JPWO2016207997A1 - Substrate detection pad using substrate detection sensor - Google Patents

Abstract

The substrate detection sensor (1) includes a coil (2) that constitutes an LC circuit, an oscillation circuit (4) that supplies current to the coil (2), and a detection circuit that detects a change in inductance of the coil (2). (3) and a CPU (6) that analyzes the number information of the substrates in proximity to the coil (2) from the result of the detection circuit (3), the detection circuit (5) includes the coil ( 2), the change of the resonance frequency when the high-frequency magnetic flux generated by the flow of the current changes is detected as the change of the inductance, and the CPU (6) detects the inductance of the coil (2) in advance of the substrate. Information on the number of substrates is analyzed by comparing the reference value with the inductance of the coil (2) detected by the detection circuit (5).

Description

  The present invention relates to a substrate detection sensor for grasping the number of substrates when the substrates are conveyed one by one in a substrate manufacturing process, and a substrate suction pad using the same.

  When a substrate is handled in the substrate manufacturing process, the substrate may be transported one by one and the processing may be performed for each one. At this time, the substrates are stacked and stored, and the substrates are taken out one by one and transported. A substrate suction pad that sucks the substrate is used for this removal. The suction pad is for bringing the pad portion into contact with the substrate and holding and transporting the substrate with a suction force.

  However, there is a case where a through hole penetrating the substrate itself is formed in the substrate, and suction by the suction pad may suck and hold the substrate located below the substrate to be transported through the through hole. . Alternatively, even when a suction pad having a function of preventing such erroneous suction is used or when a substrate having no through hole is transported, the smooth substrate surfaces overlap and the two substrates are It may be transported while overlapping.

  Such a phenomenon is called “two-sheet picking”. It is known to measure the thickness of the conveyed substrate in order to prevent the substrate from being transported with two sheets taken and the next process being performed (see, for example, Patent Document 1). The content disclosed in Patent Document 1 is to detect the double-cutting by measuring the thickness of the substrate.

JP 2000-349497 A

  However, in order to measure the thickness of the substrate, it is necessary to provide a contact portion for directly detecting the position on the substrate using a potentiometer. For this reason, the structure is complicated, and it is not preferable in terms of the quality of the substrate to contact another member with the substrate itself.

  SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described prior art, and an object thereof is to provide a substrate detection sensor capable of detecting the presence or absence of two sheets without touching the substrate and a substrate suction pad using the same with a simple structure. To do.

  In order to achieve the above object, in the present invention, a coil constituting an LC circuit, an oscillation circuit that supplies current to the coil, a detection circuit that detects a change in inductance of the coil, and a result of the detection circuit And a CPU for analyzing information on the number of substrates adjacent to the coil, wherein the detection circuit changes the resonance frequency when the high-frequency magnetic flux generated by the current flowing through the coil changes. The CPU stores the inductance of the coil in advance as a reference value according to the number of the substrates, and collates the inductance of the coil detected by the detection circuit with the reference value, and Provided is a substrate detection sensor characterized by analyzing the number of substrates information.

  Further, in the present invention, a suction part that contacts the substrate, a head in which a suction path that is continuous with the suction part is formed, a suction hose that communicates with the suction path in the head, A bobbin integrated with the head covering the periphery of the head, the coil being wound around the bobbin, and the oscillation circuit, the detection circuit, and the CPU are directly attached to the head. A substrate suction pad is provided.

  In a preferable configuration example of the substrate detection sensor, the substrate detection sensor includes a mounting table on which the substrate is to be mounted, and the mounting table includes a resin top plate and a base having an accommodation space covered by the top plate, The coil is accommodated in the accommodation space, and the oscillation circuit, the detection circuit, and the CPU are directly attached to the mounting table.

  According to the present invention, since the number of substrates is grasped by the change in inductance of the coil constituting the LC circuit, only the coil, the oscillation circuit, the detection circuit, and the CPU are necessary. That is, the number of substrates can be recognized with a simple structure, and the presence / absence of two substrates can be detected. Moreover, since the high frequency magnetic flux generated from the coil is used for grasping the number of substrates, it is possible to detect the presence / absence of two substrates without touching the substrates.

