer periphery of the substrate is sufficiently cured, and when the substrate is peeled off from the stamper, the resin on the outer periphery of the substrate can be prevented from flying off and burying the groups and bits.

In the second aspect of the present invention, when peeling the substrate from the stamper, the outer peripheral portion of the substrate is pressed toward the stamper.

Therefore, it is possible to prevent the outer circumferential portion of the substrate from springing up when the substrate is peeled off, and it is possible to prevent the resin on the outer circumferential portion of the substrate from scattering.

As a result, the conventional problem of resin adhering to the resin layer formed on the substrate is solved.

The optical disc of the present invention using the optical disc substrate manufactured by such a method has no group omissions and has good recording and reproducing characteristics.

<Specific structure of the invention> Hereinafter, the specific configuration of the present invention will be explained in detail.

In the present invention, a resin layer having a predetermined pattern such as bits or groups for tracking, addressing, etc. is formed on a substrate by the so-called 2P method, and an optical disk substrate is manufactured.

The substrate used is disk-shaped, and dimensions such as diameter and thickness are appropriately selected depending on the type of optical disk, but usually have an outer diameter of about 80 to 300 mm and a thickness of about 1 to 1.5 mm.

The material of the substrate may be glass or resin, which is conventionally known as a substrate material for optical discs, and is appropriately selected depending on the purpose and the like.

In the case of a resin substrate, for example, acrylic resin, polycarbonate, epoxy resin, polymethylpentene, polyolefin, etc. are suitable.

Further, in the case of a glass substrate, it is preferably made of tempered glass. By using tempered glass, higher rigidity, better weather resistance, and durability can be obtained.

There are two types of tempered glass, physically strengthened glass and chemically strengthened glass, which are used depending on the purpose.

There are no particular limitations on the tempered glass used in the present invention (glass tempered using a normal strengthening method is used, but chemically strengthened glass is preferably used).

Furthermore, the resin used for the resin layer on which a predetermined pattern is formed is not particularly limited as long as it is a radiation-curable resin used in the so-called 2P method.

However, in the present invention, the narrow clearance between the standber and the board (
Since the substrate is filled with a resin of about 10 to 100% and irradiated with radiation through the substrate, radiation-curable resins with anaerobic curing properties, particularly acrylic resins, are preferable.

For example, as an acrylic resin, two to three components of monomers belonging to polyfunctional ester acrylate, polyfunctional urethane acrylate, polyfunctional epoxy acrylate, etc. are mixed, or these monomers are mixed with polyester acrylate, oligoester acrylate, polyurethane acrylate, oligomer, etc. A mixture of urethane acrylate and the like and a photopolymerization initiator can be suitably used.

In addition, as the radiation-curable non-anaerobic curable resin, a cationic polymerizable epoxy resin or the like can be used.

In the present invention, the outer diameter of the stamper used to pattern the resin layer is smaller than the outer diameter of the substrate.

By using such a stand bar, it becomes possible to hold the outer peripheral portion of the substrate.

Note that the difference in outer diameter between the substrate and the stamper is 1.0 to 4 in diameter.
．． It may be about 0 mm.

Also, the inner diameter of the stand bar is usually 15 to 3 mm larger than the inner diameter of the board.
About 5mm larger.

There are no particular restrictions on the conditions other than the diameter, and a normal stamper may be used, but for example, a stamper 25 reinforced by bonding a backing member 21 as shown in FIG. 1 is preferable.

In this case, the backing member 21 is usually made of various glasses such as blue plate glass, and various resins such as acrylic resin and epoxy resin.

The stand bar 25 is usually made of a Ni electroformed film or the like, and has a predetermined pattern formed on its surface.

Hereinafter, a method for manufacturing an optical disk substrate according to the present invention will be explained with reference to FIGS. 1 to 7.

First, as shown in FIG. 1, the backing member 21 to which the stand bar 25 is adhered is placed on the mounting base 1.

