JPH04144211A - Ceramic inductor component and manufacture thereof, and lc composite component and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain ceramic inductor components and LC composite components which have superior characteristics and high productivity, by a method wherein a ceramic magnetic layer contains ferrite, and outer electrodes contain conductive material, whose main component is Ag, and ferrite. CONSTITUTION:An inductor chip body 10 constituted by laminating a ceramic magnetic layer 6 and an inner conductor 5, and outer electrodes 41, 45 formed on the chip body 10 surface are provided. The ceramic magnetic layer 6 contains ferrite, and the outer electrodes 41, 45 contain conducting material, whose main component is Ag, and ferrite. As the material of the ceramic magnetic layer 6, various kinds of spinel soft ferrite having spinel structure can be used. But, in order to enable simultaneous baking with the inner conductor 5, Ni/Cu ferrite, Ni-Zn ferrite and Ni-Cu-Zn ferrite capable of low temperature baking are desirable to be used. In particular, Ni-Cu-Zn ferrite is desirable.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a ceramic inductor component and its manufacturing method, and an LC composite component and its manufacturing method.

<Prior Art> A multilayer ceramic inductor component is composed of an inductor chip body formed by laminating a ceramic magnetic layer and an internal conductor, and an external electrode provided on the surface of the inductor chip body.

Furthermore, the multilayer ceramic LC composite component is one in which a capacitor chip body constituted by laminating a ceramic dielectric layer and an internal electrode layer is integrally formed with the above-described inductor chip body.

These are widely used in various electronic devices because of their small volume, high robustness, and high reliability.

These parts are usually made by laminating and bonding the paste for the internal conductor and the paste for the magnetic layer, or the paste for the dielectric layer and the paste for the internal electrode layer using thick film technology, and then firing the resulting sintered product. It is manufactured by printing or transferring an external electrode paste onto the surface of the body and then firing it.

In these parts, the magnetic material used for the magnetic layer is Ni-Cu-Z because it can be fired at a low temperature.
n-ferrite is commonly used.

In addition, as a conductive material for the external electrode, it does not oxidize in the air.
Furthermore, Ag or an Ag alloy is used because it has good electrical conductivity.

In addition to the conductive material raw materials, inorganic materials are added to the paste for external electrodes to improve adhesion to the chip body.
Conventionally, glass frit has been used as this inorganic material.

<Problem to be solved by the invention> However, in conventional ceramic inductor parts and LC composite parts, when the external electrode is fired, the glass frit contained in the external electrode paste and the ceramic forming the magnetic layer react with each other. There is a problem in that the glass diffuses into the magnetic layer and imparts residual stress to the ferrite constituting the magnetic layer, degrading the magnetic properties.

In addition, since there is a large difference in linear expansion coefficient between the magnetic layer and the external electrode, residual stress is generated in the magnetic layer, and problems such as deterioration of magnetic properties due to glass diffusion and cracks occurring inside the ferrite magnetic layer occur. There is.

Furthermore, although glass generally has the effect of lowering the firing temperature, the effect of lowering the firing temperature is not sufficient because the glass quickly diffuses into the magnetic layer during firing of the external electrode. Further, it is difficult to obtain good characteristics with a glass having a composition with little diffusion. For this reason, it is difficult to simultaneously fire all pastes and obtain good properties.

The present invention was made under these circumstances, and an object of the present invention is to provide ceramic inductor parts and LC composite parts having good characteristics and high productivity, and a method for manufacturing these parts.

<Means for Solving the Problems> Such objects are achieved by the following inventions (1) to (8).

(1) A ceramic inductor component having an inductor chip body formed by laminating a ceramic magnetic layer and an internal conductor, and an external electrode provided on the surface of the inductor chip body, in which the ceramic magnetic layer contains ferrite. . A ceramic inductor component, wherein the external electrode contains a conductive material mainly composed of Ag and ferrite.

(2) The ceramic inductor component according to (1) above, which has a covered electrode containing a conductive material mainly composed of Ag on the external electrode.

