TW201907132A - Vacuum drying device - Google Patents

Abstract

Provided is a reduced-pressure drying apparatus requiring a shorter time to complete a reduced-pressure drying process for a substrate. The reduced-pressure drying apparatus (1) for drying a solvent in an organic material film applied on a surface of a substrate (W) in a reduced pressure state comprises: a chamber (10) for containing the substrate, and a plurality of exhaust pipes (30) connecting to a space in the chamber (10) and connecting to an exhausting device (P) used for discharging gas in the chamber (10). Each of the plurality of exhaust pipes (30) has an APC valve (31) for freely closing the exhaust pipe (30) and includes the exhaust pipe (30) having a solvent collecting section, in which the solvent collecting section (32) for collecting the solvent vaporized from a solution on the substrate (W) is provided at a downstream of the APC valve (31), and the exhaust pipe (30) without the solvent collecting section is not provided with the solvent trapping section (21).

Description

Decompression drying device

The present invention relates to a reduced-pressure drying device for drying a solvent in an organic material film coated on a surface of a substrate under a reduced pressure.

Conventionally, an organic light emitting diode (OLED: Organic Light Emitting Diode), which is a light emitting diode using organic EL (Electroluminescence), is known. The organic EL display using this organic light emitting diode has the advantages of excellent response speed, viewing angle, and contrast, in addition to being thin and light, and has low power consumption. Therefore, in recent years, it has become the next-generation flat panel display (FPD). ) Attracted much attention.

An organic light emitting diode has a structure in which an organic EL layer is interposed between an anode and a cathode on a substrate. The organic EL layer is formed, for example, by sequentially stacking a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer from the anode side. When forming each of these organic EL layers (especially a hole injection layer, a hole transport layer, and a light emitting layer), for example, a method of ejecting droplets of an organic material on a substrate by an inkjet method can be used.

The organic material ejected onto the substrate by an inkjet method contains a large amount of a solvent. Therefore, for the purpose of removing the solvent, a reduced-pressure drying process is performed in which the solvent is dried under reduced pressure. A reduced-pressure drying device for performing reduced-pressure drying processing is provided with: a processing container, which houses a substrate for reduced-pressure drying, and can be evacuated; and an exhaust pipe, one end of which is connected to the processing container and the other end of which is provided The exhaust device is an exhaust device, and the inside of the processing container is exhausted by the exhaust device (see Patent Documents 1 and 2).

The decompression drying device of Patent Document 1 is for the purpose of quickly drying a substrate, etc. The exhaust pipe is provided with a solvent trapping unit for trapping a solvent volatile from an organic material film on the substrate. At the end, the valve provided between the solvent collection unit 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 processing container.

In addition, in the vacuum drying device of Patent Document 2, in order to efficiently remove the solvent in the processing container in a short period of time, the solvent trapping section is provided in the processing container, and an ultraviolet irradiation section is provided in the processing container. The reduced-pressure drying device irradiates ultraviolet rays from the ultraviolet ray irradiating section to the solvent trapping section to decompose the organic compounds contained in the solvent trapped by the solvent trapping section so as to be easily volatile. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2005-85814 [Patent Document 2] Japanese Patent Laid-Open No. 2014-238194

[Problems to be Solved by the Invention]

However, it is sometimes required that the time until the decompression drying of the substrate is completed, in other words, the time until the pressure in the processing container becomes below a predetermined value and no problem occurs even if the processing container returns to atmospheric pressure (tact time). It is shorter than the vacuum drying apparatus of patent documents 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 reduced-pressure drying device having a short time until the reduced-pressure drying of the substrate is completed. [Means to solve the problem]

In order to achieve the foregoing object, the present invention relates to a reduced-pressure drying device for drying a solvent in an organic material film coated on a surface of a substrate under a reduced pressure. The reduced-pressure drying device is characterized in that: Equipped with: a chamber, which houses the substrate; and a plurality of exhaust paths, which connect the space in the chamber and an exhaust device for exhausting the chamber, and the plurality of exhaust paths are each closed with a switch. The closed member of the exhaust path, the plurality of exhaust paths, includes: an exhaust path having a solvent trapping section, and downstream of the closed member, a method for trapping one of the solutions vaporized from the substrate is provided. The solvent trapping section of the solvent and the exhaust path without the solvent trapping section are not provided with the aforementioned solvent trapping section.

