WO2016170708A1 - Circuit board and filter circuit using same - Google Patents

Circuit board and filter circuit using same Download PDF

Info

Publication number
WO2016170708A1
WO2016170708A1 PCT/JP2015/084312 JP2015084312W WO2016170708A1 WO 2016170708 A1 WO2016170708 A1 WO 2016170708A1 JP 2015084312 W JP2015084312 W JP 2015084312W WO 2016170708 A1 WO2016170708 A1 WO 2016170708A1
Authority
WO
WIPO (PCT)
Prior art keywords
inductor
filter circuit
circuit
circuit board
inductance element
Prior art date
Application number
PCT/JP2015/084312
Other languages
French (fr)
Japanese (ja)
Inventor
淳 東條
Original Assignee
株式会社村田製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社村田製作所 filed Critical 株式会社村田製作所
Publication of WO2016170708A1 publication Critical patent/WO2016170708A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/01—Frequency selective two-port networks
    • H03H7/075—Ladder networks, e.g. electric wave filters
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/01—Frequency selective two-port networks
    • H03H7/09—Filters comprising mutual inductance

Definitions

  • the present invention by adopting a circuit configuration in which two capacitor elements can be mounted, the influence of the parasitic resistance of the capacitance element on the noise suppression effect is suppressed, and the parasitic capacitance of the capacitance element is reduced using the negative inductance component of the inductance element.
  • a circuit board capable of suppressing the influence of inductance on the noise suppression effect.
  • a noise suppression effect can be improved by mounting a capacitor element on the circuit board to form a filter circuit.
  • 1 is a circuit diagram of a filter circuit according to a first embodiment of the present invention. It is a circuit diagram which shows the equivalent circuit of a 3rd-order T-type LC filter circuit, and a graph which shows the transmission characteristic with respect to the frequency of this circuit diagram. 4 is a circuit diagram showing an equivalent circuit of a third-order T-type LC filter circuit when the parasitic resistance of the capacitor is large, and a graph showing transmission characteristics with respect to frequency in this circuit diagram. It is a circuit diagram which shows the equivalent circuit of a 5th-order T type
  • 4 is a circuit diagram showing an equivalent circuit of a fifth-order T-type LC filter circuit having a coupling coefficient K16 of 10%, and a graph showing transmission characteristics with respect to frequency in this circuit diagram. It is a graph which shows the transmission characteristic with respect to the frequency of a filter circuit whose coupling coefficient K16 is 1% and 0.1%.
  • FIG. 1 is a circuit diagram of a filter circuit 1 according to Embodiment 1 of the present invention.
  • Filter circuit 1 is, for example, an EMI removal filter, and is a fifth-order T-type LC filter circuit. As shown in FIG. 1, the filter circuit 1 includes a capacitor C1 (first capacitance element), a capacitor C2 (second capacitance element), an electrode T1 (first electrode), an inductor L1 (first inductance element), and an inductor L2 ( A first inductance part), an inductor L3 (second part of the second inductance element), an electrode T2 (second electrode), and an inductor L6 (third inductance element).
  • the capacitor C1 has one terminal connected to the electrode T1 and the other terminal connected to the ground electrode GND3.
  • the capacitor C1 has an inductor L4 as a parasitic inductance (equivalent series inductance (ESL)) and a resistor R1 as a parasitic resistance (equivalent series resistance (ESR)).
  • the inductor L4 and the resistor R1 are in series with the capacitor C1a. It is equivalent to the connected circuit configuration.
  • an inductor L1 and an inductor L2 are connected to the electrode T1.
  • the inductor L1 and the inductor L2 are tightly coupled, and a pseudo negative inductance component is generated.
  • This negative inductance component can cancel the parasitic inductance of the capacitor C1 (inductor L4), and the inductance component of the capacitor C1 can be apparently reduced.
  • the filter circuit has a parasitic inductance (inductor L4) due to a negative inductance component between the inductor L1 and the inductor L2.
  • the capacitor C2 has one terminal connected to the electrode T2 and the other terminal connected to the ground electrode GND4.
  • the capacitor C2 has an inductor L5 as a parasitic inductance and a resistor R2 as a parasitic resistance, and is equivalent to a circuit configuration in which the inductor L5 and the resistor R2 are connected in series to the capacitor C2a.
  • an inductor L3 and an inductor L6 are connected to the electrode T2.
  • the inductor L3 and the inductor L6 are tightly coupled, and a pseudo negative inductance component is generated. This negative inductance component can cancel the parasitic inductance of the capacitor C2 (inductor L5), and the inductance component of the capacitor C2 can be apparently reduced.
  • the filter circuit When a circuit composed of the capacitor C2, the inductor L3, and the inductor L6 is considered as a third-order T-type LC filter circuit, the filter circuit has a parasitic inductance (inductor L5) due to a negative inductance component between the inductor L3 and the inductor L6. By canceling out, the noise suppression effect in the high frequency band is improved.
  • FIG. 2 is a circuit diagram showing an equivalent circuit of a third-order T-type LC filter circuit, and a graph showing transmission characteristics with respect to frequency in this circuit diagram.
  • a filter circuit 1a illustrated in FIG. 2A is a third-order T-type LC filter circuit including a capacitor C1, an inductor L1, and an inductor L2.
  • the capacitor C1 sets the capacitor C1a as 0.1 ⁇ F, the inductor L4 as 1 nH, and the resistor R1 as 0.01 ⁇ .
  • the inductors L1 and L2 are set to 2 nH, respectively.
  • the coupling coefficient K12 between the inductor L1 and the inductor L2 is set to 0.5 (50%).
  • the filter circuit 1a cancels the 1 nH parasitic inductance of the inductor L4 with a negative inductance component ( ⁇ 1 nH) generated by coupling the 2 nH inductors L1 and L2 at 50%.
  • FIG. 2B is a graph showing the result of performing circuit simulation on the filter circuit 1a shown in FIG. 2A and showing the transmission characteristics with respect to the frequency.
  • the horizontal axis is the frequency Freq (MHz)
  • the vertical axis is the transmission characteristic S (dB).
  • the filter circuit 1a has a reduced transmission characteristic S at a frequency Freq of 1.0 MHz or higher, and can improve the noise suppression effect in the high frequency band.
  • FIG. 3B is a graph showing a result of performing circuit simulation on the filter circuit 1a shown in FIG. 3A and showing transmission characteristics with respect to frequency.
  • the filter circuit 1a has the transmission characteristic S reduced at a frequency Freq of 1.0 MHz or higher, but the noise suppression effect in the high-frequency band as compared with the graph shown in FIG. 2 (b). Can not be improved sufficiently.
  • the filter circuit 1a where the parasitic resistance (resistor R1) of the capacitor C1 is large the influence of the impedance of the parasitic resistance increases at frequencies after the self-resonance frequency, and the contribution ratio of the dielectric loss of the capacitor C1 increases according to the frequency. For this reason, the filter circuit 1a having a large parasitic resistance (resistor R1) of the capacitor C1 cannot sufficiently improve the noise suppression effect in the high frequency band only by canceling the parasitic inductance with a negative inductance component.
  • the filter circuit 1a has a small parasitic resistance and a negative parasitic inductance. By canceling out with the inductance component, it is possible to improve the noise suppression effect in the high frequency band.
  • the parasitic resistance of the capacitor C1 increases in the filter circuit 1a. Therefore, simply canceling the parasitic inductance with a negative inductance component causes noise in the high frequency band. The suppression effect cannot be improved sufficiently.
  • the circuit simulation is performed with the coupling coefficient K16 between the inductor L1 and the inductor L6 set to 0.0 (0%).
  • the coupling coefficient K16 between the inductor L1 and the inductor L6 cannot be sufficiently separated so as to be 0%, the coupling coefficient K16 has some value.
  • the inductor L1 and the inductor L2 shown in FIG. 1 are marked with a circle indicating the beginning of winding on the left side of the coil, while the inductor L3 and the inductor L6 are marked with a circle indicating the beginning of winding on the right side of the coil. . This indicates that the winding directions of the inductors L1 and L2 are different from the winding directions of the inductors L3 and L6.
  • FIG. 8 is a perspective view of the filter circuit 1 according to Embodiment 1 of the present invention.
  • FIG. 9 is a plan view and a cross-sectional view of the filter circuit 1 according to Embodiment 1 of the present invention.
  • the filter circuit 1 includes a circuit board 2, a capacitor C ⁇ b> 1 and a capacitor C ⁇ b> 2 mounted on the circuit board 2.
  • a capacitor C1 and a capacitor C2 are mounted in parallel to the circuit board 2, as shown in FIG.
  • Electrode T1 and electrode T2 are formed on the surface of circuit board 2 on which capacitors C1 and C2 are mounted.
  • the coil-shaped wiring patterns of the inductor L2 and the inductor L3 are formed continuously as shown in FIG. 9A and can be considered as one inductance element. That is, the left half of the drawing of one inductance element (the first portion of the second inductance element) functions as the inductor L2, and the right half of the drawing of one inductance element (the second portion of the second inductance element) is the inductor L3. Is functioning as Thereby, the manufacturing cost of the inductor L2 and the inductor L3 can be reduced. Of course, the inductor L2 and the inductor L3 may be manufactured separately.
  • the inductors L1 to L3 and L6 have substantially the same coil size, and the inductors L1 and L2 connected to the capacitor C1 and the inductors L3 and L6 connected to the capacitor C2 are substantially rotationally symmetric. Yes.
  • a compact filter circuit 1 can be manufactured by overlapping a plurality of inductors in the normal direction of the surface on which the capacitor C1 is mounted.
  • FIG. 10 is a graph showing transmission characteristics with respect to frequency of the filter circuit 1 according to Embodiment 1 of the present invention.
  • a graph (with a circuit board) showing the transmission characteristics with respect to the frequency of the filter circuit 1 in which the capacitors C1 and C2 are mounted on the circuit board 2a, and the transmission characteristics with respect to the frequency of the filter circuit consisting only of the capacitors C1 and C2.
  • a graph (without a circuit board) is shown.
  • the filter circuit 1 can sufficiently improve the noise suppression effect in the high frequency band by reducing the transmission characteristic S at the frequency Freq up to about 600.0 MHz as compared with the case without the circuit board.
  • the winding characteristics of the inductor L1 and the winding direction of the inductor L6 are made different so that the transmission characteristics S in a band similar to the circuit configuration when the coupling coefficient K16 is 1% in the circuit simulation result.
  • the noise suppression effect in the high frequency band can be improved.
  • the two capacitors C1 and C2 are mounted on the circuit board 2 to form the fifth-order T-type LC filter circuit, and the winding direction of the inductor L1 By making the winding direction of the inductor L6 different, the noise suppression effect in the high frequency band can be improved.
  • the capacitors C1 and C2 have been described as multilayer ceramic capacitors, not only multilayer ceramic capacitors mainly composed of BaTiO3 (barium titanate) but also multilayer ceramic capacitors mainly composed of other materials may be used. Furthermore, the capacitors C1 and C2 are not limited to multilayer ceramic capacitors, and may be other types of capacitors such as aluminum electrolytic capacitors. (Embodiment 2) In the first embodiment of the present invention, as shown in FIG. 9A, the inductors L1 to L3 and L6 formed on the circuit board 2 have almost the same coil size.
  • FIG. 11 is a plan view of a circuit board according to Embodiment 2 of the present invention, and a graph showing transmission characteristics with respect to frequency of a filter circuit using the circuit board.
  • the coil shape formed by the wiring pattern of the inductor L1a is smaller than the coil shape formed by the wiring pattern of the inductor L2.
  • the winding directions of the inductors L1a and L2 are the same counterclockwise.
  • the coil shape formed by the wiring pattern of the inductor L6a is smaller than the coil shape formed by the wiring pattern of the inductor L3. Note that the winding directions of the inductors L3 and L6a are the same clockwise.
  • the coupling coefficient K12a between the inductor L1a and the inductor L2 changes compared to the coupling coefficient K12 between the inductor L1 and the inductor L2 shown in FIG. Therefore, the negative inductance component generated by the coupling between the inductor L1a and the inductor L2 is also changed.
  • the inductors L1a and L2 connected to the capacitor C1 and the inductors L3 and L6a connected to the capacitor C2 have a substantially rotationally symmetric shape.
  • the inductance component is also changed.
  • FIG. 11B a graph (with a circuit board) showing transmission characteristics with respect to the frequency of the filter circuit in which the capacitors C1 and C2 are mounted on the circuit board 2a, and the frequency of the filter circuit consisting only of the capacitors C1 and C2 A graph (without circuit board) showing transmission characteristics is shown.
  • the filter circuit using the circuit board 2a can sufficiently improve the noise suppression effect in the high frequency band by reducing the transmission characteristic S at a frequency Freq of 1.0 MHz or higher compared to the case without the circuit board. That is, even if the circuit board 2a is a filter circuit, the transmission characteristic S can be reduced and the noise suppression effect in the high frequency band can be sufficiently improved as in the filter circuit 1 shown in FIG. As shown in FIG.
  • FIG. 12 is a plan view of a modification of the circuit board according to Embodiment 2 of the present invention.
  • the size of the coils of the inductors L1 and L2 is almost the same as the size of the coil shown in FIG. 9A, but compared with the size of the coils of the inductors L3 and L6.
  • the size of the coils of the inductors L3b and L6b is small.
  • the coil size of the inductor L3b and the coil size of the inductor L6b are substantially the same size.

