JP3491363B2 - Manufacturing method of shadow mask - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a shadow mask by a photoetching method, and more particularly to a method for producing a high-definition shadow mask having a small diameter of apertures and a large number of apertures.

[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 as shown in FIG. That is, for example, a low carbon steel plate having a 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 consisting of casein or polyvinyl alcohol and ammonium dichromate is formed on both surfaces. Is applied and dried to form a photoresist film 2. Next, one surface of the shadow mask material 1 is exposed with a negative pattern of a small hole image and the other surface is exposed with a negative pattern of a large hole image. After that, by performing a developing treatment with hot water to dissolve the unexposed and uncured photoresist film, as shown in FIG. 3A, a shadow mask having a small hole resist film 2a and a large hole resist film 2b on the front and back sides is formed. Material 1 is obtained.

After that, the resist film 2 is subjected to a hardening treatment and a burning treatment, and first-stage etching is performed from both front and back surfaces. 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 . In this first etching step, as shown in FIG. 3B, it is important to stop the etching progress on the way. Further, in this first etching step, there is also a method in which a protective film is attached to the surface of the shadow mask material 1 having the large hole resist film 2b and the shadow mask material 1 is etched halfway only from the small hole side.

Next, as shown in FIG. 3 (c), a resin is applied to the shadow mask material 1 to form an etching prevention layer 4 which completely fills the small hole side concave portion 3a formed by the preceding etching. The etching prevention layer 4 may be formed on the small hole side or the large hole side, but in most cases, the etching prevention layer 4 is formed on the small hole side. Then, FIG.
As shown in (d), 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. Finally, the etching prevention layer 4 and the resist film 2 are peeled off, washed with water and dried to obtain a flat shadow mask 6 shown in FIG.

It can be said that in the conventional method using this etching prevention layer, the side etching phenomenon, which cannot be avoided by the photo etching method, is suppressed on the small hole side. That is, the etching prevention layer 4 is formed in the concave portion on the small hole side.
And the small holes are not side-etched in the second etching step, so that the accurate small hole pattern in the first etching step can be maintained. Therefore, for example, it is possible to open a hole having a hole diameter smaller than the thickness of the material metal plate.

As a means for applying the etching preventive layer 4 to the small hole side, a resin applying cylinder roll (hereinafter referred to as a resin applying roll), which is represented by, for example, a roll coating method or a gravure coating method, is used. It has been proposed by the applicant. That is, as shown in the example of FIG. 2, a resin coating roll 10 having a resin 7 for an etching prevention layer on its surface is brought into contact with the etching prevention layer forming surface of the shadow mask material 1, for example, the small hole resist film 2a side, The resin 7 is applied to and filled in the shadow mask material 1. In the example of FIG. 2, a resin coating roll
The rotation direction of 10 is a rotation direction that is opposite to the traveling direction of the shadow mask material 1.

At the time of coating the resin for the etching prevention layer, the resin coating roll 10 supplies a sufficient amount of the resin 7 for the etching prevention layer to the surface to be coated of the shadow mask material 1 and pushes the resin into the etched recesses. Must be filled. If the resin is not sufficiently filled in the recesses, it can be said that bubbles 11 are likely to be generated in the etching prevention layer resin 7 in the recesses as shown in FIG. Then, when the opening 5 penetrating from the large hole side to the small hole is formed in the second etching, the etching liquid flows into the bubble 11,
As shown in FIG. 4B, the side etching phenomenon of the small holes may be promoted, and as a result, the shape of the opening may be enlarged, or the shape of the opening may not be a predetermined circle, which may cause a defective hole shape.

Therefore, it is necessary to press the shadow mask material 1 against the resin coating roll with an appropriate pressure to push the resin into the concave portion. Usually, the metallic pressure-bonding cylinder roll shown in FIG. 8) is provided on the side opposite to the resin coating roll 10 with the shadow mask material 1 interposed therebetween so as to be in contact with the shadow mask material 1. By applying a force in the direction of the resin coating roll 10 by the pressure bonding roll 8 and pushing the shadow mask material 1, the slack of the shadow mask material 1 during transportation is removed and at the same time a tension is applied to the shadow mask material 1, and this is applied to the resin. The roll 10 has a role of pressing the shadow mask material 1.

