JPH11219819A - Wideband thin noise filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wideband thin noise filter, which is capable of being made compact and thin by increasing a noise removal ratio, reducing signal attenuation, and realizing a wideband. SOLUTION: A composite magnetic body 2, constituted of the combination of a single body (including no-heat treatment) or plural thin film magnetic bodies, the board thickness and heat treatment condition of which are changed is interposed by two thin plate substrates 3 represented by an FPC having signal patterns 4, and signal lines are connected by providing connecting means, and the signal lines are wound around an apparent magnetic body as a first wide band thin noise filter. The composite magnetic body 2 constituted of the combination of a single body (including no-heat treatment) or plural thin film magnetic bodies the board thickness and heat treatment condition of which are the same and the self-inductance of a signal pattern is interposed by the two thin board substrates 3 represented by the FPC having the signal pattern parts 4, and the signal lines are connected by providing the connection means, and the signal lines are wound around the apparent magnetic body as a second wideband thin noise filter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible substrate (hereinafter, referred to as "FPC") suitable for removing high-frequency noise in OA equipment such as communication equipment and personal computers, game machines and the like.
The present invention relates to a (flexible printed circuit) type broadband, thin noise filter 1, and more particularly to a broadband, thin noise filter 1 with a high noise elimination ratio, a small signal attenuation, a wide band, a small size, and a low profile.

[0002]

At present, the environment of electromagnetic waves is getting worse and worse with the increase of broadcast output, the spread of illegal radio equipment, the spread of high frequency equipment, and the like. Various solutions to high frequency noise have been proposed,
A filter mainly using a coil is generally used. In recent years, electronic devices have been required to be smaller and less expensive.
From such a background, filters are no exception.
FIG. 3 is an explanatory diagram of a drop in attenuation due to resonance when a conventional general magnetic body 2 'is used. As is apparent from the figure, the conventional general magnetic material 2 'has a disadvantage that the attenuation is reduced in the high frequency range due to resonance, compared to the ideal target attenuation in the high frequency range. Further, when the conventional general thin film magnetic material 2 'is wound around a lead wire 12', there is a disadvantage that the magnetic material is thin, as shown in FIG. In addition, conventional upper and lower FPC
When the lead wire 12 'is manually wound around 3', FIG.
As shown in (b), the winding state is not uniform, and there is a large variation in characteristics. In any case, the following technical problems remain with respect to the filter for the high frequency region. 1. There is no leakage inductance, and the variation in the inductance between pairs is small. 2. Small inter-winding capacitance. 3. Crosstalk between channels is small. 4. High permeability and high resistance at high frequency.

[0003]

The first aspect of the present invention is to provide a composite magnetic material 2 composed of a single substance (including no heat treatment) or a combination of a plurality of thin film magnetic substances with different thicknesses and heat treatment conditions. A signal line is connected by providing a connecting means at the same time as being sandwiched between the thin substrate 3 typified by two FPCs having a signal pattern portion 4, and the signal line is wound around an apparent magnetic material. Type noise filter 1
It is. Secondly, a composite magnetic material 2 composed of a single material (including no heat treatment) having the same thickness and heat treatment conditions or a combination of a plurality of thin film magnetic materials and a self-inductance of a signal pattern, and a signal pattern portion Two FPCs with 4
A wide band, thin noise filter 1 characterized in that a signal line is connected by providing a connection means at the same time as being sandwiched by a thin plate substrate 3 and a signal line is wound around an apparent magnetic material. Third, as the first and second composite magnetic materials 2, a high permeability amorphous thin film magnetic material is processed and applied to a thin film magnetic material with slits, a resin mixed with a magnetic material, and a magnetic wire aggregate. is there. Fourth, the first to third signal pattern units 4 are replaced with TP (twist) pattern units 6. Fifth, there is a structure in which the broadband, thin noise filter 1 including the first to fourth filters is attached to various connectors and mounted.

[0004]

First, a composite structure comprising a combination of a plurality of thin-film magnetic materials having different thicknesses and heat treatments with respect to the occurrence of resonance due to the conventional lead wire inductance "L" and capacitance "C". By adopting a structure in which the magnetic material 2 is sandwiched between thin substrate 3 typified by upper and lower FPCs, it is possible to shift the resonance point to a higher frequency range and achieve a wider band. Secondly, the conventional lead wire 12 'is patterned with a thin substrate 3 typified by an FPC so that the thin film magnetic material is not distorted. Third, by changing the conventional structure in which the lead wire 12 'is manually wound around by using a thin substrate 3 typified by an FPC, the influence of variations at high frequencies is eliminated. Fourth, by using the signal pattern section as the TP (pair twist) pattern section 6, crosstalk between adjacent channels and EMI are improved. Fifth, the use of a high-permeability amorphous material for the composite magnetic body 2 enables a high speed and a wide band. Sixth, by attaching the broadband, thin noise filter 1 of the present invention to various connectors, noise removal efficiency and compactness can be achieved.

