JP7275588B2 - Electronic component, method for manufacturing electronic component, and method for noise reduction - Google Patents

Description

The technology of the present disclosure relates to electronic components having inductors and capacitors.

Electronic components with inductors and capacitors form, for example, filter circuits. In the filter circuit, for example, a toroidal coil is used as an inductor (for example, Patent Document 1), and an aluminum electrolytic capacitor is used as a capacitor, for example. The toroidal coil includes an annular magnetic core and a conductor wound around the core. As the number of turns of the conductor increases, the inductance L of the toroidal coil increases. The cutoff frequency f in an LC filter with inductors and capacitors is represented by 1/2π√(LC) (C is the capacitance of the capacitor). Therefore, if the inductance L of the toroidal coil is increased, the capacitance C of the capacitor can be decreased.

JP 2006-148023 A

By the way, as electronic devices such as vehicles, moving bodies, robots, medical devices, and computer devices become more complicated and have higher performance, there is a demand for installing electronic components such as noise filters in harsh environments. . For example, there is a demand to install a noise filter in a circuit in which a large current of 20 amperes or more flows (hereinafter referred to as "request for large current handling"). In addition, unlike high frequencies in the megahertz band, there is a demand for filters that have excellent noise attenuation performance in the target frequency range from several kHz to several hundred kHz (hereinafter referred to as "request for target frequency"). If noise in the target frequency range flows into, for example, a radio receiver, this noise causes noise in listening to medium-wave radio broadcasts. Also, suppression of noise is important for prevention of malfunction. In order to meet these demands, it is necessary to break away from the design concept of LC filters using toroidal coils and aluminum electrolytic capacitors and obtain novel electronic components.

Therefore, an object of the present disclosure is to attenuate noise contained in a large current in a target frequency range from several kHz to several hundred kHz.

According to a first aspect of the present disclosure, an electronic component includes an inductor including a magnetic body and a conductor passing through the magnetic body only once, and a conductive polymer connected to the conductor of the inductor. including capacitors that The inductance of the inductor when no current is superimposed and when a DC current of 30 amperes is superimposed is 1 microhenry or more and 3 microhenries or less.

In the above electronic component, the attenuation rate of an AC signal at least at a frequency of 3.6 kHz may be -40 dB/decade or about -40 dB/decade, and the electronic component may form a second-order low-pass filter. good.

The electronic component may further include a substrate including conductive wires. The inductor and the capacitor may be fixed to the substrate, and the capacitor may be connected to the conductor of the inductor via the wire.

In the electronic component described above, the capacitor may function as a capacitance for an AC signal with a frequency of at least 3.6 kHz.

In the electronic component described above, the capacitor may have a capacitance of 10 microfarads or more and 1000 microfarads or less.

In the electronic component described above, the capacitor may be a conductive polymer hybrid capacitor that further contains a liquid component.

The electronic component may further include a parallel circuit connected in parallel with the capacitor for suppressing a peak caused by resonance between the inductor and the capacitor.

According to a second aspect of the present disclosure, a method for manufacturing an electronic component includes steps of forming an inductor including a magnetic body and a conductor penetrating the magnetic body only once, and forming a capacitor including a conductive polymer. forming and connecting the capacitor to the conductor of the inductor. The inductance of the inductor when no current is superimposed and when a DC current of 30 amperes is superimposed is 1 microhenry or more and 3 microhenries or less.

According to a third aspect of the present disclosure, in a noise processing method using an electronic component including an inductor and a capacitor, the inductor includes a magnetic body and a conductor passing through the magnetic body only once, an inductance of 1 microhenry or more and 3 microhenries or less when a direct current of 30 amperes is superimposed, and attenuates an alternating current signal flowing through the conductor of the electronic component, and the capacitor comprises a conductive polymer; to absorb said AC signal and attenuate said AC signal.

According to the present disclosure, one of the following effects can be obtained.

(1) It is possible to suppress heat generation and power loss of electronic parts.

(2) The inductance of the electronic component can be stabilized, for example, in a current range of 0 amperes to 30 amperes.

(3) In the frequency range of, for example, approximately 3 kHz to approximately 300 kHz, each of the inductor and capacitor that constitute the electronic component does not generate self-resonance. Therefore, the electronic component can function as a second-order LC filter with an attenuation factor of approximately -40 dB/decade in this frequency range.

(4) The frequency characteristics of electronic parts can be stabilized in a temperature range of -40°C to +150°C, for example.

1 is a diagram showing an example of an electronic component according to an embodiment and Example 1; FIG. It is a figure which shows an example of the equivalent circuit of an electronic component. It is a figure which shows an example of the superposition characteristic of an inductor. FIG. 4 is a diagram showing an example of heat generation characteristics of an inductor; FIG. 4 is a diagram showing an example of impedance and equivalent series resistance characteristics of a capacitor and an aluminum electrolytic capacitor; An example of the characteristics of an electronic component is shown. It shows the characteristic impedance characteristics of the electronic component shown in FIG. 6, the frequency at -40 dB, and the like. It is a figure which shows an example of the simulation verification result of the characteristic (theoretical value) of an electronic component. It is a figure which shows an example of the manufacturing procedure of an electronic component. It is a figure which shows an example of the manufacturing procedure of an electronic component. It is a figure which shows the mounting example to the circuit of an electronic component. FIG. 10 is a diagram showing an example of an equivalent circuit of an electronic component according to Example 2; It is a figure which shows the outline|summary of a frequency measurement system. FIG. 3 is a diagram showing measurement results of frequency characteristics of electronic components according to Examples 1 and 2; FIG. 5 is a diagram showing changes in frequency characteristics due to temperature changes; FIG. 5 is a diagram showing changes in frequency characteristics due to temperature changes; It is a figure which shows the change of a frequency characteristic by a current amount change. FIG. 5 is a diagram showing measurement results of frequency characteristics of an electronic component according to Comparative Example 1; FIG. 5 is a diagram showing changes in frequency characteristics due to temperature changes; 8 is a diagram showing impedance and equivalent series resistance characteristics of an aluminum electrolytic capacitor included in an electronic component according to Comparative Example 2; FIG. FIG. 10 is a diagram showing measurement results of frequency characteristics of an electronic component according to Comparative Example 2; FIG. 10 is a diagram showing changes in frequency characteristics due to changes in the amount of current in an electronic component according to Comparative Example 3;

