JPH01194973A - Applicator for spin coating - Google Patents

Abstract

PURPOSE:To prevent a splash of scattered coating material from being stuck on a member to be coated by providing a nozzle for application to a supporting turntable which is rotated while supporting the member to be coated thereon and furthermore providing a plurality of fins on a concentric circle around the supporting turntable at nearly equiintervals to the nearly radiate directions from the center of this turntable. CONSTITUTION:While coating for a protective film dropped through a nozzle 10 for application allows to be transferred to the peripheral edge direction with centrifugal force caused by high-speed rotation of a compact disk 5, a paint film having uniform thickness of about 5-10mu is formed on this disk 5. At a time for this formation, excess coating is scattered from the outer peripheral edges of the disk 5 by centrifugal force but allowed to collide against the fins 7 which are provided nearly radiately from the center of a housing 4 to the vertical direction and scattered toward the outside directions of the fins 7. Therefore the coating droplets 5a directed to the direction of the compact dick 5 are made extremely little. Even if the coating droplets 5a are rebounded to the direction returned to the disk 5, these are allowed to collide against the adjacent fins 7 and do not return to the disk 5 and not stuck thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention provides a method for forming a coating film having a substantially constant average thickness on a member to be coated, such as an audio digital disc commonly referred to as a compact disc. This invention relates to an improvement in a spin coating coating device that drops coating material onto a rotating member to be coated, uses centrifugal force to stabilize the coating thickness, and blows away excess coating material using centrifugal force.

[Conventional technology]

A conventional spin coating coating device used for manufacturing compact discs will be explained with reference to FIGS. 11 and 12.

Reference numeral 1 denotes a support rotary table which supports and rotates a compact disc.A housing 2 is provided around the support rotary table at a constant interval.A reflecting plate 3 on the upper part of which intersects with the compact disc surface is connected to the compact disc surface. It has a conical surface forming an angle of 45 degrees.

Therefore, when a coating material that forms a coating film is dropped onto the compact disc surface and the compact disc is rotated at high speed, the centrifugal force causes the coating material to move outward, leaving a -like thickness of the coating material on the compact disc surface. Form.

The excess coating material after forming the coating surface is blown away from the periphery of the compact disk in a substantially tangential direction by centrifugal force, hits the reflector plate 3, and drips below the housing 2.

Therefore, a coating surface having a uniform thickness is formed on the surface of the compact disc, and excess coating material does not accumulate on the periphery of the compact disc.

[Problem to be solved by the invention]

In such a spin coating application device, the coating material that flies from the periphery of the compact disc in a substantially tangential direction hits the reflector plate 3, and a part of it bounces off.
It may re-adhere to the compact disc surface.

In order to prevent adhesion due to this rebound, reflector 3
and the periphery of the compact disc to prevent splashed coating material from reaching the compact disc.

As a result, the overall size of the device has increased, which has the disadvantage of worsening the space factor.

Moreover, even with such an increase in size, a portion of the disc still bounces off the surface of the compact disc, resulting in a poor finish of the product and a reduction in yield.

[Means to solve the problem]

The present invention solves the above-mentioned drawbacks of the conventional spin coating coating device, and although it is miniaturized and the space factor is improved, the spin coating coating device prevents the splashing of the coating material from adhering to the coated member. The means includes a support rotary table that supports and rotates a member to be coated, and a coating device for dropping a coating film material onto the rotary member supported on the support rotary table. This is done by a spin coating application device that includes a nozzle and a plurality of fins installed approximately radially from the center of the support rotary table at approximately equal intervals on a concentric circle around the support rotary table.

[Function] In the uninvented spin coating application device, the coating material scattered by centrifugal force from the periphery of the member to be coated hits the fins.

However, since the fins are arranged in a vertical direction approximately radially from the center, the droplets that bounce off the fins fly away toward the outside of the fins, causing the coating material to flow toward the member to be coated. There are very few droplets.

