JP2018152441A - Substrate transport apparatus, substrate transport method, and coating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate transfer technique which conveys the lower surface of a substrate in a state of being floated from a stage by gas blown from the upper surface of the stage while partially absorbing and retaining the lower surface of the substrate and by which absorbing and retaining are surely performed and the substrate transfer is excellently stably performed.SOLUTION: A substrate transfer device includes: a floating stage for imparting buoyancy to a substrate by ejecting gas toward the lower surface of a substrate from the stage upper surface; a transportation part having an absorbing pad for partially absorbing and retaining the lower surface of the substrate located upward of the floating stage and a travel mechanism for traveling the absorbing pad along the floating stage; and a flow rate control mechanism for controlling an ejection flow rate which is a flow rate of gas ejected from the stage upper surface per unit time. In the flow rate control mechanism, the ejection flow rate when the substrate is absorbed by the absorbing pad is reduced more than the ejection flow rate before absorption.SELECTED DRAWING: Figure 7

Description

  The present invention transports the substrate by running a suction pad that partially sucks and holds the lower surface of the substrate along a levitation stage that jets gas toward the lower surface of the substrate and imparts buoyancy to the substrate. The present invention relates to a substrate transfer device, a substrate transfer method, and a coating apparatus equipped with the substrate transfer device. The above substrates include semiconductor substrates, photomask substrates, liquid crystal display substrates, organic EL display substrates, plasma display substrates, FED (Field Emission Display) substrates, optical disk substrates, magnetic disk substrates, optical disks. Includes magnetic disk substrates.

  In the manufacturing process of electronic components such as a semiconductor device and a liquid crystal display device, a coating apparatus that discharges a coating liquid onto the upper surface of the substrate to apply the upper surface of the substrate is used. For example, in the coating apparatus described in Patent Document 1, the gas is blown onto the lower surface of the substrate and the substrate is transported from the stage while the substrate is lifted from the stage. The coating liquid is applied to almost the entire surface of the substrate by discharging from the outlet onto the surface of the substrate.

Japanese Patent No. 5346663 JP 2011-213435 A

  In the apparatus described in Patent Document 1, gas is ejected upward from the upper surface of the stage in order to float the substrate, and a substrate transport chuck is provided to transport the substrate in a state of floating from the stage. ing. The substrate transport chuck has a chuck portion for sucking and holding the substrate and a linear motor for moving the chuck portion along the stage, while sucking and holding both side edges of the substrate whose bottom surface is not in contact with the stage. Transport the substrate in the transport direction. In addition, although the specific structure of the chuck | zipper part is not described in patent document 1, it is common to use what embed | buried the suction pad described in patent document 2 in the main body of the chuck | zipper part, for example. The suction pad is a cylindrical nozzle that sucks air by a suction pump, and can suck and hold the lower surface of the edge of the substrate.

  However, a suction failure may occur when the lower surface of the floating substrate is sucked and held by the suction pad. This is because gas is blown from the upper surface of the stage to the lower surface of the substrate, and a force that lifts upward is acting on the substrate. Further, the gas blown to the lower surface of the substrate flows in the edge direction along the lower surface and is purged from the side edge of the substrate to the outside of the substrate. Since the purged gas flows into the suction pad in this way, it may be difficult to effectively suck the lower surface of the edge of the substrate by the suction pad.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and in the substrate transport technology for transporting the substrate in a state where it is floated from the stage by the gas ejected from the upper surface of the stage while partially attracting and holding the lower surface of the substrate, the suction holding is ensured. The purpose is to carry out the substrate stably and satisfactorily.

  A first aspect of the present invention is a substrate transfer apparatus, which includes a levitation stage that imparts buoyancy to a substrate by ejecting gas from the upper surface of the stage toward the lower surface of the substrate, and a lower surface of the substrate positioned above the levitation stage. Is a flow rate of gas ejected per unit time from the upper surface of the stage, a transport unit having a suction pad that partially adsorbs and holds the suction pad, a traveling mechanism that causes the suction pad to travel along the levitation stage, and The flow rate control mechanism is characterized in that the ejection flow rate when the substrate is adsorbed by the suction pad is reduced from the ejection flow rate before the adsorption.

  Further, according to a second aspect of the present invention, a substrate is provided by running a suction pad that partially sucks and holds the lower surface of the substrate along a levitation stage that jets gas toward the lower surface of the substrate and imparts buoyancy to the substrate. A substrate transport method for transporting a substrate, the first step of ejecting gas from the upper surface of the levitation stage at a first ejection flow rate per unit time to levitate the substrate from the levitation stage, and the substrate levitated from the levitation stage A second step of positioning the suction pad at a lower position of the substrate so as to partially face the lower surface of the substrate, and a second ejection flow rate at which the ejection flow rate for ejecting gas per unit time from the upper surface of the stage is lower than the first ejection flow rate And a third step in which the lower surface of the substrate is partially sucked and held by a suction pad positioned at a lower position of the substrate.

  Furthermore, a third aspect of the present invention is a coating apparatus, comprising: the above-described substrate transport device; and a nozzle that discharges and coats the coating liquid on the upper surface of the substrate transported by the substrate transport device. .

  In the invention configured as described above, when the suction pad partially sucks and holds the lower surface of the substrate, the flow rate of the gas ejected from the upper surface of the stage per unit time, that is, the jet flow rate is lower than before the suction. Is done. For this reason, the force by which the substrate is lifted by the gas ejected from the upper surface of the stage is weakened. Further, the amount of gas purged from the side edge of the substrate to the outside of the substrate is reduced. As a result, the lower surface of the substrate is reliably sucked by the suction pad.

  As described above, since the ejection flow rate (the flow rate of gas ejected from the upper surface of the stage per unit time) when adsorbing the substrate with the adsorption pad is reduced as compared with before the adsorption, the adsorption pad holds the substrate by the adsorption pad. Thus, the substrate can be transported satisfactorily and stably.

