JP2002203720A - Composite electronic part containing inductor and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite electronic part which contains an inductor and is small in size, high in characteristics, and excellent in mass productivity. SOLUTION: A composite electronic part is composed of an insulating board formed of composite material of resin and ceramic or resin and capacitor conductors laminated inside the insulating board and contains an inductor equipped with inductor conductors whose aspect ratio is 0.3 to 1.5 in cross section and organic insulating layers of composite material of resin and ceramic or rein which are alternately laminated inside the insulating board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a composite electronic component including an inductor conductor and a method of manufacturing the same.

[0002]

2. Description of the Related Art When a conventional electronic component is manufactured, a pattern forming method using a thin film method or a printing method is used when forming an inductor portion. These prior arts are disclosed in Japanese Patent Publication No. Hei 7-101652, Japanese Patent Publication No.
39521 discloses this.

[0003] The above-mentioned conventional manufacturing method is currently widely used in composite electronic components including inductors.

Japanese Patent Application Laid-Open No. 2000-223818 discloses an example of pattern formation of electroless plating + electrolytic plating.

[0005]

In the above conventional example,
The pattern configuration using a thin film has a problem that mass productivity is poor. In the above conventional example, a dry etching method is used as the etching. This method has a high patterning accuracy, but has a low etching rate and a thick conductor. The maximum thickness of the obtained film is 10 μm.

On the other hand, considering the improvement of the Q value of the coil,
The lower limit of the coil conductor thickness is 10 μm.
Designing with a conductor thickness of 0 μm or 100 μm is effective for improving the Q value of the coil.

When the inductor is formed by the printing method, the value of Q is smaller than that of the etching by the dry etching method. This is because firing is performed at a high temperature, and a large number of voids, which are considered to be caused by outgassing of the solvent during firing, are present in the coil conductor, and large irregularities are generated on the conductor surface. There is a problem that the length increases, the resistance increases, and therefore the value of Q decreases.

In order to increase the value of Q, it is necessary to increase the thickness of the conductor layer. However, when forming the conductor layer, screen printing is usually performed, and the maximum thickness is 20 μm.

In the screen printing used for forming the conductor layer, the dimensional accuracy of the pattern before firing is poor, and the entire pattern shrinks by 10 to 20% during firing. There is a problem that variation in inductance is large.

Furthermore, Japanese Patent Application Laid-Open No. 2000-223818 discloses that an electrode is formed by combining electroless plating and electrolytic plating, and describes a technique for improving the adhesion between a plated conductor and a substrate. However, there is no description of a method for reducing internal resistance or improving high-frequency characteristics. In addition, it is described that the surface is roughened in order to increase the adhesion strength. However, when the surface is roughened in this way, when the skin effect at a high frequency is considered, the conductor resistance increases, which causes deterioration of Q. There is a problem.

An object of the present invention is to provide a composite electronic component including an inductor which is small, has high characteristics, and has high mass productivity.

[0012]

SUMMARY OF THE INVENTION The present invention provides a composite material of a resin and a ceramic, or an insulating substrate made of a resin, a capacitor conductor laminated on the insulating substrate, and a resin. An inductor having an inductor conductor laminated alternately with an organic insulating layer or a resin made of a ceramic composite material, formed in the insulating substrate, and having an aspect ratio of a conductor cross section of 0.3 to 1.5. It is a composite electronic component.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view showing an LC filter 100 according to a first embodiment of the present invention, in which the substrate 1 is omitted.

FIG. 2 is a sectional view of the LC filter 100 taken along the line II-II 'in FIG.

The LC filter 100 includes a capacitor layer 2L
And a filter in which an inductor layer 3L is laminated, and has an insulating substrate 1 and terminal electrodes 4.

The insulating substrate 1 is made of a composite material of a resin and a ceramic, or a resin. The capacitor layer 2L is laminated on the insulating substrate 1,
It is constituted by a plurality of capacitor conductors 2.

The inductor layer 3L is alternately laminated with an organic insulating layer or a resin made of a material in which a ceramic is composited with a resin, is formed in the insulating substrate, has an aspect ratio of 0.3 to 1.5, It is constituted by a plurality of inductor conductors 3.

