Drying apparatus

Abstract

The present invention suppresses a decrease in temperature of a coating film when transferring a base material from a first drying part to a second drying part. Specifically, a drying apparatus 10 comprises: a first drying part 11 that dries a coating film P applied on a base material W; and a second drying part 12 that further dries the coating film P of the base material W transferred from the first drying part 11. The first drying part 11 includes: a first heating device 21 for heating the coating film P; and a second heating device 22 for raising the atmospheric temperature of the first drying part 11, or heating the base material W or the coating film P at the first drying part 11.

Description

drying equipment

[0001] The present invention relates to a drying device.

[0002] Electrodes for secondary batteries are manufactured through various processes. One of the various processes is a process of applying a liquid electrode material to a substrate and drying the coating formed on the substrate. A method for manufacturing an electrode including such a process is disclosed in Patent Document 1.

[0003] JP 2016-25051 A

[0004] 4 is an explanatory diagram of a conventional drying apparatus for drying a coating film applied to a substrate. The drying apparatus 90 is configured with multiple stages (treatment areas), and the substrate W is transported to each stage to dry the coating film P. That is, the drying apparatus 90 has a first stage, a first drying section 91, which heats and dries the coating film P, and a second stage, a second drying section 92, which further heats and dries the coating film P on the substrate W transferred from the first drying section 91.

[0005] The first drying section 91 has an infrared heating device 911. The infrared heating device 911 heats the coating film P with infrared rays. When infrared rays are irradiated onto the coating film P, it is possible to increase the surface temperature of the coating film P, but the temperature may not increase throughout the entire coating film P. In the second drying section 92 to which the substrate W moves from the first drying section 91, the coating film P is dried using, for example, hot air. As described above, the temperature of the entire coating film P does not increase in the first drying section 91, and therefore, when the substrate W moves to the second drying section 92, the temperature of the coating film P drops significantly.

[0006] Figure 5 is a graph showing the surface temperature of the coating film P. The horizontal axis of Figure 5 shows the measurement positions of the temperature of the coating film P in the first drying section 91 and the second drying section 92. Measurement position Q1 is included in the infrared radiation irradiation area (heating area S1) (see Figure 4), and the surface temperature of the coating film P is high at measurement position Q1. Measurement position Q2 is a position outside the infrared radiation irradiation area. The surface temperature of the coating film P drops sharply at measurement position Q2 (see Figure 5). This is because, as mentioned above, although the surface of the coating film P is heated by the infrared rays, the temperature of the entire coating film P is not increased.

[0007] Measurement position Q3 is an upstream position of the second drying section 92. Hot air is applied in the second drying section 92, causing a high temperature. At measurement position Q3, the temperature of the coating film P, which had once dropped, rises. As shown in Figure 5, when the substrate W moves to the second drying section 92, the temperature of the coating film P drops significantly, resulting in a problem of significant energy loss.

[0008] Therefore, an object of the present invention is to provide a drying device that can prevent the temperature of the coating film from decreasing when the substrate is transferred from the first drying section to the second drying section.

[0009] The drying device of the present invention has a first drying section that dries a coating film applied to a substrate, and a second drying section that further dries the coating film on the substrate transferred from the first drying section, and the first drying section has a first heating device that heats the coating film, and a second heating device that increases the ambient temperature of the first drying section or heats the substrate or the coating film in the first drying section.

[0010] According to the drying device of the present invention, the temperature drop of the coating film is suppressed when the substrate is transferred from the first drying section to the second drying section, which makes it possible to reduce energy loss.

[0011] Fig. 1 is a structural diagram showing an example of the drying apparatus of the present invention. Fig. 2A is an explanatory diagram regarding heating of a coating film by a first heating device and a second heating device. Fig. 2B is an explanatory diagram showing the temperatures of the coating film and the substrate by the apparatus shown in Fig. 2A. Fig. 3 is a graph showing the surface temperature of a coating film heated using the drying apparatus of this embodiment. Fig. 4 is an explanatory diagram of a conventional drying apparatus. Fig. 5 is a graph showing the surface temperature of a coating film.

