JPH02289311A - Manufacture of stamper and board for information recording medium for which stamper is used - Google Patents

Abstract

PURPOSE:To prevent the fringe part of a disc board from generating flashes, by a method wherein prior to or posterior to peeling of the board in a state of a flat plate, to which an already-cured resin film, to which a form of a stamping surface of a stamper is transferred, is stuck, from the stamper, an uncured part of curing resin is removed. CONSTITUTION:A guide groove 9 is formed by curing an ultraviolet-curing resin film 2a by applying ultraviolet rays 8 of the outside of a treatment device 4 onto a disc board 1 for 30 seconds by transmitting through an upper plate 7 made of glass and further through the top part made of the glass of an inner chamber 5 under a state where the disc board 1 and a stamper 3 are pressure-contacted together. In addition, parts of an ultraviolet-curing resin film 2a corresponding to shading patterns 3c, 3d are not exposed and kept as it is uncured, in this curing treatment. With this curing treatment, an already-cured part of the ultraviolet-curing resin film 2a and a disc board 1 are stuck to each other. Then since an outer circumferential surface of the disc board 1 is covered with a part of the shading pattern 3c obtained by overhanging in a state of eaves, sticking of resin to its outer circumferential surface through curing of the resin can be prevented effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stamper and a method for manufacturing an information recording medium substrate using the stamper.

[Prior Art] (1) Conventional Stamper Conventionally, a nickel stamper has been mainly used as a stamper used when manufacturing a substrate for an information recording medium with a guide groove. This nickel stamper was manufactured as follows.

That is, a photoresist is applied onto a glass plate to form a resist film, and then a resist pattern of a predetermined shape is formed by a normal photolithography method.

Next, a thin nickel film is formed on the glass plate by means such as vapor deposition so as to cover the resist pattern, and then a nickel plating film is formed using the thin nickel film as a conductive film by ordinary electroplating.

Finally, the resist patterned glass plate is peeled off to obtain a nickel stump bar having a pattern that is an inversion of the resist pattern.

(2) Conventional method for manufacturing substrates for information recording media The manufacturing of substrates for information recording media using the nickel stamper obtained as described above is carried out by the following method called the so-called 2P method. Ta.

That is, first, an ultraviolet curable resin is injected between the standbar and a disk substrate for manufacturing a substrate for information recording media, and then the resin is bonded between the standbar and the disk substrate by pressing with a pneumatic or hydraulic device. and fills the uneven surface (stamping surface) of the stamp bar with resin.

Next, guide grooves are formed by irradiating ultraviolet rays from above the disk substrate to harden the resin, and after fixing the cured resin with the guide grooves on the disk substrate, the disk substrate is placed in a stand bar. The substrate is peeled off from the substrate to obtain the intended information recording medium substrate.

[Problems to be Solved by the Invention] (1) Problems with conventional stampers The conventional nickel stamper described above has the following problems.

In other words, since the nickel stamper does not transmit ultraviolet rays, when curing ultraviolet curable resin using the 2P method, ultraviolet rays must be irradiated from the disk substrate side, and as a result, the disk substrate may be exposed to ultraviolet rays such as glass or plastic. The 2P method can be adopted only in the case of a substrate that transmits ultraviolet rays, and cannot be adopted in the case of a substrate that does not transmit ultraviolet rays or a substrate that hardly transmits ultraviolet rays.

Furthermore, when a substrate for an information recording medium is manufactured by the 2P method using a nickel stamper, burrs occur at the peripheral edge of the disk substrate after the ultraviolet curable resin is cured, causing various problems. This point will be explained in detail in the following section (2) Problems of the conventional manufacturing method for information recording medium substrates.

