JPH09306738A - Inductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spiral inductor element which is used for radio communication, has a small area occupied by a spiral pattern, and enables obtaining a high inductance value. SOLUTION: A first spiral pattern 12 is formed on the upper surface of a dielectric substrate 11. A second spiral pattern 13 is formed on the lower surface of the dielectric substrate 11. The direction of winding of the first spiral pattern 12 and the direction of winding of the second spiral pattern 13 are made in the same direction. A land 14a on an inner conductor end of the first spiral pattern 12 and a land 14c on an inner conductor end of the second spiral pattern 13 are connected with each other via a through-hole 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inductor element having a circuit board pattern used mainly in wireless communication.

[0002]

2. Description of the Related Art In the microwave region, any conductive linear element serves as an inductor. The spiral inductor element is intended to obtain a high inductance value with a small occupied area by using a spiral conductor line. FIG. 5 shows the configuration of an inductor element using a spiral conductor line in the conventional technique. As shown in FIG. 5, a spiral pattern is formed on one surface of the dielectric substrate 31. The length of the spiral pattern 32 is sufficiently smaller than the wavelength used. Such a spiral inductor element can be easily manufactured by forming a pattern on a substrate.

[0003]

To miniaturize the radio, it is necessary to miniaturize the circuit, and for that purpose, it is necessary to miniaturize each element that constitutes the circuit. A chip inductor can be considered as an inductor element for miniaturizing a circuit, but this chip inductor is more difficult to manufacture than a spiral inductor element that can be formed by a substrate pattern.

On the other hand, in the above-mentioned spiral inductor element, it is necessary to increase the number of spiral turns in order to obtain a high inductance value, and the pattern occupies a large area. Therefore, the spiral inductor element is not suitable for miniaturizing the circuit.

The present invention has been made in order to solve the above problems in the prior art, and provides a spiral inductor element in which the area occupied by the spiral pattern is small and a high inductance value can be obtained. The purpose is to

[0006]

In order to achieve the above-mentioned object, the inductor element according to the present invention has a structure of a substrate, a first spiral pattern formed on one surface of the substrate, and the substrate. A second spiral pattern formed on the other surface and an inner conductor end of the second spiral pattern formed inside the substrate and connecting the inner conductor end of the first spiral pattern and the inner conductor end of the second spiral pattern. It has a through hole. With this inductor element configuration, a conductor line having a length about twice that of the conventional spiral inductor element can be obtained as compared with the conventional spiral inductor element, so that the conventional spiral inductor having the same occupied area can be obtained. A higher inductance value can be obtained than the inductor element. As a result, the inductance value can be increased and at the same time the circuit can be downsized.

Further, in the above-mentioned structure of the present invention, the first
It is preferable that the winding direction of the spiral pattern and the winding direction of the second spiral pattern are the same. According to this preferable example, the magnetic flux generated by the current flowing in each spiral pattern acts so as to strengthen each other. As a result, a higher inductance value can be obtained.

Further, in the above-mentioned structure of the present invention, the first
An output terminal formed on one surface of the substrate on which the spiral pattern is formed, and a through hole formed inside the substrate and connecting an outer conductor end of the second spiral pattern to the output terminal. Is preferably further provided. According to this preferable example, the input / output terminals of the inductor element can be arranged on the same plane.

Further, in the above-mentioned structure of the present invention, the first
It is preferable that the spiral pattern and the second spiral pattern are arranged so as not to overlap each other. According to this preferable example, since the coupling capacitance between the conductor lines of the first spiral pattern and the second spiral pattern can be suppressed, it is possible to suppress the decrease of the inductance value.

