JP2022172679A - Vacuum dryer, vacuum drying method, and method for shortening the time for vacuum drying process - Google Patents

Abstract

To shorten the time for posttreatment steps in a vacuum drying process, thus shortening the total time for the whole vacuum drying process.SOLUTION: A vacuum dryer dries a solution on a substrate under reduced pressure. The vacuum dryer has: a treatment vessel that can be decompressed and houses the substrate; a mounting table that is provided in the treatment vessel and allows the substrate to be mounted thereon; and a solvent trap that traps a solvent in the solution having been vaporized from the substrate upon vacuum drying and released into the treatment vessel. The solvent trap has been processed so as to increase its radiation rate.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a vacuum drying apparatus, a vacuum drying treatment method, and a method for shortening the time required for vacuum drying treatment.

Patent Literature 1 discloses a reduced pressure drying apparatus for drying an organic material applied to a substrate under reduced pressure.
Patent Literature 2 discloses a reduced-pressure drying apparatus provided with a solvent collector that is provided to face a substrate mounted on a mounting table and temporarily collects the solvent in the solution that has evaporated from the substrate. there is

JP 2017-73338 A JP 2020-190405 A

The technology according to the present disclosure shortens the time required for the post-processing step in the reduced-pressure drying process, and shortens the time required for the entire reduced-pressure drying process.

One aspect of the present disclosure is a reduced pressure drying apparatus that dries a solution on a substrate in a reduced pressure state, comprising: a processing container configured to be decompressible and containing the substrate; a mounting table on which the , is processed to improve the emissivity of the solvent collector.

According to the present invention, the time required for the post-treatment step in the reduced pressure drying process can be shortened, and the time required for the entire reduced pressure drying process can be shortened.

It is a cross-sectional view which shows roughly the inside of the reduced-pressure drying apparatus which concerns on a 1st form. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1; FIG. 2 is a cross-sectional view taken along line BB of FIG. 1; FIG. 4 is a partially enlarged plan view of the solvent collector; 2 is a flowchart for explaining an example of a reduced pressure drying process using the reduced pressure drying apparatus of FIG. 1; FIG. 2 is a diagram showing the time change of the pressure in the chamber when the emissivity improvement treatment is not applied to the solvent collecting part of the vacuum drying apparatus of FIG. 1; It is a cross-sectional view which shows schematic structure of the reduced pressure drying apparatus concerning the modification of a 1st form. FIG. 6 is a longitudinal sectional view showing a schematic configuration of a reduced-pressure drying apparatus according to another modified example of the first embodiment; FIG. 6 is a longitudinal sectional view showing a schematic configuration of a reduced-pressure drying apparatus according to another modified example of the first embodiment; It is a vertical cross-sectional view showing a schematic configuration of a reduced pressure drying apparatus according to a second embodiment. FIG. 11 is a partially enlarged plan view of a protective net provided in a reduced-pressure drying apparatus according to a modified example of the second embodiment; FIG. 11 is a partially enlarged cross-sectional view for explaining another example of a heating unit that has a function of promoting detachment of a solvent from a protective net; FIG. 11 is a partially enlarged cross-sectional view for explaining another example of a heating unit that has a function of promoting detachment of a solvent from a protective net; It is a vertical cross-sectional view showing a schematic configuration of a reduced pressure drying apparatus according to a third embodiment. FIG. 5 is a cross-sectional view for explaining another example of the gas injection section; FIG. 10 is a cross-sectional view for explaining another example of a cooling section that cools the solvent collecting section;

2. Description of the Related Art Conventionally, an organic light emitting diode (OLED), which is a light emitting diode using organic EL (Electroluminescence) light emission, is known. Organic EL displays using such organic light-emitting diodes are thin, light, and low power consumption. In addition, they have advantages such as excellent response speed, viewing angle, and contrast ratio. In recent years, it has attracted attention as a panel display (FPD).

An 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 stacking, 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 layer of these organic EL layers (especially a hole injection layer, a hole transport layer and a light emitting layer), for example, droplets of an organic material are dispersedly arranged on a substrate by an inkjet method, and pixels of each color are formed. A method is used in which the organic material film of the pixel is applied in the bank by discharging the ink to the bank corresponding to the pixel.

A large amount of solvent is contained in the organic material ejected onto the substrate by the inkjet method. Therefore, for the purpose of removing the solvent, a reduced-pressure drying process is performed to dry the solution on the substrate under reduced pressure. This reduced-pressure drying process is performed using a reduced-pressure drying apparatus having a processing container that can be reduced in pressure and a substrate mounting table provided in the processing container (see Patent Documents 1 and 2).

Further, in the reduced-pressure drying apparatus disclosed in Patent Document 2, the solvent on the substrate is removed by providing in the processing container a solvent collecting unit that temporarily collects the solvent vaporized from the substrate placed on the mounting table. The time required for the solvent removal step, that is, the substrate drying step for drying the solution on the substrate is shortened, and the time required for the reduced-pressure drying process is shortened.

By the way, it is demanded to shorten the time required for the entire drying process under reduced pressure. Shortening the time required for the substrate drying process by providing the above-mentioned solvent collection part or the like leads to shortening the time required for the entire vacuum drying process. (hereinafter referred to as a post-treatment step), and this post-treatment step also affects the time required for the reduced pressure drying treatment. In the post-treatment process, for example, desorption of the solvent adsorbed to the constituent members (for example, the processing container) of the reduced-pressure drying apparatus during the substrate drying process is performed.

The technique according to the present disclosure shortens the time required for the post-processing step in the reduced-pressure drying process, and shortens the time required for the entire reduced-pressure drying process.

