JP2003133033A - Heating method and heater device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating method and a heater device capable of quickly equalizing the temperature distribution in a heating region between plural panel- like heaters disposed in parallel with one another in a simple structure at a low cost, and of accurately evenly heating an object. SOLUTION: By this heating device provided with the plural panel-like heaters 3 arranged in parallel with one another with spaces, the heating object 4 disposed so as to face to the heating surfaces 3a of the heaters 3 is heated between the heaters 3 adjacent to one another. A gas at a temperature lower than the set temperature of the heaters 3 is introduced into gas flow spaces 20 formed inside the respective heaters 3, and the gas introduced into the flow spaces 20 is run from the centers of the heating surfaces 3 toward the circumferences thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for heating an object to be heated by a plurality of panel-shaped heaters arranged in parallel at intervals, and can be used for heating a flat panel display substrate.

[0002]

2. Description of the Related Art A heating device provided with a plurality of panel-shaped heaters arranged in parallel at intervals is used to heat an object to be heated which is arranged between the adjacent heaters so as to face a heating surface of the heaters. Has been done conventionally.

[0003]

In the heating region between the panel-shaped heaters adjacent to each other as described above, heat radiation is less in the vicinity of the center of the heating surface of the heater than in the vicinity of the periphery. Therefore, there is a problem that the uniformity of the temperature distribution on each heating surface deteriorates. Therefore, it is conceivable to lower the output of each heater in the vicinity of the center of the heating surface than in the vicinity of the periphery. However, it takes time to adjust the heater output. Further, when the heating temperature is a relatively low temperature of, for example, 250 ° C. or less, it is difficult to sufficiently secure the uniformity of temperature distribution even if the heater output is adjusted. An object of the present invention is to provide a heating method and a heating device that can solve the above problems.

[0004]

According to the method of the present invention, a heating device having a plurality of panel-shaped heaters arranged in parallel at intervals is arranged to face a heating surface of the heater between the heaters adjacent to each other. When heating an object to be heated, the gas flowing space provided inside each heater is introduced with a gas temperature lower than the set temperature of the heater, and the gas introduced into the gas flowing space is
The heating surface is made to flow from the center toward the periphery. According to the method of the present invention, the gas having a temperature lower than the set temperature of the heater is made to flow from the center of the heating surface toward the periphery in the gas flow space provided inside the heater, so that the heating of the heater is performed in the arrangement area of the heating target. Heat dissipation in the vicinity of the center of the surface can be promoted. Thereby, the temperature distribution on the heating surface can be made uniform with high accuracy in a short time, and the heating target can be uniformly heated.

The apparatus of the present invention is a heating apparatus comprising a plurality of panel-shaped heaters arranged in parallel at intervals, and between the heaters adjacent to each other, an object to be heated is arranged so as to face the heating surface of the heater. Then, a gas flow space is provided inside each heater, gas introduction means for introducing gas into the gas flow space is provided, and the gas introduced into the gas flow space is around the center of the heating surface. The gas is introduced near the center of the heating surface so that the gas flows toward. According to the device of the present invention, the method of the present invention can be carried out. Furthermore, by providing a gas flow space in each heater, the weight can be reduced compared to a solid heater.

In the apparatus of the present invention, the gas introduction means has a blowout port for blowing out gas from the vicinity of the center of the heating surface in the gas flow space, and each heater has a discharge port for the gas introduced into the gas flow space. It is preferable that the outlet is provided at a position close to the periphery of the heating surface.
As a result, the method of the present invention can be implemented at low cost without requiring a complicated structure.

In the apparatus of the present invention, each heater is provided with a partition wall that divides the gas flow space into a chamber near the center of the heating surface and a chamber closer to the periphery than the chamber near the center. It is preferable that a gas flow hole connecting the adjacent chambers is provided, and the gas is introduced into the chamber near the center of the heating surface thereof by the gas introducing means. This ensures that the gas can flow from the center of the heating surface toward the periphery.

