JPH0935659A - Manufacture of shadow mask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the diameter of the opening of a mask constant and prevent the generation of the opening having hole diameter failure by making the small hole pattern size of a small hole pattern mask used in pattern exposure gradually large from the central part of a shadow mask toward the circumference. SOLUTION: The size of a hole pattern formed in a pattern mask 7 is set based on the side etching amount generating by etching to a shadow mask material 1. When the portion of the shadow mask material 1 exposed from an opening 9 of a resist film 2 is etched, the shadow mask material 1 is side- etched, a recess 3 larger than the diameter of the opening 9 of the resist film 2 is formed. The size of each small hole pattern 8a formed in a small hole pattern mask 7a is made gradually large according to an increase in the offset amount of a mating large hole pattern 8b. A shadow mask is manufactured with the small hole pattern mask 7a and the large pattern mask 7b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a shadow mask used for a color picture tube or the like by a photoetching method, and more particularly to a method for manufacturing a high-definition shadow mask having a small opening diameter and a large number of openings. .

[0002]

2. Description of the Related Art Conventionally, a shadow mask used for a color picture tube or the like is manufactured by a process shown in FIG. That is, for example, a low carbon steel plate having a plate thickness of 0.13 mm is used as the shadow mask material 1, and both surfaces thereof are degreased, surface-treated, and washed, and then water-soluble photosensitive liquid containing casein or polyvinyl alcohol and ammonium dichromate on both surfaces. Is applied and dried to form a photoresist film 2. Then, FIG.
As shown in (a), a small hole positive pattern mask 7a having a small hole pattern 8a portion as a light shielding portion on one surface of the shadow mask material 1 and a large hole pattern 8b portion having a large light shielding portion as a light shielding portion on the other surface. Positive hole pattern masks 7b are placed in close contact with each other and exposed from both sides. After that, when a developing process for dissolving the unexposed and unhardened photoresist film is performed with warm water, as shown in FIG. 5B, the openings 9 corresponding to the small hole patterns 8a and the large hole patterns 8b are formed. Small hole resist film
2a and a large hole resist film 2b are obtained.

Thereafter, the resist film 2 is subjected to a hardening treatment and a burning treatment, and as shown in FIG.
First-stage etching is performed from both front and back sides. The etching solution is a ferric chloride having a Baume concentration of 35 to 50, and spray etching is generally performed at a spray pressure of 1.5 to 3.5 kg / cm ² .

Then, as shown in FIG. 5 (d), an etching prevention layer 4 is formed by coating so as to completely fill the recess 3a on the small hole side formed by the preceding etching. Subsequently, FIG.
As shown in (e), the second etching step of etching the shadow mask material 1 only from the large hole side is performed to form the opening 5 penetrating from the large hole side to the small hole. Then, FIG.
As shown in (f), the etching prevention layer 4 and the resist film 2 are peeled off, washed with water and dried, and then the unnecessary portions are cut and removed to finally obtain the shadow mask 6 shown in FIG. As a method for manufacturing the shadow mask,
In addition to this, there is also a method of forming the opening 5 by etching from both sides of the shadow mask material 1 on which the resist film 2 having the opening 9 is formed without using the etching prevention layer 4.

Here, FIG. 4 is a plan view showing an example of the shadow mask 6 obtained by the above-described manufacturing method and the like, and an image area 10 in the figure is a shadow mask in which a large number of the above-mentioned openings 5 are formed. The screen portion is shown, and the skirt molding area 11 shows the outer shape portion, and is a portion that is molded by a press or the like when incorporated in a color picture tube.

The shadow mask 6 obtained by the above-described manufacturing method is incorporated in a color picture tube, and the color picture tube is composed of an electron gun and three, for example, red, green and blue in addition to the shadow mask. It is composed of color dot fluorescent screens. The shadow mask is attached between the electron gun and the phosphor screen with a certain distance from the phosphor screen and with the large hole side facing the phosphor screen. Here, the electron beam emitted from the electron gun passes through the opening 5 formed in the image area 10 on the shadow mask by the above-described manufacturing method or the like, and the opening 5 follows the image area 10 on the shadow mask at a predetermined pitch. Many are regularly arranged.