  Further, by applying the substrate detection sensor to the substrate suction pad, it is possible to detect the two-sheet picking when the substrate is transported. Therefore, it can be detected more quickly than when two sheets are picked up after being conveyed. Since the oscillation circuit, the detection circuit, and the CPU are directly attached to the head, the position with respect to the coil is close, and thus the position of the conductive wire forming the coil can be fixed. For this reason, it is possible to prevent the inductance of the coil from being changed due to a change in the position of the conducting wire during the detection of the two pieces, and the detection accuracy of the two pieces is improved.

  Further, as another substrate detection sensor, by using a mounting table in which a coil is housed, when there is a process of temporarily mounting a substrate during substrate transport, the two-piece picking is detected during this process. be able to. At this time, since the oscillation circuit, the detection circuit, and the CPU are directly attached to the mounting table, the position with respect to the coil becomes close, and therefore the position of the conducting wire forming the coil can be fixed. For this reason, it is possible to prevent the inductance of the coil from being changed due to a change in the position of the conducting wire during the detection of the two sheets, and to perform the detection operation of the two sheets with high reproducibility.

It is the schematic of the board | substrate detection sensor which concerns on this invention. It is the schematic of the board | substrate adsorption pad which concerns on this invention. It is the schematic of another board | substrate detection sensor which concerns on this invention. It is the schematic of a coil.

  As shown in FIG. 1, the board | substrate detection sensor 1 which concerns on this invention has the coil 2 and the detection unit 3 connected to this. The coil 2 forms an LC circuit in cooperation with a capacitor (not shown). Using this LC circuit, the coil 2 can oscillate a signal having a specific frequency. The detection unit 3 includes an oscillation circuit 4. The oscillation circuit 4 is for supplying a current to the coil 2. A magnetic field (high-frequency magnetic flux) is formed in the coil 2 by the current from the oscillation circuit 4. When there is a change in this magnetic field, a current change occurs in the coil 2. This change causes a change in inductance. The oscillation device 4 also includes a detection circuit 5 that detects this change in inductance. The coil 2 may be a winding by using a normal magnet wire or a coil pattern formed by applying a printed board or a flexible board. By making the coil 2 into a thin sheet shape, it can be installed even in a small space.

  This change in the magnetic field of the coil 2 occurs when the substrate (see FIGS. 2 and 3) is brought close to the coil 2. That is, since there is a conductor pattern formed of a conductive material such as copper on the substrate, the magnetic field is changed by this conductor pattern. Specifically, when a constant current is passed through the coil 2 by the oscillation circuit 4, a constant inductance value is detected by the detection circuit 5 when there is no substrate, but the inductance value decreases when there is a substrate. The oscillation frequency (resonance frequency) of the LC circuit increases. The presence / absence of a substrate close to the coil 2 can be detected by the change in inductance. In addition, when two substrates are overlapped, the inductance value further decreases (the oscillation frequency further increases). Due to this difference, the presence or absence of the substrate and the number of substrates can be detected. In other words, the detection circuit 5 detects a change in the resonance frequency when the high-frequency magnetic flux generated by the current flowing through the coil 2 changes as a change in inductance.

  The determination of the number of substrates is performed by the CPU 6 included in the detection unit 3. That is, the CPU 6 analyzes the information on the number of substrates adjacent to the coil 2 from the result of the detection circuit 5 (change in inductance and oscillation frequency). That is, the CPU 6 stores in advance the inductance of the coil 2 as a reference value according to the number of substrates. The CPU 6 collates the inductance of the coil 2 detected by the detection circuit 5 with the stored reference value, and analyzes the number information of the substrates. As the reference value, only a value when the substrate is close to the single coil 2 may be stored. This is because even if this value is stored, if the inductance increases above the reference value, it indicates that there is no substrate, and if it decreases, it indicates that two substrates overlap. When the comparison in the CPU 6 is performed using the oscillation frequency, a comparison method using an FV (frequency-voltage) conversion circuit and an analog voltage may be used.