Hereinafter, embodiments and examples will be described with reference to the drawings.

Embodiment

FIG. 1 shows an example of an electronic component according to an embodiment. In FIG. 1, front halves of exterior cases 16-1 and 16-2 of inductor 4, part of magnetic body 12-1 of inductor 4, and part of housing 24 of capacitor 6 are omitted.

The electronic component 2 comprises an inductor 4 with an inductance L, a capacitor 6 with a capacitance C and a substrate 8 forming an electronic component with L and C. The electronic component 2 has an inductance L and a capacitance C, and is used as a secondary low-pass filter, for example.

The inductor 4 includes magnetic bodies 12-1, 12-2, conductors 14, and outer cases 16-1, 16-2. A conductor 14 penetrates the magnetic bodies 12-1 and 12-2. Therefore, the magnetic bodies 12-1 and 12-2 are linked to the conductor 14 to form an inductor.

The magnetic bodies 12-1 and 12-2 have, for example, a cylindrical shape, and have a hollow portion 18 in the central portion of their circular cross section. The hollow portion 18 reaches both ends of the cylinders of the magnetic bodies 12-1 and 12-2 and penetrates the inside of the magnetic bodies 12-1 and 12-2. The magnetic bodies 12-1 and 12-2 include magnetic materials such as silicon steel, soft magnetic crystal materials, nanocrystal materials, amorphous metals or amorphous alloys. Amorphous metals are, for example, iron-based amorphous materials and cobalt-based amorphous materials, nanocrystalline materials are, for example, iron-based nanocrystalline materials, and amorphous alloys are, for example, iron-nickel alloys and iron-silicon alloys. The magnetic bodies 12-1 and 12-2 may contain multiple types of magnetic materials. A magnetic material is selected according to the use of the inductor 4, for example.

The magnetic bodies 12-1 and 12-2 are formed, for example, by winding strip-shaped magnetic foil. The magnetic bodies 12-1 and 12-2 may be sintered bodies of magnetic materials.

The conductor 14 is a conductive wire or rod, such as a copper wire or copper rod. The conductor 14 has a folded portion 14-3 in the central portion, and has a first outer conductor 14-1 and a second outer conductor 14-2 outside the folded portion 14-3. The first outer conductor 14-1 is arranged, for example, parallel or substantially parallel to the second outer conductor 14-2. The first outer conductor 14-1 passes through the magnetic body 12-1 only once and interlinks with the magnetic body 12-1, and the second outer conductor 14-2 passes through the magnetic body 12-2 only once. It penetrates and links with the magnetic body 12-2. Therefore, the inductor 4 forms, for example, a coil with a one-turn structure. The ends of the first outer conductor 14-1 and the second outer conductor 14-2 protrude from the magnetic bodies 12-1 and 12-2.

The exterior cases 16-1 and 16-2 accommodate the magnetic bodies 12-1 and 12-2 and the conductor 14. FIG. The exterior cases 16-1 and 16-2 are made of resin, for example, and protect the magnetic bodies 12-1 and 12-2 and the conductor 14. FIG. The exterior case 16-2 has through holes at positions corresponding to the first outer conductor 14-1 and the second outer conductor 14-2. The ends of the first outer conductor 14-1 and the second outer conductor 14-2 protrude from the outer case 16-2 through the through holes of the second outer conductor 14-2. Inductor 4 is mounted on substrate 8 .

Capacitor 6 includes capacitor element 20 , electrolyte 22 , housing 24 and sealing member 26 . Capacitor element 20 is an example of a capacitive element and includes laminated anode foil, separator, and cathode foil, with lead wire 28-1 connected to the anode foil and lead wire 28-2 connected to the cathode foil. further includes Electrolyte 22 is an electrolyte containing at least a conductive polymer, and capacitor element 20 is impregnated with electrolyte 22 to form a capacitance. Electrolyte 22 may be a hybrid electrolyte that includes a conductive polymer and a liquid component. That is, the capacitor 6 may be a conductive polymer capacitor containing a conductive polymer, or a conductive polymer hybrid capacitor containing a conductive polymer and a liquid component. Housing 24 is, for example, an aluminum can and houses capacitor element 20 impregnated with electrolyte 22 . The sealing member 26 is, for example, sealing rubber, and seals the opening of the housing 24 . Lead wires 28 - 1 and 28 - 2 of capacitor element 20 protrude outward from sealing member 26 through through-holes of sealing member 26 . A capacitor 6 is mounted on the substrate 8 . Although capacitor element 20 impregnated with electrolyte 22 is housed in housing 24 and sealed with sealing member 26, capacitor element 20 impregnated with electrolyte 22 may be sealed by coating with resin.

