JP6664661B2 - Electronic circuit device - Google Patents

Description

  The present invention relates to an electronic circuit device on which electronic components are mounted.

  2. Description of the Related Art In an electronic circuit device, a configuration is known in which a magnetic field generated from one inductor is canceled by a magnetic field generated from the other inductor. For example, Patent Literature 1 describes a specific configuration of an electronic circuit device having this type of configuration.

Japanese Patent No. 5262523

  Patent Literature 1 discloses a configuration in which a pair of inductors are arranged on a front surface and a back surface of a circuit board in a positional relationship in which the center axes of the magnetic fields match each other, or the pair of inductors are disposed on separate circuit boards in the center of the mutual magnetic field It describes a configuration in which the axes are arranged in the same positional relationship. However, in the configuration described in Patent Literature 1, the electromotive force generated by each of the pair of inductors is generated as noise in a pattern near each inductor, which may adversely affect a mounted circuit on a circuit board.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a pair of inductors having a magnetic field canceling effect, and to suppress an electromotive force generated in a signal line by these inductors. To provide an electronic circuit device that is suitably configured.

  An electronic circuit device according to an embodiment of the present invention includes a pair of inductors arranged so that mutually opposite magnetic fields are generated when energized, and a predetermined signal line substantially affected by electromagnetic noise due to the inductor. A predetermined signal line is substantially plane-symmetric with respect to a line segment orthogonal plane orthogonal to the line segment at the midpoint of the line segment connecting the centers of the pair of inductors. An inductor is arranged.

  In one embodiment of the present invention, for example, the pair of inductors are arranged on the same surface, a different surface, or a different layer on the same substrate as the predetermined signal line, or on a different substrate from the predetermined signal line. ing.

  In one embodiment of the present invention, the predetermined signal line includes, for example, at least one of a lead wire, a pattern formed on a circuit board, and a wiring in an electronic component mounted on the circuit board.

  In one embodiment of the present invention, the pair of inductors may be configured to be electrically connected in series.

  In one embodiment of the present invention, the pair of inductors may have the same electrical characteristics.

  According to one embodiment of the present invention, there is provided an electronic circuit device that includes a pair of inductors having a magnetic field canceling effect and is preferably configured to suppress an electromotive force generated in a signal line by these inductors. You.

FIG. 1 is a diagram illustrating a configuration of an electronic circuit device according to an embodiment of the present invention. It is a figure which shows typically the example of arrangement | positioning of a pair of inductor which suppresses the electromotive force which generate | occur | produces in a noise generation signal line in one Embodiment of this invention suitably. It is a figure showing the composition of the electronic circuit device concerning the modification of one embodiment of the present invention.

  Hereinafter, an electronic circuit device according to an embodiment of the present invention will be described with reference to the drawings. An electronic circuit device according to an embodiment of the present invention includes a digital single-lens reflex camera, a mirrorless single-lens camera, a compact digital camera, a video camera, a camcorder, a tablet terminal, a PHS (Personal Handy phone System), a smartphone, a feature phone, and a mobile phone. It is a circuit device mounted on an electronic device such as a game machine. The electronic device on which the electronic circuit device according to one embodiment of the present invention is mounted is not limited to the above, and may be another electronic device.

  1A and 1B are a top view and a side sectional view, respectively, showing the configuration of an electronic circuit device 1 according to one embodiment of the present invention. As shown in FIG. 1, the electronic circuit device 1 includes a circuit board 10.

  The circuit board 10 is a multilayer board in which a plurality of boards are stacked, and includes a pattern layer (an outer layer on the upper surface side, the surface of the circuit board 10) 10a and a pattern layer (inner layer) as a pattern layer capable of forming a pattern. ) 10b, a pattern layer (inner layer) 10c, and a pattern layer (an outer layer on the lower surface side, the back surface of the circuit board 10) 10d. Note that the circuit board 10 may be a rigid board or an FPC (Flexible Printed Circuits). Further, the circuit board 10 may be a single-layer board instead of the multilayer board.

  On the mounting surface of the circuit board 10 (on the pattern layer 10a), the inductors 20 and 30 are mounted and arranged side by side. In FIG. 1, illustration of electronic components other than the inductor 20 and the inductor 30 and patterns other than a connection pattern 40 described later, which are mounted and arranged on the circuit board 10, are omitted for convenience.

  The inductor 20 and the inductor 30 have the same shape and dimensions and have the same electrical characteristics. The electrical characteristics here include, for example, inductance, DC resistance, DC superimposed current, allowable current, Q, self-resonant frequency, impedance, and the like.

