JPH0134329Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention consists of a magnetic core composed of a coil winding part and a pair of flanges provided at both ends of the coil winding part, and a coil winding part of the magnetic core. The present invention relates to a chip-type inductance element comprising a coil and a coil, and is suitable for use when forming a high frequency circuit on a printed wiring board or the like.

Conventionally, a chip-type inductance element has a cylindrical coil winding part 1 and a circular collar part 2 provided at both ends of this coil winding part, as shown in FIGS. 1 and 2.
The magnetic core 3 is provided with a magnetic core 3 made up of cores a and 2b, and a coil 4 is wound around the coil winding portion 1 of the magnetic core 3. Both ends of this coil 4 are connected to electrodes 5a and 5 provided on the lower surfaces of the flanges 2a and 2b, respectively.
b, and these electrodes 5a, 5b are soldered 6a,
6b, it is soldered to the printed wiring board 7.

However, in this structure, the leakage magnetic flux is
Since a and 5b are cut off, the Q value deteriorates significantly. Conventionally, attempts have been made to improve the Q characteristic by improving the material or changing the shape, but the improvement has not been sufficiently achieved and the mounting area has inevitably increased.

The present invention was developed in view of the above-mentioned circumstances, and its purpose is to provide a chip-type inductance element that can maintain higher Q characteristics by preventing leakage magnetic flux that cuts the electrodes as much as possible. .

To achieve this object, the present invention includes a magnetic core composed of a coil winding part and a pair of flanges provided at both ends of the coil winding part and made of a magnetic material, and a coil winding part of the magnetic core. a coil wound around the part, a magnetic member covering the magnetic core, each having a predetermined area and thickness for soldering to a circuit board, and each provided opposite to the lower ends of the pair of flanges. In the chip-type inductance element, each of which has a pair of electrodes, the end of the coil is connected to the electrode, the magnetic core is made of ferrite, the flange is configured in the shape of a rectangular parallelepiped, and the magnetic member is connected to the magnetic core. is made of MnZn ferrite having a higher magnetic permeability than the magnetic material constituting it and configured in a flat plate shape or a U-shape of a combination of flat plates, and arranged so that the magnetic member is interposed between the electrode and the flange. The magnetic core This invention relates to a chip-type inductance element characterized in that it facilitates coupling between the magnetic member and the magnetic member, and prevents deterioration of the Q value due to leakage magnetic flux passing through the electrode.

A first embodiment of the present invention will be described below with reference to FIGS. 3 and 4. In these figures, the symbol 1
Reference numeral 1 denotes a coil winding section, and rectangular parallelepiped flanges 12a and 12b provided at both ends of this coil winding section 11 and this coil winding section 11 form a magnetic core 1 made of ferrite.
3 is formed. A magnetic plate 14 made of MnZn ferrite, which is a magnetic material with higher magnetic permeability than ferrite, is provided on the lower surface of the flanges 12a, 12b, and connects the two flanges 12a, 12b. A non-magnetic insulating layer 15 made of, for example, a glass epoxy plate is provided on the lower surface of the magnetic body 14.
Electrodes 16a, 16b are provided via a, 15b, and the magnetic core 1 is connected to the electrodes 16a, 16b.
Both ends of the coil 17 wound around the coil winding portion 11 of No. 3 are connected. Note that the insulating layer 15a,
The practical thickness of 15b is preferably 0.25 mm or more, which may vary somewhat depending on its material and size.

In the chip-type inductance element configured as described above, the electrodes 16a and 16b are soldered to solders 18a and 18a on a predetermined pattern on the printed wiring board 7.
8b, and both ends of the coil 17 are connected to the electrodes 16a and 16b, respectively, as described above. In this case, the two flanges 12 of the magnetic core 13
Since the electrodes 16a and 16b sides of a and 12b are connected by a magnetic plate 14 made of a magnetic material with high magnetic permeability, this magnetic plate 14 forms a magnetic circuit together with the magnetic core 13 described above. That is, the coil winding portion 11...
A magnetic circuit is formed that passes through the flange 12a...the magnetic plate 14...the flange 12b...the coil winding part 11, and the leakage magnetic flux attempts to pass through this magnetic circuit. Therefore, leakage magnetic flux cutting through the electrodes 16a, 16b is prevented as much as possible by the formation of this magnetic circuit, and is also prevented as much as possible by the non-magnetic insulating layers 15a, 15b, resulting in even higher Q characteristics. can be maintained.