(3) The ferrite contained in the ceramic magnetic layer and the external electrode is Ni-Cu-Zn ferrite; The ceramic inductor component according to (1) or (2) above, containing 300 parts by weight of ferrite.

(4) A method for manufacturing a ceramic inductor component according to any one of (1) to 3) above, wherein a conductive material material mainly composed of Ag and an external electrode paste containing ferrite are heated or A method for manufacturing a ceramic inductor component, comprising the steps of coating and baking an unfired inductor chip body to form external electrodes.

(5) A capacitor that integrally includes a capacitor chip body configured by laminating a ceramic dielectric layer and an internal electrode layer, and an inductor chip body configured by laminating a ceramic magnetic layer and an internal conductor; In an LC composite component having external electrodes on the surfaces of each of a chip body and an inductor chip body, the ceramic magnetic layer contains ferrite, and the external electrode comprises a conductive material mainly composed of Ag and ferrite or a dielectric material. An LC composite part characterized by containing.

(6) The LC composite component according to (5) above, which has a covered electrode containing a conductive material mainly composed of Ag on the external electrode.

(7) The ferrite contained in the ceramic magnetic layer and the external electrode is Ni-Cu-Zn ferrite; The LC composite component according to (5) or (6) above, containing 300 parts by weight of ferrite or dielectric.

(8) LC according to any one of (5) to 7) above
A method for manufacturing composite parts, the method comprising: applying an external electrode paste containing a conductive material mainly containing Ag and a ferrite or a dielectric to a fired or unfired capacitor chip body and an inductor chip body; L characterized by having a step of baking to form an external electrode.
C. Method for manufacturing composite parts.

<Function> In the present invention, ferrite contained in a paste for ceramic magnetic layers is used in place of at least a portion of the glass frit conventionally contained in pastes for external electrodes of ceramic inductor components in order to improve adhesion.

Therefore, the reaction between the ceramic magnetic layer paste and the external electrode paste is suppressed, and the difference in linear expansion coefficient between the ceramic magnetic layer and the external electrode becomes small.

Therefore, residual stress is hardly generated in the ceramic magnetic layer, and the magnetic properties are improved.

Furthermore, since the external electrode paste contains ferrite, the external electrode and the chip body can be fired simultaneously.

In addition, since ferrite has the effect of improving the adhesion between the external electrode and the chip body like glass, the adhesion does not deteriorate significantly.

Specific composition> Hereinafter, the configuration of the present invention will be explained in detail.

A first preferred embodiment of the ceramic inductor component of the present invention is described below.
As shown in the figure.

The ceramic inductor component shown in FIG. 1 includes an inductor chip body 1o formed by laminating a ceramic magnetic layer 6 and an internal conductor 5, and external electrodes 41, 45 provided on the surface of this inductor chip body 10. have

In the present invention, the ceramic magnetic layer 6 contains ferrite, and the external electrodes 41.45 contain ferrite and a conductive material mainly composed of Ag.

As the material for the ceramic magnetic layer 6, various spinel soft ferrites having a spinel structure can be used, and the effects of the present invention can be achieved no matter which ferrite is used. teeth,
N1-Cu ferrite, Ni-Zn that can be fired at low temperatures
It is preferable to use ferrite, Ni-Cu-Zn ferrite, and it is particularly preferable to use Ni-Cu-Zn ferrite.

The Ni-Cu-Zn ferrite used in the present invention is not particularly limited and may be selected from various compositions depending on the purpose. For example, the Ni content may be 45% in terms of NiO.
It is preferable that the content is 55 moβ% or less, and it is preferable that a portion of this Ni is replaced by Cu and Zn of about 40 moβ% or less.

In addition, Co, Mn, etc. may be contained in an amount of about 5 wi% or less of the total. In addition, Ca, Si, Bi, ■
, pb, etc. may be contained in an amount of about 1 wt% or less.

The conductive material containing Ag as a main component contained in the external electrode is preferably Ag or an Ag alloy, and particularly preferably Ag. When using Ag alloy, Ag-Pd alloy, Ag-C
U alloys are preferred, and among these, Ag-Pd alloys are preferred. The content of Ag in Ag alloys such as Ag-Pd alloys is preferably 75 to 100 wt%.

