JPH0765736A - Aperture grill and its manufacturing method - Google Patents

Abstract

(57) [Summary] [Structure] The iron strip portion 1 forming the stripe-shaped slit 2 includes the first layer 5 on the phosphor screen side and the second layer on the electron beam irradiation surface side.
The first layer 5 has a two-layer structure with the layer 6, and the cross-sectional shape of the first layer 5 is a substantially rectangular shape having a predetermined width and a predetermined thickness.
The cross-sectional shape of the aperture grille is such that the width of the above-mentioned two layers is larger than the width of the first layer 5 at the boundary surface 7 and is substantially trapezoidal toward the electron beam irradiation surface. Further, after forming the resist layer 11 on the conductor 10 and patterning it, the exposed conductor portion 12 is plated with electric iron 13 thicker than the thickness of the resist layer 11, and the coating of the electric iron plating 13 is peeled off from the conductor 10. A method for manufacturing the above aperture grille. [Effects] When the aperture grill of the present invention is used in a cathode ray tube, halation does not occur in an image at a screen end portion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aperture grill used for a color display picture tube and a method for manufacturing the aperture grill.

[0002]

2. Description of the Related Art There are shadow masks for general televisions and high-definition shadow masks used for high-vision and industrial displays. This high-definition shadow mask is required to have a dimensional accuracy of about several μm. Usually, the electron beam passage hole is a round hole, an ellipse, or a lattice shape, but there is also a shadow mask called an aperture grill having a slit in a stripe shape. It is used in the Trinitron system.

Conventionally, the aperture grill used in the Trinitron system has a resist layer formed on a steel plate,
After patterning the stripe slit shape,
It is manufactured by an etching method of etching a ferric chloride solution to form a large number of slits and then removing the resist layer.

However, the aperture grill mounted in a color picture tube for a display, which requires a high-precision and high-definition screen, has an extremely small width and interval of slits which are electron beam passage portions corresponding to the screen. Something has come to be used. Therefore, the aperture grille manufactured by the conventional etching method has many defects in dimensional accuracy and the product yield is low. Further, there is a drawback that it takes time to process the waste etching solution.

On the other hand, recently, an attempt has been made to manufacture an aperture grill by an electroforming method. Figure 3 shows the electroforming method
It will be described with reference to the sectional view shown in FIG. In the electroforming method, the resist layer 11 is formed on the conductor 10, and after patterning, the exposed conductor portion 12 is subjected to electric iron plating 13, and the conductor 10 is distorted by external stress or the like to coat the electric iron plating 13. The edge grill is peeled off, and the entire plating film is peeled off from that portion to manufacture the aperture grill.

[0006]

However, in the aperture grill produced by the above-mentioned ordinary electroforming method, the cross section of the iron strip portion forming the stripe slit is rectangular. When this is mounted in a cathode ray tube and an image is captured, halation occurs in the image at the edge of the screen.

Therefore, an object of the present invention is to provide an aperture grill which does not cause halation in an image at a screen edge even when an aperture grill produced by an electroforming method is used, and a manufacturing method thereof. .

[0008]

In the aperture grill of the present invention, the iron strip portion forming the stripe-shaped slit has a two-layer structure of a first layer on the phosphor screen side and a second layer on the electron beam irradiation surface side. And the cross section perpendicular to the slit direction of the first layer is
The cross section of the second layer, which has a predetermined width and a predetermined thickness and is perpendicular to the slit direction, is wider than the first layer at the boundary surface of the two-layer structure and faces the electron beam irradiation surface. It is characterized by the fact that it is a trapezoid of a predetermined thickness with a width that fits tight.

Further, in such a method for manufacturing an aperture grill, a resist layer is formed on a conductor, and after patterning, the exposed conductor portion is plated with electric iron, and then the conductor is coated with the electric iron plating. In the method of peeling
It is characterized in that the electric iron plating is applied to be thicker than the resist layer.

[0010]

A clear image on a color television can be obtained by correctly irradiating each fluorescent screen with red, green and blue electron beams. Further, the aperture grill functions as an electron beam filter so that the electron beam is correctly irradiated onto the fluorescent screen. However, the cross section of the iron strip portion 1 forming the slit of the aperture grill produced by the electroforming method is usually a rectangle as shown in FIG. Further, the thickness of the aperture grill manufactured by the electroforming method is 30 to 50.
μm. There is no problem if the incident angle of the electron beam with respect to the normal direction of the aperture grill is small, but as the distance from the center of the aperture grill increases, the incident angle of the electron beam with respect to the normal direction of the aperture grill increases, so the cross-sectional shape is rectangular. If so, the electron beam emitted to the end of the aperture grille is reflected by the side surface of the iron strip 1 in the slit 2 and halation occurs in the image.

