JP2000149775A - Manufacture of aperture grille - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of an aperture grille, enabling minute slits with intervals of the order of 200 μm to be formed with satisfactory accuracy, enhancing the rupture strength of a tape part, and preventing the tape part from being ruptured if tension is exerted on the grille after welded to a frame. SOLUTION: Metallic foil is manufactured by providing an iron coating on both surfaces of a middle layer made of nickel, cobalt, or an alloy of them, and a multiplicity of slits are formed by etching the metallic foil. Then, the iron coating is oxidized by heat treatment into a black iron coating. Preferably, the middle layer made of nickel, cobalt, or an alloy of them, is formed by an electroplating method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an aperture grill used in a color receiver such as a television.

[0002]

2. Description of the Related Art An aperture grill used as a color selection device in a color receiver such as a CRT of a television has a large number of longitudinal slits formed as electron beam passage holes in an iron foil having a thickness of about 100 μm. Things.

This aperture grill is generally manufactured by an etching method. Specifically, a photoresist layer is provided on both sides of the iron foil, and after patterning in a desired shape, the iron foil is etched with a ferric chloride solution to form a number of slits, and the photoresist layer is removed. Manufactured.

[0004] In addition, the aperture grill must have a black surface in order to prevent reflection of an electron beam applied to the surface and radiate the heat as heat. As a means for forming the surface of the aperture grill to be black, conventionally, a method has been used in which a heat treatment is applied to the iron foil after forming a large number of slits by etching, and the surface is changed to black triiron tetroxide. I have.

[0005] Recently, a color picture tube for a display, etc., requires a high-precision and high-definition screen, and accordingly, the aperture grille is also required to reduce the pitch of slits, which are holes for passing electron beams. Further refinement is being considered. Specifically, while the conventional slit pitch is about 250 μm,
There is a demand for an aperture grill having a pitch as narrow as about m.

[0006]

In the case of an aperture grill having such fine slits, a normal etching method often causes defects in terms of dimensional accuracy, resulting in an extremely low product yield. The reason for this is that, as the thickness of the iron foil is larger, the side etching peculiar to the etching method becomes larger, so that sufficient dimensional accuracy cannot be obtained with a conventionally used iron foil having a thickness of about 100 μm.

Therefore, it has been studied to reduce the thickness of the iron foil, which is the material of the aperture grill, so that sufficient dimensional accuracy can be obtained even by the etching method. As a result, the thickness 5
It was found that when a thin iron foil having a thickness of about 0 μm was used, even a fine slit having a slit pitch of about 200 μm could be accurately formed by a normal etching method.

However, in the aperture grill formed in this way, the thickness of the iron foil is smaller than before, and the width of the tape portion remaining between the slits is also smaller.
There is a disadvantage that the breaking strength of the tape portion itself is reduced. Therefore, when the aperture grill is welded to the frame and a predetermined tension is applied, there has been a problem that the tape portion is broken.

The present invention has been made in view of such conventional circumstances,
Even if the pitch is a fine slit of about 200 μm, it can be formed with high precision, enhance the breaking strength of the tape part, and the tape part does not break even if tension is applied after welding to the frame, high precision and high strength An object of the present invention is to provide a method for manufacturing an aperture grill.

[0010]

In order to achieve the above object, a method of manufacturing an aperture grill provided by the present invention comprises:
A metal foil having an iron film provided on both surfaces of a central layer made of nickel or cobalt or an alloy thereof is produced, and the metal foil is etched to form a large number of slits.

In the method for manufacturing an aperture grill according to the present invention, it is preferable that the central layer made of nickel, cobalt or an alloy thereof is formed by electroplating.

