JP2022007092A - Common mode noise suppression member - Google Patents

Common mode noise suppression member Download PDF

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JP2022007092A
JP2022007092A JP2020109813A JP2020109813A JP2022007092A JP 2022007092 A JP2022007092 A JP 2022007092A JP 2020109813 A JP2020109813 A JP 2020109813A JP 2020109813 A JP2020109813 A JP 2020109813A JP 2022007092 A JP2022007092 A JP 2022007092A
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common mode
mode noise
differential
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翔 室賀
Sho Muroga
元志 田中
Motoshi Tanaka
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Akita University NUC
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Abstract

To provide a common mode noise suppression member that can maintain good communication quality even in a frequency band of a GHz band or more while suppressing common mode noise transmitted through a differential line without hindering the mounting of a circuit board.SOLUTION: A common mode noise suppression member in which a planar magnetic material D is arranged close to differential lines A and B has a ferromagnetic resonance frequency, and the magnetic field energy generated by a common mode current is converted into heat by the ferromagnetic resonance loss of the planar magnetic material D.SELECTED DRAWING: Figure 1

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特許法第30条第2項適用申請有り 1.刊行物に発表 発行者名:The Japan Society of Applied Physics 刊行物名:Japanese Journal of Applied Physics,vol.58,080902(2019)、第1~4頁 発行年月日:令和1年7月11日 2.ウェブサイトにおいて発表 掲載アドレス:https://iopscience.iop.org/article/10.7567/1347-4065/ab2d8d 掲載年月日:令和1年6月27日There is an application for application of Article 30, Paragraph 2 of the Patent Law. Published in the publication Publisher name: The Japan Society of Applied Physics Publication name: Japanese Journal of Applied Physics, vol. 58,080902 (2019), pp. 1-4 Publication date: July 11, 1st year of Reiwa 2. Announced on the website Posting address: https: // iopscience. iop. org / article / 10.75767 / 1347-4065 / ab2d8d Date of publication: June 27, 1st year of Reiwa

本発明は、線路を伝送するコモンモードノイズを抑制するためのコモンモードノイズ抑制部材に関する。 The present invention relates to a common mode noise suppressing member for suppressing common mode noise transmitted on a line.

電子機器内の信号伝送は、2本の線路(差動線路)を1組として、それぞれの線路に同振幅で逆位相の信号を伝送するディファレンシャルモード(差動)伝送が用いられる。しかし、予期せぬ浮遊容量等によって他の配線や回路と結合してノイズが重畳することにより、また、ディファレンシャルモード信号の非対称性により、コモンモード(同相)ノイズが発生する場合がある。このようなコモンモードノイズは、機器の小型・薄型化、信号の高周波化、他周波数動作化によって顕在化するとともに、対策が困難になっている。 For signal transmission in an electronic device, differential mode (differential) transmission is used in which two lines (differential lines) are set as a set and signals of the same amplitude and opposite phase are transmitted to each line. However, common mode (common mode) noise may occur due to noise superimposed on other wiring or circuits due to unexpected stray capacitance or the like, or due to the asymmetry of the differential mode signal. Such common mode noise has become apparent due to the miniaturization and thinning of equipment, higher frequency of signals, and operation of other frequencies, and it has become difficult to take countermeasures.

従来のコモンモードフィルタは、差動線路を構成する2本の線路それぞれに接続された磁性インダクタ間の磁気結合を用いて、コモンモードノイズに対してのみ高いインピーダンスを発生させることで、コモンモード伝送を妨げることが可能である。しかし、コモンモードフィルタを用いたノイズ対策のためには実装用のフットプリント(占有面積)が必要である。また、従来のコモンモードフィルタは、ノイズエネルギー自体は減衰させず反射させるため、反射したエネルギーが新たなノイズ問題の原因となる可能性がある。さらに、GHz帯域以上の周波数帯域では高い透磁率をもつ磁性材料の実現が難しい。 Conventional common mode filters use magnetic coupling between magnetic inductors connected to each of the two lines that make up a differential line to generate high impedance only for common mode noise for common mode transmission. It is possible to prevent. However, a footprint (occupied area) for mounting is required for noise suppression using the common mode filter. Further, since the conventional common mode filter reflects the noise energy itself without attenuating it, the reflected energy may cause a new noise problem. Further, it is difficult to realize a magnetic material having a high magnetic permeability in a frequency band higher than the GHz band.

また、ディファレンシャルモード伝送用の2本の線路それぞれにフェライトや磁性微粒子を利用した磁性インダクタを接続するコモンモードチョークコイル(例えば、非特許文献1)が公知であるが、ノイズ対策のためには素子実装用の電極や空間が必要である。 Further, a common mode choke coil (for example, Non-Patent Document 1) in which a magnetic inductor using ferrite or magnetic fine particles is connected to each of two lines for differential mode transmission is known, but an element is used for noise suppression. Mounting electrodes and space are required.

また、特許文献1では、単線回路から放射される電磁波を遮断するためのノイズ抑制部材が開示され、特許文献2では複合磁性材料を用いた電磁雑音吸収体が開示されている。 Further, Patent Document 1 discloses a noise suppressing member for blocking electromagnetic waves radiated from a single wire circuit, and Patent Document 2 discloses an electromagnetic noise absorber using a composite magnetic material.

特開2013/197328号公報Japanese Unexamined Patent Publication No. 2013/197328 特開2004/95937号公報Japanese Unexamined Patent Publication No. 2004/95937

三屋 康宏、ノイズ対策の基礎(第13回)、村田製作所技術記事、https://article.murata.com/ja-jp/article/basics-of-noise-countermeasures-lesson-13、2014Yasuhiro Miya, Basics of Noise Countermeasures (13th), Murata Manufacturing Technical Articles, https://article.murata.com/ja-jp/article/basics-of-noise-countermeasures-lesson-13, 2014

本開示は、回路基板の実装の妨げとならず、差動線路を伝送するコモンモードノイズを抑制しつつ、GHz帯域以上の周波数帯域においても通信品質を良好に維持できるコモンモードノイズ抑制部材を提供することを主目的とする。 The present disclosure provides a common mode noise suppression member that does not interfere with the mounting of a circuit board, suppresses common mode noise transmitted through a differential line, and can maintain good communication quality even in a frequency band higher than the GHz band. The main purpose is to do.

本発明の一つの態様は、差動線路を伝送するコモンモードノイズを抑制するためのコモンモードノイズ抑制部材であって、差動線路に近接配置された平面型の磁性体を備え、平面型の磁性体は強磁性共鳴周波数を有し、コモンモード電流により生じる磁界エネルギーが磁性体の強磁性共鳴損失により熱に変換されることを特徴とするコモンモードノイズ抑制部材である。
さらに、差動線路の通信周波数帯域で、差動線路のディファレンシャルモードの透過係数が差動線路のコモンモードの透過係数より大きいことを特徴とする。
One aspect of the present invention is a common mode noise suppressing member for suppressing common mode noise transmitted through a differential line, which comprises a planar magnetic material arranged close to the differential line and is of a planar type. The magnetic material has a ferromagnetic resonance frequency, and is a common mode noise suppressing member characterized in that the magnetic field energy generated by the common mode current is converted into heat by the ferromagnetic resonance loss of the magnetic material.
Further, in the communication frequency band of the differential line, the transmission coefficient of the differential mode of the differential line is larger than the transmission coefficient of the common mode of the differential line.

また、平面型の磁性体は、コモンモードノイズ抑制周波数で強磁性共鳴現象を発現する磁性膜、磁性微粒子成形体、又は、磁性シートが好ましい。その材料として、Ni-Fe、Fe-Si、Fe-Si-Al、Fe-Cu-Si、 Fe-B-P、Fe-Si-B-C、Co-Fe-B、Co-Zr-Nb、Co-Cr-Nb、Co-Zr-O、Co-Zl-Oから選択される1または複数の材料で構成されていることが好ましい。さらに、平面型の磁性体は、厚みが、10nm~500μmであってもよい。さらに、平面型の磁性体と差動線路との間隔が、10nm~200μmであってもよい。 Further, as the planar magnetic material, a magnetic film, a magnetic fine particle molded body, or a magnetic sheet that exhibits a ferromagnetic resonance phenomenon at a common mode noise suppression frequency is preferable. As the material, Ni-Fe, Fe-Si, Fe-Si-Al, Fe-Cu-Si, Fe-BP, Fe-Si-BC, Co-Fe-B, Co-Zr-Nb, It is preferably composed of one or more materials selected from Co—Cr—Nb, Co—Zr—O and Co—Zl—O. Further, the planar magnetic material may have a thickness of 10 nm to 500 μm. Further, the distance between the planar magnetic material and the differential line may be 10 nm to 200 μm.

本発明の他の態様は、差動線路を伝送するコモンモードノイズを抑制するための方法であって、上記に記載のコモンモードノイズ抑制部材を選択し、差動線路に近接配置する、コモンモードノイズを抑制するための方法である。 Another aspect of the present invention is a method for suppressing common mode noise transmitted on a differential line, wherein the common mode noise suppressing member described above is selected and placed in close proximity to the differential line. This is a method for suppressing noise.

本発明によれば、回路基板の実装の妨げとならず、差動線路を伝送するコモンモードノイズを抑制しつつ、GHz帯域以上の周波数帯域においても通信品質を良好に維持できるコモンモードノイズ抑制部材を提供することができる。 According to the present invention, a common mode noise suppression member that does not interfere with the mounting of a circuit board, suppresses common mode noise transmitted through a differential line, and can maintain good communication quality even in a frequency band higher than the GHz band. Can be provided.

図1は、本発明のコモンモードノイズ抑制部材を差動線路に近接配置した状態を示す斜視図である。FIG. 1 is a perspective view showing a state in which the common mode noise suppression member of the present invention is arranged close to a differential line. 図2は、本発明のコモンモードノイズ抑制部材を差動線路に近接配置した状態を示す断面図である。FIG. 2 is a cross-sectional view showing a state in which the common mode noise suppression member of the present invention is arranged close to the differential line. 図3は、コモンモードノイズ抑制部材となる磁性体内部の磁束分布を模式的に示す断面図である。図3(a)は、ディファレンシャルモード、図3(b)はコモンモードである。FIG. 3 is a cross-sectional view schematically showing the magnetic flux distribution inside the magnetic body serving as the common mode noise suppressing member. FIG. 3A is a differential mode, and FIG. 3B is a common mode. 図4は、Co-Zr-Nb軟磁性膜を配置した差動線路に、ディファレンシャルモードが生じた場合、コモンモードが生じた場合の実効的な比透磁率を、Co-Zr-Nb軟磁性膜の磁性体固有の比透磁率と比較して示す図である。FIG. 4 shows the effective relative magnetic permeability when the differential mode occurs in the differential line on which the Co-Zr-Nb soft magnetic film is arranged, and the effective relative magnetic permeability when the common mode occurs. It is a figure which shows in comparison with the specific magnetic permeability peculiar to the magnetic material of. 図5は、差動線路上にCo-Zr-Nb軟磁性膜を配置した場合と配置しない場合との、ディファレンシャルモードおよびコモンモードの透過係数の周波数特性を示す図である。FIG. 5 is a diagram showing the frequency characteristics of the transmission coefficients in the differential mode and the common mode when the Co-Zr-Nb soft magnetic film is arranged on the differential line and when it is not arranged. 図6は、差動線路上にCo-Zr-Nb軟磁性膜を配置した場合と配置しない場合との、ディファレンシャルモードおよびコモンモードの反射係数の周波数特性を示す図である。FIG. 6 is a diagram showing the frequency characteristics of the reflection coefficients in the differential mode and the common mode when the Co-Zr-Nb soft magnetic film is arranged on the differential line and when it is not arranged. 図7(a)および図7(b)は、導体線路Aおよび導体線路Bの距離dsを変化させて差動線路上に膜厚tmの磁性膜を配置した場合の、コモンモード抑制周波数の電磁界解析値のコンター図と実測値を示す図である。7 (a) and 7 (b) show electromagnetic fields having a common mode suppression frequency when a magnetic film having a thickness of tm is arranged on a differential line by changing the distance ds between the conductor line A and the conductor line B. It is a figure which shows the contour figure of the field analysis value and the measured value.

