JP2004031601A - Multilayer circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer circuit board having a functional circuit built of internal wiring, suffering less from property variations due to unevenness in lamination during the manufacturing process. <P>SOLUTION: The multilayer circuit board is a dielectric board comprising a plurality of dielectric layers 11, 12, 13, and has one or more sets of internal wiring circuits comprising inductor electrodes 21, 22, and capacitor electrodes 31, 32 positioned facing ground conductors with the dielectric layer 11 in-between. The inductor electrodes 21, 22 and capacitor electrodes 31, 32 of each set of internal wiring circuits are arranged in between different dielectric layers 11, 12, 13, and connected by through-conductors 41, 42 running through the dielectric layer 12. Circuit property variations are suppressed because the internal wiring circuits continue to function as a lump constant circuit even in case irregular displacement occurs between the dielectric layers 11, 12, 13 during the manufacturing process. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a multilayer circuit board used in a high-frequency band such as a UHF band to a microwave band, has a built-in functional circuit, and is used as a wiring board of a wireless module contributing to downsizing of a wireless communication device. The present invention relates to a multilayer circuit board with reduced variation in frequency characteristics of a functional circuit.
[0002]
[Prior art]
Conventionally, a functional circuit such as a band-pass filter used in a wireless circuit unit of a wireless communication device used in a high-frequency band such as a UHF band to a microwave band has a high dielectric constant and low loss, and silver or copper is used for internal wiring. Using chip components made of a low-temperature fired multilayer material that can simultaneously fire low-resistance conductors at the same time, surface mounting is performed by soldering to mounting electrodes formed on the surface of the printed wiring board. This has been realized by configuring a circuit externally. With the demand for miniaturization of communication devices, the demand for miniaturization of the wireless circuit section is also increasing. By using a material having a relative dielectric constant of several tens, the size of chip components is reduced. Have been.
[0003]
However, in recent years, there has been an increasing demand for miniaturization, and in the method of externally attaching components, it is inevitable that external components occupy a considerable area on the surface of the wiring board and a space above the wiring board. It is becoming difficult to meet the demand for miniaturization.
[0004]
As a response to the demand for miniaturization, it has been proposed to realize a part or the whole of a functional circuit by wiring formed on a circuit board. In the high-frequency region from the UHF band to the microwave band, since the wavelength is short, a realistic design can be realized in the realization of a circuit element using conductor wiring, so that not only the volume of externally attached components, but also The surface of the wiring board, which has been used as a mounting area for external components, can be effectively utilized.
[0005]
[Problems to be solved by the invention]
However, when a functional circuit operating in a high-frequency band is configured by wiring formed on a circuit board, the length of the wiring, the width of the wiring, the distance between the wirings, the thickness and the dielectric constant of the dielectric layer forming the substrate, etc. There is a problem that the frequency characteristics of the functional circuit may deviate from the desired characteristics due to the variation of the physical parameters. In particular, when a functional circuit such as a band-pass filter utilizing electromagnetic coupling between wirings is to be constructed, the mutual positional relationship of the wirings due to the lamination displacement of the multilayer substrate structure generated in the circuit board manufacturing process is considered. Fluctuations in characteristics due to variations are a major problem.
[0006]
As a countermeasure for suppressing such a variation in characteristics, a configuration has been proposed in which only a part of the functional circuit is configured by wiring of a circuit board, and the other part uses external components. With this configuration, the external components are surface-mounted after the circuit board is manufactured. Therefore, the circuit characteristics can be post-adjusted by appropriately adjusting the element values of the external components to be mounted.
[0007]
However, the surface mounting of the external component on the circuit board means that the space corresponding to the volume of the external component and the area of the mounting area are occupied in the upper space and the surface of the wiring board as described above. However, there is a problem that the size reduction is disadvantageous.
[0008]
On the other hand, when the entire functional circuit is configured by the wiring of the circuit board, a structure in which a part of the wiring is exposed on the surface of the circuit board is also possible. By trimming the exposed wiring, the characteristics of the functional circuit can be adjusted after the circuit board is manufactured.
[0009]
However, exposing the wiring on the surface of the circuit board has a problem that the portion on the surface of the board cannot be used for other functions, which may also be a factor that hinders miniaturization.