It is a figure which shows typically the whole structure of the coating device equipped with one Embodiment of the board | substrate conveying apparatus concerning this invention. It is the top view which looked at the coating device from the perpendicular upper direction. It is the top view which removed the application | coating mechanism from FIG. It is the sectional view on the AA line of FIG. It is a figure which shows the structure of a board | substrate conveyance part. It is a figure which shows the structure of a floating stage part and a floating control mechanism. It is a figure which shows typically the positional relationship of each part in a process.

  FIG. 1 is a diagram schematically showing an overall configuration of a coating apparatus equipped with an embodiment of a substrate transfer apparatus according to the present invention. The coating apparatus 1 is a slit coater that applies a coating solution to the upper surface Wf of the substrate W that is transported in a horizontal posture from the left hand side to the right hand side in FIG. In the following drawings, in order to clarify the arrangement relationship of each part of the apparatus, the transport direction of the substrate W is referred to as “X direction”, and the horizontal direction from the left hand side to the right hand side in FIG. 1 is referred to as “+ X direction”. The reverse direction is referred to as the “−X direction”. Further, among the horizontal direction Y orthogonal to the X direction, the front side of the apparatus is referred to as “−Y direction” and the back side of the apparatus is referred to as “+ Y direction”. Further, the upward direction and the downward direction in the vertical direction Z are referred to as “+ Z direction” and “−Z direction”, respectively.

  First, the outline of the configuration and operation of the coating apparatus 1 will be described with reference to FIG. 1, and then the detailed structure of each part will be described. Note that the basic configuration and operation principle of the coating apparatus 1 are the same as those described in Japanese Patent No. 5346663 (Patent Document 1) previously disclosed by the applicant of the present application. Therefore, in the present specification, among the configurations of the coating apparatus 1, configurations similar to those described in these known documents can be applied, and structures can be easily understood from the descriptions of these documents. Detailed description will be omitted, and the characteristic part of this embodiment will be mainly described.

  In the coating apparatus 1, the input conveyor 100, the input transfer unit 2, the floating stage unit 3, the output transfer unit 4, and the output conveyor 110 are arranged close to each other in this order along the transport direction Dt (+ X direction) of the substrate W. Thus, as will be described in detail below, a transport path for the substrate W extending in a substantially horizontal direction is formed. In the following description, when the positional relationship is shown in association with the transport direction Dt of the substrate W, “upstream side in the transport direction Dt of the substrate W” is simply referred to as “upstream side”, and “downstream in the transport direction Dt of the substrate W”. "Side" may be simply abbreviated as "Downstream". In this example, the (−X) side relatively corresponds to “upstream side” and the (+ X) side corresponds to “downstream side” when viewed from a certain reference position.

  The substrate W to be processed is carried into the input conveyor 100 from the left hand side of FIG. The input conveyor 100 includes a roller conveyor 101 and a rotation driving mechanism 102 that rotationally drives the roller conveyor 101, and the substrate W is transported in a horizontal posture downstream, that is, in the (+ X) direction by the rotation of the roller conveyor 101. The input transfer unit 2 includes a roller conveyor 21 and a rotation / elevation drive mechanism 22 having a function of rotationally driving the roller conveyor 21 and a function of elevating and lowering the roller conveyor 21. As the roller conveyor 21 rotates, the substrate W is further transported in the (+ X) direction. Moreover, the vertical direction position of the board | substrate W is changed because the roller conveyor 21 raises / lowers. The substrate W is transferred from the input conveyor 100 to the floating stage unit 3 by the input transfer unit 2 configured as described above.

  The levitation stage unit 3 includes a flat stage divided into three along the substrate transport direction Dt. That is, the levitation stage unit 3 includes an inlet levitation stage 31, a coating stage 32, and an outlet levitation stage 33, and the upper surfaces of these stages are part of the same plane. The upper surfaces of the inlet levitation stage 31 and the outlet levitation stage 33 are provided with a large number of ejection holes for ejecting compressed air supplied from the levitation control mechanism 35 in a matrix, and the buoyancy imparted from the ejected airflow The substrate W rises. Thus, the lower surface Wb of the substrate W is supported in a horizontal posture in a state of being separated from the upper surface of the stage. The distance between the lower surface Wb of the substrate W and the upper surface of the stage, that is, the flying height can be, for example, 10 micrometers to 500 micrometers.

  On the other hand, on the upper surface of the coating stage 32, ejection holes for ejecting compressed air and suction holes for sucking air between the lower surface Wb of the substrate W and the upper surface of the stage are alternately arranged. The distance between the lower surface Wb of the substrate W and the upper surface of the coating stage 32 is precisely controlled by the levitation control mechanism 35 controlling the amount of compressed air ejected from the ejection holes and the amount of suction from the suction holes. Thereby, the vertical position of the upper surface Wf of the substrate W passing over the coating stage 32 is controlled to a specified value. As a specific configuration of the levitation stage unit 3, for example, the one described in Japanese Patent No. 5346663 (Patent Document 1) can be applied.

  As shown in FIG. 1, the outlet floating stage 33 is arranged in parallel with the coating stage 32 so as to be separated from each other in the transport direction (+ X), and a gap region CL is formed between them. A gas supply pipe 6 is disposed vertically below the gap region CL, and receives compressed air supplied from the levitation control mechanism 35 and jets compressed air into the gap region CL. This suppresses the occurrence of coating unevenness. This point will be described in detail later together with the configuration description of the levitation control mechanism 35.

  The entrance levitation stage 31 is provided with lift pins not shown in the drawing, and the levitation stage portion 3 is provided with a lift pin drive mechanism 34 for raising and lowering the lift pins.