[0005]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a wide-band, thin noise filter according to the present invention. FIG. 1 (a) shows a broadband, thin noise filter 1 in which a composite magnetic body 2 composed of a single or a plurality of thin film magnetic bodies of the present invention is sandwiched between thin plate substrates 3 typified by upper and lower FPCs.
3 is a perspective view, a sectional view, and a plan view of FIG. FIG. 1 (b) shows a composite magnetic body 2 composed of a single or a plurality of thin-film magnetic bodies of the present invention.
FIG. Next, the present invention will be described below with reference to specific examples.

[0006]

【Example】

(1) Magnetic body thickness = 0.01 μm to 500 μm (2) Insulator thickness = 0.01 μm to 500 μm (3) Pattern width = 10 μm to 500 μm (4) Gap between patterns = 10 μm to 500 μm (5) Number of turns = 10 to 50 times (appropriately set according to the amount of attenuation and band specifications) Setting conditions 1. Magnetic material (1) Material: Amorphous magnetic material: f-special setting of magnetic permeability by material composition, aging, etc. according to required characteristics. 1. Amorphous magnetic material composition used in the present invention: The following settings were made in consideration of a high magnetic permeability material. 1. Fe: 1 to 30% Ni: 30 to 82% Cu: 0 to 20% Mo: 0 to 10% Aging conditions: No heat treatment or heat treatment temperature: 500 to 1500 ° C. (2) Film thickness: Set as thin as possible to the extent that the effect of the skin effect is small. (3) Total thickness: The cross-sectional area is set to be large with multiple layers. 2. Pattern (1) Pattern width: as narrow as possible in the range that covers the required current capacity. (2) Pattern pitch: as small as possible to secure the magnetic path length. 3. Number of turns: Since L increases with the square of the number of turns, the number of turns is set to be large. 4. Insulator: (1) Pattern / magnetic material: As thick as possible considering high frequency characteristics. (2) Gap between magnetic bodies: as thin as possible. The thin substrate 3 typified by the FPC is formed by sequentially stacking a normal insulating film, an adhesive, a copper foil pattern portion, an adhesive, and an insulating film. Further, since the upper and lower patterns of the thin substrate 3 typified by the FPC are connected by through holes, a twisted pair pattern may be formed and a parallel pattern portion may be partially formed. . In the case of a fine pattern structure, bumps may be used to connect the thin substrate FPC3 represented by FPC. The present invention uses a typical permalloy sheet as a high-permeability amorphous material for this composite and utilizes the difference in the frequency characteristics of the magnetic permeability depending on the heat treatment conditions and the plate thickness to achieve the composite. Corresponding. To be more specific, the composite structure is as follows: (1) For low frequency use, the magnetic permeability is as large as possible. (2) For medium frequency use, the magnetic permeability is as large as possible. Magnetic permeability decreases (3) For high frequency, magnetic permeability draws a downward curve,
From the place where the self-inductance of the lead wire falls, the curve for decreasing the magnetic permeability is reduced. These three types are combined according to the target frequency range and the attenuation. In addition, regarding (1) to (3), depending on the heat treatment conditions and the material composition, it is possible to cope with a single magnetic substance or a combination of multiple magnetic layers and the self-inductance of the pattern itself. In FIG. 3, the resonance frequency (f ₀ ) needs to be changed to shift the attenuation phenomenon of the attenuation amount due to resonance to a higher frequency depending on the used band.

[0007]

F ₀ = 1 / 2π√ (L * C) (1)

Here, L = L ₁ + L ₂ L ₁ : self-inductance of the lead wire L ₂ : self-inductance of the inserted magnetic material C: stray capacitance of the lead wire

[0009]

## EQU2 ## Attenuation α = 50 / (50 + Z) (2)

[0010] In the Z = R + (ωL-1 / ωC) Thus the low frequency range, L ₂ is as large as possible of the insert magnetic material used Li until a high frequency range from the medium frequency range - in consideration of the inductance of the lead wire It is understood that it is necessary to gradually lower the total inductance so as not to enter the resonance region. Next, the signal pattern section is changed to a TP (twisted) pattern section 6, and the TP (twisted) pattern section 6 is more preferable in terms of crosstalk between adjacent channels. showed that.

FIG. 2 shows a typical use example of the present invention.
FIG. 4 is an explanatory view of a mounting process for mounting the same, and is an example in which a common mode choke coil is used (a signal current does not work as a coil, and a noise works as a coil). First, the output connector 8 is soldered to the broadband, thin noise filter 1 of the present invention. Next, the modular jack 7 is soldered to a long leg set in advance, inserted into the through-hole of the broadband, thin noise filter 1 of the present invention, soldered, and attached to the back of the modular jack 7. wear. Thereafter, the board mounting feet 10, jack feet, and output connector 8 feet are mounted on the hard board 11. Thereafter, the plug is inserted and fitted. Here, the representative modular jack 7 has been described as an example, but it is needless to say that the present invention is applicable to various connectors. The signal flowing through the transmission medium is output from the output pin of the modular jack 7 through an FPC type common mode choke. However, since the signal forms a TP pattern, a crosstalk in an adjacent channel or a bent portion is provided. The impact of has been reduced. Therefore, as is apparent from the figure, the wideband, thin noise filter 1 of the present invention is attached to the housing of the modular jack 7, so that it can be mounted compactly. Because of the above-described structure, a comparison between the conventional broadband, thin noise filter 1 of the present invention and the conventional case shows not only high productivity but also stable characteristics over a wide band. Have.