Landscapes

  • Filters And Equalizers (AREA)

Abstract

A circuit board (2) has first and second capacitance elements (capacitors C1, C2) mounted thereon, and is provided with a first electrode (electrode T1), a first inductance element (inductor L1), second inductance elements (inductors L2, L3), a second electrode (electrode T2), and a third inductance element (inductor L6). At least the winding directions of the first inductance element (inductor L1) and the second inductance element first section (inductor L2) are same, and those of the third inductance element (inductor L6) and the second inductance element second section (inductor L3) are same.

Description

回路基板およびこれを用いたフィルタ回路Circuit board and filter circuit using the same
　本発明は、回路基板およびこれを用いたフィルタ回路に関し、特に、キャパシタンス素子を実装する回路基板およびこれを用いたフィルタ回路に関する。 The present invention relates to a circuit board and a filter circuit using the circuit board, and more particularly to a circuit board on which a capacitance element is mounted and a filter circuit using the circuit board.
　電子機器のノイズの対策として、従来フィルタ回路、例えばＥＭＩ（Electro-Magnetic Interference）除去フィルタが使用されている。フィルタ回路は、導体を流れる電流のうち、必要な成分を通し、不要な成分を除去する回路で、回路構成にコンデンサが使用される場合がある。コンデンサを使用したフィルタ回路では、当該コンデンサの寄生インダクタンスである等価直列インダクタンス（ESL：Equivalent Series Inductance）によりノイズ抑制効果が低下することが知られている。 Conventional filter circuits such as EMI (Electro-Magnetic Interference) removal filters have been used as countermeasures against noise in electronic equipment. The filter circuit is a circuit that passes a necessary component of a current flowing through a conductor and removes an unnecessary component, and a capacitor may be used for a circuit configuration. In a filter circuit using a capacitor, it is known that the noise suppression effect is reduced by an equivalent series inductance (ESL: Equivalent Series Inductance) which is a parasitic inductance of the capacitor.
　一方、アンテナ装置において、インピーダンス変換回路の擬似的な負のインダクタンス成分を用いて、アンテナ素子の実効的なインダクタンス成分を抑制する構成が知られている（例えば、特許文献１）。 On the other hand, in an antenna device, a configuration is known in which an effective inductance component of an antenna element is suppressed using a pseudo negative inductance component of an impedance conversion circuit (for example, Patent Document 1).
特開２０１２－８５２５１号公報JP 2012-85251 A
　しかし、コンデンサなどのキャパシタンス素子では、寄生インダクタンス以外に、寄生抵抗である等価直列抵抗（ESR：Equivalent Series Resistance）が存在する。そのため、コンデンサを使用したフィルタ回路では、当該コンデンサの寄生インダクタンスを抑制しただけでは、寄生抵抗の影響によりノイズ抑制効果が低下しない場合があった。 However, a capacitance element such as a capacitor has an equivalent series resistance (ESR: Equivalent Series Resistance) in addition to the parasitic inductance. For this reason, in a filter circuit using a capacitor, the noise suppression effect may not be reduced due to the influence of the parasitic resistance only by suppressing the parasitic inductance of the capacitor.
　そこで、本発明の目的は、回路基板にキャパシタンス素子を実装することでフィルタ回路を形成する場合に、キャパシタンス素子の寄生インダクタンスおよび寄生抵抗によるノイズ抑制効果への影響を抑えることができる回路基板およびこれを用いたフィルタ回路を提供する。 Accordingly, an object of the present invention is to provide a circuit board capable of suppressing the influence of the parasitic inductance and parasitic resistance of the capacitance element on the noise suppression effect when the filter circuit is formed by mounting the capacitance element on the circuit board. A filter circuit using the above is provided.
　本発明の一形態に係る回路基板は、第１キャパシタンス素子および第２キャパシタンス素子を実装する回路基板であって、第１キャパシタンス素子の一方の端子を接続するための第１電極と、回路基板に形成され、第１電極に接続される第１インダクタンス素子と、回路基板に形成され、第１インダクタンス素子との結合部が第１電極に接続される第２インダクタンス素子と、第２キャパシタンス素子の一方の端子を接続するための第２電極と、回路基板に形成され、第２インダクタンス素子との結合部が第２電極に接続される第３インダクタンス素子とを備え、第２インダクタンス素子は、第１インダクタンス素子と結合する側の第１部分と、第３インダクタンス素子と結合する側の第２部分とに分けられ、少なくとも第１インダクタンス素子と第２インダクタンス素子の第１部分とは同じ巻き方向で、第３インダクタンス素子と第２インダクタンス素子の第２部分とは同じ巻き方向である。 A circuit board according to an aspect of the present invention is a circuit board on which a first capacitance element and a second capacitance element are mounted, and a first electrode for connecting one terminal of the first capacitance element, and the circuit board A first inductance element formed and connected to the first electrode; a second inductance element formed on the circuit board and connected to the first electrode at a coupling portion with the first inductance element; and one of the second capacitance elements And a second inductance element formed on the circuit board and coupled to the second inductance element, the third inductance element being connected to the second electrode. The first part that is coupled to the inductance element and the second part that is coupled to the third inductance element are divided into at least a first inductance. The element and the same winding direction as the first portion of the second inductance element, and the second portion of the third inductance element and the second inductance element is the same winding direction.
　本発明の一形態に係るフィルタ回路は、回路基板と、第１キャパシタンス素子および第２キャパシタンス素子として、回路基板に実装するコンデンサとを備える。 A filter circuit according to an embodiment of the present invention includes a circuit board, and a capacitor mounted on the circuit board as the first capacitance element and the second capacitance element.
　本発明によれば、２つのキャパシタ素子を実装可能な回路構成とすることでキャパシタンス素子の寄生抵抗によるノイズ抑制効果への影響を抑えつつ、インダクタンス素子の負のインダクタンス成分を用いてキャパシタンス素子の寄生インダクタンスによるノイズ抑制効果への影響を抑えることができる回路基板を提供する。また、本発明によれば、当該回路基板にキャパシタ素子を実装してフィルタ回路とすることで、ノイズ抑制効果を向上させることができる。 According to the present invention, by adopting a circuit configuration in which two capacitor elements can be mounted, the influence of the parasitic resistance of the capacitance element on the noise suppression effect is suppressed, and the parasitic capacitance of the capacitance element is reduced using the negative inductance component of the inductance element. Provided is a circuit board capable of suppressing the influence of inductance on the noise suppression effect. Further, according to the present invention, a noise suppression effect can be improved by mounting a capacitor element on the circuit board to form a filter circuit.
本発明の実施の形態１に係るフィルタ回路の回路図である。1 is a circuit diagram of a filter circuit according to a first embodiment of the present invention. ３次のＴ型ＬＣフィルタ回路の等価回路を示す回路図、およびこの回路図の周波数に対する伝送特性を示すグラフである。It is a circuit diagram which shows the equivalent circuit of a 3rd-order T-type LC filter circuit, and a graph which shows the transmission characteristic with respect to the frequency of this circuit diagram. コンデンサの寄生抵抗が大きい場合の３次のＴ型ＬＣフィルタ回路の等価回路を示す回路図、およびこの回路図の周波数に対する伝送特性を示すグラフである。4 is a circuit diagram showing an equivalent circuit of a third-order T-type LC filter circuit when the parasitic resistance of the capacitor is large, and a graph showing transmission characteristics with respect to frequency in this circuit diagram. ５次のＴ型ＬＣフィルタ回路の等価回路を示す回路図、およびこの回路図の周波数に対する伝送特性を示すグラフである。It is a circuit diagram which shows the equivalent circuit of a 5th-order T type | mold LC filter circuit, and the graph which shows the transmission characteristic with respect to frequency of this circuit diagram. コンデンサの寄生抵抗が大きい場合の５次のＴ型ＬＣフィルタ回路の等価回路を示す回路図、およびこの回路図の周波数に対する伝送特性を示すグラフである。It is a circuit diagram which shows the equivalent circuit of a 5th-order T type | mold LC filter circuit in case the parasitic resistance of a capacitor | condenser is large, and the graph which shows the transmission characteristic with respect to the frequency of this circuit diagram. 結合係数Ｋ１６が１０％の５次のＴ型ＬＣフィルタ回路の等価回路を示す回路図、およびこの回路図の周波数に対する伝送特性を示すグラフである。4 is a circuit diagram showing an equivalent circuit of a fifth-order T-type LC filter circuit having a coupling coefficient K16 of 10%, and a graph showing transmission characteristics with respect to frequency in this circuit diagram. 結合係数Ｋ１６が１％および０．１％のフィルタ回路の周波数に対する伝送特性を示すグラフである。It is a graph which shows the transmission characteristic with respect to the frequency of a filter circuit whose coupling coefficient K16 is 1% and 0.1%. 本発明の実施の形態１に係るフィルタ回路の斜視図である。It is a perspective view of the filter circuit concerning Embodiment 1 of the present invention. 本発明の実施の形態１に係るフィルタ回路の平面図および断面図である。It is the top view and sectional drawing of the filter circuit which concern on Embodiment 1 of this invention. 本発明の実施の形態１に係るフィルタ回路の周波数に対する伝送特性を示すグラフである。It is a graph which shows the transmission characteristic with respect to the frequency of the filter circuit which concerns on Embodiment 1 of this invention. 本発明の実施の形態２に係る回路基板の平面図、およびこの回路基板を用いたフィルタ回路の周波数に対する伝送特性を示すグラフである。It is a graph which shows the top view of the circuit board concerning Embodiment 2 of this invention, and the transmission characteristic with respect to the frequency of the filter circuit using this circuit board. 本発明の実施の形態２に係る回路基板の変形例の平面図である。It is a top view of the modification of the circuit board concerning Embodiment 2 of this invention.
　以下に、本発明の実施の形態に係る回路基板およびこれを用いたフィルタ回路について説明する。
（実施の形態１）
　以下に、本発明の実施の形態１に係る回路基板およびこれを用いたフィルタ回路について図面を参照しながら説明する。図１は、本発明の実施の形態１に係るフィルタ回路１の回路図である。 Hereinafter, a circuit board and a filter circuit using the circuit board according to an embodiment of the present invention will be described.
(Embodiment 1)
Hereinafter, a circuit board and a filter circuit using the circuit board according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram of a filter circuit 1 according to Embodiment 1 of the present invention.
