JP2005318643A - Distributed constant type noise filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remove an electric noise emitted from an electronic component in a wide band by providing a distributed constant circuit in which a metallic plate is constituted of a resistance, an inductance and the electrostatic capacity of an electrode when allowing currents to flow to the electrodes of a noise filter. <P>SOLUTION: A distributed constant type noise filter includes a distributed constant circuit forming part in which two almost plate-shaped dielectrics are formed with an almost plate-shaped metallic plate interposed. Moreover, this distribution constant noise filter is provided with a cathode terminal conducted to the distributed constant circuit forming part, an electrode part constituted by projecting a part of the metallic plate from the dielectrics, and an anode terminal electrically connected to the electrode part. In this distributed constant type noise filter, the ratio of length W of the short side direction of the distributed constant circuit forming part and effective thickness (h) of the dielectrics and length L of the long side direction of the distributed constant circuit forming part are set on the basis of the dielectric constant of the distributed constant circuit forming part so that any electric noise emitted from the electronic component can be removed in a wide band. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a distributed constant noise filter, and more particularly to a distributed constant noise filter having a wide band and excellent high frequency characteristics.

  Digital technology is an important technology that supports the IT (Information Technology) industry. Recently, digital circuit technology such as LSI is used not only for computers and communication-related devices but also for home appliances and in-vehicle devices.

  A high-frequency current generated in an LSI or the like is not limited to the vicinity of the LSI but spreads over a wide range in a mounting circuit board such as a printed circuit board, is inductively coupled to a signal wiring or a ground wiring, and leaks as electromagnetic waves from the signal cable or the like.

In circuits where analog circuits and digital circuits are mixedly mounted, such as circuits in which a part of conventional analog circuits is replaced with digital circuits, or digital circuits having analog input / output, the problem of electromagnetic interference from digital circuits to analog circuits becomes serious. It has become to.

  For this measure, it is effective to separate the LSI, which is the source of the high-frequency current, from the power supply system at high frequency, that is, a power supply decoupling technique. Conventionally, noise filters such as bypass capacitors have been used for decoupling elements, and although the principle of operation of power supply decoupling is simple and clear, the development of low-impedance noise filters that can cope with high-speed digital circuits has been greatly developed. It was late. In particular, it was difficult to maintain a low impedance up to a high frequency range due to the self-resonance phenomenon of the capacitor.

  For this reason, in order to cope with a higher-speed and higher-frequency digital circuit, a low impedance noise filter that can maintain decoupling up to a high frequency band is desired. A capacitor as a noise filter used in a conventional AC circuit constitutes a lumped constant type noise filter having a two-terminal configuration, and a solid electrolytic capacitor, an electric double layer capacitor, and a ceramic capacitor are often used.

  When these capacitors are used to remove electrical noise in an AC circuit over a wide frequency band, different types of capacitors, such as aluminum electrolytic capacitors, tantalum capacitors, ceramic capacitors, etc. with different self-resonant frequencies, are used. This is done by providing a plurality of capacitors in the AC circuit.

  However, in the conventional noise filter, it is troublesome to select a plurality of noise filters used for removing electrical noise of a wide frequency band. In addition, there is a problem that the cost increases because a plurality of different types of noise filters are installed.

  Accordingly, an object of the present invention is to provide a noise filter that can filter out electrical noise emitted from electronic components in a high frequency band as well as removing a wide frequency range with a single noise filter element. .

  According to the present invention, a distributed constant noise filter of a three-terminal capacitor type having a transmission line structure can be obtained.

  That is, by controlling the width, length, and thickness of the distributed constant circuit forming portion, a distributed constant type noise filter that virtually includes a distributed constant circuit capable of generating a wide range of impedance can be obtained.

  According to the present invention, in the distributed constant type noise filter, the first conductor having a first electrode connected to a power source and a second electrode connected to an electrical component at both ends; A distributed constant formed in a region where the first conductor and the second conductor are disposed opposite to each other, and a second conductor connected to a fixed potential. The distributed constant circuit forming unit has a short side length (W), a long side length (L), and an effective length so as to form a transmission line structure. A distributed constant noise filter characterized in that the thickness (h) is set is obtained.

