Reduced pressure drying apparatus and reduced pressure drying method

Abstract

The present invention provides a kind of to occur in the four corners of the substrate formed with coating film near the drying unevenness is inhibited by reduced pressure drying device and method.Reduced pressure drying device (1) is used to make coating film (90) coated on the effective area (AE) of the upper surface of substrate (9) with rectangular shape dry.Reduced pressure drying device (1) includes the chamber (10) containing substrate, the pressure in chamber (10) is reduced by the reduced pressure mechanism (30) from chamber (10) suction gas, the cooling surface (40a) opposite to substrate is cooled by cooling part (40).The cooling surface (40a) of cooling part includes the inner side area (AI) opposite to the inner side portion (PI) of substrate (9) from the outer edge of effective area (AE) to the inside, the four corner area (AC) opposite to the four corner portion (PC) of substrate effective area (AE).Cooling part is configured to make the temperature of four corner area (AC) of cooling surface (40a) lower than the temperature of inner side area (AI) of cooling surface.

Description

Technical Field

[0001] This invention relates to a vacuum drying apparatus and a vacuum drying method. Background Technology

[0002] Previously, vacuum drying apparatuses were known for drying photoresist and other coatings applied to various substrates under reduced pressure. These substrates include, for example, glass substrates, ceramic substrates, semiconductor wafers, electronic device substrates, or printing plates used for forming various devices. These devices include, for example, semiconductor devices, display panels, solar cell panels, magnetic disks, or optical disks. Display panels include, for example, liquid crystal displays, organic light-emitting diode (EL) displays, plasma display panels, or field emission displays.

[0003] When drying a coated film using a vacuum drying apparatus, for example, with a substrate supported by multiple support pins within the chamber, a vacuum pump vents air from the chamber through an exhaust port at the bottom of the chamber. This venting reduces the pressure within the chamber. As the pressure decreases, the solvent in the coated film evaporates, thus drying the film. Furthermore, for example, if a predetermined vacuum level is reached, venting from the chamber stops, and gas is supplied to the chamber to restore it to atmospheric pressure. The gas used may be, for example, an inert gas such as nitrogen or air.

[0004] According to the technology disclosed in Patent Document 1, an ink drying apparatus as a type of vacuum drying device is disclosed. The ink drying apparatus is used to dry ink, which is continuously applied along the column direction between the column ends of a plurality of adjacent columns arranged side-by-side on a substrate. The ink includes a solute and two or more solvents. The ink drying apparatus includes: a chamber for providing a substrate coated with the ink; a support platform for placing the substrate in the chamber; and a mechanism for venting gas from the chamber. The gas venting mechanism is controlled using a curve, which includes: a first period in which the pressure in the chamber is reduced from standard atmospheric pressure to a first pressure higher than the largest vapor pressure among the vapor pressures of the plurality of solvents; and a second period in which, after the first period, the pressure in the chamber is reduced to a second pressure lower than the smallest vapor pressure among the vapor pressures of the plurality of solvents. When the pressure in the chamber is expressed as 10... X When Pa (X is a real number), the absolute value of the average change in the value of X per unit time during the second period is greater than the average change in the value of X per unit time during the first period. Patent Document 1 states that the ink drying apparatus described above can achieve uniform film thickness.

[0005] According to the technology disclosed in Patent Document 2, a pressure-reducing drying apparatus is provided, which includes a lifting section for raising and lowering a support pin of a supporting substrate. During the initial stage of pressure reduction, the lifting section raises the support pin, thereby reducing the gap between the substrate and the top surface of the chamber. This reduces the rate of pressure reduction between the substrate and the top surface, thus suppressing the occurrence of boiling-up in the coated film during the initial stage of pressure reduction. Consequently, deviations in film thickness caused by this boiling-up can be suppressed.

[0006] Patent Document 1: International Publication No. 2018 / 131616

[0007] Patent Document 2: Japanese Patent Application Publication No. 2022-086766

[0008] The technologies disclosed in Patent Documents 1 and 2 above aim to suppress uneven drying in order to suppress film thickness deviations. However, based on the inventors' research, the inventors have found that even in the technologies of these documents, there are cases where uneven drying cannot be sufficiently suppressed, especially near the four corners of a rectangular substrate. Summary of the Invention

[0009] The present invention was made in view of the above-mentioned problems, and its object is to provide a technique for suppressing uneven drying near the four corners of a substrate on which a coating film is formed.

[0010] The first method is a depressurization drying apparatus for drying a coating film applied to an effective area on the upper surface of a rectangular substrate. The apparatus includes: a chamber for housing the substrate; a depressurization mechanism for drawing gas from the chamber to reduce the pressure within the chamber; a support portion for supporting the substrate within the chamber; and a cooling portion for cooling a cooling surface opposite to the substrate supported by the support portion. The cooling surface of the cooling portion includes: an inner region opposite to an inner portion of the substrate that extends inward from the outer edge of the effective area; and four corner regions opposite to the four corner portions of the effective area of ​​the substrate. The cooling portion is configured such that the temperature of the four corner regions of the cooling surface is lower than the temperature of the inner region of the cooling surface.

[0011] The second method is a pressure-reducing drying apparatus according to the first method, wherein the cooling surface is opposite to the upper surface of the substrate.

[0012] The third approach is a depressurization drying apparatus according to the first or second approach, wherein the cooling surface of the cooling unit includes a surrounding region, the surrounding region includes the four corner regions and surrounds the inner region, and the cooling unit is configured such that the temperature of the surrounding region of the cooling surface is lower than the temperature of the inner region of the cooling surface.

[0013] The fourth method is a decompression drying apparatus according to any one of the first to third methods, wherein the cooling section includes a plurality of cooling mechanisms, and the plurality of cooling mechanisms can be set to a temperature lower than room temperature in order to cool the cooling surface. The plurality of cooling mechanisms includes: a main cooling mechanism, which, when viewed from above, is located at a position overlapping the outer edge of the effective area of ​​the substrate; and at least one auxiliary cooling mechanism, which, when viewed from above, is located at a position away from the outer edge of the effective area of ​​the substrate, and can be set to a temperature higher than the temperature of the main cooling mechanism.

[0014] The fifth method is a depressurization drying method for drying a coating film applied to an effective area on the upper surface of a rectangular substrate, comprising: a) a step of placing the substrate coated with the coating film in a chamber; and b) a step of drying the coating film by reducing the pressure in the chamber after step a), wherein in step b) the following step is performed: a step of cooling the substrate so that the temperature of the four corner portions of the effective area of ​​the substrate is lower than the temperature of the inner portion of the substrate moving inward from the outer edge of the effective area.

[0015] According to the methods described above, during the drying of the coating film applied to the substrate, the temperature at the four corners of the effective area of ​​the substrate is lower than the temperature at the inner part of the effective area. Consequently, the viscosity of the coating film increases at the four corners of the effective area. In other words, the fluidity of the coating film decreases at the four corners of the effective area. As a result, uneven drying, which easily occurs at the four corners of the effective area of ​​the substrate, can be suppressed. Attached Figure Description

[0016] Figure 1 This is a diagram showing an example of a longitudinal section of the vacuum drying apparatus of the first embodiment.

[0017] Figure 2 This is a diagram showing an example of a cross-section of the vacuum drying apparatus of the first embodiment.

[0018] Figure 3 This is a diagram showing an example of a longitudinal section of the vacuum drying apparatus according to the first embodiment.

[0019] Figure 4 This is a top view showing an example of a substrate.

[0020] Figure 5 yes Figure 4 Enlarged view within the dashed line V.

[0021] Figure 6 It is along Figure 5 A cross-sectional view of line VI-VI.

[0022] Figure 7 It is used to be with Figure 6 The same viewpoint is used to illustrate the cross-sectional view of uneven drying of the coating film.

[0023] Figure 8 It is used to explain in Figure 4 The diagram shows areas on the substrate where uneven drying is likely to occur.

[0024] Figure 9 This is a top view showing an example of the imaginary division of the substrate.

[0025] Figure 10 This is a diagram that schematically shows an example of the upper surface of the vacuum drying apparatus of the first embodiment.

[0026] Figure 11 It is a block diagram that conceptually represents the functions implemented in the control unit.

[0027] Figure 12 This is a flowchart illustrating an example of the vacuum drying process of the first embodiment.

[0028] Figure 13 This is a diagram that roughly illustrates an example of the conditions inside the chamber during the first decompression process.

[0029] Figure 14 This is a diagram that roughly illustrates an example of the conditions inside the chamber during the second decompression process.

[0030] Figure 15 This is a diagram that schematically shows an example of the upper surface of the vacuum drying apparatus of the second embodiment.

[0031] Figure 16 This is a diagram that schematically shows an example of the upper surface of the vacuum drying apparatus according to the third embodiment.

[0032] Figure 17 This is a diagram showing an example of a longitudinal section of the vacuum drying apparatus according to the fourth embodiment.

[0033] Figure 18 This is a flowchart illustrating an example of the vacuum drying process of the fourth embodiment.

[0034] Figure 19 This is a diagram showing an example of a longitudinal section of the vacuum drying apparatus according to the fifth embodiment.

[0035] Figure 20 This is a diagram showing an example of a longitudinal section of the vacuum drying apparatus according to the sixth embodiment.

[0036] Figure 21This is a diagram showing an example of a longitudinal section of the vacuum drying apparatus according to the seventh embodiment.

[0037] Figure 22 This is a diagram that schematically shows an example of the upper surface of the vacuum drying apparatus according to the eighth embodiment.

[0038] Explanation of reference numerals in the attached figures

[0039] 1. 1A~1G vacuum drying device

[0040] 9 substrates

[0041] 10 chambers

[0042] 20 support sections

[0043] 30 decompression mechanism

[0044] 40 Cooling section

[0045] 40a cooling surface

[0046] 41, 41M cooling components

[0047] 60 Gas Supply Department

[0048] 80 Control Department

[0049] 90 coating film

[0050] 91 Solvent

[0051] F1 top surface (first side)

[0052] F2 lower surface (second surface)

[0053] AC four corner areas

[0054] AE effective area

[0055] AF surrounding area

[0056] AI inner area

[0057] AN edge region

[0058] AO outer region

[0059] AS edge region

[0060] Uneven drying of DV

[0061] MC and MF cooling mechanisms

[0062] MIa, MIb, MOa, MOb, MZ cooling mechanisms (auxiliary cooling mechanisms)

[0063] PC four corners

[0064] PF surrounding part

[0065] Inner part of PI

[0066] PS edge part Detailed Implementation

[0067] Hereinafter, one embodiment and various modifications of the present invention will be described with reference to the accompanying drawings. In the drawings, parts having the same structure and function are given the same reference numerals, and repeated descriptions are omitted in the following description. The drawings are schematic and do not accurately represent the dimensions and positional relationships of the various structures in each figure. Furthermore, 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 and downward directions are also collectively referred to as the vertical direction. The top view represents the planar layout. The planar layout of some components is a two-dimensional layout obtained by projecting the component onto a plane. This plane can be a surface perpendicular to the vertical direction.

