Vacuum drying equipment

Abstract

To prevent deflection and uneven drying of a substrate.SOLUTION: A vacuum dryer 100 for drying a solvent coated on a substrate 10 in an exhaustible chamber 101, has a plurality of support pins 120 in which a relation between a temperature drop ΔTp in a supporting area 10p where the support pins are in contact and a temperature drop ΔTr in a radiation area 10r where the support pins are not in contact, in a temperature drop in a direction from a lower straightening plate 102 toward the substrate is (ΔTr-ΔTp) / ΔTr≤((25+3.75)-(25+3.16)) / (25+3.75), when drying the solvent by placing the substrate on the plurality of support pins erected on the lower straightening plate in the chamber.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a vacuum drying apparatus. [Background technology]

[0002] Organic light-emitting diodes (OLEDs), which are light-emitting diodes that utilize organic electroluminescence (EL), are well known. OLED displays using 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).

[0003] An organic light-emitting diode has an anode formed on a substrate, a cathode provided on the opposite side of the substrate with respect to the anode, and an organic layer provided between them. The organic layer has, for example, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer, in this order from the anode side to the cathode side.

[0004] An inkjet coating device is used to form the hole injection layer, hole transport layer, light-emitting layer, etc. The coating device forms a coating layer by applying a coating liquid containing an organic material and a solvent onto a substrate. The hole injection layer, etc., is formed by drying and baking the coating layer under reduced pressure.

[0005] Patent Document 1 describes reducing the unevenness in the reduced pressure drying speed of a coating layer within the surface of a substrate. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-188735 Summary of the Invention [Problem to be solved by the invention]

[0007] 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 for this reason, 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.

[0008] 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 larger substrates. 2. Suppression of temperature variations caused by support pins. 3. It must be able to accommodate bending of the board. [Means for solving the problem]

[0009] 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 The substrate is placed on the plurality of support pins. The entire substrate facing the temperature-controlled lower current plate is held from below. When drying 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 in the support portion and the temperature drop ΔTpu in 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.

[0010] 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: before Inside the chamber of lower rectification On the board erected Ta When the substrate is placed on a plurality of support pins to dry the solvent, beforeThe temperature drop in the direction from the current plate to the substrate is I In the shooting area Warm The temperature drop ΔTr is Support In the holding area Warm The temperature drop ΔTp is (ΔTr-ΔTp) / ΔTr≦((25+3.75)-(25+3.16)) / (25+3.75) Tona Support It has a holding pin. 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.

[0011] 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.

[0012] 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 sufficient temperature drop that does not cause unevenness.

[0013] 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 sufficient temperature drop that does not cause unevenness.

[0014] 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.

[0015] 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 in the support portion and the temperature drop ΔTpu in 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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 of 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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. 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. [Effects of the Invention]

[0025] According to the present invention, it is possible to suppress the occurrence of temperature unevenness due to support pins and to accommodate bending of the substrate, thereby achieving the effect of enabling drying that is suitable for larger substrates. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a schematic cross-sectional side view showing a first embodiment of a vacuum drying apparatus according to the present invention. [Figure 2] 1 is a perspective view showing a support pin in a first embodiment of a vacuum drying apparatus according to the present invention. [Figure 3] 1 is an exploded cross-sectional view showing a support pin in a first embodiment of a vacuum drying device according to the present invention. [Figure 4] 3 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. [Figure 5] 3 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. [Figure 6] 3 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. [Figure 7] 3 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. [Figure 8] 8 is a graph showing an enlarged view of the circled portion of the drying curve in FIG. 7. [Figure 9] FIG. 3 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. [Figure 10]FIG. 3 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. [Figure 11] FIG. 2 is a diagram illustrating a drying process in a vacuum drying device. [Figure 12] 5A and 5B 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. [Figure 13] 5A and 5B are diagrams illustrating a temperature drop in a region in contact with a support pin during a drying process in the first embodiment of the vacuum drying device according to the present invention. [Figure 14] 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. [Figure 15] FIG. 3 is a diagram illustrating a temperature drop in the first embodiment of the vacuum drying device according to the present invention. [Figure 16] FIG. 3 is a diagram illustrating a temperature drop in the first embodiment of the vacuum drying device according to the present invention. [Figure 17] FIG. 3 is a diagram illustrating a temperature drop in the first embodiment of the vacuum drying device according to the present invention. [Figure 18] FIG. 3 is a diagram illustrating a temperature drop in the first embodiment of the vacuum drying device according to the present invention. [Figure 19] FIG. 3 is a diagram illustrating a temperature drop in the first embodiment of the vacuum drying device according to the present invention. [Figure 20] The following describes an embodiment of the present invention. [Figure 21] The following describes an embodiment of the present invention. [Figure 22] The occurrence of unevenness in an embodiment of the present invention will be described. DETAILED DESCRIPTION OF THE INVENTION

[0027] 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.

[0028] 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.

