JPH1174748A - Noise filter - Google Patents

Abstract

(57) [Summary] [Problem] To secure a sufficient current capacity and cope with low-frequency noise, and to be manufactured by a simple manufacturing process, so that it is easy to mount on a substrate, has excellent reliability, and is small and inexpensive. Noise filter. A conductive pattern having an inductor function is provided.
a and 2b are arranged on both sides of the dielectric sheet 1 and joined to the conductor pattern 2a by punching a conductor 3 having the same cross-sectional area as the conductor pattern 2a and having the same shape as the conductor pattern 2a. A noise filter having an inductor function and a capacitor function is formed by forming the first pattern 4a and guiding a noise current flowing from the main circuit pattern 4a to the conductor pattern 2b via the dielectric sheet 1 to the ground.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise filter for filtering a switching noise generated by a switching operation of a semiconductor switching element constituting a power converter such as an inverter.

[0002]

2. Description of the Related Art A switching operation of a semiconductor switch element constituting a power converter such as an inverter is performed based on a pulse width modulated (PWM) drive signal having a carrier frequency of about several KHz to about several tens KHz. During this switching operation, switching noise having a frequency component of several tens KHz or more is generated from the power converter.

[0003] In recent years, among the frequency components of the switching noise, various legal regulations have been imposed on power converters in order to suppress the adverse effect of external components on the frequency of 100 KHz or more. In order to comply with such regulations, a noise filter for a power converter is attached to the power converter.

Conventionally, as a noise filter for this type of power converter, a single reactor formed by winding an electric wire around a core made of ferrite, an amorphous alloy, a crystalline alloy, or the like, and a single reactor formed by a film, a chip, or the like are used. A capacitor is connected to, for example, an inverted L-shape to form a noise filter,
By this noise filter, switching noise generated due to the switching operation of the semiconductor switch element is filtered.

[0005] Further, as a well-known document relating to a noise filter for a power converter, for example, as the well-known document 1, “Integrated Output Filter and Diode Snubber f
or Switchmode Power Converters ”, IEEE, 199
4, pp. 1240-1245 are disclosed. This proposes a filter circuit in which a rectifier, an RC snubber circuit, and an LC filter circuit are integrated into a flat plate structure, and further provides a basic description of a manufacturing method in each circuit.

As the well-known document 2, “Integrated Fil
ters For Switch −Mode Power Supplies ”, IEEE
E, 1995, pp. 809-816. This is because the structure of the LC filter circuit is 3
We suggest by kind. That is, the dielectric is divided into a ceramic structure and a non-ceramic structure, and one type of a flat plate structure (type using BaTiO ₃ ) as a ceramic structure and two types of a film structure as a non-ceramic structure (sheet type, vapor deposition by plasma). Type) and proposes.

[0007]

However, conventionally,
Reactors used as this type of noise filter generally have a toroidal shape, and capacitors have a pin-inserted shape, such as a flat shape or a cylindrical shape, and are mounted on a printed circuit board inside the power converter. In the case of mounting on the above, a mounting space larger than each individual volume is required, and there is a problem in terms of assemblability. Furthermore, when this type of noise filter is mounted by individual wiring, there are many connection points, and there is a problem that the method of fixing individual components becomes complicated.

[0008] In a so-called composite LC filter of a chip type or a pin insertion type in which a commercially available inductor and capacitor are combined, the cut-off frequency is several MHz or more, but a power converter such as an inverter is formed. The cut-off frequency required to filter the switching noise generated due to the switching operation of the semiconductor switch element is as low as, for example, about 150 KHz, and cannot be handled by a commercially available filter.

In a power converter such as an inverter,
It is desired that a current of several amperes or more is passed through a noise filter to be used, but it is difficult to employ a commercially available composite LC filter in terms of current capacity and cost.

Further, in the examples of the known documents 1 and 2, the manufacturing method is complicated, not practical, and there is a problem in terms of cost.

An object of the present invention is to provide a noise filter which can secure a sufficient current capacity and can cope with low frequency noise.

Another object of the present invention is to provide a small, inexpensive noise filter which is manufactured by a simple manufacturing process, is easily mounted on a substrate, is excellent in reliability, and is small.

