JP2007324197A - Inductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inductor where magnetic coupling is performed between a plurality of coils, surface mounting is possible, and a profile can be lowered. <P>SOLUTION: The inductor includes a plurality of coils 40 constituted by winding 41; a first core 30 having a plate 31 arranged in a plate shape, and a plurality of pillar legs 32 which are erected from the plate 31 and into which insertion holes 40a of the coils 40 are inserted; a second core 20 disposed in the plate shape; and connection terminals 50 to which terminals 42 of a plurality of coils 40 are connected. When current in any direction flows in the coil 40 through the terminal 42; magnetic flux formed by the coils 40 passes the first core 30, the second core 20, and the pillar legs 32. A plurality of the coils 40 are installed so that they can magnetically be coupled. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an inductor mounted on various electronic devices.

  For example, in a power supply circuit such as a notebook personal computer, a multi-phase type inductor may be used in order to improve mounting efficiency. As this multi-phase type inductor, there are those disclosed in Patent Document 1 and Patent Document 2. In Patent Document 1 and Patent Document 2, a box-shaped core is provided with a magnetic core, and this magnetic core is inserted through the central hole of the coil.

JP 2001-93757 (see abstract, FIG. 1, FIG. 3 etc.) JP-A-2004-111754 (Summary, see FIGS. 1-3)

  By the way, in the structure currently disclosed by the above-mentioned patent document 1 and patent document 2, two independent magnetic paths are formed, and it will be in the state which hardly produces coupling (magnetic coupling) between each magnetic path. Yes. In particular, in the configuration disclosed in Patent Document 2, since a partition exists between two coils, the magnetic paths formed by the respective coils are in an independent state. Therefore, there is almost no magnetic coupling. Further, in the configuration disclosed in Patent Document 1, although very weak magnetic coupling exists, the magnetic coupling cannot be actively used.

  Here, among notebook personal computers and the like, particularly in a power supply circuit or the like in a secondary power supply, there is a case where magnetic coupling between two coils is strongly required. As a method for strengthening such magnetic coupling, there is a configuration in which two coils are arranged in a ring-shaped core, such as a toroidal core. However, when such a toroidal core is adopted, there is a problem that it is not suitable for surface mounting. In addition, when a toroidal core is employed, the height dimension may be increased during mounting, which is not preferable because various electronic devices to be mounted are prevented from being thinned.

  It is also conceivable to configure an inductor having two coils by combining two ER cores. However, in this case, there is a problem that the coil into which the magnetic core of the ER core is inserted is stacked in the height direction, and the height dimension becomes large.

  The present invention has been made on the basis of the above-described circumstances, and the object of the present invention is to achieve magnetic coupling between a plurality of coils, surface mounting, and reduction in height. To provide a simple inductor.

  In order to solve the above-described problems, the present invention provides a plurality of coils formed by winding a winding, a plate portion provided in a plate shape, and an insertion hole for the coil provided upright from the plate portion. Comprising a first core having a plurality of column bases into which a terminal is inserted, a second core provided in a plate shape, and a connection terminal to which terminals of the plurality of coils are respectively connected. When a current in either direction flows through the coil, the magnetic flux formed by each coil passes through the first core, the second core, and the column base, and a plurality of coils are provided so as to be magnetically coupled. It is what has been.

  As described above, since the first core includes the plate-shaped plate portion and the second core is also formed of the plate-shaped member, it is possible to reduce the height of the inductor, and the inductor is mounted. It is possible to reduce the thickness of electronic devices. In addition, since both the first core and the second core have plate-like portions, it is easy to surface mount the mounting substrate on which the inductor is mounted. For this reason, it is possible to improve the bonding strength between the inductor and the mounting substrate. Moreover, since it comprised as mentioned above, when the electric current of either direction is sent with respect to a coil, between the several coils, a magnetic coupling will arise mutually. Therefore, current conduction can be controlled using this magnetic coupling.

  In another invention, in addition to the above-described invention, a magnetic gap is provided between the column base and the second core. As described above, when a magnetic gap is formed between the column base and the second core, it is possible to suppress the occurrence of magnetic saturation as compared with a configuration in which the magnetic gap does not exist. As a result, it is possible to improve the direct current superposition characteristics, and it is possible to conduct a large current to the coil. Further, since a large current can be conducted to the coil, the inductor of the present invention can be used for a low-voltage power supply circuit or the like.