[0029] The organic EL display includes a substrate, a plurality of 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 a plurality of scanning lines connected to the scanning line driving circuit and a plurality of data lines connected to the data line driving circuit. The unit circuits include a TFT layer and an organic light-emitting diode.

[0030] 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 a scanning line drive circuit and a data line drive circuit to supply current to the organic light-emitting diode.

[0031] A TFT layer is provided for each unit circuit, and the plurality of 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.

[0032] The substrate is a transparent substrate such as a glass substrate or a resin substrate. A TFT layer is formed on the substrate. A planarizing layer is formed on the TFT layer to flatten the steps formed by the TFT layer.

[0033] The planarization layer has insulating properties. Contact plugs are formed in contact holes that penetrate the planarization layer. The contact plugs electrically connect the TFT layer to anodes, which serve as pixel electrodes formed on the flat surface of the planarization layer. The contact plugs may be made of the same material as the anodes and formed at the same time.

[0034] 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 provided on the opposite side of the substrate relative to the pixel electrode, 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.

[0035] The anode is made of, for example, ITO (Indium Tin Oxide) and transmits light from the organic layer. The light that passes through the anode passes through the substrate and is extracted to the outside. An anode is provided for each unit circuit.

[0036] 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, the anode, and the substrate and is extracted to the outside. The cathode is common to multiple unit circuits.

[0037] The organic layer includes, for example, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer in this order from the anode side to the cathode side. When a voltage is applied between the anode and the cathode, holes are injected from the anode into the hole injection layer, and electrons are injected from the cathode into the electron injection layer.

[0038] 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, causing the light emitting layer to emit light.

[0039] As the light-emitting layers, for example, a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer are formed. The red light-emitting layer is formed of a red light-emitting material that emits red light, the green light-emitting layer is formed of a green light-emitting material that emits green light, and the blue light-emitting layer is formed of a blue light-emitting material that emits blue light. The red light-emitting layer, the green light-emitting layer, and the blue light-emitting layer are formed in the opening of the bank.

[0040] 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, thereby preventing these coating liquids from mixing. The bank has insulating properties and fills the contact holes that penetrate the planarizing layer.

[0041] In the manufacturing method of an organic light-emitting diode, the first step is to form an anode as a pixel electrode. The anode is formed, for example, by evaporation. The anode is formed for each unit circuit on the flat surface of the planarization layer. A contact plug may be formed together with the anode.

[0042] In the next step, a bank is formed, which is formed using, for example, photoresist and patterned into a predetermined pattern by photolithography, with the anode exposed in the opening of the bank.

[0043] In the next step, a hole injection layer is formed. The hole injection layer is formed by an inkjet method or the like. A coating liquid for the hole injection layer is applied onto the anode by the inkjet method to form a coating layer. The coating layer is then dried and baked to form the hole injection layer.

[0044] In the next step, a hole transport layer is formed. Similar to the formation of the hole injection layer, the hole transport layer is formed by an inkjet method or the like. A coating liquid for the hole transport layer is applied onto the hole injection layer by the inkjet method to form a coating layer. The coating layer is then dried and baked to form the hole transport layer.

[0045] In the next step, the light-emitting layer is formed. To form the light-emitting layer, an inkjet method or the like is used, as in the formation of the hole injection layer and hole transport layer. The coating layer is formed by applying a coating liquid for the light-emitting layer onto the hole transport layer using the inkjet method. The coating layer is then dried and baked to form the light-emitting layer.

[0046] 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, thereby preventing these coating liquids from mixing.

[0047] In the next step, an electron transport layer is formed. 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 opening of the bank but also on the bank.

[0048] In the next step, an electron injection layer is formed. For example, a vapor deposition method is used to form the electron injection layer. The electron injection layer is formed on the electron transport layer. The electron injection layer may be common to a plurality of unit circuits.

[0049] 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 method rather than an active matrix method, the cathode is patterned into a predetermined pattern.

[0050] Through the above steps, an organic light-emitting diode is manufactured. A substrate processing system is used to form the hole injection layer, the hole transport layer, and the light-emitting layer among the organic layers.

[0051] The substrate processing system performs processes corresponding to the above steps to form a hole injection layer, a hole transport layer, and a light-emitting layer on the anode. The substrate processing system includes a loading station, a processing station, an unloading station, and a control device.

[0052] The loading station loads substrates from the outside and then sequentially removes them. Each substrate has a TFT layer, a planarization layer, an anode, a bank, and other components pre-formed on it.

[0053] The loading station includes a stage for placing a substrate thereon, a transport path provided between the stage 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 stage.

[0054] The processing stations form a hole injection layer, a hole transport layer, and a light emitting layer on the anode, and include a hole injection layer forming block for forming the hole injection layer, a hole transport layer forming block for forming the hole transport layer, and a light emitting layer forming block for forming the light emitting layer.

[0055] The hole injection layer-forming block is formed 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 to form the hole injection 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.

[0056] 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 a coating solution for the hole injection layer toward the opening of the bank. The buffer device temporarily stores substrates waiting to be processed.

