JP7342680B2 - Light irradiation device and light irradiation method - Google Patents

Description

The present invention relates to a light irradiation device and a light irradiation method, and particularly to a light irradiation device and a light irradiation method that heat a workpiece on a work stage and irradiate it with light.

Conventionally, a technology called photoalignment has been used to align the alignment films of liquid crystal display elements such as liquid crystal panels, and the alignment layer of viewing angle compensation films, in which alignment is performed by irradiating polarized light of a predetermined wavelength. has been done.
In such photo-alignment techniques, methods that use polarized light irradiation and heating in combination have been proposed in recent years.

For example, Patent Document 1 discloses a polarized light irradiation device including a heating mechanism that heats a substrate placed on a stage surface. This technique is a technique that changes the moving speed of the transport stage depending on whether the surface temperature of the substrate is unstable or stable. Specifically, the moving speed of the conveying stage on the return trip is made slower than the moving speed of the conveying stage on the outward trip.

JP 2019-101226 Publication

With the technique described in Patent Document 1, it is extremely difficult to determine what stage movement speed is appropriate when the surface temperature of the substrate is unstable. This is because, whether the condition of the substrate after polarized light irradiation is good or bad, it is difficult to determine whether the cause is the surface temperature of the substrate or the moving speed of the stage. In order to clarify this distinction, it is necessary to repeat experiments with varying stage movement speeds under various temperature conditions, and it takes a great deal of time to determine the optimal stage movement speed.

It is easier to determine the optimum stage movement speed by raising the surface temperature of the substrate to a desired preset temperature and stabilizing it at that temperature before irradiating with polarized light. However, in this case, it is necessary to wait for irradiation with polarized light until the temperature of the substrate stabilizes at a desired temperature. In other words, it is necessary to provide a predetermined waiting time, which reduces the throughput of the device.
Therefore, the present invention provides a light irradiation device and a light irradiation method that heat a workpiece and irradiate it with light, which eliminates the need for long experiments as a preparatory stage, reduces throughput, and increases takt time. An object of the present invention is to provide a light irradiation device and a light irradiation method that can appropriately suppress the phenomenon of irradiation.

In order to solve the above problems, one aspect of the light irradiation device according to the present invention is a light irradiation device that irradiates light onto a workpiece passing through a preset irradiation area, the light irradiation device including a first workpiece placed thereon. , a first stage capable of reciprocating movement on a transport axis passing through the irradiation area, with movement from a first standby position set on one side of the irradiation area toward the irradiation area as an outward movement; A second workpiece, on which a workpiece is placed, is reciprocally movable on a transport axis passing through the irradiation area, with movement from a second standby position set on the other side of the irradiation area toward the irradiation area as an outward movement. a control unit that individually controls movement of the first stage and the second stage so that the first workpiece and the second workpiece alternately pass through the irradiation area; a heating unit provided in each of the first stage and the second stage and capable of heating the workpiece placed thereon, the workpiece being placed in the first stage and the second stage; While one stage is reciprocating, the workpiece placed on the other stage is heated by the heating section.

In this way, a so-called twin stage system is adopted in which two stages on which workpieces are placed are provided and each workpiece is irradiated with light alternately. Thereby, while light is being irradiated to one stage, workpiece replacement work and the like can be performed on the other stage. Therefore, compared to the case where there is only one stage, takt time can be reduced and productivity can be improved.
Further, while the workpiece placed on one stage is being irradiated with light, the workpiece placed on the other stage can be heated by the heating section. Therefore, after the light irradiation to one workpiece is completed, the light irradiation to the other workpiece can be performed without waiting for the temperature of the other workpiece to rise. In this way, it is possible to reduce the waiting time due to heating of the workpiece, so it is possible to suppress a decrease in throughput and an increase in takt time compared to the case where there is only one stage. Furthermore, since the heated workpiece can be irradiated with light, the optimum moving speed of the stage can be easily determined. Therefore, there is no need for long experiments as a preparatory stage.

Further, in the above-mentioned light irradiation device, the temperature of the workpiece placed on the stage is set in advance by the time the stage moving in the forward direction among the first stage and the second stage reaches the irradiation area. It is preferable that the desired temperature is reached.
In this case, since the stage can enter the irradiation area while the temperature of the workpiece is stable, appropriate light irradiation processing can be performed.

Furthermore, in the light irradiation device described above, the control unit adjusts the moving speed of the stage of the first stage and the second stage, which is moving in the outward direction, from the standby position to the irradiation region, in the outward direction. The moving speed of the stage may be slower than the return movement speed from the irradiation area to the standby position.
In this case, it is possible to secure time for the temperature of the workpiece to rise to a desired temperature before the stage enters the irradiation area. Therefore, the stage can enter the irradiation area while the temperature of the workpiece is stable.

The light irradiation device further includes a temperature sensor that detects the temperatures of the first workpiece and the second workpiece, and the control unit controls the temperature of the first stage and the second stage. On the outward journey from the standby position of the moving stage to the irradiation area, if the temperature of the workpiece on the stage moving on the outward journey detected by the temperature sensor is not stable at a preset desired temperature, the outward movement is stopped. The moving speed of the stage may be slower than when the temperature of the workpiece is stable at the desired temperature.
In this way, the stage movement speed on the outward journey from the standby position to the irradiation area is controlled based on the temperature of the workpiece on the stage, so it is possible to ensure that the stage enters the irradiation area with the workpiece temperature stable. can.

