JP2002009572A - Filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a filter that can realize at least any of improvements such as a small insertion loss, capability of surface mount, possibility of downsizing, and an enhanced filter characteristic. SOLUTION: Electrodes 3, 5 and 4, 6 are respectively provided on both ends of a base 1, a winding 2 is wound in the middle of the base 1, and both ends of the winding 2 are respectively connected to the electrodes 3, 4. Furthermore, a protection member 7 is covered onto the winding 2. A capacitor C1 is formed between the electrodes 3 and 5, the winding 2 provides an inductance L1, and a capacitor C2 is formed between the electrodes 4 and 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter used for electronic equipment such as mobile communication, and particularly to a filter corresponding to a high frequency signal.

[0002]

2. Description of the Related Art A first prior art is disclosed in Japanese Unexamined Patent Publication No.
As disclosed in Japanese Patent Application Laid-Open No. 181119 and Japanese Patent Application Laid-Open No. H10-51257, there is a type in which a spiral inductor is formed on a main surface of a substrate to form an LC filter. Further, as a second prior art, Japanese Patent Laid-Open No. 11-2
As disclosed in Japanese Patent No. 34076, a coil is wound around a bobbin in which a plurality of flanges are connected, and a capacitance is obtained by a chip capacitor. As a third conventional technique, there is a multilayer capacitor in which a counter electrode is buried, a conductive film is formed on the outer periphery of the multilayer capacitor, and a groove is formed in the conductive film to form a coil portion. .

[0003] Another prior example is disclosed in Japanese Patent Laid-Open No. 5-2127.
No. 2, JP-A-6-176966, and the like.

[0004]

However, first, in the case of forming a spiral inductor on a substrate by forming a thin film as in the first prior art, it is necessary to increase the Q value of the inductor as desired. In the second prior art, the Q value can be increased by using a winding as an inductor, but in order to obtain a capacity, a separate chip capacitor or the like is not required to obtain a capacity. However, since the number of components is increased and the lead terminals are provided, they cannot be used as surface mount components, and the size of the filter increases. Further, in the third conventional technique, since a groove is formed in the conductive film as the inductance, the Q value can be secured to some extent and the size can be reduced, but the inductor covers the portion where the capacitance is formed. In addition, there is a problem in that the characteristics as a filter deteriorate due to the increase in the line capacitance of the inductor due to the configuration.

An object of the present invention is to solve the above-mentioned conventional problems, and to provide a filter capable of realizing at least one of small insertion loss, surface mounting, miniaturization, and improvement in filter characteristics. It is the purpose.

[0006]

According to the present invention, there is provided a columnar base, first and second electrodes provided on the base, and first and second electrodes provided between the first and second electrodes. A plurality of coil portions electrically connected to the second electrode and provided on the surface of the base and electrically connected to each other, a third electrode provided between the plurality of coil portions, and a third electrode And a fourth electrode provided in a non-contact manner with the third electrode and the plurality of coil portions provided in the vicinity of, and a capacitance is formed between the third and fourth electrodes.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a first embodiment of the present invention; FIG. 2 is a perspective view of a first embodiment of the present invention; The first
And a coil portion electrically connected to the second electrode and provided on the surface of the base, and a third coil provided near the first electrode and provided in non-contact with the first electrode. An electrode, and a fourth electrode provided near the second electrode and provided in non-contact with the second electrode, wherein a capacitance is formed between the first and third electrodes; By forming a capacitor between the second and fourth electrodes, a surface-mounted filter can be provided, and miniaturization can be easily realized.

According to a second aspect of the present invention, in the first aspect, the first and second electrodes are used as input / output terminals.
By connecting the first and third electrodes to ground,
A surface mount filter becomes possible, and furthermore, miniaturization can be easily realized.

According to a third aspect of the present invention, there is provided a columnar base, first and second electrodes provided on the base, and the first and second electrodes provided between the first and second electrodes. Second
A plurality of coil portions electrically connected to the respective electrodes and provided on the surface of the base and electrically connected to each other; a third electrode provided between the plurality of coil portions;
A third electrode provided in the vicinity of the third electrode and a fourth electrode provided in a non-contact manner with the third electrode and the plurality of coil portions, and constitutes a capacitance between the third and fourth electrodes; As a result, a surface-mounted filter can be provided, and the size can be easily reduced.

