JP3277420B2 - Method for etching iron-based metal sheet and method for manufacturing color selection mechanism - 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 etching an iron-based metal sheet and a method of manufacturing a color selection mechanism used for a cathode ray tube.

[0002]

2. Description of the Related Art For example, a color selection mechanism such as an aperture grill or a shadow mask incorporated in a cathode ray tube such as a color image receiver is usually manufactured by etching a ferrous metal sheet. An aperture grill of a cathode ray tube generally has a schematic partial plan view in FIG. 9A and an enlarged cross-sectional view in a width direction in FIG. 9B.
It is manufactured by continuously etching a strip-shaped metal sheet into a blind and then processing it to a predetermined size.
In FIG. 9, the outline of the aperture grill is indicated by a broken line. Also, the cross-sectional shape is schematically shown. An example of such an iron-based metal sheet etching method will be described below with reference to FIG. 6 which is a schematic partial cross-sectional view of the iron-based metal sheet and the like in the width direction. This etching method is a one-sided etching method.

[Step-10A] First, an iron-based metal sheet 10
Then, photosensitive etching resist layers 12A and 12B having a thickness of 7 to 10 μm are formed on both front and rear surfaces of the substrate (see FIG. 6A).

[Step-20A] Then, the iron-based metal sheet 1
The desired pattern shape is formed on the etching resist layer 12A by patterning the etching resist layer 12A formed on the surface of No. 0 (see FIG. 6B).

[Step-30A] Then, the iron-based metal sheet 1
A protective layer 14 made of a back coat material is formed on the etching resist layer 12B on the back surface of the No. 0 (see FIG. 6C). The purpose of forming the protective layer 14 is to
Is to reinforce the etching resist layer 12B formed on the back surface of the substrate. If the protective layer 14 is not formed, the etching liquid destroys the etching resist layer 12B formed on the back surface of the iron-based metal thin plate 10 when etching the iron-based metal thin plate 10, and etches the back surface of the iron-based metal thin plate 10. The liquid flows around, and the pattern already formed on the iron-based metal sheet 10 is further etched.

[Step-40A] Then, the iron-based metal sheet 1
An etching solution is sprayed on the surface side of the metal sheet 0 to etch the iron-based metal sheet 10 from the surface side. Iron-based metal sheet 10 not covered with etching resist layer 12A
Is removed by etching to form a through region 16 (see FIG. 6D).

[Step-50A] Finally, the etching resist layers 12A and 12B and the protective layer 14 are removed. Thus, an iron-based metal sheet having a desired pattern shape can be obtained (see FIG. 6E).

Next, another example of the method of etching an iron-based metal sheet will be described below with reference to FIG. This etching method is a double-sided etching method, and allows finer and more precise etching than the single-sided etching method.

[Step-10B] First, the iron-based metal sheet 10
Etching resist layers 12A,
Form 12B.

[Step-20B] Next, the iron-based metal sheet 1
0 etching resist layer 1 formed on the front and back surfaces
2A and 12B are patterned to form a desired pattern on the etching resist layers 12A and 12B (see FIG. 7A).

[Step-30B] Then, the iron-based metal sheet 1
An etching solution is sprayed on the surface side of the metal sheet 0 to etch the iron-based metal sheet 10 from the surface side. Iron-based metal sheet 10 not covered with etching resist layer 12A
Is etched. Etching is stopped before this portion penetrates the back surface (see FIG. 7B).

[Step-40B] Next, the iron-based metal sheet 10
A protective layer 14 made of a back coat material is formed on the entire surface of the substrate (see FIG. 7C). The purpose of forming the protective layer 14 is that when the iron-based metal sheet 10 is etched from the back side in the next step, the etchant wraps around the surface of the iron-based metal sheet 10 and is already formed on the iron-based metal sheet 10. It is to prevent the etched pattern from being further etched.

[Step-50B] Then, the iron-based metal sheet 1
The iron-based metal sheet 10 is etched from the back surface side by spraying an etchant on the back surface side of the metal plate 0. Iron-based metal sheet 10 not covered with etching resist layer 12B
Is removed by etching to form a penetrating region 16 (see FIG. 7D).