Furthermore, the above-mentioned light irradiation device further includes a temperature sensor that detects the temperature of the first workpiece and the second workpiece, and the control unit controls the temperature of the first stage and the second stage. The stage is moved in the outward direction from a standby position to the irradiation area until the temperature of the workpiece on the stage, which is detected by the temperature sensor, is stabilized at a preset desired temperature. The stage may be stopped at a predetermined position before reaching the irradiation area.
In this way, the temperature of the workpiece on the stage can be detected and the stage moving forward can be prevented from entering the irradiation area until the temperature of the workpiece is stabilized. Therefore, the stage can enter the irradiation area while the temperature of the workpiece is reliably stabilized.

Further, in the light irradiation device described above, the control unit may permit the other stage to start moving forward at a timing when one of the first stage and the second stage starts moving backward. It's okay.
In this case, for example, following the backward movement of one stage, the forward movement of the other stage can be started. Therefore, following the light irradiation process on one stage, the light irradiation process on the other stage can be performed, and further reduction in takt time can be realized. Further, since it is possible to avoid a situation in which the two stages move together in the forward direction, interference between the stages can be reliably prevented.

Furthermore, in the above-mentioned light irradiation device, the control unit controls the first stage and the second stage to move within the irradiation area at the same movement speed during outward movement and return movement, The first workpiece and the second workpiece may be irradiated with the light during both forward movement and return movement.
In this way, since light is irradiated during both the outward movement and the return movement, the light irradiation process can be performed without wasting energy. Furthermore, since there is no need to change the stage movement speed within the irradiation area between the forward and return trips, the speed of the stage can be easily controlled.

Furthermore, in the above light irradiation device, the light may be polarized light. In this way, the present invention can also be applied to a polarized light irradiation device that performs optical alignment processing by irradiating polarized light onto a workpiece.
Furthermore, in the above light irradiation device, the polarized light may be polarized light having a wavelength of 365 nm as a main component. In this case, photo-alignment treatment can be performed using a photo-alignment film whose reactivity is improved by heating.

Further, one aspect of the light irradiation method according to the present invention is a light irradiation method of irradiating light onto a workpiece passing through a preset irradiation area, wherein a first workpiece is placed and passing through the irradiation area. A first stage capable of reciprocating and a second workpiece are placed on the conveyance axis, and a first stage is movable back and forth, with movement from a first standby position set on one side of the irradiation area toward the irradiation area as an outward movement. , a second stage capable of reciprocating on a transport axis passing through the irradiation area, with movement from a second standby position set on the other side of the irradiation area toward the irradiation area as an outward movement; When individually controlling the first workpiece and the second workpiece to pass through the irradiation area alternately, one of the first stage and the second stage on which the workpiece is placed; While reciprocating, the workpiece placed on the other stage is heated by the heating section provided on the other stage.

In this way, a so-called twin stage system is adopted in which two stages on which workpieces are placed are provided and each workpiece is irradiated with light alternately. Thereby, while light is being irradiated to one stage, workpiece replacement work and the like can be performed on the other stage. Therefore, compared to the case where there is only one stage, takt time can be reduced and productivity can be improved.
Further, while the workpiece placed on one stage is being irradiated with light, the workpiece placed on the other stage can be heated by the heating section. Therefore, after the light irradiation to one workpiece is completed, the light irradiation to the other workpiece can be performed without waiting for the temperature of the other workpiece to rise. In this way, it is possible to reduce the waiting time due to heating of the workpiece, so it is possible to suppress a decrease in throughput and an increase in takt time compared to the case where there is only one stage. Furthermore, since the heated workpiece can be irradiated with light, the optimum moving speed of the stage can be easily determined. Therefore, there is no need for long experiments as a preparatory stage.

According to the present invention, in the twin stage system, while the workpiece on one stage is being irradiated with light, the workpiece on the other stage is heated, which reduces throughput and increases takt time. can be appropriately suppressed. Furthermore, since the light irradiation process can be performed after the workpiece has been raised to a set temperature, it is easy to set the stage movement speed and there is no need for long experiments as a preparatory stage.

1 is a schematic configuration diagram showing a polarized light irradiation device of this embodiment. FIG. 2 is a schematic cross-sectional view of a polarized light irradiation device. 3 is a flowchart showing a stage speed control processing procedure.

Embodiments of the present invention will be described below based on the drawings.
(First embodiment)
In this embodiment, a polarized light irradiation device that processes a workpiece by irradiating it with polarized light while heating the workpiece will be described. Although this embodiment will be explained using a polarized light irradiation device as an example, it is also applicable to a light irradiation device that does not use polarized light as long as the device performs processing by irradiating light while heating the workpiece. It is possible.

1 and 2 are schematic configuration diagrams showing a polarized light irradiation device 100 of this embodiment. FIG. 1 is a perspective view of the entire polarized light irradiation device 100 viewed from diagonally above, and FIG. 2 is a schematic cross-sectional view of the polarized light irradiation device 100 viewed from the side.
The polarized light irradiation device 100 includes light irradiation units 10A and 10B and a transport unit 20 that transports the workpiece W. Here, the workpiece W is a rectangular substrate shaped into the size of, for example, a liquid crystal panel, on which a photo-alignment film is formed.
The polarized light irradiation device 100 moves the workpiece W in a straight line using the transport unit 20 while irradiating polarized light (polarized light) of a predetermined wavelength from the light irradiation units 10A and 10B, and applies the polarized light to the optical alignment film of the workpiece W. A photo-alignment process is performed by irradiating light.

