JP2010034171A - Laminated coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated coil for enhancing a current superimposition characteristic without reducing the inductance value of a coil. <P>SOLUTION: The laminated coil includes: a nonmagnetic body 2 constituted of a nonmagnetic body layer 1; magnetic bodies 4 formed by laminating a plurality of magnetic body layers 3a-3e on the upper and lower surfaces of the nonmagnetic body 2; a plurality of coil conductors 5a-5d formed only in the magnetic bodies 4; and helical coils 6 obtained by vertically connecting the plurality of coil conductors 5a-5d. The number of windings in the coil conductor closest to the nonmagnetic body 2 is made to be larger than that in the other coil conductors. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laminated coil used in various electronic devices such as digital devices, AV devices, and information communication terminals.

  This type of conventional laminated coil includes a laminated body composed of magnetic layers, a plurality of coil conductors formed in the laminated body, and a spiral coil provided by connecting the plurality of coil conductors. And a nonmagnetic layer is formed between the adjacent coil conductors.

  By adopting such a configuration, magnetic saturation is suppressed so that magnetic flux leaks from the non-magnetic layer, thereby improving the current superposition characteristics.

As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
JP 2001-44036 A

  In the conventional laminated coil described above, since the coil conductor is formed in the nonmagnetic layer, there is a problem that the inductance value of the coil is reduced.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a laminated coil that can improve the current superposition characteristics without reducing the inductance value of the coil.

  In order to achieve the above object, the present invention has the following configuration.

  The invention described in claim 1 of the present invention is a nonmagnetic body portion comprising a nonmagnetic body layer, and a magnetic body portion formed by laminating a plurality of magnetic layers on the upper and lower surfaces of the nonmagnetic body portion, A plurality of coil conductors formed only on the magnetic body portion, and a spiral coil provided by connecting the plurality of coil conductors in the vertical direction, the coil conductor closest to the non-magnetic body portion The number of turns is greater than the number of turns of the other coil conductors. According to this configuration, the coil conductor is formed only in the magnetic part, so the inductance value of the coil decreases due to the influence of the non-magnetic part. In addition, since the number of turns of the coil conductor closest to the non-magnetic body part is larger than the number of turns of the other coil conductors, the amount of magnetic flux leakage from the non-magnetic body part is increased. Work that can improve the current superposition characteristics One in which the effect can be obtained.

  The invention described in claim 2 of the present invention is such that coil conductors adjacent in the vertical direction are arranged so as not to overlap each other when viewed from above. Since the stress between the coil conductor and the adjacent coil conductor can be dispersed, the nonmagnetic material layer and the magnetic material layer can be compressed, which makes it possible to reduce the height of the product. Is obtained.

  As described above, the laminated coil of the present invention includes a nonmagnetic body portion formed of a nonmagnetic layer, a magnetic body portion formed by laminating a plurality of magnetic layers on the upper and lower surfaces of the nonmagnetic body portion, A plurality of coil conductors formed only on the magnetic body portion, and a spiral coil provided by connecting the plurality of coil conductors in the vertical direction, the coil conductor closest to the non-magnetic body portion Since the number of turns is larger than the number of turns of the other coil conductor, and the coil conductor is formed only on the magnetic part, the inductance value of the coil does not decrease due to the influence of the non-magnetic part. Since the number of turns of the coil conductor closest to the non-magnetic part is larger than the number of turns of the other coil conductors, the amount of magnetic flux leakage from the non-magnetic part increases, thereby improving the current superposition characteristics. The excellent effect of being able to It is intended to.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  1 is an exploded perspective view of a laminated coil according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, and FIG. 3 is a perspective view of the laminated coil.

