JP3489276B2 - 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 is manufactured by a process as shown in FIG. That is,
As the shadow mask material 1, for example, a low carbon steel plate having a thickness of 0.13 mm is used, and after degreasing, surface conditioning and washing treatment on both sides, casein or polyvinyl alcohol and ammonium dichromate are applied to the water-soluble photosensitive solution. After drying, the photoresist film 2 is formed. 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, with warm water,
If the developing treatment for dissolving the unexposed and uncured photoresist film is performed, as shown in FIG. 5A, the small-hole resist film 2a is formed.
Shadow mask material 1 having a large hole resist film 2b on both sides
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. 5B, it is important to stop the etching progress in the middle. 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. 5 (c), 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. 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.

In this conventional method, it can be said that the side etching phenomenon, which cannot be avoided by the photoetching method, is suppressed on the small hole side. That is, by filling the recesses on the small hole side with the etching prevention layer and not side-etching the small holes in the second etching step, 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.

However, this conventional method is not without problems. According to the conventional method, the etching prevention layer is formed by a spray coating method, a mesh cell gravure coating method having ink cells having mesh-shaped grooves, or the like, but this method has the following drawbacks. That is, in the spray coating method, since a large number of spray nozzles are arranged, the coating apparatus becomes large. Maintenance of the coater is troublesome due to contamination by spray droplets and accumulation of coat liquid. There are drawbacks such as bubbles being easily taken in and remaining in the etching prevention layer. Next, in the mesh cell gravure coating method, the property of pushing the coating liquid into the concave portion is weak. There are drawbacks such as bubbles being easily taken in and remaining in the etching prevention layer. In particular, the defect that air bubbles are likely to be taken in and remain in the etching prevention layer common to the above two methods can be said to be a serious defect that causes defective shape of the shadow mask. That is, as shown in FIG. 6A, the bubbles 25 remaining in the etching prevention layer 4 may promote the side etching phenomenon of small holes in the second etching step, and as a result,
As shown in FIG. 6B, the shape of the opening was enlarged, or the shape of the opening was not formed into a predetermined circle, which was a cause of defective shape of the hole.

[0007]

In view of the above-mentioned circumstances, the present invention proposes a method for forming an etching preventive layer in which a bubble is not taken in and remains in a method for 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 defective openings.

[0008]

In order to solve the above-mentioned problems, the applicant of the present application has already made the following proposal. That is, the shadow mask material 1 is applied with an etching prevention layer, and a gravure coating method using a gravure roll 17 having ink cells of the oblique spiral groove 26 shown in FIG. 3 is used. The direction of rotation is opposite to the direction of travel. However, in the method proposed above, the following problems have been newly discovered. That is, diagonal spiral groove
Since the ink is supplied in a wavy manner by the 26 ink cells and the ink is supplied only in the direction of the oblique spiral, the end region of the shadow mask material 1 in the direction of the oblique spiral, the end region A shown in FIG. It could be said that the ink 14 was likely to collect on the. Ink accumulated in the end area A of the shadow mask material 1.
Numeral 14 wraps around the surface opposite to the surface of the shadow mask material 1 provided with the gravure roll 17, that is, the surface on which the etching prevention layer 4 is not formed, and forms an unnecessary etching prevention layer. As a result, in the second etching step, there is a problem in that etching is not performed on a portion that should be originally etched.

Further, since the ink is supplied in a wavy form only in the direction of the oblique spiral groove 26 provided on the gravure roll 17, as shown in FIG. 4, the ink 14 is filled only in the direction of the oblique spiral of the concave portion 3. However, there is also a problem that the bubble 25 is easily held in the recessed area on the side opposite to the direction of the oblique spiral. Furthermore, FIG.
As shown in, there is also a problem that streaky coating unevenness 13 having different coating film thickness depending on the coating site occurs in the direction of the oblique spiral.

Therefore, the present inventors have made further studies and propose a new method below. That is, the present invention etches at least one surface of a plate-shaped shadow mask metal material on which a resist film exposing a part of the metal surface according to a predetermined pattern is formed on both surfaces, A first etching step of forming a recess in the exposed metal portion, and a step of applying an etching prevention layer on one surface having the recess formed in the first etching step and filling the inside of the recess with the etching prevention layer. And a second etching step of etching a surface opposite to the surface provided with the etching prevention layer to form a concave hole leading from this opposite surface to a concave portion formed in the one surface, and the etching In a method of manufacturing a shadow mask, which comprises at least a prevention layer and a film removing step of removing a resist film, as shown in FIG. As a coating means, a gravure coating method using two gravure rolls 17 having ink cells of diagonal spiral grooves 26 is used, and the turning directions of the diagonal spiral grooves 26 provided in the two gravure rolls 17 are opposite to each other. And a method for manufacturing a shadow mask.

