JPH08200970A - Heat treating apparatus with sublimable material removing function - Google Patents

Abstract

PURPOSE: To prevent the contamination of the periphery of a heat treating apparatus with sublimable material. CONSTITUTION: An oven has a gas line 21 for sucking the air in a treating chamber 6 from the part of an opening 10 by a predetermined pressure, an atmospheric line 22 for sucking the atmosphere, a damper 23 for regulating the atmosphere suction amount, a suction fan 24, a drive motor 25 and a differential pressure sensor 41 between a machine room 2 and the chamber 6, a controller 42 and an inverter 43 for controlling the rotation of the motor so that the differential pressure becomes constant as an exhaust system 20 for sucking the gas in the chamber 6. Further, the oven has a contact type water cooler 30 for cooling the sucked gas to the temperature for solidifying sublimable material. Accordingly, the leakage of the vaporized gas of the material to the periphery of a heat treating apparatus, and the peripheral environment can be maintained clean. Further, the material can be separated and recovered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment apparatus for heat-treating an object to be processed which produces a sublimate during heat treatment in a processing chamber.

[0002]

2. Description of the Related Art In a heat treatment apparatus, there is a case where an object to be processed which produces a sublimate is processed when a resist or the like attached during a manufacturing process such as an exposure process is heat-treated, such as a liquid crystal substrate. Such a sublimate is vaporized due to the high temperature in the processing chamber during the heat treatment.

On the other hand, the heat treatment apparatus is provided with a carry-in hole and a carry-out hole for taking in and out an object to be processed. In addition, since a moving mechanism for moving an object to be processed is usually provided in the processing chamber, and the drive unit of this moving mechanism is provided in the machine room adjacent to the processing room, it is possible to move between the processing room and the machine room. Through holes for the mechanism are created. Therefore, the heat treatment apparatus does not form a completely closed container because such holes are inevitably present. Therefore, the air containing the sublimate gas vaporized in the processing chamber comes out through such holes. Then, this gas is exposed to the outside air temperature and its temperature drops, and the vaporized sublimate is deposited near the holes.

Since the heat treatment apparatus is usually installed in a room with relatively high cleanliness, if such deposits are generated, the cleanliness of the installed room cannot be maintained or the deposits are carried into the heat treatment furnace. Also, it is deposited on the object to be processed, the carrier, and the like. As a result, the room becomes dirty and needs to be cleaned, the living environment in the room deteriorates, the air conditioner in the room becomes dirty, the air conditioning performance deteriorates, and many failures occur.
This causes various problems such as that the object to be processed becomes dirty and the quality is deteriorated or the yield is deteriorated, various peripheral devices become dirty, cleaning and maintenance of them are required, and the production line is stopped. However, in the conventional heat treatment apparatus,
No measures have been taken to address this sublimation problem.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems in the prior art and to provide a heat treatment apparatus which does not scatter or deposit sublimates on the periphery.

[0006]

In order to solve the above-mentioned problems, the present invention provides a heat treatment apparatus for heat-treating an object to be processed which generates a sublimation gas during heat treatment in a processing chamber. In addition to the above, the invention according to claim 2 is characterized in that the sublimation gas in the sucked gas is solid, and has a gas suction means for sucking gas at a predetermined pressure from a conduction portion between the processing chamber and the outside. It has a cooling means for cooling to a temperature at which the sublimation gas is turned off, and a separation means for separating the sublimate in which the sublimation gas is solidified from the gas.