Hereinafter, a reduced pressure drying apparatus, a reduced pressure drying method, and a method for shortening the time required for the reduced pressure drying process according to the present disclosure will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description.

[First form]
<Decompression drying device>
1 to 3 are diagrams showing the schematic configuration of the reduced pressure drying apparatus according to the first embodiment, FIG. 1 is a cross-sectional view schematically showing the inside of the reduced pressure drying apparatus, and FIGS. 1 is a cross-sectional view taken along the line AA and a cross-sectional view taken along the line BB. FIG. 4 is a partially enlarged plan view of a solvent collecting portion, which will be described later.

The reduced-pressure drying apparatus 1 dries a solution applied on a substrate G by, for example, an ink jet method under reduced pressure. The substrate G to be processed by the reduced-pressure drying apparatus 1 is, for example, a glass substrate for an organic EL display, and has a planar size of 2.2 m×2.7 m.

The solution applied to the substrate G to be processed is composed of a solute and a solvent, and the component to be dried under reduced pressure is mainly the solvent. Many of the organic compounds contained in the solvent have high boiling points. - 4-tert-Butylanisole (boiling point 222°C, melting point 18°C), Trans-Anethole (boiling point 235°C, melting point 20°C), 1,2-Dimethoxybenzene , boiling point 206.7°C, melting point 22.5°C), 2-Methoxybiphenyl (boiling point 274°C, melting point 28°C), Phenyl Ether (boiling point 258.3°C, melting point 28°C), 2-ethoxynaphthalene (2- 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, melting point -7°C), 1,2,3,4-tetramethylbenzene (boiling point 203°C, melting point 76°C). Two or more of these high-boiling organic compounds may be combined into a solution in some cases.

The vacuum drying apparatus 1, as shown in FIGS. 1 to 3, has a chamber 10 as a processing container.

The chamber 10 is a container that can be depressurized, and is made of a metal material such as stainless steel. A substrate G is accommodated in the chamber 10 . Inside the chamber 10, a mounting table 20 on which the substrate G is mounted and a solvent collector 50, which will be described later, are provided. The chamber 10 also has side walls 11 , a top plate 12 and a bottom plate 13 .

The side wall 11 is provided so as to surround the mounting table 20 when viewed from the thickness direction (the Z direction in FIG. 1) of the solvent collecting portion 50, which will be described later. The side wall 11 has, for example, a square tubular shape and forms an opening in the upper and lower sides.
The side wall 11 is provided with a loading/unloading port 11a for loading/unloading the substrate G into/from the chamber 10 on the negative side in the X direction as shown in FIG. The loading/unloading port 11 a can be opened and closed by a gate valve 14 . The gate valve 14 is controlled by a controller U, which will be described later.

The top plate 12 is attached to the upper side of the side wall 11 so as to close the upper opening formed by the side wall 11 .

The bottom plate 13 is attached to the lower side of the side wall 11 so as to close the lower opening formed by the side wall 11 . A mounting table 20 is arranged in the center of the upper surface of the bottom plate 13 . The mounting table 20 is provided with a lifter (not shown) for transferring the substrate G between the mounting table 20 and an external transport device. The lifter can be freely moved up and down by a lifting mechanism (not shown). The elevating mechanism is controlled by a control unit U, which will be described later.

Further, the bottom plate 13 is provided with a plurality of exhaust ports 13a and 13b along the outer periphery of the mounting table 20, as shown in FIG. In this example, two exhaust ports 13 a are provided along the long side of the mounting table 20 on the negative side in the Y direction, and two exhaust ports 13 a are provided along the long side of the mounting table 20 on the positive side in the Y direction. In this example, three exhaust ports 13b are provided along the short side of the mounting table 20 on the negative side in the X direction, and three outlets 13b are provided along the short side of the mounting table 20 on the positive side in the X direction. .

An exhaust mechanism 31 for reducing the pressure in the chamber 10 is connected to the exhaust port 13a through an exhaust pipe 32, as shown in FIG. The exhaust mechanism 31 has a dry pump 31a for exhausting the inside of the chamber 10, a switching valve (not shown) for switching start/stop of exhaust by the dry pump 31a, and the like. The exhaust port 13 a , the exhaust mechanism 31 (specifically, the portion of the exhaust mechanism 31 that connects the exhaust pipe 32 and the dry pump 31 a ), and the exhaust pipe 32 constitute an exhaust line 30 . The exhaust line 30 is connected to a dry pump 31 a to exhaust the inside of the chamber 10 .

A protection net 33 is provided in the exhaust line 30 . The protection net 33 is a member that prevents objects from entering the dry pump 31a through the exhaust line 30 and protects the dry pump 31a, and is formed in a mesh shape. Stainless steel, for example, is used as the material of the protective net 33 . In this example, the protection net 33 is provided so as to cover the chamber 10 side end of the exhaust port 13a.

An exhaust mechanism 41 is connected to the exhaust port 13b through an exhaust pipe 42, as shown in FIG. The exhaust mechanism 41 further reduces the pressure in the chamber 10 that has been depressurized by the exhaust mechanism 31, and includes a turbo molecular pump 41a that further exhausts the interior of the chamber 10, and a switching valve that switches start/stop of exhaust by the turbo molecular pump 41a. (not shown). The exhaust port 13 b , the exhaust mechanism 41 (specifically, the portion connecting the exhaust pipe 42 and the turbo-molecular pump 41 a in the exhaust mechanism 41 ), and the exhaust pipe 42 constitute an exhaust line 40 . The exhaust line 40 is connected to a turbo-molecular pump 41 a to exhaust the inside of the chamber 10 .

