JP2010087025A - Electronic circuit device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic circuit device for reducing magnetic field noise. <P>SOLUTION: The electronic circuit device 100 having a circuit board 10 with an electric circuit 20 includes: an inductor 30 having a spiral internal electrode 32 to be connected to the electric circuit 20 by being mounted on the circuit board 10; and an inductor 50 which has a spiral internal electrode 52 to be connected to the electric circuit 20 by being mounted on the circuit board 10 and also is arranged at a position opposed to the inductor 30, so as to allow the same magnetic poles to come close to in the polarity. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic circuit device including a circuit board having an electric circuit.

  When a current flows through the conductive part connected to the electric circuit, a magnetic pole is formed in the vicinity of the conductor part. The radiation of so-called magnetic field noise caused by the formation of the magnetic pole induces an induced current in the electronic parts connected to the electric circuit and the conductive part of the electronic element, thereby causing malfunction or signal disturbance.

Conventionally, as a technique for reducing this magnetic field noise, Patent Document 1 discloses a linear first conductor wire that is connected to an electric circuit and flows a current in a specific direction, and a straight line that flows a current in a direction opposite to the specific direction. The structure which arrange | positions the shape 2nd conducting wire in proximity | contact is disclosed. According to this configuration, among the magnetic poles formed by the first conducting wire and the second conducting wire, magnetic poles having the same polarity are close to each other, so that the magnetic fluxes formed in the vicinity of the first conducting wire and the second conducting wire intersect each other. Therefore, since the magnetic field by the first conductor and the magnetic field by the second conductor cancel each other, reduction of the magnetic field noise radiated from the electric circuit is realized.
JP 2002-368358 A

  Now, in an electronic circuit device provided with a circuit board having an electric circuit, downsizing is being promoted by densely arranging electronic elements and wiring of the electric circuit. In such an electronic circuit device that has been reduced in size, using the technique disclosed in Patent Document 1, wirings corresponding to the first conductor and the second conductor through which the opposing current flows are shifted from each other. As a result, when an attempt was made to reduce the magnetic field noise, the magnetic field noise radiated from the electronic circuit device could not be sufficiently reduced. The reason is that, among the magnetic field noise radiated from the electronic circuit device, the electronic element having a circular conductive portion connected to the electric circuit rather than the magnetic field noise radiated from the linear wiring on which the electric circuit is formed. This is because magnetic field noise radiated from occupies a large amount.

  The present invention has been made in view of the above problems, and an object thereof is to provide an electronic circuit device that reduces magnetic field noise.

  In order to achieve the above object, the invention according to claim 1 is a first electronic device having a circuit board having an electric circuit and a circular conductive portion connected to the electric circuit by being mounted on the circuit board. And a second electronic element connected to an electric circuit by being mounted on a circuit board and having a circular conductive portion, and arranged so that a magnetic pole having the same polarity is close to a position opposite to the first electronic element A second electronic element.

  According to the present invention, when the first electronic element is mounted on the circuit board, a current is applied from the connected electric circuit to the circumferential conductor portion of the first electronic element. Thereby, a magnetic pole is formed in the first electronic element, and magnetic field noise due to the magnetic flux circulating around the magnetic pole is radiated. Further, when the second electronic element is mounted on the circuit board, a current is applied from the connected electric circuit to the circumferential conductor portion of the second electronic element. As a result, a magnetic pole is formed in the second electronic element, and magnetic field noise is radiated by the magnetic flux circulating around the direction of the magnetic pole. In addition, since the second electronic element is arranged so that the magnetic poles having the same polarity are close to each other at a position facing the first electronic element, the direction of the magnetic flux in the vicinity of the magnetic pole in any magnetic pole of each electronic element. Intersect each other. Therefore, magnetic field noise radiated from each electronic element cancels each other. Therefore, since the magnetic field noise caused by the electronic elements, which occupies most of the magnetic field noise radiated from the electronic circuit device, is reduced, it is possible to provide an electronic circuit device that realizes reduction of the radiated magnetic field noise.

  In the invention according to claim 2, the first direction from the cathode side to the anode side of the magnetic pole formed by the first electronic element, and the second direction from the cathode side to the anode side of the magnetic pole formed by the second electronic element; Are opposed to each other. According to the present invention, the first direction of the magnetic pole formed by the first electronic element and the second direction of the magnetic pole formed by the second electronic element are opposed to each other. The directions of nearby magnetic fluxes face each other. And since the 2nd electronic element is arranged in the position facing the 1st electronic element, the magnetic flux formed by the 1st electronic element and the magnetic flux formed by the 2nd electronic element cross at an angle near opposition. Will be. Such crossing of magnetic flux effectively cancels out the magnetic fields radiated from the respective electronic elements. Therefore, it is possible to provide an electronic circuit device that realizes further reduction of radiated magnetic field noise.

  According to a third aspect of the present invention, the first electronic element and the second electronic element are arranged and mounted on the electronic circuit device so that the axis in the first direction and the axis in the second direction are coaxial. According to this invention, the first electronic element and the second electronic element are arranged such that the first direction and the second direction are opposed to each other, and the axis in the first direction and the axis in the second direction are coaxial. . Therefore, the magnetic poles of either the first electronic element or the second electronic element are surely close to each other. In addition, the magnetic flux formed in the vicinity of the first electronic element and the magnetic flux formed in the vicinity of the second electronic element surely face each other and intersect with each other. According to these, the magnetic fields radiated from the respective electronic elements cancel each other out more effectively. Therefore, it is possible to provide an electronic circuit device that realizes further reduction of the radiated magnetic field noise.

  In the invention according to claim 4, a first direction from the cathode side to the anode side of the magnetic pole formed by the first electronic element, and a second direction from the cathode side to the anode side of the magnetic pole formed by the second electronic element; Are the same direction, and the second electronic element is mounted to face the first electronic element in a direction orthogonal to the first direction. According to this invention, the anodes and the cathodes in the first electronic element and the second electronic element are equally close to each other. Therefore, the magnetic flux formed in the vicinity of the first electronic element and the magnetic flux formed in the vicinity of the second electronic element can be crossed at an angle close to facing over a wide range. Therefore, the magnetic field radiated from each electronic element cancels out more effectively. Therefore, it is possible to provide an electronic circuit device that realizes further reduction of radiated magnetic field noise.

  Here, when the first electronic element and the second electronic element are mounted on the same mounting surface of the circuit board, a work space for mounting each electronic element is required around each electronic element. Therefore, it becomes difficult to bring the first electronic element and the second electronic element close to each other, and there is a concern that the magnetic fields radiated from the respective electronic elements will not effectively cancel each other. Therefore, in the invention described in claim 5, the first electronic element and the second electronic element are mounted on different mounting surfaces of the circuit board. Thereby, since the magnetic poles of the first electronic element and the second electronic element can be easily brought close to each other, the magnetic flux formed in the vicinity of the first electronic element and the magnetic flux formed in the vicinity of the second electronic element are reduced. Can be crossed over a wide range. Therefore, since the magnetic field radiated from each element cancels out more effectively, an electronic circuit device that realizes further reduction of the radiated magnetic field noise can be provided.

  In the invention according to claim 6, the first electronic element and the second electronic element are electronic elements having the same specifications. According to this invention, the magnetic fluxes formed in the vicinity of the first electronic element and the second electronic element having the same specifications are similar to each other. Therefore, it is easy to arrange the first electronic element and the second electronic element so that the magnetic fluxes formed in the vicinity of each electronic element intersect at an angle close to the facing. Therefore, it is possible to easily provide an electronic circuit device that effectively cancels the magnetic field radiated from each electronic element and realizes reduction of the radiated magnetic field noise.

  In the invention according to claim 7, the first electronic element and the second electronic element have a case part that accommodates a circular conductive part. According to the present invention, since the circular conductive portion is accommodated in the case portion, a part of the magnetic field noise radiated from the electronic component to the outside is shielded by the case portion. In addition, the case portion shields a part of the magnetic field noise radiated from the outside and suppresses induction of induced current in the conductive portion accommodated in the case portion. Even when the first electronic element and the second electronic element are brought close to each other by the magnetic field noise shielding action by the case portion, malfunction or signal of the other electronic element due to the magnetic field noise radiated from the one electronic element It is hard to be disturbed. Therefore, the magnetic field noise can be effectively canceled by bringing the first electronic element and the second electronic element closer together without impairing the operation of the electronic element.

  In the invention according to claim 8, a pulse current is applied from the electric circuit to the conductive portions of the first electronic element and the second electronic element. According to the present invention, when a pulse current is applied from the electric circuit to the conductive portion, a large magnetic flux density change occurs in the vicinity of each electronic element. However, when magnetic poles are formed in both the first electronic element and the second electronic element and magnetic fluxes formed in the vicinity of the adjacent magnetic poles intersect, the radiated magnetic field noise is reduced. Therefore, in the first electronic element and the second electronic element through which the pulse current flows, the magnetic field noise reducing effect according to the present invention is remarkably exhibited.

  In the invention according to claim 9, the first electronic element and the second electronic element are connected in series. According to this invention, when the first electronic element and the second electronic element are connected in series, the currents flowing through the first electronic element and the second electronic element are synchronized. Therefore, the magnetic field noise radiated from the first electronic element and the second electronic element is synchronized, and the magnetic fields radiated from the respective electronic elements can be stably canceled out. Therefore, it is possible to provide an electronic circuit device that realizes stable reduction of radiated magnetic field noise.

  In the invention described in claim 10, the first electronic element and the second electronic element are inductors having a circular conductive portion. According to the present invention, since the conductive portion of the inductor is generally a conductive portion in which the conducting wire circulates several times, the radiated magnetic field noise is large. Therefore, when the first electronic element and the second electronic element are inductors, the magnetic field noise reduction effect of the present invention is remarkably achieved by intersecting the directions of magnetic fluxes formed near the first electronic element and the second electronic element. It can be acquired.

  In the invention according to claim 11, the electric circuit has a power supply circuit unit that generates a required output current from the input current, and the first electronic element and the second electronic element are input to the power supply circuit unit. It is connected to the side. According to the present invention, generally, the largest current in the electric circuit flows into the power supply circuit unit that generates the required output current from the input current. In addition, since the first electronic element and the second electronic element are inductors connected to the input side of the power supply circuit unit, a large magnetic flux density change occurs in the vicinity of each electronic element. However, when magnetic poles are formed in both the first electronic element and the second electronic element and magnetic fluxes formed in the vicinity of the adjacent magnetic poles intersect, an increase in the emitted magnetic field noise can be suppressed. . Therefore, by applying the present invention to the inductor connected to the input side of the power supply circuit unit, it is possible to provide an electronic circuit device that realizes a significant reduction in the radiated magnetic field noise.

  In the invention according to claim 12, the circuit board includes a first circuit board portion on which the first electronic element is mounted, and a second circuit board on which the second electronic element is mounted and disposed opposite to the first board portion. Part. According to this invention, the circuit board has the first circuit board part and the second circuit board part, and the first electronic element and the second electronic element are mounted on the different first circuit board part and second circuit board part. . Also in the above configuration, since the magnetic poles are formed in both the first electronic element and the second electronic element and the magnetic flux formed in the vicinity of the adjacent magnetic poles intersects, the radiated magnetic field noise is reduced. The Rukoto. Therefore, even in an electronic circuit device including a wiring board portion in which each electronic element is separately mounted and arranged to face each other, reduction of magnetic field noise can be realized.

  In the invention according to claim 13, the electric circuit includes a first circuit part provided on the first circuit board part and a second circuit part provided on the second circuit board part, The second electronic element is connected to the second circuit unit. According to this invention, the first electronic element and the second electronic element are provided on the opposing first circuit board part and second circuit board part, respectively, and the first circuit part and the second circuit part that the electric circuit has. Connected to each. Even in the above configuration, magnetic poles are formed in both the first electronic element and the second electronic element, and magnetic fluxes formed in the vicinity of the adjacent magnetic poles intersect with each other, so that radiated magnetic field noise is reduced. It will be. Therefore, even when the respective electronic elements are connected to the first circuit portion and the second circuit portion respectively provided on the circuit board portions arranged so as to face each other, the magnetic field noise can be reduced. It can be done.

  The invention described in claim 14 is mounted on a vehicle-mounted instrument. As described above, according to the effect of the present invention in which the magnetic poles having the same polarity are brought close to each other by the arrangement of the first electronic element and the second electronic element and the magnetic fluxes are crossed, the wiring of the electronic element and the electric circuit is densely packed. Even in the arranged electronic circuit device, magnetic field noise can be reduced. Therefore, the invention according to claim 14 is particularly suitable as an electronic circuit device for a vehicle-mounted instrument in which spatial restrictions are severe and the influence of magnetic field noise on other electronic devices is a concern.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In addition, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol to the corresponding component in each embodiment.

(First embodiment)
FIG. 1 shows an electronic circuit device 100 according to a first embodiment of the present invention. The electronic circuit device 100 is configured by mounting inductors 30 and 50 and other electronic components (not shown) on the circuit board 10. The side on which the inductor 30 is disposed (upper side in FIG. 1) is the surface side of the circuit board 10.

  First, the electric circuit 20 shown in FIG. 2 included in the circuit board 10 will be described. The electric circuit 20 is formed on the circuit board 10 (see FIG. 1), and includes inductors 30 and 50, a capacitor 23, and a power supply circuit unit 21. The inductors 30 and 50 are electronic elements for smoothing an input current, and resist an increase in the input current. The inductor 30 and the inductor 50 have the same specifications and have the same inductance. The inductor 30 and the inductor 50 are connected in series and are connected to the input side of the power supply circuit unit 21. Similar to the inductors 30 and 50, the capacitor 23 is an electronic element for smoothing an input current, and resists a decrease in the input current. One end side of the capacitor 23 is connected to the output side of the inductor 30, and the other end side is grounded. In such a configuration, a pulse current of about several hundred mA that pulsates at 100 to 300 Hz, for example, rectified by a rectifier (not shown) flows through the inductors 30 and 50 and the capacitor 23. The inductors 30 and 50 and the capacitor 23 reduce the pulsation of the pulse current flowing from the electric circuit, and supply a smooth direct current to the power supply circuit unit 21.

  In addition, the power supply circuit unit 21 is a DC-DC power supply circuit that supplies a current having a desired voltage value from an input current, and particularly a switching control type power supply circuit that uses a switching element (not shown). It is. The power supply circuit unit 21 converts the supplied direct current into a rectangular wave current using a switching element. The rectangular wave current is rectified and smoothed again by the power supply circuit unit 21. The power supply circuit unit 21 controls the switching element to change the proportion of time during which the voltage in one cycle of the rectangular wave is high. By controlling the switching element, the power supply circuit unit 21 generates an output current having a desired voltage value.

  As shown in FIG. 1, the circuit board 10 is a multilayer board in which the electric circuit 20 having the above-described configuration is formed over a plurality of layers. The circuit board 10 is a four-layer board provided with four wiring layers 13 constituting the electric circuit 20. The circuit board 10 includes an insulating layer 11, a through hole 15, and a covering layer 17 in addition to the wiring layer 13. The insulating layer 11 is an insulating material, and is formed of a glass / epoxy plate obtained by hardening a glass fiber cloth, which is a glass fiber fabric, with an epoxy resin. The insulating layer 11 includes a front side insulating layer 11a, an internal insulating layer 11b, and a back side insulating layer 11c.

  The wiring layer 13 is made of a conductive material such as copper foil, and is formed in a predetermined wiring pattern. The wiring layer 13 includes a front surface side wiring layer 13a, a back surface side wiring layer 13d, a power supply wiring layer 13b, and a ground wiring layer 13c. The front surface side wiring layer 13a and the back surface side wiring layer 13d electrically connect each electronic component mounted on the circuit board 10, and each wiring layer 13a, 13d mainly performs electrical connection between each electronic component. Signal communication takes place. The front surface side wiring layer 13a is formed on the front surface side of the front surface side insulating layer 11a, and the back surface side wiring layer 13d is formed on the back surface side of the back surface side insulating layer 11c. The power supply wiring layer 13b is connected to each electronic component, and power is supplied to each electronic component by the power supply wiring layer 13b. The ground wiring layer 13c is connected to each electronic component, and each electronic element is grounded by the ground wiring layer 13c.

  The through hole 15 is a through hole that penetrates the insulating layer 11 and the wiring layer 13 in the plate thickness direction. A through-hole plating 16 made of a copper material or the like, which is a conductive material, is provided on the peripheral wall of the through-hole 15 and the peripheral edge of the opening on the surface side. The through-hole plating 16 forms a mounting portion 16a provided at the peripheral edge portion of the surface side opening and a connection portion 16b provided at the peripheral wall portion. The mounting portion 16a is provided on the front surface side of the front surface side wiring layer 13a, and the inductor 30 is connected to the front surface side by the solder 18. The mounting portion 16a is electrically connected to the power supply wiring layer 13b through the connection portion 16b. According to these, the power supply wiring layer 13 b and the inductor 50, and the electrical connection between the inductor 30 and the inductor 50 are formed by the through-hole plating 16.

  The covering layer 17 is a thin film-like covering formed on the front surface side of the front surface side insulating layer 11a and the front surface side wiring layer 13a and on the back surface side of the back surface side insulating layer 11c and the back surface side wiring layer 13d. The coating layer 17 is formed of an epoxy resin material that is an insulating material having heat resistance. The coating layer 17 is not formed on the surface side or the like of the mounting portion 16a, and does not hinder the connection of each electronic circuit by the solder 18.

  The inductors 30 and 50 are multilayer inductors in which conductive wires are provided in a circular shape with reference to the respective axes 30ax and 50ax. The inductors 30 and 50 have internal electrodes 32 and 52, ferrite cores 36 and 56, external electrodes 34 and 54, and the like. The inductors 30 and 50 are configured by laminating thin sheet base materials made of ferrite on which a conductive wire pattern corresponding to one-half of the circumference is printed. The internal electrodes 32 and 52 are formed in a circular shape by laminated conductive wire patterns. The ferrite cores 36 and 56 are formed of laminated ferrite base materials. The external electrodes 34 and 54 are electrically connected to the internal electrodes 32 and 52 arranged in a circular shape, and have contact portions 34 a and 54 a connected to the wiring layer 13 of the circuit board 10. The inductor 30 and the inductor 50 correspond to “first electronic element” and “second electronic element” recited in the claims, and the internal electrodes 32 and 52 correspond to “conductive portion” recited in the claims. .

  The inductor 30 is mounted on the circuit board 10 so that the inner electrode 32 having a circular shape is connected to the electric circuit 20. By applying a current from the electric circuit 20 to the internal electrode 32 of the inductor 30, the inductor 30 forms the cathode 30b on the circuit board 10 side and the anode 30h on the side opposite to the cathode 30b. Thereby, the first direction 30d in the present embodiment is orthogonal to the planar direction of the circuit board 10 and is a direction from the back surface side to the front surface side. When the inductor 30 forms such a magnetic pole, the internal electrode 32 rotates clockwise with respect to the first direction 30d, and current flows in the first direction 30d. With the above configuration, a current 40ar that circulates clockwise in the first direction 30d flows through the inductor 30, and a magnetic flux 30f that circulates along the first direction 30d is formed.

  By mounting the inductor 50 on the circuit board 10, the circular inner electrode 52 of the inductor 50 is connected to the electric circuit 20. By applying a current from the electric circuit 20 to the internal electrode 52 of the inductor 50, the inductor 50 forms a cathode 50b on the circuit board 10 side and an anode 50h on the side opposite to the cathode 50b. Thereby, the second direction 50d in the present embodiment is orthogonal to the planar direction of the circuit board 10 and is a direction from the front surface side to the back surface side. When the inductor 50 forms such a magnetic pole, the internal electrode 52 circulates clockwise in the second direction 50d, and the current flows in the second direction 50d. With the above configuration, the current 40ar that circulates clockwise in the second direction 50d flows through the inductor 50, and the magnetic flux 50f that circulates along the second direction 50d is formed.

  In addition, the inductor 50 is disposed at a position facing the inductor 30 so that the cathodes 30b and 50b having the same polarity are close to each other. Further, the second direction 50d in which the inductor 50 is mounted is opposed to the first direction 30d in which the inductor 30 is mounted. Further, the axis 50ax along the second direction 50d of the inductor 50 is coaxial with the axis 30ax along the first direction 30d of the inductor 30. The inductor 30 and the inductor 50 are mounted on different mounting surfaces of the circuit board 10.

  In the present embodiment described above, the respective inductors 30 and 50 form magnetic fluxes 30f and 50f that circulate from the anodes 30h and 50h toward the cathodes 30b and 50b. Since the inductor 30 and the cathode 30b and the cathode 50b of the inductor 50 are arranged close to each other, the directions of the magnetic fluxes 30f and 50f in the vicinity of the cathodes 30b and 50b intersect each other. As described above, the magnetic flux noises emitted from the inductors 30 and 50 cancel each other because the directions of the magnetic fluxes 30f and 50f intersect each other. Therefore, magnetic field noise due to the inductors 30 and 50 can be suppressed, and the electronic circuit device 100 that realizes reduction of the radiated magnetic field noise can be provided.

  In addition, in the present embodiment, the inductors 30 and 50 are arranged so that the first direction 30d and the second direction 50d face each other, and the axis 30ax in the first direction 30d and the axis 50ax in the second direction 50d are coaxial. Has been. For this reason, the magnetic fluxes 30f and 50f in the vicinity of the cathodes 30b and 50b intersect each other in a state where they are close to each other. Furthermore, by mounting the inductor 30 and the inductor 50 on different mounting surfaces of the circuit board 10, the distance between the cathode 30b of the inductor 30 and the cathode 50b of the inductor 50 can be reduced. Therefore, the magnetic flux 30f and the magnetic flux 50f cross in the opposing direction over a wide range. Therefore, the magnetic field noise radiated from the respective inductors 30 and 50 is effectively canceled out, and the electronic circuit device 100 that realizes further reduction of the magnetic field noise can be provided.

  In the present embodiment, since the inductor 30 and the inductor 50 have the same specifications, the magnetic flux 30f and the magnetic flux 50f formed in the vicinity of the inductors 30 and 50 are similar to each other. Further, since the axis 30ax in the first direction 30d and the axis 50ax in the second direction 50d are arranged so as to be coaxial, the magnetic fluxes 30f and 50f can be crossed at an angle close to each other. Thus, by setting the inductor 30 and the inductor 50 to the same specification, it is easy to arrange the inductors 30 and 50 that effectively cancel the magnetic field noise. Therefore, it is possible to easily provide the electronic circuit device 100 that realizes reduction of the radiated magnetic field noise.

  Furthermore, in this embodiment, since the inductor 30 and the inductor 50 are connected in series, the currents flowing through the inductors 30 and 50 are synchronized. Therefore, the magnetic field noise radiated from the inductor 30 and the inductor 50 is synchronized, and the magnetic fields radiated from the respective inductors 30 and 50 are stably canceled out. In addition, in this embodiment, one inductor is divided into inductors 30 and 50 and connected in series. Since the magnetic field noise radiated from the inductor is proportional to the inductance of the inductor, the magnetic field noise radiated from each of the divided inductors 30 and 50 is reduced. The magnetic field noises reduced by the division cancel each other. According to the above, by dividing into two inductors 30 and 50 and connecting them in series, compared with the case where one inductor is connected, the magnetic field noise radiated can be greatly reduced while maintaining the inductance. Is realized.

  In addition, in the present embodiment, the inductors 30 and 50 have internal electrodes 32 and 52 that circulate several times. As described above, among various electronic elements, the inductor is particularly susceptible to large radiated magnetic field noise. Therefore, by applying the present invention to an inductor, the magnetic field noise reduction effect of the present invention due to cancellation of magnetic field noises can be remarkably obtained.

  In addition, in the present embodiment, the maximum current in the electric circuit 20 is applied to the inductor 30 and the inductor 50 connected to the input side of the power supply circuit unit 21. Further, since the current flowing into the inductor 30 and the inductor 50 has pulsation, the magnetic flux 30f and the magnetic flux 50f undergo a large density change. However, according to the present invention in which the magnetic flux 30f and the magnetic flux 50f are formed by both the inductor 30 and the inductor 50 and the magnetic fluxes 30f and 50f cancel each other, an increase in the radiated magnetic field noise can be suppressed. . As described above, by applying the present invention to the inductors 30 and 50 connected to the input side of the power supply circuit unit 21, it is possible to provide the electronic circuit device 100 that realizes a significant reduction in the radiated magnetic field noise. It is.

(Second embodiment)
As shown in FIG. 3, the second embodiment of the present invention is a modification of the first embodiment. In the electronic circuit device 200 according to the second embodiment, inductors 230 and 250 are mounted on the same surface of the circuit board 210. The mounting surface on which the inductors 230 and 250 are mounted is the surface side of the circuit board 210. In addition, in FIG. 3, other electronic elements mounted on the circuit board 210 are omitted.

  Inductors 230 and 250 have ferrite cores 236 and 256, winding portions 231 and 251, external electrodes 234 and 254, and exterior portions 237 and 257. The ferrite cores 236 and 256 are made of a ferrite material and are cylindrical members having the axis lines 230ax and 250ax as the center line. The winding portions 231 and 251 are wound around the axis 230ax and 250ax of the ferrite cores 236 and 256 in a circular shape. The external electrodes 234 and 254 are electrically connected to the winding portions 231 and 251 arranged in a circular shape, and are connected to the wiring layer 13 formed on the surface side of the circuit board 210. , 254a. The exterior portions 237 and 257 are made of a resin material and accommodate ferrite cores 236 and 256 around which the winding portions 231 and 251 are wound. The inductor 230 and the inductor 250 are the “first electronic element” and the “second electronic element” according to the claims, and the winding parts 231 and 251 are the “conductive part” according to the claims and the exterior part. Reference numerals 237 and 257 respectively correspond to “case members” recited in the claims.

  The inductor 230 is mounted on the circuit board 210 so that the winding portion 231 having a circular shape is connected to the electric circuit 20. When current is applied from the electric circuit 20 to the winding portion 231 of the inductor 230, the inductor 230 has the cathode 230b on the inductor 250 side (left side in FIG. 3) and the side opposite to the cathode 230b (right side in FIG. 3). ) To form anodes 230h. Thereby, the first direction 230d in the second embodiment is set to the right direction along the planar direction of the circuit board 210 in FIG. When the inductor 230 forms such a magnetic pole, the winding portion 231 is wound so as to rotate clockwise with respect to the first direction 230d, and the current flows in the first direction 230d. According to the above configuration, the current 230ar that circulates clockwise in the first direction 230d flows in the inductor 230, and the magnetic flux 230f that circulates along the first direction 230d is formed.

  The inductor 250 is mounted on the circuit board 210 so that the winding portion 251 having a circular shape is connected to the electric circuit 20. By applying a current from the electric circuit 20 to the winding portion 251 of the inductor 250, the inductor 250 has the cathode 250b on the inductor 230 side (right side in FIG. 3) and the side opposite to the cathode 250b (left side in FIG. 3). ) To form anodes 250h. Accordingly, the second direction 250d in the second embodiment is set to the left in the planar direction of the circuit board 210 in FIG. When the inductor 250 forms such a magnetic pole, the winding portion 251 is wound so as to rotate clockwise with respect to the second direction 250d, and the current flows in the second direction 250d. With the above configuration, a current 40ar that circulates clockwise in the second direction 250d flows through the inductor 250, and a magnetic flux 250f that circulates along the second direction 250d is formed.

  According to the above configuration, the inductor 230 and the inductor 250 are disposed so that the first direction 230d and the second direction 250d face each other, and the cathodes 230b and 250b are close to each other. The magnetic flux 230f and the magnetic flux 250f intersect each other. Therefore, even if the magnetic field noise is radiated from the inductors 230 and 250, the magnetic field noises cancel each other, and the electronic circuit device 200 that realizes reduction of the radiated magnetic field noise can be provided.

  In addition, in the second embodiment, since the winding portions 231 and 251 having the circular shape are accommodated in the exterior portions 237 and 257, the magnetic field noise radiated from the inductors 230 and 250 to the outside by the exterior portions 237 and 257 is reduced. Part is shielded. In addition, the exterior parts 237 and 257 shield a part of the magnetic field noise radiated outside, and suppress induction of induced currents in the winding parts 231 and 251 housed in the exterior parts 237 and 257. Due to the magnetic field noise shielding action by the exterior portions 237 and 257, even when the inductor 230 and the inductor 250 are brought close to each other, the malfunction of the other inductor due to the magnetic field noise radiated from the one inductor is hardly caused. Therefore, since the deviation between the inductor 230 and the inductor 250 can be reduced without impairing the operation of the inductors 230 and 250, the magnetic field noise can be effectively canceled out.

(Third and fourth embodiments)
As shown in FIG. 4, the third embodiment of the present invention is a modification of the second embodiment. In the electronic circuit device 300 according to the second embodiment, inductors 230 and 250 are mounted on different surfaces of the circuit board 310. The surface on which the inductor 230 is mounted is the surface side of the circuit board 310. In addition, in FIG. 4, other electronic elements mounted on the circuit board 310 are omitted.

  In the third embodiment, the first direction 330d in which the inductor 230 is mounted is the left direction along the planar direction of the circuit board 310 in FIG. In addition, the second direction 350d in which the inductor 250 is mounted is the same direction as the first direction 330d, and is the left direction along the planar direction of the circuit board 310 in FIG. Further, the inductor 250 is disposed at a position that is perpendicular to the first direction 330 d with respect to the inductor 230 and is shifted in the thickness direction of the circuit board 310.

  As shown in FIG. 5, the fourth embodiment of the present invention is a modification of the third embodiment. In the electronic circuit device 400 according to the third embodiment, inductors 230 and 250 are mounted on the same surface of the circuit board 410. In FIG. 5, other electronic elements mounted on the circuit board 410 are omitted.

  In the fourth embodiment, the first direction 430d in which the inductor 230 is mounted is a direction along the planar direction of the circuit board 410, and is an upward direction in FIG. In addition, the second direction 450 d in which the inductor 250 is mounted is the same direction as the first direction 430 d and the upward direction in FIG. 4 along the planar direction of the circuit board 410. Further, the inductor 250 is arranged at a position that is perpendicular to the first direction 330 d with respect to the inductor 230 and is displaced along the planar direction of the circuit board 410.

  According to the arrangement of the third embodiment and the fourth embodiment described above, the anodes 230h and 250h and the cathodes 230b and 250b of the inductors 230 and 250 are equally close to each other. Therefore, the magnetic flux 230f formed in the vicinity of both magnetic poles 230h and 230b of the inductor 230 and the magnetic flux 250f formed in the vicinity of both magnetic poles 250h and 250b of the inductor 250 can be crossed at an angle close to facing over a wide range. Therefore, the magnetic fields radiated from the inductors 230 and 250 cancel each other more effectively. Therefore, it is possible to provide the electronic circuit devices 300 and 400 that realize reduction of the radiated magnetic field noise.

(Fifth embodiment)
As shown in FIG. 6, the fifth embodiment of the present invention is still another modification of the first embodiment.

  In the electronic circuit device 500 according to the fifth embodiment, a first circuit board portion 510a on which the inductor 30 is mounted, and a second circuit board portion 510b on which the inductor 50 is mounted and disposed opposite to the first circuit board portion 510a. Is provided. In addition, the electric circuit 520 includes a power supply circuit unit 521a provided on the first circuit board unit 510a and an illumination drive circuit unit 521b provided on the second circuit board unit 510b. Further, the inductor 30 is connected to the power supply circuit unit 521a, and the inductor 50 is connected to the illumination drive circuit unit 521b.

  The inductor 30 in the fifth embodiment is disposed on the second circuit board portion 510b side of the first circuit board portion 510a. In addition, the first direction 530d as the mounting direction of the inductor 30 is a direction from the first circuit board part 510a side to the second circuit board part 510b side along the plate thickness direction of the first circuit board part 510a. The inductor 50 is disposed on the first circuit board 510a side of the second circuit board 510b. In addition, the second direction 550d, which is the mounting direction of the inductor 50, is a direction from the second circuit board part 510b side to the first circuit board part 510a side along the plate thickness direction of the second circuit board part 510b.

  The electric circuit 520 in the fifth embodiment is, for example, an on-board instrument, and is an electric circuit used for an instrument including a stepper motor, a diode, a control circuit, and the like. The power supply circuit unit 521a is a circuit unit that supplies power to a stepper motor, a diode, a control circuit, and the like. The inductor 30 connected to the power supply circuit unit 521a smoothes the current supplied to the power supply circuit unit 521a. The illumination drive circuit unit 521b is a circuit unit that supplies power to the diode to emit light. The inductor 50 connected to the illumination drive circuit unit 521b smoothes the current supplied to the illumination drive circuit unit 521b. In the fifth embodiment, the power supply circuit unit 521a corresponds to the “first circuit unit” recited in the claims, and the illumination drive circuit unit 521b corresponds to the “second circuit unit” recited in the claims. .

  In the fifth embodiment, the electronic circuit device 500 includes the first circuit board part 510a and the second circuit board part 510b, and the inductor 30 and the inductor 50 are mounted on different first circuit board parts 510a and second circuit board parts 510b. Is done. Also in the above configuration, magnetic poles are formed in both the inductor 30 and the inductor 50, and the magnetic flux 30f and the magnetic flux 50f formed in the vicinity of the adjacent anodes 30h and 50h can be crossed. Therefore, the magnetic field noise radiated from the inductor 30 and the inductor 50 cancels each other. Therefore, even in the electronic circuit device 500 including the respective wiring board portions 510a and 510b in which the respective inductors 30 and 50 are separately mounted and disposed so as to face each other, reduction of magnetic field noise can be realized. .

  In addition, in the fifth embodiment, the inductor 30 and the inductor 50 are provided on the first circuit board part 510a and the second circuit board part 510b, respectively, and the power supply circuit part 521a and the illumination driving circuit part included in the electric circuit 520. 521b, respectively. Also in the above configuration, magnetic poles are formed in both the inductor 30 and the inductor 50, and the magnetic flux 30f and the magnetic flux 50f formed in the vicinity of the adjacent anodes 30h and 50h can be crossed. Therefore, the magnetic field noise radiated from the inductor 30 and the inductor 50 cancels each other. Therefore, even when the respective inductors 30 and 50 are connected to different power supply circuit units 521a and illumination drive circuit units 521b, reduction of magnetic field noise can be realized.

  Furthermore, according to the function of crossing and canceling out the magnetic fluxes 30f and 50f due to the arrangement of the inductor 30 and the inductor 50 according to the present invention, an electronic circuit device in which electronic elements such as inductors and wiring of the electric circuit are densely arranged. However, magnetic field noise can be reduced. Therefore, the present invention is particularly suitable as an electronic circuit device for an in-vehicle instrument in which space restrictions are severe and the influence of magnetic field noise on other electronic devices is a concern.

(Sixth embodiment)
As shown in FIG. 7, the sixth embodiment of the present invention is a modification of the fifth embodiment. In the electronic circuit device 600 according to the sixth embodiment, the first circuit board portion 610a on which the inductors 130a, 130b, and 130c are mounted, and the inductors 150a, 150b, and 150c are mounted, and the electronic circuit device 600 is disposed relative to the first circuit board portion 610a. The second circuit board portion 610b is provided.

  The inductors 130a, 130b, and 130c are connected in series. Therefore, the sum of the inductances of the inductors 130a, 130b, and 130c is set to be equal to the inductance of the inductor 30. The inductors 130a, 130b, and 130c are all arranged on the second circuit board portion 610b side of the first circuit board portion 610a. Further, the first direction 630d, which is the mounting direction of the inductors 130a, 130b, and 130c, is all the same direction, and the second circuit from the first circuit board part 610a side along the plate thickness direction of the first circuit board part 610a. The direction is toward the substrate portion 610b.

  Inductors 150a, 150b, and 150c are connected in series. Therefore, the sum of the inductances of the inductors 150a, 150b, and 150c is set to be equal to the inductance of the inductor 50. The inductors 150a, 150b, and 150c are all arranged on the first circuit board portion 610a side of the second circuit board portion 610b. Further, the second direction 650d, which is the mounting direction of the inductors 150a, 150b, and 150c, is the same direction, and the first circuit from the second circuit board part 610b side along the plate thickness direction of the second circuit board part 610b. The direction is toward the substrate portion 610a.

  In the sixth embodiment, one inductor is intentionally divided into a plurality of inductors and connected in series. Therefore, the magnetic fluxes 130f and 150f radiated from the individual inductors divided into a plurality are weaker than the magnetic fluxes 30f and 50f. Furthermore, since the opposing inductors 130a, 130b, 130c and the anodes 130h, 150h of the inductors 150a, 150b, 150c are arranged close to each other, the magnetic fluxes 130f, 150f in the vicinity of the anodes 130h, 150h intersect. As a result, the magnetic field noises cancel each other. In addition, since the magnetic poles of the inductors 130 arranged side by side on the first circuit board portion 610a are arranged close to each other, the magnetic flux 130f in the vicinity of the magnetic poles intersects each other, and magnetic field noises cancel each other. It will be. The same applies to the inductors 150 arranged side by side on the second circuit board portion 610b, and the magnetic field noise is canceled between the adjacent inductors 150. Therefore, by dividing the inductors 30 and 50 into a plurality of inductors 130a, 130b, and 130c and 150a, 150b, and 150c, the electronic circuit device 600 that can significantly reduce magnetic field noise can be provided.

(Other embodiments)
As mentioned above, although each embodiment of this invention was described, this invention is limited to the said embodiment and is not interpreted and can be applied to various embodiment in the range which does not deviate from the summary.

  In the above embodiment, the conductive portion of each inductor is provided so as to circulate clockwise with respect to the first direction or the second direction, and the current flows in the first direction or the second direction. And by this structure, the flow of the electric current 40ar which rotates in the clockwise direction with respect to the first direction or the second direction was formed. However, the conductive part may be provided so as to circulate counterclockwise with respect to the first direction or the second direction, and the current may flow in the direction opposite to the first direction or the second direction. Even in this configuration, a current 40ar flow that circulates clockwise in the first direction or the second direction is formed. Alternatively, each inductor may be formed with a current 40 ar flow that circulates counterclockwise with respect to the first direction or the second direction. In this case, the conductive portion of each inductor is provided so as to circulate clockwise with respect to the first direction or the second direction, and the current flows in the direction opposite to the first direction or the second direction, or It suffices that the conductive portion of each inductor is provided so as to circulate counterclockwise with respect to the first direction or the second direction, and the current flows in the first direction or the second direction.

  In the above embodiment, an example in which inductors having the same specifications are used as the “first electronic element” and the “second electronic element” described in the claims has been described. However, the “first electronic element” and the “second electronic element” are not limited to the same specification. Furthermore, an electronic element having a circular conductive portion other than the inductor, such as a transformer or various motors, may be used.

  In the above embodiment, the “first electronic element” and the “second electronic element” are connected in series, but may be connected in parallel. In the above embodiment, the “first electronic element” and the “second electronic element” are connected to the power supply circuit unit and the illumination driving circuit unit. However, for example, in the stepper motor drive control circuit in which a pulse current flows. It may be connected. Furthermore, the current flowing through the “first electronic element” and the “second electronic element” may not be a pulsating pulse current but may be connected to an electric circuit through which a smooth current flows.