  The substrate W carried into the levitation stage unit 3 via the input transfer unit 2 is given a propulsive force in the (+ X) direction by the rotation of the roller conveyor 21 and is conveyed onto the inlet levitation stage 31. The inlet floating stage 31, the coating stage 32, and the outlet floating stage 33 support the substrate W in a floating state, but do not have a function of moving the substrate W in the horizontal direction. The transport of the substrate W in the levitation stage unit 3 is performed by the substrate transport unit 5 disposed below the entrance levitation stage 31, the coating stage 32, and the exit levitation stage 33.

  The substrate transport unit 5 includes a chuck mechanism 51 that supports the substrate W from below by partially abutting against the peripheral edge of the lower surface of the substrate W, and an adsorption member at the upper end of the chuck mechanism 51 (see FIGS. 3, 4, and 5 to be described later). The function of holding the substrate W by suction by applying a negative pressure to the suction pads and suction grooves (reference numerals 514 and 515 in FIG. 5 later) provided in the inner reference numeral 513) and the chuck mechanism 51 reciprocally run in the X direction. And a suction / running control mechanism 52 having a function. In a state where the chuck mechanism 51 holds the substrate W, the lower surface Wb of the substrate W is positioned higher than the upper surface of each stage of the levitation stage unit 3. Therefore, the substrate W maintains the horizontal posture as a whole by the buoyancy applied from the levitation stage unit 3 while the peripheral portion is sucked and held by the chuck mechanism 51. The configuration and operation of the substrate transport unit 5 will be described in detail later.

  The chuck mechanism 51 holds the substrate W carried into the floating stage unit 3 from the input transfer unit 2, and the substrate W moves above the entrance floating stage 31 by moving the chuck mechanism 51 in the (+ X) direction in this state. From above the coating stage 32 and then conveyed above the outlet floating stage 33. The transported substrate W is transferred to the output transfer unit 4 disposed on the (+ X) side of the outlet floating stage 33.

  The output transfer unit 4 includes a roller conveyor 41, and a rotation / lift drive mechanism 42 having a function of rotating and driving the roller conveyor 41. By rotating the roller conveyor 41, a propulsive force in the (+ X) direction is applied to the substrate W, and the substrate W is further transported along the transport direction Dt. Further, the vertical position of the substrate W is changed by moving the roller conveyor 41 up and down. Then, the output transfer unit 4 transfers the substrate W to the output conveyor 110 from above the outlet floating stage 33.

  The output conveyor 110 includes a roller conveyor 111 and a rotation driving mechanism 112 that rotates and drives the substrate. The substrate W is further transported in the (+ X) direction by the rotation of the roller conveyor 111, and finally the outside of the coating apparatus 1. To be paid out. The input conveyor 100 and the output conveyor 110 may be provided as part of the configuration of the coating apparatus 1, but may be separate from the coating apparatus 1. Further, for example, a separate unit substrate dispensing mechanism provided on the upstream side of the coating apparatus 1 may be used as the input conveyor 100. Further, a substrate receiving mechanism of another unit provided on the downstream side of the coating apparatus 1 may be used as the output conveyor 110.

  A coating mechanism 7 for coating the coating liquid on the upper surface Wf of the substrate W is disposed on the transport path of the substrate W transported in this manner. The coating mechanism 7 includes a nozzle 71 that is a slit nozzle and a maintenance unit 75 for performing maintenance on the nozzle 71. A coating liquid is supplied to the nozzle 71 from a coating liquid supply unit (not shown), and the coating liquid is discharged from a discharge port that opens downward in the lower part of the nozzle.

  The nozzle 71 can be moved and positioned in the X direction and the Z direction by a positioning mechanism 73. The positioning mechanism 73 positions the nozzle 71 at a coating position (position indicated by a dotted line) above the coating stage 32. The coating liquid is discharged from the nozzle positioned at the coating position, and is applied to the substrate W transported between the coating stage 32. Thus, the coating liquid is applied to the substrate W.

  The maintenance unit 75 includes a bat 751 that stores cleaning liquid for cleaning the nozzle 71, a preliminary discharge roller 752, a nozzle cleaner 753, and a maintenance control mechanism 754 that controls operations of the preliminary discharge roller 752 and the nozzle cleaner 753. I have. As a specific configuration of the maintenance unit 75, for example, a configuration described in JP 2010-240550 A can be applied.

  At the position where the nozzle 71 is above the preliminary discharge roller 752 and the discharge port faces the upper surface of the preliminary discharge roller 752 (preliminary discharge position), the coating liquid is discharged from the discharge port of the nozzle 71 toward the upper surface of the preliminary discharge roller 752. The The nozzle 71 is positioned at the preliminary discharge position prior to being positioned at the application position, and performs a preliminary discharge process by discharging a predetermined amount of coating liquid from the discharge port. Thus, by causing the nozzle 71 before moving to the application position to perform the preliminary discharge process, the discharge of the coating liquid at the application position can be stabilized from the initial stage.

  The maintenance control mechanism 754 rotates the preliminary discharge roller 752 so that the discharged coating liquid is mixed with the cleaning liquid stored in the bat 751 and collected. Further, in a state where the nozzle 71 is located above the nozzle cleaner 753 (first cleaning position), the nozzle cleaner 753 moves in the Y direction while discharging the cleaning liquid, thereby adhering to the discharge port of the nozzle 71 and its surroundings. The coating solution is washed away.

  Further, the positioning mechanism 73 can position the nozzle 71 at a position (standby position) below the first cleaning position and where the lower end of the nozzle is accommodated in the bat 751. When the coating process using the nozzle 71 is not executed, the nozzle 71 is positioned at this standby position. Although illustration is omitted, a standby pod for preventing the coating liquid from drying at the discharge port may be arranged for the nozzle 71 positioned at the standby position.

