JP7808944B2 - vacuum dryer - Google Patents

Description

The present invention relates to a vacuum drying device.

Organic light-emitting diodes (OLEDs), which are light-emitting diodes that utilize organic electroluminescence (EL), are well known. Organic EL displays that use organic light-emitting diodes are thin, lightweight, and consume little power, and have the advantages of superior response speed, viewing angle, and contrast ratio. For these reasons, they have been attracting attention in recent years as the next generation of flat panel displays (FPDs).

An organic light-emitting diode has an anode formed on a substrate, a cathode provided on the opposite side of the substrate from the anode, and an organic layer provided between them. For example, the organic layer has, in this order from the anode side to the cathode side, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer.

Inkjet coating devices are used to form hole injection layers, hole transport layers, light-emitting layers, and other layers. The coating device forms a coating layer by applying a coating liquid containing an organic material and a solvent onto a substrate. The coating layer is then dried under reduced pressure and baked to form the hole injection layer and other layers.

Patent Document 1 describes reducing unevenness in the reduced-pressure drying speed of a coating layer within the surface of a substrate.

JP 2016-188735 A

In the technology described in Patent Document 1, it is preferable to reduce contact with the back surface of the substrate in the device formation region of the placed substrate during drying, and therefore a drying apparatus in which support pins come into contact between adjacent device regions is used.
Increasing the substrate size is undesirable because it increases the bending of the glass substrate and increases the occurrence of uneven drying. Furthermore, as the substrate size increases, the device formation area also increases, and bending cannot be ignored if left as is, so it becomes unavoidable to contact support pins with the back surface of the substrate in the device formation area.
In this case, the problem of unevenness occurring in the contact area remains unresolved.

The present invention has been made in view of the above circumstances, and aims to achieve the following objects.
1. To enable drying that corresponds to the increase in size of the substrate.
2. Suppression of temperature variations caused by support pins.
3. To be able to accommodate bending of the board.

The vacuum drying apparatus of the present invention comprises:
A vacuum drying apparatus for drying a solvent applied to a substrate in an evacuable chamber, comprising:
a lower flow plate disposed in the chamber so that its main surface is horizontal;
a temperature control mechanism that adjusts the temperature of the lower rectifying plate in accordance with the temperature at which the solvent volatilizes during drying of the substrate;
a plurality of support pins extending upward from the lower flow plate;
and
The support pin is
When the substrate is placed on the plurality of support pins and the entire substrate facing the temperature-controlled lower flow plate is held from below to dry the solvent,
The temperature drop ΔTp in the direction from the lower rectifying plate to the substrate in the support region of the substrate that is in contact with the support pins is relative to the temperature drop ΔTr in the direction from the lower rectifying plate to the substrate in the radiation region of the substrate that is not in contact with the support pins,
(ΔTr-ΔTp)/ΔTr≦((25+3.75)-(25+3.16))/(25+3.75)
The above problem was solved by providing a reduced diameter portion in a portion that abuts against the rear surface of the substrate.
The vacuum drying apparatus of the present invention comprises:
The support pin is
In the temperature drop in the direction from the lower flow plate toward the substrate,
a ratio ΔTpp/ΔTpφ of the temperature drop ΔTpφ at the reduced diameter portion to the temperature drop ΔTpp at a portion closer to the lower flow vane than the reduced diameter portion,
ΔTpp/ΔTpφ≧(25-18)/(18+3.16))
That is,
It is possible.
The vacuum drying apparatus of the present invention comprises:
The length of the reduced diameter portion is 1 mm or less.
It is possible.
The vacuum drying apparatus of the present invention comprises:
The diameter dimension Φφ of the reduced diameter portion is 0.5 mm or less.
It is possible.
The vacuum drying apparatus of the present invention comprises:
The tip of the reduced diameter portion has a spherical portion,
The radius of curvature SR of the spherical surface is 0.25 mm or less.
It is possible.
The vacuum drying apparatus of the present invention comprises:
the support pin has a support portion serving as a base end adjacent to the lower flow plate and a pin portion connected to the reduced diameter portion that abuts against the rear surface of the substrate,
In the temperature drop in the direction from the lower flow plate toward the substrate,
The ratio ΔTpd/ΔTpu of the temperature drop ΔTpd at the support portion to the temperature drop ΔTpu at the pin portion is
ΔTpd/ΔTpu≧(25-20)/(20-18)
That is,
It is possible.
The vacuum drying apparatus of the present invention comprises:
The pin portion has a diameter that decreases from the support portion toward the reduced diameter portion.
It is possible.
The vacuum drying apparatus of the present invention comprises:
the pin portion and the reduced diameter portion are separable from the support portion;
It is possible.
The vacuum drying apparatus of the present invention comprises:
The reduced diameter portion is made of a material having a thermal conductivity of 0.3 W/mk or less.
It is possible.
The vacuum drying apparatus of the present invention comprises:
The support pin is made of a material having a thermal conductivity of 0.5 W/mk or less.
It is possible.
The vacuum drying apparatus of the present invention comprises:
The support pin is
By setting the distribution of the cross-sectional area in the direction from the lower flow plate toward the substrate,
a temperature drop is set in a direction from the lower flow plate toward the substrate;
It is possible.
The vacuum drying apparatus of the present invention comprises:
The support pin has an internal space for reducing a cross-sectional area.
It is possible.
The vacuum drying apparatus of the present invention comprises:
The internal space is formed in the axial direction of the support pin.
It is possible.
The vacuum drying apparatus of the present invention comprises:
The internal space is formed in a radial direction of the support pin.
It is possible.
The vacuum drying apparatus of the present invention comprises:
The internal space formed in the radial direction of the support pin is open to the outside.
It is possible.

The vacuum drying apparatus of the present invention comprises:
A vacuum drying apparatus for drying a solvent applied to a substrate in an evacuable chamber, comprising:
When the substrate is placed on a plurality of support pins provided upright on a lower flow plate in the chamber to dry the solvent,
The temperature drop in the direction from the lower flow rectifying plate toward the substrate is a temperature drop ΔTp in the support region where the support pins are in contact with the substrate relative to a temperature drop ΔTr in the radiation region where the support pins are not in contact with the substrate,
(ΔTr-ΔTp)/ΔTr≦((25+3.75)-(25+3.16))/(25+3.75)
The support pin has a shape such that
This allows the difference between the temperature drop in the radiation area of the substrate and the temperature drop in the support area to be set within a predetermined range, thereby allowing the difference between the evaporation rate of the solvent in the radiation area of the substrate and the evaporation rate of the solvent in the support area to be set within a predetermined range, thereby suppressing unevenness caused by the difference in solvent evaporation rate and preventing unevenness in the drying state of the coating layer at different positions on the substrate surface.
At the same time, since drying can be performed with the support pins in contact with the rear surface of the substrate, problems caused by bending of the substrate do not occur.

The vacuum drying apparatus of the present invention comprises:
the support pin has a reduced diameter portion that is reduced in diameter at a portion that abuts against the rear surface of the substrate,
In the temperature drop in the direction from the lower flow plate toward the substrate,
a ratio ΔTpp/ΔTpφ of the temperature drop ΔTpφ at the reduced diameter portion to the temperature drop ΔTpp at a portion closer to the lower flow vane than the reduced diameter portion,
ΔTpp/ΔTpφ≧(25-19)/(19+3.16))
is.
This allows the temperature drop from the lower straightening plate toward the substrate to be sufficient in the portion up to the reduced diameter portion that abuts the back surface of the substrate, so that the difference between the temperature drop in the radiation region of the substrate and the temperature drop in the support region can be set to be within a specified range.

The vacuum drying apparatus of the present invention comprises:
The length of the reduced diameter portion is 1 mm or less.
This makes it possible to achieve both sufficient strength to support the substrate so that it does not bend, and a sufficient temperature drop that does not cause unevenness.

The vacuum drying apparatus of the present invention comprises:
The diameter dimension Φφ of the reduced diameter portion is 0.5 mm or less.
This makes it possible to achieve both sufficient strength to support the substrate so that it does not bend, and a sufficient temperature drop that does not cause unevenness.

The vacuum drying apparatus of the present invention comprises:
The tip of the reduced diameter portion has a spherical portion,
The radius of curvature SR of the spherical surface portion is 0.25 mm or less.
This makes it possible to achieve both sufficient strength to support the substrate so that it does not bend, and sufficient temperature drop that does not cause unevenness.

The vacuum drying apparatus of the present invention comprises:
the support pin has a support portion serving as a base end adjacent to the lower flow plate and a pin portion connected to the reduced diameter portion that abuts against the rear surface of the substrate,
In the temperature drop in the direction from the lower flow plate toward the substrate,
The ratio ΔTpd/ΔTpu of the temperature drop ΔTpd at the support portion to the temperature drop ΔTpu at the pin portion is
ΔTpd/ΔTpu≧(25-20)/(20-19)
is.
This allows for a sufficient temperature drop in the support section, reducing the amount of temperature drop required in the reduced diameter section that affects the solvent evaporation state on the substrate, while also allowing for a sufficient temperature drop in the pin section, reducing the amount of temperature drop required in the reduced diameter section that affects the solvent evaporation state on the substrate.
At the same time, the support and pin portions can be constructed with the same or different thermal conductivities, making it possible to achieve the sufficient temperature reduction in the support and pin portions as described above.
This allows the difference between the temperature drop in the radiation area of the substrate and the temperature drop in the support area to be set within a predetermined range.The difference between the evaporation rate of the solvent in the radiation area of the substrate and the evaporation rate of the solvent in the support area can be set within a predetermined range.As a result, unevenness caused by the difference in solvent evaporation rate can be suppressed, and unevenness in the drying state of the coating layer at different positions on the substrate surface can be prevented.
At the same time, since drying can be performed with the support pins in contact with the back surface of the substrate, it is possible to support the substrate so that it does not bend during drying, which makes it possible to achieve both sufficient strength to support the substrate so that it does not bend and a sufficient temperature drop that does not cause unevenness.