One opening 5 corresponds to a set of three red, green and blue phosphor dots, and the shadow mask guides the three electron beams emitted from the electron gun to the respective phosphor dots. Playing a role.

Usually, the electron gun is provided on the center line of the shadow mask, and in the center region of the shadow mask, the electron beam impinges on the shadow mask surface substantially perpendicularly. That is, it can be said that the electron beam enters the opening 5 in the central region of the shadow mask almost vertically. However, as the distance from the center of the shadow mask is increased in the vertical direction, the horizontal direction, and the diagonal direction, the electron beam gradually enters the opening 5 from the oblique direction. Therefore, the opening 5 is formed in order to prevent the electron beam that has entered the opening 5 at a position away from the center of the shadow mask from being blocked by the edge of the large hole recess 3b and to secure a certain amount of passage of the electron beam. The concave portions, in particular the large hole concave portions 3b, are gradually shifted outward as the distance from the center of the shadow mask to the peripheral portion increases.

That is, in the center of the shadow mask, as shown in the opening 5x on the left side of FIG. 2, the large hole concave portion 3b and the small hole concave portion 3a are formed.
It matches the centers of. Next, the small hole recess 3a
Are arranged on the shadow mask according to a predetermined pitch after having a certain size. For example, the openings 5y on the right side of FIG.
As shown in, the center of the large hole recess 3b is sequentially shifted from the center of the small hole recess 3a in the shadow mask peripheral direction. Incidentally, the distance from the center of the small hole recess 3a to the center of the large hole recess 3b is called the offset amount. The shadow mask described below mainly refers to the image area 10 of the shadow mask in which the opening 5 is formed.

The offset amount of the corner portion of the shadow mask farthest from the center of the shadow mask is obtained by calculation from the size of the shadow mask, the thickness of the shadow mask, etc. at the design stage before manufacturing the shadow mask. is there. Next, the offset amount at each portion from the center of the shadow mask toward the periphery of the shadow mask is obtained by, for example, the following formula (Formula 1).

[0011]

[Equation 1]

In the equation (1), A is the distance from the center of the shadow mask to the center of the small hole recess 3a located at the corner of the shadow mask. Further, B is an offset amount required in design in order to exert the performance of the shadow mask in the corner portion of the shadow mask,
The values of A and B are obtained at the stage of shadow mask design. Further, r is the distance from the center of the shadow mask to the center of each small hole recess 3a.

As described in the above-described manufacturing method, the concave portion 3 on the shadow mask is subjected to pattern exposure and development using the pattern mask 7 to form the resist film 2 having the openings 9, and then the shadow mask material 1 is formed. Is formed by etching. Therefore, conventionally, the small hole pattern mask 7a
In, for example, the small hole pattern 8a having a certain size.
Are arranged on the pattern mask at a predetermined pitch, and in the large hole pattern mask 7b, an offset amount is added to the opposing small hole pattern based on the above-mentioned equation (1) and the like. A large hole pattern 8b having a size is provided.

[0014]

The opening 5 is formed by penetrating the large hole concave portion 3b and the small hole concave portion 3a, as shown in the manufacturing process described in the above (Prior Art) section. is there. Therefore, the diameter of the opening 5 at the portion offset from the center of the shadow mask in the peripheral direction and offset to the large hole recess 3b side is in the center region of the shadow mask, and offset to the large hole recess 3b side. It can be said that the diameter is smaller than the diameter of the opening 5 at the non-existing portion. In the text, the diameter of the opening 5 refers to the diameter of the opening 5 when the shadow mask surface is viewed from the right angle direction.

For example, FIG. 2 shows an example of the openings 5 formed at positions separated from each other in the center and peripheral directions of the shadow mask as described above. Here, it can be said that the diameter C ′ of the opening 5y formed in the peripheral direction of the shadow mask is smaller than the diameter C of the opening 5x formed in the center of the shadow mask. The distance between the edges of the opening 5, that is, the linear distance between the edges K and L of the opening 5x in FIG. 2 and the linear distance between the edges M and N of the opening 5y are substantially the same. At the center of the shadow mask, the linear distance between K and L is the same as the diameter C of the opening 5x. However, at the periphery of the shadow mask, M and N are
It is the hypotenuse of a right triangle, and the diameter C'of the opening 5y
Corresponds to the base of a right triangle. Therefore, C ′ becomes shorter than the linear distance between M and N, and thus the diameter C ′ of the opening 5y becomes equal to the diameter C of the opening 5x formed at the center of the shadow mask.
It can be said that it becomes smaller.

