TW202209426A - Reduced-pressure drying apparatus and reduced-pressure drying method in which the reduced-pressure drying apparatus comprises a chamber, a substrate holding section, a pressure reducing mechanism, and a diffusion suppressing section - Google Patents

Abstract

A reduced-pressure drying apparatus comprises: a chamber; a substrate holding section, which holds a substrate in an interior of the chamber, the substrate being formed with a coating film containing a solvent; a pressure reducing mechanism, which implements pressure reduction in the interior of the chamber; and a diffusion suppressing section, which suppresses diffusion of the solvent evaporating from the coating film. The diffusion suppressing section comprises a flow regulation plate, which is arranged above the substrate held by the substrate holding section and has a dimension in plane-view greater than the substrate. The diffusion suppressing section further comprises a flow regulation plate moving mechanism to allow the flow regulation plate to approach or away from the substrate. The diffusion suppressing section further comprises a flow regulation plate temperature-control mechanism for regulating the temperature of the flow regulation plate. The diffusion suppressing section further comprises a surrounding wall disposed around the substrate held by the substrate holding section.

Description

Vacuum drying device and vacuum drying method

The present disclosure relates to a vacuum drying device and a vacuum drying method.

Conventionally, there has been known an organic light emitting diode (OLED: Organic Light Emitting Diode) utilizing the light emission of organic EL (Electroluminescence). An organic EL display using an organic light emitting diode is thin and light, has low power consumption, and has the advantages of being excellent in terms of reaction rate, viewing angle, and contrast ratio. Therefore, in recent years, it is attracting attention as a next-generation flat panel display (FPD). In addition, a quantum dot light-emitting element (QLED: Quantum-dot Light Emitting Diode) using a quantum dot light-emitting material instead of an organic EL material for the light-emitting layer is also rapidly attracting attention.

The OLED has: an anode formed on a substrate; a cathode disposed on the opposite side of the substrate based on the anode; and an organic layer disposed therebetween. 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 toward the cathode side. In the formation of the hole injection layer, the hole transport layer, the light emitting layer, and the like, a coating apparatus of an inkjet method can be used. The coating device forms a coating film by coating a coating liquid containing an organic material and a solvent on a substrate. By drying and baking this coating film under reduced pressure, a hole injection layer or the like is formed (for example, refer to Patent Document 1). prior art literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2016-77966

A reduced-pressure drying apparatus according to an aspect of the present disclosure includes: a chamber; a substrate holding unit that holds a substrate on which a coating film containing a solvent is formed in the chamber; The inside is decompressed; and the diffusion suppressing portion suppresses the diffusion of the solvent evaporated from the coating film.

Form for carrying out the invention In the apparatus described in Patent Document 1, there is a possibility that the drying speed of the coating film may be uneven within the substrate surface. If the drying speed is uneven, the thickness of the light-emitting layer or the like will vary within the substrate surface. Since the film thickness is an important factor determining the light-emitting characteristics, the variation in the film thickness causes the variation in the light-emitting characteristics, which is a serious problem.

The present disclosure has been made in view of such a problem, and an object of the present disclosure is to provide a reduced-pressure drying apparatus and a reduced-pressure drying method that can reduce unevenness in the drying rate of a coating film on a substrate surface.

<Drying device under reduced pressure and drying method under reduced pressure> FIG. 1 is a longitudinal sectional view showing the configuration of a vacuum drying apparatus according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1. FIG.

The reduced-pressure drying apparatus 100 shown in FIG. 1 accommodates the substrate 10 on which the coating film containing the solvent is formed inside the chamber 110, and in a reduced-pressure gas environment with a pressure lower than atmospheric pressure, the solvent is removed from the coating film. The cloth film evaporates. The decompression drying apparatus 100 includes a chamber 110 , a substrate holding unit 120 , a decompression mechanism 130 , a gas supply mechanism 140 , and a diffusion suppressing unit 150 .

