JPH0776888B2 - Positioning method and apparatus thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a positioning method and an apparatus therefor.

(Prior Art) Generally, in a machine that processes or inspects a semiconductor integrated circuit substrate or a liquid crystal display element substrate, the precision alignment of the substrate is performed.

Positioning of the disc-shaped plate-like body is disclosed in, for example, Japanese Patent Laid-Open No. 61-85650. This outline is shown in FIG.

According to this, the disk-shaped IC wafer (1) having an orientation flat is rotated 360 ° on the stage (2) and the IC wafer (1) is rotated by the one-dimensional scanning photoelectric conversion device (3).
IC wafer (1)
In addition to detecting the angular position of the orientation flat of the IC wafer (1), the center position of the IC wafer (1) is detected as an absolute value, and the IC wafer (1) is automatically positioned by the XY table (4) and the stage (2).

Further, as a positioning means of the rectangular plate, for example, an element having a transparent electrode, that is, a liquid crystal display element substrate is fixed on a guide plate, and the liquid crystal display element terminal and the printed wiring board terminal are precisely positioned by using a monitor. An inspection device for performing the press contact energization inspection is disclosed and disclosed in JP-A-61-162757.

(Problems to be Solved by the Invention) However, in the former automatic positioning method for the IC wafer (1), when positioning a target object having a shape that does not depend on a certain radius, for example, a rectangular plate-shaped object, a rectangular shape is used. The distance from the center of the plate is quite different near the four corners and near the center of the side,
In addition, even when there is a large difference between the long side and the short side, the distance from the center of the rectangular plate to each outer peripheral point is significantly different. Since a large number of scanning photoelectric conversion devices (3) must be mounted, it becomes difficult to precisely attach each one-dimensional scanning photoelectric conversion device (3) to an accurate position, and each one-dimensional scanning photoelectric conversion device (3) can be detected. There is a problem that the control becomes complicated, and there is also a problem that the device becomes large in size and expensive.

In addition, since the precise alignment of the liquid crystal display device element terminals and the printed wiring board terminals is enlarged by a monitor and manually aligned, it is called to improve the production efficiency by automation of production. There was a problem in terms of production efficiency in checking and adjusting manually. Further, there is also a method of positioning the rectangular substrate by detecting the edge portion, grasping and operating the opposite edge portion of this edge portion, and placing the edge portion again on the mounting table. In the case of the detection body, it has a drawback that it is difficult to perform highly accurate positioning because it is deformed into an arc shape by a gripping operation although it is minute.

The present invention has been made in consideration of the above points, corresponds to production automation, can simplify, downsize, and reduce the cost of a detection control system, and can perform non-contact control such as a liquid crystal display element substrate, etc. It is intended to provide a precise automatic body alignment method.

[Structure of Invention]

(Means for Solving Problems) The present invention, when positioning a rectangular object to be positioned on a mounting table, has a virtual circle centered on the center of the mounting table stored in advance and the side of the object to be positioned. The step of detecting the intersection with the edge, the angle between the two intersections of one long side of the object to be positioned and the virtual circle and the center of the mounting table is θy, and the other long side of the object to be positioned. When the angle formed by the two intersections with the imaginary circle and the center of the mounting table is θy ′ and the short side lx of the object to be positioned is the displacement amount in the x direction of the center of the object to be positioned, Calculated by the calculation formula, the angle formed by the two intersections of one long side of the object to be positioned and the virtual circle and the center of the mounting table is θx, the other long side of the object to be positioned and the virtual circle The angle between the two intersections with and the center of the table is θ
where x'is the long side ly of the object to be positioned, the step of calculating the amount of deviation of the center of the object to be positioned in the y direction by the second calculation formula, and the amount of positional deviation obtained by this step And a step of correcting the position of the body.

