JPS6045950B2 - Rotary coating machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spin coating machine, and particularly to a spin coating machine that can provide a coated surface with good surface properties.

When coating with a rotary coating machine, when the coating liquid is dropped onto a rotating substrate, the coating material is spread out toward the outer periphery of the substrate due to the centrifugal force that corresponds to the number of rotations. , a layer with a thickness commensurate with the number of rotations and the viscosity of the coating liquid is formed on the substrate, and the excess cloth liquid is scattered from the periphery of the substrate, so that the interior of the coating chamber is filled with droplets of coating liquid and becomes suspended. particles attached to the coating surface of the substrate and contaminating the coating surface.

Therefore, in order to prevent these problems, a partition wall is provided in the coating chamber or an exhaust duct is provided to discharge the scattered substances in the coating chamber to the outside. Conventionally, when an exhaust duct is provided to perform forced exhaust, the amount of exhaust is kept constant, and the forced exhaust is performed at an amount commensurate with the maximum speed of substrate rotation.
Therefore, at the initial stage of coating, even at low rotation speeds, the exhaust volume is large and the air flow in the coating chamber is fast, so the solvent on the coated surface of the substrate evaporates quickly and has a negative impact on the coated surface before reaching the maximum rotation speed, resulting in poor coating. I can't get a face. The present invention does not pump out a constant amount of air from a low substrate rotation speed at the beginning of coating to a high rotation speed at the end of coating, as in the conventional coating machine described above, but instead A good coating surface is obtained by controlling the air flow on the substrate coating surface by decreasing the exhaust volume when the rotation speed is low and increasing the exhaust volume when the substrate rotation speed is high. This will be explained in detail. FIG. 1 is a block diagram showing one embodiment of the present invention, in which 1 is a glass plate, 3 is a motor, 4 is a ventilation fan drive device, 5 is a ventilation fan motor, 2 is a ventilation fan, and 6 is a coating chamber.

In this case, the glass plate 1 having a diameter of 20C771 is coated by rotation using a coater having a coating chamber 6 having a volume of 161 (7).

First, how to select the displacement amount in the above configuration will be explained. The centrifugal force generated by the rotation of the motor is expressed by the following equation. F=mrω2 ω■2πN/60 ” Here F: Centrifugal force m: Mass of applied substance: Distance from the center of glass plate 1 N: Number of revolutions of glass plate 1 (rpm) Now m=1, to ■ When N is changed as O, lm (assuming a diameter of 20 cm), the centrifugal force when N rotates 30 times as compared to when it rotates 100 times is 100 times that when it rotates at 1000 times, and 3000 times when it rotates at 1000 times.
It becomes 100 halo in rotation.

From this, the displacement should be made proportional to the centrifugal force, for example 10
If LUmin is LUmin when turning the throat, it is 10eIm when turning 300 times.
In, 100/Min for 1000 rotations, and 1000eImin for 300 rotations. For this reason, in FIG. 1, the rotation speed of the motor 3 is detected and this detection method is applied to the ventilation fan drive device 4, and the rotation of the ventilation fan motor 5 is changed in proportion to the rotation of the motor 3.

Such a control mechanism is well known and detailed description of the invention will be omitted. In this way, by performing exhaust volume according to the rotation speed, it is possible to completely eliminate splashed particles from around the coating surface of the substrate, and improve the effect of air flow on the coating surface, resulting in good coating. A surface is obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an example of a rotary coating machine according to the present invention, and FIG.
The figure is a diagram showing the rotational speed and displacement of the embodiment of FIG. 1.

Claims (1)

[Claims] 1 In a rotary coating machine that rotates the substrate, drops the coating liquid, and spreads the coating liquid onto the substrate using centrifugal force to form a coating film, the rotation is made by controlling the displacement according to the number of rotations of the substrate. Coating machine.