JPH0612979A - Manufacture of shadow mask for color cathode-ray tube - Google Patents

Abstract

PURPOSE:To provide a high accurate shadow mask by forming an electron beam passing hole in a shadow mask plate of collecting crystal surfaces on a rolled surface, and thereafter performing plasticizing work. CONSTITUTION:After cold rolling a metal material of face centered cubic lattice or body centered cubic lattice structure, heat treatment is performed at a recrystallizing temperature or more, to obtain a shadow mask plate 20 of collecting 75 to 90% {200} crystal surfaces on a rolled surface. A pair of negative original plates 22a, 22b are closely attached to a sensitized film 21, formed by applying a photosensitive agent to the rolled surface of this shadow mask plate 20, and exposed, and a nonsensitized part is removed by developing after printing, to form a resist film 23. Next, the shadow mask plate 20 formed with the resist film is etched, to obtain a flat mask 25 by forming an electron beam passing hole 24. This mask 25 is annealed so as to obtain 5.0 to 6.5 crystal grain size at 950 deg.C and 1.0 to 3.0 crystal grain size at 1150 deg.C, of the rolled surface. Next, this mask 25 is plasticized by press work and molded into a predetermined shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a shadow mask for a color cathode ray tube, and more particularly to a method for producing a shadow mask for a color cathode ray tube made of amber material or the like.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 5, in a color cathode ray tube, a phosphor screen 2 composed of a phosphor layer of three colors is formed on the inner surface of a panel 1 whose effective surface is a curved surface. Opposite, funnel 3 neck 4
3 electron beams emitted from an electron gun 5 placed inside
A shadow mask 7 for selecting B, 6G, and 6R is provided. This shadow mask 7 is used for the phosphor screen 3
A large number of electron beam passage holes are formed on the effective surface opposite to, and a mask body 9 is formed on the curved surface corresponding to the inner surface of the panel 1, and a skirt portion is bent around the effective surface. It consists of a mask frame 10 welded to the skirt of the mask body 9.

Conventionally, the mask body 9 of the above-mentioned shadow mask 7
Although low-carbon steel sheets such as aluminum killed steel were used for these, in recent years, large color picture tubes, high-definition color picture tubes,
With the development of high-definition color display tubes,
Amber material with a low coefficient of thermal expansion is used. This is to prevent the doming phenomenon of the shadow mask 7 caused by the thermal expansion caused by the collision of the electron beam.

By the way, in the color picture tube or the color display tube, it is desired to display a fine image, and accordingly, the electron beam passage hole of the shadow mask 7 is different from that of a normal color picture tube. It is dense and minute.

Conventionally, the mask body 9 of the shadow mask 7
Is a photomask on both sides (rolled surface) of a shadow mask plate formed through a predetermined cold rolling process.
A large number of electron beam passage holes penetrating through are formed into a flat plate-shaped flat mask, and the flat surface-shaped flat mask is subjected to plastic working by press forming, so that the effective surface on which the electron beam passage holes are formed has a curved surface. It is manufactured by forming a skirt portion around the effective surface into a predetermined shape.

However, when the mask body 9 made of an amber material is manufactured by the above manufacturing method, as shown in FIG. 6, the position of the hole 13 of the electron beam passage hole 12 (the portion where the hole diameter becomes the minimum), the shape of the hole 13, etc. Becomes non-uniform and a high precision shadow mask cannot be obtained. This electron beam passage hole 12
The non-uniformity of the positions and shapes of the holes 13 is caused by the non-uniformity of the crystal directions on both surfaces of the shadow mask plate. That is, as shown in FIG. 7, if the crystal grains on both sides of the shadow mask plate 13 are not aligned in the direction, the crystal grains that are easily etched and the ones that are not easily etched are formed when the electron beam passage hole penetrating between the both sides is formed. A difference in etching rate is caused between the grains and the crystal grains. As a result, the progressing direction of the etching is inclined as shown by the broken line 14, and the position and shape of the electron beam passage hole are not uniform as shown in FIG. Become.

A mask body 9 made of this amber material
Is 0.18 to 0.2 for the shadow mask 7 of a large tube.
A plate having a plate thickness of 5 mm is used, and a plate having a plate thickness of 0.10 to 0.15 mm is used for a high-definition color display tube. On the other hand, regarding the molding of the mask body 9, in order to prevent deterioration of the molding accuracy due to its high tensile strength, a flat flat mask is annealed and then molded by warm pressing. However, for the mask body 9 made of amber material, the accuracy of curvature of the effective surface, the spring back of the skirt, the deformation of the effective surface due to the spring back of this skirt, the deformation when ejected from the press mold after molding, etc. There is a problem that occurs.

