JPH04307223A - Rolled stamper for forming optical information recording medium - Google Patents

Abstract

PURPOSE:To manufacture an optical information recording medium accurately by simplifying operation, improving productive efficiency, exchanging a long- sized flexible stamper in a short time and preventing the extrusion of adhesives, etc. CONSTITUTION:When fixtures 3 are installed at both ends of a long-sized flexible stamper 1 having a plurality of irregular patterns, said fixtures are inserted into the groove sections of a roller 2 having approximately the same shape as the fixtures 3 and the long-sized flexible stamper 1 is fastened to the roller 2, one of said fixtures is fixed into the groove, the other is inserted into the groove while a wedge 6 is inserted among said grooves and the fixtures, and the wedge 6 is pushed in by a tension screw 20, thus applying tension to the long-sized flexible stamper 1, then fixing the long-sized flexible stamper 1.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a roll-shaped stamper used in a roller-groove molding method for manufacturing substrates for information recording media, and particularly to a roll-shaped stamper that can be easily attached to a roller.

0002
]

2. Description of the Related Art In general, substrates for information recording media are
As described in 82204, grooves such as tracking grooves and information pits are formed on the information recording surface.

[0003] As a method for forming grooves on a substrate for information recording media, 1) when using a plastic resin as the substrate material for information recording media, injection molding, compression molding, or roller groove molding can be used. 2) When using a photocurable resin composition, a so-called 2P molding method, a 2P roller molding method, in which a replica of a stamper for forming grooves of an information recording medium is transferred to a transparent resin substrate.
It is known to form grooves by a groove forming method: 3) by a cast molding method using a resin monomer or a prepolymer containing a solvent.

In the above 2) 2P roller groove forming method, track grooves of an optical information recording medium are formed by rolling.
A roll-shaped stamper for forming the information recording medium 2P (hereinafter referred to as a 2P roll-shaped stamper), which can be formed in a two-roll continuous process, is exclusively used.

[0005] A method for manufacturing this 2P roll stamper is disclosed in Japanese Patent Application No. 1-38872 and No. 1-38346.
As described in the above issue, there is a method in which a paper-like glass stamper is produced using photolithography technology and fixed to a roller via an adhesive using a heat shrink tube or a shape memory alloy.

[0006] In the roller groove forming method of 1), track grooves of an optical information recording medium can be formed in a continuous roll-to-roll process.
A roll-shaped stamper (hereinafter referred to as a roll-shaped stamper) for molding an information recording medium is mainly used.

[0007] As described in Japanese Patent Application No. 63-264691, the method for manufacturing this roll-shaped stamper is to apply contact exposure to the roller using a paper-like glass mask, and produce a roll-shaped stamper by direct stamping. There are known ways to do this.

However, in the above-mentioned "direct stamping method," a single roll-shaped stamper is used to stamp predetermined patterns (tracking grooves,
For example, if a defect occurs in a predetermined pattern of one or several information recording media, the entire roll-type stamper may be damaged. As a result, the utilization efficiency of the predetermined pattern of the information recording medium per roll-type stamper, in which the predetermined pattern of a plurality of information recording media is formed by direct stamping, is extremely poor.

[0009] In addition, in order to improve production efficiency, 1.
Many predetermined patterns must be directly stamped on the roll-shaped stamper of the book, and for this reason, the roller diameter of the roll-shaped stamper increases, the weight increases, and it is a great effort to replace one roll-shaped stamper. The disadvantage was that it required

[0010] In order to solve these drawbacks, a sheet-like stamper is produced by electroforming, and a shape memory alloy is used to fix the stamper to the roller with an adhesive interposed therebetween (Japanese Patent Application No. 1986- 285873), or a method in which it is manufactured by paper lithography technology and fixed to a roller using an adhesive and a heat shrink tube (Japanese Patent Application No. 1-38872).

[0011]

However, in the conventional example described above, as shown in FIG. 3, a predetermined pattern for one information recording medium is formed on one sheet-like stamper 10, and the Since a roll-shaped stamper is produced by fixing a plurality of sheet-shaped stampers with an adhesive, it has the following drawbacks.

