TW201516377A - Static capacitance sensor, detection system and robot system - Google Patents

Abstract

This invention provides a static capacitance sensor having a simple construction which can be miniaturized, a detection system and a robot system. The detection system 1-1 has a static capacitance sensor 2, a rotation angle computing unit 3, and position offset computing unit 4. The static capacitance sensor 2 has a substrate 20, a guard electrode 21, a drawing electrode 22, four first electrodes 23 and two pairs of second electrode pairs 24, 25. The rotation angle computing unit 3 computes a rotation angle [theta] from an initial position of work w according to the sum of the static capacitance of overlapping parts of the first electrode 23 and work W. The position offset computing unit 4 computes the position from an initial position of work w, [delta] x in x axis direction, and [delta] y in 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 for 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 for detecting a rotation angle from an initial position of the workpiece, and the capacitance sensor is configured to arrange a plurality of first electrodes around the adsorption portion, and when the workpiece sucked by the adsorption portion is at an initial position The plurality of first electrodes are arranged such that 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 from the initial position of the workpiece 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 an initial position from the workpiece 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 one of the second electrode pairs are disposed on both sides of the x-axis, and when the workpiece sucked by the adsorption unit is at the initial position, the one side of the workpiece is placed at an overlapping position, and The two second electrodes constituting 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 is overlapped 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 from the initial position of the workpiece, 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 unit is formed by forming an adsorption electrode that adsorbs the workpiece by an electrostatic force connected to the power source, 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 a rotation angle from an initial position of the workpiece based on a sum of electrostatic capacitances generated by a plurality of overlapping portions of the first electrode and the workpiece of the capacitance sensor, 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 The offset from the initial position of the workpiece in the x-axis direction is calculated, and the shift from the initial position of the workpiece to the y-axis direction is calculated based on the change in the electrostatic capacitance generated by the overlapping portion of the other second electrode pair and 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 the seventh application of the patent application, and the second second electrode pair and the offset calculation unit included in the detection system of claim 8 are offset. The calculation unit is configured to have a function of calculating the state of the reverse rotation of the workpiece only by the rotation angle portion obtained by the rotation angle calculation unit, and generating the state based on the overlapping portion of the second electrode pair and the workpiece at the initial position. Electrostatic capacity, weight of the workpiece in the state of the second electrode pair and the counter-rotation state The difference in electrostatic capacitance generated by the stacked portions is used to determine the offset of the workpiece.

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 from the initial position of the workpiece, 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, according to the electrostatic capacitance sensor of the present invention, the protective electrode which can be laminated on the substrate by the substrate or the first dielectric layer, and the second dielectric layer can be laminated on the protective electrode. Since the first electrode and the small number of members of the adsorption portion are formed, it is possible to manufacture an electrostatic capacitance sensor having a simple structure and a small 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.

Figure 9 shows the shape of the overlap between the first electrode of the diamond and the workpiece. A schematic plan view of the state.

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 the detection system of the first embodiment of the present invention. Figure, Figure 2 is a plan view of the inspection system. Further, the electrostatic capacitance sensor 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 from an initial position of a work 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 on the side of the substrate 20, and is capable of preventing the first electrode 23 or the second electrode from the substrate 20 side. The function of the interference of the electrode pairs 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 from the initial position of the workpiece W, 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 an offset from the initial position of the workpiece W in the x-axis direction, and is rectangular in the horizontal state. The electrodes 24a and 24b are formed.

Specifically, the electrodes 24a and 24b are disposed on the x-axis, and the electrodes 24a and 24b are respectively 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 shift from the initial position of the workpiece W in the y-axis direction, and is composed of 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 the portion of the rotation angle θ from the initial position of the workpiece W 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 capacity of the portion corresponds to the work. The rotation angle of the piece W changes.

In the present embodiment, the sum of the electrostatic capacitances generated by the overlapping portions of the four first electrodes 23 and the workpiece W when the workpiece W is rotated only from the initial position and the rotation angle θ is obtained in advance (that is, the four sets of terminals 23a and 21a) The relationship between the sum of voltages V) and the angle of rotation 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.

That is, 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 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 represents the vertices of the workpiece W. The relationship between the area S and the rotation angle θ when rotating from the initial state of the center of each of the first electrodes 23. In addition, the curve M2 indicated 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 square or rhombic first electrode 23 of 20 mm angle.

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 Narrow range at a rotation angle of θ ± 2° When the ratio 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 changes 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, Obtaining an offset δ x from the initial position of the workpiece in the x-axis direction, and calculating the initial position from the workpiece toward the y-axis according to the change in electrostatic capacitance generated by the overlapping portion of the second electrode pair 25 and the workpiece W The portion of the offset δ y of the direction.

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 offset position δ x to the position indicated by the two-dotted line from the initial position indicated by the broken line, and only the offset δ is shifted from the center O of the initial position. The center O' of x is only rotated by the angle θ at the center, and reaches the position shown by the solid line.

Here, for the sake of easy understanding, as shown in Fig. 12, only the width is L. The second electrode 24a will be described with emphasis.

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, △V/β=L. δ x...(2) where ΔV=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 small 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. After δ x+V0/β is finished, (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

In other words, when the workpiece W is shifted in the x-axis direction, and the rotation is performed, the offset calculating unit 4 calculates the offset amount δ x of the workpiece W based on the equation (3), and outputs the offset from the output terminal 4a. The amount δ x.

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 assembled to the machine. Human system.