The light irradiation units 10A and 10B each include a lamp 11 that is a linear light source and a mirror 12 that reflects the light from the lamp 11. Furthermore, the light irradiation units 10A and 10B each include a polarizer 13 disposed on the light emission side. Furthermore, the light emitting units 10A and 10B each include a lamp house 14 that accommodates a lamp 11, a mirror 12, and a polarizer 13.
The light irradiation unit 10A and the light irradiation unit 10B operate in the transport direction (X direction) of the workpiece W with the longitudinal direction of the lamp 11 aligned with the direction (Y direction) orthogonal to the transport direction (X direction) of the workpiece W. are arranged in parallel along the

The specific configuration of the light irradiation units 10A and 10B will be described below.
The lamp 11 is an elongated lamp, and its light emitting portion has a length corresponding to the width of the workpiece W in a direction perpendicular to the transport direction. This lamp 11 is, for example, a high-pressure mercury lamp, a metal halide lamp made of mercury and other metals, and emits ultraviolet light with a wavelength of 200 nm to 400 nm.

As materials for photo-alignment films, there are known materials that are oriented using light with a wavelength of 254 nm, those that are oriented using light with a wavelength of 313 nm, and materials that are oriented using light with a wavelength of 365 nm. In this embodiment, as a photo-alignment film whose reactivity is improved by heating, one that is oriented by light with a wavelength of 365 nm is used. Note that the photo-alignment film may be one that can be oriented with light having a main wavelength of 365 nm. Further, the photo-alignment film used in this embodiment may be any photo-alignment film whose reactivity is improved by heating, and the wavelength of light is not limited to the above.
The type of light source can be selected as appropriate depending on the required wavelength. For example, as a light source, a linear light source in which LEDs or LDs that emit ultraviolet light are arranged in a straight line can also be used. In that case, the direction in which the LEDs and LDs are arranged corresponds to the longitudinal direction of the lamp.

The mirror 12 reflects the emitted light from the lamp 11 in a predetermined direction, and is a trough-shaped condensing mirror with an elliptical or parabolic cross section. The mirror 12 is arranged so that its longitudinal direction coincides with the longitudinal direction of the lamp 11.
The lamp house 14 has a light exit port on its bottom surface through which the light emitted from the lamp 11 and the light reflected by the mirror 12 pass. The polarizer 13 is attached to the light exit of the lamp house 14 and polarizes the light passing through the light exit.

The polarizer 13 has a configuration in which a plurality of polarizers are arranged side by side along the longitudinal direction of the lamp 11. These plurality of polarizers are supported by, for example, a frame or the like.
The polarizer is, for example, a wire grid type polarizing element, and the number of polarizers is appropriately selected depending on the size of the area to be irradiated with polarized light.

The transport unit 20 includes a first stage 21A and a second stage 21B that each hold a workpiece W. These two stages 21A and 21B are flat stages that suck and hold the work W by a method such as vacuum suction. Although each stage 21A, 21B and the workpiece W have a rectangular shape in this embodiment, they are not limited to this, and can have any shape. Further, the present invention is not limited to the structure in which the workpiece W is held by suction on a flat plate-like stage, but may be in a structure in which the workpiece W is held in suction by a plurality of pins.

Furthermore, in order to move the stages 21A and 21B in the X direction, the transport unit 20 is provided between two guides 22A extending along the X direction, which is the moving direction of the stages 21A and 21B, and two guides 22A. It includes an arranged magnet plate 22B and coil modules 23A and 23B.
The two guides 22A and the magnet plate 22B are arranged on the upper surface of an installation stand (not shown). The magnet plate 22B is composed of a plurality of magnets arranged at equal intervals in the X direction with the polarities of adjacent magnetic poles alternately changed. Further, the coil module 23A is attached to the center of the back surface of the stage 21A so as to face the magnet plate 22B, and the coil module 23B is attached to the center of the back surface of the stage 21B so as to face the magnet plate 22B. is attached to. The guide 22A, the magnet plate 22B, and the coil modules 23A and 23B constitute a linear motor drive mechanism.

In this way, stages 21A and 21B are configured to be able to reciprocate in the X direction along guide 22A, which is a common transport axis.
Note that the mechanism for moving stages 21A and 21B in the X direction is not limited to the linear motor drive mechanism described above, and any mechanism may be employed. As a mechanism for moving stages 21A and 21B in the X direction, a mechanism using a ball screw, for example, can also be adopted.

Further, the transport unit 20 includes θ movement mechanisms 24A and 24B that can rotate the stages 21A and 21B in the θ direction (around the Z axis), respectively. That is, stages 21A and 21B are mounted on fixed bases 25A and 25B, respectively, so as to be rotatable in the θ direction, and their rotation angles are adjusted by θ movement mechanisms 24A and 24B.

The movement paths of stages 21A and 21B are designed to pass directly under light irradiation units 10A and 10B. The transport unit 20 is configured to transport the workpiece W to an irradiation area 15 (see FIG. 2) of polarized light by the light irradiation units 10A and 10B, and to allow the workpiece W to pass through the irradiation area 15. Further, the transport section 20 is configured to turn the work W after it has completely passed through the irradiation area 15 and to cause the work W to pass through the irradiation area 15 again. Polarized light is irradiated onto the workpiece W during both the outward movement and the return movement, and the photo-alignment film of the workpiece W is subjected to photo-alignment processing.
The operation of the transport section 20 is controlled by a control section 30 shown in FIG.