[0010]
Under such a background, as a circuit board capable of achieving both miniaturization and improvement of the characteristic yield of the built-in functional circuit, a functional circuit having stable circuit characteristics by wiring completely built in the board without being exposed on the board surface. It is desired to realize the configuration.
[0011]
The present invention has been made in view of the above-described problems in the conventional technology, and has as its object the purpose of the present invention, in which the variation in circuit characteristics due to lamination variations in the manufacturing process is small, and all of the wiring is completely inside the circuit board. It is an object of the present invention to provide a multi-layer circuit board including a built-in functional circuit.
[0012]
[Means for Solving the Problems]
The multi-layer circuit board of the present invention has at least one capacitor electrode comprising an inductor electrode and a capacitor electrode opposed to a ground conductor layer via the dielectric layer between the dielectric layers of the dielectric substrate formed by laminating a plurality of dielectric layers. A set of internal wiring circuits, wherein the inductor electrode and the capacitor electrode in each set of the internal wiring circuits are arranged between different dielectric layers and connected by through conductors penetrating the dielectric layers. It is characterized by having been done.
[0013]
Further, in the multilayer circuit board of the present invention, in the above configuration, the internal wiring circuit constitutes a high-frequency circuit for handling a high-frequency signal, and the length of the inductor electrode is shorter than ８ of the guide wavelength of the high-frequency signal. It is a feature.
[0014]
Further, in the multilayer circuit board of the present invention, in the above configuration, the internal wiring circuit constitutes a high-frequency circuit that handles a high-frequency signal, and the capacitance electrode has a length shorter than one-eighth of a guide wavelength of the high-frequency signal. It is a feature.
[0015]
Further, in the multilayer circuit board according to the present invention, in each of the above structures, the internal wiring circuit forms a parallel resonator of an inductor formed by the inductor electrode and a capacitor formed by the capacitance electrode.
[0016]
Further, in the multilayer circuit board according to the present invention, in each of the above-described configurations, a connection wiring for connecting the internal wiring circuit to an external electric circuit is formed between the dielectric layers which are the same as the inductor electrodes. Things.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
ADVANTAGE OF THE INVENTION According to the multilayer circuit board of this invention, between the dielectric layer of the multilayer-structured dielectric substrate which laminated | stacked several dielectric layers, the inductor electrode which functions as an inductor, and the ground conductor layer via the dielectric layer At least one pair of opposed internal wiring circuits each including a capacitor electrode functioning as a capacitor is provided. The inductor electrode and the capacitor electrode in each set of the internal wiring circuits are arranged between different dielectric layers and at least one internal wiring circuit is provided. In the internal wiring circuit, the inductor electrode and the capacitor electrode, which are arranged between different dielectric layers and function as independent elements, are connected by the through conductor because they are connected by the through conductor penetrating through the two dielectric layers. Even if the dielectric layer is misaligned during the manufacturing process of the multilayer circuit board, If the conduction between the inductor electrode and the capacitor electrode is ensured, the function of the internal wiring circuit constituted by these elements as a lumped constant circuit will not be impaired. It can be reduced to a small one.
[0018]
According to the multilayer circuit board of the present invention, the internal wiring circuit constitutes a high-frequency circuit for handling high-frequency signals, and when the length of the inductor electrode is shorter than one-eighth of the guide wavelength of the high-frequency signal, the internal wiring circuit is formed. The capacitor electrodes that make up, and the inductor electrodes, which exhibit a more lumped constant behavior due to the short electrical length, are connected by the through conductors. Since the function of the wiring circuit as a lumped constant circuit is not impaired, a change in the characteristics of the internal wiring circuit due to a lamination shift can be suppressed to an extremely small value.
[0019]
Further, according to the multilayer circuit board of the present invention, the internal wiring circuit constitutes a high-frequency circuit for handling a high-frequency signal, and when the length of the capacitor electrode is shorter than one-eighth of the guide wavelength of the high-frequency signal, the internal wiring circuit is not used. The inductor electrodes that make up, and the capacitor electrodes, which exhibit a more lumped constant behavior due to the short electrical length, are connected by penetrating conductors. Since the function of the wiring circuit as a lumped constant circuit is not impaired, a change in the characteristics of the internal wiring circuit due to a lamination shift can be suppressed to an extremely small value.
