JPH047809A - Laminated inductor and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a laminated inductor which has high self resonance frequency and less leakage flux corresponding to high-frequency bands by using a non-magnetic ceramic material as a material for forming an insulating material layer. CONSTITUTION:A conductor is formed to constitute a encircling coil in the inside of a non-magnetic material 10, i.e., a burned material mixed with glass and cordierite. The conductor 11 is formed convolutionally at the same position to laminating direction, and is formed by being connected at edges from one layer to another layer of the non-magnetic material 10. In other words, in this case, non-magnetic ceramic material is used as a material to form an insulating material. As a result, a laminated inductor can be obtained, which is available in high frequency bands. Thus at the same time, burning at low temperature is made possible, and easy manufacture of the laminated inductor is also made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multilayer inductor and a method for manufacturing the same, and more particularly, to a multilayer inductor that can be used in a high frequency band of several hundred MHz and a method for manufacturing the same.

[Prior art]

With the demand for smaller and thinner electronic components, various chimp inductors are being used in the field of inductors. Among these, a laminated inductor in which a conductor coil pattern is formed within a magnetic body without using a winding is attracting attention.

In addition, the manufacturing method used is to print conductor paste and magnetic paste alternately, or to stack magnetic sheets with conductor patterns formed on them and connect them by filling the through holes with conductor. There is.

〔assignment〕

There is a need to expand the range of use of such multilayer inductors from audio and video frequency bands to communication equipment frequency bands. In other words, it is intended to utilize up to a range of several hundred MHz.

A laminated inductor has a structure in which a conductor pattern is covered with a magnetic material in order to obtain high inductance. Furthermore, the spacing between the conductor patterns is narrowed in order to reduce the thickness.

Because of this structure, it is difficult to reduce the stray capacitance between conductor patterns in the laminated inductor, and it is difficult to increase the self-resonant frequency, making it unsuitable for use in high frequency bands.

The present invention provides a multilayer inductor having a high self-resonant frequency corresponding to a high frequency band.

The present invention also provides a laminated inductor that can be fired at low temperatures and can use silver electrodes.

[Means to solve the problem]

The present invention solves the above problems by using a non-magnetic insulating material instead of a magnetic material.

That is, a laminated inductor including a conductor pattern that overlaps and circulates in the lamination direction while connecting the ends between insulator layers, is characterized in that the material forming the insulator layer is a non-magnetic ceramic material. It is something.

As the non-magnetic material, a mixture of glass and cordierite may be used, and mullite may be further added as required.

It is also possible to form a coil pattern inside a non-magnetic material by alternately printing and laminating non-magnetic paste and conductive paste, or to form a conductive pattern on non-magnetic ceramic green sheets and laminate them. , a coil pattern can be formed in a non-magnetic material.

[Effect]

By using a non-magnetic material, the coupling between the coil patterns is reduced, and the inductance is also slightly reduced. However, in a high frequency band, the inductance value can be small, so it is necessary to make the self-resonant frequency high by creating an open magnetic path.

If a mixed material of glass and cordierite is used, the line capacitance can be reduced by lowering the dielectric constant, and low-temperature firing is also possible.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front sectional view showing an embodiment of the present invention.

Non-magnetic material 1 such as a mixed fired body of glass and cordierite
A conductor 11 forming a circulating coil is formed inside the coil.

The conductors 11 are formed at the same position in the stacking direction and in an overlapping manner. That is, the nonmagnetic material 10 is formed with its ends connected from layer to layer.

As the glass material, borosilicate glass is preferably used. This borosilicate glass has a 5iOz of 63 to 85-t
%, B2O3 is preferably in the range of 3 to 28 wt%. A non-magnetic ceramic material can be obtained from this mixture of borosilicate glass and cordierite. The mixing ratio can range from 15 to 85-t% glass.

A binder or the like is added to the mixture to form a sheet or paste, a laminate is obtained by printing or stacking the sheets, and this is fired to obtain a laminate inductor. With the above composition, it was possible to bake at a temperature of 850 to 950°C. This is a very low temperature compared to the firing temperature of conventional ferrite.

It has also been found that adding 15 wt % or less of mullite can prevent the separation and accumulation of boron in the glass. This makes it possible to form a low-resistance silver conductor pattern.

Next, a method for manufacturing a laminated inductor according to the present invention will be explained. FIG. 2 shows a method of printing conductor patterns and nonmagnetic layers alternately.