Next, the movement section of stages 21A and 21B will be explained using FIG. 2.
The first stage 21A is set from a substrate mounting position (first standby position) P11, which is a workpiece mounting position set on one side of the polarized light irradiation area 15, to the other side of the irradiation area 15. It is possible to reciprocate in the section up to the return position P12. Further, the second stage 21B is positioned across the irradiation area 15 from a substrate mounting position (second standby position) P21, which is a workpiece mounting position set on the opposite side of the irradiation area 15 from the substrate mounting position P11. It is possible to reciprocate in the section up to the turn-back position P22 set on the opposite side from the turn-back position P12.

Here, for the first stage 21A, the movement from the substrate mounting position P11 to the turning position P12 is defined as the outward movement. Similarly, for the second stage, the movement from the board mounting position P21 to the turning position P22 is defined as the outward movement.
Further, the board mounting position is a position where the replacement work and alignment work of the board (work W) placed on the stage are performed, and the turning position is the position between the irradiation area 15 and the board mounting position of the other stage. This is the switching position of the stage from the forward movement to the return movement, which is set between the two positions.

For example, the distance in the X direction of the movement section (P11 to P12) of the first stage 21A and the distance in the X direction of the movement section (P21 to P22) of the second stage 21B can be set to be approximately equal. Further, there is a space between the substrate mounting position P11 of the first stage 21A and the irradiation area 15, which allows the second stage 21B to pass through the irradiation area 15 no matter which posture it is in due to rotational movement in the θ direction. Secure more space. Similarly, between the substrate mounting position P21 of the second stage 21B and the irradiation area 15, the first stage 21A can pass through the irradiation area 15 no matter which posture it is in due to rotational movement in the θ direction. Secure at least 1 minute of space.

Furthermore, in this embodiment, the polarized light irradiation device 100 includes heating means for heating the work W placed on the first stage 21A and the second stage 21B, respectively.
In this embodiment, a case will be described in which cartridge heaters 26A and 26B are used as heating means. Cartridge heaters 26A and 26B are attached to contact stages 21A and 21B, respectively. For example, holes are made in stages 21A and 21B, and cartridge heaters 26A and 26B are fitted into the holes.

The cartridge heaters 26A, 26B generate heat when energized, thereby heating the stages 21A, 21B, and increasing the temperature of the workpiece W placed thereon. The power supplied to the cartridge heaters 26A and 26B can be controlled by the control unit 30.
In other words, the target temperatures of the stages 21A and 21B are set in the control unit 30 in advance, and the control unit 30 controls the cartridge heaters 26A and 26B so that the temperatures of the stages 21A and 21B are stabilized at the target temperatures. The temperature of the work W placed on 21A and 21B is maintained at a desired temperature. Here, the desired temperature of the workpiece W is 50° C. to 100° C., although it depends on the type of photo-alignment film.

The stages 21A and 21B may be provided with temperature sensors 27A and 27B for detecting the temperature of the workpiece W, respectively. In this case, the control unit 30 acquires the temperature of the workpiece W detected by the temperature sensors 27A and 27B, and controls the power supplied to the cartridge heaters 26A and 26B so that the temperature of the workpiece W becomes a desired temperature. Good too.
Note that heaters other than the cartridge heater may be used as the heating means. Further, instead of electrically heating the stages 21A and 21B, the stages 21A and 21B may be heated by flowing hot water or a warmed solution.

The basic operation of the polarized light irradiation device 100 is as follows.
When the polarized light irradiation device 100 is powered on, the control unit 30 supplies power to the cartridge heaters 26A and 26B, and heating of the stages 21A and 21B is started. As a result, the temperatures of stages 21A and 21B rise toward a predetermined target temperature.
When the stages 21A and 21B reach the target temperature, the work W is placed on each stage 21A and 21B at the substrate mounting position, and the stages 21A and 21B start operating. At this time, the temperature of the workpiece W starts increasing from the time it is placed on the stages 21A and 21B, and after reaching a desired temperature, the workpiece W is controlled to stabilize at that temperature.

The first stage 21A is at the substrate mounting position P11, where workpiece W replacement work and alignment work are performed, and after the alignment is completed, it is rotated by the θ movement mechanism 24A. Thereby, the direction of the work W is set in a predetermined direction with respect to the polarization axis of the polarized light.
After that, the first stage 21A starts moving toward the irradiation area 15. Then, when it passes through the irradiation area 15 and reaches the turn-back position P12, it starts to move backward and returns to the substrate mounting position P11. At this substrate mounting position P11, the replacement work and the alignment work of the workpiece W are performed again, and after the alignment is completed, the first stage 21A starts moving toward the irradiation area 15 again. Repeat this action.

Similarly, the second stage 21B performs workpiece W replacement work and alignment work at the substrate mounting position P21, and after the alignment is completed, it is rotated by the θ movement mechanism 24B and starts moving forward toward the irradiation area 15. do. The rotation angle of the second stage 21B at this time may be different from the rotation angle of the first stage 21A. Then, when the second stage 21B passes through the irradiation area 15 and reaches the turn-back position P22, it starts moving backward and returns to the substrate mounting position P21. Repeat this action.