According to a fourth aspect of the present invention, in the third aspect, the first and second electrodes are used as input / output terminals.
By connecting the fourth electrode to the ground, a surface-mounted filter can be realized, and furthermore, miniaturization can be easily realized. In particular, a low-pass filter having excellent characteristics can be configured.

According to a fifth aspect of the present invention, in the third aspect, the first electrodes are divided so that they are not in contact with each other.
By constituting a capacitor between the divided electrodes, dividing the second electrode so as not to be in contact with each other, and constituting a capacitance between the divided electrodes, a surface mount filter becomes possible, and the size is reduced. Can be easily realized.

According to a sixth aspect of the present invention, in the fifth aspect, one of the divided electrodes of the first and second electrodes is used as an input / output terminal, and the divided electrodes of the first and second electrodes are connected to each other. By connecting the other electrode and the fourth electrode to the ground, a surface mount filter can be realized, and furthermore, miniaturization can be easily realized.

According to a seventh aspect of the present invention, in the first to sixth aspects, the area where the capacitance is formed between the electrodes and the area where the inductance is formed by the coil portion are provided at different positions on the base. Since the interference between the coil and the portion forming the capacitor can be suppressed, the filter characteristics can be improved.

According to the invention described in claim 8, the linear coil is wound around the base as the coil portion, so that the coil portion can have a large Q value. The insertion loss of the filter can be suppressed.

According to a ninth aspect of the present invention, in the first to seventh aspects, the conductive film provided on the base as the coil portion is provided with a groove in a spiral shape. A large value can be taken, and the insertion loss of the filter can be suppressed.

According to a tenth aspect of the present invention, in the first to seventh aspects, a circumferential step portion is provided on the base, and a coil portion is provided in the step portion, whereby a gap between the coil portion and a circuit board or the like is provided. Can be secured to some extent, and it is possible to prevent the coil portion from directly contacting the circuit board,
Since the joint portion with the circuit board can be made to protrude more than other portions, the mountability is improved.

According to the eleventh aspect of the present invention, in the first to seventh aspects, since the coil portion is covered with the protective material, the coil portion can be reliably protected, and insulation failure of the coil portion can be suppressed. Can be.

(Embodiment 1) FIGS. 1A and 1B are a perspective view and a diagram showing an equivalent circuit, respectively, of a filter according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a columnar (preferably prismatic) base. The base 1 is made of alumina alone or a material containing alumina or a dielectric ceramic material containing barium titanate (preferably a dielectric material). Rate 200 or less), and furthermore, the central portion has a stepped portion 1a in a circular shape.
Is provided. That is, the step portion 1a has a smaller diameter than both end portions of the base 1. By forming both ends of the base 1 in a substantially rectangular cross section, rolling of the element and the like can be prevented, and mountability can be improved. In the present embodiment, the step portion 1a and both ends of the base 1 are square in cross section. However, the cross section may be circular, and further, the cross sections of the step portion 1a and both ends of the base 1 may be different. Is also good.

Reference numeral 2 denotes a winding wound at least in the stepped portion 1a of the base 1. The winding 2 has an insulating property on the surface of a linear body made of a conductive metal material such as copper or a copper alloy. It has a configuration in which a film of is formed. The inductance value can be adjusted to some extent by adjusting the wire diameter, constituent material, number of turns, and the like of the winding 2. In addition, winding 2
The inductance value can also be adjusted by changing the diameter of the step portion 1a around which the wire is wound, thereby adjusting the winding diameter of the winding 2.

Reference numerals 3 and 4 denote electrodes provided at both ends of the base 1, and both ends of the winding 2 are joined to the electrodes 3 and 4, respectively. The electrodes 3 and 4 and the winding 2 are joined by a technique such as thermocompression bonding, laser welding, or applying a conductive joining material. The electrodes 3 and 4 are joined to lands formed on a circuit board or the like to form a circuit.