  Thus, since the number of substrates can be grasped by the change in inductance of the coil 2 constituting the LC circuit, the coil 2 and the detection unit 3 (the oscillation circuit 4, the detection circuit 5, and the CPU 6) are necessary members for the sensor 1. It becomes only. That is, the number of substrates can be recognized with a simple structure, and the presence / absence of two substrates can be detected. Moreover, since the high frequency magnetic flux (inductance) produced | generated from the coil 2 is utilized for grasping | ascertaining the number of board | substrates, the presence or absence of 2 board picking can be detected, without touching a board | substrate.

  When two substrates are overlapped, that is, when two sheets are detected, the information is sent from the detection unit 3 to the control device 7. This information is transmitted using digital I / O and various communication signals in conjunction with use on the control device 7 side. The control device 7 controls the steps in the substrate manufacturing process based on the information. For example, when two sheets are overlapped, all the substrates are temporarily returned and the substrates are taken out again, or the conveyance of the substrates is canceled until the two manufacturing processes are completed. For example, a PLC (programmable logic controller) or a control PC can be used as the control device 7.

  As a preferable configuration example, there is one in which the substrate detection sensor 1 is incorporated into the substrate suction pad 8. In the substrate manufacturing process, the suction pad 8 is used for substrate conveyance. The substrate suction pad 8 is for sucking and holding the substrate and transporting it. As shown in FIG. 2, the substrate suction pad 8 includes a suction portion 10 that contacts the substrate 9. The suction part 10 penetrates the inside thereof to form a suction path. The suction unit 10 is attached to the head 11. The inside of the head 11 also penetrates and a suction path is formed. The suction path in the suction unit 10 and the suction path in the head 11 communicate with each other. The suction path in the head 11 communicates with a suction hose 12 connected to the head 11. The suction hose 12 is connected to a suction device (suction pump) (not shown). By sucking air from the suction hose 12, a negative pressure is formed at the opening of the suction portion 10 and the substrate 9 can be sucked and held. As an example of the material, the head 11 is formed of an acrylic material or the like, and the suction portion 10 is formed of a rubber material.

  A part of the periphery of the head 11 is covered with a bobbin 13. The bobbin 13 is for winding a winding forming the coil 2. That is, the coil 2 is formed around the bobbin 13. Since the bobbin 13 is attached so as to be integrated with the head 11, it moves together with the head 11. Furthermore, the detection unit 3 including the oscillation circuit 4, the detection circuit 5, and the CPU 6 is also directly attached to the head 11 and integrated. Therefore, the substrate suction pad 8 moves up and down to suck and hold the substrate 9, and the coil 2 and the detection unit 3 move together with the pad 8 even if the substrate suction pad 8 further moves left and right. This indicates that the position of the winding 14 forming the coil 2 moves while being fixed. Since the positional relationship between the detection unit 3 and the coil 2 is also fixed, the position and length of the winding 14 extending from the coil 2 to the detection unit 3 are also fixed.

  In this way, by applying the substrate detection sensor 1 to the substrate suction pad 8, it is possible to detect the two-piece taking simultaneously with the transfer of the substrate 9. Therefore, it can be detected more quickly than when two sheets are detected after the conveyance. Further, since the detection unit 3 (the oscillation circuit 4, the detection circuit 5, and the CPU 6) is directly attached to the head 11, the position of the coil 2 that is also attached to the head 11 is close, and thus a coil is formed. The position of the conducting wire (winding 14) can also be fixed. For this reason, it is possible to prevent the position of the conductive wire (winding 14) from being changed during detection of the two-piece taking (while the pad 8 is moving), and to suppress the influence of this on the inductance change of the coil 2. Therefore, the detection accuracy of two-sheet picking is improved. In FIG. 2, the control device 7 to which information is sent from the detection unit 3 is omitted.

  As another configuration example of the substrate detection sensor 1, there is one having a stage shape on which the substrate 9 is mounted. As shown in FIG. 3, the sensor 1 of this example includes a mounting table 15 on which the substrate 9 is to be mounted. The mounting table 15 is used when a substrate once transported in the substrate manufacturing process is placed on standby. In this example, the number of substrates is to be detected at that time. The mounting table 15 is formed by a top plate 16 and a base 17. The base 17 supports the top plate 16. The substrate 9 is actually placed on the top plate 16. The upper surface of the base 17 is recessed, and an accommodation space 18 is formed. This accommodation space 18 is covered with a top plate.

