Vacuum drying device and vacuum drying method

Abstract

The present invention provides a reduced-pressure drying device and a reduced-pressure drying method for suppressing uneven drying of a coating film. The reduced-pressure drying device (1) includes a chamber (10), a support portion (20), a cooling portion (40), a first elevating portion (100), a reduced-pressure mechanism (30), and a control portion (80). The support portion (20) supports a substrate (9) inside the chamber. The cooling portion (40) cools a cooling surface (40a) facing the upper surface of the substrate (9). The first elevating portion (100) elevates at least one of the support portion and the cooling surface between a first state where the interval between the substrate and the cooling surface is a first interval and a second state where the interval is a second interval wider than the first interval. The reduced-pressure mechanism sucks the gas inside the chamber to reduce the air pressure inside the chamber. The control portion controls the first elevating portion and the reduced-pressure mechanism such that after the air pressure inside the chamber reaches a first air pressure in the first state, the air pressure inside the chamber reaches a second air pressure lower than the first air pressure in the second state.

Description

Technical Field

[0001] The present invention relates to a vacuum drying device and a vacuum drying method. Background Art

[0002] Conventionally, a vacuum drying device for vacuum-drying a coating film such as a photoresist coated on various substrates has been known. Various substrates include, for example, various substrates such as glass substrates, ceramic substrates, semiconductor wafers, electronic device substrates, or printing plates for printing, which are used for forming various devices. Various devices include, for example, semiconductor devices, display panels, solar cell panels, magnetic disks, or optical disks. Display panels include, for example, liquid crystal display panels, organic electroluminescence (EL) display panels, plasma display panels, or field emission displays.

[0003] When drying a coating film using a vacuum drying device, for example, in a state where a plurality of pins support a substrate in a chamber, the chamber is evacuated through an exhaust port at the bottom of the chamber using a vacuum pump. By this evacuation, the air pressure in the chamber is reduced. If the air pressure in the chamber is reduced, the solvent of the coating film evaporates, so that the coating film can be dried. And, for example, when the degree of vacuum reaches a specified value, the evacuation from the chamber is stopped, and the air pressure in the chamber is restored to atmospheric pressure by supplying gas into the chamber. The gas is, for example, an inert gas such as nitrogen or air.

[0004] However, in a vacuum drying device, if the air pressure in the chamber is rapidly reduced at the initial stage of evacuation, the coating film on the substrate may boil violently. If violent boiling occurs, it may cause, for example, a deviation in the film thickness of the coating film.

[0005] The vacuum drying device described in Patent Document 1 can suppress the occurrence of such violent boiling. In the vacuum drying device described in Patent Document 1, a lifting portion for lifting and lowering the support pins that support the substrate is provided. At the initial stage of evacuation, the lifting portion raises the support pins, thereby reducing the interval between the substrate and the top surface of the chamber. Thereby, the rate of decrease in the air pressure between the substrate and the top surface can be made small, and the occurrence of violent boiling can be suppressed.

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2022-086766

[0007] However, when the interval between the substrate and the top surface is reduced, the solvent vapor from the coating film on the substrate stays in the space between the substrate and the top surface. In particular, the solvent vapor from the vicinity of the center of the coating film is likely to stay. That is, although the solvent vapor from the vicinity of the periphery of the coating film can flow outward in the horizontal direction by concentration diffusion, in the vicinity of the center of the coating film, since the concentration gradient is small, the solvent vapor stays directly. Therefore, compared with the central portion, the solvent of the coating film is more likely to evaporate in the peripheral portion. That is, it causes non-uniform drying of the coating film. Non-uniform drying may cause, for example, a problem of deviation in the film thickness of the dried coating film. Summary of the Invention

[0008] The present invention has been completed in view of the above problems, and an object thereof is to provide a technique for suppressing uneven drying of a coating film.

[0009] [Means for Solving the Problem]

[0010] A first aspect is a reduced-pressure drying apparatus for drying a coating film applied to an upper surface of a substrate. The reduced-pressure drying apparatus includes: a chamber that houses the substrate; a support portion that supports the substrate in the chamber; a cooling portion that cools a cooling surface facing the upper surface of the substrate supported by the support portion; a first elevating portion that elevates at least one of the support portion and the cooling surface between a first state and a second state. In the first state, a distance between the substrate supported by the support portion and the cooling surface is a first distance, and in the second state, the distance between the substrate supported by the support portion and the cooling surface is a second distance wider than the first distance; a reduced-pressure mechanism that sucks gas in the chamber to reduce the air pressure in the chamber; and a control portion that controls the first elevating portion and the reduced-pressure mechanism such that after the air pressure in the chamber reaches a first air pressure in the first state, the air pressure in the chamber reaches a second air pressure lower than the first air pressure in the second state.

[0011] A second aspect is the reduced-pressure drying apparatus according to the first aspect, wherein the cooling surface is a top surface of the chamber, and the first elevating portion elevates the support portion.

[0012] A third aspect is the reduced-pressure drying apparatus according to the second aspect, wherein the cooling portion is mounted on an upper surface of a top plate portion of the chamber, and the cooling portion cools the top plate portion to cool a lower surface thereof, which is the cooling surface.

[0013] A fourth aspect is the reduced-pressure drying apparatus according to the third aspect, further including: a second elevating portion that elevates the cooling portion between a cooling position in contact with the upper surface of the top plate portion and a separation position separated from the top plate portion.

[0014] A fifth aspect is the reduced-pressure drying apparatus according to the second aspect, wherein at least a part of the cooling portion is buried in the top plate portion of the chamber.

[0015] A sixth aspect is the reduced-pressure drying apparatus according to the first aspect, wherein the cooling portion includes a cooling member that is provided in the chamber and has the cooling surface as a lower surface.

[0016] The seventh mode is a vacuum drying device according to the sixth mode, further comprising: a side rectifying plate surrounding the substrate supported by the support portion; a bottom rectifying plate opposing the lower surface of the substrate supported by the support portion, wherein the first lifting portion raises and lowers the cooling member, and in the first state and the second state, the substrate supported by the support portion is surrounded by the side rectifying plate.

[0017] The eighth mode is a vacuum drying method for drying a coating film applied to the upper surface of a substrate. The vacuum drying method includes: a first step of cooling a cooling surface opposing the upper surface of the substrate supported by a support portion in a chamber, and while the interval between the substrate and the cooling surface is a first interval, reducing the pressure in the chamber to a first pressure to evaporate the solvent of the coating film on the substrate and condensing the vapor of the solvent on the cooling surface; a second step, after the first step, while the interval between the substrate and the cooling surface is a second interval wider than the first interval, reducing the pressure in the chamber to a second pressure lower than the first pressure to evaporate both the solvent of the coating film on the substrate and the solvent of the cooling surface, thereby drying the coating film and the cooling surface.

[0018] The ninth mode is a vacuum drying method according to the eighth mode, wherein in the first step, the cooling portion is lowered to a cooling position in contact with the upper surface of the top plate portion of the chamber to cool the lower surface of the top plate portion, i.e., the cooling surface, and in the second step, the cooling portion is raised to a separation position separated from the top plate portion of the chamber.

[0019]

Advantages of the Invention

[0020] According to the first mode, in the first state, the gas in the chamber is reduced to the first pressure. Thereby, the solvent of the coating film evaporates. In the first state, since the interval between the substrate and the cooling surface is narrow, boiling over of the coating film can be suppressed. On the other hand, the solvent vapor from the coating film immediately collides with the cooling surface and cannot diffuse upward. Although the solvent vapor flows outward in the horizontal direction by concentration diffusion near the periphery of the coating film, it is difficult to flow outward near the center of the coating film and tends to stay. Therefore, from the viewpoint of the flow of the solvent vapor, the solvent of the coating film evaporates more easily at the peripheral portion than at the central portion, resulting in non-uniform drying. However, according to the first mode, the cooling portion cools the cooling surface. Therefore, the solvent vapor can be condensed on the cooling surface. So, even near the center of the coating film, the solvent vapor is not likely to stay, and the difference in the evaporation amount between the central portion and the peripheral portion of the coating film can be reduced. That is, non-uniform drying of the coating film can be suppressed.

[0021] Then, since the air pressure in the chamber further decreases in the second state, the solvent of the coating film on the substrate further evaporates. In the second state, since the gap between the substrate and the cooling surface is wide, the solvent vapor easily diffuses upward. Therefore, in the second state, non-uniform drying of the coating film is less likely to occur. Also, since the air pressure in the chamber further decreases, the solvent adhering to the cooling surface can also evaporate, and not only the coating film but also the cooling surface can be dried.

[0022] According to the second method, the existing first lifting part can be used.

[0023] According to the third method, the deviation of the temperature distribution in a top view is alleviated as it transfers heat through the top plate part from the upper surface to the lower surface (cooling surface) of the top plate part. That is to say, the temperature distribution of the cooling surface can be made more uniform. Therefore, the solvent vapor from the coating film condenses more uniformly (in other words, more evenly) on the cooling surface. Therefore, the uniformity of the concentration distribution between the substrate and the cooling surface can be improved, and non-uniform drying of the coating film can be further suppressed.

[0024] According to the fourth method, in the second state, the second lifting part can raise the temperature of the cooling surface by lifting the cooling part to the separation position. Therefore, the cooling surface can be dried more reliably.

[0025] According to the fifth method, the cooling part can efficiently cool the cooling surface.

[0026] According to the sixth aspect, the material of the cooling member can be selected separately from the chamber.

[0027] According to the seventh method, in the first state and the second state, the side rectifying plates surround the substrate. Therefore, in both the first state and the second state, the airflow concentration towards the peripheral part of the substrate can be suppressed. Therefore, the occurrence of non-uniform drying caused by the airflow can be suppressed.