[Step-60B] Finally, the etching resist layers 12A and 12B and the protective layer 14 are removed. Thus, an iron-based metal sheet having a desired pattern shape can be obtained (see FIG. 7E).

The reason for forming the penetrating region 16 having the sectional shape shown in FIG. 6E or FIG. 7E by the single-sided or double-sided etching method will be described below with reference to the schematic diagram shown in FIG. A brief description will be given with reference to a typical sectional view. For example, in a color selection mechanism made of an etched iron-based metal sheet, an electron beam passes through the through region 16 from the front side to the back side of the iron-based sheet metal 10. The incident angle of the electron beam on the color selection mechanism changes depending on the position where the electron beam is incident on the color selection mechanism. As shown in FIG. 8, the closer the side wall of the through region 16 is to the vertical,
The electron beam incident on the penetrating region 16 and reflected by the side wall of the penetrating region 16 reaches the phosphor screen. As a result, reflection (halation) of the electron beam occurs, and the characteristics of the cathode ray tube deteriorate.

On the other hand, FIG. 6 (E) or FIG. 7 (E)
When the cross-sectional shape shown in FIG. 4 is given to the through region 16, the electron beam incident on the through region 16 and reflected by the side wall of the through region 16 hardly reaches the phosphor screen. As a result, reflection (halation) of the electron beam can be effectively prevented. Incidentally, in the iron-based metal thin plate 10 shown in FIG.
The surface side is the fluorescent screen side. Further, in the iron-based metal thin plate 10 shown in FIG. 7E, the front surface is the electron gun side, and the back surface is the fluorescent screen side.

[0017]

In any of these conventional etching methods, it is necessary to form a protective layer 14 made of a back coat material made of wax or an ultraviolet curable resin. If the protective layer 14 is destroyed during the etching, the iron-based metal sheet cannot be etched with high accuracy. Therefore, the protective layer 14 having a thickness of 20 to 30 μm is conventionally formed. Therefore,
There is a demand for an etching method that can reduce the amount of the back coat material used. Also, desirably, an etching method capable of etching a ferrous metal sheet without forming a protective layer has been desired.

Accordingly, a first object of the present invention is to provide an etching method capable of etching an iron-based metal sheet without forming a protective layer. Further, the second aspect of the present invention
It is an object of the present invention to provide a method for etching an iron-based metal sheet that can reduce the amount of a back coat material used.

[0019]

SUMMARY OF THE INVENTION The first object of the present invention is as follows.
(A) after forming an etching resist layer on the surface of the iron-based metal sheet, forming a desired pattern on the etching resist layer; and (b) in a state where the magnetic belt is in close contact with the back surface of the iron-based metal sheet. And a step of etching the iron-based metal sheet from the front side, which can be achieved by the method for etching an iron-based metal sheet according to the first aspect of the present invention. The method for etching an iron-based metal sheet according to the first embodiment corresponds to a one-sided etching method.

Further, the second object is to (a) form an etching resist layer on both sides of an iron-based metal sheet and then form a desired pattern on each of the etching resist layers; (C) forming a protective layer on the surface of the iron-based metal thin plate, and (d) removing the iron from the surface while the magnetic belt is in close contact with the protective layer. Forming a through region in the iron-based metal sheet by etching the metal-based sheet from the back surface side, the method according to the second aspect of the present invention, it can. The method for etching an iron-based metal sheet according to the second embodiment corresponds to a double-sided etching method. In the step (b), the iron-based metal sheet is etched from the front side while the magnetic belt is in close contact with the back surface of the iron-based metal sheet, and the iron-based metal sheet is etched to a predetermined thickness. Can be interrupted and the state of close contact between the magnetic belt and the back surface of the iron-based metal sheet can be released.

According to the method of manufacturing a color selection mechanism of the present invention, a color selection mechanism including an aperture grill or a shadow mask is manufactured by using the method for etching an iron-based metal sheet according to the first and second aspects. .