[0013]

SUMMARY OF THE INVENTION The present invention provides a flat plate-shaped first member.
A dielectric sheet, a spiral coil pattern formed of a conductive paste having a function of an inductor and formed opposite to both surfaces of the first dielectric sheet, and one surface of the first dielectric sheet; A first main circuit pattern formed by joining a stamped conductor having a cross-sectional area through which a desired current value flows and having the same shape as the coil pattern on the formed coil pattern; A current based on noise that is connected to the coil pattern formed on the surface opposite to the main circuit first pattern and flows from the main circuit first pattern into the coil pattern via the first dielectric sheet. A first ground wire leading to ground, a flat second dielectric sheet,
A spiral coil pattern formed of a conductive paste having a function of an inductor and formed on both sides of the dielectric sheet, and the coil pattern formed on one surface of the second dielectric sheet; A second main circuit pattern formed by joining press-punched conductors having a cross-sectional area through which a desired current value flows and having the same shape as the coil pattern; and Is a second ground wire that is connected to the coil pattern formed on the opposite surface and guides a current based on noise flowing into the coil pattern from the second main circuit pattern via the second dielectric sheet to the ground. And a flat insulating sheet sandwiched between the first dielectric having the first main circuit pattern and the second dielectric having the second main circuit pattern. And connecting the one end of the first main circuit pattern to the one end of the second main circuit pattern so that the other end not connected is used as an input / output terminal, and the first circuit having the first main circuit pattern is provided. The dielectric and the second dielectric having the second main circuit pattern are integrated to form a noise filter circuit having an inductor function and a capacitor function.

Here, the first main circuit pattern and the second main circuit pattern are formed by solder plating in advance.
The solder-plated main circuit first pattern and the main circuit second pattern can be soldered on a coil pattern made of the conductive paste.

By laminating the solder-plated main circuit first pattern and the main circuit second pattern, it is possible to form a desired cross-sectional area thickness.

A plurality of said noise filter circuits are prepared,
By providing a split core accommodating the plurality of filter circuits and a resin material for sealing a gap in the split core, a filter unit having a plurality of inductor functions and a plurality of capacitor functions is formed.

The resin material can be composed of a polymer resin material filled with an inorganic filler at a predetermined ratio.

The resin material is made of silicone gel, and only the region on the side where the input / output terminals are arranged is sealed with a polymer resin material filled with an inorganic filler at a predetermined ratio, and the other internal region is sealed with the above-mentioned resin material. It can be sealed using a silicone gel.

The resin material is made of silicone gel, and a cover for fixing the input / output terminals can be provided in a region where the input / output terminals are arranged.

Further, the present invention provides the noise filter,
A power converter is connected to an input stage and / or an output stage of a power converter having a switch element and filtering switching noise generated by the switching operation of the switch element.

Further, according to the present invention, the noise filter
A power converter is configured by connecting to a circuit in a power converter having a switch element and filtering switching noise generated by the switching operation of the switch element.

The present invention is also directed to a step of forming a spiral coil pattern made of a conductive paste having a function of an inductor on both sides of a first dielectric sheet having a flat shape and facing the first dielectric sheet; On the coil pattern formed on one surface of the dielectric sheet, a main circuit is formed by joining a press-punched conductor having a cross-sectional area through which a desired current value flows and having the same shape as the coil pattern. A step of forming a first pattern, and forming the coil pattern formed on the surface opposite to the main circuit first pattern from the main circuit first pattern to the coil pattern via the first dielectric sheet. A step of connecting a first ground line for guiding a current based on the flowing noise to the ground, and a step of connecting a conductive paste having a function of an inductor to oppose both sides of the flat second dielectric sheet. Forming a spiral coil pattern having a cross-sectional area through which a desired current value flows on the coil pattern formed on one surface of the second dielectric sheet. Forming a main circuit second pattern by joining press-punched conductors of the same shape; and attaching the main circuit second pattern to the coil pattern formed on the surface opposite to the main circuit second pattern. Connecting a second ground wire for guiding a current based on noise flowing from the pattern through the second dielectric sheet to the coil pattern to the ground, and connecting the first dielectric having the main circuit first pattern to the second ground wire; Main circuit 2
Sandwiching a flat insulating sheet with the second dielectric having a pattern, and connecting one end of the first main circuit pattern and one end of the second main circuit pattern to form a connection. The other end, which is not used, is used as an input / output terminal, and the first dielectric having the first main circuit pattern and the second dielectric having the second main circuit pattern are integrated to function as an inductor and a capacitor. A method for manufacturing a noise filter is provided by configuring a noise filter circuit having:

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 to 6 show a first embodiment of the present invention.
It will be described based on. First, a method for manufacturing a noise filter according to the present invention will be described with reference to FIGS.

