JP2003017545A - Method and apparatus for positioning substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fully cope with the shift to a larger and thinner plate of a substrate, finer and more precise process, and less dust in process, and positioning at high-speed and reliably. SOLUTION: A position and an inclination of a substrate 4 which are supported by a supporting means 20 from bottom thereof are imaged by cameras 10 at angles R and S, which are opposite with each other, for image recognition, and when a deviation in position or an inclination is recognized, the substrate 4 is positioned to a predetermined location by moving the supporting means 20 in the direction of X or Y axis, or around Z axis. At this time, intersections of an extension of a line connecting two points on one of the two sides in the substrate forming angles of the substrate 4 and an extension of a line connecting two points on other side are recognized as angles R and S, and image recognition is performed, based on which the substrate is positioned, thus above purpose is achieved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for positioning a substrate in a load lock chamber of a vacuum processing apparatus, and is used in a process of processing a liquid crystal panel, an organic EL substrate or the like.

[0002]

2. Description of the Related Art Conventionally, in a load lock chamber of a vacuum processing apparatus used for vacuum processing of a liquid crystal substrate in a liquid crystal panel manufacturing process, as shown in FIG. Rotating shafts c are introduced from the outside through a rotation introducing portion b sealed with an oil seal or the like at corresponding positions, and each rotating shaft c can be driven in both forward and backward directions by an external rotary actuator d.
By rotating the rotary shafts c forward and backward, a pair of rollers f are synchronously moved toward and away from each rotary shaft via a lever g.
As shown in FIG. 5, the corners of the substrate a are simultaneously clamped and positioned.

[0003]

However, a glass substrate a used for a liquid crystal substrate or the like in recent years is, for example, 680 mm ×
Large format such as 880 mm and 730 mm × 920 mm,
Further, the thickness is as thin as about 0.7 mm, and in the positioning state where the substrate a is clamped from the periphery as in the conventional case, the substrate a bends and accurate positioning cannot be performed. In the rotary actuator d, it is difficult to synchronize and separate the respective rollers f, and the substrate a cannot be positioned with a uniform movement, and the substrate a may ride on the roller f. Even if proper positioning can be performed by improving the support method of the substrate a, the reliability is sufficiently high, such as damage to the back surface of the highly precise device due to the clamp method and the possibility of dust generation. There is a problem that cannot be secured.

Therefore, the present applicant has previously proposed a substrate positioning method and apparatus for solving such a problem (Japanese Patent Laid-Open No. 2001-006587). Referring to FIG. 2 showing an embodiment of the present invention, this is a load lock chamber in which the diagonal corners of the substrate 4 supported by the supporting means 20 are sandwiched by the substrate 4. The images are taken by the camera 10 and the illuminator 13 arranged on the opposite atmosphere side of No. 2, and the position and the inclination of the substrate 4 are image-recognized from the diagonal corners of the substrate 4 at that time, and there is a position shift or inclination. And support means 2
Positioning is carried out at a predetermined position by at least one of two movements in the X- and Y-axis directions orthogonal to each other on the horizontal plane of 0 and a rotation about the Z-axis perpendicular to these.

As a result, the substrate 4 can be made larger, thinner, finer in process, finer, and less dusty than the conventional ones. However, when the inventors of the present invention conducted various experiments and studies for further correspondence, there was an erroneous recognition of the substrate shape due to the bending of the glass substrate 4, and the edge of the substrate and the shape of the side surface of the substrate were erroneously recognized. Even if there are some manufacturing errors, we can not cope unless we have various pattern recognition methods corresponding to them.
It has been a problem that accurate image recognition takes time.

Further, in the processing of the recognized image, the edge shape of the board image (shadow of the board) varies depending on the degree of bending of the board and the chamfered shape of the board, and the system is complicated to select the difference by image recognition. There is also a problem to do. Further, if the thin support pins 14a are used to support the substrate from below with a small contact area, the substrate is slipped during the high-speed positioning operation of the supporting means 20, and the back surface of the substrate is scratched, resulting in a defective product. Particles are generated due to contact or scratches. Further, the larger and thinner the substrate is, the warp exceeding the limit occurs due to the supporting condition, and a large vertical clearance is required between the transfer mechanism such as an arm (not shown) and the supported substrate 4.

Based on such new knowledge, the object of the present invention is to sufficiently cope with the large size of the substrate, the thinning of the substrate, the miniaturization of the process, the high definition and the low dust, and the high speed and reliability. It is an object of the present invention to provide a substrate positioning method and device that can perform good positioning.

[0008]

In order to achieve the above object, the substrate positioning method of the present invention transfers a substrate between the vacuum processing chamber and the outside while maintaining the vacuum state of the vacuum processing chamber. In the load lock chamber for moving the substrate, which is transferred from the outside or the vacuum processing chamber, can be moved in two X and Y axis directions orthogonal to each other on a horizontal plane and can be rotated about a Z axis perpendicular to them. Is supported from below, the position and tilt of the supported substrate are recognized by an image of the substrate captured by a camera, and when there is a displacement or tilt of the substrate position recognized as the predetermined position of the substrate, the X and Y axes of the supporting means are detected. Positioning the substrate at a predetermined position by at least one of movement in the direction and rotation about the Z axis, and a line segment connecting two points on one side of the two sides of the substrate forming a corner of the substrate. Extension line and 2 on the other side Is mainly characterized in that the intersection points where the extension line of the line segment crossing are aware that a corner of the substrate connecting performs the image recognition and positioning based thereon.

In such a structure, in the load lock chamber, the substrate transferred from the outside or from the vacuum processing chamber is supported from below by the supporting means, and the substrate thus supported is imaged by the camera according to the position and inclination thereof. The substrate is positioned by at least one of the movement of the supporting means itself in the two directions of the X and Y axes which are orthogonal to each other on the horizontal plane and the rotation about the Z axis which is perpendicular to these, and is transferred to the vacuum processing chamber or the outside. Can be used for vacuum processing and storage in cassettes,
There is no need to apply a load to the board for positioning, which is the case with the clamp method, and accurate positioning can be achieved by making the board large or thin, and it may damage the board or cause dust to be generated. The positioning reliability is improved.

In particular, in handling a rectangular substrate, an extended line segment connecting two points on one side and two line segments connecting two points on another side of two sides forming a corner. Since the position of the board is recognized from the two-point detection data for each side with the intersection of the extension line and the corner as a corner, there is a slight manufacturing error in the two edges forming the corner of the board or the shape of the side surface. Even if there is a change in the edge shape of the board image due to the warp of the board, the chamfering of the corners, and the difference in the chamfered shape, it is not affected as much as when recognizing from the edge line detection data. Even with pattern recognition, the number of times of erroneous recognition and re-recognition due to it is reduced, and the substrate can be positioned with high accuracy in a short time.

As a positioning device for achieving such a method, a substrate is placed outside or in a load lock chamber for transferring the substrate between the vacuum processing chamber and the outside while maintaining the vacuum state of the vacuum processing chamber. Supporting means for supporting the substrate transferred from the vacuum processing chamber from below, moving in two X and Y axis directions orthogonal to each other on a horizontal plane, and rotating about a Z axis perpendicular to them, and by this supporting means From the camera that captures the image of the substrate to be supported for image recognition, and the image data captured by the camera, one of the two sides forming the corner of the substrate
A calculation for recognizing the intersection of an extension line of a line segment connecting two points on one side and an extension line of another line segment connecting two points on one side as a corner of the substrate and calculating the position and inclination of the substrate. Means and a control means for positioning the substrate at a predetermined position by at least one of movement of the supporting means in the X and Y axis directions and rotation about the Z axis when the substrate is displaced or tilted as a result of the calculation. It is sufficient and the above method can be automatically and stably achieved.

At the time of positioning based on image recognition when at least one of the detection points is applied to the part where the corner of the substrate is lacking, image recognition is performed again for the position and tilt of the substrate, and if there is a displacement or tilt of the position. Proper positioning is performed by recognition that employs a method that can cope with chipped corners of the board such as shifting the detection point while preventing the positioning operation from being unnecessarily performed due to incorrect recognition results by performing the positioning operation. You can

When recognizing an image by image pickup, by illuminating the substrate on the side opposite to the camera from a position 115 mm to 135 mm away from the substrate, the substrate can be clearly displayed on the image pickup screen, and the position and inclination of the substrate can be detected. The speed and detection accuracy can be increased.

When a substrate having an area of 660 × 880 mm or more is handled, if the deflection of the substrate is suppressed to 7 mm or less and the substrate is supported, the accuracy of recognizing the corner of the substrate is not affected and the detection speed and the detection accuracy are further improved. You can

It is easy to guarantee that the deflection is suppressed to 7 mm or less by supporting a total of 6 places, that is, one place in the center of each long side and two places in the center of each short side. If 6 parts of the substrate are supported by elastic members, even if they are supported with a small contact area with the substrate, slippage is unlikely to occur and scratches will not occur. Therefore, it is possible to further prevent the displacement of the substrate, defective products, and generation of particles. You can

In a configuration in which an O-ring made of an elastic member is laterally provided on the upper end of a support pin that supports six positions of the substrate,
To support the substrate with the support pins, a wide surface range is elastically supported without increasing the contact area on an annular line formed by the tops of the circular cross sections of the O-rings at the upper ends of the substrates,
It is possible to further suppress the bending of the substrate and make it more slippery and less likely to generate particles.

Further objects and features of the present invention will become apparent from the detailed description and drawings set forth below. To the extent possible, each feature of the invention is
Alternatively, they can be used in combination in various combinations.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION A substrate positioning method in a load lock chamber of a vacuum processing apparatus and an apparatus therefor according to an embodiment of the present invention will be described in detail below with reference to FIGS. To serve. The following examples are specific examples of the present invention and do not limit the technical scope of the present invention.

Although this embodiment is an example of the case of positioning used for vacuum processing of a glass substrate as a liquid crystal substrate, the present invention is not limited to this, and it is possible to perform vacuum processing of various substrates. The present invention is effectively applied to a positioning method and an apparatus therefor in a load lock chamber provided between the vacuum processing chamber and the outside, and both are within the scope of the present invention.

FIG. 2 shows a vacuum processing chamber 1 in the vacuum container 30.
The load lock chamber 2 is provided between the vacuum processing chamber 1 and the outside 3 to transfer the substrate 4 while maintaining the vacuum state of the vacuum processing chamber 1. List. For this transfer, gate valves 7 and 8 are provided at the loading / unloading ports 5 and 6 between the load lock chamber 2 and the vacuum processing chamber 1 and the outside 3, respectively.
It can be opened and closed by. When the substrate 4 is transferred from the exterior 3 to the load lock chamber 2, the inlet / outlet 6 with respect to the exterior 3 is opened by the gate valve 8, but the vacuum processing chamber 1 closes the inlet / outlet 5 by the gate valve 7 to maintain a vacuum state. I will keep it. A cassette (not shown) accommodating a large number of substrates 4 is located at the outside 3, and the substrates 4 accommodated therein are transferred through the loading / unloading port 6 by a transfer mechanism (not shown). In the load lock chamber 2, the substrate 4 to be transferred is supported from below by the supporting means 20, and after positioning, it is transferred to the vacuum processing chamber 1 and subjected to vacuum processing. At this time, the transfer is performed by closing the inlet / outlet 6 on the outside 3 side and then opening the inlet / outlet 5 on the vacuum processing chamber 1 side to prevent the vacuum state in the vacuum processing chamber 1 from being significantly lowered. The substrate 4 is transferred into the vacuum processing chamber 1, and after the transfer, the loading / unloading port 5 is closed to secure a predetermined degree of vacuum and vacuum processing is performed.

For the substrate 4 after vacuum processing, the loading / unloading port 6 on the vacuum processing chamber 1 side is opened while the loading / unloading port 6 on the outside 3 side is closed to support the substrate 4 after vacuum processing in the load lock chamber 2. 20 is transferred and positioned. Next, after closing the loading / unloading port 5, the loading / unloading port 6 is opened and the positioned substrate 4 is transferred to the outside 3 through the loading / unloading port 5 so as to be stored in the original cassette.

By repeating the above process, the unprocessed substrates 4 stored in the cassette are exchanged one by one for vacuum processing, and when all the substrates 4 are vacuum processed. The vacuum processing of the substrate 4 for one cassette is completed.

As described above, in order to position the substrate 4 to be transferred or transferred in the load lock chamber 2, in this embodiment, the substrate 4 is orthogonal to the horizontal plane as shown in FIGS. 1A, the position and tilt of the substrate 4 supported from below by a supporting means 20 that can move in two X and Y axis directions and that can rotate about a Z axis perpendicular to them.
As shown in FIG. 7, image recognition is performed from image data captured by one or a plurality of cameras 10, 10, and when there is a position shift or inclination, at least the movement of the support means 20 in the X and Y axis directions and the rotation around the Z axis are performed. The substrate 4 is positioned at a predetermined position by one.

As a result, in the load lock chamber 2,
The substrate 4 transferred from the external 3 or the vacuum processing chamber 1 is supported from below by the supporting means 20, and the supported substrate 4 is imaged by the appropriate number of cameras 10 and 10 in accordance with the position and inclination of the image recognized. The substrate 4 is positioned by at least one of the movement of the supporting means 20 itself in the directions of the X and Y axes 2 orthogonal to the horizontal plane and the rotation about the Z axis perpendicular to these, and the vacuum processing chamber 1 or the outside 3 Can be used for vacuum processing and storage in a cassette. In particular, in this case, the positioning load is not applied to the substrate 4 as in the case of the clamp method, and accurate positioning can be achieved even if the substrate 4 is made large or thin, and the substrate 4 is damaged or dusted. The positioning reliability is improved without causing any occurrence.

In most cases, it is shown in phantom in FIG.
The rectangular substrate 4 is handled as shown by the solid line in (a). Therefore, in handling such a rectangular substrate 4, the above-mentioned positioning is performed with the midpoint of the diagonal line P connecting the diagonals R and S as shown in FIG. Do. In this way, the position of the substrate 4 can be easily and accurately recognized and positioned accurately.

For such image recognition, FIG.
The corner image including the diagonals R and S as shown in (c) is processed. Particularly, in the corner image (b), the preset X is set.
Two points where the shade changes extremely on the extremely fine shade detection lines y1 and y2 parallel to the axis are defined as one side 4 forming a corner portion including the diagonal R.
It is detected as two points y01 and y02 on a. In addition, a very fine grayscale detection line x parallel to the Y axis set in advance
Two points whose shades change extremely on 1 and x2 are detected as two points x01 and x02 on another side 4b forming a corner portion including the diagonal S. Next, two points y01 on one side 4a,
An extension line 4a1 of a line segment connecting y02 and another side 4
The intersection with the extension line 4a2 of the line segment connecting the two points x01 and x02 relating to b is recognized as one diagonal R.

Similarly, in the corner image (c), two points where the shade changes extremely on the extremely fine shade detection lines y3 and y4 parallel to the X axis which are set in advance are defined as corners including the diagonal S. It is detected as two points y03 and y04 on one side 4c forming a part. In addition, two points on the other side 4d forming a corner including the diagonal S are defined as two points where the shade changes extremely on the preset ultra-fine shade detection lines x3 and x4 parallel to the Y axis. Points x03, x0
4 is detected. Next, two points y on one side 4a
An intersection of an extension line 4c1 of a line segment connecting 03, y04 and an extension line 4d1 of a line segment connecting two points x03, x04 on the other side 4b is recognized as the other diagonal S.

The diagonal line P and the midpoint thereof are calculated from the positions of the diagonals R and S thus obtained, and the position and tilt are detected with the midpoint as the center O of the substrate 4 to detect the position shift and tilt. If there is, the support means 20 is positioned so as to be in a predetermined position by moving at least one of the X and Y axis directions and the Z axis.

Thus, the two sides 4 forming the corner of the diagonal R
a and 4b, an extended line 4a1 of a line segment connecting two points x01 and x02 on one side 4a and two points y0 on the other side 4b.
The intersection of an extension line 4b1 of a line segment connecting 1 and y02 is a diagonal angle R, and two points x03 and x04 on one side 4c of two sides 4c and 4d forming a corner portion of the diagonal S are connected. The intersection of the extension line 4c1 of the line segment and the extension line 4d1 of the line segment connecting the two points y03 and y04 on the other side 4d is defined as a diagonal corner S, and the position of the substrate 4 is set to the sides 4a to 4d. Since there is a slight manufacturing error in the two edge shapes forming the corners R and S of the board 4, the warp of the board 4 and the chamfering of the corners R and S, Even if there is a change in the shape of the edge of the board image or the side surface of the board image due to the difference in the chamfered shape, it is not greatly affected as in the case of recognizing it from the detection data of the edge line. The number of times of false recognition and re-recognition due to it is reduced, and the position of the substrate 4 is reduced. It can be performed in a short time with high precision fit.

This feature is effective when it is applied to any method capable of detecting the position of the substrate 4 by recognizing the image of the corner of the substrate 4, and is not limited to the method using the diagonal line P.

Here, in each group of the grayscale detection lines x1 and x2, y1 and y2, x3 and x4, y3 and y4 which are parallel to the X and Y axes, at least one of them is a corner of the screen where the substrate 4 is present. Set to Q side. As a result, at least one of the points where the light and shade corresponding to the sides 4a and 4b of the substrate 4 greatly change can be detected without fail. It is better to separate the other from the above one as much as possible, but it is essential to set it at a position where it does not come off from the substrate 4. At the time of positioning based on image recognition when at least one of the detection points is applied to a portion where the corners R and S of the substrate 4 are cut off due to chamfering or the like, the position and the inclination of the substrate 4 are again image-recognized to determine the position. If there is a deviation or inclination, the positioning operation is performed. As a result, the grayscale detection lines X2, Y2, X are prevented, while preventing the positioning operation from being unnecessarily performed due to an incorrect recognition result.
A method for dealing with chipping of corners R and S of the substrate 4 by shifting the position of the detection point of the substrate 4 or Y4 that is off the substrate 4 to the side of the corresponding one of X1, Y1, X3, and Y3. Appropriate positioning can be performed by re-recognition using.

Each time the positioned substrate 4 is transferred to the vacuum processing chamber 1 or the outside 3, the supporting means 20 is returned to a predetermined origin. As a result, it is possible to prevent the influence of at least one of the movement in the XY axis 2 direction and the rotation about the Z axis being accumulated in each time of positioning and causing an error in the subsequent positioning.

Further, the substrate 4 transferred from the vacuum processing chamber 1
Is positioned with respect to the position when the substrate 4 is transferred from the outside. As a result, the substrate 4 transferred from the vacuum processing chamber 1 is transferred to the outside and stored in the cassette, but since the substrate 4 is supplied from the external cassette 3 and positioned at the time of transfer. It is possible to prevent the substrate 4 from being hit or caught and damaging the substrate 4 or causing dust to be generated even if the substrate is transferred to the outside and stored in the original cassette.

Further, since the device pattern and various films are formed on the substrate 4, the place where the change in shade, that is, the difference in shade is the largest, is separated from the sides 4a, 4b of the substrate 4 by several mm. However, there is a possibility that this will be erroneously detected as the sides 4a and 4b. Therefore, the grayscale detection line x1
And x2, y1 and y2, x3 and x4, and y3 and y4, when detecting a place with a large change in shading, from the outside direction of the substrate 4, in other words, from the place where the substrate 4 does not exist. 4 is sequentially detected toward the place where 4 exists.

As a positioning device for achieving the above positioning method, basically, the load lock chamber 2 is used.
In the above, the supporting means 20, which supports the substrate 4 from below, can move in the directions of two X and Y axes orthogonal to each other on a horizontal plane, and can rotate about the Z axis perpendicular to them,
An appropriate number of cameras 10 and 10 as described above for picking up an image of the substrate 4 supported by the supporting means 20 for image recognition.
In addition, as shown in FIG. 4, a calculation unit 31 that calculates the positional deviation and inclination of the substrate 4 from image data captured by a suitable number of cameras 10 and 10, and the result of the calculation by the calculation unit 31 indicates the position of the position on the substrate 4. If there is a deviation or inclination, X of the supporting means 20,
A controller 32 for positioning the substrate 4 at a predetermined position by at least one of movement in the Y-axis direction and rotation about the Z-axis.
It suffices to have and. The control device 32 itself may determine the positional deviation or the inclination, or may use another determination function.

In the example shown in FIG. 4, the computing means 31 adopts the internal function of a computer for controlling the operation of the vacuum processing apparatus, and the control device 32 utilizes such an operation control function of the computer itself. However, the present invention is not limited to this, and both the calculation means 31 and the control device 32 may be individual dedicated devices or dedicated devices common to them.

In order to achieve the method described above, the control device 32 performs control according to the program 33 for motion control and the program 34 for performing image recognition and calculation for positioning as described above. Further, a memory 35 for storing position information for positioning the substrate 4 transferred to the outside 3 at a position when the substrate 4 is transferred from the outside is provided as an internal function of the control device 32. There is. Further, the images captured by the recognition cameras 10 and 10 are input to the control device 32 via the video circuit 36,
The necessary calculation for image recognition is performed. The images captured by the recognition cameras 10 and 10 and the image recognition state are output to the monitor 37 and displayed on the screen.
The recognition cameras 10 and 10 are arranged so as to image the corners of the substrate 4 from the outside 3 through a transparent window 11 provided at the bottom of the load lock chamber 2 as shown in FIG. The illuminator 13 is arranged on the third side. However, it is not limited to this.

The control device 32 performs vacuum processing in accordance with the operation from the operation panel 38 and the instruction from the host computer, but in order to position the substrate 4, in particular, it controls the operation of the driver 41 that drives the positioning drive system 39. .

The image of the substrate 4 is picked up by the recognition camera 10 and the illuminator 13 to perform the image recognition as described above. In order to perform the image recognition as described above, the shade of the opaque portion formed by the side surface of the edge of the transparent substrate 4 is shaded with the adjacent portion. Although it is necessary to accurately recognize the difference, conventionally, it has been easy to make an erroneous detection due to the influence of the bending of the substrate 4, the finishing of the side surface of the peripheral edge, the damage, and the like. As a result of various experiments and studies conducted to cope with this, when the distance from the surface of the illuminator 13 to the surface of the substrate 4 is set to 125 mm ± 10 mm regardless of the vacuum and the atmosphere, the transparent substrate in the captured image is obtained. The edges of No. 4 were clearly projected. It is considered that this is related to the shape of the opaque portion formed by the side surfaces of the edges of the substrate 4, the thickness of the substrate 4, the difference in shade, and the like. This is the vacuum container 3
There was no change in the positioning experiment in the atmosphere where the quartz glass, which is the partition wall between 0 and the atmosphere, was removed. Therefore, it can be said that the above value is the optimum value for clarifying the shading with the adjacent portion in the side surface image of the edge of the substrate 4.

The supporting means 20 in the present embodiment lowers the substrate 4 as shown in FIGS. 1 and 2 by a plurality of supporting pins 14a on the supporting plate 12 connected to the driving system 39 as shown in FIG. Although it is supported from above, it is preferable to reduce the contact position with the substrate 4 and reduce the contact area in order to prevent the substrate 4 from being scratched and particles from being generated due to contact or scratch. However, when the warp due to the bending of the substrate 4 exceeds 7 mm, the position detection accuracy begins to be affected.

680 mm × 880 mm × 0.7 mm, 7
Various experiments were conducted on a large-sized substrate 4 of a class of 30 mm × 920 mm × 0.7 mm, and as shown in FIG. 3, the central portion 1 at the same distance m from both ends of each long side 4 b of the substrate 4 was obtained.
It is easy to ensure that the bending is suppressed to 7 mm or less by supporting only a total of 6 locations, which are limited to the two locations and the central distribution location of 2 depending on the distribution pitch u of each short side 4a.
By suppressing the bending to 7 mm or less, the detection speed and the detection accuracy can be further improved without affecting the accuracy of recognizing the diagonal corners R and S of the substrate 4. Further, since the contact position with the substrate 4 is small and the contact area is small, it is easy to prevent the substrate 4 from being scratched or particles from being generated due to the contact or the scratch. The distribution pitch u is, for example, 2 in the above.
It is suitable for the size of each type to be approximately 300 mm, and the distance d from both ends varies depending on the size of the substrate.

When the substrate 4 is transferred in the vacuum container 30 in the direction of its long side, the distribution pitch u = 3.
00 mm is an important value for the clearance between the vacuum processing chamber 1 and the transfer arm (not shown) passing through the gate 5 to the load lock chamber 2 side. In other words, when the substrate 4 supported by the support pins 14a is transferred by the fork type transfer arm passing immediately inside the distribution pitch of 300 mm, the amount of bending of the substrate 4 can be minimized to 7 mm or less. It is in the position. Therefore, the transfer arm can be formed as a simple and lightweight two-fork type, so that the transfer mechanism can be made compact. Furthermore, the relationship between the distribution pitch position of the support pins 14a and the transfer mechanism is not limited to the support means 20 in the load lock chamber 2, and the same applies to any part of the vacuum container 30 that supports the substrate 4. be able to.

Further, in order to support the substrate 4 from below from above with the support pins 14a, in consideration of the fact that the substrate 4 may be damaged even though it is on the back surface of the substrate 4, in order to select a region where there are no devices on the substrate 4, FIG. As shown in FIG.
It is preferable to support it within a range of about 10 mm.

Furthermore, since the substrate 4 is supported by the elastic member, even if the substrate 4 is supported with a small contact area with the substrate 4, it is less likely to slip and is not scratched. Generation of particles can be further prevented. To adopt this, in the present embodiment, as shown in FIGS. 1A and 1D, the O-ring 15 made of an elastic member is laterally bonded to the upper end of the support pin 14a that supports the substrate 4. Is provided. Therefore, when the substrate 4 is supported by the support pins 14a, the contact area is particularly large on the annular line formed by the O-rings 15 at the upper ends of the circular cross-section tops 15a shown in FIG. In this way, it is possible to elastically support a wide surface area, further suppress the bending of the substrate 4, and make it more difficult to slip.

As a result of the above, the substrate 4 has a large size and a thin plate,
It is possible to sufficiently obtain high-speed conveyance and high reliability corresponding to the miniaturization, high definition, and dust reduction of the process.

[0046]

As is apparent from the above description, according to the present invention, the substrate to be transferred is supported from below by the supporting means, and the position and the inclination are recognized by the image of the supported substrate by the camera. Accordingly, the movement of the supporting means itself in the two directions of the X and Y axes orthogonal to each other on the horizontal plane and the Z perpendicular to these
The substrate can be positioned by at least one of rotation about the axis and transferred to the vacuum processing chamber or the outside to be used for vacuum processing or storage in a cassette. For positioning, a load like in the case of a clamp system is used. It is possible to perform accurate positioning even if the substrate is made large or thin, and the positioning reliability is improved without damaging the substrate or causing dust generation.

In particular, in handling a rectangular substrate, an extension line of a line segment connecting two points on one side of two sides forming a corner and a line segment connecting two points on another side. Since the position of the board is recognized from the two-point detection data for each side with the intersection of the extension line and the corner as a corner, there is a slight manufacturing error in the shape of the two edges forming the corner of the board, or a warp of the board. Even if there is a change in the shape of the edge or side surface of the substrate image due to the presence or absence of chamfering of the corner and the difference in chamfered shape, it is not significantly affected as in the case of recognition from the edge line detection data. Even with pattern recognition, the number of times of erroneous recognition and re-recognition due to it is reduced, and the substrate can be positioned with high accuracy in a short time.

[Brief description of drawings]

FIG. 1 shows a method of positioning a substrate in a load lock chamber of a vacuum processing apparatus according to an embodiment of the present invention and the apparatus therefor, in which (a) is a perspective view showing a main part of the apparatus and (b) is a diagram showing the substrate. FIG. 6A is a recognition image view of one corner of a diagonal, FIG. 7C is a recognition image view of the other corner, and FIG. 7D is a perspective view and a cross-sectional view of the upper end of the support pin.

2 is an external perspective view of the device of FIG. 1. FIG.

FIG. 3 is an explanatory view showing a support position of a substrate by a support pin.

4 is a block diagram showing a control device of the device of FIG. 1. FIG.