[0022]

In the method for etching an iron-based metal sheet according to the first aspect of the present invention, the iron-based metal sheet is etched from the front side while the magnetic belt is in close contact with the back surface of the iron-based metal sheet. Therefore, the magnetic belt adhered to the back surface of the iron-based metal sheet can prevent the etchant from flowing around the back surface of the iron-based metal sheet and further preventing the pattern already formed on the iron-based metal sheet from being further etched. .

In the method for etching an iron-based metal sheet according to the second aspect of the present invention, the iron-based metal sheet is etched from the back surface while the magnetic belt is in close contact with the protective layer. Therefore, the destruction of the protective layer by the etching solution can be prevented by the magnetic belt, and the thickness of the protective layer can be made smaller than before. Also, if the iron-based metal sheet is etched from the front side while the magnetic belt is in close contact with the back surface of the iron-based metal sheet, uniform tension is applied to the iron-based metal sheet, and the pattern formation of the iron-based metal sheet is performed. It can be performed with high accuracy.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on embodiments with reference to the drawings.

(Example 1) Example 1 relates to a method for etching an iron-based metal sheet according to the first embodiment of the present invention. Hereinafter, first, an outline of an apparatus suitable for implementing the first embodiment will be described with reference to FIGS. 1 and 2, and then, with reference to FIG. 3 which is a schematic partial cutaway view of an iron-based metal sheet. Next, each step of the etching will be described.

FIG. 1 shows an outline of an apparatus suitable for implementing the first embodiment.
Shown in This apparatus comprises a photosensitive liquid coating device 20, a heater 22, a resist exposure / development device 30, a resist hardening device 32, a burning device 34, an etching chamber 40, and a resist peeling / washing device 60. . The photosensitive solution is circulated between the photosensitive solution application device 20 and a photosensitive solution tank (not shown) by a pump (not shown).

FIG. 2 shows an outline of the etching chamber 40. The etching chamber 40 includes the etching tank 4
2, a spray unit 44 for spraying an etching solution onto the iron-based metal sheet 10, a transport roller 46, a pump 48, a magnetic belt 50, and a magnetic belt driving unit 52. The magnetic belt 50 is formed by connecting a plurality of sheet-like permanent magnets to each other, and has a flexibility enough to be driven by the magnetic belt driving unit 52. Pump 48
Thereby, the etching liquid is circulated between the etching bath 42 and the spray unit 44. FIG. 2 schematically shows a part of the iron-based metal sheet 10 during etching.

Hereinafter, each step of the etching method of the first embodiment will be described with reference to FIG. 3, which is a schematic partial cutaway view of an iron-based metal sheet. In addition, the cut view was a partially cut view in the width direction of the iron-based metal sheet. In addition, a color selection mechanism including an aperture grille is manufactured by etching an iron-based metal sheet.

[Step-100] A plate thickness of 0.025 to 0.15, the surface of which has been previously degreased and washed.
A photosensitive liquid is applied to the surface of an iron-based metal thin plate 10 made of a long aluminum-killed low carbon steel sheet having a length of about mm by a photosensitive liquid application device 20. The photosensitive solution is composed of, for example, casein and 1% by weight of ammonium dichromate based on casein. In addition, the application of the photosensitive liquid was performed by so-called dip coating, in which the iron-based metal sheet 10 was immersed in the photosensitive liquid. Then
The photosensitive liquid is dried at about 80 to 100 ° C. using the heater 22. Thus, a photosensitive etching resist layer 12A having a thickness of 7 to 10 μm is formed on at least the surface of the iron-based metal sheet 10. Preferably, the etching resist layers 12A and 12B are formed on both sides of the iron-based metal sheet (see FIG. 3A). The following FIG.
In (B) to (D), the edges of the iron-based metal sheet were etched on both sides.
FIG. 4 shows a state in which the tinning resist layers 12A and 12B are formed.
Show.

