JPH0756857B2 - LC composite parts - Google Patents

Description

TECHNICAL FIELD The present invention relates to an LC composite component, and more particularly to a chip-type LC composite component suitable for use as a noise filter in a high frequency circuit.

[Prior Art] As a typical LC composite component used as a noise filter, as shown in FIG.
There is a three-terminal type which forms an equivalent circuit in which the individual inductors L1 and L2 are connected in a T type.

As a concrete structure for constructing such a three-terminal T-type filter circuit with one component, generally, as shown in FIG.
LC composite part 1 is known. The LC composite component 1 includes a disk-shaped capacitor 2, and a pair of capacitor electrodes 3 and 4 facing each other are formed on each main surface of the capacitor 2. A substantially inverted U-shaped signal line lead wire 5 is connected to one of the capacitor electrodes 3 by solder 6, and the legs thereof are inserted into the ferrite beads 7 and 8, respectively. A grounding lead wire 9 is soldered to the other capacitor electrode 4. Then, if necessary, an insulating sheath 10 is applied to cover the capacitor 2.

The LC composite component 1 thus configured includes three terminals, which are both legs of the signal line lead wire 5 and the ground lead wire 9. When the LC composite component 1 is mounted on, for example, a printed circuit board, these three terminals are respectively inserted into the holes provided in the printed circuit board, and in that state, they are formed on the printed circuit board. Soldered to the conductive pattern.

[Problems to be Solved by the Invention] However, the LC composite component 1 having the above-described structure is
First, we encounter a manufacturing problem that the assembly work is complicated. Further, since the capacitor 2 having the main surface having a relatively large area is used, it is difficult to downsize the LC composite component 1. In addition to this, since the LC composite component 1 is mounted on the circuit board in a state where the capacitor 2 is erected, the mounting space of the LC composite component 1 on the circuit board, especially the dimension in the height direction is large. Become. Therefore, these impede high density mounting of various components on a circuit board. Further, since the LC composite component 1 is provided with the lead wires 5 and 9, it is not possible to meet the demand for miniaturization, thinning, and high density mounting of the component into chips. Further, if the grounding lead wire 9 is made longer than necessary, there is also a problem that the noise removing effect is remarkably reduced particularly in a high frequency circuit due to the inductance component generated there.

Therefore, an object of the present invention is to be able to efficiently manufacture, to meet the demand for miniaturization and chipping, and further to prevent characteristic deterioration due to an inductance component generated by the presence of lead wires, It is to provide LC composite parts.

[Means for Solving the Problem] An LC composite component according to the present invention is formed at a different position on a surface of a laminated structure in which an inductor layer and a capacitor layer are laminated, and at a different position on the surface of the laminated structure. And a second signal line external electrode, a ground external electrode, and a connecting external electrode.

The inductor layer includes a magnetic body and first and second conductor lines formed inside the magnetic body and not connected to each other inside the magnetic body. The first conductor line is
It has one end connected to the first signal line external electrode and the other end connected to the connection external electrode. The second conductor line has one end connected to the second signal line external electrode and the other end connected to the connection external electrode.

In one aspect of the present invention, the capacitor layer includes a dielectric and first and second internal electrodes facing each other with at least a part of the dielectric interposed therebetween. The first inner electrode has an end connected to the grounding outer electrode.
The second internal electrode has an end portion connected to the connection external electrode.

In another aspect of the present invention, a dielectric and an internal electrode facing the ground external electrode with at least a part of the dielectric interposed therebetween are provided. The internal electrode has an end portion connected to the connection external electrode.

[Operation] In the LC composite component according to the present invention, two inductors are formed by the first and second conductor lines in the inductor layer, and two inductors are formed by the first and second internal electrodes in the capacitor layer. Alternatively, the external electrode for grounding and the internal electrode form one capacitor. These two inductors and one capacitor are connected by a connecting external electrode so as to form a T-type LC circuit having an equivalent circuit as shown in FIG. In the LC circuit shown in FIG. 11, the terminals at both ends of the two inductors L1 and L2 connected in series are the first and second terminals.
Of the signal line external electrodes.
Further, the terminal drawn out from the capacitor C is provided by the grounding external electrode. Therefore, the first
When the second external electrode for signal line is connected to the signal line and the external electrode for earthing is connected to earth, two inductors intervene in the signal line, and there is a static gap between the connecting portion of both inductors and the earth. Capacitance is provided, which causes the LC composite component to act as a noise filter.

[Effects of the Invention] As described above, according to the present invention, it is possible to make the components constituting the LC circuit into chips and miniaturize them. Therefore, such an LC composite component can be provided on a circuit board. It can be mounted with a small space.