In step 1 of FIG. 1A, reference numeral 1 denotes a dielectric sheet. This dielectric sheet 1 is made of BaTiO ₃
And a ferroelectric ceramic material such as PZT. The thickness of the dielectric sheet 1 is 100 μm to 1 m.
In this example, a thickness of about 0.5 mm is used.

Then, spiral coil patterns 2a and 2b made of conductive paste and having an inductor function are formed on both surfaces of the front and back surfaces of the dielectric sheet 1 so as to face each other. As the conductive paste, for example, a paste containing Ag as a main component can be used. As a method of forming a pattern in this step, a conductive paste can be applied by screen printing and cured, but in addition to this, copper or the like is formed into a pattern by a sputtering method, a vacuum evaporation method, or a plating method. Is also possible.

Next, in step 2 of FIG. 1B, a punched coil 3 having the same shape as the coil pattern 2a is joined to the coil pattern 2a formed on one surface of the dielectric sheet 1 by soldering. By this joining,
The main circuit first pattern 4a having a function of an inductor and a capacitor is formed.

The punching coil 3 has a cross-sectional area necessary for passing a current of a main circuit (for example, a circuit of a power converter), and is formed by, for example, press punching from a copper plate. In this case, for example, the current capacity is 1 A to
It is possible to take the size of the cross-sectional area necessary for flowing about several tens of amps, and the film thickness is 0.5 mm to 1.0 mm.
It is possible to form in the range of the order.

Further, at one end of the punched coil 3, a region which is drawn out by a predetermined length is formed outside so that a pin can be inserted and mounted on a printed wiring board for connection with an external circuit. In this example, the punched coil 3
Is defined as U ₁ .

One end on the inner side of the punched coil 3 and the dielectric sheet 1 located below the one end include:
As shown in FIG. 4, in order to obtain the number of turns of the coil and to connect each other with pins when other patterns are laminated,
A through hole 7 is formed in advance.

Next, in step 3 of FIG. 1 (c), a noise component is added to the coil pattern 2b formed on the surface of the dielectric sheet 1 opposite to the surface on which the first main circuit pattern 4a is formed. An earth pattern lead wire 2c for passing a current is joined by soldering. Here, the current of the noise component is the main circuit first pattern 4a.
Is a current caused by a noise component flowing into the coil pattern 2b via the dielectric sheet 1.

By the above processes 1 to 3, the first main circuit having one end U ₁ on one surface of the dielectric sheet 1 is obtained.
The substrate A having the function of an inductor / capacitor having the pattern 4a formed thereon and the coil pattern 2b having the lead wire 2c formed on the other surface can be manufactured.

Here, a substrate B having a structure similar to that of the substrate A is manufactured. In this case, the substrate B is made of the dielectric sheet 5
The main circuit second pattern 4b is formed on one surface, and the coil pattern 2b is formed on the other surface. Main circuit second pattern 4b has a region drawn by a predetermined length to the outside, the one end of the area and U _2. The substrate B thus configured is, like the substrate A,
Has the function of inductor and capacitor.

Next, in step 4 of FIG. 1D, a substrate A having the first main circuit pattern 4a formed on the dielectric sheet 1 and a second main circuit pattern 4b formed on the dielectric sheet 5 are formed. The substrate B is connected via an interlayer insulating sheet 6. The interlayer insulating sheet 6 is provided with through holes 7 similar to the substrates A and B, whereby the substrates A and B can be integrated by inserting pins into the through holes 7 and fixing them with solder. Can be. The number of turns of the coil can be increased by increasing the number of substrates.

