JP2019109111A - Circuit board and measuring apparatus - Google Patents

Abstract

To realize improvement of manufacturing efficiency and reduction of manufacturing cost.SOLUTION: A circuit board has four conductor layers 101a to 101d on which a wire W1 connecting a terminal Tv1a to a terminal Tv2a and a wire W2 connecting a terminal Tv1b to a terminal Tv2b are formed, and which are stacked in an order from a top surface 100u to an under surface 100b. The wire W1 comprises a conductor pattern P1 formed on the conductor layer 101a, a conductor pattern P2 formed on the conductor layer 101c, a via V1 connecting conductor patterns P1, P2 on a side of the terminals Tv1a, Tv1b, and a via V2 connecting conductor patterns P1, P2 on a side of the terminals Tv2a, Tv2b. The wire W2 comprises a conductor pattern P3 formed on the conductor layer 101b, a conductor pattern P4 formed on the conductor layer 101d, a via V3 connecting the conductor patterns P3, P4 on a side of the terminals Tv1a, Tv1b, and a via 4 connecting the conductor patterns P3, P4 on a side of the terminals Tv2a, Tv2b.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a circuit board on which a wire connecting a voltage detection unit and an object to be measured is formed, and a measuring apparatus including the circuit board.

  When measuring the measured amount of the measurement target by measuring the voltage generated when the measurement current is supplied to the measurement target, as a measuring device that reduces the influence of the magnetic field generated by the measurement current flowing in the current path, There is known a circuit board inspection apparatus which performs measurement by the four-terminal pair method disclosed by the applicant in Patent Document 1. In this circuit board inspection apparatus, by connecting the shield of the coaxial cable connected to the current probe for supplying the measurement current and the voltage probe for detecting the voltage with the lead wire, the direction opposite to the direction of the measurement current flowing to the measurement object is reversed. The measurement current flows in the current path formed by the shield and the lead, and the magnetic flux (magnetic field) generated by the measurement current is offset by this, so that the influence of the magnetic flux on the measurement result is reduced and the inspection accuracy It is possible to improve the

  On the other hand, when an external magnetic field passes through a voltage loop formed by the voltage detection unit, the cable, the voltage probe, and the measurement object, an induced electromotive force is generated in the voltage loop, and the voltage detection value is affected by the induced electromotive force. . For this reason, the applicant has already developed a technique for canceling the induced electromotive force generated by the external magnetic field by twisting two cables connected to the voltage detection unit. Moreover, in order to realize the technique of canceling the induced electromotive force on the circuit board in the measuring apparatus, the applicant connects the conductor patterns respectively formed in the two conductor layers in the multilayer substrate with vias to form two spirals. We have already developed a technology to form a twist-shaped wire in which the wire-like wires are twisted and to offset the induced electromotive force by this twist-shaped wire.

JP, 2011-257340, A (page 5, FIG. 4)

  However, there are the following problems to be improved in the conventional circuit board in which the twist-shaped wiring already developed by the applicant is formed in the substrate. Specifically, in order to form a twist-shaped wire in the substrate, short wires are arranged in two conductor layers at intervals, and each end of each wire of one conductor layer and another conductor are formed. A second spiral wiring is formed by connecting each end of each wiring of the layer with a via to create a first spiral wiring and twisting the first spiral wiring. Are created in the same manner as the first spiral wiring. However, in order to form the twist-shaped wiring in the substrate, it is necessary to form many vias and connect the respective ends of the wirings. Therefore, in the conventional circuit board, since the manufacturing process becomes complicated, there is a problem that the manufacturing efficiency is lowered and the manufacturing cost is increased.

  The present invention has been made in view of such problems, and has as its main object to provide a circuit board and a measuring device which can realize improvement in manufacturing efficiency and reduction in manufacturing cost.

  In order to achieve the above object, the circuit board according to claim 1 is a pair of second terminals to which one of a pair of first terminals to which a voltage detection unit is connected and a pair of probes to be brought into contact with a measurement object are respectively connected A circuit board on which a first wiring connecting any one of the first terminals and a second wiring connecting the other of the first terminals and the other of the second terminals is formed, the one surface of the circuit substrate And at least four conductor layers of a first conductor layer, a second conductor layer, a third conductor layer, and a fourth conductor layer provided from the side toward the other surface, and the first wiring is the first conductor Layer and a first conductor pattern formed on any one conductor layer of the second conductor layer, and a second conductor pattern formed on any one conductor layer of the third conductor layer and the fourth conductor layer The first conductor pattern and the second conductor pattern And a second via for connecting the first conductor pattern and the second conductor pattern at the second terminal side, and the second wiring is A third conductor pattern formed on the other conductor layer of the first conductor layer and the second conductor layer, and a fourth conductor formed on the other conductor layer of the third conductor layer and the fourth conductor layer A pattern and a third via connecting the third conductor pattern and the fourth conductor pattern on the first terminal side, and a fourth via connecting the third conductor pattern and the fourth conductor pattern on the second terminal side It is configured with a via.

  The circuit board according to claim 2 is the circuit board according to claim 1, wherein the first conductor pattern is formed on the first conductor layer, and the second conductor pattern is formed on the third conductor layer. The third conductor pattern is formed on the second conductor layer, and the fourth conductor pattern is formed on the fourth conductor layer.

  According to a third aspect of the present invention, in the circuit board according to the first or second aspect, an opening area of a first loop constituted by the first wiring and a second loop constituted by the second wiring The opening areas are configured to be equal to one another.