[0057] 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 by the heat treatment device to a predetermined temperature, for example, room temperature.

[0058] The coating device, buffer device, heat treatment device, and temperature adjustment device are maintained in an atmospheric atmosphere, while the reduced-pressure drying device switches the internal atmosphere between the atmospheric atmosphere and a reduced-pressure atmosphere.

[0059] In the hole injection layer formation block, the arrangement and number of the coating device, buffer device, reduced pressure drying device, heat treatment device and temperature control device, as well as the internal atmosphere can be selected arbitrarily.

[0060] The hole injection layer formation block also includes a plurality of substrate transport devices and corresponding delivery devices. The substrate transport devices each transport substrate to an adjacent device. For example, the substrate transport device transports substrates to an adjacent coating device and buffer device. The substrate transport device transports substrates to an adjacent reduced pressure drying device. The substrate transport device transports substrates to an adjacent heat treatment device and temperature adjustment device. The delivery devices are respectively provided between the loading station and the substrate transport device, between the substrate transport devices, and between the substrate transport devices, and relay substrates between these devices. The interiors of the substrate transport devices and the delivery devices are maintained in an atmospheric atmosphere.

[0061] A transfer device is provided between the substrate transfer device of the hole injection layer forming block and the substrate transfer device of the hole transport layer forming block, and the interior of the transfer device is maintained in an atmospheric environment.

[0062] 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.

[0063] 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 waiting to be processed. The reduced-pressure drying device dries the coating layer coated 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 by the heat treatment device to a predetermined temperature, for example, room temperature.

[0064] The coating device and buffer device are maintained in an air atmosphere inside, while the heat treatment device and temperature control device are maintained in a low-oxygen, low-dew-point atmosphere inside to suppress deterioration of the organic material of the hole transport layer, and the reduced-pressure drying device switches its internal atmosphere between a low-oxygen, low-dew-point atmosphere and a reduced-pressure atmosphere.

[0065] In the hole transport 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.

[0066] 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.

[0067] The transfer device is configured as a load lock device that switches its internal atmosphere between the air atmosphere and a low-oxygen, low-dew-point atmosphere. This is because the reduced-pressure drying device is installed downstream of the transfer device. Meanwhile, the interior of the transfer device is maintained in a low-oxygen, low-dew-point atmosphere.

[0068] 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.

[0069] The light-emitting 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 coating liquid for the light-emitting layer toward the opening of the bank. The buffer device temporarily stores substrates waiting to be processed. The reduced-pressure drying device dries the coating layer coated 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 by the heat treatment device to a predetermined temperature, for example, room temperature.

[0070] The coating device and buffer device are maintained in an air atmosphere inside, while the heat treatment device and temperature control device are maintained in a low-oxygen, low-dew-point atmosphere inside to suppress deterioration of the organic material of the light-emitting layer, and the reduced-pressure drying device switches its internal atmosphere between a low-oxygen, low-dew-point atmosphere and a reduced-pressure atmosphere.

[0071] 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.

[0072] The unloading station sequentially unloads a plurality of 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 to and from the processing station.

[0073] The control device is composed of a computer including a CPU (Central Processing Unit) and a storage medium such as a memory, and realizes various processes by having the CPU execute programs (also called recipes) stored in the storage medium.

[0074] 1, a vacuum drying apparatus 100 according to this embodiment accommodates a substrate 10, on which a coating layer containing an organic material and a solvent is 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 adjustment mechanism 106, and a support mechanism 110.

[0075] The processing vessel (chamber) 101 accommodates a substrate 10 on which a coating layer 40 (FIG. 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 port 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 port. The opening / closing shutter opens the loading / unloading port to allow loading / unloading of the substrate 10, and the opening / closing shutter closes the loading / unloading port 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 inside of the processing vessel (chamber) 101 may be set to a predetermined atmosphere, for example, a nitrogen atmosphere or the like, which is a low-oxygen and low-dew-point atmosphere.

[0076] The lower rectifying plate 102 and the upper rectifying plate 103 are arranged in a processing container (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, and undergoes drying processing. The upper rectifying plate 103 is movable in the vertical direction relative to the lower rectifying plate 102.

[0077] The upper rectifying plate 103 can be moved up and down by a driving mechanism 104. The driving mechanism 104 is located outside the processing vessel (chamber) 101. The driving mechanism 104 can drive the upper rectifying plate 103 up and down while keeping the processing vessel (chamber) 101 sealed. The driving mechanism 104 can prevent interference between the upper rectifying plate 103 and the substrate 10 when the substrate 10 is loaded or unloaded.

[0078] The exhaust mechanism 105 is capable of exhausting the processing vessel (chamber) 101 through an exhaust port 105a disposed at the bottom of the processing vessel (chamber) 101. The exhaust mechanism 105 includes, for example, a reduced pressure generating source and an APC (Adaptive Pressure Control) valve. The reduced pressure generating source may be, for example, a dry pump, a mechanical booster pump, or a turbo molecular pump. The reduced pressure generating source is connected to the processing vessel (chamber) 101 via a pipe in which an APC valve is installed.

