JPH0473255B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an image display device having a vacuum envelope.

Configuration of conventional example and its problems The conventional flat panel image display device shown in Fig. 1 utilizes thermionic emission. It has a configuration in which the light is accelerated and deflected by a group of shaped electrodes to cause a desired pixel on the image display surface to emit light. As shown in the figure, the surface of the container facing the image display surface is formed of a metal plate and maintains a vacuum. 1 in Figure 1 is the back substrate facing the image display surface, with a thickness of 1 mm.
It is made of flexible metal with a thickness of 2 mm to 2 mm, and its edge is sealed via a sealing member 2 to the tip of a side wall 3 made of an insulating material and corresponding to the periphery of the opening of the container. By evacuating the container, the back substrate 1 is deformed by atmospheric pressure, and the built-in electrode group is fixed.

However, in the case of a container with such a configuration, when the air is evacuated, stress is generated at the sealing interface between the side wall 3 and the back substrate 1 made of a metal plate, causing the back substrate 1 to separate from the sealing member 2 and causing leakage. There will be cases where a vacuum cannot be maintained. In addition, to solve the above problem, there is a method of increasing the thickness of the side wall 3 and increasing the bonding area with the rear substrate 1 to improve the bonding strength. There are disadvantages such as an increase in

Purpose of the Invention The present invention improves the adhesive strength between the tip of the side wall corresponding to the peripheral part of the container and the metal plate that is the rear substrate,
The purpose is to obtain a leak-free vacuum envelope.

Structure of the Invention In the present invention, in order to increase the adhesive strength between the rear substrate made of a metal plate and the tip of the side wall corresponding to the peripheral part of the container, a plurality of through holes are provided in the adhesive part of the rear substrate, and It is characterized by sandwiching the substrate around the periphery of the container between insulators or metal bodies in a sandwich pattern and sealing it.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. Figure 2 shows a part of the container. The side wall 3 of the container, which corresponds to the image display side of the container and the container periphery of the open part of the container, is made of soft glass for cathode ray tubes, and the coefficient of thermal expansion from room temperature to 450°C is 100.5 ×
10 ^-7 . In the container sealing process, matching of the thermal expansion coefficients of the materials used cannot be ignored. Therefore, the back substrate 1 is made of 42-6 glass made so that its thermal expansion behavior is similar to that of soft glass.
Alloy (Ni42%, Cr6%, Fe52%; thermal expansion coefficient 94~
102×10 ^-7 ), and as the sealing member 2,
We used low-melting solder glass (working temperature: 450°C) with a coefficient of thermal expansion of 95 to 100 x 10 ^-7 to match thermal expansion and reduce residual stress during sealing. Furthermore, in this example, an 18-inch container was used.

The back board 1 has a thickness of 0.2 mm, and its size is as follows.
A metal plate about 2 mm smaller in length and width than the outer circumference of the container was used. Further, as shown in FIG. 3, through holes 5 having a diameter of 2 mm are provided in the rear substrate 1 along the outer periphery of the rear substrate at a pitch of 4 mm so as to overlap the tips of the side walls 3. After going through the above steps, this rear substrate 1 is treated in a high dew point hydrogen furnace to improve adhesion with the low melting solder glass 2, and a Cr oxide film of about 1 micron is formed on the 42-6 alloy surface. _{( Cr2O3} )
was subjected to selective oxidation. Then, the rear substrate 1 made of 42-6 alloy was placed in a sandwich shape between the tip of the side wall 3 of the container made of soft glass and the plate 4 also made of soft glass, with a low melting solder glass interposed therebetween at 450°C. It took some time to seal it. This plate 4 is made of soft glass and has the same width as the side wall 33 and a thickness of 10 mm, and one or more plates form a frame along the outer periphery of the container.

As a result of configuring the container as described above, the adhesive strength between the rear substrate 1 and the tip of the side wall 3 of the container is significantly improved compared to a conventional container that does not have a through hole and is not reinforced with the plate 4. During evacuation, the back substrate 1 no longer peels off from the side wall 3 of the container, and there is no leakage from the container. Also, initially, the thickness of the side wall 3 of the container was 10 mm, but if this method is used, it is possible to obtain the same effect even if the thickness of the side wall 3 of the container is 7 mm. 10% of the weight of
We were able to plan some weight reduction.

Other examples are shown below. Plate 4 in Fig. 2
In the previous example, soft glass was used, but in order to further reduce the weight, 0.2 mm thick 42-6 alloy was used for sealing. In this case, as in the previous example, no separation occurred between the rear substrate 1 and the tip of the side wall 3 of the container during the evacuation. Further, although a single plate was used as the plate 4 in the two embodiments shown, the same effect could be obtained even if the plates were divided into the same shape and sealed. Plate 4 can be made of metal or an insulating material, as mentioned above, as long as the matching of the coefficient of thermal expansion is taken into account. It is also possible to directly adhere the substrate and press a plate onto the back substrate of the adhesive part to form a sandwich-like structure.

Effects of the Invention As described above, the present invention includes sandwiching the rear substrate around the container periphery between plates made of insulators or metal in a sandwich-like manner, sealing the rear substrate via a sealing member, and attaching the rear substrate to the sealing portion of the rear substrate. By providing a plurality of through holes, the adhesive strength and, by extension, the strength of the container are improved. Therefore, it is useful for improving the yield of manufacturing image display devices and improving the quality thereof. Furthermore, by improving the adhesive strength, it has become possible to reduce the inner thickness of the periphery of the container and make it lighter.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a part of the container of a conventional image display device, FIG. 2 is a sectional view showing the main parts of an image device according to an embodiment of the present invention, and FIG. 3 is a back substrate of the device. FIG. DESCRIPTION OF SYMBOLS 1... Rear substrate, 2... Sealing member, 3... Side wall, 4... Plate, 5... Through hole.

Claims (1)

[Claims] 1. An open part of a container made of an insulating material with one end open is sealed with a metal plate, and the metal plate is connected to the tip of the side wall of the container and one or more plates made of an insulating material or metal. An image display device characterized in that the metal plate is sandwiched in a sandwich shape, and has a plurality of through holes in a portion of the metal plate sandwiched between the tip of the side wall of the container and the plate.