  In addition, the coating apparatus 1 is provided with a control unit 9 for controlling the operation of each part of the apparatus. The control unit 9 is responsible for exchanging information with a storage means for storing a predetermined control program and various data, a calculation means such as a CPU for causing each part of the apparatus to execute a predetermined operation by executing this control program, and a user and an external device. Interface means are provided.

  FIG. 2 is a plan view of the coating apparatus as viewed from above. FIG. 3 is a plan view in which the coating mechanism is removed from FIG. 4 is a cross-sectional view taken along line AA in FIG. Furthermore, FIG. 5 is a diagram showing the configuration of the substrate transport unit. Hereinafter, a specific mechanical configuration of the coating apparatus 1 will be described with reference to these drawings. With regard to some mechanisms, a more detailed structure can be understood by referring to the description of Japanese Patent No. 5346663 (Patent Document 1). In FIGS. 2 and 3, the description of the rollers of the input conveyor 100 and the like is omitted. 5B and 5C are enlarged perspective views of the vicinity region R of the attracting member.

  The nozzle unit 70 of the coating mechanism 7 has a bridging structure as shown in FIGS. Specifically, the nozzle unit 70 is composed of a pair of column members 732 and 733 erected upward from the base 10 at both ends in the Y direction of the beam member 731 extending in the Y direction above the floating stage unit 3. It has a supported structure. An elevating mechanism 734 configured by, for example, a ball screw mechanism is attached to the column member 732, and the (+ Y) side end portion of the beam member 731 is supported by the elevating mechanism 734 so as to be movable up and down. Further, an elevating mechanism 735 configured by, for example, a ball screw mechanism is attached to the column member 733, and the (−Y) side end portion of the beam member 731 is supported by the elevating mechanism 735 so as to be movable up and down. The elevating mechanisms 734 and 735 are interlocked according to a control command from the control unit 9, so that the beam member 731 moves in the vertical direction (Z direction) while maintaining a horizontal posture.

  A nozzle 71 is attached to the lower center of the beam member 731 with the discharge port 711 facing downward. Therefore, movement of the nozzle 71 in the Z direction is realized by operating the lifting mechanisms 734 and 735.

  The column members 732 and 733 are configured to be movable in the X direction on the base 10. Specifically, a pair of travel guides 81 </ b> L and 81 </ b> R extending in the X direction are attached to the upper surfaces of the (+ Y) side and (−Y) side end portions of the base 10, and the column member 732. Is engaged with the traveling guide 81L on the (+ Y) side through a slider 736 attached to the lower part thereof. The slider 736 is movable in the X direction along the traveling guide 81L. Similarly, the column member 733 is engaged with the travel guide 81R on the (−Y) side via a slider 737 attached to the lower portion thereof, and is movable in the X direction.

  The column members 732 and 733 are moved in the X direction by the linear motors 82L and 82R. Specifically, the magnet modules of the linear motors 82L and 82R are extended along the X direction on the base 10 as stators, and the coil modules are attached to the lower portions of the column members 732 and 733 as movers. When the linear motors 82L and 82R are operated in accordance with a control command from the control unit 9, the entire nozzle unit 70 moves along the X direction. Thereby, the movement of the nozzle 71 in the X direction is realized. The X-direction positions of the column members 732 and 733 can be detected by linear scales 83L and 83R provided in the vicinity of the sliders 736 and 737.

  Thus, the nozzle 71 moves in the Z direction by operating the elevating mechanisms 734 and 735, and the nozzle 71 moves in the X direction by operating the linear motors 82L and 82R. That is, when the control unit 9 controls these mechanisms, the nozzle 71 is positioned at each stop position (application position, preliminary discharge position, etc.). Accordingly, the elevating mechanisms 734 and 735, the linear motors 82L and 82R, the control unit 9 for controlling these, and the like function as the positioning mechanism 73 in FIG.

  The maintenance unit 75 has a structure in which a preliminary discharge roller 752 and a nozzle cleaner 753 are accommodated in a butt 751. Although not shown, the maintenance unit 75 is provided with a maintenance control mechanism 754 for driving the preliminary discharge roller 752 and the nozzle cleaner 753. The bat 751 is supported by a beam member 761 extending in the Y direction, and both ends of the beam member 761 are supported by a pair of column members 762 and 763. The pair of column members 762 and 763 are attached to both ends of the plate 764 extending in the Y direction in the Y direction.

  A pair of travel guides 84 </ b> L and 84 </ b> R extend in the X direction on the base 10 below both ends in the Y direction of the plate 764. Both ends of the plate 764 in the Y direction are engaged with the travel guides 84L and 84R via sliders 766 and 767, respectively. For this reason, the maintenance unit 75 is movable in the X direction along the travel guides 84L and 84R. A linear motor 85 is provided below the (−Y) direction end of the plate 764. The linear motor 85 may be provided below the (+ Y) direction end of the plate 764, or may be provided below the both ends of the Y direction.

  In the linear motor 85, a magnet module is extended as a stator on the base 10 along the X direction, and a coil module is attached to the maintenance unit 75 as a mover. By operating the linear motor 85 according to a control command from the control unit 9, the entire maintenance unit 75 moves along the X direction. The position of the maintenance unit 75 in the X direction can be detected by a linear scale 86 provided in the vicinity of the sliders 766 and 767.

  Next, the configuration and operation of the substrate transport unit 5 will be described with reference to FIGS. The chuck mechanism 51 of the substrate transport unit 5 includes a pair of chucks 51L and 51R that are symmetrical with respect to the XZ plane and are spaced apart in the Y direction. Of these, the chuck 51L disposed on the (+ Y) side is supported by the traveling guide 87L extending in the X direction on the base 10 so as to be able to travel in the X direction. Specifically, the chuck 51L includes a base portion 512 having two horizontal plate portions provided at different positions in the X direction and a connection portion that connects these plate portions. Sliders 511 are respectively provided below the two plate portions of the base portion 512, and the base portion 512 can travel in the X direction along the travel guide 87L by engaging the slider 511 with the travel guide 87L. ing.

