JP2003087005A - Multilayer band-pass filter and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer band-pass filter and its manufacturing method, which realizes a large L-value with a short resonance line length and a small number of lamination layers. SOLUTION: The filter has a three-layer structure, composed of resonance lines B17, 18 formed on a dielectric layer which is an insulator from base ground terminals, resonance lines C19, 20 formed on a dielectric layer beneath the dielectric layer of the resonance lines B17, 18, and resonance lines A15, 16 on a dielectric layer overlying the dielectric layer of the resonance lines B17, 18. They are formed in spiral in the longitudinal direction, as seen from the side of the lamination surface, to make currents flowing on adjacent resonance lines in the same direction, thereby reducing the resonance line length.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer bandpass filter and a manufacturing method thereof, and more particularly to a multilayer bandpass filter most suitable for a mobile phone, high frequency communication and the like and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, as a multilayer bandpass filter of this type, for example, a total of nine layers shown in FIG. 12 are provided, and a protective dielectric layer 110 is provided on the upper side and a dielectric sheet 111 is provided on the lower side. Shield electrode (GND) pattern 1
12 are formed.

Further, an input / output electrode pattern 11 is provided under the electrode.
An input / output electrode layer on which the resonance lines A115 and 116 are formed, a resonance line first layer on which the resonance lines A115 and 116 are formed, a resonance line second layer on which the resonance lines B117 and 118 are formed, and a resonance line C119 are provided. , 120 of the resonance line and the resonance line D 121, 122 of the resonance line the fourth layer of which three resonance line forming portions are provided.

All the resonance lines are rectangular, and the resonance lines adjacent to each other in a zigzag shape are electrically connected by through holes or the like as shown in FIG.

[0005]

However, as shown in FIG.
In the BPF shown in (1), if (resonance line length) <(λ / 4) (λ: wavelength of resonance frequency), the resonance lines A to D have the configuration shown in FIG. The magnetic fields generated by the currents flowing in the upper and lower resonance lines were generated in directions canceling each other.

For this reason, when this resonance line is used as a resonance circuit, in order to obtain a necessary resonance frequency, as shown in FIG. It was necessary to lengthen the line until it was obtained.

If the width of the resonance line is reduced, the BPF
Since the insertion loss of No.1 becomes worse, the line must be thicker, and there is a limit to miniaturization from these conditions.

Furthermore, as another example, as shown in FIG. 14, a BPF in which a resonance line is formed in a planar spiral shape.
However, if the line width is not sufficiently obtained, the insertion loss as the BPF is deteriorated, and the size increase cannot be avoided.

[0009]

The present invention has been made for the purpose of solving the above-mentioned problems.
An object of the present invention is to provide a multilayer bandpass filter having a short resonance line length that can realize a large L value with a small number of layers and a manufacturing method thereof. And achieve that objective,
For example, the following configuration is provided as one means for solving the above-mentioned problems.

That is, there is provided a multilayer bandpass filter in which electrodes are formed on at least three layers of insulators and resonance lines are formed by electrically connecting the electrodes to each other. One end of the electrode formed on the is connected to an external ground terminal, and the electrode formed on the insulator, which is multilayered from the one end, is electrically connected so as to have a spiral shape when viewed from the laminated cross section. It is characterized in that it has a connected resonance line.

Alternatively, there is provided a method of manufacturing a multi-layer bandpass filter comprising forming electrodes on at least three layers of insulators and forming resonance lines electrically connecting the electrodes, wherein One end of the electrode formed on the insulator is connected to an external ground terminal so that the electrode formed on the insulator, which is multilayered from the one end, has a spiral shape when viewed from the laminated cross section. It is characterized in that it is electrically connected to form a resonance line.

Further, for example, the resonance line includes at least a first electrode in which two patterns are arranged in parallel from the back to the front of the insulator on the front side of the back side open end of the insulator, and The front end of the first electrode is electrically connected to the front end by a through hole, and two patterns are arranged in parallel from the front end to the back end of the insulator. A third electrode pattern provided and a back side end electrically connected to a back side end of the third electrode on an insulator between the first electrode and the third electrode. Two patterns are arranged in parallel from the back to the front of the insulator, and are arranged up to the front of the through hole connecting the first electrode and the third electrode, and the two patterns are located in front of the through hole. It is formed so as to extend to the front end of the insulator integrally with And forming the Iraru shape.

[0013]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an exploded perspective view of a multilayer bandpass filter according to an embodiment of the present invention. FIG. 2 is a front sectional view of a multilayer bandpass filter according to the present embodiment.
FIG. 4 is a side sectional view of the multilayer bandpass filter of the present embodiment, and FIG. 4 is a diagram for explaining a resonance line structure of the multilayer bandpass filter of the present embodiment.