[0012]

DETAILED DESCRIPTION OF THE INVENTION According to the study of the present inventors, the iron foil manufactured by the rolling method, which is the material of the conventional aperture grill, has a breaking strength of about 70 kg / mm ² and a thickness of 100 kg / mm ^2.
When slits having a pitch of 250 μm are formed in a μm iron foil, the tape portion has a thickness of 100 μm and a width of 195 μm, so that the breaking strength per tape portion is about 1.36 kg. However, when the thickness of the iron foil is reduced to 50 μm and the pitch of the slit is reduced to 200 μm, the tape part becomes 50 μm thick × 156 μm wide, so the breaking strength per tape part is about 0.55 kg. Decrease. As a result, when welding to the frame with a certain tension,
It has been found that the tape is likely to break when the aperture grill has a narrow pitch.

In the present invention, by improving the material of the aperture grill, it was possible to form fine slits by an etching method, and at the same time, it was possible to improve and improve the breaking strength as compared with a conventionally used iron foil. That is,
An aperture grille is manufactured by using a metal foil provided with an iron coating on both surfaces of a central layer made of a metal having a higher breaking strength than iron to make the surface black by heat treatment, and etching the metal foil. The metal constituting the central layer of the metal foil is most preferably a simple substance of nickel or cobalt, or an alloy containing at least one of nickel (Ni) and cobalt (Co).

When the breaking strength of the aperture grill is compared, the conventional iron foil manufactured by the rolling method is 70 kg / mm ^2.
On the other hand, the central layer made of nickel or cobalt or an alloy thereof in the metal foil of the present invention has a breaking strength of about 100 to 200 kg / mm ² , which is much higher than that of iron foil. ing. Further, in order to obtain high breaking strength, it is preferable to form at least the central layer of the metal foil by an electroplating method.

In the aperture grill of the present invention using a metal foil as a material, for example, if a slit having a pitch of 200 μm is formed in a metal foil having a thickness of 50 μm in the center layer (thickness of a thin iron film is ignored), the tape portion becomes Thickness 50μm x width 156
With μm, the breaking strength per tape part is about 1 kg. The breaking strength per tape part is equal to or greater than that of a conventional iron foil having a thickness of 100 μm and slits formed at a pitch of 250 μm. Of the tape portion can be prevented.

The thickness of the central layer in the metal foil can be appropriately determined according to the desired slit pitch and the required breaking strength. The thickness of the iron film may be any thickness that can form black ferric oxide on the surface by heat treatment, and specifically, is preferably 0.1 μm or more. The upper limit of the thickness of the iron film is not particularly limited, but in order to improve the breaking strength of the tape portion itself, it should be relatively thinner than the thickness of the intermediate layer having a higher breaking strength. Since the side etch increases as the thickness increases, it is usually desirable that the thickness be 20 μm or less on one side. The overall thickness of the aperture grill is desirably about 50 μm in order to obtain high image quality.

Further, the metal foil in the present invention can be produced by using an electroplating method or the like. For example, a metal plate, such as titanium or stainless steel, on which a passive body film is easily formed on the surface is used as a support, and the surface thereof is successively subjected to electroplating using an iron film, a central layer made of nickel or cobalt or an alloy thereof, and an iron film. Is formed and finally peeled off from the support to produce a metal foil. Alternatively, a metal layer may be formed by forming a central layer of nickel or cobalt or an alloy thereof on one side of an iron foil by an electroplating method, and further forming an iron film thereon by an electroplating method.

The aperture grill of the present invention is manufactured by using the thus prepared metal foil as a raw material by an etching method. The iron film can be etched using a ferric chloride solution as in the prior art, and the central layer is etched using an etching solution having the ability to dissolve its constituent components such as nickel and cobalt. In the aperture grill, after the slit is formed by etching, the surface of the iron film is oxidized by heat treatment, and is turned black by changing it to ferric oxide.

[0019]

Next, the present invention will be described in more detail by way of examples. Length 440mm, width 560mm, thickness 0.3mm
Using a titanium plate as a support, electroplating was performed on the surface thereof under the iron plating solution composition and plating conditions shown in Table 1 below to form an iron film having a thickness of 0.1 μm. Next, electroplating was performed under the plating solution composition and plating conditions shown in Table 2 to form a 50 μm thick nickel layer on the surface of the iron film. afterwards,
Electroplating was performed on the surface of the nickel layer under the same iron solution composition and plating conditions as in Table 1 to form an iron film having a thickness of 0.1 μm. After the above plating treatment, the metal foil obtained by plating was peeled from the titanium plate.