[0007]

In the heat treatment apparatus, in order to expose the object to be processed to a sufficient processing temperature and to make the processing temperature uniform, a high temperature gas heated by a blower is sent to the processing chamber containing the object to be processed. Circulate. At this time, the object to be treated may generate a vaporized gas of the sublimate. In such a heat treatment apparatus, according to the invention of claim 1, since the gas suction means for sucking gas at a predetermined pressure from the conduction portion between the processing chamber and the outside is provided, the gas in the treatment chamber is concerned with the conduction portion. It is possible to prevent the leakage from the outside. That is, when the predetermined pressure is set to an appropriate negative pressure, the gas suction means sucks the internal gas from the processing chamber side in the conducting portion and also sucks the air from the outside, thereby preventing the internal gas from leaking to the outside. To be done. In this case, if the predetermined pressure is reduced, the internal gas easily leaks to the outside due to the pressure in the processing chamber, but if a plurality of suction ports for sucking the gas are provided in the conducting direction of the conducting portion, the first suction port portion Even if a part of the internal gas leaks to the outside, the internal gas can be sucked in through the next suction port, and the internal gas can be almost completely prevented from leaking to the outside. Further, if the gas is sucked from the conducting portion at a predetermined pressure, the pressure inside the processing chamber becomes low. Therefore, when there are a plurality of conducting portions between the processing chamber and the outside, if gas is sucked from a part of the conducting portions by the gas suction means, it may be possible to prevent the internal gas from leaking to the outside in the other conducting portions. The predetermined pressure is determined to be an appropriate value in an actual device in consideration of such conditions. If the internal gas is prevented from leaking to the outside in this way, the sublimate does not deposit near the outside of the conducting portion, and the environment near the heat treatment apparatus to be kept clean is not contaminated.

On the other hand, since the gas suction means sucks the gas in the processing chamber as described above, it also sucks the vaporized gas of the sublimate generated from the object to be processed. Therefore, it is possible to ventilate the inside of the device by conveying and discharging the sucked gas to an appropriate place where dirt does not become a problem so much, and the vaporized gas of the sublimate is discharged to increase the density inside. Can be prevented.

According to the invention of claim 2, since the cooling means is provided for cooling the sucked gas to a temperature at which the sublimate solidifies, the sublimate can be deposited as a solid. In many cases, the precipitates are fine particles, but since the separating means for separating the precipitates from the sucked gas is provided, the precipitates can be recovered without being scattered.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the overall structure of an oven which is an example of a heat treatment apparatus. The oven is composed of an inner tank surrounded by a heat insulating wall 1 and a machine room 2 adjacent to the inner tank. Inside the inner tank, a blower 3 that circulates the internal air, a circulation path, a duct section 4, a high-performance filter 5, a processing chamber 6, and a large number of liquid crystal substrates W provided therein are placed in that order. A gondola 7 that moves up and down, an air-conditioning room 8, a heater 9 provided therein, and the like are provided. Further, in the figure, openings 10 for taking in and out the liquid crystal substrate W are provided on both side walls of the processing chamber 6 parallel to the paper surface, and an intake hole 11 for ventilation is provided at the suction part of the blower. . In the machine room 2, a lifting mechanism 12 for moving the gondola 7 up and down, an intake / exhaust ventilation fan 13 for ventilating the machine room to prevent an increase in room temperature,
It is equipped with 14 mag. The opening for raising and lowering the gondola 7 between the processing chamber 6 and the machine chamber 2 is sealed by a sheet-like member 15 that is unwound / rolled in as the gondola 7 is raised and lowered.

In addition to the general structure as described above, this oven is a device capable of heat-treating a liquid crystal substrate W, which is an example of an object to be processed that generates a sublimation gas during heat treatment, in the processing chamber 6. Therefore, it has an exhaust system 20 as a gas suction means for sucking gas at a predetermined pressure from the opening 10 which is a conduction part between the inside of the processing chamber 6 and the outside 100. Further, a cooling means for cooling the sucked gas to a temperature at which the sublimate solidifies and a contact water cooler 30 as a separating means for separating the solidified sublimate from the gas are provided. The contact-type water cooler 30 contains a wash water injection pipe 31 having a large number of small holes therein, and is supplied with wash water from the outside. In this cooler, when the cleaning water is sprayed, the sucked gas comes into contact with the cleaning water and exchanges heat with the cooling gas.
It is cooled to about 0 °.