  More specifically, the distributed constant type noise filter according to the present invention includes a distributed constant circuit forming unit formed by sandwiching a substantially flat plate-shaped metal plate between two substantially flat plate-shaped dielectrics, and the distributed constant circuit forming unit. A basic terminal provided with a cathode terminal electrically connected to the electrode, an electrode part in which a part of the metal plate protrudes from the dielectric, and an anode terminal electrically connected to the electrode part. The length W in the short side direction of the distributed constant circuit forming part, the length L in the long side direction of the distributed constant circuit forming part, and the effective thickness h of the distributed constant circuit forming part are the dielectric constant of the distributed constant circuit forming part. It is set based on this.

  As another embodiment of the present invention, a distributed constant noise filter having the above basic configuration includes a ratio between the length W in the short side direction of the distributed constant circuit forming portion and the effective thickness h of the dielectric, and the distributed constant. The length L in the long side direction of the circuit forming portion is set based on the dielectric constant of the distributed constant circuit forming portion.

  With these configurations, the impedance can be lowered over a wide frequency band. Furthermore, since the impedance can be lowered on the high frequency side, it is possible to provide a distributed constant type noise filter that removes electrical noise in a wide band, particularly at a high frequency.

  Still another embodiment of the present invention is characterized in that, in the distributed constant noise filter, the surface area S2 of the anode terminal is set larger than the installation area S1 between the anode terminal and the electrode portion.

  By adopting such a configuration, the impedance can be made smaller than the structure in which S1 and S2 are equal, and electrical noise can be eliminated at high frequencies.

  In the distributed constant type noise filter, the length W2 in the short side direction of the electrode connected to the power source is set to be larger than the length W1 in the short side direction of the load side electrode connected to the electronic component. Also features.

  In general, the impedance of a DC power supply is low, and the impedance of an LSI power supply terminal is high. Therefore, with such a configuration, the impedance on the load side to which an LSI or the like is connected is increased and matched, and electrical noise can be guided to the distributed constant noise filter according to the present invention to be easily attenuated.

  Furthermore, these distributed constant type noise filters can have a configuration in which one or more notches are formed on the side surface portion on the long side of the distributed constant circuit forming portion. With the configuration in which such a notch is formed, an impedance disparity is generated in the distributed constant circuit forming portion, and as a result, attenuation of electrical noise can be improved.

  Further, in the distributed constant noise filter having the configuration in which the notch portion is formed, the distributed constant circuit forming portion includes the length W2 in the short side direction of the electrode portion connected to the power source and the load side to which the electronic component is connected. It has the area | region set smaller than any one of the length W1 of the short side direction of this electrode part.

  By adopting such a configuration, it is possible to form a region with high impedance in the distributed constant circuit forming unit, form a π-type filter circuit, and improve attenuation of electrical noise.

  Furthermore, in the distributed constant type noise filter having the configuration in which the cutout portion is formed, the distributed constant circuit forming portion has one or more bent shapes such as a meandering shape. By adopting such a configuration, the attenuation of electrical noise is improved by increasing the line length of the transmission line, that is, the length of the distributed constant circuit forming portion in the long side direction.

  The distributed constant type noise filter according to the present invention described above is also characterized in that the distributed constant circuit forming portion has a structure in which a solid electrolytic capacitor, an electric double layer capacitor, or two or more electric double layer cells are laminated. . With such a configuration, the withstand voltage in the distributed constant circuit forming portion can be improved.

  The distributed constant noise filter according to the present invention is characterized in that lead wires are connected to each electrode portion or each anode terminal and cathode terminal. By adopting such a configuration, the impedance characteristics at high frequencies are slightly deteriorated, but convenience in mounting is increased.

  As described above, according to the distributed constant type noise filter according to the present invention, it is possible to accurately detect broadband frequency noise without installing a plurality of noise filters (capacitors) having different self-resonant frequencies as in the prior art. Can be removed. That is, it is not necessary to perform troublesome work such as setting a frequency band for noise removal on the capacitor installed in the AC circuit, and the cost can be reduced.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

  Referring to FIGS. 1A to 1C, a distributed constant noise filter 1 according to the present invention includes a pair of electrode portions 21a protruding in the long side direction of a rectangular parallelepiped distributed constant circuit forming portion 2. And a three-terminal capacitor structure. As shown in FIGS. 1 (b) and 1 (c) of the AA cross section and the BB cross section of FIG. 1 (a), the distributed constant circuit forming unit 2 is configured to divide a substantially flat metal plate 21 into two dielectrics. It has a transmission line structure called a strip line sandwiched between opposing metal layers 41 with the body 22 interposed therebetween. A portion where the metal plate 21 protrudes from both ends of the distributed constant circuit forming portion 2 is an electrode portion 21a. As described below, the distributed constant type noise filter element having such a configuration has both electrode portions 21a connected to a power source and a load circuit, respectively, and the opposing metal layer 41 has a fixed potential such as a ground potential. By being connected, it functions as a noise filter with a wide frequency band.

