JP2009168507A - Method and apparatus for detecting edge position of transparent substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an edge position detection method and an edge position detection apparatus of transparent substrates capable of detecting the edge positions of transparent substrates without contact nor having to apply any special processing to the substrates and reducing costs. <P>SOLUTION: The edge position detection apparatus 10 of a transparent substrate W is provided with a substrate holding part 11 capable of holding the transparent substrate W and provided with marks 12 extending in directions intersecting with edges of the substrate W; an imaging means 13 for imaging the marks 12 and the substrate W through the use of light refraction; and a position detection means 14 for detecting the edge positions of the substrate W on the basis of positional information on border parts between images of marks 12 imaged by the imaging means 13 through the substrate W and images of marks 12 imaged outside the edges of the substrate W. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a transparent substrate edge position detection method and an edge position detection device, and, for example, an edge position detection method and an edge position detection device for a transparent substrate for liquid crystal display devices in proximity exposure when pre-aligning the transparent substrate. About.

  In the proximity exposure, a transparent glass substrate coated with a photosensitive agent on the surface is held on the substrate stage of the proximity exposure apparatus, and the substrate is brought close to the mask held on the mask holding frame of the mask stage so that a gap between the two is obtained. For example, the pattern drawn on the mask is exposed and transferred onto the substrate by irradiating the exposure light toward the mask with an irradiation device from the side away from the substrate of the mask. It is a thing.

  By the way, the substrate is transported to the exposure apparatus and held on the substrate stage, but pre-alignment for positioning the substrate with respect to the substrate stage in advance is performed before the transport. That is, high-precision positioning of the substrate with respect to the substrate stage is performed after loading into the exposure apparatus. If the amount of shift of the substrate loading position into the exposure apparatus is too large, is this high-precision positioning difficult? Or it will take a long time. In order to avoid this, pre-alignment is performed.

  At the time of this pre-alignment, the positions of a plurality of edges of the substrate held on the substrate holding table of the pre-alignment apparatus are detected, and the deviation amount of the substrate is obtained from the detection result, and the substrate holding table is set according to the deviation amount. The substrate is moved relative to the substrate stage of the exposure apparatus by the driving means. Then, the substrate pre-aligned by the pre-alignment apparatus is transported to the exposure apparatus by the loader, and is sucked and held on the substrate stage.

Further, when detecting the edge position of the substrate for the liquid crystal color filter, it is necessary to detect the edge position without contact with the substrate in order to prevent the substrate from cracking and dust generation.
As a method for detecting the edge position of the substrate in a non-contact manner, for example, light is emitted from above by a light emitting sensor toward the edge of the substrate, and the irradiated light is received by a light receiving sensor disposed below the edge of the substrate. A method of receiving light and detecting the edge position of the substrate based on the light reception result has been proposed (for example, see Patent Document 1).

Further, a method is known in which the edge of the substrate held on the substrate holding table is imaged by a camera or the like and the edge position of the substrate is detected based on the captured image.
JP-A-5-326361

  However, in Patent Document 1, since it is necessary to dispose the light emitting sensor and the light receiving sensor above and below the substrate, the number of sensors increases and the cost increases. Further, since the substrate holding table is designed to be smaller than the substrate in order to transmit light, the holding of the edge portion may become unstable.

  Furthermore, when imaging the edge of the substrate with a camera or the like, since the edge is not optically visible on a transparent substrate, it is necessary to make the edge optically visible by chamfering the edge. Similar to the above, the cost increases.

  The present invention has been made to eliminate such inconveniences, and its purpose is to detect the edge position of a transparent substrate in a non-contact manner without performing special processing on the substrate, An object of the present invention is to provide a transparent substrate edge position detection method and an edge position detection apparatus capable of reducing the cost.

