JP2007329228A - Method of sorting coil component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of sorting coil components capable of highly accurately detecting disconnection and bad electrical contact in a short time for sorting out a defective product. <P>SOLUTION: An AC signal is input to a search coil 11, and a phase angle is detected by an LCR meter 40 as a phase angle θ1, based on current and voltage in the search coil 11 when a short-circuited good coil component is brought close onto a line of magnetic force of the search coil 11. A phase angle is detected as a phase angle θ2 based on the current and voltage in the search coil 11, when a coil component 3 to be inspected instead of the good product is brought close onto the line of magnetic force. The disconnection or loss can be determined in the coil component when an absolute value of θ1-θ2 is out of a predetermined range, since the phase angle θ2 varies depending on whether the disconnection or poor connection occurs in the component 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for selecting coil components.

Coil parts are used in large amounts in various electronic devices, and it is required to manufacture high-quality products efficiently. As a manufacturing method of such a coil component, both ends of the coil are locked to a lead piece protruding from the lead frame, the coil is held on the lead frame by soldering, and each lead is molded after each coil is molded. A method of manufacturing a coil component by punching out from a sheet is known (for example, see Patent Document 1).
JP-A-5-152129 (pages 2 and 3, FIG. 2)

  For the coil parts as described above, it is necessary to select defective products due to disconnection of the coil or poor connection between the coil and the terminal. Conventionally, the disconnection of a coil component is detected by separating the coil component from the lead frame and then measuring the resistance value for each coil component by bringing a probe into contact with a terminal.

  However, the conventional sorting method in which the probe is brought into contact with each coil component is very laborious and time consuming and is not efficient. Moreover, since the measurement result of the resistance value changes depending on the difference in the contact pressure of the probe during the measurement, there is a problem that the accuracy of the disconnection detection is lowered.

  Accordingly, an object of the present invention is to provide a method for selecting a coil component that can detect a disconnection failure of the coil component in a short time and with high accuracy.

  In order to achieve the above object, the present invention provides an AC signal input to a search coil to generate a magnetic line of force in the search coil, and a non-defective coil component in a short-circuited state is brought close to the magnetic line of force. A first detection step of measuring a current and a voltage in the search coil and detecting a phase angle based on the current and the voltage as a first phase angle; an AC signal is input to the search coil and a line of magnetic force is applied to the search coil; The current and voltage in the search coil when the coil component to be inspected that is generated and short-circuited is brought close to the line of magnetic force, and the phase angle based on the current and the voltage is determined as the second phase angle. And a determination step of determining that there is a disconnection or loss in the coil component when the difference between the first phase angle and the second phase angle is outside a predetermined range. It provides a method of sorting Le component.

  According to such a method, when the coil component is a non-defective product, the coil component is a closed circuit, and an electromotive force is generated in the coil component due to a change in magnetic field lines caused by an AC signal being input to the search coil. . When there is a loss due to poor connection or the like, the manner in which the electromotive force is generated is different. On the other hand, no electromotive force is generated when it is disconnected. Therefore, a difference occurs in the phase difference (phase angle) based on the current and voltage in the search coil.

  At this time, a first phase difference (first phase angle) when a non-defective coil component is brought close to the magnetic field line, and a second phase difference (second phase angle) when the coil component to be inspected is brought close to each other. By detecting this difference and determining whether or not it is outside the predetermined range, it is possible to determine the loss defect and disconnection defect of the coil component with high sensitivity in a non-contact state. Further, since the difference between the first phase difference when the non-defective coil component is brought close to the magnetic field line and the second phase difference when the coil component to be inspected is made closer is detected, the winding of the search coil is detected. The influence on the phase difference such as the number of turns and the distance between the search coil and the coil component can be offset. Therefore, disconnection and contact failure can be detected with high accuracy.

  The search coil preferably includes a conducting wire and a toroidal core around which the conducting wire is wound and has an open portion, and the magnetic lines of force of the search coil are generated in the open portion.

  According to such a configuration, it is possible to place the coil component closer to the magnetic field lines generated by the search coil and place it in a place where the magnetic flux density is high, and it is possible to detect a defect with higher accuracy.