  As shown in FIGS. 1 to 3, the laminated coil according to one embodiment of the present invention includes a nonmagnetic body portion 2 made of a nonmagnetic body layer 1 and first and second surfaces on the upper and lower surfaces of the nonmagnetic body portion 2. A magnetic part 4 formed by stacking fifth magnetic layers 3a to 3e; first to fourth coil conductors 5a to 5d formed only on the magnetic part 4; 4 coil conductors 5a to 5d connected in the vertical direction, and the number of turns of the coil conductor closest to the non-magnetic member 2 is set to the number of turns of the other coil conductors. More. Furthermore, the laminated coil according to the embodiment of the present invention is arranged such that the first to fourth coil conductors 5a to 5d adjacent in the vertical direction do not overlap in a top view.

  The said structure WHEREIN: The said nonmagnetic body layer 1 has insulation, and is comprised by the sheet form with nonmagnetic materials, such as Cu-Zn ferrite and glass ceramic. In FIG. 1, the nonmagnetic material layer 1 is a single layer, but may be a plurality of layers, and the nonmagnetic material layer 2 constitutes the nonmagnetic material portion 2.

  The first to fifth magnetic layers 3a to 3e are insulative and are formed into a sheet shape from a magnetic material such as Ni-Zn ferrite, and are stacked in order from the bottom. At this time, the third magnetic body layer 3c and the fourth magnetic body layer 3d are configured so as to sandwich the nonmagnetic body portion 2, and below the nonmagnetic body portion 2, the first to third Magnetic layers 3 a to 3 c are formed, and fourth and fifth magnetic layers 3 d and 3 e are formed above the nonmagnetic portion 2. A dummy magnetic layer 3f made of a magnetic material is formed below the first magnetic layer 3a and above the fifth magnetic layer 3e, respectively, and the first to fifth magnetic layers are formed. A magnetic part 4 including body layers 3a to 3e and a dummy magnetic layer 3f is provided. Therefore, the magnetic body portion 4 is positioned on the upper and lower surfaces of the nonmagnetic body portion 2. The number of the first to fifth magnetic layers 3a to 3e and the dummy magnetic layer 3f is not limited to the number shown in FIG.

  Further, the first to fourth coil conductors 5a to 5d are formed by plating a conductive material such as silver, and the first coil conductor 5a includes the upper surface of the first magnetic layer 3a, the first The second coil conductor 5b is on the upper surface of the second magnetic layer 3b, the third coil conductor 5c is on the upper surface of the fourth magnetic layer 3d, and the fourth coil conductor 5d is on the upper surface of the fifth magnetic layer 3e. Each is formed.

  The first to fourth coil conductors 5 a to 5 d are connected to each other through a via 7 to constitute one spiral coil 6. At this time, among the first to fourth coil conductors 5a to 5d, the second and third coil conductors 5b and 5c closest to the non-magnetic member 2 are spirally formed with about two turns, and the other first and fourth The coil conductors 5a and 5d have a spiral shape of about one turn, and the number of turns of the second and third coil conductors 5b and 5c closest to the non-magnetic member 2 is set to the other first and fourth coils. More than the number of windings of the conductors 5a and 5d. The number of coil conductors that increase the number of turns is not one, but the coil conductor that is closest to the nonmagnetic member 2 above the nonmagnetic member 2 and the nonmagnetic member 2 that is closest to the nonmagnetic member 2 below the nonmagnetic member 2. Both close coil conductors may be used, and the other coil conductors may have the same number of turns.

  In the embodiment of the present invention, as shown in FIGS. 1 and 2, the nonmagnetic material portion 2 is sandwiched between the third magnetic material layer 3c and the fourth magnetic material layer 3d. Therefore, the first to fourth coil conductors 5 a to 5 d are formed only on the magnetic body portion 4 (inside the magnetic body portion 4) without contacting the nonmagnetic body portion 2.

  The number of coil conductor layers is not limited to four as shown in FIG. 1, and may be three or more. The via 7 is formed by filling a hole penetrating the nonmagnetic layer 1 and the second to fifth magnetic layers 3b to 3e with a conductive material such as silver.

  Further, the first coil conductor 5a and the second coil conductor 5b, the second coil conductor 5b and the third coil conductor 5c, and the third coil conductor 5c and the fourth coil conductor 5d which are adjacent in the vertical direction are As shown in FIG. 2, they are arranged so as not to overlap each other when viewed from above.

