JPH10106859A - Surface-mounting type choke coil device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost and thickness of a surface-mounting type common- mode choke coil. SOLUTION: A magnetic core section 3a having first and second through holes 5 and 6 is provided in the upper section of a magnetic block 11 and a supporting section 4a which supports terminals 7a-10a is provided in the lower section of the block 11. Windings 1 and 2 for removing common-mode noise are obtained by winding a covered conducting wire around the central part of the core section 3a through the holes 5 and 6. The terminals of the conductor wires 1 and 2 are connected to the terminals 7a-10a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount type choke coil device suitable for reducing common mode noise in an input line of a power supply device.

[0002]

2. Description of the Related Art FIG. 1 shows an example of a conventional surface-mount type common mode choke coil. In FIG. 1, 1 and 2 are first and second windings, 3 is a glasses-shaped ferrite core, and 4 is a terminal plate. The first and second windings 1 and 2 are formed by arranging respective insulated conductors side by side and winding them through the first and second through holes 5 and 6 of the ferrite core 3. The terminal plate 4 is formed of an insulating synthetic resin, and two metal piece terminals 7 and 8 are led out from one side, and two metal piece terminals 9 and 9 shown in FIG.
10 have been derived. The electrical connection of the first and second windings 1 and 2 to the four terminals 7 to 10 is as shown in FIG. That is, the first winding 1 is connected between the first terminal 7 and the third terminal 9. The second winding 2 is connected between the second terminal 8 and the fourth terminal 10.

As another conventional common mode choke coil, a ring core provided with first and second windings is arranged on a terminal plate 4 similar to that shown in FIG. There is a resin case in which a resin case is arranged so as to surround a wire and a ring core, and the resin case is filled with resin and molded. The common mode choke coil is used in a configuration of a common mode noise filter for reducing noise current flowing in the same phase on a plurality of power lines connecting an AC power supply and a load circuit.

[0004]

By the way, the surface mount type choke coil shown in FIG. 1 requires the terminal plate 4, so that the number of parts is increased and the cost is increased. Further, when the eyeglass-shaped ferrite core 3 is made thinner for miniaturization and thinning, the characteristics are deteriorated. A similar problem also occurs in a conventional surface mount type choke coil using a ring core.

Accordingly, an object of the present invention is to reduce the cost, reduce the thickness, or improve the characteristics of a surface mount type choke coil device.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and to achieve the above-mentioned object, the present invention comprises a magnetic core, a winding, a terminal support, and a terminal. The terminal has a through-hole extending linearly from one end surface to the other end surface, the terminal is provided in the terminal support portion so that it can be connected to a circuit board by a surface mounting method, and the winding is The magnetic core is wound around the magnetic core through a through hole and connected to the terminal. The magnetic core and the terminal support are integrally formed of an insulating magnetic material, and the magnetic core is connected to the terminal support. A surface mount type choke coil device, wherein the surface mount type choke coil device is disposed on the terminal support portion so as to be supported by the terminal support portion. It is preferable that the terminal be a conductor layer in which a conductor is applied to the surface of the terminal support by coating or plating. Further, a terminal can be formed by providing a groove in the terminal support portion and providing a conductor layer here. Further, as described in claim 4, a terminal can be formed by providing a groove in the terminal support portion and fixing a metal piece to the groove. According to a fifth aspect of the present invention, a first and a second through-holes are provided in an insulating magnetic block, and the first and second windings are formed through these holes to form a common mode choke coil. . According to a sixth aspect of the present invention, the first and second through holes are provided in an insulator block not requiring magnetism, and the common mode choke coil is configured to pass through the first and second through holes. And a terminal for connecting the first and second windings may be supported by the insulator block.

[0007]

According to the first to fifth aspects of the present invention,
Since the terminal supporting portion is not formed independently as a terminal plate but is integrally formed of the same material as the magnetic core portion, the number of components is reduced, and the cost can be reduced. Also, since the terminal support is a magnetic material, it also functions as a part of the core,
The impedance of the winding can be increased. That is, the characteristics are improved when the size of the magnetic core is the same as the conventional one, and the thickness of the magnetic core can be reduced when the characteristics may be the same as the conventional one. Further, when the terminal is formed by the conductor layer as in the second aspect of the present invention, the cost of the terminal can be reduced. According to the third aspect of the present invention, the ends of the windings can be stably connected by the grooves. Further, according to the invention of claim 4, since the terminal is a metal piece, the degree of freedom of the shape is increased, and it is possible to provide a terminal that can be easily connected by winding the winding. Further, the groove functions as a positioning and holding portion for the metal piece, and the terminal can be stably mounted. According to the fifth and sixth aspects of the present invention, the common mode choke coil device can be formed inexpensively and thinly.

