JP2003163508A - Non-reciprocal circuit element and communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To be able to correspond to high power and provide a small non- reciprocal circuit element and a communication device. <P>SOLUTION: The non-reciprocal circuit element is roughly composed of a metal case, a permanent magnet, ferrite, a center electrode and multilayer substrate 30. The multilayer substrate 30 laminates dielectric sheets 41 to 47 on which electrode films P3, 73a, etc., and a resistor film 75 are respectively mounted, and is formulated through burning them integrally. Film thickness T2 of the electrode films 73a and 17 of a layer on which the resistor film 75 is formulated, is designed thicker than film thickness T1 of the electrode films P3, 74 and 73b of the rest layers. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a non-reciprocal circuit device and a communication device.

[0002]

2. Description of the Related Art Generally, an isolator has a function of passing a signal only in a transmission direction and blocking a transmission in the opposite direction, and is used in a transmission circuit section of a mobile communication device such as a car phone or a mobile phone. Has been done. With the miniaturization of these communication devices, the demand for smaller and thinner isolators is increasing.

As such an isolator, for example, one disclosed in Japanese Patent Laid-Open No. 7-283614 is known. In this isolator, a multilayer substrate provided with a matching capacitor and a terminating resistor is arranged on the input / output substrate. The ferrite is fitted in the hole provided in the input / output board. A permanent magnet for applying a DC magnetic field to the ferrite is arranged on the multilayer substrate. A metal case is attached so as to cover these parts.

The multi-layer substrate is formed by forming various electrode films and terminating resistance films on the surfaces of a plurality of insulating sheets by pattern printing or the like, stacking the sheets, press-bonding them, firing them, and integrating them. . Here, in the conventional multilayer substrate, the thickness of various electrode films is set to the same dimension.

[0005]

By the way, when a matching capacitor is provided on the multilayer substrate, the matching capacitor requires a large capacitance value depending on the operating frequency. It is preferentially determined to secure the capacitance value of the capacitor. Therefore, it is impossible to preferentially design the position and area of the terminating resistor in order to improve the heat dissipation efficiency of the terminating resistor provided on the multilayer substrate by thick film printing. In other words, the reflected power that has entered the isolator is absorbed by the terminating resistor and converted into heat, but it is difficult for this terminating resistor to efficiently radiate the heat generated when the reflected power is absorbed, and the heat generation temperature of the terminating resistor rises. . In order to keep the heat generation temperature within a predetermined allowable limit value, there is no choice but to suppress the reflected power. Therefore, the conventional isolator cannot be used for a high power communication device.

Therefore, an object of the present invention is to provide a small non-reciprocal circuit device and a communication device that can handle high power.

[0007]

In order to achieve the above object, the nonreciprocal circuit device according to the present invention comprises (a) a permanent magnet, and (b) a ferrite to which a DC magnetic field is applied by the permanent magnet. (C) A plurality of center electrodes arranged on the main surface of the ferrite, (d) a multilayer substrate formed by stacking at least a resistor film, an electrode film, and an insulating layer, (e)
At least a resistor formed of a resistor film and a matching capacitor formed of an electrode film are arranged on the multilayer substrate.

In the multilayer substrate, the thickness of the electrode film of the layer provided with the resistor film is thicker than the thickness of the electrode films of the remaining layers. Alternatively, in the multilayer substrate, the thickness of the electrode film of the layer provided with the resistor film and connected to the resistor film is larger than the thickness of the remaining electrode films.

With the above structure, the thickness of the electrode film of the layer provided with the resistor film or the thickness of the electrode film of the layer provided with the resistor film and connected to the resistor film is increased. Therefore, the heat generated in the resistor film is efficiently transmitted through the electrode film connected to the resistor film and radiated.

Further, when the resistor film is disposed inside the multilayer substrate, since the periphery of the resistor film is covered with an insulating material having poor thermal conductivity, the heat generated in the resistor film is reduced. Is likely to accumulate heat. Therefore, the structure in which heat is radiated by the thick electrode film is particularly effective in such a case.