However, the embodiment of the shadow mask manufacturing method of the present invention may have the following modifications. That is,
The gravure coater using the two gravure rolls 17 having the ink cells of the oblique spiral groove 26 is a reverse gravure coater. “Reverse” means a rotating direction in which the rotation direction of the gravure roll 17 that is in contact with the object to be coated is opposite to the traveling direction of the object to be coated. Hereinafter, unless otherwise specified, when simply referred to as “gravure coater”, it means a natural gravure coater in which the rotation direction of the gravure roll is the same as the traveling direction of the coated object, and is distinguished from the reverse gravure coater. To do.

Next, it is also desirable to provide impression cylinders 22 in front of and behind the pair of gravure rolls 17 of the present invention as means for solving this problem. For some reason, the impression cylinder 22 is used to apply tension to the shadow mask material 1 to prevent the slack of the metal material, and to improve the adhesion between the metal material and the gravure roll 17, thereby increasing efficiency. This is because it becomes possible to fill the inside of the recess of the metal material with the etching prevention layer.

The ink supply system of the gravure coater 10 is reverse or natural,
Ink circulation system is desirable. Because
This is because the ink can always be supplied to the plate in a clean state by attaching the filter 21 to the ink circulation path.

As a method of manufacturing a shadow mask to which the present invention can be applied, it goes without saying that the conventional technique described with reference to FIG. 5 can be applied. More generally speaking, the present invention can be applied to any method of manufacturing a shadow mask, which includes a step of dividing etching into two stages and filling an etching prevention layer into a recessed portion on one side of which halfway is etched. The recess for filling the etching prevention layer may be on the small hole side or the large hole side, but in many cases,
It is a small hole side.

[0015]

In the shadow mask manufacturing process, the present invention employs a reverse gravure coating method using two gravure rolls having ink cells with oblique spiral grooves as means for applying the etching preventive layer, and the two gravure rolls are applied. It is characterized in that the turning directions of the provided oblique spiral grooves are opposite to each other. The gravure roll coater having an ink cell with a diagonal spiral groove has an excellent property of supplying a sufficient amount of ink to the surface to be coated and pushing the ink into the etched recess. In particular, in the case of reverse coating, the gravure roll coater having the ink cells of the oblique spiral groove works to press the ink in a wavy shape into the etched recess.

Furthermore, since the turning directions of the oblique spiral grooves provided on the two gravure rolls are opposite to each other, the ink is supplied from two directions. That is, for example, when the ink is supplied from the first gravure roll toward the plate end direction on the left side of the traveling direction of the metal material, the direction of rotation is opposite to the diagonal spiral groove provided in the first gravure roll. By the second gravure roll having the diagonal spiral groove, the ink is supplied toward the plate end portion on the right side in the traveling direction of the metal material.

Therefore, the ink supplied by the first gravure roll, for example, the excess ink in the plate end region on the left side in the metal material advancing direction is scraped off by the second gravure roll to the right side in the metal material advancing direction. Will move in the direction. As a result, excess ink does not collect in both end regions of the metal material on the left and right in the traveling direction. Further, streak-shaped coating unevenness generated in the oblique spiral direction by the first gravure roll is scraped and flattened by the second gravure roll, and ink is newly supplied from the second gravure roll. It is possible to obtain a coating film having a uniform film thickness without pinholes.

Further, since the ink is supplied to the concave portion of the metal material from two directions, the ink is efficiently filled into the entire concave portion without being filled with the ink only in a certain area of the concave portion. As described above, according to the present invention, the etching prevention layer can be filled in the etched recess with a uniform coating film thickness without enclosing air bubbles.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to FIGS. In FIG. 2, the shadow mask material 1
Is a long metal plate supplied from a winding roll, and uses, for example, low carbon steel having a plate thickness of 0.13 mm or low expansion amber material. By performing the steps already described in the section (Prior Art), a shadow mask material 1 having a small hole resist film 2a and a large hole resist film 2b on the front and back sides as shown in FIG. 5A is obtained. .

Next, when the shadow mask material 1 is passed through the first etching chamber 7 shown in FIG. 2, the front and back of the shadow mask material 1 are partly etched by the etching liquid ejected from the spray nozzles 8 provided above and below, The recesses 3a and 3b are formed as shown in FIG. 5 (b).

