Coating device

Abstract

To provide a coating device capable of preventing a film thickness distribution of a coating film from changing after the coating film is formed.SOLUTION: A device comprises: a suction stage 10 including a suction surface 10a for attaching and holding a substrate W; a coating unit 20 that applies a coating liquid to the substrate W suctioned to and held by the suction stage 10 and forms a coating film M on the substrate W; and a drying promotion unit 30 that, after the coating film M is formed, promotes drying of the coating film M on the substrate W while the suction and holding of the substrate by the suction stage 10 is being maintained.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a coating apparatus that applies a coating liquid onto a substrate and dries the coating liquid to form a coating film on the substrate. [Background technology]

[0002] In flat panel displays such as liquid crystal displays and plasma displays, a substrate coated with a resist liquid (called a coated substrate) is used. This coated substrate is produced by a coating film forming apparatus such as that shown in Patent Document 1 below. The process of producing a coated substrate using this coating film forming apparatus includes a process of forming a coating film by uniformly coating a substrate with a resist liquid, and then drying the coating film by a drying apparatus. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-243670 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the production process of coated substrates shown in Patent Document 1, a resist coating device feeds resist liquid to form a coating film while transporting an LCD substrate in a horizontal position, and then a reduced-pressure drying process is performed on the coating film in a reduced-pressure drying device. Here, the substrate is transported from the resist coating device to the reduced-pressure drying device by a substrate transport mechanism such as a roller transport mechanism.

[0005] Meanwhile, in recent years, Fan-Out Panel Level Packaging (FOPLP) technology has been developed, which manufactures packages all at once on a large rectangular substrate instead of a wafer. This technology is expected to improve productivity and reduce manufacturing costs, but the carrier substrates used in FOPLP often have warping. Moreover, the carrier substrates used in the manufacture of perovskite solar cells, which have been developed in recent years, often have warping as well.

[0006] When applying a coating liquid such as resist to this carrier substrate, as shown in Fig. 7(a), the substrate W is pressed against the suction surface 110a of the suction stage 110 by a substrate correction mechanism 112 or the like to be adsorbed and held, and the shape of the substrate W is corrected so that it conforms to the suction surface 110a, and then coating is performed by the coating unit 120. At this time, immediately after coating is completed and the suction stage 110 is broken, the shape of the substrate W may return to a warped state as shown in Fig. 7(b). If this occurs, there is a problem that the coating liquid forming the coating film M flows from the edge to the center of the substrate W before the substrate W is transported to a drying device (not shown) and the coating film M on the substrate W is dried, causing a change in the film thickness distribution of the coating film M.

[0007] SUMMARY OF THE PRESENT EMBODIMENT In view of the above problems, an object of the present invention is to provide a coating apparatus capable of preventing a change in the film thickness distribution of a coating film after the coating film is formed. [Means for solving the problem]

[0008] In order to solve the above problems, the coating apparatus of the present invention is characterized by having an adsorption stage having an adsorption surface for adsorbing and holding a substrate, a coating section that applies a coating liquid to the substrate adsorbed and held by the adsorption stage to form a coating film on the substrate, and a drying promotion section that promotes drying of the coating film on the substrate while the substrate is still adsorbed and held by the adsorption stage after the coating film has been formed.

[0009] According to the coating apparatus of the present invention, by having a drying promotion section, it is possible to dry the coating film on the substrate at least until it has almost no fluidity before the suction stage destroys the suction of the substrate, and the thickness distribution of the coating film can be maintained even if the substrate warps immediately after the suction of the substrate is destroyed.

[0010] Here, the drying promotion section may be a heating and drying section that heats the coating film.

[0011] The drying promotion section may be a reduced pressure drying section that creates a reduced pressure environment around the coating film.

[0012] In addition, the drying promotion section may be moved to two positions: a retracted position for retracting from the coating section which applies the coating liquid to the substrate on the adsorption stage, and an approach position for approaching the adsorption stage to dry the coating film.

[0013] By doing this, even if the drying promotion section needs to be close to the adsorption stage in order to dry the coating film, the drying promotion section does not interfere with the coating section applying the coating liquid to the substrate.