[0020]
Further, according to the multilayer circuit board of the present invention, when the internal wiring circuit constitutes a parallel resonator composed of an inductor formed by an inductor electrode and a capacitor formed by a capacitor electrode, the internal wiring circuit can be used even when a displacement of the dielectric layer occurs. Since the function of the wiring circuit as a lumped constant circuit is not impaired, fluctuations in the characteristics of the internal wiring circuit due to lamination displacement can be suppressed, and in particular, the resonance frequency of the parallel resonator formed by the internal wiring circuit can be reduced. It can be operated stably.
[0021]
Further, according to the multilayer circuit board of the present invention, when the connection wiring for connecting the internal wiring circuit to the external electric circuit is formed between the same dielectric layers as the inductor electrode, the misalignment of the dielectric layers occurs. Even in this case, the function of the internal wiring circuit as a lumped constant circuit is not impaired, the variation in the characteristics of the internal wiring circuit with respect to the lamination deviation can be suppressed, and the influence of the lamination deviation on the coupling characteristics with the external electric circuit is also reduced It can be suppressed to an extremely small one.
[0022]
Hereinafter, the multilayer circuit board of the present invention will be described in detail with reference to the drawings.
[0023]
FIG. 1 is a perspective view showing an example of an embodiment of a multilayer circuit board according to the present invention, in a state where an internal wiring circuit is seen through. FIG. 2 is an exploded perspective view in which the perspective view of FIG. 1 is exploded for each of the dielectric layers.
[0024]
In these figures, reference numerals 11, 12, and 13 denote dielectric layers, respectively, which are vertically stacked to form a dielectric substrate. The dielectric layers 11, 12, and 13 in the multilayer circuit board of the present invention are made of an electrically insulating material such as glass ceramics, alumina ceramics, and mullite ceramics. These dielectric layers 11, 12 and 13 may be made of, for example, glass ceramics of 18 to 24% by weight of alumina, 8 to 17% by weight of quartz, 13 to 25% by weight of cordierite, and the remainder being borosilicate glass. 72-76% by weight of silicon oxide, 15-17% by weight of boron oxide, 2-4% by weight of alumina, 1.5% by weight or less of magnesium oxide, 1.1-1.4% by weight of zirconium oxide Borosilicate glass powder consisting of lithium oxide / potassium oxide / sodium oxide having a combined amount of 2 to 3% by weight, alumina powder of 18 to 24% by weight, quartz powder of 8 to 17% by weight, and corge of 13 to 25% by weight. Light powder and an appropriate organic binder, solvent, plasticizer, dispersant, etc. are added and mixed to form a slurry. A green sheet (raw sheet) is obtained by forming a sheet using the Darroll method, and then a predetermined green sheet is appropriately punched and a plurality of sheets are stacked up and down to form a green sheet laminate. None, and finally by firing the green sheet laminate at a temperature of about 900 ° C.
[0025]
Note that the dielectric layers 11, 12, and 13 in the figure are those obtained by extracting portions only including the internal wiring circuit, which is a main part of the present invention. The entire dielectric substrate includes wirings for other uses in addition to the structure shown in the figure, but is omitted in the figure. Although the illustrated structure is a laminated structure including three dielectric layers 11, 12, and 13, the dielectric substrate as a whole is not limited to the illustrated laminated portion, and can be used for other purposes. The layers may be stacked one above the other, but are omitted in the figure.
[0026]
21 and 22 are inductor electrodes formed between the dielectric layers 12 and 13. Reference numerals 31 and 32 denote capacitance electrodes formed between the dielectric layers 11 and 12, which are opposed to a ground conductor layer (not shown) formed on the upper surface of the dielectric layer 11 via the dielectric layer 11. , Functions as a capacitor connected to the shunt. One set of internal wiring circuits is formed by the inductor electrode 21 and the capacitor electrode 31, and another set of internal wiring circuits is formed by the inductor electrode 22 and the capacitor electrode 32. The inductor electrode 21 and the capacitor electrode 31 are connected to each other by a through conductor 41 penetrating the dielectric layer 12, and the inductor electrode 22 and the capacitor electrode 32 are connected to each other by a through conductor 42 penetrating the dielectric layer 12. I have.