  ADVANTAGE OF THE INVENTION According to this invention, the selection method of the coil components which can detect a disconnection and a contact failure with high precision in a short time, and can perform the selection of a defective product is provided.

  A method for selecting a coil component according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, the coil component sorting system 1 according to the present embodiment uses a detection circuit 100 to detect the disconnection of the coil component 3 that is short-circuited by the metal frame 5 and the presence or absence of a connection failure. This is a system for sorting out defective products.

  As shown in FIGS. 1 and 2, the coil component 3 includes a drum-type core (not shown) made of, for example, ferrite and a coil 4 formed by winding a conductive wire around the core. Both ends of the conductor of the coil 4 are positioned, for example, at both ends in the winding direction of the core winding, and both ends of the conductor of the coil 4 are short-circuited by bringing the metal frame 5 into contact with both ends of the winding. Yes. At this time, if the coil component 3 has no defects such as disconnection and poor connection, the coil 4 becomes a closed circuit. The coil component 3 is installed on a magnetic field line B1 (FIG. 2) formed by inputting an AC signal to the search coil 11. Here, the coil component 3 is placed in the vicinity of the gap 8 of the core 7 of the search coil 11 described later.

  As shown in FIG. 1, the detection circuit 100 includes an LRC meter 40 and a search coil 11 connected to current input terminals LC and HC and voltage detection terminals LP and HP. As the LCR meter 40, a commercially available device can be used. The LCR meter 40 has, for example, a substantially rectangular parallelepiped main body, and includes a display unit 43 that displays measurement values and the like, current input terminals LC and HC, and voltage detection terminals LP and HP on one side thereof. The current input terminals LC and HC are entrances and exits for the AC signal applied to the measurement target. The voltage detection terminals LP and HP are terminals for measuring the voltage across the measurement target.

  As shown in FIG. 2, an AC signal source 45, a voltmeter 47, and an ammeter 49 are provided inside the main body of the LCR meter 40. The AC signal source 45 is connected to both ends 9A and 9B of the coil 9 via an ammeter 49, current input terminals LC and HC (FIG. 1), cables 21 to 27 (FIG. 1), and terminals 16 and 20. An AC signal is applied to the measurement target (here, the search coil 11). The ammeter 49 measures the current flowing through the search coil 11. The voltmeter 47 is connected to both ends 9A and 9B of the coil 9 via an ammeter 49, voltage detection terminals LP and HP (FIG. 1), cables 21 to 27 (FIG. 1), and terminals 16 and 20. The voltage of the coil 11 is measured. Further, the LCR meter 40 includes a calculation unit (not shown) that calculates the phase difference θ based on the measured voltage and current.

  As described above, the LCR meter 40 connects the search coil 11 to the current input terminals LC and HC and the voltage detection terminals LP and HP, and supplies an AC signal having a predetermined frequency such as 100 KHz to the current input terminals LC and HC. The voltage is detected by the voltage detection terminals LP and HP in a state of being input from, and the phase difference θ based on the current and voltage in the search coil 11 is calculated and displayed on the display unit 43.

  The search coil 11 includes a substantially C-shaped toroidal core 7 having a gap 8 defined by an opening provided in a part of an annular ring, and a coil 9 formed by winding a conducting wire. Yes. The toroidal core 7 is made of, for example, Ni—Cu—Zn ferrite. The coil 9 is disposed in a portion on the opposite side of the gap 8 in the diameter direction of the toroidal core 7 and is formed by winding a conducting wire around the portion a predetermined number of times, for example, 50 turns. One end 9A of the coil 9 is connected to a connection terminal 13 and a connection terminal 15 (collectively referred to as terminal 16 in FIG. 2), and the other end 9B is connected to a connection terminal 17 and a connection terminal 19 (collectively terminal in FIG. 2). 20).

  Between the connection terminal 13 and the current input terminal HC, between the connection terminal 15 and the voltage detection terminal HP, between the connection terminal 17 and the voltage detection terminal LP, and between the connection terminal 19 and the current input terminal LC, respectively. The cables 21 to 27 covered with the shield 31 are connected.

