JP2012119353A - Substrate transfer device and coating applicator using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate transfer device which prevents deformation of substrate that is caused by a suction pad and reduces distortion of a substrate surface in a substrate transfer device that lifts a plate like substrate from an upper surface of a stage, grips part of a substrate lower surface with the suction pad, and transfers the substrate in a predetermined direction, and to provide an apparatus which evenly performs spinless system type application which involves substrate transfer in processing steps.SOLUTION: A substrate transfer device has a measuring apparatus which measures points that are located at different heights on a substrate and include points on a stage and points on a suction pad. The substrate transfer device adjusts the height of a suction pad based on the measurement result of the height, thereby reducing distortion of a substrate surface.

Description

  The present invention relates to a substrate transfer device for transferring a flat substrate in a processing step and a coating apparatus using the same.

  In recent years, in the process of manufacturing a flat substrate such as a driving substrate such as a TFT or a color filter (hereinafter abbreviated as CF) used for a flat panel display such as a liquid crystal display device, a processing substrate is used when performing a process by a photolithography method. In many cases, a spinless coating method suitable for efficient uniform coating on large substrates and large substrates is used.

  In the spinless coating method, the substrate or nozzle is moved in a direction substantially perpendicular to the longitudinal direction of the nozzle while the resist solution is uniformly and continuously discharged from the long slit-like nozzle to the substrate, thereby causing the substrate to move. In this coating method, a resist coating layer having a uniform thickness can be formed in a predetermined region above. As the object to be moved, either a substrate or a nozzle can be used, but when the substrate is a flat plate such as glass, the substrate can be placed on a flat stage and the nozzle can be moved in parallel above the stage. It was the Lord. However, as the size of the substrate increases, the size and weight of the long nozzle increase, so that such a heavy and long resist nozzle can be stably maintained at a constant speed while maintaining the height position above the stage. It has become difficult to translate the substrate surface.

  As described above, the parallel movement of the large nozzle is difficult, but the mechanical difficulty in moving the entire large stage on which the large substrate is placed is also large. Therefore, as shown in Patent Document 1, a flat substrate is used. Has been proposed which floats by an air stream ejected from a number of jets provided on the upper surface of the stage, and grips the peripheral edge along the moving direction of the substrate with a suction pad and transports it by a horizontal drive unit.

FIG. 2 is a schematic view for explaining an example of the conventional substrate floating-type substrate transfer apparatus and the coating apparatus using the same as described above, where (a) is a plan view and (b) is ( It is sectional drawing along the AA 'line of a).
Substrate 3 can be floated to a certain height by jetting air 21 (indicated by block arrows in (b)) jetted from jetting ports 2 provided in large numbers on the upper surface of stage 1. The floating substrate 3 is in a state where it can be easily moved if a slight force is applied in the horizontal direction because the frictional force with the stage 1 does not act. A drive unit 4 movable along the stage 1 is provided in the vicinity of at least one side of the side parallel to the substrate traveling direction of the stage 1, and the suction pad 5 connected to the upper side of the drive unit 4 is the substrate periphery on the lower surface of the substrate 3. If the drive unit 4 is moved by adsorbing the portion, the substrate can be gripped and transferred in the direction indicated by the thick solid arrow. When the substrate transported at a constant speed passes directly below the coating unit 9 composed of the slit-shaped nozzle, a resist solution that is uniformly and continuously discharged from the nozzle can be coated on the substrate. A coating device is configured using the transfer device.

  In the above-described substrate transfer device and a coating apparatus using the same, the distance between the nozzle discharge portion and the substrate surface is constant over the entire width direction by transferring the substrate 3 while keeping the substrate 3 at a uniform height from the surface of the stage 1. It is important to ensure uniform application performance. However, depending on the flying height, the suction pad 5 may be deformed when the suction pad 5 sucks the peripheral edge of the lower surface of the substrate in order to transfer the substrate. Due to this influence, the height of the surface of the substrate deviates from the uniform height at a portion close to the peripheral edge, causing uneven coating in the coating apparatus.