  In the following description, the length of the distributed constant circuit forming unit 2 in the long side direction (X direction) of the noise filter 1 is L, and the length of the short side direction (Y direction) of the distributed constant circuit forming unit 2 is W.

  The noise filter 1 according to the present invention is installed on a mounting board 30 connected to a power source and electronic components. That is, both electrode portions 21a of the noise filter 1 are connected to the power supply terminal 31 connected to the DC power supply 8 and the component terminal 32 connected to the electronic component 9 such as an LSI on the mounting substrate 30, respectively. Further, the mounting substrate 30 is provided with an electrode terminal 4 for setting the counter metal layer 41 of the distributed constant circuit forming unit 2 to a fixed potential such as a ground potential.

  As an example of the noise filter shown in FIG. 1, an aluminum solid electrolytic capacitor 6 as shown in FIG. 2 will be described. In this aluminum solid electrolytic capacitor, the surface of the foil-like aluminum 21 is roughened by an etching process, and an oxide film 22b is formed as a dielectric along the surface. Further, a solid electrolyte layer 22c such as a conductive polymer layer, graphite, and a silver paste layer 22a are formed on the surface of the oxide film as a counter electrode. This configuration has a stripline structure similar to that of the noise filter of FIG. That is, the line conductor is aluminum at the center, and the dielectric corresponds to an etching layer on which an oxide film is formed. The ground conductor corresponds to a solid electrolyte layer, graphite, and silver paste layer. Since the etching layer is processed to increase the surface area, the same shape can provide a larger capacitance than a ceramic capacitor using a single material, and is suitable for a distributed constant noise filter.

  The shape of the prototyped line element is 10 mm line width × 20 mm line length, and the thickness corresponding to the thickness of the dielectric is about 0.15 mm. Moreover, the electrostatic capacitance in the whole track | line was 330 micro F (rated voltage 4V). The characteristic impedance of this element is calculated as 0.5 mΩ by the following formula.

  As described above, the electrode portion 21a is connected to the power supply terminal 31 and the component terminal 32. As shown in FIG. 3, the surface area S2 of the power supply terminal 31 and the component terminal 32 is different from that of the electrode portion 21a and the power supply terminal 31. Further, it is desirable to set the area larger than each area S1 of the connection region with the component terminal 32. The first reason is to reduce the contact resistance by increasing the contact area between the two as much as possible. This is because if the contact resistance is large, a direct current loss occurs and heat is generated. The second reason is that if the areas of the power supply terminal 31 and the component terminal 32 are small, the impedance of these terminals becomes high and it is difficult to introduce a high frequency current as a noise component into the metal plate 21.

  Here, the structure determination of the distributed constant type noise filter according to the present invention capable of removing electrical noise of a high frequency over a wide band will be described below.

First, in a transmission line model configured as shown in FIG. 4A in which an internal metal plate 21 is sandwiched between a pair of metal plates 40 via a dielectric 20, the capacitance C and the inductance L per unit length are as follows. ,
C = 4ε ₀ ε _r W / d, L = 1/4 · μ ₀ · d / W
(Ε ₀ : dielectric constant of vacuum, ε _r : relative dielectric constant of dielectric, d: thickness of dielectric, μ ₀ : permeability of vacuum)
It can be expressed as.

Thereby, the characteristic impedance Z ₀ of this transmission line model is as follows.

Z ₀ = (L / C) ^1/2
= 1/4 · (d / W) · (μ ₀ / ε ₀ ε _r ) ^1/2
Next, consider the case where the transmission line distributed constant circuit forming portion is an aluminum solid electrolytic capacitor, an electric double layer capacitor, or a ceramic capacitor.