The end portion on the chamber side of the exhaust path with the solvent trapping portion is farther away from the end portion on the chamber side of the exhaust path without the solvent trapping portion than the end portion on the chamber side of the exhaust path without the solvent trapping portion. The corners of the substrate are preferred.

It is preferable to include a temperature variable mechanism that cools and / or heats the solvent trapping unit.

It is preferable that a gas supply portion is provided between the solvent trapping portion and the closing member. The gas supply portion supplies a gas that promotes vaporization of the solvent trapped by the solvent trapping portion.

According to the present invention according to another aspect, a reduced-pressure drying method uses a reduced-pressure drying device, and the reduced-pressure drying device uses a solvent in an organic material film coated on a surface of a substrate under a reduced pressure. Drying, the reduced-pressure drying method is characterized in that the above-mentioned reduced-pressure drying device is provided with: a chamber that houses the substrate; and a plurality of exhaust paths connecting the space in the chamber and exhausting the chamber. The exhaust device has a plurality of exhaust paths, each of which has a closing member that can freely close the exhaust path. The exhaust paths include an exhaust path with a solvent trapping section. Downstream of the closed member, a solvent trapping section for trapping the solvent in the solution vaporized from the substrate is provided; and the exhaust path without the solvent trapping section is not provided with the solvent trapping section, and the vacuum drying is performed. The method includes: a substrate drying step, for at least the exhaust path having a solvent trapping section among the plurality of exhaust paths, causing the closed member to be opened; and a chamber dry A step of, after the substrate drying step, for the exhaust path of the solvent trapping section among the plurality of exhaust paths, the closed member is closed, and for the exhaust path of the solventless trap section, The closing member is in an opened state.

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

Preferably, the chamber drying step includes a step of heating the solvent trapping portion.

It is preferable that the chamber drying step includes a step of supplying, from a gas supply section provided between the sealing member and the solvent trap section, a solvent for promoting the trapping of the solvent trapped by the solvent trap section. Vaporized gas.

The end portion on the chamber side of the exhaust path with the solvent trapping portion is farther away from the end portion on the chamber side of the exhaust path without the solvent trapping portion than the end portion on the chamber side of the exhaust path without the solvent trapping portion. The corner portion of the substrate and the substrate drying step preferably include the following steps: For the exhaust path of the solvent trapping section among the plurality of exhaust paths, the closed member is turned on, and Then, the closed member is turned on for all of the plurality of exhaust paths. [Effect of the invention]

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

Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. In this specification and the drawings, the same reference numerals are given to the constituent elements having substantially the same functional configuration, and redundant description is omitted. The invention is not limited to the embodiments described below.

(First Embodiment) FIG. 1 is a diagram showing a schematic configuration of a vacuum drying apparatus according to an embodiment of the present invention; FIG. 1 (A) is a schematic cross-sectional view showing a structure of the vacuum drying apparatus; FIG. 1 (B) is a schematic top view which shows the outline of the structure in a vacuum drying apparatus. In addition, in FIG.1 (B), illustration of the top plate etc. mentioned later is abbreviate | omitted.

The reduced-pressure drying device of this embodiment is a method for drying a solvent in an organic material film coated on the surface of a substrate by an inkjet method in a reduced-pressure state. The substrate of the substrate to be processed by the device is, for example, organic Glass substrate for EL displays. In addition, the solution applied to the substrate of the processing target of the device is composed of a solute and a solvent, and is a component of the target of the reduced-pressure drying treatment, which is mainly a solvent. The organic compounds contained in the solvent are mostly those having a high boiling point. For example, 1,3-dimethyl-2-imidazolidinone (boiling point 220 ° C, melting point 8) ℃), 4-tert-Butylanisole (4-tert-Butylanisole, boiling point 222 ° C, melting point 18 ° C), Trans-Anethole (Trans-Anethole, boiling point 235 ° C, melting point 20 ° C), 1,2- Dimethoxybenzene (1,2-Dimethoxybenzene, boiling point 206.7 ° C, melting point 22.5 ° C), 2-methoxybiphenyl (2-Methoxybiphenyl, boiling point 274 ° C, melting point 28 ° C), diphenyl ether (Phenyl Ether, boiling point 258.3 ℃, melting point 28 ° C), 2-ethoxynaphthalene (boiling point 282 ° C, melting point 35 ° C), benzyl phenyl ether (Benzyl Phenyl Ether, boiling point 288 ° C, melting point 39 ° C), 2,6- Dimethoxytoluene (2,6-Dimethoxytoluene, boiling point 222 ° C, melting point 39 ° C), 2-propoxynaphthalene (boiling point 305 ° C, melting point 40 ° C), 1,2,3-trimethoxy Benzene (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, melting point -7 ° C) ),1 , 2,3,4-tetramethylbenzene (1,2,3,4-tetramethylbenzene, boiling point 203 ° C, melting point 76 ° C) and so on. These high-boiling organic compounds may be mixed in a solution in a combination of two or more kinds.

