TWI648518B - Static capacitance sensor, detection system and robot system - Google Patents

Abstract

The present invention provides an electrostatic capacity sensor, a detection system, and a robot system that are simple in construction and can be miniaturized.

The detection system 1-1 includes a capacitance sensor 2, a rotation angle calculation unit 3, and an offset calculation unit 4. The capacitance sensor 2 includes a substrate 20, a guard electrode 21, an adsorption electrode 22, four first electrodes 23, and two pairs of second electrode pairs 24 and 25. The rotation angle calculation unit 3 calculates the rotation angle θ of the workpiece W from the initial position based on the sum of the electrostatic capacitances of the overlapping portions of the first electrode 23 and the workpiece W. The offset calculation unit 4 determines the workpiece W from the initial position based on the change in the electrostatic capacitance between the overlapping portions of the second electrode pairs 24 and 25 and the workpiece W and the rotation angle θ from the rotation angle calculating unit 3. The offsets δ x and δ y in the axial direction and the y-axis direction.

Description

Electrostatic capacity sensor, detection system and robot system

The present invention relates to an electrostatic capacitance sensor, a detection system, and a related art of a robot system for detecting an inclination angle or a positional deviation of a workpiece from an initial position.

In the conventional technique, it is a position sensor described in Patent Document 1 of the electrostatic capacitance sensor.

The sensor measures a position sensor that moves the position of the movable table in a plane relative to the fixed portion. Specifically, the fixed electrode portions of the first to third fixed counter electrode pairs that face each other at a specific interval are connected to the fixing portion. Further, the movable electrode portions having the first to third movable electrodes inserted between the first to third fixed counter electrode pairs are connected to the movable base. Further, the first fixed counter electrode pair has a first counter electrode extending in the first direction, and the second fixed counter electrode pair has a second counter electrode extending in parallel in the first direction, and the third fixed pair The electrode pair has a third counter electrode extending in a second direction intersecting the first direction. Further, each of the first to third counter electrode systems has a change depending on the respective insertion states of the first to third movable electrodes. The electrostatic capacitance of the first to third. Further, the first and third counter electrode systems are respectively disposed at positions shifted in the first and second directions with respect to the second and first counter electrodes.

According to this, since the change in the electrostatic capacitance in the opposite direction is generated by the rotation of the moving platform, the change in the electrostatic capacitance in the opposite direction can detect the rotation angle of the moving platform as the first counter electrode and The difference in electrostatic capacitance of the second counter electrode. On the other hand, the parallel movement to the second direction of the moving platform can detect the sum of the first counter electrode and the second counter electrode by canceling the influence of the rotational movement. Further, it is possible to detect the parallel movement in the first direction of the moving platform by correcting the influence of the rotational movement on the change in the electrostatic capacitance of the third counter electrode.

Previous technical literature: Patent literature:

Patent Document 1: Japanese Laid-Open Patent Publication No. 2013-024701

However, the conventional sensor described above has a large number of electrodes for detecting changes in electrostatic capacitance, and the assembly structure between the electrodes is complicated. Therefore, the sensor itself is complicated and large-sized, and as a result, there is a problem that the number of manufacturing engineering and the manufacturing cost increase.

The present invention has been made in order to solve the above problems, and an object thereof is to provide a capacitance sensor, a detection system, and a robot system which are simple in structure and can be downsized.

In order to solve the above problem, the invention of claim 1 is an electrostatic capacitance sensor comprising: a protective electrode which is laminated on a substrate and grounded by a first dielectric layer; and a plurality of first electrodes; The second dielectric layer is disposed on the protective electrode; and the adsorption portion is configured to adsorb the polygonal workpiece and maintain the opposing distance between the first electrode and the workpiece. The electrostatic capacitance sensor The method is configured to detect a rotation angle of the workpiece from an initial position, and the capacitance sensor is configured to arrange a plurality of first electrodes around the adsorption portion, and configure the plurality of first electrodes to be: When the workpiece sucked by the portion is at the initial position, the center of each of the first electrodes is located on a straight line passing through the apexes from the center of the workpiece, and the apexes of the workpiece are located in the shape of each of the first electrodes.

According to this configuration, when the workpiece is sucked by the adsorption portion, the opposing distance between the workpiece and the first electrode can be kept constant. At this time, when the workpiece to be adsorbed is rotated from the initial position, the vertices of the workpiece are shifted from the initial position. Therefore, the sum of the electrostatic capacitances generated by the overlapping portions of the plurality of first electrodes and the workpiece differs depending on when the workpiece is at the initial position and when it is rotated from the initial position. Therefore, by considering the sum of the electrostatic capacitances generated by the overlapping portions of the plurality of first electrodes and the workpieces in the respective states, the rotation angle of the workpiece from the initial position can be detected.

The invention of claim 2, wherein in the electrostatic capacitance sensor of claim 1, the number of the first electrodes is 4, and each of the first electrodes is a circular shape, a regular square shape or a diamond shape. In either case, the workpiece is formed into a shape of any one of a square or a rectangle.

The invention of claim 3 is an electrostatic capacitance sensor comprising: a protective electrode which is laminated on a substrate and grounded by a first dielectric layer; and 2 pairs of second electrode pairs, which are intermediate dielectrics a layer disposed on the protective electrode; and an adsorption portion for adsorbing the workpiece and maintaining a fixed distance between the second electrode and the workpiece, the electrostatic capacitance sensor for detecting the workpiece from the initial position The capacitance sensor is configured such that two pairs of second electrode pairs are disposed on the x-axis and the y-axis orthogonal to each other in the initial position, and two pairs of second electrode pairs are formed. The two second electrodes of the second electrode pair are disposed on both sides of the x-axis, and are disposed at positions where one side of the workpiece overlaps when the workpiece sucked by the adsorption portion is at the initial position, and is configured The two second electrodes of the other second electrode pair are disposed on both sides of the y-axis, and are disposed at positions where the other side of the workpiece overlaps when the workpiece is at the initial position.

