JPH04108209A - Lc noise filter - Google Patents

Abstract

PURPOSE:To obtain an excellent electric characteristic without lowering the inductance of a 1st conductor by forming the 1st conductor acting like an inductor to one side of a dielectric body in spiral and forming a 2nd conductor to other side of the dielectric body opposite to a inter-wire region of the 1st conductor. CONSTITUTION:A 1st conductor 12 acting like an inductor is formed in spiral to one side of an insulating board 10. Moreover, a 2nd conductor 30 is formed in spiral to other side 10b of the board 10 in a way opposite to an inter-wire region 16 of the conductor 12. Since the inter-wire distance between the conductors 12 and 30 provided to both the sides of the board 10 is shorter than the inter-wire distance of the conductor 12, the conductor 30 acts like a shield conductor preventing the line short-circuit. Thus, an excellent characteristic is obtained without losing the function of the conductor 30 as an inductor.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to improvements in LC noise filters.

[Prior Art] Conventionally, as shown in FIG. 14(A), a first conductor 12 is formed in a spiral shape on one surface of an insulating substrate 10 made of ceramic or the like, and as shown in FIG. 14(B), A noise filter is known in which a ground conductor 14 is formed on the other side. In this noise filter, as shown in FIG. 15, the spiral first conductor 12 has an inductance L, and
A capacitance C is obtained between the spiral first conductor 12 and the ground conductor 14 in a distributed constant manner, and functions as an LC noise filter.

[Problems to be Solved by the Invention] However, such conventional LC noise filters have the following problems.

(a) First problem Conventional noise filters do not have the expected inductance of the first conductor 12 formed in a spiral shape, and have electrical characteristics that are more similar to capacitors than to LC noise filters. The problem was that I couldn't get it. This is presumed to be due to the following reasons.

That is, in this LC noise filter, the ground conductor 14 is capacitively coupled to the spiral first conductor 12 by electrostatic capacitance, and is also inductively coupled. Therefore,
An electromotive force is also generated in the ground conductor 14 due to the magnetic flux generated by the current flowing through the spiral first conductor 12, and this electromotive force causes a short circuit current as shown by a solid line A to flow.

If the spiral-shaped first conductor 12 is likened to the primary film in a transformer, the ground conductor 14 acts like a shorted secondary coil, and the spiral-shaped first conductor 12 has the expected effect. Only inductance can be obtained, and this is thought to be the reason why it cannot function adequately as an LC noise filter.

(b) Second problem This noise filter has a first
A signal is passed through the electrodes 18 and 20 at both ends of the conductor 12, and noise contained in this signal is removed. However, as the frequency of the energization signal becomes high, the spirally wound first conductor 12 There was a problem in that a short circuit between the lines as shown by arrow B occurs, and the first conductor 12 no longer functions as an inductor.

In particular, such line-to-line short-circuit phenomena occur more frequently as the frequency of the energizing signal becomes higher, so there is a problem in that conventional noise filters cannot be used as high-frequency noise filters.

[Object of the Invention] The present invention has been made in view of such conventional problems, and its first purpose is to solve the first problem, and its second purpose is to solve the first problem. An object of the present invention is to provide an LC noise filter having excellent electrical characteristics that solves both of the above and the second problems.

[Means for Solving the Problem] In order to solve the problem, the LC noise filter of the present invention includes: a dielectric, a first conductor formed in a spiral shape on one surface of the dielectric and functioning as an inductor, and a first conductor that functions as an inductor. The second conductor is formed on the other surface of the dielectric so as to face the inter-line region of the first conductor, and forms a capacitor with the first conductor.

[Effect] Next, the present invention will be explained in detail.

The present inventor conducted a study as to why, for example, in the LC noise filter shown in FIG. 14, the expected inductance cannot be obtained in the first conductor 12 formed in a spiral shape.

Based on the assumption that the major cause of this is the short-circuit current flowing through the ground conductor 14 as shown by the solid line A, how should we form the second conductor that functions as a capacitor on the other side of the substrate? We investigated whether it is possible to obtain an LC noise filter with good characteristics without impairing the function of the first conductor as an inductor.

