JPH09129432A - Laminated inductor and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated inductor having a stable inductance even in a high frequency band and being excellent in a Q-characteristic. SOLUTION: In this manufacturing method, a magnetic layer paste containing spinel-type soft magnetic ferrite powder having Ni, Zn, Cu, Fe as main components and a conductor layer paste containing metal powder of Ag, Cu, or Ni are laminated by a printing method and these are simultaneously fired. In this case, spinel type soft magnetic powder and silicon resin are used in mixture as the magnet layer paste. That is, as the paste constituting the magnetic layer, 100wt.% of magnetic ferrite powder and paste containing 2 to 500wt.% of silicon resin are used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated inductor used for electronic parts and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, due to advances in electronic equipment technology, the frequency band of signals handled in electronic equipment has expanded to the high frequency side, and the band extends from several hundred MHz to several GHz. For inductors used in circuits such as signal separation or synthesis in such high frequency bands,
It is required to have a high gain (Q) in a target frequency band, and a wire-wound chip inductor is generally used.

In general, a wire-wound chip inductor has high reliability, but on the other hand, it requires die molding and cutting,
There is a problem that the cost becomes high.

On the other hand, a multilayer inductor in which a magnetic layer paste containing magnetic powder and a conductive layer paste containing conductive powder are alternately printed and cofired is more reliable than a wire-wound chip inductor. High and low cost,
Utilization in the above-mentioned high frequency band is under study.

[0005]

[Problems to be Solved by the Invention] However, 50M
High inductance can be obtained up to a frequency of about Hz, but due to phenomena such as magnetic resonance associated with higher frequencies, 100M
In a high frequency region of Hz or more, there is a problem that the inductance sharply decreases and the inductor does not function at all. In addition, the frequency range showing the Q peak is 30 MH
It was about z.

It is an object of the present invention to provide a method for manufacturing a laminated inductor having a stable inductance even in a high frequency band and an excellent Q characteristic.

[0007]

The present invention provides a laminated inductor in which a conductor layer is formed between magnetic layers having a laminated structure, wherein 100 parts by weight of the magnetic ferrite powder and the magnetic ferrite powder are used. Is a magnetic layer paste containing 2-500 parts by weight of a silicone resin.

According to the present invention, a magnetic material layer is formed from a paste obtained by kneading a magnetic material powder and a binder, and a conductor layer having a predetermined pattern is formed on the magnetic material layer. In the method for manufacturing a laminated inductor, which is configured by connecting conductors and forming external electrodes, 100 parts by weight of magnetic ferrite powder is used as a paste forming the magnetic layer, and 2 to 500 parts by weight based on the magnetic ferrite powder. A method of manufacturing a laminated inductor, characterized in that a paste containing a part of a silicone resin is used.

The magnetic layer paste is composed of a mixture of spinel type soft magnetic ferrite powder and silicone resin, and the organic substance of the silicone resin is removed by heat treatment to remove SiO ₂
To reduce the inductance and improve the frequency characteristic of the inductance, and as a result, a laminated inductor that can be used up to a high frequency band can be obtained.

[0010]

Embodiments of the present invention will be described below. As a magnetic layer powder, spinel Ni-Cu-
Zn ferrite powder was prepared. The average particle size of the powder is about 1
μm. The silicone resin mixed with the ferrite powder was solid at room temperature. These were mixed with a solvent in a ratio shown in Table 1, and the mixture was kneaded with a three-roll to prepare a magnetic layer paste.

[0011]

The powder for the conductor layer has an average particle size of 0.5 μm.
m Ag powder was prepared. This powder was mixed with a binder and a solvent in the proportions shown in Table 2, and the mixture was kneaded with a three-roll mill to prepare a conductor layer paste.

[0013]

Next, the produced magnetic layer paste was laminated by a printing method to a thickness of 0.5 mm. Printing and lamination were performed thereon by using the conductor layer paste and the magnetic layer paste to form a conductor laminated winding of 5.5 turns. At this time, the thickness of one layer is about 30μ in the magnetic layer.
m, and the conductor layer has a thickness of about 15 μm. Furthermore, a magnetic layer paste was laminated thereon by a printing method to a thickness of 0.5 mm. The total laminated thickness was about 1.3 mm.