以下、本発明の実施形態のコモンモードノイズ抑制部材を図面に基づいて説明する。なお、本発明の範囲は、以下に説明する実施形態に限定されるものではなく、ディファレンシャルモード信号を伝送する差動線路上およびディファレンシャルモード信号を取り扱う回路上で、何の制限もなく効果を奏するコモンモードノイズ抑制部材である。
また、本明細書における数値範囲の上限値及び下限値は、本発明が特定する数値範囲内
から僅かに外れる場合であっても、当該数値範囲内と同様の作用効果を備えている限り本
発明の均等範囲に包含するものとする。
Hereinafter, the common mode noise suppression member according to the embodiment of the present invention will be described with reference to the drawings. The scope of the present invention is not limited to the embodiments described below, and is effective without any limitation on the differential line for transmitting the differential mode signal and on the circuit for handling the differential mode signal. It is a common mode noise suppression member.
Further, even if the upper limit value and the lower limit value of the numerical range in the present specification are slightly out of the numerical range specified by the present invention, the present invention has the same effect as within the numerical range. It shall be included in the equal range of.

図1は、本発明のコモンモードノイズ抑制部材を差動線路に近接配置した状態を示す斜視図であり、図2はその断面図である。図1に示すように、基板C上に、互いに平行した導体線路Aおよび導体線路Bが差動線路として配置されている。ディファレンシャルモード信号を伝送する差動線路上に、磁性体Dを近接して配置する。図1における矢印はコモンモード信号の伝送方向を表している。磁性体Dが、本発明の実施形態のコモンモードノイズ抑制部材を成している。 FIG. 1 is a perspective view showing a state in which the common mode noise suppressing member of the present invention is arranged close to a differential line, and FIG. 2 is a cross-sectional view thereof. As shown in FIG. 1, a conductor line A and a conductor line B parallel to each other are arranged as differential lines on the substrate C. The magnetic material D is arranged in close proximity on the differential line that transmits the differential mode signal. The arrows in FIG. 1 indicate the transmission direction of the common mode signal. The magnetic body D forms the common mode noise suppressing member of the embodiment of the present invention.

図3は、コモンモードノイズ抑制部材となる磁性体D内部の、導体線路Aおよび導体線路Bからなる差動線路を伝送するディファレンシャルモード信号およびコモンモード信号から形成される磁束分布を模式的に示す断面図である。図3(a)に示すように、ディファレンシャルモードは、一方が紙面に垂直に奥から手前へ、他方が手前から奥へ、電流が流れる差動であり、図3(b)に示すように、コモンモードは、紙面に垂直に手前から奥へ、電流が流れる同相である。電流により形成される磁性体Dの磁界(磁場)は、ディファレンシャルモードとコモンモードとで異なる。よって、磁性体D内部の磁束分布も、ディファレンシャルモードとコモンモードとで異なる。磁性体Dが磁化した状態では磁性体内部に反磁界が発生するが、磁束の経路が異なると、磁性体D内部で生じる反磁界の大きさが異なる。 FIG. 3 schematically shows a magnetic flux distribution formed from a differential mode signal and a common mode signal that transmit a differential line composed of a conductor line A and a conductor line B inside a magnetic body D that is a common mode noise suppression member. It is a cross-sectional view. As shown in FIG. 3 (a), the differential mode is a differential mode in which one flows perpendicular to the paper surface from the back to the front and the other from the front to the back, and as shown in FIG. 3 (b). The common mode is a common mode in which current flows from the front to the back perpendicular to the paper surface. The magnetic field (magnetic field) of the magnetic body D formed by the electric current differs between the differential mode and the common mode. Therefore, the magnetic flux distribution inside the magnetic body D is also different between the differential mode and the common mode. When the magnetic body D is magnetized, a demagnetizing field is generated inside the magnetic body, but if the path of the magnetic flux is different, the magnitude of the demagnetic field generated inside the magnetic body D is different.

また、差動線路から磁場を付与された磁性体Dは、特定の周波数で強磁性共鳴をし、磁気損失するが、その強磁性共鳴損失の大きさおよび損失が最大となる強磁性共鳴周波数は、磁性体の材料特性に加え、磁性体の形状や磁性体と線路・回路の位置関係によって決定される反磁界の影響を受け変化することが知られている。すなわち、ディファレンシャルモードとコモンモードとで磁性体内部に発生する反磁界の大きさが異なることで、磁性体の強磁性共鳴損失の大きさおよび損失が最大となる強磁性共鳴周波数が異なる。
さらに、強磁性共鳴損失では、コモンモードノイズエネルギー自体を反射させるのではなく、コモンモードノイズエネルギーを磁性体Dに共鳴吸収されることにより熱に変換し、損失させることが可能なため、新たなノイズ問題を生じる可能性が小さい。
Further, the magnetic material D to which a magnetic field is applied from the differential line undergoes ferromagnetic resonance at a specific frequency and causes magnetic loss, but the magnitude of the ferromagnetic resonance loss and the ferromagnetic resonance frequency at which the loss is maximized are In addition to the material properties of a magnetic material, it is known that it changes under the influence of a demagnetic field determined by the shape of the magnetic material and the positional relationship between the magnetic material and the line / circuit. That is, since the magnitude of the demagnetic field generated inside the magnetic material differs between the differential mode and the common mode, the magnitude of the ferromagnetic resonance loss of the magnetic material and the ferromagnetic resonance frequency at which the loss is maximized differ.
Further, in the ferromagnetic resonance loss, the common mode noise energy itself is not reflected, but the common mode noise energy can be converted into heat by resonance absorption by the magnetic material D and lost. Less likely to cause noise problems.

