JPH0897664A - LC composite parts - Google Patents

Abstract

(57) [Summary] [Structure] A multi-layer LC in which a large number of green sheets made of a composite ceramic material in which magnetic ferrite powder and dielectric ceramic powder are mixed at a predetermined ratio are laminated with a printed conductor pattern and integrally fired. A choke composed of first and second coil conductors 73 and 74, which are components and are arranged in the sintered body, are wound so as to advance in the thickness direction of the sintered body, and are electrically connected to each other. An LC composite component including a coil 76 and capacitors 71 and 72 connected between terminals of these coil conductors 73 and 74. [Effect] It is possible to realize simplification of the manufacturing process of the LC composite component. Also, it is possible to minimize the thermal stress during firing,
It is possible to avoid problems such as distortion and cracks in the LC composite parts. Capacitance distributed in two coil-shaped patterns forming an inductor can be used as a filter element. Since a capacitor is provided between both ends of the two coil-shaped conductors, it can be used for removing noise in a wide range of frequencies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LC composite component used for removing noise from electronic equipment.

[0002]

2. Description of the Related Art Conventionally, various LC composite parts having a monolithic structure by combining an inductor and a capacitor have been proposed. For example, a magnetic material layer and an inductor forming conductor are alternately printed and laminated to form an inductor portion, and on this laminated body,
Alternatively, separately from that, dielectric layers and electrode forming conductors are alternately printed and laminated, and the inductor laminate and the capacitor laminate are fired in a superposed state, and an appropriate external terminal is attached to the exposed end of the internal conductor. There is known an LC composite part which is a finished product.

Further, both the multilayer inductor component and the ceramic layer of the multilayer capacitor component are made of a dielectric,
A monolithically sintered laminated LC component is also considered. In this composite component, the laminated body forming the inductor portion and the laminated body forming the capacitor portion are formed as separate laminated bodies, and the laminated body for the inductor and the laminated body for the capacitor are fired in a superposed state to expose the internal conductor. Attach a suitable external terminal to the end to make a finished product. It should be noted that the inductor component is one in which a plurality of coil-shaped conductor patterns formed on a dielectric layer are laminated and each conductor is connected via a through hole or the like in the dielectric layer.

[0004]

In the LC composite component having the structure in which the magnetic layer and the dielectric layer are superposed as described above, the thermal contraction rates of the capacitor section and the inductor section are different from each other. Thermal stress is generated from the difference, and distortion, cracking, characteristic fluctuation, etc. due to thermal stress occur even through the intermediate layer, and there is a drawback that the yield and reliability as products are poor.

Further, when a conventional LC composite component composed of only a dielectric is used for noise removal, the dielectric is always sandwiched between the windings of the coil pattern forming the inductor, and the floating between the windings is caused. There is a problem that the capacity is increased and the desired performance cannot be obtained.

[0006]

The LC composite component of the present invention is made of a composite ceramic material in which a magnetic ferrite powder and a dielectric ferrite powder are mixed in a predetermined ratio, and is composed of a large number of printed conductor patterns. A laminated LC component in which green sheets are laminated and integrally fired, which is arranged in a sintered body and is configured to be wound so as to progress in a thickness direction of the sintered body, and which are electrically connected to each other. Two coil conductors, a first capacitor connected between one end side of these coil conductors, and a second capacitor connected between the other end sides of these coil conductors. , The first and second coil conductors are electrically insulated from each other through one layer of the sintered body so as to overlap in the stacking direction, and are wound in the same direction to form a choke coil. There is something.

[0007]

According to the above construction, since the coil portion and the capacitor portion are formed by using the ceramic green sheets of the same material, the process can be simplified, and the thermal stress during firing can be suppressed to a minimum, resulting in distortion. You can avoid troubles such as cracking.

In the LC composite component of the present invention, the capacitance distributed in the two coil-shaped patterns forming the inductor can be used as a filter element. In the present invention, 2
Since a capacitor is provided between both ends of one coil-shaped conductor, it is possible to provide a high-performance LC composite component that can be used for removing noise in a wide range of frequencies.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, all insulating layers are made of the same material, and a composite functional material having a constant magnetic permeability and a constant dielectric constant is used. As a method for producing the composite functional material to be used, the following steps (1) to (4) are preferable.

