Coating device

Abstract

To suppress damage of a substrate.SOLUTION: A coating device floats and transports a substrate on a floating stage and a coating stage, and coats a processing liquid to the substrate in the coating stage. The floating stage is arranged to at least one of an upstream side and a downstream side of the coating stage in a transportation direction of the substrate. The coating device comprises: a measurement device that calculates a measurement value corresponded to a distance between an upper surface of the floating stage and an upper surface of the coating stage; and a controller that controls an actuator for driving the coating stage to a normal direction of the upper surface of the coating stage so that the measurement value is within a predetermined range.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a coating apparatus that coats a substrate with a processing liquid while floating and conveying the substrate.

Background Art

[0002] In the manufacturing process of a liquid crystal display or the like, a process of coating a processing liquid such as a resist liquid on a glass substrate or the like is included. As a coating apparatus used in this coating process, there is known an apparatus configured to convey a substrate while floating it (floating conveyance), and to discharge a processing liquid from a nozzle disposed on a floating stage onto the substrate being conveyed to form a coating film on the substrate.

[0003] The floating stage is provided with a plurality of air ejection ports for ejecting air and a plurality of suction ports for sucking air mixedly. By controlling the balance between the pressure of the air ejected from the ejection ports and the suction force sucked by the suction ports, the height at which the substrate is floated is controlled to be a predetermined height.

[0004] Literature 1 and Literature 2 describe dividing the floating stage into a plurality of separable stage blocks. The divided stage blocks include a rough floating region and a precision floating region. In the rough floating region, a large number of ejection ports are arranged at a certain density or arrangement pattern. In the precision floating region, a large number of ejection ports and suction ports are arranged at a certain density or arrangement pattern.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] Keeping the upper surface of the floating stage flat is an extremely important factor in suppressing damage to the substrate being conveyed. For example, if the upper surface of the floating stage is not flat, that is, if there is a step between the stage blocks, the base material may get caught on this step. As a result, the substrate may be damaged.

[0007] When installing the coating device, the coating device is installed so that the upper surface of the floating stage is flat for the reasons described above. Generally, when the upper surface of the floating stage is not flat, it is necessary to readjust the height of each stage block and make the upper surface of the floating stage flat again.

[0008] The inventors of the present application have found a new cause that has not been known so far as the cause of the step occurring between the stage blocks. The cause will be described in detail later, but it has been found that it is a time-dependent cause in which the floor surface sinks partially when the coating device is installed on the floor surface. Due to this cause, a step occurs between the stage blocks, and this step increases over time. When the step increases, problems such as the substrate being floated and conveyed getting caught on this step and the substrate being damaged occur.

[0009] The present invention has been made to solve the above problems, and its main object is to suppress damage to the substrate being floated and conveyed by suppressing the substrate being floated and conveyed from getting caught on the steps on the floating stage.

Means for Solving the Problems

[0010] The coating apparatus according to the present invention floats and conveys a substrate on a floating stage and a coating stage, applies a processing liquid to the substrate on the coating stage, the floating stage is arranged on at least one of the upstream side and the downstream side of the coating stage in the conveyance direction of the substrate, and the coating apparatus includes a measuring instrument that obtains a measurement value corresponding to the distance between the upper surface of the floating stage and the upper surface of the coating stage, and a controller that controls an actuator that drives the coating stage in the normal direction of the upper surface of the coating stage so that the measurement value is within a predetermined range.

Advantages of the Invention

[0011] According to the present invention, by obtaining a measurement value corresponding to the distance between the upper surface of the floating stage and the upper surface of the coating stage, the step can be detected before the substrate gets caught on the step between the floating stage and the coating stage. When the measurement value exceeds the predetermined range and before the substrate gets caught on this step, by driving the coating stage with the actuator, the distance between the upper surface of the floating stage and the upper surface of the coating stage can be reduced, and the step can be reduced. Thereby, it is possible to suppress the substrate from getting caught on the step between the floating stage and the coating stage, and suppress the breakage of the substrate that is floating and conveyed.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The following description of the preferred embodiments is merely illustrative in nature and is not intended to limit the present invention, its applications, or its uses. Also, in FIGS. 1 - 7, members having the same last two digits of the reference numbers respectively correspond to each other.

[0014] <Overview of the Invention> FIG. 1 shows a coating apparatus 100 for applying a processing liquid to a substrate S. The coating apparatus 100 includes a first stage 120, a coating stage 140, a second stage 160, and a coating unit 180. The first stage 120, the coating stage 140, and the second stage 160 are configured to lift and convey the substrate S. The substrate S is, for example, a glass substrate for a liquid crystal display or the like.

[0015] The first stage 120, the coating stage 140, and the second stage 160 lift and convey the substrate S by their upper surfaces. The substrate S is conveyed in the order of the first stage 120, the coating stage 140, and the second stage 160. For this reason, in FIG. 1, the left side is the upstream side in the conveyance direction of the substrate S, and the right side is the downstream side in the conveyance direction of the substrate S. When the substrate S is conveyed to the coating stage 140, the processing liquid is applied to its upper surface.

[0016] On the upper surfaces of the first stage 120, the coating stage 140, and the second stage 160, for example, a plurality of ejection holes (not shown) for ejecting air and a plurality of suction holes (not shown) for sucking air are provided. A pipe for supplying compressed air is connected to the ejection holes, and compressed air is supplied. Also, a pipe for supplying a vacuum pressure is connected to the suction holes, and a vacuum pressure is supplied.

[0017] The ejection holes generate a pressure that pushes the substrate S upward by compressed air. This pressure that pushes the substrate S upward may be expressed as a positive pressure. Also, the suction holes generate a pressure that attracts the substrate S downward by a vacuum pressure. This pressure that attracts the substrate S downward may be expressed as a negative pressure. By controlling the balance between this positive pressure and negative pressure, the substrate S is levitated at a predetermined height above the first stage 120, the coating stage 140, and the second stage 160.

[0018] The levitated substrate S is horizontally conveyed from left to right in FIG. 1, for example, by a conveying means. The conveying means moves the substrate S along the conveying direction by sucking the side surfaces of the substrate S from both sides, for example.