According to such a configuration, when the workpiece is sucked by the adsorption portion, the workpiece The opposing distance from the second electrode can be kept constant. At this time, when the workpiece to be adsorbed is shifted from the initial position to the x-axis direction, the electrostatic capacitance generated by the overlapping portion of one of the second electrode pairs and the workpiece is different from that when the workpiece is at the initial position. Therefore, the amount of displacement from the initial position of the workpiece to the x-axis direction can be detected by considering the electrostatic capacitance generated by the overlapping of the second electrode pair and the workpiece in one of the states. Further, when the workpiece is shifted from the initial position to the y-axis direction, the electrostatic capacitance generated by the overlapping portion of the other second electrode pair and the workpiece is different from when the workpiece is at the initial position. Therefore, the amount of displacement from the initial position of the workpiece to the y-axis direction can be detected by considering the electrostatic capacitance generated by the overlapping portion of the second electrode pair and the workpiece in the other state.

The invention of claim 4, wherein in the electrostatic capacitance sensor of claim 3, each of the second electrodes is formed into a rectangular shape or a regular square shape, and the workpiece is formed into a square or a rectangular shape. The composition of the shape of any one of them.

The invention of claim 5, which is in the electrostatic capacitance sensor of claim 1 or 2, is provided with an electrostatic capacitance sensor using the third or fourth aspect of the patent application scope. The pair of 2 pairs of second electrode pairs.

According to this configuration, the rotation angle of the workpiece from the initial position, the amount of shift on the x-axis, and the amount of shift on the y-axis can be detected by one electrostatic capacitance sensor.

The invention of claim 6 of the patent application is based on the electrostatic capacitance of any one of items 1 to 5 of the patent application scope. In the measuring device, the adsorption portion is formed by forming an adsorption electrode that is connected to a power source and adsorbs the workpiece by electrostatic force, and a third dielectric layer having a flat surface covering the adsorption electrode, the first And the second electrode.

The detection system of the invention of claim 7 is configured to have the following composition: an electrostatic capacitance sensor, which is any one of items 1, 2, or 6 of the patent application scope; The rotation angle calculation unit calculates the rotation angle of the workpiece from the initial position based on the sum of the electrostatic capacitances generated by the overlapping portions of the first electrode and the workpiece of the plurality of capacitance sensors, and the rotation angle calculation unit is The rotation angle of the current point is obtained from the sum of the electrostatic capacities of the current points based on the relationship between the sum of the electrostatic capacitances obtained in advance and the rotation angle.

According to this configuration, when the workpiece sucked by the adsorption portion of the capacitance sensor rotates from the initial position, the rotation angle calculation unit calculates the relationship between the sum of the electrostatic capacitances obtained in advance and the rotation angle. The sum of the electrostatic capacities of the points is used to obtain the rotation angle of the current point.

The detection system of the invention of claim 8 is configured to have the following composition: an electrostatic capacitance sensor, which is any one of items 3, 4 or 6 of the patent application scope; The offset calculation unit is based on a change in electrostatic capacitance generated by the second electrode pair on one side of the capacitance sensor and the overlapping portion of the workpiece Calculate the offset of the workpiece from the initial position to the x-axis direction, and calculate the offset of the workpiece from the initial position to the y-axis direction according to the change in the electrostatic capacitance generated by the other second electrode pair and the overlapping portion of the workpiece. And the offset amount calculation unit is based on the electrostatic capacitance generated by the overlapping portion of the second electrode pair and the workpiece located at the initial position, and the electrostatic capacitance generated by the overlapping portion of the workpiece between the second electrode pair and the current point position. Poor, find the offset of the workpiece.

According to this configuration, when the workpiece sucked by the adsorption portion of the capacitance sensor is shifted from the initial position to the x-axis direction, the offset calculation unit is based on one of the second electrode pairs and at the initial position. The amount of shift in the x-axis direction of the workpiece is obtained by the difference between the electrostatic capacitance generated by the overlapping portion of the workpiece and the electrostatic capacitance generated by the overlap between the second electrode pair and the workpiece at the current position. Further, when the workpiece is shifted from the initial position to the y-axis direction, the offset amount calculating unit is the electrostatic capacitance generated by the overlapping portion of the other second electrode pair and the workpiece located at the initial position, and the second electrode pair. The amount of shift in the y-axis direction of the workpiece is obtained by the difference in electrostatic capacitance generated by the overlap of the workpiece at the current point position.

The invention of claim 9 is in the detection system of claim 7 of the patent application, wherein the second second electrode pair and the offset calculation unit included in the detection system of claim 8 are used, and the offset is The quantity calculation unit is configured to have a function of calculating a state of a rotation angle portion obtained by the workpiece only by the reverse rotation angle calculation unit, and generating the result based on the overlapping portion of the second electrode pair and the workpiece located at the initial position. Electrostatic capacitance, overlap with the second electrode pair and the workpiece in the reverse rotation state The difference in electrostatic capacitance generated in part is obtained, and the offset of the workpiece is obtained.

According to this configuration, the rotation angle of the workpiece adsorbed to the adsorption portion of the capacitance sensor is calculated by the rotation angle calculation unit, and is calculated by the offset amount calculation unit in the x-axis direction of the workpiece and toward the y-axis. The offset of the direction. When detecting the offset amount, the offset calculation unit obtains the state of the reverse rotation of the workpiece only by the rotation angle portion obtained by the rotation angle calculation unit, and based on the second electrode pair and the workpiece at the initial position. The amount of shift of the workpiece is determined by the difference between the electrostatic capacitance generated by the overlap portion and the electrostatic capacitance generated by the overlap between the second electrode pair and the workpiece in the reverse rotation state.