[0027]
The inductor electrodes 21 and 22 and the capacitance electrodes 31 and 32, and the ground conductor layers and the through conductors 41 and 42 to which the capacitance electrodes 31 and 32 face each other via the dielectric layer 11 are made of, for example, copper or silver-silver-palladium alloy. And the like. When these are made of copper, a metal paste obtained by adding and mixing an appropriate organic binder, a solvent and the like to copper powder is applied to the upper and lower surfaces and through holes of the green sheets to be the dielectric layers 11, 12, and 13. By printing and applying a predetermined pattern using a thick film technique such as a screen printing method in advance, the dielectric substrate is formed and arranged in a predetermined pattern on the upper and lower surfaces and inside thereof.
[0028]
The inductor electrodes 21 and 22 have a line length shorter than a quarter of the guide wavelength of the high-frequency signal, and the ends opposite to the connection ends with the through conductors 41 and 42 are formed by grounding through conductors 61 and 62. Since the short-circuit termination is performed by being connected to the ground conductor layer formed on the upper surface of the dielectric layer 11 and the lower surface of the dielectric layer 13, the function as an inductor is exhibited.
[0029]
Further, the capacitance electrodes 31 and 32 have a line length shorter than a quarter of the guide wavelength of the high-frequency signal, and the ends opposite to the connection ends with the through conductors 41 and 42 are open-ended, so that Exhibits the function as a capacity.
[0030]
Note that a ground conductor layer (not shown) in which the capacitance electrodes 31 and 32 face each other via the dielectric layer 11 and a ground conductor layer (not shown) formed on the lower surface of the dielectric layer 13 form an inductor electrode 21. Capacitor electrodes 31 and 32 face each other with dielectric layer 11 interposed between dielectric layers 11, 12 and 13, sandwiching the region where capacitor 22 and capacitor electrodes 31 and 32 are formed. The ground conductor layer formed on the lower surface of the ground conductor layer and the dielectric layer 13 functions as a ground conductor layer for the wiring conductor functioning as each electrode and a ground shield for the entire circuit wiring.
[0031]
The through conductor 41 connects the inductor electrode 21 and the capacitor electrode 31 while penetrating the dielectric layer 12, and the through conductor 42 connects the inductor electrode 22 and the capacitor electrode 32 while penetrating the dielectric layer 12. However, the dielectric layer 12 is the upper half of the dielectric substrate when the input / output lines 51 and 52 and the inductor electrodes 21 and 22 are regarded as stripline conductors. Is very small with respect to the wavelength of the high-frequency signal, and the lengths of the through conductors 41 and 42 are also very small with respect to the wavelength of the high-frequency signal.
[0032]
Reference numerals 51 and 52 denote input / output lines formed between the same dielectric layers 12 and 13 as the inductor electrodes 21 and 22 and connected in the middle of the inductor electrodes 21 and 22, respectively. It is connected to a circuit (not shown). These input / output lines 51 and 52 are connection wires for connecting each set of internal wiring circuits to an external electric circuit.
[0033]
These input / output lines 51 and 52 are directly connected, for example, near the midpoint of the inductor electrodes 21 and 22 in the line longitudinal direction, thereby realizing tap connection to the inductor. Further, an inductive coupling structure using input / output coupling lines juxtaposed to the inductor electrodes 21 and 22 between the dielectric layers 12 and 13 may be adopted. Further, the connection may be made between the dielectric layers 12 and 13 via coupling inductor electrodes connected near the connection portions between the inductor electrodes 21 and 22 and the through conductors 41 and 42.