FIG. 5 is a schematic perspective view showing a conventional substrate positioning method and apparatus.

[Explanation of symbols]

R, S corner 1 vacuum processing chamber 2 Road lock room 3 outside 4 substrates 4a side 10 cameras 13 Illuminator 14a Support pin 15 O-ring 20 Supporting means 31 computing means 32 control device 33, 34 programs 35 memory 36 video circuits 38 Operation panel 39 Drive system 41 driver

Continued front page    F-term (reference) 5F031 CA05 HA08 HA09 HA24 JA04                       JA22 JA27 JA32 JA40 JA51                       PA18

Claims (11)

[Claims] 1. In a load lock chamber for transferring a substrate between the vacuum processing chamber and the outside while keeping the vacuum state of the vacuum processing chamber, the substrate transferred from the outside or the vacuum processing chamber is on a horizontal plane. Can be moved in the two X and Y axis directions that are orthogonal to each other,
Further, it is supported from below by a supporting means that can rotate about the Z axis perpendicular to them, and the position and tilt of the supported substrate are recognized by an image from the corners of the substrate captured by a camera. A method for positioning a substrate in a load lock chamber of a vacuum processing apparatus, which positions the substrate at a predetermined position by at least one of movement of the support means in the X and Y axis directions and rotation about the Z axis when there is a deviation or inclination. Then, on the two sides of the board forming the corner of the board, the intersection point of the extension line of the line segment connecting the two points on one side and the extension line of the line segment connecting the two points on the other side is intersected with the board. A method of positioning a substrate, characterized in that the image recognition and the positioning based on the image recognition are performed by recognizing the corners. 2. At the time of positioning based on image recognition when at least one of the detection points is applied to a portion where the corner of the substrate is lacking, image recognition is performed again for the position and inclination of the substrate,
The positioning operation is performed when there is a position shift or inclination.
The method for positioning a substrate according to. 3. The substrate positioning method according to claim 1, wherein the substrate is illuminated from a position 115 mm to 135 mm away from the substrate on the side opposite to the camera in image recognition by imaging. 4. The method for positioning a substrate according to claim 1, wherein when a substrate having an area of 660 × 880 mm or more is handled, the deflection of the substrate is suppressed to 7 mm or less and the substrate is supported. 5. The substrate according to claim 4, which supports a total of 6 places, that is, one place in the center of each long side and two places in the center of each short side. Positioning method. 6. The method for positioning a substrate according to claim 5, wherein the elastic member supports six positions of the substrate. 7. A load-lock chamber for transferring a substrate between the vacuum processing chamber and the outside while maintaining the vacuum state of the vacuum processing chamber, wherein the substrate is transferred from the outside or from the vacuum processing chamber. A support unit that supports the unit from below, can move in two orthogonal X and Y axis directions on a horizontal plane, and can rotate about a Z axis that is perpendicular to them, and images the substrate supported by this support unit for image recognition. Based on the camera used for the above, and the image data captured by the camera, an extended line segment connecting two points on one side of the two sides forming the corner of the board and a line segment connecting two points on the other side. Computing means for recognizing the intersection of the extension line and the board corner and computing the board position and tilt;
If there is a displacement or inclination as a result of the calculation, the control means is provided for positioning the substrate at a predetermined position by at least one of movement of the support means in the X and Y axis directions and rotation about the Z axis. Substrate positioning device. 8. The control means performs image recognition again on the position and inclination of the substrate at the time of positioning based on image recognition when at least one of the detection points is applied to a portion where the corner of the substrate is missing, and the position is detected. The substrate positioning apparatus according to claim 7, wherein the positioning operation is performed when there is a deviation or an inclination. 9. The substrate is on the side opposite the camera from the substrate 11
9. The substrate positioning device according to claim 7, further comprising an illuminating unit that illuminates at a position separated by 5 mm to 135 mm. 10. The support means is a central portion 1 of each long side portion of the substrate.
The substrate positioning device according to any one of claims 7 to 9, which supports a total of six positions, that is, a position and a central distribution position of each short side. 11. The substrate positioning device according to claim 10, wherein the supporting means laterally has an O-ring made of an elastic member at the upper end of a support pin that supports six positions of the substrate.