図4は、Co-Zr-Nb軟磁性膜を配置した差動線路に、ディファレンシャルモードが生じた場合、コモンモードが生じた場合の実効的な比透磁率を、Co-Zr-Nb軟磁性膜の磁性体固有の比透磁率と比較して示す図である。Co-Zr-Nb軟磁性膜は、コモンモードノイズ抑制部材の一例である。図4に示したように、磁性体固有では、比透磁率(Relative Permeability)が0.1GHzにおいて700程度、強磁性共鳴周波数foは1.1GHzである。強磁性共鳴周波数において、磁性体の比透磁率実部は0となり、虚部は最大になる。ここで、虚部は磁性体によるエネルギー吸収を表す。 FIG. 4 shows the effective relative magnetic permeability when the differential mode occurs in the differential line on which the Co-Zr-Nb soft magnetic film is arranged, and the effective relative magnetic permeability when the common mode occurs. It is a figure which shows in comparison with the specific magnetic permeability peculiar to the magnetic material of. The Co-Zr-Nb soft magnetic film is an example of a common mode noise suppressing member. As shown in FIG. 4, in the case of a magnetic material, the relative permeability is about 700 at 0.1 GHz, and the ferromagnetic resonance frequency fo is 1.1 GHz. At the ferromagnetic resonance frequency, the real part of the relative permeability of the magnetic material becomes 0, and the imaginary part becomes the maximum. Here, the imaginary part represents energy absorption by the magnetic material.

実効的な強磁性共鳴周波数fは、磁性体の形状や磁性体と線路・回路の位置関係によって決定される反磁界のため、材料固有の強磁性共鳴周波数と比較して高い周波数帯域にシフトすることが知られている。また、実効的な強磁性共鳴周波数fは,式(1)により求められることが知られている。 The effective ferromagnetic resonance frequency fc shifts to a higher frequency band than the material-specific ferromagnetic resonance frequency because it is a demagnetic field determined by the shape of the magnetic material and the positional relationship between the magnetic material and the line / circuit. It is known to do. Further, it is known that the effective ferromagnetic resonance frequency fc can be obtained by the equation (1).

Figure 2022007092000002
ここで、μは真空の透磁率である。また、γはジャイロ磁気定数、Mは飽和磁化、Hは異方性磁界であり、これらは材料固有の定数である。Hd_cはコモンモード電流から生じる磁界により磁性体内部で生じる反磁界を表す。ここで、Hd_cは、材料固有の飽和磁化Mと、磁性体の寸法および回路との位置関係で決定する反磁界係数Nd_cとの積で求められる。
コモンモードが生じた場合の実効的な強磁性共鳴周波数fをコモンモードノイズ抑制周波数ともいう。図4におけるコモンモードノイズ抑制周波数は、2.3GHz程度である。
Figure 2022007092000002
Here, μ 0 is the magnetic permeability of the vacuum. Further, γ is a gyro magnetic constant, M s is a saturation magnetization, and H k is an anisotropic magnetic field, which are constants peculiar to the material. H d_c represents the demagnetizing field generated inside the magnetic material by the magnetic field generated from the common mode current. Here, H d_c is obtained by the product of the saturation magnetization Ms peculiar to the material and the demagnetizing field coefficient N d_c determined by the positional relationship between the dimensions of the magnetic material and the circuit.
The effective ferromagnetic resonance frequency fc when the common mode occurs is also referred to as the common mode noise suppression frequency. The common mode noise suppression frequency in FIG. 4 is about 2.3 GHz.

差動線路におけるノイズフィルタの評価には、公知のミックスドSパラメータを用いる。図1の導体線路Aおよび導体線路Bにおいて、ミックスドモードSパラメータにより、コモンモードおよびディファレンシャルモードの応答は、|Scc21|はコモンモードのポート1からポート2への透過係数、|Sdd21|はディファレンシャルモードのポート1からポート2への透過係数、|Scc11|はコモンモードのポート1からポート1への反射係数、|Sdd11|はディファレンシャルモードのポート1からポート1への反射係数、で表される。 Known mixed S-parameters are used to evaluate the noise filter in the differential line. In the conductor line A and the conductor line B in FIG. 1, the response in the common mode and the differential mode is as follows: | Scc21 | is the transmission coefficient from port 1 to port 2 in the common mode, and | Sdd21 | is the differential. The transmission coefficient from port 1 to port 2 in the mode, | Scc11 | is the reflection coefficient from port 1 to port 1 in the common mode, and | Sdd11 | is the reflection coefficient from port 1 to port 1 in the differential mode. ..