The vacuum drying apparatus of the present invention comprises:
The pin portion reduces in diameter from the support portion toward the reduced diameter portion.
This allows the support column and pin sections to have sufficient strength to support the substrate, while also achieving the minor diameter required to reduce the contact area at the reduced diameter section that contacts the substrate. As a result, the temperature drop at the reduced diameter section that contacts the substrate is not too large, and the support pin as a whole can achieve a sufficient temperature drop in the direction from the lower flow plate toward the substrate.

The vacuum drying apparatus of the present invention comprises:
The pin portion and the reduced diameter portion are separable from the post portion.
This makes it easy to replace the parts that come into contact with the substrate and wear out, improves the workability of maintenance, and makes it easy to reduce replacement costs.

The vacuum drying apparatus of the present invention comprises:
The reduced diameter portion is made of a material having a thermal conductivity of 0.3 W/mk or less.
This allows the difference in temperature drop between the radiation region of the substrate that is not in contact with the reduced diameter portion and the support region that is in contact with the reduced diameter portion to be set within a predetermined range, and the difference in evaporation rate of the solvent in the radiation region of the substrate and the support region to be set within a predetermined range.

The vacuum drying apparatus of the present invention comprises:
The support pin is made of a material having a thermal conductivity of 0.5 W/mk or less.
This allows the support portion to exhibit a sufficient temperature drop in the direction from the lower straightening plate toward the substrate, and the temperature drop in the pin portion and reduced diameter portion does not become too great, and the entire support pin can exhibit a sufficient temperature drop in the direction from the lower straightening plate toward the substrate.

The vacuum drying apparatus of the present invention comprises:
The support pin is
By setting the distribution of the cross-sectional area in the direction from the lower flow plate toward the substrate,
A temperature drop is set in the direction from the lower flow plate toward the substrate.
This allows the cross-sectional area of the support pins to be distributed in the axial direction, thereby enabling the heat conduction state of the support pins to be set to a predetermined state.The temperature drop in the direction from the lower flow plate to the substrate can be set to be distributed within a predetermined range along this direction, and the support pins as a whole can exhibit a sufficient temperature drop in the direction from the lower flow plate to the substrate.
Specifically, by reducing the cross-sectional area of the support pin, the amount of heat transferred in the axial direction is reduced, preventing the temperature of the substrate from rising. For example, the cross-sectional area in the radial direction can be reduced by forming a recess or through-hole extending in the radial direction at a predetermined position on the support pin, or by forming a cavity along the axial direction in the radial center of the support pin. In this case, it is preferable to maintain the required strength.

The vacuum drying apparatus of the present invention comprises:
The support pin has an internal space for reducing the cross-sectional area.
This reduces the cross-sectional area of the support pin in the radial direction by the internal space, reducing the amount of heat conducted in the axial direction, and making it possible to prevent the temperature on the substrate side from rising.

The vacuum drying apparatus of the present invention comprises:
The internal space is formed in the axial direction of the support pin.
This reduces the cross-sectional area of the support pin in the radial direction by the internal space, reducing the amount of heat conducted in the axial direction, and making it possible to prevent the temperature on the substrate side from rising.
It is possible.
Specifically, by forming an internal space along the axial direction in the radial center of the support pin, it is possible to reduce the radial cross-sectional area. In this case, it is preferable to maintain the required strength. In this case, for example, the support part can be made pipe-shaped, or the pin part can be made cylindrical with a closed end at the reduced diameter side.

The vacuum drying apparatus of the present invention comprises:
The internal space is formed in the radial direction of the support pin.
This reduces the cross-sectional area of the support pin in the radial direction by the internal space, reducing the amount of heat conducted in the axial direction, and making it possible to prevent the temperature on the substrate side from rising.
It is possible.
Specifically, by forming an internal space as a through hole or recess extending along the radial direction of the support pin, it is possible to reduce the radial cross-sectional area. In this case, it is preferable to maintain the necessary strength. In this case, for example, the internal space can also be used as an air vent hole in the part of the pin where the support part is fitted.

The vacuum drying apparatus of the present invention comprises:
The internal space formed in the radial direction of the support pin opens to the outside.
This reduces the cross-sectional area of the support pin in the radial direction by the internal space, reducing the amount of heat conducted in the axial direction, and making it possible to prevent the temperature on the substrate side from rising.
It is possible.
Specifically, by forming the internal space as a through hole extending along the radial direction of the support pin, it is possible to reduce the radial cross-sectional area. At this time, it is preferable to maintain the necessary strength. In this case, for example, the internal space can also be used as an air vent hole in the part of the pin where the support part is fitted.

This invention has the advantage of suppressing temperature unevenness caused by support pins and being able to accommodate substrate warping, thereby enabling drying that is compatible with larger substrates.

1 is a schematic side cross-sectional view showing a first embodiment of a vacuum drying device according to the present invention. FIG. 2 is a perspective view showing a support pin in the first embodiment of the vacuum drying device according to the present invention. 2 is an exploded cross-sectional view showing a support pin in the first embodiment of the vacuum drying device according to the present invention. FIG. 4 is an enlarged cross-sectional view of the vicinity of the tip of a support pin, illustrating a drying process in the first embodiment of the vacuum drying device according to the present invention. FIG. 4 is an enlarged cross-sectional view of the vicinity of the tip of a support pin, illustrating a drying process in the first embodiment of the vacuum drying device according to the present invention. FIG. 4 is an enlarged cross-sectional view of the vicinity of the tip of a support pin, illustrating a drying process in the first embodiment of the vacuum drying device according to the present invention. FIG. 4 is a graph illustrating a drying curve in a drying process of the first embodiment of the vacuum drying device according to the present invention. 8 is a graph showing an enlarged view of the circled portion of the drying curve in FIG. 7. 4 is an enlarged cross-sectional view of the vicinity of the tip of a support pin for explaining a drying process in the first embodiment of the vacuum drying device according to the present invention. FIG. 4 is an enlarged cross-sectional view of the vicinity of the tip of a support pin for explaining a drying process in the first embodiment of the vacuum drying device according to the present invention. FIG. FIG. 2 is a diagram illustrating a drying process in a vacuum drying device. 5A to 5C are diagrams illustrating a temperature drop during a drying process in an area where there are no support pins in the first embodiment of the vacuum drying device according to the present invention. 5A and 5B are diagrams illustrating a temperature drop during a drying process in an area in contact with a support pin in the first embodiment of the vacuum drying device according to the present invention. FIG. 4 is a cross-sectional view illustrating another example of the internal space portion in the first embodiment of the vacuum drying device according to the present invention. 5A to 5C are diagrams illustrating a temperature drop in the first embodiment of the vacuum drying device according to the present invention. 5A to 5C are diagrams illustrating a temperature drop in the first embodiment of the vacuum drying device according to the present invention. 5A to 5C are diagrams illustrating a temperature drop in the first embodiment of the vacuum drying device according to the present invention. 5A to 5C are diagrams illustrating a temperature drop in the first embodiment of the vacuum drying device according to the present invention. 5A to 5C are diagrams illustrating a temperature drop in the first embodiment of the vacuum drying device according to the present invention. The following describes an embodiment of the present invention. The following describes an embodiment of the present invention. The occurrence of unevenness in an embodiment of the present invention will be described.

A first embodiment of a vacuum drying apparatus according to the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic cross-sectional side view showing a vacuum drying apparatus according to this embodiment, and in the figure, reference numeral 100 denotes the vacuum drying apparatus.

The vacuum drying apparatus 100 according to this embodiment can be used, for example, as a reduced-pressure drying apparatus for drying (reduced-pressure drying) a coating layer applied to a bank formed on a substrate (glass substrate) 10 in the manufacturing process of an organic EL display.
The organic EL display, which is the object to be treated in the vacuum drying apparatus 100 according to this embodiment, will be described below.

An organic EL display has a substrate, multiple unit circuits arranged on the substrate, a scanning line driving circuit provided on the substrate, and a data line driving circuit provided on the substrate. The unit circuits are provided in an area surrounded by multiple scanning lines connected to the scanning line driving circuit and multiple data lines connected to the data line driving circuit. The unit circuits include a TFT layer and organic light-emitting diodes.

The TFT layer has multiple TFTs (Thin Film Transistors). One TFT functions as a switching element, and another TFT functions as a current control element that controls the amount of current flowing through the organic light-emitting diode. The TFT layer is operated by the scanning line drive circuit and data line drive circuit to supply current to the organic light-emitting diode.

A TFT layer is provided for each unit circuit, and the unit circuits are controlled independently. Note that the TFT layer may have any general configuration and is not limited to this configuration.
In this configuration, the organic EL display is driven by an active matrix method, but may be driven by a passive matrix method.

A transparent substrate such as a glass substrate or a resin substrate is used as the substrate. A TFT layer is formed on the substrate. A planarization layer is formed on the TFT layer to flatten the steps formed by the TFT layer.

The planarization layer has insulating properties. Contact plugs are formed in contact holes that penetrate the planarization layer. The contact plugs electrically connect the anodes, which serve as pixel electrodes formed on the flat surface of the planarization layer, to the TFT layer. The contact plugs may be made of the same material as the anodes and formed at the same time.

The organic light-emitting diode is formed on the flat surface of the planarization layer. The organic light-emitting diode has an anode as a pixel electrode, a cathode as a counter electrode located on the opposite side of the pixel electrode from the substrate, and an organic layer formed between the anode and cathode. By operating the TFT layer, a voltage is applied between the anode and cathode, causing the organic layer to emit light.