Here, the moving speeds of the stages 21A and 21B can be set to be the same on the outward and return journeys, inside the irradiation area 15, and outside the irradiation area 15, respectively.
However, while the first stage 21A and the second stage 21B are repeatedly moving back and forth on the common conveyance axis as described above, the control unit 30 is configured such that one stage is moved in the forward direction so that the first stage 21A and the second stage 21B do not interfere with each other. While the stage is moving, only the backward movement of the other stage is allowed and the outward movement is prohibited. In this embodiment, at the timing when one stage starts its backward movement, the other stage is allowed to start its outward movement.

The control unit 30 controls each part of the transport unit 20 (see FIG. 1), which is a stage movement mechanism, so as to realize the above-described stage operation. At this time, the control unit 30 acquires the position information of each stage 21A and 21B from a linear scale etc. arranged parallel to the conveyance axis, and calculates speed information of each stage 21A and 21B based on the acquired position information. do. Then, the control unit 30 calculates the target movement position and target movement speed of each stage 21A and 21B based on the acquired position information and the calculated speed information, and outputs this to each part of the transport unit 20.

FIG. 3 is a flowchart showing a stage speed control processing procedure executed by the control unit 30. The process shown in FIG. 3 is a process executed when the control unit 30 controls the moving speed of the first stage 21A.
Regarding the process of controlling the movement speed of the second stage 21B, the "first stage" in the following description will be replaced with "second stage" and the "second stage" will be replaced with "first stage". The explanation is omitted here because it is only necessary to do so.

First, in step S1, the control unit 30 determines whether the first stage 21A is on a return trip. Here, the control unit 30 determines the position and movement direction of the first stage 21A based on the position information of the first stage 21A, and determines whether the first stage 21A is moving in the return direction. judge.

If it is determined in this step S1 that the first stage 21A is on the return trip, the process moves to step S2. On the other hand, if it is determined that the first stage 21A is not on the return trip, that is, on the outbound trip, or is stopped at the substrate mounting position, the process moves to step S3.
In step S2, the control unit 30 sets a target movement speed so that the first stage 21A moves at a preset backward movement speed, outputs this to the movement mechanism of the first stage 21A, and then steps The process moves to S6.

In step S3, the control unit 30 determines whether the second stage 21B is moving on the outward path. Here, the control unit 30 determines the moving direction of the second stage 21B based on the position information of the second stage 21B, and determines whether the second stage 21B is moving in the outward direction. . If it is determined that the second stage 21B is moving in the outward direction, the process moves to step S4, and if it is determined that the second stage 21B is not moving in the outward path, the process moves to step S5. do.

In step S4, the control unit 30 causes the first stage 21A to wait at the substrate mounting position. That is, the control unit 30 sets the target movement speed to 0 to stop the first stage 21A, outputs this to the movement mechanism of the first stage 21A, and then proceeds to step S6.
In step S5, the control unit 30 sets a target movement speed so that the first stage 21A moves at a preset outward movement speed, outputs this to the movement mechanism of the first stage 21A, and then steps The process moves to S6. Note that, as described above, the target movement speed for the outward movement of the first stage 21A may be the same as the target movement speed for the return movement of the first stage 21A.
In step S6, the control unit 30 determines whether or not to end the drive control of the first stage 21A. If it is determined to continue the control, the process returns to step S1; if it is determined to end the control, , the stage speed control process ends.

In this way, the polarized light irradiation apparatus 100 in this embodiment includes two work stages (first stage 21A and second stage 21B) that can reciprocate on the same axis, and the substrate on the work stage ( This is a light irradiation device that employs a so-called twin stage system that alternately irradiates polarized light onto a work W).
In this polarized light irradiation device 100, stages 21A and 21B operate in a state where each stage 21A and 21B is heated to a target temperature by cartridge heaters 26A and 26B, which are heating means.

The first stage 21A carries a workpiece W (hereinafter referred to as workpiece W1) and moves back and forth on the conveyance axis, and performs optical alignment processing by irradiating polarized light onto the workpiece W1 on each of the forward and return journeys. . At this time, the workpiece W1 is stable at a desired temperature.
The first stage 21A advances from the substrate mounting position P11 to the irradiation area 15, and in the irradiation area 15, the forward optical alignment process is performed on the workpiece W1, and then, when it reaches the return position P12 and starts the return movement, The second stage 21B starts moving forward. A workpiece W (hereinafter referred to as workpiece W2) is placed on the second stage 21B, and is heated to a desired temperature. The second stage 21B advances from the substrate mounting position P21 to the irradiation area 15, and enters the irradiation area 15 when the first stage 21A completes the return optical alignment process for the workpiece W1. As a result, the forward optical alignment process is performed on the workpiece W2.

When the first stage 21A returns to the substrate mounting position P11, the workpiece W1 that has undergone the optical alignment process is carried out from the first stage 21A, and the workpiece W3 to be processed next is carried in and placed on the first stage 21A. be done. At this time, the workpiece W3 is heated from the time it is placed on the first stage 21A, and the temperature of the workpiece W3 begins to rise.
Then, when the second stage 21B completes the outward optical alignment process for the workpiece W2, and the second stage 21B reaches the return position P22 and starts the return movement, the first stage 21A on which the workpiece W3 is placed is Start the outward journey. When the second stage 21B completes the return optical alignment process for the workpiece W2, the first stage 21A enters the irradiation area 15 and performs the outward optical alignment process for the workpiece W3.
This operation is repeated alternately between the first stage 21A and the second stage 21B, and the optical alignment process for the workpiece W is performed.

