JPH10270230A - Composite electronic components - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To provide a magnetic material in a composite electronic component in which a capacitor and an inductor are formed by providing internal electrodes inside a ceramic sintered body obtained by mixing and sintering a dielectric powder and a magnetic powder. To increase the insulation resistance. SOLUTION: NiZnCu ferrite having the following composition is used as a magnetic material. _{(NiO x · ZnO y · CuO} z) · (Fe 2 O 3) b x = 0.05~0.30 y = 0.10~0.35 z = 0.09~0.13 x + y + z = a a = 0.510 to 0.530 b = 0.490 to 0.470 a + b = 1 Effect By setting the composition ratio of the magnetic substance in the above specific range, the electric resistivity of the magnetic substance can be increased,
The insulation resistance of the capacitor can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite electronic component, and more particularly to a composite having a composite function of a capacitor and an inductor used for forming an electric circuit such as an EMI filter, a bypass filter, a band-pass filter, and a band elimination filter. Related to electronic components.

[0002]

2. Description of the Related Art A composite electronic component in which a capacitor and an inductor are formed by providing internal electrodes inside a ceramic sintered body obtained by mixing and sintering a dielectric powder and a magnetic powder,
Since a capacitor function and an inductor function can be obtained by one element, it is extremely useful for miniaturization of an electric circuit.

In such a composite electronic component, a dielectric powder and a magnetic powder are mixed, and a small amount of CdO—ZnO—B ₂ O ₃ material is added for preventing reaction and sintering at a low temperature. The composite paint obtained by mixing is formed into a sheet by a doctor blade method, and a conductive paste is printed on the obtained sheet to form an internal electrode such as Ag or Ag / Pd.
A plurality of these sheets are laminated and thermocompression-bonded, processed into a predetermined shape, and then fired to form terminal electrodes.

[0004]

In such a composite electronic component, the capacitor must have a high insulation resistance, while the magnetic material generally has an electric resistivity of 10 ⁴ to 10 ⁴ .
Since the resistivity is about 10 ⁶ Ω · cm, the electric resistivity of the ceramic obtained by mixing and sintering the dielectric powder and the magnetic powder is almost the same level as the resistivity of the magnetic substance. Therefore, when the interlayer of the capacitor is about 5 to 50 μm, the insulation resistance is only about 10 ³ to 10 ⁶ Ω, depending on the electrode area.

When a BaTiO ₃ -based dielectric powder is used as the dielectric powder, a reaction between the dielectric and the magnetic material is likely to occur, and CdO—
The ZnO-B ₂ O ₃ based material is observed reaction of a few percent even slightly added, a composite electronic component to be obtained, the dielectric constant (epsilon),
Electrical characteristics such as capacitance (C value) and dielectric loss (tan δ value) had large variations, and reliability and reproducibility were unstable.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a composite electronic component in which the insulation resistance of a capacitor is increased by increasing the electric resistivity of a magnetic material.

Another object of the present invention is to provide a composite electronic component which suppresses a reaction between a magnetic substance and a dielectric substance, has small variations in electrical characteristics, and is excellent in reliability and reproducibility.

[0008]

According to the composite electronic component of the present invention, a capacitor and an inductor are provided by providing internal electrodes inside a ceramic sintered body obtained by mixing a dielectric powder and a magnetic powder and sintering them. In the formed composite electronic component,
NiZnCu ferrite having the following composition is used as the magnetic material.

(NiO _x .ZnO _y .CuO _z ). (F
_{e 2 O 3) b x =} 0.05~0.30 y = 0.10~0.35 z = 0.09~0.13 x + y + z = a a = 0.510~0.530 b = 0.490 ０．４0.470 a + b = 1 By setting the composition ratio of the magnetic material in the above specific range, the electric resistivity of the magnetic material can be increased, and the insulation resistance of the capacitor can be increased.

In the present invention, the use of a dielectric powder having a lead-based perovskite structure as a dielectric powder, and furthermore, the use of a CdO-ZnO-B ₂ O ₃ -based material together with a dielectric material and a magnetic material , The variation in characteristics can be reduced, and the reliability and reproducibility can be stabilized.

[0011]

Embodiments of the present invention will be described below in detail.

In the present invention, the composition formula (NiO _x .ZnO _y .CuO _z ). (Fe ₂ O ₃ ) _{b of the} magnetic material composed of NiZnCu ferrite
In (x + y + z = a, a + b = 1), b is larger than 0.490, for example, b =
At 0.5, the electrical resistivity is as extremely low as 10 ⁴ to 10 ⁵ Ω · cm, so b is set to 0.490 or less. But,
If b is excessively small, the magnetic permeability becomes too small and the utility becomes poor, so that 0.490 ≧ b ≧ 0.470,
0.510 ≦ a ≦ 0.530.

