JPH02256218A - Lc composite part - Google Patents

Abstract

PURPOSE:To eliminate a shield electrode layer and to realize compactness of an LC composite part by forming capacitor electrode patterns to hold a coil pattern therebetween. CONSTITUTION:Coil patterns 2, 3 are printed on both sides of a junction sheet 1 which consists of an insulator. Sheet layers 4, 5 which consist of an insulator are formed on the coil patterns 2, 3. A capacitor section 9 which is provided with capacitor electrode patterns 7, 8 on the both sides of a dielectric layer 6, and a protective layer 10 which consists of an insulator or a dielectric are formed on the sheet layer 4 successively. In the meantime, a capacitor section 14 which is provided with capacitor electrode patterns 12, 13 are formed on the both sides of a dielectric layer 11 and a protective layer 15 which consists of an insulator or a dielectric are formed successively on the sheet layer 5. Thereby, one side of a print coil is covered with a pair of capacitor electrodes and the print coil can be sealed. Compactness can be realized by laminating an inductor and a capacitor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an LC composite component including a capacitor and an inductor, such as a bandpass filter, duplexer, etc.

Since this type of LC composite component includes an inductor, it is necessary to shield it. Taking a bandpass filter as an example of an LC composite component, conventionally, as shown in FIG. 5, sheet layers 46 and 47, shield electrode films 48 and 49, and protective layers 50 and 51 are provided on both sides of a bandpass filter body 40, respectively. It is common to have a structure in which these are laminated in order. The bandpass filter main body 40 includes a sixth bandpass filter main body 40.
As shown in the figure, electrode film patterns 42, 43, 44, and 45 are formed on both the front and back surfaces of the dielectric layer 41, and these electrode film patterns 42, 43, 44, and 45 form capacitors C1 and C2 and coils L1 and 45. L2, L3, and L4 are configured.

Here, L, and L2, L, and L4 are through hole 4.
6 and 47 are connected through the conductive material filled in them, so each constitutes one inductor.

Since the capacitor C1 or Cz is connected to both ends of each inductor, the electrode film patterns 42 and 44, 43 and 45
Each constitutes an LC parallel resonant circuit.

Both resonant circuits are magnetically coupled via L2, thereby forming a bandpass filter having predetermined characteristics.

However, in the above conventional structure, the capacitors C3 and C2
Since the inductor and the inductor are formed on the same substrate, the area of the substrate becomes large, and a shield electrode must be provided separately from these, resulting in a complicated structure.

Therefore, the present invention has been made in consideration of the above-mentioned problems, and aims to provide an LC composite component that can be dramatically reduced in size and made into a simpler cylinder element.

In order to achieve the above object, the present invention provides a method in which a pair of capacitor electrodes is disposed on at least one of both sides sandwiching a printed coil, and one of the pair of capacitor electrodes also serves as a shield electrode for shielding the printed coil. It is characterized by

In the above configuration, the printed coil functions as an inductor, and the capacitor electrode pair functions as a capacitor. If a capacitor electrode pair is placed on at least one of the two sides of the printed coil as described above, one side of the printed coil will be covered by the capacitor electrode pair.
Can be used to shield printed coils. Furthermore, by stacking the inductor and capacitor, it is also possible to reduce the size.

In addition, in the case where the capacitor electrode pair is arranged only on one side of the printed coil in the above configuration, it is necessary to provide a shield electrode layer on the other side.

Conversely, when capacitor electrode pairs are arranged on both sides of the printed coil, the capacitor electrode pairs also serve as shield electrodes, so there is no need to separately provide shield electrodes.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

As shown in Fig. 2, coil patterns 2 and 3 are printed on both the front and back surfaces of a bonding sheet 1 made of an insulator, and sheet layers 4 and 5 made of an insulator are printed on the coil patterns 2 and 3. It is formed. On the sheet layer 4,
Capacitor electrode patterns 7 and 8 on both sides of dielectric N6
A capacitor portion 9 having a capacitor formed thereon and a protective layer 10 made of an insulator or dielectric are formed in this order. On the other hand, on the sheet layer 5, a capacitor part 14 in which capacitor electrode patterns 2 and 3 are formed on both the front and back sides of the dielectric layer 11, and a protective layer 15 made of an insulator or dielectric are formed in this order. There is. The bonding sheet 1, the sheet layers 4 and 5, and the protective layers 10 and 15 have a structure in which a plurality of sheets are stacked one on top of the other, as shown in FIG.

Here, the capacitor electrode pattern 7 has a rectangular shape and is formed to be slightly smaller than the dielectric layer 6. A via hole 16a passing through the dielectric layer 6 is formed at one of the four corners.