[0068] <1. First Implementation Method>

[0069] Figure 1 This is a diagram showing an example of a longitudinal section of the vacuum drying apparatus 1 according to the first embodiment. Figure 2 This is a diagram showing an example of a cross-section of the vacuum drying apparatus 1 according to the first embodiment. Figure 3 This is a diagram showing an example of a longitudinal section of the vacuum drying apparatus 1 according to the first embodiment. Figure 1 Longitudinal section and Figure 3 The longitudinal section shows the structure of the decompression drying device 1 when viewed from directions approximately 90 degrees apart. Figure 3 In order to avoid complicating the accompanying drawings, the relevant structures of the pressure reducing mechanism 30, the air supply unit 60, the pressure gauge 70 and the control unit 80 described later are omitted.

[0070] In this embodiment, the substrate 9 is described in detail as being used to manufacture an organic EL (Electroluminescent) display. Figure 4 This is a top view showing an example of substrate 9. Figure 5 yes Figure 4 Enlarged view within the dashed line V. Figure 6 It is along Figure 5 A cross-sectional view of line VI-VI.

[0071] The substrate 9 is a flat substrate, rectangular when viewed from above, and has: a first surface F1 as a first main surface; and a second surface F2 opposite to the first surface F1 as a second main surface. In the vacuum drying apparatus 1, the first surface F1 of the substrate 9 is the upper surface of the substrate 9, and the second surface F2 of the substrate 9 is the lower surface of the substrate 9. The substrate 9 includes a glass substrate 95 ( Figure 5 and Figure 6On the first surface F1 of substrate 9, for example, a coating film 90 is partially formed by pre-coating a processing liquid containing organic materials and solvents. The coating film 90 is dried using a vacuum drying apparatus 1 to form a hole injection layer, hole transport layer, or light-emitting layer of the organic EL display panel.

[0072] On the first surface F1 of substrate 9, a plurality of regions (also called forming regions) A1 can be arranged for the actual formation of the product (specifically, an organic EL display). Figure 4 In the example shown, viewed from above, eight rectangular forming regions A1 are arranged in a matrix of four rows and two columns on the substrate 9. However, the shape, number, and arrangement of the forming regions A1 are not limited to this example. In the coating process prior to the vacuum drying process of the vacuum drying apparatus 1, a coating film 90 is formed on each upper surface of the forming regions A1 according to a desired pattern using an inkjet printer or a slot coater. In other words, the coating film 90 is not formed on the entire forming region A1, but rather partially formed on the forming region A1 according to a predetermined pattern. The outer side of the forming region A1 in the first surface F1 is the non-forming region A2, and the coating film 90 for constituting the product is not formed in the non-forming region A2.

[0073] The first surface F1 of the substrate 9 has an effective area AE that includes all forming areas A1. The effective area AE can be defined, for example, as the smallest rectangular area that includes all forming areas A1. In cases where it is difficult to determine which area of ​​the first surface F1 is the effective area AE, the entire first surface F1 can be regarded as the effective area AE. However, typically, for the purpose of forming a product (specifically, an organic EL display), it is difficult to actually apply the substrate 9 to the edge of the first surface F1, which has an edge area AN around the effective area AE.

[0074] The coating film 90 formed on the substrate 9 as described above is dried by the vacuum drying apparatus 1. Thus, the vacuum drying apparatus 1 is an apparatus for drying the coating film 90 applied to the effective area AE of the upper surface of the rectangular substrate 9.

[0075] On the first surface F1 of the glass substrate 95, a plurality of rows 96 and a plurality of columns 97 are formed. The rows 96 and columns 97 are formed in the formation region A1 of the effective region AE. Figure 4 Rows 96 and columns 97 constitute the light-emitting units of the organic EL display by dividing the forming region A1 into a matrix. Thus, the extending direction of the rows 96 is orthogonal to the extending direction of the columns 97. In this embodiment, as... Figure 6As shown, the surface height of the column 97 is higher than the surface height of the row 96. The surface height of the coating film 90 is higher than the surface height of the row 96 but lower than the surface height of the column 97. Therefore, the coating film 90 is divided by adjacent columns 97. Thus, a plurality of coating films 90, each extending along the y-direction, are arranged along the x-direction. Figure 5 In the example shown, to obtain an RGB display, the coating film 90R corresponding to red (R), the coating film 90G corresponding to green (G), and the coating film 90B corresponding to blue (B) are periodically arranged along the x-direction. Furthermore, although in Figure 5 and Figure 6 The illustration is omitted, but in addition to the above-mentioned components, components such as electrode layers required for the light emission of an organic EL display can also be appropriately provided on the glass substrate 95.

[0076] As described above, because each coating film 90 is formed in a groove extending in the y-direction by adjacent columns 97, the fluid coating film 90 before drying cannot flow significantly in the x-direction, but can only flow significantly in the y-direction. During the drying process, this flow results in a film thickness distribution of the dried coating film 90 that may be as follows: Figure 7 As shown, the roughly ideal state indicated by the double-dotted lines was not achieved, and instead, uneven drying (DV) with reduced film thickness was observed at the ends in the extension direction (y-direction). Therefore, refer to... Figure 8 Although uneven drying (DV) may occur at both ends of the effective region AE in the y direction ( Figure 8 The effective region AE is located near the top and bottom edges of the rectangle, but if... Figure 8 As shown, according to the inventors' research, uneven drying (DV) is particularly prone to occur at the four corners of the effective area AE. Therefore, during the drying process, by suppressing the flowability of the coating film 90 at the four corners of the effective area AE, uneven drying (DV) can be suppressed.

[0077] Figure 9 This is a top view illustrating an example of the hypothetical division of substrate 9. The effective area AE of substrate 9 ( Figure 9 The area enclosed by the double-dotted line has an inner portion PI separated from the outer edge of the effective area AE and a surrounding portion PF that surrounds the inner portion PI. The surrounding portion PF is in contact with the outer edge of the effective area AE. As mentioned above, the surrounding portion PF is particularly prone to uneven drying (DV). Figure 8 The rectangle consists of four corner portions PC and four edge portions PS. The four corner portions PC are four parts located at the four corners of the effective area AE of the rectangle, separated from each other by the edge portions PS. The edge portions PS are connected to the outer edge of the effective area AE and extend along that outer edge.

[0078] It should be noted that although the use of substrate 9 in manufacturing organic EL displays has been described in detail above, substrate 9 is not limited to this. As a variation, instead of a glass substrate, substrate 9 may include a semiconductor substrate or a ceramic substrate. Furthermore, the processing liquid used to form the coating film 90 may be, for example, a liquid containing a polyimide precursor and a solvent, or a photoresist solution. For example, polyamic acid can be used as the polyimide precursor. For example, NMP (N-methyl-2-pyrrolidone) can be used as the solvent.

[0079] <1-1. Structural Overview of the Vacuum Drying Unit>

[0080] Next, the structure of the vacuum drying apparatus 1 will be described in general. For example... Figure 1 and Figure 2 As shown, the pressure-reducing drying device 1 includes a chamber 10, a support 20, a pressure-reducing mechanism 30, a first lifting part 100, a cooling part 40, and a control part 80.

[0081] The chamber 10 is a portion for accommodating the substrate 9. The support portion 20 is disposed within the chamber 10 to support the substrate 9 in a horizontal position. Here, "horizontal position" means that the thickness direction of the substrate 9 is along the vertical direction.

[0082] The pressure reduction mechanism 30 draws in the gas inside the chamber 10 and discharges the gas to the outside of the chamber 10. The pressure inside the chamber 10 decreases due to this draw. By reducing the pressure inside the chamber 10, the solvent in the coating film 90 on the first surface F1 of the substrate 9 evaporates, and the coating film 90 is dried.

[0083] The cooling section 40 cools the cooling surface 40a. However, it is not necessary to cool the entire cooling surface 40a; in this embodiment, as described later, a portion of the cooling surface 40a is actively cooled. The cooling surface 40a is opposite to the first surface F1 (upper surface) of the substrate 9 supported by the support section 20 in the vertical direction. Figure 1 In this example, the cooling surface 40a corresponds to the top surface of the chamber 10. Viewed from above, the size of the cooling surface 40a can be larger than that of the substrate 9. That is, the size of the cooling surface 40a can be such that it is completely opposite to the first surface F1 of the substrate 9. The cooling surface 40a is, for example, a horizontal, flat surface. Cooling the cooling surface 40a by the cooling section 40 can reduce the temperature of the cooling surface 40a.

[0084] The solvent vapor (hereinafter referred to as solvent vapor) evaporated from the coating film 90 on the first surface F1 of the substrate 9 can be cooled and condensed on the cooling surface 40a. Therefore, liquid solvent 91 (refer to the description below) can adhere to the cooling surface 40a. Figure 13That is, solvent 91 can condense. Furthermore, by further reducing the pressure within chamber 10, the solvent 91 adhering to the cooling surface 40a can be evaporated. This condensation and evaporation will be described in detail later.

[0085] exist Figure 1 In the example, the first lifting part 100 causes the support part 20 to rise and fall. Specifically, the first lifting part 100 causes the support part 20 to rise and fall between a raised position H1 and a lowered position H2. The raised position H1 is the position of the support part 20 when the distance between the substrate 9 supported by the support part 20 and the cooling surface 40a is a first interval. Figure 1 In the example, the support portion 20 and the substrate 9 are represented by imaginary lines at the rising position H1. The falling position H2 is the position of the support portion 20 when the distance between the substrate 9 supported by the support portion 20 and the cooling surface 40a is a second distance wider than the first distance. That is, the first lifting portion 100 causes the support portion 20 to rise and fall between a first state and a second state. In the first state, the distance between the substrate 9 and the cooling surface 40a is the first distance, and in the second state, the distance between the substrate 9 and the cooling surface 40a is the second distance. The first distance is, for example, less than or equal to 10 mm, and as a more specific example, the first distance is about 5 mm. The second distance can be, for example, more than 5 times the first distance, or more than 10 times the first distance. To give a specific example of the value, the second distance is, for example, greater than or equal to 50 mm, and as a more specific example, the second distance is about 80 mm.