[0028] According to the eighth method, in the first process, the air pressure in the chamber is reduced to the first air pressure, and the solvent of the coating film evaporates. In the first process, since the gap between the substrate and the cooling surface is narrow, the occurrence of film boiling of the coating film can be suppressed. On the other hand, the solvent vapor from the coating film immediately collides with the cooling surface and cannot diffuse upward. Although the solvent vapor flows horizontally outward near the periphery of the coating film through concentration diffusion, it is difficult to flow outward near the center of the coating film and is likely to stay. Therefore, from the perspective of the flow of the solvent vapor, compared with the central part, the solvent of the coating film evaporates more easily at the peripheral part, resulting in non-uniform drying. However, according to the eighth method, by cooling the cooling surface, the solvent vapor condenses on the cooling surface. Therefore, even near the center of the coating film, the solvent vapor is not likely to stay, and the difference in the evaporation amount between the central part and the peripheral part of the coating film can be reduced. Therefore, the occurrence of non-uniform drying of the coating film can be suppressed.

[0029] In the second process, the air pressure in the chamber is reduced to a lower second air pressure. As a result, the solvent of the coating film on the substrate further evaporates. In the second process, since the gap between the substrate and the cooling surface is wide, the solvent vapor easily diffuses upward. Therefore, in the second process, the coating film is less likely to have uneven drying. Also, since the air pressure in the chamber is further reduced, the solvent on the cooling surface can also evaporate, and not only the coating film but also the cooling surface can be dried.

[0030] According to the ninth aspect, the solvent vapor can be more reliably condensed on the cooling surface in the first process, and the cooling surface can be more reliably dried in the second process. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 FIG. is an example of a longitudinal cross-section schematically showing a reduced-pressure drying apparatus according to the first embodiment.

[0032] Figure 2 FIG. is an example of a cross-section schematically showing a reduced-pressure drying apparatus according to the first embodiment.

[0033] Figure 3 FIG. is an example of a longitudinal cross-section showing a reduced-pressure drying apparatus according to the first embodiment.

[0034] Figure 4 FIG. is a perspective view of an example of a substrate.

[0035] Figure 5 FIG. is an example of a longitudinal cross-section showing a part of the substrate.

[0036] Figure 6 FIG. is a block diagram conceptually showing functions implemented by a control unit.

[0037] Figure 7 FIG. is a flowchart of an example of a reduced-pressure drying process according to the first embodiment.

[0038] Figure 8 FIG. is an example of a schematic view showing the condition in the chamber during the first reduced-pressure process.

[0039] Figure 9 FIG. is an enlarged view showing the cooling surface and the vicinity of the substrate in the chamber during the first reduced-pressure process.

[0040] Figure 10 FIG. is an enlarged view showing the top plate portion of the chamber and the substrate of a comparative structure.

[0041] Figure 11 FIG. is an example of a view showing the concentration distribution of the solvent vapor in the upper space of a comparative structure.

[0042] Figure 12 It is a diagram showing an example of the concentration distribution of solvent vapor in the upper space in a state where the cooling section is performing cooling.

[0043] Figure 13 It is a diagram schematically showing an example of the condition inside the chamber during the second pressure reduction treatment.

[0044] Figure 14 It is a diagram schematically showing an example of the longitudinal section of the pressure reduction drying apparatus according to the second embodiment.

[0045] Figure 15 It is a flowchart showing an example of the process of the pressure reduction drying treatment according to the second embodiment.

[0046] Figure 16 It is a diagram schematically showing an example of the longitudinal section of the pressure reduction drying apparatus according to the third embodiment.

[0047] Figure 17 It is a diagram schematically showing an example of the longitudinal section of the pressure reduction drying apparatus according to the fourth embodiment.

[0048] Figure 18 It is a diagram schematically showing an example of the longitudinal section of the pressure reduction drying apparatus according to the fifth embodiment.

[0049] Explanation of reference numerals

[0050] 1, 1A to 1D Pressure reduction drying apparatus

[0051] 10 Chamber

[0052] 13 Top plate section

[0053] 100 First lifting section

[0054] 20 Support section

[0055] 30 Pressure reduction mechanism

[0056] 40 Cooling section

[0057] 40a Cooling surface

[0058] 45 Second lifting section

[0059] 50 Bottom surface rectifying plate

[0060] 51 Side surface rectifying plate

[0061] 80 Control section

[0062] 9 Substrate

[0063] 90 Coating film

[0064] F1 Upper surface (first surface)

[0065] S4, S14 First process (step)

[0066] S6, S17 Second process (step) Detailed implementation manners

[0067] Hereinafter, an embodiment and various modification examples of the present invention will be described with reference to the accompanying drawings. The same reference numerals are given to parts having the same structure and function in the drawings, and repeated descriptions are omitted in the following description. The drawings are schematically shown and do not accurately represent the dimensions and positional relationships of various structures in each figure. In addition, in this specification, the downward direction is the direction of gravity, and the upward direction is the direction opposite to the direction of gravity.

[0068] <1. First embodiment>

[0069] Figure 1 FIG. is an example schematically showing a longitudinal section of the reduced-pressure drying apparatus 1 according to the first embodiment. Figure 2 FIG. is an example schematically showing a cross section of the reduced-pressure drying apparatus 1 according to the first embodiment. Figure 3 FIG. is an example schematically showing a longitudinal section of the reduced-pressure drying apparatus 1 according to the first embodiment. Figure 1 The longitudinal section of Figure 3 The longitudinal sections of Figure 3 show the structure of the reduced-pressure drying apparatus 1 when viewed from directions that differ by approximately 90 degrees. In

[0070] The reduced-pressure drying apparatus 1 is a device for drying a coating film 90 (see Figure 5 ) formed on the upper surface of the substrate 9.

[0071] The substrate 9 is, for example, a glass substrate, a semiconductor wafer, or a ceramic substrate, etc. The substrate 9 is, for example, a substrate having a first surface F1 (see Figure 4 and Figure 5 ) as a first main surface and a second surface F2 (see Figure 5) plate-shaped substrate. For example, in the vacuum drying apparatus 1, the first surface F1 of the substrate 9 is the upper surface of the substrate 9, and the second surface F2 of the substrate 9 is the lower surface of the substrate 9. Here, a specific example in which the substrate 9 is a rectangular glass substrate is appropriately given for illustration. For example, by previously coating a treatment liquid containing an organic material and a solvent, a coating film 90 is partially formed on the first surface F1 of the substrate 9. The coating of the treatment liquid is performed, for example, by a slit coater or an inkjet device. The treatment liquid is, for example, a coating liquid such as a liquid containing a polyimide precursor and a solvent (also referred to as a PI liquid) or a resist liquid. The polyimide precursor is, for example, polyamide acid. The solvent is, for example, NMP (N-methyl-2-pyrrolidone). In addition, for example, in the case where the vacuum drying apparatus 1 is used in the manufacturing process of an organic EL display, it is also possible to form a hole injection layer, a hole transport layer, or a light-emitting layer of an organic EL display panel by drying the coating film 90 with the vacuum drying apparatus 1.

[0072] Figure 4 is a perspective view showing an example of the substrate 9. Figure 5 is a view showing an example of a longitudinal section of a part of the substrate 9. As Figure 4 shown, the substrate 9 is, for example, a rectangle having different horizontal and vertical lengths when viewed from above. A plurality of regions (which can be referred to as formed regions or coating regions) A1 for forming devices and the like are arranged on the substrate 9. In Figure 4 the example, when viewed from above, four rectangular coating regions A1 are arranged in a two-row and two-column matrix on the substrate 9. However, the shape, number, and arrangement of the coating regions A1 are not limited to this example. In the coating process before the vacuum drying apparatus 1 performs the vacuum drying process, a coating film 90 is formed in a desired pattern on the upper surface of each coating region A1 by a slit coater or an inkjet device. The desired pattern is, for example, a circuit pattern. Here, for example, as Figure 5 shown, the first surface F1 as the upper surface of each coating region A1 has a region (also referred to as a covered region) A3 covered by the coating film 90 and an exposed region (also referred to as an exposed region) A4 not covered by the coating film 90. In addition, the region around the coating region A1 in the substrate 9 and the region between adjacent coating regions A1 are regions where the coating film 90 is not formed on the first surface F1 as the upper surface (also referred to as a non-coating region) A2. The non-coating region A2 is also an exposed region (exposed region) A4 not covered by the coating film 90.

[0073] <1-1. Structural Outline of Vacuum Drying Apparatus>

[0074] Next, the structure of the vacuum drying apparatus 1 is outlined. As Figure 1 and Figure 2As shown, the vacuum drying apparatus 1 includes a chamber 10, a support portion 20, a vacuum mechanism 30, a first lifting portion 100, a cooling portion 40, and a control portion 80.

[0075] The chamber 10 is a portion for accommodating the substrate 9. The support portion 20 is disposed within the chamber 10 to support the substrate 9 in a horizontal posture. Here, the so-called horizontal posture means that the thickness direction of the substrate 9 is in the up-and-down direction.

[0076] The vacuum mechanism 30 sucks the gas within the chamber 10 and discharges the gas to the outside of the chamber 10. By this suction, the air pressure within the chamber 10 is reduced. By reducing the air pressure within the chamber 10, the solvent of the coating film 90 on the first surface F1 of the substrate 9 evaporates, and the coating film 90 is dried.

[0077] The cooling portion 40 cools the cooling surface 40a. The cooling surface 40a is a surface that faces the first surface F1 of the substrate 9 supported by the support portion 20 in the up-and-down direction. In Figure 1 the example, the cooling surface 40a corresponds to the top surface of the chamber 10. When viewed from above, the size of the cooling surface 40a is larger than that of the substrate 9. That is, the cooling surface 40a can have a size such that it can face the entire surface of the first surface F1 of the substrate 9. The cooling surface 40a is, for example, a horizontal flat surface. The cooling portion 40 cools the cooling surface 40a, thereby being able to reduce the temperature of the cooling surface 40a.

[0078] The vapor of the solvent evaporated from the coating film 90 on the first surface F1 of the substrate 9 (hereinafter referred to as solvent vapor) can be cooled and condensed on the cooling surface 40a. Therefore, the liquid solvent 91 (see Figure 8 described later) can adhere to the cooling surface 40a. By this condensation, as will be described in detail later, drying unevenness of the coating film 90 can be suppressed. In addition, by further reducing the air pressure within the chamber 10, the solvent 91 adhering to the cooling surface 40a can also be evaporated. This condensation and evaporation will also be described in detail later.