  The circuit board according to claim 4 is any one of a pair of A terminals to which a voltage detection unit is connected and one of a pair of B terminals to which a pair of probes to be brought into contact with the object to be measured are respectively connected. A circuit board on which an A wiring to be connected and a B wiring to connect the other of the respective A terminals and the other of the respective B terminals are formed, provided from one surface side to the other surface side of the circuit substrate And at least three conductor layers of an A conductor layer, a B conductor layer, and a C conductor layer, wherein the A wiring is an A conductor pattern formed on any one conductor layer of the A conductor layer and the C conductor layer , A B conductor pattern formed in the other conductor layer of the A conductor layer and the C conductor layer, an A via connecting the A conductor pattern and the B conductor pattern on the A terminal side, and the A conductor pattern And said B lead And a B via connecting the pattern on the B terminal side, wherein the B wiring is formed on the C terminal pattern formed on the B conductor layer and on the A terminal side of the other conductor layer The D conductor pattern, the E conductor pattern formed on the B terminal side in the other conductor layer, the C via connecting the C conductor pattern and the D conductor pattern on the A terminal side, the C conductor pattern, And a D via for connecting the E conductor pattern on the B terminal side.

  The circuit board according to claim 5 is the circuit board according to claim 4, wherein the A conductor pattern, the B wiring, the voltage detection unit, the A loop constituted by the respective probes and the measurement object, and the above-mentioned A part of the A conductor pattern, the B conductor pattern, the A via, the B via, the B wiring, the voltage detection unit, the respective probes, and the B loop composed of the measuring object in the same direction and the same magnetic flux density The open areas of the respective loops are defined such that the induced electromotive forces generated in the respective loops cancel each other when the magnetic field passes.

  Moreover, the measuring apparatus of Claim 6 measures the said measurement object via the circuit board in any one of Claims 1-5, the said voltage detection part, and the 3rd wiring formed in the said circuit board. And a measurement unit configured to measure the measured amount of the measurement target based on the voltage value detected by the voltage detection unit and the current value of the measurement current.

  In the circuit board according to claim 1 and the measuring apparatus according to claim 6, the first conductor pattern formed on any one of the first conductor layer and the second conductor layer, and the third conductor layer and the fourth conductor layer A first wiring comprising a second conductor pattern formed on any one of the first conductor pattern and a first via and a second via connecting the first conductor pattern and the second conductor pattern; A third conductor pattern connecting the third conductor pattern formed on the other of the two conductor layers, the fourth conductor pattern formed on the other of the third conductor layer and the fourth conductor layer, and the third conductor pattern and the fourth conductor pattern The second wiring is configured to include the via and the fourth via. That is, in the circuit board and the measuring apparatus, the first wiring and the second wiring capable of suppressing the influence of the induced electromotive force due to the external magnetic field can be constituted by four conductor patterns and four vias. For this reason, according to this circuit board and the measuring device, it is configured such that two spiral wirings formed by connecting many wirings arranged in two conductor layers with many vias are twisted together. Compared to the conventional configuration which suppresses the influence of the induced electromotive force due to the external magnetic field by reducing the number of vias and the manufacturing process can be simplified, the manufacturing efficiency is sufficiently improved and the manufacturing cost is sufficient. Can be reduced to

  Further, according to the circuit board of claim 2 and the measuring apparatus of claim 6, the first conductor pattern is formed on the first conductor layer, the second conductor pattern is formed on the third conductor layer, and By forming the conductor pattern in the second conductor layer and forming the fourth conductor pattern in the fourth conductor layer, for example, the first conductor pattern is formed in the first conductor layer, and the second conductor pattern is formed in the fourth conductor layer Compared to the configuration in which the third conductor pattern is formed in the second conductor layer 101b and the fourth conductor pattern is formed in the third conductor layer, the opening area of the first loop formed of the first wiring and The opening area of the second loop constituted by the second wiring can be made almost the same. For this reason, according to this circuit board and the measuring device, since the induced electromotive force generated in each loop can be brought to the same degree when the external magnetic field is generated around the circuit board, the induced electromotive force is ensured. As a result, the influence of the induced electromotive force due to the external magnetic field can be reduced.

  According to the circuit board of claim 3 and the measuring apparatus of claim 6, the opening area of the first loop constituted by the first wiring and the opening area of the second loop constituted by the second wiring Since the induced electromotive forces generated in the respective loops can be equalized when an external magnetic field is generated around the circuit board, the induced electromotive forces are more reliably cancelled. As a result, the influence of the induced electromotive force due to the external magnetic field can be further reduced.

  In the circuit board according to claim 4 and the measuring apparatus according to claim 6, the A conductor pattern formed on either one of the A conductor layer and the C conductor layer, and the other of the A conductor layer and the C conductor layer The C conductor pattern formed in the B conductor layer comprising the formed B conductor pattern and the A via and B via connecting the A conductor pattern and the B conductor pattern, and the other conductor described above B wiring is configured by including D conductor pattern and E conductor pattern formed in the layer, C via connecting C conductor pattern and D conductor pattern, and D via connecting C conductor pattern and E conductor pattern There is. That is, in the circuit board and the measuring device, it is possible to configure the A wiring and the B wiring which can suppress the influence of the induced electromotive force due to the external magnetic field by four vias. For this reason, according to this circuit board and the measuring device, it is configured such that two spiral wirings formed by connecting many wirings arranged in two conductor layers with many vias are twisted together. Compared to the conventional configuration which suppresses the influence of the induced electromotive force due to the external magnetic field by reducing the number of vias and the manufacturing process can be simplified, the manufacturing efficiency is sufficiently improved and the manufacturing cost is sufficient. Can be reduced to

  Further, in the circuit board according to claim 5 and the measuring apparatus according to claim 6, when the external magnetic field having the same magnetic flux density passes through the A loop and the B loop in the same direction, the induced electromotive forces generated in the respective loops cancel each other. The open area of each loop is defined to fit. Therefore, according to the circuit board and the measuring device, when an external magnetic field is generated around the circuit board, the influence of the induced electromotive force due to the external magnetic field can be further suppressed.

It is a block diagram which shows the structure of measuring device 1, 1A, 1B. FIG. 2 is a cross-sectional view showing a configuration of a circuit board 100. FIG. 2 is an explanatory view illustrating the configuration of a circuit board 100. FIG. 2 is a cross-sectional view showing a configuration of a circuit board 200. FIG. 2 is a first explanatory view illustrating the configuration of a circuit board 200. FIG. 7 is a second explanatory view illustrating the configuration of the circuit board 200. FIG. 7 is a third explanatory view illustrating the configuration of the circuit board 200. It is sectional drawing which shows the structure of 100 A of circuit boards. It is an explanatory view explaining composition of circuit board 100A.

  Hereinafter, embodiments of a circuit board and a measuring apparatus will be described with reference to the attached drawings.

  First, the configuration of the measuring apparatus 1 shown in FIG. 1 will be described. The measuring device 1 is an example of a measuring device, and is configured to be able to measure the physical quantity (for example, resistance value) of the measuring object 50 (see FIG. 3) by a four-terminal method. Specifically, as shown in the figure, the measuring apparatus 1 includes a current supply unit 11, a voltage detection unit 12, a processing unit 13, and a circuit board 100 (see FIGS. 2 and 3).

  The current supply unit 11 outputs a measurement current (for example, a direct current constant current) according to the control of the processing unit 13.

  The voltage detection unit 12 detects the voltage value Vm of the voltage generated in the measurement target 50 by the supply of the measurement current to the measurement target 50 according to the control of the processing unit 13.

  The processing unit 13 controls the current supply unit 11 and the voltage detection unit 12. The processing unit 13 functions as a measurement unit, and the resistance of the measurement target 50 based on the voltage value Vm detected by the voltage detection unit 12 and the current value Im of the measurement current output from the current supply unit 11 Execute measurement processing to measure the value (measured amount).

  The circuit board 100 is a multilayer board on which the current supply unit 11, the voltage detection unit 12, and the processing unit 13 are mounted, and as shown in FIG. 2, the circuit board 100 from the upper surface 100u side (one surface side) to the lower surface 100b side. Four conductor layers 101a (corresponding to the first conductor layer), conductor layers 101b (corresponding to the second conductor layer) provided toward the other surface side, and conductor layers 101c (corresponding to the third conductor layer) And the conductor layer 101d (corresponding to the fourth conductor layer: hereinafter referred to as the “conductor layer 101” when the conductor layers 101a to 101d are not distinguished from one another) and the three insulating layers 102a provided between the conductor layers 101. , 102b and 102c.

  Further, as shown in FIG. 3, the conductor layer 101a is connected to a terminal Ti1a to which one electrode of the current supply unit 11 is connected and a probe 21a for current supply to be in contact with the terminal 50a of the object 50 to be measured. A terminal Ti2a is provided, a terminal Ti1b to which the other electrode of the current supply unit 11 is connected, and a terminal Ti2b to which a probe 21b for supplying current to be brought into contact with the terminal 50b of the object 50 is connected It is provided.

  Further, as shown in FIGS. 2 and 3, the conductor layer 101a is brought into contact with the terminal Tv1a (corresponding to a first terminal) to which one electrode of the voltage detection unit 12 is connected and the terminal 50a of the object 50 to be measured. A terminal Tv2a (corresponding to a second terminal) to which the voltage detection probe 22a is connected is provided, and a terminal Tv1b (corresponding to a first terminal) to which the other electrode of the voltage detection unit 12 is connected to the conductor layer 101d And a terminal Tv2b (corresponding to a second terminal) to which a voltage detection probe 22b to be brought into contact with the terminal 50b of the measurement object 50 is connected. In this case, in FIG. 2, the terminals Ti1a, Ti1b, Ti2a, Ti2b, and wirings W3a, W3b described later are not shown. In the following description, when the terminals Tv1a and Tv1b are not distinguished from each other, they are also referred to as “terminal Tv1”, and when the terminals Tv2a and Tv2b are not distinguished from each other, also referred to as “terminal Tv2”. The terminals Ti1a, Ti1b, Ti2a, Ti2b, Tv1a, Tv1b, Tv2a, Tv2b are also referred to as "terminal T".

  In addition, in the circuit board 100, a wire for connecting the terminals T is formed. Specifically, as shown in FIG. 3, in the conductor layer 101a of the circuit board 100, the wiring W3a connecting the terminals Ti1a and Ti2a is formed, and in the conductor layer 101d of the circuit board 100, the terminals Ti1b and A wire W3b connecting Ti2b is formed. In this case, the wires W3a and W3b correspond to a third wire.

  In the circuit board 100, as shown in FIGS. 2 and 3, the wiring W1 (corresponding to a first wiring) connecting the terminal Tv1a and the terminal Tv2a, and the wiring W2 connecting the terminal Tv1b and the terminal Tv2b (Corresponding to the second wiring) is formed. In this case, in the circuit board 100, the wire W1 and the wire W2 are configured to form a loop in order to reduce the influence of the external magnetic field on the voltage value Vm when detecting the voltage value Vm performed by the voltage detection unit 12. There is.

  Specifically, as shown in FIGS. 2 and 3, the wiring W1 includes a conductor pattern P1 (corresponding to a first conductor pattern) formed on the conductor layer 101a of the circuit board 100 and a conductor layer 101c of the circuit board 100. A conductor pattern P2 (corresponding to a second conductor pattern) formed in the first embodiment, a via V1 connecting the conductor patterns P1 and P2 on the terminal Tv1 side, and a via V2 connecting the conductor patterns P1 and P2 on the terminal Tv2 side It is configured to be equipped.

  Further, as shown in FIGS. 2 and 3, the wiring W2 is formed on the conductor pattern P3 (corresponding to a third conductor pattern) formed on the conductor layer 101b of the circuit board 100 and the conductor layer 101d on the circuit board 100. A conductor pattern P4 (corresponding to a fourth conductor pattern), a via V3 connecting the conductor patterns P3 and P4 on the terminal Tv1 side, and a via V4 connecting the conductor patterns P3 and P4 on the terminal Tv2 side It is done. In the following description, when the vias V1 to V4 are not distinguished from each other, they are also referred to as "vias V".

  Further, in this circuit board 100, as shown in FIG. 2, a loop L1 (a dashed loop in the figure: equivalent to a first loop) constituted by the wires W1 (the conductor patterns P1 and P2 and the vias V1 and V2). And the open surface of a loop L2 (a loop indicated by an alternate long and short dash line in the figure: corresponding to a second loop) composed of the wires W2 (conductor patterns P3 and P4 and vias V3 and V4) The opening area of the loop L1 and the opening area of the loop L2 are configured to be equal to each other (in the same direction).

  Here, when an external magnetic field is generated around the circuit board 100 and the external magnetic field passes through the loops L1 and L2, an induced electromotive force is generated in the loops L1 and L2. In this case, in the circuit board 100, as shown in FIG. 3, the loop L1 is connected to one electrode of the voltage detection unit 12, and the loop L2 is connected to the other electrode of the voltage detection unit 12. Further, in the circuit board 100, the opening faces of the loops L1 and L2 face each other, and the opening areas of the loops L1 and L2 are configured to be equal to each other. Therefore, in the circuit board 100, the induced electromotive forces generated in the loops L1 and L2 act on the voltage detection unit 12 so as to cancel each other. As a result, in the circuit board 100, the influence of the induced electromotive force due to the external magnetic field when the voltage detection unit 12 detects the voltage value Vm of the measurement target 50 can be suppressed to a low level. Therefore, in the measuring device 1 provided with the circuit board 100, it is possible to accurately measure the resistance value of the measuring object 50 based on the voltage value Vm detected by the voltage detection unit 12.

  On the other hand, in the circuit board 100, as described above, the loop W1 is formed by the wiring W1 in which the conductor patterns P1 and P2 formed on the conductor layers 101a and 101c are connected by two vias V1 and V2, respectively. By forming the loop L2 by the wiring W2 in which the conductor patterns P3 and P4 respectively formed on 101d are connected by two vias V3 and V4, it is possible to suppress the influence of the induced electromotive force due to the external magnetic field. That is, in the circuit board 100, the wirings W1 and W2 can be configured by the four vias V, which can suppress the influence of the induced electromotive force due to the external magnetic field to a small extent. For this reason, in this circuit board 100, it should be configured to be in a state in which two spiral wires formed by connecting many wires arranged in two conductor layers 101 by many vias V are twisted together. As compared with the conventional configuration which reduces the influence of the induced electromotive force due to the external magnetic field, the number of vias V is small and the manufacturing process can be simplified, so that the manufacturing efficiency is sufficiently improved and the manufacturing cost is sufficient. It is possible to reduce.

  Next, a measurement method of measuring the resistance value of the measurement target 50 as the measurement target by the four-terminal pair method using the measurement apparatus 1 and the operation of each part at that time will be described with reference to the drawings.

  First, as shown in FIG. 3, the probes 21a and 21b for supplying current are respectively connected to the terminals Ti2a and Ti2b provided on the circuit board 100, and the terminals Tv2a and Tv2b are respectively connected with the probes 22a and 22b for voltage detection. Connecting.

  Next, as shown in FIG. 3, the probes 21 a and 22 a are brought into contact with the terminal 50 a of the object to be measured 50, and the probe 21 b 22 b is brought into contact with the terminal 50 b of the object to be measured 50.

  Subsequently, an operation unit (not shown) is operated to instruct start of measurement. In response to this, the processing unit 13 executes a measurement process. In this measurement process, the processing unit 13 controls the current supply unit 11 to output a measurement current (DC constant current). At this time, the measurement current is supplied to the measurement target 50 via the wires W3a and W3b and the probes 21a and 21b.

  Next, the processing unit 13 controls the voltage detection unit 12 to detect the voltage value Vm of the voltage generated between the terminals 50a and 50b of the measurement target 50 by the supply of the measurement current. In this case, the voltage detection unit 12 detects the voltage value Vm via the probes 22a and 22b and the wires W1 and W2 in contact with the terminals 50a and 50b, respectively.

  Here, in the measuring device 1, the wires W 1 and W 2 constituting the loops L 1 and L 2 in which the opening areas are equal to each other and the opening surfaces face each other (same direction) are formed on the circuit board 100. The wires W1 and W2 are connected to the electrodes of the voltage detection unit 12, respectively. For this reason, in the measuring device 1, an external magnetic field is generated around the circuit board 100, and the external magnetic field is generated in both of the loops L1 and L2 even when passing through the loops L1 and L2. As a result of the induced electromotive forces acting on the voltage detection unit 12 so as to cancel each other, the influence of the induced electromotive force is suppressed to a low level, and the voltage detection unit 12 accurately detects the voltage value Vm.