[0012] <Outline of Embodiments of the Present Invention> The following is a list and description of outlines of embodiments of the present invention. (1) A drying device of the present invention includes a first drying section that dries a coating film applied to a substrate, and a second drying section that further dries the coating film on the substrate transferred from the first drying section, and the first drying section includes a first heating device that heats the coating film, and a second heating device that increases the atmospheric temperature of the first drying section or heats the substrate or the coating film in the first drying section.

[0013] According to the drying device, in the first drying section, the first heating device heats the coating film, and the second heating device increases the ambient temperature of the first drying section or heats the substrate or the coating film. This increases the temperature of the entire coating film, not just the surface, in the first drying section. This makes it possible to prevent the temperature of the coating film from decreasing when the substrate is transferred from the first drying section to the second drying section.

[0014] (2) In the drying device of (1), the first heating device includes an infrared heating device that irradiates the coating film with infrared rays. (3) In the drying device of (2), the infrared heating device includes a laser irradiator that irradiates the coating film with an infrared laser. According to the configurations of (2) and (3), the coating film is heated in a short time in the first drying section.

[0015] (4) In the drying device according to any one of (1) to (3), the first drying section has a first housing having a first treatment chamber therein through which the substrate passes, and the second drying section has a second housing having a second treatment chamber therein through which the substrate passes, and the first housing and the second housing are adjacent to each other. According to this configuration, heat generated in the first drying section is accumulated in the first housing, resulting in high thermal efficiency. Since the first housing and the second housing are adjacent to each other, the substrate is quickly transferred from the first treatment chamber of the first housing to the second treatment chamber of the second housing, and a decrease in the temperature of the coating film during the transfer is suppressed.

[0016] (5) In the drying device of (4), the second heating device includes a supply nozzle provided in the first treatment chamber for supplying hot air. In this case, the second heating device can increase the ambient temperature of the first drying section. When hot air is applied to the coating film, the coating film is heated by the heat. This makes it possible to increase the temperature of the substrate and the entire coating film, and suppresses a decrease in the temperature of the coating film when the substrate is transferred from the first drying section to the second drying section.

[0017] (6) In the drying device of (5), the supply nozzle is provided in the first treatment chamber and ejects hot air having a velocity component toward the second treatment chamber. For example, if the second treatment chamber is at a lower pressure than the first treatment chamber, air from the first treatment chamber flows into the second treatment chamber. If the ambient temperature in the first treatment chamber is low, the ambient temperature may drop significantly in the boundary region between the first and second treatment chambers. However, with the above configuration, the hot air from the supply nozzle flows from the first treatment chamber toward the second treatment chamber, making it possible to prevent a significant drop in ambient temperature in the boundary region. Therefore, the temperature drop of the coating film is suppressed when the substrate transitions from the first drying section to the second drying section.

[0018] (7) In the drying device of (6), the supply nozzle is located upstream of the heating area of ​​the coating film by the first heating device in the direction of movement of the substrate. According to this configuration, the second drying section is adjacent to the heating area of ​​the first heating device near the downstream side. Therefore, the substrate whose coating film has been heated by the first heating device can be quickly transferred to the second drying section, and the drying process can be continued in the second drying section.

[0019] (8) In the drying device of any one of (1) to (7), the second heating device is located on the side of the substrate opposite the surface to which the coating film is applied and heats the substrate. According to this configuration, the second heating device heats the substrate in the first drying section. The heat applied to the substrate also heats the portion of the coating film facing the substrate, making it possible to increase the temperature of the entire coating film. This makes it possible to prevent a decrease in the temperature of the coating film when the substrate is transferred from the first drying section to the second drying section.

[0020] (9) In the drying device of any one of (1) to (8), the first drying section has a first housing having a first treatment chamber therein through which the substrate passes, the first heating device includes an infrared heating device that irradiates infrared rays onto the coating film on the substrate passing through the first treatment chamber, the infrared heating device is located outside the first housing, and the first housing has an opening that allows the infrared rays to pass through. With this configuration, even if the first treatment chamber inside the first housing becomes hot, the infrared heating device is protected from the high-temperature environment of the first treatment chamber.

