JP6886866B2 - Vacuum drying device - Google Patents

Description

The present invention relates to a vacuum drying device that dries a solvent in an organic material film coated on the surface of a substrate under reduced pressure.

Conventionally, an organic light emitting diode (OLED), which is a light emitting diode utilizing light emission of organic EL (Electroluminescence), is known. An organic EL display using such an organic light emitting diode has advantages such as thinness, light weight, low power consumption, and excellent response speed, viewing angle, and contrast ratio. Therefore, it is a next-generation flat. In recent years, it has been attracting attention as a panel display (FPD).

The organic light emitting diode has a structure in which an organic EL layer is sandwiched between an anode and a cathode on a substrate. The organic EL layer is formed by laminating, for example, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer in this order from the anode side. In forming each of these organic EL layers (particularly the hole injection layer, the hole transport layer and the light emitting layer), a method of ejecting droplets of an organic material onto a substrate by, for example, an inkjet method is used.

A large amount of solvent is contained in the organic material discharged onto the substrate by the inkjet method. Therefore, for the purpose of removing the solvent, a vacuum drying treatment is performed in which the solvent is dried under reduced pressure.
The vacuum drying device for performing the vacuum drying process includes a vacuum-drawable processing container for accommodating the substrate to be vacuum-dried, and an exhaust pipe having one end connected to the processing container and the other end being an exhaust device. , The inside of the processing container is evacuated by the exhaust device (see Patent Documents 1 and 2).

The vacuum drying device of Patent Document 1 is provided with a solvent collecting portion in the exhaust pipe for collecting the solvent volatilized from the organic material film on the substrate for the purpose of quickly drying the substrate, and depressurizes the substrate. When the drying is completed, the valve provided between the solvent collecting portion and the processing container is closed, the inside of the processing container is returned to atmospheric pressure, and the substrate is carried out from the inside of the processing container.

Further, in the vacuum drying apparatus of Patent Document 2, in order to efficiently remove the solvent in the processing container in a short time, the solvent collecting unit is provided in the processing container, and the ultraviolet irradiation unit is provided on the processing container. It is provided. In this vacuum drying device, the solvent collecting part is irradiated with ultraviolet rays from the ultraviolet irradiation part, and the organic compound contained in the solvent collected in the solvent collecting part is decomposed so as to be easily volatilized.

Japanese Unexamined Patent Publication No. 2005-85814 Japanese Unexamined Patent Publication No. 2014-238194

However, the patent document describes the time until the vacuum drying of the substrate is completed, in other words, the time (tact time) until the pressure in the processing container becomes equal to or less than a predetermined value and there is no problem even if the inside of the processing container is returned to atmospheric pressure. It may be required to be shorter than the vacuum drying devices 1 and 2.

The present invention has been made in view of this point, and an object of the present invention is to provide a vacuum drying apparatus in which the time required for vacuum drying of a substrate to be completed is short.

In order to achieve the above object, the present invention is a vacuum drying device that dries a solvent in an organic material film applied to the surface of a substrate under reduced pressure, and comprises a chamber accommodating the substrate and a chamber in the chamber. A plurality of exhaust passages for connecting the space and the exhaust device for exhausting the inside of the chamber are provided, and each of the plurality of exhaust passages has a closing member for opening and closing the exhaust passage, and the plurality of exhaust passages have a closing member. An exhaust passage with a solvent collecting portion in which a solvent collecting portion for collecting the solvent in the organic material film vaporized from the substrate is provided downstream of the closing member, and the solvent collecting portion are not provided. look containing a solvent collecting unit without exhaust path, the ends of the chamber side of the exhaust passage there the solvent collecting unit, as compared to the ends of the chamber side of the solvent collecting unit without exhaust passage, said chamber It is characterized in that it is far from the corner portion of the substrate housed in the solvent.

