JP3353315B2 - Frit sealing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frit sealing method, and more particularly to a frit sealing method which is one of the steps for manufacturing a cathode ray tube (CRT).

[0002]

2. Description of the Related Art When a panel constituting a cathode ray tube (CRT) and a funnel are welded and sealed (frit sealing method) in a furnace using frit glass, an acrylic resin applied to a phosphor screen of the panel in a previous step. Is decomposed by heat and released as a gas to the outside of the CRT. If oxygen is insufficient during the intermediate film decomposition step, incomplete combustion occurs, and as a result, hydrocarbon gas (such as CH ₄ ) is generated,
As a result, there arises a problem that the adhesive strength is weakened such as floating of aluminum or blackening of frit. In order to avoid oxygen shortage, in the conventional frit sealing method, air at room temperature was always supplied into the cathode ray tube only in the furnace from the jet nozzle.

[0003]

However, in this conventional frit sealing method, since the air at room temperature is supplied, due to the temperature difference between the inside and outside of the glass (panel and funnel), the applied air and the phosphor are coated on the fluorescent screen. It takes time to react with the interlayer, and the interlayer decomposition area (260-380 ° C)
In this example, as shown in FIG. 3, air was supplied at a reduced rate of temperature increase inside the furnace (with a gentle temperature rise curve). As a result, it takes a long time to decompose the intermediate film, and as a whole, the productivity of the frit sealing process is reduced.

[0004] Further, in the course of the temperature reduction of the heat treatment curve shown in FIG. 3, dust in the furnace adheres to the inside of the CRT, thereby causing a withstand voltage failure of the CRT.

The present invention provides a frit seal method capable of guaranteeing good frit seal welding and withstand voltage of a CRT without lowering a heating rate in a decomposition region of an intermediate film applied to a phosphor screen of a CRT panel. The purpose is to provide.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a heat treatment curve having a predetermined temperature increasing process and a predetermined temperature decreasing process.
In a temperature-controlled furnace, the panels and tubes that make up the cathode ray tube
And heat bonding using frit glass.
The heat sealing process, wherein
In the decomposition area, high-temperature air is directly injected into the cathode ray tube.
Directly supplied to maintain a predetermined temperature rise rate and promote interlayer film decomposition
And a plurality of times during the cooling process.
High-temperature air is directly supplied into the cathode ray tube to prevent dust
The problem is solved by a frit sealing method characterized by preventing inflow into a pole tube .

[0007]

According to the present invention, high-temperature air is supplied from outside the furnace in FIG.
In order to supply directly into the cathode ray tube (CRT) 1 shown in FIG. 2, in the intermediate film decomposition region (260 to 380 ° C.) in the process of increasing the temperature of the heat treatment curve, as shown in FIG. In the held state, decomposition of the intermediate film applied to the phosphor screen can be completed without falling short of oxygen. Subsequently, by raising the temperature in the furnace to 440 ° C., frit sealing between the panel and the funnel is completed.

In addition, in the temperature lowering process of lowering the temperature inside the furnace, dust is discharged from the inside of the CRT by replacing it with clean air by supplying air from outside the furnace several times in the same manner, and the dust flows into the CRT. Can be avoided.

As a result, the reaction rate is increased as compared with the conventional one by the amount of maintaining the initial temperature rising rate in the intermediate film decomposition region, which contributes to an improvement in productivity.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic perspective view for explaining an embodiment of the present invention. As shown in FIG. 1, a cathode ray tube (CRT) 1 is provided in a furnace as a work (workpiece) to be frit sealed. The CRT 1 includes a panel 2 and a funnel 3, and frit seals between the panel 2 and the funnel 3 with a frit interposed therebetween. 4 is a frit seal part. An air nozzle 6 is fitted into the neck tube of the funnel 3 of the CRT 1, and a high-temperature, high-pressure gas supplied from a high-temperature gas follow-up supply device 20 outside the furnace is fed through a supply tube 7a. The supply pipe 7a is placed on a mesh table 8 and set on a transport base 9 movable in the direction of arrow A. The supply pipe 7 b of the hot gas follow-up supply device 20 is provided on the furnace wall 10
A window 13 is provided so as to follow.

The high-temperature gas follow-up supply device 20 is provided with a high-pressure air supply tube 15 and a hot air generator 16, and supplies high-temperature high-pressure air.

The frit sealing step of this embodiment was performed according to the heat pattern (heat treatment curve) shown in FIG. That is, the CRT is heated at a heating rate of 8 ° C./min in the same manner as before until 260 ° C. at which the decomposition of the interlayer on the phosphor screen starts. Is supplied into the CRT 1 and the supply of air is stopped when the temperature in the furnace reaches the intermediate film decomposition end temperature of 380 ° C.
At this time, the heating rate is kept at the initial 8 ° C./min.
When the temperature reaches 440 ° C. after passing 0 ° C., the frit is melted, and the frit seal between the panel 2 and the funnel 3 is completed. In the above-mentioned interlayer decomposition region (260 ° C. to 380 ° C.), the time was reduced by about 25 minutes as compared with the conventional method.

In the cooling process at the same cooling rate of 3 ° C./min as in the conventional case, the same high-temperature and high-pressure air as in the heating process is supplied into the CRT 1 five times as shown in the heat pattern. With this air supply, dust CRT1
It was possible to prevent the inflow into the inside. Note that the number of times of air supply during this temperature lowering process may be reduced as long as the amount of supply at one time is large.

The above 25 minutes, which is shorter than the conventional method, corresponded to about 15% of the time required for the entire heat treatment step.

[0016]

As described above, according to the present invention,
It is possible to improve the productivity of the frit sealing process, and furthermore, to have good frit welding, good fluorescent screen and cathode ray tube (CR)
T) It contributes to the improvement of the yield by guaranteeing the withstand voltage.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of an apparatus for explaining an embodiment of the present invention.

FIG. 2 is a diagram showing a frit seal heat pattern (heat treatment curve) according to an example of the present invention.

FIG. 3 is a diagram showing a frit seal heat pattern according to a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cathode ray tube (CRT) 2 Panel 3 Funnel 4 Frit seal part 6 Air nozzle 7a, 7b Supply pipe 8 Mesh table 9 Transfer stand 10 Furnace wall 13 Window 15 High-pressure air supply tube 16 Hot air generator 20 High-temperature gas follow-up supply device

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-1-236543 (JP, A) JP-A-54-69376 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 9/26

Claims (1)

(57) [Claims] 1. Heat having a predetermined temperature rising step and a predetermined temperature falling step
Configure a cathode ray tube in a furnace whose temperature is controlled by a processing curve
The panel and funnel are heated and connected using frit glass.
In the frit sealing method, in the intermediate film decomposition region in the temperature increasing process, the shadow is formed.
Predetermined temperature rise by supplying high-temperature air directly into the pole tube
While maintaining the rate and promoting the decomposition of the interlayer , and in the process of lowering the temperature, the inside of the cathode ray tube is repeated several times.
Hot air is supplied directly to the
A frit sealing method characterized by preventing entry .