[0019] On the upper surface of the conveyed substrate S, a processing liquid is applied by the applying unit 180 at the coating stage 140. The processing liquid is, for example, a resist liquid. The applying unit 180 includes a nozzle (not shown) having, for example, a slit-shaped discharge port for discharging the processing liquid. The nozzle is disposed above the coating stage 140 and is configured to discharge the processing liquid downward. Thus, when the substrate S is at the coating stage 140, the nozzle discharges the processing liquid, and the processing liquid is applied to the upper surface of the substrate S.

[0020] FIG. 2 shows a coating apparatus 200 with the coating unit 180 in FIG. 1 omitted. The first stage 220 includes a first plate 212 as a levitation plate configured to include the upper surface of the first stage 220. The coating stage 240 includes a coating plate 232 configured to include the upper surface of the coating stage 240. The second stage 260 includes a second plate 252 as a levitation plate configured to include the upper surface of the second stage 260.

[0021] That is, the upper surface of the first stage 220 is the upper surface of the first plate 212, the upper surface of the coating stage 240 is the upper surface of the coating plate 232, and the upper surface of the second stage 260 is the upper surface of the second plate 252. The coating device 200 is arranged such that the upper surfaces of the first plate 212, the coating plate 232, and the second plate 252 are substantially flush.

[0022] The so-called substantially flush here refers to a state where the first distance between the upper surface of the first stage 220 and the upper surface of the coating stage 240 is within a first range as a predetermined range, and the second distance between the upper surface of the coating stage 240 and the upper surface of the second stage 260 is within a second range as a predetermined range. For example, the first range is in the range of 0 μm - 100 μm, and the second range is in the range of 0 μm - 150 μm. That is, the substantially flush in this embodiment refers to a state where the first distance is 100 μm or less and the second distance is 150 μm or less.

[0023] The film thickness of the processing liquid applied to the substrate S is preferably uniform. For this reason, when the processing liquid is applied, the upper surface of the substrate S is preferably substantially horizontal. Therefore, the substrate S when lifted in the coating stage 240 needs to be more precisely height-controlled than the substrate S when lifted in the first stage 220 and the second stage 260. Typically, the height at which the substrate S is lifted in the coating stage 240 is lower than the height at which the substrate S is lifted in the first stage 220 and the second stage 260.

[0024] Specifically, the substrate S is lifted by about 200 μm in the first stage 220 and the second stage 260. Also, the substrate S is lifted by about 30 μm in the coating stage 240. The substrate S lifted in this way is conveyed in the order of the first stage 220, the coating stage 240, and the second stage 260.

[0025] If the first distance is large and there is a step between the first stage 220 and the coating stage 240, the substrate S being conveyed may get caught on this step. Also, if the second distance is large and there is a step between the coating stage 240 and the second stage 260, the substrate S being conveyed may get caught on this step or collide with the side surface of the second stage 260. Therefore, by making the upper surfaces of the first stage 220, the coating stage 240, and the second stage 260 substantially flush, breakage of the substrate S due to getting caught or collision and delay in the conveyance of the substrate are suppressed. As a result, the conveyance of the substrate S is performed smoothly. Hereinafter, making the upper surfaces of the first stage 220, the coating stage 240, and the second stage 260 substantially flush is referred to as flattening.

[0026] <Sinking of the floor surface> FIG. 3 shows a coating apparatus 300 installed on the floor surface F. FIG. 3(a) shows the coating apparatus 300 in a state where the upper surface of the stage is flattened. The first stage 320, the coating stage 340, and the second stage 360 of the coating apparatus 300 include support portions 314, 334, and 354 that support the first stage 320, the coating stage 340, and the second stage 360, respectively, with respect to the floor surface F.

[0027] The inventors of the present application have found that after the coating apparatus 300 is arranged on the floor surface F, the floor surface F partially sinks. Further, the inventors of the present application have found that the amount of sinking of the floor surface F is different between the location where the support portion 334 of the coating stage 340 contacts and the locations where the support portions 314 and 354 of the first stage 320 and the second stage 360 contact, respectively. Here, the amount of sinking of the floor surface F refers to the amount of downward displacement of the floor surface F at the locations where the respective support portions 314, 334, and 354 contact, with reference to the height of the floor surface F before the installation of the coating apparatus 300.

[0028] Fig. 3(b) shows the coating apparatus 300 in a state where the floor surface F at the location where the support portion 334 contacts has sunken. Typically, the coating stage 340 is heavier than the first stage 320 and the second stage 360. Therefore, the amount of sinking of the floor surface F at the location where the support portion 334 contacts is greater than the amount of sinking of the floor surface F at the locations where the support portions 314 and 354 contact. For the sake of explanation, in Fig. 3, only the sinking of the floor surface F at the location where the support portion 334 with a large amount of sinking contacts is illustrated.

[0029] Due to the partial sinking of the floor surface F, as shown in Fig. 3(b), the first distance between the upper surface of the first stage 320 and the upper surface of the coating stage 340, and the second distance between the upper surface of the coating stage 340 and the upper surface of the second stage 360 increase. In other words, due to the partial sinking of the floor surface F, a step is generated between the first stage 320 and the coating stage 340, and between the coating stage 340 and the second stage 360.

[0030] Fig. 3(c) shows the coating apparatus 300 in a state where the support portion 334 of the coating stage 340 extends in the vertical direction. The support portion 334 of the coating stage 340 is configured to be able to expand and contract in the vertical direction by being driven by an actuator described later. When the support portion 334 extends in the vertical direction, the coating stage 340 is driven in the normal direction of the upper surface of the coating stage 340.

[0031] In this way, by extending the support portion 334, the height of the coating stage 340 is compensated for the amount by which it has dropped due to the sinking of the floor surface F. Therefore, as shown in Fig. 3(c), the upper surface of the stages of the coating apparatus 300 is flattened again. In the state where the upper surface of the stages is flattened, the first distance and the second distance are smaller than the first distance and the second distance respectively in the state of Fig. 3(b). In other words, the step between the first stage 320 and the coating stage 340, and the step between the coating stage 340 and the second stage 360 become smaller.