通信周波数帯域、および/又は、コモンモードノイズを抑制したい周波数帯域で、ディファレンシャルモードの透過係数|Sdd21|がコモンモードの透過係数|Scc21|より大きければ、コモンモードノイズ抑制部材として採用することが可能である。効果的にコモンモードノイズを抑制する観点から、コモンモードの挿入損失が大きいことが好ましい。また、ディファレンシャルモードの波形歪等を抑える観点から、ディファレンシャルモードの挿入損失が小さいことが好ましい。
|Sdd21|に対する|Scc21|の比は、個々の設計で要求されるノイズ抑制量や周波数の目標値を考慮して、1未満の値を特に制限なく選択することが可能であるが、ノイズ抑制効果の観点から、0.7程度以下が好ましい。|Sdd21|に対する|Scc21|の比が、0.7程度以下であれば、ノイズ抑制効果は3dB以上となる。
|Sdd21|に対する|Scc21|の比は、小さいほど好ましいが、例えば、0.001程度あれば、十分大きなノイズ抑制効果を達成できているといえる。
上記の周波数帯域で、コモンモードの抑制効果がディファレンシャルモードと比較して大きくなることで、コモンモードノイズ抑制に対する有用性がある。
本発明のコモンモードノイズ抑制部材により、帯域除去フィルタとして、コモンモードノイズ抑制周波数帯域で、ディファレンシャルモード信号の減衰を抑えつつ、選択的にコモンモードノイズを抑制することが可能である。
If the transmission coefficient | Sdd21 | in the differential mode is larger than the transmission coefficient | Scc21 | in the common mode in the communication frequency band and / or the frequency band in which the common mode noise is desired to be suppressed, it can be adopted as a common mode noise suppression member. Is. From the viewpoint of effectively suppressing common mode noise, it is preferable that the common mode insertion loss is large. Further, from the viewpoint of suppressing waveform distortion in the differential mode, it is preferable that the insertion loss in the differential mode is small.
The ratio of | Scc21 | to | Sdd21 | can be selected from a value less than 1 without particular limitation in consideration of the noise suppression amount required in each design and the target value of the frequency, but noise suppression is possible. From the viewpoint of effect, it is preferably about 0.7 or less. When the ratio of | Scc21 | to | Sdd21 | is about 0.7 or less, the noise suppression effect is 3 dB or more.
The smaller the ratio of | Scc21 | to | Sdd21 | is, the more preferable it is, but for example, if it is about 0.001, it can be said that a sufficiently large noise suppression effect can be achieved.
In the above frequency band, the effect of suppressing the common mode is larger than that of the differential mode, which is useful for suppressing the noise in the common mode.
The common mode noise suppression member of the present invention can selectively suppress common mode noise in the common mode noise suppression frequency band as a band elimination filter while suppressing attenuation of the differential mode signal.

本発明のコモンモードノイズ抑制部材の材料は、強磁性共鳴損失を発現する既存の磁性材料を、特に限定されず用いることが可能である。GHz帯域以上の周波数帯域で、強磁性共鳴損失を発現する磁性材料であればよく、1GHz程度~15GHz程度の周波数帯域において、コモンモードノイズを抑制することが可能である。 As the material of the common mode noise suppressing member of the present invention, an existing magnetic material that exhibits a ferromagnetic resonance loss can be used without particular limitation. Any magnetic material that exhibits ferromagnetic resonance loss in a frequency band higher than the GHz band may be used, and common mode noise can be suppressed in a frequency band of about 1 GHz to about 15 GHz.

コモンモードノイズ抑制部材の材料は、コモンモードノイズ抑制周波数で強磁性共鳴現象を発現する軟磁性材料が好ましい。材料は特に限定されないが、例えば、Ni-Fe、Fe-Si、Fe-Si-Al、Fe-Cu-Si、 Fe-B-P、Fe-Si-B-C、Co-Fe-B、Co-Zr-Nb、Co-Cr-Nb、Co-Zr-O、Co-Zl-O等の磁性膜、フェライトや磁性微粒子、磁性微粒子を含む磁性微粒子成形体、磁性シート等が挙げられる。また、これらを複数種類組み合わせても良い。 The material of the common mode noise suppression member is preferably a soft magnetic material that exhibits a ferromagnetic resonance phenomenon at a common mode noise suppression frequency. The material is not particularly limited, but for example, Ni-Fe, Fe-Si, Fe-Si-Al, Fe-Cu-Si, Fe-BP, Fe-Si-BC, Co-Fe-B, Co. Examples thereof include magnetic films such as -Zr-Nb, Co-Cr-Nb, Co-Zr-O, and Co-Zl-O, magnetic fine particles such as ferrite and magnetic fine particles, magnetic fine particle molded bodies containing magnetic fine particles, and magnetic sheets. Further, a plurality of types of these may be combined.

コモンモードノイズ抑制部材の形状は、回路における狭小な空間への実装を考慮すると平面型が好ましい。平面型であれば、ノイズ対策素子を実装するための電極や面積・空間を確保する必要がなく、回路基板の実装の妨げとならない。平面型の磁性体Dの厚さtm、線路および回路と磁性体の距離d、および、平面型の磁性体Dの大きさは、コモンモードノイズ抑制量の目標値や周波数、適用する線路や回路の形状、コモンモードノイズ抑制部材の透磁率などに依存するため、これらの値に応じて適切に選択することが好ましい。
例えば、平面型の磁性体Dの厚さtmは、10nm程度~500μm程度が好ましい。また、線路および回路と磁性体の距離dは、10nm程度~200μm程度が好ましい。また、平面型の磁性体Dの大きさは、差動線路の延伸方向に沿う長さ100μm程度~100mm程度、差動線路の幅方向に沿う長さ100μm程度~100mm程度が好ましい。平面型の磁性体Dの長さはコモンモードノイズ抑制量の目標値に応じて選択でき、幅は少なくとも差動線路を覆う大きさであれば良い。
The shape of the common mode noise suppression member is preferably a planar type in consideration of mounting in a narrow space in a circuit. If it is a flat type, it is not necessary to secure an electrode and an area / space for mounting a noise suppression element, and it does not hinder the mounting of a circuit board. The thickness tm of the flat magnetic body D, the distance d between the line and the circuit and the magnetic body, and the size of the flat magnetic body D are the target value and frequency of the common mode noise suppression amount, and the line or circuit to be applied. Since it depends on the shape of the noise, the magnetic permeability of the common mode noise suppressing member, and the like, it is preferable to appropriately select the noise according to these values.
For example, the thickness tm of the planar magnetic material D is preferably about 10 nm to 500 μm. Further, the distance d between the line and the circuit and the magnetic material is preferably about 10 nm to 200 μm. Further, the size of the planar magnetic material D is preferably about 100 μm to 100 mm in length along the extending direction of the differential line, and about 100 μm to 100 mm in length along the width direction of the differential line. The length of the planar magnetic body D can be selected according to the target value of the common mode noise suppression amount, and the width may be at least as long as it covers the differential line.