　フィルタ回路１は、例えば、ＥＭＩ除去フィルタであり、５次のＴ型ＬＣフィルタ回路である。フィルタ回路１は、図１に示すように、コンデンサＣ１（第１キャパシタンス素子）、コンデンサＣ２（第２キャパシタンス素子）、電極Ｔ１（第１電極）、インダクタＬ１（第１インダクタンス素子）、インダクタＬ２（第２インダクタンス素子の第１部分）、インダクタＬ３（第２インダクタンス素子の第２部分）、電極Ｔ２（第２電極）、およびインダクタＬ６（第３インダクタンス素子）を備えている。 Filter circuit 1 is, for example, an EMI removal filter, and is a fifth-order T-type LC filter circuit. As shown in FIG. 1, the filter circuit 1 includes a capacitor C1 (first capacitance element), a capacitor C2 (second capacitance element), an electrode T1 (first electrode), an inductor L1 (first inductance element), and an inductor L2 ( A first inductance part), an inductor L3 (second part of the second inductance element), an electrode T2 (second electrode), and an inductor L6 (third inductance element).
　コンデンサＣ１は、一方の端子を電極Ｔ１に接続し、他方の端子を接地電極ＧＮＤ３に接続している。コンデンサＣ１は、寄生インダクタンス（等価直列インダクタンス（ESL））としてインダクタＬ４、および寄生抵抗（等価直列抵抗（ESR））として抵抗Ｒ１とを有しており、インダクタＬ４および抵抗Ｒ１がキャパシタＣ１ａに直列に接続された回路構成と等価である。電極Ｔ１には、コンデンサＣ１の他にインダクタＬ１およびインダクタＬ２が接続されている。インダクタＬ１とインダクタＬ２とは密結合しており、擬似的に負のインダクタンス成分が生じている。この負のインダクタンス成分は、コンデンサＣ１の寄生インダクタンス（インダクタＬ４）を打ち消すことができ、コンデンサＣ１のインダクタンス成分を見かけ上小さくすることができる。コンデンサＣ１、インダクタＬ１およびインダクタＬ２で構成される回路を３次のＴ型ＬＣフィルタ回路と考えた場合、当該フィルタ回路は、インダクタＬ１とインダクタＬ２との負のインダクタンス成分により寄生インダクタンス（インダクタＬ４）を打ち消すことで、高周波帯のノイズ抑制効果を向上させる。 The capacitor C1 has one terminal connected to the electrode T1 and the other terminal connected to the ground electrode GND3. The capacitor C1 has an inductor L4 as a parasitic inductance (equivalent series inductance (ESL)) and a resistor R1 as a parasitic resistance (equivalent series resistance (ESR)). The inductor L4 and the resistor R1 are in series with the capacitor C1a. It is equivalent to the connected circuit configuration. In addition to the capacitor C1, an inductor L1 and an inductor L2 are connected to the electrode T1. The inductor L1 and the inductor L2 are tightly coupled, and a pseudo negative inductance component is generated. This negative inductance component can cancel the parasitic inductance of the capacitor C1 (inductor L4), and the inductance component of the capacitor C1 can be apparently reduced. When a circuit composed of the capacitor C1, the inductor L1, and the inductor L2 is considered as a third-order T-type LC filter circuit, the filter circuit has a parasitic inductance (inductor L4) due to a negative inductance component between the inductor L1 and the inductor L2. By canceling out, the noise suppression effect in the high frequency band is improved.
　コンデンサＣ２は、一方の端子を電極Ｔ２に接続し、他方の端子を接地電極ＧＮＤ４に接続している。コンデンサＣ２は、寄生インダクタンスとしてインダクタＬ５、および寄生抵抗として抵抗Ｒ２とを有しており、インダクタＬ５および抵抗Ｒ２がキャパシタＣ２ａに直列に接続された回路構成と等価である。電極Ｔ２には、コンデンサＣ２の他にインダクタＬ３およびインダクタＬ６が接続されている。インダクタＬ３とインダクタＬ６とは密結合しており、擬似的に負のインダクタンス成分が生じている。この負のインダクタンス成分は、コンデンサＣ２の寄生インダクタンス（インダクタＬ５）を打ち消すことができ、コンデンサＣ２のインダクタンス成分を見かけ上小さくすることができる。コンデンサＣ２、インダクタＬ３およびインダクタＬ６で構成される回路を３次のＴ型ＬＣフィルタ回路と考えた場合、当該フィルタ回路は、インダクタＬ３とインダクタＬ６との負のインダクタンス成分により寄生インダクタンス（インダクタＬ５）を打ち消すことで、高周波帯のノイズ抑制効果を向上させる。 The capacitor C2 has one terminal connected to the electrode T2 and the other terminal connected to the ground electrode GND4. The capacitor C2 has an inductor L5 as a parasitic inductance and a resistor R2 as a parasitic resistance, and is equivalent to a circuit configuration in which the inductor L5 and the resistor R2 are connected in series to the capacitor C2a. In addition to the capacitor C2, an inductor L3 and an inductor L6 are connected to the electrode T2. The inductor L3 and the inductor L6 are tightly coupled, and a pseudo negative inductance component is generated. This negative inductance component can cancel the parasitic inductance of the capacitor C2 (inductor L5), and the inductance component of the capacitor C2 can be apparently reduced. When a circuit composed of the capacitor C2, the inductor L3, and the inductor L6 is considered as a third-order T-type LC filter circuit, the filter circuit has a parasitic inductance (inductor L5) due to a negative inductance component between the inductor L3 and the inductor L6. By canceling out, the noise suppression effect in the high frequency band is improved.
　ここで、３次のＴ型ＬＣフィルタ回路において、負のインダクタンス成分により寄生インダクタンスを打ち消すことで、高周波帯のノイズ抑制効果を向上させることについて説明する。図２は、３次のＴ型ＬＣフィルタ回路の等価回路を示す回路図、およびこの回路図の周波数に対する伝送特性を示すグラフである。図２（ａ）に示すフィルタ回路１ａは、コンデンサＣ１、インダクタＬ１およびインダクタＬ２で構成される３次のＴ型ＬＣフィルタ回路である。 Here, in the third-order T-type LC filter circuit, description will be given of improving the noise suppression effect in the high frequency band by canceling the parasitic inductance by the negative inductance component. FIG. 2 is a circuit diagram showing an equivalent circuit of a third-order T-type LC filter circuit, and a graph showing transmission characteristics with respect to frequency in this circuit diagram. A filter circuit 1a illustrated in FIG. 2A is a third-order T-type LC filter circuit including a capacitor C1, an inductor L1, and an inductor L2.
　ここで、コンデンサＣ１は、キャパシタＣ１ａを０．１μＦ、インダクタＬ４を１ｎＨ、および抵抗Ｒ１を０．０１Ωと設定する。インダクタＬ１，Ｌ２は、２ｎＨとそれぞれ設定する。さらに、インダクタＬ１とインダクタＬ２との結合係数Ｋ１２は、０．５（５０％）と設定する。フィルタ回路１ａは、インダクタＬ４の１ｎＨの寄生インダクタンスを、２ｎＨのインダクタＬ１，Ｌ２を５０％で結合したことで生じる負のインダクタンス成分（－１ｎＨ）で打ち消している。 Here, the capacitor C1 sets the capacitor C1a as 0.1 μF, the inductor L4 as 1 nH, and the resistor R1 as 0.01Ω. The inductors L1 and L2 are set to 2 nH, respectively. Furthermore, the coupling coefficient K12 between the inductor L1 and the inductor L2 is set to 0.5 (50%). The filter circuit 1a cancels the 1 nH parasitic inductance of the inductor L4 with a negative inductance component (−1 nH) generated by coupling the 2 nH inductors L1 and L2 at 50%.
　図２（ａ）に示すフィルタ回路１ａに対して回路シミュレーションを行い、周波数に対する伝送特性を示した結果が図２（ｂ）に示すグラフである。図２（ｂ）に示すグラフは、横軸を周波数Ｆｒｅｑ（ＭＨｚ）とし、縦軸を伝送特性Ｓ（ｄＢ）としている。フィルタ回路１ａは、図２（ｂ）に示すように、１．０ＭＨｚ以上の周波数Ｆｒｅｑにおいて伝送特性Ｓが低下し、高周波帯のノイズ抑制効果を向上させることができる。 FIG. 2B is a graph showing the result of performing circuit simulation on the filter circuit 1a shown in FIG. 2A and showing the transmission characteristics with respect to the frequency. In the graph shown in FIG. 2B, the horizontal axis is the frequency Freq (MHz), and the vertical axis is the transmission characteristic S (dB). As shown in FIG. 2B, the filter circuit 1a has a reduced transmission characteristic S at a frequency Freq of 1.0 MHz or higher, and can improve the noise suppression effect in the high frequency band.
　図２（ａ）に示すフィルタ回路１ａは、抵抗Ｒ１が０．０１ΩとコンデンサＣ１の寄生抵抗が小さい場合であったため、図２（ｂ）に示すように高周波帯のノイズ抑制効果を向上させることができた。しかし、フィルタ回路１ａは、コンデンサＣ１の寄生抵抗が大きくなると寄生インダクタンスを負のインダクタンス成分で打ち消しても、高周波帯のノイズ抑制効果を十分に向上させることができない。図３は、寄生抵抗が大きい場合の３次のＴ型ＬＣフィルタ回路の等価回路を示す回路図、およびこの回路図の周波数に対する伝送特性を示すグラフである。図３（ａ）に示すフィルタ回路１ａは、図２（ａ）に示すフィルタ回路１ａと同じ構成であるが、抵抗Ｒ１が０．１ΩとコンデンサＣ１の寄生抵抗が大きくなっている点が異なる。 Since the filter circuit 1a shown in FIG. 2A is a case where the resistance R1 is 0.01Ω and the parasitic resistance of the capacitor C1 is small, the noise suppression effect in the high frequency band is improved as shown in FIG. 2B. I was able to. However, when the parasitic resistance of the capacitor C1 increases, the filter circuit 1a cannot sufficiently improve the noise suppression effect in the high frequency band even if the parasitic inductance is canceled out by a negative inductance component. FIG. 3 is a circuit diagram showing an equivalent circuit of a third-order T-type LC filter circuit when the parasitic resistance is large, and a graph showing transmission characteristics with respect to frequency in this circuit diagram. The filter circuit 1a shown in FIG. 3 (a) has the same configuration as the filter circuit 1a shown in FIG. 2 (a), except that the resistance R1 is 0.1Ω and the parasitic resistance of the capacitor C1 is large.
　図３（ａ）に示すフィルタ回路１ａに対して回路シミュレーションを行い、周波数に対する伝送特性を示した結果が図３（ｂ）に示すグラフである。フィルタ回路１ａは、図３（ｂ）に示すように、１．０ＭＨｚ以上の周波数Ｆｒｅｑにおいて伝送特性Ｓが低下しているが、図２（ｂ）に示すグラフと比べて高周波帯のノイズ抑制効果を十分に向上させることができていない。コンデンサＣ１の寄生抵抗（抵抗Ｒ１）が大きいフィルタ回路１ａでは、自己共振周波数以降の周波数において寄生抵抗のインピーダンスの影響が大きくなり、コンデンサＣ１の誘電損失の寄与率が周波数に応じて大きくなる。そのため、コンデンサＣ１の寄生抵抗（抵抗Ｒ１）が大きいフィルタ回路１ａは、寄生インダクタンスを負のインダクタンス成分で打ち消しただけでは、高周波帯のノイズ抑制効果を十分に向上させることができない。 FIG. 3B is a graph showing a result of performing circuit simulation on the filter circuit 1a shown in FIG. 3A and showing transmission characteristics with respect to frequency. As shown in FIG. 3 (b), the filter circuit 1a has the transmission characteristic S reduced at a frequency Freq of 1.0 MHz or higher, but the noise suppression effect in the high-frequency band as compared with the graph shown in FIG. 2 (b). Can not be improved sufficiently. In the filter circuit 1a where the parasitic resistance (resistor R1) of the capacitor C1 is large, the influence of the impedance of the parasitic resistance increases at frequencies after the self-resonance frequency, and the contribution ratio of the dielectric loss of the capacitor C1 increases according to the frequency. For this reason, the filter circuit 1a having a large parasitic resistance (resistor R1) of the capacitor C1 cannot sufficiently improve the noise suppression effect in the high frequency band only by canceling the parasitic inductance with a negative inductance component.