The LC filter 100 is an example of a composite electronic component including an inductor.

Here, a cross section of the inductor layer when the inductor is cut on a plane orthogonal to the direction of the current flowing through the inductor layer 3L is referred to as an orthogonal cross section (a cross section of the inductor conductor 3 shown in FIG. 2).

The “aspect ratio” is the ratio of the vertical length / horizontal length of the inductor conductor 3 in FIG. That is, the aspect ratio is (length of the orthogonal cross section measured in a direction orthogonal to the direction of the current flowing through the inductor conductor and orthogonal to the surface of the capacitor conductor).
/ (Length of the orthogonal cross section measured in a direction orthogonal to the direction of the current flowing through the inductor conductor and parallel to the surface of the capacitor conductor).

When forming the capacitor layer 2L,
The capacitor layer 2L is formed by a general conductive pattern forming method such as printing, etching, plating, vapor deposition, and sputtering.

FIGS. 3 to 7 are explanatory views of the steps of manufacturing the inductor layer 3L in the LC filter 100.

[First Step] After roughening the surface of the insulating substrate 31, an electroless copper plating layer 32 of about 0.3 μm is formed.
(A base for electroplating) is formed.

[Second Step] A dry film 33 having a thickness of about 80 μm is attached on the electroless copper plating layer 32 with a laminator.

[Third Step] Using a photolithography technique, an inductor pattern 34 is formed by a parallel exposure machine.

[Fourth Step] Thereafter, bright copper sulfate plating (inductor conductor) 35 is applied to the resist groove to a thickness of about 80 μm.
The m inductor patterns 35 are formed.

[Fifth Step] The dry film 33 is peeled off, and a resist peeling portion 36 is formed.

[Sixth step] The entire surface is wet-etched, and the line-to-line conductor etched portion (the unnecessary portion of the underlying conductor layer)
37 is removed.

[Seventh Step] The photosensitive insulating resin is
8 to a thickness of about 25 μm to form an interlayer insulating layer 38.

[Eighth Step] Via holes 39 connecting the upper and lower layers of the inductor are formed.

[Ninth Step] After roughening the surface of the insulating layer 38, an electroless copper plating 32 'of about 0.3 μm is formed.

[Tenth Step] On the insulating layer, about 100 μm
A dry film 33 '.

[Eleventh Step] The pattern 34 'of the second layer of the inductor layer is formed by a parallel exposure machine.

[Twelfth Step] Thereafter, an inductor pattern 35 'having a thickness of about 100 μm is formed in the resist groove by bright copper sulfate plating (inductor conductor) 35'.

[Thirteenth step] The dry film 33 'is peeled off.

[14th step] The whole is etched by wet etching, and the line conductor etching portion 37 'is etched. Thus, the inductor layer 3L is completed.

As the material of the organic insulating layer and the material of the organic insulating plate, those having a small ε are desirable for the purpose of reducing the stray capacitance. For example, fluorine resin, polyethylene, PPO, vinylbenzyl, cyanate ester, Preferred are polyetherimide, polyimide, epoxy, BT resin, polyolefin, polyfumarate, polyarylate and the like.

FIG. 8 is a diagram showing a comparison between a cross section of the inductor conductor 3 in the above embodiment and a cross section of a conventional inductor conductor 3p formed by a printing method.

In the embodiment shown in FIG. 8, the aspect ratio of the inductor conductor 3 is 0.8, and the aspect ratio in the conventional example is 0.1.

In the above embodiment, it is desirable that the aspect ratio of the inductor conductor 3 is 0.3 to 1.5. Further, it is desirable that the unevenness of the surface is 5 μm or less.

As described above, the “aspect ratio” in the LC filter 100 is the aspect ratio in the cross section of the inductor conductor 3, and the cross section of the inductor conductor 3 forming the coil constituting the inductor is shown in FIG. When viewed (when viewed as shown in FIG. 2), the ratio is the vertical length / horizontal length. The horizontal direction in this case is a plane parallel to the plane of the capacitor conductor 2.