本実施形態にかかるコモンモードノイズ抑制部材の製造方法は、何の制限もなく周知の製造方法を用いることができる。
例えば、蒸着、めっき(化学、電気)、スパッタリング等の薄膜プロセスにより磁性膜を製造する方法が挙げられる。スパッタリングでは、スパッタリングさせる基板の種類は周知の基板材料から特に限定されずに用いることができる。例えば、シリコン基板、ガラス基板など各種セラミック基板等を用いることが可能である。スパッタリングは、例えば、RF照射で行われる。準備した基板にスパッタリングを行うことで、所望の組成を有する軟磁性膜等を成膜する。スパッタリング時の成膜速度および成膜時間を制御することにより、所望の厚さの軟磁性膜が得られる。
また、磁性微粒子成形体とは、磁性微粒子を含む平面型の成形体であればよく、磁性微粒子複合材料を含め、周知の材料を何の制限もなく用いることができる。磁性微粒子の大きさは10nm程度~100μm程度である。磁性微粒子は、例えば、機械的な粉砕、アトマイズ法等により得られる。磁性微粒子成形体の製造方法としては、例えば、磁性微粒子を絶縁性被覆した後バインダー中に分散させ圧縮成形し焼結する方法、薄膜プロセスによる磁性微粒子を含む膜生成方法、磁性微粒子と樹脂によるシート作成方法等が挙げられる。
また、例えば、磁性シートの製造方法としては、軟磁性金属等の磁性体粉末(扁平状粉末)と樹脂を混ぜた原料をカレンダーロール等でプレスしてシート状にする乾式法、軟磁性金属の粉末と樹脂、溶剤の混合液を基材に塗布する湿式法等が挙げられる。なお、磁性シートの薄型化には、塗布工法による湿式法が好ましい。
As the method for manufacturing the common mode noise suppressing member according to the present embodiment, a well-known manufacturing method can be used without any limitation.
For example, a method of manufacturing a magnetic film by a thin film process such as thin film deposition, plating (chemical, electric), and sputtering can be mentioned. In sputtering, the type of substrate to be sputtering can be used without particular limitation from known substrate materials. For example, various ceramic substrates such as a silicon substrate and a glass substrate can be used. Sputtering is performed, for example, by RF irradiation. By performing sputtering on the prepared substrate, a soft magnetic film or the like having a desired composition is formed. By controlling the film forming speed and the film forming time during sputtering, a soft magnetic film having a desired thickness can be obtained.
Further, the magnetic fine particle molded body may be a flat molded body containing magnetic fine particles, and a well-known material including a magnetic fine particle composite material can be used without any limitation. The size of the magnetic fine particles is about 10 nm to 100 μm. The magnetic fine particles are obtained by, for example, mechanical pulverization, an atomizing method, or the like. Examples of the method for producing a magnetic fine particle molded body include a method in which magnetic fine particles are insulatingly coated and then dispersed in a binder and compression-molded and sintered, a method for forming a film containing magnetic fine particles by a thin film process, and a sheet made of magnetic fine particles and a resin. The creation method and the like can be mentioned.
Further, for example, as a method for manufacturing a magnetic sheet, a dry method in which a raw material obtained by mixing a magnetic material powder (flat powder) such as a soft magnetic metal and a resin is pressed with a calendar roll or the like to form a sheet, or a soft magnetic metal Examples thereof include a wet method in which a mixed solution of powder, resin, and solvent is applied to a base material. A wet method using a coating method is preferable for reducing the thickness of the magnetic sheet.

また、図1において、平面型の磁性体Dは、差動線路の上に近接配置されていたが、本発明の効果を奏する範囲であれば、その配置場所に制限はなく、平面型の磁性体Dは差動線路に近接配置されていればよい。例えば、リジッド基板では、基板の上、及び/又は、下に配置してもよく、フレキシブル基板では、基板を巻くように配置してもよい。なお、基板を巻くように磁性体を配置する場合であっても、差動線路を被覆する部分が、概ね平面であればよい。 Further, in FIG. 1, the planar magnetic material D is arranged close to the differential line, but there is no limitation on the arrangement place as long as the effect of the present invention can be obtained, and the planar magnetic body D is arranged. The body D may be arranged close to the differential line. For example, in a rigid substrate, it may be arranged above and / or below the substrate, and in a flexible substrate, it may be arranged so as to wind the substrate. Even when the magnetic material is arranged so as to wind the substrate, the portion covering the differential line may be substantially flat.

コモンモードノイズの抑制部材として、磁性体の材料特性、形状や磁性体と線路・回路の位置を適切に設計することで、所望の周波数帯域で十分なコモンモードノイズ抑制効果を得ることが可能となる。 By appropriately designing the material characteristics and shape of the magnetic material and the positions of the magnetic material and the line / circuit as a common mode noise suppression member, it is possible to obtain a sufficient common mode noise suppression effect in a desired frequency band. Become.