Reference numerals 5 and 6 denote electrodes provided at both ends of the base. The electrodes 5 and 6 are configured so as to be in non-contact with the electrodes 3 and 4, respectively, and are preferably provided on a circuit board or the like. Ground electrode.

Reference numeral 7 denotes a protective material that covers the winding 2 and is provided at least in the step portion 1a. The protective material 7 is formed of an insulating resin material such as an epoxy resin or a resist. By providing this protective material 7, corrosion of the winding 2 and unevenness of the winding can be prevented. Note that the protective member 7 may not be provided depending on specifications and the like.

The electrode 5 and the electrode 3 are not in contact with each other by providing the gap G1 as shown in FIG. 1. Similarly, the electrode 6 and the electrode 4 are not in contact with each other by providing the gap G2. It is configured as follows. This gap G
For example, 1, G2 is formed by forming a continuous electrode in which the electrodes 3 and 5 are joined at the end of the base, and removing a portion to be the gap G1 of the continuous electrode by laser processing or grinding stone processing,
Alternatively, masking is performed on the portion that becomes the gap G1,
It is formed by plating, sputtering, vapor deposition, coating or the like. The gap G2 is formed similarly.

The gaps G1 and G2 are portions where no electrodes are provided, and are configured so that the base 1 is exposed on the surface. Note that an insulating resin material or the like may be provided in the gaps G1 and G2.

The electrodes 3, 4, 5, and 6 are made of a single conductive metal material such as gold, silver, copper, or nickel, or a material containing them, and a solder or lead-free solder. The electrodes 3, 4, 5, and 6 may be a single layer. For example, on a first conductive layer made of silver or copper made of a conductive material or a silver alloy or a copper alloy, nickel or the like is used. Provide a corrosion resistant layer,
A multilayer structure such as providing a bonding layer made of solder, lead-free solder, or the like may be provided on the corrosion-resistant layer.

In the equivalent circuit shown in FIG.
Is the inductance formed by the winding 2, and C1 is the electrodes 3, 5
The capacitance C1 can be adjusted by adjusting the interval of the gap 1, or by changing the material of the base 1, or adjusting the length of the portion facing the electrodes 3 and 5. It is. In addition, when the capacitance C1 is increased, for example, it can be realized by making the opposing portions of the electrodes 3 and 5 have a waveform and increasing the opposing length.

C2 is a capacitance formed between the electrodes 4 and 6,
Since C2 is the same as the capacitance C1, the description is omitted.

The electrodes 3 and 6 serve as terminals, and the electrodes 5 and 6
By connecting 6 to ground, a filter as shown in FIG. 2 can be constructed.

As described above, the structure in which the inductance and the capacitance are formed on the rod-shaped base 1 has a simple structure, and the Q value can be increased by forming the inductor by the windings 2. A filter with good characteristics can be obtained. A portion forming the capacitors C1 and C2;
By forming the portions constituting the inductance L1 in different portions of the base 1, mutual interference can be prevented, and the characteristics can be further improved.

FIGS. 2A and 2B are a perspective view and a diagram showing an equivalent circuit, respectively, of a filter according to an embodiment of the present invention.

The difference from the filter of FIG.
Two step portions 1a, and an intermediate portion 1 between the step portions 1a.
b (almost the same thickness as both ends of the base), the winding 2 is provided between the intermediate portion 1b and both ends, and the electrodes 8, 9 are provided in the intermediate portion.

The intermediate portion 1b is provided with electrodes 8, 9 which are not in contact with each other and have a gap G3 therebetween.

Both ends of the winding 2 wound between the intermediate portion 1b and the electrodes 3 and 5 are connected to the electrode 3 and the electrode 8, respectively.
Both ends of the winding 2 wound between the intermediate portion and the electrodes 4 and 6 are joined to the electrode 4 and the electrode 8, respectively.

