JP2002353031A - High frequency coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high frequency thin coil in which relatively high Q and SRF and high impedance can be realized at a low cost. SOLUTION: The high frequency coil has coil conductors formed, in two or more layer, on at least one side of an insulating substrate through an organic insulation layer wherein each coil conductor 11a, 13a has a part of two or more turns entirely or partially on the two or more layers and the central area not arranged with the conductor on the inside of the innermost circumferential part of the coil conductors 11a and 13a is set not smaller than 50% of the entire area surrounded by the outermost circumferential turning part including the outermost circumferential turning part of the coil conductor and the coil conductors 11a and 13a are connected in series to turn in the same direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency coil having a coil conductor formed on an insulating substrate, and more particularly to a high-frequency coil having a relatively high self-resonant frequency (SRF) and a high Q value, and a small size.
The present invention relates to a high-frequency coil which can be applied to a high-inductance coil of 0 to 200 nH to obtain suitable results.

[0002]

2. Description of the Related Art Conventional high-frequency coils of this type include:
The following configuration is known.

(1) A single-layer spiral coil formed on a ceramic substrate by a thin film technique (Japanese Patent Publication No. 7-10 / 1995)
No. 1652).

(2) A helical coil formed by a ceramic lamination method (Japanese Patent Publication No. 3-229407).

[0005]

The spiral coil formed by the thin film technique (1) has the following disadvantages.

[0006] The winding of the coil is spiral,
The coil conductor extends to the center of the coil, and the eddy current loss due to the interlinking magnetic field of the coil conductor increases.

In a single-layer spiral coil, if the floor area is fixed, the number of turns (the number of turns) cannot be increased, so that a coil having a large inductance cannot be obtained.

Since the substrate is ceramic, the dielectric constant is large, the stray capacitance increases, and the SRF decreases. When a glass-based substrate is used, the dielectric constant is reduced to some extent, but there is a problem in mechanical strength, and a problem of chip breakage and chipping occurs. If a ceramic material having high mechanical strength, such as alumina, is selected, the dielectric constant will increase.

The helical coil formed by the ceramic laminating method (2) has the following disadvantages.

When a coil having a large inductance is formed, the number of conductor layers increases, the element height increases, and the cost increases.

Since the whole is fired at a high temperature, the coil conductor has a large number of voids which are considered to be caused by outgassing of the solvent during firing, and large irregularities are generated on the conductor surface. For this reason, the current path at a high frequency becomes long, the conductor loss increases, and the Q value decreases.

Since the interlayer insulating layer is made of ceramic, the dielectric constant is high, the stray capacitance is large, and the SRF is low.

[0013] In view of the above, the present invention provides a Q and SRF
It is an object of the present invention to provide a high-frequency coil capable of realizing a high inductance in a GHz band at a low thickness at a low cost.

Other objects and novel features of the present invention will be clarified in embodiments described later.

[0015]

In order to achieve the above object, a high-frequency coil according to the first aspect of the present invention has two or more coil conductors formed on at least one surface of an insulating substrate via an organic insulating layer. In the configuration, the coil conductor in all or some of the two or more layers has a portion that circulates for approximately two or more turns, and no conductor is disposed inside the innermost circumferential portion of the coil conductor. The area of the central portion is 20% to 90% of the total area including the outermost peripheral portion of the coil conductor and surrounded by the outermost peripheral portion. It is characterized by being connected in series.

A high-frequency coil according to a second aspect of the present invention is characterized in that, in the first aspect, the coil conductor is formed of copper.

According to a third aspect of the present invention, there is provided the high-frequency coil according to the first or second aspect, wherein the aspect ratio of the coil conductor is 0.3 or more.

A high frequency coil according to a fourth aspect of the present invention is the high frequency coil according to the first, second or third aspect, wherein a relative dielectric constant of the organic insulating layer at a frequency of 1 GHz is 4 or less.

The high frequency coil according to the invention of claim 5 of the present application is the radio frequency coil according to claim 1, 2, 3, or 4 having a frequency of 1 GHz.
Wherein the Q of the organic insulating layer is 200 or more.

According to a sixth aspect of the present invention, in the high frequency coil according to the first, second, third, fourth or fifth aspect, the organic insulating layer is made of vinylbenzyl.

According to a seventh aspect of the present invention, in the high frequency coil according to the first, second, third, fourth, fifth or sixth aspect, the insulating substrate is an organic substrate.

According to an eighth aspect of the present invention, in the high frequency coil according to the first, second, third, fourth, fifth, sixth or seventh aspect, the insulating substrate is made of vinylbenzyl.