(2) Problems with the conventional method for manufacturing substrates for information recording media In the conventional method for manufacturing substrates for information recording media using the aforementioned ultraviolet opaque nickel stunbar, ultraviolet rays must be irradiated from the disk substrate side. In addition to this problem, there was a fatal problem in that burrs were generated at the peripheral edge of the disk substrate. In other words, since the ultraviolet curable resin used in the 2P method has fluidity before curing, when the resin is stretched by pressure, the resin protrudes from the periphery of the disk substrate, and this protruding portion is hardened by ultraviolet irradiation. This results in a paris with a pointed end. When such flaking occurs, the substrate is firmly adhered to the stand bar, making it difficult to easily separate the substrate from the stand bar, and a strong force is required for separation. Furthermore, when the substrate is peeled off from the stand bar, the chips with pointed edges are often chipped, and the chipped chips often become dust and adhere to the surface of the substrate where static electricity is generated due to the peeling charge. Ta. Further, even when removing paris, the removed paris may become dust and adhere to the surface of the substrate. When a recording layer is laminated on the guide groove to which dust has adhered in this manner, the dust portion cannot be completely covered by the laminated film because of the step difference, resulting in a pinhole. Moisture and oxygen enter through these pinholes, corrode the recording layer, and deteriorate recording characteristics.

The present invention has been made to eliminate these problems, and its first purpose is to eliminate the drawbacks of conventional nickel stampers, and (1) to eliminate ultraviolet rays, electron beams, etc. from the stamper side. As a result, it is possible to manufacture substrates for information recording media by the 2P method even when using substrates that do not transmit or are difficult to transmit ultraviolet rays, electron beams, etc. (if) Information by the 2P method The purpose of the stamper is to provide a stamper that has advantages such as being able to prevent the occurrence of flash when used in the production of substrates for recording media.The second purpose is to provide a stamper that has advantages such as being able to prevent the occurrence of paris when used in the production of substrates for recording media. Eliminates the drawbacks of the method for manufacturing substrates for recording media, and (a) makes it possible to manufacture substrates for information recording media by the 2P method even when using a substrate that does not transmit ultraviolet rays, electron beams, etc. or is difficult to transmit; (b) It is possible to prevent the occurrence of flash at the peripheral edge of the substrate, and as a result, the substrate can be easily peeled off from the stamper, and various problems caused by the adhesion of chipped flash to the substrate surface can be solved. An object of the present invention is to provide a method for manufacturing a substrate for an information recording medium, which has advantages such as being able to perform the following steps.

[Means for Solving the Problems] The present invention has been made to achieve the above-mentioned object, and the stamper of the present invention has a stamping surface having a shape corresponding to the guide groove of the information recording medium substrate. It is characterized by having a light-transmitting substrate formed on one main surface side thereof, and a light-shielding pattern formed in a region corresponding to the peripheral portion of the information recording medium substrate.

Further, the method for manufacturing a substrate for an information recording medium of the present invention includes a stamping surface of a stamper having the above-mentioned light-shielding pattern;
A curable resin is placed between one main surface of a flat substrate for manufacturing an information recording medium substrate with guide grooves, and then pressure is applied from at least one side of the stamper and the flat substrate, and then , the curable resin is selectively cured using the light shielding pattern as a mask, and then the stamper
The uncured portion of the curable resin is removed before or after the flat substrate to which the cured resin film to which the shape of the stamping surface has been transferred is peeled off from the stamper is removed. .

[Example] The present invention will be explained in detail below.

(1) Preparation of stamper As shown in FIG. 1(b) and FIG. 2, it has a convex portion 3a and a concave portion 3b, and further has a light shielding pattern 3C and a light shielding pattern 3d on the outer peripheral edge and the inner peripheral edge. Each stamper was produced by the following method.

