JPH0536553A - Manufacture of inductance component - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing a thin inductance component having excellent characteristics. CONSTITUTION:This invention is a method comprising steps of forming a binder layer 2 on a surface of a ceramic board (setter) 1, forming an inductor element of a ferrite magnetic layer 3, a conductor 5 for forming a coil and an insulating layer 4 as required on the layer 2, and baking it. That is, since the layer 2 is formed between the inductor element and the board 1 and baked, the layer 2 is burned to be vanished at the time of burning, the board 1 is separated from the inductor, the inductor is freely varied in shape at the time of burning, and the layer 3 having excellent soft characteristic can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a thin inductance component having excellent characteristics.

[0002]

2. Description of the Related Art Inductance parts are widely used as coils, transformers, etc. for various communication devices, consumer devices, etc., but in recent years, small or thin inductance parts are increasingly required.

As a small-sized inductor, a laminated inductor in which magnetic layers and conductor layers are alternately laminated (see, for example, Japanese Patent Laid-Open Publication No. Sho.
No. 5-91103) is proposed, but it is a method of sequentially printing a magnetic layer and a conductor layer on a film. on the other hand,
For example, there is a method of laminating ceramic sheets as disclosed in Japanese Patent Laid-Open No. 56-138909, press-bonding them, and then firing them, but a predetermined ceramic is printed on the sheets.

[0004]

Although various methods for manufacturing small or thin high-performance inductance components have been proposed, there is a problem in terms of productivity.

The present invention solves the above-mentioned conventional problems, and an object thereof is to provide a method for obtaining a small inductance component with high productivity.

[0006]

In order to achieve the above object, the present invention forms a binder layer on a ceramic substrate, and further forms an inductor element with a ferrite magnetic layer and a conductor portion on the binder layer. After that, it is baked.

[0007]

According to the present invention, that is, since the binder layer is fired between the inductor element and the ceramic substrate, the binder layer is burnt out during firing, and the inductor portion is free to change its shape while being separated from the ceramic substrate. can do. Therefore, it is possible to form a ferrite magnetic layer having excellent soft characteristics, and it is possible to obtain an inductance component which is thin but has sufficiently excellent characteristics by a method with high productivity.

[0008]

EXAMPLE A method of manufacturing an inductance component according to an example of the present invention will be described below.

In the method of manufacturing an inductance component of this embodiment, a binder layer is first formed on a ceramic substrate, and then an inductor element is formed on the binder layer with a conductor portion forming a ferrite magnetic layer and a coil, and then a predetermined process is performed. It is a method of firing at a temperature. The binder layer is formed on the ceramic substrate by a printing method, a depping method, a spin coating method, or the like. In addition, the inductor element may be configured by adding the above-mentioned ferrite magnetic layer and the conductor portion forming the coil, and further adding an insulating layer if necessary.

FIG. 1 shows a schematic cross-sectional view of a typical example of an inductance component before firing according to the method of the present invention. In FIG. 1, reference numeral 1 denotes a ceramic substrate, which serves as a setter during firing. Reference numeral 2 is a binder layer, and 3 is a ferrite magnetic layer. Reference numeral 4 is an insulating layer, and 5 is a conductor portion forming a coil. The insulating layer 4 is a layer for electrically insulating the conductor portion 5 and the ferrite magnetic layer 3. If the ferrite magnetic layer 3 is made of ferrite having high electric resistance, such as NiZn ferrite, the insulating layer 4 is unnecessary.
Further, the insulating layer 4 may be made of ferrite having high electric resistance. However, from an application point of view, by forming the insulating layer 4 with a nonmagnetic material, the DC superposition characteristics of the inductor can be made excellent. Therefore, a predetermined DC superposition characteristic can be obtained by properly using a high-resistance ferrite magnetic material and a non-magnetic material. When the transformer is manufactured by the method of this embodiment, the insulating layer 4, especially the one made of a non-magnetic material, is used to form a magnetic path for increasing the coupling coefficient between the primary coil and the secondary coil. Good.

As the ceramic substrate 1, there are various commonly used ceramics such as alumina, mullite, beryllia, steatite, forsterite, magnesia and titania.

The binder layer 2 is formed by a kneaded material in which a solvent such as butyl carbitol, terpineol, alcohol, etc., and a binder such as ethyl cellulose, polyvinyl butyral, polyvinyl alcohol, polyethylene oxide, ethylene-vinyl acetate, etc. are mixed. This constitutes a binder for producing a paste used for forming each ceramic layer described below.
The substance forming the binder layer 2 may be any substance as long as it is burned off at the time of firing at a predetermined temperature. Moreover, it is not necessary to form the organic substrate alone, and the ceramic substrate 1 and the inductor element can be sufficiently separated after firing even if a small amount of the inorganic substance is contained.