Moreover, since the electrical characteristics of each of the inductor layer and the capacitor layer included in the laminated structure can be set almost arbitrarily, various LC composite parts having different characteristics can be easily manufactured. In addition, these characteristics can be changed while keeping the area of the main surface of the laminated structure constant, so that LC composite parts with various characteristics can be used without changing the area required for mounting the LC composite parts. Can be provided.

Further, since the LC composite component according to the present invention is made into a chip as described above and does not need to have a lead wire as a terminal, it is advantageous that the presence of such a lead wire causes an unnecessary inductance component. Can be suppressed.

Further, since the first and second conductor lines for forming the inductor are not connected to each other inside the magnetic body, internal electrodes for forming a capacitor are formed from the connection points of the first and second conductor lines. The length of the conductive path can be substantially 0 or extremely short, and the unnecessary inductance component that can occur in this portion can be substantially 0 or extremely small.

When the magnetic material and the dielectric material included in the inductor layer and the capacitor layer, respectively, which form the laminated structure are both made of ceramic, the laminated structure is formed by co-firing the magnetic material and the dielectric material. It is preferably integrated.

[Embodiment] FIG. 1 to FIG. 6 are for explaining one embodiment of the present invention. The LC composite component 11 according to this embodiment is
It constitutes the T-type filter circuit shown in FIG.

The LC composite component 11 includes a laminated structure 12. Laminated structure 12
Is a laminate of an inductor layer 13 and a capacitor layer 14.

As can be seen by comparing FIG. 1, FIG. 2 and FIG. 3 with FIG. 4, the first and second end faces 15 and 16 of the laminated structure 12 facing each other are respectively 1 and 2
The signal line external electrodes 17 and 18 are formed. In addition, the first and second side surfaces 19 of the laminated structure 12 facing each other.
An outer electrode 21 for grounding and first and second outer electrodes 22a and 22b for connection are formed on and 20, respectively.

The inductor layer 13 includes a magnetic body 23 and a plurality of first conductor lines 24 and a plurality of second conductor lines 25 formed inside the magnetic body 23 and not connected to each other inside the magnetic body 23.
With. The number of each of the conductor lines 24 and 25 can be increased or decreased as required. First conductor line 24
Is one end 24a connected to the first signal line external electrode 17 and the other end connected to the first connection external electrode 22a.
With 24b. The second conductor line 25 has one end 25a connected to the second signal line external electrode 18 and the other end 25b connected to the second connection external electrode 22b.

The capacitor layer 14 includes a dielectric 26 and first and second internal electrodes 27 and 28 that face each other with at least a part of the dielectric 26 interposed therebetween. The first inner electrode 27 has an end portion 27a connected to the grounding outer electrode 21. The second inner electrode 28 is connected to the first and second connecting outer electrodes 22.
It has ends 28a and 28b connected to a and 22b, respectively. In this embodiment, the first connection external electrode 22a and the second connection external electrode 22b are electrically connected via the second internal electrode 28 in this manner. Therefore, the connection point between the first and second conductor lines 24 and 25 is located on the second internal electrode 28, and the length of the conductive path from the connection point to the internal electrode 28 is substantially zero. Therefore, the unnecessary inductance component that may occur in this portion can be substantially zero.

A more detailed structure of the LC composite component 11 will be described below together with its manufacturing method.

In this embodiment, the magnetic body 23 and the dielectric body 26 are both made of ceramic.

As shown in FIG. 5, the inductor layer 13 includes a plurality of magnetic green sheets 29a having first and second conductor lines 24 and 25 printed on the upper surface of each of them. Above and below these magnetic green sheets 29a, a plurality of magnetic green sheets 29b and 29c, each of which is not printed with a conductor line, are provided.
Are laminated respectively.

Similarly, as shown in FIG. 5, the capacitor layer 14 includes a dielectric green sheet 30a having a first internal electrode 27 printed thereon,
Dielectric green sheet 30 with second internal electrode 28 printed
b, and an appropriate number of dielectric green sheets 30c, 30d, 30e each having no such internal electrode printed. The dielectric green sheet 30c is located on the dielectric green sheet 30a, the dielectric green sheet 30d is located between the dielectric green sheet 30a and the dielectric green sheet 30b, and the dielectric green sheet 30e is a dielectric. These dielectric green sheets 30a, 30b, 30c, 30d and 30e are stacked under the green sheet 30b as shown in FIG.

As described above, the magnetic green sheets 29a, 29b, 29c included in the inductor layer 13 and the dielectric green sheets 30a, 30b, 30c, 30d, 30e included in the capacitor layer 14 are arranged at the positions shown in FIG. A laminated structure 12 is obtained by laminating the layers in a relationship and then co-firing.