Further, the thickness of the thick electrode film is approximately n times the thickness of the remaining thin electrode film (where n ≧ 2.
By setting n: an integer), a thick electrode film can be easily formed without changing the electrode film paste by a simple process of overcoating twice or more.

Further, the communication device according to the present invention includes the above-mentioned non-reciprocal circuit element, so that the electrical characteristics are improved.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a nonreciprocal circuit device and a communication device according to the present invention will be described below with reference to the accompanying drawings.

[First Embodiment, FIGS. 1 to 4] FIG. 1 is an exploded perspective view of an embodiment of a nonreciprocal circuit device according to the present invention. The non-reciprocal circuit device 1 is a lumped constant isolator. As shown in FIG. 1, a lumped constant isolator 1
Is a metal case composed of a metal upper case 4 and a metal lower case 8, a permanent magnet 9, and a ferrite 20.
And a center electrode 21 to 23
And a multilayer substrate 30.

The upper metal case 4 is substantially box-shaped and comprises an upper part 4a and four side parts 4b. The metal lower case 8 is composed of left and right side portions 8b and a bottom portion 8a. The metal upper case 4 and the metal lower case 8 form a magnetic circuit, and are therefore made of a material made of a ferromagnetic material such as soft iron, and the surfaces thereof are plated with Ag or Cu.

The center electrode assembly 13 has three center electrodes 21 to 23 on the upper surface of a rectangular microwave ferrite 20.
Are arranged so as to intersect with each other at approximately 120 degrees with an insulating layer (not shown) interposed. In the first embodiment, the center electrodes 21 to 23 are composed of two lines.

As shown in FIG. 2, the multilayer substrate 30 includes a dielectric sheet 41 having port electrode films P1 to P3, a ground lead electrode film 31, a via hole 18, capacitor electrode films 71a to 73a, and a circuit electrode film 17. Sheet 42 and capacitor electrode film 71b provided with a resistor film 75, etc.
To 73b are provided on the surface of the dielectric sheet 44 and the ground electrode film 74 is provided on the surface of the dielectric sheets 43 and 4, respectively.
5, 46, etc.

Electrode films P1 to P3, 17, 31, 71a to
73a, 71b to 73b, 74 are formed on the surface of the dielectric sheets 41 to 46 by a method such as pattern printing. Examples of materials for the electrode films P1 to P3 include Ag and Ag-
Pd, Pd, Cu or the like is used. Dielectric sheet 41
As the material of Nos. 46 to 46, a dielectric powder such as alumina is kneaded together with a binder and molded into a sheet.

The resistor film 75 is formed on the surface of the dielectric sheet 42 by a method such as pattern printing. As a material for the resistor film 75, cermet, carbon, ruthenium, or the like is used. The resistor film 75 constitutes the terminating resistor R by itself.

The via hole 18 is formed of the dielectric sheets 41 to 4
3 is formed by forming via hole holes in advance by laser processing, punching processing, or the like, and then filling the via hole holes with a conductive paste.

Capacitor electrode films 71a, 71b, 72
a, 72b, 73a, and 73b constitute matching capacitors C1, C2, and C3 facing the ground electrode film 74 with the dielectric sheets 42 to 44 interposed therebetween. The matching capacitors C1 to C3 and the terminating resistor R are connected to the electrode film P.
An electric circuit is configured inside the multilayer substrate 30 together with 1 to P3, 17, 31 and the via hole 18.

Here, as shown in FIG. 3, the resistor film 75
The film thickness T2 of the electrode films 71a to 73a, 17 of the layer in which is formed is the same as the electrode films P1 to P3, 31, 71b of the remaining layers
It is set so as to be thicker than the film thickness T1 of 73b, 74. As a result, the heat generated in the resistor film 75 is
Heat is efficiently transmitted through the electrode films 17 and 73a connected to the resistor film 75. The electrode films 17, 71a, 72a not connected to the resistor film 75 are also indirectly connected to the resistor film 7
It acts to facilitate the dissipation of the heat generated in 5.

In particular, when the resistor film 75 is disposed inside the multilayer substrate 30, the resistor film 75 is covered with an insulating material having poor thermal conductivity, so that the resistor film 75 is generated. The accumulated heat easily accumulates. Therefore, in this case, the structure in which heat is radiated by the thick electrode films 71a to 73a, 17 is more effective.