[0008]

First Embodiment Next, a surface mount type combo mode choke coil device according to a first embodiment will be described with reference to FIGS. However, in FIGS. 3 to 7 and FIGS. 8 to 20 described later, substantially the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted.

As is apparent from FIGS. 3 to 5, one magnetic block 11 made of an insulating magnetic ferrite includes:
A magnetic core 3a and a terminal support 4a are provided. The magnetic core portion 3a has the same function as the conventional magnetic core 3 of FIG. 1, and the terminal support portion 4a has the same function as the conventional terminal plate 4 of FIG. It also has the function of The magnetic block 11 is formed as a whole in a skewed shape, and the terminal support 4a is formed like a skewed plate or table, and the magnetic core 3a is disposed thereon. Therefore, the terminal support 4a also has a function as a core support. In order that the terminal support 4a stably supports the magnetic core 3a and achieves easy and stable mounting by surface mounting on a circuit board, the vertical width of the magnetic core 3a is evident from FIG. The vertical width W2 of the terminal support portion 4a is set larger than W1, and the horizontal width W4 of the terminal support portion 4a is set larger than the horizontal width W3 of the magnetic core portion 3a.

The first and second through holes 5 and 6 extend linearly from one end face 12 to the other end face 13 of the magnetic core 3a and are arranged in parallel with each other. At least below the first and second through holes 5 and 6 of the magnetic core 3a, a terminal support 4a made of ferrite is provided.
Is arranged. Therefore, at least a portion below the through hole of the terminal support portion 4a also has a function as a magnetic core portion,
This contributes to an increase in the impedance value of the choke coil.

First, second, third and fourth terminals 7a, 8 made of a conductive layer formed by applying and baking a conductive paste (silver paste) on the terminal support 4a.
a, 9a, and 10a are provided. 3 to 5
8 to 12 described later, the thickness of the conductor layers of the terminals 7a to 10a is omitted and the terminals 7a to 10a are distinguished from other regions by dots. Each terminal 7a-10
As is clear from FIG. 6, a is provided on the upper surface, the lower surface, and the side surface of the terminal support portion 4a, and is formed in a U-shape as a whole. As shown in FIG. 6, the terminals 7a to 10a are connected to the wiring conductors 15 on the circuit board 14 by solder 16 by a surface mounting method.

The first and second windings 1, 2 are juxtaposed to each other as in FIG. 1, and are wound around the magnetic core 3a through the first and second through holes 5, 6. One ends of the first and second windings 1 and 2 are fixed to the first and second terminals 7a and 8a with solders 17 and 18, and the other ends are third and fourth terminals 9 and 9, respectively.
a and 10a are fixed by solders 19 and 20. Thereby, the common mode choke coil devices of FIGS. 3 and 4 have the same circuit configuration as that of FIG. The first and second windings 1 and 2 are provided on the terminal support 4a as shown by the dotted lines in FIG.
The protective resin layer 40 is formed by applying a resin having an adhesive property and an insulating property such as an epoxy resin or a silicone resin so as to include the second terminal. This protective resin layer 40 is desirably provided so as to cover a part or all of the windings 1 and 2 including the terminals.

The choke coil device according to the first embodiment has the following effects. (A) Since the terminal supporting portion 4a is formed integrally with the magnetic core portion 3a, the number of components is reduced, and the cost can be reduced. (B) When the dimensions of the magnetic core part 3a are the same as those of the related art, the impedance of the choke coil can be increased because the terminal supporting part 4a made of a magnetic substance contributes as a part of the core. FIG. 7 shows this, in which the characteristic line of the present embodiment is A shown by a solid line, and the conventional characteristic line is B shown by a broken line. (C) When the terminal support 4a is viewed in plan, the magnetic core 3
Since it is larger than a, it can be easily and stably surface-mounted on the circuit board 14. (D) A conductor layer is provided on the terminal support portion 4a to form the terminals 7a to 1
Since it is 0a, the cost of the terminal can be reduced. (E) Since it is protected by the protective resin layer 40,
The reliability of the choke coil device is improved.