A pattern of the conductor 21a is printed on the non-magnetic layer 20a, and then a non-magnetic layer 20b is formed so that only the tip of the conductor 21a is exposed. A conductor 211) connected to the tip is formed as a coil pattern of approximately one hand turn. Next, a non-magnetic material J is applied to cover the conductor 21b except for only the tip of the conductor 21b.
Form g20e. Next, a coil pattern for approximately one turn of the conductor 21C is formed, and then this is applied to the nonmagnetic layer 20.
Cover with d. This process is repeated to form a conductor pattern with a predetermined number of turns.

FIG. 3 shows a method of manufacturing sheet lamination. In reality, a large number of sheets are stacked5, but for convenience of explanation, only three sheets are shown.

A conductor 31a of approximately one hand length is formed on the left half of the non-magnetic material sheet 30a, and a partially rounded full hole 32a is formed at the tip thereof. In the non-magnetic material sheet (301) below, there is a conductor 31 for about a hand turn on the right half.
b is formed. Similarly, through hole 32b at the tip
is formed. The conductor 31δ and the conductor 31b are connected by the conductor filled in the through holes 32a of the nonmagnetic sheets 1 to 30a, and are similarly connected to the conductor pattern of the nonmagnetic sheet 30c. By repeating this process, a predetermined number of sheets can be stacked to obtain the required number of turns.

It is also possible to form a capacitor by arranging opposing electrodes made of the same material together with an inductor to obtain an LC composite component.

FIG. 4 is an explanatory diagram of the characteristics of the multilayer inductor according to the present invention. The value of Q at each frequency is measured. A curve 46 shown by a solid line is a characteristic of an element formed with a two-turn coil, and shows that although Q is low in a low frequency band, a high Q value can be obtained even at high frequencies. No. 47 shows the characteristics of a 5-turn element, and it was possible to obtain a high Q of about I G If z.As the number of turns increases, the line capacitance also increases, making it difficult to obtain a high Q in a high frequency band. The dotted line 48 shows the characteristics of a device with 13 turns, but a drop in Q occurred above 800 MHz.The dashed double-dotted line 49 shows the characteristics of an element with a 4-turn coil formed using an insulating material containing ferrite for comparison. A comparison shows that the device according to the present invention can obtain a high Q up to a high frequency band.

Note that the dielectric constant is also about half that of a material containing ferrite, indicating that it is a low dielectric constant material.

〔effect〕

According to the present invention, a multilayer inductor that can be used in a high frequency band can be obtained.

In addition, low temperature firing becomes possible, making it easier to manufacture a multilayer inductor, and expanding the range of materials that can be used.

Furthermore, the capacitor can be formed integrally, and even if a conductive wiring pattern is formed on the surface, the characteristics will not deteriorate.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing an embodiment of the present invention, FIG. 2 is a plan view showing a manufacturing method, FIG. 3 is a perspective view, and FIG. 4 is an explanatory diagram of the characteristics of the laminated inductor according to the present invention. .

Claims (6)

[Claims] (1) A laminated inductor comprising a conductor pattern that overlaps and circulates in the lamination direction with ends connected between insulator layers, characterized in that the material forming the insulator layer is a non-magnetic ceramic material. multilayer inductor. (2) In a laminated inductor having a conductor pattern that overlaps and circulates in the lamination direction while connecting the ends between insulator layers, the material forming the insulator layer is a mixture of glass and cordierite. Characteristic multilayer inductor. (3) The laminated inductor according to claim 2, wherein the glass is borosilicate glass. (4) In a laminated inductor comprising a conductor pattern mainly composed of silver that circulates in an overlapping manner in the lamination direction while connecting the ends between the insulating layers, the materials forming the insulating layers are glass and cordierite. A multilayer inductor characterized by being a mixture of mullite and mullite. (5) In a method for manufacturing a laminated inductor having a conductor pattern that overlaps and circulates in the lamination direction while connecting the ends of insulator layers, an insulator paste made of a non-magnetic ceramic material and a conductor mainly composed of silver are used. Print the paste alternately, print the conductor pattern by about half a turn while connecting the ends, print the insulator paste leaving the ends of the conductor pattern, and connect the ends on the insulator paste. 1. A method for manufacturing a laminated inductor, characterized in that a conductive pattern is formed in the next half turn, and this process is repeated to form a conductive pattern with a predetermined number of turns in a non-magnetic material. (6) A method for manufacturing a laminated inductor comprising a conductor pattern that overlaps and circulates in the lamination direction while connecting the ends between insulator layers, forming a conductor pattern on an insulator sheet of a non-magnetic ceramic material, A method for manufacturing a laminated inductor, comprising laminating the insulating sheets and sequentially connecting the ends of the conductive patterns to form a conductive pattern with a predetermined number of turns in a non-magnetic body.