As shown in FIG. 1, the multilayer (multilayer) bandpass filter according to the present embodiment has a protective dielectric layer 10 on the upper part and a shield electrode (GND) on the dielectric sheet 11 below. The pattern 12 is formed.

Further, an input / output electrode pattern 1 is provided under the same.
Resonance line 1 provided with an input / output electrode layer on which resonance lines A15 and 16 are formed.
There are three layers of resonance line forming portions: a layer, a resonance line second layer in which the resonance lines B17 and 18 are formed, and a resonance line third layer in which the resonance lines C19 and C20 are formed.

In this embodiment, the resonance line A15,
In FIG. 1, a rectangular pattern 15 and a rectangular pattern 16 are arranged in parallel from the back to the front of the insulator rear side open end in FIG. 1, and the front side end resonates with a through hole. It is electrically connected to the front ends of the lines C19 and C20.

The resonance lines C19 and C20 are resonance lines A1.
The rectangular pattern 19 and the rectangular pattern 20 are arranged in parallel from the front end to the back end from the front end electrically connected from 5 and 16 through the through hole, respectively. The side end is a through hole and is a resonance line B17,
It is electrically connected to the rear end portion of 18.

The resonance lines B17 and B18 are resonance lines C1.
Patterns 17 and 18 are parallel to each other, and the resonance lines A15 and 16 and the resonance lines C19 and 20 are connected in parallel from the back side to the front side of the insulator, which is electrically connected to 9 and 20 by through holes. It is arranged up to the front of the through hole, and there are two patterns 1 in front of the through hole.
7 and 18 are formed in a bifurcated shape that is integrated with each other and extends to the front end portion of the insulator.

A shield electrode layer under which a shield electrode (GND) pattern 21 is formed is provided, and a protective dielectric layer 22 is provided below the shield electrode layer.

As a result, as shown in FIGS. 2 and 3, the resonance line of the present embodiment has the input / output electrode pattern 13,
Resonance line A that opposes the tip of 14 through the dielectric layer
Ends 15 and 16 are located, the other ends of the resonance lines A15 and 16 are connected to one ends of the resonance lines C19 and 20 by through holes, and the other ends of the resonance lines C19 and C20 are resonance lines B17. The end of 18 is connected by a through hole, and the base of the resonance line B extends to the end surface of the multilayer bandpass filter and is connected to the external GND terminal.

As the dielectric sheet, for example, a sheet obtained by kneading ceramic powder and a binder can be used.

Each electrode and resonance line are made of Ag, Cu, A
u, Ag-Pd, etc. can be used for printing,
It can be formed by means such as sputtering or vapor deposition.

The above-mentioned resonance line structure is schematically shown in FIG. 4, which has a spiral shape in the longitudinal direction and has a spiral resonance line. FIG. 4 is a diagram for explaining the resonance line structure of the multilayer bandpass filter according to the present embodiment.

FIG. 5 simply shows the structure of FIG. FIG. 5 is a diagram simply showing the structure of the resonance line of the present embodiment.

As shown in FIG. 5, in the present embodiment, the currents flowing through the resonance line A and the resonance line B are in the same direction, and the magnetic fields generated by the current flowing through the resonance line are also generated in the same direction and cancel each other out. There is no meeting.
For this reason, the total length of the resonance lines A to C can be shortened as compared with the length of the conventional resonance line shown in FIG. 12, so that the size can be reduced, and the resonance when compared with the conventional resonance line shown in FIG. As the line width can be made wider, insertion loss can be reduced.

In FIG. 5, d1 is the distance between the resonance line A and the resonance line B, and d2 is the resonance line B and the resonance line C.
Shows the distance between. Here, by arranging so that d1 <d2, it is possible to reduce the influence of the action of canceling out the magnetic fields generated by the current flowing in the resonance line, and as a result, it is possible to shorten the resonance line length.

For example, the equivalent circuit of the BPF circuit when the resonance line having the above structure is used and the resonance line is configured by capacitive coupling is the equivalent circuit shown in FIG.

FIG. 6 is a diagram showing an example of an equivalent circuit of the BPF when the capacitance (capacitor C) having the resonance line of this embodiment is coupled. In FIG. 6, 36 and 37 are input / output terminals, and correspond to 2 and 3 in FIGS. 1 to 3.

An equivalent circuit when the BPF is coupled with the mutual inductance M using the above resonance line is shown in FIG.
The equivalent circuit is shown in.

FIG. 7 is a diagram showing an example of an equivalent circuit of the BPF when the mutual inductance M having the resonance line of the present embodiment is coupled. Also in FIG. 7, 36 and 37 are input / output terminals, and correspond to 2 and 3 in FIGS. 1 to 3.