  At the upper part of the two plate parts of the base part 512, suction members 513 and 513 are provided at the upper end part extending upward. When the base portion 512 moves in the X direction along the travel guide 87L, the two adsorbing members 513 and 513 move in the X direction integrally therewith. The two plate portions of the base portion 512 may be separated from each other, and the plate portions may be structured to function as an integral base portion by moving while maintaining a certain distance in the X direction. If this distance is set according to the length of the substrate, it is possible to deal with substrates of various lengths.

  The chuck 51L is movable in the X direction by a linear motor 88L. That is, the magnet module of the linear motor 88L is extended as a stator on the base 10 in the X direction, and the coil module is attached as a mover to the lower part of the chuck 51L. The linear motor 88L is actuated in accordance with a control command from the control unit 9, whereby the chuck 51L moves along the X direction. The position of the chuck 51L in the X direction can be detected by the linear scale 89L.

  Similarly, the chuck 51 </ b> R provided on the (−Y) side includes a base portion 512 having two plate portions and a connection portion, and suction members 513 and 513. However, the shape is symmetrical to the chuck 51L with respect to the XZ plane. Each plate portion is engaged with the travel guide 87R by a slider 511. Further, the chuck 51R is movable in the X direction by a linear motor 88R. That is, the magnet module of the linear motor 88R is extended as a stator on the base 10 in the X direction, and the coil module is attached as a mover to the lower part of the chuck 51R. The linear motor 88R is actuated according to a control command from the control unit 9, whereby the chuck 51R moves along the X direction. The X-direction position of the chuck 51R can be detected by the linear scale 89R.

  The control unit 9 controls these positions so that the chucks 51L and 51R are always at the same position in the X direction. As a result, the pair of chucks 51L and 51R apparently move as an integrated chuck mechanism 51. Compared with the case where the chucks 51L and 51R are mechanically coupled, interference between the chuck mechanism 51 and the floating stage unit 3 can be easily avoided.

  As shown in FIG. 3, the four adsorption members 513 are arranged corresponding to the four corners of the substrate W to be held. That is, the two suction members 513 and 513 of the chuck 51L hold the upstream end and the downstream end in the transport direction Dt, respectively, on the (+ Y) side periphery of the substrate W. On the other hand, the two adsorbing members 513 and 513 of the chuck 51R respectively hold the upstream end and the downstream end in the transport direction Dt on the (−Y) side periphery of the substrate W. Specifically, the suction member 513 and the suction / running control mechanism 52 are configured as follows.

  The upper surface of each adsorption member 513 functions as a contact surface 513a that partially contacts the lower surface Wb of the substrate W. In the central portion of the contact surface 513a, two openings are provided apart from each other as shown in columns (b) and (c) of FIG. Each opening is an opening of a recess 513b for embedding the suction pad 514, and the upper end portion of the suction pad 514 can freely advance and retract in the vertical direction Z through the opening. That is, each suction pad 514 is a cylindrical member formed of an elastic material such as rubber, and the side portion is finished in a so-called bellows shape, and is extendable in the vertical direction Z. Further, a plurality (six in this embodiment) of suction grooves 515 are provided in a region of the contact surface 513a excluding the opening.

  The suction pad 514 and the suction groove 515 are connected to the suction / running control mechanism 52, and suck and hold the substrate W according to the suction command from the control unit 9, and the substrate W according to the suction release command. Release adsorption. More specifically, as shown in FIG. 5, the suction / running control mechanism 52 supplies negative pressure provided from a negative pressure supply source installed in the factory where the coating apparatus 1 is installed to the suction pad 514 and the suction groove 515. It has a function to do. Note that, instead of the negative pressure supply source, a suction pump may be provided in the coating apparatus 1 so that negative pressure is supplied.

  Two negative pressure supply systems 52L and 52R are connected to the negative pressure supply source. The negative pressure supply system 52L is for supplying negative pressure to the suction pads 514 and the suction grooves 515 provided on the chuck 51L disposed on the (+ Y) side, and the negative pressure supply system 52R is on the (−Y) side. This is for supplying a negative pressure to the suction pad 514 and the suction groove 515 provided in the chuck 51 </ b> R. Each of these negative pressure supply systems 52L and 52R has a manual regulator 521, an air operation valve 522, and a pressure gauge 523. In each of the negative pressure supply systems 52L and 52R, suction through the suction pad 514 and the suction groove 515 is stopped while the air operation valve 522 is closed in accordance with the suction command from the control unit 9. As shown in column (b) of FIG. 5, 514 is in a state in which the suction port protrudes upward from the contact surface 513 a at the upper end. Further, as shown in the column (c) of the same figure, in a state where a part of the lower surface Wb of the substrate W is supported by the upper end portion of the suction pad 514, the air operation valve 522 is set in accordance with the suction command from the control unit 9. When opened, the suction pad 514 is sucked at the pressure set by the manual regulator 521, the lower surface Wb of the substrate W is partially sucked, and the suction pad 514 is contracted in the vertical direction Z while sucking the substrate W. Thus, the upper end of the suction pad 514 is retracted into the recess 513b. As a result, the lower surface Wb of the substrate W comes into contact with the contact surface 513a while being sucked by the suction pad 514. In addition, the suction pad 514 is pulled in, so that the opening of the suction groove 515 is reliably closed, and the suction of the substrate by the suction groove 515 is added. Finally, the four corners of the substrate W are attracted and held from below by the chuck mechanism 51 by two kinds of attracting means.

  As shown in FIGS. 1 and 4, the chuck mechanism 51 holds the lower surface Wb of the substrate W above the upper surfaces of the stages of the floating stage unit 3, that is, the inlet floating stage 31, the coating stage 32, and the outlet floating stage 33. In this state, the substrate W is transferred. Since the chuck mechanism 51 only holds a part of the outer peripheral edge in the Y direction with respect to the central portion of the substrate W facing the stages 31, 32, 33, the central portion of the substrate W is at the peripheral portion. On the other hand, it will bend downward. The levitation stage unit 3 has a function of controlling the vertical position of the substrate W to maintain a horizontal posture by applying buoyancy to the central portion of the substrate W.

  Among the stages of the levitation stage unit 3, the exit levitation stage 33 has a lower position where the upper surface position is lower than the upper surface position of the chuck mechanism 51, and an upper position where the upper surface position is higher than the upper surface position of the chuck mechanism 51. Can be moved up and down. For this purpose, the outlet levitation stage 33 is supported by a lift drive mechanism 36.

  Next, the configuration of the levitation control mechanism 35 will be described with reference to FIG. FIG. 6 is a diagram showing the configuration of the levitation stage section and the levitation control mechanism. In the figure, the levitation stage section 3 is schematically shown with all of the coating stage 32 and a part of the inlet levitation stage 31 and the outlet levitation stage 33. Show.

  The levitation control mechanism 35 includes a compression unit 351 such as a compressor and a temperature control unit 352, and adjusts the air compressed by the compression unit 351 to a predetermined temperature by the temperature control unit 352 to generate compressed air for levitation. The piping 353 through which this compressed air flows is branched into three and connected to the inlet levitation stage 31, the coating stage 32, and the outlet levitation stage 33 via pressure control units 354, respectively. All of the three pressure control units 354 have the same configuration, and perform pressure control of compressed air and supply / stop of compressed air according to a command from the control unit 9.

  Each pressure control unit 354 includes a filter 354a, a needle valve 354b, a flow meter 354c, a pressure meter 354d, and an air operation valve 354e. For example, in the pressure control unit 354 provided corresponding to the outlet levitation stage 33, when the air operation valve 354e is opened in accordance with a command from the control unit 9, the compressed air cleaned through the filter 354a is supplied to the needle valve. After the pressure is adjusted by 354b, it passes through the flow meter 354c, the pressure gauge 354d, and the air operation valve 354e, and is sent by pressure to the ejection hole 331 provided in the outlet levitation stage 33. Thereby, the compressed air whose temperature is controlled from the ejection hole 331 is ejected at a predetermined ejection flow rate, and the substrate W is floated by the gas pressure. This also applies to the pressure control unit 354 provided corresponding to the inlet levitation stage 31. The “ejection flow rate” means the flow rate of the compressed air ejected from the inlet levitation stage 31 and the outlet levitation stage 33 per unit time.

  Similarly to the above, the pressure controller 354 provided corresponding to the coating stage 32 also sends compressed air toward the coating stage 32 in response to the opening of the air operation valve 354e. In this coating stage 32, a plurality of holes are distributed in a matrix at a pitch narrower than that of the ejection holes 312, 331, and half of them are supplied with the compressed air as the ejection holes 321, and the substrate W It ejects toward the lower surface Wb.

  Further, in order to stabilize the pressure in the coating atmosphere, the other half is connected as a suction hole 322 to a suction part 356 through a suction pipe 355. This suction part 356 includes a blower 356a as a suction means, a pressure gauge 356b, and a relief valve 356c, and the pressure in the suction hole 322 connected via the suction pipe 355 rather than the suction pressure obtained by the blower 356a. When the pressure is high, fine adjustment for keeping the pressure in the coating atmosphere constant can be performed by releasing air from the relief valve 356c through the suction hole 322 and the suction pipe 355 to the outside.

  Next, the coating process performed by the coating apparatus 1 configured as described above will be described with reference to FIG. In the present embodiment, the calculation means controls each part of the apparatus as follows in accordance with a control program stored in advance in the storage means, thereby increasing the certainty of suction holding of the substrate W by the suction member 513 while applying to the substrate W. Execute the process.

  In the present embodiment, the preliminary ejection process is executed by moving the nozzle 71 used for the coating process to the preliminary ejection position. In addition, the air operation valve 354e is opened to start the ejection of the compressed air in the levitation stage unit 3 so that the substrate W to be loaded can be floated. In FIG. 7, for the purpose of understanding the contents of the invention, only the compressed air ejected from the stage upper surface 31a of the inlet levitation stage 31 is indicated by a dotted arrow and the ejection flow rate is illustrated.

  Next, loading of the substrate W into the coating apparatus 1 is started as shown in the column (a) of FIG. A substrate W to be processed is placed on the input conveyor 100 by another upstream processing unit, a transport robot, and the like, and the roller conveyor 101 rotates to transport the substrate W in the (+ X) direction. At this time, the nozzle 71 performs the preliminary discharge process at the preliminary discharge position. Further, the chuck mechanism 51 is retracted and positioned downstream of the inlet levitation stage 31. Further, compressed air is ejected from the stage upper surface 31a of the inlet levitation stage 31 at an ejection flow rate FR1.

  When the input conveyor 100 and the input transfer unit 2 in which the upper surface of the roller conveyor 21 is positioned at the same height as the roller conveyor 101 of the input conveyor 100 cooperate with each other, the substrate W is ejected by compressed air. It is transported to the upper part of the entrance levitation stage 31 that gives buoyancy to the surface. At this time, the upper surface of the entrance levitation stage 31 is lower than the upper surface of the roller conveyor 21, and the substrate W is in a state where the upstream end (the rear end in the moving direction) rides on the roller conveyor 21. Therefore, the substrate W does not slide on the entrance levitation stage 31.