In the device of the present invention, the gas discharge port has a center of the heating surface rather than a region where the heating target is arranged so that the gas discharged from the discharge port is not directly blown onto the heating target. Preferably, it is provided at a position away from. As a result, it is possible to prevent the temperature fluctuation of the heating target due to the gas.

In the apparatus of the present invention, the heater is arranged inside a furnace body having an inlet / outlet for heating, and means for guiding the gas discharged from the outlet toward the inlet / outlet of the furnace body is provided. Is preferred. This prevents outside air from entering the furnace body through the entrance and exit of the furnace body.
It is possible to suppress the temperature decrease in the furnace body by suppressing it by the gas discharged from the discharge port, prevent the temperature inside the furnace body from becoming non-uniform, and save energy.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A heating device 1 shown in FIGS.
The furnace body 2 and a plurality of panel-shaped heaters 3 arranged inside the furnace body 2 are provided. In order to efficiently use the space, the heaters 3 are arranged in parallel with each other at intervals in the vertical direction with the thickness direction as the vertical direction as shown in FIG. The plate-shaped heating target 4 is arranged between the heaters 3 adjacent to each other with the thickness direction being the vertical direction so as to face the heating surface constituted by the upper surface of the heater 3. The heating surface and the upper and lower surfaces of the heating target 4 are arranged horizontally. In the present embodiment, the heating target 4 is put into and taken out from the entrances that are opened and closed by the opening and closing doors 2a and 2b on both sides of the furnace body 2.

As shown in FIG. 4, each heater 3 has a furnace body 2
Is supported via the bracket 5. Each heater 3 has a heater body 10 and a heater cover 11 that covers the lower portion of the heater body 10. The heater body 10 is configured by sandwiching a heating element 10a that generates heat when energized with aluminum plates 10b and 10c,
The upper surface is the heating surface 3a. The heating target 4 is supported by the support piece 6 protruding from the heating surface 3a. The heater cover 11 is made of stainless steel plate, and the bottom plate 11
a and the peripheral wall 11 extending upward from the outer edge of the bottom plate 11a
b and. The bottom surface of the bottom plate 11a is a reflecting surface 11a 'having a metallic luster and reflects the heat rays emitted from the heating surface 3a. As a result, the heating target 4 is directly radiantly heated from below by the heater 3 and indirectly radiantly heated from above.

A gas flow space 2 surrounded by the heater body 10 and the heater cover 11 inside each heater 3.
0 is provided. As shown in FIG. 5, the gas flow space 20 is divided by a partition wall 21 into a chamber 20a near the center of the heating surface 3a and a chamber 20b closer to the periphery than the chamber 20a near the center. The partition 21
Further, a gas flow hole 21a for connecting the adjacent chambers is provided.

A gas introduction pipe 22 is provided as a gas introduction means for introducing gas into the gas flow space 20 of each heater 3. One end of the gas introduction pipe 22 is connected to a gas supply source (not shown) outside the furnace body 2.
The other end of the gas introduction pipe 22 is branched so as to be inserted into each heater 3, and is arranged in a chamber 20a in the vicinity of the center of the heating surface 3a in each gas flow space 20. Thereby, the other end of the gas introduction pipe 22 is connected to the gas flow space 2
At 0, it is an outlet 22a that blows out gas from the vicinity of the center of the heating surface 3a. The gas blown out from the outlet 22a is introduced into the chamber 20a near the center of the heating surface 3a, and then passes through the gas circulation hole 21a as shown by an arrow in FIG. Flows into the chamber 20b. That is, the gas flow space 20
The gas introduced into the heater flows from the center of the heating surface 3a toward the periphery. In order to preheat the gas introduced into the gas flow space 20, a heater 26 for preheating the gas flowing through the gas introduction pipe 22 is attached to the furnace body 2 as shown in FIG.