[0034]
According to the multilayer circuit board of the present invention having such a configuration, the inductor electrodes 21 and 22 formed on the dielectric layer 13 have different dielectric constants from the capacitor electrodes 31 and 32 formed on the dielectric layer 12. The independent inductor electrode 21 and the capacitor electrode 31, and the independent inductor electrode 22 and the capacitor electrode 32 are connected to each other through the through conductors 41 and 42, respectively. Since the wiring circuit is formed, it is possible to stably realize the element values of the inductor element and the capacitor functioning as the lumped constant element regardless of the mutual positional relationship between the inductor electrodes 21 and 22 and the capacitor electrodes 31 and 32. Can be. Further, since the mutual inductive coupling between the inductor electrodes 21 and 22 juxtaposed between the same dielectric layers 12 and 13 is dominant in the coupling between the sets of the internal wiring circuits, the inductor electrodes 21 and 22 does not depend on the mutual positional relationship with the capacitance electrodes 31 and 32, the influence of the misalignment of the dielectric layers 11 to 13 on the variation in the characteristics of the internal wiring circuit. Can be suppressed.
[0035]
In particular, the electrical lengths of the inductor electrodes 21 and 22 and the capacitance electrodes 31 and 32 make up a high-frequency circuit that handles high-frequency signals by these internal wiring circuits. When the length is shorter than 1, the behavior of the inductor element and the capacitive element in the internal wiring circuit as a lumped constant element is strengthened, so that the displacement of the dielectric layers 11 to 13 on the variation in the characteristics of the internal wiring circuit is affected. Can be particularly effectively suppressed. As such a high-frequency circuit, there is a functional circuit such as a resonator or a band-pass filter that handles a high-frequency signal of several hundred MHz to several GHz.
[0036]
If the electrical length of the inductor electrodes 21 and 22 and the capacitance electrodes 31 and 32 exceeds one-eighth of the guide wavelength of the high-frequency signal, the effect of a distributed constant increases, and the frequency dependence of the inductor element or the capacitance element increases. For this reason, it is more susceptible to the frequency variation with respect to the design value. Therefore, it is desirable that each line length be equal to or less than ８ of the guide wavelength of the high-frequency signal. If these electric lengths are equal to or more than one-fourth of the guide wavelength, the impedance is reversed, so that they do not function as inductor elements and capacitive elements.
[0037]
Also, the shorter the electrical length of the through conductors 41 and 42, the smaller the self-inductance of the through conductors 41 and 42. The influence of the mutual inductance can be suppressed.
[0038]
In particular, when the self-inductance of the through conductors 41 and 42 is suppressed to 1% or less of the self-inductance of the inductor electrodes 21 and 22, the high-frequency circuit constituted by the inductor electrodes 21 and 22 and the capacitance electrodes 31 and 32 is used. The influence on the frequency characteristics of the internal wiring circuits of each set can be significantly reduced.
[0039]
That is, by suppressing the inductance of these through conductors 41 and 42 to 1% or less of the inductance of the inductor electrodes 21 and 22 to which they are connected, the inductance of the through conductors 41 and 42 determines the frequency characteristics of the internal wiring circuit. Since the inductance of the inductor electrodes 21 and 22 is so small as to be negligible, the effect of the through conductors 41 and 42 on the characteristics of the entire internal wiring circuit can be sufficiently suppressed. The effect of the coupling caused by a plurality of through conductors connecting the electrode and the capacitor electrode being arranged close to each other can be sufficiently suppressed.
[0040]
In the example shown in FIGS. 1 and 2, a parallel resonator is formed by adopting a structure in which the inductor electrodes 21 and 22 and the capacitance electrodes 31 and 32 are shunt-connected in a parallel circuit. By adopting such a structure, a parallel resonator in which the variation of the resonance frequency is suppressed with respect to the lamination shift of the dielectric layers 11 to 13 is realized by an internal wiring circuit and is built in a multilayer circuit board as a functional circuit. be able to.
[0041]
Further, in this example, since the inductor electrodes 21 and 22 and the input / output lines 51 and 52 are formed between the same dielectric layers 12 and 13, an external circuit can be provided regardless of the coupling structure via the dielectric layers. Can be realized, and the effect of the misalignment of the dielectric layers 11 to 13 on the coupling characteristics between the internal wiring circuit and the external electric circuit can be suppressed.
[0042]
In the illustrated example, the number of internal wiring circuits is two. However, the number of internal wiring circuits in the multilayer circuit board of the present invention is not limited to this number, and a larger number of sets of internal wiring circuits are configured. May be. Examples of such a multilayer circuit board having a large number of sets of internal wiring circuits include a multi-stage (three or more) band-pass filter.