According to a ninth aspect of the present invention, there is provided the high-frequency coil according to any one of the first, second, third, fourth, fifth, sixth, seventh and eighth aspects, wherein the odd-numbered coil conductors counted from the lowermost layer of the coil conductors , Characterized by the fact that the same pattern exists.

According to a tenth aspect of the present invention, in the high frequency coil according to the first, second, third, fourth, fifth, sixth, seventh, eighth or ninth aspect, an even-numbered coil conductor counted from the lowermost layer of the coil conductor is provided. Among them, there is a feature that the same pattern exists.

[0025] The high-frequency coil according to claim 11 of the present invention is the high-frequency coil according to any one of claims 1 to 10, wherein the coil conductor in some of the two or more layers of the coil conductor has a portion that circulates for approximately two or more turns. The area of the central portion where the conductor inside the innermost peripheral portion of the coil conductor is not disposed includes the outermost peripheral portion of the coil conductor and is surrounded by the outermost peripheral portion. 20% to 90% of total area
%, And the coil conductors in the remaining layers of the two or more coil conductors are substantially one turn or less.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the high-frequency coil according to the present invention will be described below with reference to the drawings.

A first embodiment of the high-frequency coil according to the present invention will be described with reference to FIGS. In this case, the conductor layer is 2
FIG. 1A shows a first conductor layer 11 formed on an organic or inorganic insulating substrate 1, and FIG. 1B shows a second conductor layer formed thereon. 1 organic insulating layer 12
FIG. 3C shows a second conductor layer 13 formed thereon, and shows a coil conductor 11a that makes a substantially two turn turn in the first conductor layer 11 and a second conductor layer 13 in the second conductor layer 13.
The coil conductor 13a that turns around is the first organic insulating layer 1
The series coil conductors 10 are mutually connected via the two via holes 14 and connect the terminal electrodes 5 on both side edges of the substrate as a whole.

[0028] Here, as shown in Figure 1 the dotted lines, each coil conductor 11a, the area of the central portion which is not distribution of the inner conductor from winding portions of the innermost S ₁₁ of _{13a, S 12,} the coil conductor Where S _T1 and S _T2 are the total areas including the outermost peripheral portion and surrounded by the outermost peripheral portion, 0.9 ≧ S ₁₁ / ST ₁ ≧ 0.2 and 0.9 ≧ S ₁₂ /
Let S _T2 ≧ 0.2. That is, the areas S ₁₁ , S ₁₂ of the central portion where the conductors inside the innermost peripheral portions of the coil conductors 11a, 13a are not disposed include the outermost peripheral portions of the coil conductors and the outermost peripheral portions. Total area S surrounded by the orbital part of
_T1, so that 20% to 90% of the _{S T2} (as more preferably 50% or more) sets. A coil pattern such as the coil conductors 11a and 13a of approximately two turns that satisfies this condition will be hereinafter referred to as a double helical pattern.

The coil conductors of each layer are connected in series so as to rotate in the same direction, that is, so that the winding directions of the coil conductors are the same.

The production of the first and second conductor layers 11 and 13 is as follows.
For example, it can be performed by a method using panel plating and etching, or a pattern plating method.

In the method using panel plating and etching, a plating underlayer having a thickness of 5 μm or less is formed on the insulating substrate 1, and then the surface of the plating underlayer is subjected to electrolytic plating to cover the coil conductor. A resist pattern is formed in a shape, and unnecessary portions are removed by etching to form a coil conductor layer (subtractive method). The upper coil conductor layer can be formed on the organic insulating layer between layers by the same process.

In the case of the pattern plating method, FIG.
As shown in (A), the surface of the insulating substrate 1 is roughened, and then the electroless plating of a metal such as copper is performed.
Is formed, and a dry film 31 as a photosensitive (photo-curable) photoresist is stuck thereon, and a pattern of the first conductor layer 11 of FIG. As shown in B), a plating layer 32 having a sufficient thickness is formed by electroplating a metal such as copper where the dry film 31 in the pattern portion of the first conductor layer 11 is removed. Thereafter, the dry film 31 is peeled off as shown in FIG.
Further, the underlying first conductive layer 11 is formed by removing the plating base layer 30 between the lines not covered with the plating layer 32 by etching.

The formation of the upper second conductor layer 13 is shown in FIG.
(D) First organic insulating layer 12 as interlayer insulating layer
Is formed so as to cover the first conductor layer 11, and the via hole 14 is formed.
Is formed by photolithography or laser processing, and the same steps as in the formation of the first conductor layer 11 are repeated to form via holes 14 formed in the first organic insulating layer 12 as shown in FIG. The second connected to the first conductor layer 11
The conductor layer 13 is obtained. The organic insulating layer as the interlayer insulating layer can be formed by spin coating, bar coating, coating, printing, pressing (lamination of a sheet-like material) of an insulating resin, and the like. The selection is made according to the material properties such as the viscosity of the resin.

