JPH07176277A - Vacuum vessel for thin display device - Google Patents

Abstract

PURPOSE:To attain reduction of a cost, light weight and increase of reliability of a vacuum vessel for a thin display device used in a flat panel display or the like. CONSTITUTION:A structure of a vacuum vessel is constituted of a flat glass 1 and a ceramics vessel 4, and a ceramics material is composed of forsterite or steatite ceramic. By forming a side wall part and a back plate part, formed of ceramics, into a structure of rib 5, further reducing cost and weight can be attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum container used for thin display devices.

[0002]

2. Description of the Related Art In recent years, the progress of flat panel displays as man-machine interfaces is remarkable due to the development of office automation equipment. Among them, a display device that combines electron beam control with electrostatic deflection and a matrix combines the advantages of a cathode ray tube, such as brightness, color reproducibility, and high resolution, with the advantages of a liquid crystal panel, thinness, and image reproduction without distortion. It is attracting attention as a thin display device having it. The vacuum container used for such a display device device is
As shown in FIG. 4, it is composed of one flat glass 11 and a flat glass 12 having a curved end, both of which are glass frits 13.
It is sealed with (Fig. 5). FIG. 5 shows a BB cross section of FIG.

[0003]

However, since the flat portions of the two glass plates are required to have a high degree of parallelism, the flat glass having curved end portions is extremely expensive in terms of productivity. Further, the glass is easily scratched, and once scratched, the container is immediately destroyed and there is a problem in reliability. For this reason, the thickness of the glass must be increased by all means, and there remains a problem that the weight of the container is increased. In view of the above problems, it is an object of the present invention to provide a vacuum container for a thin display device that can be manufactured at low cost and can be reduced in weight.

[0004]

In order to achieve the above object, the thin display device vacuum container of the present invention has the following constitution. That is, it is composed of one flat glass and a container made of ceramics, and forsterite porcelain or steatite porcelain is used as the ceramic material.
Further, it is possible to achieve further weight reduction and cost reduction by making the container, which is preferably made of ceramics, have a rib structure.

[0005]

One of the reasons why one set of glass plates is used in the vacuum container in the conventional method is matching of the thermal expansion coefficient. That is, a glass frit is used to seal the two glasses, and the sealing temperature is 450 to 500 ° C. Therefore, if a material whose thermal expansion coefficient is not matched with that of glass is melted in the glass frit to fix them, distortion occurs during cooling, and the glass having low mechanical strength is easily broken. Therefore, glass of the same composition was used to prevent stress generation during sealing. In the present invention, since a ceramic material having a thermal expansion coefficient similar to that of glass, that is, forsterite porcelain or steatite porcelain is used, it is possible to suppress the generation of stress generated during cooling after sealing, and as a result, it is possible to prevent the glass from breaking. Becomes Moreover, since the mechanical strength of glass is significantly reduced if it is scratched even a little, and it easily breaks, it is necessary to have a thickness of at least 10 to 15 mm for a display of a dozen or more inches. On the other hand, the mechanical strength of the above-mentioned ceramic porcelain is 2.5 to 3 times that of glass,
Even if it is scratched, its mechanical strength hardly changes. Therefore, even if the plate thickness is thinner than glass, it can withstand the vacuum withstand voltage test, and the occurrence rate of container breakage due to scratches can be suppressed. Therefore, the thickness of the container can be reduced, and as a result, the vacuum container can be made lightweight and highly reliable.

However, even if the above-mentioned ceramic material is used, there is a limit to the reduction in thickness due to the mechanical strength and the like. If a rib structure, that is, a skeleton structure with a partially large thickness is assembled in order to further increase the mechanical strength of the back surface portion and the side wall portion, the thickness of parts other than the skeleton will be thinner than that without the rib structure. It becomes possible and weight reduction can be achieved. A ceramic container can be manufactured by combining the ceramic plates for the side wall and the back surface, and a vacuum container with a flat glass can be considered, but in the case of the combination type, the assembly work is troublesome because there are too many adhesion points. The cost is increased from the aspect of productivity. Further, since there are many bonding points, the rate of occurrence of vacuum leakage due to defective bonding and the like is high and problems remain in terms of reliability, but these problems do not occur at all in the present invention in which the side wall and the back surface are integrated.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a perspective view of the vacuum container structure of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. In FIGS. 1 and 2, reference numeral 1 is a flat glass serving as an image display portion, and 2 is a container made of ceramics. The ceramic container and the flat glass are sealed with a glass frit 3. On the other hand, FIG. 3 is a view for explaining the vacuum container structure of the present invention in which the back plate and the side wall have a rib structure, 4 is a ceramic container, and 5 is a rib arranged vertically and horizontally on the side wall and the back plate. is there. Also in this case, the ceramic container and the flat glass are sealed with a glass frit.