Specifically, the inner side of the substrate 20 of the electrostatic capacitance sensor 2 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. Thus, since the workpiece W is adsorbed on the surface of the resin film 28 by the adsorption electrode 22, as shown in FIG. As shown, the workpiece W and the electrostatic capacitance sensor 2 can be lifted together by raising the robot arm 100.

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. In addition, the controller 110 rotates and moves the electrostatic capacitance sensor 2 as a whole by the robot arm 100, and The workpiece W only reversely rotates the rotation angle θ, and only moves the offset amounts δ x and δ y in the x-axis direction and the y-axis direction, and corrects the workpiece W to the initial position.

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 rotation angle Detect a dedicated system.

Specifically, the detection system 1-2 includes the capacitance sensor 2 and the rotation angle calculation unit 3, and the capacitance sensor 2 does not have the second electrode pairs 24 and 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.

2‧‧‧Electrostatic capacity sensor

3‧‧‧Rotation Angle Calculation Department

3a, 3b, 4a‧‧‧ output

4‧‧‧Offset Calculation Department

20‧‧‧Substrate

21‧‧‧Protective electrode

21a, 23a‧‧‧ terminals

22‧‧‧Adsorption electrode

22a, 22b‧‧‧ electrodes

23‧‧‧1st electrode

24, 25‧‧‧2nd electrode pair

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

δ x, δ y‧‧‧ offset

θ‧‧‧Rotation angle

Claims (10)

An electrostatic capacitance sensor includes a protective electrode that is laminated on a substrate and grounded by interposing a first dielectric layer, and a plurality of first electrodes that are disposed on the protective electrode by interposing a second dielectric layer And an adsorption portion for adsorbing the polygonal workpiece, and maintaining the opposite distance between the first electrode and the workpiece, the electrostatic capacitance sensor for detecting the rotation angle of the initial position from the workpiece In the electrostatic capacitance sensor, the plurality of first electrodes are disposed around the adsorption portion, and when the workpiece adsorbed by the adsorption portion is located at the initial position, The plurality of first electrodes are disposed such that 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. An electrostatic capacity sensor comprising: a protective electrode, which is laminated on a substrate and grounded by interposing a first dielectric layer; 2 pairs of second electrode pairs are disposed on the protective electrode by interposing a second dielectric layer; and an adsorption portion for adsorbing the workpiece, and maintaining the opposing distance between the second electrode and the workpiece, the static electricity The capacity sensor is configured to detect an offset from an initial position of the workpiece, and the electrostatic amount sensor is configured to respectively arrange the two pairs of second electrode pairs in an x-axis and a y-axis orthogonal to each other in the initial position. The two second electrodes constituting one of the pair of second electrode pairs are disposed on both sides of the x-axis and are located on the workpiece adsorbed by the adsorption unit. In the initial position, the one side of the workpiece is placed at an overlapping position, and the two second electrodes constituting the other second electrode pair are disposed on both sides of the y-axis, and the workpiece is located at the initial position. At the same time, the other side of the workpiece is placed at an overlapping position. The electrostatic capacitance sensor according to claim 3, wherein each of the second electrodes has a rectangular shape or a regular square shape, and the workpiece is formed into a shape of any one of a square shape and a rectangular shape. The electrostatic capacitance sensor according to claim 1 or 2, wherein the electrostatic capacitance described in claim 3 or 4 is used. Two pairs of second electrode pairs provided by the sensor. In the electrostatic capacitance sensor according to any one of the items 1 to 5, the adsorption unit is configured to be formed by an adsorption electrode that is electrostatically connected to a power source. And adsorbing the workpiece; and the third dielectric layer having a flat surface covering the adsorption electrode, the first and second electrodes. A detection system comprising: an electrostatic capacitance sensor according to claim 1, claim 2 or 6; and a rotation angle calculation unit according to a plurality of first electrodes of the electrostatic capacitance sensor The rotation angle of the initial position from the workpiece is calculated by the sum of the electrostatic capacitance generated by the overlapping portion of the workpiece, and the rotation angle calculation unit is based on the relationship between the sum of the electrostatic capacitances obtained in advance and the rotation angle In the formula, the rotation angle of the current point is obtained from the sum of the electrostatic capacities of the current points. A detection system comprising: an electrostatic capacitance sensor according to item 3, item 4 or item 6 of the patent application scope; and an offset calculation unit according to the second aspect of the electrostatic capacitance sensor Calculating the amount of shift from the initial position of the workpiece to the x-axis direction by the change in electrostatic capacitance generated by the electrode pair and the overlap portion of the workpiece, and according to the other second electrode pair The amount of shift from the initial position of the workpiece to the y-axis direction is calculated by a change in electrostatic capacitance generated by the overlap of the workpiece, and the offset calculation unit is located in the initial stage according to the second electrode pair The amount of shift of the workpiece is determined by the difference between the electrostatic capacitance generated by the overlapping portion of the workpiece at the position and the electrostatic capacitance generated by the overlap between the second electrode pair and the workpiece at the current position. The detection system according to claim 7, wherein the two second electrode pairs and the offset calculation unit included in the detection system of claim 8 are used, and the offset calculation unit has only The portion of the rotation angle obtained by the rotation angle calculation unit calculates the state of the reverse rotation of the workpiece, 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 counter rotation In the state of the workpiece, the difference in electrostatic capacitance generated by the overlapping portion of the workpiece is used to determine the offset of the workpiece. 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.