[0079] The reduced pressure generating source is connected to exhaust port 105a of processing vessel (chamber) 101, and reduces the pressure inside processing vessel (chamber) 101 to a pressure lower than atmospheric pressure. The pressure inside processing vessel (chamber) 101 is reduced to, for example, 1 Pa or less while being adjusted by an APC valve. In processing vessel (chamber) 101, exhaust port 105a is formed in the lower wall of processing vessel 101 as shown in FIG. 1, but may also be formed in the upper wall or side wall.

[0080] 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.

[0081] 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.

[0082] 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 can have a supply port so as to supply gas above the upper current plate 103 .

[0083] 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 the 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.

[0084] Fig. 2 is a perspective view showing a support pin in this embodiment, and Fig. 3 is an exploded view showing a support pin in this embodiment. The support mechanism 110 has a plurality of support pins 120 that stand upright in parallel upward from the lower flow plate 102 .

[0085] As shown in Figures 2 and 3, the support pin 120 has a support portion 121 which is the base end close to the lower straightening plate 102, a reduced diameter portion 122 which 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.

[0086] 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 125a are fixed to the fixing portion 102a of the lower flow plate 102.

[0087] The columnar portion 121a has a substantially cylindrical outer shape. A base end flange 125a is provided at the end of the columnar portion 121a that is close 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 that is close 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.

[0088] The base end portion 125, the base end flange 125a, the columnar portion 121a, the upper flange 121b, and the connecting portion 121c 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.

[0089] The outer diameter of upper flange 121b is set to be larger than the outer diameter of columnar portion 121a. The outer diameter of upper flange 121b is set to be smaller than the outer diameter of base end flange 125a. The outer diameter of connecting portion 121c is set to be larger than the outer diameter of columnar portion 121a. The outer diameter of connecting portion 121c is set to be smaller than the outer diameter of upper flange 121b. For example, a male screw for fixing may be formed on the outer periphery of connecting portion 121c.

[0090] 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 approximately equal to the outer diameter of the upper flange 121b.

[0091] Conical portion 123b is formed on the upper end side of cylindrical portion 123a. Conical portion 123b is formed coaxially with cylindrical portion 123a. A reduced diameter portion 122 is formed at the tip of conical portion 123b. Conical portion 123b and 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 the lower end and equal to the outer diameter of the reduced diameter portion 122 at the upper end.

[0092] 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.

[0093] An air vent hole 124 opens on the outer periphery of the cylindrical portion 123a. The air vent hole 124 communicates with the internal space 126. The air vent hole 124 is an internal space extending in the radial direction. When the support portion 121 and the pin portion 123 are connected, the air vent hole 124 is provided at a position closer to the reduced diameter portion 122 in the axial direction than the upper end of the connecting portion 121c. The air vent hole 124 can be formed in one location or in two or more locations.

[0094] The reduced diameter portion 122 is formed coaxially with the tip of the pin portion 123. The reduced diameter portion 122 has the same diameter up to the tip on the base end side. 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 becomes 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.

[0095] 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 provided 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.

[0096] In this way, by setting the cross-sectional area of ​​the support pin 120 as described above, the amount of heat conducted in the axial direction of the support pin 120 is set.

[0097] Here, the drying of the solvent in the coating layer formed on the substrate 10 in this embodiment will be described.

[0098] Fig. 4 is a schematic cross-sectional view showing an enlarged view of the vicinity of the tip of a support pin, illustrating the drying process in this embodiment. Fig. 5 is a schematic cross-sectional view showing an enlarged view of the vicinity of the tip of a support pin, illustrating the drying process in this embodiment. Fig. 6 is a schematic cross-sectional view showing an enlarged view of the vicinity of the tip of a support pin, 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).

[0099] As shown in FIG. 4, the coating layer 40 is filled in the banks 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 sake of explanation, and do not mean that the substrate 10 is configured differently in the direction along its surface.

[0100] Fig. 7 is a graph illustrating a drying curve in the drying step in this embodiment, and Fig. 8 is a graph in which the circled portion of the drying curve in Fig. 7 is enlarged. 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.

[0101] 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 volatilization temperature of the solvent to be evaporated.

[0102] At the same time, the drive mechanism 104 (FIG. 1) controls the distance between the upper rectifying plate 103 and the substrate 10 to control the conductance in the space between the upper rectifying plate 103 and the substrate 10. Specifically, narrowing the distance between the upper rectifying 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 bulk, or film thickness, of the coating layer 40 is sufficiently reduced as shown in FIG.

[0103] 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 the evaporation time TA.

[0104] In response to the vapor pressure of the solvent, the solvent rapidly evaporates from the coating layer 40 inside the bank 30, and as shown in Figure 6, the solvent dries, 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, so that the evaporation time TA of the solvent can be shortened. Therefore, the film thickness of the remaining solute inside the bank 30 can be made approximately uniform.