The content of ferrite in the external electrode is 50 to 30 parts by weight based on 100 parts by weight of the metal content of the conductive material mainly composed of Ag.
Preferably, it is 0 parts by weight. If the content is less than the above range, the effect of the present invention will be insufficient, and if it exceeds the above range, the adhesive strength will decrease, making it difficult to form a practical external electrode.

The ferrite contained in the external electrode is preferably of the same type as the ferrite contained in the magnetic layer, particularly preferably of the same composition.

In addition to these, various glasses such as lead borosilicate glass may be contained in the external electrode.

Glass has the effect of increasing the adhesive strength between the external electrode and the substrate, but as mentioned above, it reacts with the magnetic layer and gives residual stress to the magnetic layer, so the metal content contained in the conductive material is
0.01 to 5 parts by weight, especially 0.5 to 3 parts by weight
Preferably, it is expressed in parts by weight.

Note that the content of each compound in the external electrode can be measured by EPMA, fluorescent X-ray analysis, or the like.

In the present invention, Ag
It is preferable to provide a covered electrode containing a conductive material mainly composed of. Since the coated electrode does not contain ferrite,
Good adhesion when soldering.

Note that the external electrodes 41.45 may be formed as a single electrode layer or may be covered with the above-mentioned covered electrode, but may also be provided with a covering layer made of Cu, Ni, Sn, solder, or the like. preferable. Such a coating layer improves solder wettability and solder heat resistance during soldering. Moreover, the above-mentioned coated electrode improves adhesion of such a coating layer.

In the present invention, the conductive material constituting the internal conductor 5 is not particularly limited, and may be selected from Ag, Pt, Pd, Au, Cu, Ni, and alloys containing one or more of these, such as Ag-Pd alloy. However, in order to obtain a practical Q as an inductor, it is necessary to have a low resistivity, so it is preferable to use Ag, Cu, and an alloy containing one or more of these.

The ceramic inductor component of the present invention may have a conventionally known structure, and its outer shape is usually approximately rectangular parallelepiped.

As shown in FIG. 1, the inner conductor 5 is normally arranged in a spiral manner within the magnetic layer 6 to form an inner winding, both ends of which are connected to respective outer electrodes 41, 45.

In such a case, the winding pattern of the internal conductor 5, that is, the shape of the closed magnetic circuit, can be made into various patterns, and the number of turns can be appropriately selected depending on the application. Further, there are no restrictions on the dimensions of each part of the ceramic inductor component (it may be selected as appropriate depending on the application).

The thickness of the external electrode is usually 10 to 50 mm, and the total thickness including the coating layer is usually about 15 to 100 mm. The width of the external electrode is selected depending on the purpose, but is usually 0.2+am or more, particularly 0.2 to 0.4 mrrr.

Further, the thickness of the internal conductor 5 is approximately 5 to 30 μm, and the winding pitch is generally approximately 40 to 100%.

There is no particular restriction on the dimensions of the inductor chip body 10, and it may be set to an appropriate dimension depending on the application.
5.6mm)X (0,5~5,0mm)X (0,
6 to 1.9 mm).

The ceramic inductor component of the present invention can be manufactured by a normal printing method using paste or a sheet method.

The magnetic layer paste is produced as follows.

First, a predetermined amount of raw material powders of ferrite, such as various powders of NiO, ZnO1Cub, Fex Ox, etc., are wet-mixed using a ball mill or the like. The particle size of the raw material powder used is approximately 0.1 to 10%.

The wet-mixed mixture is usually dried using a spray dryer, and then calcined.

This is usually processed using a ball mill with a powder particle size of o, oi ~ 0.5.
Wet-grind to a particle size of - and dry with a spray dryer.

The obtained ferrite powder is kneaded with a binder such as ethyl cellulose and a solvent such as terpineol or butylcarpitol to form a paste.

Note that various glasses and oxides can be contained in the paste for the magnetic layer, if necessary.

The internal conductor paste may be made of the various conductive metals and alloys described above, or various oxides that become the conductive materials described above after firing.
It is produced by kneading an organometallic compound, resinate, etc., and the various binders and solvents described above.

The paste for external electrodes contains a conductive material material mainly composed of Ag.

The conductive material raw material mainly containing Ag includes the above-mentioned Ag and various Ag alloys, or various oxides, organometallic compounds, resinates, etc. that become conductive materials after firing.

The average particle size of such a conductive material raw material is 0. 1~2μs
It is preferable to set it as approximately.

In the present invention, ferrite is contained in the external electrode paste.

As the ferrite, the ferrite powder used in the magnetic layer paste described above may be used.

The content of ferrite in the paste may be determined so as to be the preferred content in the external electrode.

Glass frit may be added to the external electrode paste if necessary, but its content is preferably within the above range.

Note that the paste for coated electrodes may be the paste for external electrodes except for the ferrite raw material.

There is no particular restriction on the content of binder and solvent in each paste described above, and the usual content, for example, binder is 1
The content of the solvent may be approximately 10 to 50 wt%. In addition, each paste may contain additives selected from various dispersants, plasticizers, dielectrics, insulators, etc. as necessary.The total amount of these is 10
It is preferable that it is less than wt%.

When manufacturing ceramic inductor parts, first the paste for the magnetic layer and the paste for the internal conductor are made of PE.
A green chip is formed by laminated printing on a substrate such as T. Next, after cutting into a predetermined shape, it is peeled off from the substrate.

Note that a green chip may be formed by forming a green sheet using the magnetic layer paste, printing the internal conductor paste thereon, and then laminating these sheets.

Next, the external electrode paste is printed or transferred onto the green chip, and the magnetic layer paste, internal conductor paste, and external electrode paste are fired simultaneously. In addition, when providing a coated electrode, the paste for coated electrodes is printed or transferred onto the paste for external electrodes, and the paste is simultaneously fired.

Firing temperature is 800-930°C, especially 850-900°C
It is preferable that In addition, the firing time is 0.05
It is preferable to set it as 5 hours, especially 3 hours.

Firing is usually performed in air.

Note that the ceramic inductor component of the present invention allows simultaneous firing of the chip body and external electrodes, resulting in high productivity. It can also be fired.

The ceramic inductor component manufactured in this manner is mounted on a printed circuit board or the like by soldering or the like to external electrodes, and is used in various electronic devices.

Although a laminated ceramic inductor has been described above as an example, a laminated ceramic transformer is essentially the same, and there are no differences in the various materials used and the manufacturing process.

FIG. 2 shows an example of the LC composite component of the present invention.

The LC composite component 100 in FIG. 2 includes an inductor chip body 1
0 and a capacitor chip body 11 are laminated and fixed together. The inductor chip body 10 has the same configuration as the inductor chip body 10 described above.

The capacitor chip body 11 may have a structure similar to that of a typical ceramic chip capacitor component (in the illustrated example, the ceramic dielectric layer 3 is connected to the ceramic dielectric layer 3 via the internal electrode layer 25).
It is a layered structure.

The internal electrode layer 25 is made of Ag such as Ag or Ag-Pd alloy.
A conductive material such as an alloy may be used.

Although various dielectric materials may be used for the dielectric layer 3, it is preferable to use a titanium oxide dielectric because the firing temperature is low.

In addition, titanate-based composite oxides, zirconate-based composite oxides, or mixtures thereof can also be used. In this case, it is preferable that glass such as borosilicate glass be included in order to lower the firing temperature.

Specifically, as the titanium oxide type, Nio
lCub%Mns04, Aj2tOs, MgOl
B a TiOs, 5rTiOs, etc. as titanate-based composite oxides include B a TiOs, 5rTiOs, etc.
, CaTion, MgTiOs, and mixtures thereof, and examples of zirconate-based composite oxides include BaZrOx,
Examples include 5rZrO3CaZrOs, MgZrOs, and mixtures thereof.

The number of stacked dielectric layers may be determined depending on the purpose, but is usually about 1 to 100. Further, the thickness per layer is approximately 5 to 50 μm.