Although the number of laminated windings of the conductor is set to 5.5 here, the number of windings may be other than this, and in order to obtain the required characteristics, the winding is adjusted with a limit of about 40 turns. do it.

The laminated body produced as described above is 3 mm ×
It was cut to a size of 1.5 mm. After removing the binder from the cut laminate, co-firing was performed at 600 ° C.

Next, a conductive paste containing Ag as a main component was applied to the surface of the fired laminated body on which the leads of the laminated winding of the conductor were exposed, and the paste was baked at about 300.degree.
The external electrode was formed.

FIG. 1 shows the structure of the obtained laminated inductor. FIG. 1A is a plan view, and FIG. 1B is a cross-sectional view. Here, 1 is a magnetic layer, 2 is a conductor layer, and 3 is an external electrode.

In the laminated inductor manufactured as described above,
The relationship between the frequency and the inductance (L) and Q was evaluated using an impedance analyzer HP4191A manufactured by YHP.

FIG. 2 is a diagram showing the relationship between frequency and L and Q of the laminated inductor manufactured in the example. In addition, as a comparative example, the magnetic layer is the same spinel-based Ni-C as the example.
The relationship between the frequency, the inductance, and the Q of the laminated inductor manufactured using only u-Zn ferrite is also shown.

As shown in FIG. 2, in the laminated inductor of this example, the space factor of the powder was lower than that of the comparative example, so that L was slightly decreased, but L showed a flat characteristic up to 100 MHz or more. Frequency range showing Q peak is also 1
It can be seen that it has reached the region of 00 MHz or higher.

In the examples, the pastes were prepared with the compounding ratios shown in Tables 1 and 2. However, other components and compounding ratios can be used to obtain pastes that can be printed without causing breakage of the conductor. I wish I had it. In addition, in the magnetic layer paste of the present embodiment, the compounding ratio of the silicone resin was powder 10
The content is 10 parts by weight with respect to 0 parts by weight, but the compounding ratio may be any amount as long as the ferrite powder obtains sufficient strength.
Further, regarding the upper limit value, considering the characteristics, 500 parts by weight is preferable. Therefore, the blending amount may be 2 parts by weight or more and 500 parts by weight or less with respect to 100 parts by weight of the powder.

Furthermore, in this embodiment, three rolls were used for kneading the blend, but other than this, a homogenizer, a sand mill or the like may be used.

Further, in the present embodiment, the firing was carried out at 600 ° C., but the temperature may be any temperature at which Ag is fired.

Further, in the present embodiment, the size of one laminated body element is set to 3 mm × 1.5 mm, but other sizes may be used. In that case, the size of the laminated winding of the conductor is adjusted. do it.

In this embodiment, Ag is used as the external electrode.
Although the conductive paste containing as a main component was used, other than this, a conductive paste containing carbon, Cu, Ni, or the like as a main component may be used.

[0027]

As described above, according to the present invention,
It was possible to provide a method for manufacturing a laminated inductor having stable inductance even in a high frequency band and excellent Q characteristics.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a laminated inductor. FIG. 1A is a plan view. FIG. 1B is a sectional view.

FIG. 2 is a diagram showing the relationship between frequency, inductance, and Q in the laminated inductors of Examples and Comparative Examples.

[Explanation of symbols]

 1 Magnetic Material Layer 2 Conductive Material Layer 3 External Electrode A Example B Comparative Example

Claims (2)

[Claims] 1. A laminated inductor in which a conductor layer is formed between magnetic layers having a laminated structure, wherein 100 parts by weight of magnetic ferrite powder and 2 to 500 parts by weight of silicone based on the magnetic ferrite powder are used. A laminated inductor comprising a magnetic material layer paste containing resin. 2. A magnetic material layer is formed from a paste prepared by kneading a magnetic material powder and a binder, and a conductor layer having a predetermined pattern is formed on the magnetic material layer, and then laminated and fired to form a conductor between layers. In a method for manufacturing a laminated inductor including a connection and external electrodes, 100 parts by weight of magnetic ferrite powder is used as a paste forming the magnetic layer, and 2 to 500 parts by weight of the magnetic ferrite powder is used. A method for manufacturing a laminated inductor, comprising using a paste containing a silicone resin.