JPH01162312A - Composite inductance element - Google Patents

Abstract

PURPOSE:To integrate a plurality ot different inductance elements by a method wherein conductivity rods, having a conductive film formed on the core of an insulating material, are inserted respectively into a plurality of through holes formed on a magnetic block, and a number of kinds of conductivity rods are attached to one magnetic block. CONSTITUTION:A plurality of conductivity rods 2 and 5, having a conductive film formed on the surface of the core of an insulator, are inserted into the through holes on a magnetic block 1. Between the conductivity rods 2 and 5, and lead-out terminals 7, 8, 9 and 10 is connected by conductive paste 11, 12 and 13. The two through holes formed on the block 1 are widened at both end parts, and the distance between the surface of the conductivity rods 2 and 5 and the block 1 is increased on the circumference of the terminal parts 2a and 2b of the conductivity rod 2 and also on the circumference of the terminal pairs 5a and 5b of the conductivity rods 5. As a result, a plurality of different inductance elements can be integrated.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a composite inductance element.

Conventional technology When a pulsed signal is transmitted to the signal line of a digital circuit,
The harmonics of levers that contain high-frequency harmonics in their abrupt rise and fall waveforms may be radiated and cause reception disturbances in television receivers and the like. In addition, noise is generated due to overshoot or undershoot when voltage is suddenly applied, which can cause digital circuits to malfunction. Noise filters used by inserting into signal lines or the like for the purpose of removing noise include those using only an inductor, and those using a combination of an inductor and a capacitor to form a low-pass filter.

FIG. 8 shows a conventional noise filter, which is composed only of inductors. A ferrite core 21 is provided with through holes 22 and 23. Through hole 2
A lead-out terminal 24 and a lead-out terminal 25 are formed of a conductive film at the openings at one end of the 2 and through-hole 23, respectively, and the connecting terminal 2 is formed at the other end so as to span between both openings.
6 is formed of a conductive film. And through hole 2
A conductive film is formed over the entire inner wall surface of 2.23. That is, a cylindrical conductive line 27 and a cylindrical conductive line 28 are formed in the ferrite core. and,
Both ends of the conductive line 27 are electrically connected to the lead-out terminal 24 and the connecting terminal 26, and both ends of the conductive line 28 are connected to the lead-out terminal 25 and the connecting terminal 2.
6 is conductive. Φ3 represents the magnetic flux generated by the current in the conductive line 27, and Φ4 represents the magnetic flux generated by the current in the conductive line 28.

As described above, conventionally, a conductive line is provided by depositing a conductive film on the inner wall of the through hole of a ferrite core, and the magnetic flux Φ3. A noise filter was constructed using the effect of Φ4. FIG. 9 shows its equivalent circuit diagram. 9th
In the figure, 29 is an inductor formed by a conductive line 27;
0 is an inductor due to the conductive line 28. FIG. 10 shows a chip capacitor added to the inductance element shown in FIG. 8, and a low-pass filter consisting of the inductor and capacitor is configured. A chip capacitor 31 is attached to the outer surface of the ferrite core 21, and the hot side electrode terminal 32 and the connection terminal 26 are connected to form a T-type low-pass filter as shown in FIG.

33 is a ground side electrode terminal. By utilizing the bypass effect of the capacitor, the filter effect is improved compared to a filter using only an inductor.

Problems to be Solved by the Invention However, with such conventional inductance elements, it is difficult to individually set the magnetic characteristics of the plurality of inductance elements formed inside. For example, when applied to a filter, However, it was difficult to match the frequency characteristics, etc. to the desired characteristics.

In other words, the inductors 29 and 30 utilize conductive films formed at the same time by the same process in the through holes provided in the same ferrite core, and exhibit almost the same characteristics. Therefore, even if an attempt is made to realize a desired frequency characteristic by combining both inductance elements, if both always exhibit the same characteristics, there will be significant design limitations.