[0014]

Second Embodiment FIGS. 8 and 9 illustrate a common mode choke coil device according to a second embodiment. FIG.
In the choke coil device of the second embodiment, the terminal support 4a
The configuration of the second embodiment is different from that of the first embodiment in the shape of the first embodiment, and the other configuration is the same as the first embodiment. That is, the grooves 21 are respectively provided in the formation regions of the terminals 7 a to 10 a of the terminal support portion 4 a of the magnetic block 11. The groove 21 is formed so as to extend from the upper surface to the lower surface of the terminal support portion 4a, and has a depth and a width into which terminals of the windings 1 and 2 can be inserted. Groove 21
Since the terminals 7a to 10a made of a conductor layer are provided on the top, the terminals of the windings 1 and 2 arranged in the groove 21 can be firmly connected by a conductive bonding material such as solder. Although the groove 21 is formed in a V shape in FIGS. 8 and 9, it can be changed to a U shape, a U shape, a semicircle shape, or the like. The common mode choke coil device of the second embodiment has the same configuration as that of the first embodiment except for the groove 21, and thus has the same effect as that of the first embodiment in addition to the effect of the groove 21.

[0015]

Third Embodiment FIG. 10 shows a magnetic block 11 before a winding of a common mode choke coil device according to a third embodiment is provided. The magnetic core portion 3a in FIG. 10 has a pair of eave portions 22, 23 on the upper surface. A pair of eaves 2
Reference numerals 2 and 23 are disposed so as to cover the side surfaces on which the through holes 5 and 6 are formed, and protect the windings exposed from the through holes 5 and 6. In FIG. 10, the upper and lower terminal support portions 4a having eave portions 22, 23 to make the upper and lower portions symmetrical.
Are formed in the same shape. Therefore, terminals 7a to 1
When providing 0a, it is not necessary to pay attention to the upper and lower sides of the magnetic block 11. In FIG. 10, the magnetic block 11 is formed such that the side of the magnetic core 3a where the through holes 5 and 6 are not provided is flush with the side of the terminal support 4a. Magnetic block 11 of FIG.
Is substantially the same as the magnetic block 11 of the first embodiment shown in FIG. 3 except for the eave portions 22 and 23. Therefore, in addition to the effects of the eave portions 22 and 23, the first embodiment It also has the same effect as.

[0016]

Fourth Embodiment FIG. 11 shows a magnetic block 11 of the fourth embodiment in which the windings of the common mode choke coil device are omitted.
It shows. The magnetic block 11 shown in FIG. 11 differs from that shown in FIG. 3 in the shape of the terminal support portion 4a, and has the same configuration as the other portions. That is, in FIG. 11, the four side surfaces of the terminal supporting portion 4a do not protrude from the side surface of the magnetic core portion 3a, and are arranged on the same plane. Therefore, in the fourth embodiment, the effects of W2> W1 and W4> W3 shown in FIG. 4 cannot be obtained, but otherwise the same effects as in the first embodiment can be obtained.

[0017]

Fifth Embodiment FIG. 12 shows a common mode choke coil device according to a fifth embodiment in which three windings are omitted. Since the magnetic block 11 in FIG. 12 is for a three-phase line, two terminals 24 and 25 are added. In this embodiment, the first, second and third windings 1, 2, 26 are provided in parallel with each other as shown in FIG. That is, three covered conductors are wound around the first and second through holes 5 and 6, and these terminals are connected to the terminals 7 a to 10 a, 24 and 25. The common mode choke coil device of the fifth embodiment has the same configuration as that of the first embodiment except for the number of windings, and thus has the same effects as the first embodiment.

[0018]

Sixth Embodiment A common mode choke coil device according to a sixth embodiment shown in FIGS. 14 to 17 differs from the first embodiment in the shape of the terminal support 4a and the shapes of the terminals 7b to 10b. Are configured the same as in the first embodiment. In the sixth embodiment, the first, second, third and fourth surfaces are provided on the lower surface of the magnetic block 11, that is, the lower surface of the terminal support 4a.
Of the first, second, third and fourth terminals 7b, 8b,
Parts of 9b and 10b are inserted and fixed with an epoxy adhesive (not shown). First to fourth terminals 7b to 1
The remaining portion of Ob projects out from the terminal supporting portion 4a side in plan view and has legs for fixing to the circuit board. The connection of the first and second windings 1 and 2 to the terminals 7b to 10b is achieved by connecting the terminals of the windings 1 and 2 to the terminals 7b to 10b and fixing them with solders 17 to 20. The electric circuit of FIG. 14 is the same as that of FIG.