[0105] 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, i.e., the film thickness, of the coating layer 40 in the bank 30 is not sufficiently reduced. That is, because the initial exhaust pressure is high, evaporation of the solvent is insufficient, and the volume, i.e., the film thickness, of the coating film 40 is difficult to reduce. That is, a large amount of solvent remains that is not completely evaporated.

[0106] 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 B 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 lower than the saturated vapor pressure of the solvent.

[0107] 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, which does not evaporate completely. This causes the pressure to rise, and the heat of vaporization causes the temperature of the substrate 10 to drop rapidly. After the rapid evacuation, the evacuation curve decreases over an 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.

[0108] 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 only 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.

[0109] As a result, the difference in evaporation rate of the solvent between the support region 10p and the radiation region 10r becomes large, and coupled with the fact that the volume, i.e., the film thickness, of the coating film 40 in the bank 30 is small at the initial exhaust pressure PB, the coffee stain phenomenon shown in Figure 11 increases the likelihood that the solute will adhere to the side of the bank 30.

[0110] Here, the coffee stain phenomenon means that, 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 becomes lower due to the heat of evaporation, resulting in a larger amount of solute remaining in the peripheral portion 40a.

[0111] As a result, as shown in FIG. 10, the difference in the thickness of the solute film between the support region 10p and the radiation region 10r becomes large, causing unevenness.

[0112] In the vacuum drying apparatus 100 of this embodiment, as shown as recipe A in Figures 7 and 8, the solvent is volatilized up to an initial exhaust pressure PA, and then the pressure is reduced by rapidly exhausting the solvent up to a rapid exhaust pressure over an evaporation time TA, thereby preventing the solute from adhering to the side surface of the bank 30.

[0113] 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 Figure 5, for recipe A, the solvent is slowly evacuated up to the initial evacuation pressure PA, and then rapidly evacuated after the solvent has been sufficiently reduced. This makes it possible to sufficiently shorten the evaporation time and suppress the occurrence of unevenness.

[0114] If the recipe alone is not sufficient to suppress the occurrence of unevenness, a configuration is further provided to suppress the difference in evaporation rate between the support region 10p and the radiation region 10r.

[0115] 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 a nearly 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.

[0116] In this way, the evaporation rate of the solvent in the support region 10p can be prevented from becoming faster than that in the radiation region 10r due to the temperature difference caused by the thermal conduction of the support pins 120. Because the evaporation rate of the solvent in the support region 10p is not too fast, a further increase in the temperature drop of the substrate 10 is prevented. Furthermore, the solute does not adhere to the side surface of the bank 30 due to the coffee stain phenomenon.

[0117] As a result, it is possible to suppress the difference in temperature state, that is, the difference in heat conduction state, between the support area 10p, which is in contact with the support pins 120, and the radiation area 10r. Therefore, by suppressing the difference in drying speed due to the influence of heat conduction, it is possible to suppress the occurrence of unevenness.

[0118] Hereinafter, a specific method for suppressing the difference in evaporation rate by the support pin 120 will be described.

[0119] 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 mainly due to a temperature drop SM caused by radiation and a temperature drop SN caused by heat dissipation due to evaporation of the solvent, as shown by the arrows in Figure 12. In FIG. 12, the support pin 120 is shown by a broken line for comparison.

[0120] In the support region 10p, because of the presence of the support pins 120, the temperature from the lower straightening plate 102 to the substrate 10 drops, as shown by the arrows in Figure 13, mainly 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 evaporation of the solvent.

[0121] At this time, as shown in FIG. 13, the temperature drop in the direction from the lower rectifying plate 102 toward the substrate 10 of the support pin 120 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:

[0122] 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 portion 121 and the 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:

[0123] Furthermore, the length of reduced diameter portion 122 of support pin 120 is 1 mm or less. In this case, the length of reduced diameter portion 122 is the length from spherical portion 122a to the tip of conical portion 123b in the axial direction of support pin 120.

[0124] 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.

[0125] 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:

[0126] The support pins 120 are made of a material with a thermal conductivity of 0.5 W / mk or less. In particular, the reduced diameter portions 122 that come into contact with the substrate 10 are made of a material with a thermal conductivity of 0.3 W / mk or less. The support pins 120 are preferably made of a material with low thermal conductivity and sufficient strength, such as resin, and specific examples include PFA, PTFE, PEEK, conductive PEEK, etc. In other words, the support pins 120 can be made of a material with a lower thermal conductivity than the glass substrate (substrate) 10 that is the object to be processed.

[0127] The support portion 121, the pin portion 123, and the reduced diameter portion 122 may be made of the same material, or the support portion 121, the pin portion 123, and the reduced diameter portion 122 may be made of different materials.