As the ferrite magnetic layer 3, MnZn-based ferrite, Ni, which is often used in inductance components, is used.
Besides Zn-based ferrite and NiZnCu-based ferrite, there are various other spinel-type ferrites or mixtures.

As the material for forming the insulating layer 4, various ceramics or various glass ceramics, nitrides, carbides, NiZ are used as in the ceramic substrate 1 described above.
Examples include n-based ferrite and NiZnCu-based ferrite. Although referred to as the insulating layer 4 in the present embodiment, what is called a dielectric or a non-magnetic material other than the insulator may be used to form the insulating layer 4, and a substance having a high electric resistance may be used. Examples of the dielectric include those contained in the above-mentioned insulator, barium titanate, and potassium niobate. Examples of non-magnetic materials include zinc ferrite and iron oxide, which are compatible with spinel ferrite.

The conductor portion 5 forming the coil includes silver, copper,
There is a metal for forming a conductor, which is often used in a usual printing method such as an alloy of silver and palladium. The resistance and melting point of the conductor are important conditions for selection.

Further, as described above, the ceramic substrate 1, the binder layer 2, the ferrite magnetic layer 3, the insulating layer 4 and the conductor portion 5 do not necessarily have to be made of one substance, but are made of a mixture of various substances. May be.

As described above, after forming the binder layer 2 on the ceramic substrate 1, the ferrite magnetic layer 3 and the conductor portion 5 forming the coil, and in some cases, the insulating layer 4 is further formed, and then the inductor is formed at a predetermined temperature. When fired at, the binder layer 2 is burned off during firing, and the ceramic substrate 1 and the inductor element are physically separated. That is, the ceramic substrate 1 serves as a setter used in a general firing process, and the inductor has a ferrite magnetic layer 3 which is very thin and has excellent magnetic characteristics, particularly soft characteristics.
It is possible to obtain a high-performance inductance component. In other words, it is a method of directly forming an inductor element on a setter used during firing to obtain an inductance component having the above-mentioned excellent characteristics. Moreover, since printing is performed directly on the setter, an ultrathin inductance component can be obtained.

Although the inductor element is formed by the ferrite magnetic layer 3 and the conductor portion 5 forming the coil and the insulating layer 4 in some cases, the inductor structure is, for example, a toroidal core type using the ring-shaped ferrite magnetic layer 3. There are a solenoid coil type using the rod-shaped ferrite magnetic layer 3, a type in which the axis of the coil commonly used in the laminated inductor is perpendicular to the film, or a flat coil type such as a spiral coil described in detail below.

In the paste for forming each layer, in addition to the powder and the solvent and binder shown when forming the binder layer 2, if necessary, various oxides or sintering aids such as glasses are added. However, a plasticizer such as butylbenzyl phthalate, dibutyl phthalate, glycerin, and a dispersant may be added. Each layer is formed by using a paste obtained by mixing these, and what is laminated in a predetermined structure is fired at a predetermined temperature to obtain an inductance component.

The firing temperature range for firing the substrate on which the inductor element is thus formed is about 700 ° C. to 1200 ° C.
It is in the range of ° C. In particular, it depends on the constituent material of the conductor that forms the coil. For example, if silver is used as the conductor material, it is necessary to keep the temperature relatively low, and with an alloy of silver and palladium, the temperature can be relatively high.

Next, specific examples of the present invention will be described. (Example 1) Terpineol and ethyl cellulose were mixed at a weight ratio of 100: 6 to prepare a binder.
This binder is screen-printed by 50 mm in length and width.
After printing on a 96% alumina substrate with a thickness of 1 mm,
The drying at 20 ° C. was repeated twice to form a binder layer on the alumina substrate. The material of the plate used for screen printing is stainless steel, and the mesh is 300
And the emulsion thickness is 10 μm.

Next, 20 g of MnZn ferrite powder and 7 g of binder were mixed and kneaded to prepare an MnZn ferrite paste. Similarly, a NiZn ferrite paste was prepared using 20 g of NiZn ferrite powder and 7 g of a binder. Furthermore, a silver paste was prepared using 30 g of silver powder and 3 g of binder 1.

The printing of the MnZn ferrite paste and the drying of the MnZn ferrite paste on the alumina substrate having the binder layer formed thereon were repeated twice to form the MnZn ferrite magnetic layer, and then the NiZn ferrite magnetic layer was similarly formed.
The coil pattern shown in 1 was formed by a printing method using silver paste. Contrary to the above, a NiZn ferrite magnetic layer and a MnZn ferrite magnetic layer were formed thereon by a printing method to manufacture an inductor element.

The alumina substrate thus formed with the inductor element was held in the atmosphere at 900 ° C. for 1 hour, then held in a nitrogen atmosphere for another 30 minutes, and then fired for cooling.

After firing, the alumina substrate and the inductor were completely separated, and there was no warpage or cracking. Further, it was an inductance component showing excellent electrical characteristics, and was a very thin inductance component with a thickness of 0.1 mm. The surface smoothness and flatness were good.