A substrate holding portion 120 is provided inside the chamber 110 . The board|substrate holding part 120 is provided with the board|substrate mounting table 121, and the leg part 122, and supports the board|substrate mounting table 121 from below. The substrate 10 having the coating film formed on the upper surface is mounted on the mounting surface 123 of the substrate mounting table 121 . The loading and unloading port 112 of the substrate 10 is provided in the side wall part of the chamber 110 . An open/close door 113 is provided in the carry-in/out port 112 . As shown by the two-dotted chain line in FIG. 1 , by opening and closing the shutter 113 to open the loading/unloading port 112 , the loading and unloading of the substrate 10 becomes possible, and as shown by the solid line in FIG. The shutter 113 closes the carry-in and carry-out port 112, so that the inside of the chamber 110 can be decompressed. One exhaust port 114 is provided on the bottom surface of the chamber 110 . The exhaust port 114 is disposed at a position corresponding to the center of the substrate 10 on the substrate mounting table 121 in a plan view, that is, in an orthogonal projection of the substrate 10 to the bottom surface of the chamber 110 . The inside of the chamber 110 is already made into a low oxygen and low dew point gas environment, such as nitrogen environment, before the decompression starts.

The decompression mechanism 130 is connected to the exhaust port 114 of the chamber 110, and decompresses the inside of the chamber 110 to a pressure lower than atmospheric pressure. The decompression mechanism 130 includes, for example, a decompression generating source 131 and an APC (Adaptive Pressure Control) valve 132 . As the reduced pressure generating source 131 , for example, a dry pump, a mechanical booster pump, a turbo molecular pump, or the like can be used. The decompression generating source 131 is connected to the chamber 110 through a pipe provided with an APC valve 132 on the way, and depressurizes the inside of the chamber 110 . The air pressure inside the chamber 110 is reduced to, for example, 1 Pa or less while being adjusted by the APC valve 132 . The decompression curve is related to the evaporation behavior of the solvent of the coating film and is an important control parameter to achieve uniform drying.

In order to return the inside of the chamber 110 decompressed by the decompression mechanism 130 to the original gas environment, the gas supply mechanism 140 supplies a gas such as nitrogen gas to the inside of the chamber 110 . The gas supply mechanism 140 includes, for example, a gas supply source 141 , a mass flow controller 142 , and an on-off valve 143 . The gas supply source 141 is connected to the chamber 110 through a pipe provided with a mass flow controller 142 or an on-off valve 143 on the way, and supplies gas to the inside of the chamber 110 . Its supply amount can be adjusted by the mass flow controller 142 .

The diffusion suppressing portion 150 suppresses the diffusion of the solvent evaporated from the coating film of the substrate 10 . The diffusion suppression unit 150 includes an enclosing wall 160 , an enclosing wall moving mechanism 170 , an enclosing wall plate temperature control mechanism 180 , a rectifier plate 190 , a rectifier plate moving mechanism 200 , and a rectifier plate temperature control mechanism 210 .

The surrounding wall 160 is formed in a rectangular cylindrical shape. The surrounding wall 160 is provided on the mounting surface 123 of the substrate mounting table 121 and is arranged so as to surround the substrate 10 . Among the four flat wall portions constituting the surrounding wall 160 , one wall portion 161 provided at a position facing the carry-in/outlet 112 is configured to be movable up and down by the surrounding wall moving mechanism 170 shown in FIG. 2 . As shown by the two-dot chain line in FIG. 1 , by driving the surrounding wall moving mechanism 170 to raise the wall portion 161 , it becomes possible to perform the mounting of the substrate 10 on the substrate mounting table 121 and the transfer from the substrate mounting table 121 . taken out, and as shown by the solid line in FIG. 1 , by the wall portion 161 descending and its lower end contacting the substrate stage 121 , it becomes possible to suppress the solvent that has evaporated from the coating film of the substrate 10 toward the outside of the surrounding wall 160 of leakage. The distance from the inner surface of the surrounding wall 160 to the end of the substrate 10 is preferably 30 mm or less, and more preferably 10 mm or less. The height of the surrounding wall 160 is preferably 10 mm or more, and more preferably 50 mm or more.

The surrounding wall temperature control mechanism 180 adjusts the temperature of the surrounding wall 160 . As the surrounding wall temperature control mechanism 180, for example, a cooler in which cooling water flows, a Peltier element, a heater, or the like can be used. By adjusting the temperature of the surrounding wall 160 arranged to surround the substrate 10 , it becomes possible to control the drying rate of the solvent from the coating film formed on the substrate 10 .