[0086] As will be described in detail later, during the initial decompression phase, the first lifting unit 100 positions the support unit 20 in 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.

[0087] In addition, Figure 1 and Figure 2 In the example, the depressurization drying apparatus 1 also includes an air supply unit 60, a bottom rectifier plate 50, a side rectifier plate 51, and a barometer 70. The air supply unit 60 supplies gas into the chamber 10. This allows the air pressure inside the chamber 10 to be restored to atmospheric pressure. The bottom rectifier plate 50 and the side rectifier plate 51 are disposed within the chamber 10 to adjust the airflow within the chamber 10. The barometer 70 measures the air pressure inside 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 depressurization drying apparatus 1. For example, the control unit 80 controls the depressurization mechanism 30 based on the air pressure measured by the barometer 70 to adjust the air pressure inside the chamber 10. Additionally, the control unit 80 controls the cooling unit 40 to adjust the temperature of the cooling surface 40a, controls the first lifting unit 100, and adjusts the position of the support unit 20.

[0088] Next, detailed examples of each structure of the vacuum drying apparatus 1 will be described.

[0089] <1-1-1. Chamber 10>

[0090] The chamber 10 is a pressure-resistant container with an internal space 10s for accommodating the substrate 9. The chamber 10 is, for example, fixed to a mounting frame (not shown). The shape of the chamber 10 is, for example, a flat cuboid. The chamber 10 has, for example, a generally square base plate 11, four side wall portions 12, and a generally square top plate 13. The four side wall portions 12 connect, for example, the four end edges of the base plate 11 and the four end edges of the top plate 13 in the vertical direction. For example, one of the four side wall portions 12 is provided with an inlet / outlet 14 and a gate (also called a gate valve) 15 for opening and closing the inlet / outlet 14. The gate 15 is, for example, connected to or linked to an opening / closing drive unit 16. Figure 3 To avoid complicating the accompanying drawings, the opening / closing drive unit 16 is shown conceptually. For example, a drive device such as a cylinder is applied to the opening / closing drive unit 16. Here, for example, by the operation of the opening / closing drive unit 16, the gate 15 can move between a position where the loading / unloading outlet 14 is closed (also called the closed position) and a position where the loading / unloading outlet 14 is open (also called the open position).

[0091] 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 moved into the internal space 10s of the chamber 10 via the inlet / outlet 14, and the substrate 9 can be moved out of the internal space 10s of the chamber 10.

[0092] <1-1-2. Support Part 20>

[0093] The support portion 20 is located within the internal space 10s of the chamber 10 and is capable of supporting the substrate 9 housed within the internal space 10s of the chamber 10 from below. The support portion 20 includes, 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. A plurality of support pins 22 are erected on the upper surface of each support plate 21. When viewed from above, the plurality of support pins 22 are arranged in a two-dimensionally dispersed manner. The plurality of support plates 21 form the base of the support portion 20. The substrate 9 is positioned above the plurality of support plates 21, and the upper ends of the plurality of support pins 22 contact the second surface F2, which is the lower surface of the substrate 9, thereby supporting the substrate 9 in a horizontal position.

[0094] <1-1-3. Pressure Relief Mechanism 30>

[0095] like Figure 1 and Figure 2As shown, four exhaust ports 16a, 16b, 16c, and 16d are provided, for example, on the portion of the bottom plate 11 of the chamber 10 opposite to the base plate 9 in the vertical direction. The pressure reducing 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 independent pipe 31a is connected to exhaust port 16a, one end of independent pipe 31b is connected to exhaust port 16b, one end of independent pipe 31c is connected to exhaust port 16c, and one end of independent pipe 31d is connected to exhaust port 16d. For example, the other ends of each of the four independent pipes 31a, 31b, 31c, and 31d merge and are connected to one end of the main pipe 31e. For example, the other end of the main pipe 31e is connected to the vacuum pump 32. For example, independent valve Va is installed on the path of independent piping 31a, independent valve Vb is installed on the path of independent piping 31b, independent valve Vc is installed on the path of independent piping 31c, and independent valve Vd is installed on the path of independent piping 31d. For example, main valve Ve is installed on the path of main piping 31e.

[0096] Here, for example, with the inlet / outlet 14 closed using gate 15, if at least one of the four independent valves Va, Vb, Vc, and Vd, and one main valve Ve are opened, and vacuum pump 32 is started, the gas inside chamber 10 is discharged to the outside of chamber 10 via exhaust pipe 31. This, for example, reduces the pressure in the internal space 10s of chamber 10. The four independent valves Va, Vb, Vc, and Vd are, for example, valves used to individually adjust 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 that switches between an open and closed state according to instructions from control unit 80 (also called an on / off valve). The main valve Ve is, for example, a valve used to adjust 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 the instructions of the control unit 80 (also called an opening degree control valve).

[0097] <1-1-4. First Lifting Section 100>

[0098] In the first embodiment, the first lifting unit 100 causes the support unit 20 to move up and down within the chamber 10. In other words, the first lifting unit 100 has a mechanism (also called a lifting mechanism) capable of causing the support unit 20 to move up and down. Figure 1 To avoid complicating the accompanying drawings, the first lifting unit 100 is shown conceptually. The first lifting unit 100 may employ a drive device such as a linear motor or a cylinder. Figure 3As shown, the first lifting part 100 includes, for example, a main body 100a and a moving part 100b. The main body 100a is fixed to a device frame (not shown) outside the chamber 10. The moving part 100b is movable relative to the main body 100a in the vertical direction. The moving part 100b is, for example, a rod-shaped member. The moving part 100b exists, for example, with a through hole 11h through the bottom plate 11 of the chamber 10. Furthermore, for example, a support part 20 is fixed to the upper end of the moving part 100b. Here, for example, if a bellows or the like 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 has: a rod-shaped portion (also called a rod-shaped portion) that is fixed to each support plate 21 and passes through a through hole 11h in the base plate portion 11; a portion that connects the plurality of rod-shaped portions (also called a connecting portion); and a portion that is connected to the connecting portion and slidably supported by the main body portion 100a (also called a sliding portion). The first lifting portion 100 raises and lowers the support portion 20, thereby raising and lowering the substrate 9 supported by the support portion 20.

[0099] <1-1-5. Cooling Section 40>

[0100] Although the cooling principle of the cooling unit 40 is not particularly limited, Figure 1 In this example, refrigerant is used for cooling. Specifically, the cooling unit 40 includes a cooling component 41, a first refrigerant pipe 42, a second refrigerant pipe 43, and a refrigerant cooling source 44. Furthermore, in Figure 3 To avoid complicating the accompanying drawings, the structure of the cooling section 40 is simply shown. The cooling member 41 is plate-shaped. 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 portion 13 in a vertical orientation along its thickness direction. When viewed from above, the cooling member 41 is, for example, rectangular. The lower surface of the cooling member 41 is preferably in close contact with the upper surface of the top plate portion 13. The cooling member 41 may be formed of a material with high thermal conductivity (e.g., metal).

[0101] exist Figure 1 In this example, a refrigerant flow path 41a is formed inside the cooling component 41. The refrigerant flow path 41a can extend in either a meandering or spiral shape when viewed from above. Figure 1 In this example, the inlet 41b and outlet 41c of the refrigerant flow path 41a are formed on the upper surface of the cooling member 41. The inlet 41b is connected to the downstream end of the first refrigerant pipe 42, and the outlet 41c is connected to the upstream end of the second refrigerant pipe 43. The upstream end of the first refrigerant pipe 42 and the downstream end of the second refrigerant pipe 43 are connected to the refrigerant cooling source 44.

[0102] Refrigerant flows from the downstream end of the second refrigerant pipe 43 into the refrigerant cooling source 44. The refrigerant can be a liquid or a gas. As a specific example, water can be used as the refrigerant. The refrigerant cooling source 44 cools the refrigerant and supplies the cooled refrigerant to the upstream end of the first refrigerant pipe 42. The refrigerant cooling source 44 can also be, for example, a heat pump. The refrigerant cooled by the refrigerant cooling source 44 flows into the upstream end of the first refrigerant pipe 42 and flows into the refrigerant flow path 41a through the first refrigerant pipe 42. The low-temperature refrigerant flows in the refrigerant flow path 41a, thereby exchanging heat with the cooling member 41 to cool the cooling member 41. Because 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 by flowing through the refrigerant flow path 41a flows back into the refrigerant cooling source 44 through the second refrigerant pipe 43 and is cooled again by the refrigerant cooling source 44.

[0103] If the cooling section 40 cools the top plate portion 13 of the cooling chamber 10, then the cooling surface 40a, which is the lower surface of the top plate portion 13 (i.e., the top surface of the chamber 10), is also cooled. Figure 1 In the example, when viewed from above, the size of the cooling member 41 is larger than the effective area AE of the substrate 9. That is, when viewed from above, the outline of the cooling member 41 surrounds the outline of the effective area AE. If the cooling member 41 and the effective area AE are rectangular when viewed from above, then the longer side of the cooling member 41 is longer than the longer side of the effective area AE, and the shorter side of the cooling member 41 is longer than the shorter side of the effective area AE. Alternatively, when viewed from above, the cooling member 41 can also be square. In this case, the side length of the cooling member 41 can be greater than the shorter side of the effective area AE. Thus, regardless of the orientation of the substrate 9 disposed on the support 20, when viewed from above, the cooling member 41 is larger than the effective area AE.

[0104] Figure 10 This is a diagram schematically illustrating an example of the upper surface of the pressure-reducing drying apparatus 1 according to the first embodiment. The cooling surface 40a includes an inner region AI, a surrounding region AF, and an outer region AO. Furthermore, for ease of viewing, in... Figure 10 The area surrounding region AF is shaded. (See reference) Figure 9 and Figure 10 Inner region AI ( Figure 10 ) in the vertical direction with the inner portion PI of substrate 9 Figure 9 Relative. Around region AF( Figure 10 ) in the vertical direction and surrounding portion PF of substrate 9 Figure 9 Relative. The region AF surrounds the inner region AI, including the four corner regions AC and the edge region AS. The four corner regions AC ( Figure 10 ) in the vertical direction and the four corner parts PC ( Figure 9 In contrast, the edge region AS( Figure 10 In the vertical direction, the edge part PS ( Figure 9 Relative. External region AO( Figure 10 The outer edge of the area surrounding region AF is located outside the effective region AE when viewed from above. The outer edge of the area surrounding region AF can be located outside the effective region AE to surround the outer edge of the effective region AE of the substrate 9. Figure 10 (Double-dotted line). In this case, when viewed from above, the outer edge of the effective area AE of substrate 9 ( Figure 10 The double-dotted line in the text is contained within the area AF.