The aspect ratio in the LC filter 100 is the aspect ratio in the cross section of the inductor conductor, which is (the direction perpendicular to the direction of the current flowing through the coil constituting the inductor and the length in the direction of the core of the coil) / (Length in the direction perpendicular to the direction of the current flowing through the coil forming the inductor and perpendicular to the direction of the core of the coil)
Can also be expressed as

As shown in FIG. 8, the inductor layer of the electronic component in the above embodiment has a larger conductor surface area and a smoother surface than the conventional inductor layer. Obtainable. Therefore, in the above embodiment, an LC filter with high characteristics can be obtained.

That is, in order to obtain the same DC resistance R _DC in the inductor conductor 3, generally, the electrode width is increased. However, in this case, the area facing the capacitor layer 2 L increases, and The stray capacitance C _S increases, and the value of Q decreases. However, according to the above embodiment,
Since the vertical direction shown in FIG. 2 and FIG. 8 (the thickness direction, the vertical direction shown in FIG. 2 and FIG. 8) is long, the cross-sectional area of the inductor conductor 3 can be made large, so that the DC resistance R _DC can be reduced. Further, since it is not necessary to lengthen the horizontal direction (width direction, the horizontal direction shown in FIGS. 2 and 8) shown in FIGS. 2 and 8, the area facing the capacitor conductor 2 can be reduced. The stray capacitance C _S can be reduced. This is very important in a high-frequency circuit and greatly affects characteristics.

In order to obtain the above effects, the aspect ratio is 0.3 to 1.5. The aspect ratio in the conventional example is 0.1.

FIG. 9 is a diagram showing an equivalent circuit of the LC filter 100.

The inductor layer 3L and the capacitor layer 2L configured as described above are vertically arranged in a laminated shape by hot pressing or the like, and the respective lead electrodes are formed by the through-through holes 4 for terminals and the like. 9 to form a low-pass filter as a whole.

FIG. 10 is a diagram showing a comparison between the frequency characteristics of a low-pass filter produced by the LC filter 100 of the above embodiment and the frequency characteristics of a low-pass filter produced by a conventional printing method.

In FIG. 10, the aspect ratio in the conventional example is 0.1, and the aspect ratio in the embodiment is 0.3, 0.8, and 1.5.

As shown in FIG. 10, the L in the above embodiment is
Since the value of Q of the inductor in the low-pass filter made by the C filter 100 is higher than the value of Q in the conventional example, the roundness of the shoulder of the cutoff portion is improved,
Also, the drop of the pole at the resonance point is very large.

In the LC composite component, generally, it is relatively easy to increase the Q of the capacitor, so that the characteristics are not greatly affected. However, it is difficult to increase the Q of the inductor, and the characteristics are directly affected. Often affects the characteristics of components.

In the above embodiment, the surface irregularities of the inductor layer 3L are preferably 0.1 to 5 μm, and a plastic resin is preferably used for the interlayer insulating layer. The material of the plastic resin is
It is preferable that the material is the same as that of the insulating substrate.

The inductor layer 3L may be any one of spiral, meander, and helical inductor conductors.

The LC filter 100 of the above embodiment is
Although it is a low-pass filter, the above embodiment may be applied to a composite electronic component including an inductor such as a band-pass filter, a high-pass filter, an LC trap, a balun, and a coupler. Also in such an application example, the value of Q of the inductor layer is increased, and thus the characteristics are greatly improved.

A via hole for connecting inductor conductors 3 or inductor conductor 3 and capacitor conductor 2
The via hole connecting to is formed by laser. In this case, the via hole is formed by a photolithography method using a photosensitive interlayer insulating resin.

FIG. 11 is a transparent perspective view of an antenna 200 according to a second embodiment of the present invention.

FIG. 12 is a cross-sectional view of the antenna 200 taken along the line XII-XII ′ in FIG.

The antenna 200 is a multilayer chip antenna, which is an example of a composite electronic component including an inductor.
This is the same as the configuration method of the C filter 100.

The radiation conductors 13a, 1
Reference numeral 3b denotes a meander-shaped inductance element, in which a radiation conductor 13a is provided on the uppermost layer of the substrate 11;
The radiation conductor 13b is provided in the lowermost layer of the radiation conductor 13b.
a and 13b are configured in parallel with each other.