In order to achieve the above object, the present invention is a vacuum drying method using a vacuum drying device that dries the solvent in the organic material film coated on the surface of the substrate in a reduced pressure state. A chamber for accommodating the substrate and a plurality of exhaust passages for connecting the space in the chamber and the exhaust device for exhausting the inside of the chamber are provided, and the plurality of exhaust passages block the exhaust passages so as to be openable and closable. An exhaust passage having a solvent collecting portion having a closing member and having a solvent collecting portion for collecting the solvent in the organic material film vaporized from the substrate by the plurality of exhaust passages provided downstream of the closing member. And the exhaust passage without the solvent collecting portion, which is not provided with the solvent collecting portion, and the vacuum drying method includes the closing member for at least the exhaust passage with the solvent collecting portion among the plurality of exhaust passages. After the substrate drying step and the substrate drying step, the closing member is closed for the exhaust passage with the solvent collecting portion among the plurality of exhaust passages, and the exhaust passage without the solvent collecting portion is closed. Includes a chamber drying step that opens the closing member.

The substrate drying step preferably includes a step of cooling the solvent collecting portion.

The chamber drying step preferably includes a step of heating the solvent collecting portion.

The chamber drying step includes a step of supplying a gas for promoting vaporization of the solvent collected in the solvent collecting portion from a gas supply portion provided between the closing member and the solvent collecting portion. Is preferable.

The end of the exhaust passage with the solvent collecting portion on the chamber side is farther from the corner portion of the substrate housed in the chamber than the end of the exhaust passage without the solvent collecting portion on the chamber side. The substrate drying step is a step of opening the closing member for the exhaust passage having a solvent collecting portion among the plurality of exhaust passages, and then opening the closing member for all of the plurality of exhaust passages. It is preferable to include it.

According to the present invention, the time until the vacuum drying of the substrate is completed, that is, the tact time can be shortened.

It is a figure which shows the schematic structure of the vacuum drying apparatus which concerns on embodiment of this invention. It is a figure explaining the effect of the vacuum drying apparatus of FIG. It is a figure which shows the structure about the solvent collecting part in another example of a vacuum drying apparatus. It is a figure which shows the state around the exhaust pipe provided with the closing member of another example. It is a figure which shows another example of the bottom plate of a chamber. It is a side view which shows another example of the exhaust line of the vacuum drying apparatus. It is explanatory drawing of another example of the exhaust line of the vacuum drying apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted. Further, the present invention is not limited to the embodiments shown below.

(First Embodiment)
FIG. 1 is a diagram showing a schematic configuration of a vacuum drying device according to an embodiment of the present invention, FIG. 1 (A) is a schematic cross-sectional view showing a schematic configuration of a vacuum drying device, and FIG. 1 (B) is a reduced pressure. It is a schematic top view which shows the outline of the structure in a drying apparatus. Note that in FIG. 1B, the illustration of the top plate and the like, which will be described later, is omitted.

The vacuum drying apparatus according to the present embodiment dries the solvent in the organic material film coated on the surface of the substrate by an inkjet method in a reduced pressure state, and the substrate to be processed by this apparatus is, for example, for an organic EL display. It is a glass substrate of.
The solution applied to the substrate to be treated by this apparatus is composed of a solute and a solvent, and the component to be dried under reduced pressure is mainly a solvent. Many of the organic compounds contained in the solvent have a high boiling point, for example, 1,3-dimethyl-2-imidazolidinone (boiling point 220 ° C., boiling point 8 ° C.), 4 −tert-Butylanisole (4-tert-Butylanisole, boiling point 222 ° C, melting point 18 ° C), Trans-Anethole (boiling point 235 ° C, melting point 20 ° C), 1,2-dimethoxybenzene (1,2-Dimethoxybenzene) , Boiling point 206.7 ℃, boiling point 22.5 ℃), 2-Methoxybiphenyl (boiling point 274 ℃, boiling point 28 ℃), phenyl ether (boiling point 258.3 ℃, boiling point 28 ℃), 2-ethoxynaphthalene (2-ethoxynaphthalene) Ethoxynaphthalene, boiling point 282 ° C, melting point 35 ° C), Benzyl Phenyl Ether (boiling point 288 ° C, melting point 39 ° C), 2,6-Dimethoxytoluene (boiling point 222 ° C, melting point 39 ° C), 2-Propoxynaphthalene (boiling point 305 ° C, melting point 40 ° C), 1,2,3-Trimethoxybenzene (boiling point 235 ° C, melting point 45 ° C), cyclohexylbenzene, Boiling point 237.5 ° C, melting point 5 ° C), dodecylbenzene (boiling point 288 ° C, boiling point -7 ° C), 1,2,3,4-tetramethylbenzene (1,2,3,4-tetramethylbenzene, boiling point 203 ° C, Melting point 76 ° C) and the like. These high boiling point organic compounds may be blended in a solution in combination of two or more.