(1) If one or several sheet-shaped stampers are defective, the defective sheet-shaped stamper must be replaced, but it takes about 4 hours to fix the new sheet-shaped stamper to the roller. During this time, the roller/groove molding device must be stopped, resulting in a decrease in molding efficiency.

(2) One method is to prepare a newly reattached roll-shaped stamper and rotate it, but in order to improve production efficiency, it is necessary to use more roll-shaped stampers on one roll-shaped stamper. The sheet stamper must be fixed. For this reason, the roller diameter of the rolled stamper increases, the weight increases, and it takes a lot of effort to replace a single rolled stamper (
Currently, it takes about 3 hours for 3 to 4 people to replace a rolled stamper with a diameter of 300 mm. ). (3) Even when fixing a sheet stamper, as the roller diameter increases, the work in the gluing process becomes more difficult, and if an adhesive fixing device is required, there is a concern that the adhesive fixing device will also become larger. be done. Therefore, equipment costs, personnel costs, etc. may increase.

(4) As shown in FIG. 3, since there is an adhesive smear 11, it takes effort to remove it. Furthermore, if roller groove molding is performed with the adhesive stub intact, it will change over time in about 20 hours, and the adhesive itself will cause defects.

[0015]

[Means for Solving the Problems] The present inventors have completed the present invention as a result of intensive studies to solve the above problems. That is, the present invention provides an optical information recording medium forming roll for forming a concavo-convex signal on a thermoplastic synthetic sheet, which is a substrate material of an optical information recording medium that performs recording and reproduction using light, using a pair of forming rolls. A fixing device is attached to both ends of a flexible stamper having unevenness corresponding to the uneven signal to be transferred, and a groove of approximately the same shape as the fixing device is placed at a predetermined position on the surface of the roller serving as the roll base material. The roll-shaped stamper is characterized in that it has a mechanism in which at least one of the fixing tools is fixed in the groove by applying tension when the fixing tool is inserted into the groove and the stamper is fixed to the roller.

FIG. 1 is a schematic diagram of a roll-shaped stamper 5 of the present invention. In the figure, 1 is a long flexible stamper, 2 is a roller for fixing the long flexible stamper 1, 3 is a stamper fixture for fixing the stamper 1 to the roller 2, and 4 is a stamper formed on the long flexible stamper 1. 6 is a wedge for applying tension to the long flexible stamper 1; 7 is a wedge for applying tension to the long flexible stamper 1;
is a screw that fixes the stamper to the roller 2. Here, as the long flexible stamper 1, the same figure (b
) and (c), a plurality of striped or spiral uneven patterns are formed.

[0017]

[Examples] The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 First, as shown in FIG. 4(a), a substrate 12 such as blue plate glass
A layer of photoresist 13 (34 cm long x 30 cm wide) was formed (Step A). The photoresist 13 is Az1
370 (manufactured by Hoechst Japan), this was dropped onto the substrate 12, and coated with a spinner to a thickness of 3000 Å. Thereafter, pre-baking was performed at 90° C. for 30 minutes.

Next, as shown in the same figure (b), a laser exposure device [mirror projector mask aligner M
Using an exposure device such as PA-1500 (manufactured by Canon Inc.), a predetermined pattern (stripe shape) of multiple information recording media is exposed, and tracking is performed by developing it with a developer Az312MIF (manufactured by Hoechst Japan). ditch,
Forming a fine pattern 13' of unevenness such as information pits,
A glass master disk 14 for an optical card was manufactured (process B).

Furthermore, as shown in FIG. 2(c), as a pretreatment for forming a metal film by electroforming, conductivity treatment is performed using a film forming apparatus such as a sputtering apparatus or a vapor deposition apparatus (step C). . The conductive film 15 is formed by forming a nickel film with a thickness of 1000 Å to 2000 Å using a sputtering device.
was formed on the glass master disk 14.

Next, as shown in the same figure (d), the conductive film 1
A metal film 1 is formed by electroforming on a glass master disk 14 provided with a metal film 5.
6 (Step D).