[0128] When support portion 121, pin portion 123, and reduced diameter portion 122 are made of different materials, the thermal conductivity of pin portion 123 and reduced diameter portion 122 can be made smaller than the thermal conductivity of support portion 121. Also, the thermal conductivity of support portion 121 can be made smaller than the thermal conductivity of pin portion 123 and reduced diameter portion 122.

[0129] Furthermore, by setting the distribution of the cross-sectional area of ​​the support pins 120 perpendicular to the axis of the support pins 120 in the direction from the lower flow plate 102 toward the substrate 10, the temperature drop in this direction is set.

[0130] In order to set the distribution of this cross-sectional area (the 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 that sets 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.

[0131] The internal space 126 may be formed in the axial direction of the support pin 120 . For example, as shown in Fig. 3, in the pin portion 123, an internal space 126 serving as a connection hole for inserting and connecting the connecting portion 121c can be formed at the lower end position of the cylindrical portion 123a. The internal space 126 serving as the connection hole extends in the axial direction of the support pin 120. The internal space 126 serving as the connection hole can also 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 can also 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 can form an opening 124a that communicates with the outer circumferential surface of the conical portion 123b.

[0132] 3, the internal space 126 that serves as the connection hole may be formed so as to extend radially of the support pin 120 so as to open onto the circumferential surface of the cylindrical portion 123a and serve as the vent hole 124. The vent hole 124 may also penetrate the support pin 120 on both radial sides.

[0133] 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 support pin 120.

[0134] 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, the base end flange 125a, the upper flange 121b, or the 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, the base end flange 125a, or the upper flange 121b. In these cases, the support portion 121 can be formed in sections and then assembled.

[0135] As shown in FIG. 14, the support column 121 may have an internal space 126 extending in the radial direction of the support pin 120 so as to open to the circumferential 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.

[0136] In the vacuum drying apparatus 100 of this embodiment, the temperature drop is set according to the cross-sectional area in the axial direction of the support pins 120 and the thermal conductivity of the material, so that when the solvent is volatilized, the surface temperature in the support region 10p of the substrate 10 can be sufficiently reduced and the difference in surface temperature with the radiation region 10r can be suppressed. As a result, when the solvent is volatilized, the evaporation rate of the solvent in the support region 10p can be reduced and the difference in evaporation rate of the solvent with the radiation region 10r can be suppressed.

[0137] In this way, when the solvent is volatilized in the support region 10p, the evaporation rate of the solvent can be prevented from becoming faster than that in the radiation region 10r due to the temperature difference caused by the thermal conduction of the support pins 120. Because the evaporation rate of the solvent in the support region 10p is not too fast, a further increase in the temperature drop of the substrate 10 is prevented. Furthermore, the solute does not adhere to the side surface of the bank 30 due to the coffee stain phenomenon.

[0138] As a result, it is possible to suppress the difference in temperature state, that is, the difference in heat conduction state, between the support area 10p, which is in contact with the support pins 120, and the radiation area 10r. Therefore, by suppressing the difference in drying speed due to the influence of heat conduction, it is possible to suppress the occurrence of unevenness. [Example]

[0139] Hereinafter, examples of the present invention will be described.

[0140] Here, a confirmation test performed as a specific example of the support pin 120 in the vacuum drying apparatus 100 of the present invention will be described.

[0141] <Experimental Example 0> The distance between the lower rectifier plate 102 and the substrate 10 was set to 60 mm, the temperature of the lower rectifier plate 102 was set to 25°C, and the substrate temperature drop due to radiation was calculated 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 experimental example case 0.

[0142] Pressure: 50Pa Initial exhaust pressure PA: 3600Pa Initial exhaust time: 180 seconds

[0143] Substrate 10 Material: Glass (soda glass) Thickness: 500 μm Size: 1300mm x 1500mm

[0144] 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.

[0145] <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.

[0146] 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 1.

[0147] Support pin 120 Total length: 60mm

[0148] Pillar part 121 Material: PTFE Total length: 38.5mm Length of columnar portion 121a: 20 mm (solid) Column part 121a diameter; φ3mm

[0149] Base end 125 length: 9 mm (1.5 mm relief) Base end diameter 125; M5mm Base flange 125a length (thickness): 3mm Base flange 125a diameter: φ8mm

[0150] Upper flange 121b length (thickness): 2mm Upper flange 121b diameter: φ5mm Connection part 121c length: 4.5 mm (1 mm clearance) Connection part 121c diameter: M3mm

[0151] Pin part 123 Material: PEEK Cylindrical section 123a length: 15.6 mm Cylinder 123a diameter: φ5mm

[0152] Internal space part 126 lower end inner diameter; φ3mm Internal space 126 length: 15mm Internal space 126 female thread length: 5mm Vent hole 124 diameter: φ1.5mm Distance from bottom to center of vent hole 124 diameter: 7mm

[0153] Cone section 123b length: 8.4 mm Cone section 123b apex angle: 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

[0154] 13 shows the temperature drop results for 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.

[0155] <Experimental example case 2> As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was calculated. At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

[0156] 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 the experimental example case 1 are shown.