As shown in FIGS. 1 (A) and 1 (B), the vacuum drying device according to the present embodiment includes a chamber 10, a mounting table 20, and a plurality of exhaust pipes 30, and is connected to the exhaust device P. Has been done.

The chamber 10 is airtight and is made of a metal material such as stainless steel. The chamber 10 has a square tubular main body portion 11, a top plate 12 attached to the upper side of the main body portion 11, and a bottom plate 13 attached to the lower side of the main body portion 11.

The main body 11 is provided with a carry-in / out port (not shown) for carrying in / out the substrate W into the chamber 10.
The top plate 12 closes the opening on the upper side of the main body 11.

The bottom plate 13 closes the opening on the lower side of the main body 11, and the mounting table 20 is arranged in the center of the upper side of the bottom plate 13. Further, the bottom plate 13 is provided with a plurality of openings 13a and 13b so as to surround the outer circumference of the mounting table 20. In this example, six openings 13a and 13b are provided along one side of the mounting table 20, and six openings 13a and 13b are provided along the side facing the one side, for a total of twelve.
Further, the exhaust pipe 30 communicates with each of the openings 13a.

The mounting table 20 is for mounting the substrate W. The mounting table 20 is provided with an elevating pin (not shown) for transferring the substrate W, and the elevating pin can be freely moved up and down by an elevating mechanism.

Each of the plurality of exhaust pipes 30 connects the chamber 10 and the exhaust device P. The "exhaust passage" according to the present invention is formed by the openings 13a and 13b of the exhaust pipe 30 and the bottom plate 13. The exhaust passage connects the substrate accommodating space in the chamber 10 and the exhaust device P. In the vacuum drying device 1, the inside of the chamber 10 is depressurized by the exhaust device P through the exhaust pipe 30 and the openings 13a and 13b constituting the "exhaust passage".

The exhaust device P is composed of a vacuum pump, specifically, a turbo molecular pump and a dry pump are connected in series in this order from, for example, the upstream side. This exhaust device P is specifically arranged for each exhaust passage, specifically for each exhaust pipe 30.

Further, each of the exhaust pipes 30 has an automatic pressure control valve (APC (Adaptive Pressure Control) valve) 31 as a closing member for closing the exhaust pipe 30 so as to be openable and closable. In other words, the APC valve 31 is provided in the portion between the openings 13a and 13b of the exhaust pipe 30 and the exhaust device P. In the vacuum drying device 1, the degree of vacuum / pressure in the chamber 10 at the time of vacuum exhaust is controlled by adjusting the opening degree of the APC valve 31 while the exhaust device P is operated, and the drying speed of the substrate W is controlled. Can be controlled.

The vacuum drying device 1 has a pressure gauge (not shown) for measuring the pressure in the chamber 10. The measurement result of the pressure gauge is input to the APC valve 31 and the control unit 40 described later as an electric signal.

Further, only a part of the plurality of exhaust pipes 30 has a solvent collecting portion 32 downstream of the APC valve 31 for collecting the solvent vaporized from the solution applied on the substrate W by the inkjet method. Specifically, of the plurality of exhaust pipes 30, the exhaust pipe 30 provided for the opening 13a near the corner of the substrate W on the mounting table 20 is not provided with the solvent collecting portion 32, and the above corners. A solvent collecting portion 32 is provided in the exhaust pipe 30 provided for the opening 13b far from the portion.