By fixing with the pins as described above,
One end inside the first main circuit pattern 4a and one end inside the second main circuit pattern 4b are electrically connected, and the first main circuit pattern 4a and the second main circuit pattern 4b are connected in series. Will be. Thus, the one end U ₁ drawn out of the main circuit first pattern 4a and the one end U ₂ drawn out of the main circuit second pattern 4b can be used as electrical input / output terminals.

The grounding coil patterns 2b of the substrates A and B are not shown, like the main circuit coil patterns 2a (corresponding to the main circuit first pattern 4a and the main circuit second pattern 4b). They are connected using through holes. In this example, the connected ground terminal is P. The position of the through hole of the coil pattern 2a for the main circuit and the position of the through hole of the coil pattern 2b for the ground circuit are formed at positions shifted so as not to overlap with each other.

By the above processes 1 to 4, the substrate A on which the first main circuit pattern 4a is formed on the first dielectric 1 and the second main circuit pattern 4 on the second dielectric 5 are formed.
The substrate B on which b is formed can be integrated to form a set of noise filter circuits 100 having an inductor function and a capacitor function. in this case,
One end of the main circuit first pattern 4a and the main circuit second pattern 4
By connecting to one end of b, the other end that is not connected can be used as the input terminal U ₁ and the output terminal U ₂ .

Next, in step 5 of FIG.
, Two sets of noise filter circuits prepared in step 4 are prepared. In this case, the first-layer noise filter circuit 10
0 input and output terminals of corresponding to set to U _1, U _2, the second layer of the input-output terminal of the noise filter circuit 200 V _1, V
_{Assume 2} . Then, the first-layer noise filter circuit 100
An insulating sheet 8 is arranged between the first and second noise filter circuits 200 and the laminated circuit is sandwiched from above and below by using a magnetic material split core 9. As a result, the two sets of noise filter circuits 100 and 200 are housed in one housing.

The magnetic material split core 9 has an input / output terminal U
_1, the U ₂ and the input-output terminals V _1, V ₂ leads to taken out, and an opening portion 9a is formed on one side structure. For example, a ferrite core can be used as a material of the magnetic material divided core 9. Further, a projection 9b for positioning and fixing is formed at a central portion in the magnetic material split core 9.

If the number of noise filter circuits sandwiched between the magnetic material split cores 9 is set to two sets, a single-phase reactor is used. Can be formed as a composite filter.

Next, in step 6 of FIG. 3, the polymer resin material 10 is placed in the housing through the opening 9a of the magnetic material divided core 9 in which two sets (for single phase) of the noise filter circuits 100 and 200 are accommodated. And solidified. By mounting in this manner, the input / output terminals U ₁ and U _{2 of} the first main circuit pattern of the noise filter circuit 100 and the input / output terminals V 1 and V 2 of the second main circuit pattern of the noise filter circuit 200 from the opening 9 a. The lead terminals for two phases ₁ and V ₂ are drawn out. These protruding lead terminals can be solder-bonded to a socket or the like of a printed wiring board in the form of pin insertion or in a surface-mounting manner, so that they can be handled as one mounting component integrated with the board.

Next, the electrical properties of the substrate structure will be described with reference to FIGS. In FIG. 5, a main circuit first pattern 4a as an inductor conductor has a cross-sectional area large enough to allow a current of a main circuit of a power converter (not shown) to flow. This main circuit first pattern 4
“a” is composed of a coil pattern 2 a made of a conductive paste provided on a dielectric sheet 1 and a punched coil 3 made of a conductor. The coil pattern 2b as a ground conductor is formed at a position facing the main circuit first pattern 4a via the dielectric sheet 1.

Coil pattern 2b serving as ground conductor
Need only lead the current of the noise component flowing through the dielectric sheet 1 to the ground, so that the cross-sectional area can be made smaller than that of the main circuit first pattern 4a. The same applies to the substrate configuration of the main circuit second pattern 4b.
The description is omitted.