[0079] In Figure 1 the example, the first lifting portion 100 raises and lowers the support portion 20. Specifically, the first lifting portion 100 raises and lowers the support portion 20 between the raised position H1 and the lowered position H2. The raised position H1 is the position of the support portion 20 when the interval between the substrate 9 supported by the support portion 20 and the cooling surface 40a is the first interval. In Figure 1In the example, the support portion 20 and the substrate 9 located at the raised position H1 are represented by phantom lines. The lowered position H2 is the position of the support portion 20 when the interval between the substrate 9 supported by the support portion 20 and the cooling surface 40a is a second interval wider than the first interval. That is, the first elevating portion 100 raises and lowers the support portion 20 between a first state and a second state. In the first state, the interval between the substrate 9 and the cooling surface 40a is the first interval. In the second state, the interval between the substrate 9 and the cooling surface 40a is the second interval. The first interval is, for example, less than or equal to 10 mm. As a more specific example, the first interval is about 5 mm. The second interval can be, for example, more than 5 times the first interval or more than 10 times the first interval. If specific examples of numerical values are described, the second interval is, for example, greater than or equal to 50 mm. As a more specific example, the second interval is about 80 mm.

[0080] As will be described in detail later, at the initial stage of decompression, the first elevating portion 100 positions the support portion 20 at the raised position H1. Then, the first elevating portion 100 lowers the support portion 20 to the lowered position H2. The technical significance thereof will be described in detail later.

[0081] In addition, in Figure 1 and Figure 2 In the example, the decompression drying apparatus 1 further includes a gas supply portion 60, a bottom surface rectifying plate 50, a side surface rectifying plate 51, and a barometer 70. The gas supply portion 60 supplies gas into the chamber 10. Thereby, the air pressure in the chamber 10 can be restored to atmospheric pressure. The bottom surface rectifying plate 50 and the side surface rectifying plate 51 are provided in the chamber 10 to adjust the air flow in the chamber 10. The barometer 70 measures the air pressure in the chamber 10 and outputs an electric signal representing the measurement result to the control portion 80. The control portion 80 controls various structures of the above-described decompression drying apparatus 1. For example, the control portion 80 controls the decompression mechanism 30 based on the air pressure measured by the barometer 70 to adjust the air pressure in the chamber 10. In addition, the control portion 80 controls the cooling portion 40 to adjust the temperature of the cooling surface 40a, and controls the first elevating portion 100 to adjust the position of the support portion 20.

[0082] Next, a detailed example of each structure of the decompression drying apparatus 1 will be described.

[0083] <1-1-1. Chamber 10>

[0084] The chamber 10 employs a pressure-resistant container having an internal space 10s for accommodating the substrate 9. The chamber 10 is, for example, fixed to a device stand (not shown). The shape of the chamber 10 is, for example, a flat rectangular parallelepiped. The chamber 10 has, for example, a substantially square bottom plate portion 11, four side wall portions 12, and a substantially square top plate portion 13. The four side wall portions 12 connect, for example, the four end edges of the bottom plate portion 11 and the four end edges of the top plate portion 13 in the vertical direction. For example, an inlet / outlet 14 and a gate portion (also referred to as a gate valve) 15 for opening and closing the inlet / outlet 14 are provided on one of the four side wall portions 12. The gate portion 15 is connected or linked to an opening / closing drive portion 16, for example. In Figure 3 , in order to avoid complication of the drawings, the opening / closing drive portion 16 is conceptually shown. For example, a drive device such as a cylinder is applicable to the opening / closing drive portion 16. Here, for example, by the operation of the opening / closing drive portion 16, the gate portion 15 can move between a position where the inlet / outlet 14 is closed (also referred to as a closed position) and a position where the inlet / outlet 14 is opened (also referred to as an open position).

[0085] Here, for example, in a state where the gate portion 15 is in the closed position, the internal space 10s of the chamber 10 is sealed. For example, in a state where the gate portion 15 is in the open position, the substrate 9 can be loaded into the internal space 10s of the chamber 10 and unloaded from the internal space 10s of the chamber 10 via the inlet / outlet 14.

[0086] <1-1-2. Support portion 20>

[0087] The support portion 20 is located in the internal space 10s of the chamber 10 and can support the substrate 9 accommodated in the internal space 10s of the chamber 10 from below. The support portion 20 has, for example, a plurality of support plates 21 and a plurality of support pins 22. The plurality of support plates 21 are arranged at intervals in the horizontal direction, for example. A plurality of support pins 22 are erected on the upper surface of each support plate 21. When viewed from above, the plurality of support pins 22 are two-dimensionally and dispersedly arranged. The plurality of support plates 21 are parts constituting the base of the support portion 20. The substrate 9 is disposed above the plurality of support plates 21, and the upper end portions of the plurality of support pins 22 are in contact with the second surface F2 which is the lower surface of the substrate 9, thereby supporting the substrate 9 in a horizontal posture.

[0088] <1-1-3. Pressure reduction mechanism 30>

[0089] As Figure 1 and Figure 2As shown, for example, four exhaust ports 16a, 16b, 16c, and 16d are provided in a portion of the bottom plate portion 11 of the chamber 10 that faces the substrate 9 in the vertical direction. The decompression mechanism 30, for example, includes an exhaust pipe 31, four independent valves Va, Vb, Vc, Vd, a main valve Ve, and a vacuum pump 32. The exhaust pipe 31, for example, has four independent pipes 31a, 31b, 31c, 31d and one main pipe 31e. For example, one end of the independent pipe 31a is connected to the exhaust port 16a, one end of the independent pipe 31b is connected to the exhaust port 16b, one end of the independent pipe 31c is connected to the exhaust port 16c, and one end of the independent pipe 31d is connected to the exhaust port 16d. For example, the other ends of the four independent pipes 31a, 31b, 31c, 31d converge and are connected to one end of the main pipe 31e. For example, the other end of the main pipe 31e is connected to the vacuum pump 32. For example, the independent valve Va is provided in the path of the independent pipe 31a, the independent valve Vb is provided in the path of the independent pipe 31b, the independent valve Vc is provided in the path of the independent pipe 31c, and the independent valve Vd is provided in the path of the independent pipe 31d. For example, the main valve Ve is provided in the path of the main pipe 31e.

[0090] Here, for example, in a state where the loading / unloading port 14 is closed by the shutter portion 15, if at least one of the four independent valves Va, Vb, Vc, Vd and a main valve Ve are opened and the vacuum pump 32 is started, the gas in the chamber 10 is discharged to the outside of the chamber 10 through the exhaust pipe 31. Thus, for example, the air pressure in the internal space 10s of the chamber 10 can be reduced. The four independent valves Va, Vb, Vc, Vd are, for example, valves for individually adjusting the exhaust volume (suction flow rate) of the four exhaust ports 16a, 16b, 16c, 16d. Each of the four independent valves Va, Vb, Vc, Vd is, for example, a valve (also called an opening / closing valve) that switches between an open state and a closed state according to an instruction from the control unit 80. The main valve Ve is, for example, a valve for adjusting the total exhaust volume of the four exhaust ports 16a, 16b, 16c, 16d. The main valve Ve is, for example, a valve (also called an opening degree control valve) that can adjust the opening degree according to an instruction from the control unit 80.

[0091] <1-1-4. First lifting portion 100>

[0092] In the first embodiment, the first lifting portion 100 lifts the support portion 20 within the chamber 10. In other words, the first lifting portion 100 has a mechanism (also called a lifting mechanism) capable of lifting the support portion 20. In Figure 1 order to avoid complicating the drawings, the first lifting portion 100 is conceptually shown. The first lifting portion 100, for example, uses a driving device such as a linear motor or a cylinder. As Figure 3As shown, the first elevating unit 100 has, for example, a main body portion 100a and a moving portion 100b. The main body portion 100a is fixed, for example, outside the chamber 10 on a device rack (not shown). The moving portion 100b can move relative to the main body portion 100a in the vertical direction. The moving portion 100b is, for example, a rod-shaped member or the like. The moving portion 100b exists in a state of passing through a through-hole 11h in the bottom plate portion 11 of the chamber 10. And, for example, if a bellows or the like is provided between the lower surface of the bottom plate portion 11 and the moving portion 100b, the gap between the bottom plate portion 11 and the moving portion 100b can be sealed. For example, when the support portion 20 has a plurality of support plates 21, the moving portion 100b has: rod-shaped portions (also referred to as rod portions) respectively fixed to the respective support plates 21 and passing through the through-hole 11h in the bottom plate portion 11; a portion connecting the plurality of rod portions (also referred to as a connecting portion); and a portion connected to the connecting portion and slidably supported by the main body portion 100a (also referred to as a sliding portion). The first elevating unit 100 raises and lowers the support portion 20, and thus the substrate 9 supported by the support portion 20 also moves up and down.

[0093] <1-1-5. Cooling unit 40>

[0094] Although the specific structure of the cooling unit 40 is not particularly limited, in the Figure 1 example, the cooling unit 40 includes a cooling member 41, a first refrigerant pipe 42, a second refrigerant pipe 43, and a refrigerant cooling source 44. In addition, in the Figure 3 figure, to avoid complicating the drawing, the structure of the cooling unit 40 is simply shown. The shape of the cooling member 41 is plate-shaped. In this case, the cooling member 41 can also be referred to as a cooling plate. The cooling member 41 is mounted on the upper surface of the top plate portion 13 with its thickness direction in the vertical direction. When viewed from above, the cooling member 41 is, for example, rectangular. The lower surface of the cooling member 41 is preferably in close contact with the upper surface of the top plate portion 13. The cooling member 41 can be formed of a material with high thermal conductivity (for example, metal or the like).

[0095] In the Figure 1 example, a refrigerant flow path 41a is formed inside the cooling member 41. The refrigerant flow path 41a can extend in a meandering shape or a spiral shape when viewed from above. In the Figure 1 example, an inlet 41b and an outlet 41c of the refrigerant flow path 41a are formed on the upper surface of the cooling member 41. The inlet 41b is connected to the downstream end of the first refrigerant pipe 42, and the outlet 41c is connected to the upstream end of the second refrigerant pipe 43. The upstream end of the first refrigerant pipe 42 and the downstream end of the second refrigerant pipe 43 are connected to the refrigerant cooling source 44.

