JPH03243785A - electroforming equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an information recording medium for recording and reproducing information such as an optical card, an optical disk, and a magneto-optical disk, or a molding stamper for duplicating the substrate of the medium. The present invention relates to an electroforming device used in the production of - and a supporting device for an electroformed glass master disk used in the electroforming device.

[Conventional technology]

Conventionally, a stamper for molding an information recording medium for recording and reproducing information such as an optical card, an optical disk, or a magneto-optical disk, or a substrate of the medium (hereinafter referred to as an information recording medium, etc.) is usually manufactured by Japanese Patent Laid-Open No. 61 -284843 publication and Utility Model Publication No. 58
-141435, or “Key Points of Optical Disk Process Technology No. 5J (Japan Industrial Technology Center)
It is manufactured by the method described in .

That is, as shown in FIGS. 6(a) to (e), a photoresist 26 is coated on the surface of a glass substrate 27, and a fine pattern of 26 degrees of unevenness such as tracking grooves and information bits is formed thereon. By forming, a glass master disk 9 is obtained. Next, a conductive film 2 is applied to the surface of the glass master 9.
After forming 8 (glass master disk containing conductive film 9゛),
A stamper (mother stamper, master stamper) 30 for information recording media, etc. is manufactured by forming a metal film 29 by electroforming and peeling the conductive film 28 and the metal film 29 together from the glass master 9. do).

The conductive film is formed by a method such as metal vapor deposition or sputtering in a vacuum, and silver or nickel is generally used as the metal material to be formed. Nickel is often used. 26° fine unevenness pattern for tracking grooves, information bits, etc.
It is common to form a 50 to 1100 nm nickel layer thereon by sputtering.

In the electroforming process, a nickel sulfamate electroforming solution is generally used. For example, the liquid composition is nickel sulfamate tetrahydrate [Ni (NH2SO3) 2.4) 1203 5
00g/Flood boric acid [)13BO3] 3
5-38g #2 bit inhibitor 2.5
n+j2/β Distilled water Remainder The pH of the nickel sulfamate electroforming solution is usually adjusted to 3 to 5, and since pH fluctuations cause internal distortion and curling of the stamper, nickel bromide, sulfamic acid, and caustic soda are used. etc. by direct addition. Prior to the electroforming process, organic impurities in the nickel sulfamate electroforming solution are removed by periodic activated carbon treatment, and metal ions are segregated and removed by electrolytic cleaning.

FIG. 5 shows the basic configuration of a device conventionally used in the electroforming process. Nickel tip l (use a spherical one),
Since it is constantly immersed in the nickel sulfamate electroforming solution 3 having a pH of 3 to 5, its surface layer is oxidized and discolored to brown. If electroforming is performed in this state, electroforming will be performed up to the oxidized layer.

Usually, in order to remove this oxide layer, a dummy electrode 4 made of copper or the like with high conductivity is used, as shown in FIG. 5(a).
Electrolysis is performed using the nickel chip 1 as an anode and the dummy electrode 4 as a cathode to remove the oxide layer on the nickel chip 1. After that, as shown in FIG. 5(b),
A 9° glass master plate that has been subjected to conductivity treatment is inserted, and electroforming is performed using this as a cathode. By using the dummy electrode 4, electrolytic cleaning of the electroforming solution can be performed at the same time.

Insertion and removal of the dummy electrode 4 and the glass master disk 9° are performed by opening and closing the lid 25 of the tank.

During electroforming, the glass master disk 9° is rotated by the motor 6 so that an electroformed film of uniform thickness is obtained. In addition, the electroforming solution is guided outside the tank and circulated through a filtration filter 11 to remove dust, impurities, etc., and the temperature of the solution is controlled at 50 to 55°C for better electroforming efficiency. It is heated by a heater 10 provided in the tank 2.

In this way, an electroformed film of only nickel metal can be formed on the glass master disk 9 which has been subjected to conductivity treatment.

(Problems to be Solved by the Invention) However, the above conventional example had the following drawbacks.

l) Because the current is applied in a heated state, water in the electroforming solution evaporates during the electroforming process, and approximately 40% of the electroforming tank capacity is removed every 1O cycle.
~6% pure water needs to be added.

2) Since the glass master disk is rotated in a heated state, it is easy for droplets to fly, and the splashed liquid dries quickly, so the liquid composition and its reaction products can stain the inner space of the tank and the area around the electroforming tank. It is easy to stick.

3) Since the liquid amount, liquid composition, and pH change due to the above 1) and 2), an appropriate amount of the electroforming liquid composition alone must be directly added as appropriate for the purpose of adjustment.