That is, the plurality of exhaust passages include an exhaust passage with a solvent collecting portion in which the solvent collecting portion 32 is provided downstream of the APC valve 31 and an exhaust passage without a solvent collecting portion 32 in which the solvent collecting portion 32 is not provided. including. Further, the end portion of the exhaust passage with the solvent collecting portion on the chamber 10 side, that is, the opening 13a is accommodated in the chamber 10 as compared with the end portion of the exhaust passage without the solvent collecting portion, that is, the opening 13b, on the mounting table 20. It is far from the corner of the wafer W placed on the.

The solvent collecting unit 32 is a thin plate, that is, a net plate (not shown) having a shape in which openings are uniformly formed in a grid pattern so that the solvent in the gas can be collected while passing the gas exhausted from the chamber 10. Has. The net-like plate is formed of a metal material such as stainless steel, aluminum, copper, or gold, and is composed of, for example, expanded metal produced by cold-cutting a steel plate.
The solvent collecting unit 32 may have one net-like plate, or a plurality of net plates may be laminated. Further, the net-like plate is formed so that its outer diameter is substantially equal to the inner diameter of the exhaust pipe 30.

The vacuum drying device 1 having each of the above parts further includes a control unit 40 for controlling the APC valve 31 and the like. The control unit 40 is, for example, a computer and has a program storage unit (not shown). The program storage unit stores a program that controls the vacuum drying process in the vacuum drying device 1. The above program is recorded on a computer-readable storage medium such as a computer-readable hard disk (HD), flexible disk (FD), compact disk (CD), magnet optical desk (MO), or memory card. It may be the one installed in the control unit 40 from the storage medium.
The control unit 40 can also control the exhaust device P.

Subsequently, the vacuum drying process using the vacuum drying device 1 will be described.

(Board loading step)
In the vacuum drying process using the vacuum drying device 1, first, the substrate W coated with the processing liquid by the inkjet method is placed on the mounting table 20.

(Substrate drying step)
Next, with respect to the exhaust pipe 30 provided with at least the solvent collecting portion 32 (hereinafter, the exhaust pipe 30 having the solvent collecting portion) among the plurality of exhaust pipes 30 in the state where the dry pump of the exhaust device P is operated, the present In the example, for all the exhaust pipes 30, the APC valve 31 is opened and the decompression exhaust in the chamber 10 is started. The reduced pressure exhaust by the dry pump is performed until the pressure in the chamber 10 becomes, for example, 10 Pa.
After that, the turbo molecular pump of the exhaust device P is operated to further reduce the pressure and exhaust the gas.
When the pressure in the chamber 10 becomes equal to or less than the vapor pressure of the solvent at the temperature of the substrate W (0.2 Pa or less when the temperature of the substrate W is 23 ° C.) due to the further reduced pressure exhaust, the evaporation rate of the solvent S on the substrate W Becomes larger.
Further, at the time of reduced pressure exhaust, the gas in the chamber 10 is adiabatically expanded and cooled, and the temperature in the solvent collecting unit 32 is lowered by the gas in the chamber 10 cooled in this way. Specifically, when the pressure in the chamber 10 is reduced to 0.2 Pa, the solvent collecting unit 32 is cooled to 5 to 12 ° C. This 5 to 12 ° C. is smaller than the dew point of the solvent at 0.2 Pa, which is 23 ° C.
Further, the temperature of the solvent collecting unit 32 is maintained below the dew point of the solvent S at the pressure in the chamber 10 at each time point until the evaporation of the solvent S on the substrate W is completed.
Therefore, the solvent vaporized from the substrate W is collected with high efficiency by the solvent collecting unit 32, so that the concentration of the gaseous solvent in the chamber 10 is kept low. Therefore, the solvent on the substrate W can be quickly removed.
As a method for maintaining the temperature of the solvent collecting portion 32 below the dew point as described above, a method of using a net-like plate of the solvent collecting portion 32 having a small heat capacity can be considered.
Further, this substrate drying step is performed until the substrate W is dried, for example, until the pressure in the chamber 10 becomes equal to or lower than the first predetermined value, or a second predetermined time from the start of operation of the turbo molecular pump of the exhaust device P. It will be done until it elapses.