　例えば、誘電損失が低く高周波に対応した積層セラミックコンデンサ（multi-layer ceramic capacitor :MLCC）をコンデンサＣ１に使用するのであれば、フィルタ回路１ａは、コンデンサＣ１の寄生抵抗が小さくなり、寄生インダクタンスを負のインダクタンス成分で打ち消すことで高周波帯のノイズ抑制効果を向上させることができる。しかし、高誘電率で容量の大きいコンデンサをコンデンサＣ１に使用するのであれば、フィルタ回路１ａは、コンデンサＣ１の寄生抵抗が大きくなるので、寄生インダクタンスを負のインダクタンス成分で打ち消すだけでは高周波帯のノイズ抑制効果を十分に向上させることができない。 For example, if a multilayer ceramic capacitor (multi-layer ceramic capacitor: MLCC) with low dielectric loss and high frequency is used as the capacitor C1, the filter circuit 1a has a small parasitic resistance and a negative parasitic inductance. By canceling out with the inductance component, it is possible to improve the noise suppression effect in the high frequency band. However, if a capacitor with a high dielectric constant and a large capacity is used for the capacitor C1, the parasitic resistance of the capacitor C1 increases in the filter circuit 1a. Therefore, simply canceling the parasitic inductance with a negative inductance component causes noise in the high frequency band. The suppression effect cannot be improved sufficiently.
　そこで、本発明の実施の形態１に係るフィルタ回路１では、図１に示すようにコンデンサＣ１およびコンデンサＣ２を用いて５次のＴ型ＬＣフィルタ回路を構成している。つまり、フィルタ回路１は、コンデンサを２つ以上使って５次以上のフィルタ回路を構成し、カットオフ周波数が自己共振周波数以降においても低くなるようにしている。このことで、フィルタ回路１は、寄生抵抗のインピーダンスの影響が大きくなる自己共振周波数以降の周波数において高い減衰量が得られ、寄生抵抗による影響を抑えて高周波帯のノイズ抑制効果を十分に向上させることができる。 Therefore, in the filter circuit 1 according to Embodiment 1 of the present invention, a fifth-order T-type LC filter circuit is configured using the capacitor C1 and the capacitor C2, as shown in FIG. That is, the filter circuit 1 forms a fifth or higher order filter circuit using two or more capacitors so that the cut-off frequency becomes lower after the self-resonant frequency. As a result, the filter circuit 1 can obtain a high attenuation at frequencies after the self-resonance frequency at which the influence of the impedance of the parasitic resistance becomes large, and can sufficiently improve the noise suppression effect in the high frequency band by suppressing the influence of the parasitic resistance. be able to.
　ここで、５次のＴ型ＬＣフィルタ回路において、寄生抵抗による影響を抑えて高周波帯のノイズ抑制効果を向上させることができる点について説明する。図４は、５次のＴ型ＬＣフィルタ回路の等価回路を示す回路図、およびこの回路図の周波数に対する伝送特性を示すグラフである。図４（ａ）に示すフィルタ回路１は、コンデンサＣ１，Ｃ２、インダクタＬ１，Ｌ２およびインダクタＬ３、Ｌ６で構成される５次のＴ型ＬＣフィルタ回路である。 Here, in the fifth-order T-type LC filter circuit, a description will be given of the fact that the noise suppression effect in the high frequency band can be improved by suppressing the influence of the parasitic resistance. FIG. 4 is a circuit diagram showing an equivalent circuit of a fifth-order T-type LC filter circuit, and a graph showing transmission characteristics with respect to frequency in this circuit diagram. A filter circuit 1 shown in FIG. 4A is a fifth-order T-type LC filter circuit including capacitors C1 and C2, inductors L1 and L2, and inductors L3 and L6.
　ここで、コンデンサＣ１，Ｃ２は、キャパシタＣ１ａ，Ｃ２ａを０．１μＦ、インダクタＬ４，Ｌ５を１ｎＨ、および抵抗Ｒ１，Ｒ２を０．０１Ωとそれぞれ設定する。インダクタＬ１，Ｌ２，Ｌ３，Ｌ６は、２ｎＨとそれぞれ設定する。さらに、インダクタＬ１とインダクタＬ２との結合係数Ｋ１２は、０．５（５０％）と、インダクタＬ３とインダクタＬ６との結合係数Ｋ３６は、０．５（５０％）とそれぞれ設定する。このため、フィルタ回路１では、インダクタＬ４の１ｎＨの寄生インダクタンスを、２ｎＨのインダクタＬ１，Ｌ２を５０％で結合したことで生じる負のインダクタンス成分（－１ｎＨ）で打ち消し、インダクタＬ５の１ｎＨの寄生インダクタンスを、２ｎＨのインダクタＬ３，Ｌ６を５０％で結合したことで生じる負のインダクタンス成分（－１ｎＨ）で打ち消している。 Here, the capacitors C1 and C2 set the capacitors C1a and C2a to 0.1 μF, the inductors L4 and L5 to 1 nH, and the resistors R1 and R2 to 0.01Ω, respectively. The inductors L1, L2, L3, and L6 are set to 2 nH, respectively. Further, the coupling coefficient K12 between the inductor L1 and the inductor L2 is set to 0.5 (50%), and the coupling coefficient K36 between the inductor L3 and the inductor L6 is set to 0.5 (50%). For this reason, in the filter circuit 1, the parasitic inductance of 1 nH of the inductor L4 is canceled by the negative inductance component (−1 nH) generated by coupling the inductors L1 and L2 of 2 nH at 50%, and the parasitic inductance of 1 nH of the inductor L5 Is canceled by a negative inductance component (−1 nH) generated by coupling the inductors L3 and L6 of 2 nH at 50%.
　図４（ａ）に示すフィルタ回路１に対して回路シミュレーションを行い、周波数に対する伝送特性を示した結果が図４（ｂ）に示すグラフである。フィルタ回路１は、図４（ｂ）に示すように、１０．０ＭＨｚ以上の周波数Ｆｒｅｑにおいて伝送特性Ｓが急激に低下し、高周波帯のノイズ抑制効果を向上させることができる。 FIG. 4B is a graph showing a result of performing circuit simulation on the filter circuit 1 shown in FIG. 4A and showing transmission characteristics with respect to frequency. As shown in FIG. 4B, the filter circuit 1 has the transmission characteristic S drastically reduced at a frequency Freq of 10.0 MHz or higher, and can improve the noise suppression effect in the high frequency band.
　図４（ａ）に示すフィルタ回路１は、抵抗Ｒ１，Ｒ２がそれぞれ０．０１ΩとコンデンサＣ１，Ｃ２の寄生抵抗が小さい場合であったが、コンデンサＣ１，Ｃ２の寄生抵抗を大きくしても、高周波帯のノイズ抑制効果を十分に向上させることができる。図５は、コンデンサＣ１，Ｃ２の寄生抵抗が大きい場合の５次のＴ型ＬＣフィルタ回路の等価回路を示す回路図、およびこの回路図の周波数に対する伝送特性を示すグラフである。図５（ａ）に示すフィルタ回路１は、図４（ａ）に示すフィルタ回路１と同じ構成であるが、抵抗Ｒ１，Ｒ２がそれぞれ０．１Ωと寄生抵抗が大きくなっている点が異なる。 The filter circuit 1 shown in FIG. 4A is a case where the resistances R1 and R2 are 0.01Ω and the parasitic resistances of the capacitors C1 and C2, respectively. However, even if the parasitic resistances of the capacitors C1 and C2 are increased, The noise suppression effect in the high frequency band can be sufficiently improved. FIG. 5 is a circuit diagram showing an equivalent circuit of a fifth-order T-type LC filter circuit when the parasitic resistances of the capacitors C1 and C2 are large, and a graph showing transmission characteristics with respect to frequency in this circuit diagram. The filter circuit 1 shown in FIG. 5A has the same configuration as the filter circuit 1 shown in FIG. 4A, except that the resistances R1 and R2 are each 0.1Ω and the parasitic resistance is large.
　図５（ａ）に示すフィルタ回路１に対して回路シミュレーションを行い、周波数に対する伝送特性を示した結果が図５（ｂ）に示すグラフである。フィルタ回路１は、図５（ｂ）に示すように、１０．０ＭＨｚ以上の周波数Ｆｒｅｑにおいて伝送特性Ｓが十分に低下している。また、図２（ｂ）と図５（ｂ）とを比較することで分かるように、フィルタ回路１は、図２（ａ）に示すフィルタ回路１ａと比べても高周波帯のノイズ抑制効果を十分に向上させることができる。 FIG. 5B is a graph showing the result of performing circuit simulation on the filter circuit 1 shown in FIG. 5A and showing the transmission characteristics with respect to the frequency. As shown in FIG. 5B, the filter circuit 1 has a sufficiently low transmission characteristic S at a frequency Freq of 10.0 MHz or higher. Further, as can be seen by comparing FIG. 2B and FIG. 5B, the filter circuit 1 has a sufficient noise suppression effect in the high-frequency band as compared with the filter circuit 1a shown in FIG. Can be improved.
　図５（ａ）に示すフィルタ回路１では、インダクタＬ１とインダクタＬ６との結合係数Ｋ１６は、０．０（０％）と設定して回路シミュレーションを行っている。しかし、現実の回路基板では、インダクタＬ１とインダクタＬ６との結合係数Ｋ１６が０％となるように十分に離して配置することができないため、結合係数Ｋ１６は何らかの値を有することになる。 In the filter circuit 1 shown in FIG. 5A, the circuit simulation is performed with the coupling coefficient K16 between the inductor L1 and the inductor L6 set to 0.0 (0%). However, in an actual circuit board, since the coupling coefficient K16 between the inductor L1 and the inductor L6 cannot be sufficiently separated so as to be 0%, the coupling coefficient K16 has some value.
　フィルタ回路１において、結合係数Ｋ１６が０％以外の値となる場合について説明する。図６は、結合係数Ｋ１６が１０％の５次のＴ型ＬＣフィルタ回路の等価回路を示す回路図、およびこの回路図の周波数に対する伝送特性を示すグラフである。図６（ａ）に示すフィルタ回路１は、図５（ａ）に示すフィルタ回路１と同じ構成であるが、結合係数Ｋ１６が１０％と大きくなっている点が異なる。 In the filter circuit 1, the case where the coupling coefficient K16 is a value other than 0% will be described. FIG. 6 is a circuit diagram showing an equivalent circuit of a fifth-order T-type LC filter circuit having a coupling coefficient K16 of 10%, and a graph showing transmission characteristics with respect to frequency in this circuit diagram. The filter circuit 1 shown in FIG. 6A has the same configuration as the filter circuit 1 shown in FIG. 5A, except that the coupling coefficient K16 is as large as 10%.
　図６（ａ）に示すフィルタ回路１に対して回路シミュレーションを行い、周波数に対する伝送特性を示した結果が図６（ｂ）に示すグラフである。フィルタ回路１は、図６（ｂ）に示すように、２０．０ＭＨｚ近傍の周波数Ｆｒｅｑにおいて伝送特性Ｓが低下しているがそれ以降の周波数において伝送特性Ｓが上昇しており、高周波帯のノイズ抑制効果を十分に向上させることができない。 FIG. 6B is a graph showing a result of performing circuit simulation on the filter circuit 1 shown in FIG. 6A and showing transmission characteristics with respect to frequency. In the filter circuit 1, as shown in FIG. 6B, the transmission characteristic S decreases at a frequency Freq near 20.0 MHz, but the transmission characteristic S increases at a frequency after that. The suppression effect cannot be improved sufficiently.
　つまり、フィルタ回路１は、結合係数Ｋ１６が大きくなると高周波帯のノイズ抑制効果を十分に向上させることができない。そこで、結合係数Ｋ１６がどの程度の値であれば、高周波帯のノイズ抑制効果を十分に向上させることができるのかについて、結合係数Ｋ１６を変化させてフィルタ回路１に対して回路シミュレーションを行った。図７は、結合係数Ｋ１６が１％および０．１％のフィルタ回路の周波数に対する伝送特性を示すグラフである。図７（ａ）に示すグラフは、結合係数Ｋ１６が１％のフィルタ回路１の周波数に対する伝送特性を示している。フィルタ回路１は、図７（ａ）に示すように、６００．０ＭＨｚ程度までの周波数Ｆｒｅｑにおいて伝送特性Ｓを低下させており、高周波帯のノイズ抑制効果を十分に向上させることができている。図７（ｂ）に示すグラフは、結合係数Ｋ１６が０．１％のフィルタ回路１の周波数に対する伝送特性を示している。フィルタ回路１は、図７（ｂ）に示すように、広帯域の周波数Ｆｒｅｑにおいて伝送特性Ｓを低下させており、高周波帯のノイズ抑制効果をさらに向上することができている。 That is, the filter circuit 1 cannot sufficiently improve the noise suppression effect in the high frequency band when the coupling coefficient K16 increases. Accordingly, a circuit simulation was performed on the filter circuit 1 by changing the coupling coefficient K16 to determine the value of the coupling coefficient K16 that can sufficiently improve the noise suppression effect in the high frequency band. FIG. 7 is a graph showing the transmission characteristics with respect to the frequency of the filter circuit having the coupling coefficient K16 of 1% and 0.1%. The graph shown in FIG. 7A shows transmission characteristics with respect to the frequency of the filter circuit 1 having a coupling coefficient K16 of 1%. As shown in FIG. 7A, the filter circuit 1 reduces the transmission characteristic S at a frequency Freq up to about 600.0 MHz, and can sufficiently improve the noise suppression effect in the high frequency band. The graph shown in FIG. 7B shows transmission characteristics with respect to the frequency of the filter circuit 1 having a coupling coefficient K16 of 0.1%. As shown in FIG. 7B, the filter circuit 1 reduces the transmission characteristic S in the wideband frequency Freq, and can further improve the noise suppression effect in the high frequency band.
