JP3269225B2 - Print coil tester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed coil for inspecting the quality of a coil printed on an insulating substrate in a non-contact manner.
It is about testers. A printed coil type transformer is constructed by combining a core with a printed coil configured by laminating a plurality of coils formed by spirally printing elongated copper foil on a flat insulating substrate. . Both ends of the printed coil of such a printed coil transformer are connected to pins pressed into an insulating substrate, and connected to an external circuit via the pins. Such a printed coil type transformer is characterized in that it can be reduced in size and is suitable for mass production as compared with a conventional transformer configured by winding a coil around a bobbin.

[0002]

2. Description of the Related Art In such a print coil type transformer, it is necessary to inspect the quality of a print coil which is a component thereof. Conventionally, this inspection has been performed by supplying a voltage through a connection pin of a primary coil pressed into an insulating substrate and measuring a secondary voltage obtained through a connection pin of a secondary coil. However, in such an inspection method, the voltage for inspection is supplied and taken out through the pins, so that it is necessary to maintain mechanical contact with the pins. After the completion of all processes as a transformer, the inspection of one coil is performed, so that the inspection time becomes long. Such a long inspection time makes it impossible to make use of the features of the printed coil type transformer suitable for mass production. Since the transformer is inspected after assembling, a defective product is not known until the final process, and a loss occurs in the test process for the defective product.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the conventional coil inspection method for a printed coil type transformer. The test can be performed by contact, thereby speeding up the inspection and increasing the efficiency.

[0004]

SUMMARY OF THE INVENTION The present invention provides a pre-test
Comprising a counter arranged sensing coil vertically at predetermined intervals in Ntokoiru, generated above using the magnetic flux interlinked with the object to be inspected printed coil printed for inspection by supplying a current to the sensing coil It is configured to inspect the quality of the coil in a non-contact manner.

[0005]

According to the present invention, the quality of the non-inspection print coil is determined by the magnetic action of the sensing coil and the print coil to be inspected.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a configuration diagram of an embodiment of a printed coil tester according to the present invention. In the figure, 10 is a flat insulating substrate 11
This is a printed coil for inspection formed by spirally printing a long and narrow copper foil. A plurality of substrates 11 including the primary and secondary coils are actually stacked on the substrate 11 on which the coil 10 is printed as described above, and a core (not shown) is combined with a through hole 12 formed in the substrate 11. A transformer is formed. The figure shows a diagram in which three printed boards indicated by symbols 11 to 31 are stacked. Substrate 2
The coils 10 are printed on 1 and 31 similarly to the substrate 11.

M is a tester according to the present invention. The tester includes a sensing coil 20 formed by spirally printing a thin and long copper foil on a flat insulating substrate 21;
The measuring device 22 is connected to the coil 20. The measuring device 22 has a function of measuring impedance,
A current generating function for supplying a current to the sensing coil 20 is provided. The current supply function may be provided separately from the measuring device 22. The sensing coil board 21 is arranged to face the printed board 11 at a predetermined interval.

The operation of the tester according to the present invention having such a configuration will be described with reference to FIG. In FIG. 2, reference numeral 10 denotes a print coil to be inspected described in FIG. 1, reference numeral 20 denotes a sensing coil which is disposed to face the print coil to be inspected at a predetermined interval, and
2 is a measuring device. As described above, by arranging the sensing coil 20 opposite the printed coil 10 to be inspected at a predetermined interval, both coils form an air-core transformer.

In such a state, the measuring device 22
When a current i is supplied to the sensing coil 20,
The coil 20 generates a magnetic flux φ. This magnetic flux φ is shown in FIG.
As shown, the print coil 10 to be inspected is linked. this
In this case, the inductance of the sensing coil 20 is L0,
The inductance of the printed coil 10 to be inspected is L1.
Then, when the print coil 10 is normal. Mutual interference between the print coil 10 and the sensing coil 20
The conductance M is given by M = k (L0
・ L1)^1/2And the value of this mutual inductance M
Is measured by the measuring device 22 as a reference value. When the print coil 10 is abnormal (short-circuited). The test print coil 10 has a closed loop.
Therefore, the inductance is only the leakage inductance L '
Which is extremely small compared to the inductance L during normal operation.
Value. As a result, the mutual inductance M '= k
(L0 ・ L1 ') ^1/2<< M. This mutual inductance
M ′ is measured by the measuring device 20 and compared with the value of M in a normal state.
Is determined to be abnormal.