First, the nickel chip in the electroforming bath was set as the + side electrode, and the glass master 14 coated with the conductive film 15 was set as the - side electrode. At this time, the electrode plate is
) It is preferable to use a peripheral electrode plate 17 as shown in FIG. This is because the outer circumferential electrode plate has a better film thickness distribution when compared with the inner circumferential electrode plate. Furthermore, if the outer peripheral electrode plate 17 is made rectangular along the shape of the stamper as shown in FIG. 5(b), electric lines of force will be concentrated on the edge portion 18 of the electrode plate, and the film thickness distribution may be extremely deteriorated. Therefore, we will use Figure 5 (
A ring-shaped device as shown in a) was used.

Next, in a nickel sulfamate electroforming solution, the glass master 14 on which the conductive film 15 has been applied is heated for 20 to 30 minutes.
While rotating at rpm, the time integral value of the applied current is 17~
100-200 under 34AH (amp hour) condition
A metal film 16 was formed by depositing nickel metal with a thickness of μm.

The electroforming solution used here was nickel sulfamate tetrahydrate [Ni(NH2SO3)2.4H2O
]500g/l, boric acid [H3BO3] 35-38g/
1, pit inhibitor 2.5 ml/l.

Finally, as shown in FIG. 4(e), the conductive film 15 and the metal film 16 are integrated, and the glass master 14 is simultaneously
By peeling it off further, removing the photoresist adhering to the surface, and cutting it as shown in Figure 6, the line and space: 9.5 μm/2.5 μm, step: 25
A long flexible stamper as shown in FIG. 1(b) in which striped guide grooves of 00 Å to 3000 Å were formed was obtained (Step E).

Next, using the obtained long flexible stamper, a stamper fixture 3 is made of Ni-plated steel material.
(310 mm x 15 mm x t5) is fixed by welding. The welding methods used include EB (electron beam) welding, silver solder welding, and YAG laser welding.

As shown in FIG. 2, a stamper fixture 3 is installed at a predetermined position on a welding jig 8 having a beam slit 9. Next, align the welding surface of the long flexible stamper 1 (the surface without uneven patterns such as tracking grooves and information pits) with the welding surface of the stamper fixture 3, attach the top cover from above, and screw it in place. Complete the settings.

Using an EB welding device, EBW6LB (manufactured by Mitsubishi Electric Corporation), the set long flexible stamper was EB welded and fixed to the stamper fixture 3.

[0029] The conditions for EB welding are: degree of vacuum: 5 x 10-2
Torr, acceleration voltage: 60kV, beam current: 3.2m
A. Beam speed: 4.0 m/min.

Under these conditions, if large distortion occurs in the long flexible stamper, welding may be performed by pulsed electron beam, and the pulsed beam conditions are: frequency: 60 Hz, duty: 20-5.
0%, deflection device volume: 100 mV, offset: 50 mV.

When using YAG laser welding, align the welding surface of the long flexible stamper with the welding surface of the stamper fixture, attach the top cover of the welding jig from above, and tighten the screws in the same way as the EB welding described above. to complete the settings. This welding jig is attached to the XY stage. The XY stage is linked with the YAG laser welding device. As a YAG laser welding device,
Using ML-2220A (manufactured by Miyaji Laser System Co., Ltd.), charging voltage: 350 V, pulse width: 1.0 ms, defocus: 5 mm, REP-RATE (PPS):
20. The stamper fixture was fixed to the long flexible stamper under the conditions of power: 35 to 65W.

When fixing the stamper fixture by silver solder welding, a silver solder foil is interposed between the welded surface of the long flexible stamper and the welded surface of the stamper fixture, the welded surfaces are brought together, and from above Apply a pressure of 50 kg/cm2 to complete the setting. This is vacuum degree 2
Silver solder welding was performed in a vacuum heating furnace under the conditions of ×10 −5 Torr, peak heating temperature: 820° C., and heating time: 7 hours, and the stamper fixture was fixed to the long flexible stamper. Figure 7 shows the temperature change inside the vacuum heating furnace.