[Step-110] Next, the iron-based metal sheet 10
An etching pattern is formed on the etching resist layer 12A formed on the surface of the substrate. That is, the iron-based metal sheet 10
After a separately prepared pattern mask is brought into close contact with the surface of the etching resist layer 12A formed on the surface of the substrate, exposure and baking are performed using an ultraviolet light source such as a metal halide lamp, and then water development is performed. Thus, a desired etching pattern is formed on the etching resist layer 12A (see FIG. 3B). The surface of the iron-based metal sheet 10 is exposed at the portion where the etching resist layer 12A has been removed. Exposure and development of this etching resist layer 12A
Using a resist exposure / development device 30, it can be performed by a usual method.

[Step-120] After that, in the resist hardening device 32, the etching resist layer 12A is immersed in 5 to 10% chromic acid to perform hardening treatment of the etching resist layer 12A, and then washed with water. . Subsequently, in the burning treatment device 34, a burning treatment (heat treatment) at about 200 ° C. to 250 ° C. is performed to improve the etching resistance of the etching resist layer 12A. In addition, on the back of the iron-based metal sheet 10
When the etching resist layer 12B is formed, the etching resist layer 12 formed on the back surface of the iron-based metal sheet 10 is formed.
Exposure / development, hardening, and burning are also applied to the entire surface of B. However, pattern formation is not performed.

[Step-130] Next, the iron-based metal sheet 10 is etched in the etching chamber 40. As an etchant, for example, ferric chloride having a Baume degree of 45 to 48 ° Be was used.
Iron-based metal sheet 10 transported by transport rollers 46
Is attracted by the magnetic belt 50 driven by the magnetic belt driving unit 52. As a result, the magnetic belt 50 moves to the back of the iron-based metal sheet 10 (the back of the iron-based metal sheet 10).
When the etching resist layer 12B is formed on the surface, the etching resist layer 12B formed on the back surface of the iron-based metal sheet is formed.
B) is brought into close contact with it (see FIG. 3C). In this state, the etchant is sprayed from the spray unit 44 onto the front surface of the iron-based metal thin plate 10 to etch the iron-based metal thin plate 10 from the front. Spray pressure is 1.5-2.5
kg / cm ² -G. During the etching, the iron-based metal sheet 10 is conveyed by the magnetic belt 50.

FIG. 3D is a schematic partial cutaway view of the iron-based metal sheet 10 immediately after the completion of the etching. After the completion of the etching, the penetrating region 16 is formed in the iron-based metal sheet 10.

Since the magnetic belt 50 comes into close contact with the back surface of the iron-based metal thin plate 10,
When the etching resist layer 12B is formed, the etching resist layer 12 formed on the back surface of the iron-based metal sheet 10 is formed.
B is protected by the magnetic belt 50. As a result, it is possible to prevent the etching liquid from destroying the etching resist layer 12B. Therefore, it is possible to prevent the pattern already formed on the iron-based metal thin plate 10 from being further etched by the etchant flowing around the back surface of the iron-based metal thin plate 10. In addition, since a uniform tension is applied to the iron-based metal sheet 10 by the magnetic belt 50, the pattern formation of the iron-based metal sheet 10 can be performed with high accuracy.

[Step-140] Thereafter, the state of close contact between the magnetic belt 50 and the back surface of the iron-based metal sheet 10 is released. This operation is automatically performed because the magnetic belt 50 naturally separates from the iron-based metal sheet 10 at the rear end of the magnetic belt 50 because the iron-based metal sheet 10 is long. Next, in the resist stripping / washing device 60, a surfactant was added at 80 to 90 ° C.,
Using 0-20% caustic soda, the ferrous metal sheet 10
After the etching resist layer 12A is swelled and peeled off from the surface (the etching resist layer 12
When A and 12B are formed, both of the iron-based metal sheet
Swell and peel off the etching resist layers 12A and 12B from the surface
After that , the iron-based metal sheet 10 is washed with water and dried. Thus, a desired pattern (for example, a large number of blind-shaped penetrating regions) is formed on the long iron-based metal thin plate 10 (see FIG. 3E). In this case, the back surface of the iron-based metal thin plate 10 is the electron gun side, and the front surface side is the phosphor screen side. In a separate step, the long iron-based thin metal sheet 10 can be cut to a desired size to manufacture a color selection mechanism including an aperture grill.