Therefore, if the side surface of the iron strip 1 in the slit 2 is formed as a slope 8 as shown in FIG. 1, reflection of the irradiated electron beam can be prevented. In order to manufacture an aperture grill having a shape as shown in FIG. 1, a resist layer 11 thinner than the thickness of the electric iron plating 13 to be formed is provided, and plating is performed to a predetermined thickness thicker than the resist layer 11. Good. By this method, a plating film is formed on the left and right in the upper portion of the resist layer 11, and the cross section of the iron strip portion 1 is not rectangular, but the side surface thereof is the slope 8. Resist layer 1
Since the coating of the electric iron plating 13 on the upper part of 1 grows in the left-right direction as the plating time elapses, the plating time may be set so that the slit width becomes the required width.

The thickness of the resist layer 11 cannot be generally stated because the required slit width differs depending on the size of the cathode ray tube, but the distance in which the precipitation proceeds in the left-right direction is equal to or greater than the thickness of the resist layer 11. Good. Also,
The inclination angle of the slope 8 on the side surface of the iron strip 1 is sufficient if it is 20 degrees or more, preferably 40 degrees or more with respect to the normal direction of the aperture grill.

[0013]

【Example】

Example: The conductor 10 has a length of 300 mm and a width of 400 m
A stainless steel substrate having a thickness of 0.3 mm and a thickness of 0.3 mm is used, and a resist layer 11 is applied on the surface of the stainless steel plate to a thickness of 5 μm, and the width is 150 μm, the length in the vertical direction is 250 mm, and the interval is 1
After a photolithography mask having a slit of 00 μm was placed, exposure was performed, development was performed, and patterning was performed. Next, with the plating solution composition and conditions shown in Table 1, the exposed surface of the conductor portion 12 was plated with electric iron to form an aperture grill with a thickness of 30 μm.

[0014]

[Table 1] Plating solution composition and conditions ○ Solution composition FeCl ₂ .4H ₂ O ・ ・ ・ 2.01M CaCl ₂・ ・ ・ 1.62M saccharin ・ ・ ・ 9.13mM CH ₃ (CH ₂ ) ₆ CH ₂ OSO ₃ Na ・ ・ ・ 0.30mM ○ Plating condition Temperature ・ ・ ・ 90 ℃ Cathode current density ・ ・ ・ 5A / dm ² Anode ・ ・ ・ Pt time ・ ・ ・ 37min

The cross section of the iron strip portion 1 of the aperture grill obtained by the above method has a shape as shown in FIG. When this aperture grill was mounted inside a cathode ray tube and an image was taken, no halation occurred in the image at the edge of the screen.

Conventional example: The resist layer 11 has a thickness of 40 μm, a width of 200 mm, and a longitudinal length of 250 mm.
An aperture grill was produced in the same manner as in the example, except that a photomechanical mask having slits with an interval of 50 μm was used. The cross section of the iron strip 1 of the obtained aperture grill had a shape as shown in FIG. 2. When this was mounted in a cathode ray tube and an image was taken, halation occurred in the image at the edge of the screen.

[0017]

When the aperture grill of the present invention is used in a cathode ray tube, halation does not occur in the image at the edge of the screen, and according to the method of the present invention, an image is generated at the edge of the screen even when used in the cathode ray tube. You can get an aperture grill without halation.

[Brief description of drawings]

FIG. 1 shows an aperture grill made by the method of the present invention,
It is sectional drawing of an iron strip part.

FIG. 2 is a sectional view of an iron strip portion of an aperture grill manufactured by a conventional method.

FIG. 3 is a cross-sectional view illustrating a method for manufacturing an aperture grill by an electroforming method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Iron strip 2 Slit 3 Phosphor screen side 4 Electron beam side 5 1st layer 6 2nd layer 7 2 layer boundary surface 8 Slope 10 Conductor 11 Resist layer 12 Exposed conductor 13 Electric iron plating

Claims (2)

[Claims] 1. An iron strip portion forming a stripe-shaped slit has a two-layer structure of a first layer on the side of a phosphor screen and a second layer on the side of an electron beam irradiation surface, and is arranged in the slit direction of the first layer. The vertical cross section is substantially rectangular with a predetermined width and a predetermined thickness, and the cross section perpendicular to the slit direction of the second layer is wider than the first layer at the boundary surface of the two-layer structure and An aperture grill characterized by a trapezoidal shape with a predetermined thickness and a width that narrows toward the beam irradiation surface. 2. A method of forming a resist layer on a conductor, patterning the same, applying electroferrous plating to the exposed conductor portion, and then peeling off the electroiron plating film from the conductor. The method for manufacturing an aperture grill according to claim 1, wherein the electric iron plating is applied to a thickness greater than the thickness.