JP2000130951A - Substrate firing furnace for plasma display panel and furnace member therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress firing temperature fluctuation in a furnace while ensuring cleanliness in the furnace and to enable use of a heating source other than electricity, e.g. gas or liquid fuel, by forming the furnace lining of an Si-SiC based material. SOLUTION: Outer wall of a firing furnace 10, i.e., the furnace body 11, is protected with a panel cover 12 made of a heat resistant steel plate and a lining 14 is arranged on the inside of a heat insulating material layer 13 covering the inside of the furnace body 11. Furthermore, electric heaters 15 are arranged at the upper and bottom parts in the furnace. The lining 14 is made of an Si-SiC based material. A roller 16, a setter 17, a spacer 18 and a beam, or the like, are employed as a furnace member and at least the setter 17 and the beam are preferably made of an Si-SiC based material. A PDP substrate 19 is arranged on the setter 17. Furthermore, the roller 16 and the spacer 18 are preferably made of an Si-SiC based material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a firing furnace for a substrate for a plasma display panel (hereinafter, referred to as a PDP), and more particularly, to a PDP substrate having a reduced degree of cleanliness and temperature variation in the furnace. The present invention relates to a firing furnace and a furnace internal member used for the firing furnace.

[0002]

2. Description of the Related Art In recent years, PDPs have been attracting attention as main products for large-sized flat panel displays, and are being developed by various companies. To manufacture such a PDP, a baking furnace is indispensable, and is used in a glass substrate annealing step, a thick film process by a printing technique of electrodes, barrier ribs, dielectrics, phosphors, and the like.

In the baking step, for example, in a thick film process, it is naturally required to make the baking temperature uniform and clean in a furnace.
In the future, P is required to be larger, finer, and more importantly mass-produced and cheaper. Therefore, in the firing process, the power consumption of the firing furnace is suppressed, the running cost is reduced by gas fuel, and the equipment cost is reduced. Demands are expected to increase. At present, only the combination of crystallized glass having low thermal conductivity and an electric heater is performed in the furnace.

[0004]

Accordingly, the present invention provides
It is made in view of the above-mentioned problem, and the object is to make the firing temperature variation in the furnace small, to secure the cleanness in the furnace, and to be able to use a gas / liquid fuel other than electricity as a heating source. An object of the present invention is to provide a substrate firing furnace for a PDP and a furnace internal member used therefor.

[0005]

That is, according to the present invention, there is provided a plasma display panel substrate firing furnace, characterized in that the furnace lining is made of a Si-SiC-based material. According to the present invention, the furnace lining is made of a Si-SiC-based material, and a gas radiant tube heater or a combination of a gas radiant tube heater and an electric heater is disposed outside the lining for heating. A substrate firing furnace for a plasma display panel is provided. In the present invention, the Si—SiC-based material is formed by melting, infiltrating, and sintering Si into a compact made of a carbonaceous material.
It is preferably made of an i-SiC sintered body. As a specific composition, the Si-SiC-based material contains 0.5 to 50% by weight of Si and 50 to 99.5% by weight of SiC. Is preferred.

Further, according to the present invention, there is provided an in-furnace member for use in a baking furnace for a plasma display panel, wherein the member used in the furnace is made of a Si—SiC-based material. . Also in this furnace member, the Si-SiC-based material melts Si, penetrates, and sinters Si into the compact formed of the carbonaceous material.
-SiC sintered body is preferable, and as a specific composition, the Si-SiC-based material contains 0.5 to 50% by weight of Si and 50 to 99.5% by weight of SiC. preferable. In the present invention, when the firing furnace is a roller hearth type or walking beam type continuous firing furnace,
It is preferable that at least the material of the beam and the setter in the furnace inner member is made of a Si-SiC-based material.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A PDP substrate firing furnace according to the present invention will be described in detail based on an embodiment shown in the drawings.
The present invention is not limited to these embodiments. FIG. 1 is a schematic sectional view showing an embodiment of a substrate firing furnace for PDP according to the present invention. In FIG. 1, reference numeral 10 denotes a roller hearth type PDP firing furnace. The firing furnace 10 includes a furnace body 11 serving as an outer wall and a panel cover 12 made of a heat-resistant steel plate for protecting the furnace body 11. A heat insulating material layer 13 that covers the inside of the furnace body 11 and a lining 14 disposed inside the heat insulating material layer 13, between the heat insulating material layer 13 and the lining 14, An electric heater 15 for heating is arranged at the top and bottom. And as lining 14,
A material composed of a Si-SiC-based material is used. In addition, rollers 16 and setter 1 were used as furnace members.
7, a spacer 18, a beam (not shown), and the like are used. Of these, at least the setter 17 and the beam are preferably made of a Si-SiC-based material. PDP substrate 19 on setter 17
Is placed. The roller 16 and the spacer 1
It is further preferable that 8 and other furnace members are also made of a Si-SiC-based material.