  The inductor 20 is a multilayer inductor, and has an internal electrode 21, a magnetic core 22, and a pair of external electrodes 23. A sheet material on which a pattern of a magnetic material (for example, ferrite) constituting a part of the internal electrode (winding portion) 21 is printed is laminated in a predetermined order, thereby forming a spiral around the axis (winding shaft) 21ax. The magnetic core 22 in which the internal electrode 21 formed in the above is embedded is formed. The axis 21ax penetrates the circuit board 10 vertically (perpendicular to the circuit board 10). The external electrode 23 is adhesively fixed to the short side surface 22 a of the magnetic core 22 formed in a substantially rectangular parallelepiped shape, and is electrically connected to the internal electrode 21 and electrically connected to the pattern formed on the circuit board 10. It is connected.

  The inductor 30 is also a laminated inductor, and has an internal electrode 31, a magnetic core 32, and a pair of external electrodes 33. By laminating a sheet base on which a pattern of a magnetic material (for example, ferrite) constituting a part of the internal electrode (winding part) 31 is printed in a predetermined order, a spiral is formed around the axis (winding axis) 31ax. The magnetic core 32 in which the internal electrode 31 formed in the above is embedded is constituted. The axis 31ax vertically penetrates the circuit board 10 (perpendicular to the circuit board 10). The external electrode 33 is adhesively fixed to the short side surface 32 a of the magnetic core 32 formed in a substantially rectangular parallelepiped shape, is electrically connected to the internal electrode 31, and is also electrically connected to the pattern formed on the circuit board 10. It is connected.

  As shown in FIG. 1B, the inductor 20 and the inductor 30 are connected via a connection pattern 40 formed on the pattern layer 10b.

  When electric power is supplied to the electronic circuit device 1, a current flows in the order of the inductor 20, the connection pattern 40, and the inductor 30, as indicated by arrows in FIG.

  When the inductor 20 is energized, a magnetic field around the axis 21ax (magnetic field lines in the directions of arrows A1 to A3 in FIG. 1B) is generated.

  In the inductor 30, the direction of the current and the winding direction of the internal electrode (winding portion) 31 are set such that the direction of the magnetic pole is opposite to that of the inductor 20. Therefore, when the inductor 30 is energized, a magnetic field around the axis 31ax (magnetic field lines in the directions of arrows B1 to B3 in FIG. 1B) is generated. That is, the inductor 20 and the inductor 30 generate magnetic fields in opposite directions. Therefore, the generated mutual magnetic fields are reduced or offset by the canceling effect.

  The electronic circuit device 1 according to one embodiment of the present invention has the following features in order to improve the effect of canceling out magnetic fields and suppress the electromotive force generated in a signal line by an inductor.

[Proximity between inductors]
Generally, from the viewpoints of voltage drop, noise, high integration, and the like, the shorter the connection pattern on the circuit board that connects the inductors, the better. For example, in the case of a single-sided board, the connection pattern can be shortened by forming a connection pattern connecting two inductors arranged side by side on the mounting surface (on the pattern layer).

  However, on a single-sided board, a connection pattern cannot be formed below the mounted inductor. In order to form a connection pattern, it is necessary to mount and arrange the two inductors at least with a wider interval than the connection pattern. In the circuit board 10, it is desirable to design the pattern width wide in order to lower the impedance of the connection pattern. However, the larger the pattern width, the greater the distance between the two inductors, so that the effect of canceling out the magnetic field decreases.

  Therefore, in one embodiment of the present invention, as described above, the connection pattern 40 is formed on a pattern layer (the pattern layer 10b in the example of FIG. 1) other than the pattern layer 10a located immediately below the inductor 20 and the inductor 30. Have been. The connection pattern 40 may be formed on the pattern layer 10c or 10d instead of the pattern layer 10b.

  By forming the connection pattern 40 on a pattern layer other than the pattern layer 10a, the inductor 20 and the inductor 30 can be arranged close to each other regardless of the pattern width of the connection pattern 40. Exemplarily, the inductor 20 and the inductor 30 are mounted and arranged side by side on the mounting surface (on the pattern layer 10a) with an interval smaller than the pattern width of the connection pattern 40.

  As described above, according to the embodiment of the present invention, since the inductor 20 and the inductor 30 are mounted and arranged close to each other, the effect of canceling out the magnetic field is improved. Further, since the inductor 20 and the inductor 30 are arranged side by side on the same mounting surface (on the pattern layer 10a), the size of the entire electronic circuit device 1 is compact.

[Direct connection]
The inductor 20 and the inductor 30 are connected in series via a connection pattern 40 formed on the pattern layer 10b (or the pattern layer 10c or the pattern layer 10d). By connecting the inductor 20 and the inductor 30 having the same electrical characteristics and the like in series, the intensity of the magnetic field generated from each inductor becomes substantially the same. This makes it possible to cancel the magnetic field to almost zero.