The anode is made of, for example, ITO (Indium Tin Oxide) and transmits light from the organic layer. Light that passes through the anode passes through the substrate and is extracted to the outside. An anode is provided for each unit circuit.

The cathode is made of, for example, aluminum, and reflects light from the organic layer back toward the organic layer. The light reflected by the cathode passes through the organic layer, anode, and substrate, and is extracted to the outside. The cathode is common to multiple unit circuits.

The organic layer has, for example, a hole injection layer, a hole transport layer, an emitting layer, an electron transport layer, and an electron injection layer, in that order from the anode side to the cathode side. When a voltage is applied between the anode and cathode, holes are injected from the anode into the hole injection layer, and electrons are injected from the cathode into the electron injection layer.

Holes injected into the hole injection layer are transported to the light-emitting layer by the hole transport layer. Electrons injected into the electron injection layer are transported to the light-emitting layer by the electron transport layer. Holes and electrons then recombine in the light-emitting layer, exciting the light-emitting material in the light-emitting layer and causing the light-emitting layer to emit light.

The light-emitting layers may be, for example, a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer. The red light-emitting layer is made of a red light-emitting material that emits red light, the green light-emitting layer is made of a green light-emitting material that emits green light, and the blue light-emitting layer is made of a blue light-emitting material that emits blue light. The red light-emitting layer, green light-emitting layer, and blue light-emitting layer are formed in the openings of the bank.

The bank separates the coating liquid for the red, green, and blue light-emitting layers, preventing them from mixing. The bank has insulating properties and fills the contact holes that penetrate the planarization layer.

The first step in the manufacturing method of an organic light-emitting diode is to form an anode as a pixel electrode. Vapor deposition, for example, is used to form the anode. The anode is formed for each unit circuit on the flat surface of the planarization layer. Contact plugs may also be formed along with the anode.

The next step is to form the banks. The banks are formed using, for example, photoresist and then patterned into a predetermined pattern using a photolithography process. The anode is exposed through the openings in the banks.

The next step is to form the hole injection layer. The inkjet method or similar method is used to form the hole injection layer. The inkjet method is used to apply a coating solution for the hole injection layer onto the anode, forming a coating layer. The coating layer is then dried and baked to form the hole injection layer.

The next step is to form the hole transport layer. Similar to the hole injection layer, the hole transport layer is formed using an inkjet method or similar. The hole transport layer is formed by applying a coating liquid for the hole transport layer onto the hole injection layer using the inkjet method. The hole transport layer is then formed by drying and baking the coating layer.

The next step is to form the light-emitting layer. To form the light-emitting layer, an inkjet method or similar method is used, just like when forming the hole injection layer and hole transport layer. The coating liquid for the light-emitting layer is applied onto the hole transport layer using the inkjet method, forming a coating layer. The coating layer is then dried and baked to form the light-emitting layer.

The light-emitting layers may be, for example, a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer. The red light-emitting layer, the green light-emitting layer, and the blue light-emitting layer are formed in the openings of the bank. The bank separates the coating liquid for the red light-emitting layer, the coating liquid for the green light-emitting layer, and the coating liquid for the blue light-emitting layer, preventing these coating liquids from mixing.

The next step is to form an electron transport layer. The electron transport layer can be formed by, for example, vapor deposition. Since the electron transport layer can be common to multiple unit circuits, it can be formed not only on the light-emitting layer within the bank openings, but also on the banks.

The next step is to form an electron injection layer. The electron injection layer can be formed by, for example, vapor deposition. The electron injection layer is formed on the electron transport layer. The electron injection layer may be common to multiple unit circuits.

In the next step, a cathode is formed. The cathode is formed by, for example, vapor deposition. The cathode is formed on the electron injection layer. The cathode may be common to a plurality of unit circuits.
When the organic EL display is driven by a passive matrix system rather than an active matrix system, the cathode is patterned into a predetermined pattern.

The above steps are used to manufacture an organic light-emitting diode. A substrate processing system is used to form the organic layers: the hole injection layer, hole transport layer, and light-emitting layer.

The substrate processing system performs processes corresponding to the above steps to form a hole injection layer, a hole transport layer, and an emissive layer on the anode. The substrate processing system includes a loading station, a processing station, an unloading station, and a control device.

The loading station loads substrates from the outside and removes them one by one. Each substrate has a TFT layer, planarization layer, anode, bank, etc. pre-formed on it.

The loading station includes a mounting table on which a substrate is placed, a transport path provided between the mounting table and the processing station, and a substrate transport body provided on the transport path. The substrate transport body transports substrates between the processing station and a cassette placed on the cassette mounting table.

The processing station forms a hole injection layer, a hole transport layer, and an emissive layer on the anode. The processing station includes a hole injection layer forming block that forms the hole injection layer, a hole transport layer forming block that forms the hole transport layer, and an emissive layer forming block that forms the emissive layer.

The hole injection layer forming block forms a hole injection layer by applying a coating liquid for the hole injection layer onto the anode to form a coating layer, and then drying and baking the coating layer. The coating liquid for the hole injection layer contains an organic material and a solvent. The organic material may be either a polymer or a monomer. In the case of a monomer, it may be polymerized by baking to form a polymer.

The hole injection layer formation block includes a coating device, a buffer device, a reduced-pressure drying device, a heat treatment device, and a temperature control device. The coating device ejects droplets of the coating liquid for the hole injection layer toward the opening of the bank. The buffer device temporarily stores substrates awaiting processing.

The reduced-pressure drying device dries the coating layer applied by the coating device under reduced pressure to remove the solvent contained in the coating layer. The heat treatment device heat-treats the coating layer dried by the reduced-pressure drying device. The temperature adjustment device adjusts the temperature of the substrate heat-treated in the heat treatment device to a predetermined temperature, such as room temperature.

The coating device, buffer device, heat treatment device, and temperature control device maintain an atmospheric atmosphere inside. The reduced-pressure drying device switches the internal atmosphere between atmospheric and reduced-pressure atmosphere.

In the hole injection layer formation block, the arrangement and number of coating devices, buffer devices, reduced-pressure drying devices, heat treatment devices, and temperature control devices, as well as the internal atmosphere, can be selected as desired.

The hole injection layer formation block also includes multiple substrate transport devices and corresponding delivery devices. Each substrate transport device transports a substrate to an adjacent device. For example, the substrate transport device transports a substrate to an adjacent coating device and buffer device. The substrate transport device transports a substrate to an adjacent reduced pressure drying device. The substrate transport device transports a substrate to an adjacent heat treatment device and temperature adjustment device. Delivery devices are installed between the loading station and substrate transport device, between substrate transport devices, and between substrate transport devices, respectively, and relay substrates between these devices. The interiors of the substrate transport devices and delivery devices are maintained at atmospheric pressure.

A transfer device is provided between the substrate transfer device in the hole injection layer formation block and the substrate transfer device in the hole transport layer formation block to relay substrates between them. The interior of the transfer device is maintained in an atmospheric environment.

The hole transport layer forming block forms a hole transport layer by applying a coating liquid for the hole transport layer onto the hole injection layer to form a coating layer, and then drying and baking the coating layer. The coating liquid for the hole transport layer contains an organic material and a solvent. The organic material may be either a polymer or a monomer. In the case of a monomer, it may be polymerized by baking to form a polymer.

The hole transport layer formation block includes a coating device, a buffer device, a reduced-pressure drying device, a heat treatment device, and a temperature adjustment device. The coating device ejects droplets of the coating liquid for the hole transport layer toward the opening of the bank. The buffer device temporarily stores substrates awaiting processing. The reduced-pressure drying device dries the coating layer applied by the coating device under reduced pressure to remove the solvent contained in the coating layer. The heat treatment device heat-treats the coating layer dried by the reduced-pressure drying device. The temperature adjustment device adjusts the temperature of the substrate heated by the heat treatment device to a predetermined temperature, for example, room temperature.

The coating device and buffer device are maintained in an air atmosphere. Meanwhile, the heat treatment device and temperature control device are maintained in a low-oxygen, low-dew-point atmosphere to prevent deterioration of the organic material in the hole transport layer. The reduced-pressure drying device switches its internal atmosphere between a low-oxygen, low-dew-point atmosphere and a reduced-pressure atmosphere.

In the hole transport layer formation block, the arrangement, number, and internal atmosphere of the coating device, buffer device, reduced pressure drying device, heat treatment device, and temperature control device can be selected as desired.

Similarly to the hole injection layer formation block, the hole transport layer formation block includes a substrate transfer device and a delivery device.
The inside of the substrate transport device and the delivery device is maintained in an air atmosphere or a low-oxygen, low-dew-point atmosphere because the inside of the reduced-pressure drying device adjacent to the substrate transport device can be switched between a low-oxygen, low-dew-point atmosphere and a reduced-pressure atmosphere.

The transfer device is configured as a load lock device that switches its internal atmosphere between air and a low-oxygen, low-dew-point atmosphere. This is because a reduced-pressure drying device is installed adjacent to the transfer device downstream. Meanwhile, the interior of the transfer device is maintained in a low-oxygen, low-dew-point atmosphere.

The light-emitting layer forming block forms a light-emitting layer by applying a coating liquid for the light-emitting layer onto the hole transport layer to form a coating layer, and then drying and baking the formed coating layer. The coating liquid for the light-emitting layer contains an organic material and a solvent. The organic material may be either a polymer or a monomer. In the case of a monomer, it may be polymerized by baking to form a polymer.