In FIG. 6, the terminals U ₁ and U ₂ of the main circuit first pattern 4a, which are conductors for the inductor, have a predetermined length, so that a minute inductance is continuously distributed. Similarly, in the coil pattern 2b, which is a ground conductor connected to the terminal P, minute and minute inductances are continuously distributed. Further, since the first main circuit pattern 4 and the coil pattern 2b face each other with the dielectric sheet 1 interposed therebetween, a minute capacitance is continuously formed between the respective conductors. A distributed constant circuit having a filter function can be configured. Here, the low-pass filter is a cutoff frequency (for example, 150 KHz or more) required to filter switching noise generated by a switching operation of a semiconductor switching element constituting a power converter such as an inverter.
Shall be provided.

Next, a second embodiment of the present invention will be described with reference to FIG.
A description will be given with reference to FIG.

FIG. 7 is a cross-sectional view when the surface of the punched coil 3 constituting the first main circuit pattern 4a and the second main circuit pattern 4b is plated with solder 11. As the solder plating 11, a material such as Sn / Pb or Sn / Ag is used. By applying the solder plating in advance in this way, in the step 2, soldering can be easily performed on the coil pattern 2a formed of the conductive paste.

FIG. 8 shows an example in which punched coils 3 on which solder plating 11 has been applied are laminated in two layers and joined. By laminating the punched coils 3 in this manner, it is possible to increase the current capacity for flowing current. The number of layers can be three or more.

Next, a third embodiment of the present invention will be described with reference to FIG.
It will be described based on.

FIG. 9 shows a structure in which two sets of noise filter circuits 100 and 200 are accommodated in the magnetic material divided core 9. In the present embodiment, the gap between the magnetic material split core 9 and the noise filter circuits 100 and 200 is sealed using a polymer resin material 10 different from the example of FIG.

As the polymer resin material 10, an epoxy resin or a urethane resin to which an inorganic filler such as quartz powder or alumina powder is added is used. Further, it is necessary that the thermal expansion coefficient of the polymer resin material 10 be equal to that of the magnetic material divided core 9 in order to prevent distortion due to thermal stress.

The polymer resin material 1 made of such a material
By sealing with 0, the insulation characteristics can be improved, and contamination such as dust and the like from the opening 9a to the inside can be protected, and insulation deterioration can be prevented.

Further, by adding a filler to the polymer resin material 10, heat generated by the flow can be dissipated. Further, the lead terminals U ₁ , U ₂ of the first main circuit pattern 4a and the lead terminals V ₁ , V ₂ of the second main circuit pattern 4b are connected to a polymer resin material 10 of this kind.
Therefore, even if an external force is applied to the punched coil 3, it is possible to prevent an external force from being applied to the internal noise filter circuits 100 and 200.

Next, a fourth embodiment of the present invention will be described with reference to FIG.
Description will be made based on 0.

FIG. 10 shows a structure in which two sets of noise filter circuits 100 and 200 are accommodated in the magnetic material divided core 9. In the present embodiment, first, a silicone gel 11 is sealed in the gap between the magnetic material divided core 9 and the noise filter circuits 100 and 200 up to the vicinity of the opening 9a, and a polymer resin material 10 is further placed on the silicone gel 11 above. Seal. Various materials as described above can be used as the polymer resin material 10.

As described above, by appropriately selecting the material to be sealed between the inside and the surface of the housing, the insulation characteristics can be improved, and the contamination such as dust from the opening 9a to the inside can be protected. In addition, insulation deterioration can be prevented.

The silicone gel 11 having a small elastic force
By using, distortion due to thermal stress does not occur, so that mechanical reliability can be obtained. Further, since the lead terminals U ₁ and U ₂ of the first main circuit pattern 4a and the lead terminals V ₁ and V ₂ of the second main circuit pattern 4b are fixed by the polymer resin material 10, external force is applied to the lead terminals U ₁ and U ₂ . Even if U ₂ and V ₁ and V ₂ are applied, it is possible to prevent external force from being applied to the internal noise filter circuits 100 and 200.

Next, a fifth embodiment of the present invention will be described with reference to FIG.
1 will be described.

FIG. 11 shows a structure in which two sets of noise filter circuits 100 and 200 are accommodated in the magnetic material divided core 9. In the present example, first, the silicone gel 11 is sealed in the gap between the magnetic substance divided core 9 and the noise filter circuits 100 and 200 up to the vicinity of the opening 9 a, and the opening 9 a is covered with the terminal fixing cover 12, whereby The lead terminals U ₁ and U _{2 of} the first circuit pattern 4a and the lead terminals V ₁ and V ₂ of the second main circuit pattern 4b are fixed.