As described above, when the printed coil 10 to be inspected is assembled as a transformer, a plurality of substrates 11 to 13 on which the coil 10 is printed are actually used.
1 are laminated and used integrally. Even when a plurality of printed coil substrates 11 to 31 are stacked and integrated as described above, the sensing coil 20 is arranged as shown in FIG. If even one of the plurality of print coils 10 is abnormal, the mutual inductance M changes, and the value is measured by the measuring device 22. In that case, the entire block that has been stacked and integrated is treated as a defective product.

As described above, in the present invention, the sensing coil 20 is arranged to face the print coil 10 to be inspected, and the print coil 1 is used by utilizing a change in mutual inductance caused by supplying a current to the sensing coil 20.
Since it is configured to judge the pass / fail of 0, there is no mechanical contact unlike a conventional tester, and there is no part that deteriorates even when used in a large-scale test. Moreover, since the inspection is performed at the stage of the printed coil instead of the inspection after assembling as a conventional transformer, a tester capable of detecting a defective product in an early process can be obtained.

In the above description, the mutual inductance is used as a parameter for quality determination, but the value of Q may be focused on as a measurement parameter. That is, in the configuration of FIG. 1, the sensing coil 20 and the printed coil 10 to be inspected form a parallel resonance circuit as shown in the equivalent circuit of FIG. In FIG. 3, R is a parallel loss,
C represents a capacitor. In the configuration of FIG. 1 represented by such an equivalent circuit, if ω0 is a resonance angular frequency and f is a resonance frequency, Q is Q = (R / ω0 · M) = R / 2πf · M) expressed. Here, since Q is inversely proportional to the mutual inductance M, if there is an abnormality in M, the result appears in the Q value as shown in FIG. Therefore, if the Q value is measured by the measuring device 22, the quality of the printed coil 10 can be determined. Even in such a case, it is possible to detect a defective product in a non-contact and early process. Further, impedance, reactance, and the like may be used as measurement parameters.

The relationship between the sensing coil 20 and the diameter of the print coil 10 to be inspected is such that (diameter of the sensing coil 20)> (diameter of the print coil 10 to be inspected) as shown in FIG. If there is, among the magnetic fluxes φ generated from the sensing coil 20, the magnetic flux that is not coupled to the test print coil 10 increases. As a result, there is a problem that the coupling as the air-core transformer is deteriorated, and the sensitivity of the defect detection is reduced. In this case, if the diameters of both coils are reversed as shown in FIG.
There is an advantage that the magnetic flux φ generated from zero increases the magnetic flux coupled to the print coil 10 to be inspected, thereby increasing the sensitivity and facilitating the detection of the coil abnormality.

FIG. 1 illustrates the case where the sensing coil 20 is arranged only above the printed coil 10 to be inspected. However, the sensing coil 20 may be arranged vertically. The sensing coil 2 is provided only above the print coil 10 to be inspected.
When 0 is arranged, there is a disadvantage that when a gap occurs between the two coils, the larger the distance between the two coils, the lower the defective coil detection sensitivity. On the other hand, in the configuration in which the printed coil 10 to be inspected is sandwiched between the pair of sensing coils 20, the printed coil 1 to be inspected 1
Even if 0 is farther from one sensing coil 20, it is closer to the other sensing coil. As a result, there is an advantage that the decrease in sensitivity on one side and the improvement in sensitivity on the other side are offset, and a decrease in sensitivity is prevented.

FIG. 6 shows a case where the inspection speed is increased by using a belt conveyor. In the figure, reference numeral 30 denotes a belt conveyor on which the stacked printed coils for inspection 10 shown in FIG. 1 are placed, and the coils are successively flown by the conveyor. The sensing coil 20 is fixedly disposed at one point on the printed coil 10 to be inspected. For example, the Q value of each print coil is measured by the sensing coil 20, and the quality is determined. Inspection by such means of FIG.
Inspection of a large number of print coils 10 can be automatically performed at high speed.

In the above description, the case of inspecting one non-inspection print coil in which the coil 10 is printed on the substrate 11 or an inspection of a laminate of the print coils 10 has been described. FIG. 4 is an explanatory diagram of an embodiment of the present invention in a case where inspection is performed in a state of a board 100. That is, the printed coil board 10 shown in FIG.
Reference numeral 0 denotes a state in which a plurality of non-inspection print coils 10a to 10n, each of which is stacked, are formed in a grid on a single board, and after inspection, y1 to yn and horizontal x1 to xn
, A plurality of non-inspection print coils 10 are formed.

In FIG. 7, reference numeral 20 denotes a sensing coil formed by spirally printing elongated copper foil on a flat insulating substrate 21 as described with reference to FIG. The sensing coil 20 is a printed coil board 1
00 is maintained at a fixed distance, and is arranged such that scanning in a parallel plane in the XY direction can be performed by mechanical means. Such a sensing coil 20 is connected to a measuring device 22.