A protection net 43 is provided in the exhaust line 40 . The protection net 43 is a member that prevents objects from entering the turbo-molecular pump 41a through the exhaust line 40 and protects the turbo-molecular pump 41a, and is formed in a mesh shape. Stainless steel, for example, is used as the material of the protective net 43 . In this example, the protection net 43 is provided so as to cover the chamber 10 side end of the exhaust port 13b.

The protection nets 33 and 43 do not capture small objects such as particles that cause defects in the substrate G, but rather large objects (such as screws) having a length and diameter of 1 mm or more, for example. be.
In addition, the solvent collecting portion 50, which will be described later, is also formed in a mesh like the protective nets 33 and 43, but the protective nets 33 and 43 have larger openings and opening ratios in the mesh portion, The openings 33 and 43 are, for example, 1 to 5 mm square.

The exhaust mechanisms 31 and 41 are controlled by a controller U, which will be described later. Further, the chamber 10 is provided with a pressure gauge (not shown) for measuring the pressure inside the chamber 10 in order to adjust the exhaust by the exhaust mechanisms 31 and 41 and the like.

Furthermore, a solvent collector 50 is provided inside the chamber 10 .
The solvent collecting part 50 temporarily collects the solvent in the solution vaporized from the substrate G mounted on the mounting table 20 . The solvent collector 50 is provided above the substrate G mounted on the mounting table 20 in the chamber 10 so as to face the substrate G. As shown in FIG. Specifically, the solvent collecting part 50 is arranged in the chamber 10 so as to face the substrate G mounted on the mounting table 20, that is, substantially parallel to the substrate G mounted on the mounting table 20. So, it is provided.

The solvent trapping part 50 is a net-like member, more specifically, a mesh plate-like member. has a plurality of through holes 50a penetrating through. The through-holes 50a are formed in a grid pattern over the entire surface of the solvent collecting portion 50 in a plan view (viewed in the Z direction in FIG. 3).

As the material of the solvent collecting part 50, a material having good thermal conductivity, for example, a metal material such as stainless steel is used. Also, the solvent collecting part 50 is formed thin, for example, so that its thickness is 0.05 mm to 0.2 mm. In a plan view, the dimensions of the solvent collector 50 are substantially the same as the dimensions of the mounting table 20 . The solvent collector 50 has a large opening ratio of 60% to 90% and a thin thickness of 0.05 to 0.2 mm as described above, and thus has a small heat capacity. Therefore, when the pressure inside the chamber 10 is reduced and the gas inside the chamber 10 is cooled by adiabatic expansion, the cooled gas cools the solvent collector 50 . The open area ratio of the solvent trapping portion 50 is given by (total area of the through holes 50a of the solvent trapping portion 50 in plan view)/(total area of the solvent trapping portion 50 in plan view).

Further, the solvent trapping portion 50 is processed to improve the emissivity of the solvent trapping portion 50 (hereinafter referred to as emissivity improvement treatment).
The emissivity improvement process is, for example, a process of blackening the solvent collecting part 50 . More specifically, for example, when the solvent collector 50 is made of stainless steel, this is a process of oxidizing the stainless steel.
Also, the emissivity improvement treatment is a roughening treatment for the surface of the solvent collecting part 50 made of a metal material. By performing the roughening treatment, a myriad of fine irregularities are formed on the surface of the solvent trapping portion 50 made of a metal material, so that the emissivity of the solvent trapping portion 50 can be increased. The roughening process is performed using, for example, sandpaper.

The solvent collecting part 50 is manufactured by, for example, forming a large number of through holes 50a in a plate material made of stainless steel or the like by drilling processing such as laser processing or plasma etching, and then performing emissivity improvement treatment. . It should be noted that a plurality of mesh plate-shaped members may be combined to form one solvent collecting section 50 .

The solvent collector 50 is supported by the bottom plate 13 via a plurality of support members 60, as shown in FIGS.
Each support member 60 is a member extending in the vertical direction, and supports the solvent collector 50 at its tip. A base end of each support member 60 is connected to an elevating mechanism (not shown) for elevating the support member 60 . The elevating mechanism has a driving source (not shown) such as a motor that generates driving force for elevating the support member 60 . By raising and lowering the support member 60, the solvent collecting part 50 is moved to a first height position indicated by a solid line in FIGS. The solvent collector 50 can be moved up and down between the two height positions. The first height position (hereinafter abbreviated as "first position") is the position when the solvent is removed from the substrate G, and the second position (hereinafter abbreviated as "second position") is This is the position when the substrate G is transferred between the mounting table 20 and an external transport device.
An elevating mechanism for the support member 60 is controlled by a control unit U, which will be described later.

The reduced-pressure drying apparatus 1 also has a control unit U. As shown in FIG. This control unit is, for example, a computer having a CPU, a memory, etc., and has a program storage unit (not shown). The program storage unit stores a program for controlling the reduced pressure drying process in the reduced pressure drying apparatus 1 . The program may be recorded in a computer-readable, non-temporary storage medium H, and may be installed from the storage medium H into the control unit. Part or all of the program may be realized by dedicated hardware (circuit board).

<Reduced pressure drying treatment>
Subsequently, the reduced pressure drying process using the reduced pressure drying apparatus 1 will be described with reference to FIGS. 5 and 6. FIG. FIG. 5 is a flowchart for explaining an example of a reduced pressure drying process using the reduced pressure drying apparatus 1. As shown in FIG. FIG. 6 is a graph showing the change over time of the pressure inside the chamber 10 when the emissivity improvement treatment is not applied to the solvent collector 50 of the reduced pressure drying apparatus 1. As shown in FIG. In FIG. 6, the horizontal axis is time, and the vertical axis is pressure inside the chamber 10 . Pressure is shown on a logarithmic scale. In addition, the following reduced-pressure drying process is performed under control of the control part U. FIG. In the following example, it is assumed that the substrate G has already been loaded into the chamber 10 and placed on the mounting table 20 at the start of the reduced-pressure drying process.