  When the substrate W is thus carried to the inlet levitation stage 31, the compressed air having the ejection flow rate FR1 is blown toward the lower surface Wb of the substrate W as shown in the column (b) of FIG. Has surfaced. The lift pins provided on the inlet levitation stage 31 are positioned by the lift pin drive mechanism 34 at an upper position where the upper end protrudes above the upper surface of the inlet levitation stage 31. As a result, both ends in the Y direction of the substrate W, more specifically, the substrate W with which the lift pins abut are lifted.

  Then, the chuck mechanism 51 moves in the (−X) direction and moves to the transfer start position directly below the substrate W as shown in the column (c) of FIG. Since both ends in the Y direction of the substrate W are lifted by the lift pins 311, it is possible to avoid the chuck mechanism 51 entering the lower side of the substrate W from coming into contact with the substrate W. From this state, the upper surface of the roller conveyor 21 and the lift pins 311 descends below the upper surface of the chuck mechanism 51, whereby the substrate W is transferred to the chuck mechanism 51. The chuck mechanism 51 holds the peripheral edge of the substrate W by suction.

  At the time of this transfer adsorption, in this embodiment, the ejection of the compressed air from the stage upper surface 31a of the inlet levitation stage 31 is temporarily stopped to reduce the ejection flow rate FR2 (= 0). That is, in synchronism with the start of lowering of the roller conveyor 21 and the lift pin 311, the air operation valve 354 e of the levitation control mechanism 35 is closed to set the ejection flow rate to zero and the air operation valve 522 of the suction / travel control mechanism 52 is Opening and suction through the suction pad 514 and the suction groove 515 are started. As a result, the compressed air is not blown onto the lower surface Wb of the substrate W, and the substrate W is lowered while being supported by the roller conveyor 21 and the lift pins 311, and suction suction by the suction pad 514 and suction by the suction groove 515 are started. Is done. Since the force for lifting the substrate W by the compressed air ejected from the stage upper surface 31a does not act in this way, and there is no compressed air purged from the side edge of the substrate W to the outside of the substrate, the suction pad 514 and the suction groove The lower surface Wb of the substrate W is reliably adsorbed by 515 and firmly held by the chuck mechanism 51.

  When the substrate suction is completed in this way, as shown in the column (d) of FIG. 7, the air operation valve 354e of the levitation control mechanism 35 is opened while the substrate suction by the suction pad 514 and the suction groove 515 is continued, and the compressed air is ejected. The flow rate FR3 is returned to the original ejection flow rate FR1. Thereafter, the substrate W is transported in a state where the peripheral portion is held by the chuck mechanism 51 and the central portion is maintained in a horizontal posture by the floating stage portion 3. Subsequently, the chuck mechanism 51 moves in the (+ X) direction, so that the substrate W is transported to the application start position. In parallel with this, the nozzle 71 is moved and positioned from the preliminary discharge position to the application position. The application start position is the position of the substrate W such that the downstream end (the leading side in the movement direction) of the substrate W comes to a position immediately below the nozzle 71 positioned at the application position. In many cases, the coating liquid is not applied to the end portion of the substrate W as a blank region. In such a case, the downstream end portion of the substrate W is advanced from the position directly below the nozzle 71 by the length of the blank region. Becomes the application start position.

  When the nozzle 71 is positioned at the application position, the application process is executed as follows. That is, the coating liquid discharged from the discharge port of the nozzle 71 is deposited on the upper surface Wf of the substrate W. Further, when the chuck mechanism 51 transports the substrate W at a constant speed, the nozzle 71 performs a coating operation for coating the coating liquid on the upper surface Wf of the substrate W, and the substrate upper surface Wf is coated with a constant thickness by the coating liquid. A film is formed.

  The coating operation is continued until the substrate W is transported to the end position where the coating should be terminated. When the substrate W reaches the end position, the transport of the substrate W is temporarily stopped, and the nozzle 71 is detached from the coating position. To return to the preliminary discharge position. Thereafter, the preliminary ejection process is executed again, and the transport of the substrate W is resumed. The substrate W carrying the coating film is transported from above the coating stage 32 to above the exit floating stage 33 by such a substrate transporting operation. When the chuck mechanism 51 reaches the conveyance end position where the downstream end of the substrate W is positioned on the output transfer unit 4, the movement of the chuck mechanism 51 is stopped and the air operation of the suction / travel control mechanism 52 is performed. The valve 522 is closed to stop the suction through the suction pad 514 and the suction groove 515, thereby releasing the suction holding. And the raising of the roller conveyor 41 of the output transfer part 4 and the raising of the exit floating stage 33 are sequentially started.

  Then, the roller conveyor 41 and the outlet floating stage 33 rise above the upper surface of the chuck mechanism 51, so that the substrate W is separated from the chuck mechanism 51. When the roller conveyor 41 rotates in this state, a propulsive force in the (+ X) direction is applied to the substrate W. Accordingly, when the substrate W moves in the (+ X) direction, the substrate W is further carried out in the (+ X) direction by the cooperation of the roller conveyor 41 and the roller conveyor 111 of the output conveyor 110 (step S21), and finally downstream. It is paid out to the side unit. If there is a next substrate to be processed, the same processing as described above is repeated, and if not, the processing ends. At this time, the nozzle 71 is returned to the standby position.

  As described above, in the present embodiment, when the suction pad 514 partially sucks and holds the lower surface Wb of the substrate W, the jet flow rate of the compressed air from the stage upper surface 31a is higher than the jet flow rate FR1 before suction. A low ejection flow rate FR2 (zero in this embodiment) is set. For this reason, there is no lifting force of the substrate W by the compressed air ejected from the stage upper surface 31a, and there is no compressed air purged from the side edge of the substrate W to the outside of the substrate. As a result, the lower surface Wb of the substrate W is reliably attracted by the suction pad 514, and the suction pad 514 is attracted and attracted satisfactorily, thereby eliminating the gap between the lower surface Wb of the substrate W and the contact surface 513a. By 515, the substrate W can be attracted and held more firmly. As a result, the substrate can be transported satisfactorily and stably.