FIG. 4 is a schematic cross-sectional view showing another embodiment of the substrate firing furnace for a PDP according to the present invention, which shows a roller hearth type example in which a gas radiant tube heater is used as a heating source. The difference from the first embodiment is that a gas radiant tube heater 33 is used instead of the electric heater 15. The lining 14 is reinforced and supported from the inside of the furnace by a reinforcing and sealing member 20 to seal the inside of the furnace. Further, in the embodiment of FIG. 4, the roller 30 is used as a member in the furnace.
A PDP substrate 32 is mounted thereon. As described above, when the material of the lining of the firing furnace and the members in the furnace are made of Si-SiC-based material, Si-
Since the SiC-based material has an extremely high thermal conductivity of about 150 W / m · K, the heating efficiency by the heater 15 is excellent, and the lining material serves as a uniform surface heating source. Also, in a firing furnace using a rod-shaped electric heater or the like, the variation in the firing temperature in the furnace can be reduced. In addition, Si
-SiC-based materials have high flexural strength and high Young's modulus, so they hardly deform under load.
Since the porosity of the iC-based material can be controlled to a dense property of about 1% or less, it is excellent in oxidation resistance, and the lining is oxidized and deteriorated to generate fine powder. Cleanness in the furnace can be ensured.

FIGS. 2A and 2B show examples of a lining structure inside the furnace. FIG. 2A shows a ceiling structure, and FIG. 2B shows a wall structure. As shown in FIG. 2A, a heat insulating material layer 13 made of a ceramic fiber board or the like that covers the inside of the furnace body 11, and a lining 14 is disposed inside the heat insulating material layer 13 to form a furnace internal space. Reference numeral 20 denotes a reinforcing and sealing member,
The plate members 14a and 14b having a predetermined size of 4 are reinforced and supported from the inside of the furnace and sealed in the furnace. FIG. 2 (b) shows a wall structure in which each plate
c, 14d are sealed from the inside of the furnace by a plate material 21 of the same material from the heat insulating material layer 13 side. When the lining inside the furnace is configured as shown in FIGS. 2 (a) and 2 (b), foreign matter from the outside to the furnace interior space,
It is possible to prevent dust and the like from being mixed, and to absorb the thermal expansion of the lining 14 itself.

The Si—SiC material used in the present invention is
For example, it can be manufactured as follows. First, a predetermined amount of C powder, SiC powder, a binder, water or an organic solvent is kneaded and molded to obtain a molded body having a desired shape. Then
A method in which the molded body is placed in a reduced pressure inert gas or in a vacuum in a metal Si atmosphere to cause molten metal Si to permeate and impregnate the molded body can be mentioned. Further, as another manufacturing method of the Si-SiC-based material, a graphite sheet or a carbon sheet is placed in a crucible or the like filled with metal Si, heated to melt the metal Si, and utilizes a capillary effect. Reacting carbon and Si constituting the sheet to generate SiC,
There is a method of leaving excess Si. Note that Si
As the SiC-based material, for example, Japanese Patent No. 264257
No. 3 publication can be cited.

[0011] The Si-SiC-based material is a material in which Si is infiltrated and impregnated into pores based on a SiC-based material, and has a composition including Si and SiC. Specifically, 0.5 to 50% by weight of Si,
Those containing 99.5% by weight of SiC are preferred in terms of strength, thermal shock resistance and the like.

[0012]

EXAMPLES Hereinafter, the present invention will be further described with reference to specific examples. (Example 1) α-SiC powder (average particle size 2 μm) 100
10 parts by weight of carbon powder (average particle size 1
μm), 2 parts by weight of a binder and 3 parts by weight of water were added and kneaded.
Pressing was performed at a pressure of f / cm ² to obtain a molded body of 50 × 50 × 5 mm. The obtained molded body is kept at 1800 ° C. for 2 hours while being in contact with metal Si in a vacuum, so that dense Si—Si
A C sintered body was obtained. The characteristics of this Si-SiC sintered body were examined and are shown in Table 1. For comparison, the characteristics of the crystallized glass (trade name: Neoceram NO, manufactured by Nippon Electric Glass Co., Ltd.) are also shown.

[0013]

[Table 1]

Among the characteristics shown in Table 1, the strength is a four-point bending strength, which is measured according to JISR1601. The thermal conductivity was measured based on JISR1611.

Example 2 In the same manner as in Example 1, a roller for a roller hearth type continuous firing furnace [dimensions: outer diameter 38
mmφ × 5mm (thickness) × 2400mm (length)]
It was manufactured using an i-SiC sintered body. Next, as shown in FIG. 3, the roller 30 is moved to a support portion 31 having a width of 2200 mm.
And a PDP substrate 32 on this roller 30
Were stacked in two stages. The PDP substrate 32 is 1500 m
With a surface area of mx 1500 mm, 135 per setter
kg. Roller pitch is 250mm,
It was in a state of receiving one setter by four rollers. In addition, the same material as the roller was used for the setter and the spacer for stacking, and the same Si-SiC sintered body was used.

