JP4437927B2 - Device for measuring electrical characteristics of planar coils - Google Patents

Description

The present invention relates to electrical characteristic measuring device for measuring the electrical characteristics of the planar coil used in the antenna or the like of the non-contact IC card tag proximity-proximity type.

  Planar coils are widely used as antennas for non-contact IC cards and tags, but in order to maximize their performance (communication distance), the electrical characteristics (inductance) of the circuit (coil) must be accurately determined. Need to know. For this reason, electrical characteristics are measured for each planar coil. When measuring this electrical characteristic, in order to accurately know the electrical characteristic value, there is a method of measuring by providing a measurement terminal on the planar coil to be measured and connecting the terminal directly to a measuring machine. Has been taken.

  Although it is possible to measure without contact, in order to know accurate electrical characteristics, it was necessary to perform measurement by directly connecting a measuring machine to the planar coil.

As an example of this, there is an “inductance measuring device and its measuring probe device” described in Patent Document 1. This apparatus performs measurement by connecting two coaxial wires having a capacity to a measurement sample.
Japanese Patent Laid-Open No. 08-146060

  By the way, in the method for measuring electrical characteristics of a planar coil as described above, the electrical characteristics of a planar coil can be measured with a certain degree of accuracy. However, due to the recent increase in the amount of information, the complexity and sophistication of devices, etc. There is a demand for measuring the electrical characteristics of planar coils with higher accuracy.

  On the other hand, in the method for measuring the electrical characteristics of the planar coil as described above, the state (terminal length, connection direction) when the measurement terminal is attached to the planar coil to be measured, and the connection to the measuring machine There is a problem that a subtle difference occurs in the state or the like, and the measurement result varies due to the difference.

  Furthermore, it is very troublesome to individually attach the measurement terminals to all the planar coils to be measured, and there is a problem that quality control is not easy.

  In the case of Patent Document 1, two coaxial lines are connected to a measurement sample in a state where U-shaped wirings (U-shaped wiring composed of straight wirings and connection wirings) are connected to two coaxial lines. Therefore, the connection mechanism is complicated. Furthermore, if the routing state or length to the probe measuring machine (LCR meter) changes, it is necessary to adjust again.

The present invention has been made in view of the above problems, an object of measurement and ease of quality control, to provide an electrical characteristic measuring device of the planar coils with improved quality.

An apparatus for measuring electrical characteristics of a planar coil according to a first aspect of the present invention is directed to a measuring connection capacitor that is temporarily connected to a planar coil to be measured when measuring electrical characteristics, and facing the planar coil. A measuring coil that measures a response signal that changes according to the difference in electrical characteristics of the planar coil by passing a current at a different frequency within a set range, and having both ends of the measuring connection capacitor The measurement probe is connected to the flat coil, and the measurement probe is temporarily connected to the flat coil by contacting the flat probe with the flat probe .

With the above configuration, an oscillation circuit can be configured only during measurement by bringing the measurement probe into contact with the planar coil and temporarily connecting the measurement connection capacitor to the planar coil during measurement. When a current is passed through the measurement coil disposed facing the planar coil while changing the frequency within the set range, a response signal is sent to the measurement coil by mutual induction. And since this response signal changes according to the difference in the electrical characteristic of the said planar coil, the electrical characteristic of the said planar coil can be measured by measuring a response signal. Furthermore, since the electrical characteristics of the measurement-use connection capacitors to which the measurement probes are connected are known, when these are connected to each planar coil, variations in terminal length, connection direction, etc. may occur. Thus, the electrical characteristics of each planar coil can be accurately measured.

An apparatus for measuring electrical characteristics of a planar coil according to a second aspect of the invention includes a measuring connection capacitor connected to the planar coil when measuring the electrical characteristics of the planar coil to be measured, and the measuring connection capacitor. A measurement probe for temporarily connecting the measurement-time connection capacitor to the planar coil by contacting the planar coil by contacting the planar coil, and supporting the measurement probe during measurement with respect to the planar coil. A measuring probe connection mechanism for connecting only the plane coil, a position detecting means for detecting the position of the planar coil, and a current flowing through the planar coil by changing the frequency within the set range by facing the planar coil. A measuring coil that measures a response signal that changes according to a difference in electrical characteristics, and the position detection means that accurately measures the planar coil to be measured when measuring electrical characteristics. A measuring coil disposed so as to face the planar coil by detecting a position and bringing the measuring probe into contact with the planar coil by connecting the measuring probe to the planar coil by the measuring probe connecting mechanism. And a control means for measuring a response signal that changes in accordance with the difference in electrical characteristics of the planar coil, and an arithmetic means for deriving the inductance of the planar coil based on the change in the response signal measured by the control means. It is characterized by that.

