JP3206416B2 - 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 of manufacturing a shadow mask by a photo-etching method, and more particularly to a method of 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 as shown in FIG. That is, for example, a low carbon steel plate having a thickness of 0.13 mm is used as a metal material (hereinafter, referred to as a shadow mask material 1), and both surfaces are degreased, trimmed, and cleaned, and then both sides are treated with casein or polyvinyl alcohol and bichromium. A water-soluble photosensitive solution composed of ammonium acid or the like is applied and dried to form a photoresist film 2
To form Next, one side of the shadow mask material 1 is exposed to the negative pattern of the small hole image, and the other side is exposed to the negative pattern of the large hole image. After that, if a development process for dissolving the unexposed and uncured photoresist film with warm water is performed, FIG.
As shown in (a), a shadow mask material 1 having a small-hole resist film 2a and a large-hole resist film 2b on the front and back is obtained.

After that, a hardening process and a burning process are performed on the resist film 2, and a first stage etching is performed from both front and back surfaces. In general, the etching is performed by spray etching at a spray pressure of 1.5 to 3.0 kg / cm ² using a Baume concentration of ferric chloride solution of 35 to 50. In the first etching step, as shown in FIG. 3B, it is important to stop the etching progress halfway. In the 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 only from the small hole side.

Next, the small-hole resist film 2a on the small-hole side is peeled off. When the small-hole resist film 2a is stripped, a protective film is attached to the large-hole resist film 2b to prevent unnecessary peeling from being performed on the large-hole resist film 2b side. It is common to strip the resist film 2a. Next, as shown in FIG. 3 (c), a photo-curable resin or a thermosetting resin is used as a coating liquid, and coating is performed on the small hole side, and the small hole-side recess formed by the preceding etching. 3a
Is completely formed. Here, in order to enhance the filling property of the coating liquid into the small-hole side concave portion 3a,
After the small-hole resist film 2a is stripped, an etching prevention layer is applied and formed, but there is also a method of applying and forming an etching prevention layer on the small hole side without stripping the small-hole resist film 2a. .

Subsequently, as shown in FIG. 3D, a second etching step of etching the shadow mask material 1 only from the large hole side is performed, and an opening 5 penetrating from the large hole side to the small hole is formed.
To form Finally, the etching prevention layer 4 and the resist film 2 are peeled off, washed with water and dried to obtain a flat type shadow mask 6 shown in FIG.

In this conventional method, it can be said that the side etching phenomenon which cannot be avoided by the photo etching method is suppressed on the small hole side. That is, the concave portion on the small hole side is filled with the etching prevention layer, and the small hole is not side-etched in the second etching step, so that a precise small hole pattern in the first etching step can be maintained. Therefore, for example, it is possible to form a hole having a hole diameter smaller than the thickness of the material metal plate.

[0007]

However, the conventional method described above is not without its problems. According to the conventional method, the formation of the etching prevention layer is performed by a spray coat method, a roll coater method, or the like, but this method has the following disadvantages. That is, in the spray coating method or the roll coater method, there is a difficulty in filling the concave portion with the application liquid, and there is a disadvantage that air bubbles are easily taken in and remain in the concave portion. Further, the spray coating method or the roll coater method lacks the ability to form an etching prevention layer with a desired uniform film thickness.

The disadvantage that air bubbles tend to be trapped and remain in the etching prevention layer, especially in the concave portions, is a serious defect that causes a defect in the hole shape of the shadow mask. If the film thickness of the etching prevention layer is not the desired film thickness, the etching resistance of the etching prevention layer is insufficient, so that the shadow mask material 1 is subjected to unnecessary etching during etching, and the holes of the shadow mask are removed. In some cases, this may cause shape defects.

For this reason, a method has been proposed in which a gravure coater having a gravure roll rotating at a high speed is used for forming the etching prevention layer. This method using a gravure roll that rotates at a high speed can be said to be excellent in the filling property of the coating liquid into the concave portions and excellent in the ability to apply the coating liquid with a uniform film thickness. However, this method also has the following problems. That is, there is a problem that the gravure roll rotating at a high speed comes into contact with the shadow mask material 1 and the shadow mask material 1 is damaged. In particular, in the above-described method of manufacturing a shadow mask in which the resist film is stripped and then an etching prevention layer is applied and formed, the resist film is stripped and the exposed shadow mask material surface comes into contact with the high-speed rotating gravure roll, and the shadow is removed. It can be said that, for example, streak-like scratches are made on the surface of the mask material. At the site where the shadow mask material 1 is damaged, the opening 5 is likely to have a defective shape.

In view of the circumstances described above, the present invention provides a method of manufacturing a shadow mask in which air bubbles are not trapped and remain and the desired uniformity is obtained without damaging the shadow mask material surface. The present invention has been made by devising a method for forming an etching prevention layer having a film thickness, and an object of the present invention is to provide a method of manufacturing a shadow mask in which an opening of a defective shape does not occur in the obtained shadow mask. It is.

