JP2002220245A - Shelfing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shelfing method by which heating velocity of a substrate placed on a second setter has approximately the same as that of a substrate placed on a first setter when the two setters coated with a film forming material such as a glass substrate for use in a plasma display panel are stacked and burned. SOLUTION: This method comprises a process wherein the two setters 3, 5 which place substrates 1a, 1b, respectively, coated with the film forming material are stacked through a spacer 9a and a process wherein a plate shaped upper lid 7 covers the second setter 5 through a spacer 9b. The upper lid 7 is made of a light transmissive material and the setters 3, 5 are made of a highly thermal conductive material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of assembling shelves when a substrate coated with a film forming material such as a glass substrate for a plasma display panel is stacked in two stages and fired.

[0002]

2. Description of the Related Art In recent years, large-screen flat panel displays (hereinafter, referred to as “FPDs”) that can be used as wall-mounted televisions and multimedia displays have been steadily put into practical use. Such a large-screen FPD is a self-luminous type having a wide viewing angle and good quality display, and has a quality advantage and a manufacturing process that is simple and easy to increase in size. A display panel (hereinafter, referred to as “PDP”) is listed as a leading candidate.

As shown in FIG. 4, for example, as shown in FIG. 4, a PDP is manufactured by using a thick film method in which printing, drying, and firing steps are repeated a plurality of times on the surface of a large glass substrate called a front glass or a back glass. This is performed by sequentially forming various members such as phosphors and finally sealing the front glass and the rear glass.

[0004] The baking of a substrate coated with a film forming material such as the glass substrate for PDP is performed by placing the substrate on a setter made of a material having high thermal conductivity.
In order to improve productivity, baking is being performed in a state in which setters on which substrates are placed are stacked in two stages.

FIG. 2 shows a conventional two-stage stacking firing state. In this case, as a shelf assembling method, first, a spacer 9a is interposed on a first-stage setter 23 on which a substrate 1a is placed. Second stage setter 25 on which the substrate 1b is placed
In order to prevent contamination of the substrate due to bolstering, a plate-like upper lid 27 is put on the second-stage setter via a spacer 9b. Each of the setters 23 and 25 and the upper lid 27 is made of Si-impregnated SiC.
A material made of a light-impermeable high heat conductive material such as described above has been used.

[0006]

In the two-stage firing, the substrates 1a and 1b stacked as described above are transported to the heating chamber by the transporting means 15 such as a roller, and the upper and lower portions of the heating chamber are transported. Heating means 11 such as an electric heater provided
This is performed by heating at a and 11b.

However, when the two-stage firing is performed by the above-described shelf assembly method, the substrate 1a placed on the first-stage setter 23 is mainly heated by the lower heating means 11b. While heat is directly conducted from the second-stage setter 23, the substrate 1 placed on the second-stage setter 25
b is heated mainly by radiation from the upper lid 27 heated by the upper heating means 11a, so that the heating speed is lower than that of the substrate 1a mounted on the first stage setter 23, and the temperature distribution in the substrate is lower. There is also a problem that it is easy to occur.

The present invention has been made in view of such a conventional situation, and an object thereof is to provide a PD
When a substrate coated with a film forming material such as a glass substrate for P is fired in a two-stage stack, the heating rate of the substrate placed on the second-stage setter is the substrate placed on the first-stage setter. It is an object of the present invention to provide a method of assembling the shelves so as to be substantially equal to the heating speed of the shelves.

[0009]

According to the present invention, a setter on which a substrate on which a film-forming material is applied is placed in two stages via a spacer, and further, is set on the second-stage setter via a spacer. A shelf assembly method for covering the upper lid with a plate-like upper lid, wherein the upper lid is made of a light-transmitting material, and the setter is made of a high heat conductive material. Provided.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory diagram showing a state of two-stage firing using the shelf assembly method of the present invention. The basic structure of the shelf assembly is as follows: first, a spacer 9a is placed on a first-stage setter 3 on which a substrate (hereinafter simply referred to as “substrate”) 1a on which a film forming material is applied is placed. The second-stage setter 5 on which the substrate 1b is mounted is also stacked, and a plate-shaped upper lid 7 is further placed on the second-stage setter 5 via a spacer 9b. Is made of a light transmissive material.

As described above, when the upper lid 7 made of a light-transmitting material is used, a heating unit such as an electric heater provided at an upper portion of a heating chamber is used as compared with a case where an upper lid made of a light-impermeable material is used. The heat generated from 11a is easily transmitted directly to the substrate 1b placed on the second-stage setter 5, and as a result, the difference in heating speed between the substrate 1a placed on the first-stage setter 3 and the substrate 1b is reduced. Note that the first-stage and second-stage setters 3, 5 that are in direct contact with the substrates 1a, 1b, respectively, are made of a material having a high thermal conductivity that can efficiently transmit the heat received from the heating means to the substrates.