[0033] The method of fixing the long flexible stamper and the stamper fixture is not limited to those mentioned above, but methods such as low melting point metal, low melting point glass, heat resistant adhesive, screwing, clamping, etc. may be used. You can also do it.

[0034] Next, the stamper fixing device of the long flexible stamper is attached to the groove machined by electric discharge machining, bite machining, dressing machining, etc. on the roller with a mechanism that can apply tension by inserting a wedge. Explain the method. As shown in FIG. 8, a rectangular groove (width 20 mm, depth 5 mm) is machined on the roller 2 using an electrical discharge machine, and a fixture 3 of a long flexible stamper is attached to the groove. Next, by tightening the tension screw 19, the wedge 6 is inserted in the direction of arrow A, and accordingly, tension is applied to the long flexible stamper 1 in the direction of arrow B.

The tension applied to the long flexible stamper 1 can be set by adjusting the torque of the tension screw 19. However, in roller groove molding, the molding temperature condition is 125° C. to 145° C., so the tension applied to the long flexible stamper 1 can be set. Once reached, tighten the tension screw 19 again,
It is desirable to adjust the tension applied to the long flexible stamper 1.

At this time, since the groove formed on the roller 2 is rectangular in shape, the stamper fixture 3 tends to come off from the groove when tension is applied, so the tension adjustment is completed using the fixture holder 20. After that, the fixing tool was fixed with screws 7 so that it would not come off from the groove, and the rolled stamper of the present invention was completed. In addition, the fixture presser 20
was removed from the roller after the tension adjustment was completed.

Example 2 The grooves formed on the roller 2 were machined into a trapezoidal shape (top side 12 mm, bottom side 20 mm, depth 5 mm) using an electric discharge machine as shown in FIG. The shape is also trapezoid (top side 10mm, base 18mm, height 5m)
A roll-shaped stamper was produced in the same manner as in Example 1, except that m) was used. In this example, since the groove shape is trapezoidal, the central part of the long flexible stamper 1 (the part located in the center in the direction perpendicular to the extrusion direction)
Even in this case, the fixation was perfect.

Example 3 As shown in FIG. 10, a trapezoidal groove is formed on a roller 2 in the same manner as in Example 2, and a stamper fixture 3 is attached. Next, the beam slit 9 is brought into close contact with the long flexible stamper at a predetermined position, and the long flexible stamper 1 and the stamper fixing tool 3 are bonded by YAG laser welding.
Welded together. With the long flexible stamper 1 under tension, the other stamper fixture 3 was similarly welded using the YAG laser 21 to complete a roll-shaped stamper. By welding the stamper fixture 3 and the long flexible stamper 1 after setting the stamper fixture 3 in the groove of the roller 2 as in this embodiment, welding positioning can be performed with high accuracy.

Example 4 As shown in FIG. 11, the stamper fixture 3 was provided with a hollow structure, and the magnet rod 21 was inserted into the hollow structure and welded to the long flexible stamper 1 by YAG laser welding. As in Example 1, the stamper fixing tool 3 was fitted into the groove of a roller having a rectangular groove, and the long flexible stamper 1 was fixed. Next, when the set temperature for roller groove molding is reached in the same manner as in Example 1, tighten the tension screw 19 and adjust the tension applied to the long flexible stamper 1 in the same manner as in Example 1. A roll-shaped stamper 5 was completed that was completely fixed even in the center.

The hollow structure can be fabricated by drilling, electrical discharge machining, plate bending, or the like. In this example, it was manufactured by electrical discharge machining. Furthermore, the material of the magnet rod 21 is SmC.
o5, Nd2Fe14B, Sm(Co, Fe, Cu)6
．． 8, Sm (Co, Fe, Cu, Zr) 7.4, etc. can be used, but in this example, a Nd-Fe-B based magnet was used.

