Vacuum drying device

Abstract

The present invention provides a reduced pressure drying device that avoids reducing production efficiency and prevents adverse effects caused by excessive accumulation of liquid solvent on the cooling surface of a cooling unit. A reduced pressure drying device (1) dries a coating film applied to the upper surface of a substrate (9), wherein the device comprises: a chamber (10) for accommodating the substrate; a support portion (20) for supporting the substrate in the chamber; a reduced pressure mechanism (30) for sucking gas from the chamber to reduce the pressure in the chamber; and a cooling unit (40) for cooling a cooling surface (40a) that is opposite to the upper surface of the substrate supported by the support portion and is larger than the substrate (9). The cooling surface (40a) of the cooling unit (40) comprises: a relative region (RC) that is opposite to a region (AC) of the substrate where a coating film (90) can be formed in the thickness direction of the substrate; and an outer region (RO) that is located outside the relative region (RC). The cooling unit (40) is configured so that the temperature of the outer region (RC) is higher than the temperature of the relative region.

Description

Technical Field

[0001] The invention relates to a reduced pressure drying device. Background Art

[0002] Conventionally, there is known a vacuum drying device for vacuum drying a coating film such as a photoresist coated on various substrates. The various substrates include, for example, glass substrates, ceramic substrates, semiconductor wafers, electronic device substrates, or printing plates for forming various devices. The various devices include, for example, semiconductor devices, display panels, solar cell panels, magnetic disks, or optical disks. The display panels include, for example, liquid crystal display panels, organic electroluminescent (EL) display panels, plasma display panels, or field emission displays.

[0003] When the coating film is dried using a reduced pressure drying device, for example, in a state where a plurality of pins support the substrate in the chamber, the chamber is exhausted through the exhaust port at the bottom of the chamber by a vacuum pump. The pressure in the chamber is reduced by the exhaust. If the pressure in the chamber is reduced, the solvent of the coating film evaporates, so the coating film can be dried. And, for example, if the vacuum degree reaches a specified value, the exhaust from the chamber is stopped, and 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 reduced pressure drying device, if the pressure in the chamber is rapidly reduced at the beginning of the reduced pressure, the coating film on the substrate may bump, which may cause, for example, a variation in the film thickness of the coating film.

[0005] The reduced pressure drying device described in Patent Document 1 can suppress the occurrence of such bumping. In the reduced pressure drying device described in Patent Document 1, a lifting unit is provided for lifting and lowering support pins supporting the substrate. The lifting unit raises the support pins at the initial stage of reduced pressure, thereby reducing the gap between the substrate and the top surface of the chamber. Thus, the speed of reducing the pressure between the substrate and the top surface can be reduced and the occurrence of bumping can be suppressed.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2022-086766

[0009] However, when the interval between the substrate and the top surface is reduced, the solvent vapor from the coating film on the substrate is retained in the space between the substrate and the top surface. In particular, the solvent vapor from the center of the coating film is easily retained. In other words, although the solvent vapor from the periphery of the coating film can flow outward in the horizontal direction through concentration diffusion, near the center of the coating film, because the concentration gradient is small, the solvent vapor is directly retained. Therefore, compared with the central part, the solvent of the coating film is more likely to evaporate in the peripheral part. In other words, it will cause uneven drying of the coating film. Uneven drying, for example, will cause the problem of film thickness deviation of the dried coating film. Summary of the invention

[0010] In order to solve the above-mentioned problems, the inventors have studied the technology of using the top surface as a cooling surface by cooling it. According to this technology, the above-mentioned uneven drying can be suppressed by the action of the liquid solvent condensed on the cooling surface. On the other hand, the inventors have found that if only the top surface is set as a cooling surface, there is a new problem that the cooling surface will accumulate excessive liquid solvent. In particular, if the solvent accumulates in a place where it is difficult to vaporize the solvent, it takes a long time to vaporize the solvent and remove it, resulting in reduced production efficiency. On the other hand, if the solvent is not properly removed, the accumulated liquid solvent will have an adverse effect during the implementation of reduced pressure drying. For example, if the liquid solvent drips onto the substrate, the quality of the product using the substrate will be damaged. In particular, in industrial use, it is usually necessary to repeatedly operate the reduced pressure drying device without long time intervals. As a result, even if the accumulation amount is small in one operation, it is easy to accumulate excessive liquid solvent on the cooling surface with repeated operations.

[0011] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a technology which avoids a reduction in production efficiency and prevents adverse effects caused by excessive accumulation of liquid solvent on the cooling surface of a cooling unit.

[0012]

Methods to solve the problem

[0013] The first method is a reduced-pressure drying device for drying a coating film applied on the upper surface of a substrate, wherein the device comprises: a chamber for accommodating the substrate; a support portion for supporting the substrate in the chamber; a reduced-pressure mechanism for sucking gas from the chamber to reduce the pressure in the chamber; and a cooling portion for cooling a cooling surface that is opposite to the upper surface of the substrate supported by the support portion and is larger than the substrate, the cooling surface of the cooling portion comprising: a relative region that is opposite to a region of the substrate in the thickness direction of the substrate where the coating film can be formed; and an outer region that is located outside the relative region, the cooling portion being configured so that the temperature of the outer region is higher than the temperature of the relative region.

[0014] The second method is a reduced-pressure drying device according to the first method, wherein the cooling portion comprises: a path for a refrigerant to flow through in order to cool the cooling surface; an inlet for introducing the refrigerant into the path; and an outlet for exporting the refrigerant from the path, wherein the path of the cooling portion spans the relative area and the outer area when viewed from above, the inlet of the cooling portion is located in the relative area, and the outlet of the cooling portion is located in the outer area.

[0015] A third aspect is the reduced-pressure drying device according to the second aspect, wherein the path of the cooling portion extends in a spiral shape in a plan view.

[0016] A fourth aspect is the reduced-pressure drying device according to the second or third aspect, wherein the cooling unit includes a heat insulating member located in the outer region in a plan view, and the heat insulating member separates the path from the cooling surface.

[0017] A fifth aspect is the reduced-pressure drying device according to any one of the first to fourth aspects, wherein the cooling unit includes a heater located in the outer region in a plan view.

[0018] [Effects of the invention]

[0019] According to the above-mentioned embodiments, the temperature of the outer region outside the opposing region on the cooling surface of the cooling unit is higher than the temperature of the opposing region opposing the region of the substrate where the coating film can be formed in the thickness direction of the substrate. Thus, the desired condensation of the solvent in the opposing region can be achieved, and the accumulation of the liquid solvent in the outer region can be suppressed.

[0020] According to the research of the present inventors, since the solvent in the opposite region is more likely to be vaporized quickly than in the outer region, as long as the accumulation of the liquid solvent in the outer region is suppressed, it is not necessary to spend a long time on the treatment for preventing excessive accumulation of the liquid solvent. Therefore, it is possible to prevent the reduction of production efficiency and avoid the adverse effects caused by excessive accumulation of the liquid solvent on the cooling surface of the cooling part. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a diagram schematically showing an example of a longitudinal cross section of the reduced-pressure drying apparatus according to the first embodiment.

[0022] Figure 2 This is a diagram schematically showing an example of a cross section of the reduced-pressure drying apparatus according to the first embodiment.

[0023] Figure 3 This is a diagram showing an example of a longitudinal cross section of the reduced-pressure drying apparatus according to the first embodiment.

[0024] Figure 4 It is a perspective view showing an example of a substrate.

[0025] Figure 5 This is a diagram showing an example of a longitudinal cross section of a part of a substrate.

[0026] Figure 6 This is a diagram schematically showing an example of the upper surface of the reduced-pressure drying device according to the first embodiment.

[0027] Figure 7 This is a block diagram conceptually showing the functions implemented by the control unit.

[0028] Figure 8 This is a flowchart showing an example of the flow of the reduced-pressure drying process according to the first embodiment.

[0029] Fig. 9 This is a diagram schematically showing an example of the condition in the chamber during the first decompression process.

[0030] Fig.10 This is an enlarged view showing the cooling surface and the vicinity of the substrate in the chamber during the first reduced pressure treatment.

[0031] Fig.11 This is an enlarged view of a ceiling plate and a substrate of a chamber having a comparative structure.

[0032] Fig.12 This is a diagram showing an example of the concentration distribution of the solvent vapor in the upper space of the comparative structure.

[0033] Fig.13 This is a diagram showing an example of the concentration distribution of the solvent vapor in the upper space when the cooling unit is performing cooling.

[0034] Fig.14 This is a diagram schematically showing an example of the condition in the chamber during the second decompression process.

[0035] Fig.15 Yes means Fig. 9 FIG. 2 is a diagram of a comparative example of a processing state shown.

[0036] Fig.16 Yes means Fig.14 FIG. 2 is a diagram of a comparative example of a processing state shown.

[0037] Fig.17 This is a diagram schematically showing an example of a longitudinal cross section of a vacuum drying apparatus according to a second embodiment.

[0038] Fig.18 This is a diagram schematically showing an example of the upper surface of the reduced-pressure drying device according to the second embodiment.

[0039] Fig.19This is a diagram schematically showing an example of a longitudinal cross section of a reduced-pressure drying apparatus according to a third embodiment.