In such a configuration, by scanning the sensing coil 20 on the printed coil board 100 in the XY directions, the sensing coil 20 is scanned.
Is located on any one of the printed coils 10a to 10n to be inspected, and as described with reference to FIGS. 1 and 2, a measurement current i is passed through the coil at that time to measure its characteristic parameter, thereby obtaining a reference value and a reference value. Pass / fail is determined by comparison. For example, if the Q value is used as the characteristic parameter, each print coil 10
The quality of a to 10n is determined. As described above, in the apparatus of FIG. 7, the inspection is performed on the printed coil board 100, so that the inspection can be performed at a higher speed than the inspection for one piece described in FIG.

In FIG. 7, the sensing coil 2
The magnetic coupling is weak between 0 and each of the print coils to be inspected constituting the print coil board 100 because of the air-core transformer. In order to make up for this, the printed coil board 10
The core plate may be disposed on the lower surface of the sensing coil 20 and the core plate may be disposed on the upper surface of the sensing coil 20.

In FIG. 7, the sensing coil 20
And the sensing coil is printed coil
By arranging the board 100 so that it can move in the XY directions in synchronization with the upper and lower surfaces of the board 100, as described with reference to FIG.
It is possible to prevent a decrease in detection sensitivity due to a shift in the interval between the coils.

In FIG. 7, the coil diameters of the print coils 10a to 10n to be inspected and the diameter of the sensing coil 20 are equal to (sensing coil diameter) ≦ B as shown in FIG.
(Diameter of print coil to be inspected).

FIG. 8 is a block diagram of another embodiment of the present invention. In FIG. 8, reference numeral 100 denotes a print coil board described in FIG.
0a to 10n are formed on this board. 200
Is a sensing coil board in which the number of sensing coils 20a to 20n corresponding to the number of the test print coils 10a to 10n are printed in a grid pattern on an insulating substrate so that the coils formed on both boards face each other. This sensing coil board 200 is a printed coil
It is fixedly arranged at a fixed interval with respect to the board 100.

Reference numerals 30X and 30Y denote changeover switches, respectively. The changeover switch 30X is connected to each of the coils in the X direction among the coils 20a to 20n constituting the sensing coil board 200, and the changeover switch 30Y is arranged in the Y direction. Are connected to the respective sensing coils. These switches 30X and 30Y are connected to the measuring device 22.

In such a configuration, the switch 30
The X and Y coordinates on the sensing coil board 200 selected by X and 30Y are turned on, and only the sensing coil at the intersection is activated. Therefore, by supplying the measurement current i to the activated sensing coil and measuring the characteristic parameter, the inspection coil formed on the printed coil board 100 at the position corresponding to the selected sensing coil 20a to 20n is measured. The quality of the printed coil is checked. Accordingly, by sequentially turning on the switches 30X and 30Y, the printed coils 10a to 10n to be inspected can be inspected. In this case, for example, if the Q value is used as the characteristic parameter, the quality of each print coil to be inspected is determined based on the Q value as shown in FIG. As described above, since the apparatus shown in FIG. 8 is also configured to perform the inspection on the printed coil board 100, the inspection can be performed at a higher speed than the individual inspection as described with reference to FIG. In FIG. 8, reference numeral 40 denotes a core plate used for improving the sensitivity.

FIG. 8 also shows the coil diameters of the non-inspection print coils 10a to 10n and the sensing coil 20.
Is required to be (sensing coil diameter) ≦ (inspection print coil diameter) as shown in FIG. 5B. FIG. 9 is for realizing this. In FIG.
4 sensing coils 20a1 to 20a4, 2 for each of the non-inspection print coils 10a to 10n.
0n1 to 20n4 are provided, and each sensing coil is sequentially switched by switches 30X and 30Y.

FIG. 10 shows still another embodiment of the present invention.
In each of the above-described embodiments, the case where the sensing coil 20 is arranged so as to face the printed coil 10 to be inspected at a predetermined interval is described. Is a circular hole 12 for assembling the core at the center as shown in FIG.
Are formed. FIG. 10 shows the hole 1 for assembling the core.
2 is used. In FIG.
Reference numeral 10 denotes a coil to be inspected printed on the substrate 11. At the center of the substrate 11, a circular hole 12 into which a core when this printed coil is used as a transformer is formed as described above. Reference numeral 20 denotes a sensing coil wound in a cylindrical shape, and reference numeral 22 denotes a measuring device connected to the sensing coil. At the time of inspection,
The sensing coil 20 is inserted into a hole 12 formed in the substrate 11 on which the coil under test 10 is printed.