First, as a dielectric material, PbO, La
Wet-mix ₂ O ₃ , ZrO ₂ , and TiO _2, and mix at 1150 ° C.
After calcination for 2 hours, pulverize with a wet mill to obtain an average particle size of about 0.1μ
m powder is prepared. This composition is Pb _0.88 La _0.12 Z
r _0.7 Ti _0.3 O _3.06 .

As magnetic materials, NiO, ZnO, C
uO and Fe ₂ O ₃ are wet-mixed, baked at 1000 ° C. for 2 hours, and then wet-milled to prepare a powder having an average particle size of about 0.1 μm. This composition is Ni _0.24 Zn _0.22 Cu _0.06 Fe
_{It is 0.96} O _1.96 .

Next, each of the dielectric material and the magnetic material is
The mixture is mixed at a weight ratio of 0:60 to obtain a composite ceramic material. The firing temperature of this material is around 1030 ° C. An improving material may be used for the purpose of suppressing the firing reaction between the dielectric substance and the magnetic substance and lowering the firing temperature.

The improving material is, for example, CdO-Z as a composition system.
a _{nO-B 2 O 3, CdO} , ZnO, B 2 O 3 to 1: 1: After mixing 1 molar ratio, and burned for one hour at 900 ° C., milled, average particle size of about 0.1μm of As a powder, a dielectric material, a magnetic material, and an improving material are mixed in a weight ratio of 40: 60: 1.5, respectively. The firing temperature of this material is around 1030 ° C.

Next, a green sheet is formed by a printing method using a kneaded and pasted material together with a binder and a solvent for the binder that can be gasified during firing.

Instead of this printing method, a green sheet may be formed by a doctor blade or the like using a raw material which is mill-mixed with a binder and a solvent for the binder to form a slurry.

A through hole is formed at the connection position of the coil-shaped pattern of the green sheet thus formed. Next, the conductor paste is printed. A predetermined number of green sheets are laminated while filling the through holes with a conductive paste if necessary. The obtained laminated body is pressure-molded, cut into chips, and fired to obtain bare chips.

An electrode is formed by applying a conductive paste to the end surface of this bare chip and baking it.
A C composite part is constructed.

FIG. 1 is an exploded perspective view showing this step, in which green sheets 1, 2, 3, 4 are laminated between upper and lower cover sheets 21, 22. Green sheet 1,
Coil patterns 11, 12, 13, 14 are provided for 2, 3, and 4.
Is formed in a substantially U-shape or a substantially C-shape in a plan view. Coil patterns 11 and 13 on odd numbered green sheets 1 and 3 and even numbered green sheets 2 and 4
In order to connect the upper coil patterns 12 and 14 to each other,
Through holes 3 on each green sheet 1, 2, 3, 4
1, 32, 33 and 34 are provided, and filled with a conductive paste as needed.

The green sheets 1, 2, 3, 4 have capacitor patterns 41, 42, 43, 44 and 51, 52,
53 and 54 are formed.

On the green sheet 1, the coil pattern 11 and the capacitor pattern 51 are not electrically connected, but the coil pattern 11 and the capacitor pattern 41 are electrically connected, and internal electrodes common to these coil pattern 11 and capacitor pattern 41 are provided. The exposed end 41a is exposed on the left side of one end of the green sheet 1. The internal electrode exposed end 51a of the capacitor pattern 51 is exposed on the left side of the other side of the green sheet 1 in the figure.

On the green sheet 2, the coil pattern 12 is electrically connected to the capacitor pattern 42, and the internal electrode exposed end 42a common to these is exposed on the right side of one end of the green sheet 2. Capacitor pattern 52
The internal electrode exposed end 52a is exposed on the right side of the other end of the green sheet 2 in the figure.

On the green sheet 3, the coil pattern 13 is electrically connected to the capacitor pattern 53, and these common internal electrode exposed ends 53a are exposed on the left side of the other end of the green sheet 3 in the figure. The internal electrode exposed end 43a of the capacitor pattern 43 is exposed on the left side of one end of the green sheet 3.