The exhaust system 20 has a gas line 21 for mainly sucking high-temperature gas in the processing chamber 6 through the opening 10, an outside air line 22 for mainly sucking outside air, a damper 23 for adjusting the amount of outside air suction, and an intake fan 24. Its drive motor 2
It is composed of 5 etc. Further, in this embodiment, the intake fan control system 40 is provided, the pressure difference between the processing chamber 6 and the exhaust system 20 is detected by the differential pressure sensor 41, and the signal is input to the controller 42 so that the differential pressure becomes constant. To the inverter 43 to control the rotation speed of the motor 25. Therefore, in this embodiment, the predetermined pressure for sucking the gas is set as the differential pressure as described above. However, for example, when the pressure in the processing chamber 6 does not fluctuate much, the motor 25 is kept at a constant rotation speed, a damper or the like is provided on the suction side of the fan 24, and the suction pressure is adjusted by manual operation. You may

In the above embodiment, the contact water cooler 30 is used.
Is provided on the suction side of the intake fan 24, but it may be provided on the discharge side. By doing so, the discharge pressure of the fan can be utilized, which may increase the throughput of the sublimate. Further, in the above example, the rotation speed control of the drive motor is performed in order to keep the differential pressure constant, but instead of this, the opening degree control of the damper 23 may be performed. You may.

FIG. 2 shows a structure for sucking hot gas and outside air in the opening 10. Above and below the opening 10, respectively, an upper intake chamber 27 having an intake hole 26 formed in the processing chamber 6 side so as to mainly suck hot air from the processing chamber 6 side, and an outside air mainly sucked from the outside 100 side. A lower intake chamber 29 having an intake hole 28 is provided on the outside 100 side, and nozzles 27a and 29a are connected to the respective intake chambers. The hot gas and the outside air pass through the nozzle portion to the gas line 21 and the outside air, respectively. It is sucked into the line 22. Also, the opening 10
A sealing material 10a is erected on the inside to limit the flow of air between the inside and outside. By thus providing the intake holes 26 and 28 in a double row in the conduction direction of the conduction portion, even if the suction negative pressure is slightly reduced, the leakage of hot air in the processing chamber 6 to the outside 100 is almost completely prevented. be able to.

With the above-mentioned structure, the main oven is operated as follows. In the heat treatment step, the blower 3 and the heater 9 are turned on by the start of operation, and hot air circulates in the tank. In this state, the elevating mechanism 12 raises the gondola 7 step by step from the position indicated by the chain double-dashed line. Corresponding to the movement of the gondola 7, liquid crystal substrates W are loaded one by one from the opening 10 by an external liquid crystal substrate loading device (not shown), loaded one by one on the loading portion of the gondola 7, and raised to the top. The liquid crystal substrates W are loaded on all the stages. In this state, the gondola 7 once descends to the lowermost part, and again rises by one step every tact time, and the liquid crystal substrate W is moved to the exit side of the opening 10 by an external liquid crystal substrate carry-out device and carry-in device (not shown). After being carried out one by one from the opening, one by one is carried in from the opening on the entrance side of the opening 10, and the liquid crystal substrates W are heat-treated and discharged one by one for each tact. In the machine room 2, the ventilation fans 13 and 14 are operated, and the temperature rise inside is suppressed by ventilation.

In the heat treatment operation as described above, the exhaust system 20 is operated to ventilate and prevent outflow of the sublimate gas. That is, the blower 3 and the heater 9 are turned on, and the intake fan 24 is turned on. In this case, the exhaust system 2
The amount of outside air sucked from the intake hole 28 is adjusted in advance by the damper 23 of 0. Further, the differential pressure between the processing chamber 6 controlled by the controller 42 and the exhaust system 20 is set to about 2 mmAq. If the predetermined pressure is set in this way, the processing chamber 6
The pressure inside is the same as that of the outside 100. On the other hand, the processing chamber 6
On the machine room 2 side, the circulating air inside becomes an upward air flow, so that a slight air suction effect from the outside to the inside also occurs at the boundary between the processing chamber 6 and the machine room 2. Therefore, with such a pressure setting, the air in the processing chamber 6 is forced to flow into the sheet-shaped member 1
There is no leakage from the 5th part to the machine room 2 side. Further, the amount of outside air sucked from the machine room 2 side does not increase, and the inside of the processing room 6 does not become dirty. Furthermore, no temperature disturbance occurs in the processing chamber 6. In the case of a manually operated device that does not automatically adjust the differential pressure by controlling the rotation of the fan, such adjustment is performed at the time of shipment, for example, during a trial run.