The above object of the present invention is achieved by the following configurations.
(1) A method for detecting an edge position of a transparent substrate held by a substrate holding unit,
Holding the substrate on the substrate holding portion such that an edge extends in a direction intersecting with a mark provided on the substrate holding portion;
The mark and the substrate are imaged using light refraction, and based on positional information of a boundary between the image of the mark passing through the substrate and the image of the mark outside the edge of the substrate Detecting an edge position of the substrate;
A method for detecting an edge position of a transparent substrate.
(2) The substrate holding portion is provided with at least two marks that can intersect one edge of the substrate on a rectangle and at least one mark that can intersect another edge that is orthogonal to the one side. And
2. The position of the substrate is measured by detecting the edge position of the substrate by imaging each of the at least three marks together with the substrate in the edge position detecting step. Edge position detection method for transparent substrate.
(3) a substrate holding part that can hold a transparent substrate and has a mark that extends so as to intersect with an edge of the held substrate;
Imaging means for imaging the mark and the substrate using refraction of light;
Position detecting means for detecting an edge position of the substrate based on position information of a boundary portion between an imaged image of the mark passing through the substrate by the imaging means and an imaged image of the mark outside the edge of the substrate;
A device for detecting an edge position of a transparent substrate.
(4) The substrate holding portion is provided with at least two marks that can intersect one edge of the substrate on a rectangle and at least one mark that can intersect another edge that is orthogonal to the one side. And
The imaging means is arranged to be inclined with respect to a direction orthogonal to the substrate holding surface of the substrate holding unit, and images at least three marks and the substrate using light refraction, respectively. Having means,
The position detection means measures the position of the substrate based on the position information obtained by the at least three image pickup means, and the edge position detection device for a transparent substrate according to (3).
(5) The transparent substrate is a substrate for a liquid crystal display device,
The transparent substrate edge position detection apparatus according to (3) or (4), wherein the substrate holding unit, the imaging unit, and the position detection unit are provided in a pre-alignment apparatus that performs pre-alignment of the substrate. .

  According to the edge position detection method and the edge position detection apparatus of the transparent substrate of the present invention, the mark and the substrate are imaged using refraction of light, and the captured image of the mark passing through the substrate and the mark outside the edge of the substrate Since the edge position of the substrate is detected based on the position information of the boundary with the captured image, the edge position of the transparent substrate can be detected in a non-contact manner without performing special processing on the substrate. Cost can be reduced.

  Hereinafter, an embodiment according to an edge position detection method and an edge position detection apparatus of a transparent substrate of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic plan view showing the arrangement of a pre-alignment apparatus, a proximity exposure apparatus and a loader to which the edge position detection apparatus for a transparent substrate of the present invention is applied, FIG. 2 is a side view showing an example of the proximity exposure apparatus, and FIG. 4 is a diagram showing a pre-alignment apparatus.

  As shown in FIG. 1, the pre-alignment apparatus 20 including the transparent substrate edge position detection apparatus 10 according to the present embodiment is disposed outside the proximity exposure apparatus PE, and is a transparent substrate carried by a loader 40 from a stocker (not shown). The substrate W is held and pre-alignment of the substrate W is performed. The pre-aligned substrate W is transported to the proximity exposure apparatus PE by a loader 40 and sucked and held on a substrate stage 3 described later.

  First, for convenience of explanation, the proximity exposure apparatus PE will be described. As shown in FIG. 2, the proximity exposure apparatus PE uses a mask M smaller than the substrate W as an exposure material, and uses the mask M of the mask stage 1. While being held by the mask holding frame 2, the substrate W is held by the substrate stage 3. In this state, the substrate stage 3 is moved stepwise with respect to the mask M in two axial directions, ie, the X-axis direction and the Y-axis direction, and the mask M and the substrate W are placed close to each other and opposed to each other. By irradiating light for pattern exposure from 4 toward the mask M, a plurality of patterns of the mask M are exposed and transferred onto the substrate W.

  In FIG. 2, reference numeral 5 denotes an apparatus base. On this apparatus base 5, an X-axis stage feed mechanism 6 for stepping the substrate stage 3 in the X-axis direction is installed, and on the X-axis stage feed mechanism 6 A Y-axis stage feed mechanism 7 for moving the substrate stage 3 stepwise in the Y-axis direction is installed, and the substrate stage 3 is installed on the Y-axis stage feed mechanism 7.

