JPH0588022U - LC filter - Google Patents

Abstract

(57) [Abstract] [Purpose] To make an LC filter, which is a combination of a capacitor substrate, a hollow magnetic core, and a conductor wire, compact, robust, and easy to manufacture. [Structure] Holes 10 and 11 are provided in a dielectric ceramic substrate 1.
The front surface side capacitor electrode 2 is provided on the front surface of the dielectric ceramic substrate 1, and the back surface side capacitor electrode 3 is provided on the back surface. Hollow magnetic cores 4 and 5 are inserted into the holes 10 and 11 of the dielectric ceramic substrate 1.
The conductor wire 6 is inserted through the hollow magnetic cores 4 and 5, and is brought into contact with the front surface side capacitor electrode 2 on both the inlet side and the outlet side of the hollow magnetic cores 4 and 5.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an LC filter for use in removing high frequency noise and the like, and more particularly to a filter including a combination of a plate-shaped ceramic capacitor and a hollow magnetic core generally called a bead core.

[0002]

[Prior Art]

 The conventional noise removing T-type filter shown in FIGS. 1 to 3 is provided with a front surface side capacitor electrode 2 and a back surface side capacitor electrode 3 on a dielectric ceramic substrate 1 to form a ceramic capacitor, while two ferrite hollow magnetic cores are used. 4, 5 or the bead cores are penetrated by the conductors 6 to form two inductance elements, and the conductors 6 are electrically coupled to the surface side capacitor electrodes 2 by the solder 7 between the two magnetic cores 4 and 5. Then, one end of the conductive wire 6 is used as the first terminal 6a and the other end is used as the second terminal 6b, and the lead wire 8 is connected to the back surface side capacitor electrode 3 with the solder 9 to provide the third terminal 8a. An insulating coating 15 is provided. Note that the electrode 2 in FIG. 1 is descriptively shown with dotted diagonal lines, the solders 7 and 9 are also descriptively shown with a dotted line, and the coating 15 is also descriptively shown with a chain line. The T-type filter configured as described above uses the first terminal 6a as an input terminal, the second terminal 6b as an output terminal, the third terminal 8a as a ground terminal, and the conductor 6 as a signal transmission line. They are connected in series, and the first magnetic core 4 portion constitutes a first inductance element and the second magnetic core portion 5 constitutes a second inductance element, which is used as an LC noise elimination filter.

[0003]

[Problems to be solved by the device]

 By the way, since the filter is required to be downsized, the pair of magnetic cores 4 and 5 are arranged on the substrate 1. As a result, a difference occurs between the height position of the conductor wire 6 penetrating the magnetic cores 4 and 5 and the height position of the front surface side capacitor electrode 2, and the conductor wire 6 is connected to the substrate 1 as shown in FIGS. Since it had to be bent in the thickness direction and bonded to the surface-side capacitor electrode 2, mutual positioning was difficult, and the workability of assembly and soldering was poor. Moreover, since the substrate 1 and the magnetic cores 4 and 5 are overlapped, the height of the completed filter becomes large.

Therefore, an object of the present invention is to provide an LC filter which is small and easy to manufacture.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a dielectric ceramic substrate, a single or a plurality of surface side capacitor electrodes provided on the surface of the dielectric ceramic substrate, and a surface facing capacitor electrode. Single or a plurality of back surface side capacitor electrodes provided on the back surface of the dielectric ceramic substrate, a hollow magnetic core having a through hole, a front surface side conductor wire inserted into the through hole of the hollow magnetic core, and the back surface side capacitor electrode In the LC filter consisting of a back side conductor wire connected to the dielectric ceramic substrate and extending in parallel to the back surface of the dielectric ceramic substrate, a hole is formed in the dielectric ceramic substrate, and the hole of the hollow magnetic core is provided in the hole. Part of the hollow magnetic core is inserted, the hollow magnetic core is arranged so that the extending direction of the through hole of the hollow magnetic core coincides with the extending direction of the surface of the dielectric ceramic substrate, and the surface-side conductive wire is parallel to the surface. Together are arranged, it is engaged villain in LC filter, characterized in that in contact with the surface side capacitor electrodes on both the inlet side and the outlet side of the hollow core.