JP 2006-19396 A

  The present invention is proposed in view of the above problems, and the problem to be solved by the present invention is that a flat substrate is lifted from the upper surface of the stage, and a part of the lower surface of the substrate is held by a suction pad. In the substrate transfer device, the substrate transfer device that prevents the deformation of the substrate by the suction pad and reduces the distortion of the substrate surface is provided, thereby enabling spinless coating with substrate transfer in the processing step. It is to provide a uniform device.

  As a means for solving the above-mentioned problem, the invention according to claim 1 is a substrate transfer method in which a flat substrate is lifted from the upper surface of the stage, and a part of the lower surface of the substrate is held by a suction pad and transferred in a predetermined direction. The device has a measuring device that can measure the height of different points on the substrate including on the stage and on the suction pad, and by adjusting the height of the suction pad based on the height measurement result A substrate transfer apparatus that reduces distortion of the substrate surface.

  According to a second aspect of the present invention, there is provided a data analysis unit for analyzing the height measurement result as fluctuation data corresponding to the position in the substrate transfer direction, and the height of the suction pad based on the data analysis result. The substrate transfer apparatus according to claim 1, further comprising a linear slide unit for automatic control.

  According to a third aspect of the present invention, there is provided a coating apparatus in which a spinless type coating unit that operates in synchronization with the substrate transfer is combined with the substrate transfer apparatus according to the first or second aspect.

  In a substrate transfer device that floats a flat substrate from the upper surface of the stage and grips a part of the lower surface of the substrate with a suction pad and transfers it in a predetermined direction, the height of different points on the substrate, including on the stage and on the suction pad A substrate transfer device that has a measuring device that can measure the surface of the substrate and prevents the deformation of the substrate by the suction pad and reduces the distortion of the substrate surface by adjusting the height of the suction pad based on the height measurement result Accordingly, an apparatus for uniformly applying spinless coating with substrate transfer in a processing step can be provided.

It is a schematic cross section for explaining an example of the present invention. It is a schematic diagram for demonstrating the example of the conventional board | substrate transfer apparatus and a coating device using the same, Comprising: (a) is a top view, (b) is the cross section along the AA 'line of (a). FIG. In this invention, it is explanatory drawing for showing the example which detects and correct | amends the abnormal distortion which arises in the board | substrate height on a suction pad by comparing the fluctuation | variation of several measurement data, Comprising: (a) is FIG. (A) Schematic sectional view showing the relationship between the measurement coordinate x corresponding to the measurement position along the BB ′ line and the measurement value y in (a), (b) schematically shows an example of measurement data in which abnormal distortion is detected. The graph shown, (c) is a graph schematically showing a plurality of measurement data examples after correcting the height of the suction pad. It is a schematic cross section for explaining another example of the present invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 shows an example of the substrate transfer apparatus of the present invention in the same direction as the cross-sectional view (b) taken along the line AA ′ of FIG. 2A in order to explain an example of the present invention. It is a schematic cross section in the case.

  The substrate 3 can be lifted to a certain height by the blown air 21 (indicated by a block arrow) blown from the upper surface of the stage 1. The floated substrate 3 can be easily moved by applying a slight force in the horizontal direction. At least one side of the stage 1 is provided with a drive unit 4 that can move in a direction perpendicular to the paper surface along the stage 1, and a suction pad 5 connected above the drive unit 4 via a height adjusting mechanism 50 is provided on the substrate 3. If the drive unit 4 is moved by adsorbing the peripheral edge of the substrate on the lower surface, the substrate can be gripped and transferred in a direction perpendicular to the paper surface.

  Dry air or dry nitrogen can be used as the jet air 21. When used for processing by a photolithography method for the purpose of forming a fine pattern on a substrate, it is particularly preferable to use a clean and temperature-controlled air stream from which foreign particles are removed.