　フィルタ回路１は、図７に示す回路シミュレーション結果から、少なくとも結合係数Ｋ１６が１％以下であれば必要な帯域の伝送特性Ｓを低下させ、高周波帯のノイズ抑制効果を十分に向上させることができる。 From the circuit simulation result shown in FIG. 7, the filter circuit 1 can sufficiently improve the noise suppression effect in the high frequency band by reducing the transmission characteristic S in the necessary band if at least the coupling coefficient K16 is 1% or less. .
　実際の回路構成において、結合係数Ｋ１６を１％以下にするため、本発明の実施の形態１では、図１に示すように、インダクタＬ１を構成するコイルの巻き方向と、インダクタＬ６を構成するコイルの巻き方向とが異なる方向となっている。なお、インダクタＬ１～Ｌ３，Ｌ６をコイルで構成する場合、インダクタＬ１とインダクタＬ２とは同じコイルの巻き方向で、インダクタＬ３とインダクタＬ６とが同じコイルの巻き方向となる必要がある。そのため、インダクタＬ６のコイルの巻き方向とインダクタＬ３のコイルの巻き方向とが同じになるため、インダクタＬ３のコイルの巻き方向は、インダクタＬ１やインダクタＬ２のコイルの巻き方向と異なる方向となっている。 In the actual circuit configuration, in order to set the coupling coefficient K16 to 1% or less, in the first embodiment of the present invention, as shown in FIG. 1, the winding direction of the coil constituting the inductor L1 and the coil constituting the inductor L6 The direction of winding is different. When the inductors L1 to L3 and L6 are formed of coils, the inductor L1 and the inductor L2 need to be in the same coil winding direction, and the inductor L3 and the inductor L6 must be in the same coil winding direction. Therefore, since the winding direction of the inductor L6 and the winding direction of the inductor L3 are the same, the winding direction of the inductor L3 is different from the winding direction of the inductors L1 and L2. .
　図１に示すインダクタＬ１およびインダクタＬ２は、コイルの左側に巻はじめを示す丸印が付されているが、インダクタＬ３およびインダクタＬ６は、コイルの右側に巻はじめを示す丸印が付されている。このことにより、インダクタＬ１およびインダクタＬ２のコイルの巻き方向と、インダクタＬ３およびインダクタＬ６のコイルの巻き方向とが異なる方向であることを示している。 The inductor L1 and the inductor L2 shown in FIG. 1 are marked with a circle indicating the beginning of winding on the left side of the coil, while the inductor L3 and the inductor L6 are marked with a circle indicating the beginning of winding on the right side of the coil. . This indicates that the winding directions of the inductors L1 and L2 are different from the winding directions of the inductors L3 and L6.
　次に、図１に示したフィルタ回路１を、実際に作成した場合の構造について説明する。図８は、本発明の実施の形態１に係るフィルタ回路１の斜視図である。図９は、本発明の実施の形態１に係るフィルタ回路１の平面図および断面図である。フィルタ回路１は、図８に示すように、回路基板２と、回路基板２に実装したコンデンサＣ１およびコンデンサＣ２とを備えている。そして、フィルタ回路１は、図９（ａ）に示すように、回路基板２に対してコンデンサＣ１およびコンデンサＣ２が並列に実装されている。コンデンサＣ１およびコンデンサＣ２を実装する回路基板２に面に電極Ｔ１および電極Ｔ２が形成されている。 Next, the structure when the filter circuit 1 shown in FIG. 1 is actually created will be described. FIG. 8 is a perspective view of the filter circuit 1 according to Embodiment 1 of the present invention. FIG. 9 is a plan view and a cross-sectional view of the filter circuit 1 according to Embodiment 1 of the present invention. As illustrated in FIG. 8, the filter circuit 1 includes a circuit board 2, a capacitor C <b> 1 and a capacitor C <b> 2 mounted on the circuit board 2. In the filter circuit 1, a capacitor C1 and a capacitor C2 are mounted in parallel to the circuit board 2, as shown in FIG. Electrode T1 and electrode T2 are formed on the surface of circuit board 2 on which capacitors C1 and C2 are mounted.
　回路基板２は、ガラスエポキシ基板の多層基板であり、図９（ｂ）に示すように複数の層を有している。第１層目Ｓ１には、電極Ｔ１および電極Ｔ２が形成されている。その他、第１層目Ｓ１には、コンデンサＣ１およびコンデンサＣ２を実装する電極Ｔ１および電極Ｔ２とは別の電極と、インダクタＬ１およびインダクタＬ６の一方の端子が接続する電極とが形成されている。第２層目Ｓ２には、インダクタＬ１およびインダクタＬ６のコイル形状の配線パターンが形成されており、さらに下層の第３層目Ｓ３には、インダクタＬ２およびインダクタＬ３のコイル形状の配線パターンが形成されている。 The circuit board 2 is a multilayer board of glass epoxy board, and has a plurality of layers as shown in FIG. In the first layer S1, an electrode T1 and an electrode T2 are formed. In addition, in the first layer S1, an electrode different from the electrode T1 and the electrode T2 for mounting the capacitor C1 and the capacitor C2 and an electrode to which one terminal of the inductor L1 and the inductor L6 is connected are formed. A coil-shaped wiring pattern of the inductor L1 and the inductor L6 is formed on the second layer S2, and a coil-shaped wiring pattern of the inductor L2 and the inductor L3 is formed on the lower third layer S3. ing.
　インダクタＬ２およびインダクタＬ３のコイル形状の配線パターンは、図９（ａ）に示すように、連続して形成されており、１つのインダクタンス素子と考えることができる。つまり、１つのインダクタンス素子の図面の左側半分（第２インダクタンス素子の第１部分）がインダクタＬ２として機能し、１つのインダクタンス素子の図面の右側半分（第２インダクタンス素子の第２部分）がインダクタＬ３として機能している。これにより、インダクタＬ２およびインダクタＬ３の製造コストを低減することができる。もちろん、インダクタＬ２およびインダクタＬ３を別々に製造してもよい。 The coil-shaped wiring patterns of the inductor L2 and the inductor L3 are formed continuously as shown in FIG. 9A and can be considered as one inductance element. That is, the left half of the drawing of one inductance element (the first portion of the second inductance element) functions as the inductor L2, and the right half of the drawing of one inductance element (the second portion of the second inductance element) is the inductor L3. Is functioning as Thereby, the manufacturing cost of the inductor L2 and the inductor L3 can be reduced. Of course, the inductor L2 and the inductor L3 may be manufactured separately.
　インダクタＬ１の配線パターンは、巻き方向を一方の電極から電極Ｔ１へ反時計回りにしたコイル形状であり、インダクタＬ２の配線パターンは、巻き方向を電極Ｔ１からインダクタＬ３側へ反時計回りにしたコイル形状である。そのため、インダクタＬ１とインダクタＬ２とのコイルの巻き方向は、同じ反時計回りである。インダクタＬ６の配線パターンは、巻き方向を電極Ｔ２から他方の電極へ時計回りにしたコイル形状であり、インダクタＬ３の配線パターンは、巻き方向をインダクタＬ２側から電極Ｔ２へ時計回りにしたコイル形状である。そのため、インダクタＬ３とインダクタＬ６とのコイルの巻き方向は、同じ時計回りである。つまり、インダクタＬ１およびインダクタＬ２の巻き方向と、インダクタＬ３およびインダクタＬ６の巻き方向とが異なる方向となっている。 The wiring pattern of the inductor L1 has a coil shape in which the winding direction is counterclockwise from one electrode to the electrode T1, and the wiring pattern of the inductor L2 is a coil in which the winding direction is counterclockwise from the electrode T1 to the inductor L3. Shape. Therefore, the coil winding directions of the inductor L1 and the inductor L2 are the same counterclockwise. The wiring pattern of the inductor L6 is a coil shape in which the winding direction is clockwise from the electrode T2 to the other electrode, and the wiring pattern of the inductor L3 is a coil shape in which the winding direction is clockwise from the inductor L2 side to the electrode T2. is there. Therefore, the winding directions of the inductors L3 and L6 are the same clockwise. That is, the winding direction of the inductor L1 and the inductor L2 is different from the winding direction of the inductor L3 and the inductor L6.
　インダクタＬ１～Ｌ３，Ｌ６のコイルのサイズはほぼ同じ大きさであり、コンデンサＣ１と接続されるインダクタＬ１，Ｌ２と、コンデンサＣ２と接続されるインダクタＬ３，Ｌ６とはほぼ回転対称な形状となっている。 The inductors L1 to L3 and L6 have substantially the same coil size, and the inductors L1 and L2 connected to the capacitor C1 and the inductors L3 and L6 connected to the capacitor C2 are substantially rotationally symmetric. Yes.
　コンデンサＣ１を実装する面の法線方向から視て、インダクタＬ１とインダクタＬ２とが重なる位置に形成され、インダクタＬ３とインダクタＬ６とが重なる位置に形成されている。コンデンサＣ１を実装する面の法線方向に複数のインダクタを重ねることで、コンパクトなフィルタ回路１を製造することができる。 When viewed from the normal direction of the surface on which the capacitor C1 is mounted, the inductor L1 and the inductor L2 are formed at the overlapping position, and the inductor L3 and the inductor L6 are formed at the overlapping position. A compact filter circuit 1 can be manufactured by overlapping a plurality of inductors in the normal direction of the surface on which the capacitor C1 is mounted.
　インダクタＬ１とインダクタＬ２とは、電極Ｔ１に設けたスルーホールによって電気的に接続されている。同様に、インダクタＬ３とインダクタＬ６とは、電極Ｔ２に設けたスルーホールによって電気的に接続されている。 The inductor L1 and the inductor L2 are electrically connected by a through hole provided in the electrode T1. Similarly, the inductor L3 and the inductor L6 are electrically connected by a through hole provided in the electrode T2.
　図９（ａ）に示す回路基板２は、縦幅が４ｍｍ、横幅が５ｍｍのガラスエポキシ基板の多層基板を用いて作成する。制作した回路基板２は、第１層目Ｓ１と第２層目Ｓ２との厚みが０．０６ｍｍ、第２層目Ｓ２と第３層目Ｓ３との厚みが０．０４ｍｍ、第３層目Ｓ３と第４層目Ｓ４との厚みが０．０６ｍｍとし、各層に電極やインダクタなどの必要な配線パターンが作成してある。この回路基板２に対して、１０μＦの積層セラミックコンデンサを実装しフィルタ回路１を実際に作成して、周波数に対する伝送特性の測定を行った。 The circuit board 2 shown in FIG. 9A is formed using a multilayered glass epoxy board having a vertical width of 4 mm and a horizontal width of 5 mm. The produced circuit board 2 has a thickness of 0.06 mm between the first layer S1 and the second layer S2, a thickness of 0.04 mm between the second layer S2 and the third layer S3, and a third layer S3. And the thickness of the fourth layer S4 is 0.06 mm, and necessary wiring patterns such as electrodes and inductors are formed in each layer. A 10 μF multilayer ceramic capacitor was mounted on the circuit board 2 to actually create a filter circuit 1 and measured transmission characteristics with respect to frequency.
