JPH0790627A - Method for etching ferrous metallic sheet and production of color sorting mechanism - Google Patents

Abstract

PURPOSE:To etch a ferrous metallic sheet without forming a back coating material layer. CONSTITUTION:This method for etching the ferrous metallic sheet comprises first forming an etching resist layer 12A on the front surface of the ferrous metallic sheet 10, then forming desired patterns on this etching resist layer 12A. The ferrous metallic sheet is then etched from the front surface side in the state of bringing a magnetic belt into tight contact with the rear surface of the ferrous metallic sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for etching an iron-based thin metal plate and a method for manufacturing a color selection mechanism used in a cathode ray tube.

[0002]

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

[Process-10A] First, the iron-based metal thin plate 10
The photosensitive etching resist layers 12A and 12B having a thickness of 7 to 10 μm are formed on both the front surface and the back surface (see FIG. 6A).

[Step-20A] Next, the iron-based metal thin plate 1
The etching resist layer 12A formed on the surface of 0 is patterned to form a desired pattern shape on the etching resist layer 12A (see FIG. 6B).

[Step-30A] After that, the iron-based metal thin plate 1
A protective layer 14 made of a back coat material is formed on the etching resist layer 12B on the back surface of 0 (see FIG. 6C). The purpose of forming the protective layer 14 is to reduce the iron-based metal sheet 10.
To reinforce the etching resist layer 12B formed on the back surface of the. When the protective layer 14 is not formed, when the iron-based metal thin plate 10 is etched, the etching resist layer 12B formed on the back surface of the iron-based metal thin plate 10 is destroyed by the etching solution, and the back surface of the iron-based metal thin plate 10 is etched. The liquid flows around and the pattern already formed on the iron-based metal thin plate 10 is further etched.

[Step-40A] After that, the iron-based metal thin plate 1
An etching solution is sprayed on the surface side of 0 to etch the iron-based metal thin plate 10 from the surface side. Iron-based metal thin plate 10 not covered with the etching resist layer 12A
Is removed by etching to form a penetrating 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 thin plate having a desired pattern shape can be obtained (see (E) in FIG. 6).

Next, another example of the method for etching the iron-based thin metal plate will be described below with reference to FIG. This etching method is a double-sided etching method, and it is possible to perform finer and more precise etching processing than the single-sided etching method.

[Step-10B] First, the iron-based metal thin plate 10
Etching resist layers 12A on both front and back surfaces of
12B is formed.

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

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

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

[Step-50B] After that, the iron-based metal thin plate 1
The etching liquid is sprayed on the back surface side of 0 to etch the iron-based metal thin plate 10 from the back surface side. Iron-based metal thin plate 10 not covered with the 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 thin plate having a desired pattern shape can be obtained (see (E) of FIG. 7).

The reason for forming the penetrating region 16 having the cross-sectional shape shown in FIG. 6E or FIG. 7E by these single-sided or double-sided etching methods is shown in FIG. 8 below. A brief description will be given with reference to a typical sectional view. For example, in the color selection mechanism including the etched iron-based metal thin plate, the electron beam passes through the penetrating region 16 from the front surface side to the back surface side of the iron-based metal thin plate 10. The incident angle of the electron beam with respect to the color selection mechanism changes depending on the position where the electron beam enters the color selection mechanism. As shown in FIG. 8, as the sidewall of the penetrating region 16 becomes closer to vertical,
The electron beam incident on the penetrating region 16 and reflected by the sidewall of the penetrating region 16 reaches the phosphor screen. As a result, electron beam reflection (halation) 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 as shown in (1) is applied to the through region 16, the electron beam that enters the through region 16 and is reflected by the side wall of the through region 16 becomes hard to reach the fluorescent screen. As a result, reflection (halation) of the electron beam can be effectively prevented. In the iron-based metal thin plate 10 shown in FIG. 6E, the back surface is the electron gun side,
The front surface side is the phosphor 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 side is the phosphor screen side.

[0017]

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

Therefore, a first object of the present invention is to provide an etching method capable of etching an iron-based thin metal plate without forming a protective layer. Furthermore, 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 thin plate that can reduce the amount of back coat material used.

[0019]

The first object mentioned above is to:
(A) A step of forming an etching resist layer on the surface of the iron-based metal thin plate and then forming a desired pattern on the etching resist layer, and (b) a state in which the magnetic belt is closely attached to the back surface of the iron-based metal thin plate. And a step of etching the iron-based thin metal plate from the surface side, which can be achieved by the method for etching an iron-based thin metal plate according to the first aspect of the present invention. The etching method for the iron-based metal thin plate according to the first aspect corresponds to the one-sided etching method.

