JPS5959265A - Spin coating method - Google Patents

Abstract

PURPOSE:To perform excellent spin coating while inhibiting the splash of paint, by making the circumferential speed of a substrate at an initial time slower than that during coating in the operation of spin coating. CONSTITUTION:A substrate 1 is set up on a motor 2, and a starting signal is applied to a counter 13 so that a sequence circuit 12 is rotated with the number of rotation of NO through a circuit 10 for driving a motor. After the lapse of a predetermined time, the motor 5 is driven through a different circuit 11 for driving a motor, and nozzles 6, 6' are moved to points inside the substrate 1 and temporarily stopped. After the substrate 1 is rotated with the number of rotation at which centrifugal force is too small to spread paint, the number of rotation is raised. Thus, excellent spin coating is performed while inhibiting the splash or paint.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] This invention relates to a spin coating method I in which a rotating plate, such as a magnetic disk, is coated with paint by dropping or spraying the paint onto the same.

<Technical Background> When forming a magnetic layer on a substrate such as a magnetic disk, the substrate is rotated at a predetermined circumferential speed and paint is sprayed onto the substrate.

Furthermore, by spraying the paint near the inner circumference of the board, the paint is spread around the board depending on the circumferential speed of the board.

Further, when performing spin coating, the peripheral speed of the substrate is determined based on the viscosity of the paint and the speed of coating.

After spraying the prescribed paint, the next step is to shake off the paint using the trowel at a peripheral speed higher than the peripheral speed at which the coating is being applied. J+ Make the thickness uniform.

<Prior art and problems> Conventionally, it was difficult to use this type of spin coating method.
Previously, spin-coach ink was applied with the substrate placed horizontally, but with this method, when spin coating is performed on both sides, such as on a magnetic disk, two steps are required, one side each (this method is done separately). I had to perform spin coating.

However, if the Jjk plate is arranged vertically and 1: state spin coach ink can be applied, spin coating can be performed on both sides at the same time.

Even if spin coating is not carried out simultaneously on both sides, it is more effective to place the substrate vertically or at a predetermined angle when spin coating is carried out on a production line.

However, if spin coating is performed with the substrate in a position other than horizontal, the paint will splatter if it comes into direct contact with the substrate at the start of the spin code, and the splatter will eventually leave a mark when the spin code ends. There was a drawback.

<Objective of the Invention> The present invention aims to provide a novel spin coating method that eliminates the above-mentioned drawbacks. <Structure of the Invention> In order to achieve the above-mentioned object, the present invention When spin coating a paint onto a rotating substrate, this can be achieved by setting the peripheral speed of the substrate lower than the peripheral speed during coating only at the start of the spin code.

<Embodiment of the Invention> FIG. 1 shows an embodiment of a spin coating apparatus for carrying out the spin coating method of the present invention.

FIG. 2 is an operation chart of FIG. 1.

In the figure, 1 is the board, 2 is the board rotation motor, and 3.3'
is the feed gear, 4.4' is the worm gear, 5 is the nozzle lifting motor, 6.6' is the paint injection nozzle, 7 is the paint supply valve, 8 is the paint tank, 9 is the cover, 10.11 is the motor drive circuit , 12 is a sequence circuit, and 13 is a counter.

The spin coating apparatus shown in FIG. 1 will be briefly explained here.

1 is a substrate on which paint is spin-coded, and the substrates are arranged vertically.

Motor 2 rotates the substrate in a predetermined sequence. 6, 6 is a paint injection nozzle, and paint supply pulp 7
The paint is opened and closed by external control, and the paint is supplied from the paint tank 8.

3. 3' is the feed gear as shown in the figure (this end 1 this nozzle 6.
6' has been added.

4.4' is a worm gear, which is connected to the feed gear 3.3'ζ, and the rotation of the worm gear 4.4' rotates the feed gear 3.3.
By moving the nozzle 6.6' up and down in the figure, the nozzle 6.6' is moved over the surface of the substrate.

This worm gear 4.4' is operated by a motor 5I.

Reference numeral 10.11 is a motor drive circuit whose rotation direction and rotation speed are determined by signals from the sequence circuit 12, and drives the motors 2 and 5, respectively.