[0105] The cooling section 40 is configured such that, through its operation, the temperature of the four corner regions AC of the cooling surface 40a is lower than the temperature of the inner region AI of the cooling surface 40a. Specifically, the maximum value of the temperature distribution in the four corner regions AC can be lower than the minimum value of the temperature distribution in the inner region AI. In particular, in this embodiment, the cooling section 40 is configured such that, through its operation, the temperature of the surrounding region AF of the cooling surface 40a is lower than the temperature of the inner region AI of the cooling surface 40a. Specifically, the maximum value of the temperature distribution in the surrounding region AF can be lower than the minimum value of the temperature distribution in the inner region AI. In other words, in this embodiment, the surrounding region AF of the cooling surface 40a is essentially considered as the cooling region. Figure 10 (Mid-shaded area).

[0106] The temperature difference described above on the cooling surface 40a can be addressed by providing a cooling mechanism MF that selectively cools the surrounding region AF, which is the cooling area in this embodiment, within the cooling surface 40a. Furthermore, when the cooling mechanism MF selectively cools the surrounding region AF, it can incidentally cool other areas besides the surrounding region AF, but provides a more powerful cooling effect on the surrounding region AF compared to those other areas. As described above, the cooling mechanism MF that selectively cools the surrounding region AF can be implemented, for example, by arranging a refrigerant flow path 41a around the surrounding region AF when viewed from above. Figure 1 In another example, in a top view, a cooling member 41 is arranged around region AF, and no cooling member 41 is arranged in the inner region AI. Furthermore, in this case, it is not necessary to arrange a refrigerant flow path 41a in the outer region AO.

[0107] <1-1-6. Bottom Rectifier Plate 50>

[0108] The bottom rectifier plate 50 is a plate used to restrict the flow of gas in the internal space 10s when the pressure is reduced within the chamber 10 by the pressure-reducing mechanism 30. For example, the bottom rectifier plate 50 is positioned between the base plate 9 supported by the support portion 20 and the bottom plate portion 11 of the chamber 10. The bottom rectifier plate 50 is fixed to the bottom plate portion 11 of the chamber 10, for example, by a plurality of support pillars (not shown). Figure 2 As shown, for example, when viewed from above, the bottom rectifier plate 50 is square in shape. Furthermore, for example, when viewed from above, the side lengths of the bottom rectifier plate 50 are greater than the short side of the rectangular substrate 9. Therefore, for example, regardless of the orientation of the substrate 9 disposed on the support 20, when viewed from above, the bottom rectifier plate 50 is larger than the substrate 9. Additionally, the bottom rectifier plate 50, for example, has a through hole 50h, through which the moving part 100b of the first lifting part 100 passes. The bottom rectifier plate 50 and the moving part 100b are separated by a very small gap at the through hole 50h.

[0109] <1-1-7. Side fairing 51>

[0110] The side rectifier plate 51, together with the bottom rectifier plate 50, is used to restrict the flow of gas in the internal space 10s when the pressure is reduced within the chamber 10 by the pressure reduction mechanism 30. For example, the side rectifier plate 51 is positioned between the base plate 9, supported by the support portion 20 located in the lowered position H2, and the side wall portion 12 of the chamber 10. Here, for example, four side rectifier plates 51 are arranged to surround the base plate 9 supported by the support portion 20. For example, the four side rectifier plates 51 are generally formed as four corner cylindrical rectifier plates surrounding the base plate 9. Furthermore, for example, the bottom rectifier plate 50 and the four side rectifier plates 51 are generally formed as a bottom cylindrical box-shaped rectifier plate. Furthermore, in... Figure 1 In this example, the upper end of the side rectifier plate 51 is lower than the second surface F2 of the substrate 9, which is supported by the support portion 20 in the raised position H1. Therefore, in the first state where the support portion 20 is in the raised position H1, the substrate 9 is not surrounded by the four side rectifier plates 51.

[0111] Here, for example, when depressurization is performed inside chamber 10 in the second state where the support 20 is in the lowered position H2, the gas directly above the substrate 9 mainly flows towards the upper end of the side rectifier plate 51 (see the following description). Figure 14 The gas flows sequentially through the space between the side rectifier plate 51 and the side wall portion 12, the space between the bottom rectifier plate 50 and the bottom plate portion 11, and the exhaust ports 16a, 16b, 16c, and 16d, and is discharged to the outside of the chamber 10. Thus, the gas flows in a space away from the substrate 9, thereby preventing airflow from forming near the substrate 9. Furthermore, concentrated airflow is less likely to occur at the periphery of the substrate 9. Therefore, for example, it is possible to suppress uneven drying of the coating film 90 formed on the upper surface of the substrate 9.

[0112] Additionally, here, for example, the following structure can be used, i.e., as follows: Figure 2 As shown, when viewed from above, the four exhaust ports 16a, 16b, 16c, and 16d are all located on the diagonals 52 of the square bottom rectifier plate 50. In this case, for example, through each exhaust port 16a, 16b, 16c, and 16d, an airflow symmetrical with respect to the center of the bottom rectifier plate 50 (the intersection of the two diagonals 52) can be formed. Thus, for example, a more uniform airflow can be formed in the internal space 10s of the chamber 10.

[0113] <1-1-8. Gas Supply Section 60>

[0114] The gas supply unit 60 is the part that performs the action of supplying gas into the chamber 10 (also called gas supply). For example... Figure 1 As 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 located, for example, below the bottom rectifier plate 50. The air supply unit 60 has 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 in the path of the air supply pipe 61.

[0115] Here, for example, if the gas supply valve Vf is opened, gas is supplied from the gas supply source 62 to the internal space 10s of the chamber 10 via the gas supply pipe 61 and the gas supply port 16f. This causes the pressure inside the chamber 10 to rise. The gas supplied from the gas supply source 62 can be, for example, an inert gas such as nitrogen, or a clean, dry gas. The clean, dry gas is prepared, for example, by purifying air from the general environment to remove particles and moisture.

[0116] <1-1-9. Pressure gauge 70>

[0117] Pressure gauge 70 is a sensor that measures the pressure within the internal space 10s of chamber 10. For example... Figure 1 As shown, pressure gauge 70 is installed in a part of chamber 10. Pressure gauge 70 is capable of measuring the pressure in the internal space 10s of chamber 10 and outputting the measurement result to control unit 80.

[0118] <1-1-10. Control Unit 80>

[0119] The control unit 80 is an electronic circuit unit used to control the operation of various parts of the vacuum drying apparatus 1. The control unit 80 can control structures such as the vacuum mechanism 30, cooling unit 40, air supply unit 60, and first lifting unit 100. The control unit 80 is, for example, a computer having a processor 801 such as a CPU (Central Processing Unit), a memory 802 such as 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 called a program) 803p and various data, which is used to execute a process (also called vacuum drying process) in the vacuum drying apparatus 1 to dry the coating film 90 on the substrate 9 using vacuum. The storage unit 803 stores, for example, the program 803p and functions as a non-temporary storage medium readable by a computer. For example, the control unit 80 reads program 803p and data from the storage unit 803 to the memory 802, and performs calculations in the processor 801 based on program 803p and data, thereby controlling the operation of each part of the vacuum drying apparatus 1. Therefore, for example, in the vacuum drying apparatus 1, by using the processor 801 included in the control unit 80 to execute program 803p, vacuum drying processing can be performed.

[0120] 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. 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 the user's voice; and various sensors that input signals corresponding to the user's actions. The output unit 805 is, for example, a part that outputs various information in a user-recognizable manner. 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 between itself and external devices such as servers using wired or wireless communication methods. For example, a program 803p received from an external device using the communication unit 806 can be stored in the storage unit 803. The driver 807 is, for example, a part that can reload and unload portable storage media 807m such as a disk or optical disc. The drive 807, for example, with a storage medium 807m installed, transmits and receives data between the storage medium 807m and the control unit 80. For example, by installing the storage medium 807m storing the program 803p on the drive 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 computer-readable, non-transitory storage medium.

[0121] Figure 11 This is a block diagram that conceptually represents the functions implemented in the control unit 80. For example... Figure 11 As shown, the control unit 80 is electrically connected to, for example, the opening / closing drive unit 16, the first lifting unit 100, four independent valves Va, Vb, Vc, Vd, the main valve Ve, the vacuum pump 32, the air supply valve Vf, the cooling unit 40, and the pressure gauge 70. The control unit 80 can, for example, control the operation of the above-mentioned units by referring to the measured value output from the pressure gauge 70.

[0122] like Figure 11 As conceptually illustrated, the control unit 80, as a functional structure, includes, for example, an opening / closing control unit 81, a lifting control unit 82, a switching control unit 83, an exhaust control unit 84, a pump control unit 85, an air supply control unit 86, and a cooling control unit 87. For example, the opening / closing control unit 81 controls the operation of the opening / closing drive unit 16. For example, the lifting control unit 82 controls the operation of the first lifting unit 100. For example, the switching control unit 83 controls the opening / closing states of four independent valves Va, Vb, Vc, and Vd respectively. For example, the exhaust control unit 84 controls the opening / closing state and opening degree of the main valve Ve. For example, the pump control unit 85 controls the operation of the vacuum pump 32. For example, the air supply control unit 86 controls the opening / closing state of the air supply valve Vf. For example, the cooling control unit 87 controls the operation of the cooling unit 40. The functions of each part of the control unit 80 are implemented, for example, by the processor 801 performing calculations according to the aforementioned program 803p, etc.

[0123] <1-2. Reduced pressure drying treatment>

[0124] Next, the vacuum drying process of the substrate 9 using the vacuum drying apparatus 1 will be described. Figure 12 This is a flowchart illustrating an example of the vacuum drying process of the first embodiment. This vacuum drying process is implemented, for example, by executing program 803p in the processor 801 included in the control unit 80. Here, for example, the following steps are executed sequentially: Figure 12 The processing of steps S1 to S8.