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

The chamber 10 is configured as an airtight, and is formed of a metallic material such as stainless steel. The chamber 10 includes a rectangular cylindrical body portion 11, a top plate 12 attached to the upper side of the body portion 11, and a bottom plate 13 attached to the lower side of the body portion 11.

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

The bottom plate 13 closes the opening on the lower side of the main body portion 11, and a mounting table 20 is arranged at the center on 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 periphery 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 along the side opposite to the above side, for a total of twelve. The exhaust pipes 30 communicate with the openings 13a, respectively.

The mounting table 20 is a substrate on which the substrate W is mounted. The mounting table 20 is provided with a lifting pin (not shown) for receiving and receiving the substrate W, and the lifting pin is freely movable up and down by a lifting mechanism.

The plurality of exhaust pipes 30 are connected to the chamber 10 and the exhaust device P, respectively. The "exhaust path" of the present invention is constituted by the exhaust pipe 30 and the openings 13a and 13b of the bottom plate 13. The exhaust path connects the substrate accommodation space in the chamber 10 and the exhaust device P. In the reduced-pressure drying device 1, the inside of the chamber 10 is decompressed by the exhaust device P through the exhaust pipe 30 and the openings 13a and 13b constituting the "exhaust path" described above.

The exhaust device P is constituted by a vacuum pump, specifically, a turbo molecular pump and a dry pump are sequentially connected in series from the upstream side, for example. This exhaust device P is provided for each exhaust path, specifically for each exhaust pipe 30.

The exhaust pipe 30 includes an automatic pressure control valve (APC (Adaptive Pressure Control) Valve) 31 as a closing member that can freely close the exhaust pipe 30 by a switch. In other words, an APC valve 31 is provided in a portion between the openings 13 a and 13 b of the exhaust pipe 30 and the exhaust device P. In the reduced-pressure drying device 1, the opening and closing degree of the APC valve 31 is adjusted in a state where the exhaust device P is activated, thereby controlling the vacuum degree / pressure in the chamber 10 during the reduced-pressure exhaust. And the drying speed of the substrate W is controlled.

The reduced-pressure drying device 1 is a pressure gauge (not shown) that measures the pressure in the chamber 10. The measurement result of this pressure gauge is input as an electrical signal to the APC valve 31 or a control unit 40 described later.

In addition, only a part of the plurality of exhaust pipes 30 has a solvent trapping section 32 downstream of the APC valve 31. The solvent trapping section 32 captures the solvent that is applied to the substrate W by an inkjet method. Solvent vaporized solvent. Specifically, the exhaust pipe 30 provided to the opening 13 a of the plurality of exhaust pipes 30 that is close to the corner of the substrate W on the mounting table 20 is not provided with the solvent trapping section 32. The exhaust pipe 30 provided in the opening 13b of the section is provided with a solvent trapping section 32.

That is, the plurality of exhaust paths include: an exhaust path with a solvent trapping section, and a downstream of the APC valve 31, a solvent trapping section 32; and an exhaust path without a solvent trapping section. A solvent trapping section 32 is provided. In addition, the opening 13a on the side of the chamber 10 side of the exhaust path having the solvent trapping portion is more open than the opening 13b on the side of the exhaust path 10 side without the solvent trapping portion. The corners of the wafer W placed in the chamber 10 and placed on the mounting table 20.