[0021] (10) In the drying device of any one of (1) to (9), the second heating device includes a front-stage supply nozzle that supplies hot air, and the second drying section includes a rear-stage supply nozzle that supplies hot air. In this case, hot air is used in both the first drying section and the second drying section to dry the coating film. The first drying section and the second drying section have in common the use of hot air, which allows for a simplification of the configuration of the drying device.

[0022] <Details of the embodiment of the present invention> Hereinafter, details of the embodiment of the present invention will be described. [Overall configuration of drying device] Fig. 1 is an explanatory diagram showing an example of the drying device of the present invention. The drying device 10 shown in Fig. 1 is used for manufacturing an electrode for a secondary battery. Specifically, the method for manufacturing an electrode includes a step of applying a liquid electrode material to a substrate W and drying a coating film P made of the electrode material formed on the substrate W. As the coating film P dries, a solidified electrode layer Pa is formed on the substrate W. The drying device 10 is a device that dries the coating film P applied to the substrate W.

[0023] The drying apparatus 10 is configured to have multiple stages (treatment areas), and a drying process is performed while the substrate W is transported in each stage. That is, the drying apparatus 10 has a first drying section 11 as a first stage and a second drying section 12 as a second stage. The first drying section 11 has a function of heating and drying the coating film P applied to the substrate W. The second drying section 12 has a function of further heating and drying the coating film P on the substrate W transferred from the first drying section 11. Note that, for the sake of explanation, the length of the second drying section 12 is shown as short in the direction of movement of the substrate W in FIG. 1 , but in reality, the second drying section 12 is long (longer than the first drying section 11).

[0024] The drying apparatus 10 has a conveying device 13 that conveys the substrate W and passes through the first drying section 11 and the second drying section 12. The conveying device 13 has a plurality of rotating rollers 131 on which the substrate W is placed and conveyed. The substrate W in this embodiment is a long sheet-like member. The longitudinal direction (longitudinal direction) of the substrate W coincides with the direction of movement (conveyance direction) of the substrate W by the conveying device 13. The first drying section 11 applies heat to the substrate W being conveyed to dry the coating film P. The second drying section 12 applies heat to the substrate W being conveyed to dry the coating film P. The coating film P contains a solvent, and the solvent is volatilized in the first drying section 11 and the second drying section 12.

[0025] The first drying section 11 has a first housing 17 having a first treatment chamber 16 therein through which the substrate W passes. The coating film P is heated in the first treatment chamber 16. The second drying section 12 has a second housing 19 having a second treatment chamber 18 therein through which the substrate W passes. The coating film P is heated in the second treatment chamber 18. The first housing 17 and the second housing 19 are adjacent to each other. The first housing 17 has an entrance 25 for carrying the substrate W on the upstream side in the movement direction of the substrate W. A passage (opening) 26 is provided between the first housing 17 and the second housing 19, and the substrate W passes through the passage 26. The second housing 19 has an exit 28 for carrying the substrate W out on the downstream side in the movement direction of the substrate W.

[0026] The first drying section 11 will be described. The first drying section 11 has a first heating device 21 and a second heating device 22. The first heating device 21 heats the coating film P on the substrate W. In this embodiment, the first heating device 21 is an infrared heating device 30, which irradiates infrared rays onto the coating film P on the substrate W passing through the first treatment chamber 16. The infrared heating device 30 is configured, for example, with an infrared lamp. At least the surface of the coating film P is heated and dried by the infrared rays. With respect to the movement direction of the substrate W, the area irradiated with infrared rays by the infrared heating device 30 is the heating area S1 of the coating film P by the infrared heating device 30.

[0027] The first drying section 11 has an equipment housing 55 that is installed separately from the first housing 17. The equipment housing 55 is provided adjacent to the first housing 17. The infrared heating device 30 is housed in the equipment housing 55 and is located outside the first housing 17. The first housing 17 has an opening 27 that allows infrared rays from the infrared heating device 30 to pass through. A cover member 271 that allows infrared rays to pass through is provided in the opening 27. The cover member 271 is made of glass that has a high transmittance of infrared rays. It is noted that the cover member 271 does not necessarily have to be provided.