In order to discharge the gas introduced into the gas flow space 20, a plurality of discharge ports 23 are provided in the bottom plate 11a of the heater cover 11 of each heater 3. Each outlet 23 is close to the periphery of the heating surface 3a. Each exhaust port 23 is arranged at a position farther from the center of the heating surface 3a than the arrangement region of the heating target 4 so that the gas exhausted from each exhaust port 23 is not directly blown to the heating target 4. . In addition, the number and arrangement of the discharge ports 23 are determined by the gas flow space 20.
There is no particular limitation as long as the gas introduced into the heating surface 3a can flow from the center of the heating surface 3a toward the periphery.

In order to guide the gas discharged from the discharge port 23 to the outside of the furnace body 2, exhaust pipes 27 having a plurality of gas inflow holes 27a on the outer periphery are provided on both sides of each heater 3. . One end of each exhaust pipe 27 is closed and the other ends are connected to each other and open outside the furnace body 2.
The gas inflow hole 27a of each exhaust pipe 27 is formed at a position facing the outlet / inlet of the furnace body 2, whereby the gas discharged from the outlet 23 is guided toward the outlet / inlet of the furnace body 2. Therefore, when the entrance / exit of the furnace body 2 which is closed by the opening / closing doors 2a and 2b is opened, the outside air is prevented from entering the furnace body 2 through the entrance / exit door by the gas, and the temperature inside the furnace body 2 is controlled. The decrease can be reduced.

The type of gas is not particularly limited as long as it does not affect the object 4 to be heated, and for example, nitrogen gas or dry air can be used. The gas flow rate may be appropriately determined according to the scale of the heating device 1 and the set temperature of the heater 3. For example, the size of each heater 3 is 950 mm ×
1140 mm x 38 mm with a parallel pitch of 75 mm-9
When processing 5 heating objects 4 with 0 mm, the gas flow rate is 20 to 100 liters per minute for each heater.
As for the temperature of the gas, for example, the set temperature of the heater 3 is 100 ° C.
If the temperature is set to 180 ° C, the temperature is lowered by about 20 ° C, and if the set temperature of the heater 3 is 180 ° C to 250 ° C, it is preferable that the temperature is lowered by about 30 ° C. No need to preheat.

According to the above embodiment, when the heating target 4 arranged so as to face the heating surface 3a is radiantly heated between the heaters 3 adjacent to each other, the gas flow space 20 is heated to a temperature higher than the set temperature of the heater. A low temperature gas is introduced, and the gas introduced into the gas flow space 20 is heated by the heating surface 3
Flow from the center of a toward the periphery. This can promote heat dissipation in the vicinity of the center of the heating surface 3a in the area where the heating target 4 is arranged. Therefore, the temperature distribution on the heating surface 3a can be made uniform with high accuracy in a short time, and the heating target 4 can be heated uniformly. By providing the gas flow space 20 in each heater 3, the weight can be reduced as compared with a solid heater. Further, since it is only necessary to provide the gas outlet 22a near the center of the heating surface 3a and to provide the gas outlet 23 adjacent to the periphery of the heating surface 3a, it is possible to carry out at low cost without requiring a complicated configuration. You can In the gas flow space 20, the gas is supplied to the chamber 2 near the center of the heating surface 3a.
Since the gas flows from 0a to the chamber 20b adjacent to the periphery through the gas circulation hole 21a, the gas can be reliably flowed from the center of the heating surface 3a toward the periphery. Further, since the gas discharged from the discharge port 23 is not directly blown to the heating target 4, it is possible to prevent the temperature fluctuation of the heating target 4 due to the gas.

[0018]

