JP2000334368A - Spin coating equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To form a high-precision coating film without sucking mist-like paint into the inside. SOLUTION: A coating material is supplied to an inner peripheral end portion on one main surface of a disk-shaped substrate, and the disk-shaped substrate is rotated in an in-plane direction to form a coating film on one main surface of the disk-shaped substrate. In the spin coating apparatus, the other main surface of the disc-shaped substrate is placed, and a support table for rotatably supporting the disc-shaped substrate, and the other main surface of the disc-shaped substrate supported by the support table, And a gas flow generator for supplying a gas flow flowing outward between the other main surface of the disc-shaped substrate supported by the support and the back plate. Things.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spin coating apparatus for supplying a coating material to an inner peripheral end on one principal surface of a disk-shaped substrate and rotating the coating material to form a coating film.

[0002]

2. Description of the Related Art An optical disk such as a magneto-optical disk has a protective layer made of an ultraviolet curable resin as an outermost layer so as to cover a recording layer such as a magnetic layer and a reflective layer. This protective layer protects the recording layer and reflective layer of the optical disc,
It is formed for an antistatic effect and for improving the surface hardness.

In forming this protective film, a spin coating apparatus 100 as shown in FIGS. 4 and 5 has been conventionally used.
Is used. This spin coating apparatus 100
A support 102 on which a disc-shaped substrate 101 having a recording layer and a reflective layer formed on a substrate is placed;
An outer-side pressing member 103 disposed opposite to an outer-peripheral side 101a of the disk-shaped substrate 101 placed on the substrate 101, and an air blow is generated between the outer-side pressing member 103 and the outer-peripheral side of the disk-shaped substrate 101. An air supply device (not shown).

[0004] In the spin coating apparatus configured as described above, the disc-shaped substrate 101 is placed on the support table 102,
The paint is supplied to the inner peripheral end of the disc-shaped substrate, and the disc-shaped substrate 101 is rotated in a predetermined direction. The rotation of the disc-shaped substrate 101 causes a centrifugal force to act on the supplied paint, and spreads over one main surface of the disc-shaped substrate 101 with a predetermined thickness. Thus, in the spin coating apparatus, a coating film having a predetermined thickness can be formed on one main surface of the disc-shaped substrate 101.

At this time, in the spin coating apparatus,
An air blow is generated outward from the air supply device between the outer peripheral holding member 103 and the outer peripheral side 101a of the disc-shaped substrate 101. According to this air blow, the excessive paint shaken off from the outer peripheral side 101a of the disc-shaped substrate 101 by the centrifugal force is prevented from entering the inside of the spin coating apparatus.

[0006]

However, in the conventional spin coating apparatus described above, the disk-shaped substrate 1
When a predetermined film is formed on one main surface of the disc-shaped substrate 01, the mist-like paint may adhere to the surface of the other main surface of the disc-shaped substrate 101 in some cases. In this case, the manufactured optical disk or the like causes a reading error such as a focus error or a tracking error due to the applied paint, and thus has a practical problem.

[0007] In the above-mentioned optical disk and the like,
In some cases, a protective film is formed on not only one main surface on which the recording layer and the reflective layer are formed but also both main surfaces. In the conventional spin coating apparatus as described above, when forming a protective film or the like on both main surfaces, a mist-like paint may adhere to the previously formed protective film. As described above, the conventional spin coating apparatus has a problem that a highly accurate coating film cannot be formed.

Accordingly, the present invention has been proposed in view of such a conventional situation, and a highly accurate coating film can be formed without sucking the atomized paint into the inside. To provide a spin coating device

[0009]

Means for Solving the Problems As a result of intensive studies by the present inventors to achieve the above-mentioned object, in the conventional spin coating apparatus, even if the above-mentioned air blow is generated, the air which is a viscous fluid is generated. As a result, centrifugal force is generated near the disk-shaped substrate rotating at high speed, negative pressure is generated near the support base and the mist-like paint is sucked. As a result, the mist-like paint is placed on the surface placed on the support base. The inventors have found a phenomenon in which the particles adhere, and have completed the present invention.