As a result of this study, the inventor of the present invention formed the second conductor so as to face the interline region of the first conductor, thereby obtaining sufficient inductance for the first conductor, and
It has been found that sufficient capacitance can be obtained between the first and second conductors, resulting in a noise filter with good electrical characteristics.

Furthermore, the second conductor is formed in a spiral shape so as to face the line-to-line region of the first conductor, so that the second conductor functions as a shield conductor to prevent line-to-line short circuit of the first conductor. will also function. As a result, it was confirmed that the first conductor sufficiently functions as an inductor without causing a line-to-line short circuit as in the conventional case.

As described above, according to the present invention, it is possible to obtain an LC noise filter having excellent electrical characteristics from a low frequency region to a high frequency region.

[Example] Next, a preferred example of the present invention will be described in detail based on the drawings.

First Embodiment FIGS. 1 and 2 show a preferred first embodiment of the LC noise filter according to the present invention.

In the LC noise filter of the embodiment, as shown in FIG. 1(A), a first conductor 12 functioning as an inductor is formed in a spiral shape on one surface of an insulating substrate 10 made of ceramic or the like. The outer end of the spiral first conductor 12 is directly connected to the terminal 12, and the inner end is connected to the terminal 20 via a lead 22. In addition,
The locations where the leads 22 and the first conductor 12 intersect are insulated from each other.

Further, as shown in FIG. 1(B), a second conductor 30 is formed in a circular shape on the other surface 10b of the insulating substrate 10 so as to face the interline region 16 of the first conductor 12. The outer end of the second conductor 30 is directly connected to the terminal 32.

FIG. 2(A) shows an equivalent circuit diagram of the LC noise filter of the embodiment, in which the first conductor 12 functions as the first inductor L1, and the second conductor 30 also functions as the inductor L2. functions as

Further, the first conductor 12 and the second conductor 30 are arranged close to each other with the substrate 10 in between, as shown in FIG. 2(B). Therefore, the two are capacitively coupled to each other by electrostatic capacitance, and a capacitance C is formed between the two in a distributed constant manner.

Therefore, the noise filter of this embodiment functions as a normal mode distributed constant type LC noise filter.

In particular, in the noise filter of this embodiment, the second conductor 30
is formed to face the interline region 16 of the first conductor 12. Therefore, the distance between the first and second conductors 12 and 30 provided on both sides of the substrate 10 is shorter than the distance between the first conductors 12 formed in a spiral shape. The conductor 30 also functions as a shield conductor to prevent line-to-line short circuits of the first conductor 12.

With the above configuration, the noise filter of this embodiment solves the first and second problems described above, and is a normal mode type three-terminal noise filter that has excellent electrical characteristics from the low frequency region to the high frequency region. It will function as a filter.

Second example Next, a second preferred embodiment of the present invention will be described.

Incidentally, members corresponding to those in the first embodiment are given the same reference numerals and their explanations will be omitted.

The feature of this embodiment is that the first conductor 12 is attached to the inner end of the second conductor 30 shown in FIG. 1(B) (see FIG. 3B).
A terminal 34 is provided in the same manner as in the above, and a four-terminal common mode LC
The reason lies in the formation of a noise filter.

FIG. 3(B) shows the four-terminal common mode type L of this embodiment.
An equivalent circuit diagram of the C noise filter is shown, and as shown in the figure, the first and second conductors 12.30 of the embodiment function as inductors L1 and L2, respectively, and there is a capacitance between them. is formed in a distributed constant manner.

Third Embodiment FIGS. 4 and 5 show a third preferred embodiment of the LC noise filter of the present invention.

The LC noise filter of the embodiment has a pair of inductor conductors 12-1, 12-2 formed in a spiral shape as first conductors on the front surface of the substrate 10, and each of the inductor conductors 12-1 and 12-2 on the back side of the substrate 10. Interline area 16-1 of 1°12-2
．． A set of capacitor conductors 30 facing oppositely to 16-2.
-1.30-2 is formed in a spiral shape as the second conductor.

