JPS5888068A - Apparatus for applying thin film - Google Patents

Abstract

PURPOSE:To enable to uniformly apply a thin film, by placing a base plate to which an applying liquid is to be applied on an auxilirary rotary disc rotatably provided on the circumferential part of a large-diameter main rotary stand having a rotary shaft at its center. CONSTITUTION:When a large-diameter rotary stand 31 is rotated, a supporting disc 33 provided with blades 34 moves along the rotating direction, and the blades 34 accept wind pressure formed by the movement to reversely rotate the supporting disc 33. Consequently, by fixing a base plate 37 useful as a plasma display panel utilizing fluorescent emission, for instance, onto the supporting disc 33, dropping a proper amount of a resist liquid mixed with a fluorescent substance thereon and rotating the rotary stand 31 at a predetermined speed, the resist liquid is affected by centrifugal power having intensity uniform along nearly the same direction is applied to the entire surface of the base plate 37 so that the resist liquid is scattered along nearly the same direction and applied as a resist film 37 having uniform thickness by the rotation of the supporting disc 33.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to an improvement in a co-rotating thin film coating apparatus used for coating fluorescent films and various cypress photoresist films.

(2) Background of the technology Photoresists and photoresists are used to form fluorescent films for plasma display panels that utilize fluorescent light emission due to ultraviolet excitation, to manufacture semiconductor devices, and to manufacture photomasks used in the manufacture of semiconductor devices. A uniform thin film of a phosphor mixture or a photoresist is required, and conventional methods for obtaining such a thin film include dipping, spraying, and spinner methods. A spinner method, that is, a rotary coating device, is widely used.

(3) Prior art and problems By the way, when applying photoresist using a conventional rotary coating device, the substrate to be coated is placed at the center of a disk having a rotating shaft at the center, and the substrate is coated onto the substrate. After dropping the photoresist, the substrate is rotated at an appropriate rotational speed by a rotating mechanism connected to the rotating shaft of the disk, and the photoresist is spread from the center of the substrate toward its peripheral edge. Then, a photoresist film with a uniform thickness is formed on the surface of the substrate. However, in the photoresist film 3 coated by such an apparatus, due to the action of centrifugal force during co-rotation coating, as shown in FIG. It tends to be thin and thicken toward its periphery.

Therefore, in order to eliminate the tendency for the thickness to become non-uniform, as shown in FIG. The disk 1 is arranged as shown in the figure, and rotates around the center axis A of the disk 1 as a rotating ring, so that a centrifugal force of a uniform magnitude is applied to the entire surface of the substrate 2 in substantially the same direction, thereby uniformly coating the photoresist. Attempts have been made to apply a membrane 23. The variation in the thickness of the photoresist film 23 coated by this coating method is l/l compared to the original conventional example.
However, as shown in the figure, the board 2
There was a drawback that the thickness of the photoresist film 23 was applied unevenly from the 2a end to the 2b end.

(4) Purpose of the Invention In order to eliminate the above-mentioned drawbacks of the conventional art, the present invention provides a novel structure in which the # film can be applied uniformly by making the arrangement structure of the substrate placed on a rotating disk into a sub-rotary type. The purpose is to provide a coating device.

(5) Structure of the Invention In order to achieve the above object, in the present invention, a substrate to be coated with a thin film is placed on the periphery of a rotary table that has a rotation axis at the center and can rotate horizontally. It is characterized by a rotatable rotary disk with blades.

(6) Embodiments of the Invention Below, embodiments of the present invention will be explained in detail with reference to the drawings.

FIG. 3 and FIG. 4 are a plan view and a cross-sectional view showing an embodiment of the structure for arranging substrates on a rotary table in a thin film coating apparatus stand according to the present invention. In both of these figures (here, 31 is a large-diameter rotary table having a rotating shaft 32 in the center, and the rotary table 31
A rotatable holding plate 33 on which a substrate 35 to be coated with a thin film is placed is disposed around the periphery of the plate. The holding plate 33
Several blades are attached to the outer peripheral side of the frame as shown in the figure. Then, the rotation table 31 is rotated in the direction of the arrow 36 by a rotation drive m4II (not shown) connected to the U-rotation shaft 32.
3 moves in the direction of rotation of the rotary table 31, and the plurality of blades 34 receive the wind pressure during the rotation, so that the rotary table 31
It rotates in the opposite direction to the direction of rotation. Therefore, on the holding plate 33, for example, a display spring/L/substrate 3 for a plasma display panel using fluorescent light emission is mounted.
7 is firmly fixed in a holder (not shown), and the substrate 37 is
An appropriate amount of a resist solution containing a photoresist and a phosphor mixed at a weight ratio of 1O:1 is dropped onto the substrate 37, and when the rotary table 31 is rotated at a predetermined speed, the resist solution is applied to the substrate 37.
A centrifugal force of a uniform magnitude acts on the entire surface in almost the same direction, and the particles are scattered in the same direction, and the holding plate 3
The resist film 37 is applied to a uniform thickness by the rotation of the resist film 3 .

In addition, FIG. 5 shows a photoresist and a phosphor mixed at a weight ratio of 10:1 (resist pm for spring/I/substrate surface number 2 for a plasma display panel using fluorescent light emission). 2 is a graph showing the relationship between the thickness distribution of the resist film, in which a is a thickness distribution curve of a resist film coated by a conventional device in which a panel substrate is placed in the center of a rotary disk;
C is the thickness distribution curve of the resist film applied by a conventional device that simply arranges the panel substrate around the periphery of the rotary disk.
is a thickness distribution curve of a resist film coated on the surface of a panel substrate by the apparatus of the present invention, and this graph shows that the apparatus of the present invention is superior in uniformly applying resist.

(7) Effects of the Invention As is clear from the above description, in the thin film Y cloth apparatus according to the present invention, the substrate to which the coating liquid is applied is placed on a large-diameter main rotary table having a rotation axis at the center. The peripheral area of E (the stand is arranged on the sub-rotary disk which is freely rotatable) has the advantage of being able to apply a thin film uniformly, and is suitable for use with resists mixed with phosphor. It is extremely advantageous when applied to the application of Hashi resist films and other coating agents.

[Brief explanation of the drawing]

1 and 2 are sectional views of main parts of a conventional thin film coating device, and FIGS. 3 and 4 show an embodiment of a substrate arrangement structure on a turning table in a thin film coating device according to the present invention. FIG. 5 is a plan view and a cross-sectional view of a main part thereof, and a thickness distribution diagram of a resist film on a substrate surface, which explains the present invention in detail. In the figure, 31 is a large-diameter turntable, 32 is a single rotation shaft, and 3
3 is a holding plate, 34 is a blade, 35 is a substrate, and 37 is a resist group. Figure 1 Figure 3 Figure 5 40 30 20 10 0 10 20 30 40
Shizu-m-・-m-→-

Claims (1)

[Claims] The center part has a rotating shaft, and the peripheral part of the rotary table which can be rotated horizontally is rotatably arranged with a winged holding plate on which the substrate to be coated with a thin film is placed. A thin film coating device characterized by: