JP2006332302A - Common mode choke coil mounted substrate and common mode choke coil mounting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a common mode choke coil mounted substrate along with a common mode choke coil mounting method, where a winding type common mode choke coil that has high characteristic impedance value and low DC resistance value is mounted. <P>SOLUTION: A common mode choke coil 2 comprising a core 3, external electrodes 4-1 to 4-4, and a pair windings 5-1 and 5-2, is mounted on a pair of transmission lines 11 and 12 in which a characteristic impedance is set to be 90-110 Ω. By applying a dielectric resin 60 on the upper half of the windings 5-1 and 5-2, the characteristic impedance of the entire common mode choke coil 2 is set to be 50 Ω or less in the frequency band of 100 MHz-3 GHz. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a common mode choke coil mounting board and a common mode choke coil mounting method capable of removing common mode noise on a transmission line, and more particularly to a mounting board and mounting for a wound common mode choke coil. It is about the method.

Conventionally, as this type of common mode choke coil, for example, there is a technique disclosed in Patent Document 1.
In this common mode choke coil, a pair of conductor wires integrated with an insulating layer are wound around a core portion of a drum core, and a conductor wire end of the pair wire is provided on a flange portion of the drum core. It is configured to be electrically connected to the external electrode part. The ratio a / R between the distance a between the pair of conductor wires and the diameter R of the wire is set to 0.5 or more, and the winding interval b between the conductor wires of adjacent pair wires is By setting the wire diameter ratio b / R to 0.5 or more, in high-speed differential signal transmission, the common mode noise is suppressed without adversely affecting the high-speed transmission signal, and variation in characteristic impedance is reduced. We are trying to make it.

JP 2004-146683 A

However, the conventional techniques described above have the following problems.
In order to further enhance the common mode noise suppression effect in the high frequency band, it is necessary to increase the common mode impedance value by increasing the number of turns of the common mode choke coil and increasing the inductance value. However, if the number of winding turns is increased, the DC resistance value of the entire winding also increases.
In particular, in a common mode choke coil used for a power supply line or the like, not only a high common mode impedance but also a DC resistance value as low as possible is an essential condition. Therefore, in the conventional common mode choke coil, when the impedance is increased, the DC resistance value increases. Therefore, a common mode choke in which this high impedance and low DC resistance common mode choke coil is mounted on a transmission line such as a power supply line. A coil mounting substrate could not be realized.

  The present invention has been made to solve the above-described problems, and has a common mode choke coil mounting substrate and a common mode choke coil mounted with a wound common mode choke coil having a high characteristic impedance value and a low DC resistance value. The purpose is to provide an implementation method.

In order to solve the above problems, the invention of claim 1 is directed to a core having a core having a pair of ridges provided at both ends of the core, and an external formed on the peripheral wall of each ridge. A common mode choke coil having a common mode choke coil mounted on a transmission line, comprising an electrode and a pair of windings wound around a winding core and having ends connected to the external electrode. The mounting substrate is set so that the characteristic impedance of the transmission line is set within a range of 90Ω to 110Ω, and the characteristic impedance of the common mode choke coil is set to 50Ω or less or 200Ω or more in a frequency band of 100 MHz to 3 GHz. The configuration.
With this configuration, when common mode noise such as radiation noise enters the transmission path, this noise tends to enter the common mode choke coil mounted on the transmission line. At this time, since the characteristic impedance of the transmission line is in the range of 90Ω to 110Ω, while the characteristic impedance of the common mode choke coil is set to 50Ω or less or 200Ω or more, transmission is performed in a frequency band of 100 MHz to 3 GHz. The characteristic impedance of the line does not match the characteristic impedance of the common mode choke coil. Accordingly, common mode noise in the frequency band of 100 MHz to 3 GHz is reflected by the common mode choke coil. Moreover, since the difference in characteristic impedance is large, most of the common mode noise is reflected by the common mode choke coil.

According to a second aspect of the present invention, in the common mode choke coil mounting substrate according to the first aspect, the common mode choke coil is formed by applying a dielectric resin to a part or all of the pair of windings of the common mode choke coil. The characteristic impedance is set to 50Ω or less.
With this configuration, the characteristic impedance of the common mode choke coil is reduced to 50Ω or less without increasing the number of turns of the winding by increasing the capacitance component between the windings to a desired value depending on the amount of dielectric resin applied. Can be made.

According to a third aspect of the present invention, in the common mode choke coil mounting substrate according to the second aspect, the plate-like dielectric is formed between the pair of common mode choke coils and is close to the upper surface of the pair of windings. The configuration is as follows.
With such a configuration, the characteristic impedance of the common mode choke coil can be reduced to a certain value by the plate-like dielectric, and the characteristic impedance can be finely adjusted by adjusting the coating amount of the dielectric resin.

According to a fourth aspect of the present invention, in the common mode choke coil mounting substrate according to the first aspect, the common mode choke coil is coated with a magnetic resin on part or all of a pair of windings of the common mode choke coil. The characteristic impedance is set to 200Ω or more.
With this configuration, the characteristic impedance of the common mode choke coil is increased to 200Ω or more without increasing the number of turns of the winding by increasing the inductance component between the windings to a desired value depending on the amount of magnetic resin applied. Can be made.

According to a fifth aspect of the present invention, in the common mode choke coil mounting substrate according to the fourth aspect, the plate-like magnetic body is formed between the pair of common mode choke coils and is close to the upper surface of the pair of windings. The configuration is as follows.
With this configuration, the characteristic impedance of the common mode choke coil is increased to a certain value by the plate-like magnetic body, and the characteristic impedance can be finely adjusted by adjusting the coating amount of the magnetic resin.

  The invention of claim 6 is a common mode choke coil mounting method for mounting a wire wound common mode choke coil on a transmission line having a standard characteristic impedance in the range of 90Ω to 110Ω, and has a frequency of 100 MHz to 3 GHz. A common mode choke coil having a characteristic impedance of 50Ω or less or 200Ω or more in the band is mounted on the transmission line, and the common mode noise on the transmission path is reflected by the common mode choke coil.

  A seventh aspect of the present invention is the common mode choke coil mounting method according to the sixth aspect, wherein the common mode choke coil has a characteristic impedance of 50Ω or less by applying a dielectric resin to part or all of a pair of windings. It was set as the structure which is a coil set to.

  The invention according to claim 8 is the common mode choke coil mounting method according to claim 6, wherein the common mode choke coil has a characteristic impedance of 200Ω or more by applying a magnetic resin to a part or all of a pair of windings. It was set as the structure which is a coil set to.

  As described above in detail, according to the present invention, the characteristic impedance difference between the transmission line and the common mode choke coil can be increased, and much of the common mode noise can be reflected by the common mode choke coil. There is an excellent effect that common mode noise in the high frequency band can be suppressed without increasing the number of turns of the winding of the common mode choke coil, that is, without increasing the DC resistance value.

In particular, according to the invention of claim 2, claim 4, claim 7 and claim 8, there is an effect that the characteristic impedance of the common mode choke coil can be easily increased or decreased to a desired value.
Further, according to the inventions of claims 3 and 5, there is an effect that the characteristic impedance of the common mode choke coil can be finely adjusted.

  The best mode of the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view showing a common mode choke coil mounting board according to a first embodiment of the present invention, and FIG. 2 is a perspective view of a common mode choke coil applied to the mounting board of the first embodiment. 3 is a side view of the common mode choke coil of FIG. 2, FIG. 4 is a perspective view showing the external electrode by turning over the common mode choke coil, and FIG. 5 is an equivalent of the common mode choke coil mounting board. It is a circuit diagram.

  The common mode choke coil mounting substrate of this embodiment has a common mode choke coil 2 mounted on a pair of transmission lines 11 and 12 formed on a substrate body 1 as shown in FIG.

  The transmission lines 11 and 12 are conductor patterns formed by forming copper or the like on the surface of the substrate body 1, and their characteristic impedance is set in the range of 90Ω to 110Ω.

On the other hand, the common mode choke coil 2 is a wire-wound chip coil and, as shown in FIGS. 2 and 3, a core 3, external electrodes 4-1 to 4-4, and a pair of windings 5-1, 5. -2.
The core 3 is made of a magnetic material (Mn—Zn ferrite, Ni—Zn ferrite, etc.) and has a bobbin shape having a pair of flanges 31 and 32 at both ends of the core 30. The external electrodes 4-1 to 4-4 are provided on the lower surfaces of the peripheral walls of the flanges 31 and 32. A pair of windings 5-1 and 5-2 formed by coating a copper wire with an insulating film are wound around the core 30, and as shown in FIG. 4, the windings 5-1 and 5-2. The end portions 5-1a and 5-2a are joined to the external electrodes 4-1 and 4-2, respectively, and the end portions 5-1b and 5-2b are joined to the external electrodes 4-3 and 4-4. Yes.

  Furthermore, in this common mode choke coil 2, as shown in FIGS. 2 and 3, a dielectric resin 60 is applied to the upper half of the windings 5-1, 5-2. The dielectric resin 60 is, for example, an epoxy resin, and the dielectric resin 60 is interposed between the pair of windings 5-1 and 5-2, whereby the capacitance between the windings 5-1 and 5-2. Increases component and lowers characteristic impedance. In this embodiment, the amount of the dielectric resin 60 is set so that the characteristic impedance of the entire common mode choke coil 2 is 50Ω or less.

  As shown in FIG. 1, the common mode choke coil 2 having such a structure is connected to the transmission lines 11 and 12 by solder or the like (not shown). Specifically, the external electrodes 4-1 and 4-3 are connected to the line portions 11a and 11b of the transmission line 11, and the external electrodes 4-2 and 4-4 are connected to the line portions 12a and 12b. Thus, by mounting the common mode choke coil 2 on the board body 1, the entire common mode choke coil mounting board has an electrical structure as shown in FIG.

Next, the operation and effect of the common mode choke coil mounting substrate of this embodiment will be described. The operation of the common mode choke coil mounting substrate of this embodiment specifically executes the common mode choke coil mounting method of the present invention.
When the common mode choke coil mounting substrate of this embodiment is mounted on, for example, a Flex Ray used for a cable network inside an automobile, high-frequency common mode noise is transmitted to the transmission lines 11 and 12 from a car radio or the like. May invade. This common mode noise tends to enter the common mode choke coil 2 mounted on the transmission lines 11 and 12 shown in FIG. At this time, the characteristic impedance of the transmission lines 11 and 12 is in the range of 90Ω to 110Ω, whereas the characteristic impedance of the common mode choke coil 2 is set to 50Ω or less. The characteristic impedance of the choke coil 2 does not match. For this reason, the common mode noise on the transmission lines 11 and 12 is reflected by the common mode choke coil 2 and hardly passes through the common mode choke coil 2.
Further, since the signal communicated by FlexRay is a low-frequency signal of, for example, 5 MHz, even if there is a difference in characteristic impedance between the transmission lines 11 and 12 and the common mode choke coil 2, the common is hardly reflected. It passes through the mode choke coil 2.

  As described above, according to the common mode choke coil mounting substrate of this embodiment, the DC resistance value is increased without increasing the number of turns of the windings 5-1 and 5-2 of the common mode choke coil 2. The common mode noise in the high frequency band can be suppressed without causing the failure. Further, by increasing or decreasing the coating amount of the dielectric resin 60, the characteristic impedance of the common mode choke coil 2 can be easily and easily increased or decreased to a desired value.

In order to confirm this point, the inventor conducted the following experiment.
FIG. 6 is a correlation diagram between the characteristic impedance and frequency of the matched common mode choke coil and the mismatched common mode choke coil, and FIG. 7 shows the matching of the matched common mode choke coil and the mismatched product. It is a correlation diagram of the transmittance | permeability and frequency of a common mode which a common mode choke coil shows.

In this experiment, first, as shown by the curve S1 in FIG. 6, matching with the characteristic impedance of the common mode choke coil in which the characteristic impedance is within 90Ω to 110Ω in the range of about 10 MHz to about 3 GHz, that is, the transmission lines 11 and 12 described above. The matched common mode choke coil was mounted on the transmission lines 11 and 12, and the transmittance of signals at each frequency was measured.
Then, as shown by a curve S10 in FIG. 7, it was confirmed that the transmittance of the common mode choke coil decreases with an increase in frequency, but only decreases to about -21 dB.

Next, a dielectric resin 60 is applied to the matched common mode choke coil, and as shown by a curve S2 in FIG. 6, the common mode choke coil having a characteristic impedance of 50Ω or less in the range of about 100 MHz to about 3 GHz. That is, the common mode choke coil 2 of this embodiment, which is a mismatched common mode choke coil that does not match the characteristic impedance of the transmission lines 11 and 12, is mounted on the transmission lines 11 and 12. The signal transmittance was measured.
Then, a result as shown by a curve S20 in FIG. 7 was obtained.
That is, in the mismatched common mode choke coil, the transmittance is greatly reduced as the frequency increases in the range of about 100 MHz to about 3 GHz as compared with the matched common mode choke coil. Particularly, in the vicinity of the frequency of 1 GHz, the transmittance reaches about −32 dB. At this time, the transmittance of the matched product is about −19 dB as shown by the curve S10, and the transmittance of the mismatched product is as low as about −13 dB. Therefore, by mounting the mismatched common mode choke coil on the transmission lines 11 and 12, it can be confirmed that the common mode choke coil reflects most of the common mode noise near the frequency of 1 GHz. In addition, a signal having a frequency lower than 100 MHz is not affected by the characteristic impedance as in the matched product, and thus is transmitted with almost no reflection by the common mode choke coil.

  From the above experiment, by using the common mode choke coil mounting substrate in which the common mode choke coil 2 of this embodiment is mounted on the transmission lines 11 and 12, high frequency noise around 1 GHz is reflected and low frequency data lower than 100 MHz is reflected. It was confirmed that the signal was transmitted.

Next explained is the second embodiment of the invention.
FIG. 8 is a side view of a common mode choke coil which is the main part of the second embodiment of the present invention.
As shown in FIG. 8, in the common mode choke coil mounting substrate of this embodiment, a plate-like dielectric 61 is attached to the common mode choke coil 2.
Specifically, the plate-like dielectric 61 is made of, for example, an epoxy resin or the like formed in a rectangular shape, and is fixed on the flanges 31 and 32 of the common mode choke coil 2. As a result, the plate-like dielectric 61 is in a state of being bridged between the flanges 31 and 32, and the plate-like dielectric 61 is in a state of being close to the upper surfaces of the windings 5-1, 5-2.

With this configuration, the characteristic impedance of the common mode choke coil 2 can be greatly reduced to a constant value by the plate-like dielectric 61, and thereafter the common mode choke coil 2 can be adjusted by adjusting the coating amount of the dielectric resin 60. The characteristic impedance can be finely adjusted.
Since other configurations, operations, and effects are the same as those in the first embodiment, description thereof is omitted.

Next explained is the third embodiment of the invention.
In the common mode choke coil mounting board of this embodiment, a magnetic resin is applied instead of the dielectric resin 60 in the common mode choke coil 2 of the first embodiment.
By interposing the magnetic resin between the pair of windings 5-1 and 5-2 shown in FIGS. 1 to 4, the inductance component of the windings 5-1 and 5-2 is increased, and the characteristic impedance is increased. Increase. In this embodiment, the coating amount of the magnetic resin is set so that the characteristic impedance of the entire common mode choke coil 2 is 200Ω or more.

With this configuration, the characteristic impedance of the common mode choke coil 2 can be easily and easily increased to 200Ω or more depending on the amount of magnetic resin applied, without increasing the number of turns of the windings 5-1 and 5-2. Can do. For this reason, a large difference occurs in the characteristic impedance between the transmission lines 11 and 12 and the common mode choke coil 2, and high frequency common mode noise on the transmission lines 11 and 12 is reflected by the common mode choke coil 2 and cannot be transmitted. . As a result, similar to the first embodiment, common mode noise can be suppressed.
Since other configurations, operations, and effects are the same as those in the first embodiment, description thereof is omitted.

Next explained is the fourth embodiment of the invention.
In the common mode choke coil mounting substrate of this embodiment, a magnetic resin is applied instead of the dielectric resin 60 and the plate-like dielectric 61 in the common mode choke coil 2 of the second embodiment shown in FIG. At the same time, a plate-like magnetic body was mounted on the flanges 31 and 32, and the plate-like magnetic body was brought close to the upper surfaces of the windings 5-1, 5-2.
With this configuration, the characteristic impedance of the common mode choke coil 2 can be greatly increased to a certain value by the plate-like magnetic body. Thereafter, the characteristics of the common mode choke coil 2 can be adjusted by adjusting the coating amount of the magnetic resin. The impedance can be finely adjusted.
Since other configurations, operations, and effects are the same as those in the first embodiment, description thereof is omitted.

In addition, this invention is not limited to the said Example, A various deformation | transformation and change are possible within the range of the summary of invention.
For example, in the above-described embodiment, the example in which the dielectric resin 60 or the magnetic resin is applied to the upper half portions of the windings 5-1 and 5-2 is shown, but the present invention is not limited to this. The amount of application of these resins is determined according to the characteristic impedance desired for the common mode choke coil 2. For this reason, the dielectric resin 60 and the magnetic resin may be applied to only a part of the windings 5-1 and 5-2, or may be applied to the entire windings 5-1 and 5-2. is there.

It is a perspective view which shows the common mode choke coil mounting board | substrate which concerns on 1st Example of this invention. It is a perspective view of the common mode choke coil applied to the mounting substrate of the first embodiment. FIG. 3 is a side view of the common mode choke coil of FIG. 2. It is a perspective view which turns over a common mode choke coil and shows an external electrode. It is an equivalent circuit diagram of a common mode choke coil mounting substrate. It is a correlation diagram of the characteristic impedance and frequency which a common mode choke coil of a matching product and a common mode choke coil of a mismatching product show. It is a correlation diagram of the transmittance | permeability and frequency of a common mode which the common mode choke coil of a matching product and the common mode choke coil of a mismatching product show. It is a side view of the common mode choke coil which is the principal part of 2nd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Board | substrate body, 2 ... Common mode choke coil, 3 ... Core, 4-1 to 4-4 ... External electrode, 5-1, 5-2 ... Winding, 11, 12 ... Transmission line, 30 ... Winding core, 31, 32 ... ３２, 60 ... dielectric resin, 61 ... plate dielectric.

Claims (8)

A core having a pair of ridges provided at both ends of the core, and an external electrode formed on the peripheral wall of each of the ridges; A common mode choke coil mounting board in which a common mode choke coil having a pair of windings drawn to and joined to the external electrode is mounted on a transmission line,
The characteristic impedance of the transmission line is set within a range of 90Ω to 110Ω,
In the frequency band of 100 MHz to 3 GHz, the characteristic impedance of the common mode choke coil was set to be 50Ω or less or 200Ω or more.
A common mode choke coil mounting board. In the common mode choke coil mounting board according to claim 1,
The characteristic impedance of the common mode choke coil was set to 50Ω or less by applying a dielectric resin to part or all of the pair of windings of the common mode choke coil.
A common mode choke coil mounting board. In the common mode choke coil mounting board according to claim 2,
A plate-like dielectric was formed between the pair of common mode choke coils and was placed close to the upper surface of the pair of windings.
A common mode choke coil mounting board. In the common mode choke coil mounting board according to claim 1,
The characteristic impedance of the common mode choke coil was set to 200Ω or more by applying a magnetic resin to part or all of the pair of windings of the common mode choke coil.
A common mode choke coil mounting board. In the common mode choke coil mounting board according to claim 4,
A plate-like magnetic body was formed between the pair of common mode choke coils and was brought close to the upper surface of the pair of windings.
A common mode choke coil mounting board. A common mode choke coil mounting method for mounting a wound common mode choke coil on a transmission line having a standard characteristic impedance in a range of 90Ω to 110Ω,
The common mode choke coil having a characteristic impedance of 50Ω or less or 200Ω or more is mounted on the transmission line in the frequency band of 100 MHz to 3 GHz, and the common mode noise on the transmission line is reflected by the common mode choke coil. ,
A common mode choke coil mounting method. The common mode choke coil mounting method according to claim 6,
The common mode choke coil is a coil in which a dielectric resin is applied to part or all of a pair of windings and the characteristic impedance is set to 50Ω or less.
A common mode choke coil mounting method. The common mode choke coil mounting method according to claim 6,
The common mode choke coil is a coil in which a magnetic resin is applied to a part or all of a pair of windings and the characteristic impedance is set to 200Ω or more.
A common mode choke coil mounting method.

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