A terminal 18-1.18-2 is connected to the outer end of each of the inductor conductors 12-1.12-2, and a terminal 20-1.18-2 is connected to the inner end of the inductor conductor 12-1. 20-2
is connected. Moreover, each of the capacitor conductors 30-
The outer end of 1.30-2 is connected to the ground terminal 32 via a lead.

FIG. 5 shows an equivalent circuit diagram of the LC noise filter of the embodiment, and each inductor conductor 12-1, 12-2 provided on the front side of the substrate 10 has an inductance L,
It functions as an inductor having L2, and forms a capacitance C in a distributed constant manner between each capacitor conductor 30-1 and 30-2 provided on the back side of the substrate 10.

Furthermore, these capacitor conductors 30-1, 30-2 are
It is formed so as to face the interline region 16-1.16-2 of the first inductor conductor 12-1.12-2. Therefore, these capacitor conductors 30-1, 30-2
also functions as a shield to prevent short circuits between the lines of each of the inductor conductors 12-1, 12-2.

Therefore, terminal 32 is connected to the ground side, and each terminal 18-1
．． By using 18-2.20-1.20-2 as an input/output terminal, it is possible to obtain a common mode terminal LC noise filter having excellent electrical characteristics from a low frequency region to a high frequency region.

Fourth Embodiment Next, a fourth preferred embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 6 shows the LC noise filter of this embodiment,
The LC noise filter of the embodiment has a first conductor 12 formed in a spiral groove 24 provided on the surface of a substrate 10,
A second conductor is formed in a spiral groove 36 provided on the back side of the substrate 10 so as to face the interline region 16 of the first conductor 12.
It is characterized by forming the conductor 3o.

A radial groove 26 extending from the center to the periphery is provided on the back side of the substrate 10, and the inner end of this groove 26 connects with the inner end of the spiral groove 24 provided on the front side of the substrate 10 and a through hole. communicated through. A lead 22 is formed in the radiation groove 26 to be electrically connected to the inner end of the first conductor 12 via a through hole.

The LC noise filter of the embodiment has the first conductor 1
A terminal 18 is connected to the outer end of the terminal 2, and a terminal 2o is connected to the inner end thereof via a lead 22. Further, a ground terminal 30 is connected to the outer end of the second conductor 3o.

With the above configuration, the LC noise filter of the embodiment functions as a normal mode three-terminal LC noise filter as shown in FIG. 3(A).

In particular, in this embodiment, since each of the conductors 12, 30 is formed in a groove, it is possible to more effectively prevent short circuits between lines than in the previous embodiments.

In this embodiment, each of the conductors 12.30 and the leads 22 are formed by coating a resist on a portion of the substrate 10 other than 24.36° 26 in advance, and applying this to a conductive layer filled with a liquid conductor. It can be easily formed by dipping into the inside. Further, even if the substrate 10 is dipped without applying a resist to the surface, the grooves can be easily formed by polishing the substrate surface afterwards and removing the conductive material attached to areas other than the grooves.

In addition to dipping, a conductor can also be formed in each bay by, for example, plating the conductor.

Furthermore, in this embodiment, since the conductors 12.30 are provided in the spiral grooves 24.36, the cross-sectional shape and cross-sectional area of each conductor can be set arbitrarily, compared to forming each conductor on the surface of the substrate 10. For example, by increasing the cross-sectional area, it becomes extremely suitable as an LC noise filter for a power supply that carries a relatively large current.

Note that the groove type LC noise filter as in this embodiment is not limited to the normal mode three-terminal filter as shown in the first embodiment, but also as in the second to third embodiments as necessary.
It can be applied to various types of filters such as the embodiments.