  Furthermore, in another invention, in addition to each of the above-described inventions, two coils are provided, and a coil located on one side of the two coils is a second core adjacent to the one side. The two terminals extend toward one end in the longitudinal direction of the coil, and the coil located on the other side extends the two terminals toward the other end in the longitudinal direction of the second core adjacent to the other side. It extends.

  When configured in this way, the ends of the two coils are in a state in which the ends of the coils are respectively extended to both ends in the longitudinal direction of the inductor. The inductor is mounted on the mounting board via this terminal or a terminal connected to this terminal. In this case, since it is connected to the mounting board at both ends of the inductor, it is possible to improve the bonding strength to the mounting board. In addition, when an inductor is mounted, vibration resistance can be improved by improving the bonding strength.

  According to the present invention, magnetic coupling can be achieved between a plurality of coils. In addition, the inductor can be surface-mounted and the height can be reduced.

  Hereinafter, an inductor 10 according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing the overall configuration of inductor 10 in the present embodiment. FIG. 2 is a side view showing the configuration of the inductor 10, and FIG. 3 is a front view of the same.

  As shown in FIGS. 1 to 3 and the like, the inductor 10 includes a lower core 20, an upper core 30, a coil 40, and a connection terminal 50.

  Among these, the lower core 20 corresponds to the second core and is provided in a larger area than the upper core 30. The lower core 20 and the upper core 30 are made of a magnetic material. An example of such a magnetic material is nickel-based ferrite. However, the magnetic material is not limited to nickel-based ferrite, but Mn—Zn-based ferrite, sendust (Fe—Si—Al; iron-silicon-aluminum), permalloy (Fe—Ni), Fe—Si—Cr, etc. Various magnetic materials can be used as the material.

  Moreover, as shown in FIG. 4, FIG. 5, etc., the lower core 20 has a rectangular planar shape, and is provided in a substantially flat plate shape. Terminal attachment portions 21 are provided at both ends of the lower core 20 in the longitudinal direction. The terminal attachment portion 21 is a portion that is recessed from the other portions of the lower core 20. The terminal mounting portion 21 is provided with an upper surface recess 22 and a tip recess 23. Among these, the upper surface recess 22 is a portion that is recessed by a predetermined dimension from the upper surface side of the lower core 20 toward the lower surface side. The upper surface recess 22 is provided so as to penetrate the short direction of the lower core 20.

  Moreover, the front-end | tip recessed part 23 is a part which went to the center side from the front-end | tip part of the longitudinal direction of the lower core 20, and depressed the side wall at the front end side of the said lower core 20 only by the predetermined dimension. The tip recess 23 is recessed by a width dimension corresponding to the width dimension of the connection terminal 50 described later. Therefore, this front-end | tip recessed part 23 is surrounded by the latching convex part 24 from the both ends side of a transversal direction, and makes positioning of the connecting terminal 50 easy.

  In addition, the front-end | tip recessed part 23 is each provided in the longitudinal direction of the lower core 20 at the one end side and the other end side. And in each of a pair of front-end | tip recessed parts 23, the connection terminal 50 connected to the one end side or the other end side of the coil 40 mentioned later is each located. Moreover, as shown in FIG. 5 etc., the latching convex part 24 protrudes upwards rather than the front-end | tip recessed part 23. FIG. However, the upper end of the locking projection 24 is at the same height as the upper surface 20a of the lower core 20, or is positioned below the upper surface 20a.

  Further, an upper core 30 corresponding to the first core is located above the lower core 20 described above. The upper core 30 is located above the lower core 20 in FIGS. As shown in FIG. 6, the upper core 30 has a plate portion 31 and a column base portion 32. Of these, the plate portion 31 is a plate-like portion whose planar shape is substantially rectangular. Further, in the present embodiment, the plate portion 31 is provided with a thickness dimension substantially equal to the upper surface 20a of the lower core 20 described above.

