JPH0745932Y2 - Laminated coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a laminated coil formed by laminating a plurality of magnetic sheets having an annular conductor formed on a main surface thereof.

[Conventional technology]

The coil is generally formed by winding a copper wire around a core made of a magnetic material. However, such a coil is expensive because the winding work is expensive, and it is difficult to reduce the size. Therefore, recently, a chip-shaped laminated coil is provided by using a printing technique and a laminating technique.

A conventional example of such a laminated coil is shown in USP3765082. In this conventional example, a plurality of magnetic bodies each having a U-shaped conductor pattern formed on the main surface are laminated,
The conductor patterns of each magnetic body are connected to each other to form a coil.

[Problems to be solved by the device]

As one of the functions of the coil, there is a choke coil used as a noise countermeasure for various electronic devices. The choke coil used for the noise countermeasure is roughly classified into a common mode choke coil used for the noise countermeasure between the line and the ground and a normal mode choke coil used for the noise countermeasure between the lines.

FIG. 6 shows a conventional common mode choke coil and its operating principle. As shown in this figure, the common mode choke coil is formed by winding a plurality of insulated wires 2 in a core 1 forming a closed magnetic circuit, and winding them in phase with each other a number of times. Then, as shown in FIG. 6, A → B → C → D → E.
→ For noise of normal mode component flowing with F,
The magnetic fluxes in the core 1 cancel each other out and do not act as chokes. However, it acts as a choke as the noise of the common mode component flowing in the order of A → B → C → D → G → H.

The common mode choke coil as described above must be wound through a hole as shown in FIG.
On the other hand, there is also provided a technique of forming a choke coil by magnetically shielding the entire body after winding a cylindrical or pot-shaped core.

However, providing the winding on the core is complicated in work as described above, and the cost becomes high. Further, in the case where the pot type core or the tubular core is provided with windings and the whole is magnetically shielded, although the work of passing through the hole is eliminated, precise processing accuracy is required, and the cost also increases. Furthermore, with the recent miniaturization of electronic devices, there has been a demand for miniaturization of the coil, and a pot-type core or the like cannot cope with this.

Therefore, it is possible to use the chip-shaped laminated coil by using the printing technique and the laminating technique as described above. However, in the conventional laminated coil, a plurality of electric wires cannot be separated from each other and wound many times, and one coil is continuously formed. Therefore, when the common mode choke coil is formed by using the conventional laminated coil technique, after forming the first coil, the second coil is further formed on this coil.

However, in the common mode choke coil formed by using such a conventional technique, even if the number of turns is the same, it is not possible to generate magnetic fluxes that match each other to the extent that they can cancel each other.

An object of the present invention is to provide a laminated coil that can form a common mode choke coil by using printing technology and lamination technology.

[Means for Solving the Problems]

In the laminated coil according to the present invention, a plurality of first coil magnetic material sheets and second coil magnetic material sheets are alternately laminated.

The first coil magnetic material sheet has a substantially quadrangular shape in which a substantially one-turn annular conductor pattern having a start end and an end is formed to form the first coil. The second coil magnetic material sheet has a substantially quadrangular shape that forms a second coil by forming a substantially one-turn annular conductor pattern having a start end and an end. The start ends of the conductor patterns formed on the first coil magnetic material sheet are adjacent to each other via a through hole formed on one side of a pair of opposite end sides of the first and second coil magnetic material sheets. The first coil is formed by being connected to the end of the conductor pattern formed on the first coil magnetic material sheet. The start ends of the conductor patterns formed on the second coil magnetic material sheet are adjacent to each other via a through hole formed on the other side of a pair of opposite end sides of the second and first coil magnetic material sheets. The second coil is formed by being connected to the end of the conductor pattern formed on the second coil magnetic material sheet.

[Action]

In this invention, a plurality of first coil magnetic material sheets each having a ring-shaped conductor formed on its main surface are stacked, and
The magnetic sheet for the second coil is arranged between them,
The conductors on the first coil magnetic material sheet are electrically connected through the through holes of the second coil magnetic material sheet.

If such a configuration is continuously formed as one unit, and the conductor of the magnetic material sheet for the second coil is electrically connected through the through hole of the magnetic material sheet for the first coil, The windings (conductors) forming the coil and the windings forming the second coil are arranged alternately or every several layers.

If such a laminated coil is used, magnetic fluxes that cancel each other out are generated in the two coils, and the two coils act as a common mode choke coil, which is effective. Of course, the third coil, the fourth coil, etc. may be sequentially laminated in the same manner as described above.

〔Example〕

FIG. 1 is an exploded perspective view of a laminated coil according to an embodiment of the present invention. Here, a case where a common mode choke coil is formed will be described as an example.

As shown in this figure, the laminated coil of the present embodiment is
Body 5 and body 5 in which a coil and a second coil are formed
It is composed of upper and lower electrode portions 6 and 7 provided so as to sandwich it, and magnetic shield layers 8 and 9 provided at the outermost layers.