Further, the second purpose is: (a) a step of forming an etching resist layer on both surfaces of the iron-based metal thin plate, and then forming a desired pattern on each of the etching resist layers; and (b) iron. The step of etching the thin metal plate from the surface side to a predetermined thickness, (c) the step of forming a protective layer on the surface of the thin iron metal plate, and (d) the magnetic belt being in close contact with the protective layer. The method for etching an iron-based metal thin plate according to the second aspect of the present invention, which comprises the step of etching the system-based metal thin plate from the back surface side to form a through region in the iron-based metal thin plate. it can. The etching method for the iron-based metal thin plate according to the second aspect corresponds to the double-sided etching method. In addition, in the step (b), the magnetic belt is adhered to the back surface of the iron-based metal thin plate, the iron-based metal thin plate is etched from the front side, and the etching is performed when the iron-based metal thin plate is etched to a predetermined thickness. And the step of releasing the contact state between the magnetic belt and the back surface of the iron-based metal thin plate.

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

[0022]

In the method for etching an iron-based metal thin plate according to the first aspect of the present invention, the iron-based metal thin plate is etched from the front side in a state where the magnetic belt is in close contact with the back surface of the iron-based metal thin plate. Therefore, it is possible to prevent the etching solution from flowing around to the back surface of the iron-based metal thin plate and further etching the pattern already formed on the iron-based metal thin plate by the magnetic belt closely attached to the back surface of the iron-based metal thin plate. .

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

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the drawings.

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

An outline of an apparatus suitable for carrying out Example 1 is shown in FIG.
Shown in. This apparatus comprises a photosensitive solution coating apparatus 20, a heater 22, a resist exposure / development apparatus 30, a resist film treatment apparatus 32, a burning processing apparatus 34, an etching chamber 40, and a resist stripping / water washing apparatus 60. . The photosensitive liquid is circulated between the photosensitive liquid coating device 20 and the photosensitive liquid tank (not shown) by a pump (not shown).

An outline of the etching chamber 40 is shown in FIG. The etching chamber 40 is the etching tank 4
2. A spray unit 44 for spraying the etching liquid onto the iron-based metal thin plate 10, a conveyance roller 46, a pump 48, a magnetic belt 50, and a magnetic belt drive unit 52. The magnetic belt 50 is formed by connecting a plurality of sheet-shaped permanent magnets to each other, and is flexible enough to be driven by the magnetic belt drive unit 52. Pump 48
Thus, the etching liquid is circulated between the etching tank 42 and the spray section 44. In addition, in FIG. 2, a part of the iron-based metal thin plate 10 in the middle of etching is schematically illustrated.

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 thin plate. The cutaway view is a partial cutaway view of the iron-based metal thin plate in the width direction. In addition, a color selection mechanism consisting of an aperture grill will be manufactured by etching an iron-based thin metal plate.

[Step-100] A photosensitive liquid is applied to the surface of the iron-based metal thin plate 10 made of a smooth long aluminum-killed low carbon steel plate having a plate thickness of about 0.025 to 0.15 mm, the surface of which has been degreased and washed in advance. The device 20 applies the photosensitive liquid. The sensitizing solution comprises, for example, casein and 1% by weight of ammonium dichromate with respect to casein. Further, the application of the photosensitive liquid was carried out by a so-called dip coating method in which the iron-based thin metal plate 10 was immersed in the photosensitive liquid. Then, using the heater 22,
The photosensitive solution is dried at about 80 to 100 ° C. As a result, at least the surface of the iron-based metal thin plate 10 has a thickness of 7 to 10
A photosensitive etching resist layer 12A having a thickness of μm is formed. In addition, the etching resist layer 1 is formed on both sides of the iron-based metal thin plate.
It is preferable to form 2A and 12B ((A) of FIG. 3).
reference).

[Step-110] Next, the iron-based metal thin plate 10
An etching pattern is formed on the etching resist layer 12A formed on the surface of the. That is, the iron-based metal thin plate 10
A separately prepared pattern mask is brought into close contact with the surface of the etching resist layer 12A formed on the surface of, and exposure and baking are performed using an ultraviolet source such as a metal halide lamp, and then water development is performed. In this way, a desired etching pattern is formed on the etching resist layer 12A (see FIG. 3B). The surface of the iron-based metal thin plate 10 is exposed at the portion where the etching resist layer 12A is removed. Exposure and development of this etching resist layer 12A
The resist exposure / development apparatus 30 can be used to perform the usual method.