[0011]

According to the present invention, in order to attain the above object, according to the first aspect, a resist film is formed on both surfaces of the resist film, the metal film being partially exposed according to a predetermined pattern. Etching at least one surface of the plate-shaped shadow mask metal material, a first etching step of forming a concave portion in at least one of the metal exposed portions of the surface, and applying an etching prevention layer to this one surface, A step of filling the inside of the recess with an etching prevention layer, and a recess formed by etching a surface opposite to the surface provided with the etching prevention layer and leading from the opposite surface to the recess formed in the one surface. A method of manufacturing a shadow mask, the method comprising: at least a second etching step of forming a mask; and a stripping step of removing the etching prevention layer and the resist film. Three-stage coating of a first-stage coat using a die coater or a low-speed rotation roll, a middle-stage coat using a high-speed rotation gravure coater, and a second-stage coat using a high-speed rotation gravure coater as a coating means of the anti-agging layer. This is a method for manufacturing a shadow mask, characterized by using a method.

According to a second aspect of the present invention, after the resist film on one surface having the concave portion formed in the first etching step is removed, the etching prevention layer is formed on the one surface by using the three-step coating method. The method according to claim 1, wherein a second etching is performed after the application. Further, in claim 3, the first coat is a method of manufacturing a shadow mask according to claim 1 or 2, wherein the first coat is a gravure coater using a gravure roll rotating at a low speed. 4. A method of manufacturing a shadow mask according to claim 1, wherein the gravure coater uses a gravure roll rotating at a low speed.

Further, in the fifth aspect, the method of manufacturing a shadow mask according to the first, second, third or fourth aspect is such that the rotation direction of the coating roll and the gravure roll is reverse rotation to the traveling direction of the metal material. It is.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. In FIG. 2, a shadow mask material 1 is a long strip-shaped metal plate supplied from a winding roll, and for example, low-carbon steel or a low-expansion invar material having a plate thickness of 0.13 mm is used. Further, the shadow mask material 1 has been subjected to the steps described in the section (Prior Art), and has a small-hole resist film 2a and a large-hole resist film 2b as shown in FIG. Is what you are doing.

Next, by passing the shadow mask material 1 conveyed from left to right in the figure with the small hole side facing upward into the first etching chamber 7 in FIG. 2, etching blown out from the spray nozzles 8 installed vertically. With the liquid, the front and back of the shadow mask material 1 are partially etched, and FIG.
The recesses 3a and 3b shown in FIG.

Then, the shadow mask material 1 having passed through the first etching chamber 7 is stripped of the small-hole side resist film 2 a in the first stripping chamber 12. Note that, in the present embodiment, prior to the peeling of the small-hole-side resist film 2a, a long strip-shaped protective film is attached to the large-hole side, and the protective film is peeled off before the second etching. In the drawings, illustration is omitted.

Next, the shadow mask material 1 is conveyed upward, and is turned over such that the small hole side on which the etching prevention layer 4 is applied and formed faces downward. This is because, in the application by a cylinder roll described later, it is suitable that the application surface is on the lower side. For the shadow mask material 1 with the small hole surface on the lower side, a former coat using a die coater or a low-speed rotating coating roll, a middle coat using a high-speed rotating gravure coater, and a die coater or a low-speed rotating Coating is performed by a three-stage coating method with a subsequent coating using a coating roll. This is one of the features of the present invention.

This will be described below with reference to FIG. With respect to the shadow mask material 1 conveyed from the right side with the small hole surface as the lower side, for example, a coating solution of a preceding stage is applied by a roll coater using a coating roll rotated at a low speed of about 50 rotations per minute or a die coater. Is applied. In the example shown in FIG. 1, the roll coater 9 is used for the application in the former stage. That is, the shadow mask material 1
Is sandwiched between the coating roll 13 and the pressure roll 16, and the coating liquid 19 is supplied to the surface of the coating roll 13 by the supply roll 14, so that the coating liquid 19 is developed on the lower hole side of the shadow mask material 1.

The purpose of this pre-coating is to form a coating liquid layer serving as a cushion on the side of the small hole of the shadow mask material 1 as will be described later. Sex does not matter so much. For this reason, even if the shadow mask material 1 comes into contact with the surface,
When a roll coater is used to apply the coating liquid without damaging the coating, the coating roll is rotated at a low speed. In the former application, the application liquid 19 is applied to a thickness of, for example, about の of the finally desired thickness of the etching prevention layer.