In particular, by applying this embodiment to the filter of the type shown in the third embodiment, the inductor conductors 12-1 and 12-2 provided on the surface of the substrate 10 can be formed as shown in FIG. They face each other with the wall body 28 interposed between the spiral grooves 24-1 and 24-2 in between. Therefore, each inductor conductor 12-1, 12-2 is capacitively coupled to each other by electrostatic capacitance, and a capacitance C is formed between them in a distributed constant manner. Therefore, by using a material with a high dielectric constant as the substrate 10, each inductor conductor 1
The capacitance C between 2-1 and 12-2 can be set to a large value as necessary.

Fifth Embodiment FIGS. 8 and 9 show a fifth preferred embodiment of the present invention.

The feature of this embodiment is that a second grounding block conductor 40 or a plurality of grounding block conductors 40 are arranged on the back side of the substrate 10 so as to face the interline region 16 of the first conductor 12 formed in a spiral shape.
The reason is that the conductor 30 is provided as the conductor 30.

In the embodiment, three grounding block conductors of 40-1.40-2.40-3 are provided.

In this, each of the grounding block conductors 40-1.
It is preferable that either one of 40-2 and 40-3 is disposed opposite to the first conductor 12 at a position close to one terminal 18 of the first conductor 12 functioning as an inductor in terms of an electric circuit, Further, it is preferable that the other block conductor 50 is disposed facing the first conductor 12 at a position close to the other terminal 20 in terms of the electric circuit.

Therefore, the grounding block conductor 40-1
The terminal 18 of the conductor 12 is located close to the terminal 18 of the conductor 12 in terms of the electrical circuit. Further, the block conductor 40-2 is arranged close to the terminal 2o of the first conductor 12 in terms of an electric circuit.

In addition, the grounding block conductor 40-1.40-2 placed close to the input/output terminal 18.20 pulls out the lead 33-1.33-2 from a position near the terminal 18.2D and connects it to the grounding terminal 2o. It is preferable to connect them in order to obtain good attenuation characteristics.

FIG. 9 shows an equivalent circuit diagram of the LC noise filter of the embodiment.

In the embodiment, the spirally formed first conductor 12 functions as an inductor L1.

In addition, each grounding block conductor 4°-1, 40- faces each other with the inter-line region 16 of the first conductor 12 and the substrate 1° in between.
2, 40-3 are capacitively coupled with each region of the first conductor 12 by capacitance, and have capacitances C+, C2,
Forms Cs.

In particular, in the present invention, each grounding block conductor 4°-1, 4
0-2 and 40-3 are each formed into a block shape with a small area and are connected to the ground terminal 32. Therefore,
Since the eddy current flowing through each block conductor 40-1, 40-2, and 40-3 is small and its inductance is also small, the capacitance C, , , formed between it and the first conductor 12 is small.
C2°C9 will be directly connected to the ground terminal 32. As a result, the applicant's earlier patent application No. 1-1
As detailed in the application No. 01426, the capacitance C is increased by increasing the number of block conductors 40, which is equivalent to having multiple LC noise filters connected in series. By reducing the number of block conductors 4o, it is possible to obtain an LC noise filter with a reduced capacitance C.

In addition, each grounding block conductor 40-1.40-2.4
0-3 has a small area and the inductor conductor 1
It merely forms a capacitance with a part of the region of 2. Therefore, the mutual inductance between the first conductor 12 and each grounding block conductor 4o can be almost ignored, and the mutual inductance that causes deterioration of the characteristics of the noise filter can be significantly reduced.

In this way, according to this embodiment, by increasing or decreasing the number of the grounding block conductors 40, it is possible to obtain an LC noise filter with any capacitance.

Note that this embodiment can be applied to the type L of each of the above embodiments as necessary.
Needless to say, this method can also be applied to C noise filters.

Sixth Embodiment FIGS. 10 to 12 show a sixth preferred embodiment of the LC noise filter according to the present invention.

The LC noise filter of the embodiment includes a plurality of insulating plates 52-1.
．． Laminated body 50 formed by laminating 52-2 and 52-3
and the interlayer 56-1.56-2.56- of the insulating plate 52.
3, the first conductor 12 is provided in a spiral shape to form a coil with a predetermined number of turns, and the interlayer 56- of the insulating plate 54
2.56-3゜56-4 through the insulating plate 52
A second conductor 30 is provided in a spiral shape to face the inter-line region 16 of the conductor 12.

