JPH02109202A - Ceramic inductor parts and ceramic lc parts - Google Patents

Abstract

PURPOSE:To make these parts excellent in connection with an internal conductor layer, to elevate characteristics and to decrease their despersion by making the internal conductor layer out of conductor paste which contains conductor material mainly composed of AG, and making an external electrode out of conductive paste which contains conductive material including Ag and Pd of 1-10wt.% to Ag. CONSTITUTION:An internal conductor layer 5 is made of conductive paste which contains conductor material mainly composed of Ag. External electrodes 41 and 45 are made of conductive paste using Ag as conductor material, and in this case Pd is added to Ag by 1-10wt.%, preferably, 2-6wt.%. If this percent age is below 1wt.%, the effect of Pd addition vanishes; the characteristics deteriorates and varies widely. If it exceeds 10wt.%, sintering is checked and the film density of such an external electrode lowers, resulting in the deteriora tion and wide dispersion of physical property. By the foregoing processing, the external electrode becomes high in chemical activity and excellent in connec tion with the internal conductor layers. If it is applied to ceramic inductor parts, parts excellent in electrical characteristics such as Q-factor, etc., are obtained and further their dispersion decreases.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to ceramic inductor components and ceramic LC components.

<Prior Art> The internal conductor layer of a multilayer ceramic inductor component or a multilayer ceramic LC component is often formed from a conductive paste using Ag as a conductive material.

The reason why Ag is used as a conductive material in this way is that Iqi-based ferrite such as NLCu-Zn ferrite for low-temperature firing is often used as the magnetic material forming the magnetic layer, but in such cases, it is expensive. This is because the quality coefficient can be obtained.

Furthermore, as the conductive material for the conductive paste forming the external electrodes, a material obtained by adding glass frit to Ag in order to improve adhesiveness is mainly used.

<Problems to be Solved by the Invention> However, as described above, when a conductive paste using Ag as a conductive material is applied to the external electrode, Ag is also used in the internal conductive layer. In addition, since the outer electrode is formed and fired after the inner conductor layer is sintered, the chemical activity is low, and the connection between silver particles between the inner conductor layer and the outer electrode is poor, resulting in poor characteristics such as Q value. There is a problem that the condition worsens and the unevenness increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a ceramic inductor component and a ceramic LC component that have excellent connection between an internal conductor layer and an external electrode, have high characteristics, and have less variation.

<Means for Solving the Problems> In order to achieve the above object, a ceramic inductor component and a ceramic RC component of the present invention have an internal conductor layer, a magnetic layer, and an external N pole, and The internal conductor layer is formed from a conductive paste containing a conductive material mainly composed of Ag, and the external electrode is formed of a conductive paste containing a conductive material mainly composed of Ag.
It is formed from a conductive base containing a conductive material containing 1 to 10 wt% Pd based on Ag.

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

Ceramic inductor parts and ceramic L of the present invention
The external electrode in the C component is formed from a conductive base using Ag as a conductive material, and in this case, Pd is contained in an amount of 1 to LOwt% relative to Ag, preferably 2 to 20% by weight.
It is preferable to add 6 wt%.

By adding such an amount, an alloy reaction occurs between Ag in the inner conductor layer and Pd in the outer electrode due to the Kirkendall effect.

When the amount is less than 1 wt.%, the effect of Pd addition is lost, the properties deteriorate, and their variations increase.

Moreover, when it exceeds 1.0 wt%, sintering is reversed and the film density when used as an external electrode decreases, resulting in low FL and increased dispersion in physical properties.

Even if the added Pd is in the form of a single Pd, the Pd is added after firing.
It may also be an oxide. Moreover, an organic metal compound or resinate may be used.

In addition, the conductive material Ag can be used alone or after firing.
It may be an oxide, an organometallic compound, or a resinate.

In the present invention, A
A conductive material mainly composed of Ag is used, and Ag is also used as the conductive material in the conductive paste of the external electrode as described above.

The reason for using a conductive material mainly composed of Ag for the internal conductor layer is that, as will be described later, NLCu-based ferrite is preferably used for the magnetic layer due to the firing temperature. This is because a high quality factor can be obtained by using the conductive material.

The conductor material in the inner conductor layer is not particularly limited as long as it is mainly composed of Ag, and may be either Ag41 body or Ag alloy. In the case of Ag alloy, Ag is 95
It is preferable that it is contained in wt, % or more, specifically, A
gCu.

Examples include Ag-Pd. In the above, part of Ag may be silver oxide.

