JPS5944747A - Heat treatment jig for cathode ray tube - Google Patents

Abstract

PURPOSE:To improve yield rate and upgrade quality after completion by executing heat treatment on panel glass by supporting it with a heat resistant insulator obtained by molding a mixture of mica powder, talc powder, boric acid and zinc oxide under the condition of the high temperature and pressure. CONSTITUTION:A panel glass 1 is fitted to a heat treatment jig 13 composed of a supporting member 14 and a jig 15 under the condition that a shadow mask 3 is secured to the panel pin 2 planted in the glass 1. The member 14 is constituted with a heat resistant insulator obtained by molding a mixture of mica powder, talc powder, boric acid and zinc oxide under the condition of high temperature and pressure. After forming the phosphor surface 4 by the heat treatment using such a jig 13, additional heat treatment is further performed. At this time, use of member 14 can eliminate possibility of generating damage or crack on the seal surface 1a and side surface 1b of the glass 1. Moreover, yield rate of heat treatment can also be improved because dust is little generated and excellent electrical characteristic can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat treatment jig for cathode ray tubes with an improved support member for panel glass.

Generally, in some types of cathode ray tubes, the panel glass on which the fluorescent surface is formed and the funnel glass (not shown) in which the electron gun is housed are processed separately until midway through the process, and then the two are assembled. The cathode ray tube is completed.

Incidentally, the panel glass (1) is usually subjected to two heat treatment steps before being assembled with the funnel glass. In other words, as shown in Figure 1, panel glass (
Insert the shadow mask (
8) is heat-treated at a temperature of 400 to 500°C. Thereafter, as shown in FIG. 2, a fluorescent surface (4) is formed on the inner surface (10) of the panel glass (1).

This state is shown in detail in FIG.
) are fluorescent surface (4a), lacquer (4b) and alv
It is composed of a t film (4o).

Then, in the state shown in Figure 2, heat treatment is performed again at a high temperature of 400 to 500°C.
) with the panel glass (1) attached. That is, in the state shown in Fig. 4, these blocks are placed in a continuous furnace (not shown) whose temperature is controlled to a predetermined high temperature, and after a certain period of time, they are taken out of the continuous furnace and subjected to a heat treatment. This is the end of the process. FIG. 5 shows the panel glass (1) attached to another type of heat treatment jig (9), and the heat treatment work is no different from that described above.

By the way, as can be seen from FIGS. 4 and 5, the panel glass (1) has its sealing surface (1a) and side surface (1b) connected to the support member (1) with respect to the jig body (8), 02), respectively. 7) and +10), (1,1), these supporting members ('y), [tQ
, Qυ characteristics greatly affect the yield of the heat treatment process and the quality of the completed cathode ray tube. That is,
These support members (7), fio).

If (11) is too hard, the sealing surface (1a) and side surface (
1b) may be scratched or cracks may occur, causing glass breakage. On the other hand, if it is too soft, it will cause significant wear and tear.
In addition to shortening the lifespan, the dust can enter the cathode ray tube and cause defective products. Furthermore, if the cathode ray tube is operated at a high voltage 'C, dielectric breakdown may occur if the insulation is impaired, causing the cathode ray tube itself to become defective.

Therefore, various types of supporting members have been studied and put into practical use. For example, asbestos tape, asbestos cement, and boron nitride, etc. Although asbestos tape is suitable for preventing scratches and cracks, it has the problem of easily generating dust. This is a health and safety issue. Although asbestos cement does not easily generate dust,
Because it is too hard, defects such as scratches and cracks are likely to occur.

Boron nitride is good for scratches and cracks, but it is good for sealing surfaces (1a
), it impairs the insulation of the area and is also very expensive, making it difficult to put it into practical use.

As mentioned above, each of the conventional products has its drawbacks, and in reality, there is no material that satisfies all of them, so the reality is that they are used with the knowledge of these drawbacks.

The present invention aims to provide a heat treatment jig that can substantially eliminate the above-mentioned conventional drawbacks.

An embodiment of this invention will be described below.

The heat treatment jig according to the present invention has a feature in the support member. That is, the support member is made of a heat-resistant insulator formed by heating and pressing a mixture of mica powder, talc powder, boric acid, and zinc oxide.

Table 1 shows the characteristics of the support member in comparison with those made of boron nitride.

Table 1 As is clear from the properties in Table 1, the good points of boron nitride are similar to those of this invention, and the bad points have been improved. If the support member having the structure of the present invention is used instead of the support member, heat treatment can be performed without the drawbacks of the conventional method.

Figure 6 is above! V old jJ! A heat treatment jig (13) consisting of a support member 04) and a jig body u5) is
) is shown attached. As is clear from the figure, this support member (7) is the same as the conventional jig (6) in Figure 4.
) can be replaced with the support member (141) having the above configuration, and can be easily applied to another type of support member shown in FIG.

In this way, the jig 0B) having the above structure has excellent machinability of the supporting member 04, so it is different from the conventional jig main body (8).

In addition to being able to utilize the dE of (b), it is also possible to benefit from the excellent characteristics shown in Table 1. In other words, there is no risk of scratches or cracks on the sealing surface (1a) or side surface (1b) of the panel glass (1).
In addition, it generates extremely little dust and has excellent 111° gas insulation properties, which improves the yield of heat treatment operations and makes it possible to manufacture cathode ray tubes of extremely high quality. In addition, since it is inexpensive and has little wear and tear, it eliminates the need for maintenance, and there is no risk of pollution compared to products using asbestos or the like.

As described above, the present invention provides support members for panel glass.
A heat treatment jig that can contribute to the manufacture of highly reliable cathode ray tubes can be provided by drawing with a molded body of a mixture consisting of mica powder, talc powder, boric acid, and zinc oxide.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the panel glass before the formation of the fluorescent surface part;
FIG. 2 is a cross-sectional view showing the panel glass after the fluorescent surface portion has been formed;
Figure 6 is a partially enlarged cross-sectional view of the fluorescent surface section in Figure 2, and Figures 4 and 5 show the panel glass shown in Figures 1 and 2 attached to a different type of conventional heat treatment jig. FIG. 6 is a cross-sectional view showing the panel glass shown in FIGS. 1 and 2 attached to a heat treatment jig according to the present invention. H...Supporting member, 05)...Jig body. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Makoto Kuzuno - 1 person other than C) No. 51 Figure 6 - Li J1 -

Claims (1)

[Claims] (1) In a jig for high-temperature heat treatment of panel glass, the support member that supports the side surface of the panel glass and the surface of the panel glass on the jig body is made of a mixture of mica powder, talc powder, boric acid, and zinc oxide. A heat treatment jig for a cathode ray tube, characterized in that it is made of a heat-resistant insulator formed by heating and pressing.