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KR101626374B1 - Precision position alignment technique using edge based corner estimation - Google Patents

Precision position alignment technique using edge based corner estimation Download PDF

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KR101626374B1
KR101626374B1 KR1020160009151A KR20160009151A KR101626374B1 KR 101626374 B1 KR101626374 B1 KR 101626374B1 KR 1020160009151 A KR1020160009151 A KR 1020160009151A KR 20160009151 A KR20160009151 A KR 20160009151A KR 101626374 B1 KR101626374 B1 KR 101626374B1
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corner
coordinates
inspection
corners
image
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KR1020160009151A
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Korean (ko)
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고진석
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주식회사 마이크로비전
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/68—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for positioning, orientation or alignment
    • H01L21/681—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for positioning, orientation or alignment using optical controlling means
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/67005—Apparatus not specifically provided for elsewhere
    • H01L21/67242—Apparatus for monitoring, sorting or marking
    • H01L21/67259—Position monitoring, e.g. misposition detection or presence detection
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/677—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for conveying, e.g. between different workstations
    • H01L21/67703—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for conveying, e.g. between different workstations between different workstations
    • H01L21/67721—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for conveying, e.g. between different workstations between different workstations the substrates to be conveyed not being semiconductor wafers or large planar substrates, e.g. chips, lead frames
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/677—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for conveying, e.g. between different workstations
    • H01L21/67739—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for conveying, e.g. between different workstations into and out of processing chamber
    • H01L21/67754—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for conveying, e.g. between different workstations into and out of processing chamber horizontal transfer of a batch of workpieces
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L22/00—Testing or measuring during manufacture or treatment; Reliability measurements, i.e. testing of parts without further processing to modify the parts as such; Structural arrangements therefor
    • H01L22/10—Measuring as part of the manufacturing process
    • H01L22/12—Measuring as part of the manufacturing process for structural parameters, e.g. thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions

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  • Manufacturing & Machinery (AREA)
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  • Microelectronics & Electronic Packaging (AREA)
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  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Container, Conveyance, Adherence, Positioning, Of Wafer (AREA)
  • Length Measuring Devices By Optical Means (AREA)

Abstract

The corner-based corner estimating position correcting method according to the present invention can estimate coordinates of an estimated corner by estimating straight lines from an edge viewed from an image of an object and estimating one corner from two straight lines Therefore, even if there is no separate recognition mark, position correction is possible.

Description

[0001] The present invention relates to an edge-based corner estimation method,

The present invention relates to a precision position correcting method, and more particularly, to a precision position correcting method using a corner-based corner estimation capable of correcting a position of a bare wafer without a recognition mark or a display glass for a mobile device.

Generally, a precision position correction method based on a vision system has been used in a semiconductor or a display manufacturing process. Most of the wafers and display panels have a fiducial mark for position recognition. By detecting this fiducial mark, the position deviation of the product is easily measured and corrected.

However, since there is no recognition mark on the bare wafer and the display glass for the mobile device is also transparent and has no recognition mark, there is a problem in that the position correction method using the existing recognition mark can not be applied .

Since the conventional method using the laser displacement sensor can perform positional correction for only one axis as in the case of measuring only the distance or height, it is possible to perform positional correction for three axes for the x-, y- In order to perform axis compensation, three expensive sensors need to be installed, which results in a problem that the construction cost is high.

Korean Patent No. 10-1210303

SUMMARY OF THE INVENTION An object of the present invention is to provide a precision position correction method using corner-based corner estimation capable of correcting the position of an object without a recognition mark.

A method of correcting a position using corner-based corner estimation according to the present invention includes the steps of photographing a corner of a teaching object using a camera, estimating straight lines of two corners forming the corner of the photographed image Detecting a coordinate of an intersection at which the two straight lines intersect with coordinates of the corner, and storing the coordinates as reference coordinates; A step of photographing a corner of the object to be inspected using the camera; a step of estimating each straight line of two corners forming the corner in the photographed image; and a step of estimating coordinates of an intersection at which the two straight lines intersect A step of detecting the detected coordinates with respect to the corner; And a correction step of comparing the reference coordinates with the inspection coordinates and correcting the position by transferring the inspection object by a deviation between the reference coordinates and the inspection coordinates.

According to another aspect of the present invention, there is provided a method of correcting a position using corner-based corner estimation, comprising: capturing left and right corners of a flat zone of a teaching wafer using a camera to obtain left and right corner teaching images; A boundary surface between two edges forming the left corner of the teaching image is searched for, and each of the boundary surfaces is estimated as two straight lines. Coordinates of intersections at which the two straight lines intersect are detected as reference coordinates for the left corner And the boundary surface is estimated as two straight lines, and the coordinates of the intersection point at which the two straight lines intersect are detected in the right corner And stores the reference coordinates for the left corner and the reference coordinates for the right corner, Teaching steps to connect a reference coordinate for detecting a reference position; A left and a right corner inspection image is obtained by photographing the left and right corners of the flat zone of the inspection wafer using the camera, and the boundary between the two corners forming the left corner in the left corner inspection image is found, Wherein the coordinates of the intersection at which the two straight lines intersect are detected and stored as inspection coordinates for the left corner, and in the right corner inspection image, two edges forming the right corner and A boundary of the background is found and each of the boundary planes is estimated as two straight lines, and coordinates of an intersection at which the two straight lines intersect are detected and stored as inspection coordinates for the right corner, A checking step of connecting the inspection coordinates of the right corner to the inspection position; And a correction step of comparing the reference position with the inspection position and correcting the position by moving the wafer by a deviation between the reference position and the inspection position.

According to another aspect of the present invention, there is provided a method of correcting a position using corner-based corner estimation, comprising: capturing two corners of a first corner of a glass of a teaching mobile device using a camera, The two corners forming the second corner adjacent to the first corner are respectively photographed to acquire two edge teaching images, and the edge and background boundary faces are found in the two corner teaching images for the first corner, A coordinate of an intersection at which the two straight lines intersect is detected and stored as a reference coordinate for the first corner and an edge and a boundary of the background are found in the two corner teaching images for the second corner, The boundary surface is estimated as two straight lines, and the coordinates of the intersection point at which the two straight lines intersect each other, Stores the detection as a reference coordinate for, and with the teaching step of detecting the reference position by connecting the reference coordinates and the reference coordinates for the second corner to the first corner; Two corners forming the first corner of the glass of the inspection mobile device are respectively photographed using the camera to photograph two corners of the corners and two corners of the second corner adjacent to the first corners, The method according to claim 1, wherein the edge inspection image is obtained by two edge inspection images for the first corner, and the boundary surfaces are respectively estimated as two straight lines, and the coordinates for the intersection points, 1 corners of the corners of the first and second corners of the corners of the first and second corners of the corners of the second corners, The coordinates of the first corner are detected and stored as inspection coordinates of the second corner, A step of connecting inspection coordinates for two corners to detect inspection positions; And a correction step of comparing the reference position with the inspection position and correcting the position by moving the glass by a deviation between the reference position and the inspection position.

The position correction method according to the present invention can detect coordinates of an estimated corner by estimating straight lines from an edge viewed from an image of an object and estimating one corner from two straight lines, It is possible to correct the position even if there is no recognition mark.

The present invention is also applicable to positional correction of a wafer having no recognition mark, a transparent glass, and an object having corners of various shapes.

In addition, since expensive equipment such as a sensor is not required, the cost can be reduced.

1 is a view showing photographing positions of left and right corners of a flat zone of a bare wafer according to the first embodiment of the present invention.
2 is a view schematically showing the left and right corners of the flat zone shown in Fig.
3 is an image of the left and right corners of the flat zone shown in Fig.
4 is a flowchart illustrating a corner-based corner estimation precision position correction method according to the first embodiment of the present invention.
5 is a view showing a photographing position of the glass of the mobile device according to the second embodiment of the present invention.
6 is a view schematically showing the first corner of the glass shown in Fig.
7 is an image of the first corner of the first corner of the glass shown in Fig.
FIG. 8 is a flowchart illustrating a corner-based corner estimation precision position correction method according to a second embodiment of the present invention.
9 is a diagram illustrating a geometric relationship between a reference position and a detection position in the position correction method according to the embodiment of the present invention.
10 is a diagram illustrating positional coordinate changes according to angle compensation in a position correction method according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a view showing photographing positions of left and right corners of a flat zone of a bare wafer according to the first embodiment of the present invention. 2 is a view schematically showing the left and right corners of the flat zone shown in Fig. 3 is an image of the left and right corners of the flat zone shown in Fig. 4 is a flowchart illustrating a corner-based corner estimation precision position correction method according to the first embodiment of the present invention.

Referring to FIGS. 1 to 4, a method for correcting a corner-based corner estimation precision position according to a first embodiment of the present invention will be described with reference to a method for correcting the position of a bare wafer without a recognition mark, The bare wafer is referred to as a wafer. In addition, an edge means a side surface of a wafer, and a corner means a portion formed by two edges.

The corner-based corner estimation precision position correction method is performed by a position correction apparatus including a work table 4, a camera (not shown), a control unit (not shown), and a memory unit (not shown).

The method for correcting the position of the wafer includes a teaching step, an inspection step and a correction step, and is performed by the control part.

Referring to FIG. 4, a teaching step of designating a reference position of a wafer for position correction is performed (S10)

The left and right corners 20 and 30 of the flat zone 10 of the teaching wafer 4 placed on the work table 2 are photographed using a camera. (S11)

When using a high magnification camera to perform high-precision positional correction, the field of view (FOV) of the image is narrowed. In the case of using a large-area camera having a large number of pixels of the sensor, Although the image acquisition is possible, there is a problem that the system construction cost is high. Therefore, it is preferable that the camera uses an industrial camera having an appropriate number of pixels.

Two corner teaching images can be obtained by photographing the left and right corners 20 and 30 of the flat zone 10. (S12) A left corner teaching image PL in which the left corner 20 of the flat zone 10 is photographed and a right corner teaching image PR in which the right corner 30 of the flat zone 10 is photographed.

The left corner teaching image PL moves either the wafer 4 or the camera so that the vertex 23 representing the left corner 20 is positioned at the center of the image.

The right corner teaching image PR is obtained by moving either the wafer 4 or the camera so that the vertex 33 representing the right corner 30 is positioned at the center of the image. In the present embodiment, the vertexes of the left corner 20 and the right corner 30 are positioned at the center of the image, but the present invention is not limited thereto.

When the at least one of the wafer 4 and the camera is moved to photograph the right corner 30 after photographing the left corner 20, the relative movement distance of the wafer 4 and the camera And stores it. The relative movement distance dX (dY) is reflected upon detection of the coordinates of intersection points described later. When the wafer 4 is moved, the relative movement distance can be confirmed by the movement distance of the work table 2 on which the wafer 4 is placed.

2 and 3, left and right corner teaching images PL (PR) for the left and right corners 20 and 30 of the flat zone 10 are shown.

When the left and right corner teaching images PL are obtained, two straight lines can be estimated from each image. That is, the control unit (not shown) estimates two first and second straight lines L1 and L2 from the left corner teaching image PL and calculates two third and fourth straight lines L1 and L2 from the right corner teaching image PR. And estimates the straight line L3 (L4). (S13)

A method of estimating a straight line from the left and right corner teaching images PL is as follows.

Referring to FIG. 3, the controller (not shown) displays the boundary surfaces of the first and second edges 21 and 22 forming the left corner 20 in the left corner teaching image PL, Find. Here, the background means a portion other than a wafer in the image. The boundary between the first edge 21 and the background is estimated as a first straight line L1. That is, the first straight line L1 can be estimated by finding at least two points out of the boundary between the first edge 21 and the background and connecting the found points. In addition, the boundary between the second edge 22 and the background is estimated as a second straight line L2. A method of finding an interface from the image and estimating a straight line may be programmed in advance in the control unit (not shown) or the like.

In addition, in the right corner teaching image PR, two third and fourth corners 31 and 32 forming the right corner 30 are searched for the boundary surface of the background. The boundary between the third edge 31 and the background is estimated as a third straight line L3. In addition, the boundary between the fourth edge 32 and the background is estimated as a fourth straight line L4.

As described above, after estimating two straight lines for each image, one corner is estimated from two straight lines (S14)

A method for estimating the corner is as follows.

The intersection where the first and second straight lines L1 and L2 estimated from the left corner teaching image PL intersect with each other is found. It can be assumed that the intersection is a point corresponding to the vertex 23 of the left corner 20. Coordinates of intersections where the first and second straight lines (L1 and L2) intersect are stored as reference coordinates for the left corner (20).

In addition, an intersection where two third and fourth straight lines L3 and L4 estimated from the right corner teaching image PR intersect is found. It can be assumed that the intersection corresponds to the vertex 33 of the right corner 30. Coordinates of intersections at which the third and fourth straight lines L3 and L4 intersect are detected and stored as reference coordinates for the right corner 30. [

Equations (1) to (3) show a method of detecting coordinates of an intersection of two straight lines. Equations (1) and (2) represent equations representing two straight lines, and Equation (3) represents coordinates of intersections of two straight lines.

The control unit (not shown) includes an arithmetic unit for estimating the two straight lines and calculating coordinates of the intersection from the two straight lines.

Figure 112016008372652-pat00001

Figure 112016008372652-pat00002

Figure 112016008372652-pat00003

When the reference coordinates of the left corner 20 and the reference coordinates of the right corner 30 are detected as described above, the reference coordinates of the left corner 20 and the reference coordinates of the right corner 30, And detects the reference position of the wafer 4. Here, the reference position corresponds to the position of the flat zone 10 of the wafer 4. The reference position of the wafer 4 is stored in the memory unit and used as a reference value at the time of position correction described later.

The above-described teaching step may be performed once at the initial execution of the position correction method.

(S20) The inspection wafer is a bare wafer having no recognition mark used in the inspection step, and is hereinafter referred to as a wafer for inspection.

The method for detecting the inspection coordinates for the left and right corners of the flat zone of the inspection wafer in the inspection step is the same as the method for detecting the coordinates for the left and right corners in the teaching step.

The inspection step first photographs the left and right corners of the flat zone of the inspection wafer using the camera. (S21)

The left and right corners of the inspection wafer are respectively photographed and two left and right corner inspection images can be obtained.

When the left and right corner inspection images are obtained, two straight lines can be estimated from each image. A method of estimating a straight line from the image is the same as that performed in the teaching step (S23)

After estimating two straight lines from the left and right corner inspection images, one corner is estimated from two straight lines. The method of estimating one corner from two straight lines is the same as that performed in the teaching step, and a detailed description thereof will be omitted. (S24)

An intersection where two straight lines estimated from the left corner inspection image intersect is found, and a coordinate for the intersection is detected as inspection coordinates for the left corner. In addition, an intersection where two straight lines estimated from the right corner inspection image intersect is found, and coordinates of the intersection are detected as inspection coordinates for the right corner.

As described above, when the inspection coordinates for the left corner and the inspection coordinates for the right corner are detected, the inspection coordinates for the left corner and the inspection coordinates for the right corner are connected to the inspection position of the wafer 4 . (S25)

That is, in the inspection step, the coordinates of the left and right corners of the flat zone of the wafer are detected in the same manner as the inspection in the teaching step. At this time, the coordinates detected in the teaching step become the reference coordinates, and the coordinates detected in the inspection step become the inspection coordinates.

Thereafter, the reference position stored in the teaching step is compared with the inspection position detected in the inspection step. (S30)

Calculates a deviation between the reference position and the inspection position, and corrects the position by moving the inspection wafer by the deviation. (S40)

Therefore, according to the present invention, positional correction is possible by detecting the coordinates of the left and right corners of the flat zone from the image, even if the wafer is a bare wafer without a separate recognition mark.

The method of calculating the deviation by comparing the reference position and the inspection position with each other can utilize various known methods. Hereinafter, a known technique, such as " Kim, Hyong Tae, Chang Seop Song and Hae Jeong Yang. "Microelectronics Reliability 44.7 (2004): 1165-1179.") Will be described as an example.

Assuming that the reference coordinates for the two corners detected in the teaching image are (x1, y1), (x2, y2), the inspection coordinates for the two corners detected in the inspection image are (x1 ', y1' x2 ', y2'). At this time, the geometric relationship between the reference position and the inspection position can be expressed as shown in FIG.

The relationship between the reference coordinates and the inspection coordinates is expressed by Equation (4).

Figure 112016008372652-pat00004

Here, (? X1,? Y1), (? X2,? Y2) denotes a position error between the reference position and the detection position.

As shown in FIG. 9B, when one corresponding coordinate is matched at the reference position and the inspection position, the compensation value for the rotation angle can be calculated without coordinate information about the rotation center axis as shown in Equation (5).

Figure 112016008372652-pat00005

(X1 ', y1'), (x2 ', y2') are calculated as (x1 ", y1"), (x2 ", y2" Respectively. This is illustrated in FIG.

Now, the coordinates (x1 ", y1") and (x2 ", y2") newly expressed can be estimated through Rigid Body Transform. Assuming that (c x , c y ) is the rotation center axis, the coordinates (x 1 ", y 1"), (x 2 ", y 2") can be estimated through Equation (6).

The compensation value for translational motion (translation movement) can be calculated as shown in Equation (7). At this time, it is assumed that the compensation value of each coordinate is ideally matched.

Figure 112016008372652-pat00007

When calculating the position error value by detecting the coordinates in the real image, there are cases in which a result different from the theoretical value is obtained due to various factors. This is because the sub-pixel unit coordinates are very sensitive to the vibration of the equipment and the surface condition of the product. The process of compensating the inspection position to the reference position using the compensation value of the coordinates can be approximated as follows.

Figure 112016008372652-pat00008

In order to minimize the approximation error, an error function such as Equation (9) can be defined, and an optimal value of the error function Equation (9) satisfies Equation (10).

Figure 112016008372652-pat00009

Figure 112016008372652-pat00010

The solution of Equation (10) can be expressed as Equation (11), and if Equation (11) is symmetrically set to the center point at the time of setting the reference position, Equation (11) can be simplified to Equation (12). The center point is the center point for rotation in the X, Y, and Rotation Stages of the work table on which the wafer is placed.

Figure 112016008372652-pat00011

Figure 112016008372652-pat00012

Meanwhile, a corner-based corner estimation precision position correction method according to a second embodiment of the present invention will be described with reference to a method of correcting the position of a glass for a mobile device without a recognition mark, and is hereinafter referred to as a glass (100).

Referring to FIG. 5, the glass 100 according to the second embodiment of the present invention is a glass which has no recognition mark, is transparent, and has a rounded corners. However, the present invention is not limited to this and is also applicable to objects having corners machined into various shapes other than rounded corners. In the case where the corner is an angled glass, the wafer correction method according to the first embodiment of the present invention can be used.

The method for correcting the position of the glass 100 includes a teaching step, an inspection step, and a correction step.

Referring to FIG. 8, first, a teaching step of specifying a reference position of the glass 100 for position correction is performed.

First, the glass 100 placed on the work table 2 is photographed using a camera (S111)

Referring to FIGS. 5 and 6, since the corner 100 is rounded in the case of the glass 100, two corners forming the corners are photographed without directly photographing the corners, thereby acquiring a total of four corner teaching images (S112) That is, in the case where the corners are rounded, since two corners constituting the corners are not included in one image, it is preferable to photograph each of the two corners.

That is, the first and second corners 111 and 112 forming the first corner 110 of the glass 100 are respectively photographed to acquire two first and second edge teaching images P11 and P12, The third and fourth corners 121 and 122 forming the second corner 120 of the glass 100 are respectively photographed to acquire two third and fourth edge teaching images P13 and P14. At this time, the first corner 110 and the second corner 120 are arranged adjacent to each other.

When at least one of the glass (100) and the camera is moved to photograph the second edge teaching image (P12) after the first corner teaching image (P11) is photographed, the glass (100) The relative movement distance of the camera is calculated and stored. The relative movement distance dX (dY) is reflected upon detection of the coordinates of intersection points described later. When the glass 100 is moved, the relative movement distance can be confirmed by the movement distance of the work table 2 on which the glass 100 is placed.

Once the edge teaching images are obtained as described above, one straight line can be estimated from each image. In this embodiment, since one corner of the corner is respectively photographed, one straight line can be estimated for each image (S113)

The control unit (not shown) estimates one first straight line L1 from the first edge teaching image P11 and estimates one second straight line L2 from the second edge teaching image P12. do. One third straight line L3 is estimated from the third edge teaching image P13 and one fourth straight line L4 is estimated from the fourth edge teaching image P14.

A method of estimating a straight line from the first, second, third, and fourth edge teaching images P11, P12, P13, and P14 is as follows.

Referring to FIG. 7, a boundary surface between the first edge 111 and the background is found in the first edge teaching image P11. Here, the background means a non-glass portion in the image. The boundary between the first edge 111 and the background is estimated as the first straight line L1. That is, the first straight line L1 can be estimated by finding at least two points out of the boundary between the first edge 111 and the background and connecting the found points. In this way, the second, third, and fourth straight lines L2, L3, and L4 can also be estimated. A method of finding an interface from the image and estimating a straight line may be programmed in advance in the control unit (not shown) or the like.