[0028] 1 has a first section 551 that houses the main body of the infrared heating device 30, and a second section 552 that connects the first section 551 and the first housing 17. The second section 552 is an area through which infrared rays pass. The first housing 17 has a wall 171 between it and the second section 552, and the wall 171 has an opening 27. With the above-mentioned configuration, even if the first treatment chamber 16 becomes hot, the infrared heating device 30 is protected from the high-temperature environment of the first treatment chamber 16.

[0029] In this embodiment, the first heating device 21 includes an infrared heating device 30, but other types of heating devices may also be used. The infrared heating device 30 may include a laser irradiator that emits an infrared laser. The infrared laser heats and dries at least the surface of the coating film P. The infrared laser is preferably a semiconductor laser with a wavelength of 900 nanometers or more and 1100 nanometers or less. The coating film P contains a conductive additive or active material such as carbon black or graphite, which has a high absorption rate of infrared light of the wavelength. Using infrared light of the wavelength allows the coating film P to be heated efficiently. The use of such an infrared laser makes it possible to heat the coating film P evenly while reducing energy loss. Note that an infrared heater (near-infrared heater) as the infrared lamp can also employ the same wavelength as the infrared laser, but in this case, it has a broad spectrum and includes wavelengths absorbed by water or organic solvents evaporated from the coating film P. In contrast, the infrared laser emits light of a single wavelength that is not easily absorbed by water or organic solvents evaporated from the coating film P. Therefore, the infrared laser is less likely to be absorbed by the water or organic solvent evaporated from the coating film P, and the coating film P can be heated efficiently.

[0030] The second heating device 22 is provided inside the first housing 17, i.e., in the first treatment chamber 16. The second heating device 22 in this embodiment includes a supply nozzle 31. The supply nozzle 31 is located on the substrate W on the side of the coating surface Wa of the coating film P. The supply nozzle 31 is provided in the first treatment chamber 16 and supplies hot air to the first treatment chamber 16. Although not shown, the drying device 10 has a heat source such as a heater outside the first housing 17 and the second housing 19, and heated gas is supplied from the heat source to the supply nozzle 31 through piping. The supply nozzle 31 sprays the heated gas into the first treatment chamber 16 as hot air.

[0031] The supply nozzle 31 provided in the first treatment chamber 16 ejects hot air having a velocity component directed toward the second treatment chamber 18. In other words, the hot air ejected from the supply nozzle 31 has a velocity component directed downstream in the direction of movement of the substrate W. Furthermore, the hot air ejected from the supply nozzle 31 also has a velocity component directed toward the coating film P on the substrate W. Since the second heating device 22 includes the supply nozzle 31, the ambient temperature of the first treatment chamber 16 is increased. The heat generated in the first drying section 11 (first treatment chamber 16) is accumulated by the first housing 17, maintaining the ambient temperature of the first treatment chamber 16 and improving thermal efficiency.

[0032] The supply nozzle 31 is located upstream in the direction of movement of the substrate W from a heating region S1 (infrared irradiation region) of the coating film P by the first heating device 21 (infrared heating device 30). With this configuration, the second drying section 12 is adjacent to and near the downstream side of the heating region S1 by the first heating device 21. The substrate W, whose coating film P has been heated by the first heating device 21, is quickly transferred to the second drying section 12. Then, the drying process continues in the second drying section 12.

[0033] 1 includes, in addition to the supply nozzle 31, another heating means 33. The another heating means 33 is located in the first treatment chamber 16 on the side of the substrate W opposite the surface Wb (back side) of the surface Wa to be coated with the coating film P. Examples of the another heating means 33 include a nozzle that supplies hot air toward the opposite surface Wb of the substrate W, an IH heater, a radiant heater (infrared heater), and a heating roll that comes into contact with the substrate W (opposite surface Wb). The second heating device 22 may be configured by one of these, or may be configured by combining a plurality of these.