That is, the spin coating apparatus according to the present invention, which has achieved the above-mentioned object, supplies a coating material to an inner peripheral end on one principal surface of a disk-shaped substrate and rotates the disk-shaped substrate in an in-plane direction. In a spin coating apparatus for forming a coating film on one main surface of the disc-shaped substrate, a support base on which the other main surface of the disc-shaped substrate is placed and rotatably supports the disc-shaped substrate, A back plate facing the other main surface of the disc-shaped substrate supported by the support table at a predetermined interval,
A gas flow generator for supplying a gas flow flowing outward is provided between the other main surface of the disc-shaped substrate supported by the support table and the back plate.

[0011] In the spin coating apparatus according to the present invention having the above-described structure, the gas flow generating device outwardly extends between the other main surface of the disc-shaped substrate supported on the support table and the back plate. To generate a flowing gas stream.
In this spin coating apparatus, the backing plate faces the other main surface of the disk-shaped substrate at a predetermined interval, and this interval serves as a gas flow path. That is, the gas flow flows along the other main surface of the disk-shaped substrate and is ejected outward.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of a spin coating apparatus according to the present invention will be described with reference to the drawings.

The spin coating apparatus according to the present invention is applied to, for example, an apparatus in which a protective film such as an ultraviolet curable resin is formed on both principal surfaces 1a and 1b of a disk-shaped substrate 1 as shown in FIG. The spin coating apparatus includes a support table 2 for supporting a disk-shaped substrate 1, and a coating material supply apparatus 3 for supplying a coating material to an inner peripheral end of one main surface 1 a of the disk-shaped substrate 1 supported by the support table 2. And a back plate 4 disposed at a position facing the other main surface 1b of the disc-shaped substrate 1 supported by the support 2 at a predetermined interval. Although not shown, the spin coating apparatus includes a gas flow generator that supplies gas from between the support base 2 and the back plate 4.

An example of the disk-shaped substrate 1 is a magneto-optical disk. This disk-shaped substrate 1
It includes a hard substrate such as a glass substrate, a magnetic film formed on the hard substrate by a thin film forming method such as vapor deposition, and a reflective film made of an aluminum film and formed on the magnetic film. Although not shown, the disc-shaped substrate 1 has a center hole having a predetermined diameter. The disk-shaped substrate 1 is not limited to a magneto-optical disk having such a configuration.
In addition, a configuration having a dielectric film or the like may be employed. In addition, examples of the disk-shaped substrate 1 include a disk-shaped recording medium such as a phase-change optical disk and a vapor-deposited magnetic recording medium.

The support 2 has a columnar shape with a smaller diameter than the disk-shaped substrate 1, and has one main surface as a mounting surface 5 on which the disk-shaped substrate 1 is mounted. The mounting surface 5 is provided with a fitting protrusion 6 that fits into the center hole of the disc-shaped substrate 1. The fitting protrusion 6 has a clamping function for fitting the center hole of the disc-shaped substrate 1 and fixing the disc-shaped substrate 1. For this reason, the disc-shaped substrate 1 is fixed to the mounting surface 5 by fitting the center hole thereof to the fitting projection 6.

The support base 2 is connected to a motor (not shown) for rotating the disc-shaped substrate 1 fixed to the fitting projection 6 at a predetermined rotation speed. In other words, in this spin coating apparatus, the rotational force from the motor is transmitted to the fitting protrusion 6, and the disc-shaped substrate 1 fixed to the fitting protrusion 6 can be rotated together with the fitting protrusion 6. . Specifically, the disk-shaped substrate 1
Rotates at 2000 to 4000 [rpm].

The coating material supply device 3 includes a coating nozzle 7 disposed to face the inner peripheral side of the disk-shaped substrate 1 fixed to the support 2 and a coating tank (see FIG. 1) connected to the coating nozzle 7. Not shown). This paint supply device 3
The discharge amount of paint is controlled, and a predetermined amount of paint can be supplied onto one main surface 1a of the disc-shaped substrate 1. At this time, the paint is supplied around the center hole of the disc-shaped substrate 1 over the circumference.