In the tester having such a configuration, the current is supplied from the measuring device 22 to the sensing coil 20 so that the coil 10 to be inspected is supplied as described with reference to FIGS.
Is normal, the mutual inductance changes according to the above, thereby determining whether the print coil 10 is good or not. In the tester of FIG. 10 having such a configuration, FIG.
Compared to the case where the sensing coil 20 is simply arranged to face the printed coil 10 to be inspected as described above, the quality of the coil 10 to be inspected can be determined with higher sensitivity.

FIG. 10 shows a configuration in which the sensing coil 20 is wound in a hollow shape.
0 is printed on a cylindrical insulator 23. In FIG. 11, the measuring device is omitted. In addition, FIG.
The test efficiency can be increased by combining the testers 0 and 11 with a belt conveyor as shown in FIG.

FIG. 12 shows a state of the work board before cutting each print coil 10 to be inspected, and mechanically scans with the sensing coil 20 having the configuration shown in FIG. 10 is inserted into the hole 12 for assembling the core for inspection, and corresponds to FIG. 7 described above.

FIG. 13 shows the case where the inspection print coil 10 is inspected on a work board, in which the sensing coil 20 having the configuration shown in FIG. 11 is formed in a work board state, thereby enabling a high-speed batch inspection. This FIG.
Corresponds to FIG. 8, and 30X and 30Y indicate switches, respectively.

[0031]

As described above, according to the present invention,
The print coil used in the print coil type transformer can be inspected at a high speed in a non-contact manner, and a tester capable of detecting a defective product in an early process can be realized with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a tester of the present invention.

FIG. 2 is a diagram for explaining the operation of FIG. 1;

FIG. 3 is an equivalent circuit diagram of FIG.

FIG. 4 is a diagram showing measurement results of the tester of FIG.

FIG. 5 is a diagram for explaining the operation of FIG. 1;

FIG. 6 is a diagram illustrating one use mode of the tester of FIG.

FIG. 7 is a configuration diagram showing another embodiment of the tester of the present invention.

FIG. 8 is a configuration diagram showing another embodiment of the tester of the present invention.

FIG. 9 is a configuration diagram showing another embodiment of the tester of the present invention.

FIG. 10 is a configuration diagram showing another embodiment of the tester of the present invention.

FIG. 11 is a configuration diagram showing another embodiment of the tester of the present invention.

FIG. 12 is a configuration diagram showing another embodiment of the tester of the present invention.

FIG. 13 is a configuration diagram showing another embodiment of the tester of the present invention.

[Explanation of symbols]

 Reference Signs List 10 Printed coil to be inspected 11 Insulated substrate 12 Through hole 20 Sensing coil 21 Insulated substrate 22 Measuring instrument

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-62-37917 (JP, A) JP-A-5-223879 (JP, A) JP-A-4-1311734 (JP, A) 288436 (JP, A) Japanese Utility Model Showa 64-27663 (JP, U) Japanese Utility Model Showa 59-814 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01R 31/02 G01R 31 / 06 G01R 27/00 H01F 17/00 H01L 21/66

Claims (4)

(57) [Claims] An inspection print coil is provided with a sensing coil which is vertically disposed at a predetermined interval and is opposed to the inspection print coil . The sensing coil is generated by supplying a current to the sensing coil and is linked to the inspection print coil. A printed coil tester characterized in that the quality of a printed coil to be inspected is inspected in a non-contact manner using a magnetic flux. 2. A sensing coil having a plurality of print coils to be inspected arranged on a printed coil board formed in a lattice shape so as to be movable in X and Y directions, and a current is supplied to the sensing coil. claims that is configured to inspect the quality of the inspected printed coil in a non-contact manner using a magnetic flux interlinked with the corresponding inspection printed coils of generated said plurality of inspection for printed coil by The printed coil tester according to item (1) . 3. A plurality of print coils to be inspected are arranged corresponding to a printed coil board formed in a lattice, and are provided in a lattice corresponding to the number of the plurality of print coils to be inspected. A sensing coil board having a plurality of sensing coils, and a switch for switching the sensing coil formed on the sensing coil board from the X-Y direction, and a sensing coil at an intersection of X and Y switched by the switch. A non-contact inspection of the quality of the test print coil is performed by utilizing a magnetic flux generated by supplying a current to the test print coil and linked to the corresponding test print coil among the plurality of test print coils. The printed coil tester according to claim 1, wherein 4. A claim that a diameter of the sensing coil, characterized by being configured smaller than the diameter of the test printed coil (1) to (3) printed coil tester according.