The solvent trapping portion 32 is a thin plate, that is, a mesh plate (not shown), whose openings are uniformly formed into a grid shape, so that the gas discharged from the chamber 10 can be passed through while trapping the gas. The solvent. The mesh plate is formed of a stainless steel or a metal material such as aluminum, copper, or gold, and is made of, for example, an expanded metal produced by cold cutting a steel plate. The reticular plate of the tritium solvent collection unit 32 may be one sheet, or a plurality of sheets may be laminated. The mesh plate is formed so that its outer diameter is substantially equal to the inner diameter of the exhaust pipe 30.

The reduced-pressure drying apparatus 1 having the above-mentioned sections further includes a control section 40, an APC valve 31, and the like. The control unit 40 is, for example, a computer, and includes a program storage unit (not shown). In the program storage section, a program for controlling the reduced-pressure drying process in the reduced-pressure drying device 1 is stored. In addition, the aforementioned programs can be read by a computer that can be recorded on a computer-readable hard disk (HD), floppy disk (FD), optical disk (CD), magneto-optical disk (MO), memory card, etc. It is also possible to use a storage medium from the storage medium to the control unit 40. The control unit 40 can also perform control of the exhaust device P.

Next, a reduced-pressure drying process using the reduced-pressure drying device 1 will be described.

(Substrate carrying-in step) (1) In the reduced-pressure drying process using the reduced-pressure drying device 1, first, the substrate W on which the processing liquid is applied by the inkjet method is placed on the mounting table 20.

(Substrate drying step) Next, in a state where the dry pump of the exhaust device P is operated, at least an exhaust pipe 30 (hereinafter, there is a solvent trap) provided with a solvent trapping section 32 among the plurality of exhaust pipes 30 In this example, the APC valve 31 is opened for all the exhaust pipes 30, and the reduced-pressure 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. Thereafter, the turbo molecular pump of the exhaust device P is operated to further decompress the exhaust gas. By further depressurizing the exhaust, if the pressure in the chamber 10 becomes the vapor pressure of the solvent at the temperature of the substrate W or less (in the case where the temperature of the substrate W is 23 ° C, 0.2 Pa or less), the The evaporation rate of the solvent S is increased. In addition, when the gas is decompressed and exhausted, the gas in the chamber 10 is adiabatically expanded and cooled, and the temperature of the solvent trapping unit 32 is lowered by the gas in the cooled chamber 10 as described above. Specifically, when the pressure in the chamber 10 is reduced to 0.2 Pa, the solvent trapping unit 32 is cooled to 5 to 12 ° C. The temperature of 5-12 ° C is 23 ° C which is the dew point of the solvent less than 0.2Pa. In addition, the temperature of the solvent collection unit 32 is maintained below the dew point of the solvent S under the pressure in the chamber 10 at each point in time until the evaporation of the solvent S on the substrate W is completed. Therefore, since the solvent vaporized from the substrate W is efficiently captured by the solvent trapping unit 32, the concentration of the gaseous solvent in the chamber 10 is kept low. Therefore, the solvent on W on the substrate can be quickly removed. In addition, as a method for maintaining the temperature of the solvent collection unit 32 below the dew point as described above, a method using a smaller heat capacity as the mesh plate of the solvent collection unit 32 is considered. The 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 until the second predetermined time has elapsed since the operation of the turbo molecular pump of the exhaust device P started. until.

(Chamber drying step) After the substrate drying step, the APC valve 31 is closed for the exhaust pipe 30 having the solvent trapping section, and the exhaust pipe 30 (hereinafter, no solvent is not provided for the solvent trapping section 32). The exhaust pipe 30) of the trapping section keeps the APC valve 31 in an open state. This chamber drying step is performed, for example, until the solvent in the chamber 10 becomes less than a predetermined amount, that is, until the pressure in the chamber becomes less than a second predetermined value, or until the operation of the turbo molecular pump of the exhaust device P is performed. The second scheduled time starts. The second predetermined value or the second predetermined time is a value or time during which the solvent remaining in the chamber 10 does not adhere to the substrate W when the pressure in the chamber 10 is returned to atmospheric pressure.