　図１０は、本発明の実施の形態１に係るフィルタ回路１の周波数に対する伝送特性を示すグラフである。図１０に示すグラフでは、コンデンサＣ１，Ｃ２を回路基板２ａに実装したフィルタ回路１の周波数に対する伝送特性を示すグラフ（回路基板あり）と、コンデンサＣ１，Ｃ２のみからなるフィルタ回路の周波数に対する伝送特性を示すグラフ（回路基板なし）とが図示してある。フィルタ回路１は、回路基板なしの場合に比べ、６００．０ＭＨｚ程度までの周波数Ｆｒｅｑにおいて伝送特性Ｓを低下させ、高周波帯のノイズ抑制効果を十分に向上させることができている。つまり、フィルタ回路１では、インダクタＬ１の巻き方向とインダクタＬ６の巻き方向とを異ならせることで、回路シミュレーション結果で結合係数Ｋ１６を１％とした場合の回路構成と同程度の帯域において伝送特性Ｓを低下させ、高周波帯のノイズ抑制効果を向上させることができている。 FIG. 10 is a graph showing transmission characteristics with respect to frequency of the filter circuit 1 according to Embodiment 1 of the present invention. In the graph shown in FIG. 10, a graph (with a circuit board) showing the transmission characteristics with respect to the frequency of the filter circuit 1 in which the capacitors C1 and C2 are mounted on the circuit board 2a, and the transmission characteristics with respect to the frequency of the filter circuit consisting only of the capacitors C1 and C2. A graph (without a circuit board) is shown. The filter circuit 1 can sufficiently improve the noise suppression effect in the high frequency band by reducing the transmission characteristic S at the frequency Freq up to about 600.0 MHz as compared with the case without the circuit board. In other words, in the filter circuit 1, the winding characteristics of the inductor L1 and the winding direction of the inductor L6 are made different so that the transmission characteristics S in a band similar to the circuit configuration when the coupling coefficient K16 is 1% in the circuit simulation result. The noise suppression effect in the high frequency band can be improved.
　以上のように、本発明の実施の形態に係るフィルタ回路１では、２つのコンデンサＣ１，Ｃ２を回路基板２に実装して５次のＴ型ＬＣフィルタ回路を形成し、インダクタＬ１の巻き方向とインダクタＬ６の巻き方向とを異ならせることで、高周波帯のノイズ抑制効果を向上させることができる。 As described above, in the filter circuit 1 according to the embodiment of the present invention, the two capacitors C1 and C2 are mounted on the circuit board 2 to form the fifth-order T-type LC filter circuit, and the winding direction of the inductor L1 By making the winding direction of the inductor L6 different, the noise suppression effect in the high frequency band can be improved.
　なお、本発明の実施の形態に係る回路基板２では、図９（ａ）に示すように２つのコンデンサＣ１，Ｃ２を実装することができる電極（電極Ｔ１，Ｔ２を含む）を形成し、コンデンサＣ１，Ｃ２の寄生インダクタンスおよび寄生抵抗によるノイズ抑制効果への影響を抑えるためのインダクタＬ１～Ｌ３，Ｌ６を形成してある。そのため、回路基板２にコンデンサＣ１，Ｃ２を実装することで、伝送特性Ｓを低下させ、高周波帯のノイズ抑制効果を向上させるフィルタ回路を作成することができる。 In the circuit board 2 according to the embodiment of the present invention, as shown in FIG. 9A, electrodes (including electrodes T1 and T2) on which two capacitors C1 and C2 can be mounted are formed. Inductors L1 to L3 and L6 are formed to suppress the influence of the parasitic inductances and parasitic resistances of C1 and C2 on the noise suppression effect. Therefore, by mounting the capacitors C1 and C2 on the circuit board 2, it is possible to create a filter circuit that reduces the transmission characteristics S and improves the noise suppression effect in the high frequency band.
　コンデンサＣ１，Ｃ２は、積層セラミックコンデンサであると説明したが、BaTiO3(チタン酸バリウム)を主成分とした積層セラミックコンデンサだけでなく、他の材料を主成分とした積層セラミックコンデンサでもよい。さらに、コンデンサＣ１，Ｃ２は、積層セラミックコンデンサに限定されるものではなく、例えばアルミ電解コンデンサなどの他の種類のコンデンサでもよい。
（実施の形態２）
　本発明の実施の形態１では、図９（ａ）に示すように回路基板２に形成したインダクタＬ１～Ｌ３，Ｌ６のコイルのサイズはほぼ同じ大きさであった。しかし、インダクタＬ１～Ｌ３，Ｌ６のコイルのサイズにより、結合係数を変更することができ、寄生インダクタンスを打ち消す負のインダクタンス成分を変更することが可能である。そこで、本発明の実施の形態２に係る回路基板では、回路基板２に形成したインダクタＬ１～Ｌ３，Ｌ６のコイルのサイズを変更した構成について説明する。図１１は、本発明の実施の形態２に係る回路基板の平面図、およびこの回路基板を用いたフィルタ回路の周波数に対する伝送特性を示すグラフである。 Although the capacitors C1 and C2 have been described as multilayer ceramic capacitors, not only multilayer ceramic capacitors mainly composed of BaTiO3 (barium titanate) but also multilayer ceramic capacitors mainly composed of other materials may be used. Furthermore, the capacitors C1 and C2 are not limited to multilayer ceramic capacitors, and may be other types of capacitors such as aluminum electrolytic capacitors.
(Embodiment 2)
In the first embodiment of the present invention, as shown in FIG. 9A, the inductors L1 to L3 and L6 formed on the circuit board 2 have almost the same coil size. However, the coupling coefficient can be changed according to the sizes of the coils of the inductors L1 to L3 and L6, and the negative inductance component that cancels the parasitic inductance can be changed. Therefore, in the circuit board according to Embodiment 2 of the present invention, a configuration in which the sizes of the coils of the inductors L1 to L3 and L6 formed on the circuit board 2 are changed will be described. FIG. 11 is a plan view of a circuit board according to Embodiment 2 of the present invention, and a graph showing transmission characteristics with respect to frequency of a filter circuit using the circuit board.
　図１１（ａ）に示すように回路基板２ａでは、インダクタＬ２の配線パターンで形成したコイル形状に比べて、インダクタＬ１ａの配線パターンで形成したコイル形状が小さい。なお、インダクタＬ１ａとインダクタＬ２とのコイルの巻き方向は、同じ反時計回りである。また、回路基板２ａでは、インダクタＬ３の配線パターンで形成したコイル形状に比べて、インダクタＬ６ａの配線パターンで形成したコイル形状が小さい。なお、インダクタＬ３とインダクタＬ６ａとのコイルの巻き方向は、同じ時計回りである。 As shown in FIG. 11A, in the circuit board 2a, the coil shape formed by the wiring pattern of the inductor L1a is smaller than the coil shape formed by the wiring pattern of the inductor L2. Note that the winding directions of the inductors L1a and L2 are the same counterclockwise. In the circuit board 2a, the coil shape formed by the wiring pattern of the inductor L6a is smaller than the coil shape formed by the wiring pattern of the inductor L3. Note that the winding directions of the inductors L3 and L6a are the same clockwise.
　インダクタＬ１ａとインダクタＬ２とのコイルのサイズが異ならせることで、インダクタＬ１ａとインダクタＬ２との結合係数Ｋ１２ａは、図９（ａ）に示すインダクタＬ１とインダクタＬ２との結合係数Ｋ１２に比べ変化する。そのため、インダクタＬ１ａとインダクタＬ２との結合によって生じる負のインダクタンス成分も変更される。なお、コンデンサＣ１と接続されるインダクタＬ１ａ，Ｌ２と、コンデンサＣ２と接続されるインダクタＬ３，Ｌ６ａとはほぼ回転対称な形状となっているので、同様にインダクタＬ３とインダクタＬ６ａとの結合によって生じる負のインダクタンス成分も変更される。 By making the coil sizes of the inductor L1a and the inductor L2 different, the coupling coefficient K12a between the inductor L1a and the inductor L2 changes compared to the coupling coefficient K12 between the inductor L1 and the inductor L2 shown in FIG. Therefore, the negative inductance component generated by the coupling between the inductor L1a and the inductor L2 is also changed. Note that the inductors L1a and L2 connected to the capacitor C1 and the inductors L3 and L6a connected to the capacitor C2 have a substantially rotationally symmetric shape. Similarly, negative inductance caused by the coupling between the inductor L3 and the inductor L6a. The inductance component is also changed.
　図１１（ｂ）に示すグラフでは、コンデンサＣ１，Ｃ２を回路基板２ａに実装したフィルタ回路の周波数に対する伝送特性を示すグラフ（回路基板あり）と、コンデンサＣ１，Ｃ２のみからなるフィルタ回路の周波数に対する伝送特性を示すグラフ（回路基板なし）とが図示してある。回路基板２ａを用いたフィルタ回路は、回路基板なしの場合に比べ、１．０ＭＨｚ以降の周波数Ｆｒｅｑにおいて伝送特性Ｓを低下させ、高周波帯のノイズ抑制効果を十分に向上させることができている。つまり、回路基板２ａをフィルタ回路でも、図９（ａ）に示すフィルタ回路１と同様に伝送特性Ｓを低下させ、高周波帯のノイズ抑制効果を十分に向上させることができる。なお、図１１（ａ）に示すように回路基板２ａでは、インダクタＬ１ａ，Ｌ６ａのコイルのサイズを変更する例を示したが、これに限定されるものではなくインダクタＬ２，Ｌ３を変更してもよい。 In the graph shown in FIG. 11B, a graph (with a circuit board) showing transmission characteristics with respect to the frequency of the filter circuit in which the capacitors C1 and C2 are mounted on the circuit board 2a, and the frequency of the filter circuit consisting only of the capacitors C1 and C2 A graph (without circuit board) showing transmission characteristics is shown. The filter circuit using the circuit board 2a can sufficiently improve the noise suppression effect in the high frequency band by reducing the transmission characteristic S at a frequency Freq of 1.0 MHz or higher compared to the case without the circuit board. That is, even if the circuit board 2a is a filter circuit, the transmission characteristic S can be reduced and the noise suppression effect in the high frequency band can be sufficiently improved as in the filter circuit 1 shown in FIG. As shown in FIG. 11A, in the circuit board 2a, the example in which the sizes of the coils of the inductors L1a and L6a are changed is shown. However, the present invention is not limited to this, and the inductors L2 and L3 can be changed. Good.
　さらに、図９（ａ）に示す回路基板２では、インダクタＬ１のコイル形状とインダクタＬ６のコイル形状が同じで、インダクタＬ２のコイルの形状とインダクタＬ３のコイル形状とが同じで、インダクタＬ１，Ｌ２と、インダクタＬ３，Ｌ６とがほぼ回転対称な形状となっていると説明したが、これに限定されるものではなく非対称な形状でもよい。図１２は、本発明の実施の形態２に係る回路基板の変形例の平面図である。 Furthermore, in the circuit board 2 shown in FIG. 9A, the coil shape of the inductor L1 and the coil shape of the inductor L6 are the same, the coil shape of the inductor L2 and the coil shape of the inductor L3 are the same, and the inductors L1 and L2 In addition, the inductors L3 and L6 have been described as having a substantially rotationally symmetric shape, but the present invention is not limited to this and may be an asymmetrical shape. FIG. 12 is a plan view of a modification of the circuit board according to Embodiment 2 of the present invention.
　図１２に示すように回路基板２ｂでは、インダクタＬ１，Ｌ２のコイルのサイズは図９（ａ）に示したコイルのサイズとほぼ同じ大きさであるが、インダクタＬ３，Ｌ６のコイルのサイズに比べて、インダクタＬ３ｂ，Ｌ６ｂのコイルのサイズが小さい。なお、インダクタＬ３ｂのコイルのサイズと、インダクタＬ６ｂのコイルのサイズとはほぼ同じサイズである。 As shown in FIG. 12, in the circuit board 2b, the size of the coils of the inductors L1 and L2 is almost the same as the size of the coil shown in FIG. 9A, but compared with the size of the coils of the inductors L3 and L6. Thus, the size of the coils of the inductors L3b and L6b is small. The coil size of the inductor L3b and the coil size of the inductor L6b are substantially the same size.
　このように、インダクタＬ１～Ｌ３，Ｌ６のコイルのサイズは様々な組み合わせを考えることができ、回路基板に実装するコンデンサの容量や特性などに応じて最適なコイルのサイズを選択することで、当該回路基板を用いたフィルタ回路は、高周波帯のノイズ抑制効果をさらに向上させることができる。 As described above, the coil sizes of the inductors L1 to L3 and L6 can be considered in various combinations. By selecting the optimum coil size according to the capacity and characteristics of the capacitor mounted on the circuit board, The filter circuit using the circuit board can further improve the noise suppression effect in the high frequency band.
　今回開示された実施の形態はすべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は、上記した説明ではなく、請求の範囲によって示され、請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。 The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
　１　フィルタ回路、２　回路基板、Ｃ１，Ｃ２　コンデンサ、Ｌ１～Ｌ６　インダクタ、Ｒ１，Ｒ２　抵抗。 1 filter circuit, 2 circuit board, C1, C2 capacitor, L1-L6 inductor, R1, R2 resistance.