The shadow mask material 1 which has passed through the first etching chamber 7 is conveyed upward and inverted so that the small hole side filled with the etching prevention layer is the lower surface. This is because in the case of coating with a cylinder roll, it is suitable that the coating surface is on the lower side. Two gravure rolls 17a and 17b, each having ink cells of an oblique spiral groove 26a and a spiral groove 26b whose turning directions are opposite to each other with respect to the shadow mask material 1 with the small hole surface facing down
Gravure coater 10 will be used for gravure coating.
This is the feature of the present invention.

To explain this point with reference to FIG. 1, the shadow mask material 1 is conveyed from the right side of the drawing. Next, the first gravure roll 17a having the ink cells of the oblique spiral groove 26a, and the first gravure roll 17a
The coating is performed by the gravure coater 10 including the second gravure roll 17b having the diagonal spiral groove 26b formed in the opposite direction to the diagonal spiral groove 26a provided in the. That is, a pair of two gravure rolls 17 each having an ink cell of an oblique spiral groove 26 whose turning directions are opposite to each other.
The shadow mask material 1 is passed between the impression cylinder 22 and
In the embodiment shown in FIG. 1, the gravure rolls 17 are rotated in the reverse direction, which is opposite to the conveying direction of the shadow mask material 1.

In the case of the reverse gravure roll 17, since the relative speed with the shadow mask material 1 is large and the contact is in the opposite direction, the action of pushing the coating liquid into the concave portion 3 at the contact surface is strong, and the diagonal spiral. The ink cells of the groove 26 work to press the ink in a wavy manner. Moreover, since the gravure coater 10 is suitable for uniformly spreading the coating liquid, it does not cause coating defects such as pinholes.

According to the present inventors, the diagonal spiral grooves 26 provided on the two gravure rolls each have a pitch from peak to peak of 100 to 500 μm, and the angle of the spiral is 25 to 25 degrees with respect to the roll axis. Set at 65 ° and the depth of ink cell is 10 ~ 200
We have empirically obtained the fact that good coating results can be obtained with a thickness of μm. In addition, the spirals provided on the two gravure rolls 17 are rotated in opposite directions.

Further, in this embodiment, as shown in FIG. 1, the impression cylinders 22 are provided in front of and behind the gravure roll 17 which is a pair of two. By applying tension to the shadow mask material 1 using the impression cylinder 22, the slack of the shadow mask material 1 that occurs when the long shadow mask material 1 is conveyed is prevented and the shadow mask material 1 is gravure-rolled. It has a role of pressing against 17. As a result, the adhesion between the shadow mask material 1 and the gravure roll 17 is enhanced, and it becomes possible to more efficiently and uniformly fill the concave portion of the shadow mask material 1 with the coating liquid.

The coating liquid of the gravure coater 10 is supplied in a circulating system. The tip 23 of the coating liquid supply device 18 slides on the surface of the reverse gravure roll 17 to scrape off excess coating liquid other than the coating liquid filled in the ink cells engraved on the surface of the gravure roll. Excess coating liquid
It is circulated from the ink receiver 19 through the pump 20 and the filter 21. The advantage of this method is that the coating solution is always clean through the filter.

Next, in FIG. 2, the shadow mask material 1 for which the application of the etching prevention layer has been completed passes through the drying / curing area 24 further above, and then passes through the second etching chamber 11.
Through, and etching is performed on the large hole side. In this way, a through hole communicating from the large hole side to the small hole is opened, and the state shown in FIG. 5D is obtained. Finally, the etching prevention layer and the resist film 2 are removed in the film peeling chamber 12, and the state shown in FIG. The flat type shadow mask shown was obtained.

[0028]

INDUSTRIAL APPLICABILITY The present invention uses a reverse gravure coating method using two gravure rolls having ink cells with oblique spiral grooves as means for applying an etching preventive layer in a shadow mask manufacturing process, and said two gravure coating methods. It is characterized in that the oblique spiral grooves provided on the roll are rotated in opposite directions. The gravure roll coater having an ink cell with a diagonal spiral groove has an excellent property of supplying a sufficient amount of ink to the surface to be coated and pushing the ink into the etched recess. In particular, in the case of reverse coating, the gravure roll coater having the ink cells of the oblique spiral groove works to press the ink in a wavy shape into the etched recess.

Furthermore, since the oblique spiral grooves provided on the two gravure rolls rotate in opposite directions, the ink is supplied from two directions. That is, for example, when the ink is supplied from the first gravure roll toward the plate end direction on the left side in the traveling direction of the metal material, the direction of rotation is opposite to that of the oblique spiral groove provided in the first gravure roll. By the second gravure roll having the diagonal spiral groove, the ink is supplied toward the plate end portion on the right side in the traveling direction of the metal material.