On one main surface of a disc-shaped quartz glass plate with a diameter of 140 mm,
Positive photoresist (AZ-1350 manufactured by Hoechst)
was coated by a spin code method to form a resist film with a thickness of 3000, and then the resist film was selectively exposed by a laser cutting method (exposure method using laser light). Next, the exposed resist film is treated with a prescribed developer (
A resist pattern is formed on one main surface of the quartz glass plate by developing it using a developer developed by AZ exclusive developer, and then using CF4 as a reaction gas and applying RF power of 10%.
Using the resist pattern as a mask, the quartz glass plate was etched for 7 minutes using active ion etching at 0 W and a pressure in the reaction chamber of 0.1 Pa to form a concavo-convex pattern on the surface of the quartz glass plate. Next, the resist pattern was removed using a resist removal solution (hot concentrated sulfuric acid), and then washed to obtain a quartz glass substrate on which a pattern of protrusions and recesses corresponding to the guide grooves was formed on the surface. As shown in FIG. 1(b) and FIG.
a and a recess 3b. Thereafter, C was applied to the surface of the quartz glass plate on which the uneven pattern was formed using a sputtering method.
After forming an R film to a thickness of 500 mm and then forming a resist film to a thickness of 3000 mm on the Cr film in the same manner as described above, the resist film was passed through a photomask with a predetermined light-shielding pattern. selectively exposed. In addition, in this exposure process, the light-shielding pattern 3 of the stamper 3 finally obtained
The portions of the resist film corresponding to c and 3d are not exposed. Next, the exposed resist film is developed to form a resist pattern, and then, using the resist pattern as a mask, etching is performed using a predetermined etching solution (mixed aqueous solution of ceric ammonium nitrate and perchloric acid). Light-shielding patterns 3c and 3d made of Cr patterns are formed, and then the resist pattern is peeled off to form convex portions 3a, recesses 3b, light-shielding patterns 3c, and light-shielding patterns, as shown in FIGS. 1(b) and 2. Stamper 3 with 3d
I got it. In the obtained stamper 3, the width of the convex portion 3a is 0.6+ to 0.8 μm, and the width of the concave portion 3b is 0.8 to 1.5 μm.
The depth of 0μm1 recess 3b is approximately 750 people, light shielding pattern 3
The width of C was 7 gates, and the diameter of the light shielding pattern 3d was 25 mm. Note that the light-shielding patterns 3c and 3d mask the outer and inner peripheral edges of the disk substrate where guide grooves are not formed in the manufacture of information recording medium substrates, which will be described later. There is no problem with the formation of

(2) Manufacture of substrate for information recording media Made of soda lime glass, with a hole diameter of 15ffl in the center.
On a disk substrate 1 having an outer diameter of 130 mm and having a through-hole 1a, an ultraviolet curable resin 2 (Daicur Clear S TM-401 manufactured by Dainippon Ink ■, viscosity 320 centivoise) is applied with a dispenser to almost the entire surface of the disk substrate 1. It was applied in an annular shape at the center of the radius (see FIG. 1(a)).

Next, the disk substrate 1 and the stamper 3 were laminated so that the ultraviolet curing resin 2 on the disk substrate 1 and the uneven surface (stamping surface) of the stamper 3 faced each other (see FIG. 1(b)). .

Next, after putting the laminated disk substrate 1 and stamper 3 into the processing device 4, the disk substrate 1 and the stamper 3 are
The air bubbles remaining in the ultraviolet curable resin 2 are removed by reducing the pressure to ITorr between the disk substrate 1 and the stamper 3, and the disk substrate 1 and the stamper 3 are removed. Pressure 0°5k from both sides of
A pressure was applied at a pressure of g/cJ to form a bubble-free and uniform ultraviolet curable resin film 2a between the disk substrate 1 and the stamper 3 (see FIG. 1(c)).

To further explain the depressurization and pressurization operations inside the processing device 4, an inner chamber 5 in the processing device 4 is connected to a space portion A to be depressurized and a pressurized portion by an O-ring 6 fixed to the inner wall of the inner chamber 5. The space portion B where the stamper is placed is isolated from each other, and the pressure reduction between the disk substrate 1 and the stamper 3 is achieved by operating a vacuum pump provided in communication with the space portion A. Further, pressurization from both sides of the disk substrate 1 and stamper 3 is achieved by introducing a pressurizing gas such as N2 gas into the space B.