[0096] The refrigerant flows into the refrigerant cooling source 44 from the downstream end of the second refrigerant pipe 43. The refrigerant can be a liquid or a gas. As a specific example, water can be used as the refrigerant. The refrigerant cooling source 44 cools the refrigerant and supplies the cooled refrigerant to the upstream end of the first refrigerant pipe 42. The refrigerant cooling source 44 can also be a heat pump, for example. The refrigerant cooled by the refrigerant cooling source 44 flows into the upstream end of the first refrigerant pipe 42 and flows into the refrigerant flow path 41a through the first refrigerant pipe 42. The low-temperature refrigerant flows in the refrigerant flow path 41a, so that the refrigerant exchanges heat with the cooling member 41 to cool the cooling member 41. Since the cooling member 41 exchanges heat with the top plate portion 13, the top plate portion 13 is also cooled. The refrigerant that has flowed through the refrigerant flow path 41a and has been heated flows into the refrigerant cooling source 44 again through the second refrigerant pipe 43 and is cooled by the refrigerant cooling source 44 again.

[0097] If the cooling unit 40 cools the top plate portion 13 of the chamber 10, the cooling surface 40a, which is the lower surface of the top plate portion 13 (i.e., the top surface of the chamber 10), is also cooled. In Figure 1 the example, when viewed from above, the size of the cooling member 41 is larger than that of the substrate 9. That is, when viewed from above, the outline of the cooling member 41 surrounds the outline of the substrate 9. If the cooling member 41 is rectangular when viewed from above, the long side of the cooling member 41 is longer than the long side of the substrate 9, and the short side of the cooling member 41 is longer than the short side of the substrate 9. Thus, the cooling member 41 can appropriately cool the entire surface of the cooling surface 40a that faces the entire surface of the first surface F1 of the substrate 9. In addition, the cooling member 41 can also be square when viewed from above. In this case, it is sufficient that the side length of the cooling member 41 is larger than the short side of the substrate 9. In this way, regardless of the orientation of the substrate 9 disposed on the support portion 20, when viewed from above, the cooling member 41 is larger than the substrate 9. Therefore, regardless of the orientation of the substrate 9, the cooling member 41 can appropriately cool the entire surface of the cooling surface 40a that faces the entire surface of the first surface F1 of the substrate 9.

[0098] <1-1-6. Bottom surface rectifying plate 50>

[0099] The bottom surface rectifying plate 50 is a plate for restricting the flow of gas in the internal space 10s when the chamber 10 is decompressed by the decompression mechanism 30. For example, the bottom surface rectifying plate 50 is disposed between the substrate 9 supported by the support portion 20 and the bottom plate portion 11 of the chamber 10. The bottom surface rectifying plate 50 is fixed to the bottom plate portion 11 of the chamber 10 by a plurality of pillars (not shown), for example. As Figure 2As shown, for example, when viewed from above, the shape of the bottom surface rectifying plate 50 is square. And, for example, when viewed from above, each side length of the bottom surface rectifying plate 50 is greater than the short side of the rectangular substrate 9. Therefore, for example, regardless of the direction of the substrate 9 disposed on the support portion 20, when viewed from above, the bottom surface rectifying plate 50 is larger than the substrate 9. In addition, the bottom surface rectifying plate 50, for example, has a through hole 50h in a state where the moving portion 100b of the first lifting portion 100 penetrates therethrough. The bottom surface rectifying plate 50 and the moving portion 100b are separated by a very small interval at the through hole 50h.

[0100] <1-1-7. Side rectifying plate 51>

[0101] The side rectifying plate 51 is a plate for restricting the flow of gas in the internal space 10s together with the bottom surface rectifying plate 50 when the chamber 10 is decompressed by the decompression mechanism 30. For example, the side rectifying plate 51 is disposed so as to be located between the substrate 9 supported by the support portion 20 at the lowered position H2 and the side wall portion 12 of the chamber 10. Here, for example, four side rectifying plates 51 are disposed so as to surround the periphery of the substrate 9 supported by the support portion 20. For example, the four side rectifying plates 51 integrally form a rectifying plate in the shape of a square tube surrounding the substrate 9. In addition, for example, the bottom surface rectifying plate 50 and the four side rectifying plates 51 integrally form a box-shaped rectifying plate with a bottom tube shape. In addition, in Figure 1 the example, the upper end of the side rectifying plate 51 is lower than the second surface F2 of the substrate 9 supported by the support portion 20 at the raised position H1. Therefore, in the first state where the support portion 20 is located at the raised position H1, the substrate 9 is not surrounded by the four side rectifying plates 51.

[0102] Here, for example, when the chamber 10 is decompressed in the second state where the support portion 20 is located at the lowered position H2, the gas directly above the substrate 9 mainly flows to the upper end of the side rectifying plate 51 (see Figure 13 described later). This gas sequentially passes through the space between the side rectifying plate 51 and the side wall portion 12, the space between the bottom surface rectifying plate 50 and the bottom plate portion 11, and the exhaust ports 16a, 16b, 16c, 16d, and is discharged to the outside of the chamber 10. In this way, the gas flows in a space far from the substrate 9, so that an air flow is not easily formed near the substrate 9. And a concentrated air flow is not easily generated at the peripheral portion of the substrate 9. Thereby, for example, it is possible to suppress uneven drying of the coating film 90 formed on the upper surface of the substrate 9.

[0103] In addition, here, for example, it is adopted as Figure 2The structure shown, that is, when viewed from above, the four exhaust ports 16a, 16b, 16c, and 16d are all located on the diagonal line 52 of the square bottom fairing 50. In this case, for example, through the respective exhaust ports 16a, 16b, 16c, and 16d, an air flow symmetric with respect to the center of the bottom fairing 50 (the intersection point of the two diagonal lines 52) can be formed. Thus, for example, in the internal space 10s of the chamber 10, a more uniform air flow can be formed.

[0104] <1-1-8. Gas supply unit 60>

[0105] The gas supply unit 60 is a part that performs the action of supplying gas into the chamber 10 (also referred to as gas supply). As Figure 1 shown, a gas supply port 16f is provided on the bottom plate portion 11 of the chamber 10, for example. The gas supply port 16f is located below the bottom fairing 50, for example. The gas supply unit 60 includes a gas supply pipe 61 connected to the gas supply port 16f, a gas supply valve Vf, and a gas supply source 62. For example, one end of the gas supply pipe 61 is connected to the gas supply port 16f. For example, the other end of the gas supply pipe 61 is connected to the gas supply source 62. For example, the gas supply valve Vf is provided on the path of the gas supply pipe 61.

[0106] Here, for example, if the gas supply valve Vf is opened, gas is supplied from the gas supply source 62 to the internal space 10s of the chamber 10 via the gas supply pipe 61 and the gas supply port 16f. Thus, the air pressure inside the chamber 10 can be increased. The gas supplied from the gas supply source 62 can be, for example, an inert gas such as nitrogen, or a clean and dry gas. The clean and dry gas is prepared, for example, by performing a cleaning process of removing particles and moisture on the air in the general environment.

[0107] <1-1-9. Barometer 70>

[0108] The barometer 70 is a sensor that measures the air pressure in the internal space 10s of the chamber 10. As Figure 1 shown, the barometer 70 is installed on a part of the chamber 10. The barometer 70 can measure the air pressure in the internal space 10s of the chamber 10 and output the measurement result to the control unit 80.

[0109] <1-1-10. Control unit 80>

[0110] The control unit 80 is a unit (electronic circuit) for controlling the operations of the respective parts of the vacuum drying apparatus 1. The control unit 80 can control structures such as the vacuum mechanism 30, the cooling unit 40, the air supply unit 60, and the first elevating unit 100. The control unit 80 is constituted, for example, by a computer having a processor 801 such as a CPU (Central Processing Unit), a memory 802 such as a RAM (Random Access Memory), and a storage unit 803 such as a hard disk drive. The storage unit 803 stores, for example, a computer program (also referred to as a program) 803p and various data, and the computer program is for executing a process of drying the coating film 90 on the substrate 9 by vacuum (also referred to as a vacuum drying process) in the vacuum drying apparatus 1. The storage unit 803 stores, for example, the program 803p and functions as a computer-readable non-transitory storage medium. The control unit 80 reads, for example, the program 803p and data from the storage unit 803 into the memory 802, and performs arithmetic processing based on the program 803p and data in the processor 801, thereby controlling the operations of the respective parts of the vacuum drying apparatus 1. Therefore, for example, in the vacuum drying apparatus 1, the program 803p is executed by the processor 801 included in the control unit 80, and thus, the vacuum drying process can be executed.

[0111] For example, an input unit 804, an output unit 805, a communication unit 806, and a driver 807 may be connected to the control unit 80. The input unit 804 is a part that inputs various signals to the control unit 80 in response to a user operation or the like. The input unit 804 may include, for example: an operation unit that inputs a signal corresponding to a user operation; a microphone that inputs a signal corresponding to a user's voice; various sensors that input a signal corresponding to a user's movement, and the like. The output unit 805 is a part that outputs various information in a manner recognizable by the user. The output unit 805 may include, for example, a display unit, a projector, a speaker, and the like. The display unit may also be a touch panel integrated with the input unit 804. The communication unit 806 is a part that transmits and receives various information to and from an external device such as a server using wired or wireless communication means or the like. For example, the program 803p received from the external device using the communication unit 806 may be stored in the storage unit 803. The driver 807 is a part that can detachably mount a portable storage medium 807m such as a magnetic disk or an optical disk. The driver 807, for example, transmits and receives data between the storage medium 807m and the control unit 80 in a state where the storage medium 807m is mounted.

[0112] For example, by mounting a storage medium 807m storing the program 803p on the driver 807, the program 803p can be read from the storage medium 807m and stored in the storage unit 803. Here, the storage medium 807m stores, for example, the program 803p and functions as a computer-readable non-transitory storage medium.

[0113] Figure 6 is a block diagram conceptually showing the functions implemented in the control unit 80. As Figure 6 shown, the control unit 80 is electrically connected to, for example, the opening / closing drive unit 16, the first lifting unit 100, four independent valves Va, Vb, Vc, Vd, the main valve Ve, the vacuum pump 32, the air supply valve Vf, the cooling unit 40, and the barometer 70. The control unit 80 can control the operations of the above-mentioned units by referring to the measurement values output from the barometer 70, for example.