(S1: substrate drying step)
First, the solution on the substrate G mounted on the mounting table 20 is dried, that is, the solvent in the solution on the substrate G is removed.

Specifically, as shown in FIG. 6, the pressure inside the chamber 10 is reduced, and the solvent on the substrate G mounted on the mounting table 20 is removed under reduced pressure. At the same time, due to the reduced pressure in the chamber 10, the gas in the chamber 10 is adiabatically expanded and cooled. Solvent vaporized from the substrate G is temporarily collected. This step will be described in more detail below. In this step, the position of the solvent collector 50 is the first position described above.

First, the dry pump 31a is actuated and the inside of the chamber 10 is evacuated. Evacuation by the dry pump is performed until the pressure in the chamber 10 reaches 10 Pa, for example.
During this evacuation, the gas inside the chamber 10 is cooled by adiabatic expansion. Even if the gas in the chamber 10 is cooled in this way, the temperature of the substrate G is not affected by the cooled gas because the heat capacity of the substrate G is large, and the temperature of the substrate G hardly changes from the room temperature of 23°C. do not do. However, the solvent collector 50 with a small heat capacity is cooled by the gas cooled by adiabatic expansion as the pressure is reduced.

After that, the turbo-molecular pump 41a is actuated, and the inside of the chamber 10 is evacuated. Accompanied by this evacuation, the solvent collector 50 is further cooled by the gas cooled by the adiabatic expansion described above, and becomes below the dew point (for example, 8 to 15° C.) of the pressure in the chamber 10 at that time.

Further, when the internal pressure of the chamber 10 becomes lower than the vapor pressure of the solvent on the substrate G due to the evacuation, the evaporation of the solvent on the substrate G is accelerated.
The vaporized solvent is collected and adsorbed by the solvent collector 50 cooled as described above. By such collection, the concentration of gaseous solvent in chamber 10 is kept low. Therefore, the solvent on the substrate G can be quickly removed.

It should be noted that the solvent on the substrate G vaporized in this process is adsorbed not only on the solvent collecting part 50, but also on the chamber 10 (specifically, the inner wall surface of the chamber 10 and the protective nets 33 and 43). be done.

(S2: Drying Step (Drying Step) of Solvent Collection Unit 50 and Chamber 10)
After the removal of the solvent on the substrate G is completed, the temperature of the solvent trapping part 50 is raised, the solvent trapping part 50 is dried, and the chamber 10 is dried. That is, after the removal of the solvent on the substrate G is completed, the temperature of the solvent trapping part 50 is increased, and the solvent adsorbed to the solvent trapping part 50 is desorbed from the solvent trapping part 50 and adsorbed to the chamber 10. The desorbed solvent is desorbed from the chamber 10 .

This step is performed, for example, by moving the solvent collector 50 to a second position close to the top plate 12 while continuing the evacuation by the dry pump 31a and the evacuation by the turbo-molecular pump 41a. By continuing these evacuations, for example, as shown in FIG. The pressure in chamber 10 drops. Therefore, for example, when the pressure in the chamber 10 reaches a predetermined pressure at which the drying of the chamber 10 is completed, the drying process of step S2 ends.

In the drying process of step S2, even if the emissivity improvement treatment is not applied to the solvent collection unit 50 unlike the above-described example, the solvent collection unit 50 receives radiant heat from the top plate 12 and radiant heat from the substrate G. etc., the temperature gradually rises. However, by subjecting the solvent collecting portion 50 to emissivity improvement treatment, the rate of temperature rise of the solvent collecting portion 50 due to radiant heat from the top plate 12 or the like increases. Therefore, the time required to remove the solvent from the solvent collecting section 50 can be shortened, and the time required for the drying process in step S2 can be shortened.

(Step S3: standby process)
The reduced-pressure drying apparatus 1 is in a standby state until the purge process in the next step S4 is started. During this process, the exhaust by the dry pump 31a and the exhaust by the turbo-molecular pump 41a are continued. Also in this step, the temperature of the solvent collector 50 is gradually increased.
Note that this step may be omitted.

(Step S4: Atmospheric release step)
When the standby process is finished, the pressure reduction state inside the chamber 10 is released, and specifically, the inside of the chamber 10 is returned to the atmospheric pressure.

More specifically, for example, the exhaust by the dry pump 31a and the exhaust by the turbo-molecular pump 41a are stopped, and atmospheric gas is introduced into the chamber 10, that is, the inside of the chamber 10 is purged, as shown in FIG. , the pressure inside the chamber 10 is returned to the atmospheric pressure. During the process in which the inside of the chamber 10 returns to atmospheric pressure, the gas inside the chamber 10 is heated by adiabatic compression. ) becomes higher than when the pressure reduction in the chamber 10 is started.

(Step S5: Cooling of Solvent Collection Unit 50)
After that, the solvent collector 50 is cooled to the temperature at which the reduced pressure drying process is started. Specifically, for example, the solvent collector 50 is allowed to cool.

(Step S6: Carrying in/out substrate G)
After cooling the solvent collector 50, the substrate G is unloaded from the chamber 10 and the next substrate G is loaded.
Specifically, with the solvent collecting unit 50 at the second position described above, the loading/unloading port 11a is opened, and a lifter (not shown) provided for the mounting table 20 lifts the mounting table 20. , the dried substrate G is delivered to an external transport device. Next, the substrate G is unloaded from the chamber 10 by the transport device. After that, the next substrate G is carried into the chamber 10 by the transfer device. Subsequently, the lifter transfers the next substrate G from the transfer device to the mounting table 20 and mounts it on the mounting table 20 . Then, the solvent collecting part 50 is lowered to the above-described first position, and the loading/unloading port 11a is closed.

