JP2000106087A - Plasma display panel and its separation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reusable structure and a separation method for a plasma display panel which is used for a computer terminal or a wail-type TV. SOLUTION: A holding part 12 free of thermal contraction under a high temperature atmosphere is provided between a front substrate 1 and back substrate 2. Both substrates 1, 2 are bonded to each other with a bonding material 3 which is softened at a high temperature, leading to run. When the substrates 1, 2 are left at a high temperature, a distance between the substrates 1, 2 is held by the holding part 12, but the height of the bonding material 3 tends to decrease so that a plasma display panel can be separated into the front substrate 1 and the back substrate 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of disassembling a plasma display panel used for a computer terminal or a wall-mounted television, and to a structure and a heating method of the plasma display panel capable of effectively implementing the method. It is.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 9, a plasma display panel has a front panel in which an address electrode 5, a dielectric 6, and a protective layer 7 are provided on a glass front substrate 1, and a rear substrate. 2, an address electrode 5 and a partition 8 are provided, and a red phosphor 9,
It comprises a back panel on which green phosphors 10 and blue phosphors 11 are provided. The two panels are joined by a joining material 3, and this joining material 3 is applied over the entire circumference of both panels. As a result, the inside of the plasma display panel is in a sealed state.

Next, a rare gas such as neon or xenon is sealed between the two panels. When a voltage is applied to the address electrode 5 in this state, a discharge phenomenon occurs. As a result, light in the ultraviolet region is obtained from xenon in the discharge space, so that the red phosphor 8, the green phosphor 9, and the blue phosphor 10 emit light, and an arbitrary image can be obtained.

[0004] However, the processing after manufacturing and using this plasma display panel has not been studied until now, and there is no alternative but to treat it as industrial waste.

[0005]

In the plasma display panel, no measures have been taken from the viewpoint of recycling as a measure against environmental destruction. That is,
There is no method to effectively reuse defects found in the manufacturing process when they are found or when the product life has expired.In addition, since a large amount of lead compounds can be contained in plasma display panels, industrial waste I had to process it.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of separating a plasma display panel and a method of recovering a lead compound generated at the time of the separation, and to improve the structure and temperature uniformity of the plasma display panel for implementing the method effectively. The present invention provides a heating method, which makes it possible to reuse a plasma display panel and increases the efficiency.

[0007]

A feature of the present invention is a temperature at which a bonding material containing lead oxide and silicon oxide as a main component, which is used for bonding a front panel and a rear panel in a plasma display panel, softens. In this method, a component that does not shrink is provided between the panels to separate the substrates. Another feature of the present invention is that, at room temperature, the component has a gap with one of the front panel and the rear panel, but is provided between the substrates so that the thermal expansion occurs due to heating and the component contacts both panels. It is in.

Another feature of the present invention is to provide a groove for connecting the bonding material to the outside on at least one of the opposing surfaces of the front and rear panels. Still another feature of the present invention is that a laminated graphite sheet is provided on the surface or side surface of the plasma display panel during heating.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, a plasma display panel is heated to soften a bonding material provided between a front panel and a rear panel and bonding the two, and the two are separated. Plasma display separation method. The front panel and the rear panel can be separated by softening the bonding material.

According to a second aspect of the present invention, there is provided a plasma display separating method according to the first aspect, wherein a force is applied to at least one of the front panel and the rear panel to peel off both panels, By applying a force to at least one of the front substrate and the rear substrate, the two substrates can be separated in a state where the bonding material used for bonding the two substrates is heated and softened.

According to a third aspect of the present invention, a component which does not thermally shrink under the softening temperature of the bonding material used for bonding the two substrates is provided between the front substrate and the rear substrate. This is a plasma display panel capable of separating the two panels by heating at a softening temperature or higher to make the distance between the substrates constant or increased. Since this material does not shrink thermally, it will maintain its shape or expand thermally when heated. As a result, a force is generated that keeps the distance between the two substrates constant or increases the distance between the substrates.

