JPH09251915A - Inductance element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a quality-stabilized inductance element easily at low cost by baking a folded magnetic sheet of a spinel type soft magnetic ferrite having a stripe a conductor film. SOLUTION: Using a paste for ferromagnetic material compounded with a spinel type Ni-Zn-Cu ferrite powder, a magnetic sheet is made by the printing. Using a paste for, conductor a printed striped pattern 2 is formed on a printing face 1 of this sheet. Using a paste for, magnetic material a magnetic ferrite layer 4 is formed on this pattern 2 and the sheet is folded along folds 3 to form a compact. After removing contained binder from the compact, it is sintered, conductor paste contg. Ag as a main component is coated on the exposed conductor of the sintered block and baked to form external electrodes, thereby forming an inductance element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inductance element used for electronic parts and the like.

[0002]

2. Description of the Related Art In recent years, advances in electronic equipment technology have led to demands for small and lightweight surface mount type inductance elements. As such a surface mount component, a slurry in which powders of the respective constituent materials are dispersed is used, and by a method such as printing, a laminated inductor in which each circuit is configured or an electric conductor is wound around a ferrite magnetic core. Wound-type inductors that are configured are often used.

[0003]

Conventionally, a wire-wound inductor formed by winding an electric conductor around a ferrite magnetic core has a small variation in inductance and high reliability, but it requires mold forming or cutting. Therefore, there is a problem that the cost becomes high.

On the other hand, the multilayer inductor in which the magnetic paste and the conductive paste are alternately printed and co-fired is lower in cost than the wire-wound chip inductor.

However, as the number of layers increases,
The number of printing steps increases. Further, there is a problem that high printing accuracy is required, which makes it difficult to manufacture.

An object of the present invention is to provide an inductance element which is low in cost, can be easily manufactured, and has stable quality.

[0007]

The present invention relates to Ni, Zn,
A conductive film is formed in a striped pattern on a magnetic sheet of spinel-type soft magnetic ferrite containing Cu and Fe as main components, the magnetic sheet is folded, conductors are spirally arranged, and then sintered. It is a characteristic inductance element.

By folding and then sintering a magnetic sheet of spinel type soft magnetic ferrite having a striped conductor film formed thereon, the quality is stable, and it is possible to easily and inexpensively manufacture the sheet. An inductance element is provided.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to examples.

(Example) The inductance element of the present invention was manufactured as follows. As a powder of the magnetic paste for producing the magnetic sheet, spinel Ni-
Zn-Cu ferrite powder was prepared. The average particle size of this powder is about 1 μm. The magnetic paste was prepared by mixing the powder with the binder and the solvent in the ratio shown in Table 1, and kneading the mixture with a three-roll mill.

[0011]

Next, as the powder of the conductor paste,
An Ag powder having an average particle size of 0.5 μm was prepared. The conductor paste was prepared by blending this powder with the binder and the solvent in the proportions shown in Table 2, and kneading the blend with a three-roll mill.

[0013]

Next, a magnetic material sheet having a thickness of 0.1 mm was produced by a printing method using the above magnetic material paste.

Then, a striped print pattern 2 was formed on the print surface 1 of the magnetic material sheet with a conductor paste as shown in FIG. Here, the thickness of the conductive paste laminated by the printing method was set to 15 μm.

Next, as shown in FIG. 2, a magnetic paste is used to form a ferrite magnetic layer 4 on the striped printed pattern 2.
Was formed. The thickness of the magnetic layer laminated here is 0.1 m
m.

The sheet produced as described above is shown in FIG.
As shown in FIG. 4, it was folded in the arrow direction 5 along the fold line 3 to produce a molded body 6 as shown in FIG.

The dimension of the molded body 6 obtained here is 5 m in length.
m, width 5 mm, and the number of spirally arranged conductor windings is
It was 4 turns.

This molded body was debindered and then 900 ° C.
Sintered. The surface of the obtained sintered body where the conductor is exposed is coated with a conductor paste containing Ag as a main component and baked at about 300 ° C. to form an external electrode. It was made.

On the other hand, for comparison, the magnetic layer and the conductor layer are laminated by a printing method using the same magnetic paste and conductor paste as those of the above-mentioned element, so that the conductor layers are arranged in a spiral shape. A laminated element was manufactured.

Here, the element size and the number of conductor turns are set to be the same as those of the inductance element of the present invention.

As a result, the inductance element of the present invention could be manufactured in about half the time or less of the laminated element for comparison.

Next, the relationship between the frequencies of these elements and the inductances L and Q was evaluated using an impedance analyzer HP4191A manufactured by YHP.

The results are shown in FIGS. 5 and 6. The inductance element of the present invention has characteristics equivalent to those of the comparative product.

Therefore, the product of the present invention is equivalent to the conventional product in terms of characteristics, but can be manufactured easily in a short time in terms of manufacturing.

In the examples, the pastes were prepared with the compounding ratios shown in Tables 1 and 2, but any component and compounding ratio other than these may be used as long as a printable paste can be obtained.

Furthermore, in the examples, three rolls were used for kneading a large amount of the compound, but other than this, a homogenizer, a sand mill or the like may be used.

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

[0029]

As described above, according to the present invention, a magnetic material sheet of spinel type soft magnetic ferrite on which a conductor film is formed in a striped shape is folded and then fired, so that the quality is stable. The inductance element can be manufactured at low cost and easily.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a printing sheet manufactured in an example.

FIG. 2 is an explanatory diagram showing a state in which a ferrite magnetic layer is laminated on the printing sheet manufactured in the example.

FIG. 3 is an explanatory diagram showing a folding direction of a print sheet manufactured in an example.

FIG. 4 is an explanatory diagram of a folded molded body of a print sheet manufactured in an example.

FIG. 5 is a diagram showing frequencies and L of a laminated inductor of an example and a laminated inductor for comparison.

FIG. 6 is a diagram showing a relationship of Q between a laminated inductor of an example and a laminated inductor for comparison.

[Explanation of symbols]

 1 Printing Surface 2 Printing Pattern 3 Fold Line 4 Ferrite Magnetic Layer 5 Arrows 6 Molded Product A Present Invention Product B Conventional Product

Claims (1)

[Claims] 1. A magnetic film of spinel-type soft magnetic ferrite containing Ni, Zn, Cu and Fe as main components, a conductive film is formed in a striped pattern, and a magnetic layer is further formed on the magnetic film to form the magnetic layer. An inductance element comprising a body sheet that is folded, conductors arranged in a spiral shape, and sintered.