The light-emitting layer formation block comprises a coating device, a buffer device, a reduced-pressure drying device, a heat treatment device, and a temperature adjustment device. The coating device ejects droplets of the coating liquid for the light-emitting layer toward the opening of the bank. The buffer device temporarily stores substrates awaiting processing. The reduced-pressure drying device dries the coating layer applied by the coating device under reduced pressure to remove the solvent contained in the coating layer. The heat treatment device heat-treats the coating layer dried by the reduced-pressure drying device. The temperature adjustment device adjusts the temperature of the substrate heated by the heat treatment device to a predetermined temperature, for example, room temperature.

The coating device and buffer device are maintained in an air atmosphere. Meanwhile, the heat treatment device and temperature control device are maintained in a low-oxygen, low-dew-point atmosphere to prevent deterioration of the organic material in the light-emitting layer. The reduced-pressure drying device switches its internal atmosphere between a low-oxygen, low-dew-point atmosphere and a reduced-pressure atmosphere.

In the light-emitting layer forming block, the arrangement, number, and internal atmosphere of the coating device, buffer device, reduced-pressure drying device, heat treatment device, and temperature control device can be selected arbitrarily.
The light-emitting layer forming block also includes a substrate transport device and a delivery device, similar to the hole transport layer forming block and the hole injection layer forming block.

The unloading station sequentially unloads multiple substrates to the outside. The unloading station includes a mounting table on which the substrates are placed, a transport path provided between the mounting table and the processing station, and a substrate transport body provided on the transport path. The substrate transport body transports the substrates placed on the mounting table between the processing station and the unloading station.

The control device is composed of a computer including a CPU (Central Processing Unit) and a storage medium such as memory, and performs various processes by having the CPU execute programs (also called recipes) stored on the storage medium.

As shown in FIG. 1, the vacuum drying apparatus 100 according to this embodiment accommodates a substrate 10, on which a coating layer containing an organic material and a solvent has been formed, inside a processing vessel 101, and evaporates the solvent from the coating layer in a reduced-pressure atmosphere where the pressure is lower than atmospheric pressure. The vacuum drying apparatus 100 includes, for example, a processing vessel (chamber) 101, a lower rectifying plate 102, an upper rectifying plate 103, a driving mechanism 104, an exhaust mechanism 105, a temperature control mechanism 106, and a support mechanism 110.

The processing vessel (chamber) 101 contains a substrate 10 on which a coating layer 40 (Figure 4) containing an organic material and a solvent is formed. The coating layer 40 is formed on the upper side of the substrate 10. A loading/unloading opening for the substrate 10 is formed in the sidewall of the processing vessel (chamber) 101, and an opening/closing shutter is provided at this loading/unloading opening. The opening/closing shutter opens the loading/unloading opening to allow loading and unloading of the substrate 10, and the opening/closing shutter closes the loading/unloading opening to allow depressurization inside the processing vessel (chamber) 101. Alternatively, the top of the processing vessel (chamber) 101 can be used as a lid to open and close it. Before depressurization begins, the interior of the processing vessel (chamber) 101 may be set to a predetermined atmosphere, such as a nitrogen atmosphere, which is a low-oxygen, low-dew-point atmosphere.

The lower rectifying plate 102 and the upper rectifying plate 103 are arranged in the processing vessel (chamber) 101 so that their opposing main surfaces are horizontal. The substrate 10 is placed above the lower rectifying plate 102 and below the upper rectifying plate 103 for drying. The upper rectifying plate 103 is capable of moving its position vertically relative to the lower rectifying plate 102.

The upper rectifying plate 103 can be moved up and down by a drive mechanism 104. The drive mechanism 104 is located outside the processing vessel (chamber) 101. The drive mechanism 104 can drive the upper rectifying plate 103 up and down while keeping the processing vessel (chamber) 101 sealed. The drive mechanism 104 can prevent interference between the upper rectifying plate 103 and the substrate 10 when the substrate 10 is loaded or unloaded.

The exhaust mechanism 105 is capable of exhausting the processing vessel (chamber) 101 through an exhaust port 105 a disposed at the bottom of the processing vessel (chamber) 101 .
The exhaust mechanism 105 includes, for example, a reduced pressure source and an adaptive pressure control (APC) valve. The reduced pressure source may be, for example, a dry pump, a mechanical booster pump, or a turbomolecular pump. The reduced pressure source is connected to the processing vessel (chamber) 101 via a pipe in which the APC valve is installed.

The reduced pressure generating source is connected to the exhaust port 105a of the processing vessel (chamber) 101 and reduces the pressure inside the processing vessel (chamber) 101 to a pressure lower than atmospheric pressure. The pressure inside the processing vessel (chamber) 101 is reduced to, for example, 1 Pa or less while being adjusted by the APC valve. In the processing vessel (chamber) 101, the exhaust port 105a is formed in the lower wall of the processing vessel 101 as shown in FIG. 1, but it may also be formed in the upper wall or side wall.

The temperature adjustment mechanism 106 adjusts the temperature of the substrate 10 when the substrate 10 is dried under reduced pressure. Specifically, the temperature adjustment mechanism 106 adjusts the temperature of the lower rectifying plate 102 when the substrate 10 is dried under reduced pressure.

The support mechanism 110 holds the substrate 10 from below inside the processing vessel (chamber).
The support mechanism 110 has a plurality of support pins 120 erected upward from the lower flow plate 102. The support mechanism 110 can hold the entire substrate 10 when drying the substrate 10 under reduced pressure. The support pins 120 can prevent interference with the mounting portion of the substrate transport device on which the substrate 10 is placed when the substrate 10 is loaded or unloaded.

Furthermore, the vacuum drying apparatus 100 may also include a gas supply mechanism. The gas supply mechanism supplies gases such as air or nitrogen gas into the processing vessel (chamber) 101 to return the interior of the processing vessel 101, which has been depressurized by the exhaust mechanism 105, to its original atmosphere. The gas supply mechanism includes, for example, a gas supply source, a mass flow controller, and an on-off valve. The gas supply source is connected to the processing vessel 101 via a pipe equipped with a mass flow controller and an on-off valve, and supplies gas into the processing vessel 101. The supply amount can be adjusted by the mass flow controller.
The gas supply mechanism may have a supply port so as to supply gas above the upper flow regulating plate 103 .

The vacuum drying apparatus 100 dries the coating layer 40 (see FIG. 4 ) formed on the substrate 10 by the coating apparatus under reduced pressure, evaporating the solvent contained in the coating layer 40. The solvent vapor is transported from near the upper surface of the substrate 10 to the exhaust port 105a of the processing vessel 101. The more easily the vapor moves, the more rapidly the drying progresses. To reduce unevenness in the drying speed, the driving mechanism 104 controls the distance between the upper rectifying plate 103 and the substrate 10, thereby controlling conductance and thereby reducing this uneven drying.
At the same time, the exhaust port 105a is positioned below the lower current plate 102, thereby controlling the conductance and reducing the uneven drying.

2 and 3 are perspective and exploded views of the support pin according to the present embodiment.
The support mechanism 110 has a plurality of support pins 120 that stand upright in parallel upward from the lower flow plate 102 .

As shown in Figures 2 and 3, the support pin 120 has a support portion 121 that serves as the base end close to the lower flow plate 102, a reduced diameter portion 122 that abuts against the back surface of the substrate 10, and a pin portion 123 connected to the reduced diameter portion 122.
The support portion 121 is separable from the reduced diameter portion 122 and the pin portion 123.

The support portion 121 has a base end portion 125 and a base end flange 125a fixed to the lower flow plate 102, a columnar portion 121a, an upper flange 121b, and a connecting portion 121c.
The base end portion 125 and the base end flange 125 a are fixed to the fixing portion 102 a of the lower flow plate 102 .

The columnar portion 121a has a generally cylindrical outer shape. A base end flange 125a is provided at the end of the columnar portion 121a closest to the lower flow plate 102. A base end portion 125 is formed on the base end flange 125a at a position closer to the lower flow plate 102. An upper flange 121b is provided at the end of the columnar portion 121a closest to the upper flow plate 103. A connection portion 121c is formed on the upper flange 121b at a position closer to the upper flow plate 103.

The base end portion 125 , the base end flange 125 a , the columnar portion 121 a , the upper flange 121 b , and the connecting portion 121 c all have outer circumferential surfaces that are coaxial with the axis of the support portion 121 .
The outer diameter of the base flange 125a is set to be larger than the outer diameter of the columnar portion 121a. The outer diameter of the base end 125 is set to be smaller than the outer diameter of the base flange 125a. The outer diameter of the base end 125 is set to be larger than the outer diameter of the columnar portion 121a. For example, a male screw for fixing may be formed on the outer periphery of the base end 125. In this case, a female screw is formed on the fixing portion 102a of the lower flow plate 102.

The outer diameter of the upper flange 121b is set to be larger than the outer diameter of the columnar portion 121a. The outer diameter of the upper flange 121b is set to be smaller than the outer diameter of the base flange 125a. The outer diameter of the connecting portion 121c is set to be larger than the outer diameter of the columnar portion 121a. The outer diameter of the connecting portion 121c is set to be smaller than the outer diameter of the upper flange 121b. For example, a male thread for fixing may be formed on the outer periphery of the connecting portion 121c.

The pin portion 123 has a columnar portion 123 a connected to the support portion 121 and a conical portion 123 b whose diameter decreases from the lower flow plate 102 toward the upper flow plate 103 .
The columnar portion 123a can be connected coaxially to the support portion 121. The outer diameter of the columnar portion 123a is set to be substantially equal to the outer diameter of the upper flange 121b.