The first aspect of the present invention is the first aspect.
It is preferable that the line width of the spiral pattern and the line width of the second spiral pattern are different. According to this preferred example, the effective dielectric constants are different on both surfaces of the substrate on which the first and second spiral patterns are formed in the multilayer substrate structure in which the substrates are stacked, and the characteristic impedance of the first spiral pattern and the second Even if the characteristic impedance of the spiral pattern is different from the characteristic impedance of the first spiral pattern by appropriately changing the line width of the first spiral pattern and the line width of the second spiral pattern. The characteristic impedances of the two spiral patterns can be matched.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically with reference to embodiments. <First Embodiment> FIG. 1 is a perspective view showing a first embodiment of an inductor element according to the present invention. As shown in FIG. 1, a conductor line width of 0.2 m is provided on the upper surface of a dielectric substrate (for example, glass epoxy substrate) 11 having a thickness of 0.3 mm.
A first spiral pattern 12 (made of copper) having a square shape and having a line spacing of 0.25 mm is formed. Further, on the lower surface of the dielectric substrate 11, a rectangular second spiral pattern 13 having a conductor line width of 0.2 mm and a line interval of 0.25 mm is formed at a position facing the first spiral pattern 12. There is. The lengths of the first and second spiral patterns 12 and 13 are set sufficiently smaller than the wavelength used. The inner and outer conductor ends of the first spiral pattern 12 are provided with lands 14a and 14b each having a size of 1 mm × 1 mm as contact portions. Further, the inner and outer conductor ends of the second spiral pattern 13 also have contact dimensions of 1 mm ×
1 mm lands 14c and 14d are provided. First
The spiral direction of the spiral pattern 12 and the spiral direction of the second spiral pattern 13 are the same, and the land 14a at the inner conductor end of the first spiral pattern 12 and the inner conductor end of the second spiral pattern 13 are The land 14c is connected to the land 14c by a through hole 15 formed inside the dielectric substrate 11. An output terminal 17 is formed on the upper surface of the dielectric substrate 11, and the output terminal 17 and the land 14d at the outer conductor end of the second spiral pattern 13 are formed inside the dielectric substrate 11. Are connected by through holes 16. That is, the input terminal (land 14b at the outer conductor end of the first spiral pattern 12) and the output terminal 17 are formed on the same plane. Providing the input terminal and the output terminal on the same plane in this way is advantageous in terms of surface mounting.

In the above structure, the first spiral pattern 12 on the upper surface of the substrate and the spiral pattern 13 on the lower surface of the substrate respectively form inductor elements, and
These are connected in series through the through hole 15. Therefore, according to the present embodiment, a conductor line having a length about twice that of the conventional spiral inductor element can be obtained in comparison with the conventional spiral inductor element, so that the conventional spiral inductor having the same occupied area can be obtained. A higher inductance value can be obtained than the inductor element of. Further, as described above, since the winding direction of the first spiral pattern 12 and the winding direction of the second spiral pattern 13 are the same, the magnetic flux generated by the current flowing through the spiral patterns 12 and 13 is generated. Act to strengthen each other. As a result, a higher inductance value can be obtained.

In the above structure, the number of turns of the first and second spiral patterns 12, 13 is set to 1, 2, 3, 4
(The occupied area is 1.9 mm × 1.9 mm and 2.8, respectively.
mm x 2.8 mm, 3.7 mm x 3.7 mm, 4.6 m
m × 4.6 mm) and the inductance value was measured. FIG. 2 shows the relationship between the number of turns of the spiral pattern and the inductance value in the conventional spiral inductor element (FIG. 5) and the spiral inductor element of the present embodiment. In FIG. 2, the solid line shows the measured value of the spiral inductor element of the present embodiment, and the dotted line shows the measured value of the conventional spiral inductor element. As shown in FIG. 2, with the configuration according to the present embodiment, a high inductance value can be obtained with the same number of turns, that is, the same occupied area.

In the present embodiment, the winding direction of the first spiral pattern 12 and the winding direction of the second spiral pattern 13 are the same, but the present invention is not limited to this configuration. The winding direction of the first spiral pattern 12 and the winding direction of the second spiral pattern 13 may be opposite.

Further, in the present embodiment, the input terminal (the land 14b at the outer conductor end of the first spiral pattern 12) and the output terminal 17 are formed on the same plane, but the structure is not limited to this. Alternatively, the input terminal and the output terminal may be provided on different surfaces.

<Second Embodiment> FIG. 3 (a) is a perspective view showing an inductor element according to a second embodiment of the present invention, and FIG. 3 (b) is a plan view thereof.

