JPH05174707A - Manufacture of aperture grill - Google Patents

Abstract

PURPOSE:To manufacture an aperture grill wherein desired weight distribution can be obtained without changing the thickness of a basic material, and the property of the aperture is favorable. CONSTITUTION:A thin plate 1 is cleaned, and resist 2 is applied on both sides of a thin plate, and then the resist is exposed by using a mask 3 where an etching mask is drawn, and development is performed to form a resist pattern 4, and etchant is sprayed from both sides to etch the pattern, whereby an opening 5 and thin part 6 are formed. Hereby, the weight can be reduced without thinning the thin plate of a base material, and also the quantity to be removed by the part thinned from the center to the periphery in the direction perpendicular to a slit is made small, and weight distribution is formed in the aperture grill.

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 cathode ray tube for a color television or a color display device, and more particularly to reducing the weight of the aperture grill.

[0002]

2. Description of the Related Art In a cathode ray tube for a color television or a color display device, various shadow masks are used so that a predetermined phosphor is irradiated with an electron beam. When an aperture grill that is a shadow mask having slit-shaped openings is used, the aperture grill is fixed to the frame before use.

In recent years, along with the demand for higher definition and larger size of color televisions and color display devices and a wider variety of products, there has also been a demand for lighter weight and higher definition of aperture grilles. As a method of reducing the weight of the aperture grill,
(1) A method of reducing the plate thickness of the aperture grill itself to a thickness of about 20 to 80 μm. (2) There is a method of reducing the weight of the aperture grill by etching the material inside the aperture on the front side, that is, the display surface side, while maintaining the size of the aperture without reducing the thickness of the aperture grill. It was

[0004]

In the conventional method of reducing the weight of the aperture grill, (1) the method of reducing the plate thickness to about 20 to 80 μm, the usual 100 to 180 μm is used.
In the manufacturing process of the aperture grill or the shadow mask having a plate thickness of a certain level, it is difficult to maintain the flatness of the plate and the like, and it is difficult to maintain the quality such as the hole shape and dimensional accuracy. For this reason, it is necessary to temporarily form a reinforcing layer or the like on the surface opposite to the surface to be etched to perform etching, or to adjust or change the etching conditions etc. each time a thin material is processed. Therefore, it was not possible to simultaneously use materials with different plate thicknesses. (2) Do not reduce the plate thickness of the aperture grill, and while maintaining the size of the aperture, select the material of the part that does not affect the display performance inside the aperture on the front side of the aperture grill, that is, the display surface side. A method of reducing the weight by removing it by etching was also used. However, as shown in FIG. 4, when a thinned portion is formed by providing a removed portion 44 that is etched larger than the regulation surface 43 inside the opening portion on the surface side of the opening portion 42 of the aperture grill 41, the tip portion 45 becomes thin, This was one of the causes of defects in the thin portion at the tip of the opening and variations in the opening size.

Therefore, it is possible to reduce the weight of the aperture grill by making the plate thickness the same as a normal one, and to manufacture the aperture grill under the same conditions as the normal thickness. There has been a demand for an aperture grille capable of exhibiting the same or higher functions as in the past.

[0006]

According to the present invention, a thin portion is formed by etching in a portion which does not obstruct the passage of an electron beam other than at least one portion through which the electron beam passes on the front and back sides of the aperture grill to reduce the weight. The area or depth of the thin portion is made smaller toward the outer peripheral portion in the width direction of the slit of the aperture grill, and the distribution of the weight of the aperture grill is adjusted.

That is, in the method of the present invention, the flat plate-shaped portion other than the opening portion through which the electron beam passes is etched from at least one surface to reduce the thickness. The portion other than the opening portion is thinned. Therefore, it is possible to reduce the weight of the aperture grill without affecting the aperture and the sectional shape of the aperture.

Further, the weight distribution of the aperture grill is reduced by reducing either the area or the depth of the thin portion toward the outer peripheral portion on the entire surface of the aperture grill in a direction perpendicular to the direction of the slit of the aperture grill. Since it can be set to a desired value, it is possible to easily adjust the tension when attaching the aperture grill to the frame.

A method of manufacturing the aperture grill of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining the manufacturing process of one embodiment of the present invention. Thin plate of mild steel, amber, etc. 1
Is washed (a), resist 2 such as casein or polyvinyl alcohol is applied to both sides of the thin plate (b), and the resist is exposed using a mask 3 having an etching pattern (c).
To do. Next, in the case of a water-soluble resist, development is performed with warm water or the like to form a resist pattern 4 (d), and an etching solution is sprayed from both sides to etch the pattern to form an opening portion 5 and a thin portion 6. (E), the resist is peeled off after etching (f). The width of the pattern formed on the resist can be adjusted under the same etching condition by adjusting the width of the pattern of the opening and the thin portion.

Although the above embodiment is based on the one-step etching method, the same applies to the two-step etching method in which the etching is divided into two steps. The depth and width of the thin portion are determined from the required weight of the aperture grill and its weight distribution, and can be known in advance from the shape of the aperture and the cross-sectional area of the thinned portion.

A method of determining the area or shape of the thin portion will be described below.