In the present embodiment, the windings 2 and 2 have a discontinuous structure so that the materials and thicknesses of the windings 2 and 2 are different. Although the circuit design is simplified, the number of components can be reduced by forming the windings 2 and 2 in a continuous structure and joining the intermediate portions of the windings 2 and 2 to the electrode 8. And productivity can be improved.

In the equivalent circuit shown in FIG.
L2 is an inductance mainly composed of the winding 2 wound between the intermediate portion 1b and the electrodes 3 and 5, and L2 is an inductance mainly composed of the winding 2 wound between the intermediate portion 1b and the electrodes 4 and 6. C1 is a capacitance formed between the electrodes 4 and 6, C1 is a capacitance formed between the electrodes 4 and 6, and C3 is a capacitance formed between the electrodes 8 and 9.

As described above, the structure in which the inductance and the capacitance are formed on the rod-shaped base 1 allows the structure to be simplified and reduced in size.
The value can be increased, the mounting can be easily performed, and a filter having good characteristics can be obtained by providing the portion constituting the inductance and the portion constituting the capacitance on the base 1 at different positions. Further, by forming the parts constituting the capacitors C1, C2, C3 and the parts constituting the inductances L1, L2 in different parts of the base 1, mutual interference can be prevented and the characteristics can be further improved. .

By using the circuit configuration of the filter as shown in FIG. 2, that is, the electrodes 3 and 4 are directly connected to the lands of the circuit provided on the circuit board or the like or via a bonding material such as solder. By joining and joining the electrodes 5, 6, and 9 directly or via a joining material such as solder to an earth land portion provided on a circuit board or the like, a low-pass filter having extremely excellent characteristics can be formed. .

FIGS. 3A and 3B are a perspective view and a diagram showing an equivalent circuit, respectively, of a filter according to an embodiment of the present invention.

The difference from the filter of FIG.
Two step portions 1a, and an intermediate portion 1 between the step portions 1a.
c, 1d (having substantially the same thickness as both ends of the base 1), and between the intermediate portion 1c and the electrodes 5, 3 and between the intermediate portion 1c and the intermediate portion 1.
d, the windings 2 are provided between the intermediate portion 1d and the electrodes 4 and 6, respectively, and in addition, the electrodes 10, 11 and the electrodes 12, 13 are provided in the intermediate portions 1c, 1d, respectively. .

The intermediate portion 1c is provided with electrodes 10 and 11 which are not in contact with each other and have a gap G4 therebetween.

The intermediate portion 1d is provided with electrodes 12, 13 which are not in contact with each other and have a gap G5 therebetween.

Both ends of the winding 2 wound between the intermediate portion 1c and the electrodes 3 and 5 are connected to the electrode 3 and the electrode 10, respectively, and wound between the intermediate portion 1c and the intermediate portion 1d. Winding 2
Are connected to the electrodes 10 and 12, respectively, and the intermediate portion 1
Both ends of the winding 2 wound between d and the electrodes 4 and 6 are joined to the electrode 4 and the electrode 12, respectively.

In this embodiment, the windings 2, 2, 2
Has a non-continuous structure so that the material and thickness of the windings 2, 2, and 2 are different to facilitate circuit design. However, the windings 2, 2, and 2 have a continuous structure. Electrode 10,
By joining the intermediate portions of the windings 2 and 2 that are continuous with each other, the number of components can be reduced, and the productivity and the like can be improved.

In the equivalent circuit shown in FIG.
Is an inductance whose main component is the winding 2 wound between the intermediate portion 1c and the electrodes 3 and 5, and L2 is an inductance mainly whose winding 2 is wound between the intermediate portion 1c and the intermediate portion 1d. L3 is an inductance which is mainly constituted by the winding 2 wound between the intermediate portion 1d and the electrodes 4 and 6, C1 is a capacitance which is formed between the electrodes 3 and 5, and C2 is a capacitance which is formed between the electrodes 3 and 5. A capacitance formed between the electrodes 4 and 6, C3 is a capacitance formed between the electrodes 10 and 11, and C4 is a capacitance formed between the electrodes 12 and 13.