The invention of claim 10, which is a robot system having a detection system according to any one of the seventh or the ninth aspect of the patent application, and is configured to have the following structure: a robot arm: a front end connection The electrostatic capacity sensor and the controller control the movement of the robot arm based on the rotation angle and the offset amount obtained by the rotation angle calculation unit and the offset calculation unit.

According to this configuration, the robot arm is based on the capacitance sensor connected to the distal end portion, and when the workpiece is sucked, the rotation angle calculation unit of the detection system calculates the rotation angle of the workpiece from the initial position, and the offset calculation unit Calculate the offset on the x-axis of the workpiece and the offset on the y-axis. In this manner, the controller controls the operation of the robot arm based on the rotation angle and the offset amount obtained by the rotation angle calculation unit and the offset calculation unit, and corrects the workpiece to a desired angle and position, and arranges the workpiece. Specific premises.

As described in detail above, the electrostatic capacitor according to the present invention The quantity sensor is a small number of first electrodes that can be laminated on the protective electrode by the substrate, the protective electrode that is laminated on the substrate by interposing the first dielectric layer, the second dielectric layer, and the adsorption portion. Since the components are constituted, it is possible to manufacture an electrostatic capacitance sensor which is simple in structure and small in size. As a result, not only can the number of manufacturing processes or the manufacturing cost of the capacitance sensor be reduced, but also the number of manufacturing processes or manufacturing costs of the detection system and the robot system including the capacitance sensor can be suppressed, and the system can have excellent effects. .

1-1 to 1-3‧‧‧Detection system

2‧‧‧Electrostatic capacity sensor

3‧‧‧Rotation Angle Calculation Department

3a, 3b, 4a‧‧‧ output

4‧‧‧Offset Calculation Department

20‧‧‧Substrate

21‧‧‧Protective electrode

21a, 23a, 24c, 24d, 25c, 25d‧‧‧ terminals

22‧‧‧Adsorption electrode

22a, 22b‧‧‧ electrodes

23‧‧‧1st electrode

24, 25‧‧‧2nd electrode pair

24a, 24b, 25a, 25b‧‧‧ second electrode

26 to 28‧‧‧ resin film

26a to 28a‧‧‧

29‧‧‧Power supply

31, 32, 41 to 44‧‧‧ wiring

100‧‧‧Robot arm

110‧‧‧ Controller

120‧‧‧ pedestal

130‧‧‧ Machine

δ x, δ y‧‧‧ offset

θ‧‧‧Rotation angle

Fig. 1 is a perspective view showing a detection system according to a first embodiment of the present invention.

Figure 2 is a plan view of the inspection system.

Fig. 3 is an exploded perspective view of the electrostatic capacity sensor.

Figure 4 is a cross-sectional view of the vector view A-A of Figure 2.

Fig. 5 is a schematic plan view showing a state in which a circular first electrode and a workpiece are overlapped.

Fig. 6 is a line diagram showing the relationship between the area of the overlapping portion of the circular first electrode and the workpiece and the rotation angle of the workpiece.

Fig. 7 is a schematic plan view showing the state of the overlapping portion of the square first electrode and the workpiece.

Fig. 8 is a line diagram showing the relationship between the area of the overlapping portion of the square first electrode and the workpiece and the rotation angle of the workpiece.

Fig. 9 is a schematic plan view showing the state of the overlapping portion of the rhombic first electrode and the workpiece.

Fig. 10 is a line diagram showing the relationship between the area of the overlapping portion of the rhombic electrode and the workpiece and the rotation angle of the workpiece.

Fig. 11 is a schematic plan view for explaining the amount of shift δ x in the x-axis direction of the workpiece.

Fig. 12 (a) to (c) are partially enlarged plan views for explaining a calculation method of the offset amount δ x .

Fig. 13 is a schematic view showing a robot system using the detecting system of the first embodiment.

Fig. 14 is a schematic view showing the entire robot system.

Fig. 15 is a schematic view showing a state in which the workpiece is lifted.

Fig. 16 is a cross-sectional view showing a state in which a workpiece is adsorbed.

Fig. 17 is a schematic view showing a state in which the offset of the workpiece is corrected.

Fig. 18 is a schematic view showing a state in which a workpiece is placed at a desired position.

Figure 19 is a plan view showing a detecting system of a second embodiment of the present invention.

Figure 20 is a plan view showing a detecting system of a third embodiment of the present invention.

Fig. 21 is a schematic view showing a modification of the arrangement of the first electrodes.

Hereinafter, the best mode for carrying out the invention will be described with reference to the drawings.

(Example 1)

Fig. 1 is a perspective view showing a detection system according to a first embodiment of the present invention, and Fig. 2 is a plan view showing a detection system. Also, there is a sense of electrostatic capacitance The detector is displayed through various electrodes.

As shown in FIGS. 1 and 2, the detection system 1-1 of the present embodiment includes a capacitance sensor 2, a rotation angle calculation unit 3, and an offset calculation unit 4.

The electrostatic capacitance sensor 2 is a sensor for calculating a rotation angle of a work from an initial position and an offset amount.

FIG. 3 is an exploded perspective view of the electrostatic capacity sensor 2. Figure 4 is a cross-sectional view of the vector view A-A of Figure 2.

As shown in FIGS. 3 and 4, the capacitance sensor 2 has a protective electrode 21 on a substrate 20, an adsorption electrode 22 on the guard electrode 21, four first electrodes 23, and two pairs of second electrodes. For 24, 25.