[0008]

As described above, in large color picture tubes, high-definition color picture tubes, high-definition color display tubes, etc., the shadow mask is made of an amber material having a low thermal expansion coefficient. Is used. However, when the mask body made of this amber material is manufactured by the same method as the shadow mask made of the conventional low carbon steel plate, when the electron beam passage hole is formed by the photo etching method, the position of the hole of the electron beam passage hole, The shape becomes non-uniform, the curvature accuracy of the effective surface, the spring back of the skirt, the deformation of the effective surface due to the spring back of this skirt, the deformation when taking out from the press mold after molding, etc. occur. There is a problem that the required high precision shadow mask cannot be obtained.

The present invention has been made in order to solve the above-mentioned problems, and highly accurately manufactures a shadow mask whose mask body is made of a metal material having a face-centered cubic lattice or a body-centered cubic lattice structure such as an amber material. An object of the present invention is to obtain a method for manufacturing a shadow mask that can be used.

[0010]

A method for manufacturing a shadow mask for a color cathode ray tube, the mask body of which is made of a metal material having a face-centered cubic lattice or a body-centered cubic lattice structure, the metal having a face-centered cubic lattice or a body-centered cubic lattice structure. The material is cold-rolled, and this cold-rolled metal material is heat-treated at a temperature equal to or higher than the recrystallization temperature to form a shadow mask plate in which {200} crystal faces are gathered on the rolled surface, and the shadow mask plate is formed by photoetching. A large number of electron beam passage holes are formed on the rolled surface of the shadow mask plate, and the mask body is manufactured by forming the shadow mask plate with the electron beam passage holes formed into a predetermined shape by plastic working by press molding. did.

Further, the grain size of the crystal on the rolled surface of the shadow mask plate having the electron beam passage holes at 950 ° C. is 5.0 to 6.5, and the grain size at 1150 ° C. is 1.0 to 3.0. The mask body was manufactured by annealing the shadow mask plate into a predetermined shape by plastic working by press molding.

[0012]

As described above, a metal material having a face-centered cubic lattice or a body-centered cubic lattice structure is cold-rolled, and then heat-treated at a temperature equal to or higher than the recrystallization temperature of the metal material to form {200} on the rolled surface.
When a shadow mask plate is formed by gathering crystal planes and a large number of electron beam passage holes are formed on the rolled surface of the shadow mask plate by a photoetching method, the etching progresses to form electron beam passage holes on the rolled surface. On the other hand, it becomes almost vertical, and the position of the hole of the electron beam passage hole that has occurred conventionally,
It is possible to eliminate the non-uniformity of the shape.

Further, the grain size of the crystal on the rolled surface of the shadow mask plate having the electron beam passage holes at 950 ° C. is 5.0 to 6.5, and the grain size at 1150 ° C. is 1.
When the annealed shadow mask plate is formed by plastic working by press forming by annealing in the range of 0 to 3.0, the growth of crystals due to annealing of the rolling surface composed of {200} crystal faces is suppressed, Grain size can be adjusted to coarse grains and small mixed grains, and by homogenizing the grain size,
It is possible to solve the molding problem that has occurred conventionally.

[0014]

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

As an example of a metal material having a face-centered cubic lattice structure or a body-centered cubic lattice structure, a method of manufacturing a shadow mask made of an amber material will be described.

First, an amber alloy composed of 36Ni-Fe is melted, and a rolled plate having a predetermined plate thickness is formed through steps such as refining, casting, slab, hot rolling, annealing, pickling and cold rolling. Specifically, for example, hot rolling reduces the plate thickness to 1.2.
mm, and this rolled plate having a plate thickness of 1.2 mm is bright annealed and then cold rolled at a rolling ratio of 45.8% to a plate thickness of 0.65 mm, and further cold rolled at a rolling ratio of 76.9%. Then, a rolled plate having a plate thickness of 0.15 mm is obtained. Then, the rolled plate formed through the steps of hot rolling, annealing, cold rolling and the like is heat-treated at a temperature not lower than the recrystallization temperature of the amber alloy to form a shadow mask plate.

Next, a flat mask is manufactured by forming electron beam passage holes on the rolled surface of the shadow mask plate by photoetching.