Claims (7)

  1. 　第１キャパシタンス素子および第２キャパシタンス素子を実装する回路基板であって、
    　前記第１キャパシタンス素子の一方の端子を接続するための第１電極と、
    　前記回路基板に形成され、前記第１電極に接続される第１インダクタンス素子と、
    　前記回路基板に形成され、前記第１インダクタンス素子との結合部が前記第１電極に接続される第２インダクタンス素子と、
    　前記第２キャパシタンス素子の一方の端子を接続するための第２電極と、
    　前記回路基板に形成され、前記第２インダクタンス素子との結合部が前記第２電極に接続される第３インダクタンス素子とを備え、
    　前記第２インダクタンス素子は、前記第１インダクタンス素子と結合する側の第１部分と、前記第３インダクタンス素子と結合する側の第２部分とに分けられ、
    　少なくとも前記第１インダクタンス素子と前記第２インダクタンス素子の前記第１部分とは同じ巻き方向で、前記第３インダクタンス素子と前記第２インダクタンス素子の前記第２部分とは同じ巻き方向である、回路基板。     A circuit board on which a first capacitance element and a second capacitance element are mounted,
    A first electrode for connecting one terminal of the first capacitance element;
    A first inductance element formed on the circuit board and connected to the first electrode;
    A second inductance element formed on the circuit board and connected to the first electrode at a coupling portion with the first inductance element;
    A second electrode for connecting one terminal of the second capacitance element;
    A third inductance element formed on the circuit board and connected to the second electrode at a coupling portion with the second inductance element;
    The second inductance element is divided into a first part coupled to the first inductance element and a second part coupled to the third inductance element.
    At least the first inductance element and the first part of the second inductance element have the same winding direction, and the third inductance element and the second part of the second inductance element have the same winding direction. .
  2. 　前記第１インダクタンス素子の巻き方向と、前記第３インダクタンス素子の巻き方向とが異なる、請求項１に記載の回路基板。 The circuit board according to claim 1, wherein a winding direction of the first inductance element is different from a winding direction of the third inductance element.
  3. 　前記第１キャパシタンス素子を実装する面の法線方向から視て、前記第１インダクタンス素子と前記第２インダクタンス素子の前記第１部分とが重なる位置に形成され、前記第３インダクタンス素子と前記第２インダクタンス素子の前記第２部分とが重なる位置に形成されている、請求項１または請求項２に記載の回路基板。 The first inductance element and the second inductance element are formed at a position where the first inductance element and the second inductance element overlap with each other when viewed from the normal direction of the surface on which the first capacitance element is mounted. The circuit board according to claim 1, wherein the circuit board is formed at a position where the second portion of the inductance element overlaps.
  4. 　前記回路基板は多層基板であり、
    　前記第２インダクタンス素子が形成される層は、前記第１インダクタンス素子および前記第３インダクタンス素子が形成される層と異なる、請求項１～請求項３のいずれか１項に記載の回路基板。     The circuit board is a multilayer board;
    The circuit board according to any one of claims 1 to 3, wherein a layer in which the second inductance element is formed is different from a layer in which the first inductance element and the third inductance element are formed.
  5. 　前記第１電極および前記第２電極が形成される層は、前記第２インダクタンス素子が形成される層と異なり、前記第１インダクタンス素子および前記第３インダクタンス素子が形成される層とも異なる、請求項４に記載の回路基板。 The layer in which the first electrode and the second electrode are formed is different from the layer in which the second inductance element is formed, and is different from the layer in which the first inductance element and the third inductance element are formed. 4. The circuit board according to 4.
  6. 　前記第１インダクタンス素子の形状と前記第３インダクタンス素子の形状が同じで、前記第２インダクタンス素子の前記第１部分の形状と前記第２部分の形状とが同じである、請求項１～請求項４のいずれか１項に記載の回路基板。 The shape of the first inductance element and the shape of the third inductance element are the same, and the shape of the first part and the shape of the second part of the second inductance element are the same. 5. The circuit board according to any one of 4 above.
  7. 　請求項１～請求項６のいずれか１項に記載の前記回路基板と、
    　前記第１キャパシタンス素子および前記第２キャパシタンス素子として、前記回路基板に実装するコンデンサとを備える、フィルタ回路。     The circuit board according to any one of claims 1 to 6,
    A filter circuit comprising a capacitor mounted on the circuit board as the first capacitance element and the second capacitance element.
PCT/JP2015/084312 2015-04-20 2015-12-07 Circuit board and filter circuit using same WO2016170708A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2015-086055 2015-04-20
JP2015086055 2015-04-20

