JPH04300672A - Rotary coating method and apparatus of the same - Google Patents

Abstract

PURPOSE:To prevent liquid hanging and uneven coating, by keeping a constant resin discharge by blowing off the resin deposited at a needle end by ejecting compressed air to the end of resin discharging side of the needle every time when a nozzle returns to its original position after the completion of resin discharge. CONSTITUTION:A disk substrate 2 is placed on a rotary table 1, and a nozzle 4 equipped with a needle 3 is moved from its original point to the resin- discharge starting position above the inside diameter of a metal membrane of the substrate 2 to discharge the resin from the needle 3 while the substrate 2 being rotated. The nozzle 4 is transferred at a constant speed along the peripheral direction of the substrate 2 up to a terminal. Every time when the nozzle 4 returns to its original point, a pressure button 6A is pushed to eject compressed air to the end of resin discharging side of the needle 3 so that the hanging resin deposited at the end of the needle 3 is blown off.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to optical discs (compact discs), video discs, optical cards, their masters, semiconductor wafers, photomasks, and other substrates to be coated with resin, which are placed on a rotating table. , relates to a spin coating method and apparatus for coating a resin such as UV resin to a predetermined thickness on a substrate while rotating the substrate, and in particular, it ensures a stable resin discharge amount and prevents resin dripping. The present invention relates to a spin coating method and apparatus that can prevent the occurrence of coating unevenness.

0002

2. Description of the Related Art Optical recording has advantages over magnetic recording in that there is no contact between the recording medium and the head, and high-density recording is possible. These optical recording media are known to be read-only, additionally writable, and erasable and rewritable. Among these, read-only optical recording media are already known as optical discs (compact discs). ), optical video discs, and optical cars.
It has been put into practical use in the form of de, etc.

On the other hand, as a method for manufacturing this type of optical recording medium, for example, the following method is adopted. That is, a concavo-convex pattern of an information signal is transferred and formed one by one by, for example, injection molding onto a resin substrate made of plastic (generally polycarbonate), and then the concave-convex pattern of this resin substrate is formed. A metal reflective film is formed by depositing a metal such as aluminum, gold, silver, copper, tin, or nickel on the surface by vapor deposition or sputtering, and then a metal reflective film is formed on the metal reflective film by, for example, spin coating. A method of manufacturing an optical recording medium by coating a resin (generally an ultraviolet curable resin) whose main component is acrylic resin and forming a protective film layer by further drying (generally by irradiating ultraviolet rays) has been adopted.

By the way, in the production of such optical recording media, a method for forming a protective layer by coating a resin has conventionally been performed using a rotary coating device (spinner).
A spin coating method using In other words, in this spin coating method, a resin substrate on which a metal film surface is formed is placed on a rotating table (spinner head) and adsorbed.
At the same time, the nozzle with a needle attached to the tip is moved from the origin position to the resin discharge start position above the inner diameter of the metal film surface of the resin substrate, and the resin substrate is rotated at a low speed (about 70 rpm). The UV resin is discharged from the needle, and after going around the inner diameter part once, the nozzle is moved toward the outer circumference of the resin substrate at a constant speed in the shape of a "no", and the discharge of the UV resin is stopped near the outermost circumference. In this method, the resin substrate is rotated at a high speed (approximately 3000 rpm), and a resin is applied to a predetermined thickness on the resin substrate to form a protective layer.

[0005]

[Problems to be Solved by the Invention] However, such conventional methods have the following various problems. That is, when coating a protective layer using the spin coating method described above, the UV resin is discharged by repeatedly opening and closing a UV resin discharge electromagnetic on-off valve attached to a nozzle with a needle attached to the tip. However, even after the UV resin discharge electromagnetic on-off valve is closed, the UV resin drips at the resin discharge side tip of the needle. Then, in the next cycle, while the nozzle moves from the origin position to the resin discharge start position above the inner diameter of the metal film surface of the resin substrate, the above UV resin drips onto the substrate surface or is discharged at the beginning of the inner diameter of the metal film surface. There was a problem in that an amount of UV resin was discharged in an amount corresponding to the amount of the liquid pool in an amount larger than usual in the area where the coating was applied, causing coating unevenness.

[0006] The present invention has been made to solve the above-mentioned problems, and is a compact design that can always ensure a stable resin discharge amount and prevent the occurrence of resin dripping and coating unevenness. The purpose of the present invention is to provide an inexpensive and extremely reliable spin coating method and apparatus therefor.