In this case, the stamper 25 is preferably fixed using the mounting clamp 11.

Then, the resin 40 is spread on the surface of the stamper 25, and the resin 40 is
Expand 0.

There is no particular restriction on the method of spreading the resin 40 (for example, a method of discharging the resin 40 from the nozzle 61 is preferred. In this case, the diameter of the nozzle may be about 0.2 to 1.0 mm.

Further, the number of nozzles used may be one or more, but in order to simplify the configuration of the device, the number of nozzles is usually about one.

More preferably, as shown in the figure, the substrate 3 is held parallel to the stand bar 25 at a predetermined gap, and the resin 40 is held in contact with both the substrate 3 and the stamper 25.
Expand.

In this case, normally the stand bar 25 is rotated to develop the resin 40, but the substrate 3 may be rotated or both may be rotated relatively.

When the resin 40 is expanded in this manner, foaming of the resin can be prevented.

The distance between the substrate 3 and the standber 25 is approximately 0.3 to 1.0 mm, the rotation speed of the stamper 25 is approximately 10 to 50 rpm, the discharge rate of the resin 40 is 1 to 10 cc/min, and the discharge amount of the resin 40 is approximately 0.3 to 1.0 mm. It is preferable that the layer has a thickness of about 10 to 50 mm after curing.

When rotating the stamper 25, it is sufficient to hold the outer circumferential portion of the substrate 3 with the holding claws 6 as shown in the figure, and it is preferable to use the holding claws 6 at the same time to perform rough center positioning.

After spreading the resin 4o on the surface of the stamper 25, the holding claw 6
While roughly positioning the center, place the board 3 on the resin 4.
Lower it onto o.

Then, as shown in FIG. 2, positioning is performed by inserting the positioning shaft 53 from the hole of the substrate 3 into the positioning hole 15 of the mounting base 1.

Next, the substrate 3 is pressed in the direction of the stamper 25.

Press pressure is usually about 2 to 20 gf/cmz.

In this case, there is no particular restriction on the pressurizing method (for example, a weight 55 may be placed on the substrate 3 as shown in the figure).

After pressurizing, it is preferable that the resin 40 that flows from the outer periphery of the stamper 25 to the outer surface when the substrate 3 is pressurized as shown in FIG. 3 be sucked by the outer periphery suction nozzle 63 or the like.

As a result, when the substrate 3 is peeled off after the resin 40 has hardened, the resin on the outer periphery of the substrate 3 can be prevented from flying off, and the effects of the present invention can be further improved.

In addition, the resin 4 flowing from the inner peripheral part of the stamper 25 to the inner peripheral surface
0 is preferably sucked by the inner peripheral suction nozzle 65 or the like.

Note that the resin protruding from the inner and outer peripheries of the stamper 25 is
When sucking with a nozzle or the like, the stamper 25 may be rotated or the nozzle 63 may be rotated.

Moreover, the number of nozzles may be 1 or 2 or more. When the number of nozzles is two or more, it is desirable to arrange them at equal intervals on the circumference.

Next, as shown in FIG. 4, the resin 40 is cured by irradiation with radiation, usually ultraviolet rays, to form a resin layer 4 on which the matrix pattern on the surface of the stamper 25 is transferred.

When using a radiation-curable anaerobic resin, radiation curing is performed in an atmosphere containing 0 to 5% by volume of oxygen.

By regulating the oxygen concentration as described above, the resin 40 on the outer periphery of the substrate 3 exposed to the outside air can be sufficiently cured, and the resin can be prevented from scattering when the substrate 3 is peeled off.

In this case, since it is difficult to reduce the oxygen concentration to zero, it is usually carried out in an atmosphere containing 2 to 5% by volume of oxygen.

Note that the atmosphere may be an inert gas atmosphere such as Ar, a N2 gas atmosphere, or the like.

Further, when using a radiation-curable non-anaerobic curable resin, there is no particular restriction on the atmosphere during radiation irradiation, and the irradiation may be carried out, for example, in the air.