As described above, the configuration in which the inductance and the capacitance are formed on the rod-shaped base 1 allows the structure to be simplified and reduced in size.
The value can be increased, the mounting can be easily performed, and a filter having good characteristics can be obtained by providing the portion constituting the inductance and the portion constituting the capacitance on the base 1 at different positions. Also, by forming the parts constituting the capacitances C1, C2, C3, C4 and the parts constituting the inductances L1, L2, L3 in different parts of the base 1,
Mutual interference can be prevented, and characteristics can be further improved.

The circuit configuration of the filter as shown in FIG. 3 is adopted, that is, the electrodes 3 and 4 are directly connected to the lands of a circuit provided on a circuit board or the like or via a bonding material such as solder. By joining, the electrodes 5, 6, 11 and 13 are joined directly or via a joining material such as solder to an earth land portion provided on a circuit board or the like.
A low-pass filter with very excellent characteristics can be configured.

FIGS. 4A and 4B are a perspective view and an equivalent circuit, respectively, showing a filter according to an embodiment of the present invention.

The filter shown in FIG. 4 is a modification of the filter shown in FIG. 2. In FIG.
The filter shown in FIG. 4 is a filter in which the electrode 3 and the electrode 5 are integrated, and the electrode 4 and the electrode 6 are further integrated.
Other configurations are almost the same as those shown in FIG.

That is, in FIG. 4, an electrode 14 (integrated electrodes 3 and 5 in FIG. 2) and an electrode 15 (electrodes 4 and 6 in FIG. Are integrated).

FIG. 4 shows an equivalent circuit of such a filter.
As shown in FIG. 2B, the equivalent circuit shown in FIG. 2B has a configuration in which the capacitors C1 and C2 are omitted. Therefore, a so-called T-type filter can be configured.

FIGS. 5A and 5B are a perspective view and an equivalent circuit, respectively, showing a filter according to an embodiment of the present invention.

The filter shown in FIG. 5 is a modified example of the filter shown in FIG. 3. In FIG.
The filter shown in FIG. 5 is a filter in which the electrode 3 and the electrode 5 are integrated, and the electrode 4 and the electrode 6 are further integrated.
Other structures are almost the same as those shown in FIG.

That is, in FIG. 4, an electrode 16 (integrated with electrodes 3 and 5 in FIG. 3) and an electrode 17 (electrodes 4 and 6 in FIG. Are integrated).

FIG. 5 shows an equivalent circuit of such a filter.
As shown in FIG. 3B, the equivalent circuit shown in FIG. 3B has a configuration in which the capacitors C1 and C2 are omitted.

(Embodiment 2) FIGS. 6A and 6B are a perspective view and an equivalent circuit diagram showing a filter according to an embodiment of the present invention.

The filter shown in FIG. 6 is different from the filter shown in FIG. 1 in that the winding 2 is wound around the base 1 to form a coil portion.
The difference is that a spiral groove 21 is formed in the coil portion 0 to form a coil portion.

That is, a conductive film 20 such as copper or a copper alloy is formed in a circular shape by plating, coating, vapor deposition or the like on the base 1, especially inside the stepped portion 1 a. The groove 21 was formed into a coil portion.

The conductive film 20 constituting the coil portion is composed of the electrodes 3,
The electrode 5 is electrically connected to the conductive film 2 with the electrode 3.
0 and the electrode 6 are not electrically in contact with each other, and the electrode 6 is configured so that the electrode 4 is not in contact with the conductive film 20 and the conductive film 5.

The electrode 6 is in non-contact with other electrodes and the conductive film 20 by, for example, a gap G6 and a gap G2 provided at the boundary between the flange portion and the step portion 1a, and is not shown in FIG. Similarly, 5 is not in contact with other electrodes and the conductive film 20 due to a gap provided at a boundary between the flange portion and the step portion 1a, for example.

The equivalent circuit is the same as that shown in FIG.

In the filter configured as described above, since the inductor is constituted by the coil portion in which the groove 21 is provided in the conductive film 20 in a spiral shape, a high Q value can be obtained. With the configuration for forming the inductance and the capacitance, a filter having a simple structure, easy to mount, and excellent characteristics can be obtained. Also, the capacity C
By forming the parts constituting the components 1 and C2 and the part constituting the inductance L1 in different parts of the base 1, mutual interference can be prevented, and the characteristics can be further improved.

