JPH05290724A - Manufacture of shadow mask - Google Patents

Abstract

PURPOSE:To lessen the warp of a flat mask caused by inner stress a highly coarse material has. CONSTITUTION:A photosensitive film 11 is formed on both sides of a shadow mask material 10 and a pattern corresponding to a large number of electron beam passing holes of a shadow mask is printed and developed in the photosensitive film to form resist films 13a, 13b and then etching is carried out to manufacture a flat plate-like flat mask 15 in which electron beam passing holes are formed. A highly coarse material is used for material of the shadow mask and in the processes to manufacture the flat mask using the highly coarse material, the inner stress of the highly coarse material is lessened by rotary rolls and the warp of the flat mask caused due to the inner stress is thus lessened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shadow mask manufacturing method, and more particularly to a shadow mask manufacturing method for reducing warpage of a flat mask when a shadow mask is manufactured using a high roughness material.

[0002]

2. Description of the Related Art Generally, a shadow mask type color picture tube faces a phosphor screen composed of a three-color phosphor layer, selects three electron beams emitted from an electron gun, and makes the three-color phosphor layer enter the three-color phosphor layer. It has a shadow mask. This shadow mask has a large number of electron beam passage holes in a predetermined array, and each electron beam passage hole corresponds to a set of three-color phosphor layers.

Conventionally, this shadow mask is manufactured by manufacturing a flat plate-shaped flat mask in which a large number of electron beam passage holes are formed by a photoetching method and press-molding the flat mask into a predetermined shape. .. This flat mask is manufactured by forming photosensitive films on both main surfaces of a strip-shaped shadow mask material, and forming dot patterns corresponding to many electron beam passage holes of the shadow mask on the photosensitive films on both main surfaces. After vacuum-contacting a pair of negative master plates, baking the pattern of the negative master plates and developing,
It is manufactured by etching.

At present, as a shadow mask material used for manufacturing this flat mask, a low carbon steel plate such as aluminum killed steel or an amber material made of Fe, Ni alloy is used, and in terms of surface roughness, it is average. Roughness Ra is about 0.15 to 0.45 μm, maximum roughness Rmax is 4.5 μm
The following so-called low roughness materials and the average roughness Ra is about 0.50.
There is a so-called high-roughness material having a maximum roughness Rmax of up to 0.80 μm and a maximum roughness Rmax of 6.0 μm or less. The line 1a shown in FIG. 3 (a) is
The average roughness Ra is 0.35 μm and the maximum roughness Rmax is 2.5.
It is an example of the surface roughness of low roughness material of μm, and the line (b) of the same
1b has an average roughness Ra of about 0.60 μm and a maximum roughness Rmax.
Is an example of the surface roughness of the high-roughness material of 3.8 μm.

By the way, in manufacturing the above-mentioned flat mask, what is important for improving the productivity is to shorten the vacuum adhesion time of the pair of negative master plates to the shadow mask material. In this respect, the high-roughness material has an advantage that the negative original plate can be sufficiently adhered to the entire surface of the photosensitive film formed on both main surfaces thereof, and the time required for the vacuum adhesion can be shortened. On the other hand, as compared with the low roughness material, a large internal stress remains during the manufacturing process of the material, which causes an unacceptable warp when used as a flat mask.

That is, for the high-roughness material, in FIG. 4, the vertical axis represents the residual stress, the upper horizontal axis represents the depth in the plate thickness direction from one main surface (front surface) side, and the lower horizontal axis represents the other main surface ( As indicated by lines 2a and 2b as the depth in the plate thickness direction from the back surface side, lines 3a and 3b
A large internal stress remains as compared with the internal stress of the low roughness material indicated by. Therefore, as shown in FIG. 5, when the flat mask 6 is stripped (picked off) from the shadow mask material 5 after completion of etching, the flat mask 6 is warped with a height h. The warp height h of the flat mask 6 is, for example, 2 when the distance between the long sides of the rectangular flat mask is 2.
In the case of 1 inch, it reaches about 30 to 70 mm, and the flat mask cannot be peeled off smoothly from the shadow mask material. In addition, problems such as difficulty in stacking and packing the stripped flat masks 4 occur.

[0007]

As described above, the shadow mask materials currently used for manufacturing shadow masks include high roughness materials and low roughness materials. this house,
The high-roughness material has an advantage over the low-roughness material in that the vacuum adhesion time of the negative original plate to the photosensitive film formed on both main surfaces of the shadow mask material is shorter and the productivity of the shadow mask is improved. On the other hand, a large internal stress that remains in the manufacturing process of the material remains, which causes the flat mask to warp, making it difficult to peel the flat mask from the shadow mask material in the flat mask manufacturing process. This causes problems such as difficulty in stacking and packing the flat masks thus obtained.

The present invention has been made to solve the above problems, and in the flat mask manufacturing process, the warp of a flat mask manufactured from a high-roughness material is reduced to reduce the productivity of shadow masks. The purpose is to improve.

[0009]

A photosensitive film is formed on both main surfaces of a shadow mask material, and a pattern corresponding to a large number of electron beam passage holes of a shadow mask is printed and developed on the photosensitive film to form an electron beam passage hole. After forming a resist film consisting of a corresponding pattern, by etching, in the manufacturing method of the shadow mask to manufacture a flat plate-shaped flat mask in which electron beam passage holes are formed, the shadow mask material is a high roughness material, The internal stress of the high-roughness material was reduced by the rotating roller during the process of manufacturing the flat mask using the high-roughness material, and the warp of the flat mask caused by the internal stress was reduced.

[0010]

As described above, if the step of reducing the internal stress by the rotating roller is provided during the step of manufacturing the flat mask using the high roughness material, the flat mask caused by the internal stress of the high roughness material is provided. The warp can be reduced.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the drawings.