[0125] When performing vacuum drying using the vacuum drying apparatus 1, for example, firstly, the substrate 9 is moved 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 first surface F1. Therefore, by moving it in, the substrate 9 coated with the coating film 90 is placed in the chamber 10. In step S1, for example, under the control of the control unit 80, the gate 15 opens the loading / unloading outlet 14, and the transport robot (not shown) places the substrate 9 on its forked hand and moves the substrate 9 into the internal space 10s of the chamber 10 via the loading / unloading outlet 14. At this time, the support 20 is, for example, in the lowered position H2. Furthermore, the side rectifier plate 51 is configured to be movable so that the side rectifier plate 51 does not interfere with the transport robot. For example, the transport robot inserts its forked hand between a plurality of support plates 21 of the support portion 20 and places the substrate 9 on the support portion 20. Then, the forked hand is retracted to the outside of the chamber 10. Then, under the control of the control unit 80, the gate 15 closes the transport inlet / outlet 14. As described above, in step S1, the process of placing the substrate 9 on a plurality of support pins 22 disposed in the chamber 10 is performed.

[0126] Next, the vacuum drying apparatus 1 performs a cooling process (step S2). The cooling process involves cooling the cooling area of ​​the cooling surface 40a. Specifically, the control unit 80 activates the cooling unit 40, which cools the cooling area of ​​the cooling surface 40a, lowering its temperature. The cooling unit 40 lowers the temperature of the cooling area of ​​the cooling surface 40a to a target temperature. The target temperature is, for example, 5°C or higher and 15°C or lower. As a more specific example, the target temperature is approximately 10°C. The cooling unit 40 can continue cooling the cooling surface 40a until the vacuum drying process on the substrate 9 is completed. Furthermore, the cooling operation of the cooling unit 40 can also begin before step S1.

[0127] Next, the pressure-reducing drying apparatus 1 performs a first interval adjustment process (step S3). The first interval adjustment process is the process of setting the interval between the substrate 9 and the cooling surface 40a as a first interval. Specifically, the control unit 80 controls the first lifting unit 100 to raise the support unit 20 to the raised position H1 (see...). Figure 1 or Figure 3 In the first state where the support 20 is in the raised position H1, the substrate 9 is located above the upper end of the side rectifier plate 51 (see...). Figure 1 ).

[0128] Next, a process is performed to dry the coating film 90 by reducing the pressure inside the chamber 10 (steps S4 to S6). This process will be described in detail below.

[0129] Next, the pressure-reducing drying apparatus 1 performs a first pressure-reducing process (step S4). The first pressure-reducing process is to reduce the pressure inside chamber 10 to a first pressure (hereinafter referred to as the first target pressure). The first target pressure is lower than standard atmospheric pressure, for example, set to 10 kPa or more. Specifically, the control unit 80 causes the pressure-reducing mechanism 30 to draw gas from chamber 10 with a smaller first suction flow rate, thereby reducing the pressure inside 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 pressure-reducing process described later. Therefore, in the first pressure-reducing process, the pressure inside chamber 10 decreases at a lower rate.

[0130] In step S3, for example, the control unit 80 can also independently and appropriately control the opening and closing states of each of the plurality of independent valves Va, Vb, Vc, and Vd. This allows for control of the airflow within the chamber 10 to suppress uneven drying of the substrate 9.

[0131] Figure 13 This is a diagram that schematically illustrates an example of the conditions inside chamber 10 during the first decompression process. In the first decompression process, with the support 20 in the first state (rising position H1), the gap between the substrate 9 and the cooling surface 40a is very narrow. Therefore, the rate of pressure reduction within the upper space 10s1 becomes slower, suppressing the boiling of the coating film 90 on the first surface F1 of the substrate 9.

[0132] On the other hand, in the first state, the substrate 9 supported by the support portion 20 is positioned higher than the upper end of the side rectifier plate 51. Therefore, the rectification function of the side rectifier plate 51 has almost no effect on the upper space 10s1 between the substrate 9 and the cooling surface 40a. Therefore, the side rectifier plate 51 basically does not have the effect of suppressing uneven drying. In the first state, because the lower space 10s2, which is lower than the substrate 9, is spacious, the gas in the lower space 10s2 can be quickly discharged. Specifically, the gas in the lower space 10s2 is discharged from the chamber 10 through the space between the side rectifier plate 51 and the side wall portion 12 of the chamber 10. Figure 13 In the diagram, the airflow is schematically represented by a dashed arrow.

[0133] By performing a first decompression process, the pressure inside chamber 10 can be reduced, thereby promoting the evaporation of the solvent in the coating film 90 on the first surface F1 of substrate 9. At this time, the first surface F1 of substrate 9 can be cooled by being positioned opposite the cooling surface 40a, which is being cooled as described above, at a very narrow interval. Here, compared to the cooling surface 40a ( Figure 10 ) in substrate 9 ( Figure 9The temperature of the inner region AI of the substrate 9, opposite to the inner region PI, is reduced in the cooling surface 40a, and the temperature of the corner region AC of the substrate 9, opposite to the corner region PC, is also reduced. Therefore, through the cooling of the first surface F1 of the substrate 9, the temperature of the corner region PC of the substrate 9 is reduced compared to the temperature of the inner region PI. Specifically, the maximum value of the temperature distribution of the corner region PC of the substrate 9 can be lower than the minimum value of the temperature distribution of the inner region PI of the substrate 9. By cooling the corner region PC of the substrate 9, the viscosity of the coating film 90 on the corner region PC increases. In other words, the fluidity of the coating film 90 on the corner region PC decreases. As a result, the uneven drying DV (Difference Variation) that is particularly prone to occur in the corner region PC can be effectively addressed. Figure 8 To suppress it.

[0134] Furthermore, in this embodiment, compared to the temperature of the inner region AI in the cooling surface 40a opposite to the inner portion PI of the substrate 9, the temperature of the surrounding region AF in the cooling surface 40a opposite to the surrounding portion PF of the substrate 9 is reduced. Therefore, through the aforementioned cooling of the first surface F1 of the substrate 9, the temperature of the surrounding portion PF of the substrate 9 is reduced compared to the temperature of the inner portion PI of the substrate 9. Specifically, the maximum value of the temperature distribution of the surrounding portion PF of the substrate 9 can be lower than the minimum value of the temperature distribution of the inner portion PI of the substrate 9. By cooling the surrounding portion PF of the substrate 9, the viscosity of the coating film 90 on the surrounding portion PF increases. In other words, the fluidity of the coating film 90 on the surrounding portion PF decreases. As a result, in addition to the four corner portions PC, the edge portion PS can also be cooled along the column direction ( Figure 6 Uneven drying at the end of the coating film extending 90° in the (y-direction) direction (DV) Figure 6 To suppress it.

[0135] In this first decompression process, the target temperature of the cooling area of ​​the cooling surface 40a is set to the temperature at which the solvent vapor of the coating film 90 condenses when the pressure inside the chamber 10 is at the first target pressure. More specifically, the target temperature of the cooling area of ​​the cooling surface 40a is set to be less than or equal to the temperature at which the pressure in the solvent vapor pressure curve is the first target pressure. As a result, the solvent vapor inside the chamber 10 mainly condenses in the cooling area of ​​the cooling surface 40a of the cooling section 40. That is, the liquid solvent 91 ( Figure 13 The condensate mainly adheres to the cooling area of ​​the cooling surface 40a. Therefore, the condensation on the cooling surface 40a tends to increase in the relatively cooler parts of the cooling surface 40a, i.e., the cooling area. In this embodiment, because the cooling area of ​​the cooling surface 40a surrounds region AF, the condensate around region AF... Figure 10The amount of condensation in the cooling surface 40a is prone to increase. As mentioned above, in this embodiment, the cooling area is only a part of the cooling surface 40a. If, unlike in this embodiment, the entire cooling surface 40a is subjected to strong cooling, the proportion of solvent vapor evaporating from the coating film 90 condensing on the cooling surface 40a will increase. As a result, excessive condensation is likely to occur in the vacuum drying apparatus. In contrast, in this embodiment, because the inner region AI of the cooling surface 40a... Figure 10 Since the inner region AI is not actively cooled, the temperature of the inner region AI can be set to a higher temperature. Therefore, condensation can be prevented from occurring in the inner region AI of the cooling surface 40a, or even if condensation occurs, the amount of condensation can be significantly reduced. Thus, excessive condensation due to cooling in the vacuum drying apparatus 1 can be avoided.

[0136] Next, for example, if the pressure inside chamber 10 reaches the first target pressure, the depressurization drying apparatus 1 performs a second interval adjustment process (step S5). The second interval adjustment process is a process of setting the interval between the substrate 9 and the cooling surface 40a as 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 in the lowered position H2, the substrate 9 is located below the upper end of the side rectifier plate 51.

[0137] Next, the pressure-reducing drying apparatus 1 performs a second pressure-reducing process (step S6: equivalent to the second process). The second pressure-reducing process involves lowering the pressure inside chamber 10 to a second pressure (hereinafter referred to as the second target pressure) that is lower than the first target pressure. Specifically, the control unit 80 causes the pressure-reducing mechanism 30 to draw gas from chamber 10 at a second suction flow rate greater than the first suction flow rate, thereby reducing the pressure inside 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 pressure-reducing process. The pressure inside chamber 10 decreases to the second target pressure at a rate higher than the rate of decrease during the first pressure-reducing process. During the second pressure-reducing process, the pressure-reducing drying apparatus 1 can maintain the pressure inside chamber 10 at the second target pressure for a specified period. The second target pressure is, for example, less than 10 kPa and greater than or equal to 0.1 Pa.

[0138] In step S6, for example, the control unit 80 can independently and appropriately control the opening and closing states of each of the plurality of independent valves Va, Vb, Vc, and Vd. This allows for control of the airflow within the chamber 10 to suppress uneven drying of the substrate 9.

[0139] Figure 14 This is a diagram illustrating an example, roughly representing the conditions within chamber 10 during the second decompression process. (See diagram for example.) Figure 14As shown, in the second state where the support 20 is in 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 process, solvent vapor from the coating film 90 flows upward more easily and is less likely to cause solvent vapor stagnation. Because the upper space 10s1 is large, the pressure in the upper space 10s1 can be reduced to the second target pressure more appropriately and quickly.

[0140] Furthermore, in the second state, the substrate 9 supported by the support portion 20 is surrounded by four side rectifier plates 51. Therefore, the rectification function of the side rectifier plates 51 acts on the upper space 10s1 between the substrate 9 and the cooling surface 40a. That is, the side rectifier plates 51 can suppress the concentration of airflow towards the periphery of the substrate 9. Therefore, in the second state, although the suppression effect of drying unevenness DV obtained by cooling is small because the distance between the cooling surface 40a and the first surface F1 of the substrate 9 is large, the drying unevenness DV can be suppressed by controlling the airflow.