[0020]

[Table 1] << Iron plating solution composition and plating conditions >> Plating solution composition FeCl ₂ .4H ₂ O 2.01 M CaCl ₂ 1.62 M Saccharin 9.13 M Sodium lauryl sulfate 0.30 mM Plating condition temperature 90 ° C. Cathode current density 3 A / dm ² anode Pt time 20 sec.

[0021]

TABLE 2 "nickel plating solution composition and plating conditions" plating solution composition _{NiSO 4 · 6H 2 O 250g /} l NiCl 2 · 6H 2 O 60g / l boric acid 40 g / l brightener qs plating conditions Temperature 60 ° C. Cathode current density 6A / Dm ² anode Ni time 40min.

Thereafter, the obtained metal foil (with a breaking strength of 150
kg / mm ²⁾ a photoresist layer having a thickness of 5μm was formed on both sides of, and exposed using a predetermined photomask, after the development processing was carried out etching from both sides of the metal foil. In the etching treatment, first, the iron film on both sides was etched with the etching solution composition and etching conditions shown in Table 3 below, and then the nickel layer as the central layer was etched with the etching solution composition and etching conditions shown in Table 4. After completion of the etching process, the aperture grill was obtained by removing the photoresist layer.

[0023]

Table 3 << Etch coating composition and etching conditions >> Etching composition 300 g / l FeCl ₃ Etching conditions Temperature 40 ° C. Spray pressure 2 kg / cm ² hours 5 sec.

[0024]

<< Etching solution composition and etching conditions of nickel layer >> Etching solution composition "D-Safe Lip" (trade name: manufactured by Okuno Pharmaceutical Co., Ltd.) Etching conditions Temperature 50 ° C. Spray pressure 2 kg / cm ² hours 5 min.

The obtained aperture grill had a slit pitch of 200 μm and a width of the tape portion of 156 μm. This aperture grill was welded to a frame set with a turnback amount of 5 mm. After the welding was completed, a predetermined tension was applied to the aperture grill by releasing the external force applied to the frame, but no disconnection occurred in the tape portion.

[0026]

[Comparative example] 50 μm thick (breaking strength 70 kg / mm ² )
After forming a photoresist layer in the same manner as in the above example using the iron foil of Example 1, the iron foil was etched with the etchant composition and conditions shown in Table 5 below, whereby the slit pitch was 200 μm and the same as in the above example. An aperture grill having a tape portion with a width of 156 μm was obtained.

[0027]

Table 5 << Etch coating composition and etching conditions >> Etching composition 400 g / l FeCl ₃ Etching conditions Temperature 50 ° C Spray pressure 2 kg / cm ² hours 1 min.

After the obtained aperture grill was welded to a frame set to a turnback amount of 5 mm, the external force applied to the frame was released to apply a predetermined tension to the aperture grill. Occurred.

[0029]

According to the present invention, even if the slit pitch is fine, the dimensional accuracy is good and the breaking strength of the tape portion is high, so that the tape portion breaks even when tension is applied after welding to the frame. A high-precision, high-strength aperture grill can be provided. Therefore, the aperture grill according to the present invention can have a slit pitch of about 200 μm, which is difficult with the conventional etching method, and can be attached to the frame without breakage of the tape portion. It is extremely useful for conversion.

Claims (2)

[Claims] 1. An aperture grill, comprising: preparing a metal foil provided with an iron film on both surfaces of a central layer made of nickel or cobalt or an alloy thereof; and etching the metal foil to form a large number of slits. Manufacturing method. 2. The method according to claim 1, wherein the central layer made of nickel, cobalt, or an alloy thereof is formed by electroplating.