  Further, the column base portion 32 is erected so as to be directed downward from the lower surface of the plate portion 31. The column base portion 32 is a portion that is inserted into an insertion hole 40a of the coil 40 described later. In this embodiment, two column base portions 32 are provided along the longitudinal direction of the upper core 30 corresponding to the number of the coils 40. Is provided. The column base 32 has a substantially cylindrical shape in appearance. In addition, the height dimension which protrudes below this column base part 32 is equivalent to the height dimension of the coil 40 mentioned later. Further, the column base portion 32 is provided along a center line along the longitudinal direction of the plate portion 31. Moreover, the column base 32 is provided at a position that is symmetrical from the center of the plate 31.

  In addition, the column base part 32 is provided in the one side and the other side of the longitudinal direction of the plate part 31, respectively. However, a portion of the column base portion 32 on the most end side in the longitudinal direction is not flush with the side wall of the plate portion 31. In other words, the plate portion 31 has a slight margin S in a portion further on the end side than the portion on the most end side in the longitudinal direction of the column base portion 32.

  Further, the above-described column base portion 32 is disposed to face the upper surface 20a of the above-described lower core 20 via a certain gap G (corresponding to a magnetic gap). Here, in order to form the gap G between the column base and the upper surface 20a, for example, a spacer may be disposed on the lower surface of the column base 32. When arranging the spacer, it may be formed, for example, by applying a resin coating on the lower surface of the column base 32. In addition, a sheet-like resin member may be sandwiched between the lower surface of the column base portion 32 and the upper surface 20a of the lower core 20 and used as a spacer.

  Moreover, the coil 40 is attached to the above-mentioned column base part 32 (refer FIGS. 1-3). In the present embodiment, the coil 40 is configured by winding a rectangular wire 41 (corresponding to a winding) in a spiral shape. Since the coil 40 is configured to wind the rectangular wire 41, the number of turns of the coil 40 is not so large, for example, about 2 to 4 times (3 times in FIG. 4 and the like).

  Here, both ends 42 of the flat wire 41 constituting the coil 40 are located in the upper surface recess 22. Therefore, the rectangular wire 41 (corresponding to the terminal 42a on one side) positioned below the coil 40 is directed downward by a small amount (the amount obtained by subtracting the thickness dimension of the connection terminal 50 from the upper surface recess 22). In addition to being bent, it is bent so as to be substantially parallel to the upper surface of the upper surface recess 22. Further, the rectangular wire 41 located on the upper side (corresponding to the terminal 42b on the other side) is directed downward, bent by the height of the rectangular wire 41, and at a height position substantially equal to the terminal 42a on the one side. Thus, it is bent so as to be substantially parallel to the upper surface recess 22.

  In addition, a connection terminal 50 as shown in FIG. A pair of connection terminals 50 are provided in each terminal mounting portion 21, and correspond to the number of the pair of terminals 42 included in the coil 40. The connection terminal 50 is formed, for example, by punching a metal plate into a substantially T shape and bending the metal plate into a predetermined shape after the punching. The part formed by such bending includes a part provided in a substantially U shape when viewed from the side. This substantially U-shaped portion is a portion that enters the above-described tip recess 23, and is provided in a width dimension corresponding to the entry of the tip recess 23 (a width dimension slightly narrower than the width dimension of the tip recess 23). .

  In the following description, the portion provided in the substantially U shape is referred to as a core locking portion 51. Of the core locking portion 51, a portion located in the upper surface recess 22 is referred to as an upper surface portion 51a, a portion located in the tip recess 23 is referred to as a side surface portion 51b, and a portion located in the lower surface of the lower core 20 is referred to as a lower surface portion 51c. Among these, in a state where the upper surface portion 51 a is in contact with the upper surface of the upper surface concave portion 22, the upper surface portion 51 a is provided to be lower than the upper end of the locking convex portion 24. Further, when the lower surface portion 51c is in contact with the lower surface 20b of the lower core 20, the lower surface portion 51c protrudes downward most. The inductor 10 is mounted on a mounting board (not shown) via the lower surface portion 51c.

  The connection terminal 50 is provided with a terminal holding part 52. The terminal holding part 52 extends from the upper surface part 51 a side of the core locking part 51. Further, the terminal holding portion 52 extends so that the width direction of the core locking portion 51 (the short direction of the inductor 10) is the longitudinal direction. Further, the terminal holding part 52 is provided so that the width dimension is smaller than that of the core locking part 51 described above, and can be easily bent when the terminal 42 is held.