In the embodiment shown in FIG. 1, a roll coater 9 is used for the preceding coating, but a die coater or a gravure coater may be used instead. However, in the former application, if a gravure coater having excellent filling properties of the application liquid in the concave portions is used instead of the roll coater or the die coater,
It can be said that filling of the concave portion with the application liquid is reliable, and it can be said that this is suitable as a means for solving the above-mentioned problem. Again,
The rotation speed of the gravure roll is set at a low speed so that the shadow mask material 1 is not damaged.

Next, after the former application, the middle application is performed on the shadow mask material 1. In the middle-stage coating, a gravure coater 10 having an ink cell and performing a gravure coater 10 using a gravure roll 17 rotating at a high speed of, for example, about 200 rotations per minute is used.

That is, the application liquid 19 is supplied from the application liquid supply device 18.
Is supplied, the shadow mask material 1 is passed between the gravure roll 17 having ink cells and the impression cylinder 20. In the embodiment of FIG. 1, the rotation direction of the gravure roll 17 is the same as the transport direction of the shadow mask material 1. The direction is reversed.

Rotation of the shadow mask material 1 in a direction opposite to the conveying direction,
In the case of the gravure roll 17 rotated at a high speed, the relative speed with the shadow mask material 1 is high and the contact is made in the opposite direction. As a property of the coater 10, it is suitable for uniformly spreading the coating liquid, so that coating defects such as pinholes do not occur.

The impression cylinder 20 functions to prevent the shadow mask material 1 from sagging and to press the shadow mask material 1 against the gravure roll 17. As a result, the adhesiveness between the shadow mask material 1 and the gravure roll 17 is increased, and the coating liquid can be more efficiently and uniformly filled into the concave portions of the shadow mask material 1.

In the middle stage coating, when the gravure roll 17 rotating at high speed comes into contact with the surface of the shadow mask material 1, the coating solution is previously applied to the small hole surface side of the shadow mask material 1 in the preceding stage. Serves as a cushion. In addition, since the surface of the shadow mask material 1 is wet by the application in the previous stage, it can be said that the friction between the gravure roll 17 and the surface of the shadow mask material 1 is reduced. This allows
Even if the gravure roll 17 rotating at a high speed contacts the shadow mask material 1, the surface of the shadow mask material 1 can be prevented from being damaged.

The thickness of the coating liquid applied in the middle stage is, for example, about 1/3 to 1/2 of the finally desired coating thickness of the etching prevention layer.

Next, as described above, a feature of the present invention is a three-stage coating in which a middle-stage coating is performed and then a second-stage coating is performed. That is, as shown in the example of FIG.
In the latter stage, the final application is performed on the shadow mask material 1 on which the application in the middle stage has been completed, by the application roll 13 which is rotated at a low speed of, for example, about 50 rotations per minute. In the latter application, a film is formed to have a uniform thickness of the etching prevention layer, and a finally desired application film thickness is obtained. For this reason, it can be said that it is desirable that the rotation speed of the application roll be low.

As the application means in the latter stage, a die coater or a gravure coater may be used instead of the roll coater 9 as in the former application. However, if a gravure coater is used instead of a roll coater or a die coater for the subsequent coating, filling of the concave portion with the coating liquid, film formation, and the desired coating film thickness can be performed more reliably. It can be said that it is suitable as a means for solving the above-mentioned problem. Also in this case, the rotation speed of the gravure roll is set to low speed rotation.

The coating roll used for coating as described above
It can be said that it is preferable that the rotation direction of the gravure roll 13 or the gravure roll 17 is reverse to the conveyance direction of the shadow mask material 1. The reason is that the reverse rotation improves the filling property of the coating liquid into the concave portion, and when the coating liquid is applied to the shadow mask material 1, a portion of the stripes having a different coating film thickness in the form of a stripe is generated. This is because occurrence can be prevented.

That is, when the rotation direction of the coating roll 13 or the gravure roll 17 is the same as the conveyance direction of the shadow mask material 1, a slight difference between the set rotation speed of the roll and the conveyance speed of the shadow mask material 1 is obtained. Thus, uneven streaks easily occur. However, when the rotation direction of the roll is opposite to the transport direction of the shadow mask material 1, the coating liquid on the roll surface temporarily accumulates at a portion where the roll and the shadow mask material 1 are in contact with each other. It can be prevented.

Next, as described above, the application of the shadow mask material 1 is completed, and the coating liquid is cured through a further drying / curing area 15 as shown in FIG. When the coating liquid is a photo-curable resin, the curing is performed by light irradiation means such as ultraviolet rays, and when the coating liquid is a thermosetting resin, the curing is performed by heating means such as an infrared heater. It is what you do.

Next, after the above-mentioned protective film adhered to the large hole side is peeled off, the protective film is passed through the second etching chamber 11. The spray nozzle sprays the etching liquid from the large hole side, that is, from below. In this way, a through-hole is opened from the large hole side to the small hole, and the state shown in FIG. 3D is obtained. Finally, in the stripping chamber 12, the etching prevention layer 4 and the resist film 2b on the large hole side are removed. This is to obtain a flat type shadow mask shown in FIG.

