JP2001006539A - Exposure device for shadow mask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exposure device for a shadow mask capable of making a printing board reliably adhere to a thin metal plate and having enhanced productivity and stable quality. SOLUTION: Holding frames 16, 17 hold and fix each printing board 12, 13. A hollow packing 21 is connected to a compressor 22c to heighten its inner pressure, and is kept in a solid state. The holding frames 16, 17 are evacuated by operating a vacuum mechanism 18. Since the packing 21 is in a solid state, each printing board 12, 13 is sucked from its center part to a thin metal plate 11 by a vacuum pressure. The inner pressure of the packing 21 is then lowered to soften the packing 21, and if a vacuum adhering work is continued by keeping the air in the outer rim part of each printing board 12, 13 easily released, it reliably adheres to the thin metal plate 11 without having stagnant air in its center part. Under this condition, it is exposed and baked with a super high mercury lamp 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a shadow mask exposure apparatus used in a shadow mask manufacturing process.

[0002]

2. Description of the Related Art A shadow mask made of a thin metal plate such as aluminum killed steel having a thickness of about 0.12 mm to 0.25 mm or an invar material having a low coefficient of thermal expansion is used to form a circular or rectangular shadow mask. A large number of fine electron beam passage holes are formed at a predetermined pitch. This shadow mask is formed by a photo etching technique using a printing plate called a photo mask. The printing plate is obtained by forming a predetermined pattern on a emulsion plate obtained by applying an emulsion obtained by dispersing a silver nitrate-based photosensitive agent in gelatin onto a blue plate glass using a pattern generator called a photoplotter. Usually, the electron beam passage hole of the shadow mask is formed such that the diameter of the small hole on the electron gun side is smaller than the diameter of the large hole on the fluorescent screen side facing the inner surface of the panel.

Here, the manufacturing process of such a shadow mask will be described.

[0004] First, in order to remove oil remaining on the surface of a thin metal plate such as aluminum-killed steel or invar material, the surface is degreased with a high-temperature alkaline solution and washed with water. Thereafter, a liquid resist obtained by adding dichromate to casein is applied to both surfaces of the thin metal plate and dried. After drying, the printing plate is brought into close contact with the resist films formed on both sides of the thin metal plate and exposed.
Thereafter, the film is developed with water and dried. After that, etching is performed. Generally, the round hole type is etched in two stages of the small hole side and the large hole side, and the rectangular type is etched simultaneously from both sides. After this etching, the resist film is peeled off to complete the shadow mask.

Here, the following exposure apparatus is used for exposing the shadow mask pattern. This exposure apparatus
A printing plate of a glass dry plate having a large hole side baking negative pattern and a printing plate of a glass dry plate having a small hole side baking negative pattern are opposed to each other in a desired positional relationship.
Then, at the time of exposure, between these two printing plates, a shadow mask material having a photosensitive film of a resist film formed on both surfaces is sent out, and a vacuum system is formed to bring both printing plates into close contact with both surfaces of the shadow mask material. Exposure is performed using a light source such as ultraviolet light. After this exposure, the required amount of the shadow mask material is wound up to prepare for the next exposure.

In such an exposure apparatus, if the two printing plates are not sufficiently adhered to the shadow mask material, interference fringes are generated between the printing plate and the shadow mask material, and the interference fringes are transferred to the resist. Sometimes. Therefore, it is necessary to keep the glass dry plate and the shadow mask material in close contact with each other until the interference fringes disappear.

However, in order to bring the shadow mask material and both printing plates into close contact with each other, a long contact time of about 50 seconds or more is required, and the productivity is reduced. Also, there is a difference between the index of the subsequent development process and the index.
Between the pattern at the start of baking and the pattern at the end of baking, variations occur in the resist missing dimension after development. For this reason,
There is a problem that the quality of the shadow mask is not stable.

In addition, if the printing plate is warped during the contacting operation of the printing plate, an air trap is generated in the middle portion when the printing plate starts to be hit from the peripheral portion thereof. Air cannot escape, and a sufficient adhesion state cannot be obtained.

[0009]

As described above, in the conventional exposure apparatus, the contact work between the printing plate and the shadow mask material takes a lot of time, and the productivity is reduced and the quality of the shadow mask is not stable. In addition, depending on how the printing plate is brought into close contact, there is a problem that air accumulation occurs in the middle portion, making it difficult to adhere.

The present invention has been made in view of the above problems, and provides an exposure apparatus for a shadow mask which can surely bring a printing plate into close contact with a thin metal plate in a short time, thereby improving productivity and achieving stable quality. The purpose is to do.

[0011]

SUMMARY OF THE INVENTION The present invention is directed to a holding means for positioning and holding a printing plate on which a printing pattern is formed with respect to a thin metal plate on which a resist film is formed, and a printing plate and metal at a portion other than the center. Distance adjusting means comprising a tubular member capable of adjusting the distance of the thin plate and injecting and exhausting gas, vacuum means for evacuating the printing plate and the thin metal sheet, and exposing means for exposing the thin metal sheet. It was done.

When the printing plate is brought into close contact with the metal thin plate, the distance between the printing plate and the metal thin plate in a portion other than the center is adjusted by distance adjusting means, and when evacuation is started, the distance is lengthened. The printing plate adheres to the metal sheet from the middle part, and then the distance between the mounting plate and the metal sheet is shortened so that suction pressure is applied from the center to the outside. And firmly adhere.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the shadow mask exposure apparatus of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 11 denotes a metal thin plate as a shadow mask material. The metal thin plate 11 is made of, for example, a low-thermal-expansion amber material, and has resist films formed on both surfaces. Then, the metal sheet 11 is fed laterally by a predetermined length by a feed mechanism (not shown).

