JP2023006342A - Vacuum dryer, and vacuum drying method - Google Patents

Abstract

To provide a vacuum dryer and a vacuum drying method capable of drying a coating layer formed on the upper surface of a substrate so that its thickness becomes uniform.SOLUTION: The vacuum dryer supplies a chamber with gas by driving an air supply mechanism while temporarily stopping a pressure reducing mechanism, in a vacuum drying process of drying a coating layer by driving a pressure reducing mechanism to reduce the inner pressure of the chamber to a prescribed target value of the pressure. Thereby, the viscosity of a coating liquid can be made uniform in the coating layer, and a reflow can be generated in the coating liquid whose fluidity is decreased according to the progress of the drying. As a result, the coating layer can more uniformly be dried while suppressing the fluctuation in the thickness of the coating layer.SELECTED DRAWING: Figure 8

Description

TECHNICAL FIELD The present invention relates to a reduced pressure drying apparatus and a reduced pressure drying method for drying a coating layer formed on an upper surface of a substrate under reduced pressure.

Conventionally, in the manufacturing process of an organic EL display, a coating layer that serves as a hole injection layer, a hole transport layer, or a light emitting layer is formed on the upper surface of a substrate. The coating layer is partially applied to the upper surface of the substrate by an inkjet device. Then, the substrate on which the coating layer is formed is transported into the chamber of the reduced pressure drying device and undergoes reduced pressure drying processing. As a result, the solvent contained in the coating layer evaporates and the coating layer dries.

A vacuum drying apparatus includes a chamber for housing a substrate and a vacuum mechanism for sucking gas from the chamber. A conventional vacuum drying apparatus is described in Patent Document 1, for example.

JP 2011-86389 A

Patent Literature 1 describes a problem that when a coating liquid filled in a bank formed on a substrate is dried under reduced pressure, the film thickness tends to be uneven within the bank. In addition, when the coating solution applied on the substrate is dried, there is a problem that the coating layer is not formed uniformly due to poor drying in the central portion of the substrate and abnormal film thickness at the edge portion of the substrate. It can happen.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vacuum drying apparatus and a vacuum drying method capable of drying a coating layer formed on the upper surface of a substrate so as to have a uniform thickness. With the goal.

In order to solve the above problems, a first invention of the present application is a reduced pressure drying apparatus for drying a coating layer containing a solvent formed on a surface of a substrate by reduced pressure, comprising: a chamber for accommodating the substrate; a decompression mechanism for sucking gas, an air supply mechanism for supplying gas into the chamber, and a controller for controlling the decompression mechanism and the air supply mechanism, wherein the controller drives the decompression mechanism and lowering the pressure in the chamber to a predetermined target pressure value to dry the coating layer. Gas is supplied into the chamber.

A second invention of the present application is the reduced-pressure drying apparatus according to the first invention, wherein the control unit reduces the pressure in the chamber to a predetermined target pressure value during the reduced-pressure drying process for drying the coating layer. p) a decompression step of driving the decompression mechanism and sucking gas in the chamber at a predetermined decompression rate; and q) after step p), driving the air supply mechanism to depressurize the chamber. and r) after the step q), a decompression step of driving the decompression mechanism and sucking the gas in the chamber at the decompression speed.

A third invention of the present application is the reduced pressure drying apparatus according to the second invention, wherein the controller performs, in the reduced pressure drying process, a) a first process of sucking gas in the chamber at a predetermined first pressure reduction rate; b) after the process a), a second process of sucking the gas in the chamber at a second depressurization rate higher than the first depressurization rate; and c) after the process b), the second decompression process. a third process of sucking the gas in the chamber at a third depressurization rate smaller than the depressurization rate or so that the pressure in the chamber becomes constant, and the control unit performs the process a) , said step p), said step q) and said step r) are performed in at least one of said process b) and said process c).

A fourth invention of the present application is the reduced-pressure drying apparatus of the third invention, wherein the control unit performs the step p), the step q) and the step r) at least in the process a), and performs the process In said step p) and said step r) in a), the decompression rate is said first decompression rate.

The fifth invention of the present application is the reduced pressure drying apparatus of the third invention, wherein the control unit performs the step p), the step q) and the step r) in the processing a) and the processing b), respectively. In the steps p) and r) in the process a), the depressurization rate is the first depressurization rate, and in the steps p) and the steps r) in the process b), the depressurization rate is the This is the second decompression rate.

A sixth invention of the present application is a reduced-pressure drying method for drying a coating layer containing a solvent formed on the upper surface of a substrate by a reduced-pressure drying process for reducing the pressure in a chamber, comprising: Q) after the step P), an air supply step of supplying the gas into the chamber; and R) after the step Q), the pressure in the chamber is reduced and a depressurization step of sucking gas.

A seventh invention of the present application is the reduced pressure drying method according to the sixth invention, wherein the reduced pressure drying process includes A) a first process of sucking the gas in the chamber at a predetermined first pressure reduction rate, and B) the process. After A), a second process of sucking the gas in the chamber at a second decompression rate that is greater than the first decompression rate, and C) after the process B), the decompression rate is less than the second decompression rate. and a third process of sucking the gas in the chamber at a third depressurization rate or so that the pressure in the chamber becomes constant, wherein the process A), the process B), and the process C). At least one includes said step P), said step Q) and said step R).

The eighth invention of the present application is the reduced pressure drying method of the seventh invention, wherein at least the process A) includes the process P), the process Q) and the process R), and the process P in the process A) ) and in step R), the depressurization rate is the first depressurization rate.

The ninth invention of the present application is the reduced pressure drying method of the seventh invention, wherein the treatment A) and the treatment B) respectively include the step P), the step Q) and the step R), and the treatment A In the step P) and the step R) in the process B), the decompression rate is the first decompression rate, and in the process P) and the step R) in the process B), the decompression rate is the second decompression rate. .

According to the first to ninth inventions of the present application, the viscosity of the coating liquid in the coating layer can be made uniform, and the coating liquid whose fluidity has decreased due to the progress of drying can be caused to reflow. As a result, variations in the thickness of the coating layer can be suppressed, and the coating layer can be dried more uniformly.

In particular, according to the fourth and eighth inventions of the present application, the air supply step is performed during the first process, which is the initial stage of the reduced-pressure drying process, so that the coating liquid is dried before the solvent in the coating liquid vaporizes. Clay and fluidity can be homogenized. As a result, variations in the thickness of the coating layer can be further suppressed, and the coating layer can be dried more uniformly.

In particular, according to the fifth and ninth inventions of the present application, the air supply step is performed in both the first treatment and the second treatment before the third treatment in which the evaporation of the solvent from the coating liquid is most active. Therefore, the variation in the thickness of the coating layer can be further suppressed, and the coating layer can be dried more uniformly.