Although x and y hardly affect the electric resistivity, in consideration of practical magnetic permeability and Curie temperature, 0.05 ≦ x ≦ 0.30 and 0.10 ≦ y ≦ 0. 35
It is desirable that

In the range of b, the electric resistivity is generally 10 ⁷ to 10 ⁸ Ω · cm, but when the range of z is 0.09 ≦ z ≦ 0.13, the electric resistivity becomes It can be set to 10 ¹⁰ to 10 ¹¹ Ω · cm.

In the present invention, preferred ranges of x, y, z, a and b are as follows.

X = 0.05 to 0.30 y = 0.10 to 0.35 z = 0.09 to 0.13 a = 0.510 to 0.530 b = 0.490 to 0.470 Conventionally, there are BaTiO ₃ -based and relaxor-based dielectrics. However, BaTiO ₃ -based dielectrics have large variations in electrical characteristics and are unstable in reliability and reproducibility. It is preferable to use a dielectric material having a lead-based perovskite structure, which has almost no sapphire.

Hereinafter, a preferred example of manufacturing the composite electronic component of the present invention will be described.

In manufacturing the composite electronic component of the present invention,
First, a ceramic green sheet is manufactured using a composite paint containing a dielectric powder and a magnetic powder. Here, the average particle size of the dielectric powder and the magnetic powder is 0.1 to
It is preferably about 1.5 μm.

The mixing ratio between the dielectric powder and the magnetic powder varies depending on the relative permittivity of the dielectric, the magnetic permeability of the magnetic substance, and the like. The content is preferably in the range of 70 to 30% by weight.

The composite paint contains CdO, ZnO and B ₂ O ₃ as sintering aids, and CdO: 10 to 40.
Mol%, ZnO: 30 to 60 mol%, B ₂ O _3: 10~
It is preferable to mix a CdO—ZnO—B ₂ O ₃ material containing 40 mol%, and by using such a sintering aid, the chemical reaction between the dielectric substance and the magnetic substance during sintering can be reduced. By suppressing the temperature and lowering the sintering temperature, low-temperature sintering can further prevent the chemical reaction between the dielectric and the magnetic material, thereby producing a high-performance composite electronic component.

In this case, the CdO—ZnO—B ₂ O ₃
The compounding ratio of the system material is preferably 0.05 to 3% by weight based on the total amount of the dielectric powder and the magnetic powder. The average particle size of the sintering aid is preferably 0.5 to 2.0 μm.

The composite paint is prepared by mixing the dielectric powder, the magnetic powder and the sintering aid, adding a binder such as polyvinyl butyral to the obtained mixed powder and kneading the mixture. The composite paint is formed into a sheet having a thickness of 20 to 50 μm by a doctor blade method, and an internal electrode is printed on the sheet using a conductive paste. As this conductive paste, a commercially available conductive paste such as Ag or Ag / Pd can be used. Then, a plurality of sheets are laminated and cut into a predetermined shape after hot pressing. Thereafter, the resultant is baked at 900 to 1000 ° C. for about 1.5 to 3.0 hours to form terminal electrodes, thereby manufacturing the composite electronic component of the present invention.

The thickness of the internal electrode is usually 2
〜4 μm.

The composite electronic component of the present invention may have either a single-layer structure or a laminated structure.

[0025]

The present invention will be described more specifically below with reference to examples and comparative examples.

The used dielectric material, magnetic material and sintering aid were manufactured as follows.

Dielectric material: PbO, WO ₃ , F
Starting from ₂ O ₃ and Nb ₂ O ₅ , these were respectively 65:
After mixing at a ratio of 18: 5.5: 3 (molar ratio), 1150
C. and baked at Pb _0.65 W _0.18 Fe _0.11 Nb _0.06 O
_1.505 dielectric material (average particle size 1.0 μm) was obtained. Dielectric _{materials: PbO, TiO 2, Ta 2} O 5, Fe 2
Starting from O ₃ , these were 62.5: 12.5:
After mixing at a ratio of 6.25: 6.25 (molar ratio), 115
Baking at 0 ° C, Pb _0.625 Ti _0.125 Ta _0.125 Fe
A dielectric material of _0.125 O _1.375 (average particle size: 1.0 μm) was obtained. Dielectric material: BaTiO ₃ , CaZrO ₃ , MgZr
O ₃ was used as a starting material, these were mixed at a ratio of 89: 10: 1 (molar ratio), and calcined at 1250 ° C. to obtain BaTi
An O ₃ -based dielectric material (average particle size: 1.5 μm) was obtained. Dielectric material: BaTiO ₃ , CaSnO ₃ are used as starting materials, these are mixed at a ratio of 90:10 (molar ratio), and baked at 1250 ° C. to obtain a BaTiO ₃ -based dielectric material (average particle size of 1.5 μm). ) Got.

Magnetic materials A to O: NiO, ZnO, Cu
O and Fe ₂ O ₃ were used as starting materials, and they were mixed so as to have the composition shown in Table 1 and then fired at 1000 ° C. to obtain each magnetic material (average particle size: 1.5 μm).

[0029]

[Table 1]

Sintering aids: CdO, ZnO, B ₂ O ₃ are used as starting materials, and they are mixed at a ratio of 2: 1: 1 (molar ratio), then fired at 900 ° C., and CdO—ZnO—B ₂ O _{3 A} sintering aid (average particle size 1.5 μm) was obtained.

Examples 1 to 20 and Comparative Examples 1 to 12 The above-mentioned dielectric materials, magnetic materials A to O and a sintering aid were mixed in the following mixing ratio, and polyvinyl butyral was added to the obtained mixed powder in an amount of 10% by weight. % And kneaded to prepare a composite paint. Using this composite paint, a ceramic green sheet having a thickness of 30 μm was produced by a doctor blade method.

Mixing ratio (% by weight) Dielectric material: 40 Magnetic material: 60 Sintering aid: 2 Forty ceramic green sheets are laminated, and a commercially available Ag paste is used as an internal electrode in the middle of the lamination. And a signal electrode are printed once so that an internal electrode having a thickness of about 3 μm is formed, and after hot pressing, 1 cm × 1
The resultant was cut into a cm square to obtain an EMI filter chip having a three-terminal capacitor shape as shown in FIG. In FIG. 1,
1 is a sintered body, 2 is a ground electrode, 3 is a signal electrode, and the overlapping area of the ground electrode 2 and the signal electrode 3 is about 1.0 mm.
²

After the chip was degreased at 400 ° C., it was baked at 1000 ° C. for 2 hours. A was added to the obtained sintered body.
After the g / Pd paste was applied and baked at 750 ° C. to provide terminal electrodes, the insulation resistance value (IR value), capacitance value (C value), and dielectric loss (tan δ value) were measured (number of samples to be measured). 100) and the results are shown in Tables 2 to 4.

[0034]

[Table 2]

[0035]

[Table 3]

[0036]

[Table 4]

The following is clear from the above results. That is, when the composition ratio of the magnetic substance is out of the range of the present invention (Comparative Examples 1 to 5).
In 12), there is no problem about capacitance and dielectric loss,
Insulation resistance values tend to deteriorate by two to three digits as compared with those within the range of the present invention.

In particular, by using a lead-based perovskite dielectric and setting the composition ratio of the magnetic substance within the range of the present invention (Examples 1 to 18), more stable electric characteristics can be obtained. it can.

In the case where a BaTiO ₃ dielectric material is used as the dielectric material (Examples 19 and 20), the insulation resistance is relatively good, but the capacitance value,
It was confirmed that the variation in the dielectric loss was slightly increased and the characteristics became unstable.

[0040]

As described in detail above, according to the composite electronic component of the present invention, by setting the composition ratio of the magnetic material in a specific range, a composite electronic component having a large insulation resistance can be obtained. In particular, with the composition ratio of the magnetic material in a specific range,
Use of a lead-based perovskite dielectric as a dielectric suppresses the reaction between the dielectric and the magnetic substance, reduces variations in electrical characteristics, and provides a composite electronic component with stable reliability and reproducibility. can do.

[Brief description of the drawings]

FIG. 1 is a perspective view of a chip manufactured in an example and a comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sintered body 2 Earth electrode 3 Signal electrode

Claims (3)

[Claims] 1. A composite electronic component in which a capacitor and an inductor are formed by providing internal electrodes inside a ceramic sintered body obtained by mixing and sintering a dielectric powder and a magnetic powder. A composite electronic component characterized by using NiZnCu ferrite having the following composition: _{(NiO x · ZnO y · CuO} z) · (Fe 2 O 3) b x = 0.05~0.30 y = 0.10~0.35 z = 0.09~0.13 x + y + z = a a = 0.510 to 0.530 b = 0.490 to 0.470 a + b = 1 2. The composite electronic component according to claim 1, wherein said dielectric is a dielectric having a lead-based perovskite structure. 3. The ceramic sintered body according to claim 1, wherein the ceramic sintered body comprises a dielectric powder, a magnetic powder, and CdO—ZnO.
Complex electronic device wherein the mixed and -B ₂ O ₃ based material is obtained by sintering.