The capacitor electrode pattern 8 has substantially the same shape as the capacitor electrode pattern 7. However, a cutout 19 is formed at one of the four corners, and a via hole 16b passing through the sheet layer 4 is formed in the sheet layer 4 at this cutout portion 20. This via hole 16b and the via hole 16a are provided at the same position. Also, the other corner of the four corners is the ground electrode 1
8 is connected. A via hole 17 passing through the sheet layer 4 is formed in the ground electrode 18 portion, and the ground electrode 18 is connected to the ground terminal 31.

The coil pattern 2 has a substantially U-shape, and an output electrode 21 is connected to the coil pattern 2.

This output electrode 21 is connected to an output terminal 32.

The coil pattern 3 also has a substantially U-shape, and an input electrode 22 is connected to the coil pattern 3.

The input electrode 22 is connected to an input terminal 33. Further, via holes 23a and 24 passing through the sheet layer 5 are formed at both ends of the coil pattern 3.

The capacitor electrode pattern 12 has substantially the same shape as the capacitor electrode pattern 7. However, a cutout 25 is formed in one of the four corners, and the dielectric layer 11 is not in the cutout portion 26 of the dielectric layer 11.
A pipe hole 23b passing through 1 is formed. This via hole 23b is provided at the same position as the via hole 23a.

The capacitor electrode pattern 13 has substantially the same shape as the capacitor electrode pattern 7. However, one of the four corners is connected to the ground electrode 28. This ground electrode 28 is connected to a ground terminal 34.

In the above configuration, the capacitor electrode patterns 12 and 13 facing each other on both the front and back surfaces of the dielectric layer 11 constitute a capacitor CI with a capacity determined by the dielectric constant and thickness of the dielectric layer 11 and the opposing area of the capacitor electrode patterns. . On the other hand, in the coil pattern 3, the shaded portion 3a constitutes the coil L1, and the other portion 3b constitutes the coil L2. The coil L1 is connected to the ground electrode 28 via the via hole 24 and the capacitor C1.
The coil L2 is connected to the via hole 2.
It is connected to the ground electrode 28 only through 3a and 23b. Therefore, it is represented by an equivalent circuit in which a coil L2 is connected in parallel to a circuit in which a coil L2 is connected in series with a capacitor CI (left side in FIG. 4).

Similarly, the capacitor C2 is constituted by the capacitor electrode patterns 7 and 8 facing each other on both the front and back surfaces of the dielectric layer 6, while the shaded portion 2a of the coil pattern 2 constitutes the coil L4, and the other portions 2b constitutes a coil L3.

The coil L3 has via holes 16a and 16b.
and a capacitor C2, and the coil L4 is connected to the ground electrode 18 only through a via hole 17. Therefore, it is represented by an equivalent circuit in which coil L4 is connected in parallel to a circuit in which coil L3 and capacitor C2 are connected in series (Figure 4 right side).
.

Furthermore, since the two coil patterns 2 and 3 are placed close to each other at a constant interval (the thickness of the joining sheet 1), the coil patterns 2 and 3 generate magnetic coupling.

Based on these facts, a bandpass filter having an equivalent circuit as shown in FIG. 4 is constructed. In addition, M in the figure is mutual inductance representing the degree of magnetic coupling between the two coil patterns 2 and 3.

Here, if the capacitor electrode patterns 7, 8, 12, and 13 are formed to sandwich the coil patterns 2 and 3 as described above, the coil patterns 2 and 3 are shielded by the capacitor electrode patterns 7 and the like. Therefore, since the shield electrode layer is not required, the LC composite component can be dramatically downsized. The bandpass filter of this example was able to be downsized to about 1/4 of the size of a conventional bandpass filter.

In the above embodiment, the capacitor electrode pattern etc. are provided on both sides of the coil pattern, but the capacitor electrode pattern may be provided only on one side.

However, in this case, it is necessary to provide a shield electrode layer on the other surface.

As explained above, according to the present invention, the shield electrode layer is not required, so the configuration of the LC composite component is simplified, and the printed coil and capacitor electrode are not arranged on the same substrate. Since they are laminated, the overall structure can be made smaller.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a bandpass filter of the present invention, FIG. 2 is a sectional view taken along line nn in FIG. 1, FIG. 3 is an exploded perspective view of the bandpass filter in FIG. The figure is an equivalent circuit diagram of a band pass filter, and Figures 5 and 6 are diagrams showing conventional band pass filters. Figure 5 is a cross-sectional view, and Figure 6 is a cross-sectional view.
The figure is a plan view of the bandpass filter main body. 2.3... Coil pattern, 6.11... Dielectric layer, 7.8.12.13... Capacitor electrode pattern. Patent applicant 2 Murata Manufacturing Co., Ltd.

Claims (1)

[Claims] (1) An LC composite component characterized in that a capacitor electrode pair is disposed on at least one of both sides sandwiching a printed coil, and one of the capacitor electrode pairs also serves as a shield electrode for shielding the printed coil.