It is a longitudinal cross-sectional view of a reduced-pressure drying device. It is a cross-sectional view of a reduced-pressure drying device. It is a perspective view of a board|substrate. 4 is a flow chart showing the flow of a reduced pressure drying process; FIG. 10 is a graph showing a recipe for changing atmospheric pressure in a chamber in conventional reduced-pressure drying processing; FIG. FIG. 10 is a diagram showing the state inside the chamber when the stage is placed at the raised position; FIG. 10 is a diagram showing the state inside the chamber when the stage is placed at the lowered position; 7 is a graph showing an atmospheric pressure change recipe in the chamber in the reduced pressure drying process of the first embodiment. 4 is a flowchart showing the flow of first processing of the first embodiment; FIG. 10 is a graph showing an atmospheric pressure change recipe in the chamber in the reduced pressure drying process of the second embodiment; FIG. It is a flow chart which shows the flow of the 1st processing of a 2nd embodiment. FIG. 11 is a graph showing an atmospheric pressure change recipe in the chamber in the reduced pressure drying process of the third embodiment; FIG. It is a flow chart which shows the flow of the 1st processing of a 3rd embodiment. FIG. 11 is a graph showing an atmospheric pressure change recipe in the chamber in the reduced pressure drying process of the fourth embodiment; FIG. FIG. 14 is a flow chart showing the flow of the first process of the fourth embodiment; FIG. FIG. 16 is a graph showing a recipe for changing the atmospheric pressure in the chamber in the reduced pressure drying process of the fifth embodiment; FIG. FIG. 14 is a flow chart showing the flow of first processing and second processing of the fifth embodiment; FIG. FIG. 16 is a graph showing an atmospheric pressure change recipe in the chamber in the reduced pressure drying process of the sixth embodiment; FIG. FIG. 16 is a flow chart showing the flow of the first process and the second process of the sixth embodiment; FIG. FIG. 21 is a graph showing an atmospheric pressure change recipe in the chamber in the reduced pressure drying process of the seventh embodiment; FIG. FIG. 16 is a flow chart showing the flow of the first process and the second process of the seventh embodiment; FIG. FIG. 20 is a graph showing an atmospheric pressure change recipe in the chamber in the reduced pressure drying process of the eighth embodiment; FIG. FIG. 21 is a flow chart showing the flow of the first process and the second process of the eighth embodiment; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<1. About the configuration of the vacuum drying device>
FIG. 1 is a longitudinal sectional view of a reduced pressure drying apparatus 1 according to one embodiment of the present invention. FIG. 2 is a cross-sectional view of the reduced pressure drying apparatus 1. As shown in FIG. This reduced-pressure drying apparatus 1 is an apparatus for performing a reduced-pressure drying process on a substrate 9 in the manufacturing process of an organic EL display. A rectangular glass substrate is used for the substrate 9 . A coating layer containing an organic material and a solvent is partially formed in advance on the upper surface of the substrate 9 . The coating layer becomes a hole injection layer, a hole transport layer, or a light emitting layer of the organic EL display by being dried by the reduced pressure drying device 1 .

FIG. 3 is a perspective view of the substrate 9. FIG. The substrate 9 has a rectangular shape with different lengths and widths when viewed from above. As shown in FIG. 2, on the upper surface of the substrate 9, a plurality of circuit areas A1 forming a circuit pattern of the organic EL display are arranged. In the example of FIG. 2, four rectangular circuit areas A1 are arranged on the upper surface of the substrate 9 in a matrix of two rows and two columns. However, the shape, number, and arrangement of the circuit area A1 are not limited to this example. The coating layer is formed according to the circuit pattern in each circuit region A1 by an inkjet device in the coating process prior to the reduced pressure drying process. Therefore, each circuit area A1 has a portion covered with the coating layer and a portion exposed from the coating layer. A boundary area A2 between the adjacent circuit areas A1 is a portion exposed from the coating layer.

As shown in FIGS. 1 and 2, the vacuum drying apparatus 1 includes a chamber 10, a stage 20, a decompression mechanism 30, a bottom straightening plate 40, a side straightening plate 50, an air supply mechanism 60, a pressure gauge 70, and a controller 80. I have.

The chamber 10 is a pressure-resistant container having an internal space in which the substrate 9 is accommodated. The chamber 10 is fixed on an apparatus frame (not shown). The shape of the chamber 10 is a flat rectangular parallelepiped. The chamber 10 has a substantially square bottom plate portion 11 , four side wall portions 12 , and a substantially square top surface portion 13 . The four side wall portions 12 vertically connect the four edge sides of the bottom plate portion 11 and the four edge sides of the top surface portion 13 .

One of the four side walls 12 is provided with a loading/unloading port 14 and a shutter 15 for opening and closing the loading/unloading port 14 . The shutter 15 is connected to a shutter drive mechanism 16 composed of an air cylinder or the like. When the shutter drive mechanism 16 is operated, the shutter 15 moves between a closed position that closes the loading/unloading port 14 and an open position that opens the loading/unloading port 14 . With the shutter 15 placed in the closed position, the internal space of the chamber 10 is sealed. With the shutter 15 in the open position, the substrate 9 can be loaded into the chamber 10 and unloaded from the chamber 10 through the loading/unloading port 14 .

The stage 20 is a support that supports the substrate 9 inside the chamber 10 . The stage 20 has multiple support plates 21 . 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 . The substrate 9 is arranged on top of the plurality of support plates 21 . The substrate 9 is supported in a horizontal posture by contacting the lower surface of the substrate 9 with the upper ends of the plurality of support pins 22 .

A plurality of support plates 21 of the stage 20 are connected to an elevating mechanism 23 . In order to avoid complication of the drawing, the lifting mechanism 23 is conceptually shown in FIG. When the lifting mechanism 23 is operated, the stage 20 moves between a lowered position H1 (the position indicated by the solid line in FIG. 1) and an elevated position H2 (the position indicated by the two-dot chain line in FIG. 1) higher than the lowered position H1. move up and down between them. At this time, the plurality of support plates 21 move up and down as a unit.

The decompression mechanism 30 is a mechanism that reduces the pressure inside the chamber 10 by sucking gas from the internal space of the chamber 10 . As shown in FIGS. 1 and 2, the bottom plate portion 11 of the chamber 10 is provided with four exhaust ports 161 . Each of the four exhaust ports 161 is positioned below the substrate 9 supported by the stage 20 and below the bottom rectifying plate 40, which will be described later. The decompression mechanism 30 has an exhaust pipe 31 connected to four exhaust ports 161 , four individual valves V<b>1 , a main valve V<b>2 , and a vacuum pump 32 .

The exhaust pipe 31 has four individual pipes 311 and one main pipe 312 . One end of each of the four individual pipes 311 is connected to one of the four exhaust ports 161 . The other ends of the four individual pipes 311 merge into one and are connected to one end of the main pipe 312 . The other end of the main pipe 312 is connected to the vacuum pump 32 . The four individual valves V1 are provided on the paths of the four individual pipes 311, respectively. The main valve V2 is provided on the route of the main pipe 312 .

With the loading/unloading port 14 closed by the shutter 15, at least some of the four individual valves V1 and one main valve 2 are opened, and the vacuum pump 32 is operated. 31 to exit the chamber 10 . Thereby, the pressure in the internal space of the chamber 10 can be lowered.

The four individual valves V1 are valves for individually adjusting the exhaust amounts from the four exhaust ports 161 . The individual valve V<b>1 of this embodiment is an on-off valve that switches between an open state and a closed state based on a command from the control unit 80 . The main valve V<b>2 is a valve for adjusting the total exhaust amount from the four exhaust ports 161 . The main valve V<b>2 of this embodiment is an opening degree control valve whose opening degree can be adjusted based on a command from the control unit 80 .

The bottom straightening plate 40 is a plate for regulating the flow of gas when the pressure inside the chamber 10 is reduced. As shown in FIG. 2, the bottom current plate 40 is larger than the substrate 9 when viewed from above. The bottom plate 40 extends horizontally between the substrate 9 supported by the stage 20 and the bottom plate portion 11 of the chamber 10 . The bottom straightening plate 40 is fixed to the bottom plate portion 11 of the chamber 10 via a plurality of supports (not shown).