The conical portion 123b is formed on the upper end side of the cylindrical portion 123a. The conical portion 123b is formed coaxially with the cylindrical portion 123a. A reduced diameter portion 122 is formed at the tip of the conical portion 123b. The conical portion 123b and the reduced diameter portion 122 are formed coaxially.
The outer diameter of the conical portion 123b is set to be equal to the outer diameter of the cylindrical portion 123a at its lower end and equal to the outer diameter of the reduced diameter portion 122 at its upper end.

An internal space 126 opens at the lower end of the pin portion 123. The connecting portion 121c is inserted into the internal space 126 to connect the support portion 121 and the pin portion 123. The internal space 126 extends in the axial direction of the pin portion 123. The axial dimension of the internal space 126 can be set to be approximately equal to the axial dimension of the cylindrical portion 123a.

A vent hole 124 opens on the outer periphery of the cylindrical portion 123a. The vent hole 124 is connected to the internal space 126. The vent hole 124 is an internal space that extends radially. When the support portion 121 and the pin portion 123 are connected, the vent hole 124 is located closer to the reduced diameter portion 122 in the axial direction than the upper end of the connection portion 121c. The vent hole 124 can be formed in one location, or in two or more locations.

The reduced diameter portion 122 is formed coaxially at the tip of the pin portion 123. The reduced diameter portion 122 has the same diameter all the way to the base end tip. A spherical portion (tip portion) 122a is formed at the tip of the reduced diameter portion 122. The radius of curvature of the spherically formed spherical portion 122a of the reduced diameter portion 122 is set equal to the radius that defines the diameter dimension of the reduced diameter portion 122. The spherical portion 122a comes into point contact with the back surface of the substrate 10.

By providing the internal space 126, the distribution of the cross-sectional area of the support pin 120 in the axial direction is set.
The support column 121 can be formed in a ring shape by providing an internal space 126 in the axial direction. Furthermore, the support column 121 can also be formed with an internal space 126 in the radial direction that opens to the outer periphery.
An internal space 126 can be formed in the axial direction in the pin portion 123. Furthermore, an additional opening may be formed parallel to the vent hole 124 at a different position in the axial direction.
Furthermore, in the pin portion 123, the internal space portion 126 can be extended in the axial direction, with a part of it opening into the conical portion 123b.

In this way, by setting the cross-sectional area of the support pin 120 as described above, the amount of heat conducted axially through the support pin 120 is set.

Here, we will explain how the solvent in the coating layer formed on the substrate 10 in this embodiment dries.

Fig. 4 is a schematic cross-sectional view of the vicinity of the tip of the support pin, illustrating the drying process in this embodiment, Fig. 5 is a schematic cross-sectional view of the vicinity of the tip of the support pin, illustrating the drying process in this embodiment, Fig. 6 is a schematic cross-sectional view of the vicinity of the tip of the support pin, illustrating the drying process in this embodiment, illustrating the drying process in this embodiment.
During drying, the substrate 10 on which the coating layer 40 has been formed is supported by a plurality of support pins 120 in a vacuum drying apparatus 100 (FIG. 1).

As shown in FIG. 4, the coating layer 40 is filled in the bank 30 on the surface of the substrate 10 as a coating liquid.
Here, the drying of the substrate 10 will be explained by dividing it into a radiation region 10r that is not in contact with the support pins 120 and a support region 10p in the vicinity of the support pins 120. Note that these regions are named as such for the purpose of explanation, and the substrate 10 is not configured to differ in the direction along its surface.

Fig. 7 is a graph illustrating a drying curve in the drying process in this embodiment, and Fig. 8 is a graph showing an enlarged view of the circled portion of the drying curve in Fig. 7.
In this state, the inside of the processing vessel (chamber) 101 is evacuated by the exhaust mechanism 105 (FIG. 1) to a predetermined pressure corresponding to the vapor pressure of the solvent, as shown as recipe A in FIGS.

As a result, the inside of the processing vessel (chamber) 101 is depressurized to a predetermined initial exhaust pressure PA.
At this time, the lower straightening plate 102 (FIG. 1) is set to a predetermined temperature, for example, room temperature, about 25° C., corresponding to the temperature at which the solvent to be evaporated volatilizes.

At the same time, the drive mechanism 104 (FIG. 1) controls the distance between the upper current plate 103 and the substrate 10 to control the conductance in the space between the upper current plate 103 and the substrate 10. Specifically, narrowing the distance between the upper current plate 103 and the substrate 10 increases the conductance.
Then, the solvent gradually volatilizes from the coating layer 40 in the bank 30 until the saturated vapor pressure of the solvent is reached, and the volume, or film thickness, of the coating layer 40 is sufficiently reduced as shown in FIG.

Furthermore, from this state, the inside of the processing vessel (chamber) 101 is rapidly evacuated by the exhaust mechanism 105 (FIG. 1) as shown near the circle in FIG. 7 and as recipe A in FIG. 8. This reduces the pressure inside the processing vessel (chamber) 101 to a predetermined rapid exhaust pressure. The rapid exhaust pressure is set to a pressure even lower than the saturated vapor pressure of the solvent.
8, the vapor pressure of the solvent is reached and the solvent evaporates all at once, causing the pressure to rise and the temperature of the substrate 10 to drop rapidly due to the heat of vaporization. After the rapid evacuation, the evacuation curve decreases over an evaporation time TA.

In response to the vapor pressure of the solvent, the solvent rapidly evaporates from the coating layer 40 within the bank 30, drying as shown in Figure 6, leaving the solute near the bottom of the bank 30. At this time, the volume, or film thickness, of the coating layer 40 is sufficiently reduced before the rapid evacuation, as shown in Figure 5, which shortens the solvent evaporation time TA. Therefore, the film thickness of the remaining solute within the bank 30 can be made approximately uniform.

Fig. 9 is a schematic cross-sectional view showing an enlarged view of the vicinity of the tip of a support pin to explain the drying process, corresponding to Fig. 5 of this embodiment. Fig. 10 is a schematic cross-sectional view showing an enlarged view of the vicinity of the tip of a conventional support pin to explain the drying process, corresponding to Fig. 6 of this embodiment. Fig. 11 is a view for explaining the drying process in a vacuum drying apparatus.
7 and 8, when the interior of the processing vessel (chamber) 101 is evacuated to an initial exhaust pressure PB higher than the initial exhaust pressure PA, the evaporation rate of the solvent becomes slower than that of recipe A, as shown in Fig. 9. Therefore, as shown in Fig. 9, the volume of the coating layer 40, i.e., the film thickness, is not sufficiently reduced within the bank 30. In other words, because the initial exhaust pressure is high, evaporation of the solvent is insufficient, and the volume of the coating film 40, i.e., the film thickness, is difficult to reduce. In other words, a large amount of solvent remains that is not completely evaporated.

Furthermore, from this state, the inside of the processing vessel (chamber) 101 is rapidly evacuated by the exhaust mechanism 105 (Figure 1), as shown near the circle in Figure 7 and as recipe B in Figure 8. This reduces the pressure inside the processing vessel (chamber) 101 to a predetermined rapid exhaust pressure. The rapid exhaust pressure is set to a pressure lower than the saturated vapor pressure of the solvent.

At this time, as shown in Recipe B in Figure 8, the vapor pressure of the solvent is reached, and a large amount of solvent remains that has not evaporated completely. This causes the pressure to rise and the heat of vaporization to rapidly drop the temperature of the substrate 10. After the rapid evacuation, the evacuation curve decreases over the evaporation time TB. Because a large amount of solvent remains in the coating layer 40 within the bank 30, the evaporation time TB is longer than the evaporation time TA.

Here, as shown in FIG. 9, in the support region 10p, the support pins 12 are in contact with the support region 10p, and therefore the temperature state, that is, the heat conduction state, is different from that of the radiation region 10r.
9, in the radiation region 10r, the temperature of the substrate 10 is determined solely by radiation from the lower current plate 102. Furthermore, the temperature of the substrate 10 drops due to the heat of vaporization that accompanies the volatilization of the solvent.
In particular, the evaporation rate of the solvent in the support region 10p is faster than that in the radiation region 10r due to the temperature difference caused by the thermal conduction of the support pins 120. If the evaporation rate of the solvent in the support region 10p is too fast, the temperature drop of the substrate 10 will be even greater.

As a result, the difference in solvent evaporation rate between the support region 10p and the radiation region 10r increases, and coupled with the small decrease in the volume (film thickness) of the coating film 40 within the bank 30 at the initial exhaust pressure PB, the coffee stain phenomenon shown in Figure 11 increases the likelihood of solute adhering to the side of the bank 30.

Here, the coffee stain phenomenon refers to a state in which, as shown in Figure 11, when a coating liquid (coating layer) 40 dropped onto the surface of a flat substrate 10 is dried, the amount of solvent evaporated is greater in the peripheral portion 40a of the coating liquid 40 than in the central portion 40b, and the temperature of the peripheral portion 40a decreases due to the heat of vaporization, resulting in a larger amount of solute remaining in the peripheral portion 40a.

As a result, as shown in Figure 10, the difference in solute film thickness between the support region 10p and the radiation region 10r becomes large, causing unevenness.

In the vacuum drying apparatus 100 of this embodiment, as shown as recipe A in Figures 7 and 8, the solvent is volatilized to an initial exhaust pressure PA, and then the pressure is reduced by rapidly exhausting the solvent to a rapid exhaust pressure over an evaporation time TA, preventing the solute from adhering to the side surfaces of the bank 30.

This reduces the difference in evaporation rate between the support region 10p and the radiation region 10r, making it possible to prevent unevenness from occurring.
Here, as shown in FIG. 5, in recipe A, the solvent is slowly exhausted up to the initial exhaust pressure PA, and then the solvent is sufficiently reduced, and then rapid exhaust is performed, thereby sufficiently shortening the evaporation time and making it possible to suppress the occurrence of unevenness.