[0034] When the other heating means 33 is an IH heater, the substrate W is made of a material that can be heated by electromagnetic induction. When the substrate W is made of copper or aluminum, an IH heater compatible with such materials is adopted. When the other heating means 33 is an infrared heater, the infrared rays preferably have a wavelength that is easily absorbed by the substrate W.

[0035] When the other heating means 33 is a nozzle that supplies hot air, the hot air is generated by the heat source, such as a heater, that supplies heated gas to the supply nozzle 31. When the other heating means 33 is a heating roller, the heat generated by the heating roller is transferred to the substrate W, and the substrate W and the coating film P applied to the substrate W are heated.

[0036] As described above, in the case of the drying apparatus 10 shown in FIG. 1 , the second heating device 22 includes a heating means 33 that heats the substrate W, and is located on the side Wb of the substrate W opposite the application surface Wa of the coating film P. Such a heating means 33 heats the substrate W in the first drying section 11. The heat applied to the substrate W also heats the portion of the coating film P on the substrate W side, making it possible to increase the temperature of the entire coating film P. This makes it possible to prevent a decrease in the temperature of the coating film P when the substrate W moves from the first drying section 11 to the second drying section 12.

[0037] As described above, the second heating device 22 includes a supply nozzle 31 that supplies hot air to the first treatment chamber 16. This increases the atmospheric temperature in the first drying section 11 (first treatment chamber 16). The second heating device 22 includes another heating means 33 as described above. This heats the substrate W in the first drying section 11 (first treatment chamber 16), and also heats the coating film P.

[0038] Although not shown, the second heating device 22 may be configured to omit the supply nozzle 31 and include the separate heating means 33. Alternatively, the second heating device 22 may include only the supply nozzle 31, omitting the separate heating means 33. In the embodiment shown in FIG. 1 , the second heating device 22 (heating means 33) is located on the side of the surface Wb opposite to the coating surface Wa, but it may also be configured to be located on the side of the coating surface Wa and heat the coating film P. In other words, the second heating device 22 may be configured to increase the atmospheric temperature of the first drying section 11 or to heat the substrate W or the coating film P in the first drying section 11.

[0039] The second drying section 12 will now be described. The second drying section 12 further dries the coating film P heated in the first drying section 11. The second drying section 12 of this embodiment includes a rear-stage supply nozzle 32 that supplies hot air to dry the coating film P. The rear-stage supply nozzle 32 ejects hot air into the second treatment chamber 18. This increases the ambient temperature in the second drying section 12 (second treatment chamber 18) and dries the coating film P. The rear-stage supply nozzle 32 may be configured to eject hot air having a velocity component directed toward the coating film P on the substrate W. This improves the efficiency of drying the coating film P.

[0040] As described above, the drying device 10 has a heat source such as a heater (not shown) outside the first housing 17 and the second housing 19, and heated gas is supplied from the heat source through piping to the downstream supply nozzle 32. The supply nozzle 32 ejects the heated gas as hot air.

[0041] In the configuration shown in FIG. 1 , in the first drying section 11, which is the first stage, the second heating device 22 has a front-stage supply nozzle 31 that supplies hot air. The second drying section 12 has a rear-stage supply nozzle 32 that supplies hot air. In each of the first drying section 11 and the second drying section 12, hot air is used to dry the coating film P. The front-stage supply nozzle 31 and the rear-stage supply nozzle 32 can share a heat source such as the heater (not shown). The first drying section 11 and the second drying section 12 have in common the use of hot air, which allows for a simplification of the configuration of the drying device 10.

[0042] 2A is an explanatory diagram regarding heating of a coating film P by a first heating device 21 and a second heating device 22. The first heating device 21 is an infrared heating device 30, and the second heating device 22 has an IH heater as heating means 33. As shown in FIG. 1, the infrared heating device 30 irradiates infrared rays onto a coating surface Wa of the coating film P. The IH heater (heating means 33) is located on the side Wb opposite to the coating surface Wa.