The side rectifying plate 50 is a plate for regulating the flow of gas when the pressure inside the chamber 10 is reduced, along with the bottom rectifying plate 40 . The side straightening plate 50 is positioned between the substrate 9 supported by the stage 20 at the lowered position H1 and the side wall portion 12 of the chamber 10 . In this embodiment, four side rectifying plates 50 are arranged around the substrate 9 supported by the stage 20 . The four side straightening vanes 50 form a rectangular tubular straightening vane surrounding the substrate 9 as a whole. The bottom straightening plate 40 and the four side straightening plates 50 as a whole form a bottomed cylindrical box-shaped straightening plate. The three side straightening plates 50 are fixed to the side wall portion 12 of the chamber 10 . The remaining one side straightening plate 50 is configured to move together with the shutter 15 .

When the internal space of the chamber 10 is decompressed, the gas in the chamber 10 passes through the space between the side rectifying plate 50 and the side wall portion 12, the space between the bottom rectifying plate 40 and the bottom plate portion 11, and exits through the exhaust port 161. is discharged from the chamber 10 to the outside. In this way, the gas flows through the space separated from the substrate 9, so that the airflow formed near the substrate 9 can be reduced. As a result, uneven drying of the coating layer formed on the upper surface of the substrate 9 can be suppressed.

The air supply mechanism 60 is a mechanism for supplying gas into the chamber 10 to increase the pressure inside the decompressed chamber 10 . As shown in FIG. 1, the bottom plate portion 11 of the chamber 10 is provided with an air supply port 162 . The air supply port 162 is positioned below the bottom straightening plate 40 . The air supply mechanism 60 has an air supply pipe 61 connected to the air supply port 162 , an air supply valve V<b>3 , and an air supply source 62 . One end of the air supply pipe 61 is connected to the air supply port 162 . The other end of the air supply pipe 61 is connected to an air supply source 62 . The air supply valve V3 is provided on the route of the air supply pipe 61 .

When the air supply valve V3 is opened, gas is supplied from the air supply source 62 to the internal space of the chamber 10 through the air supply pipe 61 and the air supply port 162 . Thereby, the air pressure in the chamber 10 can be increased. The gas supplied from the air supply source 62 may be inert gas such as nitrogen gas, or may be clean dry air.

The pressure gauge 70 is a sensor that measures the air pressure inside the chamber 10 . As shown in FIG. 1, pressure gauge 70 is attached to a portion of chamber 10 . The pressure gauge 70 measures the air pressure inside the chamber 10 and outputs the measurement result to the controller 80 .

The control section 80 is a unit for controlling the operation of each section of the reduced pressure drying apparatus 1 . The control unit 80 is configured by a computer having a processor 801 such as a CPU, a memory 802 such as a RAM, and a storage unit 803 such as a hard disk drive. The storage unit 803 stores a computer program and various data for executing the reduced pressure drying process. The control unit 80 reads a computer program and various data from the storage unit 803 to the memory 802, and the processor 801 performs arithmetic processing according to the computer program and data, thereby controlling the operation of each unit in the reduced pressure drying apparatus 1.

<2. Regarding Conventional Vacuum Drying Treatment>
Next, the reduced-pressure drying process of the substrate 9 using the above-described reduced-pressure drying apparatus 1 will be described. First, the flow of a vacuum drying process using a conventional recipe will be described with reference to FIGS. 4 and 5. FIG. Note that the recipe indicates how the atmospheric pressure is changed during the reduced-pressure drying process. FIG. 4 is a flow chart showing the flow of the reduced pressure drying process. FIG. 5 is a graph showing the pressure change recipe inside the chamber 10 in the conventional reduced pressure drying process. Note that the vertical axis in FIG. 5 is a logarithmic axis.

When performing the reduced pressure drying process, first, the substrate 9 is loaded into the chamber 10 (step ST1). An undried coating layer is formed on the upper surface of the substrate 9 . The control unit 80 operates the shutter 15 to open the loading/unloading port 14 . Then, a transfer robot (not shown) loads the substrate 9 into the chamber 10 through the loading/unloading port 14 . After that, the control unit 80 operates the shutter 15 to close the loading/unloading port 14 . Thereby, the substrate 9 is accommodated in the internal space of the chamber 10 . At this point, the stage 20 is located at the lowered position H1.

Next, the reduced-pressure drying apparatus 1 raises the stage 20 (step ST2). Specifically, the control unit 80 operates the lifting mechanism 23 to move the stage 20 from the lowered position H1 to the raised position H2. FIG. 6 is a diagram showing the state inside the chamber 10 when the stage 20 is arranged at the raised position H2. As shown in FIG. 6, in step ST2, the substrate 9 is arranged above the upper end portion of the side rectifying plate 50. As shown in FIG.

Subsequently, the pressure reduction inside the chamber 10 is started. That is, the controller 80 starts operating the vacuum pump 32 and opens one or all of the individual valves V1 and the main valve V2. As a result, gas starts to be discharged from the chamber 10 to the exhaust pipe 31 . In the subsequent reduced-pressure drying process, the control unit 80 performs control for reducing the pressure at a desired pressure-reducing speed according to the recipe shown in FIG.

The reduced-pressure drying apparatus 1 first performs a first process of reducing the pressure in the internal space of the chamber 10 at a relatively slow first pressure reduction rate S1 (step ST3). At step ST3, as described above, the stage 20 is placed at the elevated position H2. 6, the gas in the chamber 10 flows from the space below the substrate 9 to the space between the side straightening plate 50 and the side wall portion 12 and the space between the bottom straightening plate 40 and the bottom plate portion. 11 and flows from the exhaust port 161 to the exhaust pipe 31 . Therefore, the airflow formed inside the chamber 10 does not easily affect the upper surface of the substrate 9 .

In order to evacuate the chamber 10 at the decompression rate according to the pressure change recipe, feedback control may be performed with reference to the measured value of the pressure gauge 70, or the individual valve V1 that can achieve the desired decompression rate. and the opening degree of the main valve V2 obtained empirically may be used for the decompression process.

Next, the reduced-pressure drying apparatus 1 lowers the stage 20 (step ST4). Specifically, the control unit 80 operates the lifting mechanism 23 to move the stage 20 from the raised position H2 to the lowered position H1. FIG. 7 is a diagram showing the state inside the chamber 10 when the stage 20 is arranged at the lowered position H1. As shown in FIG. 7, in step ST4, the substrate 9 is positioned below the upper end of the side rectifying plate 50. As shown in FIG.

Subsequently, the reduced-pressure drying apparatus 1 performs a second process of reducing the pressure at a second pressure-reducing speed S2 that is higher than that of the first process (step ST5). In this second process, the opening of the main valve V2 is changed to a larger opening than in the first process. As a result, the air pressure inside the chamber 10 is rapidly lowered as compared to period T1, as in period T2 in FIG.

In the second process, as described above, the stage 20 is placed at the lowered position H1. In the second treatment, the solvent evaporates more actively from the coating layer than in the first treatment. For this reason, vapor of the solvent tends to be generated on the upper surface side of the substrate 9 . The gas existing in the space on the upper surface side of the substrate 9, as indicated by the dashed arrows in FIG. It flows through the space from the exhaust port 161 to the exhaust pipe 31 . Thereby, generation of a strong air current in the vicinity of the substrate 9 can be suppressed. In particular, it is possible to suppress the concentration of the airflow at the peripheral portion of the substrate 9 . Therefore, uneven drying of the coating layer due to airflow can be suppressed.