  As described above, in this embodiment, the inlet levitation stage 31 and the levitation control mechanism 35 correspond to examples of the “levitation stage” and the “flow rate control mechanism” of the present invention, respectively. Compressed air corresponds to an example of “gas” in the present invention. Further, the ejection flow rates FR1, FR2, and FR3 correspond to examples of “first ejection flow rate”, “second ejection flow rate”, and “third ejection flow rate” of the present invention, respectively. Further, the suction / travel control mechanism 52 functions as a “travel mechanism” of the present invention, and the substrate transport unit 5 including the suction / travel control mechanism 52 corresponds to an example of the “transport unit” of the present invention. A combination of the transfer unit 5 and the floating stage unit 3 corresponds to an example of the “substrate transfer apparatus” of the present invention.

The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above embodiment, when the substrate W is adsorbed by the adsorption pad 514, the ejection of the compressed air is stopped and the ejection flow rate FR2 is set to zero, but the ejection flow rate FR2 is expressed by the following inequality 0 <( Ejection flow rate FR2) <(Ejection flow rate FR1)
May be set so as to satisfy the above, and the same effect as the above embodiment can be obtained.

  In the above embodiment, the ejection flow rate FR3 is returned to the ejection flow rate FR1 before suction after the suction of the substrate W by the suction pad 514 and the suction groove 515 is completed. However, the present invention is not limited to this. Any value can be set as long as the substrate W sucked and held by the pad 514 and the suction groove 515 can be levitated.

  In the above-described embodiment, the suction groove 515 is provided in addition to the suction pad 514. However, the substrate W may be sucked and held only by the suction pad 514.

  The present invention transports the substrate by running a suction pad that partially sucks and holds the lower surface of the substrate along a levitation stage that jets gas toward the lower surface of the substrate and imparts buoyancy to the substrate. It can be applied to general substrate transfer technology.

DESCRIPTION OF SYMBOLS 1 ... Coating apparatus 3 ... Floating stage part (substrate conveyance apparatus)
5 ... Substrate transport section (transport section, substrate transport apparatus)
31 ... (Inlet) Levitation stage 35 ... Levitation control mechanism (flow rate control mechanism)
52 ... Adsorption / travel control mechanism (travel mechanism, transport section)
71 ... Nozzle W ... Substrate Wf ... Upper surface of substrate Wb ... Lower surface of substrate (X) X ... Transport direction

Claims (8)

A levitation stage that imparts buoyancy to the substrate by ejecting gas from the upper surface of the stage toward the lower surface of the substrate;
A transport unit having a suction pad that partially sucks and holds the lower surface of the substrate located above the levitation stage, and a traveling mechanism that causes the suction pad to travel along the levitation stage;
A flow rate control mechanism for controlling an ejection flow rate, which is a flow rate of the gas ejected from the upper surface of the stage per unit time,
The substrate transfer apparatus, wherein the flow rate control mechanism reduces the ejection flow rate at the time of adsorbing the substrate by the adsorption pad, compared to the ejection flow rate before adsorption. The substrate transfer apparatus according to claim 1,
The transport unit includes a suction member provided with a contact surface that partially contacts the lower surface of the substrate and a concave portion in which the suction pad can be embedded,
The suction pad is configured to be stretchable in the vertical direction in a state embedded in the recess,
The suction port of the suction pad protrudes above the contact surface before suction, and retreats into the recess due to suction of the substrate. The substrate transfer apparatus according to claim 2,
The contact surface is provided with an adsorption groove,
The suction groove is a substrate transfer device that sucks the lower surface of the substrate when the suction port of the suction pad moves back into the recess and the contact surface contacts the lower surface of the substrate. A substrate transfer apparatus according to any one of claims 1 to 3,
The flow rate control mechanism is a substrate transfer apparatus that stops the gas ejection when the substrate is adsorbed by the suction pad and sets the ejection flow rate to zero. A substrate transfer apparatus according to any one of claims 1 to 4,
The flow rate control mechanism is configured to increase the ejection flow rate when the adsorption pad that adsorbs the substrate travels along the levitation stage to be larger than the ejection flow rate when the substrate is adsorbed by the adsorption pad. . A substrate transport method for transporting the substrate by running a suction pad that partially sucks and holds the lower surface of the substrate along a levitation stage that jets gas toward the lower surface of the substrate and imparts buoyancy to the substrate. There,
A first step of ejecting the gas from a top surface of the levitation stage at a first ejection flow rate per unit time to levitate the substrate from the levitation stage;
A second step of positioning the suction pad at a position below the substrate so as to partially face the lower surface of the substrate that is levitating from the levitation stage;
The lower surface of the substrate is placed on the lower surface of the substrate with the suction pad positioned at a lower position of the substrate in a state where the ejection flow rate for ejecting gas from the upper surface of the stage per unit time is set to a second ejection flow rate lower than the first ejection flow rate. A third step of partially adsorbing and holding;
A substrate carrying method comprising: It is a board | substrate conveyance method of Claim 6, Comprising:
A fourth step of causing the suction pad holding the lower surface of the substrate to travel along the levitation stage;
In the fourth step, the substrate transfer method in which the jet flow rate per unit time of the gas from the upper surface of the stage is a third jet flow rate larger than the second jet flow rate. A substrate transfer device according to any one of claims 1 to 5,
A coating apparatus comprising: a nozzle that discharges and coats a coating liquid on an upper surface of the substrate transported by the substrate transport apparatus.

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