Therefore, the ink supplied by the first gravure roll, for example, the excess ink in the plate end region on the left side in the metal material advancing direction is scraped off by the second gravure roll to the right side in the advancing direction of the metal material. Will move in the direction. As a result, excess ink does not collect in both end regions of the metal material on the left and right in the traveling direction. Further, streak-shaped coating unevenness generated in the oblique spiral direction by the first gravure roll is scraped and flattened by the second gravure roll, and ink is newly supplied from the second gravure roll. It is possible to obtain a coating film having a uniform film thickness without pinholes. Further, since the ink is supplied to the concave portion of the metal material from two directions, the ink is efficiently filled in the entire concave portion without being filled with the ink only in a certain area of the concave portion.

As described above, according to the method for producing a shadow mask of the present invention, a gravure coater having an ink cell with oblique spiral grooves supplies a sufficient amount of ink to the surface to be coated as a method for coating the etching prevention layer. In addition, since it is good at pushing the ink into the etched recess, it is good at obtaining a coating film having a uniform film thickness without pinholes without entrapment of bubbles in the recess.

Therefore, as compared with the spray method or the mesh cell gravure coating method, bubbles are not taken into the etching prevention layer. Therefore, the remaining bubbles do not promote the side etching phenomenon of the small holes in the second-stage etching, and as a result, the shape of the openings is enlarged, or a defective shape such as the shape of the opening is not formed into a predetermined circle. It can be suppressed. It is possible to prevent an etching failure caused by an unnecessary etching prevention layer being formed on the surface opposite to the surface of the metal material on which the etching prevention layer should be originally formed and the etching being disturbed. Etching defects due to coating unevenness that have occurred in the conventional coating method, that is, etching defects caused by the etching liquid penetrating a thin portion of the coating film and coming into contact with a metal material, have a uniform film thickness according to the present invention. This can be prevented by obtaining a coating film. Since the coating method is the gravure coater method, the coater is smaller than the spray method. Maintenance of the coater is easy because there is no contamination due to spray droplets and no coating liquid retention. That is, it has an excellent effect in practical use.

[0033]

[Brief description of drawings]

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

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

FIG. 3 is a plan view showing a main part of an example of a conventional shadow mask manufacturing method.

FIG. 4 is a plan view showing an example of bubbles in a conventional shadow mask manufacturing method.

FIG. 5 is an explanatory view showing an example of a method of manufacturing a shadow mask in the order of steps.

FIGS. 6A and 6B are explanatory views showing an example of a secondary etching defect due to bubbles remaining in the etching prevention layer.

[Explanation of symbols]

1 Shadow mask material 2 Resist film 3 recess 4 Etching prevention layer 5 holes 6 shadow mask 7 First etching chamber 8 nozzles 10 Gravure coater 11 Second etching chamber 12 Stripping chamber 13 Uneven coating 14 ink 17 Gravure roll 18 Coating liquid supply device 19 Ink tray 20 pumps 21 filters 22 impression cylinder 23 Tip 24 Drying and curing area 25 bubbles 26 diagonal spiral groove

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-8-111174 (JP, A) JP-A-7-121870 (JP, A) JP-A-2-52066 (JP, A) JP-A-63- 204249 (JP, A) JP-A-6-280051 (JP, A) JP-A-5-255868 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01J 9/14

Claims (4)

(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; a step of applying an etching prevention layer on one surface having the concave portion formed in the first etching step and filling the inside of the concave portion with the etching prevention layer; A second etching step of etching a surface opposite to the surface on which the etching prevention layer is provided to form a concave hole communicating from the opposite surface to a concave portion formed on the one surface; In the method for producing a shadow mask, which comprises at least a layer and a film removing step of removing the resist film, an oblique screw is used as a means for applying the etching prevention layer. Using a gravure coating method by two gravure roll having a Inkiseru grooves, and method of manufacturing a shadow mask, characterized in that the opposite direction around each other turning direction of the oblique spiral groove of the two gravure roll. 2. The method for producing a shadow mask according to claim 1, wherein the coating method using the two gravure rolls is a reverse gravure coating method of rotating in a direction opposite to the traveling direction of the metal material. 3. The method for producing a shadow mask according to claim 1, wherein an impression cylinder is provided before and after the two gravure rolls. 4. The method for producing a shadow mask according to claim 1, 2 or 3, wherein the coating solution supply system of the gravure coater is a coating solution circulation system.