Example 2 Example 2 relates to a method for etching an iron-based metal sheet according to the second embodiment of the present invention. Hereinafter, first, an outline of an apparatus suitable for implementing the second embodiment will be described with reference to FIG. 4, and then, with reference to FIG. 5 which is a schematic partial cutaway view of an iron-based metal sheet, etching will be described. Each step will be described.

FIG. 4 shows an outline of an apparatus suitable for implementing the second embodiment.
Shown in This apparatus comprises a photosensitive solution coating device 20, a heater 22, a resist exposure / development device 30, a resist hardening device 32, a burning process device 34, a first etching chamber 140, and a back coat material. Back coat material application device 7 for forming protective layer 14
0, a heater 72 for drying the back coat material, and a second
And a resist stripping / washing device 60. The photosensitive solution is circulated between the photosensitive solution application device 20 and a photosensitive solution tank (not shown) by a pump (not shown).

First and second etching chambers 14
The structure of 0,240 can be similar to that of the etching chamber shown in FIG. The back coat material application device 70 can be composed of, for example, a normal roll coater.

Hereinafter, each step of the etching method according to the second embodiment will be described with reference to FIG. 5 which is a schematic partial cutaway view of an iron-based metal sheet. In addition, the cut view was a partially cut view in the width direction of the iron-based metal sheet. Further, a color selection mechanism including an aperture grill is manufactured by etching the iron-based metal sheet.

[Step-200] First, the iron-based metal sheet 10
Etching resist layers 12A,
After the formation of the etching resist layers 12A, 1B,
A desired pattern is formed on each of 2B. That is, a photosensitive solution is applied to both the front and back surfaces of the iron-based metal thin plate 10 whose surface has been degreased and washed in advance, and then the photosensitive solution is dried. Thus, the etching resist layers 12A and 12B are formed on both surfaces of the iron-based metal thin plate 10. afterwards,
A desired pattern shape is formed on the etching resist layers 12A and 12B (see FIG. 5A). Next, a hardening process and a burning process are performed on the etching resist layers 12A and 12B. These steps are the same as those described in Example 1 [Step-10].
0] to [Step-120].

[Step-210] Next, in the first etching chamber 140, the iron-based metal sheet 10 is partially etched. That is, while the magnetic belt 50 is in close contact with the back surface of the iron-based metal sheet 10, the iron-based metal sheet 10 is etched from the front side. And the iron-based metal sheet 10
Is etched to a predetermined thickness, the etching is interrupted, and the state of adhesion between the magnetic belt 50 and the back surface of the iron-based metal thin plate 10 is released.

As an etching solution, for example, a Baume degree of 4
Ferric chloride of 5-48 ° Be was used. Transport roller 46
As shown in FIG. 2, the iron-based thin metal sheet 10 transported by the magnetic belt driving unit 52 is attracted by the magnetic belt 50 driven by the magnetic belt driving unit 52. As a result, the magnetic belt 50 is attached to the back surface of the iron-based metal sheet 10 (more specifically, the etching resist layer 1 formed on the back surface of the iron-based metal sheet).
2B). In this state, the etchant is sprayed from the spray unit 44 onto the front surface of the iron-based metal thin plate 10 to etch the iron-based metal thin plate 10 from the front. The spray pressure is 1.5-2.5 kg / cm ² -G. During the etching, the iron-based metal sheet 10 is
Conveyed by 0.

The etching is interrupted when the iron-based metal sheet 10 is etched to a predetermined thickness. That is, in the first etching chamber 140, the etching liquid is prevented from being applied to the iron-based metal sheet 10 any more.
FIG. 5B is a schematic partial cutaway view of the iron-based metal sheet 10 in this state. The magnetic belt 50 is made of the iron-based metal sheet 10.
Is in intimate contact with the back surface of the iron-based metal sheet 10, uniform tension is applied to the iron-based metal sheet 10,
Can be formed with high precision. still,
In some cases, as the etching chamber used in this step, a normal etching chamber, that is, a type in which a ferrous metal sheet is transported by a transport roller instead of a type in which a ferrous metal sheet is transported by a magnetic belt is used. be able to.