A printing plate 12 for small holes and a printing plate 13 for large holes are arranged on both sides of the metal sheet 11. Each of the printing plates 12 and 13 has a printing pattern for a shadow mask. Behind these printing plates 12 and 13, for example, an ultra-high pressure mercury lamp 14 is provided as an exposure light source as exposure means.

Further, on the corresponding printing plates 12, 13, holding frames 16, 17 having an L-shaped cross section as a holding means are formed in a frame shape along the outer periphery. As shown in the drawing, the outer edges of the corresponding printing plates 12 and 13 on the side opposite to the printing surface,
Each of the printing plates 12, 13 contacts the non-printing surface of the metal sheet 11, that is, a position deviated from the surface facing the printing plates 12, 13 to position and hold the printing plates 12, 13 in a predetermined positional relationship with respect to the metal sheet 11. . Further, the inside of each of the holding frames 16 and 17 is communicated with a vacuum mechanism 18 so that the printing plates 12 and 13 and the metal sheet 11 can be adhered by vacuuming. In addition, instead of the vacuum mechanism 18, a pressurizing mechanism 19 such as a compressor can be switched and connected. This pressurizing mechanism 19 is used to separate the printing plates 12, 13 from the metal sheet 11 after the exposure is completed. .

Reference numeral 21 denotes a hollow packing as a distance adjusting means, which is formed of a tubular member into which gas such as air can be injected and exhausted.
The hollow portions are communicated with a pressure adjusting device 22. This pressure adjusting device 22 is a vacuum pump 22 as a vacuum means.
v and a compressor 22c, which are arbitrarily switchably connected to the inside of the packing 21.
That is, when the packing 21 communicates with the compressor 22c, the internal pressure is increased, so that the packing
Communicating with 22v lowers the internal pressure and makes it softer. The packing 21 may be made of synthetic rubber, natural rubber, polyethylene, polyester, polyvinylidene chloride, polyvinyl chloride, polypropylene, or the like.

In the above configuration, when exposing,
The metal sheet 11, which is a shadow mask material, is fed out by a predetermined amount, and the printing portion is stopped at a position facing the printing plates 12, 13 as shown in the figure. At this time, the holding frames 16 and 17 are
2 and 13 are engaged with the outer edge of each printing plate 1
2 and 13 are held and fixed. The packing 21 is connected to a compressor 22c to increase the internal pressure and keep the packing 21 in a hard state.

In this state, the vacuum mechanism 18 is operated,
The inside of the holding frames 16 and 17 is evacuated. At this time, packing
Since 21 is in a hard state, the printing plates 12 and 13 are attracted to the metal sheet 11 from the central portion by the vacuum pressure. After the central part of the printing plates 12 and 13 has been evacuated in this way,
21 is switched to a vacuum pump 22v to reduce its internal pressure. That is, the packing 21 is softened,
The vacuum adhesion work is continued by making the outer edges of the printing plates 12 and 13 easily evacuate the air.

By this vacuum contact work, each of the printing plates 12, 13 is printed.
Can securely adhere to the metal sheet 11 without accumulating air in the central portion as in the related art. As a result, the time required for the close contact work can be reduced, the productivity can be improved, the influence of the dark reaction of the resist can be reduced, and the quality as a shadow mask can be improved.

Thus, the metal plates 11 of the printing plates 12 and 13 are
After the close contact work on the
Exposure is performed on the metal sheet 11 through the printing plates 12 and 13 using the printing plate.
11 Bake on top. After the completion of the exposure work, the holding frame
Switch the conduit leading to 16, 17 to the pressurizing mechanism 19, and
Raise the pressure inside 16 and 17 and put the printing plates 16 and 17
Separate from and complete the work.

Here, the following table shows the results of evaluation of the contact time until the interference fringes disappear by the exposure device and the difference between the resist missing dimension in the pattern center immediately after the start of development and immediately before the end of development.

[0023]

[Table 1] As is clear from the above table, the shadow mask exposure apparatus according to one embodiment shows better values in both the vacuum adhesion time and the resist omission dimension than the conventional shadow mask exposure apparatus, and the productivity is higher. And the quality as a shadow mask is improved.

[0024]

According to the present invention, the vacuum contact time is greatly reduced, the variation of the resist missing dimension in the same lot is reduced, and the quality as a shadow mask can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a shadow mask exposure apparatus of the present invention.

[Explanation of symbols]

 11 Metal sheet 12, 13 Printing plate 14 Ultra-high pressure mercury lamp as exposure means 16, 17 Holding frame as holding means 18 Vacuum mechanism as vacuum means 21 Packing as distance adjusting means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaru Nikaido 1-9-2, Hara-cho, Fukaya-shi, Saitama F-term in the Toshiba Fukaya Plant (reference) 5C027 HH09

Claims (1)

[Claims] 1. A holding means for positioning and holding a printing plate on which a printing pattern has been formed with respect to a metal sheet on which a resist film has been formed, and adjusting the distance between the printing plate and the metal sheet at a portion other than the center, and using a gas. A shadow adjusting device comprising: a distance adjusting means formed of a tubular member capable of injecting and exhausting air; a vacuum means for evacuating a printing plate and a thin metal sheet; and an exposing means for exposing the thin metal sheet. Exposure equipment.