In the present invention, crystallized glass is preferable as the light-transmitting material forming the upper lid 7. Further, as the high thermal conductive material constituting the first-stage and second-stage setters 3, 5, Si-impregnated SiC is preferable. Here, Si-impregnated SiC is a general term for a sintered body containing metal Si and SiC as constituent components. In the present invention, SiC powder, black smoke powder, organic binder and organic binder already disclosed by the present applicant have been disclosed. , A molding raw material containing water or an organic solvent, and molding the molded body in a metal Si atmosphere and a reduced pressure inert gas atmosphere or vacuum at 1350 to 2500 ° C.
It is preferable to use a Si-SiC sintered body (JP-A-5-270917) manufactured by a method of firing in the above. Such a setter made of Si-impregnated SiC is:
It has high strength and high thermal conductivity.

In the present invention, the length of at least one of the width direction and the longitudinal direction of the second stage setter is set to 1
It is preferable to make it longer than the setter and upper lid of the step. Usually, the cooling in the temperature lowering (gradual cooling) step of the substrate is performed by blowing air from inlet holes provided in the upper and lower portions of the heating chamber, but the temperature of one of the substrates stacked in two stages decreases. In such a case, it is necessary to selectively cool the substrate whose temperature is unlikely to decrease. However, in the conventional shelving method,
Air could not be concentrated on one of the substrates stacked in two stages, and it was difficult to control the temperature of the substrate in the temperature lowering step.

On the other hand, as shown in FIG. 1, the length of at least one of the width direction and the longitudinal direction of the second-stage setter 5 is
If it is made longer than the first-stage setter 3 and the upper lid 7, the air blown in the direction of the arrow from the upper introduction hole 13 a by the protruding portion of the second-stage setter 5 is transferred to the second-stage setter 5. The substrate 1a placed on the first stage setter 3 while intensively hitting the placed substrate 1b
Is prevented. Similarly, the lower introduction hole 13b
While the air blown from intensively strikes the substrate 1a placed on the first-stage setter 3, it is prevented from hitting the substrate 1b placed on the second-stage setter 5. As described above, the two substrates are respectively provided with the upper introduction holes 11a.
Alternatively, since cooling can be performed independently by blowing air from the lower introduction hole 11b, it is also possible to selectively cool only one of the substrates.

[0015]

EXAMPLES Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

(Embodiment) A setter made of Si-impregnated SiC on which a 60-inch glass substrate for PDP is placed,
The sheets were stacked in two stages via a spacer, and the upper set made of crystallized glass was put on the setter of the second stage via a spacer to form a shelf. The PDP glass substrates assembled as described above were transported and fired in a continuous furnace in which heating chambers having electric heaters at the top and bottom as heating means were continuously formed. Each heating chamber has a predetermined heat curve (maximum firing temperature: 580) while the glass substrate for PDP on the setter is transported from the inlet to the outlet of the furnace.
(° C.). On the surface of each PDP glass substrate placed on the first-stage and second-stage setters, thermocouples were installed at nine locations as shown in FIG. 3 as shown in FIG. 70 minutes later,
After 75 minutes, the temperature distribution in the substrate was examined. Table 1 shows the results.
Shown in

(Comparative Example) A PDP glass substrate was fired, and the temperature distribution in the substrate was examined in the same manner as in the above-described embodiment except that an upper lid made of Si-impregnated SiC was used. Table 2 shows the results.

[0018]

[Table 1]

[0019]

[Table 2]

From the results shown in Tables 1 and 2, the embodiment in which shelves are assembled using the crystallized glass upper lid, which is a light-transmitting material, shows that Si-impregnated SiC, which is a light-impermeable material, is used.
The heating speed of the substrate placed on the second-stage setter is faster than that of the comparative example in which shelves are assembled using the upper lid made of It was confirmed that heating had progressed.

[0021]

As described above, according to the present invention, when a substrate coated with a film forming material such as a glass substrate for a PDP is fired in a two-stage stack, the substrate is placed on the second-stage setter. The heating rate of the substrate thus set can be made substantially equal to the heating rate of the substrate placed on the first stage setter.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a state of two-stage stacking firing using the shelf assembly method of the present invention.

FIG. 2 is an explanatory view showing a state of two-stage firing using a conventional shelf assembly method.

FIG. 3 is an explanatory diagram showing a thermocouple installation position of a PDP glass substrate used in an example.

FIG. 4 is a process chart showing a PDP manufacturing process.

[Description of Signs] 1a: substrate, 1b: substrate, 3: first-stage setter, 5 ...
Second-stage setter, 7 ... top lid, 9a ... spacer, 9b
... spacer, 11a ... heating means, 11b ... heating means,
13a: introduction hole, 13b: introduction hole, 15: conveying means, 2
3 ... first setter, 25 ... second setter, 27
… Top lid.

Claims (3)

[Claims] 1. A shelf assembly method in which a setter on which a substrate on which a film forming material is applied is placed in two stages via a spacer, and a plate-like upper lid is further placed on the second stage setter via a spacer. And the upper lid is made of a light transmissive material,
A shelf assembly method, wherein the setter is made of a material having high thermal conductivity. 2. The shelving method according to claim 1, wherein the light-transmitting material is crystallized glass, and the highly heat-conductive material is Si-impregnated SiC. 3. The shelf assembly method according to claim 1, wherein the length of at least one of the width direction and the longitudinal direction of the second setter is longer than that of the first setter and the upper lid.