The distributed constant circuit forming part of the aluminum solid electrolytic capacitor has an oxide film formed on the aluminum whose surface area has been expanded by etching, and the distributed constant circuit forming part of the electric double layer capacitor is formed at the interface between the activated carbon electrode surface and the electrolyte. Yes. These have complicated shapes. In order to facilitate handling, these cases are handled by defining an equivalent relative dielectric constant from the capacitance per unit length and the effective thickness. Assuming that the capacitance C per unit length, the effective thickness of the distributed constant circuit forming portion is h, and the equivalent relative dielectric constant is ε _u , ε _u = 1 / from C = 4 · ε ₀ ε _u · W / h (4ε ₀ ) · C · h / W
(Ε ₀ is the dielectric constant of vacuum 8.85 × 10 ⁻¹² F / m)
Here, in the case of the general aluminum solid electrolytic capacitor as described above, the capacitance per unit length and the effective thickness and width of the distributed constant circuit forming portion (here, the etching layer on which the oxide film is formed) are as follows: Therefore, C = 1.65 × 10 ⁻² (F / m)
h = 1.5 × 10 ⁻⁴ (m), W = 1.0 × 10 ⁻² (m)
The equivalent relative dielectric constant ε _u is 7.0 × 10 ⁶ .

Similarly, in the case of a general electric double layer capacitor, the capacitance per unit length and the effective thickness and width of the distributed constant circuit forming portion (here, the portion sandwiched between the upper and lower current collectors) are: Since it is approximately the following value, C _u = 3.54 × 10 ¹ (F / m)
h = 1 × 10 ⁻⁴ (m), W = 1 × 10 ⁻² (m)
The equivalent relative dielectric constant ε _u is 1.0 × 10 ¹⁰ .

In a ceramic capacitor, when the distributed constant circuit forming portion is made of a uniform ceramic material itself, the equivalent relative dielectric constant itself is the relative dielectric constant of the ceramic material, which is about 8.0 × 10 ³ .

In the above characteristic impedance equation, if the equivalent relative dielectric constant ε _u of each capacitor is used as the relative dielectric constant ε _r of the dielectric, and the effective thickness h is used as d, the characteristic impedance is as follows.

Z ₀ = ¼ · (h / W) · (μ ₀ / ε ₀ ε _u ) ^1/2
In order to sufficiently remove electrical noise, it is desired that the characteristic impedance be 0.1Ω or less. Therefore, the condition for the characteristic impedance to be 0.1Ω or less is W / h> 2.5. (Μ ₀ / ε ₀ ε _u ) ^1/2
It is.

The vacuum permittivity ε ₀ is 8.85 × 10 ⁻¹² (F / m), and the vacuum permeability μ ₀ is 1.
26 × 10 ⁻⁶ (H / m), and substituting the value of ε _{u in} each capacitor, for an aluminum solid electrolytic capacitor, W / h> 0.36
For electric double layer capacitors, W / h> 0.009
For ceramic capacitors, W / h> 11
It becomes.

  Further, the wavelength at the distributed constant circuit forming portion can be calculated by the following formula in consideration of wavelength shortening due to the dielectric.

λ = c / fε _r ^1/2
Where λ: wavelength (m), c: speed of light 3.0 × 10 ⁸ (m / s), f: frequency (Hz)
When the frequency range of generally required noise regulation is set to 30 MHz to 1 GHz, the wavelength value at 30 MHz, which is the longest wavelength, is calculated by calculating ε _r by the value of ε _u .
3.8mm for aluminum electrolytic capacitors
0.1mm for electric double layer capacitors
112mm for ceramic capacitors
It is. Here, in order to perform sufficient attenuation, it is desirable that the length L in the long side direction of the noise filter is ¼ wavelength or more. Therefore, when looking at the case where each is adopted for the distributed constant circuit formation part,
For aluminum electrolytic capacitors L> 0.95mm
For electric double layer capacitors L> 0.025mm
For ceramic capacitors L> 28mm
By setting as above, it is possible to obtain a distributed constant type noise filter capable of removing electrical noise over a wide band.

  FIG. 4B is a graph showing the relationship between the frequency and the impedance in the distributed constant noise filter according to the present invention thus obtained.

  Here, the relationship between frequency and impedance when a conventional noise filter (0.1 μF multilayer ceramic chip capacitor) is used is also shown. In this graph, the distributed constant type noise filter according to the present invention and the conventional noise filter are installed on a mounting substrate, connected to a network analyzer, and the S parameters are measured to calculate respective impedances.