The sixth embodiment has the same operation and effect as the first embodiment, and also has the terminals of the windings 1 and 2 connected to the terminals 7b to 10b.
This has the effect that it can be firmly bonded to b. Further, the metal piece terminals 7b to 10b can be stably and easily fixed using the grooves 25 to 28.

[0020]

Seventh Embodiment FIGS. 18 to 20 illustrate a common mode choke coil device according to a seventh embodiment. The common mode choke coil device of the seventh embodiment differs from the magnetic block 11 of the sixth embodiment in that two grooves 29 and 30 are provided instead of the first to fourth grooves 25 to 28 and a metal piece. The configuration is the same as that of the second embodiment except that a wide portion 31 is provided at the tip of the terminals 7c to 10c. That is, in the seventh embodiment, grooves 29 and 30 are formed on the bottom surface of the terminal support portion 4a of the magnetic block 11 from one end surface to the other end surface. Grooves 29, 30
Has the same function as the four grooves 25 to 28 shown in FIG. 16, and is used for inserting the metal piece terminals 7c to 10c and fixing them with an adhesive. Groove 2 of this embodiment
Since 9 and 30 are provided from one end face to the other end face, they can be formed more easily than in the case of FIG.
In the present embodiment, the distal end portions 31 of the terminals 7c to 10c are formed wide to improve the tensile strength. FIG.
The terminals 7c to 10c are formed by a lead frame 32 as indicated by broken lines in FIG. Therefore, the terminals 7c to 10c are fixed to the terminal support portion 4a with an insulating adhesive and then separated from the frame portion of the lead frame 32 to be independent.
According to the seventh embodiment, the same operation and effect as those of the first and sixth embodiments can be obtained.

[0021]

Eighth Embodiment FIG. 21 shows a common mode choke coil device according to an eighth embodiment in which the windings are omitted. The common mode choke coil device according to the eighth embodiment is similar to the common mode choke coil device except that four protrusions 33, 34, 35, and 36 are provided on the terminal support 4a, and terminals 7a to 10a made of a conductive layer are provided here. The configuration is the same as that of the first embodiment. Projection 33 ~
By providing 36, the terminals 7a to 10a are reliably separated from each other, and when the common mode choke coil device is fixed to the circuit board by solder, the short circuit between the solders hardly occurs. The eighth embodiment has the same effects as the first embodiment in addition to the effects of the protrusions 33 to 36 described above.

[0022]

[Modifications] The present invention is not limited to the above-described embodiment, and for example, the following modifications are possible. (1) As shown in FIG. 22, the magnetic core part 3a of the magnetic block 11 can be formed in a prismatic shape. (2) The through holes 5 and 6 may be formed not in a circle but in a square as shown in FIG. 22 or in a polygon. (3) As shown in FIG. 23, the through holes 5 and 6 can be formed so as to be in contact with the upper surface of the lower terminal support portion 4a. In the case of FIG. 23, most of the terminal support portion 4a contributes as a magnetic core. (4) The terminals of the windings 1 and 2 can be fixed to the portions provided on the upper surface of the terminal support portions 4a of the terminals 7a to 10a. (5) Four windings can be provided for a four-line common mode choke coil, and eight terminals can be provided on the terminal support 4a. (6) An insulator such as alumina, resin (epoxy, polyimide, liquid crystal polymer, phenol, polyester), glass, or the like is used instead of the magnetic block 11 of the first to eighth embodiments and the modified examples of FIGS. It can be a block. That is, the block 11 is formed of a non-magnetic insulator, and the rest can be configured in the same manner as the first to eighth embodiments and the modified examples of FIGS. (7) A hole may be provided instead of the grooves 25 to 28 in FIGS. 14 to 16 and a metal piece terminal may be inserted into the hole and fixed with an adhesive. (8) The terminals 9a to 13a can be metal plating layers. (9) The present invention can be applied to a choke coil having only one winding.