Substrate 8 is, for example, a circuit board and includes conductors 30 . Conductor 30 is connected to first outer conductor 14-1 of inductor 4 and lead 28-1 of capacitor 6 to electrically connect inductor 4 and capacitor 6. FIG. The second outer conductor 14-2 and the lead wire 28-2 are connected to other conductor wires 30, respectively, and the connection end of the second outer conductor 14-2 or the lead wire 28-2 is pulled out to the outside of the substrate 8. is

FIG. 2 shows an example of an equivalent circuit of an electronic component. In FIG. 2, the arrows attached along the wiring in the equivalent circuit indicate the direction of signal flow.

Since one end of inductor 4 is connected to positive lead 28-1 of capacitor 6, electronic component 2 forms, for example, an L-type LC filter.

AC signal V noise flows into the electronic component 2 . This AC signal V noise is one of the signals flowing through the electronic component 2 and includes an AC signal having a frequency within a target frequency range of, for example, several kHz to several hundred kHz. The AC signal contains, for example, spike noise generated by a switching power supply and noise generated by an inverter. When this AC signal V noise flows through conductor 14 of inductor 4, inductor 4 blocks the passage of the AC signal. Capacitor 6 also absorbs and removes AC signal Va in AC signal V noise. Therefore, the electronic component 2 can attenuate the AC signal in the AC signal V noise. The capacitor 6 may pass the AC signal Va in the AC signal V noise to the ground line. A superimposed current (direct current) may be superimposed on the AC signal V noise.

FIG. 3 shows an example of superposition characteristics of the inductor 4. FIG. In FIG. 3, examples of the superimposition characteristics of the inductor 4 at temperatures of −40° C., +25° C., and +135° C. are indicated by solid lines, dashed-dotted lines, and double-dotted lines, respectively, and an example of superimposition characteristics of the toroidal coil is indicated by the dashed line. . In FIG. 3, the vertical axis represents the inductance L at a frequency of 10 kHz, and the horizontal axis represents the current value of the superimposed current (direct current). A state in which the superimposed current is 0 amperes represents a state in which no superimposed current flows, that is, a non-superimposed current state.

The inductance L of the toroidal coil is higher than the inductance L of the inductor 4 in the superimposed current range of 0 to 30 amperes. A large inductance L can be obtained by using a toroidal coil. For example, since the cutoff frequency f of an L-type LC filter is expressed by the following equation (1), if the inductance L is large, the capacitance C can be made small.
f=1/{2π√(LC)} (1)
Therefore, toroidal coils are generally used in LC electronic components such as LC filters, and have a good track record.

The inductance L of the inductor 4 is lower than the inductance L of the toroidal coil. However, as the superimposed current increases, the inductance L of the toroidal coil decreases greatly, whereas the inductance L of the inductor 4 decreases less. In other words, the inductor 4 has less current dependence and higher current stability than the toroidal coil. Also, at a current value of a large superimposed current such as 30 amperes, the difference in inductance L between the inductor 4 and the toroidal coil is relatively small. As a result, the inductor 4 can perform substantially the same function as a toroidal coil in electronic components that handle large superimposed currents.

Also, the amount of change in the inductance L is small in the temperature range from -40°C to +135°C, as shown in FIG. That is, the inductor 4 can provide a stable inductance L over a wide temperature range.

FIG. 4 shows an example of heat generation characteristics of an inductor. In FIG. 4, an example of heat generation characteristics of the inductor 4 is represented by a solid line, and an example of heat generation characteristics of the toroidal coil is represented by a broken line. In FIG. 4, the vertical axis represents the amount of temperature rise, and the horizontal axis represents the current value of the direct current (superimposed current). Note that the temperature is the temperature of the upper surfaces of the inductor 4 and the toroidal coil.

Due to the difference in the number of turns of the conductor, the amount of heat generated by the inductor 4 is less than that of the toroidal coil. For example, when a DC current of 30 amperes flows through inductor 4, the DC resistance of inductor 4 is, for example, 0.4 milliohms (mΩ), the power loss is, for example, 0.36 watts (W), and the temperature rise The quantity is, for example, 12 Kelvin (K), as shown in FIG. In contrast, when a 30 ampere DC current flows through the toroidal coil, the DC resistance of the toroidal coil is, for example, 2.4 milliohms, the power loss is, for example, 2.16 watts, and the amount of temperature rise is shown in FIG. 4, for example 62 Kelvin. As a result, the heat generation amount and power loss of the electronic component 2 including the inductor 4 can be made smaller than the heat generation amount and power loss of the electronic component including the toroidal coil. The difference in the amount of heat generated between the inductor 4 and the toroidal coil increases as the current value increases. Therefore, in the case of processing a large current, the electronic component 2 can obtain the effects of significantly low heat generation and low power loss.

The inductance L of the inductor 4 is preferably 1 microhenry (hereinafter referred to as "μH") or more, and preferably 1.5 μH or more. When the inductance L is 1 μH or more, the degree of freedom in setting the capacitor 6 combined with the inductor 4 can be ensured. When the inductance L is 1.5 μH or more, the degree of freedom in setting the capacitor 6 combined with the inductor 4 is enhanced. As the inductance L increases, the inductor 4 becomes larger, the above-described current dependence increases, and the DC resistance increases. Therefore, the inductance L is preferably 3 μH or less, and preferably 2.5 μH or less. The inductance L can be measured, for example, based on Japanese Industrial Standard JIS C 5321 6.17 (Method for measuring coil superposition characteristics).