In this case, the radiation conductors 13a and 13b
It is formed by the conductor forming method shown in FIGS.

That is, in the antenna 200, the radiation conductors 13a and 13b have an aspect ratio of 0.3 to 1.5.
It is preferable that the surface roughness is 5 μm or less.

Here, the radiating conductors 13a and 13b are also a kind of inductor conductor. When the cross section obtained by cutting the inductor conductor on a plane perpendicular to the direction of current flowing through the inductor conductor is an orthogonal cross section, The aspect ratio is (length of the orthogonal cross section measured in a direction perpendicular to the direction of the current flowing through one inductor conductor and perpendicular to the surface of the other inductor conductor) / (flowing through one inductor conductor). (Length of the orthogonal cross section measured in a direction perpendicular to the direction of the current and parallel to the surface of the other inductor conductor).

When one of the radiation conductors 13a and 13b is regarded as a capacitor electrode, a stray capacitance is generated between the radiation conductor and the other radiation conductor.

The aspect ratio of the antenna 200 is the aspect ratio in the cross section of the radiating conductor (the direction perpendicular to the direction of the current flowing through the radiating conductor and the length of the current direction of the entire antenna). / (The direction orthogonal to the direction of the current flowing through the radiation conductor and the length in the direction orthogonal to the direction of the current of the entire antenna).

Both ends of the radiating conductors 13a and 13b are connected by penetrating half through holes TH1 and TH2 for terminals, etc., and constitute an antenna element as a whole.

With the above configuration, the internal resistance of the antenna 200 can be reduced, and the radiation efficiency can be further increased. Further, since the surface is smooth, good characteristics can be obtained at high frequencies.

The material to be used is the LC filter 10
As in the case of 0, a material having a low dielectric constant is preferable in order to minimize the stray capacitance.

The radiation conductor may be in a meander shape or a helical shape in addition to the meander shape.

FIG. 13 shows a third embodiment of the present invention.
It is sectional drawing which shows CO300.

FIG. 14 is a diagram showing an equivalent circuit of the VCO 300.

The VCO 300 is an example of a composite electronic component including an inductor. The VCO 300 constitutes the LC composite network base 41 by the above-described method, and the semiconductor 4
4 and a chip component 47 are mounted, and a circuit shown in FIG. 14 is configured as a whole.

The LC composite network base 41 includes a resonator constituted by a strip line 45 and a GND conductor 46, a capacitor layer 42, and an inductor layer 4.
3 are laminated, and the respective configuration methods are as described above.

The aspect ratio of the inductor conductor of the inductor layer 43 is preferably 0.3 to 1.5, and the surface irregularities are preferably 5 μm or less.

The “aspect ratio” of the VCO 300 is the aspect ratio of the cross section of the inductor layer 43. When the cross section of the inductor layer 43 is viewed as shown in FIG. That's it.

In other words, when the cross section of the inductor conductor when the inductor layer 43 is cut along a plane orthogonal to the direction of the current flowing through the inductor layer 43 is an orthogonal cross section, VC
The aspect ratio in O300 is (length of the orthogonal cross section measured in a direction orthogonal to the direction of the current flowing through the inductor conductor and orthogonal to the surface of the capacitor conductor) / (direction of the current flowing through the inductor conductor). (The length of the orthogonal cross section measured in a direction perpendicular to the surface of the capacitor conductor).

Here, the strip line 45 constituting the resonator is formed by using the same configuration method as that of the inductor layer 43, whereby the same effect as that of the inductor layer 43 can be obtained.

Also, due to mounting problems and immunity problems, the shield case 49 is configured so as to cover the mounted components to form a module.

In the VCO 300, the inductor layer 4
3 (including the resonator) greatly affects the VCO characteristics. By increasing the Q of the inductor layer 43, high characteristics can be obtained.

The conductor shape of the inductor layer 43 is helical, meander, spiral, or the like.
By using the construction method shown in FIGS. 3 to 7, a high Q can be achieved.

Other module products include a power amplifier, a front-end module, a superposition module,
The same configuration as that of the VCO 300 may be applied to an LL module, an RF unit, and the like. An inductor or a strip line can be formed in a base substrate, and the Q characteristic thereof can be improved. The properties of the product itself can be improved.