By using the terminal fixing cover 12 in this manner, even if an external force is applied to the lead terminals U ₁ , U ₂ and V ₁ , V ₂ , the internal noise filter circuit 1
It is possible to prevent external force from being applied to 00 and 200.
Further, contamination such as dust and the like from the opening 9a to the inside can be protected and insulation deterioration can be prevented. The material of the terminal fixing cover 12 is PPS (polyphenylene sulfide), PBT (polybutylene terephthalate), which is easy to mold.
And the like can be used.

Next, a sixth embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIGS.

FIG. 12 shows a power converter 2 such as an inverter.
This is an example in which a noise filter according to the present invention is provided at the input stage of 0. Here, three sets (for three phases) of noise filter circuits 100, 200, and 300 are used.

In the examples shown in FIGS. 1 to 11, the single-phase noise filter circuits 100 and 20 are provided in the magnetic core 9.
Although the structure is a case where 0 is accommodated, if it is configured as three phases, one additional noise filter circuit 300 should be mounted below the noise filter circuit 200 in step 5 of FIG. Can be easily realized.

The lead terminals of the noise filter circuit 100 thus configured are denoted by U ₁ and U ₂ , the lead terminals of the noise filter circuit 200 are denoted by V ₁ and V _2, and the lead terminals of the noise filter circuit 300 are denoted by W _1. , W ₂ .
Then, the lead terminals U ₁ , V ₁ , W ₁ are connected to the input conductor 21.
a, 21b, 21c and lead terminals U ₂ , V ₂ ,
W ₂ is connected to power converter 20.

By connecting in this manner, low-frequency noise that enters the power converter 20 together with a signal from the input conductors 21a, 21b, and 21c can be filtered and generated by elements in the power converter 20. Switching noise is prevented from being transmitted to the input conductors 21a, 21b, 21c.

FIG. 13 shows three sets (for three phases) according to the present invention at the output stage of the power converter 20 such as an inverter.
This is an example in which the noise filter circuits 100, 200, and 300 are provided.

The lead terminals U ₁ , V ₁ and W ₁ are connected to the power converter 20, and the lead terminals U ₂ , V ₂ and W ₂ are connected to the input conductors 21a, 21b and 21c.

By connecting in this way, switching noise and the like generated by the elements in power converter 20 can be filtered, and therefore switching noise is transmitted from power converter 20 to input conductors 21a, 21b and 21c. It can be prevented from being transmitted. Further, low-frequency noise that enters the power converter 20 from the input conductors 21a, 21b, 21c can be filtered.

Next, FIG. 14 shows an example in which two sets of noise filter circuits 100 and 200 according to the present invention are provided inside a power converter 20 such as an inverter.

In the power converter 20, an input side is provided with a rectifier 21 for converting an alternating current inputted from the outside into a direct current, and a semiconductor switching element 22 is provided on the output side.
Is provided.

The lead terminals U ₁ and V ₁ are connected to the rectifier 2 on the input side.
1 and the lead terminals U ₂ and V ₂ are connected to the semiconductor switching element 22 on the output side.

By connecting in this way, it is possible to filter out switching noise generated due to the switching operation of the semiconductor switch element 22 constituting the power converter 20.

[0072]

As described above, according to the present invention,
A conductor pattern having the function of a spiral inductor made of a conductive paste is arranged on both sides of a dielectric sheet so as to face each other, and a cut-off is made so that current of a main circuit such as a power converter can flow on one of the conductor patterns. A main circuit pattern is formed by joining press-punched conductors having the same area as the conductor pattern and having the same shape as the conductor pattern, and a current based on noise flowing from the main circuit pattern into the other conductor pattern via the dielectric sheet is formed. A low-frequency noise such as a switching noise of a power converter can be sufficiently cut, and a current of several amperes or more necessary for power conversion can be sufficiently reduced by forming a filter circuit having an inductor function and a capacitor function by leading to a ground. Can be provided.