The straightening plate 190 is formed in a rectangular plate shape. The rectifying plate 190 is arranged above the substrate mounting table 121 and inside the region surrounded by the surrounding wall 160 . The surface of the rectifying plate 190 facing the substrate 10 is located below the upper end of the surrounding wall 160 . As shown in FIG. 2 , the size of the surface of the rectifying plate 190 facing the substrate 10 is formed to be larger than that of the substrate 10 . The rectifying plate 190 is arranged to cover the entire surface of the substrate 10 in a plan view. The rectifier plate 190 is provided by the rectifier plate moving mechanism 200 provided on the upper surface of the chamber 110, and as shown by the solid line and the two-dot chain line in FIG.

The rectifier plate temperature control mechanism 210 adjusts the temperature of the rectifier plate 190 . The temperature of the surface of the rectifier plate 190 can be changed by the rectifier plate temperature control mechanism 210 . As the rectifier plate temperature control mechanism 210 , for example, a cooler, a Peltier element, or the like in which cooling water flows can be used. Evaporation of the solvent of the coating film formed on the substrate 10 can be accelerated by cooling the rectifying plate 190 . The solvent evaporates from the coating film and stops when the saturated vapor pressure is reached above the coating film. However, when the baffle plate 190 is cooled and the temperature is lowered, the vapor of the evaporated solvent will liquefy on the surface of the baffle plate 190 . Since the vapor pressure decreases according to the amount of vapor liquefaction, it becomes difficult to reach the saturated vapor pressure, and drying of the solvent can be performed.

However, the vacuum drying apparatus 100 dries the coating film formed on the substrate 10 by the coating apparatus under reduced pressure to evaporate the solvent contained in the coating film. The reduced-pressure drying apparatus 100 depressurizes the inside of the chamber 110 while appropriately adjusting the decompression speed. The vapor of the solvent becomes a gas stream and is carried from the vicinity of the upper surface of the substrate 10 to the exhaust port 114 of the chamber 110 . The easier it is to move the air, the easier it is to dry. Specifically, the vapor at the end of the substrate 10 is easily diffused, so that the drying speed is increased.

Then, in order to reduce the drying unevenness of the coating film, the decompression drying apparatus 100 is provided with the diffusion suppressing part 150 including the surrounding wall 160 and the rectifying plate 190 . By the presence of the diffusion suppressing portion 150 , the solvent vapor evaporated from the coating film is trapped in the area surrounded by the surrounding wall 160 and the rectifying plate 190 , thereby reducing the difference in drying speed within the surface of the substrate 10 . Thereby, evaporation of the solvent from the coating film formed on the substrate 10 can be made uniform within the surface of the substrate 10 .

Here, the evaporation speed is adjusted by the vertical distance L1 from the lower surface of the rectifying plate 190 to the upper surface of the substrate 10 in a side view, and the outer edge of the rectifying plate 190 to the outer edge of the substrate 10 in a plan view. The distance L2, the distance L3 from the inner surface of the surrounding wall 160 to the outer edge of the substrate 10 in a plan view, the temperature of the rectifying plate 190, and the like are adjusted. Since the above-mentioned conditions vary depending on the size of the substrate 10 , the solvent amount of the coating film formed on the substrate 10 , and the like, they should be adjusted appropriately. For example, the distance L1 is adjusted by driving the rectifier plate moving mechanism 200 . The distance L1 can be shortened as necessary, so that the saturated vapor pressure of the solvent dried from the substrate 10 can be easily reached in the region above the substrate 10 , and the drying speed can be easily made uniform within the surface of the substrate 10 .

In addition, the rectifying plate 190 may function as an adsorption plate for adsorbing the vapor of the solvent. In this case, the rectifier plate temperature control mechanism 210 can have the function of increasing the temperature, and the structure for increasing the temperature of the rectifier plate 190 can also be provided separately from the rectifier plate temperature control mechanism 210 . The adsorption plate is to collect the vapor of the solvent, for example by liquefaction. When the temperature of the rectifier plate 190 is lowered by the rectifier plate temperature control mechanism 210, the solvent evaporated from the substrate 10 is liquefied. Moreover, by heating the rectifier plate 190 after drying under reduced pressure, the solvent collected by the rectifier plate 190 is re-vaporized and separated from the rectifier plate.

<Decompression drying method> Next, a vacuum drying method using the vacuum drying apparatus 100 having the above-described configuration will be described. FIG. 3 is an explanatory diagram of an example of a decompression curve when decompressing the chamber. In addition, as a coating film to be dried, a coating film for producing an organic EL light-emitting diode, a quantum dot light-emitting element, and an organic thin-film transistor can be exemplified, but is not limited thereto.