Further, at least one sensor provided so as to detect the side edge of the object to be positioned, a means for relatively rotating the sensor and the mounting table described above with the center of the mounting table as a rotation axis, and this means are depicted. Means for detecting an intersection of the sensor output with a side edge of the object to be positioned and a pre-stored virtual circle centered on the center of the mounting table, and position information of the intersection and the center obtained by this means It is characterized by comprising means for calculating the amount of positional deviation in the X and Y directions, and means for correcting the position of the object to be positioned from the amount of positional deviation obtained by this means.

(Operation) According to the positioning method of the present invention, when the rectangular object to be positioned is positioned on the mounting table, an imaginary circle centered on the center of the mounting table and a side edge of the positioned object are stored in advance. And the angle between the two intersections of one long side of the object to be positioned and the virtual circle and the center of the mounting table described above are θy, and the other long side of the object to be measured and the virtual The angle between the two intersections with the circle and the center of the table is θ
When y ′ is the short side lx of the body to be positioned, the displacement amount of the center of the body to be positioned in the x direction is calculated by the first calculation formula,
The angle between two intersections of one long side of the body to be positioned and the virtual circle and the center of the mounting table is θx, and two intersections of the other long side of the body to be positioned and the virtual circle. A step of calculating the shift amount of the center of the object to be positioned in the y direction by the second calculation formula when the angle formed with the center of the mounting table is θx ′ and the long side ly of the object to be positioned, and this step By providing the step of correcting the position of the object to be positioned from the amount of positional deviation obtained by the above, it is possible to automatically and precisely adjust the object to be positioned to a desired position and angle. as a result,
The accuracy of mounting the means for detecting the side edge of the object to be positioned is not required, and it is not necessary to detect the entire circumference contour of the object to be positioned, and the detection and control system can be simplified. Further, it is possible to perform precise automatic alignment of a positioned object having a shape that does not depend on a fixed radius including an isotropic plate-shaped body of a liquid crystal display element substrate.

(Examples) In the following, in the case of a liquid crystal display element substrate in which a positioning object having a shape not depending on a constant radius is a rectangular plate-like object, the positioning method and apparatus of the present invention will be described. An example applied to the liquid crystal display element substrate alignment step in (FA) will be described with reference to the drawings.

As a means to transfer and position the object to be positioned,
A linear movement stage that can be finely moved, for example, a uniaxial movement horizontal stage (11) using a ball screw, is provided with an elevating stage, for example, a uniaxial movement vertical stage (12) using a ball screw as described above. This Vertical Stage (12)
U-shaped aluminum arm (13) that can be moved up and down
Is supported and installed. The U-shaped tip of the arm (13) is provided with a suction hole (not shown) capable of suction-supporting the liquid crystal display element substrate (14) which is a positioned body having a shape not depending on a constant radius. Further, a mounting table (16) rotatable by a rotating stage (15) using a rotating means such as a stepping motor is provided. A liquid crystal display element substrate (14), which is a glass plate-shaped plate, is installed on the mounting table (16) so that it can be suction-held if necessary. And
Sensors (17a to 17e) for detecting at least one, for example, about five, side edges of the liquid crystal display element substrate (14) on a straight line passing through the rotation center of the mounting table (16). The sensor is installed. Then, the vertical stage (12) and the horizontal stage (11) having the arm (13) as a means for transferring and correcting the position of the liquid crystal display element substrate (14), and the mounting table (16) as a center, the liquid crystal display element. A control unit (18) connected to transmit and receive a command control signal to a rotary stage (15) that relatively rotates the substrate (14) and the sensors (17a to 17e) detects a detection signal from the sensors (17a to 17e). The sensor (17a
The control system for calculating the amount of deviation in the XY directions from the output signal (17e) is also built in the control section (18). The positioning device is configured as described above.

Next, a method of positioning the liquid crystal display element substrate in which the object to be positioned having a shape not depending on the constant radius is a rectangular plate using the positioning device described above will be described.