[0007]

[Means for Solving the Problems] In order to achieve the above object, first, in the invention as set forth in claim 1, a substrate to be coated with resin is placed on a rotating table, and a needle is attached to the tip of the substrate. The nozzle is moved from the origin position to the resin dispensing start position at the upper part of the inner diameter of the substrate, and at the same time the substrate is rotated at a predetermined speed, resin is discharged from the needle, and the nozzle is moved toward the outer circumference of the substrate at a certain speed. In the spin coating method, the resin discharge is stopped near the outermost periphery, returned to the origin position, and the substrate is rotated at a predetermined speed to coat the resin to a predetermined thickness on the substrate. Every time the nozzle returns to the original position after completion, compressed gas is discharged to the resin discharge side tip of the needle to blow away the resin accumulated at the needle tip.

In the invention as set forth in claim 2, the substrate to be coated with resin is placed on a rotating table, and the nozzle having a needle attached to the tip is moved from the origin position to the resin discharging start position at the upper inner diameter of the substrate. At the same time, the resin is discharged from the needle while the substrate is rotated at a predetermined speed, and the nozzle is moved toward the outer circumference of the substrate at a certain speed, and the resin discharge is stopped near the outermost circumference to return to the origin position. In a rotary coating device that rotates the substrate at a predetermined speed to apply resin to a predetermined thickness on the substrate, compressed gas is applied to the tip of the resin discharge side of the needle in response to the movement of the nozzle. It is configured to include a compressed gas discharge device for discharging compressed gas.

[0009]

[Operation] Therefore, in the spin coating method and apparatus of the present invention, by removing the resin accumulated at the tip of the resin discharge side of the needle, a stable resin discharge amount is always ensured, and resin dripping and coating are avoided. It is possible to prevent unevenness from occurring. Moreover, since the compressed gas discharge device can be made small, the device can be made space-saving and inexpensive.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a plan view showing an example of the structure of a spin coating apparatus (here, a spinner) according to the present invention, and FIG. 2 is a sectional view showing an example of the structure of the spin coating apparatus.

In FIGS. 1 and 2, a disk substrate 2 to be coated with resin is placed on a rotating table (spinner head) 1. As shown in FIG. On the other hand, a UV resin discharge electromagnetic on-off valve 5 is attached to the other end side of the nozzle 4 with a needle 3 attached to its tip, and by repeatedly opening and closing the UV resin discharge
It is designed to discharge V resin. Further, the nozzle 4 is equipped with a pressurizing button 6A that responds to the movement of the nozzle 4, and a compressed air discharge device 6 for discharging compressed air to the tip of the resin discharge side of the needle 3 is attached to a band 7 as shown in the figure. It is provided through. Further, the nozzle 4 is moved from the origin position to a resin discharge start position above the inner diameter of the metal film surface of the disk substrate 2, and the disk substrate 2 can be rotated at a predetermined speed. Note that 8 is a fixed plate that the pressure button 6A comes into contact with when the nozzle 4 is at the original position.

FIG. 3 is a sectional view showing an example of the configuration of the compressed air discharge device 6. As shown in FIG. In FIG. 3, one opening side of the air discharge pipe 6B, which has both ends opened as shown, is attached to the nozzle 4, and one of the pressure buttons 6A is connected from the other opening side of the air discharge pipe 6B. part is exposed. Inside the air discharge pipe 6B, there is a nozzle 4 as shown in the figure.
A spring 6C is provided between the press button 6A and the press button 6A. Further, an air flow pipe 6D is attached to a part of the air discharge pipe 6B, the tip of which is directed toward the resin discharge side tip of the needle 3 as shown in the figure. Next, the operation of the spin coating apparatus according to this embodiment configured as above will be explained.

First, as shown in FIG. 2, when the nozzle 4 is at the home position, the pressurizing button 6A of the compressed air discharge device 6 attached to the nozzle 4 is always pressed by the fixing plate 8. .

Next, while the nozzle 4 is moving from the origin position to the resin discharge start position above the inner diameter of the metal film surface of the disk substrate 2, the pressure button 6A of the compressed air discharge device 6 is pressed against the spring 6.
By being pushed back by C, the air circulation pipe 6D
Air is sucked into the air discharge pipe 6B through the air discharge pipe 6B.

Next, after the discharge of the UV resin 9 is completed, as the nozzle 4 returns to the original position, the pressurizing button 6A of the compressed air discharge device 6 is gradually pushed by the fixing plate 8, so that the air discharge pipe 6B The compressed air inside the air distribution pipe 6
The UV resin is discharged through D to the tip of the resin discharge side of the needle 3, and the dripping 9 of the UV resin accumulated at the tip of the needle is blown away. Incidentally, when the present rotary coating device is not used for a long time, the fixing plate 8 can be removed from the joint 10 so as not to apply a load to the spring 6C.