First, as shown by the two-dotted chain line in FIG. 1 , after the vacuum drying apparatus 100 lifts the shutter 113 and the wall portion 161 , a transport mechanism or an operator (not shown) removes the substrate 10 from the vacuum drying apparatus 100 . The outside is carried into the chamber 110 and placed on the substrate stage 121 . Next, as shown by the solid line in FIG. 1 , the shutter 113 and the wall 161 are lowered to make the inside of the chamber 110 a closed space, and the decompression mechanism 130 decompresses the inside of the chamber 110 . In a reduced-pressure gas atmosphere, the solvent evaporates from the coating film to dry the coating film. The vapor of the solvent becomes a gas stream and is carried from the vicinity of the upper surface of the substrate 10 to the exhaust port 114 of the chamber 110 . At this time, the rectifying plate 190 and the surrounding wall 160 restrict the airflow from the vicinity of the upper surface of the substrate 10 toward the exhaust port 114 of the chamber 110 . Due to the restriction of the air flow, the region surrounded by the rectifying plate 190 and the surrounding wall 160 is filled with the vapor of the solvent. Thereby, the unevenness of the drying rate in the surface of the substrate 10 can be reduced.

Here, the decompression in the chamber 110 is performed according to the decompression curve shown in FIG. 3 . The decompression curve has: a pressure maintenance section (a), which keeps the pressure in the chamber 110 constant; a slow exhaust section (b), which decompresses the chamber 110 at a low exhaust speed; and a rapid exhaust section (c), the inside of the chamber 110 is depressurized at a high exhaust velocity.

First, in the pressure maintaining section (a), the substrate 10 is filled with the vapor of the solvent by maintaining the pressure in the chamber 110 constant for a predetermined time. Next, in the slow exhaust section (b), the evaporation of the solvent is performed while substantially maintaining the full state of the solvent vapor. Finally, the evaporation of the solvent is completed by reducing the pressure in the rapid exhaust section (c). In addition, it is preferable to carry out slow exhausting (processing in the slow exhausting section (b)) until the saturation vapor pressure is reached, and then performing rapid exhausting after reaching the saturated vapour pressure (performing the rapid exhausting section ( c) treatment). In addition, the exhaust speed is not limited to the above-mentioned three modes, and may be more or less than three modes.

After the drying under reduced pressure is completed, the gas supply mechanism 140 supplies gas to the inside of the chamber 110 to return the inside of the chamber 110 to the original gas environment. After that, as shown by the two-dot chain line in FIG. 1 , after the decompression drying apparatus 100 lifts the shutter 113 and the wall 161 , a transfer mechanism or an operator (not shown) removes the substrate 10 on the substrate stage 121 from the cavity. Chamber 110 is removed. Then, as shown by the solid line in FIG. 1 , the reduced-pressure drying apparatus 100 lowers the opening and closing shutter 113 and the wall portion 161 .

<The effect of the embodiment> According to the reduced-pressure drying apparatus and the reduced-pressure drying method of the present disclosure, the variation in the reduced-pressure drying rate of the coating film in the substrate surface can be reduced. For example, as described above, according to the present embodiment, the reduced-pressure drying apparatus 100 includes the diffusion suppressing unit 150 including the surrounding wall 160, which surrounds the substrate 10 on the substrate mounting table 121, and the rectifying plate 190, It is arranged above the substrate 10 . Therefore, the vapor of the solvent evaporated from the coating film formed on the substrate 10 can be accumulated in the area surrounded by the surrounding wall 160 and the rectifying plate 190, and the area on the substrate 10 can be saturated with vapor pressure. Drying delay in places where drying speed has been faster in the past. Thereby, the variation in the drying rate of the coating film in the surface of the substrate 10 can be reduced. As a result, a coating film with high uniformity of film thickness can be formed on the substrate 10 .

<Example> Next, the embodiments of the present disclosure will be described.

(Example 1) FIG. 4A is a longitudinal cross-sectional view showing the configuration of a vacuum drying apparatus 100A of Example 1. FIG. Fig. 4B is a cross-sectional view taken along line A-A of Fig. 4A. Fig. 4C is a cross-sectional view taken along line B-B of Fig. 4A. 5A is an explanatory diagram of a measurement portion of the coating film in Example 1 and Comparative Example 1. FIG. 5B is a graph showing the film thickness curve of the coating film after drying in Example 1. FIG.