Conventionally, the diameter of the opening 5 formed on the shadow mask is a constant value desired at each portion of the shadow mask,
For example, the diameter C of the opening 5x at the center of the shadow mask described above is required. However, as described above, it can be said that the diameter of the opening 5 deviates from the predetermined value at the portion distant from the center of the shadow mask in the peripheral direction, and becomes smaller successively. When the diameter of the aperture 5 is reduced in the peripheral region and a shadow mask having a deviated value from the predetermined value is incorporated into the color picture tube, the passing amount of the electron beam passing through the aperture 5 deviates from the regulation and the electron beam emitted from the electron gun is fluorescent. It cannot be correctly guided to the body dot, and as a result, the display characteristics of the color picture tube, such as deterioration of color purity, are deteriorated.

In view of the above-mentioned circumstances, the present invention has devised a method for producing a shadow mask in which the diameter of the opening of each portion of the shadow mask is constant and has a desired value. It is an object of the present invention to provide a method for manufacturing a shadow mask in which an opening having a defective hole diameter does not occur in the obtained shadow mask.

[0018]

That is, the present invention provides a small hole pattern mask having a light shielding pattern of small holes on one surface of a plate-shaped shadow mask metal material having photosensitive resin layers formed on both surfaces, And, on the other surface of the shadow mask metal material, a step of performing pattern exposure through a large hole pattern mask having a large hole light-shielding pattern, and developing and hardening the shadow mask metal material, A step of forming a resist film in which metal surfaces are partially exposed according to a predetermined pattern on both surfaces, an etching step of etching the shadow mask metal material to form an opening penetrating the shadow mask metal material, and the resist film In the method for manufacturing a shadow mask, which comprises at least a film removing step for removing the small hole pattern of the small hole pattern mask, There is provided a method for manufacturing a shadow mask, characterized in that the texture is successively increased in accordance with an offset amount with respect to a small hole pattern applied to a large hole pattern from a shadow mask central portion toward a shadow mask peripheral portion. By doing so, the above problems are solved.

As described above, the opening 5 is obtained by penetrating the large hole concave portion 3b and the small hole concave portion 3a, and the size of the diameter of the opening 5 is different from that of the concave portion 3 formed in advance before the penetration. It can be said that it depends on the size.

Therefore, the inventors of the present invention have made extensive studies to solve the above-mentioned problems, and paid attention to the pattern 8 provided on the pattern mask 7 from which the recess 3 is formed. That is, although the small hole pattern 8a provided on the small hole pattern mask 7a is provided at a predetermined pitch as in the conventional case, the size of the small hole pattern 8a is set to the shadow mask center according to the offset amount from the large hole pattern 8b. It is proposed that the area be gradually enlarged from the area toward the shadow mask peripheral area. The large hole pattern mask 7b is the same as the conventional one.

That is, the size of the small hole pattern 8a is successively increased from the center of the shadow mask toward the shadow mask peripheral direction, so that the opening 9a of the small hole resist film 2a formed through the small hole pattern 8a is formed. Is gradually increased from the shadow mask center toward the shadow mask peripheral region.