[Brief description of the drawings]

FIG. 1 is a front view showing a conventional surface mount type common mode choke coil device.

FIG. 2 is an electric circuit diagram of the common mode choke coil device of FIG.

FIG. 3 is a perspective view showing a surface mount type common mode choke coil device according to the first embodiment of the present invention.

FIG. 4 is a plan view of the common mode choke coil device of FIG. 3;

FIG. 5 is a front view showing a magnetic block provided with the terminals of FIG. 3;

FIG. 6 is an enlarged sectional view of a portion corresponding to line AA in FIG. 5;

FIG. 7 shows the common mode choke coil device of FIG. 3 and FIG.
FIG. 7 is a characteristic diagram showing a relationship between frequency and impedance of one winding of the conventional common mode choke coil device of FIG.

FIG. 8 is a perspective view showing a common mode choke coil device according to a second embodiment.

FIG. 9 is a plan view showing a part of a magnetic block having the terminals of FIG. 8;

FIG. 10 is a perspective view of a magnetic block having terminals according to a third embodiment.

FIG. 11 is a perspective view showing a magnetic block having terminals according to a fourth embodiment.

FIG. 12 is a front view of a magnetic block having terminals according to a fifth embodiment.

FIG. 13 is a circuit diagram showing a relationship between windings and terminals provided in the magnetic block of FIG. 12;

FIG. 14 is a perspective view showing a common mode choke coil device according to a sixth embodiment.

FIG. 15 is a perspective view showing a magnetic block of FIG. 14;

FIG. 16 is a bottom view of the magnetic block shown in FIG. 14;

FIG. 17 is a perspective view showing the metal piece terminal of FIG. 14;

FIG. 18 is a front view showing a magnetic block according to a seventh embodiment.

19 is a diagram showing a relationship between a bottom surface of the magnetic block of FIG. 18 and a lead frame.

FIG. 20 is a plan view showing terminals separated from the lead frame of FIG. 19;

FIG. 21 is a perspective view showing a magnetic block according to an eighth embodiment.

FIG. 22 is a perspective view showing a magnetic block of a modification.

FIG. 23 is a perspective view showing a magnetic block of another modification.

[Explanation of symbols]

 1, 2 winding 3a magnetic core 4a terminal support 7a-10a terminal 11 magnetic block

Claims (6)

[Claims] 1. A magnetic core comprising a magnetic core, a winding, a terminal support, and a terminal, wherein the magnetic core has a through hole extending linearly from one end face to the other end face, The terminal is provided on the terminal supporting portion so that the terminal can be connected to the circuit board by a surface mounting method. The winding is wound around the magnetic core portion through the through hole and connected to the terminal. The body core and the terminal support are integrally formed of an insulating magnetic material, and the magnetic core is disposed on the terminal support so as to be supported by the terminal support. Mounting type choke coil device. 2. The surface mount type choke coil device according to claim 1, wherein said terminal is formed of a conductor layer attached to a surface of said terminal support. 3. The surface mount type choke coil device according to claim 1, wherein said terminal support portion has a groove, and said terminal is a conductor layer attached to said groove and the vicinity thereof. 4. The surface mount type choke coil device according to claim 1, wherein said terminal support portion has a groove, and said terminal is a metal piece fixed to said groove. 5. A magnetic core comprising a magnetic core, a terminal support, at least first and second windings, and at least first, second, third and fourth terminals. It has first and second through holes extending linearly from one end surface to the other end surface, and the first, second, third and fourth terminals are connected to a circuit board by a surface mounting method. The first and second windings are provided to the magnetic core through the first and second through holes so that a common mode choke coil can be obtained. Respectively wound and connected to the first, second, third and fourth terminals, the magnetic core and the terminal support are integrally formed of an insulating magnetic material, and the magnetic core is Arranged on the terminal support so as to be supported by the terminal support Surface mount type common mode choke coil and wherein the being. 6. An insulator block having first and second through-holes extending parallel to each other, and said insulator through said first and second through-holes so as to obtain a common mode choke coil. At least first and second windings wound on the block; and at least first and second windings connected to the first and second windings.
And second, third, and fourth terminals. The first, second, third, and fourth terminals are respectively connected to the insulator block so that they can be connected to a circuit board by a surface mounting method. A surface-mount type common mode choke coil device characterized by being supported.