However, the range of the optimum value of the force for pressing the shadow mask material 1 in the resin coating roll direction (hereinafter referred to as the pressure bonding force 12) by the pressure bonding roll as shown in FIG. The problem was that it was difficult to apply a crimping force of 12. When the pressure-bonding force is weak, the tension applied to the shadow mask material 1 is weak and the contact pressure between the shadow mask material 1 and the resin coating roll 10 is weak, so that the force for pushing the resin 7 into the concave portion becomes insufficient, and the resin is not filled in the concave portion. It is not filled sufficiently and bubbles are generated in the recess. Further, it can be said that bubbles generated in the recess are difficult to escape because the coating film thickness of the resin becomes thick. For this reason, it is general practice to increase the pressure bonding force in order to prevent the generation of bubbles. However, on the contrary, if the pressure bonding force 12 is too strong, the shadow mask material 1 and the resin coating roll 10 are in strong contact with each other, so that the resin 7 is extruded from the contacted surface, and the resin coating film thickness becomes thin.
As a result, the recess may not be sufficiently filled with the resin, the shadow mask material 1 may be exposed from the resin in the recess, or the coating film thickness may be thin, which may cause a problem in etching resistance.

In this way, the crimping force applied to the crimping roll 12
Since the optimum range of N is narrow, it is difficult to adjust the pressure bonding force 12. Therefore, during the second etching, the air bubbles in the recess or the holes caused by the shadow mask material 1 being exposed from the resin 7 or the like. It was difficult to prevent malformation.

[0011]

In view of the above circumstances, the present invention has devised a method of forming an etching prevention layer in which the resin filling property in a recess is improved in a method of manufacturing a shadow mask, The present invention has been accomplished, and an object of the present invention is to provide a method for manufacturing a shadow mask in which the resulting shadow mask does not have openings with defective shapes.

[0012]

That is, according to the present invention, at least one surface of a plate-shaped shadow mask metal material having a resist film on which a metal surface is partially exposed according to a predetermined pattern is formed on both surfaces. Then, at least a first etching step of forming a concave portion on the metal exposed portion of the one surface, and applying resin to the one surface having the concave portion formed in the first etching step to form a resin inside the concave portion. The step of filling and curing to form an etching prevention layer, and etching the surface opposite to the surface on which the etching prevention layer is provided, and forming a recess from the opposite surface to the recess formed on the one surface. A shadow mask manufacturing method comprising at least a second etching step of forming a hole and a film removing step of removing the etching prevention layer and the resist film. Means for forming an etching preventive layer on the mask metal material, comprising a cylinder roll for etching preventive layer coating, and a pressure bonding cylinder roll located on the opposite surface across the shadow mask metal material, the pressure bonding cylinder roll, an elastic body lined on the roll surface in contact with the shadow mask metal materials, piezoelectric wear Siri
The under roll is a cylinder roll for coating the etching prevention layer.
Shadow mask metal material transfer direction from directly above
The above problem is solved by providing a method for manufacturing a shadow mask, which is characterized in that it is provided at a position moved forward or backward.

A description will be given below with reference to FIG. 1, which shows a main part of an example of a method for producing a shadow mask according to the present invention.
In FIG. 1, the shadow mask material 1 is a long metal plate supplied from a take-up roll, and the first etching step is completed according to the steps described in the above (Prior Art) and the like. It is assumed that recesses are formed on both sides as shown in FIG. 3 (b). Next, with respect to the shadow mask material 1, for example, an ultraviolet curable photocurable resin 7 is applied to the small hole side of the shadow mask material 1, that is, the surface side of the resist film 2a using, for example, a gravure coating method. In this example, the resin coating roll 10 having the resin 7 on the roll surface is used, and the lower surface of the shadow mask material 1 is formed on the small hole side resist film 2a.
As a result, the resin was applied, and the pressure bonding roll was positioned on the upper surface of the shadow mask material 1. However, the resin was applied using the upper surface of the shadow mask material 1 as the small-hole-side resist film 2a, and the pressure bonding roller 8 was applied to the shadow mask material 1. It may be located on the lower surface of the.