As shown in FIGS. 4A to 4C , the vacuum drying apparatus 100A of the first embodiment has four exhaust ports 114 arranged at positions corresponding to the four corners of the substrate mounting table 121 , that is, arranged in a plane view from The substrate mounting table 121 has the same configuration as that of the vacuum drying apparatus 100 of the above-described embodiment, except that the APC valve 132 is arranged at the same distance from the center of the substrate 10 and the APC valve 132 is arranged outside each exhaust port 114 .

As the substrate 10, a glass substrate of 200 mm×200 mm was prepared. The solvent of cyclohexylbenzene was apply|coated to this board|substrate 10 by the inkjet method, and the coating film was formed. For such a substrate 10, a rectifying plate 190 having a size of 250 mm×250 mm in a plan view was used. By using such a rectifying plate 190, the outer edge of the rectifying plate 190 is located 25 mm outside the outer edge of the substrate 10 in a plan view, that is, a state where L2 is 25 mm. In addition, the distance L1 in the vertical direction from the lower surface of the rectification plate 190 to the upper surface of the substrate 10 in the side view is set to 5 mm. The distance L3 from the inner surface of the surrounding wall 160 to the outer edge of the substrate 10 in a plan view was set to 5 mm, and the height of the surrounding wall 160 was set to 50 mm. In this state, the inside of the chamber 110 was reduced in pressure to evaporate the solvent in the coating film, and the film thickness of the dried coating film at the diagonal line EE' in FIG. 5A was measured. The measurement results of the coating film are shown in FIG. 5B . In addition, E is the center of the substrate 10 , and E′ is one of the corners of the substrate 10 .

As shown in FIG. 5B , among the coating films formed on the substrate 10 , the drying speed of the four corners became the fastest, and the drying unevenness became remarkable. Therefore, the diagonal line EE′ on the substrate 10 was measured. Part of the film thickness curve. It was found that a portion with a uniform film thickness was confirmed within a range of 0.11 m from the center of the substrate 10 , and that the coating film was flat in 79% of the area of the diagonal EE′.

(Comparative Example 1) 6A is a longitudinal cross-sectional view showing the configuration of a vacuum drying apparatus of Comparative Example 1. FIG. 6B is a graph showing the film thickness curve of the coating film after drying in Comparative Example 1. FIG.

As shown in FIG. 6A , the reduced-pressure drying apparatus 100B of Comparative Example 1 has the same configuration as that of the reduced-pressure drying apparatus 100A of Example 1, except that the surrounding wall is not arranged. On the same substrate 10 as in Example 1, a coating film having the same configuration as in Example 1 was formed. The coating film of this substrate 10 was dried under the same conditions as in Example 1, and the film thickness of the diagonal line EE' shown in FIG. 5A was measured. The measurement results of the coating film are shown in FIG. 6B .

As shown in FIG. 6B , a portion with a uniform film thickness was confirmed within a range of 0.095 m from the center of the substrate 10 , and the coating film was flat in 68% of the area of the diagonal EE′ portion.

(Summarize) It can be seen that the film thickness uniformity of the coating film dried by the vacuum drying device 100A of Example 1 is higher than that of the coating film dried by the vacuum drying device 100B of Comparative Example 1, and in Example 1 In the vacuum drying apparatus 100A, it is easy to obtain a coating film with high uniformity of film thickness.

<Variation> It goes without saying that the present disclosure is not limited to the contents shown in the embodiments described so far, and various modifications can be added without departing from the gist of the present disclosure.

(Variation 1) 7 is a cross-sectional view showing the configuration of a vacuum drying apparatus according to Modification 1. FIG. As shown in FIG. 7, the reduced-pressure drying apparatus 100C of the modification 1 has the same structure as the reduced-pressure drying apparatus 100A of Example 1 except the shape of 190C of rectification|straightening plates. The rectifier plate 190C of Modification 1 includes a quadrangular base portion 191C having the same shape as the rectifier plate 190 in a plan view, and an L-shaped protrusion 192C protruding outward from each corner portion of the quadrangle of the base portion 191C. The four corners of the substrate 10 tend to have the fastest drying rate and lower film thickness uniformity. However, by using the straightening plate 190C having such a configuration, the evaporation of the coating film from the four corners of the substrate 10 can be further suppressed. The diffusion of the solvent can further improve the uniformity of the film thickness. In addition, the protruding portion 192C may not be L-shaped in a plan view, and may be, for example, a substantially circular arc shape.