The back plate 4 has a flange portion 8 facing the other main surface 1b of the disc-shaped substrate 1 fixed on the support base 1.
And a tubular portion 9 formed in a tubular shape so as to face the side surface of the support base 2 at a predetermined interval. The flange portion 8 is formed in a hollow disk shape with an inner peripheral base end portion 8a connected to the cylindrical portion 9. Also, the flange 8
The main surface 8 b of the disc-shaped substrate 1 fixed to the mounting table 5 is positioned lower than the mounting surface 5 of the support 2.
b with a predetermined interval.

The inner diameter of the cylindrical portion 9 is
Since it is formed so as to have a larger diameter, the inner peripheral surface thereof faces the side surface of the support 2 at a predetermined interval. Therefore, in this spin coating apparatus, the support 2
In the state where the disc-shaped substrate 1 is fixed to the mounting surface 5, a predetermined interval is formed between the side surface of the support base 2 and the other main surface 1 b of the disc-shaped substrate 1 and the back plate 4. .

The gas flow generating device applies, for example, an inert gas such as Ar gas to a predetermined space formed between the side surface of the support 2 and the other main surface 1b of the disc-shaped substrate 1 and the back plate 4. It is supplied under pressure to generate a gas flow in the interval. This gas flow generating device supplies gas from below between the side surface of the support base 2 and the inner peripheral surface of the tubular portion 9 to generate a gas flow. The gas flow thus supplied is ejected from the outer peripheral portion between the flange portion 8 and the other main surface 1b of the disc-shaped substrate 1.

The spin coating apparatus configured as described above forms a protective film on both main surfaces 1a and 1b of the disk-shaped substrate 1 fixed on the support 2. This protective film is formed, for example, by forming a coating film made of a UV-curable resin in a molten state with a predetermined thickness on the disc-shaped substrate 1 and then irradiating the coating film with ultraviolet rays to apply the coating film. It is formed by curing. That is, the spin coating device is
In order to form protective films on both principal surfaces 1a of the disc-shaped substrate 1, respectively, a coating film made of an ultraviolet curable resin is formed on both principal surfaces 1a of the disc-shaped substrate 1.

When forming a coating film made of an ultraviolet-curable resin on both main surfaces 1a and 1b of the disc-shaped substrate 1, first, a coating film made of an ultraviolet-curable resin is formed on one main surface 1a. Thereafter, the coating film is irradiated with ultraviolet rays to be cured, and then a coating film made of an ultraviolet-curable resin is formed on the other main surface 1b, and then the coating film is irradiated with ultraviolet rays to be cured.

When forming a coating film made of an ultraviolet curable resin on one main surface 1a of the disc-shaped substrate 1, first, the other main surface 1b of the disc-shaped substrate 1 is placed on the mounting surface 5 of the support base 2. The center hole is fitted to the fitting projection 6 so as to be placed. This allows
The disc-shaped substrate 1 is fixed to a spin coating device.

Next, a predetermined amount of an ultraviolet curable resin is supplied to one main surface of the disc-shaped substrate 1 in the vicinity of the center hole. At this time, the ultraviolet curable resin is filled in the paint tank of the paint supply device 3 in a molten state. Then, the ultraviolet curable resin is supplied along the circumference to the vicinity of the center hole on one main surface of the disc-shaped substrate 1 through the application nozzle 7.

Next, the disk-shaped substrate 1 is rotated at a predetermined speed in the in-plane direction, and the ultraviolet-curable resin supplied along the circumference in the vicinity of the center hole is uniformly centrifugally applied to the in-plane direction. Spread with. As a result, as shown in FIG. 2, a coating film having a predetermined thickness is formed on one main surface 1a of the disc-shaped substrate 1. At this time, in the spin coating device,
An excessive amount of paint is supplied on one main surface 1a, and the excess paint is shaken off from the outer peripheral side of the disc-shaped substrate 1 by centrifugal force. In addition, this coating film, due to the surface tension of the paint,
It is also formed on the outer peripheral end surface of the disc-shaped substrate 1 and the outer peripheral end of the other main surface 1b.

At this time, in the spin coating apparatus,
As described above, the gas flow is generated by the gas flow generation device on the side surface of the support base 2 and the space between the other main surface 1 b of the disc-shaped substrate 1 and the back plate 4. This gas flow is jetted from the outer periphery between the flange portion 8 and the other main surface 1b.