Means for Solving the Problems In order to solve the above problems, the present invention includes inserting a conductive rod having a conductive film formed on the surface of the insulating rod into each of a plurality of through holes formed in a magnetic block. It was configured as follows.

Function By configuring as described above, it is possible to install many types of conductive rods in one magnetic block.
It is possible to configure a plurality of inductance elements each having different characteristics using one magnetic block.

EXAMPLES Hereinafter, examples of the composite inductance element of the present invention will be described based on the drawings. In FIG. 1, reference numeral 1 denotes a ferrite core made of ferrite in the form of a block, and is provided with through holes at two locations. Reference numeral 2 denotes a rod-shaped conductor portion inserted into the through hole of the ferrite core 1. The conductor portion 2 is constructed by uniformly depositing a conductor film of copper, nickel, etc. on the surface of ferrite. Conductor part 2
A ferrite rod of any size with an outer diameter of about 1 mm and a length of about 5 mm is coated with a nickel base plating as a conductive film, and is further plated with copper to a thickness of 3 to 6 microns. Grooves 3 are formed on the surface by cutting. The width of the groove 3 is about 0.08 m, and the width of the conductive part 4 is about 0.08 m.
．． It is 2 to 0.3 mm. For example, if a groove is carved so that a band-shaped conductive part of this width is wrapped eight times, the DC resistance value between both ends of the conductor part 2 will be 1 to 2 Ω.
It will be about. In addition, when formed to the above dimensions, by selecting the type of conductor and other conditions, it is possible to create a conductor with a DC resistance value in the range of about 0.1 to 100Ω. By placing the constructed conductor film in a magnetic material, it can also serve as an RL time constant element.

Reference numeral 5 denotes a conductor rod having substantially the same structure as the conductor rod 2, and is inserted into the through hole of the ferrite core 1. A conductor film is provided on the surface of the conductor rod 5, and grooves 6 are formed by cutting.

7.8 and 9.10 are lead-out terminals formed by depositing a conductive film on the ferrite core 1, respectively;
Each is provided around the opening at the end of the through hole. 1
1.12.13 is the conductor rod 2 and the lead-out terminal? , 8, 9.10
The conductive paste 13 enables electrical conduction between the lead-out terminals 7 and 9. The through holes formed in the ferrite core 1 widen at both ends, and the ends 2a, 2b1 of the conductor rod 2 and the end 5a of the conductor rod 5.

Around 5b, the distance between the conductor bar surface and the magnetic body is widened. With this configuration, the mutual magnetic coupling between the two inductance elements formed in the negative magnetic body can be reduced, and the device can be made more compact. Furthermore, with this configuration, a sufficient amount of the conductive paste enters the through-hole and reliably contacts the conductor rods 2 and 5, and mechanical fixation is also sufficient. Also,
An insulating paint 14, 15 is applied to the center portions of the conductor bars 2, 5, that is, the portions where the spiral grooves 3, 6 are formed, thereby protecting the conductor film.

FIG. 2 shows a filter device made using the composite inductance element configured as described above. Second
In the figure, 16 is a chip capacitor, 17.18
are lead-out terminals provided at both ends. The chip capacitor 16 is fixed to the ferrite core 1, and the lead terminal 17 and the lead terminals 7 and 9 on the inductance element side are connected.

FIG. 3 shows an equivalent circuit of the above filter device. The part surrounded by the broken line 19 is the composite inductance element, 2r and 2X are the pure resistance and reactance of the inductance element constituted by the conductor bar 2, respectively, and 5r and 5x are the inductance constituted by the conductor bar 5, respectively. These are the pure resistance and reactance of the element.

FIG. 4 shows another embodiment, which is a filter device in which two inductance elements are connected by a resistor as shown in FIG. In Fig. 4, 41 is a ferrite core with through holes formed in two places, 42 and 43 are first
This is a conductor rod basically constructed in the same way as that of the embodiment. Among the conductor rods 43, spiral grooves are formed very densely. 44 is a conductive film formed in a spiral shape. 45
is the insulating paint applied to the conductor rod 43, and the conductor rod 42
A similar insulating paint is also formed on the

46, 47, 48, and 49 are lead-out terminals formed on the ferrite core 41. 50 is a resistive film formed on the ferrite core 41, and the lead-out terminal 4 is connected at both ends.
8 and a lead-out terminal 49. Further, Φ2 indicates the magnetic flux generated by the current flowing through the conductor bar 43.