Even if it bounces back toward the coating material, there is a very high probability that it will hit an adjacent fin, and there will be almost no coating material that will bounce back onto the member to be coated.

[Embodiments of the invention]

An embodiment of a spin coat coating device used for coating the back side (label side) of a compact disc according to the present invention will be described.

In FIGS. 1 and 2, reference numeral 4 denotes a housing, and a rotary shaft 6 on which a compact disk 5 is placed and rotates is provided inside the housing.

Fins 7, which will be described later, are attached to the housing 4 around the periphery of the compact disc 5, which is supported and rotated by the rotating shaft 6.

In addition, exhaust ports 8 are provided at the four corners of the housing 4, and the air supplied from the air supply port 9 provided at the center of the housing 4 is discharged from the exhaust port 8, and the air such as the solvent of the coating material is removed. These substances are discharged together with this exhaust gas.

10 is a coating nozzle, for example, 5D-1 manufactured by Dainippon Ink.
7 or the like, and can be moved between the positions indicated by the chain lines in FIG.

As shown in FIGS. 3 and 4, the fins 7 are connected to the rotating shaft 6.
40 pieces radially at 9 degree intervals in concentric circles from the center of
Moreover, they are arranged in rows with an inclination of 15 degrees in the vertical direction.

The protective coating paint dripped from the coating nozzle 10 moves toward the periphery due to the centrifugal force generated by the high-speed rotation of the compact disc 5, and is spread onto the compact disc 5 to a uniform thickness of about 5 to 10 microns. Forms a coating film.

The protective film paint that was surplus to form this paint film is scattered by centrifugal force from the outer periphery of the compact disc 5, but the direction in which the paint droplets 5a fly is as follows:
The angle α with respect to the tangent Z to the outer periphery of the compact disc 5 extends in a direction of 0 to 30 degrees.

Then, as shown in FIG. 6, the paint droplet 5a is θ
However, if the angle θ is less than 45 degrees, the reflection angle will be smaller than θ, and more paint droplets 5a will adhere to the surface Y, causing the paint droplets to bounce back. Experiments have revealed that 5a is reduced.

In this embodiment, since the fin 7 is installed at a position slightly apart from the outer periphery of the compact disc 5, the paint droplets 5a from the two points A and A' in FIG. The angle of incidence can be determined as follows.

n=oτ'=r (radius) 0 is the center of rotation 0B=f
OB' = i' ZBOA = aα = angle of deviation from the tangent of the circle of radius r β - ZBOc = ZAOA', and assuming that the angle of the installation interval of the fins 7 is ZABO = θ = - (a + α).

Also, the distance 2 from the rotation center O to which the paint droplet 5a hits the fin 7 is
Similarly, the incident angle θ' from A' and the distance 2' are ZA'
B'O=θ'-θ-β=--(a+β+α).

Then, from the cosine theorem, if we set cos a=x and sin cr=b, then f”x”
+2r2(b”1)x −b”r”−b2j!”+
r2=0.

If we calculate this in the order of radius 60 of the compact disc 5, it is α - 0 to 30 degrees as mentioned above, so we calculate it assuming a paint viscosity of about 35 cps, a rotation speed of 3000 rpm, and an installation interval of fins 7 of 9 degrees (40 discs). , when θ=45 degrees, α-0 degrees (θ'-36 degrees, a=45 degrees)! ! , = 85 valence, f' = 102 cylinder.

Therefore, the inner diameter of the fin 7 was set to 851 nI according to 2 above.
11, when α=30 degrees, ff1=85mm,
1' = 108.3 Peng.

Therefore, if the outer diameter of the fin 7 is 110 mm, the angle of incidence of the paint droplet 5a on the fin 7 will be 45° or less.

Therefore, most of the paint droplets 5a scattered by the centrifugal force adhere to the fins 7, and the paint droplets 5a that have been rebounded are scattered in the direction of the outer diameter of the fins 7.

