JP2001307625A - Manufacturing method of shadow mask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately produce a pair of printing original plates for printing a pattern corresponding to open holes of a shadow mask on a photo resist formed on both surfaces of a shadow mask material plate. SOLUTION: In a shadow mask manufacturing method, one of a pair of printing original plates is used for producing a negative original plate consisting of negative pattern by a pattern generator and a shadow mask is produced by repeating contact reversals of the negative pattern of the negative original form. The other printing original plate us used for producing a positive original plate consisting of positive pattern by a pattern generator and a shadow mask is produced by repeating contact reversals of the positive pattern of the positive original plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a shadow mask for a color cathode ray tube by a photo-etching method, and more particularly, to a pattern corresponding to an opening of a shadow mask in a photoresist applied to both surfaces of a shadow mask blank. The present invention relates to a method of manufacturing a shadow mask in which a method of manufacturing a printing master used for printing is improved.

[0002]

2. Description of the Related Art Generally, a color cathode ray tube has an envelope comprising a panel 1 and a funnel 2 having a funnel shape as shown in FIG. 4, and comprises a three-color phosphor layer provided on the inner surface of the panel 1. A shadow mask 4 is disposed inside the phosphor screen 3 so as to face the phosphor screen 3, and the three electron beams 7 B, 7 G, and 7 E emitted from an electron gun 6 disposed in a neck 5 of the funnel 2 by the shadow mask 4. 7R is formed in such a structure that it is selected so as to be correctly incident on the three-color phosphor layer.

The shadow mask 4 has a mask body 9 having a large number of apertures formed in a predetermined arrangement on a surface facing the phosphor screen 3, and a mask frame 10 attached to a periphery of the mask body 9. Consists of Generally, as shown in FIG. 5, the aperture of the mask main body 9 is formed in a composite hole shape having a small hole 11 on the electron gun side and a large hole 12 on the phosphor screen side.

Conventionally, openings in the mask body 9 are formed by a photo-etching method. A photoresist is applied to both sides of a strip-shaped shadow mask material plate made of low carbon steel or the like, and the photoresist on both sides is formed. A pair of baking masters having a negative pattern formed of opaque dots corresponding to the small holes 11 and the large holes 12 of the mask body 9 are brought into close contact with each other and exposed, and a pair of baking masters is formed on the photoresist on both surfaces. Bake the pattern. Next, the photoresist having the pattern printed thereon is developed to form a resist having a pattern corresponding to the pattern of the printing original plate. Then, an etching solution containing ferric chloride as a main component is sprayed on both surfaces of the shadow mask material plate on which the resist is formed, and the small holes 11 and the large holes 1 are sprayed.
2 is formed by etching.

In the pair of printing masters, as shown in FIG. 6, an emulsion layer 16 made of silver halide and gelatin is formed on a flat glass substrate 14 with an undercoat layer 15 interposed therebetween. Opening of mask body (small hole, large hole)
Is formed, and a portion other than the non-translucent dots 17 is formed by a translucent portion 18.
It consists of

Conventionally, a pair of negative masters are prepared by drawing a pattern of opaque dots on a negative-type dry plate using a pattern generator such as a photoplotter. It is manufactured by repeating contact inversion from a pattern.

That is, as shown in FIG. 7A, a pattern of the opaque dots 20a is drawn on a negative type dry plate by a pattern generator, as shown in FIG. 7 (a). The master 21a is manufactured. Next, the emulsion layer of the negative master 21a was brought into close contact with the emulsion layer of the negative type dry plate and exposed, and as shown in FIG.
A positive master 21b (master master) composed of the positive pattern b is prepared. Next, the emulsion layer of the positive master 21b is closely contacted with the emulsion layer of the negative type dry plate and exposed, as shown in (c), the negative opaque dots 20c having the pattern of the positive master 21b inverted. One printing original plate 21c having a pattern formed thereon is prepared. Similarly, as shown in (d) to (f), the pattern of the opaque dots 22a is drawn on the negative type dry plate by the pattern generator, as shown in FIGS.
After preparing a, the pattern of the negative master 23a is intimately reversed to form a positive master 23b (master master), and the pattern of the positive master 23b is closely inverted to prepare the other printing master 23c.

However, when a pair of printing masters 21c and 23c are produced by this method, when the pair of printing masters 21c and 23c are brought into close contact with the photoresist formed on both sides of the shadow mask material plate, they are baked. A pattern shift occurs, and a desired aperture cannot be obtained.