In the laminate 50 of the embodiment, in order to prevent the first conductor 12 and the second conductor 30 from being short-circuited or exposed, the insulating plate 52 is
are laminated via insulating sheets 54-1, 54-2...54-7. Terminals 18a, 20a of the first conductor 12 and terminals 32a, 32b of the second conductor are provided on the surfaces of the uppermost and lowermost insulating sheets 54-1, 54-7.
is coated.

The first conductor 12 is connected between each layer 56-1 of the insulating plate 52.
60-1.60-2.60-3. These spiral conductors 70-1, 70-2, 70-3 are connected to each other via through-holes 53-55 and interlayer connection leads 62 formed on these insulating plates and sheets.
They are connected in series so that they circulate continuously from one layer to another.

Similarly, the second conductor 30 is connected to the interlayer 56 of the insulating plate 52.
It is composed of a second spiral conductor 70-1.70-2,703 provided in -2.56-3.56-4, and is connected between the - They are connected in series so that they circulate continuously between the layers and other layers.

As a result, the first and second conductors 12°30 are
Even within the limited and small space of the laminate 50, it functions as a coil with sufficient singleness and inductance.

Further, the first and second spiral conductors 60 and 70 are capacitively coupled via the insulating plate 52, and a capacitance is formed between them. This results in
A sufficiently large capacitance C is formed between the first and second conductors 12.30 substantially continuously in a distributed constant manner.

Further, the terminal 18 formed on the surface of the insulating sheet 54-1
A is connected to the outer end of the first spiral conductor 70=1 provided on the insulating plate 52-1 through the through hole 55, and the terminal 20a similarly formed on the surface of the insulating sheet 54-7 is , through hole 351 provided in insulating sheet 54-7, and interlayer connection lead 62. It is connected to the inner end of the first spiral conductor 70-3 provided on the insulating plate 52-3 via a through hole 55 provided in the insulating sheet 54-6. Further, the terminal 32a provided on the insulating sheet 54-1 is connected to the insulating sheet 54-1. Insulating plate 52
-1 is connected to the outer end of a second spiral conductor 70-1 provided on the back side of the insulating plate 52-1 via through holes 55.53 provided on the insulating plate 52-1.

In the embodiment, the remaining terminals 32b are used as empty terminals to form a three-terminal normal mode LC noise filter.

FIG. 11 shows a completed diagram of the multilayer LC noise filter of this example.

The LC noise filter of the embodiment is formed by laminating an insulating plate 52 and an interlayer insulating sheet 54 shown in FIG. Then, input/output terminals 18 are provided on the surface of this laminate 50.
A conductor is coated so as to connect the terminals a and 18a and function as one external terminal 18. Similarly, the input/output terminals 20a, 20a are also coated with a conductor so as to function as one external terminal 20. Furthermore, terminals 32a, 3
2b is also coated with a conductor so as to function as one external terminal 32.

As a result, two input/output terminals 1 are provided on the outer peripheral surface of the laminate 50.
A three-terminal normal mode type LC noise filter having 8.20 and one ground terminal 32 is formed. Furthermore, since this noise filter is formed as an SMD type (surface mounted device) element, its handling is extremely easy.

FIG. 12 shows an equivalent circuit diagram of the multilayer LC noise filter of this example. According to this example, an LC element in which the capacitance C is formed in a distributed constant manner can be obtained. The inductance and capacitance C can be set to large values as necessary without increasing the size of the element itself. Therefore, according to this embodiment, it is possible to obtain an excellent noise filter that exhibits excellent attenuation characteristics over a high frequency band.

Note that when the LC element of this example is used as a normal mode LC noise filter, instead of grounding both ends of the second conductor 30 that functions as a capacitor conductor, one end of the second conductor 30 is grounded as shown in FIG. It is preferable to ground only the side to obtain good damping characteristics. Above all,
As in this embodiment, the input/output terminals 18 and 20 of the first conductor 12 function as the inductor conductor using the ground terminal 32a.
Better attenuation characteristics can be obtained by arranging it in close proximity to either one of them.