[0040] Fig. 20 This is a diagram schematically showing an example of the upper surface of the reduced-pressure drying apparatus according to the third embodiment.

[0041] Fig.21 This is a diagram schematically showing an example of the upper surface of the reduced-pressure drying apparatus according to the fourth embodiment.

[0042] Fig. 22 This is a diagram schematically showing an example of a longitudinal cross section of a vacuum drying apparatus according to a fifth embodiment.

[0043] Fig.23 This is a flowchart showing an example of the flow of the reduced-pressure drying process according to the fifth embodiment.

[0044] Fig.24 This is a diagram schematically showing an example of a longitudinal cross section of a vacuum drying apparatus according to a sixth embodiment.

[0045] Fig.25 This is a diagram schematically showing an example of a longitudinal cross section of a vacuum drying apparatus according to a seventh embodiment.

[0046] Fig.26 This is a diagram schematically showing an example of a longitudinal cross section of a reduced-pressure drying apparatus according to an eighth embodiment.

[0047] Description of Reference Numerals

[0048] 1. 1A~1D, 1H, 1N, 1T vacuum drying device

[0049] 10 chambers

[0050] 13 Top plate

[0051] 20 Support

[0052] 30 Pressure relief mechanism

[0053] 40 Cooling unit

[0054] 40a cooling surface

[0055] 44 Refrigerant cooling source

[0056] Path 46, 46a-46d

[0057] Entrance 47, 47a~47d

[0058] Exits 48, 48a to 48d

[0059] 80 Control Department

[0060] 9 substrates

[0061] 90 coating film

[0062] F1 first side

[0063] RC Relative Area

[0064] RO outer area DETAILED DESCRIPTION

[0065] Hereinafter, an embodiment of the present invention and various modified examples will be described with reference to the accompanying drawings. The same marks are given to parts having the same structure and function in the accompanying drawings, and repeated descriptions are omitted in the following description. The accompanying drawings are schematically shown and do not accurately represent the dimensions and positional relationships of the 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. The upward direction and the downward direction are also collectively referred to as the up-down direction. A top view represents a planar layout. The planar layout of a part of a component is a two-dimensional layout obtained by projecting the component onto a plane. The plane may be a surface perpendicular to the up-down direction.

[0066] <1. First Embodiment>

[0067] Figure 1 This is a diagram schematically showing an example of a longitudinal cross section of the reduced-pressure drying apparatus 1 according to the first embodiment. Figure 2 This is a diagram schematically showing an example of a cross section of the reduced-pressure drying apparatus 1 according to the first embodiment. Figure 3 This is a diagram schematically showing an example of a longitudinal cross section of the reduced-pressure drying apparatus 1 according to the first embodiment. Figure 1 The longitudinal section and Figure 3 The longitudinal sections of FIG. 1 show the structure of the vacuum drying device 1 when viewed from directions that differ by about 90 degrees. Figure 3 In order to avoid complicating the drawings, the related structures of the pressure reducing mechanism 30, the air supply mechanism 60, the pressure gauge 70 and the control unit 80 described later are omitted.

[0068] The reduced pressure drying device 1 is a device for drying a coating film 90 (see Figure 5 ) device for drying.

[0069] The substrate 9 is, for example, a glass substrate, a semiconductor wafer, or a ceramic substrate. The substrate 9 is, for example, a first surface F1 (see Figure 4 and Figure 5 ) and a second face F2 (see Figure 5) is a flat substrate. For example, in the reduced pressure drying device 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 cited for explanation. For example, a coating film 90 is partially formed on the first surface F1 of the substrate 9 by pre-coating a treatment liquid containing an organic material and a solvent. The application 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 called 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, when the reduced pressure drying apparatus 1 is used in a manufacturing process of an organic EL display, the coating film 90 may be dried by the reduced pressure drying apparatus 1 to form a hole injection layer, a hole transport layer or a light emitting layer of the organic EL display panel.

[0070] Figure 4 It is a perspective view showing an example of the substrate 9 . Figure 5 9 is a diagram showing an example of a longitudinal cross section of a portion of the substrate 9. Figure 4 As shown, the substrate 9 is, for example, a rectangular shape with different lengths in the vertical and horizontal directions when viewed from above. A plurality of regions (also referred to as formation regions) A1 for actually forming products such as devices may be arranged on the substrate 9. Figure 4 In the example, when viewed from above, on the substrate 9, four rectangular forming areas A1 are arranged in a matrix of two rows and two columns. However, the shape, number, and arrangement of the forming areas A1 are not limited to this example. In the coating process before the reduced pressure drying process performed by the reduced pressure drying device 1, a coating film 90 is formed on each upper surface of the forming areas A1 in a desired pattern by a slit coater or an inkjet device. The desired pattern is, for example, a circuit pattern. Here, Figure 4 In FIG. 1 , the coating film 90 is shown without considering the pattern. Figure 5 As shown, the first surface F1 as the upper surface of each formation area A1 has an area (also referred to as a covered area) A3 covered by the coating film 90 and an exposed area (also referred to as an exposed area) A4 not covered by the coating film 90. In addition, the area around the formation area A1 in the substrate 9 and the area between the adjacent coating areas A1 are areas (also referred to as non-coating areas) A2 where the coating film 90 is not formed on the first surface F1 as the upper surface. The non-coating area A2 is also an exposed area (exposed area) A4 not covered by the coating film 90.

[0071] The first surface F1 of the substrate 9 has a region AC where the coating film 90 can be formed. The region AC can be defined as a region including the region A1, for example, Figure 4 As shown, region AC can be defined as a region including region A1 and having a minimum rectangular shape. Although it is difficult to distinguish which range in the first surface F1 is region AC, the entire first surface F1 can be regarded as region AC, but typically, in order to form a product such as a device, it is difficult to apply the substrate 9 completely to the edge of the first surface F1, and the first surface F1 has an edge region AO around region AC.

[0072] <1-1. Overview of the structure of the vacuum drying device>

[0073] Next, the structure of the reduced pressure drying device 1 is briefly described. Figure 1 and Figure 2 As shown, the reduced pressure drying device 1 includes a chamber 10 , a support portion 20 , a reduced pressure mechanism 30 , a first lifting portion 100 , a cooling portion 40 and a control portion 80 .

[0074] The chamber 10 is a portion for accommodating the substrate 9. The support portion 20 is provided in the chamber 10 and supports the substrate 9 in a horizontal posture. Here, the horizontal posture refers to a posture in which the thickness direction of the substrate 9 is along the vertical direction.

[0075] The decompression mechanism 30 sucks the gas in the chamber 10 and discharges the gas to the outside of the chamber 10. The suction reduces the pressure in the chamber 10. By reducing the pressure in the chamber 10, the solvent of the coating film 90 on the first surface F1 which is the upper surface of the substrate 9 evaporates, and the coating film 90 is dried.

[0076] The cooling unit 40 cools the cooling surface 40a. The cooling surface 40a is a surface opposite to the first surface F1 which is the upper surface of the substrate 9 supported by the support unit 20. By cooling the cooling surface 40a by the cooling unit 40, the temperature of the cooling surface 40a can be reduced. The cooling surface 40a is opposite to the upper surface of the substrate 9 supported by the support unit 20 and is larger than the substrate 9. In other words, when viewed from above, the cooling surface 40a includes the upper surface of the substrate 9. The cooling surface 40a has an edge ED. Figure 1 In the example of , the cooling surface 40a corresponds to the top surface of the chamber 10. The cooling surface 40a is, for example, a horizontal flat surface.

[0077] The vapor of the solvent evaporated from the coating film 90 on the first surface F1 as the upper surface 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 the later-described solvent vapor) can be attached to the cooling surface 40a. Fig. 9 ). As described in detail later, this condensation can suppress the occurrence of uneven drying of the coating film 90. In addition, by further reducing the pressure in the chamber 10, the solvent 91 attached to the cooling surface 40a can also be evaporated. The condensation and evaporation will also be described in detail later.

[0078] exist Figure 1 In the example of , the first lifting unit 100 lifts the support unit 20. Specifically, the first lifting unit 100 lifts the support unit 20 between the raised position H1 and the lowered position H2. The raised position H1 is the position of the support unit 20 when the interval between the substrate 9 supported by the support unit 20 and the cooling surface 40a is the first interval. Figure 1 In the example, the support portion 20 and the substrate 9 at the rising position H1 are represented by imaginary lines. The falling 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 lifting portion 100 lifts and lowers the support portion 20 between a first state and a second state, wherein in the first state, the interval between the substrate 9 and the cooling surface 40a is the first interval, and 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, and 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. If a specific example of a numerical value is described, the second interval is, for example, greater than or equal to 50 mm, and as a more specific example, the second interval is about 80 mm.

[0079] As described in detail later, at the initial stage of decompression, the first lifting unit 100 places the support unit 20 at the raised position H1. Then, the first lifting unit 100 lowers the support unit 20 to the lowered position H2. The technical significance of this will be described in detail later.