In the above, the shape of the conductive material such as Ag contained in the conductive base is not particularly limited, and may be spherical, flaky, or a mixture of these shapes.

The conductive paste forming the external electrode or the internal conductor layer is one in which the above-mentioned conductive material is dispersed in an organic vehicle.

The organic vehicle contains a binder and a solvent.

As the binder, any known binder can be used, such as ethyl cellulose, acrylic resin, butyral resin, and the like.

The binder content is preferably about 2 to 5 wt%.

As the solvent, any known solvent can be used, such as terpineol, butylcavitol, and kerosene.

The solvent content is preferably about 20 to 50 wt%. In addition, within a total amount of about 10 wt% or less, dispersants such as sorbitan fatty acid Nisdel, glycerin fatty acid ester, plasticizers such as dibutyl phthalate, dibutyl phthalate, butyl phthalyl glycolate, delamination prevention, etc. Various ceramic powders such as dielectrics, magnetics, and insulators can also be added for the purpose of suppressing sintering.

Further, the conductive paste may contain glass frit.

In particular, in the case of conductive paste forming external electrodes, ill
It is preferable that glass frit is contained in order to improve adhesion.

As the glass frit, it is preferable to use borosilicate glass having an average particle size of about 10 to 50 pores, and the content in the paste is preferably about 2 to 20 wt%.

The external electrode of the present invention is preferably formed by a printing method such as a transfer method, and has a 550 to 750
It is obtained by baking at ℃ for about 5 to 30 minutes.

An example of a ceramic inductor component to which the external electrode of the present invention is applied is a multilayer ceramic inductor 10 as shown in FIG.

The multilayer ceramic inductor 10 is similar to the conventional one,
Inner winding 5, magnetic layer 6 and a pair of outer electrodes 41.45
has.

In this case, the external electrodes of the present invention are applied to the external electrodes 41, 45. Furthermore, the internal conductor layer described above is applied to the internal winding 5.

Various spinel soft ferrites having a spinel structure can be used as the material for the magnetic layer 6 of the multilayer ceramic inductor 10, but due to the firing temperature, NLCu
It is preferable to use a type of ferrite.

N1-Cu-based ferrite is a low temperature firing material,
When such a magnetic layer is used, the ceramic inductor of the present invention does not generate a liquid phase during firing and has better electrical resistance.

Examples of ferrites that can be fired at low temperatures include N1-C and u ferrites, as well as Ni-Zn ferrites and NLCu-Zn ferrites. In this case, the Ni content is
It is preferably 45 to 55 mof2% in terms of O, and this N
A portion of i may be replaced by Cu and/or Zn in an amount of about 40 mo % or less.

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

Such a ferrite-based magnetic layer 6 has a 600 to 100% conductive paste forming the internal winding in the present invention.
Simultaneous firing is possible at a firing temperature of 0°C, especially 800 to 1000°C.

The laminated ceramic inductor 10 may have a conventionally known structure, and its outer shape is usually approximately rectangular parallelepiped. As shown in FIG. 1, the internal winding 5 is normally arranged in a spiral shape within the magnetic layer 6, with each external electrode 41, . 45.

In such a case, the winding pattern of the internal winding 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 various dimensions of the multilayer ceramic inductor 10, and they may be appropriately selected depending on the application.

The thickness of the internal winding 5 is usually about 5 to 30 mm, and the winding pitch is usually about 40 to 100 g111.

The thickness of the external electrode 41.45 is usually 50 to 500 IIJ
11.

Further, as a method for forming the external electrodes 41, 45, it is preferable to use a transfer method.

Note that the external electrodes 41, 45 may be formed from a single electrode layer, but preferably have a multilayer structure in which a covering layer is provided on the electrode layer. The coating layer is Cu, Ni, Sn.
Alternatively, it is preferable to form it from solder or the like.

Such a coating layer improves solder wettability and solder heat resistance during soldering.

To manufacture such a multilayer ceramic inductor 10, a conventionally known printing method may be used.

Ferrite paste is produced as follows.

First, a predetermined amount of Ni01ZnO1CuO1Fez
A predetermined amount of ferrite raw material powder is wet-mixed using a ball mill or the like. The particle size of each powder used is approximately 01 to 10 μs.

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

The stiffness is usually reduced to a powder particle size of 0.01 to 0.1 using a ball mill.
Wet-grind until the particle size is about the same size as a human voice, and dry with a spray dryer.