Also, a common mode filter, an EMC filter, a power supply filter, a pulse transformer, a rotary transformer, a deflection coil, a choke coil, a DC-DC converter, a delay line, a diplexer, a duplexer, an antenna switch module, an antenna front end module, and an isolator The above embodiment can be applied to a composite electronic component including an inductor such as a power amplifier module, a tuner unit, a directional coupler, a double balanced mixer, a power combiner, a power distributor, and a motor.

According to the above embodiment, the composite electronic component including the inductor is small, has high characteristics, and has high mass productivity. In particular, since the Q value of the inductor section can be increased, a filter can provide steep characteristics, and an antenna can provide high radiation efficiency. Such an oscillation system circuit can improve characteristics such as C / N and S / N, and an amplifier circuit such as a power amplifier can improve characteristics such as efficiency.

When used as a high-frequency coil, if the inductance is 3.3 nH, 1 GHz
It is desirable that the value of Q is 40 or more when used in. In the current ceramic laminated high-frequency coil, the conductor width is 50 to 100 μm, and the conductor thickness is 10 to 20 μm.
If so, Q = about 50 (1 GHz, 3.3 nH, skin thickness 2 μm).

However, conventionally, when a thick film conductor is produced, screen printing is performed, so that the aspect ratio has an upper limit, and about 0.2 is the upper limit. That is, when the conductor width is set to 100 μm, the conductor thickness becomes about 20 μm, the aspect ratio in this case is 0.2, and when the conductor width is set to 50 μm, the conductor thickness becomes about 10 μm. In this case, the aspect ratio is also 0.2.

The above-mentioned target value takes into account LC complex,
LC filter, antenna, VCO in the above embodiment
Since each of them includes an LC resonance circuit (including a distributed constant), it is necessary to have a coil Q or more generally used at a high frequency. Power amplifier, front-end module, superposition module, PLL module, RF
The same applies to the unit.

For applications other than high frequency applications, the use of a composite material of a magnetic material allows the use of a common mode filter, an EMC filter, a power supply filter, a pulse transformer, a rotary transformer, a deflection coil, a choke coil, a DC-DC converter, and the like. The material and the composite DC may be determined so as to obtain a desired Q value at the frequency to be used. For strip lines, high Q is required, including the effect of material properties.
50 or more is required.

When the capacitor layer is manufactured, the capacitor layer is formed by using a conventional method of forming a printed circuit board or a thick film printing method, and is subjected to pressure bonding or continuous thick film printing by a hot press.

[0088]

According to the present invention, the composite electronic component including the inductor has the effects of being small, having high characteristics, and having high productivity.

[Brief description of the drawings]

FIG. 1 is an LC filter 10 according to a first embodiment of the present invention.
FIG. 2 is a perspective view showing the substrate 1 and omitting a substrate 1.

FIG. 2 is a cross-sectional view of the LC filter 100 taken along line II-II ′ in FIG.

FIG. 3 shows an inductor layer 3L in the LC filter 100;
It is process explanatory drawing which manufactures.

FIG. 4 shows an inductor layer 3L in the LC filter 100.
It is process explanatory drawing which manufactures.

FIG. 5 shows an inductor layer 3L in the LC filter 100.
It is process explanatory drawing which manufactures.

FIG. 6 shows an inductor layer 3L in the LC filter 100.
It is process explanatory drawing which manufactures.

FIG. 7 shows an inductor layer 3L in the LC filter 100.
It is process explanatory drawing which manufactures.

FIG. 8 is a diagram showing a comparison between a cross section of the inductor conductor 3 in the above embodiment and a cross section of a conventional inductor conductor 3p formed by a printing method.

FIG. 9 is a diagram showing an equivalent circuit of the LC filter 100.

FIG. 10 is a diagram showing a comparison between the frequency characteristics of a low-pass filter made by the LC filter 100 of the above embodiment and the frequency characteristics of a low-pass filter made by a conventional printing method.

FIG. 11 shows an antenna 200 according to a second embodiment of the present invention.
FIG.