[Inductor orientation]
Due to the structure of the inductor, there is a side on which the number of turns of the winding portion is one more than the other sides. In one embodiment of the present invention, the inductor 20 and the inductor 30 are arranged such that the sides having the largest number of turns of the internal electrode (winding portion) face each other. As a result, the magnetic field near the opposing sides is strengthened, and the effect of canceling out the magnetic fields is improved.

[Relationship with signal line]
Many patterns other than the connection pattern 40 are formed on the pattern layers 10a to 10d. Also, a large number of patterns are formed on another circuit board disposed near the circuit board 10. In these patterns, there is a possibility that electromotive force generated by the inductor 20 or the inductor 30 is generated as noise. Further, lead wires are connected to the circuit board 10 and other circuit boards, and electronic components other than the inductor 20 and the inductor 30 are mounted. Electromotive force due to the inductor 20 or the inductor 30 may also be generated as noise in these lead wires and wiring in the electronic component (for example, a column line of a complementary metal oxide semiconductor (CMOS) image sensor).

  In the present embodiment, a signal line (a signal line includes all electric wires such as a pattern, a lead wire, and a wiring in an electronic component) which may generate a noise of a certain level or more is formed by an inductor. It is referred to as a signal line that is substantially affected by electromagnetic noise (noise generation signal line). As a tendency, a signal line closer to the inductor 20 or the inductor 30 in terms of distance can be a noise generating signal line. Here, for example, a signal line located within a predetermined range from the inductor 20 or the inductor 30 is treated as a noise generation signal line.

In the present embodiment, the positions of the inductors 20 and 30 are set to minimize (ideally, zero) the number of noise-generating signal lines generated as noise of a certain level or more due to the electromotive force generated by the inductors 20 and 30. It is decided. Line Specifically, more noise generating signal line, the inductor 20 and in line (Figure 1 connecting the centers of the inductor 30, connecting the middle point _{P 31} of the middle point _{P 21} and the axis 31ax axis 21ax The inductors 20 and 30 are arranged so as to be substantially plane-symmetric with respect to a line segment orthogonal plane S orthogonal to the segment L). From another viewpoint, the inductor 20 and the inductor 30 are arranged so that the number of noise generating signal lines that are not substantially plane-symmetric with respect to the line segment orthogonal plane S is minimized.

Since an opposite magnetic field is generated between the inductor 20 and the inductor 30 in the noise generation signal line, an electromotive force is generated by the inductor 20 and at the same time, an electromotive force in the opposite direction (electromotive force by the inductor 30) is generated. appear. Hereinafter, for convenience of description, the electromotive force of the inductor 20 is referred to as “EMF ₂₀ ”, and the electromotive force of the inductor 30 is referred to as “EMF ₃₀ ”.

Since the distance from the inductor 20 and the distance from the inductor 30 are substantially equal to each other on the noise generating signal line which is substantially plane-symmetric with respect to the line segment orthogonal plane S, the electromotive force EMF ₂₀ having substantially equal magnitude An electromotive force EMF ₃₀ is generated. Since these electromotive forces are opposite to each other, they are offset to almost zero by the canceling effect. As described above, according to the present embodiment, the electromotive force generated in the noise generation signal line by the inductor 20 and the inductor 30 is appropriately suppressed.

  FIGS. 2A to 2C schematically show examples of the arrangement of the inductor 20 and the inductor 30 in which the electromotive force generated in the noise generating signal line is appropriately suppressed. In each of FIGS. 2A to 2C, a noise generation signal line is denoted by reference numeral 50 for convenience of explanation.

・ Arrangement example 1
In the first embodiment, as shown in FIG. 2A, the inductor 20 and the inductor 30 are arranged such that the L-shaped noise generating signal line 50 is plane-symmetric with respect to the line orthogonal plane S. I have. Therefore, the electromotive force EMF ₂₀ (the sum of the electromotive force EMF _20A and the electromotive force EMF _20B ) and the electromotive force EMF ₃₀ (the sum of the electromotive force EMF _30A and the electromotive force EMF _30B ) having the same magnitude are provided on the noise generation signal line 50. appear. Since these electromotive forces are opposite to each other, they are offset to zero by the canceling effect.

・ Arrangement example 2
In the present example 2, as shown in FIG. 2B, the inductors 20 and 30 are arranged such that the U-shaped noise generating signal line 50 is plane-symmetric with respect to the line segment orthogonal plane S. ing. Therefore, the noise generating signal line 50 includes the electromotive forces EMF ₂₀ (the sum of the electromotive forces EMF _20C , EMF _20D and EMF _20E ) and the electromotive force EMF ₃₀ (the sum of the electromotive forces EMF _30C , EMF _30D and EMF _30E ). ) Occurs. Since these electromotive forces are opposite to each other, they are offset to zero by the canceling effect.

