JP2006016265A - Method for relieving deformation of glass platen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for relieving efficiently and surely the deformation of a glass platen. <P>SOLUTION: This method for relieving the distortion of a glass platen comprises the steps: piling up a plurality of sheets of glass platens; putting the pile between the heat-resistant flat plates which have the larger size and higher flatness than those of the glass platens, with flat plates similar to the above heat-resistant flat plate inserted each at predetermined number of sheets among the above piled plurality of sheets of glass platens; and heating the glass platens while pressing the both of the most outside heat-resistant flat plates; and then cooling gradually. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for removing distortion of a glass surface plate, and more specifically, a glass surface plate used in a heat treatment process when manufacturing a flat display panel such as a plasma display panel (PDP) or a liquid crystal display device (LCD). The present invention relates to a method for removing distortion.

In a line for manufacturing a flat display panel such as a PDP, when an AC type PDP is manufactured, a dielectric layer is formed on a front side substrate and a back side substrate.
Regarding the formation of this dielectric layer, usually, a paste-like dielectric material is applied to a substrate, this substrate is placed on a glass surface plate and carried into a firing furnace, and a paste-like dielectric material is then formed. The dielectric layer is formed by firing the material.

  The glass platen used in the firing process of the dielectric layer is made of heat-resistant glass, but heat distortion occurs while it is used many times.

  However, since there is no means for correcting when the glass surface plate is distorted, it is necessary to discard the surface plate and replace it with a new glass surface plate.

  Various methods are known for flattening the plate glass (see, for example, Patent Document 1 and Patent Document 2), but the glass platen used in the heat treatment process of the flat display panel is one by one. There are different distortions, and the emergence of a method for efficiently and reliably removing such distortions has been desired.

JP-A-8-231233 Japanese Patent Application Laid-Open No. 11-11973

  The present invention has been made in consideration of such circumstances, and provides a method for efficiently and reliably removing the distortion of the glass surface plate.

  The present invention relates to a method for removing distortion of a glass surface plate in which a glass substrate for a flat display panel is placed in a heat treatment process for manufacturing a flat display panel, and a plurality of glass surface plates are stacked, and both sides thereof are made of glass. It is sandwiched between heat-resistant flat plates that are larger than the surface plate and have a high degree of flatness. At that time, a plate similar to the heat-resistant flat plate is placed between the plurality of stacked glass surface plates every predetermined number of glass surface plates. It is a glass surface plate distortion removing method in which the glass surface plate is removed by heating and slowly cooling the glass surface plate while inserting and pressing the outermost heat-resistant flat plates.

  According to the present invention, distortion of a plurality of glass surface plates can be removed by a single process. In addition, since a heat-resistant flat plate with a flatness higher than that of the glass surface plate is inserted between the glass surface plates, even if a plurality of glass surface plates have different strains, all glass The distortion of the platen can be removed evenly.

  In the present invention, a plurality of glass surface plates are stacked, and both sides thereof are sandwiched between heat-resistant flat plates that are larger than the glass surface plate and have high flatness. As a heat-resistant flat plate that is larger than a glass surface plate and has a high flatness, it is desirable to select a material having a low coefficient of thermal expansion. From this viewpoint, for example, a carbon surface plate made of isotropic graphite having a thermal expansion coefficient smaller than that of the glass surface plate can be applied as the heat-resistant flat plate. Specifically, as this heat-resistant flat plate, a carbon plate made of isotropic graphite and having a tolerance of JIS B0405 intermediate and a surface finish of ▽▽ can be applied.

  In the present invention, a flat plate similar to a heat-resistant flat plate is inserted between a plurality of stacked glass surface plates every predetermined number of glass surface plates. As the predetermined number, about 1 to 5 can be applied. The number of glass platen distortion that can be removed best is one sheet, and the number of processing sheets per unit time is the largest of five. Select the appropriate number depending on how much distortion is to be removed. To do. A flat plate similar to the heat-resistant flat plate means a plate having substantially the same material and the same flatness as the heat-resistant flat plate and having a thickness different from that of the heat-resistant flat plate. As this flat plate, a plate having a thickness smaller than that of the heat-resistant flat plate arranged on the outermost side of the glass surface plate is usually used.

  In the present invention, after that, the glass platen is heated and gradually cooled while pressing the outermost heat-resistant flat plates, thereby removing the distortion of the glass platen. Although this pressurization is not particularly limited, it is advantageous in terms of cost to adopt a method in which pressurization is performed by placing a weight on the uppermost heat-resistant flat plate stacked. In this case, the weight may be anything as long as the heat resistance is higher than that of the heat resistant flat plate, and for example, a lump of metal can be applied.