Here, the temperature of the workpiece W3 on the first stage 21A is determined by the optical alignment process on the return trip of the second stage 21B after the workpiece W3 is placed on the first stage 21A at the substrate mounting position P11. The desired temperature is reached and stabilized at that temperature.
In this way, while the second stage 21B is reciprocating and performing the optical alignment process on the workpiece W2, the workpiece W3 on the first stage 21A is heated. Therefore, the temperature of the workpiece W3 can be stabilized at a desired temperature by the time the first stage 21A moving in the forward direction reaches the irradiation area 15.
In other words, the outward optical alignment process for the workpiece W3 can be started in a state where the workpiece W3 is stabilized at a desired temperature. Further, the temperature of the workpiece W3 is maintained at a desired temperature while it is placed on the first stage 21A. Therefore, the reciprocating optical alignment process can be performed on the workpiece W while the temperature of the workpiece W remains stable at a desired temperature.

In addition, in this embodiment, a case has been described in which one stage starts its forward movement at the timing when the other stage starts its backward movement. The forward movement of the other stage may also be started.
The time from the start of the outward movement of each stage 21A, 21B to the completion of the photo-alignment process on the work W on the return path and return to the substrate mounting position depends on the size of the work W and the type of photo-alignment film. , approximately 1 to 2 minutes. Even for a large substrate, 1 to 2 minutes is sufficient time to raise the temperature of the workpiece W to a desired temperature and stabilize it at that temperature.
Therefore, by controlling the stage operation as described above, even if the workpiece is a large substrate, the temperature of the workpiece placed on the stage can be reliably brought to the desired temperature by the time the stage reaches the irradiation area 15. It can be raised and stabilized. Therefore, the photo-alignment process can be reliably performed in a stable state at a desired temperature.

As explained above, the polarized light irradiation device 100 in this embodiment includes the first stage 21A on one side of the irradiation area 15 and the second stage 21B on the other side, and one stage moves back and forth. Then, while the workpiece W (substrate) placed on that stage is being irradiated with the polarized light, the temperature of the workpiece W placed on the other stage is increased to a desired temperature. By the time the polarized light irradiation treatment (optical alignment treatment) on the workpiece W on one stage is finished, the temperature of the workpiece W on the other stage has stabilized at the desired temperature, so the polarized light irradiation treatment on the one stage is completed. After finishing, stable polarized light irradiation processing can be performed on the other stage.

In other words, while the temperature of one workpiece W rises and stabilizes, the other workpiece W is irradiated with polarized light, eliminating waiting time for the device, reducing throughput and lengthening takt time. This can prevent time lag.
Furthermore, by the time the stage moving forward reaches the irradiation area 15, the temperature of the workpiece W placed on the stage has reached the desired temperature, so the stage is moved to the irradiation area while the temperature of the workpiece W is stable. 15 can be entered. In other words, the reciprocal polarized light irradiation process can be performed while the temperature of the workpiece W is stabilized at a desired temperature. Therefore, the speed of movement within the irradiation area 15 can be made the same on the outward and return trips. Further, conditions for determining the optimal speed at which the stage should move in the irradiation area 15 can be easily determined. Therefore, there is no need for a long experiment as a preparatory stage.

Furthermore, while one stage is moving in the outward direction, the other stage is prohibited from starting its outward movement, and at the timing when one stage reaches the turn-around position and starts the return movement, the other stage is stopped in the outward movement. Since the start is permitted, it is possible to avoid a situation in which two stages move together in the outward direction, and interference between the stages can be reliably avoided. Furthermore, since the forward movement of the other stage can be started following the backward movement of one stage, the takt time can be further shortened.

(Second embodiment)
Next, a second embodiment of the present invention will be described.
In the second embodiment, while the moving speed of each stage is constant in the first embodiment described above, the moving speed of the stage on the outward path is controlled according to the temperature of the workpiece W on the stage. It was designed to do so.

The configuration of the polarized light irradiation device 100 in this embodiment is the same as that of the polarized light irradiation device 100 in the above-described first embodiment shown in FIGS. 1 and 2. Furthermore, in the polarized light irradiation device 100 in this embodiment, the control unit 30 executes the stage speed control process shown in FIG. 3 similarly to the first embodiment described above. However, the process of step S5 in FIG. 3 is different from the first embodiment.

When the control unit 30 determines in step S3 of FIG. 3 that the second stage 21B is not moving on the outward path, the control section 30 moves to step S5, sets a target movement speed of the first stage 21A on the outward path, and sets this. It is output to the moving mechanism of the first stage 21A.
At this time, the control unit 30 acquires the temperature of the workpiece W on the first stage 21A detected by the temperature sensor 27A, and determines whether the temperature of the workpiece W is stable at a desired temperature. When the control unit 30 determines that the temperature of the workpiece W is stable at a desired temperature, the control unit 30 moves the first stage 21A at a preset forward movement speed (for example, the same movement speed as the return movement). A target moving speed is set so that the moving speed is set, and this is output to the moving mechanism of the first stage 21A.
On the other hand, if the control unit 30 determines that the temperature of the workpiece W is not stable at the desired temperature, the control unit 30 moves the first stage 21A at a movement speed that is lower than the above-mentioned preset movement speed on the outward path. A target moving speed is set as follows, and this is output to the moving mechanism of the first stage 21A.