When the air pressure in the internal space of the chamber 10 drops to the predetermined pressure P2, the evaporation of the solvent from the coating layer becomes more active. Therefore, in the subsequent third process, the depressurization rate is slowed down again in order to suppress the boiling of the coating layer, and as in the period T3 of FIG. Evacuation from the chamber 10 is continued (step ST6).

Depending on the type of coating liquid, in the third process, the chamber 10 may be exhausted so that the pressure in the chamber 10 becomes substantially constant.

Eventually, the solvent component of the coating layer is sufficiently vaporized, and when the atmospheric pressure in the chamber 10 drops to about pressure P3, the vaporization of the solvent from the coating layer is almost complete. As a result, the air pressure inside the chamber 10 rapidly drops again as in period T4 in FIG. Thus, the reduced-pressure drying apparatus 1 performs the fourth process of further reducing the pressure in the internal space of the chamber 10 (step ST7). In FIG. 5, the decompression speed in the fourth process is indicated by a fourth decompression speed S4.

In this fourth treatment, although a small amount of the solvent component remaining in the coating layer is evaporated, the evaporation of the solvent component is not as active as in the first to third treatments described above. Therefore, the controller 80 opens all the four individual valves V1 and the main valve V2. This facilitates evacuation from the chamber 10 and rapidly reduces the internal space of the chamber 10 to the target pressure P4.

When the air pressure inside the chamber 10 reaches the target pressure P4, the controller 80 closes the main valve V2. This completes the suction of the gas from the chamber 10 and completes the drying of the coating layer.

After that, the controller 80 opens the air supply valve V3. Then, gas is supplied from the air supply source 62 into the chamber 10 through the air supply pipe 61 and the air supply port 162 (step ST8). As a result, the pressure inside the chamber 10 rises again to the atmospheric pressure P0. At this time, a relatively strong air current is generated in the chamber 10, but since the coating layer has already been sufficiently dried, uneven drying caused by the air current is less likely to occur. Also, the gas supplied from the air supply port 162 flows inside the chamber 10 through between the bottom straightening plate 40 and the bottom plate portion 11 and between the side straightening plate 50 and the side wall portion 12 . Thereby, generation of a strong air current in the vicinity of the substrate 9 can be suppressed.

When the pressure inside the chamber 10 reaches the atmospheric pressure P0, the controller 80 closes the air supply valve V3. Then, the controller 80 operates the shutter driving mechanism 16 . As a result, the shutter 15 is moved from the closed position to the open position to open the loading/unloading port 14 . Then, a transfer robot (not shown) carries out the dried substrate 9 supported by the stage 20 to the outside of the chamber 10 (step ST9). With the above, the reduced-pressure drying process for one substrate 9 is completed.

In this reduced pressure drying apparatus 1, a switching process for sequentially switching the open/closed states of the four individual valves V1 may be performed in the first to third processes. By doing so, the exhaust amount from the four exhaust ports 161 is switched sequentially between the first to third processes. This changes the direction of the airflow formed along the upper surface of the substrate 9 . Therefore, the coating layer on the upper surface of the substrate 9 can be dried more uniformly.

<3. First Embodiment>
Subsequently, changes in air pressure during the reduced pressure drying process according to the first embodiment will be described with reference to FIGS. 8 and 9. FIG. FIG. 8 is a graph showing the pressure change recipe inside the chamber 10 in the reduced pressure drying process of the first embodiment. FIG. 9 is a flow chart showing the flow of the first process in the reduced pressure drying process of the first embodiment.

The reduced-pressure drying process of the first embodiment differs from the above-described conventional reduced-pressure drying process in the first process of step ST3. Note that other steps are the same as in the above-described conventional reduced-pressure drying process, so descriptions thereof will be omitted.

In the first process (step ST3a) in the first embodiment, as shown in FIG. 8, the pressure in the chamber 10 is reduced from the atmospheric pressure to the target pressure P1 during the period T1 during which the first process is performed. In the process, two steps of raising the pressure (air supply step) are performed.

Specifically, as shown in FIG. 9, in the first process (step ST3a), the control unit 80 first opens at least one of the individual valves V1 and the main valve V2 to allow the air to flow from the chamber 10 at the atmospheric pressure P0. Start exhaust. Then, the pressure in the chamber 10 is reduced at the first pressure reduction rate S1 until the pressure inside the chamber 10 reaches a predetermined pressure Pa (step ST31a). The pressure Pa is lower than the atmospheric pressure P0 and higher than the target pressure P1 of the first process.

When the pressure inside the chamber 10 reaches a predetermined pressure Pa, the control unit 80 closes the main valve V2 to stop the pressure reduction from inside the chamber 10 . Subsequently, the controller 80 opens the air supply valve V3 to supply the gas from the air supply source 62 into the chamber 10 (step ST32a). In this step ST32a, the gas is supplied until the pressure inside the chamber 10 reaches the atmospheric pressure P0.

When the air pressure inside the chamber 10 reaches the atmospheric pressure P0, the controller 80 closes the air supply valve V3 to stop the supply of air to the chamber 10 . Then, at least one of the individual valves V1 and the main valve V2 are opened again to start exhausting the chamber 10 at the atmospheric pressure P0. Then, the pressure in the chamber 10 is reduced at the first pressure reduction speed S1 until the pressure inside the chamber 10 reaches a predetermined pressure Pa (step ST33a).

When the pressure inside the chamber 10 reaches a predetermined pressure Pa, the control unit 80 closes the main valve V2 to stop the pressure reduction from inside the chamber 10 . Subsequently, the controller 80 opens the air supply valve V3 to supply gas from the air supply source 62 into the chamber 10 (step ST34a). In this step ST34a, the gas is supplied until the pressure inside the chamber 10 reaches the atmospheric pressure P0 again.

Then, when the pressure inside the chamber 10 reaches the atmospheric pressure P0 again, the controller 80 stops supplying air to the chamber 10 . Then, at least one of the individual valves V1 and the main valve V2 are opened to start exhausting the chamber 10 at the atmospheric pressure P0. Then, the pressure in the chamber 10 is reduced at the first pressure reduction rate S1 until the pressure inside the chamber 10 reaches the target pressure P1 for the first process (step ST35a).

As described above, in the first embodiment, during the first process (step ST3a), which is a reduced-pressure drying process that drives the decompression mechanism 30 to reduce the pressure in the chamber 10 to a predetermined target pressure P1, temporarily A supply process (steps ST32a, ST34a) is performed in which the decompression mechanism 30 is stopped and the intake mechanism 60 is driven to supply gas into the chamber. That is, in the first process (step ST3a) of the first embodiment, the decompression process at the first decompression speed S1, the air supply process, and the second decompression process are performed.

Evaporation of the solvent from the coating layer is stopped by intentionally raising the pressure by carrying out the air supply step during the depressurization process. Depending on the conditions, part of the solvent vaporized from the coating layer temporarily condenses on the surface of the coating layer. As a result, the viscosity of the coating liquid can be made uniform within the coating layer, and reflow can occur in the coating liquid whose fluidity has decreased due to the progress of drying. As a result, variations in the thickness of the coating layer can be suppressed, and the coating layer can be dried more uniformly.