[0014] The suction stage may further include a substrate correction mechanism for pressing down a warped substrate and aligning it to the suction surface.

[0015] In this way, even a warped substrate can be adsorbed by the adsorption stage and a coating film can be formed by the coating section, and such a warped substrate greatly benefits from the presence of the drying promotion section.

[0016] The drying apparatus may further include a second drying promotion section for drying the coating film again after the substrate, on which the drying of the coating film has been promoted by the drying promotion section, is removed from the adsorption stage.

[0017] By doing this, the coating film is dried in the drying promotion section at least until the fluidity of the coating liquid is almost completely lost, and the subsequent drying is performed in the second drying promotion section, so that the drying of the coating film on the substrate and the formation of a coating film on the next substrate can be performed simultaneously. Effect of the Invention

[0018] The coating apparatus of the present invention can prevent the thickness distribution of the coating film from changing after the coating film is formed. [Brief description of the drawings]

[0019] [Figure 1] FIG. 2 is a diagram illustrating a coating device according to an embodiment of the present invention. [Diagram 2] 5A to 5C are diagrams illustrating the operation of the coating device in the present embodiment. [Diagram 3] 5A to 5C are diagrams illustrating the operation of the coating device in the present embodiment. [Figure 4] 5A to 5C are diagrams illustrating the operation of the coating device in the present embodiment. [Diagram 5] FIG. 13 is a diagram illustrating a coating device according to another embodiment of the present invention. [Figure 6] FIG. 13 is a diagram illustrating a coating device according to another embodiment of the present invention. [Figure 7] 1 is a graph illustrating a problem that occurs in a conventional coating device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] A coating apparatus according to one embodiment of the present invention will be described with reference to FIG.

[0021] The coating apparatus 1 has a suction stage 10 that suctions and holds the substrate W, a coating section 20 that applies a coating liquid, and a drying promotion section 30 provided above the suction stage 10, and the coating section 20 discharges the coating liquid while moving in one direction relative to the suction stage 10 to form a coating film M on the substrate W on the suction stage 10. The drying promotion section 30 dries the coating film M on the substrate W at least until it has almost no fluidity.

[0022] The suction stage 10 has a substantially flat suction surface 10a, and holds the substrate W placed on the suction surface 10a by vacuum suction. The suction surface 10a is provided with a large number of suction holes, which are connected to a vacuum pump 11. When the vacuum pump 11 is operated, a suction force is generated from the suction holes on the suction surface 10a, and the substrate W is sucked and held.

[0023] The suction stage 10 also has a substrate correction mechanism 12 that operates to press down the edge of the warped substrate W, thereby correcting the shape of the substrate W to conform to the suction surface 10a. The substrate correction mechanism 12 is substantially L-shaped and has a claw 12a that extends horizontally. The claw 12a comes into contact with the edge of the substrate W and presses down the edge of the substrate W.

[0024] The coating unit 20 has a nozzle 21 and a gantry 22 , and applies a coating liquid from the nozzle 21 onto the substrate W that is held by suction on the suction stage 10 .

[0025] The nozzle 21 has a slit at its lower end extending in the Y-axis direction, and ejects the coating liquid sent from a coating liquid supply unit (not shown) from the slit. In this embodiment, the coating liquid is, for example, a resist in the FOPLP process or a perovskite material in the manufacturing process of a perovskite solar cell.

[0026] The gantry 22 is a gate-shaped mechanism provided so as to straddle the suction stage 10, and the nozzle 21 is attached to the gantry 22. The gantry 22 can be moved in the X-axis direction by a movement mechanism (not shown), and the nozzle 21 moves in the X-axis direction above the suction stage 10 as the gantry 22 moves in the X-axis direction. Then, with the substrate W held on the suction stage 10, the nozzle 21 applies the coating liquid while moving in the X-axis direction, thereby forming a coating film M on the substrate W in the XY directions.

[0027] The drying promotion section 30 in this embodiment heats and dries an object to be dried, and has a heater plate 31 which is a radiation heating mechanism, and the heater plate 31 approaches the coating film M on the substrate W held on the adsorption stage 10 and operates to heat the coating film M. This heating causes the solvent in the coating film M to volatilize, and the coating film M dries and the fluidity decreases.