Next, with the disk substrate 1 and the stamper 3 pressed together, ultraviolet light 8 (using an ultraviolet lamp, output 300 W) from the outside of the processing device 4 is applied to the glass upper plate 7 and then to the glass inner chamber 5. 30 on the disk substrate 1 through the upper surface.
The guide groove 9 was formed by curing the ultraviolet curable resin film 2a by irradiating it for seconds (see FIG. 1(e)). In this curing process, the portions of the ultraviolet curable resin film 2a corresponding to the light-shielding patterns 3c and 3d were not exposed and remained uncured. Further, by this curing treatment, the cured portion of the ultraviolet curable resin film 2a and the disk substrate 1 were fixed.

Furthermore, since the outer circumferential surface of the disk substrate 1 is covered with the light-shielding pattern 3c that extends like an eaves, it is possible to effectively prevent the resin from hardening and adhering to the outer circumferential surface.

Next, after taking out the laminated disk substrate 1 and stamper 3 from the processing device 4, the former was peeled off from the latter. This peeling could be performed extremely easily. Thereafter, by dissolving and removing the uncured portion of the ultraviolet curable resin film 2a due to the presence of the light shielding patterns 3c and 3d by ultrasonic cleaning in isopropyl alcohol, the cured resin film 2b with the guide grooves 9 formed thereon is attached. Disk board 1
was obtained (see Figure 1(d)). The uncured portion of this resin could be removed very smoothly by using isopropyl alcohol which dissolves this resin.

In this embodiment, since the stamper 3 having the light shielding pattern 3c and the light shielding pattern 3d in areas facing the outer peripheral edge and the inner peripheral edge of the disk substrate 1 is used, the outer peripheral edge and the inner peripheral edge of the disk substrate 1 are Curing of the ultraviolet curable resin present in the area is prevented. Therefore, no burrs were formed on the obtained disk substrate 1 with guide grooves 9, and various problems such as adhesion of missing burrs to the surface of the guide grooves caused by occurrence of burrs could be solved.

The obtained disc substrate 1 with guide grooves 9 is stamped with a stamper 3.
The magneto-optical disk obtained by providing a recording layer etc. thereon had excellent recording properties etc. because it had a concavo-convex pattern that faithfully corresponded to the concavo-convex pattern of .

Although the present invention has been described above with reference to Examples, the present invention includes the following modifications.

(A) Modified example of stamper (1) In the example, a stamper having a light-shielding pattern in areas corresponding to the outer peripheral edge and inner peripheral edge of the disk substrate was used as the stamper, but the generation of paris was avoided. Since the light-shielding pattern is noticeable at the peripheral edge, the object of the present invention can be achieved even with a stamper in which the light-shielding pattern is provided only in the region corresponding to the outer peripheral edge. Further, as shown in FIG. 1(b), instead of providing the light-shielding pattern protruding from the outer peripheral edge of the disk substrate, the light-shielding pattern may be provided only in an area corresponding to the upper part of the outer peripheral edge.

(2) In the example, quartz glass was used as the stamper material, but soda lime glass can be used as long as it has translucency and can form a light-shielding pattern in the area corresponding to the peripheral edge of the substrate. Glasses such as aluminosilicate glass, aluminoborosilicate glass, and borosilicate glass, and materials other than glass such as ceramics and plastics may also be used.

(3) As for the material of the light-shielding pattern, any material other than Cr used in the embodiments may be used as long as it has light-shielding properties, such as Ti, Ta, MoSi, and Ni.

Cr203. Inorganic substances such as Fe203 or resins added with pigments or the like to have light-shielding properties may also be used.

Further, the thickness of the light-shielding pattern may be any thickness that can provide light-shielding properties, and is not limited to 500 people in the example. Further, the height (film thickness) of the light-shielding pattern may be lower or higher than the height of the convex portion of the stamper, or both may be the same.