In the embodiment of using the wide-band, thin noise filter 1 of the present invention, the representative modular jack 7 has been described as a representative example. However, the present invention is not limited to this, and a wide range of applications such as an interface connector is possible. is there. It goes without saying that the insulating film, the copper foil pattern portion, the TP pattern portion 6 and the like include various modifications within the scope of the present invention.

[0013]

As is evident from the above description, the broadband, thin noise filter 1 of the present invention comprises: 1. Compatible with high-speed common mode choke (Signal attenuation is small and noise attenuation is large) 2. Performance variations (attenuation and resonance frequency variations) are small. High speed, wide band (up to 1 GHz. Self resonance point: 8
(00 MHz or more) Small and thin. 5. Since it has the excellent effects of stable characteristics and high mass productivity, it has great industrial value.

[Brief description of the drawings]

FIG. 1 (a) is a perspective view of a broadband, thin noise filter 1 in which a composite magnetic body 2 composed of a single or a plurality of thin film magnetic bodies of the present invention is sandwiched between thin plate substrates 3 typified by upper and lower FPCs; Sectional view, plan view. (B) A cross-sectional view of the composite magnetic body 2 composed of a single or a plurality of thin-film magnetic bodies of the present invention.

FIG. 2 is a mounting view of a typical embodiment of the present invention, in which a wideband, thin noise filter 1 of the present invention is attached to a modular jack 7;

FIG. 3 is an explanatory diagram of a decrease in attenuation due to resonance when a conventional general magnetic body 2 ′ is used.

FIG. 4 (a) is an explanatory view of a case where a conventional general magnetic body 2 'is wound around a lead wire 12'. (B) Explanatory drawing in the case where a lead wire 12 'is manually wound around a conventional upper and lower FPC 3'.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Broadband, thin noise filter of the present invention 2 Composite magnetic material composed of one or a plurality of thin film magnetic materials 3 Thin substrate typified by FPC 4 Signal pattern portion 5 Throughhole 6 TP (twisted pair) Pattern section 7 Modular jack 8 Output connector 9 Modular jack pin insertion hole 10 Board mounting foot 11 Hard board 2 'Conventional general magnetic body 3' Conventional FPC 12 'Conventional lead wire

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masahiro Mukada 2-12-8 Shimoodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Inside Oki Electric Cable Co., Ltd.

Claims (5)

[Claims] 1. Plate thickness (magnetic material thickness: 0.01 μm to 500 μm)
μm) and a single unit with different heat treatment conditions (including without heat treatment)
Or a plurality of thin film magnetic materials (material composition (1): Fe: 1 to 3)
0%, Ni: 30 to 82%, Cu: 0 to 20%, Mo:
0 to 10% or material composition (2): Co: 60 to 80%,
A composite magnetic body 2 composed of a combination of Nb: 1 to 20% and Zr: 1 to 20% is represented by two FPCs having a signal pattern portion 4 (pattern width: 10 μm to 500 μm). A broadband, thin noise filter 1 characterized in that a signal line is connected by providing a connecting means at the same time as being sandwiched by the thin plate substrate 3 and the signal line is wound around an apparent magnetic material. 2. Plate thickness (magnetic material thickness: 0.01 μm to 500 μm)
μm) and a single or multiple thin film magnetic materials having the same heat treatment conditions (including no heat treatment) (material composition (1): Fe: 1 to 3)
0%, Ni: 30 to 82%, Cu: 0 to 20%, Mo:
0 to 10% or material composition (2): Co: 60 to 80%,
Nb: 1 to 20%, Zr: 1 to 20%) and the self-inductance of the signal pattern section 4 (pattern width: 10 μm to 500 μm) are combined with the signal pattern section 4. (Pattern width: 10 .mu.m to 500 .mu.m) sandwiched by two thin substrates 3 typified by FPCs, and at the same time, connecting means are provided to connect signal lines, and the signal lines are wound around an apparent magnetic material. Broadband,
Thin noise filter 1. 3. The composite magnetic material 2 according to claim 1, wherein the composite magnetic material 2 comprises an amorphous thin film magnetic material (material composition (1): F
e: 1 to 30%, Ni: 30 to 82%, Cu: 0 to 20
%, Mo: 0 to 10% or material composition (2): Co: 60
(80%, Nb: 1 to 20%, Zr: 1 to 20%), magnetic material thickness: 0.01 μm to 500 μm), taking into consideration the merits in processing and performance, taking into account the thin film magnetic material with slits and the magnetic material mixed A broadband, thin noise filter 1 characterized by being applied to a resin or magnetic wire aggregate. 4. A broadband, thin noise filter 1 according to claim 1, wherein the signal pattern section 4 is a TP (twisted) pattern section 6. 5. A broadband, thin noise filter 1 characterized in that the broadband, thin noise filter 1 according to claim 1, 2, 3, or 4 is mounted on various connectors. .