That is, as shown in FIG. 8, a pattern is printed on a photoresist by using a pair of printing masters 21.
The emulsion layers 16 of c and 23c are opposed to each other, and the emulsion layers 16 of the pair of printing masters 21c and 23c are brought into close contact with a photoresist 26 formed on both surfaces of a shadow mask material plate 25. Thus, a pair of printing masters 2
When the emulsion layers 16 of 1c and 23c are opposed to each other, a pair of printing masters 21c and 23c are provided by a pattern generator as shown in FIG. 7A to FIG. There is a shift when the pattern of the opaque dots 20a and 22a is drawn, and the direction of the shift is opposite to each other, so that a pattern shift occurs and the aperture shape of the shadow mask changes.

As a method for preventing the pattern shift between the pair of printing masters 21c, 23c, as shown in FIGS. 9 (a) to 9 (c), one printing master 21c is shown in FIGS. It is produced by the same method as the method shown in (c), and the other printing original plate 23c is
As shown in FIG. 9D, a pattern of the opaque dots 22a is drawn on a negative type dry plate by a pattern generator to produce a negative master 23a1 (first negative master).
The emulsion layer of this negative master 23a1 was closely contacted with an emulsion layer of a positive type dry plate (eg, a precision line plate LPDP made by Kodak) and exposed, and the pattern of the first negative master was once transferred as shown in (e). Same opaque dot 22
A negative original 23a2 (second negative original) consisting of the negative pattern a is prepared. Then, as shown in (f) and (g), there is a method of manufacturing by repeating contact inversion.

When a pair of printing masters 21c, 23c is prepared by such a method, both printing masters 21c, 23c are produced.
When the emulsion layer 16 of 23c is in close contact with the photoresist formed on both sides of the shadow mask material plate, as shown in FIG. 10, a pair of printing masters 21c and 23c are used.
And the shift directions of the patterns coincide with each other, thereby preventing a change in the shape of the opening. However, such a method uses a special dry plate (Precision Line Plate LPDP made by Kodak), so that the size variation of the opaque dots 22c becomes large, and the variation of the opening diameter of the shadow mask and the quality of the mask unevenness are increased. A drop occurs.

[0012]

As described above, the openings of the shadow mask are formed by exposing a pair of printing masters to a photoresist coated on both sides of a shadow mask material plate by a photo-etching method. The pattern is formed by baking a pattern of a pair of printing masters on photoresists on both sides, developing, and etching.

Conventionally, a pair of printing masters is used to produce a pair of negative masters by drawing a pattern of opaque dots on a negative-type dry plate using a pattern generator, and the pair of negative masters is used to reverse contact. It is made by repeating. However, when a pair of printing masters is manufactured by such a method, a pattern shift occurs due to a shift when a pattern of opaque dots is drawn by the pattern generator, and the aperture shape of the shadow mask changes.

As a method for preventing the pattern deviation of the pair of printing masters, a pattern of opaque dots is drawn on a negative type dry plate by a pattern generator for the other printing master of the pair of printing masters. First
A negative master is prepared, and then the emulsion layer of the first negative master is brought into close contact with the emulsion layer of a positive-working dry plate and exposed, and the first negative master is once transferred to have a negative pattern of the same opaque dots. There is a method in which after the second negative master is produced, the adhesion inversion is repeated to produce a printing original. However, when a pair of printing masters are manufactured by this method, the special printing plate is used, and the size of the light-transmitting dots of the other printing master becomes large, causing variations in the aperture diameter of the shadow mask and mask unevenness. Is reduced.

Meanwhile, in recent years, there has been an increasing demand for improving the quality of unevenness and the accuracy of the aperture size of a shadow mask of a high-definition color display tube, and a more accurate printing master has been required.

That is, in accordance with the demand for the improvement of the uneven quality and the accuracy of the aperture size of the shadow mask of the high-definition color display tube, a pattern of a pair of printing masters is printed on the photoresist formed on both surfaces of the shadow mask material plate. In this case, a printing apparatus for automatically aligning a pair of printing masters is introduced, and a pair of printing masters used for the printing apparatus are also provided with alignment marks in two upper portions, and a pattern of the pair of printing masters is used. Just before baking
By reading the alignment marks with a D camera and automatically correcting the alignment marks, it is possible to reduce the pattern shift between a pair of printing masters. However, a shadow mask of a high-definition color display tube requires an accuracy of ± 0.002 mm for alignment of the pattern of a pair of printing masters, so that a printing master with higher precision is required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems. In a method of manufacturing a shadow mask, a pattern corresponding to an opening of a shadow mask is formed on a photoresist applied to both surfaces of a shadow mask material plate. An object of the present invention is to enable a pair of printing masters to be printed to be manufactured with high precision.