A of FIG. 5 shows an example of impedance and equivalent series resistance (hereinafter referred to as “ESR”) characteristics of a capacitor, and B of FIG. shows an example of the characteristics of In FIG. 5A, the absolute value of impedance (Z) and ESR at -40.degree. In FIGS. 5A and 5B, the absolute value of impedance and ESR at +20° C. are indicated by the dashed-dotted line, and the absolute value of impedance and ESR at +135° C. are indicated by the dashed-double-dotted line. 5A and 5B, the vertical axis represents the absolute value of impedance and the ESR value, and the horizontal axis represents frequency.

The absolute value of the impedance of capacitor 6 containing a conductive polymer is greater than the ESR in the frequency range of 0 to about 200 kHz, as shown in FIG. 5A. Capacitor 6 therefore has a capacitance C, for example, in the frequency range from 0 to about 200 kHz. On the other hand, the absolute value of the impedance of an aluminum electrolytic capacitor that does not contain a conductive polymer, as shown in B in FIG. A capacitor functions, for example, as a resistor. In other words, an electronic component including an aluminum electrolytic capacitor, even if it apparently includes a capacitor, electrically loses the capacitance C at frequencies exceeding 70 kHz, for example. Therefore, the electronic component 2 including the capacitor 6 can function as an ideal LC electronic component in a wider frequency band than the electronic component including the aluminum electrolytic capacitor.

A second-order LC filter or low-pass filter containing inductance L and capacitance C has an attenuation factor of -40 dB/decade, for example. However, the attenuation factor of a first-order LR filter or low-pass filter including inductance L and resistance R is -20 dB/decade, for example. Therefore, the electronic component 2 including the capacitor 6 can attenuate AC signals with a frequency greater than, for example, 70 kHz more efficiently than an electronic component including an aluminum electrolytic capacitor. "dB/decade" is the unit of attenuation rate. show.

Also, the absolute value of the impedance and the ESR of the capacitor 6 containing the conductive polymer hardly fluctuate in the temperature range from -40°C to +135°C, as shown in A of FIG. That is, the capacitor 6 can provide a stable capacitance C over a wide temperature range. In contrast, the absolute impedance value and ESR of an aluminum electrolytic capacitor that does not contain a conductive polymer fluctuate in the temperature range from -40°C to +135°C, as shown in B of FIG. Therefore, the frequency range in which an electronic component including an aluminum electrolytic capacitor functions as an LC filter varies depending on the ambient temperature. Therefore, the electronic component 2 including the capacitor 6 can have a higher attenuation rate stability with respect to temperature changes than the electronic component including the aluminum electrolytic capacitor.

The electronic component 2 preferably satisfies the following first to third conditions and may efficiently attenuate AC signals in the target frequency range.
・First condition: The resonance frequency of the capacitor 6 is constant with respect to the theoretical value of the frequency of the signal when the attenuation of the signal in the electronic component 2 is -40 dB (hereinafter referred to as "frequency at -40 dB"). has a likelihood of That is, the likelihood represented by the following formula (2) is 2.0 or more.
Likelihood=Resonant frequency of capacitor 6/Frequency at −40 dB (2)
• Second condition: The characteristic impedance of the electronic component 2 is appropriate for the impedance of the power supply circuit. The characteristic impedance is a combination of a coil and a capacitor, and is represented by √L/C.
• Third condition: The frequency at -40 dB is within the target frequency range described above.

FIG. 6 shows an example of the characteristics of electronic components. FIG. 7 shows the characteristic impedance characteristics of the electronic component shown in FIG. 6, the frequency at -40 dB, and the like.

When the inductance L of the inductor 4 is 2 μH, as shown in FIG. and the third condition are satisfied. Therefore, the capacitor 6 preferably has a capacitance C of 10 μF or more and 1000 μF or less. The characteristic impedance of the electronic component 2 is distributed between 0.04 ohms and 0.45 ohms as shown in A of FIG. , there exists an electronic component 2 that satisfies the second condition.

From the viewpoint of miniaturization and capacitance of the capacitor 6, the capacitance C is desirably in the range of 47 μF or more and 330 μF or less.

Capacitor 6 may be selected such that the cut-off frequency of electronic component 2 or frequency at -40 dB is at a particular frequency within the target frequency range. The cutoff frequency of the electronic component 2 is distributed between 3.6 kHz and 35.6 kHz as shown in A of FIG. Frequency can be adjusted. The frequency at -40 dB of the electronic component 2 is distributed between 35.6 kHz and 355.9 kHz as shown in B of FIG. Frequency can be adjusted.

The capacitance C can be measured, for example, according to Japanese Industrial Standard JIS C 5101-26 4.4.2 (measurement of capacitance). FIG. 6 shows the characteristics of the electronic component 2 when the inductance L is 2 μH. However, if the inductance L is a value close to 2 μH, for example, 1 μH or more and 3 μH or less, the electronic component 2 has characteristics substantially similar to those shown in FIG. is almost unchanged.

A theoretical value was used as the frequency at -40 dB to explain the preferred range of the capacitance C (10 μF or more and 1000 μF or less). Therefore, this theoretical value is verified by simulation. For the simulation, the characteristics of each component included in the electronic component 2 are measured, and a SPICE (Simulation Program with Integrated Circuit Emphasis) model of each component is created based on the measurement results. Using the created SPICE model, the electronic circuit of the electronic component 2 is formed by a SPICE simulator, and the attenuation of the formed electronic circuit at frequencies from 100 Hz to 1 MHz, for example, is obtained. The SPICE model is created based on the characteristics of each component of the electronic component 2 and the number of components included in the electronic component 2 is small. Therefore, the SPICE simulator can output simulation results that are close to the actual characteristics of the electronic component 2 .