  The terminal holding portion 52 extends from both ends of the core locking portion 51 in the width direction. However, the terminal holding portion 52 may adopt a configuration that extends only from one side in the width direction, instead of a configuration that extends from both ends in the width direction of the core locking portion 51. Further, the pair of terminal holding portions 52 have a length dimension so as to form a substantially ring shape surrounding the terminal 42 when bent. Therefore, when the pair of terminal holding portions 52 are bent, a flat ring shape is obtained and the terminal 42 is surrounded. Further, the terminal holding part 52 is provided in a substantially central part in the longitudinal direction of the upper surface part 51a.

  Further, the connection terminal 50 and the terminal 42 are electrically connected by means such as soldering (not shown). Here, when connecting the connection terminal 50 and the terminal 42 by soldering, the solder enters the upper surface recess 22. However, the solder for holding / connecting the terminal 42a on one side and the solder for holding / connecting the terminal 42b on the other side are provided so as to be separated from each other by a predetermined distance.

  The operation of the inductor 10 having the above configuration will be described. In the inductor 10, for example, one terminal 42a or the other terminal 42b is connected to the signal input side, and the other terminal 42b or one terminal 42a is connected to the signal output side. Is done. When a common mode signal is input to the inductor 10 from the signal input side, the magnetic fluxes of the two coils 40 are added and act in a strengthening direction. As a result, a large impedance is generated, and the signal is output from the terminal 42b on the other side or the terminal 42a on the one side with the common mode signal removed.

  Further, in the inductor 10, when a normal mode signal is input from the signal input side, the magnetic fluxes of the two coils 40 cancel each other, and the impedance hardly occurs. Therefore, the normal mode signal is output from the terminal 42b on the other side or the terminal 42a on the one side without being suppressed.

  That is, in the inductor 10 according to the present embodiment, it is possible to cause magnetic coupling between the two coils 40 and to function as a common mode choke coil (common mode noise filter).

  As described above, in the inductor 10 of the present embodiment, it is possible to cause magnetic coupling between the two coils 40. In addition, the inductor 10 as in the present embodiment includes a lower core 20 and an upper core 30 as shown in FIG. 1 and the like, both of which are provided in a plate shape. It is planned. As described above, in the inductor 10 of the present embodiment, unlike the inductor having the conventional configuration, the magnetic coupling between the two coils 40 is generated while the height is reduced. Therefore, it is possible to cause the inductor 10 of the present embodiment to function as, for example, a common mode choke coil or the like by using such magnetic coupling, and it is possible to positively use the magnetic coupling.

  In addition, in the inductor 10 of the present embodiment, it is possible to reduce the thickness of various electronic devices on which the inductor 10 is mounted while causing magnetic coupling. In particular, a common mode choke coil is generally provided with a ring-shaped toroidal core, which makes it difficult to reduce the height. In addition, when the height is lowered, the toroidal core is laid sideways, but in this case, the bonding strength is not so high.

  However, in the inductor 10 of the present embodiment, the plate-like lower core 20 and upper core 30 are used, and a sufficiently low height can be achieved. Therefore, it is possible to reduce the thickness of various electronic devices on which the inductor 10 is mounted. In addition, in the inductor 10, the column bases 32 are arranged in the plane direction of the lower core 20 without being overlapped in the height direction. Therefore, compared with a configuration in which two ER cores are combined and two coils are stacked in the height direction, the height dimension is not increased, and the height can be reduced.

  The lower core 20 and the upper core 30 are both provided in a plate shape. For this reason, the inductor 10 can be surface-mounted, and the bonding strength between the inductor 10 and the mounting substrate can be improved. Further, the lower core 20 and the upper core 30 are both provided in a plate shape, and are disposed to face each other in a state in which both are parallel. Therefore, there is no outer wall or the like between the lower core 20 and the upper core 30, and even when the coil 40 is disposed between the lower core 20 and the upper core 30, the terminal 42 is It can be easily pulled out in either direction.