[Step-120] After that, in the resist film treatment apparatus 32, the etching resist layer 12A is removed by 5 times.
It is immersed in chromic acid of 10% to harden the etching resist layer 12A and then washed with water. Subsequently, in the burning treatment device 34, about 200 ° C. to 250 ° C.
By performing a burning treatment (heat treatment) at ° C, the etching resistance of the etching resist layer 12A is improved. still,
The entire surface of the etching resist layer 12B formed on the back surface of the iron-based metal thin plate 10 is also subjected to exposure / development processing, hardening processing, and burning processing. However, pattern formation is not performed.

[Step-130] Then, the iron-based metal thin plate 10 is etched in the etching chamber 40. As the etching liquid, for example, a Baume degree of 45 to 48
Ferrochloride of Be was used. The iron-based metal thin plate 10 transported by the transport rollers 46 is attached to the magnetic belt drive unit 52.
It is attracted by the magnetic belt 50 driven by. As a result, the magnetic belt 50 comes into close contact with the back surface of the iron-based metal thin plate 10 (more specifically, the etching resist layer 12B formed on the back surface of the iron-based metal thin plate) (see FIG. 3C). ). In this state, an etching solution is sprayed from the spray section 44 onto the surface side of the iron-based metal thin plate 10 to etch the iron-based metal thin plate 10 from the surface side. The spray pressure is 1.5 to 2.5 kg / cm ² -G.
During the etching, the iron-based metal thin plate 10 is conveyed by the magnetic belt 50.

A schematic partial cutaway view of the iron-based metal thin plate 10 immediately after the etching is shown in FIG. After the etching is completed, the penetrating region 16 is formed in the iron-based metal thin plate 10.

Since the magnetic belt 50 is brought into close contact with the back surface of the iron-based metal thin plate 10, the etching resist layer 12B formed on the back surface of the iron-based metal thin plate 10 has the magnetic belt 5 formed thereon.
Protected by 0. As a result, it is possible to prevent the etching resist layer 12B from being destroyed by the etching solution. Therefore, it is possible to prevent the pattern already formed on the iron-based metal thin plate 10 from being further etched by the etching liquid flowing around the back surface of the iron-based metal thin plate 10. Moreover, since the magnetic belt 50 applies a uniform tension to the iron-based metal thin plate 10, it is possible to form the pattern of the iron-based metal thin plate 10 with high accuracy.

[Step-140] Then, the magnetic belt 50
The state of close contact with the back surface of the iron-based metal thin plate 10 is released. Since the iron-based metal thin plate 10 is long, the magnetic belt 50 naturally separates from the iron-based metal thin plate 10 at the rear end portion of the magnetic belt 50, and this operation is automatically performed. Next, in the resist stripping / water washing device 60, the etching resist layers 12A and 12B are swelled from both sides of the iron-based metal thin plate 10 using a surfactant-added caustic soda at 80 to 90 ° C. and 10 to 20%. After peeling, the iron-based metal thin plate 10 is washed with water and dried. In this way, 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 (E) in FIG. 3). 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 fluorescent screen side. Long iron-based metal thin plate 10 in another process
Can be cut to the desired size to produce a color selection mechanism consisting of an aperture grill.

(Example 2) Example 2 relates to a method for etching an iron-based metal thin plate according to the second aspect of the present invention. Hereinafter, first, an outline of an apparatus suitable for carrying out Example 2 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 thin plate, etching Each step of will be described.

An outline of an apparatus suitable for carrying out Example 2 is shown in FIG.
Shown in. This apparatus comprises a photosensitive solution coating apparatus 20, a heater 22, a resist exposure / development apparatus 30, a resist film processing apparatus 32, a burning processing apparatus 34, a first etching chamber 140, and a back coat material. Backcoat material coating device 7 for forming the protective layer 14
0, a heater 72 for drying the back coat material, a second
The etching chamber 240 and the resist stripping / water washing device 60. The photosensitive liquid is circulated between the photosensitive liquid coating device 20 and the photosensitive liquid tank (not shown) by a pump (not shown).

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

Each step of the etching method of the second embodiment will be described below with reference to FIG. 5, which is a schematic partial cutaway view of the iron-based metal thin plate. The cutaway view is a partial cutaway view of the iron-based metal thin plate in the width direction. In addition, a color selection mechanism including an aperture grill is manufactured by etching a thin iron-based metal plate.