  Between the Y-axis stage feed mechanism 7 and the substrate stage 3, the clearance between the mask M and the substrate W is measured to a preset position by performing a simple vertical movement of the substrate stage 3. There are provided a vertical coarse movement device 8 that moves up and down and a vertical fine movement device 9 that finely moves the substrate stage 3 up and down to finely adjust the gap between the opposing surfaces of the mask M and the substrate W to a predetermined amount.

  Next, the pre-alignment device 20 on which the edge position detection device 10 is mounted will be described in detail with reference to FIGS. The pre-alignment apparatus 20 includes a substrate holding unit 11 that can hold a transparent substrate W and can move in the X, Y, and θ (oscillation around the Z axis) directions with respect to the base 21. On the upper surface of the substrate holder 11, a linear mark 12 extending in a direction intersecting with the edge of the substrate W is provided.

  As shown in FIG. 3, the board | substrate holding | maintenance part 11 is connected with the drive table 23 via the several connection part 22 provided in the lower surface. In the drive table 23, an X-direction drive mechanism 24 is fixed to an intermediate portion on one side surface in the X direction, and a pair of Y-direction drive mechanisms 25 and 26 are fixed to end portions on both side surfaces in the X direction. The substrate holding unit 11 moves in the X, Y, and θ directions together with the drive table 23 by driving the motors 24a, 25a, and 26a of the X direction drive mechanism 24 and the Y direction drive mechanisms 25 and 26, respectively.

  Further, a pin holding table 27 having a plurality of pins (not shown) fixed on the upper surface is provided between the substrate holding unit 11 and the drive table 23. A pin driving mechanism 28 shown in FIG. 4 is attached to the pin holding table 27. By driving a motor 28a of the pin driving mechanism 28, the pin holding table 27 is interposed via an arm 29 bent in a dogleg shape. Is driven in the Z direction, and the pin is advanced and retracted from the upper surface of the substrate holding part 11.

  As a result, the loader 40 on which the substrate W is placed places the substrate W on the pins, and the substrate W is sucked and fixed by the suction cups provided on the heads of the pins with negative pressure. Then, after the loader 40 is retracted, the pins are lowered to hold the substrate W on the substrate holding unit 11.

  Further, the mark 12 extends in a direction orthogonal to the edge along the Y-axis direction of the substrate W and is separated from each other in the Y-axis direction when the substrate W is accurately positioned on the substrate holding base 11. In addition, two places are arranged, and one place is arranged so as to cross and extend in a direction orthogonal to the edge along the X-axis direction of the substrate W.

  A camera (imaging means) 13 is provided above the substrate holding table 11 to image the marks 12 on the substrate holding table 11 obliquely from above. Three cameras 13 are installed corresponding to the number of marks 12, and the three cameras 13 are arranged so that their imaging optical axes are directed near the position where the corresponding mark 12 intersects the substrate W. Thus, the mark 12 and the substrate W are imaged.

  The three cameras 13 detect the edge position of the substrate W based on the position information of the boundary between the captured image of the mark 12 that has passed through the substrate W and the captured image of the mark 12 outside the edge of the substrate W. Connected to the control device 14 (position detecting means).

  FIG. 5 is a diagram illustrating an image when the mark 12 on the substrate holding table 11 is imaged by the camera 13, and (a) is a captured image of the mark 12 in a state where the substrate W is not held on the substrate holding table 11. FIG. 6B is a diagram illustrating a captured image of the mark 12 in a state where the substrate W is held on the substrate holding table 11.

  As can be seen from FIG. 5B, in the state where the substrate W is held on the substrate holding table 11, the captured image of the mark 12 that has passed through the substrate W by the camera 13 is the light refracting action by the transparent substrate W. Thus, the image appears to be shifted from the captured image of the mark 12 outside the edge of the substrate W. Therefore, the boundary between the captured image of the mark 12 through the substrate W by the camera 13 and the captured image of the mark 12 outside the edge of the substrate W can be detected as the edge position of the substrate W.

  The detection of the edge position of the substrate W is executed by the control device 14 based on the image data captured by the camera 13. Further, the control device 14 calculates a deviation amount with respect to a preset reference position of the substrate W from the detected edge position information of the substrate W, and drives the driving mechanisms 24, 25, and 26 according to the deviation amount. The position of the substrate W is corrected so that the position of the substrate W becomes the reference position by moving the substrate holder 11 in the X, Y, θ (oscillation around the Z axis) direction.