[0032] <Measuring instrument> FIG. 4 shows the main part of the coating apparatus 400. The coating apparatus 400 includes a measuring instrument and a reference measuring instrument. The measuring instrument is configured to obtain a measured value corresponding to the distance between the upper surfaces of the first stage 420 and the second stage 460 and the upper surface of the coating stage 440, and output the measured value. The measuring instrument includes a first measuring instrument 430 that obtains a first measured value corresponding to a first distance between the upper surface of the first stage 420 and the upper surface of the coating stage 440, and a second measuring instrument 450 that obtains a second measured value corresponding to a second distance between the upper surface of the coating stage 440 and the upper surface of the second stage 460.

[0033] The reference measuring instrument is configured to output a reference value that is not affected by changes in the distance between the upper surfaces of the first stage 420 and the second stage 460 and the upper surface of the coating stage 440. Here, not being affected by changes in the distance between the upper surfaces of the first stage 420 and the second stage 460 and the upper surface of the coating stage 440 means that the influence on the reference value caused by this change in distance is negligibly small. The reference measuring instrument includes a first reference measuring instrument 429 disposed near the first measuring instrument 430 to obtain a first reference value, and a second reference measuring instrument 449 disposed near the second measuring instrument 450 to obtain a second reference value.

[0034] The first measuring instrument 430 is first configured to obtain a first measured value and then obtain the first distance based on the obtained first measured value. The first measuring instrument 430 includes a first sensor 422 and a first target 424.

[0035] The first sensor 422 and the first target 424 are provided to detect the vertical displacement amount of the coating stage 440 with respect to the first stage 420. The first measuring instrument 430 detects this displacement amount as the first measured value.

[0036] The first measuring device 430 is configured to output a first measurement value by measuring the distance between the first sensor 422 and the first target 424. The first sensor 422 can be a sensor such as, for example, an optical sensor, a laser sensor, an eddy current sensor, a differential transformer sensor, an ultrasonic sensor, or the like. The first target 424 is appropriately selected so that the distance between the first sensor 422 and the first target 424 can be measured according to the type of the sensor.

[0037] In this embodiment, the first sensor 422 is fixed to the coating stage 440 so as to be located below the coating plate 432. The "below the coating plate 432" as referred to herein means the region below the lower surface of the coating plate 432 and above the floor surface F. The "being located below the coating plate 432" as referred to herein is not limited to the position overlapping the coating plate 432 in a top view. In this embodiment, the first sensor 422 is arranged so as to overlap the first plate 412 in a top view.

[0038] The first target 424 is fixed to the first stage 420 so that the first measurement value can be obtained. The first target 424 is arranged so as to be located below the first sensor 422 so as to overlap the first sensor 422 in a top view.

[0039] In this embodiment, the first sensor 422 is an optical sensor. The first target 424 receives and reflects the light emitted by the first sensor 422. Then, the first sensor 422 receives the light reflected by the first target 424. Thereby, the first measurement value is obtained.

[0040] As shown in FIG. 4, the first measuring device 430 is fixed in a region closer to the first stage 420 below the coating plate 432. Therefore, for example, when the floor surface on the side of the coating stage 440 closer to the first stage 420 sinks and the first distance increases, the distance between the first sensor 422 and the first target 424 becomes shorter. The change in the distance between the first sensor 422 and the first target 424 corresponds to the first distance.

[0041] The first reference measuring device 429 includes a first reference sensor 426 and a first reference target 428. The first reference sensor 426 and the first reference target 428 are provided to output a first reference value corresponding to a first measurement value in a flattened state. In this embodiment, the first reference sensor 426 and the first reference target 428 are provided such that the first reference value becomes the same value as the first measurement value in the flattened state. A first difference, which is the difference between the first reference value and the first measurement value, corresponds to the first distance.

[0042] The first reference measuring device 429 outputs a first reference value by measuring the distance between the first reference sensor 426 and the first reference target 428. The first reference sensor 426 can be a sensor such as, for example, an optical sensor, a laser sensor, an eddy current sensor, a differential transformer sensor, an ultrasonic sensor, or the like. The first reference target 428 is appropriately selected so that the distance between the first reference sensor 426 and the first reference target 428 can be measured according to the type of the sensor.

[0043] In this embodiment, the first reference sensor 426 is fixed to the coating plate 432 of the coating stage 440 so as to be located below the coating plate 432. The first reference target 428 is arranged so as to be located below the first reference sensor 426 so as to overlap the first reference sensor 426 in a top view, and is fixed to a location other than the coating plate 432 of the coating stage 440.

[0044] Both the first reference sensor 426 and the first reference target 428 are fixed to the coating stage 440. Therefore, even if the floor surface sinks, the distance between the first reference sensor 426 and the first reference target 428 does not change. For this reason, for example, when the upper surface of the first stage 420 and the upper surface of the coating stage 440 are substantially flush, by adjusting the first reference value and the first measurement value to the same value in advance, as the first reference value output by the first reference sensor 426, the first measurement value in the state where the upper surface of the stage is flattened can be saved.

[0045] Further, the first reference sensor 426 is fixed to the coating plate 432 of the coating stage, and the first reference target 428 is fixed to a location other than the coating plate 432 of the coating stage. Therefore, when the coating plate 432 is bent or distorted, the distance between the first reference sensor 426 and the first reference target 428 changes, and the first reference value changes. Thus, the first reference measuring device 429 can detect the bending or distortion of the coating plate 432 based on the change in the first reference value.

[0046] In this embodiment, the second measuring device 450 has substantially the same configuration as the first measuring device 430. The second measuring device 450 is configured to first obtain a second measurement value and then obtain a second distance based on the obtained second measurement value. The second measuring device 450 includes a second sensor 442 and a second target 444.

[0047] The second sensor 442 and the second target 444 are provided to detect the vertical displacement amount of the coating stage 440 with respect to the second stage 460. The second measuring device 450 detects this displacement amount as the second measurement value.

[0048] The second measuring device 450 is configured to output a second measurement value by measuring the distance between the second sensor 442 and the second target 444. The second sensor 442 can be, for example, a sensor such as an optical sensor, a laser sensor, an eddy current sensor, a differential transformer sensor, an ultrasonic sensor, or the like. The second target 444 is appropriately selected so that the distance between the second sensor 442 and the second target 444 can be measured according to the type of the sensor.