[0043]
【Example】
Next, a specific example of the multilayer circuit board of the present invention will be described.
[0044]
Using a glass ceramic having a relative dielectric constant of 9.6 as a dielectric material, a multilayer circuit board including three dielectric layers shown in FIG. 1 was produced. The thickness of each dielectric layer was 0.05 mm for the uppermost layer, and 0.2 mm for the middle and lower layers.
[0045]
Further, on the upper surface of the lowermost dielectric layer, copper wires having a width of 0.13 mm and a length of 2.2 mm are juxtaposed at intervals of 0.18 mm to form inductor electrodes, and one end thereof is a via hole as a through conductor. Grounding was performed by connecting to a ground conductor layer formed on the upper and lower surfaces of the dielectric substrate by a conductor.
[0046]
The end of the inductor electrode on the non-grounded side is formed on the upper surface of the middle dielectric layer with a width of 1.0 mm and a length of 1 through a via-hole conductor penetrating the middle dielectric layer. It was connected to the end of the capacitor electrode which was a copper wiring of 0.8 mm. The capacitor electrode forms a capacitor by opposing the ground conductor layer formed on the upper surface of the uppermost dielectric layer via the uppermost dielectric layer.
[0047]
In addition, a wiring perpendicular to the longitudinal direction of the inductor electrode was connected to an intermediate point of the inductor electrode on the upper surface of the lowermost dielectric layer to form an input / output line.
[0048]
With the above internal wiring circuit, a frequency selection circuit similar to a double tuning circuit was configured.
[0049]
When a plurality of samples of the multilayer circuit board of the present invention having such an internal wiring circuit were prepared and the transfer characteristics of the internal wiring circuit in each sample were measured and evaluated, the results shown in FIGS. 3 and 4 were obtained.
[0050]
FIG. 3 is a diagram plotting the transfer characteristics between the input and output terminals of the internal wiring circuit of each sample for each sample, and FIG. 4 is an enlarged view near the pass band in FIG. In these figures, the horizontal axis represents the normalized frequency normalized by the average value of the center frequency of each sample, the vertical axis represents the S parameter S21 (unit: dB), and the characteristic curve represents the transfer characteristics of each sample. I have.
[0051]
As is clear from these figures, according to each of these samples, it can be seen that a frequency selection circuit having a very small variation in the center frequency was realized.
[0052]
Thus, according to the present invention, it was confirmed that a functional circuit was built in the internal wiring circuit to enable further miniaturization, and that a multilayer circuit board with small variations in the characteristics of the internal wiring circuit could be obtained. .
[0053]
It should be noted that the above is only an example of the embodiment of the present invention, and the present invention is not limited thereto, and various changes and improvements may be added without departing from the gist of the present invention. .
[0054]
【The invention's effect】
As described above, according to the multilayer circuit board of the present invention, an inductor electrode functioning as an inductor and a dielectric layer are interposed between dielectric layers of a multilayer dielectric substrate formed by laminating a plurality of dielectric layers. And at least one set of internal wiring circuits each including a capacitor electrode functioning as a capacitor facing the ground conductor layer. The inductor electrode and the capacitor electrode in each set of internal wiring circuits are arranged between different dielectric layers. Are connected by a through conductor penetrating at least one dielectric layer, the inductor electrode and the capacitor electrode arranged between different dielectric layers and functioning as independent elements from each other are formed in the internal wiring circuit. In the case where the dielectric layers are misaligned in the manufacturing process of the multilayer circuit board, If conduction between the inductor electrode and the capacitor electrode by the conducting conductor is ensured, the function of the internal wiring circuit constituted by these components as a lumped constant circuit is not impaired. Characteristics fluctuation can be suppressed to a small value.
[0055]
According to the multilayer circuit board of the present invention, the internal wiring circuit constitutes a high-frequency circuit for handling high-frequency signals, and when the length of the inductor electrode is shorter than one-eighth of the guide wavelength of the high-frequency signal, the internal wiring circuit is formed. The capacitor electrodes that make up, and the inductor electrodes, which exhibit a more lumped constant behavior due to the short electrical length, are connected by the through conductors. Since the function of the wiring circuit as a lumped constant circuit is not impaired, a change in the characteristics of the internal wiring circuit due to a lamination shift can be suppressed to an extremely small value.
[0056]
Further, according to the multilayer circuit board of the present invention, the internal wiring circuit constitutes a high-frequency circuit for handling a high-frequency signal, and when the length of the capacitor electrode is shorter than one-eighth of the guide wavelength of the high-frequency signal, the internal wiring circuit is not used. The inductor electrodes that make up, and the capacitor electrodes, which exhibit a more lumped constant behavior due to the short electrical length, are connected by penetrating conductors. Since the function of the wiring circuit as a lumped constant circuit is not impaired, a change in the characteristics of the internal wiring circuit due to a lamination shift can be suppressed to an extremely small value.
[0057]
Further, according to the multilayer circuit board of the present invention, when the internal wiring circuit constitutes a parallel resonator composed of an inductor formed by an inductor electrode and a capacitor formed by a capacitor electrode, the internal wiring circuit can be used even when a displacement of the dielectric layer occurs. Since the function of the wiring circuit as a lumped constant circuit is not impaired, fluctuations in the characteristics of the internal wiring circuit due to lamination displacement can be suppressed, and in particular, the resonance frequency of the parallel resonator formed by the internal wiring circuit can be reduced. It can be operated stably.
[0058]
Further, according to the multilayer circuit board of the present invention, when the connection wiring for connecting the internal wiring circuit to the external electric circuit is formed between the same dielectric layers as the inductor electrode, the misalignment of the dielectric layers occurs. Even in this case, the function of the internal wiring circuit as a lumped constant circuit is not impaired, the variation in the characteristics of the internal wiring circuit with respect to the lamination deviation can be suppressed, and the influence of the lamination deviation on the coupling characteristics with the external electric circuit is also reduced. It can be suppressed to an extremely small one.
[0059]
As described above, according to the present invention, fluctuations in circuit characteristics such as variations in frequency characteristics due to variations in lamination due to variations in lamination in a manufacturing process of an internal wiring circuit, which is a functional circuit configured by inner layer wiring, are small, and all of the wiring is inside the circuit board. It was possible to provide a multilayer circuit board including a functional circuit that is completely embedded and configured.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of an embodiment of a multilayer circuit board according to the present invention, in a state where an internal wiring circuit is seen through;
FIG. 2 is an exploded perspective view in which the perspective view of FIG. 1 is exploded for each dielectric layer.
FIG. 3 is a diagram showing transfer characteristics of an internal wiring circuit in an embodiment of the multilayer circuit board of the present invention.
FIG. 4 is a diagram showing transfer characteristics in the vicinity of a pass band in FIG. 3;
[Explanation of symbols]
11, 12, 13,... Dielectric layer
21, 22 ... Inductor electrode
31, 32 ... capacitance electrode
41, 42 ... Through conductor
51, 52... Input / output lines (connection wiring)
61, 62 ..... Through conductor for grounding

Claims (5)

At least one set of internal wiring circuits comprising an inductor electrode and a capacitor electrode opposed to a ground conductor layer via the dielectric layer is provided between the dielectric layers of the dielectric substrate formed by laminating a plurality of dielectric layers. Wherein the inductor electrode and the capacitor electrode in each set of the internal wiring circuits are arranged between different dielectric layers and connected by a through conductor penetrating the dielectric layer. Multilayer circuit board. 2. The multilayer circuit board according to claim 1, wherein said internal wiring circuit constitutes a high-frequency circuit for handling a high-frequency signal, and said inductor electrode has a length shorter than one-eighth of a guide wavelength of said high-frequency signal. 2. The multilayer circuit board according to claim 1, wherein said internal wiring circuit constitutes a high-frequency circuit for handling a high-frequency signal, and said capacitor electrode has a length shorter than one-eighth of a guide wavelength of said high-frequency signal. 4. The multilayer circuit board according to claim 1, wherein the internal wiring circuit forms a parallel resonator of an inductor formed by the inductor electrode and a capacitor formed by the capacitance electrode. The multilayer according to any one of claims 1 to 4, wherein a connection wiring for connecting the internal wiring circuit to an external electric circuit is formed between the same dielectric layers as the inductor electrode. Circuit board.

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