Coating device and coating system

Abstract

Provided is a coating device that prevents uneven drying of a coating film formed on a substrate. Specifically, a coating device (100) comprises: a chamber (10) that accommodates a substrate (50); an applicator (20) that applies a coating liquid (30) to the substrate accommodated in the chamber to form a coating film (51) on the substrate; and a supply means (60) for supplying into the chamber a gas (32) obtained by vaporizing a solvent (31) contained in the coating liquid. The coating film is formed on the substrate in the chamber, in a gas atmosphere of the solvent gas supplied from the supply means.

Description

Coating Device and Coating System

[0001] The present invention relates to a coating device for forming a coating film on a substrate, and a coating system for drying the coating film after forming the coating film on the substrate.

[0002] As a coating device for forming a coating film on a substrate, for example, a coater that discharges a coating liquid from a slit-shaped nozzle is relatively moved with respect to a stage on which the substrate is placed, and the coating liquid is discharged from the coater onto the substrate while moving, to form a coating film on the substrate, there is a slit coat type coating device.

[0003] However, in such a slit coat type coating device, while forming a coating film on the entire surface of the substrate, the coating film applied on the substrate gradually dries naturally, so there is a problem that drying unevenness occurs in the coating film. In particular, when forming a perovskite film on a substrate, if drying unevenness occurs in the coating film formed on the substrate, the crystal state of the perovskite changes during subsequent annealing. Therefore, when the perovskite film is used as a material for a solar cell, there is a problem of affecting the performance of the solar cell.

[0004] As a method for preventing drying unevenness of the coating film, Patent Document 1 discloses a method of drying the coating liquid by injecting a drying gas toward the substrate on which the coating liquid is applied.

[0005] Japanese Patent Application Laid-Open No. 2006-26591

[0006] However, in the above method disclosed in Patent Document 1, it is difficult to uniformly inject the drying gas onto the coating liquid applied on the substrate, and drying unevenness of the coating film cannot be sufficiently prevented.

[0007] Also, usually, after forming a coating film on a substrate, the substrate on which the coating film is formed is transferred to a drying device, and a step of drying the solvent remaining in the coating film is performed in the drying device. However, in this case as well, while the substrate on which the coating film is formed is being transferred to the drying device, natural drying of the solvent progresses, which becomes a factor causing drying unevenness of the coating film.

[0008] The present invention has been made in view of the above, and its main objective is to provide a coating apparatus that can prevent uneven drying of a coating film formed on a substrate.

[0009] The coating apparatus according to the present invention comprises a chamber for housing a substrate, a coater for applying a coating liquid to the substrate housed in the chamber to form a coating film on the substrate, and a supply means for supplying a gas obtained by vaporizing the solvent contained in the coating liquid into the chamber. The formation of the coating film on the substrate is carried out in the chamber in a gas atmosphere of the solvent supplied from the supply means.

[0010] The coating system according to the present invention is a coating system in which a coating device that applies a coating liquid to a substrate to form a coating film on the substrate and a vacuum dryer that dries the coating film formed on the substrate are housed in a chamber, and the chamber is equipped with a supply means for supplying a gas obtained by vaporizing the solvent contained in the coating liquid, and after forming a coating film on the substrate with the coating device while the chamber is filled with solvent gas from the supply means to create a solvent gas atmosphere in the chamber, the substrate on which the coating film has been formed is transferred to the vacuum dryer to dry the coating film under reduced pressure.

[0011] According to the present invention, it is possible to provide a coating apparatus that can prevent uneven drying of a coating film formed on a substrate.

[0012] This figure schematically shows the configuration of a coating apparatus in the first embodiment of the present invention. This figure schematically shows another configuration of the coating apparatus in the first embodiment of the present invention. This figure schematically shows the configuration of a coating system in the second embodiment of the present invention. This figure illustrates the operation of drying the coating film after forming a coating film on a substrate using the coating system. This figure illustrates the operation of drying the coating film after forming a coating film on a substrate using the coating system.

[0013] (First Embodiment) Figure 1 is a schematic diagram showing the configuration of a coating apparatus in the first embodiment of the present invention.