(Chamber drying step)
After the substrate drying step, the APC valve 31 is closed for the exhaust pipe 30 with the solvent collecting portion, and the exhaust pipe 30 without the solvent collecting portion 32 (hereinafter, the exhaust pipe 30 without the solvent collecting portion) is closed. Keep the APC valve 31 open.
This chamber drying step is performed, for example, until the solvent in the chamber 10 becomes a predetermined amount or less, that is, until the pressure in the chamber becomes a second predetermined value or less, or from the start of operation of the turbo molecular pump of the exhaust device P. It is performed until the second predetermined time elapses. The second predetermined value and the second predetermined time are values such that the solvent remaining in the chamber 10 does not reattach to the substrate W when the pressure in the chamber 10 is returned to the atmospheric pressure. It's time.

(Solvent collector drying step)
During the chamber drying step, the solvent collecting part drying step is also performed in parallel. In the solvent collecting section drying step, the solvent collecting section 32 is heated and dried by using the radiant heat from the side wall of the exhaust pipe 30, the turbo molecular pump, or the like. For example, the temperature of the solvent collecting unit 32 rises above the dew point of the solvent at the pressure inside the exhaust pipe 30 at that time (18 to 23 ° C. or more when the pressure inside the exhaust pipe 30 is 0.05 Pa) due to the radiant heat. To do. Therefore, the solvent can be quickly removed / removed from the solvent collecting unit 32, and the solvent collecting unit 32 can be dried.

(Board unloading step)
After the chamber drying step and the solvent collecting section drying step are completed, the APC valves 31 are closed for all the exhaust pipes 30, and then the pressure in the chamber 10 is returned to the atmospheric pressure, and the substrate W is carried out from the chamber 10.

After this substrate loading step, the turbo molecular pump of the exhaust device P is stopped, and each step is repeated in order from the substrate loading step.

As described above, in the vacuum drying device 1, only a part of the plurality of exhaust pipes 30 has the solvent collecting portion 32 downstream of the APC valve 31. Therefore, the substrate drying step in which the APC valve 31 is opened for the exhaust pipe 30 having the solvent collecting portion among the plurality of exhaust pipes 30, and the APC valve 31 for the exhaust pipe 30 having the solvent collecting portion among the plurality of exhaust pipes 30. For the exhaust pipe 30 without the solvent collecting portion, the chamber drying step for maintaining the open state of the APC valve 31 can be sequentially performed. Therefore, it has the following effects.

FIG. 2 is a diagram for explaining the effect of the vacuum drying device 1. The horizontal axis is the elapsed time from the start of exhaust gas, specifically, the APC valve 31 is in the open state when the pressure in the chamber 10 is atmospheric pressure. The elapsed time from is shown, and the vertical axis shows the pressure in the chamber 10.

(Case 1)
In the vacuum drying device 1, when all of the plurality of exhaust pipes 30 do not have the solvent collecting portion 32, even if the APC valves 31 are opened for all the exhaust pipes 30, as shown in FIG. 2, in the chamber 10. After the pressure is maintained in a high state (about 1 Pa), it gradually decreases, but it takes 140 seconds or more until the pressure in the chamber 10 becomes equal to or less than the above-mentioned second predetermined value (for example, 0.09 Pa). It takes.

(Case 2)
In the vacuum drying device 1, when all of the plurality of exhaust pipes 30 have the solvent collecting portion 32, even if the APC valve 31 is opened for all the exhaust pipes 30, the pressure in the chamber 10 is up to about 0.2 Pa. , It can be lowered faster than the above case 1. However, even after 200 seconds have passed, the pressure in the chamber 10 cannot be set to the above-mentioned second predetermined value (0.09 Pa) or less.