Specifically, the curled protective electrode 21 is formed on the extremely thin resin film 26 belonging to the first dielectric layer, and the resin film 26 is attached to the substrate 20 by the bonding material 26a. Further, the adsorption electrode 22, the four first electrodes 23, and the pair of second electrode pairs 24 and 25 are formed on the extremely thin resin film 27 belonging to the second dielectric layer, and the resin film 27 is capable of covering the protective electrode. The method of 21 is attached to the resin film 26 by the bonding material 27a. Further, the resin film 28 which is flat on the surface of the third dielectric layer is attached to the adsorption electrode 22, the four first electrodes 23, and the pair of second electrode pairs 24 and 25 by means of the bonding material 28a. On the resin film 27.

The protective electrode 21 is an electrode for canceling the change in capacitance of the substrate 20 side, and has a function of preventing interference from the substrate 20 side to the first electrode 23 or the second electrode pair 24, 25.

As shown in Fig. 2, the adsorption electrode 22 is for adsorbing the electrode of the square workpiece W shown by the two-dot chain line.

Specifically, the adsorption electrode 22 is a bipolar adsorption electrode formed of two electrodes 22a and 22b, and the adsorption electrode 22 and the resin film 28 constitute an adsorption portion.

In detail, the power source 29 is connected between the electrodes 22a and 22b. When the power source voltage is supplied to the electrodes 22a and 22b by the power source 29, the electrodes 22a and 22b are placed on the resin film 28 by electrostatic force (refer to The workpiece W on the third and fourth drawings is adsorbed on the surface of the resin film 28. That is, the adsorption electrode 22 has the entire workpiece W adsorbed on the surface of the resin film 28, and can maintain the opposing distance between the workpiece W and the first electrode 23 or the opposing distance between the workpiece W and the second electrode pair 24, 25. The function.

The four first electrodes 23 are electrodes for detecting the rotation angle of the workpiece W from the initial position, and are disposed around the adsorption electrode 22.

Specifically, the four first electrodes 23 are disposed directly above the four corners of the guard electrode 21 . Each of the first electrodes 23 is set in a circular shape, and the terminals 23a extend outward from the respective first electrodes 23.

Further, in the present embodiment, when the workpiece W is located at the initial position, the four first electrodes 23 are arranged such that the centers of the respective first electrodes 23 are aligned with the apexes P of the workpiece W.

The second electrode pair 24 is an electrode for detecting the amount of shift of the workpiece W from the initial position in the x-axis direction, and is composed of rectangular electrodes 24a and 24b in the horizontal state.

Specifically, the electrodes 24a, 24b are disposed on the x-axis, and the electrodes are 24a, 24b are located on both sides of the x-axis. Further, when the workpiece W is located at the initial position, the electrodes 24a and 24b are disposed on one side (right side) of the workpiece W such that the central portions of the electrodes 24a and 24b overlap each other.

On the other hand, the second electrode pair 25 is an electrode for detecting the amount of deviation of the workpiece W from the initial position in the y-axis direction, and is constituted by rectangular electrodes 25a and 25b in the horizontal state.

Specifically, the electrodes 25a and 25b are disposed on the y-axis orthogonal to the x-axis in the initial position, and the electrodes 25a and 25b are located on both sides of the y-axis. Further, when the workpiece W is located at the initial position, the one side (lower side) of the workpiece W is such that the electrodes 25a and 25b are disposed so that the central portions of the electrodes 25a and 25b overlap each other.

The rotation angle calculation unit 3 calculates a portion of the rotation angle θ of the workpiece W from the initial position based on the sum of the electrostatic capacitances generated by the overlapping portions of the four first electrodes 23 and the workpiece W.

Specifically, as shown in Fig. 1, the terminals 23a of the first electrodes 23 and the wirings 31 and 32 connected to the terminals 21a of the guard electrode 21 are pulled into the rotation angle calculating unit 3, and the rotation angle calculating unit 3 detects the voltage between the terminals 23a, 21a.

The voltage between the terminals 23a and 21a corresponds to the electrostatic capacitance generated by the overlap between the workpiece W and each of the first electrodes 23. Therefore, when the workpiece W is rotated from the initial position (refer to FIG. 2), the overlapping portion of the workpiece W and each of the first electrodes 23 changes, and the electrostatic capacitance of the portion changes in accordance with the rotation angle of the workpiece W.

In this embodiment, the workpiece W is preliminarily determined to rotate from the initial position. The relationship between the sum of the electrostatic capacitances generated by the overlapping portions of the first electrode 23 and the workpiece W at the rotation angle θ (that is, the sum V of the voltages between the four sets of terminals 23a and 21a) and the rotation angle θ (1) ).

θ=f(V)...(1)

The rotation angle calculation unit 3 calculates the rotation voltage θ input from the terminals 23a and 21a and the rotation angle θ from the current point to the current point based on the above formula (1), and outputs the obtained rotation angle θ from the output end 3a to the specific device. The function output from the output terminal 3b to the offset calculation unit 4.

Fig. 5 is a schematic plan view showing a state in which a circular first electrode 23 and a workpiece W overlap, and Fig. 6 is a view showing an area of a circular overlapping portion of the first electrode 23 and the workpiece W and a rotation angle of the workpiece W. A line drawing of the relationship.

As described above, the inventors used the circular first electrode 23 in the present embodiment. This is based on the results of the simulations shown in Figures 5 and 6.

In other words, as shown in Fig. 5, first, a circular first electrode 23 having a diameter of 20 mm is arranged in a square shape, and as shown by a solid line, a workpiece W having a square shape of 150 mm square is disposed on the first electrode 23. on. Further, the simulation shows the rotation angle θ and the area S of the overlapping portion of the four first electrodes 23 and the workpiece W when the workpiece W is rotated by the angle θ from the original position as shown by the dotted line of the two dots (=S1+S2+). The relationship of S3+S4). In this way, the result shown in Fig. 6 is obtained.