FIG. 7 is a perspective view showing a filter according to an embodiment of the present invention.

The filter shown in FIG. 7 is different from the filter shown in FIG. 2 in that the winding 2 is wound around the base 1 to form a coil portion.
The difference is that a spiral groove 21 is formed in the coil portion 0 to form a coil portion.

That is, a conductive film 20 such as copper or a copper alloy is formed in a circular shape by plating, coating or vapor deposition on the base 1, especially on the inside of the stepped portion 1 a, and the conductive film 20 is spirally formed on the conductive film 20. The groove 21 was formed into a coil portion.

The conductive film 20 forming the coil between the intermediate portion 1b and the electrodes 3 and 5 is electrically connected to the electrode 3 and the electrode 8, and forms the coil between the intermediate portion 1b and the electrodes 4 and 6. The conductive film 20 to be electrically connected to the electrode 8 and the electrode 4.
The electrodes 5, 6, and 9 are configured so as not to be in contact with both the electrodes 3, 4, and 8 and the conductive film 20.

The electrodes 5, 6, 9 are, for example, a flange portion and a step portion 1a.
Gaps G1, G2, G7, and G8 provided at the borders of FIG.

The equivalent circuit is the same as that shown in FIG.

In the filter configured as described above, since the inductor is constituted by the coil portion in which the groove 21 is provided in the conductive film 20 in a spiral shape, a high Q value can be obtained. With the configuration for forming the inductance and the capacitance, a filter having a simple structure, easy to mount, and excellent characteristics can be obtained.

FIG. 8 is a perspective view showing a filter according to an embodiment of the present invention.

The filter shown in FIG. 8 is different from the filter shown in FIG. 3 in that the winding 2 is wound around the base 1 to form a coil portion.
This embodiment differs from the equivalent circuit shown in FIG. 3 in that the spiral groove 21 is formed in the coil portion by forming a spiral groove 21 in FIG.

FIG. 9 is a perspective view showing a filter according to an embodiment of the present invention.

The filter shown in FIG. 9 is different from the filter shown in FIG. 4 in that the winding 2 is wound around the base 1 to form a coil portion.
This embodiment differs from the equivalent circuit shown in FIG. 4 in that a spiral groove 21 is formed in the coil portion to form a coil portion, and the operation and effect are the same as those in the above embodiments.

FIG. 10 is a perspective view showing a filter according to an embodiment of the present invention.

The filter shown in FIG. 10 differs from FIG. 5 in that a spiral groove 21 is formed in the conductive film 20 instead of winding the winding 2 around the base 1 to form a coil. And is the same as the equivalent circuit shown in FIG.
Moreover, the operation and effect are the same as those of the above embodiments.

In the present embodiment, when there are two or more coil portions, all the grooves are formed in the winding or the conductive film.
For example, when two coil portions are provided, one of the coil portions may be formed by winding, and the other coil portion may be formed by forming a spiral groove in the conductive film.

[0077]

According to the present invention, there are provided a columnar base, first and second electrodes provided on the base, and first and second electrodes provided between the first and second electrodes. A plurality of coil portions electrically connected to each other and provided on the surface of the base, and a third electrode provided between the plurality of coil portions; and a third electrode provided in the vicinity of the third electrode. And a fourth electrode provided in a non-contact manner with the third electrode and the plurality of coil portions, and a capacitance is formed between the third and fourth electrodes. Miniaturization can be easily realized.

[Brief description of the drawings]

FIG. 1A is a perspective view illustrating a filter according to an embodiment of the present invention. FIG. 1B is a diagram illustrating an equivalent circuit of the filter according to an embodiment of the present invention.

FIG. 2A is a perspective view illustrating a filter according to an embodiment of the present invention. FIG. 2B is a diagram illustrating an equivalent circuit of the filter according to the embodiment of the present invention.

FIG. 3A is a perspective view illustrating a filter according to an embodiment of the present invention. FIG. 3B is a diagram illustrating an equivalent circuit of the filter according to the embodiment of the present invention.

4A is a perspective view illustrating a filter according to an embodiment of the present invention. FIG. 4B is a diagram illustrating an equivalent circuit of the filter according to an embodiment of the present invention.

FIG. 5A is a perspective view illustrating a filter according to an embodiment of the present invention. FIG. 5B is a diagram illustrating an equivalent circuit of the filter according to the embodiment of the present invention.

FIG. 6A is a perspective view illustrating a filter according to an embodiment of the present invention. FIG. 6B is a diagram illustrating an equivalent circuit of the filter according to the embodiment of the present invention.

FIG. 7 is a perspective view showing a filter according to an embodiment of the present invention.

FIG. 8 is a perspective view showing a filter according to an embodiment of the present invention.

FIG. 9 is a perspective view showing a filter according to an embodiment of the present invention.

FIG. 10 is a perspective view showing a filter according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Base 1a Step part 1b, 1c, 1d Intermediate part 2 Winding 3,4,5,6,8,9,10,11,12,13,1
4, 15, 16, 17 electrode 7 protective material 20 conductive film 21 groove

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiromi Sakita 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Iso ▲ saki ▼ Kenzo 1006 Odakadoma Kadoma, Osaka Matsushita Electric Industrial Co. In-house (72) Inventor Kazuhiro Eguchi 1006 Kadoma, Kazuma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Katsumi Sasaki 1006 Oaza Kadoma, Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. AA05 AB01 AB06 BA01 CA12 CB12 CC03 DA12 DA15 DB08 5E082 AB01 AB02 BB01 DD07 DD08 EE04 EE05 EE13 EE18 EE23 EE26 EE35 EE37 EE39 FF01 FG26 FG27 5J024 AA01 BA01 BA11 DA04 DA27

Claims (11)

[Claims] A first base provided on the base; and a first base provided on the base.
And a second electrode, a coil portion provided between the first and second electrodes and electrically connected to the first and second electrodes, respectively, and provided on a surface of the base, A third electrode provided near the first electrode and provided in non-contact with the first electrode; and a fourth electrode provided near the second electrode and provided in non-contact with the second electrode. And a capacitor is formed between the first and third electrodes,
A filter, wherein a capacitance is formed between the second and fourth electrodes. 2. The filter according to claim 1, wherein the first and second electrodes are used as input / output terminals, and the first and third electrodes are connected to ground. 3. A column-shaped base, and a first base provided on the base.
And a second electrode, provided between the first and second electrodes and electrically connected to the first and second electrodes, respectively, provided on the surface of the base and electrically connected to each other. A plurality of coil portions, a third electrode provided between the plurality of coil portions, and a third electrode provided near the third electrode and provided in non-contact with the third electrode and the plurality of coil portions. And a fourth electrode, wherein a capacitor is formed between the third and fourth electrodes. 4. The filter according to claim 3, wherein the first and second electrodes are used as input / output terminals, and the fourth electrode is connected to ground. 5. The first electrode is divided so as not to be in contact with each other, a capacitance is formed between the divided electrodes, and the second electrode is divided so as to be in non-contact with each other. 4. The filter according to claim 3, wherein a capacitance is formed between the electrodes. 6. One of the divided electrodes of the first and second electrodes is used as an input / output terminal, and the other of the divided electrodes of the first and second electrodes and the fourth electrode are connected to ground. The filter according to claim 5, wherein: 7. The base according to claim 1, wherein a region where a capacitance is formed between the electrodes and a region where an inductance is formed by the coil portion are provided at different positions on the base. filter. 8. The filter according to claim 1, wherein a linear winding is wound around the base as the coil portion. 9. The filter according to claim 1, wherein a groove is formed in a spiral shape in a conductive film provided on the base as a coil portion. 10. A circuit according to claim 1, wherein a circular step is provided on the base, and a coil is provided inside said step.
The filter according to any one of the above. 11. The filter according to claim 1, wherein the coil portion is covered with a protective material.