Therefore, according to the spin coating apparatus, the paint that has been shaken off from the outer periphery of the disk-shaped substrate 1 can be blown off by the gas flow ejected from the outer periphery between the flange portion 8 and the other main surface 1b. For this reason, in the spin coating apparatus, it is possible to prevent the paint shaken off from the outer periphery of the disk-shaped substrate 1 from flowing into the apparatus.

In particular, in this spin coating apparatus,
The gap between the other main surface 1b of the disc-shaped substrate 1 and the side surface of the support 2 and the back plate 4 forms a gas flow passage. In particular, in the coating apparatus, the other main surface 1b of the disc-shaped substrate 1
From the inner peripheral side to the outer peripheral side in the other main surface 1b
Will flow along the line. For this reason, in this coating apparatus, the vicinity of the other main surface 1b of the disc-shaped substrate 1 is prevented from becoming negative pressure. That is, when the disc-shaped substrate 1 rotates at a high speed such as 2000 to 4000 [rpm], a centrifugal force acts on air which is a viscous gas existing near the other main surface 1 b. The other main surface 1 because the nearby space is a gas flow path
The space near b and the support 2 does not become negative pressure due to this gas flow.

As described above, in the spin coating apparatus, since there is no negative pressure space near the other main surface 1b of the disc-shaped substrate 1, the paint blown off by the gas flow is sucked in the form of mist. Nothing. Thus, in the spin coating apparatus, a desired coating film can be formed on one main surface 1a without contaminating the other main surface 1b of the disc-shaped substrate 1. For example, specifically, the coating film is formed by setting the rotation speed of the disc-shaped substrate 1 to 3000 rpm, the rotation time to 3 seconds, and the pressure of the supplied gas to ² to 3 kgf / cm ² .

Next, the coating film formed on one main surface 1a of the disc-shaped substrate 1 is irradiated with ultraviolet rays. Thereby, the coating film formed on one main surface 1a is cured, and the one main surface 1a is cured.
The first protective film 10 can be formed on a.

Next, a coating film made of an ultraviolet curable resin is formed on the other main surface 1b of the disc-shaped substrate 1. The first protective film 10 formed on one main surface 1a of the disk-shaped substrate 1
The center hole is fitted to the fitting convex portion 6 so as to be placed on the placing surface 5 of. Thus, the disc-shaped substrate 1 is fixed to the spin coating device.

Then, as shown in FIG. 3, in the same manner as described above, a coating film made of an ultraviolet-curable resin is formed on the other main surface 1b of the disc-shaped substrate 1 and irradiated with ultraviolet light to form a coating film. A second protective film 11 is formed. Note that the second protective film 11 is also formed on the outer peripheral end surface of the disc-shaped substrate 1 and the outer peripheral end of the first protective film 10 due to the surface tension of the paint.

In this case, one main surface 1a of the disc-shaped substrate 1
Since the flow path of the gas flow is formed between the first protective film 10 formed above and the flange 8, it is possible to prevent the mist-like paint from adhering to the first protective film 10. Is done. Therefore, this spin coating apparatus can manufacture a magneto-optical disk having excellent recording / reproducing characteristics without causing a focus error or a tracking error due to adhesion of mist-like paint.

In the spin coating apparatus as described above, the main surface 8a of the flange 8 is preferably located at a position lower than the mounting surface 5 of the support 2 by 1 to 3 mm. That is, in this spin coating apparatus, in the state shown in FIG. 2, the distance between the other main surface 1b of the disc-shaped substrate 1 and the main surface 8b of the flange portion 8 is preferably 1 to 3 mm. If this interval is smaller than 1 mm, the disc-shaped substrate 1 rotating at a high speed is likely to come into contact with the back plate 4 due to surface deviation or the like, and the disc-shaped substrate 1 is damaged. There is a risk of doing this. When the distance is larger than 3 mm, a negative pressure area is generated near the other main surface 1b of the disk-shaped substrate 1 and the support 2 in the state shown in FIG. There is a possibility that the paint may be sucked. Therefore, this interval is 1 to 3 mm
By doing so, the suction of the mist-like paint is reliably prevented, the disc-shaped substrate 1 can be stably rotated at a high speed, and a magnetic disk can be manufactured with excellent productivity.