Next, as shown in FIGS. 1, 2 and 4, the first and second signal line external electrodes 17 and 18 are provided at different positions on the surface of the laminated structure 12 as described above. , The grounding external electrode 21, and the first and second connecting external electrodes 22a and 22b are printed with, for example, a metal paste,
It is formed by baking. As a result, the electrical connection as described above is achieved between the external electrodes 17, 18, 21, 22a, 22b and the conductor lines 24, 25 and the internal electrodes 27, 28. When this electrical connection is achieved, an LC composite component 11 is obtained which gives a T-filter circuit, the equivalent circuit of which is shown in FIG.

The LC composite component 11 obtained in this way is, for example, the sixth
As shown in the figure, it is mounted on the circuit board 31. First and second signal line conductive patterns 32 and 33 and a ground conductive pattern 34 are formed on the circuit board 31. The LC composite component 11 is placed on the circuit board 31 with the ground external electrode 21 facing downward, and the first and second signal line external electrodes 17 and 18 are respectively placed by the solders 35 and 36, for example. It is electrically connected to the conductive patterns 32 and 33 for the first and second signal lines, and the grounding external electrode 21 is electrically connected to the conductive pattern 34 for grounding by the solder 37.

Although the present invention has been described with reference to the embodiments shown in FIGS. 1 to 6, various other modifications can be made within the scope of the present invention.

For example, as shown in FIGS. 3 and 5, the ends 28a and 28b of the second internal electrode were separated from each other by providing a notch 38 between them, but the notch 38 Alternatively, the ends 28a and 28b may be formed so as to form a series of straight lines.

Further, in relation to the above, as shown in FIGS. 4 and 6, the first and second connection external electrodes 22a and 22b formed on the side surface 20 of the laminated structure 12 are mutually Instead of being separated, as shown in FIG. 7, the connecting external electrode 22 may be replaced with a series of extending external electrodes 22. In this case, the connection points of the first and second conductor lines 24 and 25 with each other are located on the connection external electrode 22, but from the connection point to the internal electrode.
The length of the conductive path up to 28 is within the vertical dimension of the connecting external electrode 22, and is extremely short. Therefore, the inductance component that can be generated in this portion can be extremely reduced. Note that FIG. 7 is a diagram corresponding to FIG. 4, and regarding the elements shown in FIG. 7, those corresponding to the elements shown in FIG. 4 are assigned the reference numerals used in FIG. The duplicate description will be omitted.

In the illustrated embodiment, the upper first inner electrode 27 is used as the inner electrode electrically connected to the grounding outer electrode 21.
And the lower second internal electrode 28 was selected as the internal electrode connected to the first and second conductor lines 24 and 25 via the connecting external electrodes 22a and 22b or 22. By doing so, it is possible to prevent the formation of undesired stray capacitance between the second internal electrode 28 and the first and second conductor lines 24 and 25, but such an advantage is desired. If not, even if the second internal electrode 28 is electrically connected to the grounding external electrode 21 and the first internal electrode 27 is electrically connected to the connecting external electrodes 22a and 22b or 22. Good.

Further, the number of pairs of the first and second internal electrodes 27 and 28 may be plural in order to increase the capacitance formed in the capacitor layer 14.

Further, in order to obtain the laminated structure 12, the magnetic body 23 contained in the inductor layer 13 and the dielectric body 26 contained in the capacitor layer 14 are not integrated by being fired at the same time. Alternatively, they may be joined later.

Furthermore, in the capacitor layer, one of the opposing electrodes for forming the capacitance may be provided by the external electrode instead of the internal electrode. A specific example of such a structure will be described with reference to FIGS. 8 and 9. FIG. 8 is a view corresponding to FIG. 3 described above and shows a laminated structure 12a. FIG. 9 shows the above-mentioned fourth part.
It is a figure equivalent to a figure, and LC composite component 11a is shown.
In FIGS. 8 and 9, FIGS.
The elements corresponding to those shown in the figure are designated by the same reference numerals, and the duplicated description will be omitted.

Referring to FIG. 8, the capacitor layer 14a has a third
An internal electrode corresponding to the first internal electrode 27 shown in the figure is not formed, and an internal electrode 39 corresponding to the second internal electrode 28 is not formed.
Only formed. The internal electrode 39 has end portions 39a and 39b connected to the first and second external connecting electrodes 22a and 22b, respectively, as shown in FIG. 9, like the second internal electrode 28 described above. . The grounding external electrode 21a extends over a relatively large area on the upper surface of the laminated structure 12a, and sandwiches a part of the dielectric 26 to form an internal electrode.
It is facing 39. Therefore, a capacitance is formed at a portion where the internal electrode 39 and the grounding external electrode 21a face each other.

