JP2009037914A - Burning chamber, and sealing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for burning sealing material in a vacuum atmosphere. <P>SOLUTION: A first and a second panels are disposed in a vacuum tank 31 with a ring of sealing material (a subject item to be sealed 60) held between them. The subject item to be sealed 60 is heated while the inside of the vacuum tank 31 is evacuated by an evacuation system 50 for burning the sealing material, where oxygen gas and diluent gas are introduced into the vacuum tank 31 from a gas introducing system 40. During the burning, total pressure inside the vacuum tank 31 is measured by a pressure measuring device 39. Oxygen gas pressure is determined by a control device based on above result and measurements of gas flow meters 45 and 55. Oxygen gas flow and diluent gas flow are controlled by gas flow controllers 42 and 52 in such a way as not to be lower than the lower limit pressure while keeping the inside of the vacuum tank 31 at lower pressure than 1 barometric pressure. Organic binder in the sealing material is burnt by oxygen, and the sealing material is discharged as carbon dioxide or water. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for sealing a glass panel, and more particularly to a technique for firing a sealing material.

In a display device such as a plasma display or a field emission display, a sealing material made of paste-like glass powder (frit) is arranged in a ring shape near the outer periphery between a glass substrate on the front side and a glass substrate on the rear side. After firing with the sealing material placed on top and removing the organic binder, the front panel is placed on the fired sealing material and sealed by heating. Combined.
The space between the glass substrates is hermetically sealed with a sealing material, and the plasma of the discharge gas introduced into the interior emits light for display.

Conventionally, firing of the sealing material has been performed in the air, but there is a demand for firing in a vacuum atmosphere in order to remove the gas generated during firing.
However, if the sealing material is solidified by firing in a vacuum atmosphere, the organic components in the sealing material are not sufficiently removed. As a result, organic gas is generated during the sealing process after firing, and the front panel There is a problem that the rear panel is contaminated and the adhesive strength of the sealing material after sealing becomes insufficient.
JP 2005-142139 A JP 2001-319572 A JP 2007-128824 A

  An object of the present invention is to provide a technique capable of firing a sealing material in a vacuum atmosphere.

  The inventors of the present invention do not sufficiently remove the organic component when the sealing material is baked in a vacuum atmosphere because the organic binder cannot bind to oxygen due to insufficient oxygen in the vacuum atmosphere. I guessed there was.

  That is, carbon and hydrogen, which are the main constituent elements of the organic binder, react with oxygen and are released into the atmosphere as carbon dioxide and water, so the organic binder is removed if firing in the air. On the other hand, oxygen is insufficient in a vacuum atmosphere, and carbon and its compounds in the organic binder are hardly released as gases. Therefore, when oxygen was introduced into the firing atmosphere, it was confirmed that the sealing material was easily solidified and the adhesive strength was increased.

The present invention was created based on the above knowledge, and connects a vacuum chamber, an evacuation system that evacuates the vacuum chamber, the vacuum chamber and a gas source, and receives an input control signal. A gas introduction system for introducing oxygen gas and dilution gas into the vacuum chamber at respective flow rates, and the control signal is output to the gas introduction system to control the flow rate of the oxygen gas and the flow rate of the dilution gas. A sealing device having a control device and a heating device for heating an object to be sealed, wherein the vacuum chamber measures the pressure of the vacuum chamber and outputs a measurement result to the control device. The flow rate ratio between the flow rate of the oxygen gas and the flow rate of the dilution gas and the minimum oxygen pressure are stored in the control device, the control device controls the gas introduction system, and the oxygen gas and The dilution gas in the vacuum chamber at the flow rate ratio In addition, the oxygen pressure in the vacuum chamber is calculated from the measurement result of the pressure measuring device, and when the calculation result falls below the minimum oxygen pressure, the gas introduction system is controlled to increase the oxygen flow rate. It is a firing chamber.
Further, according to the present invention, when the measurement result of the pressure measuring device indicates 1 atm or more, the control device controls the gas introduction system, reduces the dilution gas flow rate, and reduces the pressure in the vacuum chamber. It is a firing chamber.
Further, the present invention provides a sealing chamber between the processing chamber and the baking chamber while a processing chamber to which a vacuum exhaust device is connected is connected to the baking chamber and the sealing target is left in a vacuum atmosphere. This is a sealing device configured to be able to move an object.