In particular, by performing the air supply step in the middle of the first process, which is the initial stage of the reduced pressure drying process, the viscosity and fluidity of the coating liquid can be made uniform before the solvent in the coating liquid vaporizes. As a result, variations in the thickness of the coating layer can be further suppressed, and the coating layer can be dried more uniformly.

In the first embodiment, the air supply process (steps ST32a, ST34a) for supplying air is performed twice after the pressure reduction process (steps ST31a, ST33a) in which the pressure reduction process progresses to some extent. It is not limited to twice. The number of such air supply steps may be one, or may be three or more.

<4. Second Embodiment>
Air pressure changes during the reduced pressure drying process according to the second embodiment will be described with reference to FIGS. 10 and 11. FIG. FIG. 10 is a graph showing the pressure change recipe inside the chamber 10 in the reduced pressure drying process of the second embodiment. FIG. 11 is a flow chart showing the flow of the first process in the reduced pressure drying process of the second embodiment.

As shown in FIG. 10, in the second embodiment, as in the first embodiment, air is supplied twice during the first process. A different point from the first embodiment is the pressure in the chamber 10 immediately before the start of air supply.

In the first process (step ST3b) in the second embodiment, as shown in FIG. 10, the pressure in the chamber 10 is reduced from the atmospheric pressure to the target pressure P1 during the period T1 during which the first process is performed. In the process, two steps of raising the pressure (air supply step) are performed.

Specifically, as shown in FIG. 11, in the first process (step ST3b), the control unit 80 first opens at least one of the individual valves V1 and the main valve V2 to allow the air to flow from the chamber 10 at the atmospheric pressure P0. Start exhaust. Then, the pressure in the chamber 10 is reduced at the first pressure reduction speed S1 until the pressure inside the chamber 10 reaches a predetermined pressure Pb (step ST31b). The pressure Pb is lower than the atmospheric pressure P0 and higher than the target pressure P1 of the first process.

When the pressure inside the chamber 10 reaches a predetermined pressure Pa, the control unit 80 closes the main valve V2 to stop the pressure reduction from inside the chamber 10 . Subsequently, the controller 80 opens the air supply valve V3 to supply the gas from the air supply source 62 into the chamber 10 (step ST32b). In this step ST32b, the gas is supplied until the pressure inside the chamber 10 reaches the atmospheric pressure P0.

When the air pressure inside the chamber 10 reaches the atmospheric pressure P0, the controller 80 closes the air supply valve V3 to stop the supply of air to the chamber 10 . Then, at least one of the individual valves V1 and the main valve V2 are opened again to start exhausting the chamber 10 at the atmospheric pressure P0. Then, the pressure in the chamber 10 is reduced at the first pressure reduction rate S1 until it reaches a predetermined pressure Pc (step ST33b). Note that the pressure Pc is lower than the pressure Pb and higher than the target pressure P1 of the first process.

When the pressure inside the chamber 10 reaches a predetermined pressure Pc, the control unit 80 closes the main valve V2 to stop depressurization from inside the chamber 10 . Subsequently, the controller 80 opens the air supply valve V3 to supply gas from the air supply source 62 into the chamber 10 (step ST34a). In this step ST34a, the gas is supplied until the pressure inside the chamber 10 reaches the atmospheric pressure P0 again.

Then, when the pressure inside the chamber 10 reaches the atmospheric pressure P0 again, the controller 80 stops supplying air to the chamber 10 . Then, at least one of the individual valves V1 and the main valve V2 are opened to start exhausting the chamber 10 at the atmospheric pressure P0. Then, the pressure in the chamber 10 is reduced at the first pressure reduction rate S1 until the pressure inside the chamber 10 reaches the target pressure P1 for the first process (step ST35a).

Thus, in the first process (step ST3b) of the second embodiment, the air pressure in the chamber 10 immediately before the two air supply steps (steps ST32b and 34b) is lower in the second time than in the first time. . In this manner, the depressurization process may proceed step by step.

<5. Third Embodiment>
Air pressure changes during the reduced pressure drying process according to the third embodiment will be described with reference to FIGS. 12 and 13. FIG. FIG. 12 is a graph showing the pressure change recipe inside the chamber 10 in the reduced pressure drying process of the third embodiment. FIG. 13 is a flow chart showing the flow of the first process in the reduced pressure drying process of the third embodiment.

As shown in FIG. 12, in the third embodiment, as in the first and second embodiments, air is supplied twice during the first process. A different point from the first embodiment and the second embodiment is the pressure in the chamber 10 immediately before the start of air supply.

In the first process (step ST3c) in the third embodiment, as shown in FIG. 12, during a period T1 during which the first process is performed, the pressure in the chamber 10 is reduced from the atmospheric pressure to the target pressure P1 for that period. and the air supply process are repeated.

Specifically, as shown in FIG. 13, in the first process (step ST3c), the control unit 80 first opens at least one of the individual valves V1 and the main valve V2 to allow the air to flow from the chamber 10 at the atmospheric pressure P0. Start exhaust. Then, the pressure in the chamber 10 is reduced at the first pressure reduction rate S1 until the pressure inside the chamber 10 reaches the target pressure P1 for the first process (step ST31c).

When the pressure inside the chamber 10 reaches the target pressure P1, the control unit 80 closes the main valve V2 to stop depressurization from inside the chamber 10 . Subsequently, the controller 80 opens the air supply valve V3 to supply gas from the air supply source 62 into the chamber 10 (step ST32c). In this step ST32c, the gas is supplied until the pressure inside the chamber 10 reaches the atmospheric pressure P0.

When the air pressure inside the chamber 10 reaches the atmospheric pressure P0, the controller 80 closes the air supply valve V3 to stop the supply of air to the chamber 10 . Then, at least one of the individual valves V1 and the main valve V2 are opened again to start exhausting the chamber 10 at the atmospheric pressure P0. Then, the pressure in the chamber 10 is reduced at the first pressure reduction speed S1 until the pressure inside the chamber 10 reaches the target pressure P1 for the first process (step ST33c).

When the pressure inside the chamber 10 reaches the target pressure P1, the control unit 80 closes the main valve V2 to stop depressurization from inside the chamber 10 . Subsequently, the controller 80 opens the air supply valve V3 to supply gas from the air supply source 62 into the chamber 10 (step ST34c). In this step ST34c, the gas is supplied until the pressure inside the chamber 10 reaches the atmospheric pressure P0 again.

Then, when the pressure inside the chamber 10 reaches the atmospheric pressure P0 again, the controller 80 stops supplying air to the chamber 10 . Then, at least one of the individual valves V1 and the main valve V2 are opened to start exhausting the chamber 10 at the atmospheric pressure P0. Then, the pressure in the chamber 10 is reduced at the first pressure reduction rate S1 until the pressure inside the chamber 10 reaches the target pressure P1 for the first process (step ST35c). Then, when the target pressure P1 is reached for the third time, the first process (step ST3c) ends.

Thus, in the first process (step ST3c), the depressurization process to the target pressure P1 may be repeated multiple times.

<6. Fourth Embodiment>
Air pressure changes during the reduced pressure drying process according to the fourth embodiment will be described with reference to FIGS. 14 and 15. FIG. FIG. 14 is a graph showing the pressure change recipe inside the chamber 10 in the reduced pressure drying process of the fourth embodiment. FIG. 15 is a flow chart showing the flow of the first process in the reduced pressure drying process of the fourth embodiment.

As shown in FIG. 14, the fourth embodiment is different from the first to third embodiments except for the number of times of air supply. This is the point to be careful about.