  With the above configuration, the position detection unit detects the position of the planar coil under the control of the control unit, and when the planar coil is moved to the set position, the measurement probe connection mechanism causes the measurement probe to contact the planar coil. The oscillation circuit is composed of the connection capacitor for measurement and the planar coil. At this time, the measuring coil is disposed facing the planar coil, and a current is passed through the measuring coil at a frequency within a set range, and the response varies depending on the difference in electrical characteristics of the planar coil. Measure the signal. Next, the inductance of the planar coil is derived by the calculation means based on the change in the response signal.

A planar coil electrical characteristic measuring apparatus according to a third aspect of the present invention is the planar coil electrical characteristic measuring apparatus according to the fourth aspect of the present invention, wherein a strip-like substrate having a plurality of planar coils to be measured is arranged vertically and horizontally. A feeding mechanism for feeding out to the measuring coil side is provided, wherein the measuring connection capacitor and the measuring coil are arranged in accordance with the number of planar coils arranged in the width direction of the belt-like substrate. To do.

  With the above configuration, when the strip-shaped substrate is fed out to the measuring coil side by the feeding mechanism, each measuring coil is connected to each planar coil arranged in a row in the width direction, and each measuring coil is connected to each measuring coil. The response signal is measured at.

  As described above in detail, the thin plate support container of the present invention has the following effects.

(1) Since the electrical characteristics of the planar coil are measured based on the change in the response signal between the connecting capacitor and the planar coil during measurement, which depends only on the electrical characteristics of the planar coil, The characteristic can be easily and more accurately measured. As a result, it is possible to facilitate quality control and improve the quality of the planar coil and products using the planar coil.

(2) By connecting the measuring probe to the planar coil to connect the measuring connection capacitor to the planar coil, the electrical characteristics can be measured while suppressing variations in terminal length, connection direction, etc. The electrical characteristics of the planar coil can be accurately measured, and the quality control of the planar coil and the product using the planar coil can be facilitated and the quality can be improved.

(3) In order to detect the position of the planar coil, contact the measuring probe with the planar coil, supply a current with a different frequency to the measuring coil, measure the response signal, and derive the inductance by controlling the control means. It becomes possible to easily and more accurately measure the electrical characteristics of a large number of planar coils. As a result, it is possible to efficiently measure the electrical characteristics of a large number of planar coils, facilitating quality control and quality improvement of a large number of planar coils and a large number of products using the planar coils. .

(4) Each planar coil arranged in a line in the width direction of the belt-shaped substrate fed out by the feeding mechanism is measured simultaneously with each measuring connection capacitor and each measuring coil, and continuously measured according to the feeding of the belt-shaped substrate. Therefore, it is possible to efficiently measure the electrical characteristics of a large number of planar coils, and to facilitate the quality control and quality improvement of a large number of planar coils and a large number of products using the planar coils. .

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Electrical characteristic measuring apparatus of the planar coil of the present invention is a measurement unit for a planar coil used in the non-contact IC card tag, or the like. Specifically, such as an antenna of the contactless IC card tag proximity-proximity type, a equipment suitable for measuring the type of planar coils being thinner disposed.

[Equipment measurement device for planar coil]
First, an electrical characteristic measuring apparatus used in the planar coil electrical characteristic measuring method will be described with reference to FIGS. Note that the electrical characteristic measured here is inductance.

  The electrical characteristic measuring apparatus 1 includes a measuring connection capacitor 2, a measuring probe 3, a measuring probe connecting mechanism 4, a position detecting means 5, a measuring coil 6, a control means 7, and a calculating means 8. And a belt-like substrate feeding mechanism 9 and a mark applicator 10.