Under the above conditions, the PDP substrate 32 was subjected to a heat treatment in a roller hearth type continuous firing furnace shown in FIG. In the heat treatment, the temperature is increased at a rate of 5 to 10 ° C./hr,
Hold at a maximum temperature of 600 ° C. for 10 minutes, then 600-3
This was performed by a step of gradually cooling to 50 ° C. at a rate of 5 ° C./hr. As a result, the amount of deflection of the Si—SiC-based roller was 0.08 mm at the maximum at 600 ° C. in the atmosphere. For comparison, a SUS-roller [dimensions: outer diameter 60.
5 mmφ × 3.9 mm (thickness) × 2400 mm (length)], and the heat treatment was performed in the same manner as described above. As a result, the amount of deflection of the SUS-roller was 0.17 mm at maximum.

The PDP substrate 32 was measured for the temperature distribution in the substrate during the holding step at the maximum temperature of 600 ° C. and the annealing step, and was found to be within ± 2 ° C.
Furthermore, Si-S in a class 100 clean booth
In the sample in which the temperature of the iC plate (100 mm × 100 mm × 5 mm (thickness)) was raised to 600 ° C. and then lowered to 22 ° C., there was no change in the numerical value of the generation of foreign particles in the laser type particle counter, and the cleanness was ensured. Do you get it.

(Discussion) From the results of Examples 1 and 2,
By using a Si-SiC-based material for the furnace lining, the thermal conductivity is extremely high at about 150 W / m · K, and the electric heating, radiation, and heating efficiency are excellent, and the variation in the firing temperature in the furnace can be reduced. I knew I could do it. Also,
The inside of the firing furnace was clean and proved to be extremely good for PDP substrates. Further, it has been found that the Si—SiC-based material has a high bending strength and a large Young's modulus, so that there is almost no load deformation.

[0019]

As described above, according to the present invention, in addition to the electric surface heater, a gas radiant tube heater which has a small variation in the firing temperature in the furnace, ensures a clean degree, and has a low fuel consumption is used. PDP that can also be used
Substrate baking furnace and a furnace internal member used therefor can be provided.

[Brief description of the drawings]

1 is a substrate firing furnace for a PDP according to the present invention,
It is a schematic sectional drawing which shows one Example of the baking furnace which used the electric heater as a heating source by the roller hearth type.

FIG. 2 shows an example of a lining structure inside a furnace, and (a)
Is a ceiling structure, and (b) is a wall structure.

FIG. 3 is an explanatory diagram showing dimensions and arrangement of a roller and a PDP substrate in Example 2.

FIG. 4 is a substrate firing furnace for a PDP according to the present invention,
It is a schematic sectional drawing which shows one Example which used the gas radiant tube heater by a roller hearth type as a heating source.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Roller hearth type substrate firing furnace for PDP, 11 ... Furnace body, 12 ... Panel cover, 13 ... Heat insulation material layer, 14 ... Lining, 15 ... Electric heater for heating, 16 ... Roller, 17 ...
Setter, 18 spacer, 19 PDP substrate, 20
... reinforcing and sealing member, 21 ... plate, 30 ... roller, 3
DESCRIPTION OF SYMBOLS 1 ... Support part, 32 ... PDP board, 33 ... Gas radiant tube heater.

Continued on the front page F term (reference) 4K050 AA04 BA17 CB06 CD05 CD14 CG04 CG13 4K051 AA03 AB03 BB06 BE01 5C012 AA09 BD05 5C040 FA01 FA02 JA21 JA40 MA23

Claims (8)

[Claims] 1. A substrate firing furnace for a plasma display panel, wherein a lining of the furnace is made of a Si—SiC-based material. 2. A furnace lining comprising a Si-SiC-based material and a gas radiant tube heater or a combination of a gas radiant tube heater and an electric heater disposed outside the lining for heating. Substrate firing furnace for plasma display panels. 3. The plasma according to claim 1, wherein the Si—SiC-based material is a Si—SiC sintered body obtained by melting, infiltrating, and firing Si in a molded body made of a carbonaceous material. -Substrate firing furnace for display and panel. 4. The plasma display panel substrate according to claim 1, wherein the Si—SiC-based material contains 0.5 to 50% by weight of Si and 50 to 99.5% by weight of SiC. Firing furnace. 5. The substrate display furnace for a plasma display panel according to claim 1, wherein the firing furnace is a continuous heating furnace of a roller hearth type or a walking beam type. 6. The member used in the furnace is Si-Si
An in-furnace member for use in a substrate baking furnace for a plasma display panel, comprising a C-based material. 7. The furnace member according to claim 6, wherein the Si—SiC-based material is a Si—SiC sintered body obtained by melting, infiltrating, and firing Si in a molded body made of a carbonaceous material. . 8. The furnace member according to claim 6, wherein the Si—SiC-based material contains 0.5 to 50% by weight of Si and 50 to 99.5% by weight of SiC.