(4) As a stamper, in addition to the stamper manufactured and used in the example, a Cr
After forming a light-shielding film such as a film, a resist film is formed on the light-shielding film, then the resist film is selectively exposed and developed to form a resist pattern, and then the resist pattern is used as a mask to shield light. After etching the transparent film, the resist pattern is peeled off, and a convex portion 3a made of a light-shielding film and a light-shielding pattern 3 made of a light-shielding film are formed on one main surface of the glass substrate.
It is also possible to use one obtained by forming c and 3d. Note that in this case, the convex portion 3a is also made of a light-shielding film,
As mentioned above, the width of the convex portion 3a is, for example, 0.6 to 0.6 mm. 8μm
Since the convex portion 3a is narrow, the ultraviolet light incident from the concave portion 3b goes around and hardens the resin in the portion corresponding to the convex portion 3a, so there is no problem even if the convex portion 3a is a light-shielding film. On the other hand, the width of the light shielding patterns 3c and 3d is 7QII11125ffIIl.
Since the area is wide, the influence of UV radiation can be ignored, and the resin in the portions corresponding to the light-shielding patterns 3e and 3d is not cured.

(5) In the embodiment, a disk-shaped stamper was used as shown in FIG. 2, but a square-shaped stamper may also be used. Also, corresponding to the through hole in the center of the disk board,
A through hole may be formed in the center of the stamper, and in this case, a light shielding pattern is formed around the periphery of the through hole of the stamper. Note that a stamper having a through hole in the center is preferable because it increases the ease of peeling from the disk substrate. Furthermore, the dimensions of the light-shielding pattern are not limited to those described in the examples. Further, the guide grooves formed on the surface of the disk substrate are not limited to the uneven shape, but may be pits, small holes, or continuous grooves.

(6) As shown in FIG. 3, as a stamper, on the other main surface opposite to the main surface having an uneven shape,
A stamper 3 may be used in which light-shielding patterns 3c and 3d are formed, and as shown in FIG.
The stamper 3 may be obtained by forming an i02 film, then selectively etching this 5i02 film to form a 5i02 film 32 having an uneven surface, and then forming light shielding patterns 3c and 3d.

The method for forming the 5LO2 film on one main surface of the transparent substrate 31 includes a sputtering method using a 5i02 target, and a sol-gel method that includes a step of applying a solution containing a silicon alkoxide and then heating it. etc. may be adopted.

Further, an AltO3 film or the like may be used instead of the 5i02 film.

As shown in FIG. 5, as a stamper, an ultraviolet curable resin containing a light-shielding pigment such as a black pigment is applied to an area of the transparent substrate 31 corresponding to the peripheral edge of the disk substrate by screen printing or the like. After coating and then curing with ultraviolet light to form light-shielding patterns 3c and 3d, a 5i02 film is formed to cover these light-shielding patterns 3c and 3d, and then this 5i02 film is selectively etched to have an uneven surface. Stamper obtained by forming 5i02 film 32
3 is also fine.

Furthermore, as shown in FIG. 6, the stamper is an ultraviolet curing type stamper containing a light-shielding pigment, which is formed by screen printing or the like on a region of the light-transmitting substrate 31 corresponding to the peripheral edge of the disk substrate. A resin layer is formed and then cured with ultraviolet light to form relatively thick light-shielding patterns 3C and 3d.
After forming the SiO2 film, a 5i02 film having a thickness smaller than that of the light shielding patterns 3c and 3d is formed in the gap between the light shielding patterns 3c and 3d, and then this SiO2 film is selectively etched to form a 5i02 film having an uneven surface. A stamper 3 obtained by forming a stamper 32 may also be used.

(B) Modification of method for manufacturing substrate for information recording medium (1) In the embodiment, an ultraviolet curable resin was used, but an electron beam curable resin or the like may also be used.

(2) In the embodiment, the resin was applied onto the disk substrate, but it may also be applied onto the stamper. It may also be applied onto the substrate and stamper. As a coating method, in addition to the method using a dispenser used in the examples, a spin cord method, a roll coating method, etc. can be used depending on the properties of the resin.