This was also confirmed experimentally from the frequency characteristic diagram of the Q value and L value shown in FIG. 5, which was actually measured using chip-type inductance elements having substantially the same size, shape, and coil. In this figure, the solid line represents the Q value, and the dotted line represents the L value. And A is the figure 1 and 2.
The graph shows the conventional chip-type inductance element shown in the figure, and B corresponds to the chip-type inductance element according to the first embodiment shown in FIGS. 3 and 4. However, for comparison, these two inductance elements do not use a nonmagnetic insulating layer. From these experimental values, it was confirmed that in the case of B, both the L value and the Q value are high.

Furthermore, in this embodiment, the flanges 12a and 12b of the magnetic core 13 are rectangular parallelepipeds as described above.
It is easier to fix onto the substrate than the conventional circular shape.

6 and 7 show a second embodiment of the present invention. In these figures, the parts with the same reference numerals as those in FIGS. 3 and 4 are the same as those in the first embodiment, so their explanations will be omitted. However, in the second embodiment, the tsuba in the first embodiment Part 12a,
A thermoplastic resin 19 such as polyethylene or polyurethane containing magnetic powder with high magnetic permeability such as MnZn ferrite is injected into the gap between 12b.

Therefore, in this second embodiment, the magnetic core 1
The electrodes 16a and 16b sides of the flanges 12a and 12b of No. 3 are connected by a magnetic plate 14 made of a magnetic material with high magnetic permeability, and the above-mentioned resin portion 19 containing magnetic powder with high magnetic permeability is connected to both flanges. Parts 12a, 12b
Since the leakage magnetic flux is interposed between the magnetic plates 1 and 1,
4 and further attempts to pass through the resin portion 19. Therefore, leakage magnetic flux cutting through the electrodes 16a and 16b is prevented as much as possible by the magnetic plate 14 and also by the presence of the resin part 19, so that even higher Q characteristics are maintained. be able to.

Furthermore, since this inductance element is integrally hardened with resin 19, the fragile magnetic core 13, coil 16, etc. are reinforced and will not be damaged. Furthermore, in this second embodiment, laser trimming, etc. Since the L value can be adjusted by cutting off the resin 19 together with the magnetic powder contained therein, for example, in the form of the groove 20, a chip-type inductance element with a highly accurate L value can be obtained depending on the purpose.

Next, a third embodiment shown in FIGS. 8 and 9 will be described. This third embodiment differs from the first embodiment in that the mounting position of the magnetic plate with high magnetic permeability is different, and the rest is the same as the first embodiment. are given the same reference numerals as in the first embodiment. That is, the magnetic plate 22 made of MnZn ferrite, which is a magnetic material with higher magnetic permeability than ferrite, is connected to the upper surface of the two flanges 12a and 12b of the magnetic core 13.
Therefore, also in this third embodiment, since the magnetic plate 22 forms a magnetic circuit together with the magnetic core 13, the leakage magnetic flux tends to pass through this magnetic circuit.
Therefore, although there is a slight difference, leakage flux cutting through the electrodes 16a and 16b is prevented, and a higher Q characteristic can be maintained, as in the first embodiment.

Further, in the fourth embodiment shown in FIGS. 10 and 11, the only difference from the third embodiment is the shape of the magnetic plate 23 made of a magnetic material with high magnetic permeability. That is, in this fourth embodiment, the magnetic plate in the third embodiment is further extended to form a U-shape, and this extension is connected to the two flanges 12.
It has a structure in which it is fixed to the side surfaces of a and 12b. Therefore, it is clear that a higher Q characteristic can be obtained in this fourth embodiment than in the third embodiment.