In any of the above-described embodiments, the end surfaces 15, 16 and the side surfaces 19, 16 and the side surfaces 19, 12 of the laminated structure 12 or 12a of the first and second signal line external electrodes 17 and 18 and the ground external electrode 21 or 21a, An exterior coating material such as an insulating resin may be applied so as to cover the outer surface of the laminated structure 12 or 12a except for at least the portions located above 20.

[Brief description of drawings]

FIG. 1 is a left side view showing an LC composite component 11 as one embodiment of the present invention, in which external electrodes are shown in cross section and internal electrodes and conductor lines are seen through. Fig. 2 shows an LC composite component shown in the same way as Fig. 1.
11 is a front view of FIG. FIG. 3 is a perspective view showing the laminated structure 12 included in the LC composite component 11, in which the conductor lines 24 and 25 and the internal electrodes 27 and 28 formed therein are seen through. FIG. 4 is a perspective view showing the appearance of the LC composite component 11. FIG. 5 is an exploded perspective view of the laminated structure 12. FIG. 6 is a perspective view showing a state in which the LC composite component 11 is mounted on the circuit board 31. FIG. 7 shows an LC composite component 11 as another embodiment of the present invention.
FIG. FIG. 8 is a view corresponding to FIG. 3 for explaining still another embodiment of the present invention. FIG. 9 is a perspective view showing the appearance of the LC composite component 11a obtained by the embodiment shown in FIG. FIG. 10 is a front view showing a conventional LC composite component 11. FIG. 11 is a circuit diagram showing a T-type LC filter circuit. In the figure, 11 and 11a are LC composite components, 12 and 12a are laminated structures, 13 is an inductor layer, 14 and 14a are capacitor layers, 17 is an external electrode for the first signal line, and 18 is for the second signal line. External electrodes, 21 and 21a are grounding external electrodes, 22, 22a and 22b are external connecting electrodes, 23 is a magnetic material, 24 is a first conductor line, and 24a
Is one end of the first conductor line 24, 24b is the other end of the first conductor line 24, 25 is the second conductor line, and 25a is the second end.
One end of the conductor line 25 of the second conductor line 25
The other end, 26 is a dielectric, 27 is the first internal electrode, 27a is the end of the first internal electrode 27, 28 is the second internal electrode, and 28a, 28a.
b is the end of the second internal electrode 28, 39 is the internal electrode, and 39a, 39b are the ends of the internal electrode 39.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location H03H 7/075 A 8321-5J (72) Inventor Yoshiaki Kono 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Prefecture Issuer Murata Manufacturing Co., Ltd. (72) Inventor Yukio Sakamoto 2-26-10 Tenjin, Nagaokakyo City, Kyoto Prefecture Murata Manufacturing Co., Ltd. (56) Bibliography Sho 60-9220 (JP, U) Shokai Sho 59- 44032 (JP, U)

Claims (2)

[Claims] 1. A laminated structure in which an inductor layer and a capacitor layer are laminated, and first and second signal line external electrodes and a grounding external formed at different positions on the surface of the laminated structure. An electrode and an external electrode for connection, wherein the inductor layer is formed inside the magnetic body and the magnetic body, and is not connected to each other inside the magnetic body.
And a second conductor line, and the first conductor line has one end connected to the first signal line external electrode and the other end connected to the connection external electrode. In addition, the second conductor line has one end connected to the second signal line external electrode and the other end connected to the connection external electrode, and the capacitor layer is a dielectric layer. A body and first and second internal electrodes facing each other with at least a part of the dielectric interposed therebetween, the first internal electrode having an end connected to the ground external electrode, An LC composite component, wherein the second internal electrode has an end portion connected to the connection external electrode. 2. A laminated structure in which an inductor layer and a capacitor layer are laminated, and first and second external electrodes for signal lines and an external for grounding, which are formed at different positions on the surface of the laminated structure. An electrode and an external electrode for connection, wherein the inductor layer is formed inside the magnetic body and the magnetic body, and is not connected to each other inside the magnetic body.
And a second conductor line, and the first conductor line has one end connected to the first signal line external electrode and the other end connected to the connection external electrode. In addition, the second conductor line has one end connected to the second signal line external electrode and the other end connected to the connection external electrode, and the capacitor layer is a dielectric layer. An LC composite component, comprising a body and an internal electrode that faces the ground external electrode with at least a portion of the dielectric sandwiched therebetween, the internal electrode having an end connected to the external electrode for connection. .