As described above, one straight line is estimated for each image, and one corner is estimated from two straight lines (S114)

A method for estimating the corner is as follows.

An intersection where the first straight line L1 and the second straight line L2 intersect is found. It can be assumed that the intersection is a point corresponding to a virtual vertex of the first corner 110 formed by the first corner 111 and the second corner 112. Accordingly, the coordinates of the intersection point at which the first and second straight lines L1 and L2 intersect are stored as reference coordinates for the first corner 110. FIG.

Further, an intersection where the third straight line L3 intersects with the fourth straight line L4 is found. It can be assumed that the intersection point corresponds to a virtual vertex of the second corner 120 formed by the third corner 121 and the fourth corner 122. Therefore, the coordinates of the intersection points where the third and fourth straight lines L3 and L4 intersect are stored as reference coordinates for the second corner 120. [

The above equations (1) to (3) show a method of detecting coordinates of an intersection of two straight lines. Equations (1) and (2) represent equations representing two straight lines, and Equation (3) represents coordinates of intersections of two straight lines.

When the reference coordinates for the first corner 110 and the reference coordinates for the second corner 120 are detected as described above, the reference coordinates for the first corner 110 and the reference coordinates for the first corner 110, 120) are detected and detected as reference positions of the glass (100). Here, the reference position corresponds to the position of one side of the glass 100. The reference position of the glass 100 is stored in the memory unit and used as a reference value at the time of position correction described later.

The above-described teaching step may be performed once at the initial execution of the position correction method.

After the teaching step, an inspection step of inspecting the inspection glass, which is a prototype product, is performed. (S120) The inspection glass is also a glass which is transparent without a recognition mark and has a rounded corners, and is hereinafter referred to as inspection glass.

The method for detecting the inspection coordinates for the corners of the inspection glass in the inspection step is the same as the method for detecting the coordinates for the corners in the teaching step. Hereinafter, the same method as the above-mentioned teaching step will be briefly described.

In the inspecting step, each of the corners constituting the first and second corners of the inspection glass are respectively photographed using the camera to obtain a total of four edge inspection images (S121) (S122)

When a total of four edge inspection images are acquired, one straight line can be estimated from each image. Since the method of estimating a straight line from the image is the same as that performed in the teaching step, a detailed description thereof will be omitted (S123)

After estimating one straight line from each of the four edge inspection images, one corner is estimated from two straight lines. The method of estimating one corner from two straight lines is the same as that performed in the teaching step, and a detailed description thereof will be omitted (S 124)

It can be assumed that an intersection point where the two straight lines intersect is found, and that the intersection point is a point corresponding to a virtual vertex of a corner formed by two edges. And detects coordinates of the intersection as inspection coordinates for the corner.

When the inspection coordinates of the first and second corners are detected, the inspection coordinates of the first corner and the inspection coordinates of the second corner are connected to each other, . (S125)

Thereafter, the reference position stored in the teaching step is compared with the inspection position detected in the inspection step. (S130)

Calculates a deviation between the reference position and the inspection position, and corrects the position by moving the inspection glass by the deviation. (S140)

Therefore, in the case of a glass which is transparent and has a rounded corners without a separate recognition mark, two straight lines of two corners are estimated after two corners forming one corner are respectively photographed, and two straight lines By detecting the coordinates of the crossing points that intersect, coordinate detection with respect to the corner is possible.

A method of calculating the deviation by comparing the reference position and the inspection position with each other can be performed by various known methods. In this embodiment, for example, the method shown in the first embodiment is used, A detailed description thereof will be omitted.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

2: wafer 10: flat zone
100: Glass

Claims (19)

A step of photographing a corner of the object to be taught using a camera; a step of estimating two straight lines for two corners forming the corner in the image of the corner of the object to be taught; Detecting coordinates of an intersection at which the two straight lines intersected by the image are detected as coordinates with respect to the corner, and storing the coordinates as reference coordinates;
A step of photographing a corner of the object to be inspected using the camera; a step of estimating two straight lines of two corners forming the corner in the image of the corner of the object to be inspected; Detecting coordinates of an intersection at which the two straight lines estimated from an image intersect with inspection coordinates for the corner;
And a correction step of comparing the reference coordinates with the inspection coordinates and correcting the position by transferring the inspection object by a deviation between the reference coordinates and the inspection coordinates. The method according to claim 1,
Wherein the teaching object and the inspection object are based on edge-based corner estimation including a wafer. The method of claim 2,
In the photographing process, the left and right corners of the flat zone of the wafer are respectively photographed to obtain two left and right corner images,
Based corner estimation for detecting respective coordinates of the left and right corners in the left and right corner images. The method of claim 2,
The step of estimating the straight line includes:
Based corner estimation method for estimating a boundary between the wafer and a background in the photographed image and estimating the boundary plane as the straight line. The method of claim 3,
The step of estimating the straight line includes:
A boundary between the two corners of the left corner and the background is found in the left corner image, the boundary is estimated as the first and second straight lines,
Based corner estimation that detects coordinates of an intersection at which the first and second straight lines intersect with coordinates of the left corner. The method of claim 3,
The step of estimating the straight line includes:
The boundary surfaces of the two corners forming the right corner and the background are found in the right corner image to estimate the boundary surfaces as the third and fourth straight lines,
Based corner estimation that detects coordinates of an intersection at which the third and fourth straight lines intersect with coordinates of the right corner. The method of claim 3,
In the photographing process,
Based corner estimation for moving the wafer so that the left and right corners of the flat zone are located at the center of the image, respectively. The method of claim 3,
In the correcting step,
The reference coordinates of the left corner of the flat zone and the reference coordinates of the right corner of the flat zone are connected and calculated as a reference position,
A test position is calculated by connecting the inspection coordinates of the left corner of the flat zone and the inspection coordinates of the right corner of the flat zone,
Based corner estimation that compares the reference position with the inspection position and corrects the position by transferring the wafer by a deviation between the reference position and the inspection position. The method of claim 3,
Based corner estimation for calculating a relative movement distance between the camera and the wafer when photographing the left and right corners of the flat zone of the wafer, respectively. The method according to claim 1,
Wherein the object to be taught and the object to be inspected include corners of a rounded object. The method of claim 10,
Wherein the object is a corner-based corner estimate comprising a glass of a mobile device. The method of claim 11,
The step of estimating the straight line includes:
Based edge estimation method for estimating a boundary between the glass and a background in the photographed image and estimating the boundary plane as the straight line. The method of claim 11,
The photographing process may include photographing two first and second corners of the first corner of the glass to obtain two first and second corner images, and obtaining a second corner of the glass in the vicinity of the first corner And two third and fourth edge images are captured respectively to obtain two third and fourth edge images,
Based corner estimation that detects coordinates of the first corner in the first and second edge images and detects coordinates of the second corner in the third and fourth edge images. 14. The method of claim 13,
The step of estimating the straight line includes:
A boundary line between the first corner image and the background is found to estimate the boundary line as a first straight line, a boundary surface between the second corner image and the background is found on the second edge image, and the boundary line is estimated as a second straight line and,
Based corner estimation that detects coordinates of an intersection point where the first and second straight lines intersect with coordinates of the first corner. 14. The method of claim 13,
The step of estimating the straight line includes:
The boundary surface between the third corner and the background is found to estimate the boundary line as a third straight line, the boundary surface between the fourth edge and the background is found from the fourth image, and the boundary is estimated as a fourth straight line ,
And corner-based corner estimation for detecting coordinates of an intersection at which the third and fourth straight lines intersect with coordinates for the second corner. 14. The method of claim 13,
In the correcting step,
The reference coordinates of the first corner of the glass and the reference coordinates of the second corner are connected to calculate a reference position,
The inspection coordinates of the first corner of the glass and the inspection coordinates of the second corner are connected to each other,
Based corner estimation that compares the reference position with the inspection position and corrects the position by transferring the glass by a deviation between the reference position and the inspection position. 14. The method of claim 13,
Based corner estimation that calculates and stores a relative movement distance between the camera and the glass when photographing the first and second corners of the glass, respectively. The left and right corner teaching images are acquired by photographing the left and right corners of the flat zone of the teaching wafer by using a camera, and in the left corner teaching image, the boundary between the two corners forming the left corner is found, Wherein the coordinates of the intersection at which the two straight lines intersect are detected and stored as reference coordinates for the left corner, and in the right corner teaching image, two corners forming the right corner and a background And the coordinates of the intersection where the two straight lines intersect are detected and stored as the reference coordinates for the right corner, and the reference coordinates for the left corner and the reference coordinates for the right corner are stored, Connecting a reference coordinate to a corner and detecting it as a reference position;
A left and a right corner inspection image is obtained by photographing the left and right corners of the flat zone of the inspection wafer using the camera, and the boundary between the two corners forming the left corner in the left corner inspection image is found, Wherein the coordinates of the intersection at which the two straight lines intersect are detected and stored as inspection coordinates for the left corner, and in the right corner inspection image, two edges forming the right corner and A boundary of the background is found and each of the boundary planes is estimated as two straight lines, and coordinates of an intersection at which the two straight lines intersect are detected and stored as inspection coordinates for the right corner, A checking step of connecting the inspection coordinates of the right corner to the inspection position;
And a correction step of comparing the reference position with the inspection position and correcting the position by moving the wafer by a deviation between the reference position and the inspection position. Two corners forming the first corner of the glass of the teaching mobile device are respectively photographed using a camera to photograph two corners teaching images and two corners forming a second corner adjacent to the first corner, A boundary surface between the corner and the background is found in the two corner teaching images for the first corner, and the boundary surface is estimated as two straight lines, and the coordinates for the intersection point where the two straight lines cross each other is referred to as the first And a boundary surface between the corner and the background is found in the two corner teaching images of the second corner to estimate the boundary surface as two straight lines and the intersection where the two straight lines cross each other is detected, Wherein the reference coordinates for the first corner and the second corner are detected and stored as reference coordinates for the second corner, To a reference position;
Two corners forming the first corner of the glass of the inspection mobile device are respectively photographed using the camera to photograph two corners of the corners and two corners of the second corner adjacent to the first corners, The method according to claim 1, wherein the edge inspection image is obtained by two edge inspection images for the first corner, and the boundary surfaces are respectively estimated as two straight lines, and the coordinates for the intersection points, 1 corners of the corners of the first and second corners of the corners of the first and second corners of the corners of the second corners, The coordinates of the first corner are detected and stored as inspection coordinates of the second corner, A step of connecting inspection coordinates for two corners to detect inspection positions;
And a correction step of comparing the reference position with the inspection position and correcting the position by moving the glass by a deviation between the reference position and the inspection position.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190181026A1 (en) * 2017-12-13 2019-06-13 Ebara Corporation Substrate processing device, method for controlling substrate processing device, and storage medium storing a program
KR102031103B1 (en) * 2019-05-28 2019-10-11 (주)케이테크놀로지 Inspection method for slope type corner seal line of flat-panel display cell