[0043] The left diagram of FIG. 2A is a diagram of the substrate W as viewed from the coating surface Wa, and the right diagram of FIG. 2A is a diagram of the substrate W as viewed from the opposite surface Wb (back surface). The direction perpendicular to the direction of movement of the substrate W is called the width direction of the substrate W. The coating film P is formed in the central portion C of the substrate W, excluding both side portions E in the width direction. The width D1 of the infrared radiation irradiated by the infrared heating device 30 in the width direction is equal to the width dimension B of the substrate W. The heating width D2 of the substrate W by the IH heater (second heating device 22) is equal to the width dimension B of the substrate W. In FIG. 2A, the heating area S by the infrared heating device 30 and the heating area by the IH heater are hatched. Note that the irradiation width D1 only needs to be greater than at least the dimension of the coating film P in the width direction of the substrate W.

[0044] Fig. 2B is an explanatory diagram showing the temperatures of the coating film P and the substrate W heated by the device shown in Fig. 2A. The left diagram of Fig. 2B is an explanatory diagram of the temperature (surface temperature) of the coating film P heated by the infrared heating device 30, the center diagram of Fig. 2B is an explanatory diagram of the temperature (rear surface temperature) of the substrate W heated by the IH heater (second heating device 22), and the right diagram of Fig. 2B is an explanatory diagram of the temperature of the coating film P heated by the infrared heating device 30 and the IH heater (second heating device 22).

[0045] The infrared heating device 30 heats the coating film P (its surface) with infrared rays, but the infrared rays are reflected from both side portions E, which are exposed surfaces of the substrate W, and both side portions E are not heated as much as the central portion C where the coating film P is present (see the left diagram in FIG. 2B ). In contrast, because the coating film P is formed in the central portion C, the IH heater (second heating device 22) causes the temperature of both side portions E of the substrate W to rise more than the temperature of the central portion C where the coating film P is formed (see the center diagram in FIG. 2B ).

[0046] Therefore, when the first drying section 11 has an infrared heating device 30 and an IH heater (second heating device 22) and these are combined to heat the coating film P and the substrate W, it is possible to uniformly increase the heating temperature of the entire substrate W in the width direction, as shown in the right diagram of Figure 2B. As a result, a difference in thermal shrinkage is unlikely to occur between the center portion C and both side portions E, and the occurrence of wrinkles in the substrate W is prevented.

[0047] [Drying Apparatus 10 of the Present Embodiment] As described above, the drying apparatus 10 of the present embodiment (see FIG. 1 ) has a first drying section 11 that dries the coating film P applied to the substrate W, and a second drying section 12 that further dries the coating film P on the substrate W transferred from the first drying section 11. The first drying section 11 has a first heating device 21 that heats the coating film P, and a second heating device 22. The second heating device 22 has, for example, a supply nozzle 31, thereby increasing the atmospheric temperature in the first drying section 11. The second heating device 22 has heating means 33 separate from the supply nozzle 31, thereby heating the substrate W or the coating film P in the first drying section 11.

[0048] According to the drying apparatus 10 of this embodiment, in the first drying section 11, the first heating device 21 heats the coating film P, and the second heating device 22 increases the ambient temperature of the first drying section 11 (first treatment chamber 16) or heats the substrate W or the coating film P. This increases the temperature of the entire coating film P, not just the surface of the coating film P, in the first drying section 11. As a result, when the substrate W moves from the first drying section 11 to the second drying section 12, a decrease in the temperature of the coating film P is suppressed. It is possible to suppress energy loss in the drying apparatus 10.

[0049] In the case of the drying apparatus 10 shown in FIG. 1 , the first heating device 21 is an infrared heating device 30 that irradiates infrared rays onto the coating film P. The infrared heating device 30 allows the coating film P (particularly the surface of the coating film P) to be heated in a short period of time in the first drying section 11. In the drying apparatus 10 shown in FIG. 1 , a measuring device 29 that measures the surface temperature of the substrate W is provided in the first housing 17 (first treatment chamber 16). The measuring device 29 is, for example, a thermal camera. The output of infrared rays from the infrared heating device 30 is preferably adjusted based on the measurement results from the measuring device 29.