[0028] The dimensions of the heater plate 31 in the X-axis and Y-axis directions are equal to or greater than the dimensions of the substrate W in the X-axis and Y-axis directions, and the coating film M on the substrate W is heated uniformly.

[0029] The heater plate 31 is attached to a beam 32 extending in the Y-axis direction, and both ends of the beam 32 are attached to a movable support 33. The movable support 33 is a column extending in the Z-axis direction, and has a drive mechanism in the Z-axis direction. The beam 32 is attached to this drive mechanism, and the beam 32 and the heater plate 31 attached to the beam 32 move up and down by operating the drive mechanism. This allows the heater plate 31 to take a position close to the suction stage 10 and a position separated to a position higher than the coating unit 20. In this description, the position where the heater plate 31 is close to the suction stage 10 is called the close position, and the position where the heater plate 31 is separated to a position higher than the coating unit 20 is called the retracted position. Here, the movable support 33 is provided at a position farther away from the suction stage 10 than the gantry 22 in the Y-axis direction, and when the heater plate 31 is in the retracted position, the drying promotion unit 30 does not hinder the movement of the coating unit 20.

[0030] 2 to 4 show the flow of the operation of forming a coating film M on a substrate W in the coating apparatus 1 having the above configuration.

[0031] 2(a), the substrate W is transported to above the suction stage 10. At this time, the heater plate 31 is located at the retracted position, and the substrate W is transported by the robot hand 13 to between the suction surface 10a of the suction stage 10 and the heater plate 31. From this state, the robot hand 13 descends to deliver the substrate W to the suction stage 10. Here, the suction stage 10 has lift pins 14, and the robot hand 13 descends with the lift pins 14 protruding from the suction surface 10a, thereby enabling the robot hand 13 to deliver the substrate W to the lift pins 14.

[0032] 2(b), the lift pins 14 are lowered and accommodated in the suction stage 10, so that the substrate W is placed on the suction surface 10a. In this embodiment, the substrate W is warped, and in this state the entire lower surface of the substrate W is not placed so as to conform to the suction surface 10a. Therefore, the substrate correction mechanism 12 is moved by a drive mechanism (not shown) so that the claws 12a are positioned above the end of the substrate W, and the substrate correction mechanism 12 is lowered from that state.

[0033] As the substrate correction mechanism 12 descends, the edge of the substrate W is pressed down, and the entire lower surface of the substrate W is pressed against the suction surface 10a as shown in Fig. 2(c). In this state, the vacuum pump 11 of the suction stage 10 is operated, so that the entire lower surface of the substrate W is suction-held on the suction surface 10a. As a result, the upper surface of the substrate W is held so as to be approximately flat. After the substrate W is suction-held in this manner, the substrate correction mechanism 12 retreats, and the coating unit 20 starts moving in the X-axis direction.

[0034] While the coating unit 20 moves in the X-axis direction and the slit of the nozzle 21 is positioned above the substrate W, the coating unit 20 ejects the coating liquid. As a result, a coating film M is formed on the upper surface of the substrate W, as shown in Fig. 3(a). At this time, the coating liquid that forms the coating film M has sufficient fluidity.

[0035] Next, as shown in FIG. 3(b), after the coating unit 20 has completed coating of the coating liquid and is separated from the suction stage 10, the heater plate 31 is lowered by the operation of the drive mechanism of the movable support 33.

[0036] 3(c) is a diagram showing a state in which the heater plate 31 has descended to the close position. In this state, the heater plate 31 operates to heat the coating film M on the substrate W on the adsorption stage 10, whereby the solvent in the coating liquid forming the coating film M volatilizes, accelerating the drying of the coating film M.

[0037] Here, the substrate W is maintained in suction and holding by the suction stage 10. If the suction and holding were to be released, the warping of the substrate W may return to its original state, as shown in Fig. 7(b). At this time, if the coating film M is not yet dried to the extent that it has no fluidity, the coating liquid forming the coating film M will flow from the edge to the center of the substrate W, causing a change in the film thickness of the coating film M.