Moreover, the paint droplet 5a that bounced back due to diffused reflection hits the adjacent fin 7.
Most of the paint drops 5a reach the compact disc 5, and almost no paint drops 5a reach the compact disc 5.

In this way, the paint droplets 5a attached to the fins 7
Since the fins are tilted at an angle of 15 degrees in the vertical direction, this makes it easier for them to flow down, and fewer things get stuck on the fins 7.

As shown in FIG. 8, the fin 7 has an end surface, and the reflection angle of the paint droplet 5a that hits this end surface is directed toward the compact disc 5.
There is a risk that a may adhere to the compact disc 5.

In order to reduce this as much as possible, it is desirable to chamfer the end faces of the fins 7 to reduce the amount of paint droplets 5a hitting the end faces.

Furthermore, FIGS. 9 and 10 show another embodiment, in which the angle of the fin 7 is oblique by an angle T with respect to the radiation ffl passing through the center of rotation.

The incident angles θ", θ" of the paint droplets 5a in this example are as follows: ZBOA-r=θ"=θ-γ ZBDA'=θ'-θ-T-β ZDOB=ψ.

Therefore, the incident angles θ'', θ~ of the paint droplets 5a become smaller, making it possible to reduce the number of paint droplets 5a that bounce back than in the previous embodiment.

However, the angle of incidence of the paint droplets 5a on the end surface of the fin 7 is 45 degrees or more as shown in FIG. is more necessary than in the previous example.

Furthermore, even if the inner diameter P = 85 of the body and the interval angle β of the fins 7 = 9 degrees, and the inclination angle T of the fins 7 = 10 degrees, 0D = 119.4 mm.
Therefore, the inner diameter of the housing 4 has to be increased.

[Effects of the Invention] The present invention provides ridges on the outer periphery of the member to be coated.
Since the fins are arranged radially from the center, the coating droplets scattered by centrifugal force from the member to be coated will be incident on the fins at an angle of 45 or less, so most of them will stick to the fins and only a few will bounce back. .

Even if it rebounds, the angle of reflection is in the direction away from the member to be coated, so the rebounded coating droplet will not adhere to the member to be coated.

Furthermore, even if some coating droplets bounce back due to diffuse reflection, most of them will hit the adjacent fins, so the scattered coating droplets will not return and adhere to the member to be coated.

Furthermore, by installing such fins, the outer diameter of the fins is reduced, so that the overall device is miniaturized and the space factor is improved.

This has effects such as improving product yield and reducing contamination inside and outside the device.

[Brief explanation of the drawing]

1 is a sectional view taken along the line A-A in FIG. 2 showing an embodiment of the present invention, FIG. 2 is a plan view of the same as above, FIG. 3 is a side view of the fin, FIG. 4 is a plan view thereof, Figure 5 is an explanatory diagram of the scattering direction of paint droplets, Figure 6 is an explanatory diagram of the angle of incidence, Figure 7 is an explanatory diagram of the fin and the paint droplets that scatter, and Figure 8 is an enlarged explanatory diagram of a part of it. Figure 9 is an explanatory diagram of another embodiment of the fin and the paint droplets that fly away, Figure 10 is an enlarged explanatory diagram of a part of the same as above, and Figure 11 is B-B in Figure 12 of a conventional spin coating applicator. A line sectional view, and FIG. 12 is a plan view of the same. 5...Compact disc, 5a...Paint drop, 6.
... Rotating shaft, 7... Fin, 8... Exhaust port, 9...
・Air supply port, 10... Application nozzle.

Claims (1)

[Claims] a support rotary table that supports and rotates a member to be coated; a coating nozzle that drips a coating film material onto the member to be coated that is supported and rotates on the support rotary table; and a concentric circle around the support rotary table. 1. A spin coating coating device comprising: a plurality of fins installed at substantially equal intervals in a substantially radial direction from the center of a support rotary table.