[0049] In this embodiment, the second sensor 442 is fixed to the coating stage 440 so as to be located below the coating plate 432. In this embodiment, the second sensor 442 is arranged so as to overlap the coating plate 432 in a top view.

[0050] The second target 444 is fixed to the second stage 460 such that a second measurement value is obtained. The second target 444 is arranged to be positioned below the second sensor 442 so as to overlap the second sensor 442 in a top view. In this embodiment, the second target 444 is fixed to the upper part of the left end of a fixing member 456 extending leftward from the second stage 460.

[0051] In this embodiment, the second sensor 442 is an optical sensor. The second target 444 receives and reflects the light emitted by the second sensor 442. Then, the second sensor 442 receives the light reflected by the second target 444. Thereby, the second measurement value is obtained.

[0052] As shown in FIG. 4, the second measuring instrument 450 is fixed in a region closer to the second stage 460 below the coating plate 432. For this reason, for example, when the floor surface on the side of the coating stage 440 closer to the second stage 460 sinks and the second distance increases, the distance between the second sensor 442 and the second target 444 becomes shorter. The change in the distance between the second sensor 442 and the second target 444 corresponds to the second distance.

[0053] The second reference measuring instrument 449 includes a second reference sensor 446 and a second reference target 448. The second reference sensor 446 and the second reference target 448 are provided to output a second reference value corresponding to the second measurement value in a flattened state. In this embodiment, the second reference sensor 446 and the second reference target 448 are provided such that the second reference value becomes the same value as the second measurement value in the flattened state. A second difference, which is the difference between the second reference value and the second measurement value, corresponds to the second distance.

[0054] The second reference measuring device 449 outputs a second reference value by measuring the distance between the second reference sensor 446 and the second reference target 448. The second reference sensor 446 can be, for example, a sensor such as an optical sensor, a laser sensor, an eddy current sensor, a differential transformer sensor, or an ultrasonic sensor. The second reference target 448 is appropriately selected so that the distance between the second reference sensor 446 and the second reference target 448 can be measured according to the type of the sensor.

[0055] In this embodiment, the second reference sensor 446 is fixed to the coating plate 432 of the coating stage 440 so as to be located below the coating plate 432. The second reference target 448 is arranged so as to be located below the second reference sensor 446 so as to overlap the second reference sensor 446 in a top view, and is fixed to a location other than the coating plate 432 of the coating stage 440.

[0056] Both the second reference sensor 446 and the second reference target 448 are fixed to the coating stage 440. Therefore, even if the floor surface sinks, the distance between the second reference sensor 446 and the second reference target 448 does not change. For this reason, for example, when the upper surface of the coating stage 440 and the upper surface of the second stage 460 are substantially flush, by adjusting the second reference value and the second measurement value to the same value in advance, as the second reference value output by the second reference sensor 446, the second measurement value in a state where the upper surface of the stage is flattened can be saved.

[0057] Also, the second reference sensor 446 is fixed to the coating plate 432 of the coating stage, and the second reference target 448 is fixed to a location other than the coating plate 432 of the coating stage. For this reason, when the coating plate 432 is bent or distorted, the distance between the second reference sensor 446 and the second reference target 448 changes, and the second reference value changes. Therefore, the second reference measuring device 449 can detect the bending or distortion of the coating plate 432 based on the change in the second reference value.

[0058] FIG. 5 shows a second measuring instrument 550 and a second reference measuring instrument 549 surrounded by a two-dot chain line circle in FIG. 4. As shown in FIG. 5, the second sensor 542 and the second reference sensor 546 include a light emitting element E and a light receiving element R. Here, the second measured value and the second reference value when the floor surface sinks are described using the second measuring instrument 550 and the second reference measuring instrument 549. Although the description is omitted, the same applies to the first measured value and the first reference value.

[0059] FIG. 5 shows the second measuring instrument 550 and the second reference measuring instrument 549 when the upper surface of the coating stage 540 and the upper surface of the second stage 560 are flattened. In this embodiment, when flattened, the second sensor 542 and the second reference sensor 546 are arranged so that their vertical positions are the same. Also, in this embodiment, when flattened, the second target 544 and the second reference target 548 are arranged so that their vertical positions are the same. Therefore, when flattened, the second reference value obtained by the second reference measuring instrument 549 is the same as the second measured value obtained by the second measuring instrument 550.

[0060] For example, when the floor surface at the location where the coating stage 540 touches is partially sunken, the second sensor 542, the second reference sensor 546, and the second reference target 548 fixed to the coating stage 540 are moved downward. On the other hand, the second target 544 fixed to the fixing member 556 extending leftward from the second stage 560 does not move downward. For this reason, the distance between the second sensor 542 and the second target 544 becomes shorter, and the second measured value becomes smaller. However, the distance between the second reference sensor 546 and the second reference target 548 does not change, and the second reference value does not change.

[0061] <Compensation method for flattening> FIG. 6 shows the coating stage 640 as viewed from below. The coating plate 632 of the coating stage 640 is in the shape of a rectangular plate. The coating stage 640 includes five support portions 634. The five support portions 634 are respectively provided at the four corners and the central portion below the coating plate 632. That is, these five support portions 634 are two support portions 634 provided in the region closer to the first stage (the region on the left side of the coating stage 640), two support portions 634 provided in the region closer to the second stage (the region on the right side of the coating stage 640), and one support portion 634 provided in the region where the distances from the first stage and the second stage are equal (the central region in the left-right direction of the coating stage 640).

[0062] The support portion 634 includes an actuator 670 for compensating the height of the coating stage 640 when the floor surface sinks. The actuator 670 is provided one by one for each of the five support portions 634. For this reason, the coating stage 640 includes five actuators 670. The support portion 634 is configured to be able to expand and contract in the vertical direction by driving the actuator 670. For example, as the actuator 670, there may be a wedge mechanism, a screw jack, a hydraulic jack, etc. The actuator 670 may be manually operated or automatically controlled.

[0063] The actuator 670 provided in the support portion 634 provided in the region closer to the first stage (the region on the left side of the coating stage 640) of the coating stage 640 is referred to as the first actuator 670. Also, the actuator 670 provided in the support portion 634 provided in the region closer to the second stage (the region on the right side of the coating stage 640) of the coating stage 640 is referred to as the second actuator 670. The first actuator 670 and the second actuator 670 have the same configuration.