  As a drive system of the drive unit 4, a system capable of acquiring position information from the outside such as a servo motor is used. Further, a plurality of suction pads 5 provided above the drive unit 4 are arranged in a line on the drive unit 4 so that the positions of the pads are clarified. The material of the suction pad 5 can be a flexible silicone rubber or the like, but it is necessary not to leave a mark on the suction surface after the suction is released. Do as appropriate.

  In the present invention, since the suction pad is connected to the drive unit via the height adjusting mechanism, the height of the suction pad 5 can be freely adjusted. The height adjustment mechanism 50 is not limited as long as it can be adjusted in the height direction. For example, if a linear slide unit including a linear servo motor and a linear guide having a linear scale is used, the height adjustment mechanism 50 has a height of about 30 to 50 μm. Adjustment can be performed with an accuracy of several μm.

  As a premise for using the height adjusting mechanism 50, an accurate measurement value of the height position is necessary. The present invention has a measuring device that can measure the height of different points on the substrate including the stage and the suction pad, and adjusts the height of the suction pad based on the measurement result of the height. Thus, distortion of the substrate surface can be reduced. In the example shown in FIG. 1, the distance between the substrate surface in the dotted line direction by the laser displacement meter 6 installed above the substrate on the stage 1 and the laser installed above the substrate on the suction pad 5 near the stage. The distance between the substrate surface in the dotted line direction by the displacement meter 7 is measured, and the height of the suction pad can be adjusted based on the measurement result of each measured value as described later.

  In the above description, the two laser displacement meters 6 and 7 are used, but the present invention is not limited to this configuration. In other words, it is possible to measure the measured values at a plurality of points by moving one laser displacement meter in the horizontal direction in the figure, and it is also possible to move many laser displacement meters along the substrate transfer direction perpendicular to the paper surface. It is also possible to arrange and perform high-speed data processing. However, the configuration of FIG. 1 in which one laser displacement meter is associated along each of a plurality of parallel traveling axes is usually appropriate.

Next, a method for specifically adjusting the height of the suction pad using the substrate transfer apparatus of the present invention having the above-described configuration will be described.
FIG. 3 is an explanatory diagram for showing an example of detecting and correcting an abnormal distortion occurring in the substrate height on the suction pad by comparing fluctuations of a plurality of measurement data in the present invention. Fig. 2A is a schematic cross-sectional view showing a relationship between a measurement coordinate x corresponding to a measurement position along the line BB 'in Fig. 2A and a measured value y of a distance from the displacement meter to the substrate surface; The graph which shows typically the example of measurement data which detected abnormal distortion, (c) is a graph which shows typically the example of several measurement data after correcting the height of a suction pad.

  The substrate 3 having its peripheral portion adsorbed by the three suction pads 5 moves in the left-right direction in FIG. 3A, and moves at a position x in the driving direction x of the substrate passing immediately below the stationary laser displacement meter 7. The measurement value y of the distance from the substrate surface to the substrate surface can be obtained continuously. When this result is displayed in the graph of (b), the measurement data 71 by the laser displacement meter 7 is represented, for example, in a form having three bumps as indicated by a broken line. In addition, measurement data 61 indicated by a solid line also shown in the graph is a position in the driving direction position x of the substrate passing directly under the stationary laser displacement meter 6 along the traveling axis on the stage parallel to the traveling axis on the suction pad. The measurement value y of the distance from the displacement meter 6 to the substrate surface is obtained continuously.

  The two measurement data 61 and 71 are almost identical except for the three bumps of the measurement data 71 by the laser displacement meter 7. The three bumps in this case indicate that the measurement distance 10 from the laser displacement meter when the three suction pads 5 shown in FIG. 3A pass directly under the displacement meter 7 is locally increased. In the driving direction position x where the suction pad 5 is attracted to the substrate 3, the substrate surface is in a lower position than in the other driving direction positions x.