[0041] When grooving the roller 2, if the groove is rectangular in shape, it is easier to process the groove than in a trapezoidal shape, but the stamper fixture 3 is more likely to come off the groove. Therefore, as in this embodiment, the stamper fixture 3
A hollow structure is provided in the hollow structure, and a magnet rod 2 is attached to this hollow structure.
1, the fixing is complete without using the fixing device presser 20 used in Examples 1 and 2, and it is possible to minimize the occurrence of unevenness when applying tension. The shape of the hollow structure and the shape of the magnet rod can be as shown in FIGS. 11(b) to 11(d), but are not limited to these shapes.

Example 5 As shown in FIG. 12, a slide portion 24 was provided on the side surface of the roller 2 in order to adjust the mounting position of the tension rod 23. Next, as shown in the figure, one end of the tension rod 23 was placed on the stamper fixture 3, and the other end was fitted into the slide portion 23. As a material for the tension rod 23, a shape memory alloy that recovers its shape when the set temperature of the roller groove molding temperature is reached, a bimetal that changes its shape at the set temperature, or the like can be used.

[0043] As the shape memory alloy, Au-Cd alloy,
Cu-Al-Zn alloy, Cu-Al-Ni alloy, In-
Tl alloy, Ni-Al alloy, Ni-Ti alloy, etc., which are commonly known as shape memory alloys, can be used as long as they can recover their shape at a temperature close to the roller groove molding set temperature. This time, we will introduce Ni-
A Ti alloy was used and the tension rod 23 was designed to deform into a dogleg shape when the set temperature exceeds 80°C. At that time, the end of the tension rod slides in the slide section 24,
When the shape of the tension rod is deformed, tension is applied to the long flexible stamper 1, and the rolled stamper 5 is completed.

Although the example in which a shape memory alloy is used as the tension rod has been described above, a bimetal can also be used as described above. Bimetal materials include brass (30-40% Zn) and nickel steel (Ni3).
4%), brass (Zn30-40%) and invar (Ni3
6%), monel metal (Ni-Cu) and nickel steel (N
Bimetal combinations such as i34-42%) can be used.

Example 6 Next, an example in which a helical spring is used as a method of applying tension to the long flexible stamper 1 will be described. In this embodiment, since the helical spring is an elastic body, the long flexible stamper 1 has a feature that it is difficult to be damaged even when an overload occurs on the long flexible stamper 1.

As shown in FIG. 13, a helical spring 25 was fixed to the side surface of the roller 2. Further, the other end of the helical spring was fixed to the stamper fixture 3. A slide portion 24 is provided to fix the helical spring to the side surface of the roller 2, so that the helical spring can be fixed while adjusting the tension strength.

Example 7 As shown in FIG. 14, a wedge 6 was used in which both the surface in contact with the stamper fixture 3 and the surface in contact with the side surface of the roller groove were tapered. By using a wedge having such a shape, tension can be simultaneously applied to the central part of the stamper fixing tool, making it possible to fix the long flexible stamper 1 without further distortion.

[0048]

Effects of the Invention As is clear from the above description, the roll-shaped stamper according to the present invention can provide the following remarkable effects.

(1) Since the predetermined patterns of a plurality of information recording media can be formed on one roll-shaped stamper in about 10 minutes, it is possible to simplify the work and improve production efficiency at the same time.

(2) The long flexible stamper can be replaced in a very short time, and the roller/groove molding device does not have to be stopped during that time, reducing wasted time.

(3) Since no adhesive is used, the adhesive does not ooze out, and the adhesive itself does not cause defects. Also, no adhesive fixing device is required.

(4) By molding the information recording medium substrate with a roll-shaped stamper using a long flexible stamper, the manufacturing cost of the information recording medium substrate can be reduced, and an inexpensive information recording medium can be provided. .

[Brief explanation of the drawing]

FIG. 1 (a) is a schematic diagram of a roll-shaped stamper of the present invention, and (b) and (c) are schematic diagrams of flexible stampers that can be installed on the roll-shaped stamper of (a), respectively.

FIG. 2(a) is a schematic diagram of a jig for welding a stamper fixture to a long flexible stamper, and FIG. 2(b) is a diagram of the long flexible stamper 1 to which a stamper fixture 3 is attached.

FIG. 3 shows a conventional roll stamper.

FIG. 4 is a schematic diagram showing the manufacturing process of a long flexible stamper that can be used in the present invention.

FIG. 5 is a schematic diagram showing an example of attachment of a peripheral electrode plate used in an electroforming process during the manufacturing process of the long flexible stamper 1.

FIG. 6 is a schematic diagram showing a method of cutting the long flexible stamper 1.

FIG. 7 is a graph showing the temperature change in the vacuum heating furnace when the stamper fixture 3 is attached to the long flexible stamper 1 by silver solder welding.

FIG. 8 is a schematic diagram showing an example of a mechanism for applying tension to the long flexible stamper 1 using a wedge;
a) is a side view, and (b) is a plan view.

FIG. 9 is a schematic diagram showing another example of a mechanism for applying tension to the long flexible stamper 1 using a wedge, in which (a) is a side view and (b) is a plan view.

FIG. 10 is a schematic diagram showing a method for manufacturing a roll-shaped stamper used in Example 3.

FIG. 11 is a schematic diagram showing a method of fixing the stamper fixture 3 to the roller 2 by inserting a magnetic rod;
FIG. 3A is a side view of the roller, and FIGS. 3B to 3D are cross-sectional views of the stamper fixture.

FIG. 12 is a schematic diagram showing an example of a mechanism for applying tension to the long flexible stamper 1 using a tension rod.

FIG. 13 is a schematic diagram showing an example of a mechanism for applying tension to the long flexible stamper 1 using a helical spring.

[Figure 14] Long flexible stamper 1 with wedge
FIG. 3 is a schematic diagram showing another example of a mechanism for applying tension to the holder.

[Explanation of symbols]

1. Long flexible stamper 2 Roller 3 Stamper fixture 4 Uneven pattern 5　Rolled stamper 6 Wedge 7 Screw 8 Welding jig 9 Slit for beam 19 Tension screw 20 Fixture retainer 22 Magnet stick 23 Tension rod 25 Helical spring

Claims (11)

[Claims] Claim 1: An optical information recording medium forming roll for forming uneven signals by a pair of forming rolls on a thermoplastic synthetic sheet that serves as a substrate material for an optical information recording medium that performs recording and reproduction using light. Attaching stamper fixtures to both ends of a long flexible stamper, which is a long flexible stamper having unevenness corresponding to the uneven signal to be transferred,
Further, a groove having substantially the same shape as the fixing device is provided at a predetermined position on the surface of the roller serving as the roll base material, and when the fixing device is inserted into the groove and the stamper is fixed to the roller, at least one of the fixing devices is tensioned. A roll-shaped stamper characterized by having a mechanism for hanging and fixing in the groove. 2. The roll-shaped stamper according to claim 1, wherein the tension applying mechanism is a wedge inserted between the groove and the fixture. 3. The roll-shaped stamper according to claim 2, wherein the wedge has a tapered surface on both the fixture and the surface in contact with the side wall of the groove formed on the roller. 4. The roll-shaped stamper according to claim 2, wherein the shape of the fixture is a trapezoid whose upper base is the joint surface with the long flexible stamper. 5. The roll-shaped stamper according to claim 2, wherein the fixture is fixed to the roller by screwing from above the fixture. 6. The fixing device according to claim 2, wherein the fixing device is fixed to the roller by a magnetic rod inserted into a hollow structure provided in the fixing device. Rolled stamper. 7. The mechanism for applying tension is a tension rod whose one end is fixed to the stamper fixture and the other end is movably attached to the side surface of the roller, and whose shape changes as the temperature rises. The rolled stamper according to claim 1. 8. The rolled stamper according to claim 7, wherein the tension rod is made of a shape memory alloy. 9. The rolled stamper according to claim 7, wherein the tension rod is made of bimetal. 10. The rolled stamper according to claim 1, wherein the tension applying mechanism is a helical spring having one end fixed to the stamper fixture and the other end movably attached to the side surface of the roller. . 11. The rolled stamper according to claim 1, wherein the long flexible stamper and the stamper fixture are fixed by welding.