First, the arm (13) is moved to the vertical stage (12) according to the carry-in command control signal of the liquid crystal display element substrate (14) of the controller (18).
The ball screw (not shown) is rotated by a stepping motor (not shown) to move up, and similarly, the ball screw (not shown) of the horizontal stage (11) is rotated at a high speed by a stepping motor (not shown) to perform rough movement in the horizontal direction. . The arm (13) is formed at the U-shaped tip by inserting the U-shaped tip into a carrier (not shown) containing a plurality of unprocessed liquid crystal display element substrates (14), for example, 15 to 25 sheets. A single liquid crystal display element substrate (14) is suction-held by a suction hole (not shown). Then, the liquid crystal display element substrate (14) sucked and held by the coarse movement of the horizontal stage (11) is conveyed to above the aluminum columnar mounting table (16), and the vertical stage (12) is lowered to move the mounting table ( 16) Mount the liquid crystal display element substrate (14) on it.

Here, a command control signal for detecting the position of the liquid crystal display element substrate (14) is transmitted from the control section (18), and the mounting table (16) is driven to rotate a stepping motor (not shown) of the rotary stage (15). Is transmitted by a timing belt and a pulley (not shown) to rotate 360 °, and the liquid crystal display element substrate (14) sucked and held on the mounting table (16) is rotated 360 °.

When the liquid crystal display element substrate (14) crosses over the sensors (17a to 17e), for example, the reflection type photodiode, the sensors (17a, 17e) among the sensors (17a to 17e) are crossed.
The side edge of the liquid crystal display element substrate (14) is detected depending on whether the emitted light of b) is reflected by the back surface of the liquid crystal display element substrate (14) and enters the light receiving part of the sensor (17a, 17b). .

In other words, it is relatively the same even if the liquid crystal display element substrate (14) rotates and the sensors (17a to 17e) rotate.
As shown in FIG. 2, assuming that the liquid crystal display element substrate (14) is fixed and the sensors (17a, 17b) among the sensors (17a to 17e) rotate, the rotation center which is the center of the mounting table (16) is assumed. The radius is the imaginary circle (21) of the sensor (17a), that is, the locus circle whose radius is the distance r _y from (20) to the sensor (17a), and the radius r _x from the center of rotation (20) to the sensor (17b). A virtual circle (22) of the sensor (17b), that is, a locus circle is drawn. Then, it is placed on the mounting table (16), and the operator has a short side length l _x, for example, 152 mm to 300 mm and a long side length l _y, for example, 152 m.
Sensors (17a, 17b) at the intersections (24a to 24h) of the liquid crystal display element substrate (14) side edges in the substrate center (23) where m to 400mm is input.
Detect with. Then, the detection signal is transmitted to the control section (18). Here, the rotation center (20) is set to a fixed value and the control unit (1
8) is stored in advance, and the approximate value of the distance from the rotation center (20) to each sensor (17a to 17e) is also stored in the control unit (18) in advance, which of the sensors (17a to 17e) It can be recognized by the control unit (18) whether or not is used, and if it is different from the input substrate size of the liquid crystal display element substrate (14), the control unit (18)
It is possible to issue an alarm such as a buzzer to the operator, and the accuracy of mounting the sensors (17a to 17e) need not be precise. Then, the short side length l _x and the long side length of the liquid crystal display element substrate (14) input by the operator
The control unit (18) selects the sensor to be used in the sensors (17a to 17e), for example, the sensors (17a, 17b), based on l _y and the position information of the center of the mounting table (16) stored in advance. The virtual circles (21, 22) of the selected sensors (17a, 17b) are the side edges of the liquid crystal display element substrate (14) and eight fulcrums (24a-2).
4h) is not formed, the moving direction of the liquid crystal display element substrate (14) is adjusted by the rotary stage (15) by the command control signal of the control unit (18), and then the vertical stage (12) is used to adjust the arm (13). ) Ascends and holds the liquid crystal display element substrate (14) by suction based on the information of the mounting table (16), and drives a ball screw (not shown) of the horizontal stage (11) at a low speed by a stepping motor (not shown) to rotate it to a predetermined amount. Only the liquid crystal display element substrate (14) is slightly moved horizontally. After the horizontal fine movement is completed, the vertical stage (12) lowers the arm (13),
The liquid crystal display element substrate (14) is mounted again on the mounting table (16). Then, a command control signal for detecting the position of the liquid crystal display element substrate (14) is transmitted again from the control unit (18), and the virtual circle (21,22) of the selected sensor, for example, the sensor (17a, 17b). ) Forms eight fulcrums (24a to 24h) with the side edge of the liquid crystal display element substrate (14), and repeats the above detection operation until a detection signal of the fulcrums (24a to 24h) is transmitted to the control unit (18). .

Next, the positional deviation amount in the X direction and the Y direction is calculated from the positional information of the intersections (24a to 24h) and the rotation center (20) detected by the control section (18), and is calculated as follows.

First, the controller (18) calculates the angle at which the bisector of the angle θ _x formed by the intersections (24a, 24b) and the rotation center (20) becomes parallel to the moving direction of the horizontal stage (11). Ask for.

Next, the angle θ _x ′ formed by the intersection points (24c, 24d) and the rotation center (20) is calculated. Here, the liquid crystal display element substrate (1
4) Let y be the distance from the short side to the center of rotation (20).
_y , y, r _x , θ _x , θ _x ′
StepY is guided.

From formula (30 to 32) That is, from the position information of the intersections (24a to 24d) and the center of rotation (20) and the input long side length l _{y of} the liquid crystal display element substrate (14), the Y-direction positional deviation amount StepY of the equation (33) is calculated. The calculation is performed by the control unit (18). Similarly, from the position information of the intersections (24e to 24h) and the rotation center (20), the angle θ _y ′ formed by the intersections (24e, 24f) and the rotation center (20) and the intersection (24g, 24g)
the angle θ _y ′ formed by h) and the center of rotation (20)
Calculated in 8). Here, assuming that the distance from the long side of the liquid crystal display element substrate (14) to the rotation center (20) is x, the amount of misalignment in the X direction is as follows by l _x , x, r _y , θ _y , and θ _y ′. StepX is guided.

From equations (34-36) That is, from the position information of the intersections (24e to 24h) and the center of rotation (20) and the input short side length l _{x of} the liquid crystal display element substrate (14), the X-direction positional deviation amount StepX of the equation (37) is calculated. The calculation is performed by the control unit (18). Then, as a result of these calculations, the position and orientation of the liquid crystal display element substrate (14) mounted on the mounting table (16) are derived.

Next, X is calculated from the rotation center (20) calculated by the control unit (18).
A command control signal for correcting the positional displacement amount in the direction Y and the angle from the moving direction of the horizontal stage (11) is transmitted from the control unit (18).

First, the angle at which the bisector of the angle θ _x formed by the intersections (24a, 24b) and the center of rotation (20) calculated by the control unit (18) becomes parallel to the moving direction of the horizontal stage (11). The liquid crystal display element substrate (14) is rotated by the rotating stage (15). By this operation, the long side of the liquid crystal display element substrate (14) becomes parallel to the moving direction of the horizontal stage (11).

Then, in order to correct the position shift amount in the Y direction, the arm (13) is lifted by the vertical stage (12), the liquid crystal display element substrate (14) is suction-held above the mounting table (16), and the horizontal stage (11 ), The liquid crystal display element substrate (14) is horizontally moved so that the Y direction displacement amount StepY becomes zero. Then, after the horizontal movement is completed, the arm (13) by the vertical stage (12) is lowered to mount the liquid crystal display element substrate (14) again on the mounting table (16). With the above, the correction of the positional deviation in the Y direction is completed.

In addition, the rotary stage (15) has a liquid crystal display element substrate (14).
Is rotated by 90 °, and the X-direction positional deviation amount is corrected in the same manner as the Y-direction positional deviation amount is corrected. That is, after rotating the liquid crystal display element substrate (90) by 90 °, the vertical stage (12) raises the arm (13) and sucks and holds the liquid crystal display element substrate (14) above the mounting table (16). The liquid crystal display element substrate (14) is horizontally moved so that the position shift amount StepX in the X direction becomes zero by the fine movement of the horizontal stage (11). After that, the arm (13) is lowered by the vertical stage (12), and the mounting table (1
The liquid crystal display element substrate (14) is placed on 6), and the liquid crystal display element substrate (14) is rotated 90 ° again by the rotating stage (15). This completes the correction of the Y-direction position shift amount.

In other words, by the positional deviation correction operation by the command control signal of the control unit (18), the long side of the liquid crystal display element substrate (14) is parallel to the moving direction of the parallel stage (11), and the center of rotation at the substrate center (23) ( The precision automatic positioning of the liquid crystal display element substrate (14) matching with 20) is completed.

Then, the liquid crystal display element substrate (14) after the alignment is completed.
Is inspected by energizing the energization type test head above the mounting table (16) (not shown) with a step-down voltage, and is transferred to a chemical reaction chamber or the like by a hand arm (not shown).

As a result, in the precision automatic positioning, the sizes l _x and l _{y of} the liquid crystal display element substrate (14) input by the operator, the rotation center (20) of the mounting table (16) stored in advance, and the rotation center ( The intersection (24a) between the imaginary circle of the sensor (17a to 17e) drawn centering on 20) and the side edge of the liquid crystal display element substrate (14).
The position and angle of the liquid crystal display element substrate (14) can be calculated by the control section (18) from the information of (~ 24h), so the mounting positions of the sensors (17a-17e) need not be precise. Since it suffices to be able to detect, the detection width may be narrow, detection control is simple, and an inexpensive and small sensor can be used.

In the above embodiment, the liquid crystal display element substrate in which the positioned body having a shape not depending on the constant radius is the rectangular plate-shaped body has been described, but it may be a square-shaped body, a triangular-shaped body, or a light-transmitting body. The object to be positioned may be a to-be-positioned object, a non-transparent object to be positioned, or any object having a shape not depending on a fixed radius.

Further, in the above-described embodiment, at least one sensor for detecting the side edge of the positioned object and a means for relatively rotating the positioned object and the sensor around the mounting table are provided, and the positioned object and the sensor are relatively moved. The device for detecting the intersection of the virtual circle of the sensor drawn by rotating the side and the side edge of the object to be positioned has been described, but the virtual circle drawn by the center of the mounting table stored in advance and the object to be positioned are described. Anything can be used as long as it can detect the intersection with the side edge, and by using a pattern recognition device having an imaging means, a virtual circle drawn by the center of the mounting table stored in advance and the side edge of the object to be positioned imaged by the imaging means. The intersection may be detected by performing image processing.

Further, the means for detecting the intersection of the virtual circle and the side edge of the body to be positioned in the above-mentioned embodiment is provided with five opposite type photodiodes on a straight line passing through the center of the mounting table, and two out of five are provided. Although it has been described using one piece, one piece may be provided as long as it is installed at a position where the side edge of the object to be positioned can be detected, and any number of pieces may be installed according to various kinds of objects to be positioned. It goes without saying that any detection method may be used without being limited to the reflection type photodiode as long as it can detect the side edge of the body.

Further, in the above-mentioned embodiment, the sensor for detecting the side edge of the object to be positioned is fixed and the object to be positioned is rotated, but it is sufficient if the object to be positioned and the sensor are relatively rotated around the mounting table. The body may be fixed and the sensor may be rotated.

Further, in the above embodiment, the rotation center (20) and the substrate center (2
Positioning was performed so that the moving direction of 3) and the horizontal stage (11) and the long side direction of the liquid crystal display element substrate (14) match.
Needless to say, it can be adjusted to a desired angle and position, and the present invention is not limited to the above embodiment.

As described above, according to this embodiment, the sensor for detecting the side edge of the liquid crystal display element substrate and the means for relatively rotating the liquid crystal display element substrate and the sensor about the mounting table are provided. The intersection of the virtual circle of the sensor drawn by rotating the element substrate and the sensor relative to the side edge of the liquid crystal display element substrate is detected, and the detected intersection and the position information of the center are used to determine the X direction and the Y direction. The liquid crystal display device substrate is provided with a means for calculating the amount of positional deviation of the liquid crystal and a means for correcting the position of the liquid crystal display element substrate based on the amount of positional deviation obtained by this means. Precise automatic positioning of display elements is possible.