  The oxygen gas pressure can be controlled within a certain range while maintaining the optimum pressure ratio between the oxygen gas and the dilution gas for firing the sealing material, so that the sealing material can be solidified reliably.

Reference numeral 1 in FIG. 1 indicates a sealing device of the present invention.
The sealing device 1 includes a carry-in chamber 11, a deaeration chamber 20, a baking chamber 30, a sealing chamber 15, and a carry-out chamber 19. The carry-in chamber 11, the deaeration chamber 20, the baking chamber 30, the sealing chamber 15, and the carry-out chamber 19 are connected in this order via the gate valve 13.

  Each chamber 11, 20, 30, 15, 19 is connected to an evacuation system, and with the gate valve 13 closed, the inside of the deaeration chamber 20 and the firing chamber 30 is set in a vacuum atmosphere in advance. The object to be sealed is carried into the carry-in chamber 11, the inside of the carry-in chamber 11 is evacuated, the inside of the carry-in chamber 11 and the inside of the deaeration chamber 20 is connected, and the object to be sealed is carried into the deaeration chamber 20. Then, the gate valve 13 between the deaeration chamber 20 and the carry-in chamber 11 is closed, and the inside of the deaeration chamber 20 is separated from the inside of the carry-in chamber 11.

  2A is a plan view of the sealing object 60, and FIG. 2B is a cross-sectional view taken along line AA. The sealing object 60 includes first and second panels 61 and 62 and a ring-shaped sealing material 65.

The first and second panels 61 and 62 are parts of a display device in which a transparent conductive film, a thin film transistor, and the like are formed on a glass substrate, and the first and second panels 61 and 62 are aligned. Thus, the sealing material 65 is overlapped with the sealing material 65 interposed therebetween. The sealing material 65 is in contact with the surfaces near the outer periphery of the first and second panels 61 and 62. The sealing material 65 is a paste in which powder glass is dispersed in an organic binder.
A heating device is provided in the deaeration chamber 20, and the sealing object 60 is heated by operating the heating device while evacuating the inside of the deaeration chamber 20.

Thereby, the sealing material 65 is heated, heated up, the solvent contained in the sealing material 65 is evaporated, and the sealing material 65 is in contact with the first and second panels 61 and 62. Degassed.
This process is called a deaeration process, which is heated for a predetermined time, and when the solvent is evaporated and the deaeration process is completed, the heating is stopped.

  When the deaeration chamber 20 is lowered to a predetermined pressure, the gate valve 13 between the deaeration chamber 20 and the baking chamber 30 is opened, the deaeration chamber 20 and the baking chamber 30 are connected, and the sealing object 60 is fired from the deaeration chamber 20. Move to chamber 30. The firing chamber 30 is previously in a vacuum atmosphere, and the sealing object 60 is moved from the deaeration chamber 20 to the firing chamber 30 while being placed in the vacuum atmosphere.

FIG. 3 is a view for explaining the inside of the baking chamber 30.
The firing chamber 30 has a vacuum chamber 31, and a resistance heating element 33 is disposed inside the vacuum chamber 31.
A vacuum exhaust system 50 and a gas introduction system 40 are connected to the vacuum chamber 31.
The gas introduction system 40 includes an oxygen gas source 41 such as an oxygen cylinder and a dilution gas source 51 such as a nitrogen gas cylinder.

The oxygen gas source 41 is connected to the vacuum chamber 31 via an oxygen gas flow rate controller 42, an oxygen gas flow meter 45, and an oxygen gas opening / closing valve 46, and the dilution gas source 51 is a dilution gas flow rate controller 52. Are connected to the vacuum chamber 31 via a dilution gas flow meter 55 and a dilution gas opening / closing valve 56.
The oxygen gas source 41 and the dilution gas source 51 are filled with an oxygen gas and a dilution gas (inert gas such as nitrogen gas or argon gas) at a pressure higher than one atmospheric pressure.