[0157] Pillar part 121 Material: PFA

[0158] Pin part 123 Material: PFA Reduced diameter portion 122 (integrated with pin portion 123) Material: PFA

[0159] 15 shows the temperature drop results for Experimental Example Case 2. In FIG. 15, 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 2, the temperature of the surface of the support region 10p of the substrate 10 was -3.25°C.

[0160] <Experimental example case 3> As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was calculated. At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

[0161] 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 the experimental example case 1 are shown.

[0162] Pillar part 121 Material: SUS304

[0163] Pin part 123 Material: Conductive PEEK Reduced diameter portion 122 (integrated with pin portion 123) Material: Conductive PEEK

[0164] 16 shows the temperature drop results for Experimental Example Case 3. In FIG. 16, 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 3, the temperature of the surface of the support region 10p of the substrate 10 was -2.85°C.

[0165] <Experimental example case 4> As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was calculated. At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

[0166] 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 experimental example case 4. Here, only the specifications that are different from the experimental example case 1 are shown.

[0167] Pillar part 121 Material: SUS304

[0168] Pin part 123 Material: A5052 (aluminum alloy) Reduced diameter portion 122 (integrated with pin portion 123) Material: A5052 (aluminum alloy)

[0169] 17 shows the temperature drop results for Experimental Example Case 4. In FIG. 17, 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 4, the temperature of the surface of the support region 10p of the substrate 10 was -2.39°C.

[0170] <Experimental example case 5> As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was calculated. At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

[0171] 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 the experimental example case 1 are shown.

[0172] Pillar part 121 Material: SUS304

[0173] Pin part 123 Material; PTFE Reduced diameter portion 122 (integrated with pin portion 123) Material: PTFE

[0174] 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.

[0175] <Experimental example case 6> As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was calculated. At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

[0176] 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 the experimental example case 1 are shown.

[0177] Pillar part 121 Material: A5052

[0178] Pin part 123 Material: Conductive PEEK Reduced diameter portion 122 (integrated with pin portion 123) Material: Conductive PEEK

[0179] 19 shows the temperature drop results for Experimental Example Case 6. In FIG. 19, 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 6, the temperature of the surface of the support region 10p of the substrate 10 was -2.84°C.

[0180] The thermal conductivities of the constituent materials of the support pin 120 used in the experimental examples, cases 1 to 6, are shown below. Dry air: 0.0241W / mK PFA: 0.19 W / mK PTFE; 0.25W / mK PEEK: 0.25W / mK Conductive PEEK; 0.46W / mK SUS304; 15W / mK A5052; 236W / mK Glass: 0.6W / mK Si3N4; 24W / mK

[0181] Furthermore, the presence or absence of unevenness on the surface of the substrate 10 after drying in Experimental Examples Cases 1 to 6 was observed. In experimental example case 1 and experimental example case 2, no unevenness was observed, but in experimental examples case 3 to case 6, visible unevenness was observed. The temperature drops in experimental cases 1 to 6 are shown in Figure 20. The evaporation rates [pl / S] of the corresponding solvents are also shown.

[0182] 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.

[0183] From the results shown in FIGS. 13 and 15 to 20, it can be seen that when the support pin 120 is made of a material with a thermal conductivity greater than 1 W / mK, unevenness occurs.

[0184] 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.

[0185] Similarly, the slope ΔDpp of the temperature curve drop in the support part 121 and the pin part 123 to the slope ΔDr of the temperature curve in the radiation area 10r shown in FIG. 12 is the ratio ΔDpp / ΔDr, 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.

[0186] In experimental example case 1, from the results shown in Fig. 13, the inflection point Dpφ on the temperature curve from pin portion 123 to reduced diameter portion 122 is a temperature of 19°C. From the results shown in Fig. 13, the inflection point Dpp on the temperature curve from support portion 121 to pin portion 123 is a temperature of 20°C.

[0187] In experimental example case 2, from the results shown in Fig. 15, the inflection point Dpφ on the temperature curve from pin portion 123 to reduced diameter portion 122 is at a temperature of 18°C. From the results shown in Fig. 15, the inflection point Dpp on the temperature curve from support portion 121 to pin portion 123 is at a temperature of 20°C.

[0188] In experimental example case 3, from the results shown in Fig. 16, the inflection point Dpφ on the temperature curve from pin portion 123 to reduced diameter portion 122 is at a temperature of 24°C. From the results shown in Fig. 16, the inflection point Dpp on the temperature curve from support portion 121 to pin portion 123 is at a temperature of 25°C.

[0189] In experimental example case 4, from the results shown in Fig. 17, the inflection point Dpφ on the temperature curve from pin portion 123 to reduced diameter portion 122 is at a temperature of 25°C. From the results shown in Fig. 17, the temperature of the inflection point Dpp on the temperature curve from support portion 121 to pin portion 123 is unknown.