[0014] As shown in Figure 1, the coating apparatus 100 in this embodiment includes a chamber 10 for housing a substrate 50 placed on a stage 40, a coater 20 for applying a coating liquid to the substrate 50 housed in the chamber 10 to form a coating film on the substrate 50, and a supply means 60 for supplying a gas obtained by vaporizing the solvent contained in the coating liquid into the chamber 10.

[0015] The coating device 20 moves in a specific direction relative to the substrate 50, and discharges the coating liquid 30 stored in the tank 21 from the slit-shaped nozzle 22 onto the substrate 50, forming a coated film (not shown) on the substrate 50. The coating method by the coating device 20 is not limited to this slit coating method, and may also be a spin coating method, an inkjet method, or the like.

[0016] The coating solution 30 contains a solvent in which the material for the coating film to be formed on the substrate 50 (e.g., a perovskite film, a resist film, a battery electrode film, etc.) is dissolved. Examples of solvents include N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), and N-methyl-2-pyrrolidone (NMP).

[0017] The supply means 60 includes a tank 61 for storing the solvent 31 contained in the coating liquid, and a vaporizer 62 that vaporizes the solvent 31 sent from the tank 61 by a push gas 65 and supplies the vaporized gas 32 into the chamber 10. The solvent 31 sent to the vaporizer 62 is vaporized by a heater (not shown) provided inside the vaporizer 62, and the vaporized gas 32 is supplied into the chamber 10 by a carrier gas 66. The flow rate of the solvent 31 sent from the tank 61 to the vaporizer 62 and the flow rate of the carrier gas 66 sent to the vaporizer 62 are controlled by mass flow controllers 63 and 64, respectively. Note that the vaporizer 62 is not limited to this direct vaporization method, and for example, a vaporizer of the bubbling type or the like can be used.

[0018] In this embodiment, the formation of the coating film on the substrate 50 is carried out in a sealed chamber 10 in a gas atmosphere of solvent 31 supplied from the supply means 60, so the evaporation rate of solvent 31 is slower than in an open space. As a result, the amount of solvent 31 that evaporates due to natural drying can be reduced, and uneven drying of the coating film formed on the substrate 50 can be prevented.

[0019] The gas concentration of the solvent 31 inside the chamber 10 can be appropriately determined depending on the type of coating film to be formed and the type of solvent used.

[0020] If the solvent 31 used is flammable, it is preferable to control the gas concentration of the solvent 31 in the chamber 10 to be above the upper explosive limit when forming the coating film on the substrate 50. For example, when N,N-dimethylformamide (DMF) is used as the solvent 31, it is preferable to control the gas concentration of the solvent 31 in the chamber 10 to be above the upper explosive limit of DMF (15.2%).

[0021] Furthermore, as shown in Figure 2, the coating apparatus 100 may also be equipped with a filling means 70 for filling the chamber 10 with an inert gas such as nitrogen. In this case, the formation of the coating film on the substrate 50 is performed after filling the chamber 10 with an inert gas using the filling means 70 and then creating an atmosphere of solvent 31 gas 32 supplied from the supply means 60. Alternatively, the air in the chamber 10 may be exhausted, and then solvent 31 gas 32 may be supplied into the chamber 10 from the supply means 60 to create an atmosphere of solvent 31 gas 32 before forming the coating film on the substrate 50. In either case, even if the solvent 31 used is flammable, the gas concentration of the solvent 31 in the chamber 10 can be kept below the upper explosive limit of the solvent 31.

[0022] (Second Embodiment) Figure 3 is a schematic diagram showing the configuration of the coating system in the second embodiment of the present invention.

[0023] As shown in Figure 3, the coating system 200 in this embodiment includes a coater 20 that applies a coating liquid 30 to a substrate 50 placed on a stage 40 to form a coating film (not shown) on the substrate 50, and a vacuum dryer 80 that dries the coating film formed on the substrate 50, both housed in a chamber 10. The coater 20 is supplied with the coating liquid 30 stored in a tank 21 located outside the chamber 10.

[0024] Furthermore, the coating system 200 includes a supply means 60 that supplies a gas 32, which is obtained by vaporizing the solvent contained in the coating liquid 30, into the chamber 10. Note that the supply means 60 has the same configuration as shown in Figure 1, so its explanation will be omitted.

[0025] Next, with reference to Figures 4 and 5, the operation of forming a coating film on the substrate 50 using the coating system 200 of this embodiment, and then drying the coating film, will be described.