  And by setting it as above-mentioned structure, the main-body part 8 of a laminated coil as shown in FIG. 3 is formed. In addition, a pair of external electrodes 9 a and 9 b are provided at both ends of the main body 8, and the pair of external electrodes 9 a and 9 b is made of silver so as to be connected to both ends of the coil 6. It is formed by printing. In addition, a nickel plating layer and a tin plating layer are respectively provided on the surfaces of the pair of external electrodes 9a and 9b.

  The first to fourth coil conductors 5a to 5d are not formed by plating, but may be formed by other methods such as printing and vapor deposition.

  Next, the manufacturing method of the laminated coil in one embodiment of this invention is demonstrated.

  1 to 3, first, a rectangular nonmagnetic layer 1 and first to fifth magnetic layers 3a to 3e are made of a mixture of magnetic material and nonmagnetic material powder and resin as raw materials. Then, a predetermined number of dummy magnetic layers 3f are produced. At this time, holes are formed by laser, punching, or the like at predetermined positions of the nonmagnetic material layer 1 and the second to fifth magnetic material layers 3b to 3e. Form.

  Next, the dummy magnetic layer 3f and the first magnetic layer 3a are stacked, and then a spiral first coil conductor 5a of about 1 turn is formed on the upper surface of the first magnetic layer 3a by plating. .

  Next, a second magnetic layer 3b having a via 7 is laminated on the upper surface of the first coil conductor 5a. At this time, the first coil conductor 5a and the via 7 are connected.

  Next, the second coil conductor 5b is formed in a spiral shape of about 2 turns on the upper surface of the second magnetic layer 3b by plating. At this time, the second coil conductor 5b and the via 7 are connected.

  Next, a third magnetic layer 3c, a nonmagnetic layer 1 and a fourth magnetic layer 3d each having a via 7 are sequentially laminated on the upper surface of the second coil conductor 5b. At this time, each via 7 is connected to the second coil conductor 5b.

  Next, the third coil conductor 5c is formed in a spiral shape of about 2 turns on the upper surface of the fourth magnetic layer 3d by plating. At this time, the third coil conductor 5c and the via 7 are connected.

  Next, a fifth magnetic layer 3e having a via 7 is laminated on the upper surface of the third coil conductor 5c. At this time, the third coil conductor 5c and the via 7 are connected.

  Next, a fourth coil conductor 5d is formed on the upper surface of the fifth magnetic layer 3e in a spiral shape of about one turn by plating. At this time, the fourth coil conductor 5d and the via 7 are connected. In this way, one helical coil 6 is configured by connecting the first to fourth coil conductors 5 a to 5 d via the via 7. Further, the first coil conductor 5a and the second coil conductor 5b, the second coil conductor 5b and the third coil conductor 5c, and the third coil conductor 5c and the fourth coil conductor 5d are respectively overlapped in a top view. Arrange so that it does not become.

  In addition, the formation method of the said 1st-4th coil conductors 5a-5d forms the conductor of a predetermined pattern shape by plating on the base plate (not shown) prepared separately, and transcribe | transfers this conductor to each layer after that. To form.

  Next, a plurality of dummy magnetic layers 3f are laminated on the upper surface of the fourth coil conductor 5d to form the main body portion 8 of the laminated coil.

  Next, the body 8 is fired at a predetermined temperature and time, and silver is printed on both end faces of the body 8 so as to be connected to both ends of the coil 6, respectively. 9a and 9b are formed.

  Finally, a nickel plating layer and a tin plating layer are formed on the surface of the pair of external electrodes 9a and 9b by plating.

  As described above, in the embodiment of the present invention, since the first to fourth coil conductors 5a to 5d are formed only in the magnetic body portion 4, the inductance of the coil 6 is influenced by the influence of the non-magnetic body portion 2. The value never drops. Furthermore, since the number of turns of the second and third coil conductors 5b and 5c closest to the non-magnetic part 2 is made larger than the number of turns of the other first and fourth coil conductors 5a and 5d, non-magnetic The amount of leakage of the magnetic flux from the body part 2 is increased, thereby obtaining the effect that the current superposition characteristics can be improved.