[0190] In experimental example case 5, from the results shown in Fig. 18, the inflection point Dpφ on the temperature curve from pin portion 123 to reduced diameter portion 122 is at a temperature of 24°C. From the results shown in Fig. 18, the inflection point Dpp on the temperature curve from support portion 121 to pin portion 123 is at a temperature of 25°C.

[0191] In experimental example case 6, from the results shown in Fig. 19, the inflection point Dpφ on the temperature curve from pin portion 123 to reduced diameter portion 122 is at a temperature of 24°C. From the results shown in Fig. 19, the inflection point Dpp on the temperature curve from support portion 121 to pin portion 123 is at a temperature of 25°C.

[0192] <Experimental example case A> As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was calculated. At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

[0193] 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 the experimental example case 1 are shown.

[0194] Pillar part 121 Material: PFA

[0195] Pin part 123 Material: PFA Instead of the reduced diameter portion 122, the contact portion 12h (integrated with the pin portion 123) shown in FIG. Material: PFA Contact diameter; φ23mm Contact surface: Flat ring-shaped; Ring width: 1mm

[0196] The results of visually checking the occurrence of unevenness in 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.

[0197] <Experimental example case B> As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was calculated. At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

[0198] 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. This was experimental example case B. Here, only the specifications that are different from the experimental example case 1 are shown.

[0199] Pillar part 121 Material: PFA

[0200] Pin part 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

[0201] FIG. 22 shows the results of visually checking the occurrence of unevenness in experimental example case B. The results of experimental example case B show that unevenness occurs.

[0202] <Experimental example case C> As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was calculated. At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

[0203] 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. This was designated as experimental example case C. Here, only the specifications that are different from the experimental example case 1 are shown.

[0204] Pillar part 121 Material: SUS304

[0205] Pin part 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

[0206] FIG. 22 shows the results of visually checking the occurrence of unevenness in experimental example case C. The results of experimental example case C show that unevenness occurs.

[0207] <Experimental example case D> As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was calculated. At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

[0208] 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. This was designated as experimental example case D. Here, only the specifications that are different from the experimental example case 1 are shown.

[0209] Pillar part 121 Material: SUS304

[0210] Pin part 123 Material: PEEK Instead of the reduced diameter portion 122, the contact portion 12h (integrated with the pin portion 123) shown in FIG. Material: PEEK Contact diameter; φ23mm Contact surface: Flat ring-shaped; Ring width: 1mm

[0211] FIG. 22 shows the results of visually checking the occurrence of unevenness in experimental example case D. The results of experimental example case D show that unevenness occurs.

[0212] <Experimental example case E> As in Experimental Example Case 1, the substrate temperature drop due to heat conduction and solvent evaporation was calculated. At this time, the drying conditions were set to be the same as those in Experimental Example Case 1.

[0213] 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 the experimental example case 1 are shown.

[0214] Pillar part 121 Material: PFA

[0215] Pin part 123 Material: PEEK Reduced diameter portion 122 (integrated with pin portion 123) Material: PEEK

[0216] 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.

[0217] From the results shown in FIG. 22, it can be seen that when reduced diameter portion 122 is in point contact with 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. [Industrial Applicability]

[0218] Examples of applications of this invention include drying in the manufacturing process of FPDs such as organic EL, as well as drying of moisture from electrical and electronic components, and drying of metals and machined products after washing with water. [Explanation of symbols]

[0219] 10...Substrate (glass substrate) 100...Vacuum drying equipment 10p…Support area 10r…Radiation area 30...Bank 40...Coating layer 101...Processing vessel (chamber) 102…Lower rectifier plate 102a…Fixed part 103...Upper current plate 104...Drive mechanism 105...Exhaust mechanism 105a...Exhaust port 106…Temperature control mechanism 110...Support mechanism 120...Support pin 121...Strut part 121a...Columnar part 121b...Upper flange 121c…Connection 122...Reduced diameter part 122a...Spherical part (tip part) 123...Pin part 123a...Cylindrical part 123b...cone section 124...Ventilation hole 125...Proximal end 125a...Base flange 126...Interior space 130...Upper rectifier plate 150...Processing container Dpφ…Inflection point PA: Initial exhaust pressure SC…Temperature drop SM…Temperature drop SN…Temperature drop SR…curvature radius 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

1. 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:

2. 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.

3. The length of the reduced diameter portion is 1 mm or less.

3. The vacuum drying apparatus according to claim 2.

4. The diameter dimension Φφ of the reduced diameter portion is 0.5 mm or less.

4. The vacuum drying apparatus according to claim 3.

5. 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.

6. 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.

7. 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.

8. 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.

9. 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 vacuum drying apparatus is a vacuum drying apparatus.

10. 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.

11. 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.

12. The support pin has an internal space for reducing a cross-sectional area.

12. The vacuum drying apparatus according to claim 11.

13. The internal space is formed in the axial direction of the support pin.

13. The vacuum drying apparatus according to claim 12.

14. The internal space is formed in a radial direction of the support pin.

13. The vacuum drying apparatus according to claim 12.

15. 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.

Images