Each conductor layer 1 is formed by this pattern plating method.
By producing the conductor layers 1 and 13, voids in the conductor layers, which are common in the conventional ceramic lamination method, are eliminated.
The surfaces of 1 and 13 are smooth.

It is preferable that the material of the insulating substrate 1 and the organic insulating layer 12 serving as an interlayer insulating film have a small dielectric constant in order to reduce the stray capacitance. Further, a material having a large Q is preferable in order to reduce the dielectric loss. Specifically, at 1 GHz, it is particularly desirable that the relative permittivity of the insulating substrate 1 and the organic insulating layer 12 is 4 or less and the Q (initial value) is 200 or more, respectively. When the relative permittivity of the insulating substrate 1 and the organic insulating layer 12 is higher than 4, the use of the organic insulating material becomes less significant. If Q is less than 200, the Q value of the entire coil cannot be increased.

The materials of the insulating substrate 1 and the organic insulating layer 12 may be selected from, for example, the following Table 1 in consideration of the operating frequency, the target Q value, and the cost. Among them, an organic material, that is, vinylbenzyl as an insulating resin is a preferable material because it has a good balance of dielectric constant, Q, and cost.

Table 1 (Measurement frequency 1 GHz) Product name Relative permittivity Q (Initial value) Fluororesin 2.1 10,000 Polyethylene 2.2 5000 PPO 2.5 1200 Vinylbenzyl 2.5 260 Cyanate ester 2.7 1000 Polyether Imide 3670 Polyimide 3.6 200 Epoxy 3-70 BT Resin 2.5 500 Polyolefin 2.6 2000 Polyfumarate 2.6 250 Polyarylate 2.6 220

When the insulating substrate 1 is an organic substrate, and for the organic insulating layer 12, a core material can be used for improving mechanical strength. As the core material, D glass cloth, E glass cloth, Kepler cloth and the like can be used as shown in Table 2 below. Generally, a material having a low dielectric constant and a low loss is more expensive, but it is preferable to use a material having a low dielectric constant as far as the cost permits.

[0039]

In the case of a ceramic substrate, there are two materials: a material having excellent mechanical strength such as alumina but having a large dielectric constant of about 10; and a material such as glass having a small dielectric constant of about 4 but fragile. Fortunately, no material has both mechanical strength and low dielectric constant.

It is preferable that the material of the insulating substrate 1 and the organic insulating layer 12 does not react with each coil conductor. For example, when the coil conductor is made of copper, it is not preferable to use polyimide for the insulating substrate or the insulating layer because the copper surface turns blue-green to produce so-called patina. Also,
Those having appropriate heat resistance are preferred. For example, Tg
If the (glass transition point) is extremely low, the reliability at high temperatures is affected, which is not preferable. It is preferable that Tg ≧ 60 ° C. For example, a polyamide resin has a Tg of about 50 ° C., which is not preferable.

The material of the coil conductors 11a and 13a, that is, the first and second conductor layers 11 and 13 is preferably low in specific resistance, good in workability and formability, and inexpensive. Silver, copper, aluminum, gold and the like can be cited as material candidates, but copper is most preferable in consideration of the above three points.

The aspect ratio (conductor height / conductor width) of each of the coil conductors 11a and 13a is as large as possible. Specifically, it is preferable that the aspect ratio of the circling portion of the coil conductor is 0.3 or more. By increasing the aspect ratio, the cross-sectional area of the current path can be increased without increasing the eddy current loss of the conductor. In addition, since the inductance value hardly changes, Q can be increased efficiently. When the aspect ratio is less than 0.3, the cross-sectional area of the current path increases only slightly, and the effect of improving Q cannot be expected much.

When the width of the coil conductor is increased, the cross-sectional area of the current path increases, but the area of the upper part of the conductor interlinking with the magnetic field increases, and the inductance value decreases, which is not preferable.

Smoothing the surfaces of the coil conductors 11a and 13a is a fundamental matter for improving the Q in the high frequency region. In order to realize this, the method of forming the coil conductor is a method using electrolytic plating, preferably a bright electrolytic plating, furthermore, a thin film method such as vapor deposition and sputtering,
Alternatively, a combination of these methods may be used.