  The oxygen gas flow rate controller 42 and the dilution gas flow rate controller 52 are connected to the control device 35. The control device 35 is configured to calculate an oxygen gas flow rate and a dilution gas flow rate according to a procedure described later, and to output a control signal to the oxygen gas flow rate controller 42 and the dilution gas flow rate controller 52. While the inside of the vacuum chamber 31 is evacuated, the oxygen gas on / off valve 46 and the dilution gas on / off valve 56 are opened to operate the control device 35, the oxygen gas flow rate controller 42, and the dilution gas flow rate controller 52. 41 and the dilution gas source 51 are supplied to the inside of the vacuum chamber 31 with oxygen gas and dilution gas at a flow rate corresponding to the control signal output from the control device 35, respectively. Thereby, the inside of the vacuum chamber 31 becomes a mixed gas atmosphere of oxygen gas and dilution gas.

  The flow rate of oxygen gas supplied from the oxygen gas source 41 to the vacuum chamber 31 and the flow rate of dilution gas supplied from the dilution gas source 51 to the vacuum chamber 31 are measured by the oxygen gas flow meter 45 and the dilution gas flow meter 55, respectively. Has been.

  The oxygen gas flow meter 45 and the dilution gas flow meter 55 are connected to the control device 35, and the measured oxygen gas flow rate and dilution gas flow rate are input to the control device 35, and the oxygen gas flow rate controller 42 and the dilution gas flow rate are inputted. The flow rate controller 52 is controlled so that the flow rates of the oxygen gas and the dilution gas supplied into the vacuum chamber 31 become the flow rates calculated by the control device 35.

The control device 35 is provided with a storage device 37, and the storage device 37 stores a flow rate ratio between the oxygen gas flow rate and the dilution gas flow rate.
Here, the flow rate ratio is a constant value, and the control device 35 operates the oxygen gas flow rate controller 42 and the dilution gas flow rate controller 52 so that the oxygen gas flow rate and the dilution gas flow rate maintain the stored ratio.

  Further, a pressure measuring device 39 is connected to the vacuum chamber 31, and the internal pressure (total pressure) of the vacuum chamber is also measured. The pressure measuring device 39 is also connected to the control device 35, and the measured pressure value is input to the control device 35.

  After the inside of the vacuum chamber 31 is evacuated to a low pressure, when the oxygen gas and the dilution gas are introduced at the flow rate ratio stored in the storage device 37, the oxygen gas pressure is calculated from the pressure value and the flow rate ratio. be able to.

  The storage device 37 stores a lower limit value of the oxygen gas pressure. When the calculated oxygen gas pressure falls below the lower limit value, the oxygen gas flow rate and the dilution gas are maintained while maintaining the stored flow rate ratio. Increase the flow rate.

The storage device 37 stores an upper limit value of the total pressure inside the vacuum chamber 31. When the pressure in the vacuum chamber 31 measured by the pressure measuring device 39 exceeds the upper limit value, the flow rate ratio is maintained. While decreasing the oxygen gas flow rate and the dilution gas flow rate.
The flow rate ratio of oxygen gas and dilution gas is set to 1: 4, the upper limit of the total pressure is set to 1 atm, and the pressure inside the vacuum chamber 31 is maintained at a pressure lower than 1 atm.

The resistance heating element 33 is disposed inside the vacuum chamber 31, and the carried sealing object 60 is disposed inside the region where the resistance heating element 33 is disposed.
The inside of the firing chamber 30 is shut off from the sealing chamber 15, the gate valve 13 between the deaeration chamber 20 is closed, the inside of the firing chamber 30 and the deaeration chamber 20 is shut off, and the vacuum in the firing chamber 30 is closed. While the inside of the tank 31 is evacuated, the heating power source 36 is activated to energize the resistance heating element 33 to generate heat.

At this time, the oxygen gas and the dilution gas are introduced into the vacuum chamber 31 while being controlled by the control device 35, the oxygen gas pressure is higher than the lower limit value, and the total pressure is maintained at a pressure lower than 1 atm. When the dressing material 65 is heated, the organic binder combines with oxygen, that is, burns and is removed as carbon dioxide and other gases.
The first and second panels 61 and 62 are temporarily fixed by the fired sealing material 65.