As an example of the BPF characteristic of the present embodiment, an example of capacitive coupling is shown in FIG. FIG. 8 is a diagram showing a characteristic example of the BPF circuit in the case of capacitive coupling of the present embodiment. As shown in FIG. 8, a good filter effect can be obtained. Further, in the present embodiment, when the distance d1 between the resonance line A and the resonance line B and the distance d2 between the resonance line B and the resonance line C shown in FIG. 5 are arranged so that d1 <d2, Especially by reducing d1
The resonance frequency can be lowered and the required effect of shortening the resonance line length can be enhanced.

For example, when the resonance line width is 0.5 mm and the layer length is 1.4 mm, the condition 1 is d1 = 0.02 mm, d2 = 0.13 mm The condition 2 is d1 = 0.05 mm, d2 = 0 The measurement result of the resonance impedance of the resonance circuit in the case of 0.1 mm is shown in FIG. FIG. 9 is a diagram showing an example of the measurement result of the resonance impedance when the distance between the resonance lines according to the present embodiment is changed.

As shown in FIG. 9, the resonance frequency can be lowered by reducing the distance d1 between the resonance line A and the resonance line B, and the effect of shortening the resonance line length can be confirmed.

As described above, according to the present embodiment, the resonance line is at least the resonance line B1 formed on the dielectric layer which is an insulator from the base ground terminal portion.
7, 18 and the resonance lines C19 and 20 formed on the dielectric layer below the dielectric layer of the resonance lines B17 and 18, and the dielectric lines above the dielectric layer of the resonance lines B17 and 18 The resonance lines A15 and 16 have a three-layer structure and are formed in a spiral shape by spiraling in the vertical direction when viewed from the side surface of the stacking surface, so that the directions of the currents flowing through the adjacent resonance lines can be made the same and Since the line length can be shortened, the resonance line and the BPF can be downsized.

Further, according to the present embodiment, since the resonance line can be downsized, the resonance line can be formed in the multilayer chip of the multilayer bandpass filter even if a dielectric material having a relatively low dielectric constant is used. It is also possible to improve the problem of yield caused by the variation in stray capacitance and internal electrode dimensions, which is a problem when a high dielectric constant dielectric material is used.

The shield electrode pattern layers 12 and 21
The distance between the resonance line and the resonance line is preferably set to 300 μm or more because the insertion loss of the filter may increase. Because, if this space is small, the electrode pattern layer 1
This is because eddy current loss is generated in 2 and 21, the magnetic field in the bandpass filter is attenuated, and the insertion loss of the filter increases.

Further, the material is not limited to the dielectric material as in the above example, and a magnetic material or a magnetic material and a dielectric material may be mixed or combined.

<Other Embodiments> In the above description, the case where the resonance lines are formed in three layers has been described. However, the present invention is not limited to the above examples, the resonance characteristics are not limited, and it is needless to say that the invention is included in the scope of the present invention even when formed in four layers or more multilayers. is there.

Even in this case, it may be formed in a spiral shape so that the directions of the currents flowing in the vertically adjacent resonance lines are the same. For example, in the case of forming four layers, it may be formed simply as shown in FIG.
Even in the case of forming a multilayer including more layers, the resonance line of the newly formed layer is formed so that the current flows in the same direction as that of the adjacent resonance line.

With the above structure, even if the resonance lines are formed in more layers, the resonance lines are formed so as to spiral in the vertical direction when viewed from the side surface of the laminated surface, and are formed in a spiral shape so that they are vertically adjacent to each other. The direction of the current flowing through the resonance line can be made the same, and the resonance line length can be shortened.

In the above description, the resonance line B1
Reference numerals 7 and 18 are resonance lines A15, 16 and resonance line C19 in which the pattern 17 and the pattern 18 are arranged in parallel from the back side to the front side of the insulator from the back side end electrically connected to the resonance lines C19 and 20, respectively. , 20 is provided up to the front of the through hole connecting the two, and the two patterns 17 and 18 are formed in a bifurcated shape that is integrated with each other and extends to the front end of the insulator before the through hole. did.

However, the present invention is not limited to the above example, and two patterns 1 are provided before the through hole portion.
7 and 18 are integrated with each other and do not extend to the front end portion of the insulator, and the through hole (V
It may be electrically connected to the lower GND pattern 21 by an IA hole).

In this case, it may be connected to the GND external terminal on the front side through the GND pattern 21. FIG. 11 shows an exploded perspective view of the multilayer bandpass filter in this case. FIG. 11 is an exploded perspective view of a multilayer bandpass filter according to another embodiment of the present invention.

[0045]

As described above, according to the present invention, it is possible to provide a multilayer bandpass filter and a method for manufacturing the same, which can realize miniaturization by forming resonance lines with a small number of layers.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a multilayer bandpass filter according to an exemplary embodiment of the present invention.