The main body portion 5 includes a plurality of first coil magnetic sheet 10,1.
It is composed of 1 and 12 and second coil magnetic material sheets 20, 21, and 22. Second coil magnetic sheet 20-22
Are arranged between the first coil magnetic material sheets 10 to 12, respectively. That is, the first coil magnetic material sheet 10
The second coil magnetic material sheet 20 is disposed between the first coil magnetic material sheet 11 and the first coil magnetic material sheet 11, and the second coil magnetic material sheet 11 is disposed between the first coil magnetic material sheet 11 and the first coil magnetic material sheet 12. The seat 21 is arranged. In addition, a magnetic sheet for the second coil is provided between the magnetic sheet 12 for the first coil and the lower electrode portion 7.
22 are arranged.

On the main surface of each of the magnetic material sheets 10 to 12 and 20 to 22, a square-shaped first coil-forming conductor pattern 13, which has approximately one turn and is arranged such that the starting end and the terminating end are displaced from each other so as not to be electrically connected, 14,
15 and the second coil forming conductor patterns 23, 24, 25 are printed. The starting end and the terminating end of each conductor pattern vary depending on the winding direction and the current flow direction. The end 13b of the conductor pattern 13 formed on the magnetic sheet 10 is the start end of the conductor pattern 14 formed on the magnetic sheet 11 via the through hole 13c at the end 13b and the through hole 20a of the magnetic sheet 20. It is electrically connected to 14a. In addition, the end 14 of the conductor pattern 14 of the magnetic sheet 11
b is the through hole 14c at the end 14b, the magnetic sheet 21
Is connected to the starting end 15a of the conductor pattern 15 of the magnetic sheet 12 through the through hole 21a. Further, the end 23b of the conductor pattern 23 of the magnetic sheet 20 is connected to the starting end 24a of the conductor pattern 24 of the magnetic sheet 21 through the through hole 23c of the end 23b and the through hole 11a of the magnetic sheet 11. . Similarly, the end 24b of the conductor pattern 24 is
It is connected to the starting end of the conductor pattern 25 of the magnetic material sheet 22 through the through hole 24c of the portion 4b and the through hole of the magnetic material sheet 12.

In this way, the conductor patterns 13 of the magnetic sheets 10 to 12 are
To 15 and the conductor patterns 23 to 25 of the magnetic sheets 20 to 22 and the second coil L2 having the same phase and the same number of turns as the first coil L1 are formed in every other layer. .

Further, the upper electrode portion 6 is composed of magnetic sheets 30, 31, and 32. Lead-out electrode conductor patterns 34a, 34b, 34c and 35a, 35b, 35c are formed on each of the magnetic sheets 30 to 32. Then, the extraction electrode conductor pattern 34a
34c are electrically connected to each other by through holes, and the starting ends 13a of the conductor patterns 13 of the magnetic material sheet 10 forming the first coil L1 are connected to these. Similarly, the lead-out electrode conductor patterns 35a to 35c are connected to each other by through holes. Then, in these patterns 35a to 35c, the magnetic material sheet 2 forming the second coil L2 is provided through the through holes 10a of the magnetic material sheet 10.
The starting end 23a of the conductor pattern 23 of 0 is connected.

In this way, the lead electrode terminal T1a of the first coil L1 and the lead electrode terminal T2a of the second coil L2 are formed in the upper electrode portion 6, respectively.

The lower electrode portion 7 is composed of magnetic sheets 36, 37 and 38. Lead-out electrode conductor patterns 39a, 39b, 39c and 40a-40c (40b, 40c are not shown in the figure) are formed on each of the magnetic sheets 36-38. Then, the conductor patterns 39a to 39c are connected to each other, and the terminal end 15b of the conductor pattern 15 of the magnetic sheet 12 constituting the first coil L1 is connected via the through hole 22a of the magnetic sheet 22. . Similarly, the electrode conductor pattern 40a,
Conductor pattern of the magnetic sheet 22 forming the second coil L2
25 start ends are connected. In this way, the lower electrode 7 has a lead electrode terminal T1b for the first coil L1.
And a lead electrode terminal T2b for the second coil L2.

FIG. 2 shows an external electrode connected to the laminated coil shown in FIG. 1. External electrodes 41 to 44 are connected to the respective lead electrode terminals T1a and T1b and the lead electrode terminals T2a and T2b. Has been done.

The magnetic material sheet is made of an insulating material such as Ni-Zn ferrite, and the conductor pattern is made of Ag, Pd, Ag.
-Pd or the like is used, and it is desirable that the line width is twice or more than the diameter of each through hole. Furthermore, for example, when Mn-Zn ferrite having no insulating property is used as the magnetic material sheet, an insulating film such as glass may be formed between the sheet and each conductor pattern.

In the laminated coil having the above-described structure, a conductor pattern is printed on a green sheet made of a magnetic material to prepare a main body portion 5 and upper and lower electrode portions 6 and 7, and these and the magnetic shield layers 8 and 9. Laminate, press-bond, and integrally sinter. Then, by attaching an external electrode to each lead electrode terminal, an integrated chip type common mode choke coil is obtained. FIG. 3 shows an equivalent circuit diagram of the common mode choke coil.