  Although heating of a glass surface plate is not specifically limited, The method of carrying in and heating the heat-resistant flat plate and glass surface plate which were piled up in a heating furnace is applicable. Various conventionally known electric furnaces can be applied as the heating furnace. In the step of heating the glass platen, when a carbon plate or the like is used as a heat-resistant flat plate, it is desirable that the inside of the furnace be an oxygen-free atmosphere, specifically a nitrogen atmosphere or a hydrogen atmosphere.

  The glass platen is preferably heated by heating with a predetermined temperature profile. The heating temperature in this heating step needs to be higher than the temperature at which the distortion of the glass surface plate is guaranteed.

  In this invention, after removing the distortion of a glass surface plate, you may further implement the process of giving the glass surface plate the blast process for finishing surface roughness.

  In addition, before removing the distortion of the glass surface plate, a step of performing a blasting process for preventing the glass surface plate from being damaged when removing the distortion may be further performed.

  Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. In addition, this invention is not limited by this, A various deformation | transformation is possible.

FIG. 1 is an explanatory view showing an embodiment of a method for removing distortion of a glass surface plate of the present invention. In this figure, 1 is a glass surface plate, 2 is a carbon plate, and 3 is a weight.
The glass surface plate 1 is for placing a glass substrate in a heat treatment process when manufacturing a flat display panel. This heat treatment step includes a firing step when a dielectric layer is formed on the front and back glass substrates, a firing step when partition walls are formed on the rear glass substrate, and the like.

  In the present embodiment, 11 carbon plates 2 are stacked, and a glass surface plate 1 is disposed between the carbon plates 2. Therefore, the carbon plate 2 and the glass surface plate 1 are alternately stacked. A weight 3 is disposed on the uppermost carbon plate 2. The number of stacked carbon plates 2 is not limited to this, and may be 11 or less, or 11 or more.

  The carbon plate 2, the glass surface plate 1, and the heavy stone 3 are carried into a heating furnace while being stacked in this state, heated with a predetermined temperature profile, and then gradually cooled to remove the distortion of the glass surface plate 1.

  The glass surface plate 1 of the present embodiment is one in which distortion, warpage, unevenness, and the like are generated by use in the manufacturing process of a flat display panel. The glass surface plate 1 to be applied has a size of 1200 mm × 1600 mm, a thickness of 5 mm, and a surface polishing treatment: Rmax × 3-6 μm. The strain guarantee temperature is 850 ° C. As this glass surface plate, for example, a glass plate made of glass such as Neoceram (registered trademark) N-0 or N-11 manufactured by Nippon Electric Glass Co., Ltd. can be used. In addition, it can replace with a glass surface plate and can also apply a normal plate glass.

  The carbon plate 2 is a heat-resistant surface plate that is larger than the glass surface plate 1 and has a high flatness. The heat resistant temperature is higher than that of the glass surface plate 1 and is 1000 ° C. or higher. As the carbon plate 2, it is important to select a material having a small thermal expansion coefficient. The carbon plate 2 has a size of 1300 mm × 1700 mm, a material of isotropic graphite, a tolerance of JIS B0405 intermediate, and a surface finish of ▽▽. As this carbon plate, for example, a product made by Tokai Carbon Co., Ltd. can be applied.

  The carbon plate 2 having a thickness of about 35 to 45 mm for the bottom plate, a thickness of about 25 to 35 mm for the top plate, and a thickness of about 10 to 25 mm for the middle plate is used.

  The weight 3 is about 300 Kg per 10 glass plates. In this embodiment, it is 300 kg. Any material may be used as long as it has a heat resistance of about 1000 ° C., for example, a lump of metal such as soft iron is used.

FIG. 2 is a graph showing a temperature profile of the heating furnace when the glass surface plate is heated.
When the glass platen 1 is heated, the glass platen 1 is carried into a heating furnace, and the inside of the furnace is made a nitrogen atmosphere in order to prevent the carbon plate from burning. That is, the furnace is heated to a nitrogen atmosphere while introducing nitrogen and purging air. As the heating furnace, an electric furnace called a stand-alone elevator furnace can be applied. Note that the inside of the furnace may be a hydrogen atmosphere. In this case, the furnace is first evacuated and hydrogen is introduced.

  The heating profile was gradually heated from room temperature to 850 ° C., maintained at 850 ° C. for about 8 hours, and then stopped and gradually cooled to 350 ° C. in the furnace. Move to room and further cool until about 20 ° C. The reason why the heating temperature is set to 850 ° C. is that the guaranteed temperature (maximum safe use temperature) of the glass surface plate 1 is about 850 ° C. By heating to a temperature higher than the guaranteed temperature, distortion, warpage, unevenness and the like of the glass surface plate 1 are forcibly removed.