Note that the multilayer LC element of this embodiment can be used not only as a normal mode type LC noise filter but also as a four-terminal common mode type LC noise filter. In this case, terminals 32a are provided at both ends of the second conductor 32.

32b should be connected.

In addition, when the present invention is applied to such a laminated type LC element, it is possible to apply not only the above-mentioned embodiments but also various types of laminated layers detailed in Japanese Patent Application No. 2-7590 previously filed by the present applicant. It can also be applied to type LC elements.

For example, although the above-described laminated LC element uses an insulating plate as the insulating layer, the present invention is not limited to this, and it is also possible to form the insulating layer using thin film forming technology, and a specific example thereof is shown below. Explain.

FIGS. 13(a) to 13(1) show an example of a manufacturing process for forming a three-terminal normal mode LC noise filter using thin film molding technology.

The feature of this embodiment is that an insulating thin film 200 is used as an insulating layer instead of the insulating plate 52, and this insulating thin film 200 and the first .
The second conductor 12.30 is formed using a thin film forming technique.

That is, in the LC element of the example, first, as shown in FIG.
A first spiral conductor 601 continuous from the auxiliary terminal portion 18a is formed on the surface of the auxiliary terminal portion 18a.

Next, as shown in FIG. 2B, an insulating thin film 200-1 is formed on the surface of the substrate 100 so that the end of the first spiral conductor 60 is exposed.

Next, as shown in FIG. 3C, an auxiliary terminal portion 32a' is formed to cover the substrate 100 from the back side to the side surface, and is continuous from the auxiliary terminal portion 328' on the insulating thin film 200-1. A second spiral conductor 70-1 facing the interline region 16 of the first spiral conductor 60-1 is coated with an insulating thin film 200-1.

Next, as shown in the same figure (d), each spiral conductor 60-
1. Insulating thin film 200-2 so that the end of 70-1 is exposed.
Form a coating.

Next, as shown in the same figure (e), this insulating thin film 200-2
Interlayer connection lead 62.72 on top, conductor 60-1.70
A coating is formed from the exposed end of -1 to the outer periphery of the insulating substrate 100. Then, as shown in FIG. 6(f), an insulating thin film 200-3 is formed so that the ends of the interlayer connection leads 62 and 72 are exposed.

Next, as shown in the same figure (g), the insulating thin film 200-3
, 200-2, the second spiral conductor 70-
A first spiral conductor 60-2 is formed to cover the first spiral conductor 60-2 so as to face the first inter-line region 17. At this time, the first spiral conductor 60-2 has its outer peripheral end connected to the interlayer connection lead 60.
connected to the exposed end of the

Next, as shown in FIG. 6(h), an insulating thin film 200-4 is formed so that the inner peripheral end of the first spiral conductor 70-2 and the end of the interlayer connection lead 72 are exposed. Then, as shown in FIG. 6(i), a second spiral conductor 70-2 is formed to cover the interline region 16 of the first spiral conductor 60-2 so as to face each other with an insulating thin film 200-4 interposed therebetween. do. At this time, this second spiral conductor 70-
The outer peripheral end of No. 2 is formed to be connected to the exposed end of the interlayer connection lead 72 .

The process of forming such an insulating thin film and the process of forming a spiral conductor and an interlayer connection lead are shown in FIG. 13(j) below.
A laminate 50 is formed by repeating the steps as shown in (r). At this time, in the step shown in FIG. 2(q), auxiliary terminal portions 1gb-, which are continuous with the glabella connection leads 62, are formed to cover the side and back surfaces of the substrate 100.

Then, in the step shown in FIG.
0, the auxiliary terminal portions 18a18b-, 32
conductive caps 19a, 19b electrically connected to a-
, 33a are fitted and fixed.

As a result, according to this embodiment, as shown in FIG. 13(1), the input/output terminals 18 and 20 connected to both ends of the first conductor 12 and one end of the second conductor 3o A ground terminal 32 connected to the ground terminal 32 is formed.