On the green sheet 4, the coil pattern 14 is electrically connected to the capacitor pattern 54, and the internal electrode exposed end 54a common to them is exposed to the right side of the other side. The internal electrode exposed end 44a of the capacitor pattern 44 is exposed on the left side of one end.

When these green sheets 1 to 4 and cover sheets 21 and 22 are laminated and fired, as shown in FIG.
The sintered bare chip 61 having a rectangular parallelepiped shape is obtained. The internal electrode exposed ends 41a to 44a and 51a to 54a are exposed on a pair of opposed end surfaces of the bare chip 61. The terminal electrodes 62, 63, 64, 65 are formed by applying a conductive paste to the end faces of these bare chips and baking them. Thereby, the LC composite part 60 is obtained.

An equivalent circuit of this LC composite component 60 is shown in FIG.

The capacitor patterns 41 and 43 and the capacitor patterns 42 and 44 form a capacitor 71, and the capacitor patterns 51 and 53 and the capacitor patterns 52 and 54 form a capacitor 72. The coil patterns 11 and 13 form the coil conductor 73, the coil patterns 12 and 14 form the coil conductor 74, and the iron core 7 is formed by the sintered body of the green sheets 1 to 4.
5, and a choke coil 76 is constituted by them.

The capacitor 71 is the choke coil 7
6 is connected between one ends of the capacitors 6, and the capacitor 72 is connected between the other ends of the choke coils 76.

Although four green sheets are laminated in the above embodiment, it is obvious that a larger number of green sheets may be laminated.

[0029]

According to the present invention, since the LC composite component having the coil and the capacitor is formed by using the ceramic green sheet of the same material, the manufacturing process of the LC composite component can be simplified. Further, the thermal stress at the time of firing can be suppressed to a minimum, and troubles such as distortion and crack of the LC composite component can be avoided.

In the LC composite component of the present invention, the capacitance distributed in the two coil-shaped patterns forming the inductor can be used as a filter element. In the present invention, 2
Since a capacitor is provided between both ends of one coil-shaped conductor, it is possible to provide a high-performance LC composite component that can be used for removing noise in a wide range of frequencies.

[Brief description of drawings]

FIG. 1 is a perspective view showing a method for manufacturing a laminated LC composite component of the present invention.

FIG. 2 is an external perspective view of a laminated LC composite component of the present invention.

FIG. 3 is an equivalent circuit diagram of the laminated LC composite component of the present invention.

[Explanation of symbols]

1, 2, 3, 4 Green sheet 11, 12, 13, 14 Coil pattern 41, 42, 43, 44, 51, 52, 53, 54 Capacitor pattern 60 LC composite component 71, 72 Capacitor 76 Choke coil

[Procedure amendment]

[Submission date] November 7, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006]

The LC composite component of the present invention is made of a composite ceramic material in which a magnetic ferrite powder and a dielectric ceramic powder are mixed in a predetermined ratio, and includes a large number of printed conductor patterns. A laminated LC component in which green sheets are laminated and integrally fired, which is arranged in a sintered body and is configured to be wound so as to progress in a thickness direction of the sintered body, and which are electrically connected to each other. Two coil conductors, a first capacitor connected between one end side of these coil conductors, and a second capacitor connected between the other end sides of these coil conductors. , The first and second coil conductors are electrically insulated from each other through one layer of the sintered body so as to overlap in the stacking direction, and are wound in the same direction to form a choke coil. There is something.

Claims (1)

[Claims] 1. A laminated LC component in which a large number of green sheets made of a composite ceramic material in which magnetic ferrite powder and dielectric ferrite powder are mixed at a predetermined ratio and having conductor patterns printed thereon are laminated and integrally fired. The first and second conductive elements are arranged in the sintered body and wound so as to advance in the thickness direction of the sintered body, and are electrically connected to each other.
Of the coil conductor, a first capacitor connected between one end side of these coil conductors, and a second capacitor connected between the other end sides of these coil conductors, The first and second coil conductors are electrically insulated from each other through one layer of the sintered body so as to be superposed in the stacking direction and are wound in the same direction to form a choke coil. LC
Composite parts.