  In this way, multiple carbon plates are stacked, one glass surface plate is sandwiched between the carbon plates, and a heavy stone is placed on the uppermost carbon plate to guarantee warpage (distortion) of the glass surface plate. By heating to a temperature higher than the applied temperature and then gradually cooling it, it becomes possible to uniformly flatten a plurality of glass surface plates having different irregularities in size at a time.

FIG. 3 is an explanatory view showing another embodiment.
In the present embodiment, a plurality of glass surface plates 1 are sandwiched and sandwiched between carbon plates 2. Specifically, four sheets are stacked and sandwiched. A weight 3 is placed on the uppermost carbon plate 2. The weight 3 is set to 450 kg because about 300 kg is used for 10 glass plates.

  Thereby, the reproduction | regeneration processing capability (the number of processed sheets per unit time) of a glass surface plate can be improved. The number of the glass surface plates 1 sandwiched between the carbon plate 2 and the carbon plate 2 is preferably about 5 from the viewpoint of surely removing the distortion of the glass surface plate 1. If it is more than that, the number of processed sheets per unit time is improved, but the probability that the distortion of the glass surface plate 1 cannot be sufficiently removed increases.

FIG. 4 is an explanatory view showing an example in which the distortion of the glass surface plate is actually removed.
In this example, four carbon plates 2 were stacked. A carbon plate having a size of 1300 mm × 1700 mm, material: isotropic graphite, tolerance: JIS B0405 intermediate, and surface finish: ▽▽ was used.

  The carbon plate 2 has a thickness of 40 mm at the bottom, a thickness of 30 mm at the top, and a thickness of 25 mm at the middle.

  Between the carbon plates 2, 20 glass surface plates 1 were sandwiched. Specifically, seven glass platens 1 are sandwiched between the bottom and the second carbon plate 2 from the bottom, and seven glass plates 2 are sandwiched between the second and third carbon plates 2 from the bottom. The glass surface plate 1 was sandwiched, and six glass surface plates 1 were sandwiched between the third and uppermost carbon plates 2 from the bottom.

This glass surface plate 1 has a size of 1200 mm × 1600 mm, a thickness of 5 mm, and a surface polishing treatment: Rmax × 3-6 μm.
As for the weight stone 3, a mass of 350 kg of iron was used.

  The carbon plate and the glass surface plate stacked as described above were carried into a vacuum heating furnace, the inside of the furnace was put into a nitrogen atmosphere, and heated with a temperature profile as shown in FIG. That is, the heating was started at a temperature of 40 ° C. or lower, and the temperature was increased to 850 ° C. over about 5 hours. Then, after holding at a temperature of 850 ° C. for 10 to 11 hours, heating is stopped and the glass is gradually cooled in the furnace. When the temperature reaches 350 ° C., the heat is transferred from the vacuum heating furnace to the cooling chamber, and the temperature is increased in the cooling chamber. For about 3 hours.

  FIG. 6 shows the measurement results of the distortion amount before and after removing the distortion of the glass surface plate. FIG. 6A is before correction (before distortion removal), and FIG. 6B is after correction (after distortion removal). As shown in this measurement result, the distortion is clearly removed after the distortion is corrected.

  FIG. 7 is a graph showing the amount of distortion before and after removing the distortion of the glass surface plate. FIG. 7A is before distortion removal, and FIG. 7B is after distortion removal. In the graph, the difference before and after the removal of distortion is clear.

  Next, the glass surface plate from which the distortion has been removed as described above is subjected to blasting by spraying an abrasive such as glass beads or alumina beads to finish the surface roughness of the glass surface plate.

In this treatment, the following steps are carried out in order to finish the glass surface plate from which distortion has been removed to a predetermined surface roughness (Ry 3 to 6 μm).
[First Step] Zblasting [Second Step] High Pressure Cleaning [Third Step] Ultrasonic Cleaning with Pure Water [Fourth Step] Rinsing with Pure Water [Fifth Step] Air Blow [Sixth Step] Drying (120 ° C. × 1 hour)

  In the above, the glass platen from which distortion has been removed has been subjected to blasting. However, since the glass platen is used in the heat treatment step, foreign matter is often attached to form a protrusion. For this reason, when the glass surface plates are stacked, or when the glass surface plate and the carbon plate are stacked, the glass surface plate is likely to be scratched. Therefore, before removing the distortion of the glass surface plate, foreign matters attached to the glass surface plate may be removed by blasting as described above.

FIG. 8 is an explanatory view showing a processing apparatus for removing the distortion of the glass surface plate.
This processing apparatus includes a glass surface plate carriage set unit 11, a heating furnace 12, a control unit 13, and a glass surface plate transport unit 14. The glass surface plate transport unit 14 includes a glass surface plate receiving unit 15, a carbon plate storage unit 16, a glass surface plate stacking unit 17, and a heavy stone storage unit 16.