  Here, in general, in the case of a coil having a closed magnetic circuit, when the current exceeds a certain value, magnetic saturation of the magnetic flux occurs, the inductance value decreases, and the current superposition characteristics (relationship between the current flowing through the coil and the inductance value) It will get worse. As a countermeasure, it is conceivable to improve the current superposition characteristics by forming a nonmagnetic layer between the coil conductors to form a closed magnetic circuit so that magnetic saturation of the magnetic flux is less likely to occur. However, if the coil conductor is configured to be in contact with the nonmagnetic material layer, or if the coil conductor is surrounded by the nonmagnetic material layer, the current superimposition characteristics can be improved, but the initial coil in the case where no current is passed can be obtained. Since the inductance value is low, the inductance value when a current is passed is also low. Furthermore, in order to suppress a decrease in the inductance value of the coil, it is conceivable to shorten the distance between the coil conductors (thinning the thickness of the magnetic layer), but this is not preferable because a short circuit or an interlayer crack occurs.

  On the other hand, in the laminated coil according to the embodiment of the present invention, the first to fourth coil conductors 5a to 5d are configured to be in contact with the nonmagnetic body 2 or surrounded by the nonmagnetic body 2. The initial inductance value of the coil 6 does not decrease because it is surrounded by the magnetic part 4 without being sluggish. In this case, there is little possibility that a short circuit or an interlayer crack will occur.

  In addition, since the number of turns of the second and third coil conductors 5b and 5c closest to the nonmagnetic body portion 2 is larger than the number of turns of the other first and fourth coil conductors 5a and 5d, nonmagnetic Even if the magnetic body part 4 exists between the body part 2 and the first to fourth coil conductors 5a to 5d, the leakage amount of the magnetic flux from the non-magnetic body part 2 is increased. Since saturation is less likely to occur, current superposition characteristics can be improved.

  In addition, the first coil conductor 5a and the second coil conductor 5b, the second coil conductor 5b and the third coil conductor 5c, and the third coil conductor 5c and the fourth coil conductor 5d which are adjacent in the vertical direction are Since they are arranged so as not to overlap each other when viewed from above, when the layers are pressed and laminated, the stress between the coil conductor and the adjacent coil conductor can be dispersed, whereby the nonmagnetic layer 1 Since the first to fifth magnetic layers 3a to 3e can be compressed, the product can be reduced in height. Further, when the first to fourth coil conductors 5a to 5d are formed by plating, the number of coil conductors made of hard metal arranged in the stacking direction is reduced, so that the first to fourth coil conductors 5a to 5d are the first ones. The first to fifth magnetic layers 3a to 3e can be easily cut into the first and fifth magnetic layers 3a to 3e, thereby suppressing the occurrence of delamination.

  The laminated coil according to the present invention has an effect of improving the current superposition characteristics without lowering the inductance value of the coil, and in particular, various electronic devices such as digital devices, AV devices, information communication terminals, and the like. This is useful in laminated coils used as noise countermeasures.

1 is an exploded perspective view of a laminated coil according to an embodiment of the present invention. AA line sectional view of FIG. Perspective view of the laminated coil

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nonmagnetic body layer 2 Nonmagnetic body part 3a-3e 1st-5th magnetic body layer 4 Magnetic body part 5a-5d 1st-4th coil conductor 6 Coil

Claims (2)

A non-magnetic part made of a non-magnetic layer, a magnetic part formed by laminating a plurality of magnetic layers on the upper and lower surfaces of the non-magnetic part, and a plurality of coils formed only on the magnetic part A conductor and a spiral coil provided by connecting the plurality of coil conductors in the vertical direction, and the number of turns of the coil conductor closest to the non-magnetic body portion is larger than the number of turns of the other coil conductors. Laminated coil. The laminated coil according to claim 1, wherein coil conductors adjacent in the vertical direction are arranged so as not to overlap in a top view.

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