This completes the reduced-pressure drying process using the reduced-pressure drying apparatus 1 for one substrate G, and subsequently, the next substrate G is subjected to the reduced-pressure drying process in the same manner as described above.

The cooling of the solvent collecting section 50 in step S5 and the loading/unloading of the substrate G in step S6 may be performed in parallel.

Also, the reason for cooling the solvent collector 50 in step S5 is as follows. When the temperature of the solvent collection part 50 is high at the start of the reduced-pressure drying process for the next substrate G (specifically, when the pressure reduction in the chamber 10 is started), in the substrate drying process of step S1 for the next substrate G, This is because the temperature of the solvent collector 50 cannot be lowered sufficiently, and the solution on the substrate G cannot be dried quickly.

As described above, in the first embodiment, the emissivity improvement treatment is applied to the solvent collecting section 50 .
Therefore, in the drying process of step S2 after the substrate drying process of step S1, the temperature of the solvent collection part 50 can be raised early, and the solvent adsorbed to the solvent collection part 50 in the substrate drying process of step S1 can be heated quickly. The solvent can be quickly desorbed from the solvent collecting part 50 . Therefore, the time required for the drying process in step S2 can be shortened. Therefore, in the reduced-pressure drying process, the time required for the processes after the substrate drying process of step S1 including the drying process of step S2 (that is, the post-processing process) can be shortened, and the time required for the entire reduced-pressure drying process can be shortened. can be shortened.
In other words, in the first embodiment, the emissivity of the solvent collecting part 50 is improved to shorten the time until the next substrate G is dried under reduced pressure, that is, the post-treatment time.

In fabricating the solvent trapping part 50, the processing treatment for improving the emissivity may be performed uniformly over the entire solvent trapping part 50, or the solvent trapping part 50 may be processed in a plurality of areas when viewed from above. , the degree of processing may be different for each region.
For example, in the solvent collection unit 50, the region that is most cooled by the adiabatically expanded gas in the chamber 10 is the central region in a plan view, so the degree of processing by the emissivity improvement treatment of the central region is may be larger than the area of .

[Modification of the first form]
FIG. 7 is a cross-sectional view showing a schematic configuration of a reduced-pressure drying apparatus according to a modification of the first embodiment.
A conductive material such as stainless steel is basically used for the material of the solvent collector 50 . In this way, when the solvent trapping part 50 is made of a conductive material, an energizing part 70 for heating the solvent trapping part 50 by energizing the solvent trapping part 50 is provided as shown in FIG. good too.
The current-carrying part 70 has, for example, a power supply 71 that supplies electric power to the solvent collecting part 50 and wiring 72 that connects the power supply 71 and the solvent collecting part 50 .

By thus providing the energizing unit 70 and energizing the solvent collecting unit 50 in the drying process of step S2, the rate of temperature increase of the solvent collecting unit 50 in the drying process is further increased, and the solvent from the solvent collecting unit 50 desorption of the solvent can be accelerated. Therefore, the time required for the drying process in step S2 can be further shortened.

FIG. 8 is a vertical cross-sectional view showing a schematic configuration of a reduced-pressure drying apparatus according to another modification of the first embodiment.
As shown in FIG. 8 , a heat medium pipe 80 may be provided as a heat medium flow path inside the chamber 10 . The heat transfer pipe 80 is provided between the solvent collector 50 and the top plate 12, and more specifically, between the solvent collector 50 and the top plate 12 at the second position. Further, the heat medium pipe 80 is provided so as to cover substantially the entire solvent collecting portion 50 in plan view. A high-temperature heat medium supplied from a chiller unit (not shown) provided outside the chamber 10 flows through the heat medium pipe 80 .

By providing such a heat medium pipe 80 and causing a high-temperature heat medium to flow through the heat medium pipe 80 in the drying process of step S2, the rate of temperature rise of the solvent collecting section 50 in the drying process is further increased, and the solvent trapping process is performed. Desorption of the solvent from the collecting portion 50 can be promoted. Therefore, the time required for the drying process in step S2 can be further shortened.

FIG. 9 is a vertical cross-sectional view showing a schematic configuration of a reduced-pressure drying apparatus according to another modification of the first embodiment.
As shown in FIG. 9, an infrared light source 90 may be provided as an infrared ray irradiating section that irradiates the solvent collecting section 50 with infrared rays to heat the solvent collecting section 50 . The infrared light source 90 is, for example, a halogen lamp. The infrared light source 90 is provided, for example, on the side of the solvent collector 50, and the optical axis of the infrared light source 90 is horizontal. Also, the infrared light sources 90 are provided on both the positive side in the X direction and the negative side in the X direction, for example. A plurality of infrared light sources 90 may be provided along the Y direction on both the positive side in the X direction and the negative side in the X direction.

By providing such an infrared light source 90 and irradiating the solvent collecting section 50 with infrared rays from the infrared light source 90 in the drying process of step S2, the temperature rise rate of the solvent collecting section 50 in the drying process is further increased, Desorption of the solvent from the solvent collection part 50 can be accelerated. Therefore, the time required for the drying process in step S2 can be further shortened.

In the drying process of step S2, the temperature of the solvent collecting section 50 is raised by the radiant heat from the top plate 12 as described above. Therefore, at least the inner wall surface of the top plate 12 may be blackened in order to further increase the temperature rise rate of the solvent collecting portion 50 in the drying process of step S2. The blackening treatment of the top plate 12 is, for example, alumite treatment when aluminum is used as the material of the top plate 12 .