8A, 8B, 8C, and 8D show examples of theoretical values and simulation results of the frequency characteristics of the electronic component 2 including the capacitors 6 of 47 μF, 100 μF, 270 μF, and 330 μF, respectively. ing. In FIGS. 8A, 8B, 8C and 8D, simulation results are indicated by solid lines and theoretical values are indicated by dashed lines. In FIGS. 8A, 8B, 8C and 8D, the vertical axis represents attenuation and the horizontal axis represents frequency.

As shown in A of FIG. 8, B of FIG. 8, C of FIG. 8, and D of FIG. 8, the theoretical values substantially agree with the simulation results. That is, the preferable range of the capacitance C obtained using the theoretical value represents the preferable range of the capacitance C of the electronic component 2 .

9 and 10 show an example of the manufacturing procedure of the electronic component.

As shown in FIG. 9A, the first outer conductor 14-1 of the conductor 14 is inserted into the hollow portion 18 of the magnetic body 12-1, and the second outer conductor 14-2 is inserted into the hollow portion of the magnetic body 12-2. Insert into section 18 . As shown in FIG. 9B, the conductor 14 and the magnetic bodies 12-1 and 12-2 are housed in exterior cases 16-1 and 16-2 to obtain the inductor 4. As shown in FIG.

As shown in FIG. 10A, a capacitor element 20 is formed. This capacitor element 20 is impregnated with an electrolyte 22 . As shown in FIG. 10B, capacitor element 20 impregnated with electrolyte 22 is housed in housing 24 and the opening of housing 24 is sealed with sealing member 26 to obtain capacitor 6 .

As shown in FIG. 10C, inductor 4 and capacitor 6 are placed on substrate 8 . Also, the electronic component 2 is obtained by connecting the conductor 14 to the lead wire 28-1 via the lead wire 30. FIG.

FIG. 11 shows an example of mounting an electronic component on a circuit.

Circuit 32 includes electronic component 2 , power supply 34 and load 36 , and wiring 38 . Power supply 34 is connected to load 36 via electronic component 2 . The power supply 34 is an example of a noise source, such as a switching power supply. Power supply 34 supplies power to load 36 . The load 36 is, for example, an electric motor of an automobile, or a solenoid actuator. Electronic component 2 is placed on wiring 38 between power supply 34 and load 36 . The electronic component 2 reduces noise included in the current output from the power supply 34 or the load 36 and supplies the noise-suppressed current to the wiring 38 of the circuit 32 . The placement of the electronic component 2 suppresses the adverse effects of noise on the load 36 .

The number of electronic components 2, power supplies 34 and loads 36 is not limited to one. The number of electronic components 2, power supplies 34 and loads 36 may be plural.

In order to respond to the above-mentioned demand for high current and target frequency, we broke away from the design concept of the existing LC filter using aluminum electrolytic capacitors that use only electrolytic solution for the toroidal coil and electrolyte, and changed the design concept. I tried to convert. This shift in design philosophy includes the adoption of an inductor 4 whose inductance characteristics are significantly different from those of a toroidal coil. Also, this change in design concept includes the adoption of a capacitor 6 containing a conductive polymer. For example, according to the electronic component 2 of the embodiment created through this change in design concept, the following effects can be obtained.

(1) The conductor 14 of the inductor 4 penetrates the magnetic body 12-1 only once and penetrates the magnetic body 12-2 only once. .

(2) Inductor 4 includes conductor 14 and is suitable for circuits carrying large currents. In addition, the conductor 14 of the inductor 4 penetrates the magnetic body 12-1 only once and penetrates the magnetic body 12-2 only once. L can be stabilized.

(3) Since the capacitor 6 contains a conductive polymer, it can have a capacitance C in a frequency range of, for example, several hundred kHz or less. The electronic component 2 can thus function, for example, as an LC filter in this frequency range. The attenuation rate of the LC filter is, for example, −40 dB/decade, while the attenuation rate of the LR filter is, for example, −20 dB/decade. Therefore, the electronic component 2 can form a filter having an attenuation factor superior to that of the LR filter in a wide frequency range.

(4) Since the capacitor 6 contains a conductive polymer, the characteristics of the capacitance C of the electronic component 2 are stabilized in the temperature range of -40°C to +135°C, and further in the temperature range of -40°C to +150°C. be able to.

(5) The inductor 4 can stabilize the inductance L over a wide current range and a wide temperature range. Also, the capacitor 6 can stabilize the characteristics of the capacitance C over a wide temperature range. Therefore, the electronic component 2 can obtain stable characteristics in a wide temperature range and a wide current range. Therefore, the frequency of requests for fine adjustment of the electronic component 2 after the electronic component 2 is mounted on the circuit can be suppressed, and the adjustment burden of the electronic component 2 can be suppressed.

The electronic component 2 of the embodiment may be modified as follows.

(1) In the above embodiment, the inductor 4 and the capacitor 6 are mounted on the substrate 8 , and the conductor 30 of the substrate 8 connects the inductor 4 to the capacitor 6 . However, the inductor 4 may be connected to the capacitor 6 with a connection line without using the substrate 8, or the inductor 4 may be directly connected to the capacitor 6. FIG.