The present invention will be specifically described below. First, as a first example, forsterite powder (2 mg
A ceramic container molded body as shown in FIG. 1 was manufactured by a mold molding method using O.SiO ₂ ) under a molding pressure condition of 800 kg / cm ² . The molded body was fired at 1300 ° C. for 2 hours to prepare a ceramic container made of forsterite porcelain. The length of the outer part of the container after sintering is 290 × 380 × 30.
It was designed to have a thickness of 6 mm and a thickness of 6 mm. Next, the ceramic container part that is fixed to the flat glass is mirror-polished, and the polished part is coated with lead borosilicate-based glass frit and dried, and then the flat glass is stacked and heat-treated at 470 ° C. Then, a vacuum device for a thin display device having the structure of the present invention as shown in FIG. 1 was produced. In the case of the conventional manufacturing method, glass breakage is likely to occur even with a small scratch, and the glass portion having a curved surface needs a thickness of at least 10 mm in order to have pressure resistance under vacuum. It has been confirmed that the mechanical strength of stellite porcelain is about 2.5 times that of glass, and it is also resistant to scratches, so that a thickness of 6 mm can withstand a vacuum resistance test. Therefore, it is about 25
% Of the weight is reduced, and the container can be manufactured at a cost of about 1/3. The thermal expansion coefficient of the forsterite porcelain used in this experiment is 9.4 × 10 to ⁶ / ° C, and that of glass is 9.5 × 10 to ⁶ / ° C. It was found that there was no problem such as chipping or breaking of the glass due to the occurrence of strain at the time and there was no problem in productivity.

Next, as a second example, a molded ceramic container having a rib structure as shown in FIG. 3 was produced by a cast molding method using steatite powder (MgO.SiO ₂ ). It was fired at 1300 ° C. for 2 hours to prepare a ceramics container made of steatite porcelain. The length of the outer part of the ceramic container after sintering is 290 x 380.
The shape of the sintered body of the rib portion was designed to be 1 cm in width, 7 mm in thickness, 7 mm in thickness, the rib interval was 5 cm, and the thickness at a portion where no rib was formed was 4 mm, as shown in FIG. Next, the ceramics container portion to be fixed to the flat glass is mirror-polished, and the polished portion is coated with lead borosilicate glass frit and dried, and then the flat glass is stacked on the ceramics container.
A flat glass and a ceramics container were fixed by heat treatment at 0 ° C. to fabricate a vacuum device for a thin display device having the structure of the present invention as shown in FIG. As described in the first embodiment, the conventional manufacturing method requires a glass thickness of at least 10 mm in order to break the glass against scratches or to withstand pressure in vacuum. The mechanical strength is about twice that of glass,
Further, it is resistant to scratches, and further, in this embodiment, since the side wall portion and the back plate portion have the rib structure, the mechanical strength is further increased. As a result, the container thickness other than the skeleton is 4
There was no particular problem even if the wall thickness was extremely thin (mm). As a result, it is possible to achieve a weight reduction of about 30% compared to the conventional container, and by reducing the amount of raw materials used, it is possible to further reduce the cost compared to a container that does not have a rib structure. The thermal expansion coefficient of steatite ceramic is 9.8 × 10 ~ ⁶ / ℃, its glass 9.5
Since it is very close to × 10 ~ ⁶ / ℃, the number of prototypes is 100
It was confirmed that the glass was not chipped or broken due to distortion during sealing and the production yield was high.
In the present embodiment, both the side wall portion and the back plate portion have the rib structure, but it goes without saying that any one of them may have the rib structure.

[0010]

As described above, the vacuum container for a thin display device according to the present invention is composed of a flat glass and a ceramic container, and forsterite porcelain or steatite porcelain is used as the ceramic material. As a result, cost reduction, weight reduction, and high reliability can be achieved as compared with the conventional thin display device vacuum container. Further, by forming the back plate portion and the side wall portion in a rib structure, further weight reduction and cost reduction can be achieved, which is extremely effective.

[Brief description of drawings]

FIG. 1 is a perspective view of a vacuum container for a thin display device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view of a vacuum container for a thin display device having a rib structure according to an embodiment of the present invention.

FIG. 4 is a perspective view of a conventional vacuum container for a thin display device.

5 is a sectional view taken along line BB of FIG.

[Explanation of symbols]

1, 11 ... Flat glass, 2, 4 ... Ceramic container,
3, 13 ... Glass frit, 5 ... Rib, 12 ... Flat glass having a curved end.

Claims (2)

[Claims] 1. A vacuum container for a thin display device, comprising a ceramics container made of forsterite porcelain or steatite porcelain and a flat glass. 2. The vacuum container for a thin display device according to claim 1, wherein the ceramics container has a rib structure.