  In the said embodiment, the example which uses the electronic circuit device by this invention for a vehicle-mounted instrument was demonstrated. However, it is possible to apply the present invention to electronic circuit devices used for various on-board “electronic devices” in addition to instruments. Furthermore, the present invention can be applied to electronic circuit devices used in various “electronic devices” other than vehicles.

It is a schematic diagram for demonstrating the noise reduction effect of the electronic circuit apparatus by 1st embodiment of this invention. It is a block diagram which shows the structure of the electric circuit with which the electronic circuit apparatus by one Embodiment of this invention is provided. It is a modification of 1st embodiment of this invention, Comprising: It is a schematic diagram for demonstrating the noise reduction effect of the electronic circuit apparatus by 2nd embodiment. It is a modification of 2nd embodiment of this invention, Comprising: It is a schematic diagram for demonstrating the noise reduction effect of the electronic circuit apparatus by 3rd embodiment. It is a modification of 3rd embodiment of this invention, Comprising: It is a schematic diagram for demonstrating the noise reduction effect of the electronic circuit apparatus by 4th embodiment. It is another modification of 1st embodiment of this invention, Comprising: It is a schematic diagram for demonstrating the noise reduction effect of the electronic circuit apparatus by 5th embodiment. It is a modification of 5th embodiment of this invention, Comprising: It is a schematic diagram for demonstrating the noise reduction effect of the electronic circuit apparatus by 6th embodiment.

Explanation of symbols

10, 210, 310, 410 Circuit board, 510a, 610a First circuit board part, 510b, 610b Second circuit board part, 11 Insulating layer, 11a Front side insulating layer, 11b Internal insulating layer, 11c Back side insulating layer, 13 Wiring layer, 13a Front side wiring layer, 13b Power supply wiring layer, 13c Ground wiring layer, 13d Back side wiring layer, 15 through hole, 16 through hole plating, 16a mounting portion, 16b connection portion, 17 coating layer, 18 solder, 20,520 Electric circuit, 21,521a Power supply circuit part (first circuit part), 521b Illumination drive circuit part (second circuit part), 23 Capacitor, 30, 130a, 130b, 130c, 230 Inductor (first electronic element) ), 50, 150a, 150b, 150c, 250 Inductor (second electronic element), 30ax, 23 ax, 50ax, 250ax Axis, 30d, 230d, 330d, 430d, 530d, 630d First direction, 50d, 250d, 350d, 450d, 550d, 650d Second direction, 30b, 230b, 50b, 250b Cathode, 30h, 230h, 50h, 250h Anode, 30f, 130f, 230f, 50f, 150f, 250f Magnetic flux, 231, 251 Winding part (conductive part), 32, 52 Internal electrode (conductive part), 34, 234, 54, 254 External electrode, 34a , 234a, 54a, 254a Contact part, 36, 56 Ferrite core, 237, 257 Exterior part, 40ar current, 100, 200, 300, 400, 500, 600 Electronic circuit device

Claims (14)

A circuit board having an electrical circuit;
A first electronic element having a circular conductive part connected to the electric circuit by being mounted on the circuit board, and forming a magnetic pole by applying a current to the conductive part;
A second electronic element having a circular conductive part connected to the electric circuit by being mounted on the circuit board and forming a magnetic pole by applying a current to the conductive part, wherein the first electronic element And a second electronic element arranged so that magnetic poles having the same polarity are close to each other at a position opposite to the electronic circuit device.   The first direction from the cathode side to the anode side of the magnetic pole formed by the first electronic element is opposed to the second direction from the cathode side to the anode side of the magnetic pole formed by the second electronic element. The electronic circuit device according to claim 1.   3. The circuit board according to claim 2, wherein the first electronic element and the second electronic element are mounted on the circuit board such that the axis in the first direction and the axis in the second direction are coaxial. Electronic circuit device. The first direction of the magnetic pole formed by the first electronic element and the second direction of the magnetic pole formed by the second electronic element are the same direction,
The electronic circuit device according to claim 1, wherein the second electronic element is mounted to face the first electronic element in a direction orthogonal to the first direction.   5. The electronic circuit device according to claim 1, wherein the first electronic element and the second electronic element are mounted on different mounting surfaces of the circuit board.   The electronic circuit device according to claim 1, wherein the first electronic element and the second electronic element are electronic elements having the same specifications.   The electronic circuit device according to claim 1, wherein the first electronic element and the second electronic element have a case portion that accommodates the circular conductive portion.   The electronic circuit device according to any one of claims 1 to 7, wherein a pulse current is applied from the electric circuit to the conductive portion of the first electronic element and the second electronic element. .   The electronic circuit device according to claim 1, wherein the first electronic element and the second electronic element are connected in series.   10. The electronic circuit device according to claim 1, wherein the first electronic element and the second electronic element are inductors having a circular conductive portion. The electric circuit includes a power supply circuit unit that generates a required output current from an input current,
The electronic circuit device according to claim 10, wherein the first electronic element and the second electronic element are connected to an input side of the power supply circuit unit.   The circuit board includes a first circuit board part on which the first electronic element is mounted, and a second circuit board part on which the second electronic element is mounted and disposed opposite to the first board part. The electronic circuit device according to claim 1, wherein the electronic circuit device is characterized in that The electrical circuit comprises a first circuit part provided on the first circuit board part and a second circuit part provided on the second circuit board part,
The first electronic element is connected to the first circuit unit,
The electronic circuit device according to claim 12, wherein the second electronic element is connected to the second circuit unit.   The electronic circuit device according to claim 1, wherein the electronic circuit device is mounted on an instrument mounted on a vehicle.

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