That is, as shown in FIG. 1 (a), both sides (rolled surfaces) of the shadow mask plate 20 are coated with a photosensitizer containing, for example, milk caseinate alkali and ammonium dichromate as main components. The film 21 is formed. Then, as shown in (b), a pair of negative masters 22a and 22b are closely contacted and exposed on the photosensitive films 21 on both sides to expose the photosensitive films 21 on both sides.
The pattern of a pair of negative master plates 22a and 22b is printed on. Next, the photosensitive film 21 on both sides of which the pattern has been baked is developed to remove the unexposed portion, and as shown in FIG. 7C, the resist film 23 in which the rolled surface of the electron beam passage hole forming portion is exposed.
To form. After that, the shadow mask plate 20 having the resist film 23 formed thereon is etched to form electron beam passage holes 24 as shown in FIG. After that, the resist film 23 is peeled and removed with a caustic alkali to obtain a flat mask 25 as shown in FIG.

For etching the electron beam passage hole,
For example, ferric chloride 44%, ferrous chloride 5% hydrochloric acid 0.2
It is carried out by heating an etching solution containing 0% to 70 ° C. and spraying this. As the etching method, there are a two-step etching method in which the etching is divided into front and rear two steps, one side each, and a simultaneous etching method in which both sides are simultaneously etched.

Next, the flat plate-shaped flat mask 25 in which the electron beam passage holes 24 are formed is annealed in an atmosphere of 800 to 1150 ° C. for about 8 minutes. This annealed flat mask is then subjected to plastic working by press forming so that the portion where the electron beam passage hole is formed (effective surface) has a curved surface with a predetermined curvature, and the skirt portion is bent around the effective surface. Molded into a predetermined shape.

By the way, as described above, hot rolling, annealing,
Prior to forming the electron beam passage hole, a rolled plate made of an amber alloy having a predetermined plate thickness formed through each step such as cold rolling is heat treated at a temperature equal to or higher than the recrystallization temperature of the amber alloy, the rolling surface is The 200} crystal planes are aggregated at a ratio of about 82%, and the rolled surface forming the electron beam passage holes can be a plane with uniform crystal grains. As a result, when the rolled plate subjected to the heat treatment is used as the shadow mask plate 20 and the electron beam passage holes 24 are formed on the rolled surface by the photo-etching method, the directions of the crystal grains are aligned, and the broken line 26 and the arrow in FIG.
As shown by 27, etching progresses in a direction perpendicular to the rolling surface, and as shown in FIG. 3, the position and shape of the electron beam passage hole 24 can be made uniform, and the amber material can be made uniform. It is possible to form a high precision shadow mask made of. Moreover, since the cold rolling is performed before the heat treatment at a temperature of the recrystallization temperature or higher, a shadow mask plate having a predetermined plate thickness can be easily obtained.

Incidentally, the shadow mask in which the positions and shapes of the electron beam passage holes are uniform is heat-treated at a temperature higher than the recrystallization temperature of the amber alloy before the electron beam passage holes are formed by the photoetching method. The rolling surface {2
It is obtained when the {00} crystal planes are aggregated in the range of 70 to 90%.

Before molding the flat mask having a flat plate having the electron beam passage holes 24, 800 to 1150
When annealed for about 8 minutes in an atmosphere at ℃, in the shadow mask made of conventional amber alloy, crystal grains grow and coarse grains or mixed grains increase, which causes deformation during molding and slight impact during assembly of the shadow mask. The problem of deformation due to stress occurred, but in the case where {200} crystal faces were aggregated in the rolling face at a ratio of about 82% as described above, there was no increase in coarse grains and mixed grains due to the growth of crystal grains, High precision molding can be obtained.

The above flat mask is heated at 800 to 1150 ° C.
As shown in FIG. 4, the relationship between the degree of aggregation of {200} crystal faces and the crystal grains in the case of annealing for 8 minutes in the atmosphere of
When the degree of aggregation of {200} crystal planes is in the range of 70 to 90%, the area is sandwiched between two straight lines 29 and 30, and it is possible to suppress crystal coarsening and increase in mixed grains. For example, when the {200} crystal plane having a grain size of 9.0 before annealing is annealed in an atmosphere of 950 ° C., the grain size of the {200} crystal face becomes 5.0 to 6.5 and an atmosphere of 1150 ° C. When annealed, the crystal grain size of the {200} crystal face becomes 1.0 to 3.0, coarsening due to crystal grain growth and increase in mixed grains can be suppressed, and high precision molding is possible.
However, if the degree of aggregation of {200} crystal faces exceeds the above range, for example, 95%, even if annealed under the same conditions, the grain size of the {200} crystal faces before annealing is 9.0. As a result, crystal grains grow to 3.6 to 6.0, and coarse grains and mixed grains increase, making it difficult to perform high-precision molding. Also {20
Similar results were obtained even when the degree of aggregation of 0} crystal faces was 75%.