For the disk-shaped substrate 1 having a radius of 130 mm, the number of rotations is 3000 rpm, and the rotation time is 3 minutes.
And the pressure of the supplied gas is 2-3 kgf / cm ^2.
When the distance was set to 3 mm, suction of the mist-like paint could be reliably prevented.

Further, in this spin coating apparatus, the larger the width dimension of the flange portion 8 indicated by L in FIG. 2 is, the more effective it is. However, when the radius of the disc-shaped substrate 1 is 130 mm, it is more than 10 mm. Preferably, it is more preferably 15 mm or more. When the radius of the disk-shaped substrate 1 is 130 mm, the flange 8
By setting the width dimension to 10 mm or more, suction of the mist-like paint can be reliably prevented.

Further, the flange portion 8 is formed on the disc-shaped substrate 1.
Are projected between the outer peripheral end surface of the disc-shaped substrate 1 and the outer peripheral end surface of the flange portion 8 (indicated by M in FIG. 3).
mm. Both main surfaces 1 of disc-shaped substrate 1
At the outer peripheral end portions a and 1b, there is a region where the first protective film 10 and the second protective film 11 overlap each other. For this reason, when the disk-shaped substrate 1 is rotated to cause surface blur, the thick region where the first protective film 10 and the second protective film 11 overlap with each other collides with the flange portion 8. Cheap. For this reason, by setting the interval indicated by M in FIG. 3 to 1 to 3 mm, even when an unexpected surface shake or the like occurs on the disc-shaped substrate 1, the flange portion 8 collides with the outer peripheral side of the disc-shaped substrate 1. Can be reliably prevented.

Further, in the spin coating apparatus, the back plate 4 is preferably made of polytetrafluoroethylene. By forming the back plate 4 from polytetrafluoroethylene, the back plate 4 is excellent in water repellency, and can prevent adhesion of paint. For this reason, in the spin coating apparatus, by forming the back plate 4 from polytetrafluoroethylene, it is possible to reliably prevent the paint from flowing into the apparatus.

[0039]

As described in detail above, the spin coating apparatus according to the present invention flows outward between the other main surface of the disc-shaped substrate supported by the support and the back plate. Supplying gas flow. Therefore, according to the spin coating apparatus, a highly accurate coating film can be formed without sucking the atomized paint into the inside.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a spin coating apparatus shown as an example of the present invention.

FIG. 2 is a sectional view of a main part of the spin coating apparatus showing a state where a first protective film is formed.

FIG. 3 is a sectional view of a main part of a spin coating apparatus showing a state where a second protective film is formed.

FIG. 4 is a schematic configuration diagram of a conventional spin coating apparatus.

FIG. 5 is a sectional view of a main part of a conventional spin coating apparatus.

[Brief description of reference numerals]

1 disk-shaped substrate, 2 support base, 3 paint supply device, 4
Back plate, 5 mounting surface, 6 fitting projection, 7 coating nozzle, 8 flange, 9 cylindrical portion, 10 first protective film, 11 second protective film

Claims (5)

[Claims] 1. A coating material is supplied to an inner peripheral end portion on one main surface of a disc-shaped substrate, and the disc-shaped substrate is rotated in an in-plane direction to form a coating film on one main surface of the disc-shaped substrate. In the spin coating apparatus to be formed, the other main surface of the disc-shaped substrate is placed, and a support base rotatably supports the disc-shaped substrate; and the other main surface of the disc-shaped substrate supported by the support base. A back plate facing at a predetermined interval, and a gas flow generator for supplying a gas flow flowing outward between the other main surface of the disc-shaped substrate supported by the support base and the back plate. A spin coating apparatus, comprising: 2. The spin coating apparatus according to claim 1, wherein a surface of the back plate facing the disk-shaped substrate supported by the support table has a smaller diameter than that of the disk-shaped substrate. 3. The spin coating according to claim 2, wherein a surface of the back plate facing the disk-shaped substrate supported by the support is smaller by 1 to 3 mm than the disk-shaped substrate. apparatus. 4. The spin coating apparatus according to claim 1, wherein a distance between the back plate and the other main surface of the disc-shaped substrate supported by the support is 1 to 3 mm. 5. The spin coating apparatus according to claim 1, wherein said back plate is coated with polytetrafluoroethylene.