[0080] In addition, Figure 1 and Figure 2 In the example, the reduced pressure drying device 1 also includes an air supply unit 60, a bottom straightening plate 50, a side straightening plate 51, and a pressure gauge 70. The air supply unit 60 supplies gas into the chamber 10. In this way, the pressure in the chamber 10 can be restored to atmospheric pressure. The bottom straightening plate 50 and the side straightening plate 51 are arranged in the chamber 10 to adjust the airflow in the chamber 10. The pressure gauge 70 measures the pressure in the chamber 10 and outputs an electrical signal indicating the measurement result to the control unit 80. The control unit 80 controls various structures of the above-mentioned reduced pressure drying device 1. For example, the control unit 80 controls the decompression mechanism 30 according to the pressure measured by the pressure gauge 70 to adjust the pressure in the chamber 10. In addition, the control unit 80 controls the cooling unit 40 to adjust the temperature of the cooling surface 40a, and controls the first lifting unit 100 to adjust the position of the support unit 20.

[0081] Next, a detailed example of each structure of the reduced-pressure drying apparatus 1 will be described.

[0082] <1-1-1. Chamber 10>

[0083] The chamber 10 adopts a pressure-resistant container having an internal space 10s for accommodating the substrate 9. The chamber 10 is fixed on a device frame (not shown), for example. 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 sides of the bottom plate portion 11 and the four end sides of the top plate portion 13 in the up and down directions. For example, a loading and unloading port 14 and a gate portion (also referred to as a gate valve) 15 for opening and closing the loading and unloading port 14 are provided on one of the four side wall portions 12. The gate portion 15 is linked or connected to, for example, an opening and closing drive portion 16. In Figure 3 In order to avoid complication of the drawings, the opening and closing drive unit 16 is conceptually shown. For example, a drive device such as a cylinder is suitable for the opening and closing drive unit 16. Here, for example, by the operation of the opening and closing drive unit 16, the gate unit 15 can move between a position (also referred to as a closed position) for closing the loading and unloading port 14 and a position (also referred to as an open position) for opening the loading and unloading port 14.

[0084] Here, for example, when the gate 15 is in the closed position, the internal space 10s of the chamber 10 is sealed. For example, when the gate 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 through the loading and unloading port 14.

[0085] <1-1-2. Supporting section 20>

[0086] 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 uprightly provided on the upper surface of each support plate 21. When viewed from above, the plurality of support pins 22 are two-dimensionally dispersed. The plurality of support plates 21 are part of the base constituting the support portion 20. The substrate 9 is arranged above the plurality of support plates 21, and the upper ends of the plurality of support pins 22 are in contact with the second surface F2 of the substrate 9, which is the lower surface, thereby supporting the substrate 9 in a horizontal posture.

[0087] <1-1-3. Pressure Reducing Mechanism 30>

[0088] like Figure 1 and Figure 2As shown, four exhaust ports 16a, 16b, 16c, and 16d are provided at a portion of the bottom plate 11 of the chamber 10 that faces the substrate 9 in the vertical direction. The decompression mechanism 30 includes, for example, an exhaust pipe 31, four independent valves Va, Vb, Vc, and Vd, a main valve Ve, and a vacuum pump 32. The exhaust pipe 31 includes, for example, four independent pipes 31a, 31b, 31c, and 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 end of each of the four independent pipes 31a, 31b, 31c, and 31d merges and is 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 on the path of the independent pipe 31a, the independent valve Vb is provided on the path of the independent pipe 31b, the independent valve Vc is provided on the path of the independent pipe 31c, and the independent valve Vd is provided on the path of the independent pipe 31d. For example, the main valve Ve is provided on the path of the main pipe 31e.

[0089] Here, for example, in a state where the loading and unloading port 14 is closed by the gate portion 15, if at least one of the four independent valves Va, Vb, Vc, and Vd and the 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. As a result, for example, the pressure of the internal space 10s of the chamber 10 can be reduced. The four independent valves Va, Vb, Vc, and Vd are, for example, valves for individually adjusting the exhaust volume (suction flow rate) of the four exhaust ports 16a, 16b, 16c, and 16d. Each of the four independent valves Va, Vb, Vc, and Vd is, for example, a valve (also referred to as an on-off valve) that switches between an open state and a closed state according to a command of 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, and 16d. The main valve Ve is, for example, a valve whose opening degree can be adjusted according to a command from the control unit 80 (also referred to as an opening control valve).

[0090] <1-1-4. First lifting unit 100>

[0091] In the first embodiment, the first lifting unit 100 lifts the support unit 20 in the chamber 10. In other words, the first lifting unit 100 has a mechanism (also referred to as a lifting mechanism) that can lift the support unit 20. Figure 1 In order to avoid the complication of the drawings, the first lifting unit 100 is conceptually shown. The first lifting unit 100 is driven by a linear motor or a cylinder, for example. Figure 3As shown, the first lifting part 100, for example, has a main body 100a and a moving part 100b. The main body 100a is fixed on a device frame (not shown) outside the chamber 10, for example. The moving part 100b is, for example, capable of moving in the up and down directions relative to the main body 100a. The moving part 100b is, for example, a rod-shaped member. The moving part 100b exists in a state of a through hole 11h that penetrates the bottom plate 11 of the chamber 10. And, for example, a support part 20 is fixed to the upper end of the moving part 100b. Here, for example, if a bellows is provided between the lower surface of the bottom plate 11 and the moving part 100b, the gap between the bottom plate 11 and the moving part 100b can be sealed. For example, when the support portion 20 has a plurality of support plates 21, the moving portion 100b includes: a rod-shaped portion (also referred to as a rod-shaped portion) fixed to each support plate 21 and passing through the through hole 11h of the bottom plate portion 11; a portion connecting the plurality of rod-shaped 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 lifting portion 100 lifts and lowers the support portion 20, so that the substrate 9 supported by the support portion 20 is also lifted and lowered.

[0092] <1-1-5. Cooling Unit 40>

[0093] refer to Figure 1 The cooling surface 40a of the cooling unit 40 has: a relative region RC, which is adjacent to the region AC of the substrate 9 where the coating film 90 can be formed in the thickness direction of the substrate 9 (in other words, the vertical direction) (see Figure 4 ) relative; the outer region RO is located outside the relative region RC. The cooling unit 40 is configured so that the temperature of the outer region RO is higher than the temperature of the relative region RC. Specifically, the cooling unit 40 has the following structure.

[0094] Cooling unit 40( Figure 1 ) uses a refrigerant to cool the cooling surface 40a. Specifically, the cooling unit 40 includes a cooling member 41, a refrigerant supply pipe 42, a refrigerant recovery pipe 43, and a refrigerant cooling source 44. A path 46 is formed inside the cooling member 41 for the refrigerant to flow through in order to cool the cooling surface 40a. Figure 3 and the following Fig. 9 and Fig.14 In order to avoid complicating the drawings, illustration of the specific structure of the cooling unit 40 is omitted. The cooling member 41 is in the shape of a plate. In this case, the cooling member 41 may also be referred to as a cooling plate. The cooling member 41 is mounted on the upper surface of the top plate 13 with its thickness direction along the up-down 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 13. The cooling member 41 may be formed of a material with high thermal conductivity (for example, metal, etc.).

[0095] The refrigerant flows into the refrigerant cooling source 44 from the downstream end of the refrigerant recovery pipe 43. The refrigerant may be a liquid or a gas. As a specific example, water may be used for the refrigerant. The refrigerant cooling source 44 cools the refrigerant and supplies the cooled refrigerant to the upstream end of the refrigerant supply pipe 42. The refrigerant cooling source 44 may be, for example, a heat pump. The refrigerant cooled by the refrigerant cooling source 44 flows into the upstream end of the refrigerant supply pipe 42, and flows into the path 46 through the refrigerant supply pipe 42. The low-temperature refrigerant flows in the path 46, 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 been heated up by flowing in the path 46 flows again into the refrigerant cooling source 44 through the refrigerant recovery pipe 43, and is cooled again by the refrigerant cooling source 44.

[0096] When the cooling unit 40 cools the top plate 13 of the chamber 10, the lower surface of the top plate 13 (that is, the top surface of the chamber 10), that is, the cooling surface 40a, is also cooled. Figure 1 In the example, the size of the cooling member 41 is larger than the substrate 9 when viewed from above. 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 fully cool the entire surface of the relative region RC of the cooling surface 40a. The above-mentioned rectangle can also be a square. In this case, the side length of the cooling member 41 is longer than the short side of the substrate 9. Thus, regardless of the direction of the substrate 9 arranged on the support portion 20, the cooling member 41 is larger than the substrate 9 when viewed from above. Therefore, regardless of the direction of the substrate 9, the cooling member 41 can properly cool the entire surface of the relative region RC of the cooling surface 40a.

[0097] Figure 6 This is a diagram schematically showing an example of the upper surface of the vacuum drying device 1 according to the first embodiment, and also showing a part of its internal structure. Figure 1 and Figure 6 In the first embodiment, the cooling unit 40 has: a plurality of paths 46a to 46d as paths 46; inlets 47a to 47d for introducing refrigerant into each of the paths 46a to 46d; and outlets 48a to 48d for extracting refrigerant from each of the paths 46a to 46d. Figure 6 ) and outlets 48a to 48d ( Figure 6 ) is formed on the upper surface of the cooling member 41 (see Figure 1Each of the inlets 47a to 47d is connected to the downstream end of the refrigerant supply pipes 42a to 42d, and each of the outlets 48a to 48d is connected to the upstream end of the refrigerant recovery pipes 43a to 43d. The upstream end of the refrigerant supply pipe 42 and the downstream end of the refrigerant recovery pipe 43 are connected to the refrigerant cooling source 44.