In the illustrated example, the radiation is emitted from the substrate 3 side for ease of arrangement, but the radiation is not necessarily limited to this, and in some cases, for example, the radiation may be emitted from the stamper 25 side, or from both sides. It may be irradiated from

However, in the present invention, in order to cure the resin 40 on the outer periphery of the substrate 3 more fully, the radiation is reflected and irradiated to the outer periphery of the substrate, so that the amount of radiation irradiated on the outer periphery of the substrate is higher than on other parts, usually 15 It is preferable to set it to about 20 times.

In this way, when the substrate 3 is peeled off, the resin on the outer periphery of the substrate can be prevented from flying off, and the effects of the present invention are further improved.

In this case, there is no particular restriction on the method of reflecting and irradiating the radiation, but for example, as shown in the figure, a mirror 57 or the like may be used to reflect the radiation.

Note that the radiation dose may be increased in the same manner for the inner peripheral portion of the substrate.

After radiation curing, the positioning shaft 53 is removed,
The substrate 3 having the resin layer 4 on its surface is peeled off from the stamper 25.

The substrate 3 is peeled off by pushing up the substrate 3 from the stamper 25 side using a substrate peeling jig 7, as shown in FIG.

In this case, the substrate 3 and the pushing-up portion 71 of the jig 7 are in contact over a wide area, and there needs to be enough room to accommodate even if some deviation occurs during pushing-up, so the substrate is Push up the inner circumference of 3.

There is no limit to the method of pushing up the substrate 3 (for example, the pushing up portion 71 may be pushed up with a predetermined force using the cylinder 75).

It is preferable that the thrusting force is constant, usually 20 to 1
00 kgf.

In the present invention, when the substrate 3 is peeled off as described above, the outer periphery of the substrate 3 is pressed to prevent the outer periphery of the substrate 3 from suddenly springing up.

Although there is no particular restriction on the method of suppressing the outer circumferential portion of the substrate, a method using the outer circumferential holding portion 8 having a spring 81 will be described as a preferred example.

First, as shown in FIG. 5, the outer periphery of the substrate 3 is pressed by the outer periphery presser 8. As shown in FIG.

The pressing force in this case depends on the diameter of the substrate 3, etc., but is usually 5.
~20 kgf.

Further, the number of outer circumferential pressing parts 8 to be used is usually about 3 to 8.

When peeling is performed by pushing up the inner circumference of the substrate while pressing the outer circumference of the substrate 3 in this way, the substrate 3 is warped from the inner circumference as shown in FIG. 6, and finally the outer circumference of the substrate is peeled off. The spring 81 absorbs the impact when it bounces up.

Therefore, the outer circumferential portion of the substrate can be peeled off in substantially the same manner as the inner circumferential portion, and an optical disk substrate having the resin layer 4 without resin scattering can be manufactured.

After the substrate 3 is completely peeled off, the outer periphery holding part 8 is removed from the substrate 3 as shown in FIG. 7, and an optical disc substrate is obtained.

In order to prevent damage to the substrate 3, it is preferable to attach, for example, urethane rubber to the tip of the outer circumferential pressing portion 8 and the tip of the push-up portion 71.

In addition, if the substrate 3 is to be peeled off by pushing up the outer circumferential portion of the substrate 3, the inner circumferential portion of the substrate 3 may be pressed in the same manner as described above.

The optical disc substrate thus obtained can be used for various optical discs, such as rewritable optical discs such as magneto-optical recording discs and optical recording discs having a phase change recording layer, or write-once optical discs such as bit-forming optical recording discs. It is suitably used as a substrate for optical discs, as well as read-only optical discs such as optical video discs and optical digital audio discs.

Further, the optical disc of the present invention has the above-described optical disc substrate, and an information carrying portion such as a recording layer is formed on the resin layer 4, and other layers depending on the type of optical disc are formed.