[0038] In contrast, in the present invention, drying is promoted by the heater plate 31 before the suction hold is released, so that it is possible to make the fluidity of the coating film M on the substrate W almost zero when the suction hold is released. Therefore, even if the substrate W warps immediately after the suction hold of the substrate W is broken, the thickness distribution of the coating film M can be maintained.

[0039] In addition, while the heater plate 31 is thus promoting the drying of the substrate W, in order to prevent the coating liquid from solidifying at the tip of the nozzle 21 of the coating unit 20, the tip of the nozzle 21 is preferably immersed in the wetness retaining unit 23. In this embodiment, the wetness retaining unit 23 is a container having an opening at the top so that the tip of the nozzle 21, in which the coating liquid is stored, can enter. By immersing the tip of the nozzle 21 in the coating liquid in the wetness retaining unit 23, volatilization of the solvent from the coating liquid at the tip of the nozzle 21 is prevented, and clogging of the nozzle 21 is prevented.

[0040] After the fluidity of the coating film M on the substrate W is almost completely lost, the heater plate 31 rises to the retreated position as shown in Fig. 4(a). Then, the coating unit 20 starts moving in the X-axis direction and returns to the position before coating of the coating liquid as shown in Fig. 4(b) to prepare for coating the coating liquid onto the next substrate W.

[0041] After the coating unit 20 has returned completely, the vacuum pump 11 of the suction stage 10 is stopped, and the suction and holding of the substrate W is released. This may cause the substrate W to return to its original warp as shown in Fig. 4(c), but since the fluidity of the coating film M has been almost completely eliminated by the heater plate 31 as described above, the thickness distribution of the coating film M is maintained. Thereafter, the guide pins 14 (see Fig. 2(a)) rise to separate the substrate W from the suction surface 10a, preparing for transport of the substrate W to the equipment for the next process.

[0042] Next, a coating apparatus according to another embodiment of the present invention will be described with reference to FIG.

[0043] The drying promotion section 30 in the coating apparatus 1 of this embodiment dries an object to be dried under reduced pressure, and includes a chamber 34 and a decompression pump 35 as shown in FIG. 5(a).

[0044] The chamber 34 has a top plate portion that is slightly larger than the adsorption surface 10a of the adsorption stage 10, and side wall portions extending downward from each end of the top plate portion. By bringing the chamber 34 close to the adsorption surface stage 10, a substantially sealed space is formed around the adsorption surface 10a of the adsorption stage 10, the substrate W adsorbed and held on the adsorption surface 10a, and the coating film M formed on the substrate W, as shown in Figure 5(b).

[0045] The vacuum pump 35 exhausts air from the space surrounded by the top plate and side walls of the chamber 34, and as shown in Fig. 5(b), the vacuum pump 35 operates when the chamber 34 is close to the adsorption stage 10, thereby reducing the pressure in the substantially sealed space around the coating film M. This reduces the pressure around the coating film M, accelerating the evaporation of the solvent in the coating film M. In other words, drying is accelerated.

[0046] In the coating apparatus 1 of this embodiment, too, by promoting drying using the drying promotion section 30 before the suction hold of the substrate W after formation of the coating film M on the substrate W is released, it is possible to make the coating film M on the substrate W have almost no fluidity by the time the suction hold is released, and the thickness distribution of the coating film M can be maintained even if the substrate W warps immediately after the suction hold of the substrate W is broken.

[0047] Next, a coating apparatus 1 according to still another embodiment of the present invention will be described with reference to FIG.

[0048] The coating apparatus 1 of the present embodiment has, in addition to the drying promotion section 30 located above the suction stage 10, a second drying promotion section 40 that dries the coating film M again on the substrate W after it has been removed from the suction stage 10. The second drying promotion section 40 is, for example, a heating and drying furnace.

[0049] In the coating apparatus 1 of the present invention, the coating process of the coating liquid by the coating unit 20 is put on hold while the drying acceleration unit 30 dries the coating film M on the substrate W. Therefore, if the coating film M on the substrate W is to be completely dried only by the drying acceleration unit 30, the waiting time becomes relatively long, which may cause a long manufacturing takt time for a product using the substrate W on which the coating film M is formed.