[0098] In a plan view, each of the paths 46a to 46d crosses the opposing region RC and the outer region RO. Each of the inlets 47a to 47d is located in the opposing region RC. Each of the outlets 48a to 48d is located in the outer region RO. In a plan view, each of the paths 46a to 46d may extend in a spiral shape.

[0099] By configuring the cooling unit as described above, the cooled refrigerant flows from the opposing region RC to the outer region RO, and the temperature of the refrigerant rises accordingly. Therefore, the opposing region RC is cooled more strongly than the outer region RO. Therefore, the temperature of the outer region RO is higher than the temperature of the opposing region RC. For example, even when compared with the temperature at all positions of the opposing region RC, the temperature at the edge ED of the outer region RO can be higher. In other words, the temperature at the edge ED of the outer region RO can be higher than the highest temperature of the opposing region RC.

[0100] <1-1-6. Bottom straightening plate 50>

[0101] The bottom straightening plate 50 is a plate for restricting the flow of gas in the internal space 10s when the pressure in the chamber 10 is reduced by the pressure reducing mechanism 30. For example, the bottom straightening plate 50 is arranged so as to be located between the substrate 9 supported by the support 20 and the bottom plate 11 of the chamber 10. The bottom straightening plate 50 is fixed to the bottom plate 11 of the chamber 10 by, for example, a plurality of pillars (not shown). Figure 2 As shown, for example, the bottom straightening plate 50 is square when viewed from above. Also, for example, when viewed from above, the length of each side of the bottom straightening plate 50 is longer than the short side of the rectangular substrate 9. Therefore, for example, regardless of the direction of the substrate 9 arranged on the support portion 20, the bottom straightening plate 50 is larger than the substrate 9 when viewed from above. In addition, the bottom straightening plate 50 has, for example, a through hole 50h, and the through hole 50h is in a state where the moving portion 100b of the first lifting portion 100 passes through. The bottom straightening plate 50 and the moving portion 100b are separated by a very small gap at the through hole 50h.

[0102] <1-1-7. Side fairing 51>

[0103] The side straightening plates 51 are plates used together with the bottom straightening plates 50 to restrict the flow of gas in the internal space 10s when the pressure in the chamber 10 is reduced by the pressure reducing mechanism 30. For example, the side straightening plates 51 are arranged so as to be located between the substrate 9 supported by the support portion 20 located at the descending position H2 and the side wall portion 12 of the chamber 10. Here, for example, four side straightening plates 51 are arranged so as to surround the substrate 9 supported by the support portion 20. For example, the four side straightening plates 51 as a whole form a square cylindrical straightening plate surrounding the substrate 9. In addition, for example, the bottom straightening plate 50 and the four side straightening plates 51 as a whole form a box-shaped straightening plate with a bottom cylindrical shape. In addition, in Figure 1 In the example, the upper end of the side straightening plate 51 is below 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 at the raised position H1, the substrate 9 is not surrounded by the four side straightening plates 51.

[0104] Here, for example, when the pressure in the chamber 10 is reduced in the second state where the support portion 20 is located at the lowered position H2, the gas directly above the substrate 9 flows mainly toward the upper end of the side rectifying plate 51 (see the following description). Fig.14 ). The gas passes through the space between the side rectifying plate 51 and the side wall portion 12, the space between the bottom rectifying plate 50 and the bottom plate portion 11, and the exhaust ports 16a, 16b, 16c, and 16d in sequence, and is discharged to the outside of the chamber 10. In this way, the gas flows in the space away from the substrate 9, so that it is difficult to form an airflow near the substrate 9. In addition, it is difficult to generate a concentrated airflow around the edge of the substrate 9. As a result, for example, it is possible to suppress the occurrence of uneven drying of the coating film 90 formed on the upper surface of the substrate 9.

[0105] In addition, here, for example, Figure 2 In the structure shown, that is, in a plan view, the four exhaust ports 16a, 16b, 16c, and 16d are all located on the diagonal lines 52 of the square bottom face rectifying plate 50. In this case, for example, symmetrical airflows can be formed with respect to the center (intersection of the two diagonal lines 52) of the bottom face rectifying plate 50 through the exhaust ports 16a, 16b, 16c, and 16d. Thus, for example, a more uniform airflow can be formed in the internal space 10s of the chamber 10.

[0106] <1-1-8. Air supply unit 60>

[0107] The gas supply unit 60 is a part that performs the operation of supplying gas into the chamber 10 (also referred to as gas supply). Figure 1As shown, the bottom plate 11 of the chamber 10 is provided with, for example, an air supply port 16f. The air supply port 16f is, for example, located below the bottom rectifying plate 50. The air supply unit 60 includes an air supply pipe 61 connected to the air supply port 16f, an air supply valve Vf, and an air supply source 62. For example, one end of the air supply pipe 61 is connected to the air supply port 16f. For example, the other end of the air supply pipe 61 is connected to the air supply source 62. For example, the air supply valve Vf is provided on the path of the air supply pipe 61.

[0108] Here, for example, when 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. As a result, the pressure in the chamber 10 can be increased. The gas supplied from the gas supply source 62 may be, for example, an inert gas such as nitrogen or a clean dry gas. The clean dry gas is prepared by, for example, performing a cleaning process to remove particles and moisture from air in a general environment.

[0109] <1-1-9. Pressure gauge 70>

[0110] The pressure gauge 70 is a sensor for measuring the pressure of the internal space 10s of the chamber 10. Figure 1 As shown, the pressure gauge 70 is installed on a part of the chamber 10. The pressure gauge 70 can measure the pressure of the internal space 10s of the chamber 10 and output the measurement result to the control unit 80.

[0111] <1-1-10. Control unit 80>

[0112] The control unit 80 is a unit (electronic circuit) for controlling the operation of each part of the reduced pressure drying device 1. The control unit 80 can control the structure of the reduced pressure mechanism 30, the cooling unit 40, the air supply unit 60 and the first lifting unit 100. The control unit 80 is composed of, for example, 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 used to perform a process of drying the coating film 90 on the substrate 9 by reducing pressure in the reduced pressure drying device 1 (also referred to as a reduced pressure drying process). The storage unit 803 stores, for example, a program 803p, and has a function as a non-temporary storage medium that can be read by a computer. The control unit 80 reads the program 803p and data from the storage unit 803 to the memory 802, and performs calculations based on the program 803p and the data in the processor 801, thereby controlling the operation of each part of the reduced pressure drying device 1. Therefore, for example, in the reduced pressure drying device 1, the processor 801 included in the control unit 80 executes the program 803p, thereby performing the reduced pressure drying process.

[0113] For example, the control unit 80 may be connected to an input unit 804, an output unit 805, a communication unit 806, and a driver 807. The input unit 804 is, for example, a part that inputs various signals to the control unit 80 in response to user operations, etc. The input unit 804 may include, for example: an operation unit that inputs signals corresponding to user operations; a microphone that inputs signals corresponding to user voices; various sensors that input signals corresponding to user actions, etc. The output unit 805 is, for example, a part that outputs various information in a manner recognizable to the user. The output unit 805 may include, for example, a display unit, a projector, a speaker, etc. The display unit may also be a touch panel integrated with the input unit 804. The communication unit 806 is, for example, a part that sends and receives various information to and from an external device such as a server using wired or wireless communication means, etc. For example, a program 803p received from an external device using the communication unit 806 may be stored in the storage unit 803. The driver 807 is, for example, a part that can load and unload 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 when the storage medium 807m is installed. For example, by installing the 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, for example, stores the program 803p and functions as a non-transitory storage medium readable by a computer.

[0114] Figure 7 80 is a block diagram conceptually showing the functions implemented in the control unit 80. Figure 7 As shown, the control unit 80 is electrically connected to, for example, the opening and closing drive unit 16, the first lifting unit 100, the four independent valves Va, Vb, Vc, and Vd, the main valve Ve, the vacuum pump 32, the air supply valve Vf, the cooling unit 40, and the pressure gauge 70. The control unit 80 can control the operation of each of the above-mentioned units by referring to the measured value output from the pressure gauge 70, for example.

[0115] like Figure 7As conceptually shown, as a functional structure to be implemented, the control unit 80 includes, for example, an opening and 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 and closing control unit 81 controls the operation of the opening and 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 and closing states of the four independent valves Va, Vb, Vc, and Vd, respectively. For example, the exhaust control unit 84 controls the opening and 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 and 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 each unit of the control unit 80 are implemented, for example, by the processor 801 performing calculation processing according to the above-mentioned program 803p.

[0116] <1-2. Reduced pressure drying treatment>

[0117] Next, the reduced-pressure drying process of the substrate 9 using the reduced-pressure drying apparatus 1 will be described. Figure 8 80 is a flowchart showing an example of a process of the reduced pressure drying process of the first embodiment. The process of the reduced pressure drying process is implemented by, for example, executing a program 803p in the processor 801 included in the control unit 80. Here, for example, Figure 8 The processing of steps S1 to S8.

[0118] When the reduced pressure drying device 1 is used to perform the reduced pressure drying process, for example, first, the substrate 9 is carried into the chamber 10 (step S1). At this time, the substrate 9 is in a state where an undried coating film 90 is formed on the upper surface of the substrate 9. In step S1, for example, the gate 15 opens the loading and unloading port 14 under the control of the control unit 80, and the transport robot (not shown) places the substrate 9 on the fork-shaped hand, and carries the substrate 9 into the internal space 10s of the chamber 10 through the loading and unloading port 14 of the chamber 10. At this time, the support part 20 is, for example, located at the lowered position H2. In addition, the side straightening plate 51 is configured to be movable so that the side straightening plate 51 does not interfere with the transport robot. The transport robot, for example, inserts the fork-shaped hand between the plurality of support plates 21 of the support part 20, places the substrate 9 on the support part 20, and then retreats the fork-shaped hand to the outside of the chamber 10. Then, the gate 15 closes the loading and unloading port 14 under the control of the control unit 80. As described above, in step S1 , a process (also referred to as a placing process) of placing the substrate 9 on the plurality of support pins 22 disposed in the chamber 10 is performed.

[0119] Next, the reduced pressure drying device 1 performs a cooling process (step S2). The cooling process is a process of cooling the cooling surface 40a. Specifically, the control unit 80 starts the cooling unit 40, so that the cooling unit 40 cools the cooling surface 40a to reduce the temperature of the cooling surface 40a. The cooling unit 40 reduces the temperature of the cooling surface 40a to the target temperature. For example, the central portion of the relative area RC of the cooling surface 40a is about 15°C, and the edge ED of the outer area RO of the cooling surface 40a is about 20°C. The cooling unit 40 can continue to cool the cooling surface 40a until the reduced pressure drying process of the substrate 9 is completed. In addition, the cooling action of the cooling unit 40 can also be started before step S1.

[0120] Next, the vacuum drying device 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 unit 20 to the raised position H1. In the first state where the support unit 20 is located at the raised position H1, the substrate 9 is located at a position higher than the upper end of the side straightening plate 51 (see Figure 1 ).

[0121] Next, the reduced pressure drying device 1 performs a first reduced pressure treatment (step S4: equivalent to the first process). The first reduced pressure treatment is a treatment for reducing the pressure in the chamber 10 to a first pressure (hereinafter referred to as the first target pressure). The first target pressure is lower than the standard atmospheric pressure, for example, set to be greater than 10 kPa. Specifically, the control unit 80 causes the reduced pressure mechanism 30 to suck the gas in the chamber 10 at a smaller first suction flow rate, thereby reducing the pressure in the chamber 10. For example, the control unit 80 may also make the opening of the main valve Ve smaller than the opening during the second reduced pressure treatment described later. Thus, in the first reduced pressure treatment, the pressure in the chamber 10 is reduced at a lower reduction rate.

[0122] In step S3 , for example, the control unit 80 may independently and appropriately control the opening and closing states of the plurality of independent valves Va, Vb, Vc, and Vd, thereby controlling the air flow in the chamber 10 to suppress uneven drying of the substrate 9 .

[0123] Fig. 9 and Fig.10 FIG. 1 is a diagram schematically showing an example of the condition in the chamber 10 during the first decompression process. Fig. 9 represents the entire chamber 10, Fig.10 The cooling surface 40 a and the vicinity of the substrate 9 in the chamber 10 are shown in an enlarged manner.

[0124] like Fig. 9As shown, in the first decompression process, when the support portion 20 is in the first state at the raised position H1, the interval between the substrate 9 and the cooling surface 40a is very narrow. Therefore, the pressure reduction rate in the upper space 10s1 is further reduced, and the coating film 90 on the upper surface of the substrate 9 can be suppressed from boiling.

[0125] 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 straightening plate 51. Therefore, the airflow adjustment function of the side straightening plate 51 has almost no effect on the upper space 10s1 between the substrate 9 and the cooling surface 40a. Therefore, the side straightening plate 51 basically does not bring about the effect of suppressing the occurrence of uneven drying. In the first state, because 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 straightening plate 51 and the side wall portion 12 of the chamber 10 and is discharged from the chamber 10. Fig. 9 In FIG. 1 , the airflow is schematically represented by a dotted arrow.

[0126] The pressure in the chamber 10 is reduced by the first decompression treatment, so that the solvent of the coating film 90 on the upper surface of the substrate 9 evaporates. Fig.10 In the figure, the flow of the solvent vapor from the coating film 90 is schematically indicated by the dotted arrows. In the first decompression treatment, 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. Fig.10 As 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 when the pressure in the chamber S510 reaches the first target pressure. As a more specific example, the target temperature of the cooling surface 40a is set to a temperature less than or equal to the temperature when the pressure reaches the first target pressure in the vapor pressure curve of the solvent. As a result, the solvent 91 can be roughly uniformly attached to the area of ​​the cooling surface 40a opposite to the coating film 90. In this way, the solvent vapor in the upper space 10s1 condenses on the cooling surface 40a, thereby reducing the concentration of the solvent vapor in the upper space 10s1 and making the concentration distribution of the solvent vapor more uniform when viewed from above.

[0127] For comparison, a comparative structure in which the cooling unit 40 is not provided will be described. Fig.11 FIG. 1 is an enlarged view showing the top plate 13 and the substrate 9 of the chamber 10 of a comparative structure. Fig.10 In the example of FIG. 1 , 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, substantially room temperature.

[0128] In the first decompression treatment, since the interval 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, the solvent vapor tends to stay in the central area opposite to the central part of the coating film 90 in the upper space 10s1. On the other hand, in the peripheral area opposite to the peripheral part of the coating film 90 in the upper space 10s1, the solvent vapor can flow out in the horizontal direction due to concentration diffusion. Therefore, the peripheral part of the coating film 90 is easier to evaporate than the central part. In other words, the coating film 90 is unevenly dried.

[0129] Fig.12 1 is a diagram showing an example of the concentration distribution of the solvent vapor in the upper space 10s1 of the comparative structure. Fig.12 (a) shows the concentration distribution of solvent vapor when viewed from above. Fig.12 (b) shows the concentration distribution of solvent vapor when viewed from the side. Fig.12 In (a), the concentration distribution of the solvent vapor is represented by contour lines T1 to T10. The smaller the number marked on the contour lines T1 to T10, the higher the concentration represented. That is, among the contour lines T1 to T10, the contour line T1 represents the highest concentration. Fig.12 In (b), the concentration distribution of the solvent vapor is represented by contour lines T11 to T21. The smaller the number of the marker of the contour lines T11 to T21, the higher the concentration represented. That is, among the contour lines T11 to T21, the contour line T11 represents the highest concentration.

[0130] from Fig.12 As can be seen from (a), in the comparative structure, the solvent vapor flows from the periphery of the coating film 90 to the outside. Fig.12 As shown in (b), in the peripheral region 10r of the upper space 10s1 facing the peripheral portion of the coating film 90, the concentration of the solvent vapor decreases toward the outside of the coating film 90. This shows that the peripheral portion of the coating film 90 is more likely to evaporate than the central portion.

[0131] Fig.13 1 is a diagram showing an example of the concentration distribution of the solvent vapor in the upper space 10s1 in a state where the cooling unit 40 is performing cooling. Fig.13 (a) shows the concentration distribution of solvent vapor when viewed from above. Fig.13 (b) shows the concentration distribution of solvent vapor when viewed from the side. Fig.13As can be seen from (a), the solvent vapor does not flow out 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, both the solvent vapor from the central portion of the coating film 90 and the solvent vapor from the peripheral portion thereof flow upward in an ascending airflow corresponding to the temperature difference of the cooling surface 40a and condense on the cooling surface 40a (see Fig.10 ). Thus, the solvent vapor from the peripheral portion is also condensed on the cooling surface 40a, so the solvent vapor does not flow outward very much. In addition, the solvent vapor from the coating film 90 does not stay in the upper space 10s1 very much.

[0132] like Fig.13 As shown in (b) of FIG. 1 , in the peripheral region 10 r , the concentration of the solvent vapor decreases as it becomes farther away from the coating film 90 in the vertical direction, but is substantially uniform in the horizontal direction.

[0133] Therefore, the difference between the evaporation amount in the central part and the evaporation amount in the peripheral part of the coating film 90 can be reduced, and the occurrence of uneven drying 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 capacity of the reduced pressure drying process can also be improved.

[0134] Next, for example, if the pressure in the chamber 10 reaches the first target pressure, the reduced pressure drying device 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 lifting 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 straightening plate 51.

[0135] Next, the reduced pressure drying device 1 performs a second reduced pressure treatment (step S6: equivalent to the second process). The second reduced pressure treatment is a process for reducing the pressure in the chamber 10 to a second pressure (hereinafter referred to as the second target pressure) lower than the first target pressure. Specifically, the control unit 80 causes the reduced pressure 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 pressure in the chamber 10. For example, the control unit 80 can set the opening of the main valve Ve to be greater than the opening during the first reduced pressure treatment. The pressure in the chamber 10 is reduced to the second target pressure at a reduction rate higher than the reduction rate during the first reduced pressure treatment. In the second reduced pressure treatment, the reduced pressure drying device 1 can maintain the pressure in the chamber 10 at the second target pressure for a specified period of time. The second target 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 may independently and appropriately control the opening and closing states of the plurality of independent valves Va, Vb, Vc, and Vd, thereby controlling the airflow in the chamber 10 to suppress uneven drying of the substrate 9 .

[0137] Fig.14 1 is a diagram schematically showing an example of the condition in the chamber 10 during the second decompression process. Fig.14 As shown, in the second state where the support portion 20 is located at the lowered position H2, the gap between the substrate 9 and the cooling surface 40a is wide. In other words, the height of the upper space 10s1 is large. Therefore, unlike the first decompression treatment, the solvent vapor from the coating film 90 easily flows upward and is less likely to cause the solvent vapor to stagnate. Because the upper space 10s1 is large, the pressure in the upper space 10s1 can be more appropriately and quickly reduced to the second target pressure.

[0138] In addition, in the second state, the substrate 9 supported by the support portion 20 is surrounded by the four side rectifying plates 51. Therefore, the rectifying function of the side rectifying plates 51 acts on the upper space 10s1 between the substrate 9 and the cooling surface 40a. In other words, the side rectifying plates 51 can suppress the airflow from concentrating on the peripheral edge of the substrate 9. Therefore, it is possible to further suppress the occurrence of uneven drying of the coating film 90 due to the airflow.

[0139] If the pressure in the chamber 10 reaches the second target pressure, the solvent in the coating film 90 boils, and the coating film 90 is dried at a higher speed. The decompression mechanism 30 can suck the gas in the chamber 10 so that the pressure in the chamber 10 is approximately constant at the second target pressure. In other words, the decompression mechanism 30 can maintain the pressure in the chamber 10 at the second target pressure for a specified period of time. In this embodiment, in the second decompression treatment, 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 when the pressure in the chamber 10 is the second target pressure. As a more specific example, the target temperature of the cooling surface 40a is set to: a temperature greater than or equal to the temperature when the pressure reaches the second target pressure in the vapor pressure curve of the solvent.

[0140] The solvent vapor from the coating film 90 and the cooling surface 40a flows from the upper end side of the side straightening plate 51 into the space between the side straightening plate 51 and the side wall portion 12 of the chamber 10, and is discharged to the outside through the exhaust ports 16a, 16b, 16c, and 16d. Fig.14 In the figure, the flow of these solvent vapors is schematically represented by dashed arrows.

[0141] When the boiling of the coating film 90 ends, that is, when a predetermined period of time has passed, the decompression mechanism 30 can further reduce the pressure in the chamber 10. In other words, the decompression mechanism 30 can reduce the pressure in the chamber 10 to a third target pressure lower than the second target pressure. Thus, 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 unit 100 lowers the support unit 20 to the lowered position H2, and the decompression mechanism 30 makes the pressure in the chamber 10 less than or equal to the second target pressure. Thus, in the second decompression process, the decompression drying device 1 can dry not only the coating film 90 on the upper surface of the substrate 9 but also the cooling surface 40a.

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

[0144] And, for example, finally, the substrate 9 is unloaded from 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 the transport robot (not shown) unloads the dried substrate 9 placed on the support unit 20 to the outside of the chamber 10 through the loading / unloading port 14 of the chamber 10. Thus, the reduced pressure drying process for one substrate 9 can be completed.

[0145] Fig.15 yes Fig. 9 The comparative example shows that the vacuum drying device 1 ( Figure 1 ) and use the reduced pressure drying device 1Z. In the reduced pressure drying device 1Z, a cooling unit 40Z is provided instead of the cooling unit 40 of the present embodiment. Unlike the cooling unit 40, the cooling unit 40Z is configured to cool the cooling surface 40a approximately uniformly. As a result, the liquid solvent 91 is easily attached to the entire cooling surface 40a, and therefore, is also easily attached to the edge ED of the cooling surface 40a. In particular, if the treatment of a plurality of substrates 9 is repeated, the liquid solvent 91 is likely to spread to the edge ED or exceed the edge ED.

[0146] Fig.16 yes Fig.14 The comparative example shows the case where the above-mentioned vacuum drying device 1Z is used. At the edge ED of the cooling surface 40a, since the air flow during the vacuum process is slow, it is difficult to carry out the liquid solvent 91 ( Fig.15) is dried, the solvent 91 is likely to remain as condensation 91R. This is particularly noticeable at the corners of the rectangular edge ED. If a complicated structure such as an O-ring is provided near the edge ED, it is even more difficult to dry. In addition, as a result of the condensation 91R hanging down from the edge ED along the side wall portion 12, the liquid solvent may intrude into the complicated structure, and in this case, it is also difficult to dry. In order to dry the condensation 91R, a very long drying time is required, and in this case, the production efficiency is greatly reduced.

[0147] In contrast, according to the first embodiment, reference Fig. 9 and Fig.14 By making the temperature of the outer region RO higher than the temperature of the counter region RC on the cooling surface 40a of the cooling unit 40, it is possible to achieve the desired condensation of the solvent 91 in the counter region RC and suppress the accumulation of the liquid solvent 91 in the outer region RO. According to the research of the present inventors, since the solvent is more likely to be vaporized quickly in the counter region RC than in the outer region RO, as long as the accumulation of the liquid solvent 91 in the outer region RO is suppressed, it is not necessary to spend a long time on the process for avoiding excessive accumulation of the liquid solvent 91. Thus, it is possible to prevent a decrease in production efficiency and avoid adverse effects caused by excessive accumulation of the liquid solvent 91 on the cooling surface 40a of the cooling unit 40.

[0148] In particular, in the first embodiment, four paths 46a to 46d ( Figure 6 ). Thus, it is easy to set the path 46 to uniformly cool the rectangular substrate, i.e., the substrate 9 having a shape with four corners. Each of the four paths 46a to 46d may have a portion extending in a straight line along each side of the rectangle of the substrate 9. In other words, each of the four paths 46a to 46d may have a portion extending in a straight line along each side of the rectangle of the cooling surface 40a. In other words, each of the four paths 46a to 46d may have a portion extending in a straight line along each side of the rectangle of the cooling member 41.

[0149] In addition, the control unit 80 can control the first lifting unit 100 and the pressure reducing mechanism 30 so that after the pressure in the chamber 10 is set to the first pressure in the first state where the interval between the substrate 9 and the cooling surface 40a is the first interval, the pressure in the chamber 10 is set to the second pressure in the second state where the interval between the substrate 9 and the cooling surface 40a is the second interval.

[0150] Specifically, first, in the first decompression process, the decompression mechanism 30 can reduce the pressure in the chamber 10 to the first target pressure 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. In the first decompression process, since the support unit 20 is located at the raised position H1, the interval between the substrate 9 and the cooling surface 40a is narrow. Therefore, it is possible to suppress a rapid drop in the pressure in the upper space 10s1 between the substrate 9 and the cooling surface 40a, and to suppress the occurrence of bumping of the coating film 90.

[0151] In addition, during the first decompression treatment, the cooling unit 40 can cool the cooling surface 40a. More specifically, the cooling unit 40 can reduce the temperature of the cooling surface 40a to a target temperature at which the solvent vapor condenses under the first target 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 area) can be suppressed, and the occurrence of uneven drying of the coating film 90 can be suppressed.

[0152] On the other hand, in the second decompression treatment after the first decompression treatment, the decompression mechanism 30 can reduce the pressure in the chamber 10 to below the second target pressure in a state where the first lifting unit 100 lowers the support unit 20 to the lowered position H2. Since the support unit 20 is located at the lowered position H2, the interval between the substrate 9 and the cooling surface 40a is wide. Thus, the pressure in the chamber 10 can be reduced more appropriately and quickly. Therefore, the coating film 90 can be dried more appropriately and quickly. In addition, in the second decompression treatment, since the interval between the substrate 9 and the cooling surface 40a is wide, the stagnation of the solvent vapor is less likely to occur, and the occurrence of uneven drying is less likely to occur.

[0153] In addition, in the second decompression treatment, the temperature of the cooling surface 40a may be a temperature at which the solvent evaporates at the second target pressure. Therefore, in the second decompression treatment, not only the coating film 90 on the substrate 9 but also the cooling surface 40a can be dried. Therefore, before the next substrate 9 is processed, there is no need to perform a drying treatment of the cooling surface 40a separately, and the next substrate 9 can be processed quickly. As a result, the processing capacity of the decompression drying treatment for a plurality of substrates 9 can be improved.

[0154] In the first embodiment, the top surface of the chamber 10 may correspond to the cooling surface 40 a . Therefore, if the cooling unit 40 is externally connected to the upper surface of the chamber 10 , the already installed chamber 10 can be used as it is.

[0155] In addition, in the first embodiment, the top plate portion 13 is cooled by the cooling member 41, and the lower surface of the top plate portion 13, that is, the cooling surface 40a, can be cooled. Although the temperature distribution in the cooling member 41 may be slightly deviated due to the extended shape of the path 46 when viewed from above, the deviation of the temperature distribution is alleviated as it moves toward the cooling surface 40a through the heat transfer in the top plate portion 13. In other words, 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 evenly on the cooling surface 40a. Therefore, the uniformity of the concentration distribution of the solvent vapor in the upper space 10s1 can be improved. As a result, the occurrence of uneven drying can be further suppressed.

[0156] In the first embodiment, the first lifting unit 100 for lifting the support unit 20 can be used to adjust the distance between the substrate 9 and the cooling surface 40a. Therefore, the first lifting unit 100 that has already been installed can be used as it is.

[0157] <2. Second Embodiment>

[0158] Fig.17 and Fig.18 1H and 1H are diagrams schematically showing an example of a longitudinal section and a top surface of a vacuum drying device 1H according to the second embodiment. The cooling unit 40 of the vacuum drying device 1H has a vertical section and a top surface. Fig.18 ) The heater 49H is located in the outer region RO. Thus, the temperature of the outer region RO can be more reliably increased compared to the temperature of the counter region RC. Fig.17 In the illustrated example, the heater 49H is disposed separately from the cooling member 41 on the ceiling 13 of the chamber 10. The other configurations of the reduced-pressure drying apparatus 1H are the same as those of the reduced-pressure drying apparatus 1 described above, and thus description thereof is omitted.

[0159] <3. Third Embodiment>

[0160] Fig.19 and Fig. 20 1N and 1N are diagrams schematically showing an example of a longitudinal section and a top surface of a vacuum drying device 1N according to the third embodiment. The cooling unit 40 of the vacuum drying device 1N has a vertical section and a top surface. Fig. 20 ) is located in the outer region RO. The heat insulating member 49N separates the path 46 from the cooling surface 40a. The heat insulating member 49N has a lower thermal conductivity than the member constituting the cooling surface 40a (the top plate 13 in this embodiment). As a result, the temperature of the outer region RO can be more reliably increased compared to the temperature of the relative region RC. Fig.19 In the example shown, the heat insulating member 49N is disposed in a groove provided in the top plate portion 13 of the chamber 10 (see Fig.19) inside, and in addition, when viewed from above, the insulating member 49N is configured in a manner that spans the inner and outer sides of the edge of the cooling member 41.

[0161] Since the other structures of the reduced-pressure drying device 1N are the same as those of the reduced-pressure drying device 1 (first embodiment), the description thereof will be omitted. In addition, the heater 49H of the second embodiment can also be used in this embodiment.

[0162] <4. Fourth Embodiment>

[0163] Fig.21 1T is a diagram schematically showing an example of the upper surface of the reduced pressure drying device 1T according to the fourth embodiment. Figure 6 ) in the paths 46b, 46c, the entrances 47b, 47c, and the exits 48b, 48c. Fig.21 In the example shown, inlet 47a and inlet 47d are arranged on a common diagonal line of the rectangle of cooling surface 40a when viewed from above. In addition, outlet 48a and outlet 48d are arranged on a common diagonal line of the rectangle of cooling surface 40a when viewed from above. Furthermore, inlet 47a, inlet 47d, outlet 48a and outlet 48d are arranged on a common diagonal line of the rectangle of cooling surface 40a when viewed from above.

[0164] <5. Fifth embodiment>

[0165] Fig. 22 1A is a diagram schematically showing an example of a longitudinal section of a vacuum drying device 1A according to the fifth embodiment. Fig. 22 Although not shown in the figure, it is similar to the reduced pressure drying device 1 ( Figure 1 ) Similarly, the reduced pressure drying device 1A also includes a refrigerant supply pipe 42, a refrigerant recovery pipe 43, a refrigerant cooling source 44 and a path 46. The structure of the reduced pressure drying device 1A is the same as that of the reduced pressure drying device 1 except for the second lifting portion 45. The second lifting portion 45 lifts and lowers the cooling member 41 of the cooling portion 40 between a cooling position H3 and a separation position H4. The cooling position H3 is a 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 a position where the cooling member 41 leaves the top plate portion 13. Fig. 22 In the example of FIG. 4 , the cooling member 41 located at the separation position H4 is schematically indicated by an imaginary line. For example, the second lifting unit 45 adopts a driving device such as a linear motor or a cylinder.

[0166] Fig.23 : is a flowchart showing an example of a process of the reduced pressure drying process of the fifth embodiment. Here, for example, Fig.23The cooling member 41 is initially located at the cooling position H3.

[0167] First, the reduced pressure drying device 1A sequentially performs steps S11 to S15. Steps S11 to S15 are respectively the same as steps S1 to S5. However, the cooling operation of the cooling surface 40a by the cooling unit 40 can be substantially completed at step S15.

[0168] After step S15, the reduced pressure drying device 1A performs the cooling part separation process (step S16). The cooling part separation process is a process of moving the cooling part 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 substantially interrupting the cooling operation on the cooling surface 40a.

[0169] Next, the reduced-pressure drying apparatus 1A executes steps S17 to S19. Steps S17 to S19 are respectively the same as steps S6 to S8.

[0170] As described above, according to the fifth embodiment, in the first decompression treatment (step S14), the cooling member 41 descends to the cooling position H3 to cool the lower surface of the top plate portion 13, i.e., the cooling surface 40a. Therefore, in the first decompression treatment, the decompression drying device 1A can more reliably condense the solvent vapor on the cooling surface 40a. And, according to the fifth embodiment, in the second decompression treatment (step S17), the cooling member 41 rises to the separation position H4. Therefore, in the second decompression treatment, the cooling action on the cooling surface 40a can be substantially interrupted. The cooling member 41 leaves the cooling surface 40a, and thus, the temperature of the cooling surface 40a rises with the passage of time, so that the evaporation of the solvent 91 attached to the cooling surface 40a can be promoted. Therefore, in the second decompression treatment, the decompression drying device 1A can more reliably dry the cooling surface 40a.

[0171] <6. Sixth Implementation>

[0172] Fig.24 1B is a diagram schematically showing an example of a longitudinal cross section of a vacuum drying device 1B according to the sixth embodiment. The structure of the vacuum drying device 1B is similar to that of the vacuum drying device 1 ( Figure 1 )same.

[0173] like Fig.24 As shown, a portion of the cooling unit 40 of the reduced pressure drying device 1B is buried in the top plate 13 of the chamber 10. Here, the top plate 13 functions as a cooling member 41. The top plate 13 may also be formed of a material with high thermal conductivity (for example, metal). Fig.24In the example of FIG. 1 , a path 46 that is a part of the cooling unit 40 is formed inside the top plate 13 . Fig.24 In the example of FIG. 4 , the entry 47 of the path 46 (see Figure 6 ) and exit 48 (see Figure 6 ) is formed on the upper surface of the top plate portion 13. The inlet 47 is connected to the downstream end of the refrigerant supply pipe 42, and the outlet 48 is connected to the upstream end of the refrigerant recovery pipe 43.

[0174] The refrigerant cooling source 44 cools the refrigerant and circulates it, thereby cooling the top plate 13 of the chamber 10. That is, the cooling surface 40a, which is the lower surface of the top plate 13, can be cooled.

[0175] An example of the flow of the reduced-pressure drying process using the reduced-pressure drying apparatus 1B is the same as that of the reduced-pressure drying process in the first embodiment.

[0176] According to the sixth embodiment, the top plate 13 functions as the cooling member 41. Therefore, the number of components of the reduced-pressure drying device 1B can be reduced, and the size and manufacturing cost of the reduced-pressure drying device 1B can be reduced. In addition, since the interval between the path 46 and the cooling surface 40a can be reduced, the cooling unit 40 can cool the cooling surface 40a more efficiently.

[0177] <7. Seventh Implementation Method>

[0178] Fig.25 1C is a diagram schematically showing an example of a longitudinal cross section of a reduced-pressure drying apparatus 1C according to the seventh embodiment. The reduced-pressure drying apparatus 1C has the same structure as the reduced-pressure drying apparatus 1 except for the internal structure of the cooling unit 40 .

[0179] like Fig.25 As shown, a part of the cooling part 40 of the reduced pressure drying device 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. In the chamber 10, the cooling member 41 is arranged at a position opposite to the upper surface of the substrate 9 supported by the support part 20. In other words, the cooling member 41 is arranged above the substrate 9 supported by the support part 20. The cooling member 41 is arranged in the chamber 10 in a posture in which its thickness direction is along the up-down direction. The cooling member 41 is fixed to the chamber 10 by a fixing part not shown in the figure. The cooling member 41 can be fixed to the top plate part 13 of the chamber 10 by a fixing part such as a screw, for example. In the seventh embodiment, the lower surface of the cooling member 41 corresponds to the cooling surface 40a.

[0180] exist Fig.25In the example of , the refrigerant supply pipe 42 and the refrigerant recovery pipe 43 penetrate the top plate portion 13, and the refrigerant cooling source 44 is provided outside the chamber 10. The refrigerant cooling source 44 cools the refrigerant and circulates the refrigerant, thereby cooling the cooling member 41. That is, the cooling surface 40a of the cooling member 41 is cooled.