FIG. 2 is a front sectional view of a multilayer bandpass filter according to the present embodiment.

FIG. 3 is a side sectional view of a multilayer bandpass filter according to the present embodiment.

FIG. 4 is a diagram for explaining a resonance line structure of the multilayer bandpass filter according to the present embodiment.

FIG. 5 is a diagram simply showing a structure of a resonance line according to the present embodiment.

FIG. 6 is a diagram showing an example of an equivalent circuit of a BPF when a capacitor (capacitor C) having a resonance line of the present embodiment is coupled.

FIG. 7 is a diagram showing an equivalent circuit example of a BPF when coupled by a mutual inductance M including a resonance line according to the present embodiment.

FIG. 8 is a BPF in the case of capacitive coupling according to the present embodiment.
It is a figure which shows the example of a characteristic as a circuit.

FIG. 9 is a diagram showing an example of measurement results of resonance impedance when the distance between the resonance lines according to the present embodiment is changed.

FIG. 10 is a diagram simply showing a structure of a resonance line according to another embodiment of the present invention.

FIG. 11 is an exploded perspective view of a multilayer bandpass filter according to another embodiment of the present invention.

FIG. 12 is a diagram showing a configuration example of a conventional multilayer bandpass filter.

FIG. 13 is a diagram simply showing a configuration of a resonance line of a conventional multilayer bandpass filter.

FIG. 14 is a diagram showing a structure of a conventional BPF in which a resonance line is formed in a spiral shape in a plane.

[Explanation of symbols]

10 Protective dielectric layer 11,22 Dielectric sheet 12, 21 electrode pattern 13, 14 Input / output electrode pattern 15, 16 Resonance line A 17, 18 Resonance line B 19, 20 Resonance line C

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H03H 7/075 H03H 7/075 Z 7/09 7/09 Z F term (reference) 5E070 AA01 AB02 BA12 CB03 CB13 CB17 CC01 EA01 5J006 HB05 HB13 HB21 HB22 JA01 LA23 NA04 NC03 5J024 AA01 CA06 DA04 DA29 DA32 DA35 EA03

Claims (4)

[Claims] 1. A multi-layer bandpass filter comprising electrodes formed on at least three layers of insulators and resonance lines electrically connected to the electrodes, wherein a single layer of the insulator is formed. One end of the electrode formed on the is connected to an external ground terminal, and the electrode formed on the insulator, which is multilayered from the one end, is electrically connected so as to have a spiral shape when viewed from the laminated cross section. A multilayer bandpass filter comprising connected resonant lines. 2. The resonance line includes at least a first electrode in which two patterns are arranged in parallel from the back to the front of the insulator on the front side of the insulator rear-side open end portion, and the first electrode. The front end of the first electrode is electrically connected to the front end by a through hole, and two patterns are arranged in parallel from the front end to the back of the insulator at the back end of the front end. Insulated from the back side end electrically connected to the back side end of the third electrode on the formed third electrode pattern and the insulator between the first electrode and the third electrode. Two patterns are arranged in parallel from the back to the front of the body, and are arranged up to the front of a through hole connecting the first electrode and the third electrode, and two patterns are located in front of the through hole. It is formed so as to be integrated and extends to the front end of the insulator, and the electrode is shaped like a spiral when viewed from the laminated section. The multilayer bandpass filter according to claim 1, wherein the multilayer bandpass filter is formed. 3. A method for manufacturing a multi-layer bandpass filter, comprising forming electrodes on at least three layers of insulators and forming resonance lines electrically connecting the electrodes, wherein a single layer of One end of the electrode formed on the insulator is connected to an external ground terminal so that the electrode formed on the insulator, which is multilayered from the one end, has a spiral shape when viewed from the laminated cross section. A method of manufacturing a multilayer bandpass filter, which comprises electrically connecting to form a resonance line. 4. The resonance line comprises at least a first electrode having two patterns arranged in parallel from the back to the front of the insulator on the front side of the insulator rear-side open end, and the first line. The front end of the first electrode is electrically connected to the front end by a through hole, and two patterns are arranged in parallel from the front end to the back of the insulator at the back end of the front end. Insulated from the back side end electrically connected to the back side end of the third electrode on the formed third electrode pattern and the insulator between the first electrode and the third electrode. Two patterns are arranged in parallel from the back to the front of the body, and are arranged up to the front of a through hole connecting the first electrode and the third electrode, and two patterns are located in front of the through hole. It is formed so as to be integrated and extends to the front end of the insulator, and the electrode is shaped like a spiral when viewed from the laminated section. 4. The method for manufacturing a multilayer bandpass filter according to claim 3, wherein