[0114] As Figure 6 conceptually shown, as a functional structure to be implemented, the control unit 80 has, for example, an opening / closing control unit 81, a lifting control unit 82, a switching control unit 83, an exhaust control unit 84, a pump control unit 85, an air supply control unit 86, and a cooling control unit 87. For example, the opening / closing control unit 81 controls the operation of the opening / closing drive unit 16. For example, the lifting control unit 82 controls the operation of the first lifting unit 100. For example, the switching control unit 83 controls the opening / closing states of the four independent valves Va, Vb, Vc, Vd, respectively. For example, the exhaust control unit 84 controls the opening / closing state and the opening degree of the main valve Ve. For example, the pump control unit 85 controls the operation of the vacuum pump 32. For example, the air supply control unit 86 controls the opening / closing state of the air supply valve Vf. For example, the cooling control unit 87 controls the operation of the cooling unit 40. The functions of the respective units of the control unit 80 are realized, for example, by the processor 801 included in the control unit 80 performing arithmetic processing based on the above-mentioned program 803p and the like.

[0115] <1-2. Vacuum drying process>

[0116] Next, the vacuum drying process of the substrate 9 using the vacuum drying apparatus 1 will be described. Figure 7 is a flowchart showing an example of the process of the vacuum drying process of the first embodiment. The process of this vacuum drying process is realized, for example, by executing the program 803p in the processor 801 included in the control unit 80. Here, for example, the processes of step S1 to step S8 are sequentially executed Figure 7 as follows.

[0117] When performing vacuum drying treatment using the vacuum drying apparatus 1, for example, first, the substrate 9 is carried into the chamber 10 (step S1). At this time, the state is such that the undried coating film 90 is formed on the first surface F1 of the substrate 9. In step S1, for example, under the control of the control unit 80, the gate portion 15 opens the loading / unloading port 14, and a transfer robot (not shown) places the substrate 9 on the fork-shaped hand portion and carries the substrate 9 into the internal space 10s of the chamber 10 through the loading / unloading port 14 of the chamber 10. At this time, the support portion 20 is located, for example, at the lowered position H2. In addition, the side rectifying plate 51 is configured to be movable so that the side rectifying plate 51 does not interfere with the transfer robot. The transfer robot, for example, inserts the fork-shaped hand portion between the plurality of support plates 21 of the support portion 20, places the substrate 9 on the support portion 20, and then retracts the fork-shaped hand portion to the outside of the chamber 10. Then, under the control of the control unit 80, the gate portion 15 closes the loading / unloading port 14. As described above, in step S1, the process of placing the substrate 9 on the plurality of support pins 22 disposed in the chamber 10 (also referred to as the placing process) is performed.

[0118] Next, the vacuum drying apparatus 1 performs a cooling process (step S2). The cooling process is a process of cooling the cooling surface 40a. Specifically, the control unit 80 activates the cooling unit 40, and thus, the cooling unit 40 cools the cooling surface 40a to lower the temperature of the cooling surface 40a. The cooling unit 40 lowers the temperature of the cooling surface 40a to the target temperature. The target temperature is, for example, greater than or equal to 5°C and less than or equal to 15°C. As a more specific example, the target temperature is about 10°C. The cooling unit 40 can continuously perform the cooling operation of the cooling surface 40a until the vacuum drying treatment of the substrate 9 is completed. In addition, the cooling operation of the cooling unit 40 can also start before step S1.

[0119] Next, the vacuum drying apparatus 1 performs a first interval adjustment process (step S3). The first interval adjustment process is a process of setting the interval between the substrate 9 and the cooling surface 40a to the first interval. Specifically, the control unit 80 controls the first lifting unit 100 to raise the support portion 20 to the raised position H1. In the first state where the support portion 20 is located at the raised position H1, the substrate 9 is located at a position higher than the upper end of the side rectifying plate 51 (see Figure 1 ).

[0120] Next, the pressure reduction drying apparatus 1 performs a first pressure reduction process (step S4: equivalent to the first process). The first pressure reduction process is a process of reducing the air pressure in the chamber 10 to a first air pressure (hereinafter referred to as the first target air pressure). The first target air pressure is lower than the standard atmospheric pressure. For example, it is set to be greater than or equal to 10 kPa. Specifically, the control unit 80 causes the pressure reduction mechanism 30 to suck the gas in the chamber 10 with a relatively small first suction flow rate, thereby reducing the air pressure in the chamber 10. For example, the control unit 80 may also make the opening degree of the main valve Ve smaller than the opening degree during the subsequent second pressure reduction process. Thus, in the first pressure reduction process, the air pressure in the chamber 10 decreases at a lower reduction rate.

[0121] In step S3, for example, the control unit 80 may also independently and appropriately control the opening and closing states of each of the plurality of independent valves Va, Vb, Vc, Vd. Thereby, the air flow in the chamber 10 can be controlled to suppress non-uniform drying of the substrate 9.

[0122] Figure 8 and Figure 9 is a diagram schematically showing an example of the state in the chamber 10 during the first pressure reduction process. Figure 8 represents the entire chamber 10, Figure 9 and magnifies and shows the vicinity of the cooling surface 40a and the substrate 9 in the chamber 10.

[0123] As Figure 8 shown, in the first pressure reduction process, in the first state where the support portion 20 is located at the raised position H1, the interval between the substrate 9 and the cooling surface 40a is very narrow. Therefore, the reduction rate of the air pressure in the upper space 10s1 becomes lower, and boiling of the coating film 90 on the first surface F1 of the substrate 9 can be suppressed.

[0124] On the other hand, in the first state, the substrate 9 supported by the support portion 20 is located above the upper end of the side flow rectifying plate 51. Therefore, the air flow regulating function of the side flow rectifying plate 51 hardly acts on the upper space 10s1 between the substrate 9 and the cooling surface 40a. Therefore, the side flow rectifying plate 51 basically does not bring an effect of suppressing the occurrence of non-uniform drying. In the first state, since the lower space 10s2 below the substrate 9 is spacious, the gas in the lower space 10s2 can be quickly discharged. Specifically, the gas in the lower space 10s2 passes between the side flow rectifying plate 51 and the side wall portion 12 of the chamber 10 and is discharged from the chamber 10. In Figure 8 this, the air flow is schematically shown by a dotted arrow.

[0125] Through the first pressure reduction process, the air pressure in the chamber 10 decreases, so the solvent of the coating film 90 on the first surface F1 of the substrate 9 evaporates. In Figure 9In the figure, the flow of solvent vapor from the coating film 90 is schematically indicated by a dashed arrow. In the first pressure reduction process, since the cooling unit 40 cools the cooling surface 40a, the solvent vapor from the coating film 90 is cooled and condensed on the cooling surface 40a. That is, as Figure 9 shown, the liquid solvent 91 adheres to the cooling surface 40a. In other words, the target temperature of the cooling surface 40a is set to a temperature at which the solvent vapor condenses in a state where the air pressure in the chamber 10 reaches the first target air pressure. As a more specific example, the target temperature of the cooling surface 40a is set to be less than or equal to the temperature at which the pressure reaches the first target air pressure in the vapor pressure curve of the solvent. Thereby, the solvent 91 can adhere to the area of the cooling surface 40a opposite to the coating film 90 substantially uniformly. Thus, the solvent vapor in the upper space 10s1 condenses on the cooling surface 40a, and thereby, the concentration of the solvent vapor in the upper space 10s1 decreases, and the concentration distribution of the solvent vapor when viewed from above becomes more uniform.

[0126] For comparison, a comparative structure without the cooling unit 40 will be described. Figure 10 is a diagram showing an enlarged view of the top plate portion 13 and the substrate 9 of the chamber 10 of the comparative structure. In Figure 9 this example, the lower surface 13a of the top plate portion 13 of the chamber 10 is not cooled by the cooling unit 40. The temperature of the lower surface 13a of the top plate portion 13 is, for example, approximately normal temperature.

[0127] In the first pressure reduction process, since the gap between the substrate 9 and the lower surface 13a is narrow, the solvent vapor from the coating film 90 immediately collides with the lower surface 13a of the top plate portion 13. Therefore, in the central region of the upper space 10s1 that is opposite to the central portion of the coating film 90, the solvent vapor easily stays. On the other hand, in the peripheral region of the upper space 10s1 that is opposite to the peripheral portion of the coating film 90, due to concentration diffusion, the solvent vapor can flow out in the horizontal direction. Therefore, compared with the central portion, the peripheral portion of the coating film 90 is more likely to evaporate. That is, uneven drying occurs on the coating film 90.

[0128] Figure 11 is a diagram showing an example of the concentration distribution of the solvent vapor in the upper space 10s1 of the comparative structure. Figure 11 (a) of shows the concentration distribution of the solvent vapor when viewed from above, Figure 11 (b) of shows the concentration distribution of the solvent vapor when viewed from the side. In Figure 11 (a) of, the concentration distribution of the solvent vapor is represented by contour lines T1 to T10. For the contour lines T1 to T10, the smaller the marked number, the higher the represented concentration. That is, among the contour lines T1 to T10, the contour line T1 represents the highest concentration. In Figure 11In (b), the concentration distribution of the solvent vapor is represented by contour lines T11 to T21. Among contour lines T11 to T21, the smaller the marked number, the higher the concentration it represents. That is to say, among contour lines T11 to T21, contour line T11 represents the highest concentration.

[0129] It can be obtained from Figure 11 (a) that in the comparison structure, the solvent vapor flows from the periphery of the coating film 90 to the outside. In addition, as Figure 11 (b) shows, in the peripheral region 10r opposite to the peripheral portion of the coating film 90 in the upper space 10s1, the lower the concentration of the solvent vapor is towards the outside of the coating film 90. It can be seen from this that the peripheral portion of the coating film 90 evaporates more easily than the central portion.