(Drying step of solvent trapping section) During the drying step of the chamber, the drying step of the solvent trapping section is also performed at the same time. In the solvent trapping section drying step, the solvent trapping section 32 is heated and dried by using heat radiation from a side wall of the exhaust pipe 30 or a turbo molecular pump or the like. For example, the temperature of the solvent trapping part 32 is the dew point of the solvent which rises to the pressure in the exhaust pipe 30 at that time by the above-mentioned heat radiation (when the pressure in the exhaust pipe 30 is 0.05 Pa, 18 ~ 23 ℃). Therefore, the solvent can be quickly removed / detached from the solvent collection unit 32 and the solvent collection unit 32 can be dried.

(Substrate removal step) 后 After the chamber drying step and the solvent trapping section drying step are completed, the APC valve 31 is closed for all the exhaust pipes 30, and then the pressure in the chamber 10 is returned to atmospheric pressure. The substrate W is carried out from the chamber 10.

After the substrate carrying-out step, the turbo molecular pump of the exhaust device P is stopped, and the steps are sequentially repeated from the substrate carrying-in step.

As described above, in the reduced-pressure drying apparatus 1, only a part of the plurality of exhaust pipes 30 is provided, and the solvent trap portion 32 is provided downstream of the APC valve 31. Therefore, the substrate drying step and the chamber drying step can be sequentially performed. The substrate drying step is to open the APC valve 31 to the exhaust pipe 30 of the plurality of exhaust pipes 30 having a solvent trapping section. The chamber drying step is to close the APC valve 31 to the exhaust pipe 30 having the solvent trapping section among the plurality of exhaust pipes 30, and to maintain the APC valve for the exhaust pipe 30 having no solvent trapping section. Open state of 31. Therefore, it has the following effects.

FIG. 2 is a diagram illustrating the effect of the decompression drying device 1. The horizontal axis represents the elapsed time from the start of exhaust. Specifically, the pressure in the chamber 10 is at the atmospheric pressure, and the APC valve 31 is set. The elapsed time after the state is turned on, the vertical axis indicates the pressure in the chamber 10.

(Case 1) In the reduced-pressure drying device 1, when all the plurality of exhaust pipes 30 do not have the solvent trapping section 32, even if the APC valves 31 are opened for all the exhaust pipes 30, As shown in FIG. 2, after the pressure in the chamber 10 is maintained at a relatively high state (about 1 Pa), it gradually decreases, but until the pressure in the chamber 10 reaches the aforementioned second predetermined value (for example, 0.09). Pa) It takes more than 140 seconds for the following.

(Case 2) In the reduced-pressure drying apparatus 1, when all of the plurality of exhaust pipes 30 have a solvent trapping section 32, the APC valve 31 may be opened for all the exhaust pipes 30. The pressure in the chamber 10 is lowered to about 0.2 Pa more rapidly than in the case 1 described above. However, even when 200 seconds have elapsed, the pressure in the chamber 10 cannot be reduced to the aforementioned second predetermined value (0.09 Pa) or less.

In this regard, only a part of the plurality of exhaust pipes 30 has a solvent trapping section 32 downstream of the APC valve 31, and a substrate drying step is performed for about 80 seconds. Thereafter, a chamber drying step is performed. The APC valve 31 is opened for all the exhaust pipes 30 including the exhaust pipe 30 including the solvent trapping portion. This chamber drying step is performed by using the APC valve 31 for the exhaust pipe 30 having the solvent trapping portion. The closed state is maintained, and the open state of the APC valve 31 is maintained with respect to the exhaust pipe 30 of the non-solvent trapping section. In this case, the pressure in the chamber 10 can be reduced to 0.2 Pa at the same speed as in Case 1, and the pressure in the chamber 10 can be made not only below the second predetermined value but also until the first 2 It only takes about 85 seconds to reach the predetermined value. (2) In the reduced-pressure drying step using the reduced-pressure drying device 1 as described above, the pressure in the chamber 10 can be rapidly reduced to the aforementioned second predetermined value or less.