  Subsequently, the processing unit 13 determines the resistance value of the measurement target 50 based on the voltage value Vm detected by the voltage detection unit 12 and the current value Im of the measurement current output from the current supply unit 11 (measured amount Measure). In this case, as described above, the voltage detection unit 12 correctly detects the voltage value Vm. For this reason, in this measuring device 1, it is possible to sufficiently improve the measurement accuracy of the resistance value.

  In the circuit board 100 described above, the conductor pattern P1 is formed in the conductor layer 101a, the conductor pattern P2 is formed in the conductor layer 101c, the conductor pattern P3 is formed in the conductor layer 101b, and the conductor pattern P4 is formed in the conductor layer 101d. Instead of the configuration to be formed, conductor pattern P1 is formed in conductor layer 101b, conductor pattern P2 is formed in conductor layer 101d, conductor pattern P3 is formed in conductor layer 101a, and conductor pattern P4 is formed in conductor layer 101c. Configurations can also be adopted.

  As described above, in the circuit board 100 and the measuring device 1, the wiring W1 includes the conductor patterns P1 and P2 formed on the conductor layers 101a and 101c and the vias V1 and V2 connecting the conductor patterns P1 and P2, respectively. The wiring W2 is configured to include the conductor patterns P3 and P4 that are configured and formed in the conductor layers 101b and 101d, respectively, and the vias V3 and V4 that connect the conductor patterns P3 and P4. That is, in the circuit board 100 and the measuring device 1, the wires W1 and W2 capable of suppressing the influence of the induced electromotive force due to the external magnetic field can be configured by the four conductor patterns P and the four vias V. For this reason, according to the circuit board 100 and the measuring device 1, two spiral wires formed by connecting many wires arranged in two conductor layers 101 with many vias V are twisted together. As compared with the conventional configuration in which the influence of the induced electromotive force due to the external magnetic field is reduced by configuring as described above, the number of vias V can be small and the manufacturing process can be simplified, so that the manufacturing efficiency is sufficiently improved. Thus, the manufacturing cost can be sufficiently reduced.

  Further, according to the circuit board 100 and the measuring device 1, the conductor pattern P1 is formed on the conductor layer 101a, the conductor pattern P2 is formed on the conductor layer 101c, the conductor pattern P3 is formed on the conductor layer 101b, and the conductor pattern P4 is formed. Is formed in the conductor layer 101d, for example, the conductor pattern P1 is formed in the conductor layer 101a, the conductor pattern P2 is formed in the conductor layer 101d, the conductor pattern P3 is formed in the conductor layer 101b, and the conductor pattern P4 is formed As compared with the structure formed in the layer 101c, the opening area of the loop L1 formed by the wiring W1 and the opening area of the loop L2 formed by the wiring W2 can be made nearly equal. For this reason, according to the circuit board 100 and the measuring device 1, when the external magnetic field is generated around the circuit board 100, it is possible to bring the induced electromotive forces generated in the loops L1 and L2 close to the same degree. As a result of being able to reliably cancel out the induced electromotive force, the influence of the induced electromotive force due to the external magnetic field can be further suppressed.

  Further, according to the circuit board 100 and the measuring device 1, the circuit is configured such that the opening area of the loop L1 formed by the wiring W1 and the opening area of the loop L2 formed by the wiring W2 are equal. Since the induced electromotive forces generated in the loops L1 and L2 can be equalized when an external magnetic field is generated around the substrate 100, the induced electromotive forces can be canceled with each other more reliably. The influence of the induced electromotive force can be further reduced.

  Next, a circuit board 200 as another example of the circuit board and a measuring apparatus 1A provided with the circuit board 200 will be described. In the following description, the same components as those of the circuit board 100 and the measuring device 1 described above are denoted by the same reference numerals, and redundant description will be omitted. As shown in FIG. 4, the circuit board 200 corresponds to three conductor layers 201a (A conductor layer) provided from the upper surface 200u side (one surface side) to the lower surface 200b side (the other surface side) of the circuit substrate 200. Conductor layer 201b (corresponding to B conductor layer), and conductor layer 201c (corresponding to C conductor layer: hereinafter referred to as “conductor layer 201” when conductor layers 201a to 201c are not distinguished), and each conductor layer It comprises two insulating layers 202a and 202b provided between the electrodes 201.

  Further, as shown in FIG. 5, the conductor layer 201a is connected to a terminal Ti1a to which one electrode of the current supply unit 11 is connected and a probe 21a for supplying current to be in contact with the terminal 50a of the object 50 to be measured. A terminal Ti2a is provided, a terminal Ti1b to which the other electrode of the current supply unit 11 is connected, and a terminal Ti2b to which a probe 21b for supplying current to be brought into contact with the terminal 50b of the object 50 is connected It is provided.

  Further, as shown in FIGS. 4 and 5, the conductor layer 201a has a terminal TvAa (corresponding to an A terminal) to which one electrode of the voltage detection unit 12 is connected and a voltage to be brought into contact with the terminal 50a of the object 50 to be measured. A terminal TvBa (corresponding to a B terminal) to which the detection probe 22a is connected is provided, and a terminal TvAb (corresponding to an A terminal) to which the other electrode of the voltage detection unit 12 is connected is provided on the conductor layer 201c. A terminal TvBb (corresponding to a B terminal) to which a voltage detection probe 22b to be brought into contact with the terminal 50b of the measurement target 50 is connected is provided. In this case, in FIG. 4, the terminals Ti1a, Ti1b, Ti2a, Ti2b and wires W3a, W3b described later are not shown. In the following description, when terminals TvAa and TvAb are not distinguished from each other, they are also referred to as “terminal TvA”, and when terminals TvBa and TvBb are not distinguished from each other, also referred to as “terminal TvB”. The terminals Ti1a, Ti1b, Ti2a, Ti2b, TvAa, TvAb, TvBa, and TvBb are also referred to as "terminal T".

  Further, on the circuit board 200, a wire for connecting the terminals T is formed. Specifically, as shown in FIG. 5, a wiring W3a connecting the terminals Ti1a and Ti2a is formed in the conductor layer 201a of the circuit board 200, and the terminals Ti1b and W1a are formed in the conductor layer 201c of the circuit board 200. A wire W3b connecting Ti2b is formed.

  In the circuit board 200, as shown in FIGS. 4 and 5, the wiring Wa (corresponding to the A wiring) connecting the terminal TvAa and the terminal TvBa, and the wiring Wb (B connecting the terminal TvAb and the terminal TvBb) (Corresponding to wiring) is formed. In this case, in the circuit board 200, when detecting the voltage value Vm detected by the voltage detection unit 12, in order to reduce the influence of the external magnetic field on the voltage value Vm, a loop is formed by the wire W1 and the wire W2.

  Specifically, as shown in FIGS. 4 and 5, the wiring Wa is formed on the conductor pattern Pa (corresponding to the A conductor pattern) formed on the conductor layer 201 a of the circuit board 200 and the conductor layer 201 c of the circuit board 200. The formed conductor pattern Pb (corresponding to the B conductor pattern) and the via Va (corresponding to the A via) connecting the conductor patterns Pa and Pb on the terminal TvA side and the conductor patterns Pa and Pb connected on the terminal TvB side And a via Vb (corresponding to a B via).

  In addition, as shown in FIGS. 4 and 5, the wire Wb has a conductor pattern Pc (corresponding to a C conductor pattern) formed on the conductor layer 201 b of the circuit board 200 and a terminal TvA side of the conductor layer 201 c of the circuit board 200. A conductor pattern Pd (corresponding to a terminal TvAb) (corresponding to a D conductor pattern) and a conductor pattern Pe (a terminal TvBb) formed on a terminal TvB side of the conductor layer 201c (to be connected to the terminal TvBb). E) corresponding to a conductor pattern, a via Vc (corresponding to a C via) connecting the terminal TvA side of the conductor pattern Pc to the conductor pattern Pd, and a terminal TvB side of the conductor pattern Pc to the conductor pattern Pe And a via Vd (corresponding to a D via). In the following description, when the vias Va to Vd are not distinguished, they are also referred to as “vias V”.

  Further, in this circuit board 200, as shown in FIG. 6, a part of the wiring Wa (conductor pattern Pa), the wiring Wb (conductor patterns Pc to Pe, vias Vc, Vd), the voltage detection unit 12, the probes 22a, 22b And an opening surface of a loop La (a hatched loop in the figure: equivalent to the A loop) constituted by the measurement target 50 and a part of the wiring Wa (conductor pattern Pa, as shown in FIG. A loop Lb configured by a portion, a conductor pattern Pb, vias Va and Vb, wires Wb (conductor patterns Pc to Pe, vias Vc and Vd), a voltage detection unit 12, probes 22a and 22b, and a measurement target 50 (see FIG. The hatched loop in (: corresponding to the B loop) is configured to face in the same direction as the opening surface of the loop. Further, in this circuit board 200, when the external magnetic field of the same magnetic flux density passes through the loops La and Lb in the same direction, the induced electromotive forces generated in the loops La and Lb cancel each other out. The opening area is defined. Specifically, based on the opening area of the entire area A-1 of the loop La shown in FIG. 6 and the opening area of the area B-1 of the loop Lb shown in FIG. 7, the area B-2 and the area B-3 The opening areas are equal to the opening areas minus the opening areas. Therefore, in the circuit board 200, when an external magnetic field is generated around the circuit board 200, the induced electromotive forces generated in the loops La and Lb act on the voltage detection unit 12 so as to cancel each other. As a result, in the circuit board 200, the influence of the induced electromotive force due to the external magnetic field when the voltage detection unit 12 detects the voltage value Vm of the measurement target 50 can be reduced. Therefore, in the measuring device 1 provided with the circuit board 200, it is possible to accurately measure the resistance value of the measuring object 50 based on the voltage value Vm detected by the voltage detection unit 12.

  Further, in the circuit board 200, as described above, the conductor Wa formed by connecting the conductor patterns Pa and Pb respectively formed on the conductor layers 201a and 201c by two vias Va and Vb, and the conductor formed respectively to the conductor layers 201b and 201c By forming the loops La and Lb by the wire Wb connecting the patterns Pc to Pe with two vias Vc and Vd, the voltage detection unit 12, the probes 22a and 22b, and the measurement target 50, the influence of the induced electromotive force due to the external magnetic field can be obtained. It is possible to reduce the number. That is, in the circuit board 200, the interconnections Wa and Wb can be configured by the four vias V which can reduce the influence of the induced electromotive force due to the external magnetic field. Therefore, also in the circuit board 200 and the measuring device 1A, two spiral wires formed by connecting many wires arranged in two conductor layers 201 with many vias V are twisted together. As compared with the conventional configuration in which the influence of the induced electromotive force due to the external magnetic field is reduced by configuring as described above, the number of vias V is small and the manufacturing process can be simplified, so that the manufacturing efficiency is sufficiently improved. The manufacturing cost can be sufficiently reduced.

