JPH07105864A - Aperture grille and its manufacture - Google Patents

Abstract

PURPOSE:To provide an aperture grille which never cause an image halation in a faceplate end part when used in a cathode-ray tube by forming the section vertical to a slit direction of a stripe slit inner iron belt part into a two-layer structure in which two rectangles different in width are put one over another. CONSTITUTION:Resist layers 11a, 11b are formed on a conductor 10, and patterned, the exposed conductor part is then electrically plated in a stripe form to form a first layer 5 on electron beam emitting side. The strip pattern is again patterned on the resist layers 11a, 11b of the conductor having the first layer 5 formed thereon, an electric iron plating is narrowed more than the first layer 5 to form a second layer 6 on phosphor screen side. The film of the electric iron plating consisting of the first layer 5 and the second layer 6 is peeled from the conductor to provide an intended aperture grille. This aperture grille is used for a color display image tube.

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, after forming a resist layer 11 on the conductor 10 and patterning the same, the exposed conductor portion 12 is plated with electric iron 13, and the conductor 10 is distorted by external stress or the like to form a film of 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 manufactured 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 slit has a two-layer structure of a first layer on the electron beam irradiation surface side and a second layer on the fluorescent surface side. And the cross sections of the first layer and the second layer perpendicular to the slit direction are both rectangular with a predetermined width and a predetermined thickness, and the width of the first layer is the same as that of the second layer. The feature is that it is larger than the width.

Further, in such a method for manufacturing an aperture grill, after forming a resist layer on a conductor and patterning, the exposed conductor portion is subjected to stripe-shaped electric iron plating to form a first layer on the electron beam irradiation surface side. Forming layers, and then
A resist layer is formed again on the conductor on which the first layer has been formed, and after patterning, a stripe shape is patterned on the exposed first layer, and electric iron plating is performed with a width narrower than that of the first layer to form a phosphor screen side. Forming a second layer of
It is characterized in that the electric iron plating film comprising the layer and the second layer is peeled off.

[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 iron strip portion 1 forming the slit of the conventional aperture grill manufactured by the electroforming method
The cross section of is normally rectangular as shown in FIG. The thickness of the aperture grill 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 cross section of the iron strip portion 1 in the slit 2 perpendicular to the slit direction has a two-layer structure in which two rectangles having different widths are stacked as shown in FIG. The side area of the part can be reduced, and the reflection of the electron beam can be reduced. Here, the thickness of the first layer on the electron beam irradiation surface side is preferably 15 μm or less.

The width of the first layer cannot be generally stated because the slit width required depends on the size of the cathode ray tube, but it is necessary to be larger than the width of the second layer, which is about twice the thickness of the second layer. Is desirable.

Further, in order to manufacture an aperture grill having a shape as shown in FIG. 1, the steps of forming a resist layer, patterning, exposing, and forming electric iron plating are carried out by changing the patterning shape, plating time, etc. You only have to do it twice.

[0014]

【Example】

Example ... FIG. 4 is a cross-sectional view illustrating a method for manufacturing an aperture grill of the present invention. Conductor 10 length 300m
m, width 400 mm, thickness 0.3 mm substrate made of stainless steel plate, and a resist layer 11a having a thickness of 5 on the surface of the substrate.
4 μm (A in FIG. 4), a photolithography mask having slits having a width of 200 μm, a length of 250 μm in the longitudinal direction, and an interval of 50 μm was placed thereon, followed by exposure, development, and patterning (in FIG. 4). B). Next, with the following plating solution composition and conditions, the exposed conductor surface was electroplated with iron to a thickness of 5 μm (C in FIG. 4).

Further, a resist layer 11b having a thickness of 30 μm is applied to the surface of the plated substrate, and a photolithographic mask having slits having a width of 150 μm, a length in the vertical direction of 250 mm, and an interval of 100 μm is placed, and then exposure is carried out. It was developed and patterned (D in FIG. 4). Next, with the composition and conditions of the plating solution shown below, the exposed conductor surface was electroplated with iron to a thickness of 25 μm (FIG. 4).
Medium E). An aperture grill having a thickness of 30 μm was formed by the above method.

Plating 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 .30 mM

○ Plating conditions Temperature ・ ・ ・ 90 ° C. Cathode current density ・ ・ ・ 5 A / dm ² Anode ・ ・ ・ Pt time ・ ・ ・ 37 min

The cross section of the iron strip portion 1 of the aperture grill obtained by the above method had 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 11a has a thickness of 40 μm, a width of 200 mm, and a longitudinal length of 250 m.
An aperture grill was produced in the same manner as in the example except that a photolithographic mask having m slits and a gap of 50 μm was used and only one layer of electric iron plating was formed. 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.

[0020]

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 of manufacturing an aperture grill by a conventional electroforming method.

FIG. 4 is a cross-sectional view illustrating the method of manufacturing the aperture grill of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Iron strip part 2 Slit 3 Phosphor screen side 4 Electron beam side 5 1st layer 6 2nd layer 7 2 layer boundary surface 10 Conductors 11, 11a, 11b Resist layer 12 Exposed conductor part 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 an electron beam irradiation surface side and a second layer on a fluorescent surface side, the first layer and the second layer. An aperture grill characterized in that each of the layers has a rectangular cross section perpendicular to the slit direction and has a predetermined width and a predetermined thickness, and the width of the first layer is larger than the width of the second layer. 2. A resist layer is formed on a conductor and after patterning, the exposed conductor portion is subjected to electric iron plating in a stripe shape to form a first layer on the electron beam irradiation surface side,
Next, a resist layer is formed again on the conductor on which the first layer has been formed, and after patterning, a stripe shape is patterned on the exposed first layer, and electric iron plating is applied with a width narrower than that of the first layer. 2. The method of manufacturing an aperture grill according to claim 1, wherein a second layer on the phosphor screen side is formed, and the electric iron plating film formed of the first layer and the second layer is peeled from the conductor.