That is, in forming a shadow mask made of amber material, {200} crystal planes are aggregated on the rolled surface, and the degree of aggregation of the {200} crystal planes is set in the range of 70 to 90%, and the rolled surface is formed. Forming an electron beam passage hole,
The grain size of the {200} crystal face is 5.0 at 950 ° C.
By annealing to a range of 1.0 to 3.0 at 16.5 ° C to 6.5 ° C, it becomes possible to perform molding with a required high accuracy.

In the above embodiment, the method of manufacturing a shadow mask made of amber material has been described. However, the present invention is not limited to the amber material, and the mask body is made of a metal material of face centered cubic lattice or body centered cubic lattice structure. It is applicable to a method for manufacturing a shadow mask for forming a.

[0027]

[Effects of the Invention] A metal material having a face-centered cubic lattice or a body-centered cubic lattice structure is cold-rolled, and the cold-rolled metal material is heat-treated at a temperature equal to or higher than the recrystallization temperature to form a {20
When a shadow mask plate in which 0} crystal planes are aggregated is formed and a large number of electron beam passage holes are formed on the rolled surface of the shadow mask plate by a photoetching method, the rolling direction in which the etching progresses forms the electron beam passage holes. It becomes almost perpendicular to the surface, and it is possible to eliminate the nonuniformity of the position and shape of the electron beam passage hole that has been conventionally generated.

Further, the cold-rolled metal material is heat-treated at a temperature not lower than the recrystallization temperature to form a shadow mask plate in which 75 to 90% of {200} crystal faces are aggregated on the rolled surface, and the shadow mask plate is formed. After forming the electron beam passage holes on the rolled surface, the grain size of the crystal at 950 ° C. on the rolled surface of the shadow mask plate on which the electron beam passage holes are formed is 5.
0 to 6.5, the grain size of the crystal at 1150 ° C is 1.0 to
When annealed to a range of 3.0 and the annealed shadow mask plate is formed by plastic working by press forming,
The crystal grain size of the rolled surface composed of {200} crystal faces can be adjusted with coarse grains and few mixed grains, and by homogenizing the crystal grains, the conventional problems in forming can be solved. The shadow mask can be molded with high precision.

[Brief description of drawings]

1A to 1E are views for explaining a method of forming an electron beam passage hole in a shadow mask plate by a photoetching method according to an embodiment of the present invention.

FIG. 2 is a diagram showing a crystal direction and an etching direction of a shadow mask plate in which a cold-rolled metal material is heat-treated at a temperature equal to or higher than a recrystallization temperature to collect {200} crystal faces on a rolled face.

FIG. 3 shows the positions of electron beam passage holes formed in a shadow mask plate in which {200} crystal faces are gathered on a rolled surface,
It is a figure which shows a shape.

FIG. 4 is a diagram showing a relationship between the degree of aggregation of {200} crystal faces and crystal grains in annealing before forming.

FIG. 5 is a diagram showing a configuration of a color CRT.

FIG. 6 is a view showing positions and shapes of electron beam passage holes formed in a conventional shadow mask plate made of an amber material.

FIG. 7 is a diagram showing a crystal direction of a shadow mask plate made of a conventional amber material.

[Explanation of symbols]

 20 ... Shadow mask plate 21 ... Photosensitive film 23 ... Resist film 24 ... Electron beam passage hole 25 ... Flat mask

Claims (2)

[Claims] 1. A metal material having a face-centered cubic lattice or a body-centered cubic lattice structure is cold-rolled, and the cold-rolled metal material is heat-treated at a temperature equal to or higher than a recrystallization temperature to form a rolled surface on {200}.
A step of forming a shadow mask plate in which crystal planes are aggregated, a step of forming a large number of electron beam passage holes on the rolled surface of the shadow mask plate by a photo-etching method, and a step of forming the electron beam passage holes by plastic working by press molding. And a step of molding the formed shadow mask plate into a predetermined shape. 2. A metal material having a face-centered cubic lattice or a body-centered cubic lattice structure is cold-rolled, and the cold-rolled metal material is heat-treated at a temperature equal to or higher than a recrystallization temperature to form a rolled surface on {200}.
A step of forming a shadow mask plate having 75 to 90% of crystal planes aggregated therein, a step of forming a large number of electron beam passage holes in the rolled surface of the shadow mask plate by a photoetching method, and a formation of the electron beam passage holes The grain size of the rolled shadow mask plate at 950 ° C. on the rolled surface is 5.0 to 6.
5, a step of annealing the grain size of the crystal at 1150 ° C. to a range of 1.0 to 3.0, and a step of forming the annealed shadow mask plate into a predetermined shape by plastic working by press forming. A method for producing a shadow mask for a characteristic color cathode ray tube.