Further, in the above example, the position of the solvent collecting part 50 in the drying process of step S2 is set to the second position. As described above, the second position is the position when the substrate G is transferred between the mounting table 20 and the external transport device, and may not be the optimum position for raising the temperature of the solvent collector 50 . In this case, the position of the solvent collecting part 50 in the drying process of step S2 may be set to a position closer to the top plate 12 than the second position, for example. Thereby, the temperature rise of the solvent collecting part 50 by the radiant heat from the top plate 12 may be further accelerated.

[Second form]
<Decompression drying device>
FIG. 10 is a longitudinal sectional view showing a schematic configuration of a reduced pressure drying apparatus according to the second embodiment.
In the reduced-pressure drying apparatus according to the second embodiment, the solvent collection unit 50 may or may not be subjected to emissivity improvement treatment as in the first embodiment. At least one of the configurations according to the modification of may be provided.

As described above, in the reduced-pressure drying process using the reduced-pressure drying apparatus 1 according to the first embodiment, the solvent vaporized from the substrate G is adsorbed not only on the solvent collecting part 50 but also on the inner wall surface of the chamber 10 and the The protection nets 33 and 43 are also adsorbed. In particular, the protection net 33 for the dry pump 31a passes a large amount of adiabatically expanded gas when the pressure in the chamber 10 is reduced, so that the temperature is lower than that of the other portions, and the amount of solvent adsorbed is large. In addition, the protective net 33 is made of a material such as stainless steel, which has a relatively high thermal conductivity, and is difficult to be heated.

Therefore, unlike the reduced pressure drying apparatus according to the first embodiment, the reduced pressure drying apparatus 1a of FIG. It has a promotion function that promotes detachment.

In the example of FIG. 10, the reduced-pressure drying apparatus 1a has the above-mentioned promotion function by forming the protective net 100 for the dry pump 31a from a material having a higher thermal conductivity than stainless steel.
Examples of materials having higher thermal conductivity than stainless steel include aluminum, copper, and silver.

<Reduced pressure drying treatment>
The reduced-pressure drying process using the reduced-pressure drying apparatus 1a of FIG. 10 is the same as the reduced-pressure drying process using the reduced-pressure drying apparatus 1 shown in FIGS. 1 to 3, and includes steps S1 to S6 described above.

As described above, in the second embodiment, the reduced-pressure drying apparatus 1a has a function of promoting detachment of the solvent from the protective net 100 . Therefore, the solvent can be rapidly removed from the protective net 33 in the drying process of step S2. Therefore, the time required for the drying process in step S2 can be shortened. Therefore, the time required for the post-treatment process including the drying process of step S2 in the reduced pressure drying process can be shortened, and the time required for the entire reduced pressure drying process can be shortened.
In other words, in the second embodiment, desorption of the solvent from the protective net 33 is accelerated to shorten the time until the next substrate G is dried under reduced pressure, that is, the post-treatment time.

[Modification of Second Mode]
FIG. 11 is a partially enlarged plan view of a protective net provided in a reduced-pressure drying apparatus according to a modified example of the second embodiment.
As described below, the reduced-pressure drying apparatus according to the second embodiment is provided with a heating unit that heats the protective net for the dry pump 31a, and the function of promoting detachment from the protective net is the above-mentioned protection by the heating unit. The detachment may be accelerated by heating the mesh.

A protective net 110 for the dry pump 31a of FIG. 11 is formed therein with a heat medium flow path 110a as a heating part that has a function of promoting detachment of the solvent from the protective net 110. As shown in FIG.
The protection net 110 has through-holes 110b arranged in a grid pattern for allowing the gas exhausted from the chamber 10 to pass therethrough. The heat medium flow path 110a has a shape corresponding to the arrangement state of the through holes 110b in plan view.

By providing the heat medium flow path 110a in the protection net 110 in this way and flowing a high-temperature heat medium through the heat medium flow path 110a in the drying process of step S2, the solvent can be removed from the protection net 110 in the drying process. can be done quickly.

FIG. 12 is a partially enlarged cross-sectional view for explaining another example of the heating unit that has the function of promoting detachment of the solvent from the protective net.
In the example of FIG. 12, a direct heating unit 120 that is installed in the protective net 33 and directly heats the protective net 33 is provided as a heating unit that has a function of promoting detachment of the solvent from the protective net 33 to the dry pump 31a. ing. The direct heating unit 120 is, for example, a mesh-like member similar to the protective net 33, and a resistance heater wire (not shown) is provided inside thereof so as to be in contact with the protective net 33 in the exhaust port 13a. be provided.

By thus providing the direct heating unit 120 and heating the protective net 33 with the direct heating unit 120 in the drying process of step S2, the solvent can be rapidly removed from the protective net 33 in the drying process. .

FIG. 13 is a partially enlarged cross-sectional view for explaining another example of the heating unit that has the function of promoting detachment of the solvent from the protective net.

In the example of FIG. 13, an exhaust mechanism 31 for reducing the pressure in the chamber 10 is connected through an exhaust pipe 131 to the exhaust port 13a. The exhaust port 13 a , the exhaust mechanism 31 (specifically, the portion connecting the exhaust pipe 131 and the dry pump 31 a in the exhaust mechanism 31 ), and the exhaust pipe 131 constitute an exhaust line 130 . The exhaust line 130 is connected to the dry pump 31 a and exhausts the inside of the chamber 10 .

The exhaust line 130 is provided with a protective net 132 similar to the protective net 33 described above. However, unlike the protective net 33 , the protective net 132 is provided inside the exhaust pipe 131 .
In addition, in the example of FIG. 13 , a heating section 133 having a function of promoting detachment of the solvent from the protective net 132 is provided outside the exhaust pipe 131 . The heating unit 133 heats the protective net 132 by heating the exhaust pipe 131 . The heating unit 133 is, for example, a resistance heater.