[0130] Figure 12 It is a diagram showing an example of the concentration distribution of the solvent vapor in the upper space 10s1 in a state where cooling is performed in the cooling unit 40. Figure 12 (a) represents the concentration distribution of the solvent vapor when viewed from above, Figure 12 (b) represents the concentration distribution of the solvent vapor when viewed from the side. It can be obtained from Figure 12 (a) that the solvent vapor does not flow out much from the periphery of the coating film 90. This is because the solvent vapor from the coating film 90 is cooled and condensed on the cooling surface 40a. That is to say, whether it is the solvent vapor from the central portion of the coating film 90 or the solvent vapor from its peripheral portion, it all flows upward as an updraft corresponding to the temperature difference with the cooling surface 40a and condenses on the cooling surface 40a (see Figure 9 ). In this way, the solvent vapor from the peripheral portion also condenses on the cooling surface 40a, so the solvent vapor does not flow out much to the outside. In addition, the solvent vapor from the coating film 90 does not stay much in the upper space 10s1.

[0131] As Figure 12 (b) shows, in the peripheral region 10r, although the lower the concentration of the solvent vapor is in the vertical direction as it is farther away from the coating film 90, it is substantially uniform in the horizontal direction.

[0132] Therefore, the difference between the evaporation amount of the central portion and the evaporation amount of the peripheral portion of the coating film 90 can be reduced, and the occurrence of drying unevenness can be suppressed. In addition, because the concentration of the solvent vapor in the upper space 10s1 is reduced by the condensation of the solvent vapor on the cooling surface 40a, the evaporation of the coating film 90 can also be promoted. Therefore, the processing ability of the reduced-pressure drying process can also be improved.

[0133] Next, for example, when the air pressure in the chamber 10 reaches the first target air pressure, the vacuum drying apparatus 1 performs a second interval adjustment process (step S5). The second interval adjustment process is a process of setting the interval between the substrate 9 and the cooling surface 40a to a second interval. Specifically, the control unit 80 controls the first elevating unit 100 to lower the support unit 20 to the lowered position H2. In the second state where the support unit 20 is located at the lowered position H2, the substrate 9 is located at a position lower than the upper end of the side flow rectifying plate 51.

[0134] Next, the vacuum drying apparatus 1 performs a second pressure reduction process (step S6: equivalent to the second process). The second pressure reduction process is a process of reducing the air pressure in the chamber 10 to a second air pressure (hereinafter referred to as the second target air pressure) lower than the first target air pressure.

[0135] Specifically, the control unit 80 causes the pressure reduction mechanism 30 to suck the gas in the chamber 10 at a second suction flow rate greater than the first suction flow rate, thereby reducing the air pressure in the chamber 10. For example, the control unit 80 can set the opening degree of the main valve Ve to be greater than the opening degree during the first pressure reduction process. The air pressure in the chamber 10 is reduced to the second target air pressure at a reduction speed higher than the reduction speed during the first pressure reduction process. During the second pressure reduction process, the vacuum drying apparatus 1 can maintain the air pressure in the chamber 10 at the second target air pressure for a specified period. The second target air pressure is, for example, less than 10 kPa and greater than or equal to 0.1 Pa.

[0136] In step S6, for example, the control unit 80 can independently and appropriately control the opening and closing states of each of the plurality of independent valves Va, Vb, Vc, and Vd. Thereby, the air flow in the chamber 10 can be controlled to suppress non-uniform drying of the substrate 9.

[0137] Figure 13 is a diagram schematically showing an example of the state in the chamber 10 during the second pressure reduction process. As Figure 13 shown, in the second state where the support unit 20 is located at the lowered position H2, the interval between the substrate 9 and the cooling surface 40a is wide. In other words, the height of the upper space 10s1 is large. Therefore, different from the first pressure reduction process, the solvent vapor from the coating film 90 easily flows upward, and it is not easy to cause retention of the solvent vapor. Since the upper space 10s1 is large, the air pressure in the upper space 10s1 can be reduced to the second target air pressure more appropriately and quickly.

[0138] In addition, in the second state, the substrate 9 supported by the support unit 20 is surrounded by the four side flow rectifying plates 51. Therefore, the flow rectifying function of the side flow rectifying plates 51 acts on the upper space 10s1 between the substrate 9 and the cooling surface 40a. That is, the concentration of the air flow toward the peripheral portion of the substrate 9 can be suppressed by the side flow rectifying plates 51. Therefore, non-uniform drying of the coating film 90 due to the air flow can be further suppressed.

[0139] When the air pressure in the chamber 10 reaches the second target air pressure, the solvent of the coating film 90 boils, and the drying of the coating film 90 proceeds at a higher speed. The decompression mechanism 30 can suck the gas in the chamber 10 so that the air pressure in the chamber 10 is approximately constant at the second target air pressure. That is to say, the decompression mechanism 30 can maintain the air pressure in the chamber 10 at the second target air pressure within a specified period. In the present embodiment, in the second decompression process, the solvent 91 attached to the cooling surface 40a also evaporates. In other words, the target temperature of the cooling surface 40a is set to a temperature at which the solvent evaporates in a state where the air pressure in the chamber 10 is the second target air pressure. As a more specific example, the target temperature of the cooling surface 40a is set to be greater than or equal to the temperature when the pressure reaches the second target air pressure in the vapor pressure curve of the solvent.

[0140] The solvent vapor from the coating film 90 and the cooling surface 40a flows into the space between the side rectifying plate 51 and the side wall portion 12 of the chamber 10 from the upper end side of the side rectifying plate 51, and is discharged to the outside through the exhaust ports 16a, 16b, 16c, 16d. In Figure 13 the figure, the flow of these solvent vapors is schematically shown by dotted arrows.

[0141] If the boiling of the coating film 90 ends, that is to say, if a specified period has elapsed, the decompression mechanism 30 can further reduce the air pressure in the chamber 10. In other words, the decompression mechanism 30 can reduce the air pressure in the chamber 10 to a third target air pressure lower than the second target air pressure. Thereby, the coating film 90 and the cooling surface 40a can be dried more reliably.

[0142] As described above, in the second decompression process, the first lifting portion 100 lowers the support portion 20 to the lowering position H2, and the decompression mechanism 30 makes the air pressure in the chamber 10 less than or equal to the second target air pressure. Thereby, in the second decompression process, the decompression drying device 1 can not only dry the coating film 90 on the first surface F1 of the substrate 9, but also dry the cooling surface 40a.

[0143] If both the coating film 90 and the cooling surface 40a are sufficiently dried, the control unit 80 opens the air supply valve Vf. Thereby, gas is supplied from the air supply source 62 to the internal space 10s of the chamber 10 through the air supply pipe 61 and the air supply port 16f (step S7). Thereby, the air pressure in the chamber 10 rises to the atmospheric pressure again.

[0144] And, for example, finally, the substrate 9 is taken out of the chamber 10 (step S8). In step S8, for example, first, under the control of the control unit 80, the gate unit 15 opens the loading / unloading port 14, and a transfer robot (not shown) transfers the dried substrate 9 placed on the support unit 20 out of the chamber 10 via the loading / unloading port 14 of the chamber 10. Thus, the reduced-pressure drying process for one substrate 9 can be completed.

[0145] As described above, in the present embodiment, the control unit 80 controls the first lifting unit 100 and the decompression mechanism 30 such that the air pressure in the chamber 10 reaches the first air pressure in the first state where the first interval is formed between the substrate 9 and the cooling surface 40a, and then the air pressure in the chamber 10 reaches the second air pressure in the second state where the second interval is formed between the substrate 9 and the cooling surface 40a.

[0146] Specifically, first, in the first decompression process, while the cooling unit 40 cools the cooling surface 40a and the first lifting unit 100 raises the support unit 20 to the raised position H1, the decompression mechanism 30 reduces the air pressure in the chamber 10 to the first target air pressure. In the first decompression process, since the support unit 20 is at the raised position H1, the interval between the substrate 9 and the cooling surface 40a is narrow. Therefore, a rapid decrease in the air pressure in the upper space 10s1 between the substrate 9 and the cooling surface 40a can be suppressed, and boiling of the coating film 90 can be suppressed.

[0147] In addition, in the first decompression process, the cooling unit 40 cools the cooling surface 40a. More specifically, the cooling unit 40 reduces the temperature of the cooling surface 40a to a target temperature at which the solvent vapor condenses under the first target air pressure. Therefore, the solvent vapor from the coating film 90 on the substrate 9 condenses on the cooling surface 40a. Therefore, the retention of the solvent vapor in the upper space 10s1 (especially the central region) can be suppressed, and non-uniform drying of the coating film 90 can be suppressed.

[0148] On the other hand, in the second decompression process after the first decompression process, while the first lifting unit 100 lowers the support unit 20 to the lowered position H2, the decompression mechanism 30 reduces the air pressure in the chamber 10 to be less than or equal to the second target air pressure. Since the support unit 20 is at the lowered position H2, the interval between the substrate 9 and the cooling surface 40a is wide. Thus, the air pressure in the chamber 10 can be reduced more appropriately and rapidly. Therefore, the coating film 90 can be dried more appropriately and rapidly. In addition, in the second decompression process, since the interval between the substrate 9 and the cooling surface 40a is wide, the solvent vapor is not likely to be retained and non-uniform drying is not likely to occur.

[0149] In addition, in the second pressure reduction process, the temperature of the cooling surface 40a is the temperature at which the solvent evaporates under the second target air pressure. Therefore, in the second pressure reduction process, not only can the coating film 90 on the substrate 9 be dried, but also the cooling surface 40a can be dried. Therefore, before performing the pressure reduction drying process on the next substrate 9, it is not necessary to separately dry the cooling surface 40a, and the pressure reduction drying process can be quickly performed on the next substrate 9. Thus, the processing ability of the pressure reduction drying process for a plurality of substrates 9 can be improved.

[0150] In addition, in the first embodiment, the top surface of the chamber 10 corresponds to the cooling surface 40a. Therefore, as long as the cooling unit 40 is externally provided on the upper surface of the chamber 10, the chamber 10 can be directly used.

[0151] In addition, in the first embodiment, the cooling member 41 cools the lower surface of the top plate portion 13, that is, the cooling surface 40a, through the cooling top plate portion 13. Although the temperature distribution in the cooling member 41 deviates slightly according to the extending shape of the refrigerant flow path 41a when viewed from above, through heat transfer in the top plate portion 13, the deviation of the temperature distribution is alleviated as it approaches the cooling surface 40a. That is, the temperature distribution of the cooling surface 40a of the top plate portion 13 can be made more uniform. Therefore, the solvent vapor from the coating film 90 on the first surface F1 of the substrate 9 can be condensed more uniformly on the cooling surface 40a. Therefore, the uniformity of the concentration distribution of the solvent vapor in the upper space 10s1 can be improved. Thus, the occurrence of uneven drying can be further suppressed.