  Next, the operation of the coil component sorting system 1 will be described. As shown in FIG. 2, when an AC signal is input from the LCR meter 40, a magnetic force line B <b> 1 is generated in the search coil 11. The magnetic lines B1 are also formed in the gap 8 of the core 7 and in the vicinity of the gap 8, and the magnetic flux density changes according to the AC signal.

  A non-defective coil component 3 that is short-circuited while an AC signal is being input from the LCR meter 40 to the search coil 11 is placed close to the vicinity of the gap 8. At this time, the number of turns of the search coil 11 and the installation position of the coil component 3 are adjusted so that the magnetic field lines B1 do not interfere with the metal frame 5. Then, an electromotive force e is generated in the coil 4 which is a closed circuit due to a change in the magnetic force line B1 due to the AC signal. At this time, the current and voltage in the search coil 11 change conversely under the influence of the magnetic force line B2 generated in the coil 4 by the electromotive force e. When there is a connection failure in the coil component 3, the way in which the electromotive force e is generated becomes smaller than that in the case of a non-defective product. When there is a disconnection, the electromotive force e hardly occurs. Depending on the state of the coil component 3, changes in current and voltage in the search coil 11 are different.

  The LCR meter 40 measures the current and voltage in the search coil 11 that is affected by the coil component 3 as described above, and displays the phase difference of the voltage with respect to the current, for example, on the display unit 43 as the phase angle θ. The phase angle θ takes a value in a different range depending on whether the coil component 3 is a non-defective product, has a poor connection, or is disconnected. That is, when there is a loss such as a connection failure or a disconnection, the phase change is smaller than the change with respect to the case where only the search coil 11 is made of the non-defective coil component 3.

  Hereinafter, a method for selecting a coil component using the coil component selection system 1 will be described with reference to FIG. As shown in FIG. 3, first, in step 151 (hereinafter, step is abbreviated as “S”), an AC current having a predetermined frequency ω is opened by the LCR meter 40 in an open state in which the search coil 11 is not connected to the connection terminals 13 to 19. Measure the phase angle with the signal and perform open correction. Next, in S152, the coil ends 9A and 9B of the search coil 11 are connected to the connection terminals 13 to 19, and the phase angle is similarly measured at the predetermined frequency ω with no conductive object in the vicinity of the search coil 11. And correct the short. By the above correction, the influence of the capacitance component, inductor component, etc. of the detector 100 itself is removed.

  Subsequently, the process proceeds to S153, where a reference coil component that has been determined to be non-defective in advance by another method such as a tester is brought close to a predetermined position near the gap 8 of the search coil 11 and installed. In a state where an AC signal having a predetermined frequency ω is input, for example, the phase angle θ1 of the voltage with respect to the current flowing through the search coil 11 is measured. After the measurement, the reference coil component is separated from the predetermined position. Instead, the coil component 3 to be inspected is short-circuited and placed at the same predetermined position near the gap 8, and an AC signal having a predetermined frequency ω is input by the LCR meter 40. The phase angle θ2 is measured in the same manner as in the case of a non-defective product (S154).

  If the absolute value of θ2−θ1 is within the first range, for example, within x degrees (Yes in S155), the coil component is determined to be non-defective (S156), and the process ends. If it is outside the first range (No in S155), it is determined whether or not the absolute value of θ2−θ1 is the second range, for example, within y degrees (y> x). (Yes in S157), the coil component 3 is determined to have a loss failure due to a connection failure or the like (S158), and the process ends. When it is not also the second range (No in S157), it is determined that there is a disconnection failure (S159), and the process ends. Note that x and y are preferably determined in consideration of variations due to measurement conditions of the reference coil phase angle θ1 and individual differences.

  Note that S153 corresponds to the first detection process, S154 corresponds to the second detection process, and S155 to S159 correspond to the determination process. The phase angle θ1 corresponds to the first phase angle, and the phase angle θ2 corresponds to the second phase angle.