If the recipe alone is not sufficient to suppress unevenness, a configuration is added to further suppress the difference in evaporation rate between the support region 10p and the radiation region 10r.

In the support pin 120 of this embodiment, the spherical portion 122a formed on the reduced diameter portion 122 is in contact with the substrate 10, resulting in almost point contact. In addition, the diameter dimension of the reduced diameter portion 122 is small, that is, the cross-sectional area of the reduced diameter portion 122 in the axial direction is small.
At the same time, the pin portion 123 and the support portion 121 have a set axial distribution of cross-sectional area, and are made of a material with low thermal conductivity.

In this way, the temperature difference caused by the thermal conduction of the support pins 120 in the support region 10p prevents the evaporation rate of the solvent from becoming faster than in the radiation region 10r. Because the evaporation rate of the solvent in the support region 10p is not too fast, the temperature drop of the substrate 10 is prevented from further increasing. Furthermore, the solute does not adhere to the side surface of the bank 30 due to the coffee stain phenomenon.

As a result, the difference in temperature state, i.e., the difference in heat conduction state, between the support area 10p, where the support pin 120 is in contact, and the radiation area 10r can be suppressed. Therefore, by suppressing the difference in drying speed due to the influence of heat conduction, it is possible to suppress the occurrence of unevenness.

The specific suppression of evaporation rate differences using the support pin 120 is explained below.

Fig. 12 is a diagram illustrating a temperature drop during the drying process in an area where there are no support pins in the vacuum drying apparatus of this embodiment. Fig. 13 is a diagram illustrating a temperature drop during the drying process in an area where there are support pins in the vacuum drying apparatus of this embodiment.
In the radiation region 10r, since there are no support pins 120, the temperature from the lower straightening plate 102 to the substrate 10 drops, as shown by the arrows in Figure 12, mainly due to the temperature drop SM caused by radiation and the temperature drop SN caused by heat dissipation due to evaporation of the solvent.
In FIG. 12, the support pin 120 is shown by a broken line for comparison.

In the support region 10p, due to the presence of the support pins 120, the temperature from the lower rectifying plate 102 to the substrate 10 drops primarily due to a temperature drop SC caused by heat conduction through the support pins 120 and a temperature drop SN caused by heat dissipation due to solvent evaporation, as shown by the arrows in Figure 13.

At this time, as shown in FIG. 13 , the temperature drop of the support pin 120 in the direction from the lower rectifying plate 102 toward the substrate 10 is such that the relationship between the temperature drop ΔTr in the radiation region 10r and the temperature drop ΔTp in the support region 10p is as follows:
(ΔTr-ΔTp)/ΔTr≦((25+3.75)-(25+3.16))/(25+3.75)
It is configured so that:

At the same time, as shown in FIG. 13 , the relationship between the temperature drop ΔTpφ at the reduced diameter portion 122 and the temperature drop ΔTpp at the support pin 120's support portion 121 and pin portion 123, which are closer to the lower flow plate 102 than the reduced diameter portion 122, is as follows:
ΔTpp/ΔTpφ≧(25-19)/(19+3.16))
It is configured so that:

Furthermore, the length of the reduced diameter portion 122 of the support pin 120 is 1 mm or less. In this case, the length of the reduced diameter portion 122 is the length from the spherical portion 122a to the tip of the conical portion 123b in the axial direction of the support pin 120.

The diameter dimension Φφ of the reduced diameter portion 122 is 0.5 mm or less. The radius of curvature SR of the spherical portion 122a formed at the tip of the reduced diameter portion 122 is 0.25 mm or less.

As shown in FIG. 13, the relationship between the temperature drop ΔTpd at the support portion 121 and the temperature drop ΔTpu at the pin portion 123 of the support pin 120 is as follows:
ΔTpd/ΔTpu≧(25-20)/(20-19)
It is configured so that:

The support pin 120 is made of a material with a thermal conductivity of 0.5 W/mK or less. In particular, the reduced diameter portion 122 that abuts the substrate 10 is made of a material with a thermal conductivity of 0.3 W/mK or less. The support pin 120 is preferably made of a material with low thermal conductivity and sufficient strength, such as resin; specific examples include PFA, PTFE, PEEK, conductive PEEK, etc. In other words, the support pin 120 can be made of a material with a lower thermal conductivity than the glass substrate (substrate) 10, which is the object to be processed.

The support portion 121, the pin portion 123, and the reduced diameter portion 122 can be made of the same material. Alternatively, the support portion 121, the pin portion 123, and the reduced diameter portion 122 can be made of different materials.

When the support portion 121, the pin portion 123, and the reduced diameter portion 122 are made of different materials, the thermal conductivity of the pin portion 123 and the reduced diameter portion 122 can be made lower than the thermal conductivity of the support portion 121. Furthermore, the thermal conductivity of the support portion 121 can be made lower than the thermal conductivity of the pin portion 123 and the reduced diameter portion 122.

Furthermore, the support pins 120 set the temperature drop in the direction from the lower flow plate 102 toward the substrate 10 by setting the distribution of cross-sectional area perpendicular to the axis of the support pins 120.

In order to set this cross-sectional area distribution (rate of change in the axial direction), the support pin 120 has an internal space 126 for reducing the cross-sectional area.
The internal space 126 for setting the cross-sectional area can be formed in either the support column 121 or the pin 123 , or in both the support column 121 and the pin 123 .

The internal space 126 may be formed in the axial direction of the support pin 120 .
For example, as shown in Fig. 3, the pin portion 123 may have an internal space 126 at the lower end of the cylindrical portion 123a, which serves as a connection hole for inserting and connecting the connecting portion 121c. The internal space 126 serving as a connection hole extends in the axial direction of the support pin 120. The internal space 126 serving as a connection hole may extend further toward the upper end of the cylindrical portion 123a from the portion that abuts against the connecting portion 121c to connect the connecting portion 121c. In this case, the internal space 126 may be formed over the entire length of the cylindrical portion 123a.
Furthermore, as shown in FIG. 14, the upper end of the internal space 126 may form an opening 124a that communicates with the outer circumferential surface of the conical portion 123b.

Furthermore, as shown in Figure 3, the internal space 126 that serves as the connection hole can be formed so that it extends radially of the support pin 120 and opens onto the circumferential surface of the cylindrical portion 123a to form the vent hole 124. The vent hole 124 can also penetrate both radial sides of the support pin 120.

14, the vent hole 124 may penetrate only one side of the support pin 120 in the radial direction.
As shown in FIG. 14, a plurality of vent holes 124 may be formed, such as holes 124b, which open at different positions in the axial direction of the support pin 120.

As shown in Figure 14, the support portion 121 can have an internal space 126 formed by hollowing out the inside of the columnar portion 121a in the axial direction. In this case, the internal space 126 does not have to be formed in the base end portion 125, base end flange 125a, upper flange 121b, or connecting portion 121c. Alternatively, if the support portion 121 can maintain sufficient strength, the internal space 126 can be formed in the base end portion 125, base end flange 125a, and upper flange 121b. In these cases, the support portion 121 can be formed in sections and assembled.

As shown in FIG. 14, the support column 121 may have an internal space 126 extending radially of the support pin 120 so as to open on the peripheral surface of the columnar portion 121a and serve as a vent hole 124d.
Similar to the hole 124b, a plurality of vent holes 124d may be formed in the axial direction of the support pin 120. Furthermore, the vent holes 124d may penetrate the support pin 120 on both sides in the radial direction.

In the vacuum drying apparatus 100 of this embodiment, the temperature drop is set based on the cross-sectional area in the axial direction of the support pins 120 and the thermal conductivity of the material. This allows the surface temperature of the support region 10p of the substrate 10 to be sufficiently reduced when volatilizing the solvent, thereby minimizing the difference in surface temperature with the radiation region 10r. As a result, when volatilizing the solvent, the evaporation rate of the solvent in the support region 10p can be reduced, minimizing the difference in evaporation rate with the radiation region 10r.

In this way, when the solvent is volatilized in the support region 10p, the temperature difference caused by the thermal conduction of the support pins 120 prevents the evaporation rate of the solvent from becoming faster than in the radiation region 10r. Because the evaporation rate of the solvent in the support region 10p is not too fast, the temperature drop of the substrate 10 is prevented from further increasing. Furthermore, the solute does not adhere to the side surface of the bank 30 due to the coffee stain phenomenon.

As a result, the difference in temperature state, i.e., the difference in heat conduction state, between the support area 10p, where the support pin 120 is in contact, and the radiation area 10r can be suppressed. Therefore, by suppressing the difference in drying speed due to the influence of heat conduction, it is possible to suppress the occurrence of unevenness.

The following describes examples of the present invention.

Here, we will explain the confirmation test performed as a specific example of the support pin 120 in the vacuum drying apparatus 100 of the present invention.

<Experimental Example 0>
The distance between the lower rectifying plate 102 and the substrate 10 was set to 60 mm, the temperature of the lower rectifying plate 102 was set to 25°C, and the substrate temperature drop due to radiation was determined when the pressure inside the processing vessel (chamber) 101 during rapid exhaust reached 50 Pa.
At this time, the drying conditions such as the initial exhaust pressure PA were set as follows, and a simulation was performed, which was designated as an experimental example, case 0.

Pressure: 50 Pa
Initial exhaust pressure PA: 3600 Pa
Initial exhaust time: 180 seconds

Substrate 10
Material: Glass (soda glass)
Thickness: 500 μm
Size: 1300mm x 1500mm

The results of the temperature drop in the experimental example case 0 are shown in FIG.
From the results of the experimental example case 0, the temperature of the surface of the radiation region 10r of the substrate 10 was -3.75°C.