As explained above, according to the chip-type inductance element of the present invention, the inductance element is arranged so as to be interposed between the electrode and the flange, or at least on the opposite side of the flange from the electrode. A magnetic member made of MnZn ferrite, which has a higher magnetic permeability than ferrite, which is the magnetic material constituting the magnetic core, is provided to connect the corresponding surfaces of the pair of rectangular parallelepiped-shaped flanges. , a magnetic circuit passing through the coil winding portion and the magnetic member is formed, and in particular, the magnetic member is made of MnZn ferrite, which has a higher magnetic permeability than the ferrite constituting the magnetic core, so the leakage magnetic flux mainly passes through the magnetic member, Leakage flux that cuts the electrode is prevented as much as possible,
As a result, a high Q value characteristic can be maintained. Furthermore, since a pair of electrodes having a predetermined area and thickness for soldering to a circuit board are provided opposite to each other at the lower ends of the pair of collars, attachment to a printed wiring board is extremely easy. Moreover, the flange is configured in the shape of a rectangular parallelepiped, and the magnetic member is configured in a flat plate shape or a U-shape of a combination of flat plates, and the corresponding surfaces of the pair of rectangular parallelepiped flanges are connected to each other by the magnetic member. This allows the flat surface of the magnetic member and the flat surfaces of the pair of flanges to be joined together in a state where they are in surface contact with each other. For this reason, the bonding and contact between the two can be easily and reliably performed, so that a higher Q characteristic can be maintained, and it is particularly suitable for implementation in ultra-small parts. Therefore, the miniaturization of chip-type inductance elements is promoted, and the mounting of components on hybrid integrated circuits and printed wiring boards is also becoming easier.
Further advantages include miniaturization, weight reduction, and cost reduction.

[Brief explanation of the drawing]

Fig. 1 is a front view of a conventional chip-type inductance element, Fig. 2 is a side view of the inductance element shown in Fig. 1, and Fig. 3 is a front view of a chip-type inductance element showing the first embodiment of the present invention. , FIG. 4 is a side view of the inductance element shown in FIG. 3, FIG. 5 is a frequency characteristic diagram of the Q value and L value, and FIG. 6 is a front view of the inductance element showing the second embodiment of the present invention. 7 is a side view of the inductance element shown in FIG. 6, FIG. 8 is a front view of the inductance element showing the third embodiment, FIG. 9 is a side view of the inductance element shown in FIG. 8, and FIG. 11 is a front view of an inductance element showing the fourth embodiment, and
The figure is a side view of the inductance element shown in FIG. 10. In addition, in the symbols used in the drawings, 11
... Coil winding part, 12a, 12b ... Flange part, 1
3...Magnetic core, 14, 22, 23...Magnetic plate (magnetic member), 17...Coil.

Claims (1)

[Claims for Utility Model Registration] A magnetic core made of a magnetic material and consisting of a coil winding portion and a pair of flanges provided at both ends of the coil winding portion, and a winding around the coil winding portion of the magnetic core. a magnetic member that covers the magnetic core; and a pair of electrodes each having a predetermined area and thickness for soldering to a circuit board and provided opposite to the lower ends of the pair of flanges. and a chip-type inductance element in which an end of the coil is connected to the electrode, wherein the magnetic core is made of ferrite, the flange has a rectangular parallelepiped shape, and the magnetic member constitutes the magnetic core. It is made of MnZn ferrite having a higher magnetic permeability than a magnetic material and is configured in a flat plate shape or a U-shaped combination of flat plates, and is arranged so that the magnetic member is interposed between the electrode and the flange. Alternatively, the mutually corresponding surfaces of the pair of rectangular parallelepiped-shaped flanges are connected to each other so as to be located on the opposite side of the electrode from at least the flanges, and thereby the magnetic core and the above-mentioned A chip-type inductance element characterized in that it facilitates coupling with a magnetic member and prevents deterioration of the Q value due to leakage magnetic flux passing through the electrodes.