  As described above in detail, according to the coil component sorting method according to the embodiment of the present invention, when the coil component is a non-defective product, the coil 4 of the coil component 3 is closed by the metal frame 5. Thus, an electromotive force e is generated in the coil component 3 due to a change in the lines of magnetic force generated when an AC signal is input to the search coil 11. When there is a loss due to poor connection or the like, the manner in which the electromotive force is generated is different. In case of disconnection, no electromotive force is generated. Therefore, a difference occurs in the phase difference (phase angle) based on the current and voltage in the search coil 11.

  At this time, the difference between the first phase difference when the non-defective coil component is brought close to the magnetic field line and the second phase difference when the coil component to be inspected is made to approach is detected, and whether or not it is outside the predetermined range. By determining the above, it is possible to determine the loss defect and disconnection defect of the coil component with high accuracy in a non-contact state. Since the determination is made based on the difference between the first phase difference and the second phase difference, the number of turns of the coil 9 of the search coil 11 and the phase difference such as the distance between the search coil 11 and the coil component 3 are affected. Can be offset. Therefore, disconnection and contact failure can be detected with high accuracy.

  Further, since the search coil 11 has the toroidal core 7 having the gap 8 and the magnetic force line B1 is generated in the gap 8 and in the vicinity of the gap 8, the coil component 3 is brought closer to the magnetic force line B1 generated by the search coil 11 and the magnetic flux density is high. It can be placed in a place, and a defect can be detected with higher accuracy.

  The coil component selection method according to the present invention is not limited to the above-described embodiments, and various modifications and improvements can be made within the scope described in the claims. For example, the shape of the coil component 3 is not limited to the above-described embodiment, and may be other shapes such as a shape having flanges at both ends of a cylinder. The search coil 11 is not limited to the one having the toroidal core 7, and may have other shapes such as an annular core, a square core, and a core having a gap in a part of the square.

  Moreover, in the said embodiment, although the metal frame 5 was used in order to make the coil component 3 a short state, it is not limited to the metal frame 5, and it is good also as a short state using another conductor.

  In the above embodiment, the coil component 3 is positioned close to the gap 8 of the search coil 11, but the positional relationship with the coil component 3 is not limited to the above, and the coil component 3 is located in the gap 8. It may be located. At this time, the width of the gap 8 in the circumferential direction of the toroidal core 11 is preferably longer than the length of the coil component 3 in the winding direction of the coil 4.

  In the above-described embodiment, the method of performing the defective product determination for one coil component 3 has been described. However, if the process returns to S154 without ending in the flowchart of FIG. Can be continuously determined.

  Furthermore, in the detection circuit 100 according to the above-described embodiment, the example using the commercially available LCR meter 40 has been described. However, a dedicated measuring instrument having the above functions and configuration may be used.

  The coil component selection method of the present invention can be used as a coil component selection method used in various electronic devices.

Schematic which shows the structure of the selection system used for the selection method of the coil components by one embodiment of this invention. Schematic which shows the state which the selection system used for the selection method of the coil components by one embodiment of this invention is operating. The flowchart explaining the selection method of coil components.

Explanation of symbols

1: Coil parts selection system 3: Coil parts 4: Coil 5: Metal frame 7: Core 8: Gap 9: Coil 11: Search coil 13-19: Connection terminal 40: LCR meter 43: Display unit

Claims (2)

An AC signal is input to the search coil to generate a magnetic line of force in the search coil, and the current and voltage in the search coil when a short-circuited good coil component is brought close to the magnetic line of force are measured, A first detection step of detecting a phase angle based on the current and the voltage as a first phase angle;
An AC signal is input to the search coil to generate a magnetic line of force in the search coil, and the current and voltage in the search coil when the coil part to be inspected in a short state is brought close to the magnetic line of force are measured, A second detection step of detecting a phase angle based on the current and the voltage as a second phase angle;
And a determination step of determining that the coil component is disconnected or lost when the difference between the first phase angle and the second phase angle is outside a predetermined range.   2. The coil component according to claim 1, wherein the search coil includes a conducting wire and a toroidal core having the open portion around which the conducting wire is wound, and the magnetic field lines of the search coil are generated in the open portion. Sorting method.

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