The resulting mixed ferrite powder is dissolved in a binder such as ethyl cellulose and a solvent such as terpineol or butylcarpitol to create a base!・Suppose.

Note that various glasses and oxides can be contained in the paste.

Such a multilayer ceramic inductor 10 is mounted on a printed circuit board or the like by soldering the external electrodes 4.1 and 4.5, 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 multilayer ceramic +-C component of the present invention.

The LC composite component 100 shown in FIG. 2 is one in which a multilayer ceramic inductor 10 and a multilayer ceramic capacitor 11 are integrated. The lid 10 is made by laminating 6H layers 6 with intervening internal windings 5 formed in a predetermined pattern. Also, the product of this inductor 10 is 19! The integrally fixed capacitor 11 has ceramic dielectric layers 3 laminated with internal electrodes 21 and 25 interposed therebetween.

The inductor 10 of such a laminated ceramic LC composite component 100 is shown in FIG. This is similar to the multilayer ceramic inductor 10 shown in FIG.

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

Example 1 As shown in Table 1, spherical Pd powder (average particle size: 0:3) was added to spherical Ag powder (average particle size: 2), and □ was added to 1 part by weight of borosilicate glass. Frit 0.
A conductive paste for external electrodes was prepared by adding 1 part by weight, 2 parts by weight of Terpine Seal 0, 0.03 parts by weight of ethyl cellulose, and 0.2 parts by weight of butylcarpitol.

Further, 0.2 parts by weight of terpineol, 3 parts by weight of ethyl cellulose, and 0.1 parts by weight of butyl calpitol were added to 1 part by weight of Ag powder (average particle size 2) to form a conductor for internal conductor 1! I closed the attached paste.

Next, powders of Ni01Cu, O, ZnO, and Fe20m with a particle size of about 0.1 to 10 units were used as ferrite raw materials, and these were wet mixed using a ball mill, and then,
This wet mixture was dried with a spray dryer, and
Calcined at 50℃, granulated, crushed in a ball mill, and dried in a spray dryer to obtain an average particle size of 0.
．． 1) It was made into a powder of IJll.

Next, this powder is dissolved in terpineol along with a predetermined amount of ethyl cellulose and mixed in a Henschel mixer to prepare a ferrite paste of NLCu-Zn ferrite. After printing and laminating a conductive paste for a conductor and a ferrite paste, it was fired.

The firing temperature was 850°C, the firing time was 2 hours5, and the firing atmosphere was air.

Next, external electrodes were formed using the above-mentioned various conductive pastes for external electrodes by a transfer method, and baked at 600'C for 10 minutes.

In this way, the 4.5mm x 3.2mm x 1mm first
A ceramic inductor sample as shown in the figure was fabricated.

The thickness of each ferrite layer is 40 mm, and the thickness of the internal winding is 20 mm.
The wire width is 300M, and the coil has a long axis of 2.5 mm and a short axis of 1. ．． 3mm oval shape.

For these inductance samples, 10 M
The Q value in Hz was measured. In this case, 3
Measurement was performed on 0 samples to find a difference of 0, and the variation in the Q value was investigated from the value of 3σ/X.

Table 1 shows the values of X and 3a/x.

table (Comparison) (Present invention) (Present invention) (Present invention) (Present invention) (Present invention) (Comparison) From the results in Table 1, Ru.

The effects of the present invention are obvious. <Effects of the Invention> The external electrode of the present invention has high chemical activity and excellent connection with the internal conductor layer.

Therefore, when such external electrodes are applied to ceramic inductor parts and ceramic LC parts, they have excellent electrical characteristics such as Q value, and their variation A- is small.

Explanation of symbols 10... Multilayer ceramic inductor 100... Multilayer ceramic LC component 5... Internal winding 6... Magnetic material 14 Brief description of the drawings Fig. 1 6j shows that the thick film component of the present invention FIG. 2 is a partially cutaway plan view showing an example of a laminated ceramic inductor.

FIG. 2 is a partially cutaway perspective view showing an example of the thick film component of the present invention being a laminated ceramic component (1) or (C).

Claims (1)

[Claims] (1) A ceramic inductor component and a ceramic LC component having an inner conductor layer, a magnetic layer, and an outer electrode, wherein the inner conductor layer is formed from a conductive paste containing a conductor material mainly composed of Ag. A ceramic inductor component and a ceramic LC component, wherein the external electrode is formed from a conductive paste containing Ag and a conductive material containing 1 to 10 wt% of Pd based on Ag.