(2) The number of inductors 4 and capacitors 6 is not limited to one, and may be plural. If the number of inductors 4 or capacitors 6 is plural, for example, the inductance L or the capacitance C of the electronic component 2 can be finely adjusted, and the degree of freedom in adjusting the inductance L or the capacitance C can be increased. .

(3) In the above embodiment, the inductor 4 includes two magnetic bodies 12-1 and 12-2. However, the number of magnetic bodies may be one, or three or more.

(4) In the above embodiment, the inductor 4 is formed by inserting the conductor 14 into the hollow portion 18 of the magnetic bodies 12-1 and 12-2. However, the magnetic bodies 12-1 and 12-2 may be formed by winding strip-shaped magnetic foil around the conductor 14, for example. When the belt-shaped magnetic foil is wound around the conductor 14, there is no need to provide a gap between the side surface of the conductor 14 and the inner surface of the magnetic body. Therefore, the inductor 4 can be made smaller.

(5) The electronic component 2 may include other electronic elements such as a Q-dump resistor so that the electronic component 2 can obtain effects such as reduction of the quality factor Q.

The electronic component 2 according to Example 1 has the same configuration as the electronic component 2 shown in FIG. 1, similarly to the embodiment. An equivalent circuit of the electronic component 2 according to Example 1 is represented by the equivalent circuit shown in FIG. Characteristics of the inductor 4 and the capacitor 6 of the electronic component 2 according to Example 1 are as follows.
[Inductor 4]
Material of conductor 14: Material of bar magnetic bodies 12-1 and 12-2 containing copper: Iron-based amorphous material obtained by winding strip-shaped iron-based amorphous foil Direct current resistance (DCR): Approximately 0.4 milliohm superposition Characteristics: The same characteristics as the superimposed characteristics indicated by the solid line, the one-dot chain line and the two-dot chain line in FIG. 3 Heat generation characteristics: The same characteristics as the heat generation characteristics indicated by the solid line in FIG.
Type: Conductive polymer hybrid aluminum electrolytic capacitor Electrolyte: Conductive polymer and liquid component Capacitance: 100μF
Characteristics: the same impedance and ESR characteristics as shown in FIG. 5A

An electronic component 42 according to Example 2 includes the electronic component 2 according to Example 1 and further includes a parallel circuit 44 connected in parallel to the capacitor 6 . An equivalent circuit of the electronic component 42 is represented by the equivalent circuit shown in FIG.

A parallel circuit 44 includes a capacitor 44-1 and a resistor 44-2 connected in series to form a Q-dump resistor and reduce the quality factor Q. Capacitor 44-1 prevents the passage of DC current and resistor 44-2 reduces the quality factor Q. A preferable range of the quality factor Q is, for example, 0.5 to 0.7, and the resistance value of the resistor 44-2 is determined, for example, by the product of the quality factor Q and √(L/C). Characteristics of the capacitor 44-1 and resistor 44-2 are as follows.
[Capacitor 44-1]
Type: Aluminum electrolytic capacitor Capacitance: 4700μF
[Resistance 44-2]
Resistance Value: The characteristics of the 0.1 ohm capacitor 44-1 and resistor 44-2 are adjusted so that the quality factor Q is small.

The frequency characteristics of the electronic components 2 and 42 according to Examples 1 and 2 were evaluated using a frequency measurement system 52 shown in FIG. FIG. 13 shows an overview of the frequency measurement system. The frequency measurement system shown in FIG. 13 is connected to the electronic component 2 according to the first embodiment to measure the electronic component 2, but is connected to the electronic component 42 according to the second embodiment to measure the electronic component 42. You may

The frequency measurement system 52 includes a frequency response analyzer (FRA) 54 , a DC current superposition unit 56 , a regulated power supply 58 , a variable load resistor 60 and circuit wiring 62 . The frequency analyzer 54 applies a signal to an object to be measured, such as the electronic components 2 and 42, and analyzes the frequency characteristics of the object to be measured using the response signal from the object to be measured. The DC current superposition unit 56 is connected to the regulated power supply 58 and the circuit wiring 62, and superimposes the DC current of the regulated power supply 58 on the circuit wiring 62 regardless of the presence or absence of a signal. Electronic component 2 and variable load resistor 60 are arranged on circuit wiring 62 . By changing the resistance value of the variable load resistor 60, the amount of direct current (superimposed current) flowing through the circuit wiring 62 can be changed. Also, when the variable load resistor 60 is removed from the circuit wiring 62, a state in which the amount of DC current is 0 amperes, that is, a non-superimposed current state can be created. The frequency measurement system 52 is adjusted so that the electronic components included in the frequency measurement system 52 do not affect the analysis of frequency characteristics.

FIG. 14 shows measurement results of frequency characteristics of the electronic components according to Examples 1 and 2. FIG. In FIG. 14, the frequency characteristics of the electronic component 2 according to Example 1 are represented by a dashed line, and the frequency characteristics of the electronic component 42 according to Example 2 are represented by a solid line.

The electronic components 2, 42 according to Examples 1 and 2 have a -40 dB/decade, or about - It has an attenuation rate of 40 dB/decade and has sufficient performance as a secondary LC low-pass filter. Further, the electronic components 2 and 42 maintain an attenuation of -40 dB or less in the range of 200 kHz to several hundred kHz, and attenuate AC signals in the target frequency range at a high rate.

Electronic component 42, including parallel circuit 44, eliminates peak 46 at the cutoff frequency. Therefore, the electronic component 42 can prevent an increase in the AC signal at the cutoff frequency, and can be applied to a circuit containing noise above the cutoff frequency, for example.