[0018]

A pair of printing masters having a negative pattern corresponding to the openings of the shadow mask are brought into close contact with the photoresist applied on both sides of the shadow mask material plate, and exposed to light. After baking the pattern of the baking master on the resist, in a shadow mask manufacturing method of forming the opening in the shadow mask material plate by developing and etching, among the pair of baking masters,
On the other hand, for the printing master, a negative master consisting of a negative pattern was prepared by a pattern generator, and the contact reversal was repeatedly performed from the negative pattern of the negative master,
For the other printing master, a positive master consisting of a positive pattern was prepared by a pattern generator, and the positive pattern of this positive master was produced by intimately inverting the positive pattern.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows main manufacturing steps of a shadow mask for a color cathode ray tube. In the shadow mask for a color cathode ray tube, as shown in FIG. 1A, first, a photosensitive agent is applied to both sides of a strip-shaped shadow mask material plate 25 made of low carbon steel or the like, and dried to form a photoresist 30. Next, as shown in FIG. 1B and FIG. 2, a negative pattern composed of opaque dots corresponding to the large holes and the small holes (see FIG. 5) of the mask body is formed on the photoresist 30 on both sides. The pair of printing masters 31 and 32 are closely contacted and exposed, and the patterns of the pair of printing masters 31 and 32 are printed on the photoresist 30 on both sides. Next, the photoresist 30 having the pattern printed thereon is developed with hot water to remove unexposed portions. As shown in FIG. 1 (c), the pattern of the printing master is placed on both sides of the shadow mask material plate 25. Are formed with resists 33 and 34 having a pattern corresponding to. Next, the resists 33 and 34 are burned to enhance corrosion resistance. Next, the resist 33,
The shadow mask material plate 25 is etched by spraying an etching solution containing ferric chloride as a main component on both surfaces of the shadow mask material plate 25 on which the 34 is formed, as shown in FIG. Small hole 11 on the other side, large hole 12 on the other side
Is formed, and an opening 35 in which the small hole 11 and the large hole 12 communicate with each other is formed. Thereafter, as shown in FIG. 1 (e), the resist remaining on both sides is removed with an alkaline solution, washed with water, and dried to manufacture the semiconductor device.

In particular, in this embodiment, a pair of printing original plates 31 and 32 manufactured as follows are used.

That is, a pair of printing masters 31, 32
Among them, one of the printing masters 31 is manufactured by the same method as that shown in FIGS. 7 or 9A to 9C, and as shown in FIG. A pattern of the opaque dots 20a is drawn on a negative type dry plate by the pattern generator (1) to prepare a negative original plate 21a. Next, the emulsion layer of the negative master 21a is brought into close contact with the emulsion layer of the negative type dry plate and exposed to light, and as shown in FIG. A positive master 21b (master master) is prepared. Next, this positive master 21b
The emulsion layer of the negative type dry plate was exposed to the emulsion layer in close contact with the emulsion layer, and as shown in (c), the negative master having the negative pattern formed of the opaque dots 20c obtained by inverting the pattern of the positive master 21b was formed. This negative master is used as one printing master 31.

On the other hand, as shown in FIG. 3 (d), the pattern of the light-transmitting dots 36a is first drawn on a positive type dry plate by a pattern generator such as a photo plotter as shown in FIG. Positive master 37a
Is prepared. Next, the positive master 37a was used as a master master, and the emulsion layer of the positive master 37a was brought into close contact with the emulsion layer of the negative type dry plate and exposed to light, and the pattern of the positive master 37a was inverted as shown in FIG. A negative master having a negative pattern formed of the opaque dots 38b is prepared, and this negative master is used as the other printing master 32.