[0152] In addition, in the first embodiment, the first lifting unit 100 that lifts the support portion 20 is used to adjust the interval between the substrate 9 and the cooling surface 40a. Therefore, the existing first lifting unit 100 can be directly used.

[0153] <2. Second Embodiment>

[0154] Figure 14 FIG. is an example showing a longitudinal section schematically of the pressure reduction drying apparatus 1A of the second embodiment. Except for the second lifting unit 45, the structure of the pressure reduction drying apparatus 1A is the same as that of the pressure reduction drying apparatus 1. The second lifting unit 45 lifts the cooling member 41 of the cooling unit 40 between the cooling position H3 and the separation position H4. The cooling position H3 is the position where the lower surface of the cooling member 41 contacts the upper surface of the top plate portion 13 of the chamber 10, and the separation position H4 is the position where the cooling member 41 is separated from the top plate portion 13. In Figure 14 the example, the cooling member 41 located at the separation position H4 is schematically shown by a phantom line. For example, the second lifting unit 45 uses a driving device such as a linear motor or a cylinder.

[0155] Figure 15It is a flowchart showing an example of the process of the pressure-reducing drying process of the second embodiment. Here, for example, the processes of steps S11 to S19 in Figure 15 are performed in sequence. The cooling member 41 is initially located at the cooling position H3.

[0156] First, the pressure-reducing drying apparatus 1A sequentially executes steps S11 to S15. Steps S11 to S15 are the same as steps S1 to S5 respectively. However, the cooling operation of the cooling surface 40a by the cooling unit 40 can substantially end at the end of step S15.

[0157] After step S15, the pressure-reducing drying apparatus 1A performs a cooling unit separation process (step S16). The cooling unit separation process is a process of moving the cooling unit 40 to the separation position H4. Specifically, the control unit 80 controls the second lifting unit 45 to raise the cooling member 41 from the cooling position H3 to the separation position H4. The cooling member 41 rises to the separation position H4, thereby being able to substantially interrupt the cooling operation of the cooling surface 40a.

[0158] Next, the pressure-reducing drying apparatus 1A executes steps S17 to S19. Steps S17 to S19 are the same as steps S6 to S8 respectively.

[0159] As described above, according to the second embodiment, in the first pressure-reducing process (step S14), the cooling member 41 descends to the cooling position H3 to cool the lower surface of the top plate portion 13, that is, the cooling surface 40a. Therefore, in the first pressure-reducing process, the pressure-reducing drying apparatus 1A can more reliably condense the solvent vapor on the cooling surface 40a. And according to the second embodiment, in the second pressure-reducing process (step S17), the cooling member 41 rises to the separation position H4. Therefore, in the second pressure-reducing process, the cooling operation of the cooling surface 40a can be substantially interrupted. The cooling member 41 moves away from the cooling surface 40a, and thus, as time passes, the temperature of the cooling surface 40a rises, so that the evaporation of the solvent 91 attached to the cooling surface 40a can be promoted. Therefore, in the second pressure-reducing process, the pressure-reducing drying apparatus 1A can more reliably dry the cooling surface 40a.

[0160] <3. Third Embodiment>

[0161] Figure 16 It is a diagram schematically showing an example of the longitudinal section of the pressure-reducing drying apparatus 1B of the third embodiment. Except for the internal structure of the cooling unit 40, the structure of the pressure-reducing drying apparatus 1B is the same as that of the pressure-reducing drying apparatus 1.

[0162] As Figure 16As shown, a part of the cooling unit 40 of the vacuum drying device 1B is buried in the top plate portion 13 of the chamber 10. Here, the top plate portion 13 functions as a cooling member 41. The top plate portion 13 may also be formed of a material with high thermal conductivity (e.g., metal). In Figure 16 the example of Figure 16 , a refrigerant flow path 41a, which is a part of the cooling unit 40, is formed inside the top plate portion 13. For example, when viewed from above, the refrigerant flow path 41a may be serpentine or helically extend inside the top plate portion 13. In

[0163] the example of

[0164] , an inlet 41b and an outlet 41c of the refrigerant flow path 41a are formed on the upper surface of the top plate portion 13. The inlet 41b is connected to the downstream end of the first refrigerant pipe 42, and the outlet 41c is connected to the upstream end of the second refrigerant pipe 43.

[0165] Moreover, the refrigerant cooling source 44 cools the refrigerant and circulates it, so that the top plate portion 13 of the chamber 10 can be cooled. That is, the lower surface of the top plate portion 13, i.e., the cooling surface 40a, can be cooled.

[0166] In addition, a part of the cooling unit 40 buried in the top plate portion 13 is a low-temperature part that absorbs heat from the top plate portion 13. For example, when the cooling unit 40 has a cooling element such as a Peltier element, the cooling element is buried in the top plate portion 13.

[0167] <4. Fourth Embodiment>

[0168] Figure 17 is a diagram schematically showing an example of a longitudinal section of the vacuum drying device 1C according to the fourth embodiment. The vacuum drying device 1C has the same structure as the vacuum drying device 1 except for the internal structure of the cooling unit 40.

[0169] As Figure 17As shown, a part of the cooling section 40 of the reduced-pressure drying apparatus 1C is located in the internal space 10s of the chamber 10. Specifically, the cooling member 41 is located in the internal space 10s of the chamber 10. Inside the chamber 10, the cooling member 41 is disposed at a position opposite to the first surface F1 of the substrate 9 supported by the support section 20. That is to say, the cooling member 41 is disposed above the substrate 9 supported by the support section 20. The cooling member 41 is disposed in the chamber 10 in a posture where its thickness direction is along the vertical direction. The cooling member 41 is fixed in the chamber 10 by a fixing section (not shown). The cooling member 41 can be fixed to the top plate section 13 of the chamber 10 by a fixing section such as a screw. In the fourth embodiment, the lower surface of the cooling member 41 corresponds to the cooling surface 40a.

[0170] In Figure 17 the example of, the first refrigerant pipe 42 and the second refrigerant pipe 43 penetrate the top plate section 13, and the refrigerant cooling source 44 is disposed outside the chamber 10. The refrigerant cooling source 44 cools the refrigerant and circulates it, whereby the cooling member 41 can be cooled. That is to say, the cooling surface 40a of the cooling member 41 can be cooled.

[0171] In Figure 17 the example of, when viewed from above, the size of the cooling member 41 is larger than that of the substrate 9. When viewed from above, the cooling surface 40a of the cooling member 41 may have the same rectangular shape as the substrate 9. At this time, the long side of the cooling surface 40a is larger than the long side of the substrate 9, and the short side of the cooling surface 40a is larger than the short side of the substrate 9. Thereby, the cooling surface 40a can face the entire surface of the first surface F1 of the substrate 9 in the vertical direction. In addition, when viewed from above, the cooling surface 40a may be square. At this time, the side length of the cooling surface 40a may be larger than the short side of the substrate 9. Thereby, regardless of the direction of the substrate 9 disposed on the support section 20, when viewed from above, the cooling surface 40a is larger than the substrate 9. Therefore, regardless of the direction of the substrate 9, the cooling surface 40a can face the entire surface of the first surface F1 of the substrate 9.

[0172] An example of the process of the reduced-pressure drying process using the reduced-pressure drying apparatus 1C is the same as the reduced-pressure drying process in the first embodiment. Thereby, in the fourth embodiment, the occurrence of drying unevenness can be suppressed, and the processing ability of the reduced-pressure drying process for a plurality of substrates 9 can be improved.

[0173] Further, in the fourth embodiment, the cooling surface 40a is the lower surface of the cooling member 41 different from the chamber 10. Therefore, the material of the cooling member 41 having the cooling surface 40a can be separately selected distinct from the specification requirements for the chamber 10. That is, the selectivity of the material of the cooling member 41 can be improved. Further, since the cooling surface 40a is the lower surface of the cooling member 41, the interval between the low-temperature portion (here, the refrigerant flow path 41a) of the cooling unit 40 and the cooling surface 40a can be reduced. Therefore, the cooling unit 40 can cool the cooling surface 40a more efficiently.

[0174] <5. Fifth Embodiment>

[0175] Figure 18 FIG. is an example of a longitudinal section schematically showing the pressure-reducing drying apparatus 1D of the fifth embodiment. The pressure-reducing drying apparatus 1D has the same structure as the pressure-reducing drying apparatus 1C except for the object to be lifted by the first lifting unit 100. As Figure 18 shown, the first lifting unit 100 lifts and lowers the cooling unit 40. Specifically, the first lifting unit 100 lifts and lowers the cooling member 41 of the cooling unit 40 between the raised position H11 and the lowered position H12. The lowered position H12 is the position of the cooling member 41 when the interval between the substrate 9 and the cooling surface 40a is the first interval. In Figure 18 , the cooling member 41 located at the lowered position H12 is indicated by a phantom line. The raised position H11 is the position of the cooling member 41 when the interval between the substrate 9 and the cooling surface 40a is the second interval. That is, the first lifting unit 100 lifts and lowers the cooling member 41 between the first state and the second state, in the first state, the interval between the substrate 9 and the cooling surface 40a is the first interval; in the second state, the interval between the substrate 9 and the cooling surface 40a is the second interval.

[0176] As Figure 18 shown, the support unit 20 is located at the lowered position H2 described in the first to fourth embodiments. That is, the substrate 9 supported by the support unit 20 is located at a position lower than the upper end of the side rectifying plate 51 and is surrounded by the four side rectifying plates 51. In the fifth embodiment, in the first state where the interval between the substrate 9 and the cooling surface 40a is the first interval and the second state where the interval between the substrate 9 and the cooling surface 40a is the second interval, the substrate 9 is surrounded by the four side rectifying plates 51.

[0177] The lowered position H12 may be a position where the cooling surface 40a of the cooling member 41 is lower than the upper end of the side rectifying plate 51. That is, in a plan view, the size of the cooling member 41 is smaller than the size of the space surrounded by the four side rectifying plates 51.