On the other hand, when the bonding material is softened by heating the plasma display panel, it is difficult to keep the initial shape, and so-called "sagging" occurs. Therefore, since the two substrates are kept at least at the initial distance by the components, the bonding force of the bonding material is reduced and the two substrates can be separated. When a material that expands thermally is used, the two substrates can be separated by a force that increases the distance between panels generated by the thermal expansion.

According to a fourth aspect of the present invention, there is provided a component according to the third aspect, wherein the component has a gap with respect to one of the front and rear substrates at room temperature and comes into contact with both substrates by heating. A plasma display panel.
Thereby, the two panels can be easily aligned at room temperature, and thermal expansion at the time of heating causes a force to increase the distance between the panels, thereby separating the two substrates.

According to an eighth aspect of the present invention, there is provided a plasma display panel in which a groove is provided on at least one of opposing surfaces of a front substrate and a rear substrate from a bonding material of the two substrates in an outward direction, and heating the panel. This is a separation method that sucks or adsorbs the bonding material. Accordingly, the softened bonding material can be suctioned or adsorbed and removed, so that the plasma display panel can be separated into a front panel and a back panel.

The invention according to claim 9 of the present invention is a heating method in which a laminated graphite sheet is provided on a substrate or a side surface, and the substrate surface temperature during heating or cooling is made uniform. Glass is used for the substrate of the plasma display panel, and thermal shock or uneven temperature distribution on the substrate causes cracks and breakage.

Further, a joining material for joining the front panel and the back panel, or a partition provided on the back substrate is also made of glass or ceramic. In the case of heating a panel once completed, further uniformity with respect to temperature is required from the properties of these materials. Laminated graphite sheets exhibit a very rapid thermal diffusion in the direction parallel to the laminating direction, but have the characteristic that thermal diffusion hardly occurs in the vertical direction.
Therefore, by providing the laminated graphite sheet on the substrate, the uniformity of the substrate temperature during heating is maintained, and as a result, the rate of occurrence of cracks and breakage of the substrate or the like can be reduced.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) In a plasma display panel, as shown in FIG. 1, a front substrate 1 and a rear substrate 2 generally have portions that do not completely overlap. This portion is mainly used as an outlet for an address electrode (not shown).

Therefore, when this plasma display panel is set up vertically and viewed from the direction indicated by the arrow in FIG. 1, a side view is shown in FIG. When viewed from this direction,
A gap is formed at the lower end of the front panel.

Therefore, the plasma display panel is set to 45
When heated at a temperature of 0 ° C. or more, preferably 450 ° C. or more and 550 ° C. or less, the bonding material 3 is softened. Therefore, a pressing part 4 is provided on the front panel 1 in FIG. Front panel 1 when force is applied downward
And the rear panel 2 can be separated.

In the present embodiment, the pressing component 4 is provided on the front substrate 1, but the same result can be obtained by providing the pressing component 4 on the rear substrate 2. When the front substrate 1 and the rear substrate 2 are all overlapped, similar results can be obtained by providing components or the like at the lower end of one of the substrates and providing a gap at the lower end of the other substrate.

In the present embodiment, the pressing is performed by the pressing part 4, but the same result can be obtained by a method such as pulling up. Further, in this embodiment, the plasma display panel is set up vertically, but the same result can be obtained by making the plasma display panel horizontal and pushing or pulling at least one side of the front substrate 1 or the rear substrate 2 in the horizontal direction. .

(Embodiment 2) FIG. 3 is a sectional view of a main part of a plasma display panel according to the present invention. The plasma display panel has a structure in which a front panel and a rear panel are joined together by a joining material 3. At this time, the bonding material 3 contains lead oxide and silicon oxide as main components. The configuration of the front panel is such that an address electrode 5, a dielectric 6, and a protective layer 7 are formed on a front substrate 1 made of glass.
Is provided. In the configuration of the rear panel, address electrodes 5 and partition walls 8 are provided on the rear substrate 2. Red phosphors 9, green phosphors 10, and blue phosphors 1 are provided in the partition walls.
1 is provided. The joining with the joining material 3 is performed over the entire circumference of both panels.

As a result, the inside of the plasma display panel is in a sealed state. Further, a holding component 12 is provided between the front substrate 1 and the rear substrate 2. At this time, the holding component 12 is made of stainless steel.
It has a coefficient of thermal expansion of 2 × 10 −5 / K. 450 ° C
As described above, more preferably, it is placed in a high-temperature atmosphere of 450 ° C. or more and 550 ° C. or less. In this atmosphere, the holding component 12 thermally expands and tries to increase the distance between the front substrate 1 and the rear substrate 2.

On the other hand, when the joining material 3 is softened in the high temperature atmosphere and cannot withstand the force of the holding component 12 to spread, the joining material 3 is dissociated. As a result, the plasma display panel can be separated into a front panel including the front substrate 1 and the like and a back panel including the rear substrate 2 and the like, and can be reused.

In this embodiment, the holding component 12 is provided outside the bonding material 3 in FIG. 3, but the same effect can be obtained anywhere between the front substrate 1 and the rear substrate 2. Is obtained. Further, in the present embodiment, stainless steel is used for the holding component 12. However, the bonding material 3 not only softens in a high-temperature atmosphere, but also generates so-called “sag” as shown in FIG. 4, and the height of the bonding material 3 decreases. Therefore, similar results can be obtained even if the holding component 12 is not made of stainless steel but is made of a material having a smaller coefficient of thermal expansion, for example, silicon nitride.

Further, in the present embodiment, the holding component 12 is provided between the front panel and the back panel in advance, but the holding component 12 may be pushed between the two panels immediately before heating to separate the plasma display panel. The effect of is obtained.

(Embodiment 3) FIG. 5 is a sectional view of a main part of a plasma display panel according to the present invention. The plasma display panel has a structure in which a front panel and a rear panel are joined together by a joining material 3. The bonding material at this time is mainly composed of lead oxide and silicon oxide. Further, a holding component 12 is provided between the front substrate 1 and the rear substrate 2. At this time, the holding component 12 is in contact with the rear substrate 2, but has a gap 13 with the front substrate 1.

When the plasma display panel is heated at 450 ° C., which is the softening temperature of the bonding material 3, the gap 13 disappears as a result of the thermal expansion of the holding component 12. When the heating is further continued, a force for pushing and spreading is generated by the holding component 12, and when the force cannot be withstand, the bonding material 3 is dissociated.

As a result, the plasma display panel can be separated into a front panel composed of the front substrate 1 and the like and a rear panel composed of the rear substrate 2 and the like, which can be reused. At this time, the holding component 12 is made of stainless steel. Generally, stainless steel has a thermal expansion coefficient of 1 to 2 × 10 −5 / K.

Also, even if the holding component 12 generates a slight force to push the two substrates apart, so-called "sagging" occurs as shown in FIG. 4 and the height of the bonding material 3 is reduced. Can be separated. In the present embodiment, the holding component 12 is provided between the front panel and the back panel in advance. However, the same effect can be obtained by pushing the holding component 12 between the two panels immediately before heating to separate the plasma display panel. can get.

(Embodiment 4) FIG. 6 shows a main part of a side surface of a plasma display panel. Groove 1 on rear substrate 2
4 is provided, which extends from the bonding material 3 to the outside. The plasma display is heated at 450 ° C. or higher, preferably 450 ° C. or higher and 550 ° C. or lower. Next, the atmosphere is depressurized while maintaining the temperature. At this temperature, the bonding material 3 is softened, and since the outside of the plasma display panel is in a reduced pressure state, the bonding material 3 is removed through the groove 14.

Accordingly, the plasma display panel can be separated into a front panel and a rear panel and can be reused. In this embodiment, the bonding material 3 is suction-removed by depressurizing the outer periphery of the plasma display panel. However, the same effect can be obtained by suction-removing using a nozzle-like object. The same effect can be obtained by inserting a porous material, for example, alumina ceramic, and adsorbing and removing the bonding material 3 using this.

(Embodiment 5) As shown in FIG.
The laminated graphite sheet 16 is provided on the front substrate 1 and the rear substrate 2. As the laminated graphite sheet 16 at this time, as shown in FIG. 8, the graphite sheet 16 is used by vertically laminating the front substrate 1 or the rear substrate (not shown). This laminated graphite sheet 1
6 is 10 to 87 W / m · K with respect to the lamination direction and the vertical direction A.
And relatively high thermal conductivity, but in the
Shows a relatively low thermal conductivity of 0.4 to 1.2 W / m · K.

Accordingly, the temperature within the front substrate 1 and the rear substrate 2 under the laminated graphite sheet 16 shown in FIG. 7 can be kept uniform. As a result, it is possible to prevent the substrate or the like from being cracked or damaged due to uneven temperature or thermal shock generated by heating the plasma display panel.

[0035]

As described above, according to the present invention, although the conventional plasma display panel has not been reused, the panel has the advantageous effect that the panel can be separated and reused. can get. Further, an advantageous effect is obtained that the plasma display panel can be heated without cracking or breakage.

[Brief description of the drawings]

FIG. 1 is a sectional view showing only a main part of a plasma display panel.

FIG. 2 is a side view showing a main part of the plasma display panel and a pressurizing method.

FIG. 3 is a diagram showing a cross section of the plasma display panel of the present invention.

FIG. 4 is a diagram showing a state in which the plasma display panel of the present invention is left in a high-temperature atmosphere.

FIG. 5 is a diagram showing a cross section of the plasma display panel of the present invention.

FIG. 6 is a cross-sectional view showing a state in which a gap is provided between a supporting component and a substrate in the plasma display panel of the present invention.

FIG. 7 is a cross-sectional view showing a state in which a laminated graphite sheet is provided on a plasma display in the plasma display separation method of the present invention.

FIG. 8 is a cross-sectional view showing a graphite sheet laminating direction of the laminated graphite sheet in the plasma display heating method of the present invention.

FIG. 9 is a diagram showing a cross section of a conventional plasma display panel.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 front substrate 2 back substrate 3 bonding material 4 pressurized component 5 address electrode 6 dielectric 7 protective layer 8 partition 9 red phosphor 10 green phosphor 11 blue phosphor 12 holding component 13 void 14 groove 15 laminated graphite sheet 16 graphite sheet

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yoshio Watanabe 3-10-1, Higashi-Mita, Tama-ku, Kawasaki-shi, Kanagawa Prefecture Inside Matsushita Giken Co., Ltd. (72) Tetsuya Kato 3-chome, Higashi-Mita, Tama-ku, Kawasaki-shi, Kanagawa No.10 No.1 Matsushita Giken Co., Ltd. F-term (reference) 5C012 AA09 5C040 FA01 GA01 HA02 JA21 JA25 JA26 KA01 KB11 KB24 LA17 MA26

Claims (9)

[Claims] 1. A plasma display panel is heated,
A plasma display separation method for softening a bonding material provided between a front panel and a rear panel and bonding the two, and separating the two. 2. The plasma display separation method according to claim 1, wherein a force is applied to at least one of the front panel and the rear panel to peel off both panels. 3. A plasma display panel having a part between a front panel and a rear panel which does not thermally shrink at a softening temperature of a bonding material used for bonding the two panels. 4. A plasma display panel provided with a component according to claim 3, which has a gap at room temperature with respect to one of the front panel and the rear panel, and is in contact with both panels by heating. 5. The plasma display separation method according to claim 3, wherein the distance between the substrates is kept constant or increased by heating the plasma display panel at a temperature equal to or higher than the softening temperature of the bonding material. 6. A plasma display panel according to claim 3, wherein the component is a metal. 7. The plasma display panel according to claim 3, wherein the component is a ceramic. 8. A plasma display panel in which a groove is provided on at least one of opposing surfaces of a front panel and a rear panel from a bonding material of both panels in an outward direction, and a separation method of heating the same and sucking or adsorbing the bonding material. 9. A plasma display panel separating method in which a laminated graphite sheet is provided on a substrate or a side surface, and the substrate surface temperature during heating or cooling is made uniform.