[0050] Figure 3 is a graph showing the surface temperature of the coating film P heated using the drying device 10 of this embodiment. In Figure 3, the temperature is shown by a solid line, and the temperature in the case of the prior art shown in Figure 5 is shown by a dotted line. The horizontal axis of Figure 3 shows the measurement positions of the temperature of the coating film P in the first drying section 11 and the second drying section 12. Measurement position Q1 is a position included in the infrared radiation area (heating area S1, see Figure 1) irradiated by the infrared heating device 30. At measurement position Q1, the surface temperature of the coating film P increases due to heating by infrared rays.

[0051] Measurement position Q2 is a position outside the infrared irradiation area. As shown in Figure 3, the temperature of the surface of the coating film P drops slightly at measurement position Q2. In the drying apparatus 10 of this embodiment, as described above, the second heating device 22 has the supply nozzle 31, thereby increasing the ambient temperature of the first drying section 11. The second heating device 22 has a heating means 33 separate from the supply nozzle 31, thereby heating the substrate W and further the coating film P in the first drying section 11. For this reason, in this embodiment, the temperature drop of the coating film P at measurement position Q2 is smaller than in the case of the conventional technology shown by the dotted line in Figure 3.

[0052] Measurement position Q3 is an upstream position of the second drying section 12 (see FIG. 1). The second drying section 12 is heated to a high temperature by the application of hot air. At measurement position Q3, the temperature of the coating film P, which had initially dropped slightly, rises. As shown by the solid line in FIG. 3, the drying device 10 of this embodiment makes it possible to prevent the temperature of the coating film P from dropping when the substrate W moves from the first drying section 11 to the second drying section 12. This promotes drying of the coating film P in the second drying section 12. Furthermore, energy loss is reduced compared to conventional systems.

[0053] In the drying apparatus 10 of this embodiment, the first drying section 11 has a first housing 17 having a first treatment chamber 16 therein for heating the coating film P. The second drying section 12 has a second housing 19 having a second treatment chamber 18 therein for heating the coating film P. Heat generated in the first drying section 11 (first treatment chamber 16) is accumulated by the first housing 17, resulting in good thermal efficiency. The first housing 17 and the second housing 19 are adjacent to each other. Therefore, the substrate W is quickly transferred from the first treatment chamber 16 of the first housing 17 to the second treatment chamber 18 of the second housing 19, and a decrease in the temperature of the coating film P during the transfer is suppressed.

[0054] The temperatures of the substrate W and the coating P are increased by the ambient temperature of the first treatment chamber 16 of the first housing 17. The ambient temperature of the first treatment chamber 16 is increased by, for example, the second heating device 22 supplying hot air to the first treatment chamber 16, and is also increased indirectly by the second heating device 22 increasing the temperature of the substrate W.

[0055] 1 includes a supply nozzle 31 that is provided in the first treatment chamber 16 and supplies hot air. When the hot air from the supply nozzle 31 is applied to the coating film P, the coating film P is heated by the heat. This makes it possible to increase the overall temperature of the substrate W and the coating film P, and suppresses a decrease in the temperature of the coating film P when the substrate W moves from the first drying section 11 to the second drying section 12.

[0056] In the drying apparatus 10 of this embodiment, the second treatment chamber 18 is under lower pressure than the first treatment chamber 16. This causes air in the first treatment chamber 16 to flow into the second treatment chamber 18. If the ambient temperature in the first treatment chamber 16 is low, the ambient temperature may drop significantly in the boundary region between the first treatment chamber 16 and the second treatment chamber 18 (between positions Q2 and Q3 in FIG. 1 ). The supply nozzle 31 shown in FIG. 1 ejects hot air having a velocity component directed toward the second treatment chamber 18. The hot air from the supply nozzle 31 flows from the first treatment chamber 16 toward the second treatment chamber 18, preventing a significant drop in ambient temperature in the boundary region. This prevents a decrease in the temperature of the coating film P when the substrate W transitions from the first drying section 11 to the second drying section 12.