Note that the information carrying section in the present invention refers to both a section that carries information in advance, as in a read-only disk, and a recording layer that carries information, as in a recording/playback disk.

FIG. 9 shows an example of a magneto-optical recording disk as a preferred embodiment of the optical disk of the present invention.

The magneto-optical recording disk 1 shown in FIG. 9 has a protective layer 91.on the optical disk substrate in which the resin layer 4 is formed on the substrate 3. It has an intermediate layer 92, a recording layer 93 as an information carrying section, a protective layer 94, a protective coat 95, an adhesive layer 96, and a protective substrate 97 in this order.

The intermediate layer 92 is provided to improve the C/N ratio,
It is preferably formed from various dielectric materials, and the layer thickness is usually about 30 to 150 nm. Further, as the layer forming method, it is preferable to use a vapor phase film forming method such as a sputtering method.

Note that such an intermediate layer material may be provided as a protective layer 94 on a recording layer 93, which will be described later, and used in combination with the intermediate layer 92. When used together, the compositions of the intermediate layer 92 and the protective layer 94 may be the same or different.

The protective layer 91 and the protective layer 94 are provided to improve the corrosion resistance of the recording layer 93, and it is preferable that the number of these layers is small (one, preferably both).
These protective layers are preferably composed of inorganic thin films made of various oxides, carbides, nitrides, sulfides, or mixtures thereof. Further, as described above, the intermediate layer may be formed of the above-mentioned materials. The thickness of the protective layer is 30-3
A thickness of about 0.00 nm is preferable from the viewpoint of improving corrosion resistance.

Such a protective layer is preferably formed by various vapor phase deposition methods such as sputtering.

Information is magnetically recorded in the recording layer 93 using a modulated heat beam or a modulated magnetic field, and the recorded information is reproduced by magneto-optical conversion.

The material of the recording layer 93 is not particularly limited as long as magneto-optical recording can be performed, but an alloy containing a rare earth metal element, particularly an alloy of a rare earth metal and a transition metal, is used by sputtering,
It is preferable that the film be formed as an amorphous film by a vapor deposition method, an ion blating method, or the like.

The thickness of such a recording layer 93 is usually 10 to 500
It is about nm.

Protective coats 1 to 95 are provided to improve corrosion resistance and scratch resistance, and are preferably composed of various organic substances, but especially those that are hardened by radiation such as electron beams and ultraviolet rays. Preferably, it is made of a material that is

The radiation-curable compound used to form the protective coat 95 preferably contains oligoester acrylate.

The thickness of the protective coat 95 made of such a radiation-curable compound is usually about 0.1 to 100 mm.

Such a coating film may usually be formed by combining various known methods such as spinner coating, gravure coating, spray coating, and dipping.

The protective substrate 97 is provided to effectively prevent damage to the recording layer 93, and is usually made of glass or resin.

The thickness of the protective substrate 97 is usually set to a certain value in order to ensure rigidity.
The thickness should be approximately 0.5 to 2.0 mm.

The protective substrate 97 is bonded, for example, with an adhesive layer 96 as shown in the figure, and is integrated with the substrate 2.

There are no particular restrictions on the adhesive used, but hot melt adhesives are preferred.

Hot melt adhesives are generally composed of a base polymer, to which additives such as tackifiers, softeners, plasticizers, and waxes are added.

The thickness of the adhesive layer 96 is usually about 10 to 100 microns.

Although the case where the optical disk of the present invention is applied to a single-sided recording type magneto-optical recording disk has been described above, it can also be applied to a double-sided recording type magneto-optical recording disk.

A double-sided recording type magneto-optical recording disk uses two substrates 3 having each of the above-mentioned constituent layers, and is bonded with, for example, an adhesive layer 96 so that a recording layer 93 as an information-bearing portion is enclosed. can be obtained.

Furthermore, the present invention can also be applied to optical recording disks that have a so-called phase change type recording layer and perform recording and reproduction by changing reflectance.