(Variation 2) 8 is a longitudinal cross-sectional view showing the configuration of a vacuum drying apparatus according to Modification 2. FIG. As shown in FIG. 8, the reduced-pressure drying apparatus 100D of Modification 2 has the same configuration as that of the reduced-pressure drying apparatus 100A of Example 1 except for the shape of the rectifying plate 190D. The lower surface 191D of the rectification plate 190D of Modification 2 is provided with the rectification plate concave portion 192D which is recessed into a quadrangle (square) in a plan view. The center of the rectifier plate recess 192D overlaps the center of the substrate 10 in a plan view. That is, the straightening plate 190D is formed such that the distance L4 from the center of the substrate 10 to the straightening plate 190D is longer than the distance L5 from the outer edge of the substrate 10 to the straightening plate 190D. By using the straightening plate 190D having such a configuration, the substrate The end of 10 will quickly reach the saturated vapor pressure. After reaching the saturated vapor pressure, the evaporation of the solvent does not continue. In the case where the concave portion 192D is not provided, the drying speed of the end portion of the substrate 10 may be slower than that of the central portion. However, by providing the concave portion 192D, the drying of the end portion of the substrate 10 can be delayed. speed. As a result, the drying rate in the surface of the substrate 10 can be made uniform, and the uniformity of the film thickness of the coating film can be improved.

(Variation 3) 9 is a longitudinal cross-sectional view showing the configuration of a vacuum drying apparatus according to Modification 3. FIG. As shown in FIG. 9, the reduced-pressure drying apparatus 100E of the modification 3 has the same structure as the reduced-pressure drying apparatus 100A of Example 1 except the shape of the board|substrate mounting table 121E. The mounting surface 123E of the substrate mounting table 121E according to Modification 3 is provided with a holding recess 124E formed to have almost the same depth as the thickness of the substrate 10 and arranging the substrate 10 inside. That is, the surface of the board|substrate 10 arrange|positioned in the holding recessed part 124E becomes flush with the mounting surface 123E. The specific gravity of the solvent of the coating film formed on the substrate 10 is often larger than 1, and the evaporated solvent is accumulated on the lower side. Here, when the board|substrate 10 is arrange|positioned on the mounting surface in which the holding|maintenance recessed part 124E is not provided, the drop will generate|occur|produce between the board|substrate 10 and the mounting surface 123E. When there is such a drop, the evaporated solvent will move below the surface of the substrate 10, resulting in a faster drying rate. On the other hand, if the substrate 10 is disposed in the holding recess 124E and the drop around the substrate 10 is eliminated, the above-mentioned phenomenon does not occur, so that the drying speed of the outer peripheral portion of the substrate 10 can be suppressed from increasing. As a result, the drying rate in the surface of the substrate 10 can be made uniform, and the uniformity of the film thickness of the coating film can be improved.

(Variation 4) 10A is a longitudinal cross-sectional view showing the configuration of a vacuum drying apparatus according to Modification 4. FIG. Fig. 10B is a cross-sectional view taken along line C-C of Fig. 10A. As shown in FIGS. 10A and 10B , the reduced-pressure drying apparatus 100F of Modification 4 has the same configuration as that of the reduced-pressure drying apparatus 100A of Embodiment 1, except that the substrate mounting table 121 is provided with a frame portion 125F. The frame portion 125F is formed in a frame shape having substantially the same thickness as the thickness of the substrate 10 . The board|substrate 10 is arrange|positioned inside the frame part 125F. The surface of the board|substrate 10 arrange|positioned in the frame part 125F becomes flush with the frame part 125F. The effect of providing the frame portion 125F is the same as that of Modification 3. By arranging the substrate 10 in the frame portion 125F, the drop around the substrate 10 can be eliminated, thereby preventing the evaporated solvent from diffusing into the substrate 10 . Since the surface of the substrate 10 is further down, the increase in the drying rate of the outer peripheral portion of the substrate 10 can be suppressed. As a result, the drying rate in the surface of the substrate 10 can be made uniform, and the uniformity of the film thickness of the coating film can be improved.