  Next, the height of the suction pad is adjusted by the height adjusting mechanism 50 based on the measurement result of the height. In the case of the above example, correction is performed in the direction of raising the suction pad 5. According to the graph (c) schematically showing the measurement data example after the pad height correction, the three bumps of the measurement data 71 by the laser displacement meter 7 disappear by performing the optimal correction. The measurement data 71 including the measurement distance 11 from the laser displacement meter when the suction pad 5 passes directly under the displacement meter 7 is a stationary laser displacement along the traveling axis on the stage parallel to the traveling axis on the suction pad. It becomes a graph substantially along the measurement data 61 by the total 6, and it can be seen that the abnormal distortion of the substrate 3 as seen from the height of the substrate surface disappeared.

  The adjustment of the height of the suction pad as described above can generally be confirmed by comparing only the measurement data 71 measured by the laser displacement meter 7 before and after the pad height correction. Thus, by comparing with the measurement data 61 of the stationary laser displacement meter 6 along the traveling axis on the stage where the influence of the suction pad height is considered to be relatively small, factors other than the suction pad height can be obtained. This is preferable because it can be evaluated by canceling.

  The local abnormality such as the measurement distance 10 when the suction pad passes directly under the displacement meter is not limited to the bump in the above example, and may be a dent. In this case, the set height of the suction pad 5 is Since it can be interpreted that the distance between the laser displacement meter 7 and the substrate surface is shorter than other places because it is too high, correction is performed in the direction of lowering the suction pad 5.

  Further, in the substrate transfer apparatus of the present invention, if the apparatus automatically adjusts the height of the suction pad by automatically feeding back the measurement result of the height of the substrate surface, the usage method can be made easier and in a shorter time. As a result, it is possible to expect reliable correction. FIG. 4 is a schematic cross-sectional view for explaining another example of the present invention considering the above automation. The measurement result y from the laser displacement meters 6 and 7 is input to the data analysis unit 8 together with the driving direction position x of the measurement point. If a certain rule corresponding to the above description of the height adjustment method is set in the data analysis unit 8 in advance, the height measurement result is analyzed as fluctuation data corresponding to the position in the substrate transfer direction. Determine the direction and reasonable values for the height correction of each suction pad. The result is output to the linear slide unit 51, the linear slide unit is operated, and the suction pad height adjustment is completed.

Further, by utilizing the substrate transfer function for reducing the distortion of the substrate surface of the substrate transfer device of the present invention, a spinless method is combined with the substrate transfer device, and the spinless method is combined with the substrate transfer device. It is possible to provide a coating apparatus that uniformly coats.

DESCRIPTION OF SYMBOLS 1 ... Stage 2 ... Spout 3 ... Substrate 4 ... Drive unit 5 ... Suction pad 6 ... Laser displacement meter (on stage)
7 ... Laser displacement meter (on suction pad)
8 ... Data analysis unit 9 ... Coating unit 10 ... Measurement distance when the suction pad passes directly under the displacement meter (before pad height correction)
11 ... Measurement distance when the suction pad passes directly under the displacement meter (after pad height correction)
21 ... Blowing air 50 ... Height adjustment mechanism 51 ... Linear slide unit 61 ... Measurement data 71 with laser displacement meter 6 ... Measurement data with laser displacement meter 7

Claims (3)

  In a substrate transfer device that floats a flat substrate from the upper surface of the stage and grips a part of the lower surface of the substrate with a suction pad and transfers it in a predetermined direction, the height of different points on the substrate, including on the stage and on the suction pad A substrate transfer apparatus comprising: a measuring device capable of measuring a thickness of the substrate; and adjusting the height of the suction pad based on a height measurement result to reduce distortion of the substrate surface.   A data analysis unit for analyzing the height measurement result as fluctuation data corresponding to the position in the substrate transfer direction and a linear slide unit for automatically controlling the height of the suction pad based on the data analysis result are provided. The substrate transfer apparatus according to claim 1.   3. A coating apparatus comprising a spin-less coating unit that operates in synchronism with substrate transfer in the substrate transfer apparatus according to claim 1.