In this way, the polarized light irradiation apparatus 100 according to the present embodiment adjusts the moving speed of the stage moving in the outward direction from the substrate waiting position to the irradiation area 15 from the irradiation area of the stage to the substrate waiting position. The moving speed may be slower than the moving speed on the return trip.
In this case, time can be secured for the temperature of the workpiece W to rise to a desired temperature before the stage enters the irradiation area 15. Therefore, the stage can enter the irradiation area 15 while the temperature of the workpiece W is stable. In addition, since the stage on which the workpiece W that has been subjected to the reciprocating polarized light irradiation process is placed can be quickly returned to the substrate standby position, the workpiece W to be processed next can be loaded and placed earlier, and accordingly, The heating time for the workpiece W can be secured.

Further, at this time, the temperature of the workpiece W is detected by the temperature sensor, and based on the detected temperature, the stage moving speed on the outward journey from the substrate standby position to the irradiation area 15 of the stage moving on the outward journey is controlled. Therefore, the stage can enter the irradiation area 15 while the temperature of the workpiece W is reliably stabilized.

Note that in this embodiment, if it is determined in step S5 of FIG. 3 that the temperature of the workpiece W is not stable at the desired temperature, the target moving speed of the first stage 21A is changed to a preset forward path speed. The case where the moving speed is set to be slower than the moving speed has been described. However, regardless of the temperature of the workpiece W, the moving speed of the stage moving in the outward direction from the substrate standby position to the irradiation area 15 may be made slower than the moving speed in the backward direction.
Further, it is only necessary to prevent the stage on which the workpiece W is placed from entering the irradiation area 15 until the temperature of the workpiece W is stabilized at a desired temperature. For example, until the temperature of the workpiece W is stabilized at a desired temperature, The target moving speed of the moving stage may be set to 0 (stopped). At this time, the stage may be stopped at a predetermined position in the section from the substrate mounting position to the irradiation area 15.

(Modified example)
In each of the embodiments described above, the moving speed of the stages 21A and 21B may be changed between inside the irradiation area 15 and outside the irradiation area 15. Specifically, the stages 21A and 21B move within the irradiation area 15 at a first movement speed, and move outside the irradiation area 15 at a second movement speed (maximum movement speed) that is faster than the first movement speed. It may also be controlled to move.
In this case, considering that there may be a movement speed difference between the first stage 21A and the second stage 21B, the irradiation area 15 is The moving speed of the stage traveling outward may be controlled.

For example, when the distance between the stages 21A and 21B is longer than a predetermined distance (nearest distance), the stage moving in the outward direction is controlled to move at a high second moving speed, and the stage When the distance between them is less than or equal to a predetermined distance (nearest distance), the stage moving in the outward direction may be controlled to move at the same moving speed as the stage moving in the backward direction.
In this case, without causing the stages to interfere with each other, immediately after the stage moving in the return path passes the irradiation area 15 (depending on the closest distance, the stage moving in the return path may pass through the irradiation area 15). (b), the stage moving in the forward direction can enter the irradiation area 15, and the optical alignment process can be performed efficiently.

Further, for example, when one stage is moving in the outward direction and the other stage is moving in the backward direction, the other stage may be made to follow the one stage immediately after the start of the outward movement.
In this case, the movement speed of one stage is controlled according to the movement speed of the other preceding stage, and even if the movement speed of the other stage differs depending on the movement section, there is no interference between the stages. This can be reliably prevented from occurring. However, if the purpose is to further shorten the takt time, it is preferable to move the succeeding stages at the high second moving speed until the distance between the stages reaches the closest distance, as described above.

Furthermore, in each of the above embodiments, while one stage is moving in the outward direction, the other stage is prohibited from starting its outward movement. It's okay. For example, while one stage is moving forward, the other stage is directed to a target stop position that is set on the standby position side of the other stage by the closest distance to the turn-around position of one stage. The outward movement may be started. In this case, if one stage is moving forward when the other stage reaches the target stop position, the other stage is stopped at the target stop position until the one stage starts moving backward.
In this case, it is possible to perform optical alignment processing on the two works W more efficiently while reliably preventing interference between the stages.

Furthermore, in each of the above embodiments, a case has been described in which the stage rotates in the θ direction at the substrate mounting position and starts the forward movement after the rotation is completed, but the forward movement is performed while performing the θ rotation You can do it like this. Thereby, the takt time can be further shortened.

Further, in each of the above embodiments, the case where the present invention is applied to a polarized light irradiation device has been described, but the present invention is not limited to this. For example, two stages are configured to be able to reciprocate along the same axis, and the two stages are alternately transported to the light irradiation area from standby positions set on the same axis with the light irradiation area in between. As long as the light irradiation device has the above configuration, the same effects as those of the above embodiments can be obtained by applying the present invention. Examples of such a light irradiation device include a DI (direct image) exposure device and an ultraviolet irradiation device that performs heat curing treatment using ultraviolet rays.