As a result, the size of the small hole concave portion 3a formed by etching the shadow mask material 1 exposed from the opening 9a of the small hole resist film 2a is directed from the central portion of the shadow mask to the peripheral direction of the shadow mask. It will gradually increase. Here, as shown in FIG. 1, the diameter of the opening 5 formed in the recessed portion 3 with an offset, which occurs in the conventional manufacturing method described in the above-mentioned (problem to be solved by the invention), is reduced. By enlarging the small hole pattern 8a in order to compensate for this, that is, by enlarging the small hole recessed portion 3a, the diameter of the opening 5 formed through the large hole recessed portion 3b and the small hole recessed portion 3a is It can be a constant and desired value. The dotted lines in FIG. 1 indicate the open hole portion and the small hole concave portion of the small hole resist film 2a obtained by the conventional small hole pattern.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Normally, the size of the hole pattern 8 provided in the pattern mask 7 is set based on the side etching amount generated when the shadow mask material 1 is etched. That is, as shown in FIG. 5C, when the portion of the shadow mask material 1 exposed from the opening 9 of the resist film 2 is etched, the shadow mask material 1 undergoes side etching and the opening 9 of the resist film 2 is etched. A recess 3 having a larger diameter is formed. Therefore, the pattern mask 7
The size of the hole pattern 8 provided above is required in designing the shadow mask and is set to be smaller than the size of the concave portion 3 to be actually formed on the shadow mask material 1 by the side etching amount.

For example, conventionally, the size of the small hole pattern 8a provided on the small hole pattern mask 7a is obtained from the following equation (2).

[0025]

[Equation 2]

In the equation (2), (target size) is the shadow mask material 1 required for the performance of the shadow mask.
The diameter of the designed opening 5 to be actually formed is shown above. The (SE amount) indicates the side etching amount generated when the shadow mask material 1 is etched. In the example of FIG. 3, the value is the sum of E and F. By the way, the side etching amount is empirically obtained from the etching conditions for the metal material.

Next, in the present invention, the size of each small hole pattern 8a provided on the small hole pattern mask 7a is successively increased in accordance with the increase in the offset amount of the large hole pattern 8b facing each other. The size of the small hole pattern 8a,
For example, it is obtained by the equation (3) shown below.

[0028]

(Equation 3)

In the equation (3), (target size) is the shadow mask material 1 required for the performance of the shadow mask.
The diameter of the designed opening 5 to be actually formed is shown above. The (SE amount) indicates a side etching amount generated when the shadow mask material 1 is etched, and is a value obtained by adding E and F in the example of FIG. Then A is
The distance from the center of the shadow mask to the center of the small hole pattern 8a located at the corner of the shadow mask, and R is the distance from the center of the shadow mask to the center of each small hole pattern 8a.

In the shadow mask obtained by the conventional manufacturing method, that is, the conventional small hole pattern mask, X is the diameter of the opening 5 desired in the shadow mask design, and actually formed on the shadow mask. The shadow mask corner opening 5 that is smaller than the desired value.
It is the difference from the diameter of. For example, the opening 5x on the left side of FIG. 2 is the center opening of the shadow mask and has the diameter C of the opening 5 desired in the shadow mask design, and the opening 5y on the right side of FIG. 2 is the opening of the shadow mask corner portion. And the diameter C ′ of the opening 5 is smaller than the desired value, X is a value obtained by subtracting C ′ from C.

In the small hole pattern mask 7a used in the present invention, the size of the small hole pattern 8a is obtained by the equation (3), and the pitch of the small hole pattern 8a is the same as the conventional one. is there. The large hole pattern 8b provided on the large hole pattern mask 7b is the same as the conventional one, and the small hole pattern 8a is offset according to the equation (1).

Next, using the small hole pattern mask 7a and the large hole pattern mask 7b described above, a shadow mask is manufactured by the manufacturing method described in the above (Prior Art) or the like.

[0033]

EXAMPLES Examples of the present invention are shown below. <Example> As a metal plate for a shadow mask, a thickness of 0.13 mm
Using a long strip-shaped alloy material (amber material) containing iron and nickel as the main components, the shadow mask is manufactured using the manufacturing method of forming the etching prevention layer on the small hole side as shown in FIG. A rectangular metal plate with a size of about 31.6 × 42.0 cm was obtained as a flat shadow mask that was cut into pieces. A rectangular image area having a size of about 23.5 × 31.5 cm is formed in the metal plate.