[Step-200] First, the iron-based metal thin plate 10
Etching resist layers 12A on both front and back surfaces of
After forming 12B, etching resist layers 12A, 1
A desired pattern is formed on each of 2B. That is, the surface of the thin iron-based metal plate 10 whose surface has been degreased and washed in advance is coated with a photosensitive solution, and then the photosensitive solution is dried. As a result, 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). Then, the etching resist layers 12A and 12B are hardened and burned. These steps are the same as those in [Step-10 of Example 1].
0] to [step-120] can be performed.

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

As the etching liquid, for example, a Baume degree 4
Ferric chloride at 5 to 48 ° Be was used. Conveyor roller 46
The iron-based metal thin plate 10 conveyed by is attracted by the magnetic belt 50 driven by the magnetic belt drive unit 52, as shown in FIG. As a result, the magnetic belt 50 has the back surface of the iron-based metal thin plate 10 (more specifically, the etching resist layer 1 formed on the back surface of the iron-based metal thin plate 1).
2B) is in close contact. In this state, an etching solution is sprayed from the spray section 44 onto the surface side of the iron-based metal thin plate 10 to etch the iron-based metal thin plate 10 from the surface side. The spray pressure is 1.5 to 2.5 kg / cm ² -G. During etching, the iron-based thin metal plate 10 is the magnetic belt 5
Carried by 0.

When the iron-based metal thin plate 10 is etched to a predetermined thickness, the etching is stopped. That is, in the first etching chamber 140, the iron-based metal thin plate 10 is prevented from being further exposed to the etching solution.
A schematic partially cutaway view of the iron-based metal thin plate 10 in this state is shown in FIG. The magnetic belt 50 is the iron-based thin metal plate 10.
Since it is in close contact with the back surface of the iron-based metal thin plate 10, uniform tension is applied to the iron-based metal thin plate 10.
It becomes possible to perform the pattern formation with high precision. still,
Depending on the case, as the etching chamber used in this step, a normal etching chamber, that is, an etching chamber in which the iron-based metal thin plate is transported by a transport roller, is used instead of the type in which the iron-based metal thin plate is transported by the magnetic belt. be able to.

After that, the magnetic belt 50 and the iron-based metal thin plate 1
Release the close contact with the back side of 0. Since the iron-based metal thin plate 10 is long, the magnetic belt 50 naturally separates from the iron-based metal thin plate 10 at the rear end portion of the magnetic belt 50, and this operation is automatically performed. Then, the iron-based metal thin plate 10 is washed with water.

[Step-220] Next, the iron-based metal thin plate 10
A protective layer 14 made of a back coat material is formed on the surface of the. For this purpose, a back coat material coating device 70 composed of a normal roll coater is used to coat the back coat material made of wax onto the surface of the iron-based metal thin plate 10. The etching resist layer 12A remains on the surface of the iron-based metal thin plate 10. Then, 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 thin plate 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, the iron-based metal thin plate 10 is etched from the back surface side while the magnetic belt 50 is in close contact with the protective layer 14, and the iron-based metal is etched. A through region 16 is formed in the thin plate 10.

As the etching liquid, for example, a Baume degree of 4 is used.
Ferric chloride at 5 to 48 ° Be was used. Conveyor roller 46
The iron-based metal thin plate 10 conveyed by is attracted by the magnetic belt 50 driven by the magnetic belt drive unit 52, as shown in FIG. As a result, the magnetic belt 50 has the protective layer 1 formed on the surface of the iron-based metal thin plate 10.
It will be in a state of being in close contact with 4. In this state, the spray unit 44
Is sprayed onto the back surface side of the iron-based metal thin plate 10 to etch the iron-based metal thin plate 10 from the back surface side.
The spray pressure is 1.5 to 2.5 kg / cm ² -G. During the etching, the iron-based metal thin plate 10 is the magnetic belt 50.
Transported by.

FIG. 5D shows a schematic partial cutaway view of the iron-based metal thin plate 10 at the time when the etching is completed and the penetrating region 16 is formed. Magnetic belt 50 is iron-based metal thin plate 1
Since it 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 it is possible to prevent the protective layer 14 from being destroyed by the etching solution. Therefore, the surface of the iron-based metal thin plate 10 can be sufficiently protected by the protective layer 14 which is thinner than the conventional one. Moreover, since the magnetic belt 50 applies uniform tension to the iron-based metal thin plate 10, the iron-based metal thin plate 10
It becomes possible to perform the pattern formation with high precision.