[0181] exist Fig.25 In the example, when viewed from above, the size of the cooling member 41 is larger than the substrate 9. When viewed from above, the cooling surface 40a of the cooling member 41 can 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. Thus, the cooling surface 40a can be opposite to the entire upper surface of the substrate 9 in the up and down direction. In addition, when viewed from above, the cooling surface 40a can also be square. In this case, the side length of the cooling surface 40a is longer than the short side of the substrate 9. Thus, regardless of the direction of the substrate 9 arranged on the support portion 20, the cooling surface 40a is larger than the substrate 9 when viewed from above. Therefore, regardless of the direction of the substrate 9, the cooling surface 40a can be opposite to the entire upper surface of the substrate 9.

[0182] An example of the flow 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.

[0183] According to the seventh embodiment, the cooling surface 40a is a 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 selected separately from the specification requirements for the chamber 10. In other words, the selectivity of the material of the cooling member 41 can be improved. In addition, because the cooling surface 40a is the lower surface of the cooling member 41, the interval between the low-temperature portion of the cooling unit 40 (here, the path 46) and the cooling surface 40a can be reduced. Therefore, the cooling unit 40 can cool the cooling surface 40a more efficiently.

[0184] <8. Eighth Implementation Method>

[0185] Fig.26 1 is a diagram schematically showing an example of a longitudinal section of a vacuum drying device 1D according to the eighth embodiment. The structure of the vacuum drying device 1D is the same as that of the vacuum drying device 1C except for the lifting object of the first lifting unit 100. Fig.26 As shown, the first lifting unit 100 lifts the cooling unit 40. Specifically, the first lifting unit 100 lifts the cooling member 41 of the cooling unit 40 between the rising position H11 and the falling position H12. The falling 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. Fig.26In FIG. 1 , the cooling member 41 at the lowered position H12 is indicated by an imaginary 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 a first state and a second state, in which the interval between the substrate 9 and the cooling surface 40a is the first interval and in which the interval between the substrate 9 and the cooling surface 40a is the second interval.

[0186] like Fig.26 As shown, the support portion 20 is located at the lowered position H2 mentioned in the first to seventh embodiments. That is, the substrate 9 supported by the support portion 20 is located at a position lower than the upper end of the side straightening plates 51 and is surrounded by the four side straightening plates 51. In the eighth embodiment, the substrate 9 is surrounded by the four side straightening plates 51 in both the first state in which the interval between the substrate 9 and the cooling surface 40a is the first interval and the second state in which the interval between the substrate 9 and the cooling surface 40a is the second interval.

[0187] The lowered position H12 may be a position where the cooling surface 40a of the cooling member 41 is below the upper end of the side straightening plate 51. That is, the size of the cooling member 41 is smaller than the size of the space surrounded by the four side straightening plates 51 in a plan view.

[0188] The raised position H11 is a position where the cooling surface 40a of the cooling member 41 is above the upper end of the side straightening plate 51. When the cooling member 41 is located at the raised position H11, the interval between the cooling surface 40a and the upper end of the side straightening plate 51 may be, for example, greater than or equal to twice the first interval, or greater than or equal to five times the first interval. As a result, the gas directly above the substrate 9 easily flows from the upper end side of the side straightening plate 51 into the space between the side straightening plate 51 and the side wall portion 12 of the chamber 10.

[0189] For example, the first lifting unit 100 adopts a driving device such as a linear motor or a cylinder. The main body 100a of the first lifting unit 100 is fixed on a device frame (not shown) outside the chamber 10, for example. The moving part 100b of the first lifting unit 100 is, for example, capable of moving in the up and down directions relative to the main body 100a. The moving part 100b is, for example, suitable for a rod-shaped member. The moving part 100b is, for example, provided in a state of a through hole 13h that passes through the top plate 13 of the chamber 10. And, for example, the cooling member 41 is fixed to the lower end of the moving part 100b. Here, for example, if a bellows is provided between the upper surface of the top plate 13 and the moving part 100b, the gap between the top plate 13 and the moving part 100b can be sealed.

[0190] The 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 lifting 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. In addition, in the second interval adjustment process (step S5), the first lifting 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.

[0191] According to the eighth embodiment, the cooling member 41 is a member different from the chamber 10. Therefore, as in the seventh embodiment, the selectivity of the material of the cooling member 41 can be improved. In addition, since the cooling surface 40a is the lower surface of the cooling member 41, the cooling unit 40 can cool the cooling surface 40a more efficiently as in the seventh embodiment.

[0192] In the eighth 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 decompression 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.

[0193] <9. Modifications>

[0194] The present invention is not limited to the above-described embodiments, and various changes and improvements can be made without departing from the gist of the present invention.

[0195] In order to cool the cooling surface 40a, in each of the above-mentioned embodiments, the cooling unit 40 uses a refrigerant, but as long as the cooling unit is configured so that the temperature of the outer region RO is higher than the temperature of the relative region RC, the cooling principle of the cooling unit is not limited. For example, instead of a structure using a refrigerant, a structure using a Peltier element may be adopted. In this case, by optimizing at least one of the position where the Peltier element is installed when viewed from above and optimizing the temperature control of a plurality of Peltier elements, the cooling unit can be configured so that the temperature of the outer region RO is higher than the temperature of the relative region RC. The installation method of the Peltier element is not particularly limited, and for example, it can be buried in the top plate portion 13.

[0196] Although in the above-mentioned embodiments, the first lifting unit 100 lifts or lowers the support unit 20 or the cooling unit 40, it is also possible to lift or lower both the support unit 20 and the cooling unit 40. In short, as long as the first lifting unit 100 lifts or lowers at least one of the support unit 20 and the cooling surface 40a between the first state and the second state, in which the interval between the substrate 9 supported by the support unit 20 and the cooling surface 40a is the first interval, the interval between the substrate 9 supported by the support unit 20 and the cooling surface 40a is the second interval wider than the first interval.

[0197] In the above embodiments, for example, the chamber 10 has four exhaust ports 16a, 16b, 16c, and 16d, but the present invention is not limited thereto. For example, the number of exhaust ports in the chamber 10 may be one to three, or five or more. In addition, for example, the independent valves Va, Vb, Vc, and Vd may not be provided.

[0198] In the above embodiments, the reduced pressure drying apparatuses 1, 1A to 1D dry the coating film 90 on the substrate 9 by reducing pressure, but the invention is not limited thereto. For example, the reduced pressure drying apparatuses 1, 1A to 1D may dry the coating film 90 on the substrate 9 by reducing pressure and heating.

[0199] In the above-mentioned embodiments, a 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 of the chamber 10 and the top plate portion 13 constitute an integral cover portion, and the cover portion can be separated from the bottom plate portion 11 and evacuated upward. In this case, for example, the cover portion can be moved up and down by an opening and closing drive portion 16 or the like. In addition, the chamber 10 can be selectively set to a 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 (sealed state); and a state in which the cover portion separates upward from the bottom plate portion 11 and opens the internal space 10s (open state). Here, if the chamber 10 is in an open 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 a closed state, the coating film 90 on the substrate 9 can be dried by reducing the pressure by exhausting gas from the internal space 10 s and supplying gas to the internal space 10 s.

[0200] In the above-mentioned embodiments, for example, the support portion 20 may have various forms. For example, the plurality of support plates 21 may be one integrated support plate 21 .

[0201] In each of the above-described embodiments, for example, the bottom straightening plate 50 may be omitted, and the side straightening plate 51 may be omitted.

[0202] In the above-described embodiments, various operations in the reduced-pressure drying apparatus 1 can be started or ended, for example, based on an operation of the input unit 804 by the user or a signal input to the communication unit 806 from an external device.

[0203] In each of the above-described embodiments, for example, at least a portion of the functional configuration implemented in the control unit 80 may be implemented by hardware such as a dedicated electronic circuit.

[0204] In addition, it is needless to say that all or part of the above-mentioned one embodiment and various modifications can be configured by appropriate combination within a range that does not contradict each other.

Claims

1. A reduced pressure drying device for drying a coating film applied on an upper surface of a substrate, wherein: have: a chamber accommodating the substrate; a supporting portion, supporting the substrate in the chamber; a decompression mechanism for sucking gas from the chamber to reduce the pressure in the chamber; as well as a cooling portion for cooling a cooling surface which is opposite to the upper surface of the substrate supported by the supporting portion and is larger than the substrate, The cooling surface of the cooling unit has: an opposing region that is opposed to a region of the substrate where the coating film can be formed in the thickness direction of the substrate; and an outer region, located outside the relative region, The cooling unit is configured such that the temperature of the outer region is higher than the temperature of the opposite region. The cooling unit has: a path for a refrigerant to flow through in order to cool the cooling surface; an inlet for introducing the refrigerant into the path; and an outlet for conducting the refrigerant from the path, In a plan view, the path of the cooling portion crosses the opposing region and the outer region, the inlet of the cooling portion is located in the opposing region, and the outlet of the cooling portion is located in the outer region.

2. The reduced pressure drying device according to claim 1, wherein: The path of the cooling portion extends in a spiral shape when viewed from above.

3. The reduced pressure drying device according to claim 1 or 2, wherein: The cooling unit includes a heat insulating member located in the outer region in a plan view, and the heat insulating member separates the path from the cooling surface.

4. The reduced pressure drying device according to claim 1 or 2, wherein: The cooling unit includes a heater located in the outer region in a plan view.

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