As shown in FIG. 1A, the plate thickness is 0.22.
0 mm, width 460 mm, average roughness Ra 0.60 μ
The shadow mask material 10 is a strip-shaped high-roughness material having a surface roughness of m and a maximum roughness Rmax of 3.8 μm. Casein and ammonium dichromate are main components on both main surfaces of the shadow mask material 10. Apply a photosensitizer and dry to a thickness of about 7
A photosensitive film 11 of μm is formed.

Next, as shown in FIG. 2B, a pair of dot patterns of different sizes corresponding to the electron beam passage holes of the shadow mask to be formed are formed on the photosensitive films 11 on the both main surfaces. The negative masters 12a and 12b are closely contacted and exposed, and a pair of negative masters 12a and 12b are formed on the photosensitive films 11 on both main surfaces.
Bake the pattern. This baking is performed by using a vacuum contact baking frame (not shown) to bring the photosensitive films 11 on both main surfaces into vacuum contact with a pair of negative master plates 12a and 12b, and from a 5kW mercury lamp installed at a distance of about 1m for about 30 seconds. It is performed by irradiating with ultraviolet light.

In this case, in a low roughness shadow mask material, a pair of negative master plates 12 are formed on the photosensitive films formed on both main surfaces thereof.
It takes about 50 seconds to sufficiently vacuum-bond a and 12b, but with the above-described high-roughness shadow mask material 10, it can be sufficiently vacuum-bonded in about 30 seconds, and the time required for exposure is greatly shortened. be able to.

Next, the photosensitive films 11 on both principal surfaces, on which the patterns of the pair of negative masters 12a and 12b have been baked, are developed with warm water at about 40 ° C. for about 1 minute to remove the unexposed portion, and further surface active. After being drained with a chemical and dried, resist films 13a and 13b, which are exposed portions of the shadow mask material 10 in the electron beam passage hole forming portion, are formed as shown in (c).
Then, if necessary, baking is performed to form a resist film 13a,
Improves the etching resistance of 13b.

Next, as shown in (d), the shadow mask material 10 on which the resist films 13a and 13b are formed is etched from both sides to form electron beam passage holes 14 penetrating between the both sides. This etching is performed by running both main surfaces of the strip-shaped shadow mask material 10 horizontally and spraying ferric chloride solution having a specific gravity of 1.480 at about 70 ° C. for about 9 minutes on both main surfaces. It is carried out. After that, wash with water and then use an alkaline solution to resist the resist film on both main surfaces.
Peel off 13a and 13b, then wash with water and dry.
A flat mask 15 shown in is obtained.

Further, in this shadow mask manufacturing method, the shadow mask material 10 from which the resist films 13a and 13b are peeled off has a diameter of about 200 as shown in FIG.
A plurality of rotating rollers (17) made of hard rubber rollers of mm are passed between the rotating rollers (17) of the straightening device which are alternately arranged to reduce the internal stress of the shadow mask material (10) having high roughness. Then, the flat mask 15 is peeled off from the shadow mask material 10. The shadow mask is manufactured by thereafter press-molding the flat mask 15 into a predetermined shape.

By the way, as described above, when the flat mask 15 is peeled from the shadow mask material 10 and passed between the plurality of rotating rollers 17 of the straightening device, the rotating rollers are
By appropriately adjusting the tension applied to the shadow mask material 10 when passing between the number of 17 and between the rotating rollers 17,
The internal stress of the high roughness shadow mask material 10 can be reduced. Therefore, then the shadow mask material
The warp caused by the internal stress of the flat mask 15 peeled from 10 can be reduced, and the flat mask 15 can be smoothly peeled from the shadow mask material 10 which has been a conventional problem. The flat masks 15 thus taken can be easily stacked and packed.

[0019]

EFFECTS OF THE INVENTION If an internal stress removing step for reducing the internal stress of a high roughness material by a rotating roller is provided in the step of manufacturing a flat mask using a high roughness shadow mask material, the internal stress is reduced. The warp of the flat mask caused by the cause can be reduced, the flat mask can be peeled off smoothly from the shadow mask material, and the peeled flat masks can be easily stacked and packed. The productivity of the shadow mask can be improved.

[Brief description of drawings]

1A to 1E are views for explaining a method of manufacturing a shadow mask according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a method of reducing internal stress of a high roughness material.

FIG. 3 (a) is a diagram showing surface roughness of a low-roughness material,
FIG. 3B is a diagram showing the surface roughness of the high-roughness material.

FIG. 4 is a diagram showing internal stress of a high roughness material in comparison with internal stress of a low roughness material.

5 (a) and 5 (b) are diagrams for explaining a warp that occurs when a flat mask is stripped from a high-roughness material.

[Explanation of symbols] 10 ... Shadow mask material 11 ... Photosensitive films 12a, 12b ... Negative original plates 13a, 13b ... Resist film 14 ... Electron beam passage hole 15 ... Flat mask 17 ... Rotating roller

Claims (1)

[Claims] 1. A pattern corresponding to the electron beam passing holes is formed by forming a photosensitive film on both main surfaces of a shadow mask material, and baking and developing a pattern corresponding to the electron beam passing holes of the shadow mask on the photosensitive film. In a method for producing a shadow mask in which a resist film made of is formed and then etched to produce a flat plate-shaped flat mask in which the electron beam passage holes are formed, a high roughness material is used as the shadow mask material. The internal stress of the high roughness material is reduced by the rotating roller during the process of manufacturing the flat mask using the roughness material, and the warp of the flat mask caused by the internal stress is reduced. And a method for manufacturing a shadow mask.