As described above, in this embodiment, the disk substrate 2 to be coated with resin is placed on the rotary table 1, and the nozzle 4 with the needle 3 attached to the tip is inserted into the metal of the disk substrate 2 from the origin position. The disc substrate 2 is moved to the resin discharge start position at the upper part of the inner diameter of the membrane surface, and at the same time, the UV resin is discharged from the needle 3 and the nozzle 4 is rotated at a predetermined speed.
is moved toward the outer circumference of the disk substrate 2 at a certain speed, stops discharging the UV resin 9 near the outermost circumference, and returns to the origin position, and rotates the disk substrate 2 at a predetermined speed to move the UV resin 9 onto the disk substrate 2. When applying UV resin to a predetermined thickness, the device has a pressurizing button 6A that responds to the movement of the nozzle 4, and is equipped with a compressed air discharge device 6 that discharges compressed air to the tip of the resin discharge side of the needle 3. Then, each time the nozzle 4 returns to the original position after the discharge of the UV resin is completed, compressed air is discharged to the tip of the resin discharge side of the needle 3 to blow away the drip 9 of the UV resin accumulated at the tip of the needle. This is what I did.

Therefore, the dripping 9 of UV resin accumulated at the tip of the resin discharge side of the needle 3 can be removed each time UV resin discharge is completed, so that a stable UV resin discharge amount can always be ensured and the UV resin It is possible to prevent resin dripping and coating unevenness. Moreover, since the compressed air discharge device 6 can be made small, the device does not take up much space and can be manufactured at low cost.

In the above embodiment, the present invention is applied to an optical disc, but the present invention is not limited to this, and can be applied to optical video discs, optical cards, and other sheet-shaped optical recording media. Alternatively, the present invention can be applied in exactly the same manner to a substrate for a photomask to obtain the same effect.

In the above embodiment, the compressed air discharge device 6 discharges compressed air to the tip of the resin discharge side of the needle 3.
Although the case is described above, it goes without saying that the present invention is not limited to this, and a compressed gas discharge device for discharging other compressed gases may be provided.

[0020]

[Effects of the Invention] As explained above, according to the present invention, a substrate to be coated with resin is placed on a rotary table, and a nozzle with a needle attached to the tip is used to discharge resin from an origin position to an upper part of the inner diameter of the substrate. Move the nozzle to the starting position, rotate the substrate at a predetermined speed, simultaneously discharge resin from the needle, move the nozzle toward the outer circumference of the substrate at a certain speed,
Stop dispensing resin near the outermost circumference and return to the origin position.
When rotating the substrate at a predetermined speed to apply resin to a predetermined thickness on the substrate, compressed gas is discharged to the tip of the resin discharge side of the needle every time the nozzle returns to the origin position after discharging the resin is completed. Since the resin accumulated at the tip of the needle is blown away, a small, inexpensive, and extremely reliable product that can always ensure a stable resin discharge amount and prevent resin dripping and coating unevenness. It is possible to provide a high speed spin coating method and apparatus.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of a spin coating apparatus according to the present invention.

FIG. 2 is a sectional view showing an example of the configuration of a spin coating device in the same embodiment.

FIG. 3 is a sectional view showing a detailed configuration example of the compressed air discharge device in the same embodiment.

[Explanation of symbols]

1...Rotary table (spinner head), 2...Disc substrate, 3
... Needle, 4... Nozzle, 5... UV resin discharge electromagnetic on-off valve, 6... Compressed air discharge device, 6A... Pressure button, 6B...
Air discharge pipe, 6C...Spring, 6D...Air circulation pipe, 7...Mounting band, 8...Fixing plate, 9...UV resin dripping.

Claims (2)

[Claims] 1. A substrate to be coated with resin is placed on a rotary table, and a nozzle with a needle attached to the tip is moved from an origin position to a resin discharging start position at the upper part of the inner diameter of the substrate. While rotating at a predetermined speed, resin is discharged from the needle, the nozzle is moved toward the outer circumference of the substrate at a certain speed, and the discharge of the resin is stopped near the outermost circumference and returned to the original position, In the spin coating method, in which the substrate is rotated at a predetermined speed to apply resin to a predetermined thickness on the substrate, each time the nozzle returns to the origin position after discharging the resin, the resin in the needle is A spin coating method characterized in that compressed gas is discharged to a discharge-side tip to blow away resin accumulated at the needle tip. 2. A substrate to be coated with resin is placed on a rotary table, and a nozzle with a needle attached to the tip is moved from the origin position to a resin discharge start position at the upper part of the inner diameter of the substrate, and the substrate is coated with the resin. While rotating at a predetermined speed, resin is discharged from the needle, the nozzle is moved toward the outer circumference of the substrate at a certain speed, and the discharge of the resin is stopped near the outermost circumference and returned to the original position, In a rotary coating device that rotates the substrate at a predetermined speed to apply resin to a predetermined thickness on the substrate, compressed gas is applied to the resin discharge side tip of the needle in response to movement of the nozzle. A rotary coating device comprising a compressed gas discharge device for discharging compressed gas.