Here, as a cause of making it difficult to adjust the pressure-bonding force described in the section (Prior Art), the present inventors
We paid attention to the fact that the pressure roll is made of metal. That is,
Since the crimping roll is made of metal, it does not have elasticity, and the physical force applied to the crimping roll is transmitted as it is without being attenuated in the crimping roll. Vibrations, such as those generated when the shadow mask material is conveyed, and mechanical vibrations, are transmitted to the pressure bonding rolls. For this reason, the crimping force slightly changes due to the vibration transmitted to the metal crimping roll. Therefore, it is presumed that a slight change in the pressure bonding force is directly transmitted to the shadow mask material 1 and the tension applied to the shadow mask material 1 changes, which may cause difficulty in adjusting the pressure bonding force.

Therefore, the inventors of the present invention have made extensive studies in view of this problem, and arrived at the present invention. That is,
In the present invention, as shown in FIG. 1, the surface of the metal pressure roll 8 is covered with the elastic body 9.

According to the present invention, the surface of the pressure roll 8 is made of an elastic material 9
By covering with, the slight variation of the pressure bonding force 12 can be absorbed by the deformation of the elastic body 9. As a result, even if the pressure bonding force 12 slightly fluctuates, the force transmitted to the shadow mask material 1 can be transmitted to the shadow mask material 1 with the fluctuation removed, that is, a stable force.

Further, even if the crimping force 12 is increased to exceed the proper value to some extent, the excess force exceeding the proper value is absorbed by the deformation of the elastic body 9 on the surface of the crimping roll, and the shadow mask material 1 is absorbed. Can transmit appropriate power.

Next, the present inventors actually manufactured a shadow mask by covering the surface of the metal pressure-bonding roll 8 by using materials having various hardnesses as the elastic body 9, and investigated the formation state of the etching prevention layer. . As a result, in the measurement according to JIS-K6301, that is, the measurement using the spring type hardness tester type A as the elastic body 9 covering the metal pressure roll 8, the measured value at a temperature of 20 ° C. is 10 to 50. It has been empirically obtained from the examples shown below that the elastic body is suitable as a condition for solving this problem. Also, regarding the thickness of the elastic body, it is empirically obtained from the examples shown below that a thickness of 5 to 10 mm is suitable as a condition for solving this problem. By the way, the reason why the thickness of the elastic body 8 is set to 5 to 10 mm is as follows. That is, in the ordinary shadow mask material 1, the left and right plate ends are corrugated in the carrying direction, and the wave height is about 1 to 2 mm. The corrugated portion of the shadow mask material 1 deteriorates the adhesion between the shadow mask material 1 and the pressure-bonding roll 8. Therefore, the wave height of the corrugated portion is deformed and absorbed by the elastic body 9 of the pressure-bonding roll 8, and the shadow mask material 1 and the pressure-bonding roll 8 are pressed. It is necessary to contact 8 and 8 uniformly. Therefore, the elastic body 9 having the above-mentioned hardness has a thickness of 5 to 10 mm so that the wave height of the corrugated portion can be deformed and absorbed.

As the material of the elastic body 9, it is conceivable to use synthetic rubber such as urethane rubber, nitrile rubber or neoprene rubber which is generally used as a material for forming a rubber cylinder roll. In consideration of chemical resistance, silicone rubber or natural rubber may be used.

Further, the inventors of the present invention solve the problem of improving the filling property of the resin 7 into the concave portion of the shadow mask material by
Pressure-bonding roll 8 whose surface is lined with the elastic body 9 described above
It is proposed not to place the above directly above the resin coating roll 10 but at a position moved from directly above the resin coating roll 10 to the front or the rear with respect to the conveying direction of the shadow mask material. For example, in the example of FIG. 1, the pressure bonding roll 8 is shifted right above the resin coating roll 10 to the right.