<Experimental Example Case 1>
The distance between the lower rectifying plate 102 and the substrate 10 was set to 60 mm, the temperature of the lower rectifying plate 102 was set to 25° C., and the temperature drop of the substrate due to heat conduction and solvent evaporation was determined.
At this time, the drying conditions were set to be the same as those in Experimental Example Case 0.

In addition, multiple support pins 120 with the following specifications were installed upright on the lower flow plate 102. The support pins 120 were dried while in contact with the device area of the substrate 10, and this was experimental example case 1.

Support pin 120
Total length: 60mm

Strut part 121
Material: PTFE
Total length: 38.5mm
Length of columnar portion 121a: 20 mm (solid)
Columnar part 121a diameter: φ3mm

Base end 125 length: 9 mm (1.5 mm clearance)
Base end 125 diameter; M5mm
Base flange 125a length (thickness): 3 mm
Diameter of base flange 125a: φ8 mm

Upper flange 121b length (thickness): 2 mm
Diameter of upper flange 121b: φ5 mm
Length of connecting portion 121c: 4.5 mm (1 mm clearance)
Diameter of connecting portion 121c: M3 mm

Pin portion 123
Material: PEEK
Length of cylindrical portion 123a: 15.6 mm
Diameter of the cylindrical portion 123a: φ5 mm

Internal space part 126 lower end inner diameter; φ3mm
Length of the internal space 126: 15 mm
Internal space 126 female thread length: 5 mm
Vent hole 124 diameter: φ1.5 mm
Distance from the bottom end of the vent hole 124 to the center: 7 mm

Length of conical portion 123b: 8.4 mm
Apex angle of conical portion 123b: 30°
Length of reduced diameter portion 122: 1 mm (integrated with pin portion 123)
Material: PEEK
Reduced diameter part 122 diameter: 0.5mm
Spherical part 122a curvature radius: 0.25mm

13 shows the temperature drop results in Experimental Example Case 1. In FIG. 13, the temperature drop curve from the lower rectifying plate 102 to the substrate 10 is shown along the axial direction of the support pin 120.
From the results of the experimental example case 1, the temperature of the surface of the support region 10p of the substrate 10 was −3.16°C.

<Experimental Example Case 2>
As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was determined.
At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

A plurality of support pins 120 having the following specifications were erected on the lower current plate 102. The support pins 120 were dried in a state where they were in contact with the device region of the substrate 10, and this was designated as experimental example case 2.
Here, only the specifications that are different from those in Experimental Example Case 1 are shown.

Strut part 121
Material: PFA

Pin portion 123
Material: PFA
Reduced diameter portion 122 (integrated with pin portion 123)
Material: PFA

15 shows the temperature drop results for Experimental Example Case 2. In FIG. 15, the temperature drop curve from the lower current plate 102 to the substrate 10 is shown along the axial direction of the support pin 120.
From the results of the experimental example case 2, the temperature of the surface of the support region 10p of the substrate 10 was -3.25°C.

<Experimental Example Case 3>
As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was determined.
At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

A plurality of support pins 120 having the following specifications were erected on the lower current plate 102. The support pins 120 were dried in a state where they were in contact with the device region of the substrate 10, and this was designated as experimental example case 3.
Here, only the specifications that are different from those in Experimental Example Case 1 are shown.

Strut part 121
Material: SUS304

Pin portion 123
Material: Conductive PEEK
Reduced diameter portion 122 (integrated with pin portion 123)
Material: Conductive PEEK

16 shows the temperature drop results in Experimental Example Case 3. In FIG. 16, the temperature drop curve from the lower current plate 102 to the substrate 10 is shown along the axial direction of the support pin 120.
From the results of the experimental example case 3, the temperature of the surface of the support region 10p of the substrate 10 was -2.85°C.

<Experimental Example Case 4>
As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was determined.
At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

A plurality of support pins 120 having the following specifications were erected on the lower current plate 102. The support pins 120 were dried in a state where they were in contact with the device region of the substrate 10, and this was designated as experimental example case 4.
Here, only the specifications that are different from those in Experimental Example Case 1 are shown.

Strut part 121
Material: SUS304

Pin portion 123
Material: A5052 (aluminum alloy)
Reduced diameter portion 122 (integrated with pin portion 123)
Material: A5052 (aluminum alloy)

17 shows the temperature drop results in Experimental Example Case 4. In FIG. 17, the temperature drop curve from the lower current plate 102 to the substrate 10 is shown along the axial direction of the support pin 120.
From the results of Experimental Example Case 4, the temperature of the surface of the support region 10p of the substrate 10 was -2.39°C.

<Experimental Example Case 5>
As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was determined.
At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

A plurality of support pins 120 having the following specifications were erected on the lower current plate 102. The support pins 120 were dried in a state where they were in contact with the device region of the substrate 10, and this was designated as experimental example case 5.
Here, only the specifications that are different from those in Experimental Example Case 1 are shown.

Strut part 121
Material: SUS304

Pin portion 123
Material: PTFE
Reduced diameter portion 122 (integrated with pin portion 123)
Material: PTFE

18 shows the temperature drop results for Experimental Example Case 5. In FIG. 18, the temperature drop curve from the lower current plate 102 to the substrate 10 is shown along the axial direction of the support pin 120.
From the results of the experimental example case 5, the temperature of the surface of the support region 10p of the substrate 10 was -3.04°C.

<Experimental Example Case 6>
As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was determined.
At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

A plurality of support pins 120 having the following specifications were erected on the lower current plate 102. The support pins 120 were dried in a state where they were in contact with the device region of the substrate 10, and this was designated as experimental example case 6.
Here, only the specifications that are different from those in Experimental Example Case 1 are shown.

Strut part 121
Material: A5052

Pin portion 123
Material: Conductive PEEK
Reduced diameter portion 122 (integrated with pin portion 123)
Material: Conductive PEEK

19 shows the temperature drop results for Experimental Example Case 6. In FIG. 19, the temperature drop curve from the lower current plate 102 to the substrate 10 is shown along the axial direction of the support pin 120.
From the results of Experimental Example Case 6, the temperature of the surface of the support region 10p of the substrate 10 was -2.84°C.

The thermal conductivities of the constituent materials of the support pin 120 used in Experimental Examples Cases 1 to 6 are shown below.
Dry air: 0.0241 W/mK
PFA; 0.19W/mK
PTFE; 0.25W/mK
PEEK; 0.25W/mK
Conductive PEEK; 0.46W/mK
SUS304; 15W/mK
A5052; 236W/mK
Glass: 0.6 W/mK
_Si3N4 ; _24W /mK

Furthermore, in Experimental Examples Cases 1 to 6, the presence or absence of unevenness on the surface of the substrate 10 after drying was observed.
In Experimental Example Case 1 and Experimental Example Case 2, no unevenness was observed, but in Experimental Examples Cases 3 to 6, visible unevenness was observed.
The temperature drops in Experimental Examples 1 to 6 are shown in Figure 20. The evaporation rates [pl/S] of the corresponding solvents are also shown.

From the results shown in FIG. 20, it can be seen that when the ratio of the glass surface temperature in the support region 10p to the glass surface temperature in the radiation region 10r is smaller than 3.16/3.75, unevenness occurs.
From the results shown in FIG. 20, it can be seen that when the ratio of the evaporation rate in the support region 10p to the evaporation rate in the radiation region 10r is greater than 1130/20.3, unevenness occurs.

The results shown in Figures 13 and 15 to 20 show that unevenness occurs when the support pin 120 is made of a material with a thermal conductivity greater than 1 W/mK.

13 and 15 to 20, the temperature drop caused by the support pin 120 in the support region 10p occurs suddenly at the reduced diameter portion 122, and the ratio ΔDpφ/ΔDr of the gradient of this temperature curve to the gradient ΔDr of the temperature curve in the radiation region 10r shown in FIG. 12 is as follows, as shown in FIG.
ΔDpφ/ΔDr≦(19+3.16)/(25+3.75)
It is preferable that the range is within this range in order to prevent unevenness.

Similarly, the ratio ΔDpp/ΔDr of the drop in the temperature curve at the support portion 121 and the pin portion 123 to the slope ΔDr of the temperature curve at the radiation region 10r shown in FIG. 12 is expressed as follows, as shown in FIG. 15:
ΔDpp/ΔDr≧(25-20)/(25+3.75)
It is preferable that the range is within this range in order to prevent unevenness.

In experimental example case 1, the results shown in Figure 13 indicate that the inflection point Dpφ on the temperature curve from the pin portion 123 to the reduced diameter portion 122 is at a temperature of 19°C. The results shown in Figure 13 also indicate that the inflection point Dpp on the temperature curve from the support portion 121 to the pin portion 123 is at a temperature of 20°C.

In experimental example case 2, the results shown in Figure 15 indicate that the inflection point Dpφ on the temperature curve from the pin portion 123 to the reduced diameter portion 122 is at a temperature of 18°C. The results shown in Figure 15 also indicate that the inflection point Dpp on the temperature curve from the support portion 121 to the pin portion 123 is at a temperature of 20°C.

In experimental example case 3, the results shown in Figure 16 indicate that the inflection point Dpφ on the temperature curve from the pin portion 123 to the reduced diameter portion 122 is at a temperature of 24°C. The results shown in Figure 16 also indicate that the inflection point Dpp on the temperature curve from the support portion 121 to the pin portion 123 is at a temperature of 25°C.

In experimental example case 4, the results shown in Figure 17 indicate that the inflection point Dpφ on the temperature curve from the pin portion 123 to the reduced diameter portion 122 is at a temperature of 25°C. From the results shown in Figure 17, the temperature of the inflection point Dpp on the temperature curve from the support portion 121 to the pin portion 123 is unknown.