[0006]

[Operation and effect of the device]

 According to the above invention, since the hole is formed in the dielectric ceramic substrate and a part of the hollow magnetic core is put therein, the thickness of the LC filter is as much as the hollow magnetic core is inserted into the hole of the dielectric ceramic substrate. Can be small. In addition, the step difference between the through hole of the hollow magnetic core and the surface of the surface-side capacitor electrode becomes zero, and the surface-side conductor wire that penetrates the hollow magnetic core is easily coupled to the surface-side capacitor electrode. In addition, since the front surface side conductor contacts the front surface side capacitor electrode on both the inlet side and the outlet side of the hollow magnetic core, a stable assembly can be obtained.

[0007]

【Example】

 Next, a filter according to an embodiment of the present invention will be described with reference to FIGS. However, in FIGS. 4 to 18, the same parts as those in FIGS. 1 to 3 are designated by the same reference numerals and the description thereof will be omitted.

4 to 7 show a noise elimination T-type filter according to the first embodiment. In this filter, two holes 10 and 11 are provided in the substrate 1 as shown in FIG. 2, and two cylindrical ferrite magnetic cores 4 and 5 are fitted therein as shown in FIGS. The width W of the holes 10 and 11 is formed to be slightly smaller than the diameter of the magnetic cores 4 and 5. Therefore, the magnetic cores 4 and 5 are stably supported by the holes 10 and 11.

As is apparent from FIGS. 5 and 6, the magnetic cores 4 and 5 are inserted into the holes 10 and 11 so as to penetrate from the front surface to the back surface of the substrate 1, and the magnetic cores 4 and 5 are inserted into the through holes 12 and 13. The inserted conductive wire 6 is arranged without being bent in the thickness direction of the substrate 1, that is, all of the conductive wires 6 penetrating the magnetic cores 4 and 5 are in contact with the surface-side capacitor electrode 2 and extend. 4 and 5 are arranged. Therefore, the portion for connecting the conductor wire 6 to the front-side capacitor electrode 2 with the solder 7 is not bent in the thickness direction of the substrate 1. The electric circuit of this filter is shown in FIG. 8 and includes two inductance elements L1 and L2 and one capacitor C.

As is apparent from the above, this embodiment has the following operational effects. (A) Since the magnetic cores 4 and 5 are inserted into the holes 10 and 11, the filter can be formed as thin as the thickness of the substrate 1. (B) Since the magnetic cores 4 and 5 are inserted into the holes 10 and 11 and the conductor wire 6 bridges the holes 10 and 11, it is not necessary to bend the conductor wire 6 in the thickness direction of the substrate 1, and It becomes easy to attach the wires 4, 5 and the conductive wire 6. Further, since the conductive wire 6 is in contact with the electrode 2 on both the inlet side and the outlet side of the magnetic cores 4 and 5, a stable assembly can be obtained. (C) By inserting the magnetic cores 4 and 5 into the holes 10 and 11, the positioning and holding of the magnetic cores 4 and 5 are completed, which facilitates the assembly. (D) The step difference between the three terminals 6a, 6b, 8a becomes small.

9 to 12 show a π-type filter according to the second embodiment of the present invention. In this embodiment, in order to form a π-type filter composed of the two capacitors C1 and C2 and the two inductance elements L1 and L2 shown in FIG. 12, the first and second surface side capacitors are formed on the surface of the substrate 1. Electrodes 2a and 2b are provided, and a conductor wire 6 is inserted into the magnetic cores 4 and 5 between one capacitor electrode 2a and the other capacitor electrode 2b, and the conductor wire 6 connects one electrode 2a and the other electrode 2b. Are connected to each other by solders 7a and 7b. Then, in order to prevent the two electrodes 2a and 2b from being short-circuited by the conductor 6, a separating portion 14 is provided corresponding to the U-shaped bent portion of the conductor 6. The magnetic cores 4 and 5 are inserted into the holes 10 and 11 of the substrate 1 as in the first embodiment. Therefore, also in this embodiment, the same operational effects as those in the first embodiment can be obtained.

13 to 16 show a filter according to a third embodiment of the present invention. In the third embodiment, one hole 10 is provided in the substrate 1 to form a π-type filter composed of one inductance element L and two capacitors C 1 and C 2 shown in FIG. Two magnetic cores 4 are inserted. Even with this structure, the same operational effects as those of the first and second embodiments can be obtained.

17 and 18 show a π-type filter according to a fourth embodiment of the present invention. In the fourth embodiment, a plurality of π type filters shown in FIG. 16 are provided on one substrate 1. Further, the first and second capacitor electrodes 2a and 2b are arranged along the plurality of linearly extending conductive wires 6. Further, the magnetic cores 4 are respectively inserted in the plurality of holes 10 provided in parallel. The back surface side capacitor electrode 3 is provided on the entire surface so as to be a common electrode. Even in the case of such a configuration, it is possible to obtain the same operational effects as those of the first to third embodiments.

Although the embodiment of the present invention has been described above, the present invention is not limited to this, but can be modified. For example, the lead wire 8 may be a plate-shaped member on the back surface side capacitor electrode 3. It is also applicable to the case of configuring a filter including one capacitor and one inductance element.

[Brief description of drawings]

FIG. 1 is a plan view showing a conventional T-type filter.

2 is a front view of the filter of FIG. 1. FIG.

FIG. 3 is a right side view of the filter of FIG.

FIG. 4 is a plan view of the T-type filter according to the first embodiment of the present invention.

5 is a front view of the filter of FIG.

FIG. 6 is a right side view of the filter of FIG.

7 is a plan view showing only a capacitor portion of the filter of FIG.

FIG. 8 is a circuit diagram of the filter of FIG.

FIG. 9 is a plan view of a π-type filter according to a second embodiment.

FIG. 10 is a front view of the filter of FIG.

11 is a right side view of the filter of FIG. 9. FIG.

FIG. 12 is a circuit diagram of the filter of FIG.

FIG. 13 is a plan view of a π-type filter according to a third embodiment.

FIG. 14 is a front view of the filter of FIG.

FIG. 15 is a right side view of the filter shown in FIG.

16 is a circuit diagram of the filter shown in FIG.

FIG. 17 is a plan view of the filter according to the fourth embodiment.

FIG. 18 is a side view of the filter of FIG.

[Explanation of symbols]

 1 Porcelain Substrate 2 Front Side Capacitor Electrode 3 Back Side Capacitor Electrode 4, 5 Magnetic Core 6 Conductor 8 Lead Wire 10, 11 Hole 12, 13 Through Hole

Claims (1)

[Scope of utility model registration request] 1. A dielectric ceramic substrate, a single or a plurality of front surface side capacitor electrodes provided on the front surface of the dielectric ceramic substrate, and a back surface of the dielectric ceramic substrate so as to face the front surface side capacitor electrodes. A single or a plurality of back surface side capacitor electrodes, a hollow magnetic core having a through hole, a front surface side conductor wire inserted into the through hole of the hollow magnetic core, and the dielectric material connected to the back surface side capacitor electrode. In an LC filter consisting of a back surface side conductor wire extending in parallel to the back surface of the porcelain substrate, a hole is provided in the dielectric porcelain substrate, and a part of the hollow magnetic core is inserted into the hole, The hollow magnetic core is arranged so that the extending direction of the through hole of the hollow magnetic core matches the extending direction of the surface of the dielectric ceramic substrate, and the surface-side conductor is arranged parallel to the surface, and An LC filter, characterized in that the front side capacitor electrode is in contact with both the inlet side and the outlet side of the hollow magnetic core.