The reduced-pressure drying device 1 has the following effects. When the substrate W having a quadrangular shape in plan view is dried under reduced pressure, the corners of the substrate W are more easily dried than other portions. However, it is preferable that the drying time of the substrate W is uniform within the same substrate. In addition, the portion closer to the exhaust pipe 30 provided with the solvent collecting portion 32 than the portion remote from the exhaust pipe 30 provided with the solvent collecting portion 32 in the substrate is more easily dried. Therefore, in the reduced-pressure drying apparatus 1, a solvent trap portion is provided only in the exhaust pipe 30 provided in the opening 13 b of the corner portion of the plurality of exhaust pipes 30 that is remote from the substrate W on the mounting table 20. 32. Thereby, even if the opening and closing degree of the APC valve 31 is not changed for each exhaust pipe 30, the in-plane uniformity of the drying time of the substrate W can be improved.

FIG. 3 is a diagram showing a structure of a solvent trapping unit 32 in another example of the reduced-pressure drying apparatus 1. In the foregoing example, the cooling or heating of the solvent trapping unit 32, that is, heating is performed by the gas in the chamber 10 cooled by adiabatic expansion during decompression or heat radiation from the exhaust pipe 30 or the like.

Alternatively, it may be configured as shown in FIG. 3, and a plurality of refrigerant pipes 50 may be used as a temperature-varying mechanism for cooling and heating the solvent trapping unit 32, and the refrigerant pipes 50 may be fixed by welding or the like. The cooling plate and the heated cooling medium are alternately flowed on the mesh plate 32a that collects the solvent, thereby cooling and heating the solvent collecting portion 32, that is, the mesh plate 32a. Thereby, the solvent collection part 32 can be cooled / heated more quickly and appropriately.

When the temperature-variable mechanism is provided in the reduced-pressure drying device 1 as described above, in the substrate drying step described above, it is preferable to cool the solvent collection unit 32 by the temperature-variable mechanism. This can shorten the time required for the substrate drying step. In the case where a temperature-variable mechanism is provided, it is preferable that the solvent-trapping unit 32 is heated by the temperature-variable mechanism in the solvent-trapping unit drying step performed simultaneously with the chamber drying step. This can shorten the time required for the drying step of the solvent trapping section.

FIG. 4 is a view showing the state of the periphery of the exhaust pipe 30 provided with the closing member for explaining another example of the closing member, and only shows a cross section of the exhaust pipe 30. In the aforementioned example, although the decompression drying device 1 has the APC valve 31 whose opening and closing degree can be adjusted as a "closed member", as shown in Fig. 4, it is also possible to have the opening and closing of the exhaust gas freely closed although the opening and closing degree cannot be adjusted The baffle 60 of the tube 30 serves as a "closed member". In the example of FIG. 4, the baffle 60 is hingedly attached to the exhaust pipe 30. The baffle 60 is controlled by the control unit 40.

In addition, in the configuration having the baffle 60, the pressure reduction speed in the chamber 10 can be controlled by adjusting the number of the exhaust pipes 30 that make the baffle 60 into an open state. For example, in the configuration having the baffle 60, when it is necessary to reduce the decompression speed in the first half of the substrate drying step and increase it in the second half, first, the exhaust pipe 30 having the solvent trapping section is maintained at The plate 60 is turned off, and the baffle 60 is turned on for the exhaust pipe 30 without the solvent trapping section. After the decompression speed does not need to be reduced, the exhaust pipe 30 with the solvent trapping section is also turned off. The plate 60 is turned on. Also, for example, in a configuration having a baffle 60, when it is necessary to increase the decompression speed in the first half of the substrate drying step and decrease it in the second half, first, for all the exhaust pipes 30, the baffle 60 is made In the opened state, and after it is necessary to reduce the decompression speed, the baffle 60 is maintained in the open state only for the exhaust pipe 30 with the solvent trapping portion, and the baffle 60 becomes the exhaust pipe 30 without the solvent trapping portion. Disabled.

FIG. 5 is a diagram showing another example of the bottom plate 13 of the chamber 10. In the aforementioned example, the bottom plate 13 is provided with a plurality of openings 13a, 13b along one side of the mounting table 20, and the same number is provided along the side opposite to the above side. However, the bottom plate 13 is not limited to this example, and as shown in FIG. 5, the same number may be provided one by one along each side of the mounting table 20. In addition, in the above example, although the number of the openings 13a, 13b provided in the bottom plate 13 is twelve, as long as it is plural, it may be less than twelve or more. The exhaust pipe 30 is connected to 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 shows only the bottom plate 13 and the exhaust line of the chamber 10. In the foregoing example, the exhaust line of the vacuum drying device 1 is configured such that one exhaust device P is connected to the exhaust pipe 30. However, the exhaust line of the reduced-pressure drying device 1 is not limited to this example, and as shown in FIG. 6, a configuration in which one exhaust device P is commonly used for a plurality of exhaust pipes 30 may be used.