  The measurement-time connection capacitor 2 is a capacitor that is temporarily connected to the planar coil 11 to be measured when measuring electrical characteristics. The measurement connection capacitor 2 is connected to the planar coil 11 so that the measurement connection capacitor 2 and the planar coil 11 constitute an oscillation circuit. As the connection capacitor 2 at the time of measurement, a capacitor whose electrical characteristics are previously measured and known is used. As a result, among the members constituting the oscillation circuit, the electrical characteristics of the measurement-time connection capacitor 2 including the later-described measurement probe 3 are known in advance. It can be seen that this is due to the difference in electrical characteristics of the planar coil 11. Six measuring connection capacitors 2 are arranged in parallel in accordance with the number of planar coils 11 arranged in the width direction of a belt-like substrate 16 described later.

  The measurement probe 3 is a probe for temporarily connecting the measurement connection capacitor 2 to the planar coil 11 by contacting the planar coil 11. The measurement probe 3 is connected to both ends of the connection capacitor 2 at the time of measurement. Each measurement probe 3 is brought into contact with both end portions of the planar coil 11 so that the connection capacitor for measurement 2 and the planar coil 11 are connected to each other. With the measurement probe 3 connected to the measurement connection capacitor 2, the electrical characteristics of the element composed of the measurement probe 3 and the measurement connection capacitor 2 are examined in advance.

  The measurement probe connection mechanism 4 is a mechanism for supporting the measurement probe 3 and bringing it into contact with the planar coil 11 during measurement. The measurement probe connection mechanism 4 includes a support part 12 and an elevating part 13. The support part 12 is a member for supporting the measurement probe 3. The support 12 integrally supports the measurement-time connection capacitor 2 and the measurement probe 3 in a state where the measurement probe 3 is connected to the measurement-time connection capacitor 2. The elevating part 13 is a member for elevating the support part 12. The elevating unit 13 includes, for example, an elevating shaft with a screw thread and an elevating nut unit that is screwed into the elevating shaft and accurately controls the rotation angle by a stepping motor or the like to accurately move the elevating shaft up and down. The support part 12 can be moved up and down accurately. The elevating unit 13 is connected to the control means 7. The measurement probe 3 to which the support portion 12 is attached is disposed so as to extend obliquely from the outer side of the wire wound in an annular shape with respect to the planar coil 11 and to contact each end of the planar coil 11. This prevents the magnetic flux penetrating through the annular planar coil 11 from being affected, and ensures that the tip of each measurement probe 3 is attached to both ends of the planar coil 11 by the bending (elastic deformation) of the measurement probe 3. It is for making it contact. The measurement probe connection mechanism 4 connects the measurement probe 3 to the planar coil 11 only at the time of measurement.

  The position detection means 5 is a means for detecting the position of the planar coil 11. Various types of position detecting means 5 can be used. A sensor for detecting the boundary of the planar coil 11 from the reflection state of the light or the image to identify the positions of both ends of the planar coil 11, or a mark or notch directly attached to the belt-like substrate 16 to be described later is detected. A sensor or the like that identifies the positions of both ends of the planar coil 11 from the position can be used.

  The measuring coil 6 is a coil for measuring a response signal from the planar coil 11. The measuring coil 6 is disposed facing the planar coil 11. Specifically, it is a position that is aligned with the planar coil 11 at a position (measurement position) where the both ends of the planar coil 11 and the tip of each measurement probe 3 are aligned, and is 5 to 5 from the lower surface of the belt-like substrate 16. They are spaced about 10 mm apart. A measuring unit 15 is connected to the measuring coil 6. The measuring unit 15 has a function of adjusting the frequency of the alternating current supplied to the measuring coil 6 and a function of detecting a response signal from the planar coil 11. Thereby, the measurement unit 15 changes the frequency of the current within the set range (for example, a range of 10 to 15 MHz centered on the reference frequency of 13.56 MHz) and supplies it to the measurement coil 6, and the response signal from the planar coil 11. Is detected. Since this response signal changes according to the difference in electrical characteristics of the planar coil 11, the difference in the response signal can be accurately measured by the measuring unit 15. Similar to the measuring connection capacitor 2, six measuring coils 6 and measuring units 15 are arranged in parallel in accordance with the number of planar coils 11 arranged in the width direction of the strip-shaped substrate 16.

  The control means 7 is a device for controlling the whole. Specifically, the control means 7 stores the processing functions of the flowchart shown in FIG.

The computing means 8 is means for deriving the inductance of the planar coil 11 based on the change in the response signal measured by the control means 7. This calculation means 8 is incorporated in the control means 7. Specifically, the computing means 8 calculates the inductance of the planar coil 11 based on the following equation.