The curve M1 shown by the solid line in Fig. 6 indicates the relationship between the area S and the rotation angle θ when the respective vertices of the workpiece W are rotated from the initial state of the center of each of the first electrodes 23. In addition, the curve M2 shown by the broken line indicates The relationship between the area S and the rotation angle θ when the respective vertices of the workpiece W are rotated in a state where the center of each of the first electrodes 23 is shifted by 2 mm above the fifth figure. In addition, the curve M3 indicated by the two-dotted line indicates that the respective vertices of the workpiece W are rotated in a state where the center of each of the first electrodes 23 is rotated by 2 mm from the upper side of the fifth figure by 2 mm. The relationship of the rotation angle θ.

As shown in Fig. 6, the areas S of the curves M1, M2, and M3 are uniform over a wide range of the rotation angle θ of ±5°. When the range is exceeded, the area S of the curve M1 and the curve M2 are obtained. The area S and the area S of the curve M3 differ depending on the rotation angle θ.

Fig. 7 is a schematic plan view showing the state of the overlapping portion of the square first electrode 23 and the workpiece W, and Fig. 8 is a view showing the relationship between the area of the overlapping portion of the square first electrode 23 and the workpiece W and the rotation angle of the workpiece W. FIG. 9 is a schematic plan view showing a state in which a diamond-shaped overlapping portion of the first electrode 23 and the workpiece W is overlapped, and FIG. 10 is a view showing an area of a overlapping portion of the rhombic first electrode 23 and the workpiece W and the workpiece W. A line graph of the relationship of the angle of rotation.

Further, the inventors also performed the same simulation as described above for the 20 mm square or the diamond-shaped first electrode 23.

As described above, when the square or rhombic first electrode 23 is used as shown in Fig. 7 or Fig. 9, as shown in Fig. 8 or Fig. 10, the respective areas S shown by the curves M1, M2, and M3 are only In the narrow range of the rotation angle θ±2°, when the range is exceeded, the area S of the curve M1, the area S of the curve M2, and the area S of the curve M3 differ depending on the rotation angle θ.

As can be understood from the above simulation results, when the circular first electrode 23 is used, as shown in FIGS. 5 and 6, in the initial position, even if the apex of the workpiece W and the center point of the first electrode 23 are In the case of an offset, a correct relationship can be obtained between the overlap area S and the rotation angle θ in a wide range of the rotation angle θ of ±5°. In other words, by using the circular first electrode 23, the above-described formula (1) can be used to accurately calculate the rotation angle θ based on the detection voltage V over a wide range of rotation angles.

On the other hand, when the square or rhombic first electrode 23 is used, as shown in FIGS. 7 to 10, in the initial position, the apexes of the workpiece W and the center point of the first electrode 23 are somewhat offset. In this case, the correct relational expression can be obtained only between the overlap area S and the rotation angle θ within a narrow range in which the rotation angle θ is ±2°.

From this point of view, in the present embodiment, the circular first electrode 23 is used, and the rotation angle θ of the workpiece W in the offset state is accurately determined based on the voltage V. Further, the offset amount can be obtained from the second electrode pairs 24 and 25 and the offset amount calculating unit 4 which will be described later.

Further, in the present embodiment, the capacitance sensor is a circular first electrode 23, but a capacitance sensor using a square or rhombic first electrode 23 is not excluded from the scope of the present invention. Can also be used.

In the first diagram, the offset calculation unit 4 obtains the change in the electrostatic capacitance generated by the overlapping portion of the second electrode pair 24 and the workpiece W, and the rotation angle θ input by the rotation angle calculation unit 3. The offset δ x of the workpiece from the initial position toward the x-axis direction, and the electrostatic capacitance generated according to the overlapping portion of the second electrode pair 25 and the workpiece W The change is performed to calculate the portion of the workpiece that is shifted by the amount δ y from the initial position toward the y-axis.

In the second electrode pair 24, as shown in FIG. 2, the wirings 41 and 42 connected to the terminals 24c and 24d of the second electrodes 24a and 24b are pulled into the offset calculation unit 4, and the offset calculation unit is used. 4 detects the voltage between the terminals 24c, 24d. The voltage between the terminals 24c and 24d corresponds to the electrostatic capacitance generated by the overlapping portion of the workpiece W and the second electrodes 24a and 24b.

That is, when the workpiece W is displaced from the initial position to the x-axis direction and rotated, the overlapping portion of the workpiece W and the second electrodes 24a, 24b changes, and the electrostatic capacity of the portion also corresponds to the offset of the workpiece W or The angle of rotation changes. Therefore, the offset calculation unit 4 can calculate the rotation angle θ obtained by the rotation angle calculation unit 3 or the capacitance of the overlapping portion between the workpiece W and the second electrodes 24a and 24b (that is, the second electrodes 24a and 24b). The offset δ x is obtained by the voltage between them. The details are as follows.

Fig. 11 is a schematic plan view for explaining the shift amount δ x of the workpiece W in the x-axis direction, and Fig. 12 is a partially enlarged plan view for explaining the calculation method of the offset amount δ x .

As shown in Fig. 11, it is assumed that the workpiece W is offset from the center O of the initial position by only the offset δ from the initial position indicated by the broken line only after shifting the offset δ x to the position indicated by the two-dotted line. The center O' after x is rotated as the center only by the angle θ and reaches the position indicated by the solid line.

Here, for the sake of easy understanding, as shown in FIG. 12, only the second electrode 24a having a wide width L will be mainly described.

As shown in Fig. 12(a), the workpiece W is located at the initial position. When the detection voltage is V0, the capacitance of the overlap between the workpiece W and the second electrode 24a, that is, the area, can be "V0/β". Said. Where β is a coefficient (V/m ² ).