As shown in FIG. 3, the first spiral pattern 12 on the upper surface of the substrate and the second spiral pattern 13 on the lower surface of the substrate are arranged so as not to overlap each other. Since other configurations are similar to those of the first embodiment, the same parts are designated by the same reference numerals and the description thereof will be omitted.

By adopting the above-mentioned structure, the coupling capacitance between the conductor lines of the first spiral pattern 12 and the second spiral pattern 13 can be suppressed, so that the reduction of the inductance value can be suppressed. it can.

<Third Embodiment> FIG. 4A is a perspective view showing an inductor element according to a third embodiment of the present invention, and FIG. 4B is a sectional view taken along the line A--A of FIG. 4A. FIG.

As shown in FIG. 4, in the present embodiment, the conductor line width of the first spiral pattern 12 and the conductor line width of the second spiral pattern 13 are different. Since other configurations are similar to those of the first embodiment, the same parts are designated by the same reference numerals and the description thereof will be omitted.

By the way, in a multi-layer substrate structure in which substrates are stacked, the first and second spiral patterns 12 and 1 are formed.
In some cases, the effective permittivity differs between the upper surface and the lower surface of the dielectric substrate 11 on which 3 is formed. If the effective permittivity is different,
The characteristic impedances of the conductor lines are different, and the first spiral pattern 12 and the second spiral pattern 13 are different.
Impedance cannot be matched between and. However, if the configuration like this embodiment is adopted,
By making the conductor line width of the first spiral pattern 12 different from the conductor line width of the second spiral pattern 13, the characteristic impedance of the conductor line can be changed appropriately, so that the first spiral pattern 12
And the second spiral pattern 13 can be matched in impedance.

In the present embodiment, the conductor line width of the first spiral pattern 12 and the conductor line width of the second spiral pattern 13 are different from each other in the first embodiment. It uses the same configuration as the configuration,
If the configuration of the second embodiment is also adopted, it is possible to suppress the decrease of the inductance value in addition to the above effect.

In the first to third embodiments described above, the rectangular spiral patterns 12 and 13 have been described as an example, but the present invention is not necessarily limited to this configuration, and for example, a circular spiral. The same effect can be obtained by using a striped pattern.

[0024]

As described above, according to the inductor element of the present invention, a conductor line having a length about twice that of the conventional spiral inductor element can be obtained in the same occupied area. , A higher inductance value can be obtained as compared with the conventional spiral inductor element having the same occupied area. As a result, the inductance value can be increased and at the same time the circuit can be downsized.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of an inductor element according to the present invention.

FIG. 2 is a diagram showing a relationship between the number of turns of a spiral pattern and an inductance value in the spiral inductor element according to the first embodiment of the present invention and the conventional spiral inductor element.

3A is a perspective view showing a second embodiment of an inductor element according to the present invention, and FIG. 3B is a plan view thereof.

4A is a perspective view showing an inductor element according to a third embodiment of the present invention, and FIG. 4B is a sectional view taken along line AA of FIG.

FIG. 5 is a perspective view showing a configuration of an inductor element using a spiral conductor line in a conventional technique.

[Explanation of symbols]

 11 Dielectric Substrate 12 First Spiral Pattern 13 Second Spiral Pattern 14a, 14b, 14c, 14d Land 15, 16 Through Hole 17 Output Terminal

Claims (5)

[Claims] 1. A substrate, a first spiral pattern formed on one surface of the substrate, a second spiral pattern formed on the other surface of the substrate, and formed inside the substrate. And an through hole connecting the inner conductor end of the first spiral pattern and the inner conductor end of the second spiral pattern. 2. The inductor element according to claim 1, wherein the winding direction of the first spiral pattern and the winding direction of the second spiral pattern are the same. 3. An output terminal formed on one surface of a substrate on which a first spiral pattern is formed, an outer conductor end of a second spiral pattern formed inside the substrate, and the output terminal. The inductor element according to claim 1 or 2, further comprising: a through hole that connects to and. 4. The inductor element according to claim 1, wherein the first spiral pattern and the second spiral pattern are arranged so as not to overlap with each other. 5. The line width of the first spiral pattern and the line width of the second spiral pattern are different.
4. The inductor element according to any one of 3 to 3.