15 and 16 show changes in frequency characteristics due to temperature changes. FIG. 15 shows the measurement results of the frequency characteristics of the electronic component 42 at −40° C., +25° C., and +135° C. when 30 amperes of DC current is superimposed. FIG. 16 shows the measurement results of the frequency characteristics of the electronic component 42 at −40° C., +25° C., and +135° C. when 0 ampere DC current is superimposed. In FIGS. 15 and 16, the solid line, one-dot chain line, and two-dot chain line represent the measurement results at −40° C., +25° C., and +135° C., respectively.

As shown in FIG. 15, the frequency characteristics at −40° C., +25° C., and +135° C. are almost the same when 30 ampere DC current is superimposed. In addition, in a state in which 0 amperes of DC current is superimposed, that is, in a non-superimposed state, the frequency characteristics slightly change with temperature, as shown in FIG. As shown in FIG. 3, the temperature change of the inductance L in the non-superimposed current state is slightly larger than the temperature change of the inductance L in the superimposed DC current of 30 amperes. due to that. However, the difference in the cutoff frequency f represented by the above equation (1) is only about 3 kHz, and approximately -40 dB of attenuation is obtained at a frequency of 110 kHz. Therefore, according to the electronic component 42, the frequency characteristics can be stabilized regardless of the temperature in a wide current range.

FIG. 17 shows changes in frequency characteristics due to changes in the amount of current. FIG. 17 shows measurement results of the frequency characteristics of the electronic component 42 when DC currents of 0 ampere, 15 ampere, and 30 ampere are superimposed. In FIG. 17, a solid line, a one-dot chain line, and a two-dot chain line represent measurement results when DC currents of 0 ampere, 15 ampere, and 30 ampere are superimposed, respectively.

As shown in FIG. 17, the frequency characteristics when 0 ampere, 15 ampere, and 30 ampere DC currents are superimposed are substantially the same. That is, according to the electronic component 42, the frequency characteristics can be stabilized over a wide current range.

The electronic component 2 according to Example 1 includes the same inductor 4 and capacitor 6 as the electronic component 42 . Therefore, according to the electronic component 2, like the electronic component 42, the frequency characteristics can be stabilized regardless of the temperature over a wide current range, and the frequency characteristics can be stabilized over a wide current range.

In Examples 1 and 2, a capacitor of 100 μF is used, and the attenuation rate of −40 dB/decade or approximately −40 dB/decade is realized when the AC signal has a cut-off frequency of 10 kHz. and the frequency is 100 kHz. However, when a capacitor with a higher capacity is used as the capacitor, for example, when a 1000 μF capacitor is used, the cutoff frequency of the AC signal is 3.6 kHz, as shown in FIG. At a frequency of 35.6 kHz, an attenuation rate of -40 dB/decade or about -40 dB/decade can be achieved.

Comparative example 1

The electronic component according to Comparative Example 1 is the same as the electronic component 42 according to Example 2, except for the capacitor 6 . The electronic component according to Comparative Example 1 includes an aluminum electrolytic capacitor shown below instead of the capacitor 6 .
〔Aluminum electrolytic capacitor〕
Electrolyte: Electrolyte Capacitance: 100 μF
Characteristics: the same impedance and ESR characteristics shown in FIG. 5B

The frequency characteristics of the electronic component according to Comparative Example 1 at +25° C. when the DC current is 0 amperes were measured by the frequency measurement system 52 . 18 shows measurement results of frequency characteristics of the electronic component according to Comparative Example 1. FIG. In FIG. 18, the frequency characteristic of the electronic component according to Comparative Example 1 is represented by a dashed line. Further, in FIG. 18, the frequency characteristic of the electronic component 42 at +25° C. shown in FIG. 16 is indicated by a solid line.

Capacitor 6 of electronic component 42 functions as a capacitor up to approximately 200 kHz. Therefore, the electronic component 42 can ensure an attenuation characteristic of -40 dB/decade up to about 200 kHz. However, in the aluminum electrolytic capacitor of the electronic component according to Comparative Example 1, the absolute value of the impedance matches the ESR at about 30 kHz as shown in FIG. 5B. Therefore, the aluminum electrolytic capacitor according to Comparative Example 1 loses its function as a capacitor at about 30 kHz, and the electronic component according to Comparative Example 1 operates as an LR filter at frequencies exceeding 30 kHz.

FIG. 19 shows changes in frequency characteristics due to temperature changes. FIG. 19 shows measurement results of the frequency characteristics of the electronic component according to Comparative Example 1 at −40° C., +25° C., and +135° C. when the DC current is 0 amperes. In FIG. 19, the dashed line, the one-dot chain line, and the two-dot chain line represent the measurement results at -40°C, +25°C, and +135°C, respectively. Incidentally, in the measurement at -40°C, the parallel circuit 44 was removed from the electronic component according to the first comparative example.

As shown in FIG. 19, the frequency characteristics of the electronic component according to Comparative Example 1 change greatly depending on the temperature. It is clear that the electronic components 2 and 42 according to Examples 1 and 2 are significantly superior to the electronic component according to Comparative Example 1.

Comparative example 2

The electronic component according to Comparative Example 2 is the same as the electronic component 42 according to Example 2 except for the capacitor 6 . The electronic component according to Comparative Example 2 includes an aluminum electrolytic capacitor shown below instead of the capacitor 6 . The electronic component according to Comparative Example 2 is adjusted so that the attenuation at the frequency of 100 kHz is substantially the same as that of the electronic component 42 .
〔Aluminum electrolytic capacitor〕
Capacitance: 4700μF
Characteristics: the same impedance and ESR characteristics shown in FIG.