In experimental example case 5, the results shown in Figure 18 indicate that the inflection point Dpφ on the temperature curve from the pin portion 123 to the reduced diameter portion 122 is at a temperature of 24°C. The results shown in Figure 18 also indicate that the inflection point Dpp on the temperature curve from the support portion 121 to the pin portion 123 is at a temperature of 25°C.

In experimental example case 6, the results shown in Figure 19 indicate that the inflection point Dpφ on the temperature curve from the pin portion 123 to the reduced diameter portion 122 is at a temperature of 24°C. The results shown in Figure 19 also indicate that the inflection point Dpp on the temperature curve from the support portion 121 to the pin portion 123 is at a temperature of 25°C.

<Experimental Example Case A>
As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was determined.
At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

A plurality of support pins 12 having the following specifications were erected on the lower current plate 102. The support pins 12 were dried in a state where they were in contact with the device region of the substrate 10, and this was designated as experimental example Case A.
Here, only the specifications that are different from those in Experimental Example Case 1 are shown.

Strut part 121
Material: PFA

Pin portion 123
Material: PFA
Instead of the reduced diameter portion 122, a contact portion 12h (integral with the pin portion 123) shown in FIG.
Material: PFA
Contact diameter: φ23mm
Contact surface: Flat ring-shaped; ring width 1 mm

The results of visually checking the occurrence of unevenness in the experimental example case A are shown in Fig. 22. Note that Fig. 22 also shows the results of experimental examples case 1, 2, and 3.
The results of the experimental example case A show that unevenness occurs.

<Experimental Example Case B>
As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was determined.
At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

A plurality of support pins 12 having the following specifications were erected on the lower current plate 102. The support pins 12 were dried in a state where they were in contact with the device region of the substrate 10, and this was designated as experimental example Case B.
Here, only the specifications that are different from those in Experimental Example Case 1 are shown.

Strut part 121
Material: PFA

Pin portion 123
Material: PFA
Instead of the reduced diameter portion 122, the contact portion 12h shown in FIG. 21 is made flat (integral with the pin portion 123).
Material: PFA
Contact diameter: φ25mm
Contact surface; flat

FIG. 22 shows the results of visually checking the occurrence of unevenness in Experimental Example Case B.
The results of the experimental example case B show that unevenness occurs.

<Experimental Example Case C>
As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was determined.
At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

A plurality of support pins 12 having the following specifications were erected on the lower current plate 102. The support pins 12 were dried in a state where they were in contact with the device region of the substrate 10, and this was designated as experimental example case C.
Here, only the specifications that are different from those in Experimental Example Case 1 are shown.

Strut part 121
Material: SUS304

Pin portion 123
Material: PEEK
Instead of the reduced diameter portion 122, the contact portion 12h shown in FIG. 21 is made flat (integral with the pin portion 123).
Material: PEEK
Contact diameter: φ25mm
Contact surface; flat

FIG. 22 shows the results of visually checking the occurrence of unevenness in experimental example case C.
The results of the experimental example case C show that unevenness occurs.

<Experimental Example Case D>
As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was determined.
At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

A plurality of support pins 12 having the following specifications were erected on the lower current plate 102. The support pins 12 were dried in a state where they were in contact with the device region of the substrate 10, and this was designated as experimental example case D.
Here, only the specifications that are different from those in Experimental Example Case 1 are shown.

Strut part 121
Material: SUS304

Pin portion 123
Material: PEEK
Instead of the reduced diameter portion 122, a contact portion 12h (integral with the pin portion 123) shown in FIG.
Material: PEEK
Contact diameter: φ23mm
Contact surface: Flat ring-shaped; ring width 1 mm

FIG. 22 shows the results of visually checking the occurrence of unevenness in experimental example case D.
The results of the experimental example case D show that unevenness occurs.

<Experimental Example Case E>
As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was determined.
At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

A plurality of support pins 12 having the following specifications were erected on the lower current plate 102. The support pins 120 were dried in a state where they were in contact with the device region of the substrate 10, and this was designated as experimental example case E.
Here, only the specifications that are different from those in Experimental Example Case 1 are shown.

Strut part 121
Material: PFA

Pin portion 123
Material: PEEK
Reduced diameter portion 122 (integrated with pin portion 123)
Material: PEEK

FIG. 22 shows the results of visually checking the occurrence of unevenness in experimental example case E.
The results of the experimental example case E show that no unevenness occurs.

From the results shown in FIG. 22, it can be seen that when the reduced diameter portion 122 is in point contact with the substrate 10, no unevenness occurs.
From the results shown in FIG. 22, it can be seen that when the contact portion 12h is in surface contact with the substrate 10 as shown in FIG. 21, unevenness occurs regardless of the material.

Examples of applications of this invention include drying in the manufacturing process of FPDs such as organic EL, as well as drying moisture from electrical and electronic components, and drying metal and machined products after water washing.

10...Substrate (glass substrate)
100... Vacuum drying apparatus 10p... Support region 10r... Radiation region 30... Bank 40... Coating layer 101... Processing container (chamber)
102... Lower rectifying plate 102a... Fixed portion 103... Upper rectifying plate 104... Driving mechanism 105... Exhaust mechanism 105a... Exhaust port 106... Temperature adjustment mechanism 110... Support mechanism 120... Support pin 121... Support portion 121a... Column portion 121b... Upper flange 121c... Connection portion 122... Reduced diameter portion 122a... Spherical portion (tip portion)
123...Pin portion 123a...Cylindrical portion 123b...Conical portion 124...Vent hole 125...Base end portion 125a...Base end flange 126...Internal space portion 130...Upper flow straightening plate 150...Processing vessel Dpφ...Inflection point PA...Initial exhaust pressure SC...Temperature drop SM...Temperature drop SN...Temperature drop SR...Radius of curvature TA...Evaporation time TB...Evaporation time ΔTp...Temperature drop ΔTpd...Temperature drop ΔTpp...Temperature drop ΔTpu...Temperature drop ΔTpφ...Temperature drop ΔTr...Temperature drop Φφ...Diameter dimension

Claims (15)

A vacuum drying apparatus for drying a solvent applied to a substrate in an evacuable chamber, comprising:
a lower flow plate disposed in the chamber so that its main surface is horizontal;
a temperature control mechanism that adjusts the temperature of the lower rectifying plate in accordance with the temperature at which the solvent volatilizes during drying of the substrate;
a plurality of support pins extending upward from the lower flow plate;
and
The support pin is
When the substrate is placed on the plurality of support pins and the entire substrate facing the temperature-controlled lower flow plate is held from below to dry the solvent,
The temperature drop ΔTp in the direction from the lower rectifying plate to the substrate in the support region of the substrate that is in contact with the support pins is relative to the temperature drop ΔTr in the direction from the lower rectifying plate to the substrate in the radiation region of the substrate that is not in contact with the support pins,
(ΔTr-ΔTp)/ΔTr≦((25+3.75)-(25+3.16))/(25+3.75)
a reduced diameter portion having a reduced diameter at a portion that abuts against the rear surface of the substrate so as to
A vacuum drying apparatus characterized by: The support pin is
In the temperature drop in the direction from the lower flow plate toward the substrate,
a ratio ΔTpp/ΔTpφ of the temperature drop ΔTpφ at the reduced diameter portion to the temperature drop ΔTpp at a portion closer to the lower flow vane than the reduced diameter portion,
ΔTpp/ΔTpφ≧(25-19)/(19+3.16))
That is,
2. The vacuum drying apparatus according to claim 1. The length of the reduced diameter portion is 1 mm or less.
3. The vacuum drying apparatus according to claim 2. The diameter dimension Φφ of the reduced diameter portion is 0.5 mm or less.
4. The vacuum drying apparatus according to claim 3. The tip of the reduced diameter portion has a spherical portion,
The radius of curvature SR of the spherical surface is 0.25 mm or less.
5. The vacuum drying apparatus according to claim 4. the support pin has a support portion serving as a base end adjacent to the lower flow plate and a pin portion connected to the reduced diameter portion that abuts against the rear surface of the substrate,
In the temperature drop in the direction from the lower flow plate toward the substrate,
The ratio ΔTpd/ΔTpu of the temperature drop ΔTpd at the support portion to the temperature drop ΔTpu at the pin portion is
ΔTpd/ΔTpu≧(25-20)/(20-19)
That is,
3. The vacuum drying apparatus according to claim 2. The pin portion has a diameter that decreases from the support portion toward the reduced diameter portion.
7. The vacuum drying apparatus according to claim 6. the pin portion and the reduced diameter portion are separable from the support portion;
8. The vacuum drying apparatus according to claim 6 or 7. The reduced diameter portion is made of a material having a thermal conductivity of 0.3 W/mk or less.
9. The vacuum drying apparatus according to claim 2, wherein the drying apparatus is a vacuum drying apparatus. The support pin is made of a material having a thermal conductivity of 0.5 W/mk or less.
10. The vacuum drying apparatus according to claim 1. The support pin is
By setting the distribution of the cross-sectional area in the direction from the lower flow plate toward the substrate,
a temperature drop is set in a direction from the lower flow plate toward the substrate;
11. The vacuum drying apparatus according to claim 1. The support pin has an internal space for reducing a cross-sectional area.
12. The vacuum drying apparatus according to claim 11. The internal space is formed in the axial direction of the support pin.
13. The vacuum drying apparatus according to claim 12. The internal space is formed in a radial direction of the support pin.
13. The vacuum drying apparatus according to claim 12. The internal space formed in the radial direction of the support pin is open to the outside.
15. The vacuum drying apparatus according to claim 14.