Panel plating and etching method,
That is, a plating base layer is formed on an insulating substrate or an insulating layer,
The method of forming the coil by a subtractive method after applying electrolytic plating thereafter is preferable because the upper surface of the coil conductor can be formed smoothly. It is preferable to use bright plating for electrolytic plating because the unevenness on the surface becomes smoother (mirror state). The etching method may be wet or dry, but in the former case, large irregularities are often formed on the conductor side, which is not preferable. When patterning is performed by dry etching, the conductor side portion is relatively smooth, but mass productivity is poor.

The pattern plating method described with reference to FIG. 2, that is, a plating base layer is formed on an insulating substrate or an insulating layer, a resist pattern having a coil conductor portion as an opening is formed thereon, and electrolytic plating is performed. When the coil conductor is manufactured by removing the entire surface by etching and removing the unnecessary plating base layer after removing the resist, the three surfaces of the coil conductor are preferably smooth. Here, it is more preferable to make the electrolytic plating a bright plating, since the unevenness on the surface is further reduced. When the coil conductor is formed in a high aspect, the aspect ratio of the coil conductor is set to a maximum of 0.
The limit is about 2, but this method has an aspect ratio of 0.3.
As described above, a coil conductor having an aspect ratio of about 1 can be easily formed.

Further, it is preferable to adopt an electroless plating method for forming the plating underlayer and to perform etching on the entire surface by a wet method because mass productivity is increased.

The formation of the plating underlayer may be a thin film dry method such as sputtering, vapor deposition, or ion plating, or a wet method such as electroless plating. Among these, the electroless plating method is preferable because of its excellent mass productivity. In the case of this electroless plating, it is necessary to roughen the underlayer surface. However, in this example, since the underlayer is a resin, it can be easily roughened by a physical method such as polishing or a chemical method using potassium permanganate or the like. This is preferable.

For the etching of the entire surface, both dry etching and wet etching are possible, but the latter is preferable because of its excellent mass productivity.

It is most preferable that the irregularities on the surface of the coil conductor be smaller than the skin depth at the upper limit of the operating frequency range. However, even if the irregularities exceed the value, the effective resistance is reduced by reducing the irregularities, and the Q is increased. Become. In particular, it is desirable that the irregularities on at least one surface of the coil conductor be three times or less the skin depth at the operating frequency (for example, 1 GHz). preferable. Also,
It is most preferable that all four sides of the coil conductor surface be smooth. However, if at least one of the surfaces is smooth, it is effective to improve the Q.

According to the first embodiment, the following effects can be obtained.

(1) Since the conductor layers 11 and 13 are coil conductors 11a and 13a having a double helical pattern, the number of turns of the individual coil conductors 81 and 82 shown in FIGS. Is a helical pattern of approximately one turn or less (hereinafter referred to as a single helical pattern for convenience)
The inductance per layer can be increased compared to
A required inductance value can be secured with a smaller number of layers than in a single helical pattern. Therefore, the thickness can be reduced, and the cost can be reduced.

(2) Since the conductor layers 11 and 13 are coil conductors 11a and 13a having a double helical pattern, the floating capacitance is generally increased as compared with the single helical pattern shown in FIG. Decreases,
As described above, when the organic insulating layer 12 made of vinylbenzyl or the like is used, since the dielectric constant is small, the stray capacitance between lines is reduced, and a decrease in SRF can be avoided.

[0055] (3) the coil conductor 11a in a double helical pattern, 13a, the area _S 11 of the central portion which is not distribution of the inner conductor from winding portions of the _{innermost, S 12} is the coil conductors 11a, 13a of the The total area S _T1 , S including the outermost circumference and surrounded by the outermost circumference
_T2 to be 20% to 90% (more preferably, 5%).
0% to 90%), and there are many vacant lots where no conductor is arranged in the center of the coil conductor. Therefore, the eddy current loss due to the interlinking magnetic field of the coil conductor is suppressed and the eddy current loss is caused. Q can be prevented from decreasing. If the area of the central portion is less than 20%, the effect of suppressing the eddy current loss is lost, which is not preferable. It is difficult to set the area to exceed 90% because of the coil conductor width and pitch. . In addition, a high Q value can be realized by using an organic material such as vinylbenzyl having a Q of 200 or more at 1 GHz as the insulating substrate 1 and the insulating layer 12.

(4) Increasing the aspect ratios of the series coil conductors 10, ie, the first conductor layer 11 and the second conductor layer 13, can increase the cross-sectional area of the current path, thereby reducing the DC resistance and improving the Q value. In particular, according to the pattern plating method of FIG. 2, the coil conductors 11 of the first conductor layers 11 and 13 are formed.
The aspect ratio of a and 13a can be 0.3 or more, and the Q value can be further improved.