10A, 10B...Light irradiation part, 11...Discharge lamp, 12...Mirror, 13...Polarizer, 14...Lamp house, 15...Irradiation area, 20...Transportation part, 21A...First stage, 21B...Second stage , 22A...Guide, 22B...Magnetic plate, 23A, 23B...Coil module, 24A, 24B...θ movement mechanism, 26A, 26B...Cartridge heater, 27A, 27B...Temperature sensor, 30...Control unit, 100...Polarized light irradiation device

Claims (15)

A light irradiation device that irradiates light onto a workpiece passing through a preset irradiation area,
A first workpiece is placed thereon, and is capable of reciprocating movement on a transport axis passing through the irradiation area, with movement from a first standby position set on one side of the irradiation area toward the irradiation area as an outward movement. the first stage and
A second workpiece is placed thereon, and is capable of reciprocating movement on a transport axis passing through the irradiation area, with movement from a second standby position set on the other side of the irradiation area toward the irradiation area as an outward movement. second stage and
a control unit that individually controls movement of the first stage and the second stage so that the first workpiece and the second workpiece alternately pass through the irradiation area;
a heating unit provided in each of the first stage and the second stage and capable of heating the placed work;
While one stage of the first stage and the second stage on which the work is placed is reciprocating, the work placed on the other stage is heated by the heating section. Characteristic light irradiation device. The temperature of the workpiece placed on the stage has reached a preset desired temperature by the time one of the first stage and the second stage that moves outward reaches the irradiation area. The light irradiation device according to claim 1, characterized in that: The control unit includes:
The moving speed of the reciprocating stage of the first stage and the second stage on the outward path from the standby position to the irradiation area is set to the moving speed of the reciprocating stage on the return path from the irradiation area to the standby position. 3. The light irradiation device according to claim 1, wherein the light irradiation device has a moving speed slower than that of the light irradiation device. further comprising a temperature sensor that detects the temperature of the first workpiece and the second workpiece,
The control unit includes:
When the reciprocating stage of the first stage and the second stage moves on an outgoing path from the standby position to the irradiation area, the workpiece on the stage moving on the outgoing path detected by the temperature sensor If the temperature of the workpiece is not stable at a preset desired temperature, the moving speed of the stage moving on the outward path is made slower than when the temperature of the workpiece is stable at the desired temperature. The light irradiation device according to claim 1 or 2 . When a reciprocating stage of the first stage and the second stage moves on an outgoing path from the standby position to the irradiation area, the control unit moves the outgoing path detected by the temperature sensor. When the temperature of the workpiece on the stage is stable at a preset desired temperature, the moving speed of the stage moving on the outward path is changed so that the stage moves on the return path from the irradiation area to the standby position. 5. The light irradiation device according to claim 4, wherein the light irradiation device is set to the same moving speed as the current moving speed. further comprising a temperature sensor that detects the temperature of the first workpiece and the second workpiece,
The control unit includes:
On an outgoing path from a standby position of a reciprocating stage of the first stage and the second stage to the irradiation area, a temperature of a workpiece on the stage moving on the outgoing path detected by the temperature sensor is set in advance. The stage according to any one of claims 1 to 5 , characterized in that the stage moving on the outward path is stopped at a predetermined position before reaching the irradiation area until the stage is stabilized at a desired desired temperature. Light irradiation device. The control unit includes:
7. Any one of claims 1 to 6 , wherein at the timing when one of the first stage and the second stage starts backward movement, the other stage is allowed to start outward movement. The light irradiation device described in section. The control unit includes:
Controlling the first stage and the second stage to move within the irradiation area at the same movement speed during outward movement and return movement,
The light irradiation device according to any one of claims 1 to 7 , wherein the light irradiation device irradiates the first workpiece and the second workpiece with the light during both outward movement and return movement. . 9. The light irradiation device according to claim 1, wherein the light is polarized light. The light irradiation device according to claim 9 , wherein the polarized light has a wavelength of 365 nm as a main component. A light irradiation method that irradiates a workpiece passing through a preset irradiation area with light,
A first workpiece is placed thereon, and is capable of reciprocating movement on a transport axis passing through the irradiation area, with movement from a first standby position set on one side of the irradiation area toward the irradiation area as an outward movement. A first stage and a second workpiece are placed on the transport axis passing through the irradiation area, and are moved toward the irradiation area from a second standby position set on the other side of the irradiation area. When separately controlling a second stage capable of reciprocating movement so that the first workpiece and the second workpiece alternately pass through the irradiation area,
While one of the first stage and the second stage on which a work is placed is reciprocating, the work placed on the other stage is heated by heating the work placed on the other stage. A light irradiation method characterized by heating parts. The moving speed of the reciprocating stage of the first stage and the second stage on the outward path from the standby position to the irradiation area is set to the moving speed of the reciprocating stage on the return path from the irradiation area to the standby position. 12. The light irradiation method according to claim 11, wherein the light irradiation method is made slower than the moving speed of . When the reciprocating stage of the first stage and the second stage moves on an outgoing path from a standby position to the irradiation area, the temperature of the workpiece on the stage moving on the outgoing path is at a preset desired temperature. 12. If the temperature of the workpiece is not stable at the desired temperature, the moving speed of the stage moving on the forward path is made slower than when the temperature of the workpiece is stable at the desired temperature. Light irradiation method. When the reciprocating stage of the first stage and the second stage moves on an outgoing path from the standby position to the irradiation area, the temperature of the workpiece on the stage that moves on the outgoing path is set in advance. When the temperature is stable at the desired temperature, the moving speed of the stage moving on the outward path is set to the same moving speed as the moving speed when the stage moves on the returning path from the irradiation area to the standby position. The light irradiation method according to claim 12, characterized in that: When a reciprocating stage of the first stage and the second stage moves on an outgoing path toward the irradiation area from a standby position, the temperature of the workpiece on the stage that moves on the outgoing path is at a preset desired temperature. The light irradiation method according to any one of claims 11 to 14, characterized in that the stage moving on the outward path is stopped at a predetermined position before reaching the irradiation area until the temperature stabilizes at a temperature of . .

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