The sequence circuit 12 controls the motor drive circuit 10.11 and the paint supply pulp 7 according to a predetermined sequence I based on the count value l of the counter 13.

The counter 13 counts the clock CL in response to the start signal ST. Further, this counter 13 has a t-bar 70
-Then the counter is reset from the blind code F'C0Wi and the count is stopped.

Reference numeral 9 denotes a cover and the paint from the substrate 1 is removed. Next, the operation shown in FIG. 1 will be explained using the time chart shown in FIG. 2.

In FIG. 2, the horizontal axis shows time and the vertical axis shows the rotational speed of the motor 2.

Further, 2a is a rotation speed curve with respect to time of the motor 2, 2a
5a is the operating time range of the motor 2, 7a is the operating time range of the motor 5, and 7a is the range of one operation time during which the paint supply pulp is open.

Separate Tanabata 21, set the left board l, and start the illusion of counter 131.1e! When the number υ is given, the counter 13 starts counting.

Sequence LL'J beginning 12i Mako's 6th valley of unta 13, if, ); 1 beginning -Φ.

II (+ This is -i&, if the drying area of the base is 0.75 to 1.5 centimeters, the rotation V will be rotated at 150 to 300 rpm. 42
In Figure 5a, the motor 5 is connected to the motor 5 through the four-way rotation 11, so that the paint should be spin-coded. Turn on the nozzle 6.6' until it turns on, then stop.

This point is the position of phantom R1205g on the 14 inner gate plate.

The rotational speed determined above is calculated by adding the starting point of blood coughing from the nozzle 6.6' to the circumferential speed of the plate L and the viscosity of the pigment mentioned above.

This depends on the viscosity of the paint, but the centrifugal force should be set so that it is weak (at a rotation speed that does not prevent the paint from spreading) and so that it does not splash back on the substrate surface at the moment of injection.

The settings must be visually checked in advance to ensure that they do not bounce back.

In this way, when the nozzle is set to the injection start point, the sequence circuit 1
2, the paint supply pulp 7 is opened and paint starts to be ejected, and the motor 5 is operated to move the nozzle to the inner circumference, and after reaching this point, the innermost area of the paint coating is moved to the outer circumference again. The paint supply pulp 7 is closed at a point moved approximately half the radius of the substrate l.

On the other hand, the rotation speed of the substrate 1 is 0.1 to 5 seconds from the start of paint injection.
After elapse of EC, increase the rotation speed to N1. This Nl) rotational speed is the rotational speed for spin coating, and the rotation is performed at 450 to 600 rpm under the conditions described above.

Thereafter, after a period of time (1 to 4 seconds) until the paint spreads over the entire surface of the substrate 1, the rotation speed is increased to N.

The rotational speed N is a rotational speed of 500 to 000 rpm to shake off unnecessary paint.

The time to rotate the board 1 at the rotational speed of N and N is set appropriately.The motor 5 continues to operate even after the paint jetting has stopped, as can be seen from 58 and 7 colors in Fig. 2. This is the time for retracting the nozzle 6.6' out of the substrate l.

By operating in this way, it is possible to finish coating the substrate. <Effects of the Invention> As described above, in the present invention, when starting the spraying of the paint, it is possible to finish coating the substrate during spin coating. Since it is set lower than the circumferential speed, there is no splash of paint from the substrate surface, and good spin code can be performed.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of a spin coating apparatus for carrying out the spin coating method of the present invention, and FIG. 2 shows the operation chart of FIG. 1, respectively. In the figure, 1 is a board, 2 is a motor for rotating the board,
3.3' is a feed gear, 4.4' is a worm gear, 5 is a nozzle lifting motor, 6 and 6' are paint injection nozzles, 7 is paint supply pulp, 8 is a paint tank, 9 is a cover, 10.1
1 is a motor drive circuit, 12 is a sequence circuit, and 13 is a counter.

Claims (1)

[Claims] A spin coating method characterized in that when spin coating a paint onto a substrate rotating at a predetermined circumferential speed, the circumferential speed of the substrate is set lower than the circumferential speed during coding only at the start of the spin code.