When tension is applied to the shadow mask material using a pressure bonding roll provided at a position offset from just above the resin coating roll, the pressure bonding roll 8 pushes the shadow mask material 1 to bend it as shown in FIG. The mask material 1 is curved along the resin coating roll 10. As a result, the contact area between the shadow mask material 1 and the resin coating roll 10 is increased, and the resin coating roll 10 supplies a sufficient amount of the resin 7 to the surface to be coated of the shadow mask material 1 and inside the recessed portion. It is possible to push the resin 7 into. By the way, A in FIG. 1 and B in FIG. 2 indicate the angle formed by the rotation axis of the resin coating roll 10 in the region where the resin coating roll 10 and the shadow mask material 1 contact each other. As is clear, A is larger than B. Since the amount of displacement of the pressure bonding roll 8 varies depending on manufacturing conditions such as the diameter of the roll, the thickness of the shadow mask material, and the spacing between the shadow mask material transporting rollers, it can be said that it is desirable to set it appropriately according to the manufacturing conditions. Further, by increasing the contact area between the shadow mask material 1 and the resin coating roll 10,
It can be said that even if the pressure bonding force 12 is too strong, the contact pressure between the shadow mask material 1 and the resin coating roll 10 per unit contact area does not become so strong.

Next, in the method for producing a shadow mask according to the present invention, after the ultraviolet curable resin is applied by the method described above, the resin is photocured by irradiating ultraviolet rays to form an etching prevention layer, and then the above-mentioned ( The shadow mask is obtained by performing the second etching, peeling film, etc. according to the steps described in the section (Prior art). In the above example, the resin is the ultraviolet curable resin, but the resin is not necessarily limited to this, and it can be said that, for example, a heat curable resin or the like may be used.

[0023]

By covering the surface of the metal pressure-bonding roll with the elastic body according to the present invention, a slight variation in the pressure-bonding force applied to the pressure-bonding roll is absorbed by the deformation of the elastic body. Further, even if the pressure bonding force is strengthened and exceeds the appropriate value to some extent, the excess force exceeding the appropriate value is absorbed by the deformation of the elastic body on the surface of the pressure bonding roll, and the shadow mask material 1 has an appropriate value. It is possible to transmit the crimping force.

Next, a pressure-bonding roll is provided at a position offset from directly above the resin-coating roll to apply a pressure-bonding force, whereby the shadow mask material is curved along the resin-coating roll. It is possible to increase the contact area of the rolls.

[0025]

EXAMPLES Examples of the present invention will be described below. <Example> As the shadow mask material 1, an amber material, which is a long metal plate supplied from a winding roll and having a plate thickness of 0.13 mm, is used. Then, according to the steps described in the above (Prior art), the first etching step was performed to obtain a shadow mask material 1 having concave portions on the front and back sides as shown in FIG.

Then, as shown in FIG. 1, the surface of the shadow mask material 1 conveyed with the small hole side resist film 2a as the lower surface is on the small hole side and is coated with a UV curable resin using a roll coater having a diameter of 30 mm. It was applied at 30 μm. At this time, according to the present invention, 45 silicon rubber was lining the surface with a hardness measurement value according to JIS-K6301 (using a spring type hardness tester A type, measurement temperature 20 ° C.) with a thickness of 5 mm and a diameter of 35 mm.
The pressure roller was provided on the upper surface of the shadow mask material 1. Further, as shown in FIG. 1, the rotation center of the pressure bonding roll is moved to the right of the rotation center of the roll coater, that is, in the X axis direction.
The distance between the center of rotation of the pressure bonding roll and the center of rotation of the roll coater in the vertical direction (Y-axis direction) was 30 mm.

Then, the ultraviolet curable resin after coating was irradiated with ultraviolet rays to photo-cur the resin to obtain an etching prevention layer shown in FIG. 3 (c). Then, according to the steps described in the above (Prior Art), the second etching,
Stripping was performed to obtain a shadow mask.

[0028]

As described above, according to the method for manufacturing a shadow mask of the present invention, the surface of the pressure-bonding roll used in the step of forming the etching-prevention layer is covered with an elastic body having an elastic force. A slight change in the pressure applied to the roll is absorbed by the deformation of the elastic body. As a result, even if the pressure bonding force fluctuates slightly, the force transmitted to the shadow mask material 1 can be transmitted to the shadow mask material 1 with the fluctuation eliminated, that is, a stable force.