As such a recording layer, for example,
Te described in No. 902, Patent No. 1004835, etc.
Se-based alloy, JP-A-58-54338, Patent No. 974
No. 257, Patent No. 974258, Patent No. 974257
Te oxide system described in the No. 1, various other chalcogen systems mainly composed of Te and Se, alloys that cause amorphous-crystalline transition such as Ge-3n and 5i-5n, Ag-Zn, Ag-Al-Cu, Cu. -Alloys that change color due to changes in crystal structure, such as -AA, and alloys that change crystal grain size, such as In-3b.

Furthermore, the present invention can also be applied to an optical recording disk having a so-called bit-forming type recording layer in which the reflectance changes due to bit formation.

The bit-forming recording layer may contain pigments such as cyanine, phthalocyanine, naphthalocyanine, anthraquinone, azo, triphenylmethane, pyrylium or thiapyrylium salts, or Te-based pigments mainly containing Te. material is used.

In addition, the present invention may be a read-only optical disc.

<Example> Hereinafter, the present invention will be explained in further detail by giving specific examples of the present invention.

[Example 1] A resin layer 4 having spiral groups with a pitch of 1.6 μm for tracking was formed on a substrate 3 in the following manner to manufacture an optical disc substrate A of the present invention.

The substrate 3 was made of alumina-silicate-based chemically strengthened glass, and was in the shape of a disk with an outer diameter of 200 mm and a thickness of 1.2 mm.

Further, the resin layer 4 was made of ester acrylate resin and had a thickness of 20 units.

First, as shown in FIG.
In the meantime, the resin 40 is discharged from the nozzle 61 and the standby bar 25 is
The resin 40 was developed while rotating.

Then, as shown in FIG. 2, after inserting the positioning shaft, pressure was applied to the substrate 3 using a 1.600 g weight.

Next, as shown in FIG. 3, excess resin on the inner and outer peripheries of the substrate 3 was sucked out by a suction nozzle 63.6S.

Next, as shown in FIG. 4, the resin 40 was cured by irradiating ultraviolet rays from the substrate 3 side to form the resin layer 4.

The atmosphere during radiation irradiation was a mixed gas of N2 and 0□ containing 3 to 4% by volume of oxygen.

Further, the outer peripheral portion of the substrate was irradiated with ultraviolet light by reflecting it using a mirror 57.

Next, as shown in FIG. 5, the outer peripheral part of the substrate was pressed using the outer peripheral part 8 having a spring 81.

The pressure was set to lokgf, and the substrate 3 was pressed at four locations.

Then, the inner peripheral portion of the substrate 3 was pushed up using the push-up portion 71, and the stand bar 25 was separated from the substrate 3 having the resin H4.

When the resin layer 4 of the obtained optical disc substrate A of the present invention was observed in a dark room using a visual light source, no resin adhesion was observed.

In addition, a comparison sample was prepared in the same manner as described above except that when the substrate 3 and the stand bar 25 were separated from each other by irradiation with ultraviolet rays in the atmosphere as shown in FIG. A standard material B for optical discs was manufactured.

When the resin layer 4 of the obtained optical disc material B was observed in a dark room using a visual light source, adhesion of the resin was confirmed.

Next, using the optical disk substrates A and B, a glass protective layer 91 and a SiNx intermediate layer 92 are placed on the optical disk substrates.
, a TbFeCo recording layer 93, a SiNx protective layer 94, and a protective coat 95, and finally a resin protective substrate 97 is bonded with an adhesive layer 96 to obtain a single-sided recording type magneto-optical recording disk sample shown in FIG. No. 1 (invention) and No. 2 (comparison) were manufactured, respectively.

In this case, a sputtering method was used to form the protective layer 91, intermediate layer 92, recording layer 93, and protective layer 94.

In addition, the protective coat 95 is formed by coating oligoester acrylate and then cross-linking and curing it by irradiating it with ultraviolet rays.
10- was installed.

The adhesive layer 96 was formed using a hot melt adhesive using a roll coater, and had a thickness of 80 mm.