Here, the frequency characteristics will be explained based on FIG. 6. 6th
In the figure, a represents the frequency characteristic of the inductance between the lead-out terminals 46 and 47 in this embodiment. In this example, the magnetic flux Φ
In addition to the inductance due to 1, the inductance due to magnetic flux Φ2 is large (acts), and at a frequency around 100 MHz, the reduction rate of inductance with respect to IMHz is about a fraction of that of IMHz. There is a large difference compared to the standard (about 1/20), and the frequency characteristics are improved accordingly.

Next, a description will be given based on FIG. 7. First, in Figure 7, b
is a characteristic of a conventional inductance element, and the pure resistance component at IMHz is 1Ω or less.

In the conventional example, the pure resistance component is insufficient at low frequencies. Therefore, in this embodiment, as shown in FIG. 5, a resistor 51 is provided between one inductor and the other inductor to make the pure resistance component as large as possible. A in FIG. 7 is the frequency characteristic of the pure resistance component when the resistance value of the resistor 51 is 5Ω in this embodiment. in this way,
The resistor 51 can compensate for the pure resistance component from low frequencies to high frequencies, and at high frequencies, the pure resistance component becomes even larger due to magnetic loss and eddy current loss of the spiral conductive film, for example, 100 MHz. As described above, the resistance is about 20 to 30Ω larger than the conventional one. Therefore, a good noise absorption effect occurs from low frequencies to high frequencies.

As explained above, in this embodiment, from the low range to the high range,
Impedance can be increased over a wider frequency range than before.

Effects of the Invention As described above, the present invention has a configuration in which conductive rods each having a conductive film formed on an insulating core are inserted into a plurality of through holes formed in a magnetic block, thereby making it possible to form a single magnetic block. It becomes possible to install many types of conductive rods in the magnetic material block, and it becomes possible to integrate and configure a plurality of inductance elements each having different characteristics in one magnetic block. Therefore, although it is a very small chip, it is possible to incorporate a high-precision inductance element. For example, if it is applied as a filter device, it is possible to create a chip-type filter device that is small but achieves desired frequency characteristics.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a composite inductance element according to a first embodiment of the present invention, FIG. 2 is a perspective view of a filter device to which the composite inductance element is applied, and FIG. 3 is an equivalent circuit diagram of the filter device. FIG. 4 is a perspective view of a filter device using a composite inductance element as a second embodiment;
Figure 5 is an equivalent circuit diagram of the filter device, Figure 6 is a diagram showing the frequency characteristics of the inductance of the filter device, and Figure 7 is a diagram showing the frequency characteristics of the inductance of the filter device.
The figure shows the frequency characteristics of the pure resistance component of the filter device, Figure 8 is a perspective view of a conventional composite inductance element, Figure 9 is an equivalent circuit diagram of the same composite inductance element, and Figure 10 is a diagram showing the frequency characteristics of the pure resistance component of the filter device.
The figure is a perspective view of a filter device using the same composite inductance element, and FIG. 11 is an equivalent circuit diagram of the same filter device. 1... Ferrite core 2, 5... Conductor rod 3.6
... Groove 7, 8, 9. 10 ... Output terminal 11.
12.13... Conductive paste 14.15... Name of insulating paint agent Patent attorney Toshio Nakao and one other person

Claims (1)

[Claims] It has a plurality of conductive rods each having a conductive film formed on the surface of an insulator core, and a magnetic block in which a plurality of through holes are formed and a terminal is provided around the entrance of the through hole. A composite inductance element characterized in that the above-mentioned conductive rods are respectively inserted and both ends of the above-mentioned conductive rods are connected to the above-mentioned terminals.