[0064] When the first actuator 670 is driven and the support portion 634 extends in the vertical direction, the left side of the coating stage 640 is raised. Also, when the second actuator 670 is driven and the support portion 634 extends in the vertical direction, the right side of the coating stage 640 is raised. The coating stage 640 of this embodiment can, for example, raise only one of the right side and the left side of the coating stage 640, or make the amounts of elevation on the right side and the left side different amounts, by driving the first actuator 670 and the second actuator 670 separately.

[0065] FIG. 7 shows the support portion 734. FIG. 7(a) shows the support portion 734 in a state where the upper surface of the stage is flattened, which was described using FIG. 3(a). The support portion 734 is arranged such that its lower end contacts the floor surface F. The support portion 734 includes an actuator 770 and a third measuring device 790 as a measuring device. The third measuring device 790 is provided near the floor surface of the support portion 734. In this embodiment, the actuator 770 is a wedge mechanism.

[0066] The actuator 770 is configured to be able to expand and contract in the vertical direction. When the actuator 770 expands and contracts in the vertical direction, the entire support portion 734 expands and contracts in the vertical direction. The actuator 770 includes a driving portion 762. In this embodiment, the driving portion 762 is a screw. By the screw of the driving portion 762, the wedge is driven, and the wedge mechanism of the actuator 770 can be expanded and contracted in the vertical direction.

[0067] If the actuator 770 is a screw jack, the driving portion 762 can be something like a screw or the like. In this case, the actuator 770 is expanded and contracted in the vertical direction by rotating the screw. Also, if the actuator 770 is a hydraulic jack, the driving portion 762 can be something like a pump or a piston or the like. In this case, the actuator 770 is expanded and contracted in the vertical direction by driving the pump or the piston.

[0068] A controller 764 for controlling the movement of the drive unit 762 is connected to the drive unit 762. The controller 764 controls the expansion and contraction of the actuator 770 by controlling the drive of the drive unit 762. The controller 764 may be any device as long as it can control the movement of the drive unit 762. For example, if the drive unit 762 is a screw, the controller 764 may be configured to control the rotation of the screw. Also, for example, if the drive unit 762 is a pump, a piston, or the like, the controller 764 may be configured to control the drive of the pump or the piston.

[0069] In this embodiment, the controller 764 has a function of flattening the upper surface of the stage without user intervention. For example, this function of flattening the upper surface of the stage may be realized by one or more processors and the memory associated therewith. The controller 764 controls the actuator 770 based on the measured values and reference values measured by each measuring instrument in order to flatten the upper surface of the stage.

[0070] In this embodiment, one third measuring instrument 790 is provided for each of the five support portions 734 of the coating stage 740. Therefore, the coating stage 740 has five third measuring instruments 790. These five third measuring instruments 790 output different values respectively.

[0071] The structure of the third measuring instrument 790 is substantially the same as that of the second measuring instrument 550 shown in FIG. 5. Each of the third measuring instruments 790 includes a third sensor 782 and a third target 784.

[0072] The third sensor 782 and the third target 784 are provided to detect the displacement amount in the vertical direction of the coating stage 740. The third measuring device 790 is configured to output a third measurement value by measuring the distance between the third sensor 782 and the third target 784. The third sensor 782 can be, for example, a sensor such as an optical sensor, a laser sensor, an eddy current sensor, a differential transformer sensor, an ultrasonic sensor, or the like. The third target 784 is appropriately selected so that the distance between the third sensor 782 and the third target 784 can be measured according to the type of the sensor.

[0073] In this embodiment, the third sensor 782 of the third measuring device 790 is fixed to the support portion 734 of the coating stage 740. Further, the third sensor 782 is disposed at a position separated from the support portion 734 by a predetermined distance or more via a bracket or the like. For example, the third sensor 782 is disposed in the vicinity of the support portion of the floating stage via a bracket extending from the support portion 734 of the coating stage 740 to the vicinity of the support portion of the floating stage. The third target 784 is disposed on the floor surface F located below the third target 784 so as to overlap the third sensor 782 in a top view.

[0074] In this embodiment, the third sensor 782 is an optical sensor. The third target 784 receives and reflects the light emitted by the third sensor 782. Then, the third sensor 782 receives the light reflected by the third target 784. Thereby, the third measurement value is obtained.

[0075] Among the five third measuring devices 790, the third measuring devices 790 of the two support portions 734 provided in the region closer to the first stage of the coating stage 740 can each output a different third measurement value. The decrease amount of the third measurement values output by these two third measuring devices 790 corresponds to the increase amount of the first distance between the upper surface of the first stage and the upper surface of the coating stage 740 in the vicinity of each of the support portions 734 where each of the third measuring devices 790 that outputs the third measurement value is provided.

[0076] Of the five third measuring devices 790, the two third measuring devices 790 provided in areas closer to the second stage of the coating stage 740 output different third measurement values respectively. The decrease amount of the third measurement values output by these two third measuring devices 790 corresponds to the increase amount of the second distance between the upper surface of the second stage and the upper surface of the coating stage 740 near each of the support portions 734 where each of the third measuring devices 790 that outputs the third measurement value is provided.

[0077] Of the five third measuring devices 790, the third measuring device 790 of the support portion 734 provided at the central portion of the coating stage 740 outputs a third measurement value. The decrease amount of the third measurement value of this third measuring device 790 corresponds to, for example, the deflection or distortion of the coating stage 740. Specifically, if the decrease amount of the third measurement value output by the third measuring device 790 provided at the central portion of the coating stage 740 is larger than the decrease amounts of the third measurement values output by the other four third measuring devices 790, the coating stage 740 is distorted and deflected such that the central portion is concave.

[0078] In the state of Fig. 7(a), that is, the state where the upper surface of the stage is flattened, the third measurement values output by the respective third measuring devices 790 are the third measurement values at flat time of the respective third measuring devices 790. These third measurement values at flat time are stored in the memory respectively so as to be able to distinguish which third measuring device 790 output the third measurement value at flat time.

[0079] Fig. 7(b) shows the support portion 734 in the state where the floor surface F at the location where the support portion 734 contacts, as described with reference to Fig. 3(b), has sunk. When the floor surface F sinks partially, the distance between the third sensor 782 and the third target 784 of the third measuring device 790 decreases. Therefore, the third measurement value in this state becomes smaller than the third measurement value at flat time.