The embodiment of the present invention is not limited to the above-described drawings and description, and it goes without saying that various modifications can be made based on the spirit of the present invention.

For example, in the above-described drawings and descriptions, the etching prevention layer is formed after the small-hole resist film 2a is stripped, but the etching prevention layer is formed without stripping the small-hole resist film 2a. It goes without saying that the three-step coating method used in the present invention can be applied to a method for manufacturing a shadow mask.

[0035]

As described above, according to the shadow mask manufacturing method of the present invention, as the means for applying the etching preventing layer, the former stage using a roll coater or a gravure coater in which a die coater or an application roll is rotated at a low speed. A three-step coating method is used, in which a coat, a middle coat using a high-speed gravure coater, and a second coat using a roll coater or a gravure coater in which a die coater or an application roll is rotated at a low speed.

That is, in the former coat, a roll coater or a gravure coater in which the die coater or the application roll is rotated at a low speed is used to cushion the shadow mask material 1 without damaging the shadow mask material 1. To form a layer of a coating liquid that serves as a coating liquid. Next, in the middle coat using a high-speed gravure coater, the coating liquid is filled in the recesses. When the high-speed gravure roll comes into contact with the shadow mask material 1, the coating liquid layer formed in the previous coating is removed. It can be said that the friction between the gravure roll 17 rotating at a high speed and the surface of the shadow mask material 1 is reduced because it serves as a cushion and the surface of the shadow mask material 1 is moistened by the previous application. Thereby, even if the gravure roll rotating at high speed contacts the shadow mask material 1, it is possible to prevent the surface of the shadow mask material 1 from being damaged, and to reliably fill the concave portion with the coating liquid. A die coater or a subsequent coater using a roll coater or a gravure coater in which the coating roll is rotated at a low speed is used to form a film having a uniform thickness of the etching prevention layer, and finally a coating film which is desired. Thickness.

Thus, an etching prevention layer having a uniform and desired film thickness can be formed without causing bubbles to be trapped and remaining in the concave portions and without damaging the surface of the shadow mask material 1. Becomes possible.

Therefore, the present invention has the following problems which have occurred in the conventional method of manufacturing a shadow mask, that is, bubbles remain in the concave portions, the shadow mask material 1 is damaged when the etching preventing layer is formed, and the problem of etching occurs. High-quality shadow masks that solve the problem of poor hole shape such as the shape of the opening being enlarged or not being a predetermined circular shape due to the uneven thickness of the prevention layer, etc. Has an excellent practical effect.

[0039]

[Brief description of the drawings]

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

FIG. 2 is an explanatory view showing one embodiment of a method of manufacturing a shadow mask according to the present invention.

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

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 shadow mask material 2 resist film 3 recess 4 etching prevention layer 5 opening 6 shadow mask 7 first etching chamber 8 nozzle 9 roll coater 10 gravure coater 11 second etching chamber 12 stripping chamber 13 coating roll 14 supply roll 15 drying / drying Curing area 16 Pressure roll 17 Gravure roll 18 Coating liquid supply device 19 Coating liquid 20 Impression cylinder

Claims (5)

(57) [Claims] At least one surface of a plate-shaped shadow mask metal material on which a resist film partially exposing a metal surface is formed in accordance with a predetermined pattern on both surfaces is etched, and at least one surface of the metal is removed. A first etching step of forming a concave portion in an exposed portion, a step of applying an etching preventing layer to one surface thereof and filling the inside of the concave portion with an etching preventing layer, and a surface provided with the etching preventing layer. A second etching step of etching the opposite surface to form a recess from the opposite surface to the recess formed in the one surface, and a film removing step of removing the etching prevention layer and the resist film. In a method for manufacturing a shadow mask having at least a pre-stage using a die coater or a low-speed rotation coating roll as a coating means for the etching prevention layer. Over preparative and high-speed rotation and the middle coat using a gravure coater method of the shadow mask, which comprises using a three-step coating process with subsequent coating using a coating roll of a die coater or a low speed rotation. 2. After removing the resist film on one surface having the concave portion formed in the first etching step, an etching prevention layer is applied and formed on the one surface using the three-stage coating method. 2. The method according to claim 1, wherein a second etching is performed thereafter. 3. The method according to claim 1, wherein the first coat is a gravure coater using a gravure roll rotating at a low speed. 4. The gravure coater using a gravure roll rotating at a low speed as the second coat.
The manufacturing method of the shadow mask of the description. 5. The method according to claim 1, wherein the rotation direction of the coating roll and the gravure roll is opposite to the traveling direction of the metal material.
5. The method for producing a shadow mask according to 2, 3, or 4.