JPH09134827A - Common mode choke coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide strength having little DC resistance, good operation efficiency and enduring mechanical mounting. SOLUTION: Two pieces of coils having the same number of windings and being composed by edgewise winding of a flat wire with an insulating coating are provided to be laminated in the same winding direction. Then, the insulation film peeling parts 9a, 9b of both ends of a one side coil 9 are pulled out as they are from one side of a bobbin 7 to be wound about the coil winding parts, 7e, 7f for being made terminals and the insulation film peeling parts 10b of both ends of the other side coil 10 are pulled out crosswise from the opposite side of the bobbin to be wound about the coil winding part of the bobbin so as to be made terminals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mounting common mode choke coil used in a thin power supply device.

[0002]

2. Description of the Related Art A common mode choke coil has been used as a countermeasure component for removing electromagnetic noise by inserting it into a power supply line of a switching power supply. Conventionally, a copper round wire is the same as that of a bobbin 1 as shown in FIG. A common mode choke coil in which two coils 2 and 3 wound in the same direction as the number of turns are incorporated in a core 4 is used.

The terminal 5 has a gull wing structure,
The ends of the coils 2 and 3 are pulled out and wound around the root of the terminal and soldered, and the tips of the terminals are parallel to the board so that they can be placed on the board (not shown) and soldered. The core 4 is fixed with an adhesive 6.

[0004]

However, in such a conventional common mode choke coil, since the copper wire used is a round wire, the space factor occupied by this copper round wire is about 70%. However, even if multiple copper round wires are wound or a thick round wire is used to reduce the DC resistance, the size of the winding becomes large, so there is a limit to the reduction of the DC resistance.

The connection between the lead wire of the coil and the terminal by solder has a resistance of several mΩ at one place, which hinders an increase in efficiency. In addition, since an adhesive is used to fix the core, there have been problems such as loosening of the core due to variations in heat resistant temperature, coating method, amount, material, curing temperature and time.

In terms of structure, the terminal fixed to the bobbin does not become small because it is a gull wing type, and
Bending or floating of terminals is likely to occur during transportation or on a machine.
There was a waste of rework after soldering.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 prepares two coils having the same number of turns, which are obtained by edgewise winding a rectangular wire with an insulating film, and the same winding. The coils are laminated in the direction of rotation, and the insulation film exfoliation parts on both ends of one coil are drawn out from one side of the bobbin as is and wound around the coil winding part of the bobbin to form terminals. (EN) A common mode choke coil characterized in that it is crossed and drawn from the opposite side and wound around a coil winding portion of a bobbin to form a terminal.

In order to solve the above-mentioned problems, the invention according to claim 2 forms two coils which are laminated in the same winding direction by stacking two rectangular wires with an insulating film and edgewise winding them, Pull out the insulation coating stripped portion on one end of one coil from one side of the bobbin as it is and wind it around the coil winding portion of the bobbin to form a terminal. The present invention provides a common mode choke coil which is drawn out and wound around a coil winding portion of a bobbin to form a terminal.

In order to solve the above problems, the invention according to claim 3 is characterized in that the coil winding portions are formed at the four corners of the bobbin so that the terminals are formed at the four corners of the common mode choke coil. Claim 1 or 2
The common mode choke coil described in 1. is provided.

In order to solve the above-mentioned problems, the present invention as set forth in claim 4 is arranged such that the lead wires at both ends of the one coil and the lead wires at both ends of the other coil are once horizontally projected from the coil. 4. The common mode according to claim 1, wherein the bobbin is formed with a guide having substantially the same height as the height of the lead wire of each coil so as to be directed to each coil winding portion. A choke coil is provided.

[0011]

1 to 4 are views for explaining one embodiment of the present invention.

In these figures, FIG. 1 is an assembly diagram of a common mode choke coil. (A) shows the common mode choke coil seen from one side, and (B) shows the common mode choke coil seen from the other side. Show.

FIG. 2 is a diagram showing a bobbin 7 and a metal fitting 8 made of an insulating material such as resin used in a common mode choke coil, and FIG. 3 is a flat wire with an insulating coating and the surfaces of the flat wire are in contact with each other. Two coils 9 and 1 having the same number of turns formed by so-called edgewise winding, which are spirally laminated and wound.
FIG. 4 is a view showing a stack of 0s in the same winding direction, and FIG. 4 is a view showing two coils 9 stacked in the same winding direction, which are formed by stacking two rectangular wires with insulating coating and edgewise winding. , 10 is a diagram showing.

Reference numerals 9a and 10a are coils 9 and 1, respectively.
Insulating film peeling portion formed at the winding start portion of 0, 9
Reference numerals b and 10b denote insulating film peeling portions formed at the winding end portions of the coils 9 and 10, respectively, and these insulating film peeling portions are plated with solder.