・ Arrangement example 3
In Example 3, as shown in FIG. 2C, the L-shaped noise generating signal line 50 is not strictly symmetric with respect to the line segment orthogonal plane S. However, since the linear portion 50A of the noise generation signal line 50 is separated from the inductor 20 and the inductor 30, only a small electromotive force is generated by the inductor 20 and the inductor 30 in the linear portion 50A (the electromotive force EMF _20F). , EMF _30F is small). On the other hand, the linear portion 50B of the noise generation signal line 50 is close to the inductor 20 and the inductor 30. Therefore, in the linear portion 50B, a large electromotive force is generated by the inductors 20 and 30 (the electromotive forces EMF _20G and EMF _30G are large). The magnitude of the electromotive force EMF _20G is much larger than the electromotive force EMF _20F , and the magnitude of the electromotive force EMF _30G is much larger than the electromotive force EMF _30F .

In the third example, focusing on the magnitude of the generated electromotive force, when the inductor 20 and the inductor 30 are arranged adjacent to the linear portion 50B of the noise generating signal line 50, the positional relationship with the linear portion 50B is mainly determined. It turns out that you should consider it. In the third example, since the generated straight line portion 50B having a large electromotive force is plane-symmetric with respect to the line segment orthogonal plane S, the noise generation signal line 50 is substantially substantially entirely with respect to the line segment orthogonal plane S. It can be said that the inductors 20 and 30 are arranged so as to be plane-symmetric. Since the electromotive force EMF _20G and the electromotive force EMF _30G are equal in magnitude and opposite to each other, they are offset to zero by the canceling effect. On the other hand, the electromotive force EMF _20F and the electromotive force EMF _30F are not equal in magnitude to each other, but are small, so that they are almost offset by the canceling effect. Therefore, also in the third embodiment, the electromotive force generated in the noise generation signal line 50 is almost canceled.

  According to the third example, even if the inductor 20 and the inductor 30 are not arranged, the noise generation signal line 50 is formed such that the noise generation signal line 50 is completely plane-symmetric with respect to the line segment orthogonal plane S. If the inductor 20 and the inductor 30 are arranged so as to be substantially symmetric with respect to the minute orthogonal plane S, the electromotive force generated in the noise generating signal line 50 is almost canceled out by the canceling effect. I understand.

  The above is the description of the exemplary embodiment of the present invention. The embodiments of the present invention are not limited to those described above, and various modifications are possible within the scope of the technical idea of the present invention. For example, the embodiments of the present application include the embodiments exemplarily specified in the specification or the contents obtained by appropriately combining the obvious embodiments and the like.

  FIGS. 3A and 3B are a top view and a side sectional view, respectively, of an electronic circuit device 1z according to a modification of the embodiment of the present invention. This modified example is different from the above-described embodiment in the way of connecting patterns connecting the inductors 20 and 30. Specifically, in the present modification, the connection pattern 40z for connecting the inductor 20 and the inductor 30 is provided on the same mounting surface as the inductor 20 and the inductor 30 (on the pattern layer 10a) in a shape that is substantially shortest. . According to this modification, the manufacturing cost can be reduced because the inductor 20 and the inductor 30 are connected by an extremely general method (the connection pattern 40z formed on the same mounting surface). Further, since the connection pattern 40z is formed short, the voltage drop is small.

DESCRIPTION OF SYMBOLS 1 Electronic circuit device 10 Circuit board 10a-10d Pattern layer 20,30 Inductor 21,31 Internal electrode 21ax, 31ax Axis 22,32 (of internal electrode) Magnetic core 22a, 32a Short side surface 23,33 (of magnetic core) External Electrode 40 Connection pattern 50 Noise generation signal line

Claims (5)

A pair of inductors arranged to generate mutually opposite magnetic fields when energized,
A predetermined signal line substantially affected by electromagnetic noise due to the inductor,
With
The pair of inductors are arranged such that the predetermined signal line is substantially plane-symmetric with respect to a line segment orthogonal plane orthogonal to the line segment at a midpoint of the line segment connecting the centers of the pair of inductors. Are placed,
Electronic circuit device. The pair of inductors,
The same surface on the same substrate as the predetermined signal line, a different surface or a different layer, or the predetermined signal line is disposed on a different substrate,
The electronic circuit device according to claim 1. The predetermined signal line,
Including at least one of a lead wire, a pattern formed on a circuit board, and wiring in an electronic component mounted on the circuit board.
The electronic circuit device according to claim 1. The pair of inductors,
Electrically connected in series,
The electronic circuit device according to claim 1. The pair of inductors,
Have the same electrical characteristics,
The electronic circuit device according to claim 1.

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