FIG. 2 shows an example of the shape of the cross section of the aperture grill and the shape of various thin portions.
FIG. 2 (a) shows a cross-sectional shape between adjacent openings when a thin portion is not formed. From the cross-sectional area and the density of the base material, the linear density of this cross-sectional shape, that is, the weight per unit length (g
/ Mm). Next, the amount of the linear density to be removed from this cross-sectional shape by thinning is shown by various patterns for the thin portion for the back surface shown in FIG. The linear density can be obtained by selecting one or a plurality of patterns for the thin portion for the surface and drawing the cross-sectional shape formed by etching as shown in (c).

On the other hand, the resist pattern formed on the resist in order to obtain the required etching pattern is determined by the etching conditions and can be known by measuring the etching characteristics in advance.

FIG. 3 is a diagram for explaining an example of etching characteristics. FIG. 3 (A) shows the etching characteristics on the front surface side, in which the horizontal axis represents the width of the pattern formed on the resist on the base material surface, and the vertical axis represents the width and depth of the etching pattern formed on the base material by etching. And the linear density removed by etching. Similarly, FIG.
(B) shows the etching characteristics on the back surface side.

From these characteristics, the width of the resist pattern corresponding to the required thin portion can be determined.

[0016]

When a hole is formed in the aperture grill by etching, a thin portion is formed in a portion other than the hole on at least one surface of the aperture grill to reduce the weight without impairing the function of the aperture grill. The amount removed from the base material by the thin-walled part without causing problems such as strength reduction or loss of the opening part and non-uniformity of etching size that would occur if the weight is reduced by using a thin base material. The weight distribution of the aperture grill can be set arbitrarily by decreasing the width of the slit from the center to the outer periphery in the width direction of the slit, facilitating the adjustment of the tension when attaching to the frame of the cathode ray tube. You can Further, when the thin portion is formed on the front and back sides, finer weight distribution can be adjusted.

In addition, the method of the present invention can be carried out under the same manufacturing conditions as the normal ones, using equipment for manufacturing a product having a normal plate thickness.

[0018]

EXAMPLES The present invention will be described below by showing Examples of the present invention. A water-soluble casein resist was applied to both sides of a substrate made of low carbon steel and having a thickness of 150 μm, and after drying, the resist on both sides of the substrate was patterned using a glass dry plate in which a pair of front and back patterns were drawn. .. The front and back patterns for forming the half etching used here are slit-shaped, and each slit has the same width in the length direction of the slit, and the slits have the same width from the central portion toward the outer peripheral portion. The width was gradually reduced, and a difference of 40 μm was formed between the central portion and the outer peripheral portion.

Next, exposure, hardening treatment and baking treatment are performed. Then, etching was performed on both surfaces of the patterned resist by spraying a ferric chloride solution having a liquid temperature of 60 ° C. and a specific gravity of 48 ° Be as an etching liquid from a spray. After etching, it was washed with water, the resist was peeled off with an alkaline aqueous solution, washed and dried.

As a result, the weight of the central portion can be reduced by about 50% when the entire thin-walled portion is provided, and the weight of the central portion can be reduced by about 50% as compared with a normal aperture grill having no thin-walled portion. When provided, it could be reduced by about 10%. In addition, the dimensional accuracy and the rate of chipping at which defects occur at the openings are similar to those of products with normal plate thickness, but with a linear density similar to that when a 50 μm thick substrate is used. Was given.

[0021]

As described above, according to the method of manufacturing an aperture grill of the present invention, it is possible not only to manufacture an aperture grill that is light in weight and has a high precision of an aperture portion as in a thin substrate by using a substrate having a normal thickness. An arbitrary weight distribution can be formed on the aperture grill.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a manufacturing process of an aperture grill of the present invention.

FIG. 2 is a diagram showing an example of a cross-sectional shape of an aperture grill and shapes of various thin-walled portions.

FIG. 3 is a diagram illustrating an example of etching characteristics.

FIG. 4 is a diagram illustrating a method of removing a base material inside an opening.

[Explanation of symbols]

1 ... thin plate, 2 ... resist, 3 ... mask, 4 ... resist pattern, 5 ... opening part, 6 ... thin-walled part, 41 ... aperture grill, 42 ... opening part, 43 ... defining surface, 44 ... removed part,
45 ... Tip

Front page continuation (72) Inventor Osamu Nakamura 1-1-1, Ichigaya-Kagacho, Shinjuku-ku, Tokyo Within Dai Nippon Printing Co., Ltd. (72) 1-1-1 Ichigaya-Kagacho, Shinjuku-ku, Tokyo Within Dai Nippon Printing Co., Ltd.

Claims (2)

[Claims] 1. A method of manufacturing an aperture grill, comprising:
The aperture grill is lightened by forming a thin portion at the same time as forming the opening portion by forming a pattern for forming the thin portion on the resist other than the portion where the opening portion is formed and performing etching. Aperture grille manufacturing method. 2. The aperture grill according to claim 1, wherein an arbitrary weight distribution is formed on the aperture grill by changing the amount of the thin portion removed from the base material from the central portion toward the outer peripheral portion. Manufacturing method.