  As is apparent from the comparison with this graph, the distributed constant noise filter according to the present invention has a smaller impedance from low frequency to high frequency than the conventional one. In addition, the impedance difference is not only small over a wide band, but also the impedance is not significantly increased for high frequencies of 10 MHz or more unlike the conventional noise filter. Can be obtained.

  Next, the operation of the embodiment of the distributed constant noise filter according to the present invention will be described with reference to FIG.

  In the distributed constant noise filter according to the present invention, a DC power source 8 is indirectly connected to one electrode portion 21a via an anode terminal 3, and an electronic device such as an LSI is indirectly connected to the other electrode portion 21a via an anode. The component 9 is connected and implemented.

  Next, a configuration of the distributed constant noise filter according to the second embodiment of the present invention will be described. However, in this description, description of portions having the same configuration as that of the above-described embodiment of the present invention will be omitted.

  FIG. 5 is a plan view showing the configuration of the distributed constant noise filter according to the second embodiment of the present invention. As shown in FIG. 5, the distributed constant circuit forming unit 2 may be formed so that the lengths of both short sides thereof are different.

  That is, if the length of the long short side of the distributed constant circuit forming unit 2 is W2, and the length of the short short side is W1, of the two electrode portions 21a protruding from both short sides of the distributed constant circuit forming unit 2, A power source 8 is connected to the electrode portion 21 a protruding from the long short side via the anode terminal 3.

  Further, of the two electrode portions 21 a protruding from both short sides of the distributed constant circuit forming portion 2, an electronic component 9 such as an LSI is connected to the electrode portion 21 a protruding from the short short side via the anode terminal 3. Is done.

    Next, the configuration of the third embodiment of the distributed constant noise filter according to the present invention will be described. However, in this description, description of portions having the same configuration as that of the above-described embodiment of the present invention will be omitted.

  FIG. 6 is a plan view showing the configuration of the distributed constant noise filter according to the third embodiment of the present invention.

  As shown in FIG. 6, in the third embodiment of the distributed constant type noise filter according to the present invention, the shape of the distributed constant circuit forming section 2 has a region constricted substantially at the center. Specifically, one or more notches are provided on the long side surface of the distributed constant circuit forming unit 2, and the short length satisfying W> W3 with respect to the length W of both short sides of the distributed constant circuit forming unit 2. A region having a side length W3 is formed.

  At this time, the lengths of both short sides of the distributed constant circuit forming unit 2 do not have to be equal, and it is sufficient that W3 is at least smaller than the length of either one of the short sides of the distributed constant circuit forming unit 2.

  Next, the configuration of the fourth embodiment of the distributed constant noise filter according to the present invention will be described. However, in this description, description of portions having the same configuration as that of the above-described embodiment of the present invention will be omitted.

  FIG. 7 is a plan view showing a configuration of the distributed constant noise filter according to the fourth embodiment of the present invention.

  As shown in FIG. 7, in the fourth embodiment of the distributed constant noise filter according to the present invention, two or more notches are formed on the side surface on the long side of the distributed constant circuit forming unit 2, and the distribution The constant circuit forming portion 2 itself has a bent zigzag shape. By adopting such a shape for the distributed constant circuit forming unit 2, the line length of the distributed constant circuit forming unit 2 is increased, and electrical noise can be filtered over a wide band of frequencies.

  FIG. 8 is a graph showing the relationship between the frequency and the impedance in the embodiment of the distributed constant noise filter according to the present invention thus obtained. Here, the relationship between frequency and impedance in the case of using a conventional noise filter (0.1 μF chip capacitor) is also shown.

  In this graph, the distributed constant type noise filter according to the present invention and the conventional noise filter are installed on a mounting substrate, connected to a network analyzer, and the S parameters are measured to calculate respective impedances. As is clear from the comparison, it can be seen that the distributed constant noise filter according to the present invention has a smaller impedance from a low frequency to a high frequency as compared with the prior art.

  Further, not only the impedance change is small over a wide band, but also the impedance is not significantly increased for a high frequency of 10 MHz or more unlike the conventional noise filter, so that a noise filter that is more stable than the conventional noise filter is obtained. be able to.

  In particular, in any of the embodiments of the distributed constant type noise filter according to the present invention, since the impedance is lower on the higher frequency side than the conventional noise filter, the removal of high frequency electrical noise accompanying the improvement of LSI technology. Can be achieved.

  As described above, in the embodiment of the distributed constant type noise filter according to the present invention, a solid electrolytic capacitor can be mainly used as the distributed constant circuit forming unit, but an electric double layer capacitor is particularly used in the distributed constant circuit forming unit. In the following, a fifth embodiment will be described.

  However, in this description, description of portions having the same configuration as that of the above-described embodiment of the present invention will be omitted.

  FIG. 9A is a plan view showing the configuration of the fifth embodiment of the distributed constant noise filter according to the present invention.

  As shown in FIG. 9A, in the fifth embodiment of the distributed constant noise filter according to the present invention, an electric double layer capacitor is employed in the distributed constant circuit forming section. The withstand voltage can be further increased by using the distributed constant circuit forming portion including the electric double layer cell 71.

  Further, as shown in FIG. 9B, each electric double layer capacitor 7 includes an activated carbon electrode 24 that is electrically connected to the current collector 23, with current collectors 23 arranged above and below the gasket 27 forming an anode and a cathode. And the electrolyte solution 25 is formed so that the separator 26 which can pass electrolyte solution is pinched | interposed.

  FIGS. 10A and 10B are a plan view and a CC cross-sectional view showing the configuration of the distributed constant noise filter according to the sixth embodiment of the present invention. As shown in FIG. 10A, in the sixth embodiment of the distributed constant noise filter according to the present invention, lead wires 311 and 321 are connected to each electrode part or each anode terminal, and the cathode terminal 4 is connected. One lead wire 400 or a plurality of lead wires 400 (two in the figure) are connected. As a result, the impedance characteristics at high frequencies are slightly deteriorated, but convenience in mounting is increased.

  Finally, the main features of the present invention are listed below.

(1) In a distributed constant noise filter, a first conductor having both ends of a first electrode connected to a power source and a second electrode connected to an electrical component, and the first conductor And a second conductor connected to a fixed potential, and a distributed constant circuit forming unit formed in a region where the first conductor and the second conductor are arranged opposite to each other The distributed constant circuit forming unit has a short side length (W), a long side length (L), and an effective thickness (form) so as to form a transmission line structure. h) is set, a distributed constant type noise filter.

(2) The distributed constant according to (1), wherein the length (L) in the long side direction is set to be a length of ¼ wavelength or more of a high frequency generated from the electronic component. Type noise filter.

(3) The ratio of the length (W) in the short side direction to the thickness (h) is set so that the characteristic impedance in the transmission line model of the distributed constant noise filter is 0.1Ω or less. The distributed constant noise filter according to (1) above, characterized in that:

(4) The distributed constant noise filter according to (1), wherein a surface area (S2) of the anode terminal is set larger than an installation area (S1) between the anode terminal and the electrode portion.

(5) The length (W2) in the short side direction of the first electrode part is set to be larger than the length (W1) in the short side direction of the second electrode part. (1) The distributed constant type noise filter according to (1).

(6) The distributed constant noise filter according to the above (1), wherein one or more notches are formed in a side portion on the long side of the distributed constant circuit forming portion.

(7) It is characterized in that it is set smaller than either the length W2 in the short side direction of the first electrode part or the length (W1) in the short side direction of the second electrode part. The distributed constant noise filter according to (5) above.

(8) The distributed constant noise filter according to the above (1), wherein the distributed constant circuit forming section has one or more bent shapes.

(9) The distributed constant noise filter according to (1), wherein the distributed constant circuit forming unit is a solid electrolytic capacitor.

(10) The distributed constant type noise filter according to (1), wherein the distributed constant circuit forming unit is an electric double layer capacitor.

(11) The solid electrolytic capacitor is an aluminum solid electrolytic capacitor, and is set so that a ratio between the length (W) in the short side direction and the thickness (h) is larger than 0.36. The distributed constant noise filter according to (9), characterized in that it is characterized in that

(12) The ratio of the length (W) in the short side direction to the thickness (h) is 0.
The distributed constant noise filter according to the above (10), which is set to be larger than 009.

(13) The above (1), wherein each lead wire is connected to the first electrode portion and the second electrode portion, and one or more lead wires are connected to the second conductor. ) Distributed constant noise filter as described.

The top view and sectional drawing which show the structure in 1st embodiment of the distributed constant type noise filter which concerns on this invention. The cross-sectional perspective view which shows the case of the solid electrolytic capacitor of 3 terminal structure as a noise filter of this invention. The top view for demonstrating the preferable form of the electrode part in Fig.1 (a). The perspective view which shows the distributed constant circuit formation part of the distributed constant type noise filter by 1st embodiment which concerns on this invention, and the graph which shows the frequency characteristic compared with a prior art example. The top view which shows the structure in 2nd embodiment of the distributed constant type noise filter which concerns on this invention. The top view which shows the structure in 3rd embodiment of the distributed constant type noise filter which concerns on this invention. The top view which shows the structure in 4th Embodiment of the distributed constant type noise filter which concerns on this invention. The graph which shows the frequency characteristic in the 1st-4th embodiment of the distributed constant type noise filter concerning this invention compared with a prior art example. Sectional drawing which shows the structure in 5th Embodiment of the distributed constant type noise filter which concerns on this invention, and a cross-sectional perspective view which shows the structure of the single cell of the electric double layer capacitor shown in the figure. The top view which shows the structure in 6th Embodiment of the distributed constant type noise filter which concerns on this invention, and its sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Distributed constant type noise filter 2 Distributed constant circuit formation part 3 Anode terminal 4 Cathode terminal 5 Insulation part 6 Solid electrolytic capacitor 7 Electric double layer capacitor 8 Power supply 9 Electronic component 20, 22 Dielectric 21 Metal plate 21a Electrode part 22a Graphite, silver Paste layer 22b Oxide film 22c Solid electrolyte layer such as conductive polymer layer 23 Current collector 24 Activated carbon electrode 25 Electrolytic solution 26 Separator 27 Gasket 30 Mounting substrate 40 Metal plate 41 Opposing metal layer 71 Electric double layer cell 311, 321, 400 Lead

Claims (9)

  Distributed constant noise of a transmission line structure including substantially flat first and second conductors arranged opposite to each other and an electric double layer capacitor structure formed between the first and second conductors filter.   2. The distributed constant type noise filter according to claim 1, wherein the electric double layer capacitor structure includes a current collector and an electric double layer cell formed by sandwiching the activated carbon electrode and the separator.   3. The distributed constant noise filter according to claim 2, wherein a plurality of the electric double layer cells are stacked.   4. The distributed constant noise according to claim 1, wherein the first conductor has a first electrode terminal at one end and a second electrode terminal at the other end. filter.   When the electric double layer capacitor structure has a length (W) in the short side direction, a length (L) in the long side direction, and an effective thickness (h), the length (W) in the short side direction 5. The distributed constant noise filter according to claim 1, wherein a ratio with the thickness (h) is set to be larger than 0.009. 6. A flat plate-like capacitor including first and second substantially flat plate-like conductors arranged opposite to each other and a dielectric sandwiched between the first and second conductors;
The capacitor is formed such that a current collector, an activated carbon electrode, and an electrolytic solution sandwich a separator, and the dielectric is formed at an interface between the surface of the activated carbon electrode and the electrolytic solution. An electric double layer capacitor constituting the body,
One end of the first conductor is electrically connected to a power source;
The other end of the first conductor is electrically connected to an electronic component;
The second conductor is electrically connected to another potential of the power source;
The capacitor has a length (W) in a short side direction, a length (L) in a long side direction, and an effective thickness (h) set based on a dielectric constant of the capacitor to form a transmission line structure. A distributed constant noise filter characterized by   7. The distributed constant noise filter according to 6, wherein the electric double layer capacitor includes a plurality of electric double layer cells.   8. The distributed constant noise filter according to claim 7, wherein the ratio of the length (W) in the short side direction to the thickness (h) is set to be larger than 0.009.   In a distributed constant type noise filter, a first conductor having a first electrode connected to a power source and a second electrode connected to an electrical component at both ends, and disposed opposite to the first conductor And a second constant conductor connected to a fixed potential, and a distributed constant circuit forming portion formed in a region where the first conductor and the second conductor are arranged to face each other. The distributed constant circuit forming unit has a short side length (W), a long side length (L), and an effective thickness (h) so as to form a transmission line structure. A distributed constant type noise filter characterized by being set.

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