  Further, in the circuit board 200, as described above, the induced electromotive forces generated in the loops La and Lb cancel each other when the external magnetic field having the same magnetic flux density passes in the same direction in the loops La and Lb. The open areas of the loops La and Lb are defined. Therefore, also in the circuit board 200 and the measuring apparatus 1A, when an external magnetic field is generated around the circuit board 100, the influence of the induced electromotive force due to the external magnetic field can be further suppressed.

  In the circuit board 200 described above, instead of forming the conductor pattern Pa in the conductor layer 201a and forming the conductor patterns Pb, Pd, Pe in the conductor layer 201c, the conductor patterns Pb, Pd, Pe in the conductor layer 201a Can be employed to form a conductor pattern Pa on the conductor layer 201c.

  Next, a circuit board 100A as another example of the circuit board and a measuring apparatus 1B provided with the circuit board 100A will be described. In the following description, the same components as those of the circuit board 100 and the measuring device 1 described above are denoted by the same reference numerals, and redundant description will be omitted. This circuit board 100A is, as shown in FIG. 8, similar to the above circuit board 100, between the four conductor layers 101a to 101d provided from the upper surface 100u side to the lower surface 100b side, and the respective conductor layers 101. And three insulating layers 102a to 102c provided.

  Further, as shown in FIGS. 8 and 9, terminals Ti1a, Ti2a, Tv1a, Tv2a are provided in the conductor layer 101a of the circuit board 100A as in the circuit board 100 described above, and the terminal Ti1b is provided in the conductor layer 101d. , Ti2b, Tv1b, Tv2b are provided. Further, similarly to the circuit board 100 described above, the wiring W3a connecting the terminals Ti1a and Ti2a is formed on the conductor layer 101a, and the wiring W3b connecting the terminals Ti1b and Ti2b is formed on the conductor layer 101d. (See FIG. 9). In FIG. 8, the terminals Ti1a, Ti1b, Ti2a, Ti2b, and the wirings W3a, W3b are not shown.

  In the circuit board 100A, a wire W1 (corresponding to a first wire) connecting the terminal Tv1a and the terminal Tv2a, and a wire W2 (corresponding to a second wire) connecting the terminal Tv1b and the terminal Tv2b are formed. It is done. Further, in the circuit board 100A as well as the circuit board 100 described above, when detecting the voltage value Vm detected by the voltage detection unit 12, in order to reduce the influence of the external magnetic field on the voltage value Vm, the wiring W1 and the wiring W2 is configured to form a loop.

  Specifically, as shown in FIGS. 8 and 9, the wiring W1 includes a conductor pattern P1 (corresponding to a first conductor pattern) formed on the conductor layer 101a of the circuit board 100 and a conductor layer 101d of the circuit board 100. A conductor pattern P2 (corresponding to a second conductor pattern) formed in the first embodiment, a via V1 connecting the conductor patterns P1 and P2 on the terminal Tv1 side, and a via V2 connecting the conductor patterns P1 and P2 on the terminal Tv2 side It is configured to be equipped.

  Further, as shown in FIGS. 8 and 9, the wiring W2 is formed on the conductor pattern 101 (corresponding to the third conductor pattern) formed on the conductor layer 101b of the circuit board 100 and the conductor layer 101c on the circuit board 100. A conductor pattern P4 (corresponding to a fourth conductor pattern), a conductor pattern P5 formed on the terminal Tv1 side of the conductor layer 101c (so as to be connected to the terminal Tv1b), and a terminal Tv2 side of the conductor layer 101c (terminal Conductor pattern P6 formed so as to connect to Tv2b, via V3 connecting conductor patterns P3, P4 and P5 on the terminal Tv1 side, and via V4 connecting conductor patterns P3, P4 and P6 on the terminal Tv2 side It is configured with.

  Further, in the circuit board 100A, as shown in FIG. 8, an opening surface of a loop L1 (a loop indicated by a broken line in the figure) constituted by the wires W1 (the conductor patterns P1 and P2 and the vias V1 and V2) The opening surface of a loop L2 (a loop indicated by an alternate long and short dash line in the same figure) composed of W2 (conductor patterns P3 and P4 and vias V3 and V4) faces (same direction), the opening area of the loop L1 and the loop The opening areas of L2 are configured to be equal to each other. Therefore, in the circuit board 100A as well, when the external magnetic field is generated around the circuit board 100A, the induced electromotive forces generated in the loops L1 and L2 act on the voltage detection unit 12 so that they cancel each other, resulting in voltage The influence of the induced electromotive force due to the external magnetic field when the detection unit 12 detects the voltage value Vm of the measurement target 50 can be suppressed to a low level. Therefore, also in the measuring device 1 provided with the circuit board 100A, the resistance value of the measuring object 50 based on the voltage value Vm detected by the voltage detection unit 12 can be accurately measured.

  Further, in the circuit board 100A, as described above, the loop W1 is formed by the wire W1 in which the conductor patterns P1 and P2 formed in the conductor layers 101a and 101d are connected by two vias V1 and V2, respectively. By forming the loop L2 by the wiring W2 in which the conductor patterns P3 and P4 respectively formed in 101c are connected by two vias V3 and V4, it is possible to suppress the influence of the induced electromotive force due to the external magnetic field. That is, in the circuit board 100A, the wirings W1 and W2 can be configured by the four vias V that can reduce the influence of the induced electromotive force due to the external magnetic field. Therefore, also in this circuit board 100A, it is configured to be in a state where two spiral wirings formed by connecting many wirings arranged in two conductor layers 101 with many vias V are twisted together. Therefore, the number of vias V is small and the manufacturing process can be simplified, as compared with the conventional configuration that suppresses the influence of the induced electromotive force due to the external magnetic field, and the manufacturing efficiency is sufficiently improved and the manufacturing cost is sufficient. Can be reduced to