[0080] Figure 7(c) shows the support portion 734 in the state where the support portion 734 of the coating stage 740, which was described using Figure 3(c), extends in the vertical direction. When the floor surface F is partially sunken, the controller 764 drives the actuator 770. Then, the actuator 770 is extended in the vertical direction, and the support portion 734 extends in the vertical direction. Therefore, compared with the state of Figure 7(b), the third measurement value becomes larger. And the coating stage 740 supported by this support portion 734 is driven in the normal direction of the upper surface of the coating stage 740.

[0081] Therefore, when the support portion 734 is extended in the vertical direction, the upper surface of the stage is flattened. At this time, it is preferable that the support portion 734 is extended so that the first measurement value is within the first range and the second measurement value is within the second range. The actuators 770 provided respectively on the support portions 734 may be extended in the vertical direction so that the third measurement values of the third measuring instruments 790 provided on the support portions 734 become substantially the same as the respective third measurement values when flat.

[0082] In this way, by providing the third measuring instrument 790 at a position close to the floor surface F, that is, on the support portion 734, the vertical displacement amount of the coating stage 740 caused by the sinking of the floor surface F can be detected more accurately.

[0083] Furthermore, since the third sensor 782 is arranged at a position separated from the support portion 734 by a predetermined distance or more, when the floor surface F in contact with the support portion 734 sinks, it is possible to prevent the third target 784 from sinking as the floor surface F sinks. Therefore, the vertical displacement amount of the coating stage 740 caused by the sinking of the floor surface F can be detected more accurately.

[0084] <Automatic Control of Controller> Figure 8 shows an exemplary process 800 for realizing the function of flattening the upper surface of the stage. The controller flattens the upper surface of the stage by executing the process 800 to control the actuator. For the sake of easy understanding of the explanation, here, the third measuring instrument is omitted, and the explanation is made using the first measuring instrument and the second measuring instrument.

[0085] Process 800 first executes in a state where the upper surface of the stage is flattened (also referred to as a flush state), and various values are acquired from a measuring instrument, that is, a first measuring instrument and a second measuring instrument (820). As described above, the first measuring instrument outputs a first measured value and a first reference value. Also, the second measuring instrument outputs a second measured value and a second reference value. In 820, these values are stored as flush state values.

[0086] Next, the first measured value and the first reference value, and the second measured value and the second reference value are compared respectively, and a first difference and a second difference are determined (840). The first difference is the difference between the first measured value and the first reference value. The second difference is the difference between the second measured value and the second reference value. As described above, when the floor surface where the coating stage contacts sinks, the first difference and the second difference increase. The first difference corresponds to a first distance, and the second difference corresponds to a second distance.

[0087] Next, based on the first difference, it is determined whether the first distance is within a first range (860). When it is determined that the first distance is within the first range, then, based on the second difference, it is determined whether the second distance is within a second range (880). These determinations are executed without user intervention. When it is determined that the first distance is within the first range and the second distance is within the second range, again, the first difference and the second difference are determined (840).

[0088] When it is determined that the first measured value exceeds the first range, or when it is determined that the second measured value exceeds the second range, a controller 910, which will be described later with reference to FIG. 9, determines a distance to drive the coating stage in the normal direction of the upper surface of the coating stage based on the first difference or the second difference (870). This distance is determined so that the first difference and the second difference are respectively within the first range and the second range. For example, this distance may be the minimum distance at which the first measured value and the second measured value are respectively within the first range and the second range, or may be the distance that coincides with the first reference value and the second reference value respectively.

[0089] After the distance for driving the coating stage is determined, the actuator is driven (890). Each actuator is driven corresponding to the determined distance, and the coating apparatus becomes flush. Thereafter, in process 800, a first difference and a second difference are determined (840).

[0090] <Hardware> FIG. 9 is a block diagram showing the structure of a controller 910 (corresponding to 764 in FIG. 7) having a function of flattening the stage. The controller 910 includes a processor 920, a memory 940, and an input / output unit 960. The processor 920, the memory 940, and the input / output unit 960 are connected via a bus 980.

[0091] The processor 920 executes each process constituting the process 800 as shown in FIG. 8, for example. The memory 940 stores computer-readable instructions and parameters. The processor 920 reads the instructions stored in the memory 940 and executes the process 800.

[0092] A sensor 950 and an actuator 970 are connected to the input / output unit 960. In FIG. 9, the sensor 950 is illustrated as one block representing all the sensors included in the coating apparatus of this embodiment. For example, the sensor 950 corresponds to the sensors 422, 426, 442, 446 in FIG. 4 and the sensor 782 in FIG. 7, respectively. Also, in FIG. 9, the actuator 970 is illustrated as one block representing all the actuators included in the coating apparatus of this embodiment. For example, the actuator 970 corresponds to each of the five actuators 670 in FIG. 6.

[0093] Measurement values and reference values are input to the input / output unit 960 from the sensor 950. The input / output unit 960 outputs the measurement values and reference values to the processor 920 and the memory 940. Also, the input / output unit 960 outputs a control signal to the actuator 970 based on the output of the processor 920. The input / output unit 960 may be incorporated in the processor 920.

[0094] <Software> Processor 920 executes process 800. At 820, processor 920 receives data from input / output unit 960. This data is, for example, measurement values and reference values output by sensor 950. When input / output unit 960 transmits this data to processor 920, it may also transmit the same data to memory 940. Memory 940 stores these data as parameters.

[0095] At 840, processor 920 receives, via input / output unit 960 and bus 980, the measurement value output from sensor 950. Processor 920 compares the measurement value input at 840 with the measurement value or reference value stored in memory 940 to determine a first difference and a second difference.

[0096] At 860 and 880, processor 920 compares the first difference and the second difference with a first range and a second range, respectively. Processor 920 reads the values of the first range and the second range from memory 940. Then, processor 920 compares the first difference and the second difference with the first range and the second range, respectively. Processor 920 determines whether the first difference and the second difference are within the first range and the second range, respectively.