[0141] If the pressure inside chamber 10 reaches the second target pressure, the solvent in the coating film 90 boils, and the drying of the coating film 90 proceeds at a higher rate. The pressure reduction mechanism 30 can draw gas from the chamber 10 to keep the pressure inside the chamber 10 approximately constant at the second target pressure. That is, the pressure reduction mechanism 30 can maintain the pressure inside the chamber 10 at the second target pressure for a specified period. In this embodiment, during the second pressure reduction process, the solvent 91 adhering to the cooling surface 40a also evaporates. In other words, the target temperature of the cooling surface 40a is set to the temperature at which the solvent evaporates to the extent that the pressure inside the chamber 10 is at the second target pressure. As a more specific example, the target temperature of the cooling surface 40a is set to be greater than or equal to the temperature at which the pressure is at the second target pressure in the solvent's vapor pressure profile.

[0142] Solvent vapor from the coating film 90 and the cooling surface 40a flows from the upper end of the side rectifier plate 51 into the space between the side rectifier plate 51 and the side wall portion 12 of the chamber 10, and is discharged to the outside through exhaust ports 16a, 16b, 16c, and 16d. Figure 14 In the diagram, dashed arrows schematically represent the flow of these solvent vapors.

[0143] If the boiling of the coating film 90 ends, that is, if a predetermined period has elapsed, the pressure reduction mechanism 30 can further reduce the pressure inside the chamber 10. In other words, the pressure reduction mechanism 30 can reduce the pressure inside the chamber 10 to a third target pressure lower than the second target pressure. As a result, the coating film 90 and the cooling surface 40a can be dried more reliably.

[0144] 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 inside the chamber 10 less than or equal to the second target pressure. Thus, in the second decompression process, the decompression drying device 1 can not only dry the coating film 90 on the first surface F1 of the substrate 9, but also dry the cooling surface 40a.

[0145] If both the coating film 90 and the cooling surface 40a are sufficiently dry, the control unit 80 opens the gas supply valve Vf. As a result, gas is supplied from the gas supply source 62 through the gas supply pipe 61 and the gas supply port 16f to the internal space 10s of the chamber 10 (step S7). Consequently, the pressure inside the chamber 10 rises again to atmospheric pressure.

[0146] Furthermore, for example, finally, the substrate 9 is removed from the chamber 10 (step S8). In step S8, for example, firstly, under the control of the control unit 80, the gate 15 opens the loading / unloading outlet 14, and the transport robot (not shown) moves the dried substrate 9, placed on the support unit 20, out of the chamber 10 via the loading / unloading outlet 14. This completes the decompression drying process on one substrate 9.

[0147] <1-3. Summary of Effects>

[0148] The cooling section 40 is configured such that the four corner regions AC of the cooling surface 40a are ( Figure 10 The temperature of ) is higher than that of the inner region AI of the cooling surface 40a. Figure 10 The temperature of PC is low. Therefore, in the effective area AE of substrate 9, the four corners of PC ( Figure 9 The viscosity of the coating film 90 is increased. In other words, the flowability of the coating film 90 is reduced in the four corner portions PC of the effective area AE of the substrate 9. As a result, the uneven drying DV that easily occurs in the four corner portions PC of the substrate 9 can be reduced. Figure 8 This can be suppressed. It should be noted that the effect can also be achieved through other implementation methods described later.

[0149] On the other hand, cooling of the substrate 9 sometimes leads to condensation within the reduced-pressure drying apparatus 1. If the amount of condensation is excessive, it can have adverse effects on the implementation of the reduced-pressure drying method; for example, if condensation falls onto the substrate 9, it can damage the quality of products using the substrate 9. Although condensation can be removed by sufficiently extending the drying time under reduced pressure, this can easily lead to an excessive reduction in production efficiency. In particular, in industrial applications, the reduced-pressure drying apparatus 1 is typically operated repeatedly without long intervals, resulting in the accumulation of excessive condensation even if the amount of condensation is small in a single operation, due to repeated operation. Regarding this condensation problem, according to this embodiment, as described above, the cooling section 40 is configured such that the four corner regions AC ( Figure 10The temperature of ) is higher than that of the inner region AI of the cooling surface 40a. Figure 10 The temperature is low. Therefore, it helps to suppress uneven drying (DV). Figure 8 From the perspective of ), even if the effective area AE of the substrate 9 is sufficiently cooled, the four corner portions PC ( Figure 9 It can also avoid overcooling the inner part PI of the effective area AE of the substrate 9. Figure 9 Therefore, excessive condensation on the cooling surface 40a of the cooling section 40 can be avoided. In summary, according to this embodiment, even when cooling is used to suppress uneven drying, excessive condensation on the cooling surface 40a of the cooling section 40 can be avoided.

[0150] In particular, according to the vacuum drying apparatus 1 of this embodiment, a surrounding area AF (of cooling surface 40a) is provided. Figure 10 The temperature of ) is lower than that of the inner region AI of the cooling surface 40a. Figure 10 The temperature of the substrate 9 is thus reduced. This not only suppresses the temperature of the four corner portions of the PC (in the effective area AE of the substrate 9) Figure 9 The uneven drying DV of the PC at the four corners can also suppress uneven drying near the outer edge of the effective area AE outside the four corners of the PC. Specifically, it can not only be achieved in the four corners of the PC, but also in the edge area PS ( Figure 9 ) along the column direction ( Figure 6 Uneven drying at the end of the coating film extending 90° in the (y-direction) direction (DV) Figure 6 To suppress it.

[0151] Additionally, cooling surface 40a ( Figure 1 The coating film 90 is opposite to the first surface F1 of the substrate 9. This allows for effective cooling of the coating film 90 on the first surface F1. Figure 6 ).

[0152] Furthermore, the top surface of the chamber 10 corresponds to the cooling surface 40a of the cooling section 40. Therefore, there is no need to prepare a special chamber, and the cooling section 40 can be constructed using a general chamber 10.

[0153] Furthermore, the support portion 20 can be used not only for moving the substrate 9 in and out, but also for adjusting the gap between the substrate 9 and the cooling surface 40a. Therefore, there is no need to provide a dedicated mechanism for gap adjustment only.

[0154] According to the reduced pressure drying method of this embodiment, the substrate 9 is cooled so that the four corner portions PC of the effective area AE of the substrate 9 ( Figure 9 The temperature of ) is lower than that of the inner part of the effective area AE of substrate 9, PI( Figure 9The temperature of the effective area AE of the substrate 9 is thus adequately cooled. This allows for sufficient cooling of the four corner portions PC of the effective area AE of the substrate 9, without over-cooling the inner portion PI of the effective area AE of the substrate 9. Firstly, by adequately cooling the four corner portions PC of the effective area AE of the substrate 9, the uneven drying (DV) that easily occurs in the corner portions PC can be effectively reduced. Figure 8 The control is performed. Secondly, by not overcooling the inner portion PI of the effective region AE of the substrate 9, excessive condensation can be avoided in the apparatus used for vacuum drying. As described above, it is possible to both suppress uneven drying and avoid excessive condensation in the vacuum drying apparatus 1. It should be noted that this effect can also be obtained through other embodiments described later.

[0155] <2. Second Implementation Method>

[0156] Figure 15 This is a diagram schematically showing an example of the upper surface of the vacuum drying apparatus 1A according to the second embodiment. This is in contrast to the case of the first embodiment described above (see...). Figure 10 Similarly, the cooling section 40 of the vacuum drying apparatus 1A in this embodiment ( Figure 15 (The overall structure is not shown) is configured such that the temperature of the four corner regions AC of the cooling surface 40a is lower than the temperature of the inner region AI of the cooling surface 40a. On the other hand, in this embodiment, the cooling section 40 is configured such that the temperature of the four corner regions AC of the cooling surface 40a is lower than the temperature of the edge regions AS of the cooling surface 40a. Specifically, the maximum value of the temperature distribution in the four corner regions AC can be set lower than the minimum value of the temperature distribution in the edge regions AS. In other words, in this embodiment, the four corner regions AC of the cooling surface 40a are essentially the cooling regions (…). Figure 15 (Mid-shaded area).

[0157] By providing a cooling mechanism MC that selectively cools the four corner regions AC of the cooling surface 40a, which are the cooling areas in this embodiment, the temperature difference in the cooling surface 40a as described above can be achieved. Furthermore, as a result of the cooling mechanism MC, some additional cooling can be applied to areas other than the four corner regions AC, but the four corner regions AC are cooled more powerfully than these other areas. The cooling mechanism MC that selectively cools the four corner regions AC as described above can, for example, be implemented in such a way that, when viewed from above, the refrigerant flow path 41a (… Figure 1 The cooling member 41 is positioned in the four corner regions AC, but not in the side regions AS and the inner region AI. Furthermore, in this case, the refrigerant flow path 41a does not need to be positioned in the outer region AO. As a variation, when viewed from above, the cooling member 41 can be positioned in the four corner regions AC, but not in the side regions AS and the inner region AI. Furthermore, in this case, the cooling member 41 does not need to be positioned in the outer region AO.

[0158] According to this embodiment, the temperature of the four corner regions AC of the cooling surface 40a is lower than the temperature of the edge regions AS of the cooling surface 40a. In other words, the temperature of the edge regions AS of the cooling surface 40a is higher than the temperature of the four corner regions AC. Therefore, it is possible to avoid unnecessarily lowering the temperature of the edge regions AS. As a result, it is possible to more effectively prevent excessive condensation from occurring on the cooling surface 40a of the cooling section 40.

[0159] <3. Third Implementation Method>

[0160] Figure 16 This is a diagram schematically showing an example of the upper surface of the vacuum drying apparatus 1B according to the third embodiment. This is in contrast to the case of the first embodiment described above (see...). Figure 10 Similarly, the cooling section 40 of the pressure-reducing drying apparatus 1B in this embodiment ( Figure 16 The overall structure (not shown in the diagram) is configured such that the temperature of the four corner regions AC of the cooling surface 40a is lower than the temperature of the inner region AI of the cooling surface 40a. For cooling purposes, in the first embodiment ( Figure 10 In this embodiment, a single cooling mechanism MF capable of being set to a temperature below room temperature is sufficient. However, in this embodiment, to cool the cooling surface 40a, the cooling unit 40 includes a plurality of cooling mechanisms capable of being set to a temperature below room temperature. The plurality of cooling mechanisms includes a main cooling mechanism MF, which, when viewed from above, is located at the outer edge of the effective area AE of the substrate 9. Figure 16 The overlapping position of the double-dotted lines; at least one secondary cooling mechanism MZ, which, when viewed from above, is located at the outer edge of the effective area AE of the substrate 9, and can be set to a temperature higher than that of the cooling mechanism MF. Figure 16 In the example shown, the secondary cooling mechanism MZ includes: a cooling mechanism MIa that cools the inner side of the cooling area of ​​the cooling mechanism MF; a cooling mechanism MIb that cools the inner side of the cooling area of ​​the cooling mechanism MIa; a cooling mechanism MOa that cools the outer side of the cooling area of ​​the cooling mechanism MF; and a cooling mechanism MOb that cools the outer side of the cooling area of ​​the cooling mechanism MOa. If the set temperature of the cooling mechanisms is exemplified by the difference from room temperature (e.g., 20 degrees Celsius), then the set temperature of the cooling mechanism MF is -10 degrees Celsius, the set temperature of the cooling mechanism MIa is -8 degrees Celsius, the set temperatures of the cooling mechanisms MIb and MOa are -6 degrees Celsius, and the set temperature of the cooling mechanism MOb is -2 degrees Celsius. A plurality of the cooling mechanisms can be configured to independently adjust their set temperatures.