On the other hand, only a part of the plurality of exhaust pipes 30 has the solvent collecting portion 32 downstream of the APC valve 31, and the APC valve 31 is provided for all the exhaust pipes 30 including the exhaust pipe 30 having the solvent collecting portion. The substrate drying step is performed for about 80 seconds, after which the APC valve 31 is closed for the exhaust pipe 30 with the solvent collecting portion and the APC valve 31 is opened for the exhaust pipe 30 without the solvent collecting portion. Suppose a chamber drying step is performed to maintain. In this case, the pressure in the chamber 10 can be reduced to 0.2 Pa at the same speed as in the case 1, and the pressure in the chamber 10 can be reduced to the above-mentioned second predetermined value or less. Instead, it takes only about 85 seconds to bring it below the second predetermined value.
As described above, in the vacuum drying step using the vacuum drying device 1, the pressure in the chamber 10 can be rapidly reduced to the above-mentioned second predetermined value or less.

In addition, the vacuum drying device 1 has the following effects. When the substrate W having a quadrangular top view is dried under reduced pressure, the corners of the substrate W are more likely to be dried than other portions. However, it is preferable that the drying time of the substrate W is uniform in the same substrate. Further, the portion of the substrate closer to the exhaust pipe 30 provided with the solvent collecting portion 32 is easier to dry than the portion farther from the exhaust pipe 30. Therefore, in the vacuum drying device 1, the solvent collecting portion 32 is provided only in the exhaust pipe 30 provided for the opening 13b far from the corner portion of the substrate W on the mounting table 20 among the plurality of exhaust pipes 30. There is. As a result, the in-plane uniformity of the drying time of the substrate W can be improved without making the opening degree of the APC valve 31 different for each exhaust pipe 30.

FIG. 3 is a diagram showing a configuration regarding a solvent collecting unit 32 in another example of the vacuum drying device 1.
In the above example, the solvent collecting unit 32 is cooled or raised, that is, heated by the gas in the chamber 10 which is adiabatically expanded and cooled at the time of depressurization, or the radiant heat from the exhaust pipe 30 or the like.

Instead of this, as shown in FIG. 3, a plurality of refrigerant pipes 50 are provided as a temperature variable mechanism for cooling and heating the solvent collecting portion 32, and these refrigerant pipes 50 are welded to the net-like plate 32a for collecting the refrigerant. The solvent collecting portion 32, that is, the net-like plate 32a may be cooled and heated by fixing the refrigerant with or the like and allowing the cooled refrigerant and the heated refrigerant to flow in a switchable manner. As a result, the solvent collecting unit 32 can be appropriately cooled / heated more quickly.

When the vacuum drying device 1 is provided with the temperature variable mechanism in this way, it is preferable to cool the solvent collecting unit 32 by the temperature variable mechanism in the substrate drying step described above. This is because the time required for the substrate drying step can be shortened.
When the temperature variable mechanism is provided, it is preferable to heat the solvent collecting unit 32 by the temperature variable mechanism in the solvent collecting unit drying step performed in parallel with the chamber drying step described above. This is because the time required for the solvent collecting part drying step can be shortened.

FIG. 4 is a diagram showing a state around the exhaust pipe 30 provided with the closing member in order to explain another example of the closing member, and only the exhaust pipe 30 is shown in cross section.
In the above example, the vacuum drying device 1 has an APC valve 31 whose opening degree can be adjusted as a "closing member", but as shown in FIG. 4, the opening degree cannot be adjusted, but the exhaust pipe 30 is provided. A shutter 60 that can be opened and closed and closed may be provided as a "closing member". In the example of FIG. 4, the shutter 60 is hinged and attached to the exhaust pipe 30. The shutter 60 is controlled by the control unit 40.

Further, in the configuration having the shutter 60, the decompression speed in the chamber 10 can be controlled by adjusting the number of the exhaust pipes 30 that open the shutter 60. For example, in a configuration having a shutter 60, when it is necessary to lower the decompression rate in the first half of the substrate drying step and increase it in the second half, first, the shutter 60 is closed for the exhaust pipe 30 with the solvent collecting portion. The shutter 60 is opened for the exhaust pipe 30 without the solvent collecting portion, and the shutter 60 is also opened for the exhaust pipe 30 with the solvent collecting portion after it is no longer necessary to reduce the depressurizing speed. Further, for example, in a configuration having a shutter 60, when it is necessary to increase the decompression speed in the first half portion of the substrate drying step and decrease it in the second half portion, first, the shutter 60 is opened for all the exhaust pipes 30 to reduce the pressure. After it becomes necessary to reduce the speed, the shutter 60 is kept in the open state only for the exhaust pipe 30 with the solvent collecting portion, and the shutter 60 is closed for the exhaust pipe 30 without the solvent collecting portion.