Thereafter, the magnetic belt 50 and the iron-based metal sheet 1
Release the close contact state with the back surface of No. 0. This operation is automatically performed because the magnetic belt 50 naturally separates from the iron-based metal sheet 10 at the rear end of the magnetic belt 50 because the iron-based metal sheet 10 is long. Thereafter, the iron-based metal sheet 10 is washed with water.

[Step-220] Next, the iron-based metal sheet 10
A protective layer 14 made of a back coat material is formed on the surface of the substrate. For this purpose, a back coat material made of wax is applied to the surface of the iron-based metal thin plate 10 using a back coat material application device 70 including a normal roll coater. The etching resist layer 12A remains on the surface of the iron-based metal sheet 10. Thereafter, the back coat material is dried by the heater 72 to form the protective layer 14 made of the back coat material on the surface of the iron-based metal sheet 10. When an ultraviolet curing resin is used as the back coat material, an ultraviolet curing device is used instead of the heater 72.

[Step-230] Then, using the second etching chamber 240, while the magnetic belt 50 is in close contact with the protective layer 14, the iron-based metal thin plate 10 is etched from the back side, and the iron-based metal sheet 10 is etched. The penetration region 16 is formed in the thin plate 10.

As an etching solution, for example, a Baume degree of 4
Ferric chloride of 5-48 ° Be was used. Transport roller 46
As shown in FIG. 2, the iron-based thin metal sheet 10 transported by the magnetic belt driving unit 52 is attracted by the magnetic belt 50 driven by the magnetic belt driving unit 52. As a result, the magnetic belt 50 has the protective layer 1 formed on the surface of the iron-based metal sheet 10.
4 comes into close contact with it. In this state, the spray unit 44
Then, an etching solution is sprayed on the back side of the iron-based metal sheet 10 to etch the iron-based metal sheet 10 from the back side.
The spray pressure is 1.5-2.5 kg / cm ² -G. During the etching, the iron-based metal sheet 10 is placed on the magnetic belt 50.
Conveyed by

[0048] shows a schematic partial cutaway view of an iron-based metal sheet 10 at which the through region 16 is etched to complete is formed in (C) of FIG. The magnetic belt 50 is made of a ferrous metal sheet 1
Since the protective layer 14 is in close contact with the protective layer 14 formed on the surface of No. 0, the protective layer 14 is protected by the magnetic belt 50, and the protective layer 14 can be prevented from being destroyed by the etchant. Therefore, the surface of the iron-based metal sheet 10 can be sufficiently protected by the protective layer 14 which is thinner than the conventional one. Moreover, since the iron-based metal sheet 10 is uniformly tensioned by the magnetic belt 50, the iron-based metal sheet 10
Can be formed with high precision.

Thereafter, the magnetic belt 50 and the iron-based metal sheet 1
The state of close contact with the protective layer 14 formed on the surface of No. 0 is released.
Since the iron-based metal sheet 10 is long, the magnetic belt 50
This operation is automatically performed because the magnetic belt 50 naturally separates from the iron-based metal sheet 10 at the rear end of the metal belt.

[Step-240] Next, in the resist stripping / washing device 60, the etching resist layers 12A, 1
After stripping 2B and the protective layer 14, washed and dried the iron-based metal sheet 10. Thus, a desired pattern is formed on the long iron-based metal thin plate 10 (see FIG. 5D) .
In this case, the front surface of the iron-based metal thin plate 10 is on the electron gun side, and the back surface is on the fluorescent screen side. In a separate step, the long iron-based thin metal sheet 10 can be cut to a desired size to manufacture a color selection mechanism including an aperture grill.

Although the present invention has been described based on the preferred embodiments, the present invention is not limited to these embodiments. The various materials and processing conditions used in the examples are examples, and can be changed as appropriate. As the iron-based metal sheet, for example, a cold-rolled steel sheet or an amber steel sheet can be used. As the photosensitive liquid coating device, various coating devices such as a roll coater can be used. The back coat material application device can also be replaced with an arbitrary application device.