Further, even if the pressure bonding force exceeds a proper value to some extent, the excess force exceeding the proper value is absorbed by the deformation of the elastic body on the surface of the pressure bonding roll, and the shadow mask material 1 has a proper value. It is possible to transmit the crimping force. That is, it can be said that the pressure-bonding force applied to the pressure-bonding roll is easily adjusted in the sense that the pressure-bonding force may be varied to some extent.

Next, a pressure-bonding roll is provided at a position offset from directly above the resin-coating roll and a pressure-bonding force is applied to increase the contact area between the shadow mask material and the resin-coating roll. Therefore, the contact area between the shadow mask material and the resin coating roll is increased, so that the resin can be efficiently supplied to the shadow mask material. Further, even if the pressure bonding force is too strong, the contact pressure between the shadow mask material and the resin coating roll per unit contact area does not become so strong due to the increased contact area, and the resin can be efficiently used as a shadow mask material. Can be supplied.

Thus, in the shadow mask manufacturing method of the present invention, it becomes easy to bring the shadow mask material and the resin coating roll for the etching prevention layer into contact with each other with appropriate force and contact area, and bubbles are generated in the etching prevention layer. It is possible to prevent this, and to obtain a shadow mask of good quality that does not cause defective openings.

Conventionally, the resist film present on the surface of the shadow mask material is adhered to the metal pressure roller, or the air flowing out of the etching process due to the acidic atmosphere caused by the etching solution touches the metal pressure roller. The pressure roller of was easy to rust. Therefore, the rust of the pressure roller scratches the shadow mask material, especially the resist film,
The shadow mask material receives unnecessary etching during the second etching, or the rust peeled off from the pressure bonding roller adheres to the shadow mask material as foreign matter, so that the etching liquid contacts the shadow mask material during the second etching. There was a problem that hindered them from doing so.

However, in the present invention, the surface of the pressure roller made of metal is covered with the elastic body, and the resist film and the air in the acidic atmosphere do not come into contact with the metal surface of the pressure roller, so that the surface of the pressure roller is rusted. Can be prevented. Therefore, it can be said that the present invention is practically excellent in obtaining a high-definition shadow mask, such as preventing etching shape defects due to rust generated on the pressure roller.

[0034]

[Brief description of drawings]

FIG. 1 is an explanatory view showing a main part of an embodiment of a method for manufacturing a shadow mask according to the present invention.

FIG. 2 is an explanatory diagram showing an example of a conventional resin coating method.

3A to 3E are explanatory views showing an example of a method of manufacturing a shadow mask in the order of steps.

4A to 4B are explanatory views showing an example of an etching hole shape defect due to bubbles generated in a concave portion in the order of steps.

[Explanation of symbols]

1 Shadow mask material 2 Resist film 3 recess 4 Etching prevention layer 5 holes 6 shadow mask 7 resin 8 Crimping roll 9 elastic body 10 Resin coating roll 11 bubbles 12 Crimping force

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Claims (2)

(57) [Claims] 1. A metal on at least one of the surfaces of a plate-shaped shadow mask metal material having a resist film on which a metal surface is partially exposed according to a predetermined pattern is etched on at least one surface. A first etching step of forming a concave portion in the exposed portion and a resin is applied to one surface having the concave portion formed in the first etching step, the resin is filled into the concave portion and cured to form an etching prevention layer. And a second etching step of etching a surface opposite to the surface provided with the etching prevention layer, and forming a recessed hole from this opposite surface to a recess formed in the one surface, In the method for producing a shadow mask, which comprises at least the etching preventing layer and a film removing step for removing the resist film, an etching preventing layer is provided on the shadow mask metal material. The means for forming is composed of a cylinder roll for coating an anti-etching layer, and a pressure-bonding cylinder roll located on the opposite surface across the shadow mask metal material, and the pressure-bonding cylinder roll is in contact with the shadow mask metal material. Lined with an elastic body, the cylinder roll for pressure bonding is coated with an etching prevention layer.
Shadow mask metal element from directly above the cloth cylinder roll
Install it at a position that is moved forward or backward with respect to the material transport direction.
A method for manufacturing a shadow mask, characterized in that 2. The method of manufacturing a shadow mask according to claim 1, wherein the hardness of the elastic body is 10 to 50 (measured by JIS-K6301 using a spring type hardness tester A type, measuring temperature 20 ° C.). .