(Other modifications) The arrangement position of the surrounding wall moving mechanism 170 is not limited to the position shown in FIG. 2 . Moreover, you may provide the surrounding wall moving mechanism which raises and lowers all the four wall parts which comprise the surrounding wall 160, for example. It is also possible to provide a surrounding wall moving mechanism that rotates the wall portion 161 with a rotation axis provided at the upper end, side end portion or lower end portion of the wall portion 161 as the center. Access to chamber 110. Although the diffusion suppressing portion 150 is constituted by the surrounding wall 160 and the rectifying plate 190, a diffusion suppressing portion having a shape in which the surrounding wall 160 and the rectifying plate 190 are integrated may also be used. In this case, the diffusion suppressing portion is preferably Provide through holes. The surrounding wall 160 may not be included, and the diffusion suppressing portion 150 may be constituted only by the rectifying plate 190 .

industrial availability The reduced-pressure drying apparatus and the reduced-pressure drying method of the present disclosure can be suitably used in the manufacture of a display panel in which the film thickness of the coating film formed on the substrate is uniform in the plane.

10: Substrate 100, 100A, 100B, 100C, 100D, 100E, 100F: Decompression drying device 110: Chamber 112: Move in and move out 113: switch door 114: exhaust port 120, 120E: Substrate holding part 121, 121E: Substrate mounting table 122: Feet 123, 123E: Mounting surface 124E: Hold Recess 125F: Frame part 130: Decompression mechanism 131: Decompression generation source 132: APC valve 140: Gas supply mechanism 141: Gas supply source 142: Mass Flow Controller 143: On-off valve 150: Diffusion Suppression Section 160: Surrounding Wall 161: Wall 170: Surrounding wall moving mechanism 180: Surrounding wall temperature control mechanism 190, 190C, 190D: Rectifier plate 191C: Base 191D: Lower Surface 192C: Protrusions 192D: Rectifier plate recess 200: Rectifier plate moving mechanism 210: Rectifier plate temperature control mechanism A-A, B-B, C-C: line E: Center E': angle EE': Diagonal L1,L2,L3,L4,L5: Distance

FIG. 1 is a longitudinal sectional view showing the configuration of a vacuum drying apparatus according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1. FIG. 3 is an explanatory diagram of an example of a decompression profile when decompressing the chamber according to the embodiment of the present disclosure. 4A is a longitudinal cross-sectional view showing the structure of the vacuum drying apparatus of Example 1 of the embodiment of the present disclosure. Fig. 4B is a cross-sectional view taken along line A-A of Fig. 4A. Fig. 4C is a cross-sectional view taken along line B-B of Fig. 4A. 5A is an explanatory diagram of a measurement portion of a coating film in Example 1 and Comparative Example 1 of an example of the present disclosure. 5B is a graph showing the film thickness curve of the coating film after drying in Example 1 of the embodiments of the present disclosure. 6A is a longitudinal cross-sectional view showing the configuration of a vacuum drying apparatus in Comparative Example 1 of the embodiments of the present disclosure. 6B is a graph showing the film thickness curve of the coating film after drying in Comparative Example 1 of the embodiments of the present disclosure. 7 is a cross-sectional view showing the configuration of a vacuum drying apparatus according to Modification 1 of the present disclosure. 8 is a longitudinal cross-sectional view showing the configuration of a vacuum drying apparatus according to Modification 2 of the present disclosure. 9 is a longitudinal cross-sectional view showing the configuration of a vacuum drying apparatus according to Modification 3 of the present disclosure. 10A is a longitudinal cross-sectional view showing the configuration of a vacuum drying apparatus according to Modification 4 of the present disclosure. Fig. 10B is a cross-sectional view taken along line C-C of Fig. 10A.