The external electrode of the LC composite component of the present invention contains ferrite or a dielectric material in addition to a conductive material mainly composed of Ag.

When the external electrode contains ferrite, the configuration of the external electrode is similar to that of the ceramic inductor component described above.

Furthermore, when the external electrode contains a dielectric, it is preferable that this dielectric is of the same type, particularly of the same composition, as the dielectric that constitutes the capacitor chip body 11. The preferred content range of the dielectric is the same as the preferred content range of the ferrite.

When manufacturing the LC composite component 100, the above-described printing method or sheet method may be used.

Specifically, the same paste as described above may be used for the inductor chip body 10 (and various pastes may be prepared for the capacitor chip body 11 according to the internal electrode layers and dielectric layers described above).

The external electrodes 41 on the surfaces of the inductor chip body 10 and the capacitor chip body 11 are formed in the same manner as the external electrodes of the ceramic inductor component described above.

In addition, in the LC composite component of the present invention, all pastes can be fired simultaneously. The firing temperature and firing time may be the same as those for the ceramic inductor component described above.

<Example> Hereinafter, the present invention will be specifically explained with reference to Examples.

[Production code for ceramic inductor parts] The following pastes were prepared.

(Paste for magnetic layer) Using powders of Ni01CuO1ZnO and FexOs with a particle size of about 0.1 to 3.0,
This was wet mixed using a ball mill, and then this wet mixture was dried using a spray dryer at 750°C.
The powder is calcined in a granule, which is ground in a ball mill and dried in a spray dryer to give an average particle size of 0.1-
was used as Ni-Cu-Zn raw material powder.

Next, 100 parts by weight of this raw material powder was kneaded with 3.84 parts by weight of ethyl cellulose and 78 parts by weight of terpineol to form a paste.

(Paste for internal conductor) 100 parts by weight of Ag particles having an average particle size of 0.84 were kneaded with 2.5 parts by weight of ethyl cellulose and 40 parts by weight of terpineol to form a paste.

(Paste for external electrodes) 100 parts by weight of Ag particles with an average particle size of 0.5, the Ni-Cu-Zn raw material powder used for the paste for the magnetic layer, 20 parts by weight of terpineol, and 20 parts by weight of lacquer were kneaded to form a paste. did.

Note that various pastes were prepared by changing the content of the Ni-Cu-Zn raw material powder.

For comparison, a paste containing glass frit with an average particle size of 1 was also prepared. The composition of the glass frit was as follows.

PbOnia 9.6wt% SiOx: 10.1wt% BiOs: 9.65wt% AQ20x: 0.65wt% The magnetic layer paste and internal conductor paste thus produced were printed and laminated to form a green chip. The external electrode paste was transferred to this green chip.

Next, it was baked at 875° C. for 2 hours in air.

Note that sample No. 11 could not be fired at the same time, so the paste was transferred after the chip body was fired.
It was baked at 0°C for 0.1 hour.

In this way, a ceramic inductor component sample as shown in FIG. 1, measuring 4.5 mm x 3.2 mm x 1.1 mm, was produced.

The thickness of the magnetic layer is 40-1. The thickness of the internal winding (inner conductor) is 20μ, the wire width is 300M, and the major diameter of the coil is 2.5mm.
, and an elliptical shape with a minor axis of 1.3 mm. The number of windings is 10.5
It was a turn.

Ni in the external electrode paste used for each sample
Table 1 shows the ratio of the -Cu-Zn raw material powder to the parts by weight of AglOO (parts by weight when converted to Ni-Cu-Zn ferrite). The ratio of glass frit to 100 parts by weight of Ag is also listed.

For each sample, an impedance analyzer (YHP
-4192A) was used to measure the inductance and Q at 2 MHz and 0.1 mA.

In addition, the wire was soldered to an external electrode using cream solder, and the tensile strength was measured using an ordinary testing machine.

The results are shown in Table 1.

57.1 56.6 55.9 54.3 57.3 59.4 60.1 50.1 55.2 49.2 44.1 *Sample with ferrite content in the preferred range Next, on the external electrode A ceramic inductor sample with covered electrodes was fabricated. The paste for coated electrodes had the same structure as the paste for external electrodes described above except that it did not contain ferrite.