By the operation of the exhaust system 20, the high temperature gas in the processing chamber 6 is sucked from the intake hole 26 of the opening 10 to prevent its leakage to the outside and the outside air is sucked from the intake hole 28. Even if the high temperature gas in the processing chamber 6 is sucked from the intake hole 26, the high temperature gas which is about to leak to the outside is caught in the intake hole 28 together with the outside air, and the leakage of the high temperature gas from the opening 10 is completely prevented. .

The mixed gas of the sucked high temperature gas and the outside air is
While passing through the inside of the cooler 30, at this time, the cooling water containing the solvent injected into the inside of the cooler 30 is contacted and cooled. And
The vaporized gas of the sublimate contained in the mixed gas is also cooled, and once the sublimate is deposited as solid particles, it is dissolved in water containing a solvent and discharged together with water.

As described above, the intake hole 2 is provided at the opening 10.
Although it is convenient to prevent the high temperature gas from leaking from the opening 10 by providing 6 and connecting the suction means to this, for example, another through hole in the processing chamber 6 such as the drive shaft (even if there are a plurality of through holes). Hot gas may be sucked. The pressure in the processing chamber varies depending on various conditions such as the structure of the air circulation system, the method of loading and unloading the object to be processed, the method of moving the object inside, and the like.
Since the location where the high temperature gas leaks in the processing chamber also differs depending on the arrangement of the internal device, the location and amount of suction by the gas suction means are designed to be optimal for a specific apparatus.

In the present embodiment, the contact type water cooler is used as a means that also serves as a cooling means and a means for separating sublimates, but, for example, the cooling means does not directly contact the cooling medium and the object to be cooled. As the cooling means, the separating means may be provided with various appropriate devices such as a device having a dust collecting function such as a vacuum cleaner, a water-soluble device, a solvent device, and a catalyst device. That is, as the cooling means and the separating means, appropriate means are selected in consideration of the physicochemical properties of the sublimate, the influence on the environment, etc., according to the sublimate generated in the actual device. It is also possible to use a system in which the exhaust heat of the high-temperature gas is used, for example, for producing hot water, or is returned to the heat treatment apparatus.

[0021]

As described above, according to the present invention, in the first aspect of the invention, the ambient environment is maintained in a clean state by preventing the sublimate vaporized gas from leaking to the periphery of the heat treatment apparatus by the gas suction means. can do. According to the invention of claim 2, in addition to the above, the sublimate can be recovered by precipitating and separating the sublimate by the cooling means and the separating means, which can contribute to environmental protection.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an overall configuration of an oven according to an embodiment.

FIG. 2 shows a structure of an opening portion of the oven, (a)
Is a front view, (b) is a sectional view, (c) is an upper plan view,
(D) is a bottom plan view.

[Explanation of symbols]

 6 Processing Chamber 21 Gas Line (Gas Suction Means) 22 Outside Air Line (Gas Suction Means) 24 Intake Fan (Gas Suction Means) 30 Contact Water Cooling Device (Cooling Means, Separation Means) W Liquid Crystal Substrate (Workpiece)

Claims (2)

[Claims] 1. A heat treatment apparatus for heat-treating an object to be treated which generates a sublimation gas during heat treatment in a processing chamber, comprising gas suction means for sucking gas at a predetermined pressure from a connecting portion between the processing chamber and the outside. A heat treatment apparatus characterized by the above. 2. A cooling unit that cools the sublimated gas in the sucked gas to a temperature at which the sublimated gas solidifies, and a separating unit that separates a sublimate in which the sublimated gas solidifies from the gas.
The heat treatment apparatus according to claim 1, further comprising: