JP2003164787A - Liquid discharge port - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid discharge port, for preventing drying of the opening of the discharge port in a liquid application device so as to stably form a coating film and prevent contamination by foreign matters. <P>SOLUTION: The surface of the discharge port is roughened in order to positively draw solvent component toward a liquid-wetted part in the outside of the discharge port. Thus, the discharge opening is prevented from drying, which prevents solid foreign matters from growing, and further, the form of the discharged fluid is maintained without being effected by solid foreign matters. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating device for preventing a discharge port opening of a liquid coating device from drying, to stably form a coating film, and prevent foreign matter from entering.

[0002]

2. Description of the Related Art Flow coating, spin coating, die coating, slit coating, and the like are known as methods for forming a thin film by discharging a liquid from a discharge port onto an object to be coated.

During coating of these devices, the coating liquid gets wet outside the discharge port, and when it dries, the solid content of the coating liquid appears as foreign matter in the vicinity of the discharge port, and the coating liquid is pulled by the surface tension. As a result, the shape of the discharged fluid is deformed.

Then, the formed film thickness varies, and a thin film having a desired accuracy cannot be obtained.

Furthermore, if the solid content of the dried coating liquid is peeled off from the discharge port and mixed into the coating liquid again, or if it falls onto the formed thin film, foreign matter becomes defective and desired quality cannot be obtained.

To solve these problems, Japanese Patent Laid-Open No. 08-1
There is a method of preventing the wetting of the coating liquid by coating the outside of the discharge port with a stain-proof resin such as Teflon (registered trademark) as in Japanese Patent No. 55369, but it cannot completely prevent the wetting.

Therefore, in Japanese Patent Laid-Open No. 08-173891, an attempt is made to solve this problem by discarding the coating liquid before or after the coating is started and periodically wiping the outside of the discharge port.

Another method is disclosed in Japanese Patent Laid-Open No. 10-2165.
No. 98, JP-A-12-042468, and JP-A-12-140735 prevent the drying by keeping the discharge port in the vapor atmosphere of the coating liquid solvent.

[0009]

However, in the method of performing the waste ejection as in the above-mentioned prior art and periodically wiping the outer side of the discharge port, the application liquid for the waste ejection is wasted.
Especially when applying an expensive liquid, the cost is inevitably increased. Further, the wiping operation lengthens the manufacturing tact time, and it is difficult to reproduce the same level of cleanliness every time, and it is difficult to form a thin film of the same quality.

[0010] With the technique of keeping the other vapor atmosphere, it is difficult to make a device that keeps the vapor from leaking, and it is not suitable for mass production because of the danger of fire and explosion due to solvent vapor. .

[0011]

In order to solve the above-mentioned problems, the liquid discharge port of the present invention has a roughened surface of the discharge port, so that the coating liquid wet-up portion on the outer side of the discharge port does not have a special mechanism. It is possible to positively suck up the solvent component, prevent drying, maintain the shape of the discharged fluid, and prevent the formation of foreign matter solid content.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The portion to be actually treated is a discharge port surface where three parts of a coating liquid, an atmospheric gas, and a discharge port structure are in contact, which may be a metal surface or a resin surface. As a processing method, sandblasting, The surface is roughened using a method such as polishing or acid treatment.

Particularly in sandblasting, the surface roughness can be easily controlled by adjusting the grain size of the sand to be used and the spraying pressure, so that uniform and reproducible processing can be performed.

As for the surface roughness, Ra representing the center line average roughness is preferably 0.4 μm to 50 μm, particularly 0.8 μm to 5 μm.
μm is good.

(Embodiment 1) SU of slit coater
The surface of the S head was roughened by sandblasting.

The surface roughness Ra was 0.1 μm before processing and the roughness after processing was 0.5 μm.

Using this head, a photoresist coating CFPR CL- manufactured by Tokyo Ohka Kogyo Co., Ltd. containing an organic solvent is used.
When 016S was applied, the head can always be kept wet with the solvent, and the head coating liquid stain that had occurred before processing did not occur, resulting in coating streaks (film thickness unevenness). Can be avoided.

When the contact angle of the head surface was measured with the CL-016S liquid, it was 12 ° before the processing, but it was 8 ° after the processing, and the unevenness of the surface made it easier for the solvent to get wet, thus improving the holding ability of the coating liquid. I found out.

(Embodiment 2) Similarly, SUS of slit coat coated with PTFE for preventing stains.
The surface of the manufactured head was roughened by sandblasting.

The surface roughness Ra was 0.8 μm before processing and the roughness after processing was 1.5 μm. CL using this head
By applying -016S, the head can always be kept wet with the solvent, the head coating liquid stain that had occurred before processing did not occur, and the coating stripe (film thickness unevenness) ) Can now be avoided.

When the contact angle of the head surface was measured with the CL-016S liquid, it was 54 ° before processing, but it was 23 ° after processing, and the unevenness of the surface made it easier for the solvent to get wet, increasing the ability to retain the coating liquid. I found out.

[0022]

According to the liquid discharge port of the present invention, the coating liquid on the outside of the discharge port is prevented from being dried and the shape of the discharge fluid is maintained without performing frequent cleaning operations or a special mechanism to perform coating with a high film thickness accuracy. You can

Further, since it is possible to prevent the solid content of foreign matter from being formed, it is possible to eliminate defective foreign matter in the formed thin film.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a head of a slit coater according to an embodiment of the present invention.

[Explanation of symbols]

1 Head of slit coater 2 coating liquid 3 Part where the coating liquid gets wet

Claims (2)

[Claims] 1. A liquid discharge port, characterized in that a liquid channel outlet of a liquid containing an organic solvent is roughened. 2. The liquid discharge port according to claim 1, wherein the liquid discharge port is a head of a slit coater coating apparatus for a liquid containing an organic solvent.