Further, according to the present invention, after a plurality of noise filters are accommodated in the magnetic material divided core, the gap is sealed with a polymer resin material. This makes it possible to provide a structure that is easy to mount on a printed wiring board, and that provides a small and inexpensive noise filter that is excellent in insulation and mechanical reliability.

[Brief description of the drawings]

FIG. 1 is a process chart showing a method for manufacturing a noise filter according to a first embodiment of the present invention.

FIG. 2 is a process chart illustrating a method of manufacturing the noise filter following FIG. 1;

FIG. 3 is a process chart illustrating a method of manufacturing the noise filter following FIG. 2;

FIG. 4 is a perspective view showing a shape of a through hole provided at one end of a punched coil.

FIG. 5 is a perspective view showing a basic structure of a noise filter.

FIG. 6 is a circuit diagram showing a distributed constant circuit of LC.

FIG. 7 is a sectional view showing a structure of a punched coil plated with solder according to a second embodiment of the present invention.

FIG. 8 is a sectional view showing a structure in which punched coils are stacked.

FIG. 9 is a cross-sectional view showing a structure according to a third embodiment of the present invention when a noise filter is housed in a housing.

FIG. 10 is a cross-sectional view illustrating a structure when a noise filter is housed in a housing according to a fourth embodiment of the present invention.

FIG. 11 is a cross-sectional view showing a structure in which a noise filter is housed in a housing according to a fifth embodiment of the present invention.

FIG. 12 is a block diagram illustrating a configuration when a noise filter for three phases is connected to an input stage of a power converter according to a sixth embodiment of the present invention.

FIG. 13 is a block diagram showing a configuration when a noise filter for three phases is connected to an output stage of the power converter.

FIG. 14 is a block diagram showing a configuration when a noise filter is connected in the power converter.

[Explanation of symbols]

Reference Signs List 1 first dielectric sheet 2a, 2b coil pattern 2c first ground line 2d second ground line 3 conductor 4a main circuit first pattern 4b main circuit second pattern 5 second dielectric sheet 6 insulating sheet 9 split core 10 resin material (Polymer resin material) U ₁ , U _{2 I} / O terminal V ₁ , V _{2 I} / O terminal W ₁ , W _{2 I} / O terminal

Claims (16)

