JP3307382B2 - Variable inductance element and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable inductance element, and more particularly to a variable inductance element used for a mobile communication device such as a mobile phone and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, in mobile communication devices such as mobile phones, which have been remarkably miniaturized, strict miniaturization is required for electronic components used therein. In addition, the circuits of these mobile communication devices become more complicated as the frequency used increases, and electronic components to be mounted are required to have a constant deviation and a high accuracy.

[0003] However, even if a circuit is formed by using electronic components each having a narrow deviation and high precision as individual electronic components, deviations of the constants of the electronic components to be mounted are accumulated and a desired function cannot be exhibited. Things also happen. Therefore,
The constants of necessary electronic components constituting the circuit are made variable, and the constants of the electronic components are finely adjusted so that the circuit can exhibit a desired function.

FIG. 1 shows an example of such a conventional fine adjustment method.
It is shown in FIG. The method of the fine adjustment is as follows.
Between them, a trimming electrode 34 functioning as an inductance element is formed, and a laser beam emitted from a laser trimming machine (not shown) is moved linearly while irradiating the trimming electrode 34. The trimming electrode 34 is partially removed according to the movement trajectory of the laser beam, and a linear trimming groove 35 is formed. Thereby, a substantially meandering inductor pattern is formed on the trimming electrode 34,
The inductance value of the trimming electrode 34 is finely adjusted.

[0005]

By the way, in the conventional variable inductance element, if the trimming electrode 34 is small, the variable range of the inductance value is narrowed and fine adjustment of the circuit cannot be performed. I have. However, as the miniaturization of communication devices progresses, the proportion of the trimming electrode 34 occupying on the circuit board increases, which hinders miniaturization and space saving.

For this reason, when it is necessary to widen the variable range of the inductance value, as shown in FIG. 12, by forming the trimming grooves 35 alternately, the substantially meandering inductor pattern formed on the trimming electrode 34 is formed. It has been proposed to increase the line length. However, when a high-precision laser trimming machine is used, the width (trimming width) of the trimming groove 35 formed by one trimming is generally as thin as 30 to 50 μm. For this reason, the magnetic fields generated in the adjacent portions of the substantially meandering inductor pattern interfere with each other and cancel each other out. Even if the line length is increased, the inductance value does not become a desired value. Therefore, the number of trimming grooves 35 is increased more than necessary, and there is a problem that the trimming operation time becomes longer, the pattern width of the inductor pattern becomes narrower, and the Q characteristic deteriorates.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a variable inductance element having a wide variable inductance value range, a high Q value, and capable of finely adjusting the inductance value efficiently, and a method of manufacturing the same. .

[0008]

In order to achieve the above object, a variable inductance element according to the present invention is characterized in that at least two trimming grooves are formed from at least the same end face of the conductor pattern, so that the conductor pattern is formed. A dummy pattern region for preventing magnetic field interference is formed between the trimming grooves, and a substantially meandering inductor pattern region is formed in the conductor pattern, and the dummy pattern region is formed in a portion adjacent to the substantially meandering inductor pattern region. It is characterized by being sandwiched.

Further, the method for manufacturing a variable inductance element according to the present invention includes: (a) forming a conductor pattern on the surface of an insulating substrate; and (b) forming two trimming grooves from at least the same end face of the conductor pattern. Forming a dummy pattern region for preventing magnetic field interference between the trimming grooves of the conductor pattern, and forming a substantially meandering inductor pattern region in the conductor pattern. I do.

Here, the conductor pattern is provided on the surface of the insulating substrate of the chip component, or on the surface of the circuit substrate on which the circuit pattern is provided. Preferably, the two or more trimming grooves are formed substantially in parallel, and the interval between adjacent portions of the substantially meandering inductor pattern region is set to be at least twice the pattern width of the substantially meandering inductor pattern region.

According to the above configuration, since the dummy pattern region is sandwiched between the adjacent portions of the substantially meandering inductor pattern region, the distance between the magnetic fields generated in the adjacent portions of the inductor pattern region increases, and the Interference is suppressed. By changing the position, length, or number of two or more trimming grooves formed from at least the same end face of the conductor pattern, the number and area of dummy pattern regions formed between the trimming grooves for preventing magnetic field interference are increased. The space between the dummy pattern area and the dummy pattern area changes. At the same time, the pattern width and line length of the substantially meandering inductor pattern area change, and the inductance value changes.

Further, by alternately forming two or more sets of trimming grooves from two opposing end faces of the conductor pattern, the line length of the inductor pattern region can be further lengthened.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a variable inductance element according to the present invention and a method for manufacturing the same will be described with reference to the accompanying drawings.

[First Embodiment, FIGS. 1 to 5] As shown in FIG. 1, after the upper surface of an insulating substrate 1 is polished to a smooth surface, a thick film printing method, sputtering, vapor deposition or the like is used. The conductor pattern 2 having a large area is formed on the upper surface of the insulating substrate 1 by the thin film forming method described above. In the thick film printing method, for example, after a screen plate having an opening having a desired pattern shape is covered on the upper surface of the insulating substrate 1, a conductive paste is applied from above the screen plate and exposed from the opening of the screen plate. This is a method of forming a conductor (conductor pattern 2 in the case of the first embodiment) having a desired pattern shape with a relatively large film thickness on the upper surface of the insulating substrate 1 thus formed.

The thin film forming method is, for example, a method described below. After forming a relatively thin conductive film on substantially the entire upper surface of the insulating substrate 1 by a sputtering method or the like,
A resist film (for example, a photosensitive resin film or the like) is formed on substantially the entire conductive film by spin coating or printing. Next, a mask film having a predetermined image pattern formed thereon is put on the upper surface of the resist film, and a method of irradiating ultraviolet rays or the like is used.
A desired portion of the resist film is cured. Next, after the resist film is removed while leaving the cured portion, the exposed portion of the conductive film is removed by etching to form a conductor having a desired pattern shape. Thereafter, the cured resist film is removed.

Further, as another forming method, a method may be used in which a photosensitive conductive paste is applied to the upper surface of the insulating substrate 1, and thereafter, a mask film on which a predetermined image pattern is formed is covered, exposed, and developed. The conductor pattern 2 is provided on substantially the entire surface of the insulating substrate 1.

One end 2 a of the conductor pattern 2 is drawn toward the left side of the insulating substrate 1, and the other end 2 b is drawn toward the right side of the insulating substrate 1. As a material of the insulating substrate 1, glass, glass ceramics, alumina, ferrite, Si, SiO ₂ or the like is used. As a material of the conductor pattern 2, Ag, Ag-P
d, Cu, Au, Ni, Al and the like are used.

Further, if necessary, a liquid insulating material (polyimide, glass, glass ceramic, or the like) is applied to the entire upper surface side of the insulating substrate 1 by spin coating or printing, dried, and fired to form a conductor pattern. 2 is formed.

Next, input / output external electrodes 6 and 7 are provided on the left and right ends of the insulating substrate 1 in the longitudinal direction. Input / output external electrode 6
Is electrically connected to the end 2 a of the conductor pattern 2, and the input / output external electrode 7 is electrically connected to the end 2 b of the conductor pattern 2. The input / output external electrodes 6 and 7 are made of Ag, Ag-P
A conductive paste such as d, Cu, Ni, NiCr, and NiCu is applied and baked, and then Ni,
A metal film such as Sn or Sn-Pb is formed, or formed by sputtering, vapor deposition, or the like.

After the thus obtained variable inductance element 9 is mounted on a printed wiring board or the like, the conductor pattern 2 is trimmed. That is, as shown in FIG. 2, the laser beam L is irradiated from the upper surface side of the variable inductance element 9 while being moved, and two trimming grooves 10a and 10b are formed in parallel from the end face on the far side of the conductor pattern 2. . Similarly, two trimming grooves 11a and 11b are formed in parallel from the front end face of the conductor pattern 2. As shown in FIG. 3, these trimming grooves 10a, 10b, 11a, 11b are formed with ends 2a and 2b which are drawn out for input and output.
Are formed so as to cross an imaginary line P connecting. Thus, the two trimming grooves 10a and 10
b, a rectangular dummy pattern region 3a for preventing magnetic field interference is formed, and between the trimming grooves 11a and 11b, a rectangular dummy pattern region 3b for preventing magnetic field interference is formed. Then, these dummy pattern regions 3a,
A meandering inductor pattern region 4 is formed in the conductor pattern 2 other than 3b. Both ends 2 a and 2 b of the meandering inductor pattern region 4 are electrically connected to input / output external electrodes 6 and 7.

Since the dummy pattern regions 3a and 3b are sandwiched between the adjacent portions of the meandering inductor pattern region 4, the distance between the magnetic fields generated in the adjacent portions of the inductor pattern region 4 becomes large. Magnetic field interference can be suppressed.

Then, the trimming grooves 10a, 10b, 1
When the position and length J of 1a and 11b are changed, the area of the dummy pattern regions 3a and 3b and the space between the regions 3a and 3b change. Thereby, the pattern width and the line length of the meandering inductor pattern region 4 change, and the inductance value of the meandering inductor pattern region 4 can be changed in a wide range and steplessly, so that the desired inductance value can be finely adjusted efficiently. . At this time, the inductance element 9 secures a high Q value required for the high-frequency circuit.

As described above, by forming the dummy pattern regions 3a and 3b adjacent to the meandering inductor pattern region 4 so as to suppress the interference of the magnetic field, it is possible to adjust the inductance in a wider range than before. Becomes FIG. 4 is a graph showing the result of measuring the inductance change rate when the length J of the trimming groove is changed using the variable inductance element 9 having a size of 2.0 mm × 1.25 mm (see a solid line 15). ). For comparison, FIG.
12 also shows the measurement results of the conventional variable inductance element shown in FIG. 12 having only a trimming groove between adjacent portions of the meandering inductor pattern (see dotted line 16). FIG. 4 shows that the variable inductance element 9 of the first embodiment has an inductance adjustable range that is about 10% wider than that of the conventional inductance element.

In the first embodiment, the pattern width V of the portion of the inductor pattern region 4 extending parallel to the width direction of the insulating substrate 1 and the pattern width H of the portion extending parallel to the longitudinal direction are defined as Are made substantially equal so that the pattern width of the inductor pattern region 4 becomes substantially constant over the entire length. The distance D between the trimming grooves 10a and 10b and the distance D between the trimming grooves 11a and 11b are set to be at least twice the pattern width V. As a result, the interval D between adjacent portions of the inductor pattern region 4 becomes twice or more the pattern width V. As a result, the distance between the magnetic fields generated in the adjacent portions of the inductor pattern region 4 is further increased, and the interference of the magnetic field can be reliably suppressed. Therefore, the Q value of the inductance element 9 can be further increased.

FIG. 5 is a graph showing the results of measuring the Q characteristic using the variable inductance element 9 having a size of 2.0 mm × 1.25 mm. A solid line 17 indicates a distance D between adjacent portions of the inductor pattern region 4 by a pattern width V
Display the measurement result when set to twice the
Indicates a measurement result when the interval D is set to be the same as the pattern width V. A comparison between the solid line 17 and the solid line 18 shows that the Q value is improved by about 10% by setting the interval D to twice the pattern width V. For comparison, FIG. 5 also shows the measurement results of the conventional variable inductance element shown in FIG. 11 (see dotted line 19). The variable inductance element 9 of the first embodiment includes:
Compared with the conventional variable inductance element, the Q value is about 4
0% higher.

The trimming of the conductor pattern 2 is not limited to a laser beam, but may be performed by any means such as sandblasting. If the conductor pattern 2 is electrically cut, the trimming grooves 10a, 10b, 11a, 11
b does not need to have a physically concave structure.

[Second Embodiment, FIGS. 6 and 7]
In the embodiment, as shown in FIG. 6, the conductor pattern 22 is formed directly on the printed wiring board 21. As a material of the printed wiring board 21, glass epoxy resin, glass fluorine resin,
Alumina, paper phenol resin and the like are used. The conductor pattern 22 functioning as the inductance element 20 is inserted between the signal patterns 28 and 29.

As shown in FIG. 7, the conductor pattern 22 is irradiated while moving a pulsed laser beam, and the laser beam irradiated portion of the conductor pattern 22 is removed by the energy of the laser beam, and the laser beam is irradiated from one end face of the conductor pattern 22 in parallel. Are formed with two trimming grooves 26a and 26b. Similarly, two trimming grooves 27a and 27b are formed in parallel from the other end face of the conductor pattern 22. As a result, a rectangular dummy pattern area 23a for preventing magnetic field interference is formed between the two trimming grooves 26a and 26b of the conductor pattern 22, and a rectangular dummy pattern area for preventing magnetic field interference is formed between the trimming grooves 27a and 27b. A dummy pattern region 23b is formed. Then, these dummy pattern regions 23a, 23b
A meandering inductor pattern region 24 is formed on the other conductive patterns 22. Both ends of the meandering inductor pattern region 24 are electrically connected to the signal patterns 28 and 29.

Since the dummy pattern regions 23a and 23b are sandwiched between the adjacent portions of the meandering inductor pattern region 24, the distance between the magnetic fields generated in the adjacent portions of the inductor pattern region 24 is increased. Magnetic field interference can be suppressed.

[Other Embodiments] The variable inductance element and the method of manufacturing the same according to the present invention are not limited to the above embodiment, but can be variously modified within the scope of the gist.

Although the first embodiment has been described by taking the case of individual production as an example, in the case of mass production, it is manufactured in the state of a mother substrate (wafer) having a plurality of variable inductance elements, It is effective to use a method such as dicing, scribe breaking, or laser to cut out each product size. Also, two trimming grooves 10a and 10b
Although (or 11a and 11b) are formed in parallel, they are not necessarily parallel, and one trimming groove may be inclined with respect to the other trimming groove. Further, the trimming groove may be a curved shape other than a linear shape, and the shape of the inductor pattern region may be a substantially meandering shape, for example, a shape having a sin curve.

In the variable inductance element,
The trimming grooves 10a and 10b may be formed such that one (see FIG. 8) dummy pattern region 3a is formed according to a required inductance value. Alternatively, in order to further increase the line length of the meandering inductor pattern region 4, three (see FIG. 9) or more dummy pattern regions 3a, 3b, 3c are opposed to the conductor pattern 2 so as to be formed. Two trimming grooves 10a, 10b, 11a, 11b, 12 are respectively parallel from two end faces.
A set of a and 12b may be formed alternately.

The trimming grooves do not necessarily have to be a set of two. Instead, seven trimming grooves 10a to 10g may be formed from one end surface of the conductor pattern 2 as shown in FIG. In this case, the trimming groove 10a
Dummy pattern regions 3a to 3f are formed between 10 and 10g.

[0034]

As is apparent from the above description, according to the present invention, a dummy pattern region for preventing magnetic field interference is formed between the trimming grooves, and the dummy pattern region is formed adjacent to the substantially meandering inductor pattern region. Since the dummy pattern region is sandwiched, the distance between the magnetic fields generated in adjacent portions of the inductor pattern region is increased, and the interference of the magnetic field can be suppressed. Then, the pattern shape of the dummy pattern area is changed by changing the position, length, and number of the trimming grooves, and the inductance value of the inductor pattern area is changed by changing the pattern width and the number of meandering inductor pattern areas. Therefore, the inductance value can be finely adjusted efficiently in a wide range and steplessly, and has a desired inductance value, and
A highly accurate variable inductance element having a high Q value can be obtained.

Further, by setting the interval between adjacent portions of the substantially meandering inductor pattern region to be at least twice the pattern width, the distance between the magnetic fields generated in the adjacent portions is further increased. Interference can be reliably suppressed. Therefore, the Q value of the inductance element can be further increased.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a first embodiment of a variable inductance element according to the present invention.

FIG. 2 is a perspective view for explaining a method of adjusting the inductance of the variable inductance element shown in FIG. 1;

FIG. 3 is a plan view of a meandering inductor pattern region and a dummy pattern region of the variable inductance element shown in FIG. 1;

4 is a graph showing an inductance change rate when the length of a trimming groove of the variable inductance element shown in FIG. 1 is changed.

FIG. 5 is a graph showing a Q characteristic of the variable inductance element shown in FIG.

FIG. 6 is a plan view of a conductor pattern of a second embodiment of the variable inductance element according to the present invention.

FIG. 7 is a plan view of a meandering inductor pattern region and a dummy pattern region of the variable inductance element shown in FIG. 6;

FIG. 8 is a plan view showing a modification of the meandering inductor pattern region and the dummy pattern region.

FIG. 9 is a plan view showing another modified example of the meandering inductor pattern region and the dummy pattern region.

FIG. 10 is a plan view showing another modified example of the meandering inductor pattern region and the dummy pattern region.

FIG. 11 is an explanatory diagram of a conventional method for adjusting an inductance value of a variable inductance element.

FIG. 12 is an explanatory diagram of a problem which is present in the conventional method of adjusting the inductance value of the variable inductance element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Insulating substrate 2, 22 ... Conductor pattern 3a-3f, 23a, 23b ... Dummy pattern area 4, 24 ... Serpentine inductor pattern area 9, 20 ... Variable inductance element 10a-10g, 11a, 11b, 12a, 12b, 2
6a, 26b, 27a, 27b: trimming groove 21: printed wiring board D: distance V, H: pattern width L: laser beam

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01F 21/06 H01F 41/04

Claims (6)

(57) [Claims] 1. A dummy pattern area for preventing magnetic field interference is formed between the trimming grooves of the conductor pattern by forming at least two trimming grooves from at least the same end face of the conductor pattern. Forming a substantially meandering inductor pattern area in the pattern,
A variable inductance element, wherein the dummy pattern region is sandwiched between adjacent portions of a substantially meandering inductor pattern region. 2. The two or more trimming grooves are formed substantially in parallel, and an interval between adjacent portions of the substantially meandering inductor pattern region is at least twice the pattern width of the substantially meandering inductor pattern region. The variable inductance element according to claim 1, wherein: 3. The conductive pattern is provided on a surface of an insulating substrate of a chip component.
Or the variable inductance element according to claim 2. 4. The variable inductance element according to claim 1, wherein the conductor pattern is provided on a surface of a circuit board on which the circuit pattern is provided. 5. The variable inductance element according to claim 1, wherein two or more sets of trimming grooves are alternately formed from two opposing end faces of the conductor pattern. 6. A step of forming a conductor pattern on the surface of an insulating substrate; and forming at least two trimming grooves from at least the same end face of the conductor pattern to prevent magnetic field interference between the trimming grooves of the conductor pattern. Forming a dummy pattern region and forming a substantially meandering inductor pattern region in the conductor pattern.