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20070038679A (en) * 2005-10-06 2007-04-11 주식회사 탑 엔지니어링 Glass cutting system and inspection method of cutting position
KR20070083287A (en) * 2006-02-13 2007-08-24 삼성전자주식회사 Apparatus and method to align wafer
JP4946668B2 (en) * 2007-07-02 2012-06-06 日本電気株式会社 Substrate position detection device and substrate position detection method
KR101210303B1 (en) 2010-07-23 2012-12-10 세크론 주식회사 Method for aligning a semiconductor device and Apparatus for transferring a semiconductor device using the method
KR20150052230A (en) * 2012-10-29 2015-05-13 로제 가부시키가이샤 Device and method for detecting position of semiconductor substrate

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20070038679A (en) * 2005-10-06 2007-04-11 주식회사 탑 엔지니어링 Glass cutting system and inspection method of cutting position
KR20070083287A (en) * 2006-02-13 2007-08-24 삼성전자주식회사 Apparatus and method to align wafer
JP4946668B2 (en) * 2007-07-02 2012-06-06 日本電気株式会社 Substrate position detection device and substrate position detection method
KR101210303B1 (en) 2010-07-23 2012-12-10 세크론 주식회사 Method for aligning a semiconductor device and Apparatus for transferring a semiconductor device using the method
KR20150052230A (en) * 2012-10-29 2015-05-13 로제 가부시키가이샤 Device and method for detecting position of semiconductor substrate

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190181026A1 (en) * 2017-12-13 2019-06-13 Ebara Corporation Substrate processing device, method for controlling substrate processing device, and storage medium storing a program
US10991605B2 (en) * 2017-12-13 2021-04-27 Ebara Corporation Substrate processing device, method for controlling substrate processing device, and storage medium storing a program
KR102031103B1 (en) * 2019-05-28 2019-10-11 (주)케이테크놀로지 Inspection method for slope type corner seal line of flat-panel display cell

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