FIG. 3 shows a second embodiment of the high-frequency coil according to the present invention. In this case, a two-layer product having two conductor layers is shown. FIG. 3A shows the first conductor layer 41 formed on the organic or inorganic insulating substrate 1 and FIG. The first organic insulating layer 42 formed by lamination is formed by
Indicates a second conductor layer 43 formed thereon, and the coil conductor 41a of the first conductor layer 41 that makes approximately three turns and the coil conductor 43a of the second conductor layer 43 that makes almost three turns are the same as A series coil conductor 40 is connected to each other via a via hole 44 of one organic insulating layer 42 and connects the terminal electrodes 5 on both side edges of the substrate as a whole.

Also in this case, each of the coil conductors 41a, 43a
The area of the central portion where the conductor inside the innermost peripheral portion of the coil conductor is not disposed is 20% of the total area including the outermost peripheral portion of the coil conductor and surrounded by the outermost peripheral portion.
To 90% (more preferably 50% to 90%). A coil pattern such as the coil conductors 41a and 43a of approximately three turns satisfying this condition will be hereinafter referred to as a triple helical pattern.

The coil conductors of each layer are connected in series so as to rotate in the same direction, that is, so that the winding directions of the coil conductors are the same.

The production of the first and second conductor layers 41 and 43 is as follows.
For example, it can be performed by a method using panel plating and etching, or a pattern plating method. Also,
The first organic insulating layer 42 serving as an interlayer insulating layer can be formed by spin coating, bar coating, coating, printing, pressing (lamination of a sheet-like material) of an insulating resin, and the like. Is selected according to the material characteristics such as the viscosity of the resin and the resin.

According to the second embodiment, by increasing the number of turns of the coil conductor of each conductor layer, the above-described first embodiment is improved.
It is possible to increase the inductance value as compared with the embodiment. The other configuration, operation and effect are the same as those of the above-described first embodiment.

FIG. 4 shows a third embodiment of the high-frequency coil according to the present invention, which shows a four-layer product having four conductor layers. FIG. 4A shows a first conductor layer 51 formed on an organic or inorganic insulating substrate 1 and FIG. 4B shows a second conductor layer formed thereon with an interlayer organic insulating layer interposed therebetween. 52
FIG. 3C shows a third conductor layer 53 laminated thereon with an interlayer organic insulating layer interposed therebetween, and FIG. 4D shows a third conductor layer 53 laminated thereon with an interlayer organic insulating layer interposed therebetween. The fourth conductor layer 5
4, a coil conductor 51a that makes a substantially two-turn turn in the first conductor layer 51, a coil conductor 52a that makes a two-turn turn in the second conductor layer 52, and a two-turn turn in the third conductor layer 53. A coil conductor 53a;
The coil conductor 54a, which rotates substantially two turns in the fourth conductor layer 54, is connected to each other via via holes in the organic insulating layer between the respective layers, and the series coil conductor 50 connecting the terminal electrodes 5 on both side edges of the substrate as a whole is connected to the coil conductor 54a. Make up.

Also in this case, each of the coil conductors 51a to 54a
The area of the central portion where the conductor inside the innermost circumference of the coil conductor is not disposed is 20% of the entire area including the outermost circumference of the coil conductor and surrounded by the outermost circumference.
To 90% (more preferably 50% to 90%) to form a double helical pattern.

The coil conductors of each layer are connected in series so as to rotate in the same direction, that is, so that the winding directions of the coil conductors are the same.

The production of the first to fourth conductor layers 51 to 54 is as follows.
For example, it can be performed by a method using panel plating and etching, or a pattern plating method.

According to the third embodiment, by increasing the number of conductor layers, the inductance value can be increased as compared with the first embodiment. The other configuration, operation and effect are the same as those of the above-described first embodiment.

FIG. 5 shows a fourth embodiment of a high-frequency coil according to the present invention, which is a four-layer product having four conductor layers. FIG. 5 (A) shows a first conductor layer 61 formed on an organic or inorganic insulating substrate 1, and FIG. 5 (B) shows a second conductor layer laminated thereon with an organic insulating layer between them. 62
FIG. 3C shows a third conductor layer 63 laminated thereon with an interlayer organic insulating layer interposed therebetween, and FIG. 4D shows a third conductor layer 63 laminated thereon with an interlayer organic insulating layer interposed therebetween. The fourth conductor layer 6
4, a coil conductor 61a that makes a substantially three-turn turn in the first conductor layer 61, a coil conductor 62a that makes a three-turn turn in the second conductor layer 62, and a three-turn turn in the third conductor layer 63. A coil conductor 63a;
The coil conductor 64a, which rotates around three turns in the fourth conductor layer 64, is connected to each other through via holes in the organic insulating layer between the respective layers, and as a whole, a series coil conductor 60 connecting the terminal electrodes 5 on both side edges of the substrate is formed. Make up.