Example 2 The same alumina substrate as in Example 1 was dipped with the binder produced in Example 1 to obtain 120
The drying at ℃ was repeated twice to form a binder layer on the surface of the alumina substrate.

Next, 20 g of NiZn ferrite powder and 7 g of binder were mixed and kneaded to prepare a NiZn ferrite paste. Alloy of silver and palladium (8
A weight ratio of 0:20) 30 g of the powder and 10 g of the binder were mixed and kneaded to prepare a silver-palladium paste.

Ni was formed on the alumina substrate on which the binder layer was formed.
Printing and drying the Zn ferrite paste by printing method 2
After the ferrite magnetic layer was formed by repeating the process, the coil pattern (solid line portion) shown in FIG. 3 was formed by printing using a silver-palladium paste. A NiZn ferrite magnetic layer was printed thereon, and the coil pattern (broken line portion) shown in FIG. 3 was formed by printing using silver-palladium paste to form an inductor element.

The alumina substrate on which the inductor element was thus formed was baked in the atmosphere at 1100 ° C. for 1 hour.

The inductor thus obtained was a thin inductance component exhibiting the same excellent electric characteristics as the inductor obtained in Example 1.

Example 3 The same alumina substrate as in Example 1 was spin-coated with a binder and then dried at 120 ° C. four times to form a binder layer on the surface of the alumina substrate.

Next, 30 g of NiZnCu ferrite powder is added.
And 20 g of binder are mixed and kneaded to form NiZn
A Cu ferrite paste was prepared.

The NiZnCu ferrite paste was printed and dried twice on the alumina substrate on which the binder layer had been formed by the printing method to form the ferrite magnetic layer, and the solid line portion of the coil pattern shown in FIG. It was formed by printing using the silver paste prepared in 1. A NiZnCu ferrite magnetic layer was printed thereon, and the broken line portion of the coil pattern shown in FIG. 3 was formed by printing using a silver paste to form an inductor element.

The alumina substrate thus formed with the inductor element was held in the atmosphere at 900 ° C. for 1 hour for firing.

The inductor thus obtained was a thin inductance component exhibiting the same excellent electric characteristics as the inductor obtained in Example 1.

(Example 4) 10 g of a mixture of butyl carbitol, ethyl cellulose and butyl benzyl phthalate in a weight ratio of 100: 6: 1 and N.
30 g of iZnCu ferrite powder was mixed and kneaded to prepare a NiZnCu ferrite paste.

After printing the NiZnCu ferrite paste on the alumina substrate having the binder layer formed by the same method as in Example 1 by the printing method and repeating the drying twice to form the ferrite magnetic layer, the coil pattern shown in FIG. Was formed by a printing method using the silver paste prepared in Example 1. A NiZnCu ferrite magnetic layer was printed thereon to form an inductor element.

The alumina substrate thus formed with the inductor element was baked in the air at 900 ° C. for 1 hour.

The inductor thus obtained was a thin inductance component exhibiting the same excellent electrical characteristics as the inductor obtained in Example 1.

Instead of the alumina substrate, mullite, beryllia, steatite, forsterite, magnesia,
Using the titania substrate and the magnesia-silica system, magnesia system, beryllia system, alumina-silica system glass ceramic substrate, and quartz glass substrate, an inductance component of the present invention was similarly prepared. After that, each substrate and the inductor element were completely separated, and there was no warp or crack in the inductor.
In addition, it is an inductance component that exhibits excellent electrical characteristics,
Moreover, it was extremely thin and had good surface smoothness and flatness.

[0041]

As described above, according to the present invention, the binder layer is first formed on the ceramic substrate, and then the inductor element is formed on the binder layer by the ferrite magnetic layer and the conductor portion or the insulating layer as required. After that, by firing these, the inductor and the ceramic substrate can be completely separated, and a thin inductance component having excellent soft characteristics can be obtained while partially simplifying the printing, drying and firing steps. . That is, the present invention provides a method for obtaining an inductance component having excellent electrical characteristics, which can be made extremely thin and which is difficult to obtain by the method using a sheet as a support.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the configuration of an inductance component before firing according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a coil pattern in the embodiment of the present invention.

FIG. 3 is an explanatory view showing a coil pattern in the embodiment of the present invention.

[Explanation of symbols]

1 Ceramic substrate 2 binder layers 3 Ferrite magnetic layer 4 insulating layers 5 conductor

Claims (2)

[Claims] 1. A binder layer is formed on a ceramic substrate,
Furthermore, a method of manufacturing an inductance component, in which an inductor element is formed on the binder layer by a ferrite magnetic layer and a conductor portion and then fired. 2. A binder layer is formed on a ceramic substrate,
Furthermore, a method of manufacturing an inductance component in which an inductor element is formed with a ferrite magnetic layer, an insulating layer and a conductor portion and then fired.