図1および図2に示すように、比誘電率9.8の低温同時焼成セラミックス製(LTCC)基板C上に、2本の差動線路であるマイクロストリップライン(MSL)からなる導体線路Aおよび導体線路Bを配置した。マイクロストリップライン1本の特性インピーダンスは50Ωである。導体線路Aおよび導体線路Bは、信号線幅ws=100μm、厚さts=3μm、長さ10mmとし、導体線路Aおよび導体線路Bの距離ds=50μmとして並行に配置した。2本の差動線路から距離d=50μm程度で近接するよう磁性体Dを配置した。磁性体Dは、差動線路の延伸方向に沿う長さ4mm*差動線路の幅方向に沿う長さ10mmの平面型の一軸磁気異方性の磁性体膜で、厚さ100nmのSiO基板Eの上にRFスパッタリング法により、(250nmのCo85ZrNb12膜層)/(10nmのSiO層)を4層成膜し、作製した。すなわち、磁性体Dの厚さtmに該当するCo-Zr-Nb磁性膜の総厚は、1.04μmである。
ネットワークアナライザ(N5244A、Keysight Tech.)を用いて、磁性体DのミックスドSパラメータを計測した。ネットワークアナライザより、-5dBmの電力を2本の差動線路のポート1から入力し、ポート1で反射信号を検出し、2本の差動線路のポート2で透過信号を検出した。1本の線路の特性インピーダンスは50Ωである。
As shown in FIGS. 1 and 2, a conductor line A composed of two differential lines, a microstrip line (MSL), and a conductor line A composed of two differential lines on a low-temperature co-fired ceramics (LTCC) substrate C having a relative permittivity of 9.8. The conductor line B was arranged. The characteristic impedance of one microstrip line is 50Ω. The conductor line A and the conductor line B were arranged in parallel with a signal line width ws = 100 μm, a thickness ts = 3 μm, and a length 10 mm, and a distance ds = 50 μm between the conductor line A and the conductor line B. The magnetic material D was arranged so as to be close to the two differential lines at a distance d = about 50 μm. The magnetic material D is a planar uniaxial magnetic anisotropy magnetic material film having a length of 4 mm along the extending direction of the differential line and a length of 10 mm along the width direction of the differential line, and is a SiO 2 substrate having a thickness of 100 nm. Four layers of (250 nm Co 85 Zr 3 Nb 12 film layer) / (10 nm SiO 2 layer) were formed on E by an RF sputtering method. That is, the total thickness of the Co—Zr—Nb magnetic film corresponding to the thickness tm of the magnetic material D is 1.04 μm.
The mixed S-parameters of the magnetic material D were measured using a network analyzer (N5244A, Keysight Tech.). From the network analyzer, a power of -5 dBm was input from the port 1 of the two differential lines, the reflected signal was detected at the port 1, and the transmitted signal was detected at the port 2 of the two differential lines. The characteristic impedance of one line is 50Ω.

図5は、差動線路上にCo-Zr-Nb膜を配置した場合と配置しない場合の、ディファレンシャルモードおよびコモンモードにおける透過係数の周波数特性の測定結果を示す図である。
Co-Zr-Nb膜を配置した場合のディファレンシャルモードの透過係数|Sdd21|は、約3GHzで極小値をとり、ディファレンシャルモードの抑制効果が極大となった。一方で、Co-Zr-Nb膜を配置した場合のコモンモードの透過係数|Scc21|は、約2GHzで極小値をとり、コモンモードの抑制効果が極大となった。
これより、0.8GHzから2.5GHz程度の周波数範囲で、コモンモードの抑制効果がディファレンシャルモードと比較して大きくなり、コモンモードノイズ抑制に対する有用性が実験的に示されている。
FIG. 5 is a diagram showing the measurement results of the frequency characteristics of the transmission coefficient in the differential mode and the common mode when the Co-Zr-Nb film is arranged on the differential line and when it is not arranged.
The transmission coefficient | Sdd21 | in the differential mode when the Co-Zr-Nb film was arranged had a minimum value at about 3 GHz, and the effect of suppressing the differential mode was maximized. On the other hand, the transmission coefficient | Scc21 | in the common mode when the Co-Zr-Nb film was arranged had a minimum value at about 2 GHz, and the effect of suppressing the common mode was maximized.
From this, in the frequency range of about 0.8 GHz to 2.5 GHz, the suppression effect of the common mode becomes larger than that of the differential mode, and the usefulness for the suppression of the common mode noise is experimentally shown.

図6は、差動線路上にCo-Zr-Nb膜を配置した場合と配置しない場合の、ディファレンシャルモードおよびコモンモードにおける反射係数の周波数特性の測定結果を示す図である。
コモンモードノイズ抑制周波数帯域である約2.3GHzにおいて、Co-Zr-Nb膜を配置していない場合と配置した場合とで、コモンモードノイズの反射係数|Scc11|およびディファレンシャルモードの反射係数|Sdd11|に大きな変化がないことがわかる。
すなわち、本発明のコモンモードノイズ抑制部材によって、新たなノイズ問題を生じていないことが実験的に示されている。
FIG. 6 is a diagram showing the measurement results of the frequency characteristics of the reflectance coefficient in the differential mode and the common mode when the Co-Zr-Nb film is arranged on the differential line and when it is not arranged.
Reflection coefficient of common mode noise | Scc11 | and reflectance coefficient of differential mode | Sdd11 depending on whether the Co-Zr-Nb film is arranged or not in the common mode noise suppression frequency band of about 2.3 GHz. It can be seen that there is no significant change in |.
That is, it has been experimentally shown that the common mode noise suppressing member of the present invention does not cause a new noise problem.