By thus providing the heating unit 133 and heating the protective net 132 with the heating unit 133 in the drying process of step S2, the solvent can be rapidly removed from the protective net 132 in the drying process.

The protective net for the turbo-molecular pump 41a begins to be exhausted by the turbo-molecular pump 41a after the exhaust by the dry pump 31a. less than Therefore, the protective net for the turbo-molecular pump 41a does not reach a lower temperature than the protective net for the dry pump 31a, and the amount of adsorbed solvent is small. Therefore, the reduced-pressure drying apparatus according to the second embodiment also does not have the function of accelerating the detachment of the solvent from the protective net for the turbo-molecular pump 41a. However, an acceleration function may be provided to accelerate detachment of the solvent from the protective net for the turbomolecular pump 41a.

In the above example, the exhaust line for the dry pump 31a and the exhaust line for the turbo-molecular pump 41a were provided separately, but the dry pump 31a and the turbo-molecular pump 41a are connected in series, and the exhaust line for both pumps is shared. good too.

[Third form]
<Decompression drying device>
FIG. 14 is a vertical cross-sectional view showing a schematic configuration of a vacuum drying apparatus according to the third embodiment.
In the reduced-pressure drying apparatus according to the third embodiment, the solvent collection unit 50 may or may not be subjected to emissivity improvement treatment as in the first embodiment. At least one of the configurations according to the modification of may be provided. Furthermore, the reduced-pressure drying apparatus according to the third embodiment may have a function of promoting detachment of the solvent from the protective net for the dry pump 31a, as in the second embodiment.

As described above, in the reduced-pressure drying process using the reduced-pressure drying apparatus 1 according to the first embodiment, when the reduced-pressure state inside the chamber 10 is released (specifically, when the inside of the chamber 10 is returned to atmospheric pressure), The adiabatic compression heats the gas in the chamber 10, and the heated gas raises the temperature of the solvent collector 50 to a higher temperature than when the reduced pressure drying process is started.

Therefore, unlike the reduced pressure drying apparatus according to the first embodiment, the reduced pressure drying apparatus 1b of FIG.

In the example of FIG. 14, the reduced-pressure drying apparatus 1b includes a gas injection section 200 that injects a cooling gas for cooling the solvent collection section 50 as the cooling section.
The gas injection part 200 injects cooling gas toward the solvent collection part 50 from above the solvent collection part 50, for example. The gas injection unit 200 has, for example, a pipe 201 extending in the X direction. The pipe 201 is provided between the solvent collector 50 and the top plate 12 in the chamber 10, more specifically, between the solvent collector 50 and the top plate 12 at the second position. be provided. Further, the pipe 201 has an injection port (not shown) for injecting cooling gas downward at its lower portion. For example, a plurality of pipes 201 are provided along the Y direction. Thereby, the solvent collection part 50 whole can be cooled. The gas injection section 200 injects cooling gas supplied from a cooling gas source provided outside the chamber 10 toward the solvent collection section 50 through an injection port (not shown) of the pipe 201 . The cooling gas is an inert gas such as _N2 gas.

<Reduced pressure drying treatment>
The reduced pressure drying process using the reduced pressure drying apparatus 1b in FIG. 14 is basically the same as the reduced pressure drying process using the reduced pressure drying apparatus 1 shown in FIGS. 1 to 3, and includes steps S1 to S5 described above. , the specific contents of the cooling step of the solvent collecting section 50 in step S6 described above are different. In the reduced-pressure drying process using the reduced-pressure drying apparatus 1 shown in FIGS. 1 to 3, the solvent collecting section 50 is radiatively cooled in the process of step S6. On the other hand, in the reduced pressure drying process using the reduced pressure drying apparatus 1b of FIG.

As described above, in the third embodiment, the reduced-pressure drying apparatus 1b includes a cooling section that cools the solvent collecting section 50. FIG. Therefore, in the step of cooling the solvent collector 50 in step S6, the solvent collector 50 can be rapidly cooled to the temperature at which the reduced-pressure drying process is started. Therefore, it is possible to shorten the time required for the step of cooling the solvent collector 50 in step S6. Therefore, in the reduced pressure drying process, the time required for the post-treatment process including the cooling process of the solvent collecting part 50 in step S6 can be shortened, and the time required for the entire reduced pressure drying process can be shortened. .
In other words, in the third embodiment, by cooling the solvent collecting part 50 which has been heated when the depressurized state in the chamber 10 is released, the time until the next substrate G is dried under reduced pressure, that is, the post-treatment It shortens the process time.

[Modified example of gas injection part]
FIG. 15 is a cross-sectional view for explaining another example of the gas injection section.

The gas injection part in the example of FIG. 15 receives the cooling gas from the side of the solvent collection part 50 and injects it into the solvent collection part 50 . This gas injection section has a gas injection port 210 provided on the side of the solvent collection section 50 . The gas injection port 210 is provided in the side wall 11, for example. Further, a plurality of gas injection ports 210 are provided along the Y direction, for example, on both the positive side in the X direction and the negative side in the X direction. The height position of the gas injection port 210 is the aforementioned second position. The gas injection port 210 injects the cooling gas supplied from the cooling gas source provided outside the chamber 10 toward the solvent collector 50 .

Even if the cooling unit having such a gas injection port 210 is used, the solvent collecting unit 50 can be quickly cooled to the temperature at which the reduced pressure drying process is started in the step of cooling the solvent collecting unit 50 in step S6. can be done.