[0050] In contrast, in the coating apparatus 1 of this embodiment, the drying process of the coating film M by the drying acceleration section 30 is limited to at least bringing the coating film M to a first dry state, which is an intermediate stage of drying and in which the fluidity of the coating liquid is almost lost, and then the substrate W is transported to the second drying acceleration section 40 and dried to a second dry state, which is the completion stage of drying, thereby simultaneously drying the coating film M on the n-th substrate W by the second drying acceleration section 40 and forming the coating film M on the (n+1)-th substrate W by the coating section 20. Therefore, the waiting time of the coating section 20 can be relatively short, and the manufacturing takt time of the product can be improved.

[0051] The above coating apparatus makes it possible to prevent the film thickness distribution of the coating film from changing after the coating film is formed.

[0052] Here, the coating apparatus of the present invention is not limited to the above-described form, and may be of other forms within the scope of the present invention. For example, the substrate W is not limited to a warped substrate, and may be a substrate having a flat shape, but it is considered that the benefits of the present invention are greater when the substrate is warped. In addition, in the above description, the substrate W is warped so that both ends are higher than the center, but the center may be warped so that both ends are higher.

[0053] Furthermore, the coating unit 20 is not limited to a slit coating mechanism, and may be, for example, an inkjet coating mechanism.

[0054] In addition, in the above description, the suction stage 10 is fixed and the coating unit 20 moves in the X-axis direction, but this is not limited to the above. The coating unit 20 may be fixed and the suction stage 10 may move in the X-axis direction below the nozzle 21, thereby causing relative movement between the nozzle 21 and the substrate W on the suction stage 10.

[0055] In the above description, the heater plate 31 capable of heating the entire coating film M of the substrate W on the adsorption surface 10a at once is provided as the drying promotion section 30 using heating, but the present invention is not limited to this. For example, the entire coating film M of the substrate W on the adsorption surface 10a may be heated by a rod-shaped heater extending in the Y-axis direction reciprocating in the X-axis direction.

[0056] In addition, in the above description, the retracted position of the drying promotion section 30 is set above the approach position, and the drying promotion section 30 retracts above the application section 20 during the application operation by the application section 20, but this is not limited to this, and the drying promotion section 30 may be retracted to the side of the application section 20, for example.

[0057] Furthermore, the suction stage 10 is not limited to a type that suctions the substrate W by reducing pressure, and may be of an electrostatic suction type, for example. [Explanation of symbols]

[0058] 1 Coating equipment 10 Adsorption stage 10a Adsorption surface 11 Pressure reducing pump 12 Board straightening mechanism 12a Claw 13 Robot Hand 20 Application section 21 Nozzle 22 Gantry 23 Wet retention section 30 Drying acceleration part 31 Heater plate 32 Beam 33 Movable strut 34 Chamber 35 Pressure reducing pump 40 Second drying promotion section 110 Adsorption stage 110a Adsorption surface 112 Board straightening mechanism 120 Application section M coating film W substrate

Claims

1. a suction stage having a suction surface for suction-holding a substrate; a coating section that applies a coating liquid to the substrate that is adsorbed and held on the adsorption stage to form a coating film on the substrate; a drying promotion unit that promotes drying of the coating film on the substrate that is maintained by suction and holding the coating film after the coating film is formed; A coating apparatus comprising:

2. The coating apparatus according to claim 1 , wherein the drying promotion section is a heating and drying section that heats the coating film.

3. The coating apparatus according to claim 1 , wherein the drying promotion section is a reduced pressure drying section that creates a reduced pressure environment around the coating film.

4. The drying promotion unit includes: a withdrawal position which is a position for withdrawing from the coating unit which applies a coating liquid to the substrate on the suction stage; an approaching position for drying the coating film in proximity to the adsorption stage; 2. The coating device according to claim 1, which is movable to two positions:

5. 2. The coating apparatus according to claim 1, wherein the suction stage further comprises a substrate correction mechanism for pressing down a warped substrate to align it with the suction surface.

6. 2. The coating apparatus according to claim 1, further comprising a second drying acceleration section for drying the coating film again after the substrate, on which the drying of the coating film has been accelerated by the drying acceleration section, is removed from the suction stage.

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