The configurations of these samples other than the covered electrode were the same as those of the above-mentioned samples having an external electrode containing ferrite.

In these samples, improvement in solder wettability during soldering was observed.

[Production of LC composite parts] The following pastes were prepared.

(paste for internal electrode layer) starting material Conductive material raw material: 70wt% Ag with an average particle size of 0.8- Terpineol: 20wt% Lacquer ・ 10wt% These were kneaded to form a paste.

(Paste for dielectric layer) As a dielectric material, TiOx with a particle size of 0.1 to 3-
: 91wt% NiO: 3wt% CuO: 3wt% MnO: 3wt% were used. 100 parts by weight of this dielectric material, 3.5 parts by weight of ethyl cellulose, and 76 parts by weight of terpineol were kneaded to form a paste.

Using each of the pastes described above and each of the pastes used in the production of the ceramic inductor component, LC composite component samples as shown in FIG. 2 were produced according to the method described above.

When these samples were measured in the same manner as above, it was found that the same inductance improvement effect as each sample shown in Table 1 was observed, depending on the ferrite content of the external electrode.

Also, instead of ferrite, T i Ox i3 and C
An LC composite component sample having an external electrode containing .

The effects of the present invention are clear from the results of these Examples.

<Effects of the Invention> According to the present invention, ceramic inductor parts and LC composite parts having good characteristics and high productivity can be obtained.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway plan view of the ceramic inductor component of the present invention. FIG. 2 is a partially cutaway perspective view of the LC composite component of the present invention. Explanation of symbols 10... Inductor chip body 11... Capacitor chip body 100... LC composite component 25... Internal electrode layer 3... Dielectric layer 41.45... External electrode 5... Internal conductor 6...Magnetic layer application agent TDA-K Co., Ltd. Patent attorney Yo Ishii

Claims (8)

[Claims] (1) A ceramic inductor component having an inductor chip body formed by laminating a ceramic magnetic layer and an internal conductor, and an external electrode provided on the surface of the inductor chip body, in which the ceramic magnetic layer contains ferrite. . A ceramic inductor component, wherein the external electrode contains a conductive material mainly composed of Ag and ferrite. (2) The ceramic inductor component according to claim 1, further comprising a coated electrode containing a conductive material mainly composed of Ag on the external electrode. (3) The ferrite contained in the ceramic magnetic layer and the external electrode is Ni-Cu-Zn ferrite; The ceramic inductor component according to claim 1 or 2, containing 300 parts by weight of ferrite. (4) A method for manufacturing a ceramic inductor component according to any one of claims 1 to 3, wherein an external electrode paste containing a conductive material material mainly composed of Ag and a ferrite is used as a fired or unfired paste. A method for manufacturing a ceramic inductor component, comprising the step of forming an external electrode by coating and baking an inductor chip body. (5) A capacitor that integrally includes a capacitor chip body configured by laminating a ceramic dielectric layer and an internal electrode layer, and an inductor chip body configured by laminating a ceramic magnetic layer and an internal conductor; In an LC composite component having external electrodes on the surfaces of each of a chip body and an inductor chip body, the ceramic magnetic layer contains ferrite, and the external electrode comprises a conductive material mainly composed of Ag and ferrite or a dielectric material. LC characterized by containing
Composite parts. (6) The LC composite component according to claim 5, further comprising a coated electrode containing a conductive material mainly composed of Ag on the external electrode. (7) The ferrite contained in the ceramic magnetic layer and the external electrode is Ni-Cu-Zn ferrite; L according to claim 5 or 6, containing 300 parts by weight of ferrite or dielectric.
C composite parts. (8) A method for manufacturing an LC composite component according to any one of claims 5 to 7, which comprises firing an external electrode paste containing a conductive material material mainly composed of Ag and a ferrite or a dielectric material. A method for manufacturing an LC composite component, comprising the step of coating and baking a finished or unfired capacitor chip body and an inductor chip body to form external electrodes.