12 is a cross-sectional view of the antenna 200, taken along the line X in FIG.
It is sectional drawing seen from the II-XII 'line.

FIG. 13 is a sectional view showing a VCO 300 according to a third embodiment of the present invention.

FIG. 14 is a diagram showing an equivalent circuit of the VCO 300.

[Explanation of symbols]

 100: LC filter, 1: substrate, 2: capacitor conductor, 2L: capacitor layer, 3: inductor conductor, 3L: inductor layer, 31: insulating layer substrate, 32: electroless plating layer, 33: dry film, 34: inductor Pattern, 35: electrolytic plating, 36: resist stripping part, 37: inter-line conductor etching part, 38: interlayer insulating layer, 39: via hole, 200: antenna, 11: substrate, 13a, 13b: radiation conductor, 300: VCO 42, a capacitor layer; 43, an inductor layer.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5E062 DD04 DD10 5E070 AA05 AB10 CB13 CB17 5E082 AB03 BC39 DD08 FF14 FG26 FG34 PP09

Claims (15)

[Claims] 1. An insulating substrate made of a composite material of a resin and a ceramic, or a resin;
A capacitor conductor laminated in the insulating substrate;
An organic insulating layer or a resin made of a composite material of a ceramic and a resin is alternately laminated with the resin, formed in the insulating substrate, and has an aspect ratio of a conductor cross section of 0.3 to 1.5.
And a composite electronic component including an inductor. 2. The method according to claim 1, wherein a cross section of the inductor conductor when the inductor conductor is cut along a plane orthogonal to a direction of a current flowing through the inductor conductor is an orthogonal cross section. A direction orthogonal to the direction of the current flowing through the conductor, the length of the orthogonal cross section measured in a direction orthogonal to the plane of the capacitor conductor) / (a direction orthogonal to the direction of the current flowing through the inductor conductor, (The length of the orthogonal cross section measured in a direction parallel to the surface of the capacitor conductor). 3. The composite electronic component according to claim 1, wherein the unevenness on the surface of the inductor conductor is 0.1 to 5 μm. 4. The composite electronic component according to claim 1, wherein a plastic resin is used for the interlayer insulating layer. 5. The composite electronic component according to claim 4, wherein the plastic resin is made of the same material as the insulating substrate. 6. The composite electronic component according to claim 1, wherein the inductor conductor is at least one of a spiral shape, a meander shape, and a helical shape. 7. The electronic component according to claim 1, wherein the inductor conductor is a radiation conductor, and the composite electronic component including the inductor is a multilayer chip antenna having the radiation conductor. A composite electronic component including an inductor, characterized in that: 8. The composite electronic component according to claim 7, wherein the radiation conductor has at least one of a spiral shape, a meander shape, and a helical shape. 9. An insulating substrate forming step of forming an insulating substrate with a composite material of a resin and a ceramic or a resin; a capacitor layer stacking step of stacking a capacitor conductor in the insulating substrate; Forming an inductor conductor by alternately laminating an organic insulating layer or a resin made of a composite material and the inductor conductor on the insulating substrate to form an inductor conductor; on top of,
The inductor conductor is formed by patterning the inductor conductor with a photosensitive resist by using a photolithography method, and the inductor conductor is formed by electrolytic plating on the patterning portion, and has an aspect ratio of 0.3 to 1 5. A composite electronic component including an inductor, the composite electronic component comprising: 10. The method for manufacturing a composite electronic component including an inductor according to claim 9, wherein the first layer of the base conductor layer for plating is formed by electroless plating. 11. The method according to claim 10, wherein the electroless plating is copper plating. 12. The method according to claim 10, wherein the electrolytic plating is a bright plating. 13. The method for manufacturing a composite electronic component including an inductor according to claim 9, wherein the plating is copper. 14. The via hole according to claim 9, wherein the via hole connecting the inductor conductors or the via hole connecting the inductor conductor and the capacitor conductor is formed by a laser. A method of manufacturing a composite electronic component including an inductor, the method comprising: 15. The composite electronic component according to claim 14, wherein the via hole is formed by a photolithography method using a photosensitive interlayer insulating resin. Method.