The magnetic belt has a structure in which an electromagnet or a permanent magnet is attached to the inner surface of a flexible magnetic metal belt, a flexible magnetic metal belt, and a fixed inside the magnetic metal belt along the magnetic metal belt. It is possible to adopt a structure including the provided electromagnets and permanent magnets, a structure in which the belt driving unit is formed from the electromagnets and the permanent magnets, and a structure for magnetizing the magnetic metal belt.

[0053]

According to the method for etching an iron-based metal sheet according to the first aspect of the present invention, an iron-based metal sheet can be etched without forming a protective layer. Also,
In the method for etching an iron-based metal sheet according to the second aspect of the present invention, the thickness of the protective layer can be made smaller than before. In addition, in these etching methods, a uniform tension can be applied to the iron-based metal sheet by the magnetic belt, so that a very thin and extremely thin iron-based metal sheet can be etched.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of an apparatus suitable for implementing a first embodiment.

FIG. 2 is a diagram showing an outline of an etching chamber.

FIG. 3 is a schematic partial cutaway view of an iron-based metal sheet or the like for explaining each step of the etching method of Example 1.

FIG. 4 is a diagram showing an outline of an apparatus suitable for implementing a second embodiment.

FIG. 5 is a schematic partial cutaway view of an iron-based metal sheet or the like for explaining each step of an etching method according to a second embodiment.

FIG. 6 is a schematic partial cutaway view of an iron-based metal sheet or the like for explaining a conventional one-sided etching method.

FIG. 7 is a schematic partial cut-away view of an iron-based metal sheet or the like for explaining a conventional double-sided etching method.

FIG. 8 is a diagram illustrating a state in which an electron beam incident on the through region 16 is reflected by a side wall of the through region formed on the iron-based metal sheet.

FIG. 9 is a schematic partial plan view and an enlarged cutaway view of the aperture grill.

DESCRIPTION OF SYMBOLS 10 Iron-based metal sheet 12A, 12B Etching resist layer 14 Protective layer 16 Penetration area 20 Photosensitive solution coating device 22, 72 Heater 30 Resist exposure / development device 32 Resist hardening device 34 Burning device 40, 140 , 240 Etching chamber 42 Etching tank 44 Spraying unit 46 Conveying roller 48 Pump 50 Magnetic belt 52 Magnetic belt driving unit 60 Resist stripping / washing device 70 Back coat material coating device

Claims (5)

(57) [Claims] (A) forming an etching resist layer on the surface of an iron-based metal sheet and then forming a desired pattern on the etching resist layer; and (b) attaching a magnetic belt to the back surface of the iron-based metal sheet. A step of etching the iron-based metal sheet from the surface side in a state of being in direct contact with the iron-based metal sheet. 2. In the step (a), an etching resist layer which is not patterned at all is further formed on the back surface of the iron-based metal sheet, and in the step (b), the magnetic belt is fixed to the iron-based metal sheet.
Instead of sticking directly to the back, use a magnetic belt
Adhesion to the etching resist layer formed on the back of the thin plate
The method for etching an iron-based metal sheet according to claim 1, wherein the iron-based metal sheet is etched from a surface side in a state where the iron-based metal sheet is left. (A) forming an etching resist layer on both sides of the iron-based metal sheet and then forming a desired pattern on each of the etching resist layers; and (b) removing the iron-based metal sheet from the front side. (C) a step of forming a protective layer on the surface of the iron-based metal sheet, and (d) a step of etching the iron-based metal sheet from the back side with the magnetic belt in close contact with the protective layer. Etching the iron-based metal sheet to form a through region in the iron-based metal sheet. 4. The step (b) includes etching the iron-based metal sheet from the front side while the magnetic belt is in close contact with the back surface of the iron-based metal sheet, and etching the iron-based metal sheet to a predetermined thickness. 4. The method according to claim 3, further comprising the step of interrupting the etching at a point of time and releasing a state of close contact between the magnetic belt and the back surface of the iron-based metal sheet. 5. A method for manufacturing a color selection mechanism comprising an aperture grill or a shadow mask, using the method for etching a thin iron-based metal sheet according to any one of claims 1 to 4.