As described above, the pair of printing masters 31, 3
2 is manufactured, the patterns of the printing masters 31 and 32 are printed on the photoresist 30 formed on both sides of the shadow mask material plate 25, so that the emulsion layers of the pair of printing masters 31 and 32c are opposed to each other. When the emulsion layer is brought into close contact with the photoresist 30, the direction of the shift generated when the pattern of the opaque dots 20a is drawn on the negative type dry plate or the pattern of the light permeable dots 37a on the positive type dry plate by the pattern generator matches (see FIG. 10). Conventionally, it is possible to prevent a change in the shape of the opening due to a pattern shift that has occurred when a pair of printing masters is conventionally manufactured by the method of FIG. Moreover,
The printing master 32 can be manufactured without using a special drying plate as in the method shown in FIG. 9, and the opening of the shadow mask that has conventionally occurred when a pair of printing masters was manufactured by the method of FIG. Variations in hole diameter and deterioration in mask unevenness can be prevented, and a high-quality shadow mask can be easily manufactured.

In the above-described embodiment, a case has been described where the pattern of the pair of printing masters is formed of circular dots and circular openings are formed in the shadow mask.
The present invention can also be applied to a case where the pattern of a pair of printing masters is rectangular dots and rectangular openings are formed in a shadow mask.

In the above embodiment, of the pair of printing masters, the other printing master for forming large holes in the shadow mask material plate is formed by drawing a pattern of light-transmitting dots by a pattern generator. The case of producing a positive master was explained, but one baking master for forming small holes in the shadow mask material was manufactured by drawing a pattern of transparent dots with a pattern generator to create a positive master. Alternatively, the other printing master for forming large holes in the shadow mask material may be manufactured by a method of manufacturing a negative master by drawing a pattern of opaque dots by a pattern generator.

In the above embodiment, the case where the opening is formed by simultaneously spraying the etching solution on both surfaces of the shadow mask material has been described.
The present invention can be applied to a method of manufacturing a shadow mask in which etching is divided into two stages and one surface is etched.

[0028]

As described above, when a pair of printing masters is manufactured, a change in hole shape due to a pattern shift caused when a pair of printing masters is manufactured by a conventional method can be prevented. By using the improved method, it is possible to prevent a variation in the opening diameter of the shadow mask and a decrease in the quality of the mask unevenness caused when a pair of printing masters are manufactured, and it is possible to easily manufacture a high-quality shadow mask.

[Brief description of the drawings]

FIGS. 1A to 1E are diagrams showing main manufacturing steps of a shadow mask for a color cathode ray tube according to an embodiment of the present invention.

FIG. 2 is a view showing a step of baking a pair of baking original patterns on photoresist formed on both surfaces of a shadow mask material plate in the manufacturing process.

FIGS. 3A to 3E are views for explaining a method of manufacturing the pair of printing masters.

FIG. 4 is a diagram showing a configuration of a color cathode ray tube.

FIG. 5 is a view showing an aperture shape of a shadow mask of the color cathode ray tube.

FIG. 6 is a view showing a configuration of a pair of printing masters for printing a pattern corresponding to an opening of a shadow mask on photoresist formed on both surfaces of a shadow mask material plate.

FIGS. 7A to 7F are views for explaining a conventional method for producing a pair of printing original plates.

8A is a plan view for explaining a pattern shift of a pair of printing masters produced by the method of FIG. 7, and FIG. 8B is a BB cross-sectional view thereof.

9 (a) to 9 (g) are views for explaining a conventional method for producing a pair of improved original printing plates.

10 (a) is a plan view for explaining pattern matching of a pair of printing masters produced by the method of FIG. 9, and FIG. 10 (b) is a BB cross-sectional view thereof.

[Explanation of symbols]

 21a: negative master 25: shadow mask material plate 30: photoresist 31: one printing master 32: other printing master 35: aperture 37a: positive master

Continued on the front page (72) Inventor Katsumi Ichikawa 1-9-2, Hara-cho, Fukaya-shi, Saitama F-term in Toshiba Fukaya Plant Co., Ltd. (Reference) 2H095 AA02 AB23 AB25 AB30 5C027 HH05

Claims (1)

[Claims] 1. A pair of printing masters having a negative pattern corresponding to the openings of a shadow mask are brought into close contact with a photoresist applied on both surfaces of a shadow mask material plate, and the photoresist is exposed to the photoresist. In a method of manufacturing a shadow mask, in which the opening of the pattern of the printing master is printed and then developed and etched to form the opening in the shadow mask material plate, one of the printing masters is used for one of the printing masters. A negative master consisting of a negative pattern is produced by a pattern generator, and the negative reversal of this negative original is repeated to make a close contact inversion, and for the other printing master, a positive original consisting of a positive pattern is produced by a pattern generator. A shadow characterized by being produced by inverting the original positive pattern in close contact Method of manufacturing a mask.