In this way, according to this embodiment, a three-terminal normal mode type LC noise filter as shown in FIG. 1 (1) can be formed using thin film molding technology.

In addition, when the present invention is applied to such a stacked LC element, the split grounding type described in detail in Japanese Patent Application No. 2-11540 previously filed by the present applicant is applicable, rather than the above-mentioned embodiments. It can also be applied to a stacked type LC device. In this case,
By dividing the second conductor 30 into a plurality of parts as in the fifth embodiment, a laminated LC element having an arbitrary C can be obtained.

[Effects of the Invention] As explained above, according to the present invention, a first conductor functioning as an inductor is formed in a spiral shape on one surface of a dielectric, and the first conductor is opposed to the interline region of the first conductor. By forming the second conductor on the other surface of the dielectric, a distributed constant LC noise filter having excellent electrical characteristics can be obtained without reducing the inductance of the first conductor. be.

Further, according to the present invention, the second conductor formed to face the inter-line region of the first conductor also functions as a shield conductor to prevent line-to-line short circuit of the first conductor. , a distributed constant type L that can eliminate noise components without causing line-to-line short circuits even in high frequency ranges.
This has the effect that a C noise filter can be obtained.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a preferred first embodiment of the distributed constant type LC noise filter according to the present invention, in which (A) is an explanatory diagram of the front surface of the substrate, and (B) is an explanatory diagram of the back side of the substrate. Figure 2 is a ■-■ cross-sectional explanatory diagram of the noise filter shown in Figure 1. Figure 3 is an isotonic circuit diagram of the LC noise filter according to this embodiment. Figure 4 is an LC noise filter according to the present invention. FIG. 5 is an explanatory diagram of a preferred third embodiment of the present invention. FIG. 5 is an equivalent circuit diagram thereof. FIG. 6 is an explanatory diagram of a groove-type LC noise filter according to a fourth preferred embodiment of the present invention. An explanatory diagram of the line capacitance formed between each inductor conductor when the type LC noise filter is applied to the LC noise filter according to the third embodiment, 8th v! J is a schematic explanatory diagram of a preferred fifth embodiment of the present invention, FIG. 9 is an equivalent circuit diagram thereof, FIG. 10 is an explanatory diagram when the present invention is applied to a stacked LC element, and FIG. The figure is an equivalent circuit diagram, Figure 13 is an explanatory diagram showing an example of forming a stacked LC element using thin film molding technology, Figure 14 is an explanatory diagram of a conventional LC element, and Figure 15 is its equivalent. It is a circuit diagram. DESCRIPTION OF SYMBOLS 10... Substrate, 12... First conductor, 16... Line area, 30... Second conductor, 40... Grounding block conductor.

Claims (6)

[Claims] (1) a dielectric, a first conductor formed in a spiral shape on one surface of the dielectric and functioning as an inductor, and a first conductor formed on the other surface of the dielectric so as to face an interline region of the first conductor; and a second conductor forming a capacitance with the first conductor. (2) The LC noise filter according to claim (1), wherein the second conductor is formed in a spiral shape so as to face the interline region of the first conductor. (3) In claim (1), both ends of the first conductor are connected to input/output terminals, and the second conductor is connected to a ground terminal and is formed as a normal mode type. LC noise filter. (4) In claim (3), the second conductor includes one or more grounding block conductors formed to face oppositely to the interline area of the first conductor. IC noise filter. (5) In claim (4), the grounding block conductor includes: a first block conductor placed close to the input terminal of the first conductor; and a first block conductor placed close to the output terminal of the first conductor. An LC noise filter comprising: 2 block conductors; (6) In any one of claims (1) to (5), the dielectric is formed as a plurality of insulating layers stacked on each other to constitute a laminate, and the first conductor is arranged between the insulating layers. The second conductor is formed so as to continuously circulate in a spiral shape from one layer to another, and the second conductor is formed between the insulating layers so as to face the interline region of the first conductor. A multilayer LC noise filter characterized in that: