JP2605565Y2 - Multilayer noise removal components - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated noise removing component having a small loss.

[0002]

2. Description of the Related Art A conventional laminated noise elimination component is a component in which a conductor is buried in a magnetic ceramic (ferrite) body and terminals of the conductor are connected to external terminal electrodes formed on both end surfaces of the body. The basic structure of the conductor is a straight line formed at both ends, but a coil having a structure of orbiting a magnetic body in a coil shape is widely used in order to obtain a long magnetic path length.

A laminated noise removing component is used by being connected to an electric circuit, and removes noise generated in the circuit at the time of output so as not to be transmitted to the outside, or superimposes the noise on an externally received signal. It has the effect of removing noise and receiving it as a clean signal.

For example, assuming that the signal waveform is a geometric rectangular wave, FIG. 2A shows an example of a signal waveform when noise is superimposed on this signal. In particular, FIG. 3B shows a so-called rounded waveform in which the shape of a rectangular wave is rounded and distorted, and FIG. .

[0005] represents leaving the impedance of the laminated noise removal component used for removing the noise (Z) the real part (R) and imaginary part and the (X _L), 3 the relationship thereof with the frequency (f) This will be described below with reference to FIG. In addition,
The frequency of the noise that can be removed by this Zf curve is R = X _L
It is said that the frequency f _{R = XL} as a guide, and that noise of a higher frequency can be removed.

For example, a relatively high magnetic permeability (μ = 800)
When the number of windings is small using the magnetic material of the above, there is a region where noise cannot be removed, which is not preferable.
The peak value of The number of turns is Z is increased if Maze, X _L
The portion increases and the curve Z covers the noise removal band.

The above will be described with reference to FIGS.

[0008] If the required bandwidth of a frequency required for noise attenuation f _n and the time required impedance Z (R) is in FIG. 3 (a), a Z-f curve as shown in the same figure (b) If the inductor is used, fR _{= XL} is in a band lower than the desired band, Z (R) is small, and a region 4 (shown by hatching) in which noise cannot be completely removed occurs.

Therefore, as shown in FIG. 1C, when the number of turns is increased and the peak value of the curve Z is increased, Z (R) is increased so that a necessary fZ (R) region can be secured. Become.

However, in FIG. 3 (c), a portion where Z (R) is surplus and a loss more than necessary occur, so that the response of the rising and falling of the signal is deteriorated, and the R due to the increase in the number of turns is reduced. effect of increased _DC and X _L can also attenuate the signal system is large. Particularly X _L in the low frequency because of the low f _{R = XL} is larger than in the case of low magnetic permeability. The waveform of this type of laminated noise removing component is a blunt waveform.

Therefore, when a magnetic material having a low magnetic permeability is selected and the number of turns is reduced, the peak of Z moves to the high frequency side, and the peak value of Z increases. The waveform of this type of laminated noise removing component has a smaller R portion and can avoid rounding of the waveform, but increases ringing.

The above case is specifically shown in FIGS.
This will be described with reference to FIG.

Assuming that the required band of the frequency required for noise attenuation and the necessary impedance Z (R) at that time are the same as those of FIG. 3A, as shown in FIG. In the fZ curve, the maximum value of Z (R) is sufficient, but an area 4 is formed where the peak of the Z curve is too small to be removed. Therefore, when the number of turns is increased and Z (R) is increased as shown in FIG.
(R) An area is secured.

However, in FIG. 4B, R _DC and X _L
Is large, and Z is particularly large compared to a magnetic material having a high magnetic permeability.
Since R (R) is large, a portion where Z (R) is surplus and loss more than necessary occurs, and as a result, the response of the rising (falling) of the signal deteriorates. These are f
_{R = XL} is on the high frequency side, so Z is required until the required low frequency
This is because the Z (R) value must be unnecessarily large in order to extend (R).

[0015]

As described above, in the conventional laminated noise elimination component, whether the signal waveform is ignored and the rounding is avoided or the ringing is avoided with some knowledge of the waveform rounding depends on the side to be used. Choose one at your discretion,
There was a problem that there was no satisfaction with both.

The present invention has been developed for the purpose of removing noise that blunts an electric signal and noise that rings an electric signal. That is, an object of the present invention is to provide a laminated noise removing component that can easily remove noise. In other words, an object of the present invention is to provide a low-loss laminated noise elimination component that covers a required noise elimination band almost exactly.

[0017]

Means for Solving the Problems The present inventor has found that a conventional laminated noise elimination component is composed of a single kind of magnetic material, and that loss is large in order to cover a required noise elimination band. As a result of diligent research, the present inventor has developed a multilayer noise elimination component in which a coil conductor is covered with a plurality of magnetic materials having different magnetic permeability. Therefore, the peak frequency f of the total impedance Z of the developed laminated noise elimination component is located between the Z peak frequencies f of the plurality of magnetic materials having different magnetic permeability. In other words, the peak of the Zf curve of the developed laminated noise removing component becomes broad and the rise of the Zf curve becomes steep. As a result, the inventors have found that a laminated noise elimination component with a small loss that covers the required noise elimination band almost accurately can be obtained, and reached the present invention.

Therefore, the present invention is a laminated noise elimination component in which a conductor is formed in a coil shape in a ceramic laminate and each end of the conductor is led out to the surface of the laminate, wherein the ceramic laminate is at least a ceramic laminate. A first ceramic laminate having a first magnetic permeability and a first number of conductor turns and having a first impedance peak due to frequency change; and a second magnetic permeability and a second number of conductor turns. And a second ceramic laminated portion having a second impedance peak due to a frequency change.

[0019]

As described above, in the laminated noise elimination component of the present invention, a plurality of magnetic materials having different magnetic permeability cover the periphery of the coil conductor. Therefore, the Z
The peak frequency f of the impedance Z in the −f curve is located between the peak frequencies f of the respective materials Z of different materials. Therefore, the peak of the Zf curve of the laminated noise elimination component of the present invention becomes broad and the rise of the Zf curve becomes steep. That is, in the present invention, the overlap between the Zf curve and the noise elimination band is increased, and the laminated noise elimination component with less loss is obtained.

The above operation and effect will be described in detail with reference to FIGS. FIG. 1A shows the state of FIG.
And shows the necessary impedance at that time required band f _n of frequencies also required to noise attenuation in the case of, as shown in (b) of FIG. 1, a relatively high permeability as the material 2 (mu = 800 In the Zf curve when the magnetic material of (3) is selected and a three-turn conductor is internally provided, the contribution of the material 2 to Z (R) mainly attenuates low-frequency noise while lowering magnetic permeability (μ) = 120), the Z-f curve when a two-turn conductor is internally provided, as shown in FIG. 1C, the contribution of the material 1 to Z (R) is mainly It can be seen that high frequency noise is attenuated.

When the laminate of the material 2 is laminated on the laminate of the material 1 and integrated to form a 5-turn laminate, the number of turns is maintained at 5 as shown in FIG. The necessary Z (R) value has been cleared in the entire required frequency band, and as can be seen from the Z-f curve, there is little extra Z,
Since responsiveness rise and fall of the signal as described above is good, increase the number of turns is not as in the prior art, R _DC and X _L
Does not increase, and the signal loss is small.

[0022]

Embodiment 1 FIGS. 1 (a) to 1 (d) are Zf curve diagrams showing the characteristics of the laminated noise elimination component used in this embodiment, which will be described below with reference to these figures.

A ferrite raw material having a magnetic permeability of 120 is kneaded with an organic binder to form a first ferrite green sheet having a thickness of 50 μm, and a ferrite raw material having a magnetic permeability of 800 is kneaded with an organic binder to form a second ferrite green sheet having a thickness of 50 μm. Was formed.

A coil conductor pattern for forming a coil by laminating the first green sheet and the second green sheet is screen-printed, a plurality of first green sheets are stacked, and a plurality of second green sheets are stacked thereon. The first green sheet has two turns, the second green seed has three turns, and the coil has three turns, and a five-turn coil is internally provided. A laminate led to the end face of the element was obtained.

This was fired to form an external terminal electrode on the end face of the laminate, and the coil conductor terminal was connected to the external terminal electrode. FIG. 6 shows a transparent perspective view of the obtained laminated noise removing component.

FIG. 8 is a cross-sectional view of a laminate of a material 2 having a high magnetic permeability superposed on a laminate of a material 1 having a low magnetic permeability, and being parallel to the end face. (A) of the same figure is an example in which the inner conductors circulating around the materials 1 and 2 are close to each other, and (b) of the same figure is an example in which the circulating portions of the materials 1 and 2 are also separated. is there.

When the noise was removed by the laminated noise removing component, a signal waveform was not rounded and a waveform with little ringing was obtained as shown in FIG. 1D.

[0028]

Embodiment 2 FIGS. 5 (a) to 5 (e) are Zf curve diagrams showing characteristics of a laminated noise elimination component made of three different materials used in this embodiment. This will be described below.

In the first embodiment, a laminated noise elimination component is formed by laminating two magnetic materials having different magnetic permeability. In this embodiment, a magnetic material of material 1 having a low magnetic permeability and a high magnetic permeability are used. A magnetic material having a material 2 and a magnetic material having a material 3 having an intermediate magnetic permeability are prepared, and three magnetic materials having different magnetic permeability are prepared. One turn in the laminate and material 2
After laminating each laminate in the order of 1, 3, and 2 from the bottom so that the coil conductor of three turns goes around in the laminate of
According to the procedure of Example 1, a laminated noise removing component was obtained.

FIG. 7 is a transparent perspective view of the obtained part, and FIG.
(B) is a sectional view parallel to the end face. FIG. 9A shows an example in which a material 3 made of a magnetic / non-magnetic material is disposed between the materials 1 and 2, and FIG. (D) of the same figure is an example in which a part of a coil conductor portion circling over three materials is close to and partly apart.

The application of the present embodiment to the case where the required band required for noise attenuation shown in FIG. 1A is further widened in the first embodiment will be described.

That is, when the band 7 added in the direction of the white arrow in FIG. 5A is added, each Z (R) of each material portion constituting the laminated noise removing component is added.
5 (b) for material 2, FIG. 5 (c) for material 3, and FIG.
(D), there was a region 4 in which noise could not be completely removed in each Z curve, but in a five-turn laminate formed by laminating these materials 1, 2 and 3, the Z curve As shown in FIG. 5 (e), the required Z (R) value is covered in the required frequency band including the overfilled band, and the shape of the Z curve is good. It shows that noise of a wider band can be absorbed by increasing the noise.

[0033]

[Effects of the Invention] As described above, the present invention has solved the problem of the laminated noise removing component formed of a single magnetic material. That is, the present invention is characterized in that the coil conductor is covered by a laminated body integrated by a combination of a plurality of magnetic materials having different magnetic permeability. As a result, the peak of the Zf curve of the laminated noise elimination component according to the present invention becomes broad and the rise of the Zf curve becomes steep. Therefore, according to the present invention, it is possible to obtain a low-loss laminated noise elimination component that covers the required noise elimination band almost accurately. Thus, the noise elimination component having a small loss according to the present invention has a large effect of contributing to miniaturization such as high density mounting is possible because of little heat generation.

[Brief description of the drawings]

FIG. 1 is a Zf diagram showing characteristics of a laminated noise elimination component made of two different materials used in an embodiment of the present invention.

FIGS. 2A to 2C are examples of signal waveforms when noise is superimposed.

FIG. 3 is a Zf diagram showing characteristics of a conventional laminated noise elimination component composed of a single magnetic body having a relatively high magnetic permeability.

FIG. 4 is a Zf diagram showing the characteristics of a conventional laminated noise elimination component made of a single magnetic material having a relatively low magnetic permeability.

FIG. 5 is a Zf diagram showing characteristics of a laminated noise elimination component made of three different materials used in another embodiment of the present invention.

FIG. 6 is a transparent perspective view of the laminated noise elimination component of the present invention made of two different materials.

FIG. 7 is a transparent perspective view of the laminated noise elimination component of the present invention made of three different materials.

8 (a) and 8 (b) are cross-sectional views parallel to the end faces of the laminated noise elimination component shown in FIG. 6;

9 (a) to 9 (d) are cross-sectional views parallel to the end faces of the laminated noise elimination component shown in FIG. 7;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Laminated body made of material 1 2 Laminated body made of material 2 3 Laminated body made of material 3 4 Unremovable area 5 Internal conductor pattern 6 External terminal electrode 7 Overfilled area

Claims (1)

(57) [Scope of request for utility model registration] 1. A laminated noise removing component in which a conductor is formed in a coil shape in a ceramic laminate and each end of the conductor is led out to the surface of the laminate, wherein the ceramic laminate has at least a first transparent member. A first having a first impedance peak due to frequency change having a magnetic susceptibility and a first number of conductor turns;
A second laminated body having a second permeability peak and a second impedance peak due to a frequency change having a second magnetic permeability and a second number of conductor turns.
A multilayer noise elimination component comprising: a ceramic laminated portion;