  A portion of the first or second panel 61, 62 surrounded by the sealing material 65 is provided with a vent hole, and is discharged between the first and second panels 61, 62 during firing. The release gas from the sealing material 65 such as carbon dioxide is released from the vent hole into the vacuum chamber 31 and evacuated together with oxygen gas and dilution gas by the evacuation system 50.

During this time, the control device 35 introduces the oxygen gas and the dilution gas at a flow rate ratio stored in the storage device 37, and the control device 35 calculates the oxygen gas pressure from the pressure value and the flow rate ratio, and calculates the calculated oxygen gas pressure. Decreases below the lower limit value stored in the storage device 37, the flow rate of oxygen gas and dilution gas is increased while maintaining the flow rate ratio.
Moreover, when the total pressure in the vacuum chamber 31 becomes 1 atmosphere or more, the control device 35 reduces the flow rates of the oxygen gas and the dilution gas while maintaining the flow rate ratio.

  As described above, since the firing proceeds within a certain range of the oxygen gas pressure, the organic binder is burned and removed by oxygen, the glass powder in the sealing material 65 is melted, the glass powders are bonded, and the sealing is performed. The dressing material 65 is solidified.

  When firing is completed, the introduction of oxygen gas and the introduction of dilution gas are stopped, and the gas inside the space surrounded by the ring-shaped sealing material 65 between the first and second panels 61 and 62 is vented. Exhaust from the hole.

  After the evacuation between the first and second panels 61 and 62 is completed, the sealing object 60 is moved to the sealing chamber 15 and heated in the sealing chamber 15 to melt the glass powder. The first and second panels 61 and 62 and the sealing material 65 are in close contact with each other, and the first and second panels 61 and 2 are fixed by the sealing material 65.

At this time, by evacuating the inside of the sealing chamber 15, the gas released between the first and second panels 61 and 62 is exhausted from the vent holes, and the first and second panels 61 and 62 are exhausted. When the discharge gas is introduced into the sealing chamber 15 after the heating is completed and the temperature is lowered, the discharge gas is introduced between the first and second panels 61 and 62 through the vent holes.
When the gas vent hole is closed in this state, the space surrounded by the first and second panels 61 and 62 and the ring-shaped sealing material 65 is hermetically separated from the external space.

  The above describes the case where the sealing material 65 is disposed between the first and second panels 61 and 62 and fired, but the present invention is not limited thereto.

The sealing device 2 shown in FIG. 4 includes first and second carry-in chambers 11 and 41, a baking chamber 30, an alignment / sealing chamber 42, a sealing chamber 43, and a carry-out chamber 19. ing.
The first carry-in chamber 11, the firing chamber 30, the align / sealing chamber 42, the sealing chamber 43, and the carry-out chamber 19 are connected in this order, and the second carry-in chamber 41 is aligned / It is connected to the sealing chamber 42. The firing chamber 30, the alignment / sealing chamber 42, and the sealing chamber 43 are evacuated in advance.

FIG. 5 shows a sealing object 66 in which a ring-shaped sealing material 65 is arranged on the first panel 61.
The sealing material 65 is deaerated and is placed in the carry-in chamber 11.
After the inside of the carry-in chamber 11 is evacuated and the inside of the carry-in chamber 11 is made into a vacuum atmosphere, the valve 13 between the carry-in chamber 11 and the firing chamber 30 is opened, and the sealing object 66 is carried into the firing chamber 30.

  The structure of the baking chamber 30 is the same as that of the baking chamber 30 described in the above embodiment. As shown in FIG. 6, the carried sealing object 66 is arranged between the resistance heating elements 33, and the resistance heating element is arranged. When 33 is energized to generate heat and oxygen gas and dilution gas are introduced into the baking chamber 30 in the same procedure as in the above embodiment, the organic binder in the sealing material 65 is burned. The gas generated by the combustion is removed by evacuation.