As shown in FIG. 3, coils 9 and 10 having the same number of turns, in which a rectangular wire with an insulation film is edgewise wound, are laminated in the same winding direction, and insulation film peeling portions 9a and 9 of coil 9 are laminated.
b is pulled out from one side, and the insulating coating stripped portions 10a and 10b of the coil 10 are pulled out from the opposite side. The coil thus constructed is incorporated into the bobbin 7 shown in FIG. 2 as shown in FIG.

In FIGS. 1 and 2, reference numeral 7a designates a winding start portion of the coil 9 (the side on which the insulating film peeling portion 9a is formed).
And is formed so as to have a height substantially the same as the height of the winding start portion of the coil 9.

Reference numeral 7b is a guide for pulling out the winding end portion of the coil 9 (the side on which the insulating film peeling portion 9b is formed), and has a height approximately equal to the height of the winding end portion of the coil 9. Is formed in.

Reference numeral 7c is a guide for pulling out the winding start portion of the coil 10 (the side on which the insulating film peeling portion 10a is formed), and has a height approximately equal to the height of the winding start portion of the coil 10. Is formed in.

Reference numeral 7d is a guide for pulling out the winding end portion of the coil 10 (the side on which the insulating film peeling portion 10b is formed), and has a height approximately the same as the height of the winding end portion of the coil 10. Is formed in.

As described above, the bobbins 7 are formed with the guides 7a to 7d having a height substantially equal to the height of the lead wire of each coil.

Reference numerals 7e to 7h denote coil winding portions formed at the four corners of the bobbin, and the terminals are formed by winding the insulating film peeling portion of the lead wire of the coil around the coil winding portions.

The winding start portion of the coil 9 (insulating film peeling portion 9
The lead wire drawn out from the side where a is formed is supported and bent by a guide 7a having a height approximately the same as the height of the winding start portion of the coil 9, and is bent at the bottom of the coil winding portion 7e (substrate). It is wound from the inside so that it will reach the connection part) with the shortest distance.

The lead wire drawn from the winding end portion of the coil 9 (on the side where the insulating film peeling portion 9b is formed) is a guide 7b having a height substantially equal to the height of the winding end portion of the coil 9. It is supported and bent, and is wound from the inside so as to reach the bottom portion (connection portion with the substrate) of the coil winding portion 7f in the shortest distance.

The lead wire drawn out from the winding start portion of the coil 10 (on the side where the insulating film peeling portion 10a is formed) is a guide 7c having a height substantially equal to the height of the winding start portion of the coil 10. It is supported and bent, and is wound from the inside so as to reach the bottom portion (connection portion with the substrate) of the coil winding portion 7g in the shortest distance.

The lead wire drawn from the winding end portion (the side where the insulating film peeling portion 10b is formed) of the coil 10 is a guide 7d having a height substantially the same as the height of the winding end portion of the coil 10. Supported and bent,
The coil is wound from the inside so as to reach the bottom of the coil winding portion 7h (connection portion with the substrate) in the shortest distance.

In this case, the winding start portion (the side on which the insulating coating stripped portion 9a is formed) and the winding end portion (the side on which the insulating coating stripped portion 9b is formed) of the coil 9 are
Each of the coils is wound around the coil winding portions 7e and 7f on the side where the lead wire is drawn out. The winding start portion (the side where the insulating coating stripping portion 10a is formed) and the winding end portion (forming the insulating coating stripping portion 10b) of the coil 10 are formed. The wound side) is wound around the coil winding portions 7g and 7h on the side opposite to the side where the lead wire is pulled out.

In this way, the bobbins 7 have coils 9, 1
Incorporating No. 0, the insulation coating stripping portions 9a, 9b, 10a, 10b which have been pre-solder plated are wound around the coil winding portions 7e to 7h of the bobbin, respectively, and the outside of the bobbin is sandwiched by the core 4 The whole is integrated by sandwiching with the metal fitting 8 to complete the common mode choke coil.

Next, the common mode choke coil is housed in a taping or tray, mounted on a substrate by a mounter, and reflowed.

FIG. 4 is a diagram showing another embodiment of the present invention. This embodiment is constructed by overlapping two rectangular wires with an insulating film and edgewise winding them instead of the coil of FIG. Two coils 9 and 1 stacked in the same winding direction
0 is used.

In this embodiment, the leakage inductance becomes smaller, the resonance frequency of the coil at high frequencies becomes higher, and the high frequency characteristics are improved, as compared with the above-mentioned embodiments.

[0031]

As described above, according to the present invention, the following effects can be obtained.