10: Substrate

100: Decompression drying device

110: Chamber

112: Move in and move out

113: switch door

114: exhaust port

120: Substrate holding part

121: Substrate mounting table

122: Feet

123: Mounting surface

130: Decompression mechanism

131: Decompression generation source

132: APC valve

140: Gas supply mechanism

141: Gas supply source

142: Mass Flow Controller

143: On-off valve

150: Diffusion Suppression Section

160: Surrounding Wall

161: Wall

180: Surrounding wall temperature control mechanism

190: Rectifier plate

200: Rectifier plate moving mechanism

210: Rectifier plate temperature control mechanism

A-A: Line

L1: Distance

Claims (19)

A vacuum drying device, comprising: Chamber; a substrate holding part for holding a substrate in the interior of the chamber, the substrate having a coating film containing a solvent formed thereon; a decompression mechanism for decompressing the interior of the chamber; and The diffusion suppressing portion suppresses the diffusion of the solvent evaporated from the coating film. The vacuum drying device according to claim 1, wherein the diffusion suppressing part is provided with: The rectifying plate is arranged above the substrate held by the substrate holding portion, and is formed to have a larger size in a plan view than the substrate. The vacuum drying device according to claim 2, wherein the diffusion suppressing part further comprises: The rectifier plate moving mechanism moves the rectifier plate closer to and away from the substrate. The vacuum drying device according to claim 2 or 3, wherein the diffusion suppressing part further comprises: The rectifier plate temperature control mechanism adjusts the temperature of the aforesaid rectifier plate. The vacuum drying apparatus according to any one of claims 2 to 4, wherein the straightening plate is formed such that the distance from the center portion of the substrate to the straightening plate is longer than the distance from the outer edge portion of the substrate to the straightening plate. The vacuum drying apparatus according to any one of claims 2 to 5, wherein the substrate is formed in a rectangular plate shape, The aforementioned rectifier plate has: the base, which is rectangular in shape when viewed in plan; and The protruding portion protrudes outward from each corner portion of the aforementioned rectangle of the aforementioned base portion. The vacuum drying device according to any one of claims 2 to 6, wherein the aforementioned diffusion suppressing part further comprises: The surrounding wall is arranged around the substrate held by the substrate holding portion. The decompression drying device according to claim 7, wherein the surrounding wall is disposed outside the rectifying plate, The chamber is provided with a loading and unloading port for carrying the substrate in and out in the horizontal direction, The aforementioned diffusion suppressing part further includes: The surrounding wall moving mechanism lifts and lowers at least a portion of the surrounding wall facing the carrying-in/out port. The vacuum drying device according to claim 7 or 8, wherein the diffusion suppressing part further comprises: The temperature control mechanism of the surrounding wall adjusts the temperature of the surrounding wall. The vacuum drying device according to any one of claims 7 to 9, wherein the aforementioned substrate holding portion has: a mounting surface capable of mounting the substrate and provided with the surrounding wall, The height of the surrounding wall from the mounting surface is 10 mm or more, The distance from the inner surface of the surrounding wall to the outer edge of the substrate is 10 mm or less. The decompression drying device according to any one of claims 1 to 10, wherein the chamber is provided with an exhaust port connected to the decompression mechanism, The said exhaust port is provided in the orthogonal projection of the said board|substrate in a planar view below the said board|substrate hold|maintained by the said board|substrate holding|maintenance part. The decompression drying device according to claim 11, wherein one of the aforementioned exhaust ports is provided in the aforementioned chamber, The one exhaust port is provided at a position corresponding to the center of the substrate in a plan view. The vacuum drying device according to any one of claims 1 to 10, wherein the substrate is formed in a rectangular plate shape, The aforementioned chamber is provided with four exhaust ports connected to the aforementioned decompression mechanism, The four exhaust ports are provided below the substrate held by the substrate holding portion, and are provided at equal distances from the center of the substrate in a plan view. The reduced-pressure drying apparatus according to any one of claims 1 to 13, wherein the substrate holding portion is provided with a holding concave portion, the holding concave portion is formed to the same depth as the thickness of the substrate, and the substrate is disposed inside. The reduced-pressure drying apparatus according to any one of claims 1 to 13, wherein the substrate holding portion is provided with a frame portion, the frame portion is formed in a frame shape having the same thickness as the substrate, and the frame portion is disposed inside. substrate. A method of drying under reduced pressure for drying a coating film formed on the aforementioned substrate by using the drying apparatus under reduced pressure according to any one of claims 1 to 15. The method of drying under reduced pressure according to claim 16, wherein the coating film is a coating film for producing an organic EL light-emitting diode. The method of drying under reduced pressure according to claim 16, wherein the coating film is a coating film for manufacturing a quantum dot light-emitting element. The method of drying under reduced pressure according to claim 16, wherein the coating film is a coating film for manufacturing an organic thin film transistor.

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