  When the firing process in the firing chamber 30 is completed, the introduction of oxygen gas and dilution gas into the firing chamber 30 is stopped, and after the interior of the firing chamber 30 has dropped to a predetermined pressure, the firing chamber 30 and the alignment / sealing chamber The valve 13 between the two is opened, and the processing object 66 is carried into the align / seal chamber 42 without being exposed to the atmosphere.

  At this time, the second panel 62 is arranged in the second carry-in chamber 41, and after the second carry-in chamber 41 is evacuated, the second carry-in chamber 41 and the alignment / sealing chamber are arranged. The valve 13 between 42 is opened, and the second panel 62 is carried into the align / sealing chamber 42.

An alignment device is provided in the align / sealing chamber 42, and the first panel 61 on which the fired sealing material 65 is disposed and the second panel 62 carried in are relatively positioned. After being combined, the second panel 62 is placed on the sealing material 65.
The valve 13 is closed, the alignment / sealing chamber 42 is shut off from the firing chamber 30 and the second carry-in chamber 41, the sealing material 65 is heated, the powdered glass is melted and solidified, and the first and second panels 61 , 62 is sealed.

Next, when the sealed first and second panels 61 and 62 are moved from the align / sealing chamber 42 to the sealing chamber 43 and the vent holes are closed, the first and second panels 61 and 62 are The sealed space surrounded by the first and second panels 61 and 62 and the ring-shaped sealing material 65 is airtightly separated from the external atmosphere.
The sealed first and second panels 61 and 62 are taken out from the carry-out chamber 19 to the atmosphere.

  In the above, the oxygen gas pressure in the firing chamber 30 is maintained within a certain range by controlling the flow rates of the oxygen gas and the dilution gas. 35 may change the exhaust speed of the vacuum exhaust system 50 so that the oxygen gas pressure in the firing chamber 30 is within a certain range.

  In the above embodiment, the oxygen gas pressure is calculated from the total pressure and the flow rate ratio. However, the oxygen gas pressure in the firing chamber 30 is measured by a mass spectrometer or the like, and the oxygen gas pressure is kept constant while maintaining the flow rate ratio. The range can be controlled.

The figure for demonstrating the sealing apparatus of the 1st example of this invention (a): Plan view of the object to be sealed (b): Cross section taken along line AA Diagram for explaining the firing chamber The figure for demonstrating the sealing apparatus of the 2nd example of this invention Sealing object in which sealing material is placed on the first panel The figure for demonstrating the baking chamber of the sealing apparatus of a 2nd example

Explanation of symbols

  1, 2 ... Sealing device 20 ... Deaeration chamber 30 ... Firing chamber 31 ... Vacuum chamber 40 ... Gas introduction system 35 ... Control device 39 ... Pressure measuring device

Claims (3)

A vacuum chamber;
An evacuation system for evacuating the vacuum chamber;
A gas introduction system for connecting the vacuum chamber and a gas source, and introducing oxygen gas and dilution gas into the vacuum chamber at a flow rate according to an input control signal;
A control device that outputs the control signal to the gas introduction system and controls the flow rate of the oxygen gas and the flow rate of the dilution gas;
A sealing device having a heating device for heating a sealing object,
The vacuum chamber is provided with a pressure measuring device that measures the pressure of the vacuum chamber and outputs a measurement result to the control device,
The control device stores a flow rate ratio between the flow rate of the oxygen gas and the flow rate of the dilution gas, and a minimum oxygen pressure,
The control device controls the gas introduction system, introduces the oxygen gas and the dilution gas into the vacuum chamber at the flow rate ratio, and determines the oxygen pressure in the vacuum chamber from the measurement result of the pressure measurement device. A calcining chamber that calculates and, when the calculation result falls below the minimum oxygen pressure, controls the gas introduction system to increase the oxygen flow rate.   The said control apparatus controls the said gas introduction system, when the said measurement result of the said pressure measuring device shows 1 atmosphere or more, The said dilution gas flow rate is decreased, The pressure in the said vacuum chamber is reduced. Firing chamber.   A processing chamber to which a vacuum exhaust device is connected is connected to the baking chamber so that the sealing object can be moved between the processing chamber and the baking chamber while the sealing object is placed in a vacuum atmosphere. Constructed sealing device.

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