  In addition, in the present embodiment, the inductor 10 has two coils 40, and the terminals 42 of the two coils 40 are located at both ends in the longitudinal direction of the inductor 10, respectively. Therefore, since the inductor 10 is connected to the mounting board via the connection terminals 50 at both end sides, it is possible to improve the bonding strength to the mounting board. Further, the vibration resistance can be improved by improving the bonding strength of the inductor 10.

  A gap G (magnetic gap) is provided between the upper surface 20 a of the lower core 20 and the column base portion 32. Therefore, the inductor 10 can suppress the occurrence of magnetic saturation. In particular, as in the present embodiment, when the coil 40 is configured by winding a rectangular wire 41, a large current is conducted to the coil 40, and magnetic saturation becomes a problem. However, when the gap G is provided between the upper surface 20a and the column base 32, a magnetic gap exists inside the magnetic path (closed magnetic path) formed by the coil 40. As a result, it is possible to improve the direct current superimposition characteristics, and it is possible to cope with an increase in current as in the case of the coil 40 constituted by the flat wire 41. Further, since a large current can be conducted to the coil 40, the inductor 10 of the present invention can be used for a low-voltage power supply circuit or the like.

  Furthermore, in the present embodiment, the upper core 30 has a margin portion S between both longitudinal end portions and the base of the column base portion 32. As described above, when the margin part S is provided, the inductor 10 can have a slight margin in the part through which the magnetic flux passes, and the characteristics can be improved.

  Although the inductor 10 of the present invention has been described above, the present invention can be variously modified in addition to this. This will be described below.

  In the above-described embodiment, the inductor 10 includes the two coils 40. However, the inductor 10 may employ a configuration having three or more coils as long as magnetic fluxes generated by the respective coils are added and magnetic coupling is possible.

  In the above-described embodiment, the column base portion 32 is provided on the upper core 30. However, the column base is not limited to the configuration provided in the upper core 30, and a configuration provided in the lower core 20 may be employed. Moreover, you may employ | adopt the structure which provides a column base part in both the lower core 20 and the upper core 30. FIG. In addition, when providing a column base part in the lower core 20, while the lower core 20 respond | corresponds to a 1st core, the upper core 30 respond | corresponds to a 2nd core.

  In the above-described embodiment, a magnetic gap is provided between the upper surface 20a of the lower core 20 and the lower surface of the column base 32 so as to correspond to the increase in current. However, when it is not necessary to flow a large current through the coil 40, the magnetic gap need not be provided.

  The inductor of the present invention can be used in the field of electrical equipment.

It is a perspective view which shows the structure of the inductor which concerns on one embodiment of this invention. It is a side view which shows the structure of the inductor of FIG. It is a front view which shows the structure of the inductor of FIG. It is a perspective view which shows the structure of a coil and a lower core among the inductors of FIG. It is a perspective view which shows the structure of a lower core among the inductors of FIG. It is a perspective view which shows the state seen from the downward side while showing the structure of an upper core among the inductors of FIG. It is a perspective view which shows the structure of a connection terminal among the inductors of FIG.

Explanation of symbols

10 ... Inductor 20 ... Lower core (corresponding to the second core)
21 ... Terminal mounting portion 22 ... Upper surface recess 23 ... Tip recess 30 ... Upper core (corresponding to the first core)
31 ... Plate part 32 ... Column base part 40 ... Coil 41 ... Flat wire (corresponding to winding)
42 ... Terminal 50 ... Connection terminal 51 ... Core locking part 52 ... Terminal holding part G ... Gap

Claims (3)

A plurality of coils configured by winding windings;
A first core comprising: a plate portion provided in a plate shape; and a plurality of column base portions that are erected from the plate portion and into which the insertion hole of the coil is inserted;
A second core provided in a plate shape;
A connection terminal to which terminals of the plurality of coils are respectively connected;
Comprising
When a current in any direction flows through the terminal via the terminal, the magnetic flux formed by each coil passes through the first core, the second core, and the column base, The coil is provided to be magnetically coupled,
An inductor characterized by that.   The inductor according to claim 1, wherein a magnetic gap is provided between the column base and the second core. Two coils are provided,
The coil located on one side of these two coils extends two terminals toward one end side in the longitudinal direction of the second core close to the one side,
The coil located on the other side extends two terminals toward the other end side in the longitudinal direction of the second core adjacent to the other side.
The inductor according to claim 1 or 2, wherein

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