Prior to the production of the shadow mask, the large hole and small hole pattern masks 7 used for pattern exposure of the resist film 2 formed on the shadow mask material 1 were prepared by the following procedure. That is, using a pattern drawing machine (manufactured by Nippon Seiko Co., Ltd., trade name “LZ-1000”) on two glass substrates on which a silver salt emulsion type photographic photosensitive layer is formed, a large hole and a small hole pattern are formed, respectively. After exposure, development, stopping and fixing processes were performed to prepare a master original plate. Then
The master master plate is prepared by contacting and exposing the separately prepared glass substrate having a photographic photosensitive layer on its surface to develop a substantially same mask except that the light-shielding part and the light-transmitting part of the master master plate are reversed. It was used as an inversion mask. Further, by exposing and developing the above-mentioned reversal mask on a glass substrate having a photographic photosensitive layer on the surface separately prepared, a mask having a light-shielding portion and a light-transmitting portion which are the same as those of the master original plate is obtained. It was used as the large-hole and small-hole pattern mask 7 in the pattern exposure of the mask metal material.

At this time, the small hole pattern mask 7a was as follows. That is, the size of the small hole pattern 8a at each site is determined by the above equation (3), and the small hole pattern 8a is obtained.
The pitch of 8a is the same as before. Here, in the equation (3), A was set to 19.65 cm. Further, as described above, X is the difference between the diameter of the opening 5 at the center of the shadow mask and the diameter of the opening 5 at the shadow mask corner portion in the shadow mask obtained by manufacturing using the conventional small hole pattern mask. Yes, in the case of this embodiment, the thickness is 2 μm. Further, the large hole pattern mask 7b is formed by offsetting the small hole pattern 8a according to the formula (Formula 1) as described above. Also, in the formula of (Equation 1), A is set to 19.65 cm,
B was 12 μm. In this embodiment, except for the pattern mask 7 described above, etching conditions, etc.
It is manufactured in the same manner as the conventional one.

In the shadow mask obtained in this embodiment, the diameter of the opening 5 at the center of the shadow mask and the diameter of the opening 5 located at each part of the shadow mask are constant and desired. The diameter of the value obtained was obtained.

[0037]

In the method for manufacturing a shadow mask according to the present invention, the diameter of the opening 5 formed on the shadow mask is constant at each portion of the shadow mask, and a desired diameter can be obtained. As a result, the problem that occurred in the conventional manufacturing method, that is, the diameter of the opening 5 becomes smaller at the portion away from the center of the shadow mask to the peripheral region, and when the shadow mask is incorporated into the color picture tube, the opening 5 passes through the opening 5. Prevents the problem that the electron beam emitted from the electron gun is not properly guided to the phosphor dots and the display characteristics of the color picture tube, such as the deterioration of color purity, are deteriorated. it can. Further, although the present invention only needs to change the small hole pattern mask, the present invention can be used as it is without changing the manufacturing apparatus, etching conditions and the like. It has excellent practical effects.

[0038]

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of an opening of a shadow mask formed by the present invention.

FIG. 2 is a cross-sectional view showing an example of openings formed in a shadow mask.

FIG. 3 is a sectional view showing an example of side etching.

FIG. 4 is a plan view showing an example of a shadow mask.

5A to 5F are explanatory views showing an example of a method of manufacturing a shadow mask in the order of steps.

[Explanation of symbols]

 1 Shadow Mask Material 2 Resist Film 3 Recess 4 Etching Prevention Layer 5 Opening 6 Shadow Mask 7 Pattern Mask 8 Pattern 9 Opening 10 Image Area 11 Skirt Forming Area

Claims (1)

[Claims] 1. A small-hole pattern mask having a light-shielding pattern of small holes on one surface of a plate-shaped shadow mask metal material having photosensitive resin layers formed on both surfaces, and the other of the shadow mask metal materials. On one surface, a step of performing pattern exposure through a large-hole pattern mask having a large-hole light-shielding pattern, and developing and hardening the shadow mask metal material, and forming a metal surface on both sides according to a predetermined pattern. A step of forming an exposed resist film,
In the method of manufacturing a shadow mask, which comprises at least an etching step of etching the shadow mask metal material to form an opening penetrating the shadow mask metal material, and a film removing step of removing the resist film, the small hole pattern mask Of the shadow mask characterized in that the size of the small hole pattern is sequentially increased in accordance with the offset amount with respect to the small hole pattern applied to the large hole pattern from the shadow mask central portion toward the shadow mask peripheral portion. Production method.