図7(a)および図7(b)は、導体線路Aおよび導体線路Bの距離dsの差動線路上に膜厚tmの磁性膜を配置した場合の、コモンモード抑制周波数の電磁界解析値のコンター図と実測値を示す図である。 磁性膜として、図7(a)では、Co-Zr-Nb軟磁性膜を、図7(b)では、Co-Zr-O軟磁性膜を用いた。電磁界解析は、3次元電磁界(EM)シミュレーションソフトウェアであるAnsys社のHFSSを使用し、実験で用いた線路の寸法および導電率、誘電率ならびに軟磁性膜の寸法および透磁率を用いてコモンモードノイズ抑制効果が最大となる周波数を算出した。
図7(a)および図7(b)より、線路の寸法や磁性材料の寸法および材料を選択することで、コモンモードノイズ抑制周波数を制御することが可能であることが示されている。つまり、本発明のコモンモードノイズの抑制部材は、磁性体の材料特性、形状や磁性体と線路・回路の位置を適切に設計し、所望の周波数でコモンモードノイズ抑制効果を得ることが可能であるといえる。
7 (a) and 7 (b) show electromagnetic field analysis values of the common mode suppression frequency when a magnetic film having a thickness of tm is placed on a differential line having a distance ds between the conductor line A and the conductor line B. It is a figure which shows the contour diagram and the measured value of. As the magnetic film, a Co—Zr—Nb soft magnetic film was used in FIG. 7 (a), and a Co—Zr—O soft magnetic film was used in FIG. 7 (b). Electromagnetic field analysis uses HFSS from Ansys, a three-dimensional electromagnetic field (EM) simulation software, and is common using the line dimensions and conductivity, permittivity, and soft magnetic film dimensions and permeability used in the experiment. The frequency at which the mode noise suppression effect is maximized was calculated.
From FIGS. 7 (a) and 7 (b), it is shown that the common mode noise suppression frequency can be controlled by selecting the size of the line and the size and material of the magnetic material. That is, the common mode noise suppression member of the present invention can appropriately design the material characteristics and shape of the magnetic material and the positions of the magnetic material and the line / circuit, and can obtain the common mode noise suppression effect at a desired frequency. It can be said that there is.

導体線路 A B
基板 C
磁性体 D
ガラス板 E
グラウンド F
ポート 1 2
Conductor line AB
Board C
Magnetic material D
Glass plate E
Ground F
Port 1 2

Claims (7)

差動線路を伝送するコモンモードノイズを抑制するためのコモンモードノイズ抑制部材であって、前記差動線路に近接配置された平面型の磁性体を備え、前記平面型の磁性体は強磁性共鳴周波数を有し、コモンモード電流により生じる磁界エネルギーが前記平面型の磁性体の強磁性共鳴損失により熱に変換されることを特徴とするコモンモードノイズ抑制部材。 It is a common mode noise suppressing member for suppressing the common mode noise transmitted through the differential line, and includes a planar magnetic material arranged close to the differential line, and the planar magnetic material has ferromagnetic resonance. A common mode noise suppressing member having a frequency and characterized in that magnetic field energy generated by a common mode current is converted into heat by the ferromagnetic resonance loss of the planar magnetic material. 前記差動線路の通信周波数帯域で、前記差動線路のディファレンシャルモードの透過係数が前記差動線路のコモンモードの透過係数より大きい請求項1に記載のコモンモードノイズ抑制部材。 The common mode noise suppressing member according to claim 1, wherein in the communication frequency band of the differential line, the transmission coefficient of the differential mode of the differential line is larger than the transmission coefficient of the common mode of the differential line. 前記平面型の磁性体は、コモンモードノイズ抑制周波数で強磁性共鳴現象を発現する磁性膜、磁性微粒子成形体、又は、磁性シートである請求項1または2に記載のコモンモードノイズ抑制部材。 The common mode noise suppressing member according to claim 1 or 2, wherein the planar magnetic material is a magnetic film, a magnetic fine particle molded body, or a magnetic sheet that exhibits a ferromagnetic resonance phenomenon at a common mode noise suppressing frequency. 前記平面型の磁性体は、Ni-Fe、Fe-Si、Fe-Si-Al、Fe-Cu-Si、Fe-B-P、Fe-Si-B-C、Co-Fe-B、Co-Zr-Nb、Co-Cr-Nb、Co-Zr-O、Co-Zl-Oから選択される1または複数の材料で構成されている請求項3に記載のコモンモードノイズ抑制部材。 The planar magnetic material is Ni-Fe, Fe-Si, Fe-Si-Al, Fe-Cu-Si, Fe-BP, Fe-Si-BC, Co-Fe-B, Co-. The common mode noise suppressing member according to claim 3, which is composed of one or a plurality of materials selected from Zr-Nb, Co-Cr-Nb, Co-Zr-O, and Co-Zl-O. 前記平面型の磁性体は、厚みが、10nm~500μmである請求項1乃至4のいずれか1項に記載のコモンモードノイズ抑制部材。 The common mode noise suppressing member according to any one of claims 1 to 4, wherein the planar magnetic material has a thickness of 10 nm to 500 μm. 前記平面型の磁性体と前記差動線路との間隔が、10nm~200μmである請求項1乃至5のいずれか1項に記載のコモンモードノイズ抑制部材。 The common mode noise suppressing member according to any one of claims 1 to 5, wherein the distance between the planar magnetic material and the differential line is 10 nm to 200 μm. 差動線路を伝送するコモンモードノイズを抑制するための方法であって、請求項1乃至6のいずれか1項に記載のコモンモードノイズ抑制部材を選択し、前記差動線路に近接配置する、コモンモードノイズを抑制するための方法。 A method for suppressing common mode noise transmitted on a differential line, wherein the common mode noise suppressing member according to any one of claims 1 to 6 is selected and arranged in close proximity to the differential line. Common mode A method for suppressing noise.
JP2020109813A 2020-06-25 2020-06-25 Common mode noise suppression member Pending JP2022007092A (en)

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