[0057] In the first drying section 11, when the coating film P is heated by the infrared heating device 30, the solvent contained in the coating film P volatilizes. If the volatilized solvent remains in the first treatment chamber 16, the solvent concentration in the first treatment chamber 16 increases, which may slow the drying of the coating film P. Therefore, the supply nozzle 31 shown in FIG. 1 ejects hot air having a velocity component in a direction toward the second treatment chamber 18. This hot air prevents the volatilized solvent from remaining and allows it to move (diffuse). The solvent concentration in the first treatment chamber 16 does not increase, and the drying of the coating film P is promoted.

[0058] Furthermore, if the infrared rays irradiated by the infrared heating device 30 are absorbed by the solvent that has evaporated from the coating film P, they may not be irradiated uniformly onto the coating film P, which may result in uneven heating of the coating film P. With the supply nozzle 31 shown in Figure 1, the hot air can move (diffuse) the solvent from the first treatment chamber 16, preventing uneven heating of the coating film P.

[0059] [Others] In the embodiment described above (see FIG. 1 ), the supply nozzle 31 is provided upstream of the infrared radiation irradiation region (heating region S1) in the first processing chamber 16. The position of the supply nozzle 31 is not limited to this. The supply nozzle 31 may be provided downstream of the heating region S1, for example, in the vicinity of the passage (opening) 26 between the first housing 17 and the second housing 19.

[0060] In the above embodiment (see FIG. 1 ), the coating film P is formed only on one surface (front surface) of the substrate W, but the coating film P may be formed on both one surface (front surface) and the other surface (rear surface) of the substrate W. In this case, the infrared heating device 30 is installed not only on one surface side of the substrate W but also on the other surface side of the substrate W. The coating films P on both the one surface and the other surface of the substrate W are heated by the infrared heating devices 30 on both sides.

[0061] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The technical scope of the present invention is not limited to the above-described embodiments, and includes all modifications within the scope of equivalents to the configurations described in the claims.

[0062] REFERENCE SIGNS LIST 10 Drying device 11 First drying section 12 Second drying section 16 First treatment chamber 17 First housing 18 Second treatment chamber 19 Second housing 21 First heating device 22 Second heating device 27 Opening 30 Infrared heating device 31 Supply nozzle (front supply nozzle) 32 Rear supply nozzle P Coating film S1 Heated area W Substrate Wa Coating surface Wb Opposite surface

Claims

1. A drying apparatus comprising: a first drying section that dries a coating film applied to a substrate; and a second drying section that further dries the coating film on the substrate transferred from the first drying section, wherein the first drying section comprises: a first heating device that heats the coating film; and a second heating device that increases the ambient temperature of the first drying section or heats the substrate or the coating film in the first drying section.

2. The drying device according to claim 1, wherein the first heating device includes an infrared heating device that irradiates the coating film with infrared rays.

3. The drying device according to claim 2, wherein the infrared heating device includes a laser irradiator that irradiates the coating with an infrared laser.

4. A drying device according to any one of claims 1 to 3, wherein the first drying section has a first housing having a first treatment chamber therein through which the substrate passes, and the second drying section has a second housing having a second treatment chamber therein through which the substrate passes, and the first housing and the second housing are adjacent to each other.

5. The drying device according to claim 4, wherein the second heating device includes a supply nozzle that is provided in the first treatment chamber and supplies hot air.

6. The drying device according to claim 5, wherein the supply nozzle is provided in the first treatment chamber and ejects hot air having a velocity component in a direction toward the second treatment chamber.

7. The drying device according to claim 6, wherein the supply nozzle is located upstream of a heating area of ​​the coating film by the first heating device in the direction of movement of the substrate.

8. A drying device according to any one of claims 1 to 3, wherein the second heating device is located on the opposite side of the substrate to the surface to which the coating film is applied and heats the substrate.

9. A drying device as described in any one of claims 1 to 3, wherein the first drying section has a first housing having a first treatment chamber therein through which the substrate passes, the first heating device includes an infrared heating device that irradiates infrared rays onto the coating film on the substrate passing through the first treatment chamber, the infrared heating device is located outside the first housing, and the first housing has an opening that allows the infrared rays to pass through.

10. A drying device according to any one of claims 1 to 3, wherein the second heating device includes a front-stage supply nozzle that supplies hot air, and the second drying section includes a rear-stage supply nozzle that supplies hot air.

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