Also in this case, each of the coil conductors 61a to 64a
The area of the central portion where the conductor inside the innermost peripheral portion of the coil conductor is not disposed is 20% of the total area including the outermost peripheral portion of the coil conductor and surrounded by the outermost peripheral portion.
To 90% (more preferably 50% to 90%) to form a triple helical pattern.

The coil conductors of each layer are connected in series so as to rotate in the same direction, that is, so that the winding directions of the coil conductors are the same.

The production of the first to fourth conductor layers 61 to 64 is as follows.
For example, it can be performed by a method using panel plating and etching, or a pattern plating method.

According to the fourth embodiment, by increasing the number of turns of the coil conductor of each conductor layer, it is possible to increase the inductance value as compared with the third embodiment. The other configuration, operation, and effect are the same as those of the third embodiment.

FIG. 6 shows a fifth embodiment of the high-frequency coil according to the present invention, which shows an eight-layer product having eight conductor layers. 6A shows the lowermost first conductive layer 71 formed on the organic or inorganic insulating substrate 1, and FIG. 6B shows the second, fourth, and fourth even-numbered layers counted from the lowermost layer. 6 conductor layer 7
2 (C) shows the third, fifth, and seventh conductor layers 73 which are odd-numbered from the bottom layer, and FIG. 4 (D) shows the eighth conductor layer 74 of the top layer. An organic insulating layer is interposed between the conductor layers.

The first conductor layer 71 includes a coil conductor 71a that makes a substantially three turns, and the second, fourth, and sixth conductor layers 72 include a coil conductor 71a.
The third, fifth and seventh conductor layers 73 form a coil conductor 73a that makes approximately three turns.
And the eighth conductor layer 74 is formed of the coil conductor 7 that makes approximately three turns.
4a, the coil conductors 71a to 74a of the respective conductor layers from the first conductor layer 71 to the eighth conductor layer 74 are connected to each other via via holes of the organic insulating layer between the respective layers, and as a whole, both side edges of the substrate are provided. A series coil conductor 70 for connecting the terminal electrodes 5 is formed.

Also in this case, each of the coil conductors 71a to 74a
The area of the central portion where the conductor inside the innermost peripheral portion of the coil conductor is not disposed is 20% of the total area including the outermost peripheral portion of the coil conductor and surrounded by the outermost peripheral portion.
To 90%, more preferably (50% to 90%
), Respectively, as a triple helical pattern.

The coil conductors of each layer are connected in series so as to rotate in the same direction, that is, so that the winding directions of the coil conductors are the same.

The production of the first to eighth conductor layers 71 to 74 is as follows.
For example, it can be performed by a method using panel plating and etching, or a pattern plating method.

According to the fifth embodiment, by increasing the number of conductor layers, it is possible to increase the inductance value as compared with the fourth embodiment. For example, 16
08 size (vertical and horizontal dimensions: 1.6 × 0.8 mm), coil conductor line width 30 μm, line height 50 μm, pitch 3
0 μm, aspect ratio 1.7, area ratio 37% ｛(area of the central part where the conductor inside the innermost circumference of each coil conductor is not arranged) / (the outermost circumference of the coil conductor In the case where a high-frequency coil is configured so as to include (and the entire area surrounded by the outermost circumferential portion)}, an inductance value of about 220 nH can be obtained at a measurement frequency of 1 GHz. In addition, the even-numbered coil conductor patterns in the lowermost layer and the intermediate layer other than the uppermost layer can have the same pattern, and the odd-numbered coil conductor patterns can also have the same pattern. The number of types of photomasks when exposing the conductor pattern can be reduced, and the manufacturing cost can be reduced. The other configuration, operation and effect are the same as those of the fourth embodiment.

In each of the above embodiments, the example in which the coil conductors of all the conductor layers have approximately two or more turns has been described. However, the coil conductors of some conductor layers have a single helical pattern of approximately one turn or less. You may.

Although a plurality of conductor layers are formed on one side of the insulating substrate, a plurality of conductor layers may be formed on both sides of the insulating substrate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a high-frequency coil according to the present invention will be described in detail with reference to embodiments.

Example 1 E glass cloth having a relative dielectric constant of 7.2 was used as a core material (reinforcing material) and impregnated with vinylbenzyl having a relative dielectric constant of 2.5 at 1 GHz and Q = 260 to a thickness of 0.5. A 3 mm organic insulating substrate was produced. At this time, the relative permittivity of the entire substrate is 3.2 and Q
= 250.

After the surface of the substrate was roughened, an electroless copper plating layer having a thickness of 0.3 μm was formed by electroless copper plating. A dry film having a thickness of 80 μm was stuck thereon, and a double helical pattern of the first conductor layer 11 of FIG. 1A was formed by a parallel exposure machine. Here, the high-frequency coil is 1608 size, and the overall length and width are 1.6 × 0.8.
mm. The line width of the coil conductor forming the double helical pattern is 85 μm, the line height is 70 μm, and the pitch is 85
μm, aspect ratio 0.82, area ratio 42% ｛(area of the central part where the conductor inside the innermost circumference of each coil conductor is not arranged) / (outer circumference of the coil conductor (The entire area enclosed by the outermost circumference)). After that, the grooves (grooves formed in the dry film) of the resist were plated with bright copper sulfate to a thickness of 70 μm.
Was prepared. After peeling off the dry film,
The entire substrate was wet-etched to remove unnecessary base conductor film (electroless copper plating layer between lines) by etching.

Thereafter, a photosensitive insulating resin (for example, a modified epoxy resin or the like) to be an interlayer insulating layer is applied to a thickness of 25 μm on the first conductor layer, and the first organic insulating layer shown in FIG. 12, and a via hole 14 was formed. The formation of the via hole 14 is performed by a photolithography method. The diameter of the via hole is 100 μm. The curing temperature of the resin of the organic insulating layer 12 is 160 ° C. The relative dielectric constant of the resin at 1 GHz is 3.5.

Then, after the surface of the insulating layer is roughened,
A μm electroless copper plating layer was formed. On top of this, a thickness of 10
A dry film of 0 μm was applied, and a parallel exposure machine
A double helical pattern of the second conductor layer 13 of (C) was formed. Here, the line width of the coil conductor forming the double helical pattern is 85 μm. Thereafter, a conductive pattern having a thickness of 100 μm was formed in the groove of the resist (the groove formed in the dry film) by bright copper sulfate plating. After peeling off the dry film, the unnecessary underlying conductor film was removed by wet etching. The high-frequency coil of Example 1 manufactured in this manner has a measurement frequency of 10 nH at a frequency of 100 MHz, and the frequency characteristics of the Q value are shown in FIG.

Embodiment 2 Under the same conditions as in Embodiment 1, the coil conductors of the conductor layers 41 and 43 were formed in a triple helical pattern as shown in FIGS. 3 (A) and 3 (B). However, the line width of the coil conductor is 30 μm, the line height is 50 μm, the pitch is 30 μm, and the aspect ratio is 1.
7, the area ratio 37% ｛(the area of the central part where the conductor inside the innermost circumference of each coil conductor is not arranged) / (including the outermost circumference of the coil conductor and including the outermost circumference) The total area surrounded by the orbital portion) is｝. FIG. 7 shows the frequency characteristic of the Q value of the high-frequency coil of Example 2 manufactured in this manner.

Comparative Example 1 Under the same conditions as in Example 1, the coil conductors of the conductor layers 81 and 82 were formed into a single helical pattern as shown in FIGS. 8A and 8B. However, the coil conductor has a line width of 100 μm, a line height of 100 μm, a pitch of 100 μm, an aspect ratio of 1, and an area ratio of 58% (the area of the central portion where the conductor inside the innermost circumference of each coil conductor is not disposed). ) / (Whole area including the outermost circumference of the coil conductor and surrounded by the outermost circumference). FIG. 7 shows the frequency characteristic of the Q value of the high-frequency coil of Comparative Example 1 thus manufactured.

Comparative Example 2 Under the same conditions as in Example 1, a high-frequency coil having a coil conductor 90 having a single-layer spiral pattern as shown in FIGS. 9A and 9B was used. However, the line width of the coil conductor is 30 μm,
Line height 50 μm, pitch 30 μm, aspect ratio 1.7, area ratio 40% {(area of central part where conductors inside innermost circumference of each coil conductor are not arranged) /
(The total area including the outermost circumference of the coil conductor and surrounded by the outermost circumference). FIG. 7 shows the frequency characteristics of the Q value of the high-frequency coil of Comparative Example 2 thus manufactured.

From FIG. 7, it can be seen that the high frequency coils of the double helical or triple helical patterns of Examples 1 and 2 have a lower Q value than the single helical pattern, but have a considerably higher Q value than the spiral pattern. As can be seen, the number of layers can be reduced as compared with the single helical pattern.

The high-frequency coil according to the present invention is applicable to electronic component modules such as common mode choke coils, transformers, filters, power amplifiers, VCOs, and the like.
That is, by replacing the coil component in the module with that of the present invention, a high-performance and small-sized module can be configured. For example, in the case of a filter, high-performance contents can have sharp attenuation characteristics. The reason for this is that the filter is L,
This is because although C is composed of C, the Q of C is generally large enough and the overall performance is mainly controlled by the Q characteristic of L.

Although the embodiments of the present invention have been described above, it is obvious to those skilled in the art that the present invention is not limited to the embodiments and various modifications and changes can be made within the scope of the claims. There will be.

[0090]

As described above, according to the present invention,
It is possible to realize a high-frequency coil having a relatively high Q and SRF as compared with a spiral pattern, a high inductance, a thin (reduced number of layers) and a low cost as compared with a single helical pattern. For example, length 1.6mm, width 0.8m
Even with a size of 0.8 mm and a thickness of 0.8 mm, a larger inductance value than conventional products can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view showing a conductor layer and an interlayer organic insulating layer according to a first embodiment of the high-frequency coil according to the present invention.

FIG. 2 is an explanatory diagram illustrating an example of a manufacturing method according to the first embodiment.

FIG. 3 is a plan view showing a conductor layer and an interlayer organic insulating layer according to a second embodiment of the present invention.

FIG. 4 is a plan view showing a third embodiment of the present invention and showing a plurality of conductor layers.

FIG. 5 is a plan view showing a plurality of conductor layers according to a fourth embodiment of the present invention.

FIG. 6 is a plan view showing a fifth embodiment of the present invention and showing a plurality of conductor layers.

FIG. 7 is a graph showing frequency characteristics of Q values of Examples 1 and 2 and Comparative Examples 1 and 2.

FIG. 8 is a plan view showing a plurality of conductor layers in Comparative Example 1.

FIG. 9 is a plan view showing a plurality of conductor layers in Comparative Example 2.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Insulating substrate 5 Terminal electrode 10, 40, 50, 60, 70 Series coil conductor 11, 13, 41, 43, 51, 52, 53, 54, 6
1, 62, 63, 64, 71, 72, 73, 74 Conductive layers 11a, 13a, 41a, 43a, 51a, 52a, 52a, 5
3a, 54a, 61a, 62a, 63a, 64a, 71
a, 72a, 73a, 74a Coil conductor 12, 42 Organic insulating layer 14, 44 Via hole 30 Plating base layer 31 Dry film 32 Plating layer

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yumiko Ozaki 1-13-1 Nihonbashi, Chuo-ku, Tokyo T-DC F-term (reference) 5E070 AA01 AB04 AB06 BA01 CB04 CB12

Claims (11)

[Claims] 1. A high-frequency coil having two or more coil conductors formed on at least one surface of an insulating substrate via an organic insulating layer, wherein the coil conductors in all or some of the two or more layers are substantially two turns. The coil conductor has a portion that circulates, and the area of the central portion where the conductor inside the innermost peripheral portion of the coil conductor is not disposed includes the outermost peripheral portion of the coil conductor and the outermost peripheral portion. 20% of the total area enclosed by the parts
A high-frequency coil, wherein each coil conductor is connected in series so as to go around in the same direction. 2. The high-frequency coil according to claim 1, wherein said coil conductor is formed of copper. 3. An aspect ratio of said coil conductor is 0.3.
The high-frequency coil according to claim 1 or 2, which is as described above. 4. The high-frequency coil according to claim 1, wherein the relative dielectric constant of the organic insulating layer is 1 or less at a frequency of 1 GHz. 5. The high-frequency coil according to claim 1, wherein the organic insulating layer has a Q of 200 or more at a frequency of 1 GHz. 6. The high frequency coil according to claim 1, wherein said organic insulating layer is vinylbenzyl. 7. The high-frequency coil according to claim 1, wherein said insulating substrate is an organic substrate. 8. The high-frequency coil according to claim 1, wherein said insulating substrate is vinylbenzyl. 9. The high-frequency coil according to claim 1, wherein the odd-numbered coil conductors counted from the lowest layer of the coil conductor have the same pattern. . 10. The coil conductor according to claim 1, wherein the even-numbered coil conductors counted from the lowest layer of the coil conductor have the same pattern. High frequency coil. 11. A coil conductor in a part of the two or more layers of coil conductors has a portion that circulates for approximately two or more turns, and a conductor inside the innermost peripheral portion of the coil conductor is arranged. The area of the central portion that is not included is 20% to 90% of the entire area including the outermost peripheral portion of the coil conductor and surrounded by the outermost peripheral portion, and the remaining portion of the two or more layers of the coil conductor The high-frequency coil according to any one of claims 1 to 10, wherein the number of turns of the coil conductor in the layer is approximately one turn or less.