In the common mode choke coil configured as described above, as shown in FIG. 4, the signal input from A of the first coil L1 is output to B and the magnetic flux α is generated. However, when this signal is input from C of the second coil L2 and output to D, the second coil L2 is wound in the same phase as the first coil L1, and therefore the magnetic flux β in the opposite direction to the magnetic flux α. To occur.
Further, since the first coil L1 and the second coil L2 have the same number of turns and the conductor pattern is formed for the same core, the magnetic flux α and the magnetic flux β generated by the coils L1 and L2 have the same density. Therefore, the magnetic fluxes α and β cancel each other out in the magnetic body. That is, it does not act as a choke coil in the normal mode, but acts as a choke only for common mode noise.

In such a common mode choke coil of the present embodiment, unlike the conventional one in which a conductive wire is wound in a coil shape, a coil pattern is printed on a magnetic sheet,
Since they are electrically connected by through holes to form a coil, mass production is possible. Moreover, the chip shape can be made small and suitable for surface mounting.

Further, the pitch of the signal line patterns in the common mode choke coil is becoming narrower year by year, but if the pitches of the external electrodes are matched, it is possible to sufficiently cope with the narrow pitch.

[Other Examples]

(A) Although the present invention is applied to the common mode choke coil in the above embodiment, the present invention can be similarly applied to the case of forming another transformer of the present invention, for example.

FIG. 5 is a partially exploded perspective view of a transformer having a coil winding ratio of 2: 1. As shown in the figure, the magnetic material sheets 50 and 51 forming the primary coil correspond to the magnetic material sheet 52 forming the secondary coil, and the magnetic material sheet 50 forming the primary coil. And 51 are arranged between a magnetic material sheet 52 and a magnetic material sheet 53 that form the secondary coil. The unit composed of the three sheets 50, 51 and 52 is continuously laminated to form a transformer.

Similar to the above embodiment, each sheet is printed with annular conductor patterns 54, 55, 56, 57 having a start end and an end.
Conductor pattern 54 and conductor pattern forming the primary coil
It is electrically connected to 55. Also, each conductor pattern
54 and 55 are magnetic material sheets 52 and 5 that form the secondary coil on the conductor pattern that forms the primary coil of another unit.
It is connected through three through holes 52a and 53a. Conductor pattern 56 of magnetic sheet 52 that constitutes the secondary coil
Is connected to the conductor pattern 57 of the magnetic sheet 53 forming the secondary coil of another unit via the through holes 50a and 51a of the magnetic sheets 50 and 51 forming the primary coil.

In this way, a compact transformer can be realized by alternately stacking the primary side coil and the secondary side coil.

(B) In the above embodiment, two coils are connected to every other layer to form a laminated coil. However, in general, when n coils having the same number of turns are formed as a laminated coil in one chip, For example, a coil may be formed every (n-1) layer.

[Effect of device]

As described above, according to the present invention, the plurality of magnetic sheets for the first coil are laminated so that the magnetic sheet for the second coil is arranged, and the magnetic sheets are formed through the through holes of the adjacent magnetic sheets. Since the conductors on the sheet are connected and a plurality of coils are formed into a single laminated coil, when forming a common mode choke coil, for example, it is small and suitable for surface mounting, and can be mass-produced. .

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a chip inductor according to an embodiment of the present invention, FIG. 2 is an external view of the chip inductor of the embodiment, FIG. 3 is an equivalent circuit diagram thereof, and FIG. 4 is an operation of the embodiment. FIG. 5 is a partially exploded perspective view of a laminated coil according to another embodiment of the present invention, and FIG. 6 is a view for explaining the appearance and operation principle of a conventional common mode choke coil. Is. 10-12 ... Magnetic sheet for 1st coil, 13-15 ... 1st
Coil conductor pattern, 10a, 11a, 20a, 21a, 22a ... through hole, 20-22 ... second coil magnetic material sheet, 23-
25 …… Conductor pattern for the second coil, 30 to 32, 36 to 38 ……
Magnetic sheet for electrodes, 41-44 ... External electrodes.

Claims (1)

[Scope of utility model registration request] 1. A magnetic sheet for a first coil having a substantially rectangular shape in which a substantially one-turn annular conductor pattern having a start end and an end is formed to form a first coil, and a substantial portion having a start end and an end. And a substantially square-shaped magnetic material sheet for a second coil, which forms a second coil by forming a one-turn annular conductor pattern, are alternately laminated, and is formed on the magnetic material sheet for the first coil. The starting ends of the conductor patterns are formed on the first coil magnetic material sheets that are adjacent to each other through the through holes formed on one side of the pair of opposite end sides of the first and second coil magnetic material sheets. The first coil is formed by connecting to the end of the conductor pattern, and the starting end of the conductor pattern formed on the second coil magnetic material sheet is a pair of opposite ends of the second and first coil magnetic material sheets. Side Second laminated coil connected to the end of the conductor pattern formed on the magnetic sheet coil formed by connecting the second coil adjacent to each other via a through hole formed in the other closer.