(1) Since the insulating coating stripped portions at both ends of one coil are drawn out from one side of the bobbin as they are, and the insulating coating stripped portions at both ends of the other coil are drawn out while intersecting from the opposite side of the bobbin. It is possible to match the current flow direction and the magnetic flux direction with respect to the cores of the two coils so that the magnetic fields generated when the currents flowing in the same direction flow in the respective coils are mutually biased. As a result, the inductance for the line current flowing back and forth in the line is zero, while the inductance for the common mode current parallel to the line is high.

(2) Since the terminals are formed at the four corners of the common mode choke coil, the common mode choke coil can be stably arranged on the substrate. In addition, since it is easy to check the solder fillet when the terminal is soldered to the board from the outside of the terminal, it is easy to inspect the soldering after mounting the common mode choke coil on the board, and it is possible to maintain sufficient connection strength. it can.

(3) The bobbin made of an insulating material such as resin is provided with a guide having a height approximately the same as the height of the lead wire of each coil. Since the coil is supported and bent by each guide, the lead wire of the coil does not come into contact with the corner of the coil body. As a result, due to the gelation of the insulation film of the rectangular wire generated by high heat during reflow and the bending stress on the point contact portion between the coil lead wire and the corner of the coil body, the coil lead wire It is possible to prevent a short circuit accident with the coil body.

(4) Each lead wire pulled out from the coil, supported by the guide and bent is wound from the inside so as to reach the bottom of each coil winding portion (connection portion with the substrate) in the shortest distance. Therefore, the DC resistance is reduced and the efficiency is improved.

(5) By winding the insulating coating stripped portion of the coil around the coil winding portion of the bobbin made of an insulating material such as resin, the insulating coating stripped portion of the coil itself is used as a terminal. The need for soldering is eliminated, and the DC resistance at the connection between the coil and the terminal due to soldering is eliminated, improving efficiency.

(6) A coil is incorporated in the bobbin, and the insulation coating stripped portion, which has been pre-solder plated, is wound around the coil winding portion of the bobbin, and the outside of the bobbin is sandwiched by the core to be integrated. Since it has a simple structure, it is economical not only because it requires less assembly man-hours, but also because it has the strength to withstand machine mounting, it can be stored in taping or a tray, and can be surface-mounted on a board by a mounter and reflowed. You can

(7) Since a rectangular wire is used for the coil,
Compared with the conventional copper round wire, the space factor of the winding space is improved, and the size of the winding can be reduced when using the same winding.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an embodiment of the present invention.

FIG. 2 is a diagram for explaining an embodiment of the present invention.

FIG. 3 is a diagram for explaining an embodiment of the present invention.

FIG. 4 is a diagram for explaining one embodiment of the present invention.

FIG. 5 is a diagram for explaining a conventional common mode choke coil.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Bobbin 2, 3 ... Coil 4 ... Core 5 ... Terminal 6 ... Adhesive 7 ... Bobbin 7a-7d ... Guide 7e-7h ... Coil winding part 8 ... Metal fitting 9 ... Coil 9a, 9b ... Insulation film peeling part 10 ... Coil 10a, 10b ... Insulating film peeling portion

Continued Front Page (72) Inventor Naoki Murakami 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Nobuhiko Yamashita 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation Phone Co., Ltd.

Claims (4)

[Claims] 1. A coil having the same number of turns formed by edgewise winding a rectangular wire with an insulating film is prepared and laminated in the same winding direction. From the other side and wound around the coil winding part of the bobbin to form a terminal, and the insulating film peeling parts on the opposite ends of the other coil crossed out from the opposite side of the bobbin and drawn around to form a terminal on the bobbin coil winding part. Characteristic common mode choke coil. 2. A coil formed by laminating two rectangular wires with an insulating coating and edgewise winding the layers in the same winding direction to form two coils, and the insulating coating stripping portions at both ends of one coil of one of the bobbins. From the other side and wound around the coil winding part of the bobbin to form a terminal, and the insulating film peeling parts on the opposite ends of the other coil crossed out from the opposite side of the bobbin and drawn around to form a terminal on the bobbin coil winding part. Characteristic common mode choke coil. 3. The common mode choke coil according to claim 1, wherein the coil winding portions are formed at the four corners of the bobbin so that the terminals are formed at the four corners of the common mode choke coil. 4. The lead wires of the respective coils so that the lead wires at both ends of the one coil and the lead wires at both ends of the other coil respectively come out from the coil once in the horizontal direction and then go to the respective coil winding portions. The common mode choke coil according to any one of claims 1 to 3, wherein the bobbin is formed with a guide having a height substantially equal to that of the bobbin.