The frequency characteristics of the electronic component according to Comparative Example 2 at +25° C. when the DC current is 0 amperes were evaluated by the frequency measurement system 52 . 21 shows measurement results of frequency characteristics of the electronic component according to Comparative Example 2. FIG. In FIG. 21, the frequency characteristic of the electronic component according to Comparative Example 2 is represented by a dashed line. Further, in FIG. 21, the frequency characteristic of the electronic component 42 at +25° C. shown in FIG. 16 is indicated by a solid line.

Capacitor 6 of electronic component 42 functions as a capacitor up to approximately 200 kHz. Therefore, the electronic component 42 can ensure an attenuation characteristic of -40 dB/decade up to about 200 kHz. However, in the aluminum electrolytic capacitor of the electronic component according to Comparative Example 2, the impedance matches the ESR at about 5 kHz as shown in FIG. Therefore, the aluminum electrolytic capacitor according to Comparative Example 2 loses its function as a capacitor at about 5 kHz, and the electronic component according to Comparative Example 2 operates as an LR filter in the target frequency range.

比較例３ The capacitors 6 of Examples 1 and 2 have smaller capacitances than the aluminum electrolytic capacitor of Comparative Example 2. Therefore, the capacitor 6 is smaller and lighter than the aluminum electrolytic capacitor of Comparative Example 2, as shown in Table 1. Therefore, according to the electronic components 2 and 42 of Examples 1 and 2, the electronic components can be miniaturized.

Comparative example 3

The electronic component according to Comparative Example 3 is the same as the electronic component 42 according to Example 2, except for the inductor 4 . The electronic component according to Comparative Example 3 includes a toroidal coil shown below instead of the inductor 4 . The electronic component according to Comparative Example 3 is adjusted so that the attenuation of the frequency of 100 kHz when a DC current of 30 amperes is superimposed is approximately the same as that of the electronic component 42 .
[Toroidal coil]
DC resistance: about 2.4 milliohms Superimposed characteristics: the same characteristics as the superimposed characteristics indicated by broken lines in FIG. 3 Heat generation characteristics: the same characteristics as the heat generation characteristics indicated by broken lines in FIG.

The frequency characteristics of the electronic component according to Comparative Example 3 change according to the amount of superimposed DC current, as shown in FIG.

As described above, the most preferred embodiments and the like of the present disclosure have been described, but the present disclosure is not limited to the above description, and the gist described in the claims or disclosed in the specification Based on this, it goes without saying that various modifications and changes can be made by those skilled in the art, and such modifications and changes are naturally included in the scope of the present disclosure.

The technology of the present disclosure is useful because it can be used to remove noise from electronic devices such as vehicles.

2, 42 Electronic component 4 Inductor 6 Capacitor 8 Substrate 12-1, 12-2 Magnetic body 14 Conductor 14-1 First outer conductor 14-2 Second outer conductor 14-3 Folded portion 16-1, 16-2 Outer Case 18 Hollow Part 20 Capacitor Element 22 Electrolyte 24 Case 26 Sealing Member 28-1, 28-2 Lead Wire 30 Lead Wire 32 Circuit 34 Power Supply 36 Load 38 Wiring 44 Parallel Circuit 44-1 Capacitor 44-2 Resistor

Claims (9)

an inductor including a magnetic body and a conductor passing through the magnetic body only once;
a capacitor comprising a conductive polymer and connected to the conductor of the inductor;
with
An electronic component, wherein the inductance of the inductor is 1 microhenry or more and 3 microhenries or less when no current is superimposed and when a direct current of 30 amperes is superimposed. 2. The electronic component according to claim 1, wherein the attenuation rate of an alternating signal at a frequency of at least 3.6 kHz is -40 dB/decade or about -40 dB/decade, forming a second-order low-pass filter. . further comprising a substrate including conductors;
the inductor and the capacitor are secured to the substrate;
3. The electronic component according to claim 1, wherein the capacitor is connected to the conductor of the inductor through the lead wire. 4. The electronic component according to any one of claims 1 to 3 , wherein the capacitor functions as a capacitance for an AC signal with a frequency of at least 3.6 kHz. 5. The electronic component according to claim 1, wherein said capacitor has a capacitance of 10 microfarads or more and 1000 microfarads or less. 6. The electronic component according to claim 1 , wherein the capacitor is a conductive polymer hybrid capacitor that further contains a liquid component. 7. The electronic component according to any one of claims 1 to 6 , further comprising a parallel circuit connected in parallel with the capacitor for suppressing a peak caused by resonance of the inductor and the capacitor. forming an inductor including a magnetic material and a conductor passing through the magnetic material only once;
forming a capacitor comprising a conductive polymer;
connecting the capacitor to the conductor of the inductor;
with
A method of manufacturing an electronic component, wherein the inductance of the inductor is 1 microhenry or more and 3 microhenries or less when no current is superimposed and when a direct current of 30 amperes is superimposed. A noise processing method using an electronic component including an inductor and a capacitor,
The inductor includes a magnetic body and a conductor passing through the magnetic body only once, and has an inductance of 1 microhenry or more and 3 microhenries or less when no current is superimposed and when a direct current of 30 amperes is superimposed. attenuating an alternating current signal flowing through the conductor of the electronic component;
The noise processing method, wherein the capacitor includes a conductive polymer, absorbs the AC signal, and attenuates the AC signal.

Images