[0161] According to this embodiment, it is possible to locally and forcefully target the outer edge of the effective region AE of the substrate 9. Figure 16The double-dotted lines in the image are cooled, and the surrounding area is moderately cooled. This strong cooling effectively addresses the uneven drying (DV) that easily occurs in the effective area AE of substrate 9, particularly in the corner PC areas. Figure 8 In addition to suppressing condensation, the cooling of the latter also suppresses uneven drying in the inner portion PI of the effective area AE of the substrate 9. Furthermore, by appropriately setting the cooling of the latter to be slight, excessive condensation on the cooling surface 40a of the cooling section 40 can be avoided (see...). Figure 13 Solvent 91 in it.

[0162] <4. Fourth Implementation Method>

[0163] Figure 17 This is a diagram showing an example of a longitudinal section of the vacuum drying apparatus 1C according to the fourth embodiment. Except for the second lifting section 45, the structure of the vacuum drying apparatus 1C is the same as that of the vacuum drying apparatus 1 (…). Figure 1 The first embodiment is the same. The second lifting part 45 moves the cooling member 41 of the cooling part 40 up and down between the cooling position H3 and the separation position H4. The cooling position H3 is the position where the lower surface of the cooling member 41 contacts the upper surface of the top plate portion 13 of the chamber 10, and the separation position H4 is the position where the cooling member 41 leaves the top plate portion 13. Figure 17 In the example, the cooling component 41 located at the separation position H4 is schematically represented by an imaginary line. For example, the second lifting unit 45 is driven by a linear motor or cylinder or similar device.

[0164] Figure 18 This is a flowchart illustrating an example of the vacuum drying process according to the fourth embodiment. Here, for example, it is performed sequentially. Figure 18 The processing of steps S11 to S19. The cooling component 41 is initially located in the cooling position H3.

[0165] First, the reduced pressure drying device 1C sequentially executes steps S11 to S15. Steps S11 to S15 are respectively related to steps S1 to S5 (…). Figure 12 The first embodiment is the same. However, the cooling action of the cooling section 40 on the cooling surface 40a can be essentially completed in step S15.

[0166] After step S15, the pressure-reducing drying apparatus 1C performs a cooling section separation process (step S16). The cooling section separation process is a process that moves the cooling section 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 departure position H4. As the cooling member 41 rises to the separation position H4, the cooling operation on the cooling surface 40a is substantially interrupted.

[0167] Next, the reduced pressure drying apparatus 1C proceeds to steps S17 to S19. Steps S17 to S19 are respectively related to steps S6 to S8. Figure 12 The first implementation method is the same.

[0168] As described above, according to the fourth 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 1C can be used with the decompression drying device 1 ( Figure 1 The cooling surface 40a is cooled in a substantially similar manner to the first embodiment. However, according to this fourth embodiment, in the second decompression process (step S17), the cooling member 41 rises to the separation position H4. Therefore, the cooling operation on the cooling surface 40a can be substantially interrupted during the second decompression process. As the cooling member 41 moves away from the cooling surface 40a, the temperature of the cooling surface 40a rises over time, thus promoting the evaporation of the solvent 91 condensed on the cooling surface 40a. This further suppresses the accumulation of condensation.

[0169] <5. Fifth Implementation Method>

[0170] Figure 19 This is a diagram showing an example of a longitudinal section of the vacuum drying apparatus 1D according to the fifth embodiment. Except for the internal structure of the cooling section 40, the structure of the vacuum drying apparatus 1D is the same as that of the vacuum drying apparatus 1 (…). Figure 1 The first implementation method is the same.

[0171] like Figure 19 As shown, a portion of the cooling section 40 of the vacuum drying apparatus 1D is embedded in the top plate portion 13 of the chamber 10. This portion of the cooling section 40 embedded in the top plate portion 13 is a low-temperature portion that absorbs heat from the top plate portion 13. Thus, the top plate portion 13 functions as a cooling member 41. The top plate portion 13 may also be formed of a material with high thermal conductivity (e.g., metal). Figure 19 In this example, a refrigerant flow path 41a, which is part of the cooling section 40, is formed inside the top plate portion 13. The refrigerant flow path 41a, when viewed from above, can extend in a meandering or spiral shape inside the top plate portion 13. Figure 19 In this example, the inlet 41b and outlet 41c of the refrigerant flow path 41a are formed on the upper surface of the top plate portion 13. The inlet 41b is connected to the downstream end of the first refrigerant pipe 42, and the outlet 41c is connected to the upstream end of the second refrigerant pipe 43. The refrigerant cooling source 44 cools the refrigerant and circulates it, thereby cooling the top plate portion 13 of the chamber 10. That is, it can cool the lower surface of the top plate portion 13, i.e., the cooling surface 40a.

[0172] Furthermore, an example of the process for vacuum drying using vacuum drying apparatus 1D is the same as that in the first embodiment.

[0173] According to this embodiment, the top plate portion 13 functions as a cooling member 41. Therefore, the number of components in the depressurization drying device 1D can be reduced, the size of the depressurization drying device 1D can be reduced, and the manufacturing cost can be lowered. In addition, since the interval between the refrigerant flow path 41a and the cooling surface 40a can be reduced, the cooling portion 40 can cool the cooling surface 40a more efficiently.

[0174] <6. Sixth Implementation Method>

[0175] Figure 20 This is a diagram showing an example of a longitudinal section of the vacuum drying apparatus 1E according to the sixth embodiment. Except for the internal structure of the cooling section 40, the structure of the vacuum drying apparatus 1E is the same as that of the vacuum drying apparatus 1 (…). Figure 1 The first implementation method is the same.

[0176] like Figure 20 As shown, a portion of the cooling section 40 of the vacuum drying apparatus 1E is located within the internal space 10s of the chamber 10. Specifically, the cooling member 41 is located within the internal space 10s of the chamber 10. Within the chamber 10, the cooling member 41 is positioned opposite the first surface F1 of the substrate 9 supported by the support portion 20. That is, the cooling member 41 is positioned above the substrate 9 supported by the support portion 20. The cooling member 41 is positioned within the chamber 10 in a vertical orientation along its thickness direction. The cooling member 41 is fixed to the chamber 10 by a fixing portion (not shown). The cooling member 41 can be fixed to the top plate portion 13 of the chamber 10, for example, using a fixing portion such as screws. In the sixth embodiment, the lower surface of the cooling member 41 corresponds to the cooling surface 40a. Figure 20 In this example, the first refrigerant pipe 42 and the second refrigerant pipe 43 pass through the top plate portion 13, and the refrigerant cooling source 44 is disposed outside the chamber 10. The refrigerant cooling source 44 cools the refrigerant and circulates it, thereby cooling the cooling member 41. That is, it can cool the cooling surface 40a of the cooling member 41.

[0177] Furthermore, an example of the process for vacuum drying using vacuum drying apparatus 1E is the same as that for vacuum drying in the first embodiment.

[0178] According to this embodiment, the cooling surface 40a is a different lower surface from the cooling member 41 of the chamber 10. Therefore, the material of the cooling member 41 having the cooling surface 40a can be selected separately from the specifications of the chamber 10. In other words, the selectivity of the material for the cooling member 41 can be improved. In addition, since the cooling surface 40a is the lower surface of the cooling member 41, the distance between the low-temperature portion of the cooling section 40 (here, the refrigerant flow path 41a) and the cooling surface 40a can be reduced. Therefore, the cooling section 40 can cool the cooling surface 40a more efficiently.

[0179] <7. Seventh Implementation Method>

[0180] Figure 21 This is a diagram showing an example of a longitudinal section of the vacuum drying apparatus 1F according to the seventh embodiment. Except for the object being lifted by the first lifting unit 100, the structure of the vacuum drying apparatus 1F is similar to that of the vacuum drying apparatus 1E. Figure 20 The sixth implementation method is the same. Figure 21 As shown, the first lifting section 100 raises and lowers the cooling section 40. Specifically, the first lifting section 100 raises and lowers the cooling member 41 of the cooling section 40 between a raised position H11 and a lowered position H12. The lowered position H12 is the position of the cooling member 41 when the distance between the substrate 9 and the cooling surface 40a is a first interval. Figure 21 In the diagram, the cooling member 41 at the lowered position H12 is represented by an imaginary line. The raised position H11 is the position of the cooling member 41 when the distance between the substrate 9 and the cooling surface 40a is the second distance. That is, the first lifting part 100 causes the cooling member 41 to move up and down between a first state and a second state. In the first state, the distance between the substrate 9 and the cooling surface 40a is the first distance; in the second state, the distance between the substrate 9 and the cooling surface 40a is the second distance.

[0181] like Figure 21 As shown, the support portion 20 is located at the lowered position H2 described in the first to sixth embodiments. That is, the substrate 9 supported by the support portion 20 is located below the upper end of the side rectifier plates 51 and is surrounded by the four side rectifier plates 51. In the seventh embodiment, in the first state where the interval between the substrate 9 and the cooling surface 40a is a first interval and in the second state where the interval between the substrate 9 and the cooling surface 40a is a second interval, the substrate 9 is surrounded by the four side rectifier plates 51.

[0182] The lowered position H12 can be a position where the cooling surface 40a of the cooling component 41 is lower than the upper end of the side fairing 51. That is, when viewed from above, the size of the cooling component 41 is smaller than the size of the space surrounded by the four side fairings 51.