Thereafter, as shown in Fig. 12(b), the workpiece W is shifted only by the offset amount δ x in the x-axis direction, and when the detection voltage at that time is V1, the area of the overlapping portion of the workpiece W and the second electrode 24a is That is, it can be expressed as "V1/β".

Therefore, the following formula (2) is established.

V1/β-V0/β=(V1-V0)/β=L‧δ x

Therefore, ΔV/β=L‧δ x...(2)

Where △V=V1-V0

In other words, when the workpiece W is shifted in the x-axis direction and does not rotate, the offset calculating unit 4 calculates the offset amount δ x of the workpiece W based on the equation (2), and is output from the output terminal 4a (refer to Fig. 2) Output offset δ x.

Further, as shown in Fig. 12(c), when the workpiece W is rotated by only a small rotation angle θ according to the state of Fig. 12(b), and the detection voltage at that time is V2, the area of the overlapping portion of the workpiece W is Only reduce the part of the rotation. Specifically, since the rotation angle θ is a minute angle, only "L ² ‧ θ/2" of the triangle ABC of Fig. 12(c) is reduced.

Therefore, the following formula (3) is established according to the above formula (2).

V2/β+L ² ‧θ/2=V1/β=L‧δ x+V0/β

After finishing, (V2-V0)/β+(L ² ‧θ)/2=L‧δ x

Therefore, ΔV/β+(L ² ‧θ)/2=L‧δ x...(3)

Where △V=V2-V0

That is, the workpiece W is offset from the x-axis direction, and when rotated, it is biased. The shift amount calculation unit 4 calculates the offset amount δ x of the workpiece W based on the equation (3), and outputs the offset amount δ x from the output terminal 4a.

Further, the meaning of the formula (3) is as follows.

When the workpiece W is only reversely rotated by the rotation angle θ according to the state of Fig. 12(c), the workpiece W returns to the state shown in Fig. 12(b), which is as shown in the above formula (2), according to the initial stage. The offset δ x is obtained by the difference between the electrostatic capacitance (V0/β) at the position and the electrostatic capacitance (V1/β) in the reverse rotation state.

In the second electrode pair 25, as shown in FIG. 2, the wirings 43 and 44 connected to the terminals 25c and 25d of the second electrodes 25a and 25b are pulled into the rotation angle calculating unit 3, and the offset calculating unit 4 is used. The voltage between the terminals 25c and 25d is detected.

Similarly to the second electrode pair 24, the offset amount calculation unit 4 is based on the rotation angle θ obtained by the rotation angle calculation unit 3 or the overlapping portion of the workpiece W and the second electrode 25, similarly to the second electrode pair 24. The electrostatic capacitance (that is, the voltage between the second electrodes 25a and 25b) determines the amount of shift δ y of the workpiece W in the y-axis direction. Since the calculation method of the offset amount δ y at this time is also the same as the case of the offset amount δ x , the repeated description is omitted.

Next, an example of use of the detection system of the present embodiment will be described.

Fig. 13 is a schematic view showing a robot system using the detecting system 1-1 of the first embodiment.

As shown in Fig. 13, the robot system includes a robot arm 100 and a controller 110, and the detection system 1-1 of the present embodiment is incorporated in the robot system.

Specifically, the substrate 20 of the electrostatic capacitance sensor 2 The inner side is connected to the front end of the robot arm 100. The adsorption electrode 22, the wirings 31, 32, 41 to 44 extending from the first electrode 23 and the second electrode pair 24, 25 pass through the inside of the robot arm 100, and are respectively connected to the power supply 29 disposed on the controller 110 side. The rotation angle calculation unit 3 and the offset calculation unit 4.

The controller 110 is a machine for controlling the motion of the robot arm 100. The controller 110 can control not only the rotation and movement of the robot arm 100 as a whole, but also the rotation/rotation state of the power source 29 of the electrostatic capacitance sensor 2, the rotation angle θ obtained by the rotation angle calculating unit 3, and the bias. The offset amounts δ x and δ y obtained by the shift amount calculation unit 4 cause the capacitance sensor 2 at the tip end of the robot arm 100 to rotate.

Fig. 14 is a schematic view showing the entire robot system, Fig. 15 is a schematic view showing a state in which the workpiece W is lifted, and Fig. 16 is a cross-sectional view showing a state in which the workpiece W is adsorbed.

By using the robot system, for example, as shown in Fig. 14, the workpiece W placed on the pedestal 120 such as a workpiece cassette or the like can be placed on the machine 130 such as an aligner or the like at a desired angle. Hope location.

That is, in a state where the power source 29 (refer to FIG. 13) of the adsorption electrode 22 of the electrostatic capacitance sensor 2 is turned on by the controller 110, the robot arm 100 is lowered, and the electrostatic capacitance sensor 2 is placed. The surface of the resin film 28 (refer to Fig. 13) is in contact with the workpiece W. As described above, since the workpiece W is adsorbed on the surface of the resin film 28 by the adsorption electrode 22, as shown in FIG. 15, the workpiece W and the capacitance sensor 2 can be collectively raised by raising the robot arm 100. Start.

At this time, since the workpiece W is adsorbed by the adsorption electrode 22, as shown in Fig. 16, the workpiece W is not inverted as shown by a broken line, and the entire workpiece W is adsorbed to the resin as indicated by a solid line. The surface of the film 28 is. As a result, the opposing distance between the workpiece W and the first electrode 23 or the opposing distance between the workpiece W and the second electrode pair 24 (25) is maintained at a fixed distance d.

Further, as shown in FIG. 5, the workpiece W adsorbed to the electrostatic capacitance sensor 2 rotates only the rotation angle θ from the initial position, and as shown in FIG. 11, is shifted only in the x-axis direction and the y-axis direction. When the offsets δ x and δ y are first, the rotation angle θ is calculated by the rotation angle calculating unit 3 based on the above formula (1), and the rotation angle θ is output to the offset from the output ends 3a and 3b, respectively. The quantity calculation unit 4 and the controller 110. Further, in the offset calculation unit 4, the offset amounts δ x and δ y are calculated based on the rotation angle θ from the rotation angle calculation unit 3 and the above equation (3), and are output from the output terminal 4a to the controller. 110.

Fig. 17 is a schematic view showing a state in which the offset of the workpiece W is corrected, and Fig. 18 is a schematic view showing a state in which the workpiece W is placed at a desired position.

As described above, when the rotation angle θ or the deviation amounts δ x and δ y of the workpiece W are output from the rotation angle calculating unit 3 and the offset amount calculating unit 4 to the controller 110, as shown in Fig. 17, the controller The 110 series rotates the robot arm 100 as a whole to the machine 130 side. Further, the controller 110 rotates and moves the electrostatic capacitance sensor 2 as a whole by the robot arm 100, and rotates the workpiece W only by the rotation angle θ, and only moves the offset amounts δ x and δ y on the x-axis. Direction, y-axis direction, and correct workpiece W to initial position status.

In this state, as shown in Fig. 18, the controller 110 lowers the robot arm 100 to the machine 130, and the workpiece W is placed on the machine 130, and the power source 29 of the electrostatic capacity sensor 2 is turned off. The state is broken and the robot arm 100 is raised. In this manner, the workpiece W is released by the adsorption force of the adsorption electrode 22, and is disposed at a desired position on the machine 130 at a desired angle, thereby ending the conveyance of the workpiece W.

As described in detail above, the electrostatic capacitance sensor 2 used in the detecting system 1-1 according to the present embodiment is as shown in FIGS. 3 and 4, because the resin film 26 to 28 is laminated on the base. In the material 20, the protective electrode 21, the adsorption electrode 22, the first electrode 23, and the second electrode pair 24, 25 are formed on the respective resin films 26 and 27, so that the capacitance sensor 2 can be realized. As a result of miniaturization and thinning, it is possible to suppress the number of manufacturing processes or manufacturing costs of the electrostatic capacitance sensor 2, the detection system 1-1, and the robot system. In particular, when a semiconductor manufacturing system necessary for performing high-precision positioning of a workpiece using a pre-alignment meter and a master aligner uses the above-described robot system, a machine such as a pre-aligner is not required, and thus the system can be achieved. cut costs.

(Example 2)

Next, a second embodiment of the present invention will be described.

Figure 19 is a plan view showing a detecting system of a second embodiment of the present invention.

As shown in Fig. 19, the detection system 1-2 of the present embodiment is a system dedicated to the detection of the rotation angle.

Specifically, the detection system 1-2 is provided with an electrostatic capacitance sensor 2 And the rotation angle calculation unit 3, and the capacitance sensor 2 does not have the second electrode pair 24, 25.

According to this configuration, when the workpiece W (not shown) sucked by the capacitance sensor 2 rotates only the rotation angle θ from the initial position, the rotation angle calculating unit 3 calculates the rotation based on the above formula (1). The angle θ is outputted from the output end 3a.

Since the other configurations, operations, and effects are the same as those of the first embodiment described above, the description thereof will be omitted.

(Example 3)

Next, a third embodiment of the present invention will be described.

Figure 20 is a plan view showing a detecting system of a third embodiment of the present invention.

As shown in Fig. 20, the detection system 1-3 of the present embodiment is a system dedicated to offset detection.

Specifically, the detection system 1-3 includes the capacitance sensor 2 and the offset calculation unit 4, and the capacitance sensor 2 does not have the first electrode 23.

According to such a configuration, when the workpiece W (not shown) adsorbed by the electrostatic capacitance sensor 2 is offset from the initial position by only the offset amounts δ x and δ y in the x-axis direction and the y-axis direction, The shift amount calculation unit 4 calculates the offset amounts δ x and δ y based on the above formula (2), and outputs them from the output end 4a.

Since the other configurations, operations, and effects are the same as those of the first embodiment described above, the description thereof will be omitted.

The present invention is not limited to the above embodiments, and various modifications and changes can be made without departing from the spirit and scope of the invention.

For example, in the above embodiment, the adsorption electrode 22 is used as the adsorption portion, but it is of course possible to use an adhesive gasket or the like instead of the adsorption electrode 22. The surface of the adhesive pad is set to be exposed from the surface of the resin film 28, whereby the adhesive pad can perform the same function as the adsorption electrode 22.

In the above-described embodiment, the capacitance sensor 2 using the four first electrodes 23 is exemplified. However, the number of the first electrodes 23 is not limited to four, and may be arbitrarily plural. Further, although an example in which the shape of the workpiece W is set to a square is described, the shape of the workpiece W may be polygonal or rectangular.

Further, the shape of the second electrode pairs 24 and 25 is also arbitrary, and it is not limited to a rectangular shape, and a second electrode pair such as a regular square may be used.

In the above-described embodiment, as shown by the solid line in FIG. 21, in the initial position, the four first electrodes 23 are arranged such that the center of the first electrode 23 coincides with the vertex P of the workpiece W.

However, the arrangement of the first electrodes 23 is not limited to this. As shown by a dotted line or a two-dotted line in Fig. 21, in the initial position, the center of the first electrode 23 is a straight line m passing through the vertex P from the center O of the workpiece W, and the vertex P of the workpiece W is located. The first electrode 23 is disposed so as to be inside the circular shape of the first electrode 23.

Claims (10)

An electrostatic capacitance sensor comprising: a protective electrode, which is laminated on a substrate and grounded by a first dielectric layer; and a plurality of first electrodes are disposed on the protective electrode by interposing a second dielectric layer; And the adsorption portion is configured to adsorb the polygonal workpiece, and maintain the opposite distance between the first electrode and the workpiece, and the electrostatic capacitance sensor is configured to detect the electrostatic capacitance of the workpiece from the initial position. a sensor in which the plurality of first electrodes are disposed around the adsorption unit, and the plurality of first electrodes are disposed such that the workpiece is adsorbed by the adsorption unit In the initial position, the center of each of the first electrodes is located on a straight line passing through the apexes from the center of the workpiece, and the apexes of the workpiece are located in the shape of each of the first electrodes. The electrostatic capacitance sensor according to claim 1, wherein the number of the first electrodes is four, and each of the first electrodes is any one of a circular shape, a regular square shape, and a rhombic shape, and the workpiece is formed. The shape of any of a square or rectangle. The electrostatic capacitance sensor according to claim 1 or 2, wherein the pair of second electrode pairs are disposed between the second dielectric layer and the second dielectric layer And the second electrode layer is disposed on the x-axis and the y-axis orthogonal to each other in the initial position, and the second electrode constituting one of the two pairs of second electrode pairs is disposed on the second electrode layer The two second electrodes are respectively disposed on both sides of the x-axis, and are disposed at positions where one side of the workpiece overlaps when the workpiece sucked by the adsorption unit is located at the initial position, and the other one is configured The two second electrodes of the second electrode pair are disposed on both sides of the y-axis, and are disposed at positions where the other side of the workpiece overlaps when the workpiece is located at the initial position, and the capacitance sensor may be The offset of the workpiece from the initial position is detected. An electrostatic capacitance sensor comprising: a protective electrode that is laminated on a substrate and grounded by interposing a first dielectric layer; and two pairs of second electrodes are disposed on the protective electrode by interposing a second dielectric layer And an adsorption portion for adsorbing the workpiece, and maintaining an opposite distance between the second electrode and the workpiece, wherein the electrostatic capacitance sensor is configured to detect an offset of the workpiece from an initial position, and the static electricity The sensor system is configured such that the two pairs of second electrode pairs are disposed on the x-axis and the y-axis orthogonal to each other in the initial position, and the second pair constituting one of the two pairs of second electrode pairs Each of the two second electrodes of the electrode pair is disposed on both sides of the x-axis, and is disposed at a position where one side of the workpiece overlaps when the workpiece sucked by the adsorption unit is located at the initial position, and the other one is configured The two second electrodes of the second electrode pair are disposed on both sides of the y-axis, and are disposed at positions where the other side of the workpiece overlaps when the workpiece is positioned at the initial position. The electrostatic capacitance sensor according to claim 4, wherein each of the second electrodes is any one of a rectangular shape and a regular square shape, and the workpiece is formed into a shape of any one of a square shape and a rectangular shape. In the electrostatic capacitance sensor according to any one of the first aspect, the second aspect, the fourth aspect, or the fifth aspect, the adsorption unit is configured to be formed by: an adsorption electrode; The workpiece is attracted to the power source by electrostatic force; and the third dielectric layer having a flat surface covers the adsorption electrode and the first and second electrodes. A detection system comprising: an electrostatic capacitance sensor according to any one of claims 1, 2, or 6; and a rotation angle calculation unit according to the plural of the electrostatic capacitance sensor The sum of the electrostatic capacitances generated by the overlapping portions of the first electrode and the workpiece, and the rotation angle of the workpiece from the initial position The rotation angle calculation unit obtains the rotation angle of the current point from the sum of the electrostatic capacitances of the current points based on the relationship between the sum of the electrostatic capacitances obtained in advance and the rotation angle. The detection system according to claim 7, comprising: an offset calculation unit that changes a capacitance according to a capacitance generated by a second electrode pair of one of the capacitance sensors and an overlapping portion of the workpiece; Calculating an offset amount of the workpiece from the initial position to the x-axis direction, and calculating the workpiece from the initial position according to a change in electrostatic capacitance generated by the overlapping portion of the other second electrode pair and the workpiece An offset amount in the y-axis direction, and the offset amount calculation unit is based on a capacitance generated by the second electrode pair and a portion overlapping the workpiece at the initial position, and a workpiece between the second electrode pair and the current point position The offset amount of the workpiece is obtained by the difference in electrostatic capacitance generated by the overlap portion, and the offset calculation unit has a function of calculating a rotation angle portion obtained by rotating the workpiece only by the rotation angle calculation unit The state, and the electrostatic capacitance generated by the overlapping portion of the second electrode pair and the workpiece at the initial position, and the second electrode pair and the reverse rotation state The difference between the capacitance of the overlap portion produced, to obtain the offset of the work function. A detection system comprising: an electrostatic capacitance sensor according to any one of claims 4, 5, or 6; and an offset calculation unit according to the electrostatic capacitance sensor One Calculating the amount of shift of the workpiece from the initial position to the x-axis direction by the change in the electrostatic capacitance generated by the overlapping portion of the second electrode pair and the workpiece, and according to the other second electrode pair and the workpiece The offset of the workpiece from the initial position to the y-axis direction is calculated by the change in the electrostatic capacitance generated by the overlapping portion, and the offset calculating unit is based on the second electrode pair and the workpiece located at the initial position The difference between the electrostatic capacitance generated by the overlapping portion and the electrostatic capacitance generated by the overlapping portion between the second electrode pair and the workpiece at the current point position is obtained. A robot system, comprising: the detection system according to any one of claims 7 to 9, further comprising: a robot arm, the front end portion is connected to the electrostatic capacitance sensor; and a controller The operation of the robot arm is controlled based on the rotation angle and the offset amount obtained by the rotation angle calculation unit and the offset calculation unit.