FIG. 5 is a diagram showing another example of the bottom plate 13 of the chamber 10.
In the above example, the bottom plate 13 is provided with a plurality of openings 13a and 13b along one side of the mounting table 20 and the same number of openings 13a and 13b along the side facing the one side. However, the number of bottom plates 13 is not limited to this example, and as shown in FIG. 5, the same number of bottom plates 13 may be provided along each side of the mounting table 20.
Further, in the above example, the number of openings 13a and 13b provided in the bottom plate 13 is 12, but it may be a plurality of openings, and may be less than 12 or more than 12.
Further, the exhaust pipe 30 communicates with each of the openings 13a and 13b.

FIG. 6 is a side view showing another example of the exhaust line of the vacuum drying device 1, and in the above-mentioned example showing only the bottom plate 13 of the chamber 10 and the exhaust line, the exhaust line of the vacuum drying device 1 is exhausted. One exhaust device P was connected to each of the pipes 30. However, the exhaust line of the vacuum drying device 1 is not limited to this example, and as shown in FIG. 6, a plurality of exhaust pipes 30 may share one exhaust device P.

Also in this case, only a part of the plurality of exhaust pipes 30 is provided with the solvent collecting portion 32 downstream of the APC valve 31, and the substrate drying step and the chamber drying step are performed in the same manner as described above to perform the plurality of exhaust pipes. Achieving a state in which a small amount of solvent is contained in the chamber 10 more quickly than a configuration in which the solvent collecting unit 32 is provided in all 30 or a configuration in which the solvent collecting unit 32 is not provided in any of the plurality of exhaust pipes 30. That is, a state in which the pressure in the chamber 10 is sufficiently low can be achieved.

FIG. 7 is a diagram showing a state around the exhaust pipe 30 in order to explain another example of the exhaust line of the vacuum drying device 1.
In the above example, in the exhaust pipe 30 of the exhaust line of the vacuum drying device 1, nothing was provided between the closing member and the solvent collecting portion 32, but as shown in FIG. 7, the closing member ( In the example of the figure, a gas supply unit 70 is provided between the APC valve 31) and the solvent collection unit 32 to supply the gas that promotes the vaporization of the solvent collected in the solvent collection unit 32 into the exhaust pipe 30. You may.

When the gas supply unit 70 is provided in this way, when the APC valve 31 of the exhaust pipe 30 with the solvent collection unit is closed in the chamber drying step and the solvent collection unit drying step described above, the gas supply unit 70 is interlocked with the gas supply unit 70. Therefore, it is preferable to start the gas supply to the gas supply unit 70, that is, the gas supply to the solvent collection unit 32. The gas supplied from the gas supply unit 70 is, for example, an inert gas. If the supply amount of the gas is such that the pressure around the solvent collecting portion 32 in the exhaust pipe 30 does not exceed the vapor pressure of the solvent collected in the solvent collecting portion 32, the solvent is efficiently collected. The part 32 can be dried.

(Other variants)
In the above example, the APC valves 31 were opened for all the exhaust pipes 30 at the time of decompression exhaust in the chamber 10 in the substrate drying step. However, in the substrate drying step, the APC valve 31 may be opened only for the exhaust pipe 30 having the solvent collecting portion among the plurality of exhaust pipes 30. In this case, all the APC valves 31 may be opened after the pressure in the chamber 10 becomes smaller than the predetermined value, that is, after the substrate W has been dried to some extent.
By opening the APC valve 31 only for the exhaust pipe 30 having the solvent collecting portion among the plurality of exhaust pipes 30, the substrate W can be dried more uniformly depending on the solvent. In this case, the time required for drying the substrate W is longer than in the case where all the exhaust pipes 30 are opened from the beginning, but after the substrate W has been dried to some extent, all the APC valves 31 are opened. By setting the state, it is possible to achieve both uniform drying of the substrate W and drying of the substrate W in a short time.