[0183] The rising position H11 is a position where the cooling surface 40a of the cooling member 41 is higher than the upper end of the side rectifier plate 51. When the cooling member 41 is in the rising position H11, the distance between the cooling surface 40a and the upper end of the side rectifier plate 51 can be, for example, greater than or equal to twice the first distance, or greater than or equal to five times the first distance. Therefore, gas directly above the substrate 9 can easily flow from the upper end of the side rectifier plate 51 into the space between the side rectifier plate 51 and the side wall portion 12 of the chamber 10.

[0184] For example, the first lifting unit 100 employs a drive device such as a linear motor or a cylinder. The main body 100a of the first lifting unit 100 is fixed to a device frame (not shown) outside the chamber 10. The moving part 100b of the first lifting unit 100 is capable of moving vertically relative to the main body 100a. The moving part 100b may be a rod-shaped member. The moving part 100b is provided, for example, with a through hole 13h penetrating the top plate 13 of the chamber 10. Furthermore, for example, a cooling member 41 is fixed to the lower end of the moving part 100b. Here, for example, if a bellows or similar conduit 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.

[0185] An example of the vacuum drying process using vacuum drying apparatus 1F is the same as the vacuum drying process in the first embodiment. However, the process is adjusted at the first interval ( Figure 12 In step S3), the first lifting unit 100 lowers the cooling member 41 to the lowered position H12, so that the gap between the substrate 9 and the cooling surface 40a is the first gap. Additionally, in the second gap adjustment process... Figure 12 In step S5), the first lifting part 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.

[0186] According to the seventh embodiment, the cooling member 41 is a separate member from the chamber 10. Therefore, similar to the sixth embodiment, the selectivity of the material for the cooling member 41 can be improved. In addition, since the cooling surface 40a is the lower surface of the cooling member 41, similar to the sixth embodiment, the cooling section 40 can cool the cooling surface 40a more efficiently.

[0187] Furthermore, in the seventh embodiment, even in the first state where the interval between the substrate 9 and the cooling surface 40a is narrower, the substrate 9 supported by the support portion 20 is still surrounded by four side rectifier plates 51. Therefore, during the first decompression process ( Figure 12 In step S4), the rectification function of the four side rectifier plates 51 also acts on the upper space 10s1 between the substrate 9 and the cooling surface 40a. Therefore, it is possible to further suppress the occurrence of uneven drying.

[0188] Furthermore, in this seventh embodiment, the first lifting portion 100 raises and lowers the support portion 20. However, as a variation, the first lifting portion 100 can raise and lower both the support portion 20 and the cooling surface 40a. In short, as long as the first lifting portion 100 raises and lowers at least one of the support portion 20 and the cooling surface 40a between a first state and a second state, in the first state, the distance between the substrate 9 supported by the support portion 20 and the cooling surface 40a is a first distance; in the second state, the distance between the substrate 9 supported by the support portion 20 and the cooling surface 40a is a second distance wider than the first distance.

[0189] <8. Eighth Implementation>

[0190] Figure 22 This is a diagram schematically showing an example of the upper surface of the vacuum drying apparatus 1G according to the eighth embodiment. Except for the internal structure of the cooling section 40, the structure of the vacuum drying apparatus 1G is the same as that of the vacuum drying apparatus 1 (…). Figure 1 Similar to the first embodiment. Specifically, instead of the cooling member 41 having the cooling surface 40a ( Figure 1 First embodiment), vacuum drying apparatus 1G ( Figure 22 The cooling component 41M has a cooling surface 40a. The temperature distribution of the cooling surface 40a of the cooling component 41M can be compared with that of the cooling component 41M. Figure 1 The temperature distribution of the cooling surface 40a in the first embodiment is the same. The cooling surface 40a of the cooling member 41M is different from the cooling surface 40a of the cooling member 41, and is opposite to the second surface F2 (lower surface) of the substrate 9.

[0191] In addition, although Figure 22 The diagram is omitted, but the vacuum drying apparatus 1G has a support portion that functions the same as the support portion 20 of the vacuum drying apparatus 1. Similar to the first embodiment, this support portion can be positioned in the raised position H1 and the lowered position H2 (see...). Figure 1 The support can move up and down between chambers 10. In addition, similar to the first embodiment, the support is configured to move the substrate 9 into and out of chamber 10.

[0192] Furthermore, the cooling section 40 of the pressure-reducing drying device 1G is configured such that the cooling member 41 is raised and lowered in conjunction with the raising and lowering of the aforementioned support section. Additionally, although in Figure 22 The illustration is omitted, but it is related to the vacuum drying device 1 ( Figure 1Similarly, the cooling section 40 of the pressure-reducing drying apparatus 1G may also include a refrigerant flow path 41a, a first refrigerant pipe 42, a second refrigerant pipe 43, and a refrigerant cooling source 44. Furthermore, in this embodiment, the first refrigerant pipe 42 and the second refrigerant pipe 43 penetrate the top plate section 13.

[0193] According to this embodiment, by utilizing the structure in which the cooling surface 40a faces the second surface F2 of the substrate 9, it is possible to suppress uneven drying and avoid excessive condensation on the cooling surface 40a of the cooling section 40 in a manner substantially similar to that of the first embodiment.

[0194] <9. Variations>

[0195] The present invention is not limited to the above-described embodiments and their variations. Various changes and improvements can be made without departing from the spirit of the present invention.

[0196] To cool cooling surface 40a (see...) Figure 1 In the embodiments described above, the cooling unit 40 uses a refrigerant, but the cooling principle of the cooling unit is not limited. For example, instead of a structure using a refrigerant, a structure utilizing Peltier elements can be adopted. In this case, the cooling unit in the embodiments described above can be constructed by optimizing at least one of optimizing the position of the Peltier elements when viewed from above and optimizing the temperature control of the plurality of Peltier elements. The method of installing the Peltier elements is not particularly limited; for example, they can be embedded in the top plate portion 13.

[0197] If so Figure 5 and Figure 6 As shown, when the coating film 90 is formed only in a portion of the effective area AE of the substrate 9 under a state where its flow direction is restricted, the resulting reduction in drying unevenness (DV) is achieved. Figure 8 The effect is particularly significant, but even when the coating film 90 is formed over the entire effective area AE of the substrate 9, the effect of reducing uneven drying can be expected by employing the reduced pressure drying described in the above embodiments.

[0198] Chamber 10 (see Figure 1 It has four exhaust ports 16a, 16b, 16c, and 16d, but the number of exhaust ports is arbitrary. Furthermore, if the effect obtained using independent valves Va, Vb, Vc, and Vd is not required, these independent valves can be omitted.

[0199] Chamber 10 (see Figure 3The side wall portion 12 is provided with a loading outlet 14 for the substrate 9, but the location of the loading outlet is not limited to this. For example, the following structure can be adopted: the four side wall portions 12 and the top plate portion 13 of the chamber 10 form an integral cover portion, which can be separated from the bottom plate portion 11 and retracted upward. In this case, for example, the cover portion can be moved up and down using an opening and closing drive portion 16, etc. Furthermore, 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 (closed state); and a state in which the cover portion separates from the bottom plate portion 11 upward and opens the internal space 10s (open state). Here, if the chamber 10 is in the 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. If the chamber 10 is closed, the coating film 90 on the substrate 9 can be dried by depressurization through exhaust from the internal space 10s and supplying air to the internal space 10s.

[0200] The specific structure of the support part 20 (see) Figure 2 and Figure 3 (This is an example; other general support components can be used. For instance, multiple support plates 21 can be a single, integral support plate 21.)

[0201] If the bottom rectifier plate 50 is not required (see below) Figure 1 If the desired effect is achieved, the bottom fairing 50 can be omitted. If the side fairing 51 is not needed (see...),... Figure 1 The side rectifier plate 51 can be omitted if the desired effect is achieved.

[0202] Reduced pressure drying device 1 (see Figure 1 Various actions in the depressurization drying device 1 can be started or stopped based on user operation of the input unit 804 or signals input from external devices to the communication unit 806.

[0203] In control unit 80 (see Figure 11 In this context, at least a portion of the functional structure can also be implemented using dedicated electronic circuits or other hardware.

[0204] Furthermore, it goes without saying that all or part of the structures of the above-described embodiments and various modifications can be appropriately combined within a non-contradictory scope.

Claims

1. A reduced pressure drying apparatus that dries a coating film coated on an effective area of an upper surface of a substrate having a rectangular shape, wherein, having: a chamber that accommodates the substrate; a pressure reduction mechanism that draws gas from the chamber to reduce the pressure in the chamber; a support portion that supports the substrate in the chamber; and a cooling portion that cools a cooling surface opposite the substrate supported by the support portion, the cooling surface of the cooling portion includes: an inner side region opposite an inner side portion of the substrate that departs inward from an outer edge of the effective region; and a corner region opposite a corner portion of the effective region of the substrate, the cooling portion is configured so that the temperature of the corner region of the cooling surface is lower than the temperature of the inner side region of the cooling surface, the cooling surface is opposite the upper surface of the substrate, the pressure reduction drying device further has a lifting portion that lifts the support portion so that the interval between the cooling surface of the cooling portion and the substrate can be either a first interval of 10 mm or less or a second interval wider than the first interval.

2. The pressure reduction drying device according to claim 1, wherein the cooling surface of the cooling portion includes a surrounding region that includes the corner region and surrounds the inner side region, the cooling portion is configured so that the temperature of the surrounding region of the cooling surface is lower than the temperature of the inner side region of the cooling surface.

3. The pressure reduction drying device according to claim 1 or 2, wherein the cooling portion includes a plurality of cooling mechanisms that can be set to a temperature lower than room temperature in order to cool the cooling surface, the plurality of cooling mechanisms include: a main cooling mechanism that, when viewed from above, is located at a position overlapping the outer edge of the effective region of the substrate; and at least one sub cooling mechanism that, when viewed from above, is located at a position departing from the outer edge of the effective region of the substrate and can be set to a temperature higher than the temperature of the main cooling mechanism. including: a) a step of arranging the substrate coated with the coating film in a chamber; and 4. A reduced pressure drying method for drying a coating film coated on an effective area of an upper surface of a substrate having a rectangular shape, wherein b) a step of drying the coating film by reducing the pressure in the chamber after the a) step, in the b) step, a step of cooling the substrate so that the temperature of a corner portion of the effective region of the substrate is lower than the temperature of an inner side portion of the substrate that departs inward from an outer edge of the effective region, and increasing the viscosity of the coating film on the corner portion by cooling the corner portion, thereby suppressing drying unevenness that occurs in the corner portion, the step of cooling the substrate in the b) step includes an interval of 10 mm or less between a cooling surface of a cooling portion used to cool the substrate and the substrate. ​ ​ ​

Images