[0178] The raised position H11 is a position where the cooling surface 40a of the cooling member 41 is higher than the upper end of the side rectifying plate 51. In a state where the cooling member 41 is at the raised position H11, the interval between the cooling surface 40a and the upper end of the side rectifying plate 51 can be, for example, greater than or equal to twice the first interval, or greater than or equal to five times the first interval. Thus, the gas directly above the substrate 9 easily flows into the space between the side rectifying plate 51 and the side wall portion 12 of the chamber 10 from the upper end side of the side rectifying plate 51.

[0179] For example, the first elevating unit 100 uses a driving device such as a linear motor or a cylinder. The main body portion 100a of the first elevating unit 100 is fixed, for example, to a device rack (not shown) outside the chamber 10. The moving portion 100b of the first elevating unit 100 can move relative to the main body portion 100a in the vertical direction, for example. The moving portion 100b is, for example, a rod-shaped member or the like. The moving portion 100b is provided in a state of passing through the through-hole 13h of the top plate portion 13 of the chamber 10, for example. And, for example, the cooling member 41 is fixed to the lower end portion of the moving portion 100b. Here, for example, if a bellows or the like is provided between the upper surface of the top plate portion 13 and the moving portion 100b, the gap between the top plate portion 13 and the moving portion 100b can be sealed.

[0180] An example of the process of the reduced-pressure drying process using the reduced-pressure drying device 1D is the same as the reduced-pressure drying process in the first embodiment. However, in the first interval adjustment process (step S3), the first elevating unit 100 lowers the cooling member 41 to the lowered position H12 so that the interval between the substrate 9 and the cooling surface 40a is the first interval. Further, in the second interval adjustment process (step S5), the first elevating unit 100 raises the cooling member 41 to the raised position H11 so that the interval between the substrate 9 and the cooling surface 40a is the second interval. Thus, in the fifth embodiment, the occurrence of uneven drying can be suppressed, and the processing ability of the reduced-pressure drying process for a plurality of substrates 9 can be improved.

[0181] And, in the fifth embodiment, the cooling member 41 is a member different from the chamber 10. Therefore, similarly to the fourth embodiment, the selectivity of the material of the cooling member 41 can be improved. Further, since the cooling surface 40a is the lower surface of the cooling member 41, similarly to the fourth embodiment, the cooling unit 40 can cool the cooling surface 40a more efficiently.

[0182] In addition, in the fifth embodiment, even in the first state where the interval between the substrate 9 and the cooling surface 40a is the narrower first interval, the substrate 9 supported by the support portion 20 is surrounded by the four side rectifying plates 51. Therefore, in the first depressurization process (step S4), the rectifying function of the four side rectifying plates 51 also acts on the upper space 10s1 between the substrate 9 and the cooling surface 40a. Therefore, the occurrence of uneven drying can be further suppressed.

[0183] <6. Modified Example>

[0184] The present invention is not limited to the above-described one embodiment, and various changes and improvements can be made without departing from the gist of the present invention.

[0185] In the above-described one embodiment, for example, the first elevating portion 100 elevates the support portion 20 or the cooling portion 40, but it is also possible to elevate both the support portion 20 and the cooling portion 40. In short, as long as the first elevating portion 100 elevates at least one of the support portion 20 and the cooling surface 40a between the first state and the second state, in the first state, the interval between the substrate 9 supported by the support portion 20 and the cooling surface 40a is the first interval; in the second state, the interval between the substrate 9 supported by the support portion 20 and the cooling surface 40a is the second interval wider than the first interval.

[0186] In the above-described one embodiment, for example, the chamber 10 has four exhaust ports 16a, 16b, 16c, 16d, but it is not limited thereto. For example, the number of exhaust ports that the chamber 10 has may be 1 to 3 or may be greater than or equal to 5. In addition, for example, the independent valves Va, Vb, Vc, Vd may not be provided.

[0187] In the above-described one embodiment, the depressurization drying apparatuses 1, 1A to 1D dry the coating film 90 on the substrate 9 by depressurization, but it is not limited thereto. For example, the depressurization drying apparatuses 1, 1A to 1D may also dry the coating film 90 on the substrate 9 by depressurization and heating.

[0188] In the above-described one embodiment, the loading and unloading port 14 for the substrate 9 is provided on the side wall portion 12 of the chamber 10, but it is not limited thereto. For example, the following structure may be adopted: The four side wall portions 12 and the top plate portion 13 of the chamber 10 form an integral cover portion, and the cover portion can be separated from the bottom plate portion 11 and moved upward for avoidance. In this case, for example, the cover portion can be moved up and down by an opening / closing drive portion 16 or the like. Further, the chamber 10 can be selectively set to a state (sealed state) in which the cover portion contacts the bottom plate portion 11 via a sealing material such as an O-ring and seals the internal space 10s; a state (opened state) in which the cover portion is separated upward from the bottom plate portion 11 and the internal space 10s is opened. Here, when the chamber 10 is in the opened state, the substrate 9 can be loaded into the internal space 10s of the chamber 10 and the substrate 9 can be unloaded from the internal space 10s of the chamber 10. When the chamber 10 is in the closed state, the coating film 90 on the substrate 9 can be dried by reducing the pressure by exhausting air from the internal space 10s and supplying air to the internal space 10s.

[0189] In the above-described one embodiment, for example, the support portion 20 can have various forms. For example, the plurality of support plates 21 can be an integral one support plate 21.

[0190] In the above-described one embodiment, for example, the bottom surface rectifying plate 50 may be absent, or the side surface rectifying plate 51 may be absent.

[0191] In the above-described one embodiment, for example, various operations in the pressure-reducing drying apparatus 1 can be started or ended according to an operation of the user on the input portion 804 or a signal input from an external device to the communication portion 806 or the like.

[0192] In the above-described one embodiment, for example, at least a part of the functional structure implemented in the control portion 80 can also be implemented by hardware such as a dedicated electronic circuit.

[0193] In addition, it goes without saying that all or a part of the above-described one embodiment and various modification examples can be appropriately combined within a non-contradictory range.

Claims

1. A reduced-pressure drying device for drying a coating film applied to the upper surface of a substrate, wherein, Comprising: A chamber for accommodating the substrate; A support part for supporting the substrate in the chamber; A cooling part for cooling a cooling surface opposite to the upper surface of the substrate supported by the support part; A first lifting part for lifting at least one of the support part and the cooling surface between a first state and a second state. In the first state, the interval between the substrate supported by the support part and the cooling surface is a first interval, and in the second state, the interval between the substrate supported by the support part and the cooling surface is a second interval wider than the first interval; A pressure reducing mechanism for sucking the gas in the chamber to reduce the air pressure in the chamber; And A control part for controlling the first lifting part and the pressure reducing mechanism so that after the air pressure in the chamber reaches a first air pressure in the first state, the air pressure in the chamber reaches a second air pressure lower than the first air pressure in the second state, The control part controls the cooling part to cool the cooling surface to a temperature less than or equal to the temperature when the pressure reaches the first air pressure in the vapor pressure curve of the solvent on the substrate in the first state, and to cool the cooling surface to a temperature greater than or equal to the temperature when the pressure reaches the second air pressure in the vapor pressure curve in the second state.

2. The pressure reducing drying device according to claim 1, wherein, The control part reduces the air pressure in the chamber to the first air pressure in the first state, evaporates the solvent of the coating film on the substrate, and condenses the vapor of the solvent on the cooling surface. In the second state, the air pressure in the chamber is reduced to the second air pressure to evaporate both the solvent of the coating film on the substrate and the solvent of the cooling surface, so as to dry the coating film and the cooling surface.

3. The pressure reducing drying device according to claim 1 or 2, wherein, The cooling surface is the top surface of the chamber, The first lifting part lifts the support part.

4. The pressure reducing drying device according to claim 3, wherein, The cooling part is installed on the upper surface of the top plate part of the chamber, and the cooling part cools the top plate part to cool the lower surface of the top plate part, i.e., the cooling surface.

5. The pressure reducing drying device according to claim 4, wherein, It further comprises: a second lifting part for lifting the cooling part between a cooling position in contact with the upper surface of the top plate part and a separation position separated from the top plate part.

6. The pressure reducing drying device according to claim 3, wherein, At least a part of the cooling part is buried in the top plate part of the chamber.

7. The pressure reducing drying device according to claim 1 or 2, wherein, The cooling part includes a cooling member which is arranged in the chamber and has the cooling surface as its lower surface.

8. The pressure reducing drying device according to claim 7, wherein, The first lifting part lifts the cooling member.

9. The pressure reducing drying device according to claim 8, wherein, It further comprises: A side rectifying plate surrounding the substrate supported by the support part; The bottom surface rectifying plate is opposite to the lower surface of the substrate supported by the support portion. In the first state and the second state, the substrate supported by the support portion is surrounded by the side surface rectifying plates.

10. A pressure-reducing drying method for drying a coating film applied to the upper surface of a substrate, wherein, Comprising: A first step of cooling a cooling surface opposite to the upper surface of the substrate supported by a support portion in a chamber, and in a state where the interval between the substrate and the cooling surface is a first interval, reducing the air pressure in the chamber to a first air pressure, evaporating the solvent of the coating film on the substrate, and condensing the vapor of the solvent on the cooling surface; A second step, after the first step, in a state where the interval between the substrate and the cooling surface is a second interval wider than the first interval, reducing the air pressure in the chamber to a second air pressure lower than the first air pressure, evaporating both the solvent of the coating film on the substrate and the solvent of the cooling surface to dry the coating film and the cooling surface. In the first step, the cooling surface is cooled to a temperature less than or equal to the temperature at which the pressure reaches the first air pressure in the vapor pressure curve of the solvent on the substrate, and in the second step, the cooling surface is cooled to a temperature greater than or equal to the temperature at which the pressure reaches the second air pressure in the vapor pressure curve.

11. The reduced-pressure drying method according to claim 10, wherein In the first step, the cooling portion is lowered to a cooling position in contact with the upper surface of the top plate portion of the chamber to cool the lower surface of the top plate portion, i.e., the cooling surface. In the second step, the cooling portion is raised to a separation position separated from the top plate portion of the chamber.

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