In the first process (step ST3d) in the fourth embodiment, during the period T1 during which the first process is performed, the pressure inside the chamber 10 is reduced from the atmospheric pressure to the target pressure P1 for that period. A step of raising (air supply step) is performed.

Specifically, as shown in FIG. 15, in the first process (step ST3d), the control unit 80 first opens at least one of the individual valves V1 and the main valve V2 to allow the air to flow from the chamber 10 at the atmospheric pressure P0. Start exhaust. Then, the pressure in the chamber 10 is reduced at the first pressure reduction rate S1 until the pressure inside the chamber 10 reaches a predetermined pressure Pd (step ST31d). The pressure Pd is lower than the atmospheric pressure P0 and higher than the target pressure P1 for the first process.

When the pressure inside the chamber 10 reaches a predetermined pressure Pd, the control unit 80 closes the main valve V2 to stop the pressure reduction from inside the chamber 10 . Subsequently, the controller 80 opens the air supply valve V3 to supply gas from the air supply source 62 into the chamber 10 (step ST32d). In this step ST32b, gas is supplied for a predetermined time (for example, 2 sec).

After a predetermined period of time has elapsed, the controller 80 closes the air supply valve V3 to stop the supply of air to the chamber 10 . Then, at least one of the individual valves V1 and the main valve V2 are opened again, and exhaustion from the chamber 10 is started. Then, the pressure in the chamber 10 is reduced at the first pressure reduction speed S1 until it reaches a predetermined pressure Pe (step ST33d). The pressure Pe is lower than the pressure Pd and higher than the target pressure P1 for the first process.

When the pressure inside the chamber 10 reaches a predetermined pressure Pe, the control unit 80 closes the main valve V2 to stop the pressure reduction from inside the chamber 10 . Subsequently, the controller 80 opens the air supply valve V3 to supply the gas from the air supply source 62 into the chamber 10 (step ST34d). In step ST34d, gas is supplied for the same predetermined time as in the first gas supply step (step ST32d).

After a predetermined time has passed, the controller 80 stops supplying air to the chamber 10 . Then, at least one of the individual valves V1 and the main valve V2 are opened, and the evacuation from the chamber 10 is started. Then, the pressure in the chamber 10 is reduced at the first pressure reduction speed S1 until it reaches a predetermined pressure Pf (step ST35d). Note that the pressure Pf is lower than the pressure Pe and higher than the target pressure P1 of the first process.

When the pressure inside the chamber 10 reaches a predetermined pressure Pf, the control unit 80 closes the main valve V2 to stop the pressure reduction from inside the chamber 10 . Subsequently, the controller 80 opens the gas supply valve V3 to supply gas from the gas supply source 62 into the chamber 10 (step ST36d). In this step ST36d, gas is supplied for the same predetermined time as the first air supply process (step ST32d) and the second air supply process (step ST34d).

After a predetermined time has passed, the controller 80 stops supplying air to the chamber 10 . Then, at least one of the individual valves V1 and the main valve V2 are opened, and the evacuation from the chamber 10 is started. Then, the pressure in the chamber 10 is reduced at the first pressure reduction rate S1 (step ST37d) until the pressure inside the chamber 10 reaches the target pressure P1 of the first process (step ST3d).

In the first process (step ST3d) of the fourth embodiment, in each air supply step (steps ST32d, 34d, and 36d), air is supplied for a predetermined time, and the pressure inside the chamber 10 is not returned to the atmospheric pressure P0. Thus, in the air supply step performed during the first process, it is not necessary to supply air up to the atmospheric pressure P0. As a result, the time required for the reduced-pressure drying process can be shortened compared to the case where air supply up to the atmospheric pressure P0 is performed the same number of times in the air supply process.

<7. Fifth Embodiment>
Air pressure changes during the reduced pressure drying process according to the fifth embodiment will be described with reference to FIGS. 16 and 17. FIG. FIG. 16 is a graph showing the pressure change recipe inside the chamber 10 in the reduced pressure drying process of the fifth embodiment. FIG. 17 is a flow chart showing the flow of the first process and the second process in the reduced pressure drying process of the fifth embodiment.

As shown in FIGS. 16 and 17, in the fifth embodiment, one air supply step is performed during the period T1 during which the first process (step ST3e) in the fifth embodiment is performed, and the second process (step ST5e ) is performed, one air supply step is performed in the period T2.

Specifically, as shown in FIG. 17, in the first process (step ST3e), the control unit 80 first opens at least one of the individual valves V1 and the main valve V2 to allow the air to flow from the chamber 10 at the atmospheric pressure P0. Start exhaust. Then, the pressure in the chamber 10 is reduced at the first pressure reduction speed S1 until the pressure inside the chamber 10 reaches a predetermined pressure Pg (step ST31e). The pressure Pg is lower than the atmospheric pressure P0 and higher than the target pressure P1 for the first process.

When the pressure inside the chamber 10 reaches a predetermined pressure Pg, the control unit 80 closes the main valve V2 to stop depressurization from inside the chamber 10 . Subsequently, the controller 80 opens the gas supply valve V3 to supply gas from the gas supply source 62 into the chamber 10 (step ST32e). In this step ST32e, the gas is supplied until the pressure inside the chamber 10 reaches the atmospheric pressure P0.

When the air pressure inside the chamber 10 reaches the atmospheric pressure P0, the controller 80 closes the air supply valve V3 to stop the supply of air to the chamber 10 . Then, at least one of the individual valves V1 and the main valve V2 are opened again to start exhausting the chamber 10 at the atmospheric pressure P0. Then, the pressure in the chamber 10 is reduced at the first pressure reduction speed S1 until it reaches the target pressure P1 for the first process (step ST35e). In this manner, one air supply step (step ST32e) is performed during the first process.

After the first process (step ST3e) is completed and the stage position is changed (step ST4), the second process (step ST5e) is performed. In this second process (step ST5e), the control unit 80 first opens at least one of the individual valves V1 and the main valve V2 to start exhausting the pressure P1 from the chamber 10 . Then, the pressure in the chamber 10 is reduced at the second pressure reduction speed S2 until the pressure in the chamber 10 reaches a predetermined pressure Ph (step ST51e). The pressure Ph is lower than the target pressure P1 for the first process and higher than the target pressure P2 for the second process.

When the pressure inside the chamber 10 reaches a predetermined pressure Ph, the control unit 80 closes the main valve V2 to stop depressurization from inside the chamber 10 . Subsequently, the controller 80 opens the air supply valve V3 to supply the gas from the air supply source 62 into the chamber 10 (step ST52e). In this step ST52e, the gas is supplied until the pressure inside the chamber 10 reaches the atmospheric pressure P0.

When the air pressure inside the chamber 10 reaches the atmospheric pressure P0, the controller 80 closes the air supply valve V3 to stop the supply of air to the chamber 10 . Then, at least one of the individual valves V1 and the main valve V2 are opened again to start exhausting the chamber 10 at the atmospheric pressure P0. Then, the pressure inside the chamber 10 is reduced at the second pressure reduction rate S2 until it reaches the target pressure P2 for the second process (step ST53e). In this way, one air supply step (step ST52e) is performed during the second process.

As in the fifth embodiment, the air supply step may be performed both during the first process and during the second process. By performing the air supply step in both the first treatment and the second treatment before the third treatment in which the evaporation of the solvent from the coating liquid is most active, the air supply is performed not only during the first treatment but also in the second treatment. By performing an air step, the viscosity of the coating liquid can be made uniform, or reflow can be caused in the coating liquid. As a result, variations in the thickness of the coating layer can be suppressed, and the coating layer can be dried more uniformly.