Also in this case, only a part of the plurality of exhaust pipes 30 is provided with a solvent trapping section 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, thereby comparing with The configuration in which the solvent trapping section 32 is provided in all of the plurality of exhaust pipes 30 or the configuration in which the solvent trapping section 32 is not provided in any of the plurality of exhaust pipes 30 can be quickly achieved in the chamber 10. The solvent is in a small amount, that is, a state in which the pressure in the chamber 10 is sufficiently low is achieved.

FIG. 7 is a view showing the state of the periphery of the exhaust pipe 30 for explaining another example of the exhaust line of the vacuum drying device 1. In the foregoing example, although it is in the exhaust pipe 30 of the exhaust line of the vacuum drying device 1, no member is provided between the closing member and the solvent trapping section 32, but as shown in FIG. 7, A gas supply unit 70 may be provided between the closed member (in the illustration, APC valve 31) and the solvent collection unit 32. The gas supply unit 70 promotes the vaporization of the solvent captured by the solvent collection unit 32. The gas is supplied into the exhaust pipe 30.

When the gas supply unit 70 is provided as described above, in the chamber drying step and the solvent trapping section drying step described above, the APC valve 31 is closed for the exhaust pipe 30 having the solvent trapping section. In this case, it is preferable to start supplying gas to the gas supply unit 70 in conjunction with this, that is, to start supplying gas to the solvent collection unit 32. The gas supplied from the gas supply unit 70 is, for example, an inert gas. As long as the supply amount of the gas is such that the pressure around the solvent trapping portion 32 in the exhaust pipe 30 does not exceed the vapor pressure of the solvent trapped to the solvent trapping portion 32, the solvent trapping can be efficiently performed. Portion 32 is dry.

(Other Modifications) In the above example, when the reduced-pressure exhaust is performed in the chamber 10 in the substrate drying step, the APC valves 31 are opened for all the exhaust pipes 30. However, in the substrate drying step, the APC valve 31 may be opened only for the exhaust pipe 30 having the solvent trap 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 a predetermined value, that is, after the substrate W is dried to a certain degree. Only for the exhaust pipe 30 having the solvent trapping section among the plurality of exhaust pipes 30, the APC valve 31 is opened, whereby the substrate W can be dried more uniformly depending on the solvent. In this case, although the time required for drying the substrate W is longer than when all the exhaust pipes 30 are turned on from the beginning, all the APCs are made after the drying of the substrate W is performed to a certain degree. The valve 31 is in an opened state, whereby both the substrate W can be dried uniformly and the substrate W can be dried in a short time.

In the above example, the substrate carrying-out step is performed after the drying step of the solvent trapping section is completed. However, as long as one exhaust device P is provided for each of the exhaust pipes 30, when the time required for the drying step of the solvent trapping section is longer than the time required for the chamber drying step, the Before the completion of the drying step of the solvent trapping unit, a substrate carrying-out step or a next substrate carrying-in step is performed.

In the above example, although the closing members such as the APC valve 31 are provided in the exhaust pipe 30, they may be provided in the exhaust path. For example, they may be provided in the openings 13a and 13b. It can also be arranged on the bottom plate 13 in a manner of closing the openings 13a, 13b. Similarly, the solvent trapping section 32 may be provided in the opening 13b instead of the exhaust pipe 30 as long as it is located downstream of the closed member. [Industrial availability]

The present invention is useful for a technique in which a substrate coated with a solution by an inkjet method is dried under reduced pressure.