Z: impedance of measurement system L2: inductance of measurement target coil L1: inductance of measurement coil (known)
rL: DC resistance of measuring coil (known)
r: DC resistance of the coil to be measured (theoretical calculation value is applied)
C: Capacitance of capacitor for connection during measurement (known)
M: Mutual inductance between measuring coil and measuring coil (determined by distance between coils)
w: 2π × measurement frequency [Hz]
i: Imaginary unit L2 is derived from the above equation.

  The belt-like substrate feeding mechanism 9 is a feeding mechanism for feeding the belt-like substrate 16 intermittently in the flow direction X sequentially. The belt-like substrate feeding mechanism 9 includes a feeding roll 18 around which the belt-like substrate 16 is wound, a feeding-side drive unit 19 that rotationally drives the feeding roller 18, a winding roll 20 that winds the belt-like substrate 16, and this winding roll. It is comprised from the winding side drive part 21 which rotationally drives 20. The feeding side driving unit 19 and the winding side driving unit 21 are configured by driving means such as a stepping motor that can accurately control the feeding amount of the belt-like substrate 16. The feeding side driving unit 19 and the winding side driving unit 21 are connected to the control means 7. The feeding-side driving unit 19 and the winding-side driving unit 21 controlled by the control unit 7 accurately feeds the belt-like substrate 16 and the position detecting unit 5 detects the position of the planar coil 11 to be inspected. It is designed to be positioned.

  The strip-shaped substrate 16 is a substrate in which a plurality of planar coils 11 to be measured are arranged vertically and horizontally. The strip-shaped substrate 16 is formed in a strip shape having a width of 50 cm and being elongated in the vertical direction. Six planar coils 11 are arranged in parallel with respect to the flow direction X of the strip-shaped substrate 16, and a large number are provided at intervals of 2 cm in the vertical direction.

  The mark applicator 10 is an apparatus for applying a mark to the planar coil 11 that is determined to be defective by the control means 7. The mark applicator 10 is constituted by a stamp, a printing device, or the like, and attaches a mark indicating that it is defective to the planar coil 11. Six mark appliers 10 are provided in parallel in the width direction of the belt-like substrate 16 in accordance with the planar coil 11 disposed on the belt-like substrate 16.

[Method for measuring electrical characteristics of planar coil]
Next, a method for measuring electrical characteristics of the planar coil 11 will be described. Specifically, the method of measuring the electrical characteristics of the planar coil 11 is performed under the control of the control means 7. Hereinafter, description will be made based on the flowchart of FIG.

  First, the position detector 5 detects the position of the planar coil 11 (step S1). Next, the feeding side driving unit 19 and the winding side driving unit 21 of the belt-like substrate feeding mechanism 9 are operated (step S2). As a result, the feeding roll 18 and the take-up roll 20 rotate to feed the strip-shaped substrate 16 in the flow direction X. The planar coil 11 to be measured is monitored by the position detecting means 5, and it is determined whether or not the planar coil 11 is aligned with the measurement position (step S3). If not, the process returns to step S2 to further operate the belt-like substrate feeding mechanism 9 to align the planar coil 11 with the measurement position.

  When the planar coil 11 to be measured is aligned with the measurement position, the feeding of the belt-like substrate feeding mechanism 9 is stopped (step S4). Next, the measurement probe connection mechanism 4 is activated (step S5). Thereby, the measurement probe 3 is lowered and brought into contact with both ends of the planar coil 11, and the connection capacitor for measurement 2 and the planar coil 11 are connected.

  Next, the measuring unit 15 of the measuring coil 6 is activated (step S6). Thereby, the current is passed through the measuring coil 6 while changing the frequency within the set range. The magnetic flux generated in the measuring coil 6 is changed by this current, and the oscillation circuit composed of the measuring connection capacitor and the planar coil 11 resonates and sends a response signal to the measuring coil 6. This response signal is detected by the measuring coil 6 (step S7). Then, the inductance is calculated by the calculation means 8 based on the detected response signal (step S8).

  Next, it is determined whether or not the calculated inductance is within the set value (step S9). If it exceeds the set value, it is determined as a defective product, and the flat coil 11 is marked with the mark applier 10 (step S10). The mark may be applied to the defective product position on the spot where it is determined as a defective product, or the defective device position may be stored by the control means 7 and applied at the next intermittent feed stop. good. The mark applicator 10 is attached at a position corresponding to the mode of applying the mark.