Publications (1)

Publication Number Publication Date
WO2016170708A1 true WO2016170708A1 (en) 2016-10-27

Family

ID=57143502

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2015/084312 WO2016170708A1 (en) 2015-04-20 2015-12-07 Circuit board and filter circuit using same

Country Status (1)

Country Link
WO (1) WO2016170708A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022070888A1 (en) * 2020-10-01 2022-04-07 株式会社村田製作所 Coil component, filter circuit containing same, and electronic device
US11451319B2 (en) 2019-11-25 2022-09-20 Murata Manufacturing Co., Ltd. High-frequency signal transmission-reception circuit

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56128007A (en) * 1980-03-11 1981-10-07 Nec Corp Low-pass filter
JPH08250962A (en) * 1995-03-10 1996-09-27 Tdk Corp Lc filter
JP2007202380A (en) * 2005-07-04 2007-08-09 Tdk Corp Surge absorbing element

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56128007A (en) * 1980-03-11 1981-10-07 Nec Corp Low-pass filter
JPH08250962A (en) * 1995-03-10 1996-09-27 Tdk Corp Lc filter
JP2007202380A (en) * 2005-07-04 2007-08-09 Tdk Corp Surge absorbing element

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11451319B2 (en) 2019-11-25 2022-09-20 Murata Manufacturing Co., Ltd. High-frequency signal transmission-reception circuit
WO2022070888A1 (en) * 2020-10-01 2022-04-07 株式会社村田製作所 Coil component, filter circuit containing same, and electronic device
JP7107463B1 (en) * 2020-10-01 2022-07-27 株式会社村田製作所 Electronics

Similar Documents

Publication Publication Date Title
US20160344181A1 (en) Composite electronic component
US9722567B2 (en) Variable-frequency resonance circuit and variable-frequency filter
US9843299B2 (en) Multilayer electronic component
US10530322B2 (en) Resonant circuit, band elimination filter, and band pass filter
US9893703B2 (en) Multilayer electronic component
WO2015037374A1 (en) Inductor and band elimination filter
US11699544B2 (en) Coil component and filter circuit including same
US20230071624A1 (en) Filter circuit and power supply device including the same
WO2016170708A1 (en) Circuit board and filter circuit using same
US11264162B2 (en) Coil component and filter circuit including the coil component
US10284164B2 (en) Circuit substrate, filter circuit, and capacitance element
US20230198490A1 (en) Coil component, filter circuit including the coil component, and electronic device
CN217588590U (en) Coil component and filter circuit including the same
US9948263B2 (en) Multilayer electronic component
US10382000B2 (en) Circuit board, filter circuit using the same, and capacitance element
JP6981584B2 (en) Multilayer boards, circuit devices, and filter circuit boards
US20160128177A1 (en) Multilayer electronic component
KR20150002345A (en) Band pass filter

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15889947

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

NENP Non-entry into the national phase

Ref country code: JP

122 Ep: pct application non-entry in european phase

Ref document number: 15889947

Country of ref document: EP

Kind code of ref document: A1