  As described above, according to the present embodiment, when the mark 12 is imaged together with the transparent substrate W, the captured image of the mark 12 through the substrate W and the captured image of the mark 12 outside the edge of the substrate W are displayed. Since the edge position of the substrate W can be detected based on the boundary position information, the edge position of the transparent substrate W is detected in a non-contact manner without performing special processing such as chamfering on the edge of the substrate W. be able to.

  Further, since the edge position of the transparent substrate W can be detected based on the image data obtained by the camera 13 installed above the substrate holding table 11, a light receiving sensor or the like is provided below the substrate holding table 11 as in the prior art. In combination with the fact that no special processing such as chamfering is required on the edge of the substrate W, the cost can be reduced.

In addition, this invention is not limited to what was illustrated to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.
For example, in the above embodiment, the case where the edge position detection device of the present invention is mounted on the pre-alignment device 20 is illustrated, but the present invention is not limited to this, and the present invention is not limited to a proximity exposure device or a pre-alignment device for an exposure device. You may make it mount an edge position detection apparatus.
The substrate of the present invention may be a transparent substrate, and for a liquid crystal display device, not only the above-described color filter substrate but also an array substrate.

It is a schematic plan view which shows arrangement | positioning of a pre-alignment apparatus provided with the edge position detection apparatus of the transparent substrate which is an example of embodiment of this invention, a proximity exposure apparatus, and a loader. It is a figure for demonstrating an example of a proximity exposure apparatus. It is a side view of a pre-alignment apparatus. It is the bottom view which looked at the pre-alignment apparatus from the base side. It is a figure which shows the image at the time of imaging the mark provided in the board | substrate holding stand with a camera, (a) is a figure which shows the picked-up image of the mark in the state in which the board | substrate is not hold | maintained at a board | substrate holding stand, (b). FIG. 5 is a diagram showing a captured image of a mark in a state where the substrate is held on the substrate holding table.

Explanation of symbols

W substrate (transparent substrate)
10 Edge position detection device 11 Substrate holder (substrate holder)
12 mark 13 camera (imaging means)
14 Control device (position detection means)

Claims (5)

A method for detecting the edge position of a transparent substrate held by a substrate holding unit,
Holding the substrate on the substrate holding portion such that an edge extends in a direction intersecting with a mark provided on the substrate holding portion;
The mark and the substrate are imaged using light refraction, and based on positional information of a boundary between the image of the mark passing through the substrate and the image of the mark outside the edge of the substrate Detecting an edge position of the substrate;
A method for detecting an edge position of a transparent substrate. The substrate holding portion is provided with at least two marks that can intersect one edge of the substrate on a rectangle and at least one mark that can intersect another edge that is orthogonal to the one side. ,
2. The position of the substrate is measured by detecting the edge position of the substrate by imaging each of the at least three marks together with the substrate in the edge position detecting step. Edge position detection method for transparent substrate. A substrate holding part capable of holding a transparent substrate and having a mark extending so as to intersect with an edge of the held substrate;
Imaging means for imaging the mark and the substrate using refraction of light;
Position detecting means for detecting an edge position of the substrate based on position information of a boundary portion between an imaged image of the mark passing through the substrate by the imaging means and an imaged image of the mark outside the edge of the substrate;
A device for detecting an edge position of a transparent substrate. The substrate holding portion is provided with at least two marks that can intersect one edge of the substrate on a rectangle and at least one mark that can intersect another edge that is orthogonal to the one side. ,
The imaging means is arranged to be inclined with respect to a direction orthogonal to the substrate holding surface of the substrate holding unit, and images at least three marks and the substrate using light refraction, respectively. Having means,
4. The transparent substrate edge position detection apparatus according to claim 3, wherein the position detection unit measures the position of the substrate based on the position information obtained by the at least three imaging units. The transparent substrate is a substrate for a liquid crystal display device,
The transparent substrate edge position detection apparatus according to claim 3, wherein the substrate holding unit, the imaging unit, and the position detection unit are provided in a pre-alignment apparatus that performs pre-alignment of the substrate.

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