EXAMPLE FIG. 6 shows changes with time of temperature and temperature deviation of the glass substrate for a flat panel display heated by the heating device 1 of the above embodiment. The dimensions of the glass substrate were 730 mm × 920 mm × 0.7 mm, the set temperature of the heater 3 was 230 ° C., and the gas flow rate was 30 liters per minute. The horizontal axis of the figure shows the heating time, the left vertical axis shows the surface temperature of the glass substrate, and the right vertical axis shows the deviation of the surface temperature of the glass substrate. In the figure, the solid line A shows the time change of the temperature at the maximum surface temperature position of the glass substrate, the solid line B shows the time change of the temperature at the minimum surface temperature position of the glass substrate, and the broken line C shows the deviation from the set temperature of the maximum surface temperature position of the glass substrate. , The broken line D shows the time variation of the deviation of the minimum surface temperature position of the glass substrate from the set temperature,
The broken line E shows the time change of the deviation between the temperature at the highest surface temperature position and the temperature at the lowest surface temperature position of the glass substrate. From this, it was confirmed that according to the heating device 1 of the above-described embodiment, the deviation between the maximum surface temperature and the minimum surface temperature can be set to 5 ° C. or less in about 6 minutes. On the other hand, when the gas is not supplied, the deviation does not become smaller than about 10 ° C. over time, and it takes a very long time to reach the target deviation. In some cases it took. That is, according to the present invention, it was confirmed that the temperature distribution in the heating region can be made uniform in a short time and the object to be heated can be uniformly heated with high accuracy.

[0019]

According to the present invention, the temperature distribution in the heating region between a plurality of panel-shaped heaters arranged in parallel is
Low cost and simple structure enables uniformization in a short time,
It is possible to provide a heating method and a heating device capable of uniformly heating an object to be heated with high accuracy, reducing the weight of each heater, and saving energy.

[Brief description of drawings]

FIG. 1 is a side view of a heating device according to an embodiment of the present invention.

FIG. 2 is a plan view of the heating device according to the embodiment of the present invention.

FIG. 3 is a perspective view showing a parallel state of panel heaters in the heating device according to the embodiment of the present invention.

FIG. 4 is a side sectional view of a main part of the heating device according to the embodiment of the present invention.

FIG. 5 is a plan sectional view of a main part of the heating device according to the embodiment of the present invention.

FIG. 6 is a diagram showing the temperature of the substrate heated by the heating device of the present invention and the time variation of the temperature deviation.

[Explanation of symbols]

1 heating device 2 furnace body 3 panel heater 3a Heating surface 4 heating target 20 gas flow space 20a Room near the center of the heating surface 20b Room closer to the periphery than room near the center of the heating surface 21 partition 21a Gas flow hole 22 Gas introduction piping 22a outlet 23 outlet

Claims (6)

[Claims] 1. A heating device provided with a plurality of panel-shaped heaters arranged in parallel with each other at intervals to heat an object to be heated arranged between the heaters adjacent to each other so as to face a heating surface of the heater. On the occasion,
A gas having a temperature lower than the set temperature of the heater is introduced into the gas flow space provided inside each heater, and the gas introduced into the gas flow space is caused to flow from the center of the heating surface toward the periphery. And heating method. 2. A heating device comprising a plurality of panel-shaped heaters arranged in parallel at intervals, wherein heating objects are arranged between the heaters adjacent to each other so as to face a heating surface of the heaters. A gas flow space is provided inside each heater, and gas introduction means for introducing gas into the gas flow space is provided, and the gas introduced into the gas flow space flows from the center of the heating surface toward the periphery. So that the gas is introduced near the center of the heating surface. 3. The gas introducing means has an outlet for ejecting gas from the vicinity of the center of the heating surface in the gas flow space, and each heater has an outlet for the gas introduced into the gas flow space. The heating device according to claim 2, wherein the heating device is provided in a position close to the periphery of the heating surface. 4. Each of the heaters is provided with a partition wall that divides the gas flow space into a chamber near the center of the heating surface and a chamber closer to the periphery than the chamber near the center.
The heating device according to claim 3, wherein a gas flow hole that connects the chambers adjacent to each other is provided, and the gas is introduced into the chamber near the center of the heating surface by the gas introducing unit. 5. The gas discharge port is located farther from the center of the heating surface than the heating target arrangement region so that the gas discharged from the discharge port is not directly sprayed onto the heating target. The heating device according to claim 3, which is provided at a position. 6. The heater is arranged inside a furnace body having an inlet / outlet port to be heated, and means for guiding the gas discharged from the exhaust port to the inlet / outlet port of the furnace body is provided. The heating device according to claim 5.