The resin protective substrate 97 is made of polycarbonate, manufactured by injection molding, and has a disk shape having the same size as the substrate 3.

Both samples were then evaluated for group omissions.

11 Samples No. 1 and No. 12 were added to 3
0 sheets were prepared and the tracking error signal was measured.

In this case, if the tracking error signal fluctuated to the plus or minus side by 60% or more of the absolute value of the track jump signal peak value, it was counted as one missing group, and the entire surface of the disk was measured.

Then, the average value X and standard deviation C of the counts of group dropouts were determined.

The results are shown in Table 1.

table 1 (present invention) 2 (comparison) The effects of the present invention are clear from the results shown in Table 1.

<Effects of the Invention> According to the method for manufacturing an optical disk substrate of the present invention, a resin layer can be formed on the substrate without resin adhesion, and in which the master pattern on the stamper surface is accurately transferred.

Therefore, an optical disc without defects such as group omissions can be realized.

[Brief explanation of the drawing]

FIGS. 1 to 7 are cross-sectional views for explaining the method of manufacturing an optical disc according to the present invention. FIG. 8 is a cross-sectional view for explaining a conventional method of manufacturing an optical disc substrate. FIG. 9 is a sectional view showing an example of the optical disc of the present invention. Explanation of symbols 1...Mounting stand 1...Mounting clamp 15...Positioning hole 17...Hole 21...Backing member 25...Stambar 3...Base 1 anti-4 Resin Layer 40...Resin 51...Holding claw 53...Positioning shaft 55...Weight 57...Mirror 61...Nozzle 63...Outer circumference suction nozzle 65...Inner circumference suction nozzle 7... Substrate peeling jig 71... Push-up part 75... Cylinder 8... Outer periphery pressing part 81... Spring 91... Protective layer 92... Intermediate layer 93... Recording M 94...Protective layer 95...Protective coat 96...Adhesive layer 97...Protective board application agency Doujin TDC Co., Ltd.

Claims (4)

[Claims] (1) A method of forming a resin layer having a matrix pattern on the surface of the stamper on a substrate using a stamper having an outer diameter smaller than that of the substrate, the radiation curing type having an anaerobic curing property between the substrate and the stamper. 1. A method for manufacturing an optical disc substrate, which comprises spreading a resin, pressurizing the substrate, and then irradiating the resin with radiation in an atmosphere containing 0 to 5% by volume of oxygen to cure the resin. (2) A method of forming a resin layer having a matrix pattern on the surface of the stamper on a substrate using a stamper having an outer diameter smaller than that of the substrate, the method comprising: spreading a radiation-curable resin between the substrate and the stamper; After pressurizing, the resin is cured by irradiation with radiation, and then when peeling the substrate together with the resin layer from the stamper, press the outer or inner circumference of the substrate toward the stamper while pressing the substrate. 1. A method for manufacturing an optical disc substrate, which comprises pushing up and peeling off an inner peripheral portion or an outer peripheral portion of the substrate. (3) A method of forming a resin layer having a matrix pattern on the surface of the stamper on a substrate using a stamper having an outer diameter smaller than that of the substrate, the method comprising a radiation curing type having anaerobic curing properties between the substrate and the stamper. After developing the resin and pressurizing the substrate, the resin is cured by irradiation with radiation in an atmosphere containing 0 to 5% by volume of oxygen, and then when the substrate is peeled together with the resin layer from the stamper, the A method for manufacturing an optical disc substrate, which comprises pushing up and peeling an inner or outer peripheral part of the substrate while pressing the outer or inner peripheral part of the substrate toward a stamper. (4) The method for manufacturing an optical disc substrate according to any one of claims 1 to 3, wherein radiation is irradiated through the substrate, and the radiation is reflected to irradiate the outer peripheral portion of the substrate. (5) An optical disc comprising an optical disc substrate manufactured by the method according to any one of claims 1 to 4.