  The configurations of the circuit board and the measuring device are not limited to the above configurations. For example, although the example applied to the circuit board 100, 100A having four conductor layers 101 and the circuit board 200 having three conductor layers 201 has been described above, the circuit board 100, 100A having five or more conductor layers 101 is described above. A configuration in which the wirings W1 and W2 are formed using four conductor layers 101 of each conductor layer 101, and three conductor layers 201 of each conductor layer 201 in the circuit board 200 having four or more conductor layers 201. It is also possible to employ a configuration in which the wirings Wa and Wb are formed using

  Although the circuit boards 100 and 100A are configured as described above so that the opening areas of the loops L1 and L2 are equal to each other, configurations in which the opening areas of the loops L1 and L2 are different may be employed. Also, the opening area of the area A-1 of the loop La and the opening area obtained by subtracting the opening areas of the area B-2 and the area B-3 from the opening area of the area B-1 of the loop Lb are equal to each other As described above, the circuit board 200 is configured (the induced electromotive forces generated in the respective loops La and Lb cancel each other), but the configuration in which the opening areas are different (the induced electromotive forces generated in the respective loops La and Lb are completely Can also be adopted.

  Although the example applied to measuring device 1 which measures resistance as a to-be-measured amount was mentioned above, it is applicable to a measuring device which measures other than resistances, such as impedance, inductance, and capacity.

1, 1A, 1B measuring device 12 voltage detection unit 11 current supply unit 13 processing unit 22a, 22b probe 100, 100A, 200 circuit board 100b, 200b lower surface 100u, 200u upper surface 101a, 101b, 101c, 101d, 201a to 201c conductor layer Im current values P1 to P4, Pa to Pe conductor patterns Tv1a, Tv1b, Tv2a, Tv2b terminals TvAa, TvAb, TvBa, TvBb terminals V1 to V4, Va to Vd Via Vm voltage values W1, W2, Wa, Wb, W3a, W3b Wiring L1, L2, La, Lb loop

Claims (6)

A first wiring for connecting one of a pair of first terminals to which a voltage detection unit is connected and one of a pair of second terminals to which a pair of probes to be brought into contact with a measurement object are connected, and each of the above It is a circuit board in which the 2nd wiring which connects the other of the 1st terminal, and the other of said each 2nd terminal was formed,
At least four conductor layers of a first conductor layer, a second conductor layer, a third conductor layer, and a fourth conductor layer provided from one surface side to the other surface side of the circuit board,
The first wiring includes a first conductor pattern formed in any one of the first conductor layer and the second conductor layer, and any one of the third conductor layer and the fourth conductor layer. A second conductor pattern formed in the conductor layer, a first via connecting the first conductor pattern and the second conductor pattern at the first terminal side, the first conductor pattern and the second conductor pattern; And a second via connected at the second terminal side,
The second wiring is formed in a third conductor pattern formed in the other conductor layer of the first conductor layer and the second conductor layer, and in the other conductor layer of the third conductor layer and the fourth conductor layer. And the third via connecting the third conductor pattern and the fourth conductor pattern on the first terminal side, the third conductor pattern and the fourth conductor pattern on the second terminal side And a fourth via connected to each other.   The first conductor pattern is formed on the first conductor layer, the second conductor pattern is formed on the third conductor layer, and the third conductor pattern is formed on the second conductor layer. The circuit board according to claim 1, wherein four conductor patterns are formed in the fourth conductor layer.   3. The circuit board according to claim 1, wherein an opening area of the first loop formed of the first wiring and an opening area of the second loop formed of the second wiring are equal to each other. . The A wiring connecting one of a pair of A terminals to which the voltage detection unit is connected and one of a pair of B terminals to which a pair of probes to be brought into contact with the object to be measured are connected It is a circuit board in which B wiring which connects the other and the other of said each B terminal was formed, and
And at least three conductor layers of an A conductor layer, a B conductor layer, and a C conductor layer provided from one surface side to the other surface side of the circuit board,
The A wiring includes an A conductor pattern formed in any one of the A conductor layer and the C conductor layer, and a B conductor formed in the other conductor layer of the A conductor layer and the C conductor layer. It comprises a pattern, an A via connecting the A conductor pattern and the B conductor pattern on the A terminal side, and a B via connecting the A conductor pattern and the B conductor pattern on the B terminal side,
The B wiring is formed on a C conductor pattern formed on the B conductor layer, a D conductor pattern formed on the A terminal side of the other conductor layer, and on the B terminal side of the other conductor layer And a C via connecting the C conductor pattern and the D conductor pattern on the A terminal side, and a D via connecting the C conductor pattern and the E conductor pattern on the B terminal side. Circuit board configured.   The A conductor pattern, the B wiring, the voltage detection unit, an A loop composed of the respective probes and the measurement target, and a part of the A conductor pattern, a B conductor pattern, the A via, the B via, When the external magnetic field of the same magnetic flux density passes in the same direction in the same direction in the B loop composed of the B wire, the voltage detection unit, the probes, and the measurement object, the induced electromotive forces generated in the loops cancel each other 5. The circuit board according to claim 4, wherein the open area of each loop is defined.   The circuit substrate according to any one of claims 1 to 5, the voltage detection unit, and a current supply unit for supplying a measurement current to the measurement target through a third wiring formed on the circuit substrate, A measuring unit comprising: a measuring unit configured to measure an amount to be measured of the measurement target based on a voltage value detected by the voltage detecting unit and a current value of the measuring current.

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