FIG. 16 is a cross-sectional view for explaining another example of the cooling section that cools the solvent collecting section 50. As shown in FIG.
In the example of FIG. 16, a blower 220 that blows air into the chamber 10 is provided as a cooling unit that cools the solvent collector 50 .

The blower section 220 has a fan filter unit (FFU) 221 and a pipe 222 .
The air blower 220 is connected to, for example, the side wall 11 opposite to the loading/unloading port 11a. An opening 11b is provided on the side wall 11 opposite to the loading/unloading port 11a (positive side in the X direction in the drawing), that is, at a portion of the side wall 11 facing the loading/unloading port 11a. The opening 11b is provided at a height position corresponding to the second position. An FFU 221 is connected via a pipe 22 to this opening 11b.
The air blowing unit 220 uses the FFU 221 to blow air in the direction of the loading/unloading port 11 a through the opening 11 b to cool the solvent collecting unit 50 . In other words, the air blower 220 sends the clean gas from the FFU 221 into the chamber 10 through the opening 11b, and cools the solvent collector 50 at the second position with the clean gas. In addition, the air blower 220 forms a laminar flow along the solvent collector 50 in the chamber 10 with the clean gas from the FFU 221 .

The opening 11b can be opened and closed by a gate valve 230. As shown in FIG. The FFU 221 and the gate valve 230 are controlled by the controller U.

The air blower 220 is used after opening the opening 11b of the chamber 10 in the step of cooling the solvent collector 50 in step S6. Further, the air blower 220 is used after opening the loading/unloading port 11a of the chamber 10 in the step of cooling the solvent collector 50 in step S6.

Even if the air blower 220 as described above is used, the solvent collector 50 can be rapidly cooled to the temperature at which the reduced pressure drying process is started in the step of cooling the solvent collector 50 in step S6.

In addition, by cooling the solvent collector 50 with a laminar flow along the solvent collector 50 using the air blower 220, unnecessary parts (for example, the mounting table 20, etc.) are suppressed from being cooled. can do.
Furthermore, when cooling the solvent collection unit 50 by blowing air from the air blowing unit 220, the loading/unloading port 11a of the chamber 10 is opened, and the solvent collecting unit 50 is cooled by the gas blown from the air blowing unit 220 toward the loading/unloading port 11a. , the gas from the air blower 220 is smoothly discharged from the chamber 10 through the loading/unloading port 11a. Therefore, it is possible to suppress the particles in the chamber 10 from being stirred up by the gas from the air blower 220 .

It should be considered that the forms disclosed this time are illustrative in all respects and not restrictive. The above aspects may be omitted, substituted or changed in various ways without departing from the scope and spirit of the appended claims.

1 vacuum drying device 10 chamber 20 mounting table 50 solvent collector G substrate

Claims (12)

A reduced pressure drying apparatus for drying a solution on a substrate under reduced pressure,
a processing container configured to be depressurized and containing the substrate;
a mounting table provided in the processing container on which the substrate is mounted;
a solvent collection unit that collects the solvent in the solution that is vaporized from the substrate and discharged into the processing container during the reduced-pressure drying process;
The reduced-pressure drying device, wherein the solvent trapping part is processed to improve the emissivity of the solvent trapping part. 2. The reduced-pressure drying apparatus according to claim 1, wherein said processing is a process of blackening said solvent collector formed of a metal material. 3. The reduced-pressure drying apparatus according to claim 1, wherein said processing is roughening of the surface of said solvent collector made of a metal material. The reduced-pressure drying apparatus according to any one of claims 1 to 3, further comprising a current-carrying part that energizes the solvent collecting part made of a conductive material. The reduced-pressure drying apparatus according to any one of claims 1 to 4, further comprising a heat medium flow path provided within said processing container. The reduced-pressure drying apparatus according to any one of claims 1 to 5, further comprising an infrared irradiation section for irradiating the solvent collecting section with infrared rays. The reduced-pressure drying apparatus according to any one of claims 1 to 6, wherein the solvent collecting section is divided into a plurality of regions, and the degree of processing by the processing treatment differs for each region. an exhaust line connected to an exhaust device for exhausting the inside of the processing container;
a protective net for preventing objects from entering the exhaust system through the exhaust line;
8. The method according to any one of claims 1 to 7, further comprising a promoting function of promoting detachment from the protective net of the solvent vaporized from the substrate and adsorbed on the protective net during the reduced-pressure drying process. The reduced-pressure drying apparatus according to . The vacuum drying apparatus according to any one of claims 1 to 8, further comprising a cooling unit that cools the solvent collecting unit heated when the reduced pressure state in the processing container is released. A reduced pressure drying treatment method for drying a solution on a substrate under reduced pressure using a reduced pressure drying apparatus,
The vacuum drying device is
a processing container configured to be depressurized and containing the substrate;
a mounting table provided in the processing container on which the substrate is mounted;
and a solvent collector,
The solvent trapping part is processed to improve the emissivity of the solvent trapping part,
The inside of the processing container is decompressed, the gas in the processing container is cooled by adiabatic expansion, the cooled gas cools the solvent collector, and the cooled solvent collector cools the mounting table. a step of temporarily collecting the solvent in the solution vaporized from the placed substrate and released into the processing container;
and a step of increasing the temperature of the solvent trapping part to desorb the trapped solvent from the solvent trapping part. A readable computer storage medium storing a program that runs on a computer of a control unit that controls a reduced pressure drying apparatus so that the reduced pressure drying processing method according to claim 10 is executed by the reduced pressure drying apparatus. By improving the emissivity of the solvent collector that collects the solvent in the solution on the substrate that is vaporized from the substrate during the reduced pressure drying process, the time until the next substrate starts the reduced pressure drying process is shortened. how to.

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