〔The invention's effect〕

As described above, according to the present invention, when positioning a quadrangular object to be positioned on the mounting table, an imaginary circle centered on the center of the mounting table stored in advance and a side edge of the object to be positioned. The step of detecting the intersection, the angle formed by the two intersections of one long side of the body to be positioned and the virtual circle with the center of the mounting table is θy, and the other long side of the body to be positioned and the virtual When the angle formed by the two intersections with the circle and the center of the mounting table is θy ′ and the short side lx of the object to be positioned is the amount of deviation in the x direction of the center of the object to be positioned by the first calculation formula. The angle between the two intersections of one long side of the object to be positioned and the virtual circle and the center of the mounting table is θx, and 2 between the other long side of the object and the virtual circle is calculated. The angle between the two intersections and the center of the table is θx ′, the long side of the object to be positioned ly
In this case, a step of calculating the amount of deviation of the center of the object to be positioned in the y direction by the second calculation formula and a step of correcting the position of the object to be positioned from the amount of position deviation obtained in this step are provided. As a result, the means for detecting the side edge of the body to be positioned that does not have a constant radius does not require mounting accuracy, etc., and detection control is easy, which makes it possible to realize a rated price and downsizing. Thus, it is possible to efficiently and precisely position the object to be positioned, which does not have a constant radius, and improve the production efficiency.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a positioning device in a method of positioning a positioned object according to the present invention, FIG. 2 is a diagram for explaining detection of a positioned object in the positioning device of FIG. 1, and FIG. FIG. 4 is a block diagram showing a positioning operation in the positioning device, and FIG. 4 is a configuration diagram of a conventional automatic positioning device. In the figure, 13 ... Arm 14 ... Liquid crystal display element substrate 15 ... Rotation stage, 16 ... Mounting table 17a to 17e ... Sensor, 18 ... Control unit 20 ... Rotation center, 21, 22 ... Virtual Circle 23 …… Center of board, 24a ～ 24h …… Intersection

Claims (4)

[Claims] 1. A step of detecting an intersection of a preliminarily stored virtual circle centered on the center of the mounting table and a side edge of the positioning target when positioning the rectangular positioning target on the mounting table. , The angle between two intersections of one long side of the object to be positioned and the virtual circle and the center of the mounting table is θy, and two intersections of the other long side of the object to be positioned and the virtual circle When the angle between the center of the mounting table and the center of the table is θy ′ and the short side lx of the body to be positioned, the displacement amount of the center of the body to be positioned in the x direction is calculated by the first calculation formula, and the body to be positioned is calculated. The angle between the two intersections of one of the long sides of the above-mentioned virtual circle and the center of the mounting table is θx, the two intersections of the other long side of the object to be positioned and the above-mentioned virtual circle, and the mounting table described above. When the angle formed by the center of the object is θx 'and the long side of the object is ly, the center of the object is in the y direction. Step and positioning method characterized by comprising; and a step of correcting the position of the positioning body from a position deviation amount obtained by the step of calculating a shift amount in the second equation. 2. A positioning device for positioning an object to be positioned on a mounting table, at least one sensor provided to detect a side edge of the object to be positioned, the sensor and the mounting table described above. Detects an intersection of a means for relatively rotating with the center as a rotation axis, and a side edge of the positioned body of the sensor output drawn by this means and a virtual circle centered on the center of the above-mentioned mounting table stored in advance. Means for calculating the amount of positional deviation in the X and Y directions from the position information of the intersection and the center obtained by this means and the shape data of the object to be positioned, and from the amount of positional deviation obtained by this means. A positioning device comprising means for correcting the position of an object to be positioned. 3. The positioning device according to claim 2, wherein the virtual circle is a locus circle of the sensor drawn by relatively rotating the object to be positioned and the sensor. 4. The positioning device according to claim 2, wherein the object to be positioned is a liquid crystal display element substrate.