After that, the magnetic belt 50 and the iron-based metal thin plate 1
The adhesion state with the protective layer 14 formed on the surface of No. 0 is released.
Since the iron-based metal thin plate 10 is long, the magnetic belt 50
This operation is automatically performed because the magnetic belt 50 spontaneously separates from the iron-based metal thin plate 10 at the rear end portion of.

[Step-240] Next, the resist is peeled off.
In the water washing device 60, after the etching resist layers 12A and 12B and the protective layer 14 are peeled off from both surfaces of the iron-based metal thin plate 10, the iron-based metal thin plate 10 is washed and dried (see FIG. 5 (E)). In this way, a desired pattern is formed on the long iron-based metal thin plate 10. In this case, the front surface of the iron-based metal thin plate 10 is the electron gun side, and the back surface side is the phosphor screen side. In a separate process, the long iron-based metal thin plate 10 can be cut into a desired size to manufacture a color selection mechanism including an aperture grill.

The present invention has been described above based on the preferred embodiments, but the present invention is not limited to these embodiments. The various materials and processing conditions used in the examples are examples, and can be appropriately changed. As the iron-based metal thin plate, for example, a cold rolled steel plate or an amber steel plate can be used. As the photosensitive liquid coating device, other various coating devices such as a roll coater can be used. The back coat material coating device can also be replaced with any coating 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 magnetic metal belt disposed inside the flexible magnetic metal belt. A structure composed of an electromagnet or a permanent magnet provided, or a structure in which the belt driving unit is composed of an electromagnet or a permanent magnet and thereby magnetizes the magnetic metal belt, can be adopted.

[0053]

In the method for etching an iron-based metal thin plate according to the first aspect of the present invention, the iron-based metal thin plate can be etched without forming a protective layer. Also,
In the method for etching an iron-based metal thin plate according to the second aspect of the present invention, the thickness of the protective layer can be made thinner than before. Moreover, in these etching methods, a uniform tension can be applied to the iron-based metal thin plate by the magnetic belt, so that the very thin iron-based metal thin plate can be etched with high accuracy.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of an apparatus suitable for carrying out Example 1.

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 thin plate 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 carrying out Example 2.

5 is a schematic partial cutaway view of an iron-based metal thin plate or the like for explaining each step of the etching method of Example 2. FIG.

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

FIG. 7 is a schematic partial cutaway view of an iron-based metal thin plate 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 a through region 16 is reflected by a side wall of the through region formed on an iron-based metal thin plate.

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

[Explanation of symbols]

 10 Iron-based metal thin plates 12A, 12B Etching resist layer 14 Protective layer 16 Penetration region 20 Photosensitive solution coating device 22, 72 Heater 30 Resist exposure / developing device 32 Resist film treatment device 34 Burning treatment device 40, 140, 240 Etching chamber 42 Etching tank 44 Spray unit 46 Conveying roller 48 Pump 50 Magnetic belt 52 Magnetic belt drive unit 60 Resist stripping / washing device 70 Back coat material coating device

Claims (4)

[Claims] 1. A step of: (a) forming an etching resist layer on the surface of an iron-based metal thin plate and then forming a desired pattern on the etching resist layer; and (b) placing a magnetic belt on the back surface of the iron-based metal thin plate. A step of etching the iron-based metal thin plate from the surface side in the state of being closely attached,
A method for etching an iron-based thin metal plate, which comprises: 2. A step of: (a) forming an etching resist layer on both surfaces of the iron-based metal thin plate and then forming a desired pattern on each of the etching resist layers; and (b) the iron-based metal thin plate from the front surface side. Step of etching to a predetermined thickness, (C) Step of forming a protective layer on the surface of the iron-based metal thin plate, and (D) With the magnetic belt adhered to the protective layer, the iron-based metal sheet from the back side. A method for etching an iron-based metal thin plate, comprising the step of etching to form a through region in the iron-based metal thin plate. 3. In the step (b), the iron-based metal thin plate is etched from the front side while the magnetic belt is in close contact with the back surface of the iron-based metal thin plate, and the iron-based metal thin plate is etched to a predetermined thickness. 3. The method for etching an iron-based metal thin plate according to claim 2, further comprising the step of interrupting the etching at that time to release the close contact between the magnetic belt and the back surface of the iron-based metal thin plate. 4. A method of manufacturing a color selection mechanism comprising an aperture grill or a shadow mask, which uses the method for etching an iron-based thin metal plate according to claim 1.