(3) In the example, a disk substrate made of soda lime glass was used, but glass substrates such as aluminoborosilicate glass, borosilicate glass, quartz glass, plastic substrates such as epoxy resin or polycarbonate, or ceramic substrates may also be used. May be used.

However, the method of the present invention is particularly effective when the substrate is made of a hard and brittle material such as glass. This is because, in the case of a plastic substrate, after the guide grooves are formed, the peripheral edge of the substrate is punched out using a punching tool, thereby removing pars, but in the case of glass, such processing is not possible.

In addition, although a substrate made of transparent glass was used in the example,
Since the method of the present invention exposes to light from the stamper side, the substrate may be opaque (for example, aluminum).

(4) In the embodiment, after the substrate and stamper were laminated, pressure was applied from both sides of the substrate and stamper, but as long as either the substrate or the stamper is fixed, pressure may be applied only to one side. As the pressurizing means, any method other than the method using pressurizing gas, such as using hydraulic equipment, can be adopted.

(5) As the solution used to remove the uncured resin, in addition to the isopropyl alcohol used in the examples, alcohol such as ethyl alcohol or other solutions capable of dissolving the uncured resin can be used as appropriate.

Further, in the embodiment, the uncured resin was removed after peeling the substrate from the stamper, but the uncured resin may be removed before peeling. Removal of the uncured resin before peeling is performed, for example, by immersing the substrate and stamper in a solution that dissolves the uncured resin.

[Effects of the Invention] As detailed above, according to the present invention, unlike conventional nickel stampers, by using a stamper that can transmit ultraviolet rays and electron beams, it is possible to prevent ultraviolet rays and electron beams from the stamper side. It has become possible to irradiate with radiation such as radiation, and it has become possible to manufacture substrates for information recording media even when using substrates that do not transmit or are difficult to transmit ultraviolet rays, electron beams, etc. Further, according to the present invention, by using a stamper having a light-shielding pattern in an area corresponding to the peripheral edge of the substrate, the curable resin present in the peripheral edge of the substrate is not cured when manufacturing a substrate for an information recording medium. Therefore, the generation of paris is prevented, and various problems associated with the generation of pars, such as difficulty in peeling the substrate from the stamper and adhesion of chipped pars to the substrate surface, can be solved. .

[Brief explanation of the drawing]

FIG. 1 is a process diagram showing an embodiment of the present invention, FIG. 2 is a plan view of a stamper used in an embodiment of the present invention, and FIGS. 3, 4, 5, and 6 are FIG. 2 is a sectional view of another preferred stamper of the present invention. DESCRIPTION OF SYMBOLS 1... Disk substrate, 1a... Through hole, 2... Ultraviolet curable resin, 2a... Ultraviolet curable resin film, 2b
... Cured resin film, 3... Stamper 13a...
- Convex portion, 3b... Concave portion, 3c, 3d... Light shielding pattern, 31... Transparent substrate, 32... 5i02 film having an uneven surface, 4... Processing device, 5...・Inner room, 6
...0 ring, 7... Glass top plate, 8... Ultraviolet rays, 9... Guide groove, A... Space to be depressurized, B
...A space that is pressurized.

Claims (2)

[Claims] (1) A transparent substrate having a stamping surface having a shape corresponding to the guide groove of the information recording medium substrate formed on one main surface thereof, and a stamping surface formed in an area corresponding to the peripheral edge of the information recording medium substrate. A stamper characterized by having a light-shielding pattern. (2) A curable resin is provided between the stamping surface of the stamper having a light-shielding pattern and one main surface of a flat substrate for producing a substrate for an information recording medium with a guide groove according to claim (1). Then, pressure is applied from at least one side of the stamper and the flat substrate, and then the curable resin is selectively cured using the light shielding pattern as a mask, and then the shape of the stamping surface of the stamper is transferred. Before or after peeling off the flat substrate to which the cured resin film is fixed from the stamper,
A method for manufacturing a substrate for an information recording medium, comprising removing an uncured portion of the curable resin.