[0097] At 870, processor 920 receives data regarding the first difference and the second difference from memory 940. Based on this data, processor 920 determines the distance to drive each actuator 970. For example, this data may be a function that converts the first difference and the second difference into the vertical distance by which each actuator 970 is driven. In this case, processor 920 determines the distance by calculating based on the first difference, the second difference, and the function.

[0098] At 890, the processor 920 outputs a control signal to the actuator 970 via the input / output unit 960. This control signal includes the distance determined at 870. The actuator 970 is driven based on this control signal. The process 800 is repeatedly executed by the control returning from 980, 890 to 840.

[0099] Each of the various functions in the present disclosure may be implemented by a single element or by a plurality of elements. Conversely, a plurality of functions may be implemented by a single element. Each function may be implemented by hardware, software, or a combination of hardware and software. The flowcharts in the present disclosure include a plurality of blocks. The processing of these blocks may be performed serially, in parallel, or the order of some blocks may be changed.

[0100] The subject of the apparatus, system, or method in the present disclosure includes a computer. By executing a program on this computer, the functions of the subject of the apparatus, system, or method in the present disclosure are realized. The computer mainly includes a processor that operates according to the program as a hardware configuration. The type of the processor is not limited as long as it can realize functions by executing the program. The processor is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or LSI (large scale integration). Here, although referred to as IC or LSI, the name may change depending on the degree of integration, and it may be called system LSI, VLSI (very large scale integration), or ULSI (ultra large scale integration). A field programmable gate array (FPGA) programmed after the manufacture of the LSI, or a reconfigurable logic device capable of reconfiguring the bonding relationship inside the LSI or setting up the circuit sections inside the LSI can also be used for the same purpose. The plurality of electronic circuits may be integrated on one chip or provided on a plurality of chips. The plurality of chips may be integrated in one device or provided in a plurality of devices. The program is recorded on a non-transitory recording medium such as a computer-readable ROM, optical disk, or hard disk drive. The program may be pre-stored in the recording medium or supplied to the recording medium via a wide area communication network including the Internet or the like.

[0101] <Effects of the present embodiment> In the conventional example, for example, when the floor surface F at the contact portion of the coating stage 340 sinks partially as shown in FIG. 3(b) and a step is generated between the coating stage 340 and the floating stages 320 and 360, it was determined that such a step occurred when the substrate S was caught by this step or the substrate S collided with the side surface on the upstream side of the second stage. That is, the occurrence of this step was not known until the substrate S was actually damaged or the conveyance speed of the substrate S decreased.

[0102] According to the coating apparatus 300 of the present embodiment, the measuring instrument obtains a measured value corresponding to the distance between the upper surfaces of the floating stages 320 and 360 and the upper surface of the coating stage 340. Therefore, when the first distance exceeds the first range or the second distance exceeds the second range, the first distance and the second distance can be compensated by the actuator to achieve flattening. As a result, flattening can be achieved before the substrate S is damaged or the speed of transporting the substrate S decreases. Thus, breakage of the substrate S can be suppressed.

[0103] <Other Embodiments> As a typical example of the cause of the increase in the first distance and the second distance, the coating stage 340 may be heavier than the floating stages 320 and 360, causing the floor surface F to sink significantly in part. However, the cause of the significant partial sinking of the floor surface F is not limited to this. For example, the present invention can compensate for the increased first distance and second distance even when the floor surface F sinks due to insufficient strength of the floor surface F.

[0104] In the first measuring instrument 430 of the embodiment shown in FIG. 4, the first sensor 422, the first reference sensor 426, and the first reference target 428 are fixed to the coating stage 440, and the first target 424 is fixed to the first stage 420. However, the first sensor 422, the first reference sensor 426, and the first reference target 428 of the first measuring instrument 430 may be fixed to the first stage 420, and the first target 424 may be fixed to the coating stage 440.

[0105] In the second measuring instrument 450 of the embodiment shown in FIG. 4, the second sensor 442, the second reference sensor 446, and the second reference target 448 are fixed to the coating stage 440, and the second target 444 is fixed to the second stage 460. However, the second sensor 442, the second reference sensor 446, and the second reference target 448 of the second measuring instrument 450 may be fixed to the second stage 460, and the second target 444 may be fixed to the coating stage 440.

[0106] In the embodiment shown in FIG. 4, one first measuring device 430 and one second measuring device 450 are provided respectively. However, two or more first measuring devices 430 and two or more second measuring devices 450 may be provided respectively. By doing so, a plurality of first measurement values and a plurality of second measurement values can be obtained. At this time, for example, in order to make one of the plurality of first measurement values fall within the first range, it may be assumed that only the actuator closest to the first measuring device 430 that output the first measurement value is driven. Also, in order to make one of the plurality of second measurement values fall within the second range, it may be assumed that only the actuator closest to the second measuring device 450 that output the second measurement value is driven.

[0107] In the embodiment shown in FIG. 4, the first measuring device 430 and the first reference measuring device 429 are provided such that the first measurement value and the first reference value become the same value when the stage is flattened. However, the first measurement value and the first reference value when the stage is flattened do not have to be the same value. For example, the difference between the first measurement value and the first reference value when the stage is flattened may be stored in the memory as the first difference when flat, and at 860 in FIG. 8, it may be determined whether the difference between the first difference when flat and the first difference is within the first range.

[0108] In the embodiment shown in FIG. 4, the second measuring device 450 and the second reference measuring device 449 are provided such that the second measurement value and the second reference value become the same value when the stage is flattened. However, the second measurement value and the second reference value when the stage is flattened do not have to be the same value. For example, the difference between the second measurement value and the second reference value when the stage is flattened may be stored in the memory as the second difference when flat, and at 880 in FIG. 8, it may be determined whether the difference between the second difference when flat and the second difference is within the first range.

[0109] In the embodiment shown in FIG. 4, the first measuring device 430 and the first reference measuring device 429 are separated in the left-right direction and provided separately. However, the first measuring device 430 and the first reference measuring device 429 may be integrally formed. In this case, it is sufficient if one measuring device includes the first sensor 422 and the first reference sensor 426. Further, it is preferable that one measuring device including the first sensor 422 and the first reference sensor 426 is fixed to the coating plate 432.