[Claims] A first dielectric sheet having a flat plate shape, and formed on opposite sides of the first dielectric sheet;
A spiral coil pattern having a function of an inductor and made of a conductive paste; and a cross-sectional area for allowing a desired current value to flow on the coil pattern formed on one surface of the first dielectric sheet. A main circuit first pattern formed by joining press-punched conductors having the same shape as the coil pattern; and a coil pattern formed on a surface opposite to the main circuit first pattern. A first ground wire for guiding a current based on noise flowing from the first pattern of the main circuit into the coil pattern via the first dielectric sheet to the ground; a second dielectric sheet having a flat plate shape; Formed opposite to both sides of the dielectric sheet,
A spiral coil pattern having a function of an inductor and made of a conductive paste, and a cross-sectional area for allowing a desired current value to flow on the coil pattern formed on one surface of the second dielectric sheet. A main circuit second pattern formed by joining press-punched conductors having the same shape as the coil pattern; and a coil pattern formed on a surface opposite to the main circuit second pattern. A second current for guiding a current based on noise flowing into the coil pattern from the second main circuit pattern via the second dielectric sheet to the ground.
A ground wire, and a flat insulating sheet sandwiched between the first dielectric having the first main circuit pattern and the second dielectric having the second main circuit pattern; By connecting one end of a first pattern and one end of the main circuit second pattern, the other end not connected is used as an input / output terminal, and the first dielectric having the main circuit first pattern and the main circuit A noise filter comprising a filter circuit having an inductor function and a capacitor function integrally with the second dielectric having two patterns. 2. The main circuit first pattern and the main circuit second pattern are formed by solder plating in advance, and the solder-plated main circuit first pattern and the main circuit second pattern are combined with the conductive paste. The noise filter according to claim 1, wherein the noise filter is soldered on a coil pattern made of: 3. The main circuit first pattern and the main circuit second pattern, each of which is plated with solder, are formed to have a desired cross-sectional area by laminating the main circuit first pattern and the main circuit second pattern, respectively. Noise filter. 4. A function of an inductor by providing a plurality of the filter circuits, a divided core accommodating the plurality of filter circuits, and a resin material for sealing a gap in the divided cores. 4. The noise filter according to claim 1, wherein the noise filter is configured as a filter unit having a plurality of functions of capacitors. 5. The noise filter according to claim 4, wherein said resin material is made of a polymer resin material filled with an inorganic filler at a predetermined ratio. 6. The resin material is made of silicone gel, and only a region on the side where the input / output terminals are arranged is sealed with a polymer resin material filled with an inorganic filler at a predetermined ratio. 5. The noise filter according to claim 4, wherein is sealed using said silicone gel. 7. The noise filter according to claim 4, wherein the resin material is made of silicone gel, and a cover for fixing the input / output terminals is provided in a region on the side where the input / output terminals are arranged. . 8. The noise filter according to claim 1, which is connected to an input stage and / or an output stage of a power converter having a switch element, and is generated in accordance with a switching operation of the switch element. A power converter characterized by filtering switching noise. 9. The noise filter according to claim 1, wherein the noise filter is connected to a circuit in a power converter having a switching element, and a switching noise generated by a switching operation of the switching element is filtered. A power conversion device characterized in that: 10. A step of forming a spiral coil pattern made of a conductive paste having a function of an inductor on both sides of a first dielectric sheet having a flat shape, and opposing each other; On the coil pattern formed on one surface, a press-punched conductor having a cross-sectional area through which a desired current value flows and having the same shape as the coil pattern is joined to form a main circuit first pattern. Configuring and based on noise flowing into the coil pattern from the first main circuit pattern via the first dielectric sheet to the coil pattern formed on the surface opposite to the first main circuit pattern. A step of connecting a first ground wire for conducting a current to the ground; and a spiral shape made of a conductive paste having a function of an inductor, opposing to both side surfaces of the plate-shaped second dielectric sheet. Forming a coil pattern, and having a cross-sectional area through which a desired current value flows on the coil pattern formed on one surface of the second dielectric sheet and having the same shape as the coil pattern. Forming a main circuit second pattern by joining the stamped conductors; and forming the main circuit second pattern from the main circuit second pattern to the coil pattern formed on the surface opposite to the main circuit second pattern. Connecting a second ground line for guiding a current based on noise flowing into the coil pattern via the second dielectric sheet to the ground; and connecting the first dielectric having the main circuit first pattern and the main circuit Sandwiching a flat insulating sheet with the second dielectric having two patterns, wherein one end of the main circuit first pattern and one end of the main circuit second pattern are By connecting, the other end not connected is used as an input / output terminal, and the first dielectric having the first main circuit pattern and the second dielectric having the second main circuit pattern are integrated into an inductor. A method for manufacturing a noise filter, comprising a filter circuit having the function of (1) and the function of a capacitor. 11. The step of solder-plating the first main circuit pattern and the second main circuit pattern, and the step of solder-plated forming the first main circuit pattern and the second main circuit pattern from the conductive paste. 11. The method for manufacturing a noise filter according to claim 10, further comprising a step of soldering on the coil pattern. 12. The main circuit first pattern and the main circuit second pattern, each of which is plated with solder, are each laminated to form a desired cross-sectional area. A method for manufacturing a noise filter. 13. A method of preparing an inductor, comprising the steps of: preparing a plurality of the filter circuits, housing the plurality of filter circuits in a split core, and sealing a gap in the split core with a resin material. 13. The method for manufacturing a noise filter according to claim 10, wherein the filter unit is configured as a filter unit having a plurality of functions and functions of a capacitor. 14. The method for manufacturing a noise filter according to claim 13, wherein the resin material is a polymer resin material filled with an inorganic filler at a predetermined ratio. 15. The resin material is made of silicone gel, and only a region on the side where the input / output terminals are arranged is sealed with a polymer resin material filled with an inorganic filler at a predetermined ratio. 14. The method for manufacturing a noise filter according to claim 13, wherein is sealed using the silicone gel. 16. The noise filter according to claim 13, wherein the resin material is made of silicone gel, and a cover for fixing the input / output terminals is provided in a region on the side where the input / output terminals are arranged. Manufacturing method.