The air supply process may be performed only during the second process without performing the air supply process during the first process. Moreover, the air supply process performed during the first process and the second process is not limited to one time, and may be performed multiple times.

Further, in the fifth embodiment, during the second process, in the decompression process (step ST53e) performed after the air supply process (step ST52e), while the pressure P1 is reached from the atmospheric pressure P0, the first process (step ST3e ), the decompression process is performed at the second decompression speed S2, which is faster than the second decompression speed S2. As a result, the reduced-pressure drying process can be shortened as a whole compared to the sixth embodiment described later.

<8. Sixth Embodiment>
Air pressure changes during the reduced pressure drying process according to the sixth embodiment will be described with reference to FIGS. 18 and 19. FIG. FIG. 18 is a graph showing the pressure change recipe inside the chamber 10 in the reduced pressure drying process of the sixth embodiment. FIG. 19 is a flow chart showing the flow of the first process and the second process in the reduced pressure drying process of the sixth embodiment.

As shown in FIGS. 18 and 19, in the sixth embodiment, as in the fifth embodiment, one air supply step is performed during the period T1 during which the first process (step ST3f) is performed, and the second process is performed. One air supply process is performed in the period T2 during which (step ST5f) is performed. Note that the first process (step ST3f) of the sixth embodiment is the same as the first process (step ST3e) of the fifth embodiment, so description thereof will be omitted.

After the first process (step ST3f) is completed and the stage position is changed (step ST4), the second process (step ST5f) is performed. In this second process (step ST5f), first, the control section 80 opens at least one of the individual valves V1 and the main valve V2 to start exhausting the pressure P1 from the chamber 10 . Then, the pressure in the chamber 10 is reduced at the second pressure reduction speed S2 until the pressure in the chamber 10 reaches a predetermined pressure Ph (step ST51f).

When the pressure inside the chamber 10 reaches a predetermined pressure Ph, the control unit 80 closes the main valve V2 to stop depressurization from inside the chamber 10 . Subsequently, the controller 80 opens the air supply valve V3 to supply gas from the air supply source 62 into the chamber 10 (step ST52f). In this step ST52f, the gas is supplied until the pressure inside the chamber 10 reaches the atmospheric pressure P0.

When the air pressure inside the chamber 10 reaches the atmospheric pressure P0, the controller 80 closes the air supply valve V3 to stop the supply of air to the chamber 10 . Then, at least one of the individual valves V1 and the main valve V2 are opened again to start exhausting the chamber 10 at the atmospheric pressure P0. Then, the pressure in the chamber 10 is reduced at the first pressure reduction speed S1 until the pressure inside the chamber 10 reaches the target pressure P1 for the first process (step ST53f).

When the air pressure inside the chamber 10 reaches the target pressure P1 for the first process, the controller 80 changes the opening degree of the main valve V2, and increases the pressure inside the chamber 10 until it reaches the target pressure P2 for the second process. 2 Depressurization is performed at depressurization speed S2 (step S54f).

As in the sixth embodiment, when air is supplied to a pressure exceeding the target pressure P1 of the first process during the second process, the same first pressure reduction as in the first process is performed in the pressure band exceeding the target pressure P1 The decompression process may be performed at speed S1. By doing so, it is possible to suppress the bumping of the coating liquid in the pressure zone.

<9. Seventh Embodiment>
Air pressure changes during the reduced pressure drying process according to the seventh embodiment will be described with reference to FIGS. 20 and 21. FIG. FIG. 20 is a graph showing the pressure change recipe inside the chamber 10 in the reduced pressure drying process of the seventh embodiment. FIG. 21 is a flow chart showing the flow of the first process and the second process in the reduced pressure drying process of the seventh embodiment.

As shown in FIG. 20, in the seventh embodiment, as in the fifth embodiment, the air supply process is performed once during the period T1 during which the first process (step ST3g) is performed, and the second process (step ST5g) is performed. ) is performed, one air supply step is performed in the period T2. Note that the first process (step ST3g) of the sixth embodiment is the same as the first process (step ST3e) of the fifth embodiment, so description thereof will be omitted.

After the first process (step ST3g) is completed and the stage position is changed (step ST4), the second process (step ST5g) is performed. In this second process (step ST5g), first, the control section 80 opens at least one of the individual valves V1 and the main valve V2 to start exhausting the pressure P1 from the chamber 10 . Then, the pressure in the chamber 10 is reduced at the second pressure reduction speed S2 until the pressure inside the chamber 10 reaches a predetermined pressure Ph (step ST51g).

When the pressure inside the chamber 10 reaches a predetermined pressure Ph, the control unit 80 closes the main valve V2 to stop depressurization from inside the chamber 10 . Subsequently, the controller 80 opens the air supply valve V3 to supply gas from the air supply source 62 into the chamber 10 (step ST52g). In this step ST52g, the gas is supplied until the pressure inside the chamber 10 reaches the target pressure P1 for the first process.

When the air pressure inside the chamber 10 reaches the pressure P1, the controller 80 closes the air supply valve V3 to stop supplying air to the chamber 10 . Then, at least one of the individual valves V1 and the main valve V2 are opened again to start exhausting the pressure P1 from the chamber 10 . Then, the pressure inside the chamber 10 is reduced at the second pressure reduction rate S2 until it reaches the target pressure P2 for the second process (step ST5g).

As in the sixth embodiment, during the second process, air is not supplied to a pressure exceeding the target pressure P1 for the first process, and air is supplied to the pressure P1, which is the pressure at which the second process is started. . By doing so, the time required for the reduced-pressure drying process can be shortened compared to the fifth and sixth embodiments.

<10. Eighth Embodiment>
Air pressure changes during the reduced pressure drying process according to the eighth embodiment will be described with reference to FIGS. 22 and 23. FIG. FIG. 22 is a graph showing the pressure change recipe inside the chamber 10 in the reduced pressure drying process of the eighth embodiment. FIG. 23 is a flow chart showing the flow of the first process and the second process in the reduced pressure drying process of the eighth embodiment.

As shown in FIGS. 22 and 23, in the eighth embodiment, as in the fourth embodiment, during the period T1 during which the first process (step ST3h) is performed, the air supply process is performed three times for a predetermined time, During the period T2 during which the second process (step ST5h) is performed, the air supply process is performed twice for a predetermined time. Note that the first process (step ST3h) of the eighth embodiment is the same as the first process (step ST3d) of the fourth embodiment, so description thereof will be omitted.

After the first process (step ST3h) is completed and the stage position is changed (step ST4), the second process (step ST5h) is performed. In this second process (step ST5h), first, the controller 80 opens at least one of the individual valves V1 and the main valve V2 to start exhausting the pressure P1 from the chamber 10 . Then, the pressure in the chamber 10 is reduced at the second pressure reduction speed S2 until the pressure inside the chamber 10 reaches a predetermined pressure Pm (step ST51h). The pressure Pm is lower than the target pressure P1 for the first process and higher than the target pressure P2 for the second process.

When the pressure inside the chamber 10 reaches a predetermined pressure Pm, the control unit 80 closes the main valve V2 to stop depressurization from inside the chamber 10 . Subsequently, the controller 80 opens the air supply valve V3 to supply the gas from the air supply source 62 into the chamber 10 (step ST52h). In this step ST52h, gas is supplied for a predetermined time (for example, 2 sec).

After a predetermined period of time has elapsed, the controller 80 closes the air supply valve V3 to stop the supply of air to the chamber 10 . Then, at least one of the individual valves V1 and the main valve V2 are opened again to start exhausting the chamber 10 at the atmospheric pressure P0. Then, the pressure inside the chamber 10 is reduced at the second pressure reduction rate S2 until it reaches a predetermined pressure Pn (step ST53h). Note that the pressure Pn is lower than the pressure Pm and higher than the target pressure P2 for the second process.

When the pressure inside the chamber 10 reaches a predetermined pressure Pn, the control unit 80 closes the main valve V2 to stop depressurization from inside the chamber 10 . Subsequently, the controller 80 opens the air supply valve V3 to supply the gas from the air supply source 62 into the chamber 10 (step ST54h). In step ST54h, gas is supplied for the same predetermined time as in the first gas supply step (step ST52h).

After a predetermined time has passed, the controller 80 stops supplying air to the chamber 10 . Then, at least one of the individual valves V1 and the main valve V2 are opened, and the evacuation from the chamber 10 is started. Then, the pressure inside the chamber 10 is reduced at the second pressure reduction rate S2 until it reaches the target pressure P2 for the second process (step ST55h).

In the first process (step ST3h) and the second process (step ST5h) of the eighth embodiment, in each air supply process (steps ST32h, 34h, 36h and steps ST52h, 54h), air is supplied for a predetermined time, The pressure inside the chamber 10 is not returned to the pressure P0. Thus, in the air supply step performed during the first process and the second process, it is not necessary to supply air up to the atmospheric pressure P0. As a result, the time required for the reduced-pressure drying process can be shortened compared to the case where air supply up to the atmospheric pressure P0 is performed the same number of times in the air supply process.

<11. Variation>
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

In the above embodiment, the air supply step was performed only in the first process or in the first process and the second process among the four stages of the reduced pressure drying process of the first process to the fourth process, but the present invention It is not limited to this. The air supply step may be performed only in any one of the second treatment, the third treatment, and the fourth treatment, or the first treatment and the third treatment, the second treatment and the third treatment, or the second treatment to the third treatment. As in the 4th treatment, the gas supply step may be performed in any of the first to fourth treatments.

In the above-described embodiment, four stages of reduced-pressure drying processes, ie, first to fourth processes, are performed, but the present invention is not limited to this. During the stepless reduced-pressure drying process or the reduced-pressure drying process divided into 2, 3, or 5 or more stages, the air supply step may be performed during the decompression step.

In the embodiments described above, the chamber 10 had four exhaust ports 161 . However, chamber 10 may have one, two, three, five or more outlets. Also, in the above embodiment, the chamber 10 had one air supply port 162 . However, the number of air supply openings that the chamber 10 has may be two or more.

In the above embodiment, the final target pressure P4, which is the lowest pressure, is between 100 and 10 Pa, but the present invention is not limited to this. The final target pressure may be 10-1 Pa.

The reduced-pressure drying apparatus 1 of the above embodiment dries the coating layer on the substrate 9 only by reduced pressure. However, the reduced-pressure drying apparatus 1 may dry the coating layer on the substrate 9 by reducing the pressure and heating.

Further, the reduced-pressure drying apparatus 1 of the embodiment described above is for processing a substrate for an organic EL display. However, the vacuum drying apparatus of the present invention may also be used to process substrates for other precision electronic components such as liquid crystal displays and semiconductor wafers.

Also, the elements appearing in the above embodiments and modified examples may be appropriately combined within a range that does not cause contradiction.

1 decompression drying device 9 substrate 10 chamber 30 decompression mechanism 60 air supply mechanism 80 controller S1 first decompression speed S2 second decompression speed S3 third decompression speed

Claims (9)

A reduced pressure drying apparatus for drying a coating layer containing a solvent formed on the surface of a substrate by reducing pressure,
a chamber containing a substrate;
a decompression mechanism for sucking gas in the chamber;
an air supply mechanism for supplying gas into the chamber;
a control unit that controls the decompression mechanism and the air supply mechanism;
has
The control unit temporarily stops the decompression mechanism during a decompression drying process in which the coating layer is dried by driving the decompression mechanism to decrease the pressure in the chamber to a predetermined target pressure value. and driving the air supply mechanism to supply gas into the chamber. The vacuum drying apparatus according to claim 1,
The control unit reduces the pressure in the chamber to a predetermined target pressure value during a reduced pressure drying process for drying the coating layer. a decompression step of sucking gas;
q) after the step p), an air supply step of driving the air supply mechanism to supply gas into the chamber;
r) after the step q), a decompression step of driving the decompression mechanism to suck the gas in the chamber at the decompression speed;
A vacuum drying device that performs The vacuum drying apparatus according to claim 2,
The control unit, in the reduced pressure drying process,
a) a first process of sucking gas in the chamber at a predetermined first pressure reduction rate;
b) after the process a), a second process of sucking the gas in the chamber at a second pressure reduction rate that is greater than the first pressure reduction rate;
c) after the process b), a third process of sucking the gas in the chamber at a third decompression rate that is smaller than the second decompression rate, or so that the pressure in the chamber is constant;
and run
The reduced pressure drying apparatus, wherein the control unit executes the step p), the step q) and the step r) in at least one of the processing a), the processing b) and the processing c). The vacuum drying apparatus according to claim 3,
The control unit executes the step p), the step q) and the step r) at least in the process a),
The reduced pressure drying apparatus, wherein in the step p) and the step r) in the process a), the reduced pressure speed is the first reduced pressure speed. The vacuum drying apparatus according to claim 3,
The control unit executes the step p), the step q) and the step r) in the processing a) and the processing b), respectively;
In the step p) and the step r) in the process a), the pressure reduction rate is the first pressure reduction rate,
The reduced pressure drying apparatus, wherein in the step p) and the step r) in the process b), the pressure reduction speed is the second pressure reduction speed. A reduced-pressure drying method for drying a coating layer containing a solvent formed on the upper surface of a substrate by a reduced-pressure drying process that reduces the pressure in the chamber,
P) a decompression step of sucking the gas in the chamber at a predetermined decompression rate;
Q) after step P), an air supply step of supplying gas into the chamber;
R) after the step Q), a decompression step of sucking the gas in the chamber at the decompression rate;
A vacuum drying method, comprising: The vacuum drying method according to claim 6,
The reduced-pressure drying process includes
A) a first process of sucking the gas in the chamber at a predetermined first depressurization rate;
B) after the process A), a second process of sucking the gas in the chamber at a second pressure reduction rate that is higher than the first pressure reduction rate;
C) after the process B), a third process of sucking the gas in the chamber at a third decompression rate smaller than the second decompression rate, or so that the pressure in the chamber is constant;
including
A vacuum drying method, wherein at least one of the treatment A), the treatment B) and the treatment C) includes the step P), the step Q) and the step R). The vacuum drying method according to claim 7,
At least said treatment A) includes said step P), said step Q) and said step R),
The reduced pressure drying method, wherein in said step P) and said step R) in said treatment A), the reduced pressure speed is said first reduced pressure speed. The vacuum drying method according to claim 7,
Said treatment A) and said treatment B) respectively comprise said step P), said step Q) and said step R),
In the step P) and the step R) in the process A), the pressure reduction rate is the first pressure reduction rate,
The reduced pressure drying method, wherein in the step P) and the step R) in the process B), the pressure reduction rate is the second pressure reduction rate.

Images