[0026] First, as shown in Figure 4, solvent gas 32 is supplied from the supply means 60 into the chamber 10 to create a solvent gas atmosphere in the chamber 10, and then the coating device 20 forms a coating film 51 on the substrate 50. Here, the stage 40 on which the substrate 50 is placed is moved relative to the coating device 20 in the direction of the vacuum dryer 80, and the coating liquid 30 is discharged from the coating device 20 onto the substrate 50 to form a coating film 51 on the substrate 50. Note that the discharge of the coating liquid 30 onto the substrate 50 may also be performed while moving the stage 40 in the direction opposite to the vacuum dryer 80.

[0027] Next, as shown in Figure 5, the stage 40 is moved to directly below the vacuum dryer 80, and the vacuum dryer 80 is lowered to the stage 40, thereby transferring the substrate 50 on which the coating film 51 has been formed into the vacuum dryer 80. At this time, the inside of the vacuum dryer 80 becomes a sealed space 82 partitioned by the stage 40 and the side wall of the vacuum dryer 80. In this state, the sealed space 82 is evacuated by the vacuum pump 81, thereby drying the coating film 51 formed on the substrate 50 under reduced pressure.

[0028] In this embodiment, after forming a coating film 51 on the substrate 50 in the coating unit 20 while the chamber 10 is in a gas atmosphere of solvent 31, the substrate 50 on which the coating film 51 has been formed is transferred to the vacuum dryer 80 to dry the coating film 51. As a result, not only is the formation of the coating film 51 on the substrate 50 carried out in a gas atmosphere of solvent 31, but the transfer of the substrate 50 on which the coating film 51 has been formed to the vacuum dryer 80 is also carried out in the chamber 10. This reduces the amount of evaporation of solvent 31 due to natural drying and prevents uneven drying of the coating film formed on the substrate 50.

[0029] Although the present invention has been described above with reference to preferred embodiments, this description is not limiting, and various modifications are, of course, possible.

[0030] 10 Chamber 20 Applicator 21 Tank 22 Nozzle 30 Coating liquid 31 Solvent 32 Solvent gas 40 Stage 50 Substrate 51 Coating film 61 Tank 62 Vaporizer 63, 64 Mass flow controller 65 Push gas 66 Carrier gas 70 Filling means 80 Vacuum dryer 81 Vacuum pump 82 Sealed space 100 Coating apparatus 200 Coating system

Claims

1. A coating apparatus comprising: a chamber for housing a substrate; a coater for applying a coating liquid to the substrate housed in the chamber to form a coating film on the substrate; and a supply means for supplying a gas obtained by vaporizing a solvent contained in the coating liquid into the chamber, wherein the formation of the coating film on the substrate is performed inside the chamber in a gas atmosphere of the solvent supplied from the supply means.

2. The coating apparatus according to claim 1, wherein the formation of the coating film on the substrate is carried out by controlling the gas concentration of the solvent in the chamber to be above the upper limit of explosion.

3. The coating apparatus according to claim 1, further comprising a filling means for filling the chamber with an inert gas, wherein the formation of the coating film on the substrate is performed in a gas atmosphere of the solvent supplied from the supply means, after the chamber has been filled with the inert gas by the filling means.

4. A coating method for forming a coating film on a substrate housed in a chamber, wherein the chamber is kept in a gas atmosphere of a solvent contained in the coating liquid, and the coating film is formed on the substrate.

5. The coating method according to claim 4, wherein the gas concentration of the solvent in the chamber is above the upper explosion limit.

6. The coating method according to claim 4, wherein the chamber is filled with an inert gas, and then the chamber is made into a gas atmosphere of the solvent to form the coating film on the substrate.

7. A coating system comprising a coating apparatus for applying a coating solution to a substrate to form a coating film on the substrate, and a vacuum dryer for drying the coating film formed on the substrate, all housed in a chamber, wherein the chamber is provided with a supply means for supplying a gas obtained by vaporizing a solvent contained in the coating solution, and after forming a coating film on the substrate with the coating apparatus while the solvent gas is supplied into the chamber from the supply means to create a solvent gas atmosphere in the chamber, the substrate on which the coating film has been formed is transferred to the vacuum dryer to dry the coating film under reduced pressure.

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