[0110] In the embodiment shown in FIG. 4, the second measuring device 450 and the second reference measuring device 449 are separated in the left-right direction and provided separately. However, the second measuring device 450 and the second reference measuring device 449 may be integrally formed. In this case, it is sufficient if one measuring device includes the second sensor 442 and the second reference sensor 446. Further, it is preferable that one measuring device including the second sensor 442 and the second reference sensor 446 is fixed to the coating plate 432.

[0111] In the second measuring device 550 of the embodiment shown in FIG. 5, a second target 544 is provided below the second sensor 542. However, the light-emitting element E of the second sensor 542 may emit light upward. In this case, the second target 544 is provided above the light-emitting element E. Further, when the second target 544 is provided above the light-emitting element E, the second target 544 may be the lower surface of the second stage. This also applies to the first measuring device.

[0112] In the second reference measuring instrument 549 of the embodiment shown in FIG. 5, a second reference target 548 is provided below the second reference sensor 546. However, the light emitting element E of the second reference sensor 546 may emit light upward. In this case, the second reference target 548 is provided above the light emitting element E. At this time, the second reference target 548 is fixed to the coating plate 532 of the coating stage 540, and the second reference sensor 546 is fixed to a location other than the coating plate 532 of the coating stage 540. Further, when the second reference target 548 is provided above the light emitting element E, the second reference target 548 may be the lower surface of the coating stage. This is the same for the first reference measuring instrument.

[0113] The coating stage 640 of the embodiment shown in FIG. 6 includes five support portions 634. However, the number of support portions 634 included in the coating stage 640 does not have to be five. It is preferable that a plurality of support portions 634 are provided on the coating stage 640 so that the coating stage 640 is supported in a well-balanced manner.

[0114] The third measuring instrument 790 of the embodiment shown in FIG. 7 includes a third sensor 782 and a third target 784. However, without arranging the third target 784, the floor surface F may be used as the third target. In this case, the third sensor 782 emits light toward the floor surface F, and it is sufficient if the floor surface F reflects this light.

[0115] A display for displaying the measured value, reference value, or the difference between the measured value and the reference value output by the measuring instrument may be arranged near the support portion 734 of the embodiment shown in FIG. 7. Thereby, when the user manually operates the actuator 770, the user can operate the actuator 770 while checking the measured value, reference value, and difference.

[0116] The coating apparatus according to an embodiment of the present invention may further include an alarm. The alarm may be connected to the input / output unit 960 shown in FIG. 9. For example, when the first measurement value exceeds the first range or when the second measurement value exceeds the second range, the processor 920 may output a command to cause the alarm to issue an alarm via the input / output unit 960. The alarm may be, for example, an alarm that emits a sound, a display device that displays information, or the like. The alarm may be an alarm sound, voice information, character information, or the like. These alarm sounds, voice information, character information, etc. may be stored in the memory 940.

[0117] In the above embodiment, the first range is 0 μm - 100 μm, and the second range is 0 μm - 150 μm or less. The specific numerical values of these first range and second range are merely examples. The first range and the second range may be set so that the substrate is not caught by the step between the coating stage and the floating stage.

Description of Reference Numerals

[0118] Substrate S Coating apparatuses 100, 200, 300, 400, 500, 600, 700 Floating stage First stages 120, 220, 320, 420 Second stages 160, 260, 360, 460, 560 Coating stages 140, 240, 340, 440, 540, 640, 740 Measuring instrument First measuring instrument 430 Second measuring instruments 450, 550 Third measuring instrument 790 Actuators 670, 770 Controller 764

Claims

1. A coating apparatus that floats and conveys a substrate above a floating stage and a coating stage, and applies a processing liquid to the substrate on the coating stage, wherein the floating stage is disposed on at least one of the upstream side and the downstream side of the coating stage in the conveyance direction of the substrate, a measuring instrument for obtaining a measured value corresponding to the distance between the upper surface of the floating stage and the upper surface of the coating stage; a controller for controlling an actuator that drives the coating stage in the normal direction of the upper surface of the coating stage so that the measured value is within a predetermined range; A coating apparatus comprising the above.

2. The coating stage is heavier than the floating stage, The coating apparatus according to claim 1.

3. The coating stage includes a coating plate including the upper surface of the coating stage, a support portion that supports the coating plate with respect to the floor surface, and The floating stage includes a floating plate including the upper surface of the floating stage, a support portion that supports the floating plate with respect to the floor surface, and The measuring instrument includes a sensor and a target, and outputs the measured value by measuring the distance between the sensor and the target. (i) The sensor is fixed to the coating stage so as to be located below the coating plate, and the target is fixed to the floating stage so that the measured value is obtained, or (ii) The sensor is fixed to the floating stage so as to be located below the floating plate, and the target is fixed to the coating stage so that the measured value is obtained. The coating apparatus according to claim 1.

4. The coating stage includes a coating plate including the upper surface of the coating stage, a support portion that supports the coating plate with respect to the floor surface, and The measuring instrument is provided near the floor surface of the support portion. The coating apparatus according to claim 1.

5. The sensor is an optical sensor, The target receives and reflects the light emitted by the sensor, The sensor receives the light reflected by the target. The coating apparatus according to claim 3.

6. The actuator is provided in a region closer to the floating stage of the coating stage and drives the coating stage based on the measured value. The coating apparatus according to claim 1.

7. The controller determines whether the measured value is within the predetermined range without user intervention. When the measured value exceeds the predetermined range, control an actuator that drives the coating stage in the normal direction of the upper surface of the coating stage so that the measured value falls within the predetermined range. The coating apparatus according to claim 1.

8. Comprising an alarm that issues an alarm to the user when the measured value exceeds the predetermined range. The coating apparatus according to claim 1.

9. The floating stage is a floating plate including the upper surface of the floating stage, and a support portion that supports the floating plate with respect to the floor surface. The measuring instrument provided in the support portion of the coating stage includes a sensor. The sensor is disposed at a position separated from the support portion of the coating stage by a predetermined distance or more so as to be located in the vicinity of the support portion of the floating stage. The coating apparatus according to claim 4.

10. Further comprising a reference measuring instrument that outputs a reference value that is a value not affected by a change in the distance between the upper surface of the floating stage and the upper surface of the coating stage. The controller controls the actuator based on the difference between the measured value and the reference value. The coating apparatus according to claim 7.

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