  The distorted glass surface plate is transported to the glass surface plate carriage set unit 11 and delivered to the glass surface plate receiving unit 15. Thereafter, the glass platen stacking unit 17 alternately stacks the carbon plates stored in the carbon plate storage unit 16 and the glass platen received by the glass platen receiving unit 15. Then, an appropriate weight of the weight is selected from the plurality of weights stored in the weight storage 18, and the weight is placed on the uppermost carbon plate and is carried into the heating furnace 12 in this state.

  When heating and slow cooling are completed, the glass platen is transferred to the glass platen stacking unit 17 where the heavy stone is removed and stored in the heavy stone storage unit 18, and the carbon plate is removed and stored in the carbon plate storage unit 16. The glass surface plate is sent to the glass surface plate receiving portion 15 and returned to the glass surface plate carriage set portion 11. These controls are performed by the control unit 13.

  In this way, one or more glass surface plates are sandwiched between the stacked carbon plates, and a heavy stone is placed on the uppermost carbon plate and carried into a heating furnace. After heating, it is gradually cooled. By removing the distortion of the glass surface plate, the distortion of the plurality of glass surface plates can be removed by a single treatment. In addition, since the carbon plate is inserted between the glass surface plates, even if the glass surface plates have different distortions, the distortion of all the glass surface plates can be evenly removed. it can.

  The distortion removal of the glass surface plate may be automatically performed by being incorporated in a flat panel production line. Specifically, the glass platen after the baking process is conveyed to the above-described processing apparatus, and distortion removal is automatically processed.

It is explanatory drawing which shows one Embodiment of this invention. It is a graph which shows the temperature profile at the time of heating a glass surface plate. It is explanatory drawing which shows other embodiment. It is explanatory drawing which shows the example which actually removed the distortion of the glass surface plate. It is a graph which shows the heating temperature profile of a glass surface plate. It is explanatory drawing which shows the measurement result of the distortion amount of a glass surface plate. It is the graph which showed the distortion amount of the glass surface plate. It is explanatory drawing which shows the processing apparatus for removing the distortion of a glass surface plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass surface plate 2 Carbon plate 3 Heavy stone 11 Glass surface plate trolley set part 12 Heating furnace 13 Control part 14 Glass surface plate conveyance part 15 Glass surface plate receiving part 16 Carbon plate storage part 17 Glass surface plate stacking part 16 Heavy stone storage part

Claims (7)

A glass surface plate distortion removing method for placing a glass substrate for a flat display panel in a heat treatment step when manufacturing a flat display panel,
Multiple glass surface plates are stacked, and both sides are sandwiched between heat-resistant flat plates that are larger and flatter than the glass surface plate.
At that time, between the plurality of stacked glass surface plates, a flat plate similar to the heat-resistant flat plate is inserted every predetermined number of glass surface plates,
A method for removing distortion of a glass surface plate, in which the glass surface plate is heated and gradually cooled while pressurizing the outermost heat-resistant flat plates to remove the distortion of the glass surface plate. A glass surface plate distortion removing method for placing a glass substrate for a flat display panel in a heat treatment step when manufacturing a flat display panel,
Multiple glass surface plates are stacked, and both sides are sandwiched between heat-resistant flat plates that are larger and flatter than the glass surface plate.
At that time, between the plurality of stacked glass surface plates, a flat plate similar to the heat-resistant flat plate is inserted every predetermined number of glass surface plates,
A method for removing distortion of a glass surface plate, in which the glass surface plate is heated by slowly pressing the outermost heat-resistant flat plates in a nitrogen atmosphere and then gradually cooled.   The step of inserting a flat plate similar to the heat-resistant flat plate every predetermined number of glass surface plates comprises inserting a flat plate similar to the heat-resistant flat plate into each glass surface plate. 2. A method for removing distortion of a glass surface plate according to 2.   3. The method for removing strain from a glass surface plate according to claim 1, wherein the heat-resistant flat plate is a carbon surface plate made of isotropic graphite having a smaller thermal expansion coefficient than that of the glass surface plate.   The distortion removal method for a glass surface plate according to claim 1 or 2, wherein the heating temperature in the heating step of the glass surface plate is higher than a temperature at which the distortion of the glass surface plate is guaranteed.   The method for removing distortion of a glass surface plate according to claim 1 or 2, further comprising a step of blasting the glass surface plate for finishing the surface roughness after removing the distortion of the glass surface plate.   The glass surface plate according to claim 1 or 2, further comprising a step of blasting the glass surface plate to prevent scratches when removing the distortion before removing the distortion of the glass surface plate. How to remove distortion on the board.

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