1‧‧‧ vacuum drying device

10‧‧‧handling container

11‧‧‧Body

12‧‧‧ roof

13‧‧‧ floor

13a, 13b‧‧‧ opening

20‧‧‧mounting table

30‧‧‧Exhaust pipe

31‧‧‧ Valve

32‧‧‧Solvent Capture Department

32a‧‧‧ mesh plate

40‧‧‧Control Department

50‧‧‧Refrigerant tube

60‧‧‧ bezel

[Fig. 1] A diagram showing a schematic configuration of a reduced-pressure drying apparatus according to an embodiment of the present invention. [Fig. 2] A diagram explaining the effect of the reduced-pressure drying device of Fig. 1. [Fig. [Fig. 3] A diagram showing the structure of a solvent trapping unit in another example of the vacuum drying apparatus. [Fig. 4] A diagram showing a state around the exhaust pipe provided with the closing member of another example. [Fig. 5] A diagram showing another example of the bottom plate of the chamber. [Fig. 6] A side view showing another example of the exhaust line of the vacuum drying device. [Fig. 7] An explanatory diagram showing another example of the exhaust line of the vacuum drying device.

Claims (9)

A reduced-pressure drying device for drying a solvent in an organic material film coated on a surface of a substrate under a reduced-pressure state. The reduced-pressure drying device is characterized by comprising: a chamber that houses the substrate; and A plurality of exhaust paths connect the space in the chamber with an exhaust device for exhausting the aforementioned chamber. The aforementioned plurality of exhaust paths each have a closing member which can freely close the exhaust path. 开关 The aforementioned plural The exhaust path includes an exhaust path including a solvent trapping section, and a solvent trapping section for trapping a solvent in the solution vaporized from the substrate is provided downstream of the sealing member; and a solventless trapping section; The exhaust path of the collecting part is not provided with the aforementioned solvent collecting part. For example, the reduced-pressure drying device of the scope of patent application, wherein: the end portion on the chamber side of the exhaust path having the solvent trapping portion is compared with the cavity on the exhaust path of the non-solvent trapping portion; The end portion on the chamber side is further away from the corner portion of the substrate accommodated in the chamber. For example, the reduced-pressure drying device according to the first or second aspect of the patent application scope includes: (i) a temperature-variable mechanism for cooling and / or heating the solvent trapping unit; For example, the reduced-pressure drying device according to the first or second aspect of the patent application, wherein: 供给 a gas supply unit is provided between the solvent collection unit and the closed member, and the gas supply unit is configured to facilitate the capture by the solvent collection unit The gas of the collected solvent. A reduced-pressure drying method using a reduced-pressure drying device for drying a solvent in an organic material film coated on a surface of a substrate under a reduced-pressure state. A feature: The aforementioned decompression drying device is provided with: a chamber that houses the substrate; and a plurality of exhaust paths connecting the space in the chamber and an exhaust device that exhausts the chamber, the plurality of rows The air path is a closed member with a switch that can freely close the exhaust path. The aforementioned plurality of exhaust paths include: an exhaust path with a solvent trapping section, and a trap is disposed downstream of the closed member. The solvent trapping portion of the solvent in the solution vaporized from the substrate; and the exhaust path of the solvent-free trapping portion is not provided with the solvent trapping portion. The reduced-pressure drying method includes: a substrate drying step , For at least the exhaust path having the solvent trapping section among the plurality of exhaust paths, the closed member is turned on; and the chamber A drying step, after the substrate drying step, for the exhaust path having the solvent trapping section among the plurality of exhaust paths, the closed member is closed, and for the exhaust path without the solvent trapping section, The closed member is brought into an open state. For example, the vacuum drying method according to item 5 of the patent application scope, wherein the substrate drying step includes a step of cooling the solvent trapping section. For example, the vacuum drying method according to item 5 or 6 of the scope of patent application, wherein: the aforementioned chamber drying step includes a step of heating the solvent trapping section. The reduced-pressure drying method according to claim 5 or 6, wherein the above-mentioned chamber drying step includes the following steps: from a gas supply section provided between the closed member and the solvent trap section; A gas is supplied to promote the vaporization of the solvent trapped by the solvent trapping section. For example, the method of decompressing and drying according to item 5 or 6 of the scope of patent application, wherein: 端 the end portion on the chamber side of the exhaust path having the solvent trapping portion is smaller than that of the exhaust path of the solvent-free trapping portion; The end portion on the side of the chamber is further away from the corner portion of the substrate housed in the chamber. The substrate drying step preferably includes the following steps: For the aforementioned solvent in the plurality of exhaust paths, The exhaust path of the trapping unit causes the closed member to be opened, and thereafter, the closed member is opened to all the plurality of exhaust paths.