  The coil 2 is housed in the housing space 18. The winding 14 of the coil 2 extends from the accommodation space 18 to the outside of the base 17 and is connected to the detection unit 3 (the oscillation circuit 4, the detection circuit 5, and the CPU 6) directly attached to the base 17. With such a structure, when there is a process for placing the substrate 9 once during the transfer of the substrate 9, it is possible to detect the two-piece taking during this process. At this time, since the detection unit 3 (the oscillation circuit 4, the detection circuit 5, and the CPU 6) is directly attached to the mounting table 15, the position with respect to the coil 2 is close, and therefore the conductive wire (winding) that forms the coil 2 is used. The position 14) can also be fixed. For this reason, it is possible to prevent the inductance of the coil 2 from being changed due to a change in the position of the conducting wire (winding 14) during the detection of the two-piece taking, and to perform the two-piece detecting operation with high reproducibility. Since the top plate 16 is made of resin, the presence of the top plate 16 does not affect the inductance of the coil 2.

  Regardless of whether the sensor 1 is applied to the pad 8 or the stage shape as described above, the shape of the coil 2 is an air core as shown in FIG. The shape is not limited to an ellipse and may be a rectangular shape. By enlarging the diameter of the coil 2, the range in which the conductor pattern formed on the substrate 9 can be detected is expanded. If the coil 2 has a large diameter as described above, it is possible to detect two-pieces without adjusting the position of the coil 2 with respect to the substrate 9 having various shapes. For this reason, it is possible to suppress a situation in which it is impossible to detect two-pieces without a conductor pattern at a position corresponding to the coil 2.

  Preferably, the substrate 9 may be handled so that the conductor pattern exists at a position corresponding to the magnetic field of the coil 2 regardless of whether the sensor 1 is applied to the pad 8 or the stage shape. For example, in the case of the stage shape in FIG. 3, the position where the conductor pattern is arranged at the same time when the substrate 9 is placed is determined in advance as a conductor pattern arrangement area, and the coil is placed at a position corresponding to the conductor pattern arrangement area. Distribute two. Thereby, it is possible to reliably detect two sheets. The same applies when applied to the pad 8 of FIG.

1: substrate detection sensor, 2: coil, 3: detection unit, 4: oscillation circuit, 5: detection circuit, 6: CPU, 7: control device, 8: substrate suction pad, 9: substrate, 10: suction unit, 11 : Head, 12: Suction hose, 13: Bobbin, 14: Winding, 15: Mounting table, 16: Top plate, 17: Base, 18: Storage space,

Claims (3)

A coil constituting the LC circuit;
An oscillation circuit for supplying current to the coil;
A detection circuit for detecting a change in inductance of the coil;
A CPU for analyzing information on the number of substrates in proximity to the coil from the result of the detection circuit,
The detection circuit detects a change in resonance frequency when the high-frequency magnetic flux generated by the current flowing through the coil changes as a change in the inductance,
The CPU stores in advance the inductance of the coil as a reference value in accordance with the number of the substrates, and compares the inductance of the coil detected by the detection circuit with the reference value to determine the number of pieces of the substrate. A substrate detection sensor characterized by analyzing the above. An adsorbing portion in contact with the substrate;
A head in which a suction path continuous with the suction portion is formed;
A suction hose in communication with the suction path in the head;
A bobbin integrated with the head covering the periphery of the head;
The coil is formed by being wound around the bobbin,
The substrate suction pad using the substrate detection sensor according to claim 1, wherein the oscillation circuit, the detection circuit, and the CPU are directly attached to the head. A mounting table on which the substrate is to be mounted;
The mounting table is composed of a resin top plate and a base having a storage space covered by the top plate,
The coil is housed in the housing space;
The substrate detection sensor according to claim 1, wherein the oscillation circuit, the detection circuit, and the CPU are directly attached to the mounting table.

Images