  Next, returning to step S1, the electrical characteristics of the planar coil 11 in the next row are measured.

Next, an example in which the inductance value of the planar coil 11 is actually measured by the above-described electrical characteristic measuring method will be shown below. Here, the planar coil 11 having the same performance was applied to the sample number 25 by the conventional method and the sample number 25 by the method of the present invention.

  As a result, as shown in the above table, the standard deviation was improved to ½ or less.

  Thereby, the electrical characteristics of the planar coil 11 can be measured more accurately. Furthermore, it becomes easy to measure the electrical characteristics of the planar coil 11. As a result, the quality control of the planar coil 11 and the product using the planar coil 11 is facilitated, and the quality can be improved.

[Modification]
(1) In the above embodiment, the measurement probe 3 is connected to the measurement connection capacitor 2 and the measurement connection capacitor 2 is temporarily connected to the planar coil 11 during measurement. The connection capacitor 2 for measurement may be connected with solder or the like. In this case, the measurement connection capacitor 2, the measurement probe 3, and the measurement probe connection mechanism 4 are not required. Also in this case, the same operations and effects as the above embodiment can be achieved.

(2) In the above embodiment, the strip-shaped substrate 16 in which a large number of planar coils 11 are arranged in the vertical and horizontal directions is used as a measurement target. It goes without saying that it may be arranged in rows.

(3) In the above embodiment, the mark applicator 10 is provided to identify the planar coil 11, but other means such as making a hole may be used. Also in this case, the same operations and effects as the above embodiment can be achieved.

It is a schematic block diagram which shows the electrical property measuring apparatus of the planar coil which concerns on embodiment of this invention. It is a top view which shows the strip | belt-shaped board | substrate which arrange | positioned the planar coil which concerns on embodiment of this invention. It is a flowchart which shows the function in the control means of the electrical property measuring device which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1: Electrical characteristic measuring apparatus, 2: Capacitor for connection at the time of measurement, 3: Probe for measurement, 4: Connection mechanism for measurement probe, 5: Position detection means, 6: Coil for measurement, 7: Control means, 8: Calculation Means: 9: strip substrate feeding mechanism, 10: mark applicator, 11: planar coil, 12: support, 13: lifting unit, 15: measuring unit, 16: strip substrate, 18: feeding roll, 19: feeding side drive Part, 20: winding roll, 21: winding side drive part.

Claims (3)

A measurement-time connection capacitor that is temporarily connected to the planar coil to be measured when measuring electrical characteristics; and
A measuring coil that is arranged facing the planar coil and that measures a response signal that changes according to the difference in electrical characteristics of the planar coil by changing the frequency within a set range and passing a current ;
A measurement probe is connected to both ends of the measurement connection capacitor, and the measurement probe is temporarily connected to the planar coil by contacting the measurement probe with the planar coil during measurement. An apparatus for measuring the electrical characteristics of a planar coil. A measuring connection capacitor connected to the planar coil when measuring the electrical characteristics of the planar coil to be measured;
A measurement probe for temporarily connecting the measurement connection capacitor to the planar coil by being connected to both ends of the measurement connection capacitor and contacting the planar coil;
A measurement probe connection mechanism that supports the measurement probe and connects to the planar coil only at the time of measurement;
Position detecting means for detecting the position of the planar coil;
A measuring coil that faces the planar coil and measures a response signal that changes according to a difference in electrical characteristics of the planar coil by changing the frequency within a set range and passing a current;
When measuring the electrical characteristics, the position detecting means detects the exact position of the planar coil to be measured, and the measuring probe connecting mechanism brings the measuring probe into contact with the planar coil to connect the measuring connection capacitor. A control means for connecting to a planar coil and measuring a response signal that changes in accordance with the difference in electrical characteristics of the planar coil with a measuring coil disposed facing the planar coil;
An apparatus for measuring electrical characteristics of a planar coil, comprising: arithmetic means for deriving the inductance of the planar coil based on a change in response signal measured by the control means. The planar coil electrical characteristic measuring device according to claim 2 ,
A feeding mechanism for feeding a strip-like substrate on which a plurality of planar coils to be measured are arranged vertically and horizontally to the measuring coil side;
An apparatus for measuring electrical characteristics of a planar coil, wherein the measuring connection capacitor and the measuring coil are arranged in accordance with the number of planar coils arranged in the width direction of the strip substrate.

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