In the above example, the substrate is carried out after the solvent collecting part drying step is completed. However, in the case where one exhaust device P is provided for each of the exhaust pipes 30, if the time required for the solvent collecting unit drying step is longer than the time required for the chamber drying step, the solvent collecting unit drying step is completed. Before, the board unloading step and the next board loading step may be performed.

Further, in the above example, the closing member such as the APC valve 31 is provided in the exhaust pipe 30, but it may be provided in the exhaust passage, for example, even if it is provided in the openings 13a and 13b. It may be provided on the upper surface of the bottom plate 13 so as to close the openings 13a and 13b.
Similarly, the solvent collecting portion 32 may be provided in the opening 13b instead of the exhaust pipe 30 as long as it is downstream of the closing member.

The present invention is useful in a technique for vacuum drying a substrate coated with a solution by an inkjet method.

1 Vacuum drying device 10 Processing container 11 Main body 12 Top plate 13 Bottom plates 13a, 13b Opening 20 Mounting stand 30 Exhaust pipe 31 Valve 32 Solvent collecting part 32a Net-like plate 40 Control part 50 Refrigerant pipe 60 Shutter

Claims (6)

A vacuum drying device that dries the solvent in the organic material film applied to the surface of the substrate under reduced pressure.
A chamber for accommodating the substrate and
A plurality of exhaust passages connecting the space in the chamber and the exhaust device for exhausting the inside of the chamber are provided.
Each of the plurality of exhaust passages has a closing member that closes the exhaust passage so as to be openable and closable.
The plurality of exhaust passages include an exhaust passage having a solvent collecting portion in which a solvent collecting portion for collecting a solvent in the organic material film vaporized from the substrate is provided downstream of the closing member, and the solvent collecting portion. part saw including a solvent collecting unit without exhaust passage is not provided,
The end of the exhaust passage with the solvent collecting portion on the chamber side is farther from the corner portion of the substrate housed in the chamber than the end of the exhaust passage without the solvent collecting portion on the chamber side. A vacuum drying device characterized by. A vacuum drying method using a vacuum drying device that dries the solvent in the organic material film applied to the surface of the substrate under reduced pressure.
The vacuum drying device includes a chamber for accommodating the substrate and a plurality of exhaust passages connecting a space in the chamber and an exhaust device for exhausting the inside of the chamber, and the plurality of exhaust passages each have the exhaust. A solvent having a closing member that opens and closes the path so as to be openable and closable, and a solvent collecting portion that collects the solvent in the organic material film vaporized from the substrate by the plurality of exhaust passages is provided downstream of the closing member. Includes an exhaust passage with a collecting portion and an exhaust passage without a solvent collecting portion without the solvent collecting portion.
The vacuum drying method is
Of the plurality of exhaust passages, at least the exhaust passage with a solvent collecting portion has a substrate drying step in which the closing member is opened.
After the substrate drying step, the chamber in which the closing member is closed for the exhaust passage with the solvent collecting portion and the closing member is opened for the exhaust passage without the solvent collecting portion among the plurality of exhaust passages. A vacuum drying method comprising a drying step. The vacuum drying method according to claim 2 , wherein the substrate drying step includes a step of cooling the solvent collecting portion. The vacuum drying method according to claim 2 or 3 , wherein the chamber drying step includes a step of heating the solvent collecting portion. The chamber drying step includes a step of supplying a gas for promoting vaporization of the solvent collected in the solvent collecting portion from a gas supply portion provided between the closing member and the solvent collecting portion. The vacuum drying method according to any one of claims 2 to 4, wherein the method is characterized by that. The end of the exhaust passage with the solvent collecting portion on the chamber side is farther from the corner portion of the substrate housed in the chamber than the end of the exhaust passage without the solvent collecting portion on the chamber side.
The substrate drying step is a step of opening the closing member for the exhaust passage with the solvent collecting portion among the plurality of exhaust passages, and then opening the closing member for all of the plurality of exhaust passages. The vacuum drying method according to any one of claims 2 to 5, wherein the method comprises the same.

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