4) Mist accumulates in the space above the electroforming solution in the electroforming tank, which adversely affects the conductor portion of the rotating shaft of the motor.

[Means for Solving the Problems] The present invention was made in view of the above-mentioned drawbacks of conventional electroforming devices. Specifically, the present invention performs electroforming by keeping an electroforming liquid in a tank in a hermetically sealed state. An electroforming device that includes a filtration filter, a pump that circulates the electroforming liquid through the filtration filter, and an electroforming wave! ! ! The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view of an electroforming device according to an embodiment of the present invention,
FIG. 2 is a perspective view of an electroformed glass master support device used in the electroforming apparatus. Further, FIGS. 3 and 4 are sectional views of electroforming equipment according to other embodiments of the present invention, respectively,
FIG. 2 is a perspective view of an electroformed glass master support device used in the electroforming apparatus.

In FIGS. 1 and 3, 3 is a nickel sulfamate electroforming solution for precipitating nickel metal and performing electroforming, 2 is an electroforming tank for containing the nickel sulfamate electroforming solution, and 11 is an electroforming tank. A filtration filter that circulates the nickel sulfamate electroforming solution in the casting tank and removes dust, impurities, etc. 1 is a nickel chip for forming a metal film on a conductive glass master disk, 10 is for adjusting the temperature of the liquid This is a heater for heating.

In Fig. 1, reference numeral 12 indicates an electroforming system that enables adding a required amount of electroforming liquid composition in advance and quickly mixing it with the electroforming liquid in the electroforming tank when controlling the liquid composition of the electroforming liquid. A liquid adjustment tank, 13 is a pressure pump PI for sending the electroforming liquid or adjustment liquid from the adjustment tank to the filtration filter, 14 is a liquid adjustment tank for controlling the electroforming liquid from the electroforming tank and the gas accumulated in the upper part of the electroforming tank. This is a pressurizing pump P2 for feeding into the tank.

First, in the electroforming apparatus shown in FIG. 1, the inside of an electroforming tank 2 is filled with a nickel sulfamate electroforming solution 3. An opening for inserting an electroformed glass master supporting device is provided in the upper part of the electroforming tank, into which the electroformed glass master supporting device having the configuration shown in FIG. 2 is inserted.

Electroformed glass master support device 5 used in the device shown in Fig. 1
is a holder 8 for holding a glass master disk 9 degrees formed by forming a conductive film on a glass master disk 9 having a fine pattern of irregularities such as tracking grooves and information bits, and for rotating the glass master disk 9 degrees together with this holder. A subunit consisting of a motor 6, a shaft 7 for transmitting the rotation of the motor 6 to the holder, and a subunit that is positioned at a desired position when the subunit is attached to and removed from the electroforming tank and when performing the electroforming process. a movable part 15 for setting, a flexible hatch 16 that is deformable in response to the movement of the movable part and substantially blocks the electroforming tank from the outside world while the subunit is attached to the electroforming tank; and a sealing material 17 for protecting the main body of the motor 6 from electroforming liquid.

The glass master disk 9' on which the conductive film has been formed is mounted on the holder 8 of the electroforming glass master support device 5, and inserted through the minimum necessary hole drilled in the upper part of the electroforming apparatus main body 2. The hole is covered with a flexible hatch 16 provided on the holder unit to shut off the outside atmosphere and the inside of the electroforming tank.Next, the glass master disk is rotated by 9 degrees around the movable part 15, and the electroforming tank is heated. Fix it in the optimal position for the casting process. During this movement and while the master plate 9° is set at the electroforming configuration position, the hatch 16 continues to deform and shut off the inside and outside of the electroforming tank. The material for the hatch 16 is desirably a material that does not react with the electroforming solution, has a shape that can achieve the desired deformation during the rotational movement, and does not deteriorate even if the deformation is repeated, such as Piton, which has excellent chemical resistance. (Product name) bellows etc. can be used.

In this configuration, the electroforming solution is isolated from the outside atmosphere and no space is formed above the electroforming solution, so changes in the composition of the electroforming solution due to evaporation of the solution are significantly suppressed compared to conventional devices. , the liquid composition is extremely stable. This has the effect of improving the characteristics of the metal film formed and improving the quality of the stand bar.

The electroformed glass master support device having the structure and function described above can be made into various sizes by changing the size of the opening provided in the electroforming tank and the flexible hatch provided in the electroformed glass master support device. The present invention is suitable for manufacturing optical recording media of 5.25 inches or less, especially stub bars for molding optical disks and optical cards of 3.5 inches or less.

On the other hand, the composition of the electroforming liquid, the pH 1 liquid temperature, etc. are determined in a liquid adjustment tank 12 provided separately from the electroforming tank 2. Since the present invention has a structure that suppresses evaporation of the electroforming solution as much as possible, the frequency of adjustment of the solution composition can be kept as low as possible, and the addition of the solution composition is not required for at least 20 cycles. Compared to the electroforming equipment described above, the number of times of liquid adjustment is extremely small, and the operating rate of the equipment is improved.

In FIG. 3 showing another embodiment of the present invention, the most distinctive feature is that a front chamber 18 is provided in a manner that projects from the upper part of the electroforming tank 2. This front chamber 18 plays the role of a liquid adjustment tank in the apparatus shown in FIG. The flow is controlled from the electroforming tank body 2 to the filtration filter 11 via the valve 19. As shown in FIG. 4(a), the electroformed glass master support device 5° used in this device includes a subunit similar to that shown in FIG. 2, and the electroformed glass master support device 5°. Shielding plates 20 and 21 which, when set in the front chamber 18, substantially form the ceiling and bottom of the front chamber. It is comprised of shutters 22 and 23 that are provided on the shielding plates 20 and 21 and can be opened and closed as necessary, and a flange 24 for fixing the electroformed glass master support device 5' to the front chamber.

Also in this embodiment, it is possible to suppress evaporation of the electroforming liquid as much as possible, and adjustment of the liquid composition is almost unnecessary.

The shutters 22 and 23 provided on the shielding plates 20 and 21 are opened when the electroformed glass master supporting device 5° is attached and removed, and when the electroforming liquid is circulated, thereby preventing unnecessary flow and excessive pressure. As a result, it is possible to omit a pressure release mechanism from the front chamber and the electroforming tank body, and the chances of contact with the external atmosphere can be further reduced.

The material of the 5° blocking plate and shutter of the electroformed glass master support device does not react with the electroforming liquid, maintains airtightness when attached to and removed from the front chamber, and protects the inner wall of the front chamber. It is necessary to slide. Since the shape is simple, there is a large degree of freedom in selecting the material, and as long as it has excellent chemical resistance, it can be selected from a wide range of materials, including inorganic/metallic materials and organic/polymeric materials.

Alternatively, the structural function and the sliding function of the front interior wall may be separated and combined using different materials. For example,
A suitable material is one in which a skeleton made of high-quality stainless steel is coated with a resin material such as Pyton (trade name), which has excellent chemical resistance.

The shape and diameter of the opening of the front chamber in this embodiment are as follows:
It can be set freely as long as it is within the design constraints of being installed on the top of the electroforming tank, but it will not be effective if it is substantially smaller than the top lid of the electroforming tank in the conventional example (for example, Fig. 5-25). The size of the glass master disk that can be electroformed using the electroforming apparatus with this configuration, which has a high can be produced. Furthermore, depending on the shape of the opening of the front chamber, it is also possible to manufacture an irregularly shaped stun R-. Also, as shown in Figure 4(b),
By configuring the holder part 8 to be swingable around the rotation axis of 15 degrees with respect to the shaft 7, it is possible to electroform a glass master without being restricted by the shape or size of the opening. For example, a stamper (two-cavity stamper) capable of molding two disc-shaped media at the same time can be produced seamlessly using a single electroforming process.

As mentioned above, by providing a front chamber at the top of the electroforming tank,
There is no need to provide a liquid adjustment tank outside the electroforming tank, and the apparatus can be more space-saving than the embodiment shown in FIG.

[Example] Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 An optical disk stamper was produced using an electroforming apparatus having the configuration shown in FIG.

An electroforming tank with a capacity of 100 ff was filled with an electroforming solution having the following composition up to the bottom of the opening of the electroforming tank.

Nickel sulfamate tetrahydrate [Ni (N)ltsOs)2 4H,0 no
500g #2 boric acid [83BO3]
35-38g/Flood bit inhibitor
2.5nl / 1 Next, a glass master plate 9' with a diameter of 35 cm on which a conductive film has been formed in advance is set on the electroformed glass master support device 5 having the configuration shown in Fig. 2, and inserted through the opening of the electroforming tank. Then, the flexible hatch 16 is fixed in the opening and sealed to prevent liquid leakage. Further, the electroforming liquid is added from the liquid adjustment tank 12 to fill the inside of the electroforming tank with the electroforming liquid. At this time, the pH of the electroforming solution is adjusted to between 3 and 5.

After setting as above, apply the IOV DC voltage so that the nickel chip is positive and the glass master is negative. The electroforming solution was circulated at a rate of 5 to 104/min using pumps Pl and P2, and electroforming was performed for 4 hours while rotating the motor 6 at a speed of 30 rpm.
A 200 μm thick nickel film was deposited on a glass master. Note that the liquid temperature was set at 55°C. A nickel stump bar with excellent performance was obtained by peeling off the nickel film from the glass master disk.

Electroforming was performed 20 times in the same manner without adjusting the liquid, but all of the stampers obtained were the same as those of the first stamper.

Example 2 An electroforming device having a capacity of 100° C. as shown in FIG. 3 was used. The same apparatus was filled with the same electroforming solution as in Example 1 up to the top of the piping in the front chamber, and a 35 cm diameter plate with a conductive film pre-formed at 5 degrees of the electroformed glass master support device having the configuration shown in Fig. 4(a) was prepared. A glass master disk 9゛ was set and inserted into the electroforming tank from the front chamber.

At this time, the shutters 22 and 23 provided on the shielding plates 20 and 21 were opened and slowly inserted.

After setting as above, shutters 22 and 23
Close the IOV DC voltage plus the nickel tip,
Apply voltage to the glass master so that it becomes negative. The electroforming solution is circulated at a rate of 5 to 104/min by pumps P1 and P2, and electroforming is carried out for 4 hours while rotating the motor 6 at a speed of 30 rpm, so that a nickel film with a thickness of 200 μm is formed on the glass master disk. was deposited in Note that the liquid temperature was set at 55°C. A nickel stamper with excellent performance was obtained by peeling off the nickel film from the glass master.

Electroforming was performed 20 times in the same manner without adjusting the liquid, but all of the stampers obtained were the same as those of the first stamper.

〔Effect of the invention〕

As explained above, according to the apparatus of the present invention, contact between the electroforming liquid and the outside air can be minimized, evaporation of the liquid is suppressed, and the frequency of replenishment of pure water and electroforming liquid composition is reduced. This significantly reduces the amount of dirt inside and around the electroforming tank, making it safer to work with.Also, when adjusting the liquid, the electroforming liquid composition can be replenished as the adjustment liquid, reducing the time it takes to equalize the concentration. Since the liquid composition is stabilized, the quality of the metal film formed is good, and it becomes possible to manufacture a high quality stamper.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an electroforming device according to an embodiment of the present invention;
FIG. 2 is a perspective view of an electroformed glass master support device used in the electroforming apparatus. 3 and 4 are respectively a sectional view of an electroforming apparatus according to another embodiment of the present invention, a perspective view of an electroformed glass master support device used in the electroforming apparatus, and FIG. 5 is a conventional FIG. 6 is a cross-sectional view showing a typical aspect of the electroforming apparatus of FIG. 1... Nickel chip 2... Electroforming tank body 3...
Electroforming liquid 5...Electroformed glass master support device 6...Motor 7...Shaft 8...Holder 9...Glass master 10...Heater 11...Filtration filter 12... Liquid adjustment tank 13.14...Pump 15...Movable part
16... Flexible hatch 18... Front chamber

Claims (1)

[Scope of Claims] 1. An electroforming device that performs electroforming by keeping an electroforming liquid in a tank hermetically, which comprises a filtration filter, a pump that circulates the electroforming liquid through the filtration filter, and an electroforming device. 1. A closed type electroforming device comprising a casting liquid adjustment tank and a removable electroformed glass master supporting device. 2. The electroforming apparatus according to claim 1, further comprising a pump for degassing and an opening for the electroformed glass master support device in the upper part of the electroforming apparatus. The casting device 3, the electroformed glass master support device includes a subunit consisting of at least a holder for holding the electroformed glass master, a motor for rotating the holder, a shaft for transmitting the rotation of the motor to the holder, and the subunit. 3. The electroforming tank according to claim 2, further comprising a member fixed to the unit and operatively connecting the subunit to the electroforming tank body, and a flexible hatch for keeping the electroforming tank sealed. electroforming equipment. 4. The electroforming apparatus according to claim 1, wherein the electroforming liquid adjustment tank is a front chamber protruding from the upper part of the electroforming tank main body. 5. An electroformed glass master support device includes the subunit, a member fixed to the subunit and connecting the subunit to the electroforming tank body, and a member that maintains the electroforming tank hermetically and supports the electroforming equipment. 5. The electroforming apparatus according to claim 4, further comprising a blocking plate constituting a front chamber.