Specifically, in the case of the first embodiment, the film thickness T2 of the electrode films 71a to 73a, 17 is about 10 μm, and the film thickness T1 of the other electrode films P1 to P3, 31, 71b to 73b, 74. Was about 5 μm. The loss is reduced by making the film thicknesses T1 and T2 sufficiently thicker than the skin depth. The film thickness T2 of the electrode films 71a to 73a, 17 is approximately twice the film thickness T1 of the electrode films P1 to P3, etc. (approximately n times,
By setting n ≧ 2, n: an integer), the electrode films 71a to 73a, 17 can be easily formed by a simple process of overcoating twice (n times) without changing the electrode film paste. be able to. The thickness of the dielectric sheets 41 to 46 of the first embodiment is about 25 μm.

The above-mentioned dielectric sheets 41 to 46 are laminated, and further, a plurality of dummy dielectric sheets having no electrodes formed on their surfaces in advance are laminated thereunder, and then they are integrally fired. The multilayer substrate 30 as shown in FIG.
The input terminal electrodes 1 are formed on both ends of the multilayer substrate 30, respectively.
4, an output terminal electrode 15 and a ground terminal electrode 16 are provided. The input terminal electrode 14 is a capacitor electrode film 71.
a, 71b, and the output terminal electrode 15 is electrically connected to the capacitor electrode films 72a, 72b. Each of the ground terminal electrodes 16 has a circuit electrode film 1
7 and the ground electrode film 74 are electrically connected. These terminal electrodes 14 to 16 are made of Ag, Ag-Pd, Cu.
After applying a conductive paste such as
It is formed by dry plating.

The multilayer substrate 30 thus obtained has the matching capacitors C1 to C3 and the terminating resistor R inside. Then, by increasing the film thickness of the electrode films 71a to 73a, 17 of the layer in which the resistor film 75 which is the heat source is formed, the heat dissipation is enhanced without increasing the number of resistors, and the resistor film 75 It prevents the temperature from rising. As a result, the power resistance can be improved without increasing the size of the isolator 1.

The above components are assembled as follows. That is, as shown in FIG. 1, the permanent magnet 9 is fixed to the ceiling of the metal upper case 4 with an adhesive. On the multi-layer substrate 30, the center electrode assembly 13 is soldered to the port electrode films P1 to P3 of the multi-layer substrate 30 at one end of each of the center electrodes 21 to 23 of the center electrode assembly 13 and the center electrode 21. The other end of each of Nos. 23 to 23 is mounted by being soldered to the ground lead electrode film 31.

The multilayer substrate 30 is placed on the bottom portion 8a of the metal lower case 8, and the ground terminal electrode 16 is electrically connected and fixed to the bottom portion 8a by soldering. As a result, sufficient grounding can be achieved, and the electrical characteristics of the isolator 1 can be improved.

Then, the side portion 8b of the metal lower case 8 and the side portion 4b of the metal upper case 4 are joined by solder or the like to form a metal case, which also functions as a yoke.
That is, this metal case forms a magnetic path that surrounds the permanent magnet 9, the center electrode assembly 13, and the multilayer substrate 30. Further, the permanent magnet 9 applies a DC magnetic field to the ferrite 20.

FIG. 4 is an electrical equivalent circuit diagram of the isolator 1. The matching capacitor C3 and the terminating resistor R are connected in parallel between the port electrode film P3 and the ground terminal electrode 16.

[Second Embodiment, FIGS. 5 to 7] FIG. 5 is an exploded perspective view of an isolator according to a second embodiment. The isolator 100 generally includes a metal case including a metal upper case 125 and a metal lower case 121, a ferrite 122, an input / output board 123, and a dielectric multilayer board 11.
0 and a permanent magnet 124.

A ferrite 122 is arranged on the bottom of the metal lower case 121. The input / output board 123 having a ferrite fitting hole provided in the center and the input / output board 1
A dielectric multilayer substrate 110 integrated with 23 is mounted so as to cover the ferrite 122. The metal upper case 125 having the permanent magnets 124 attached to the ceiling is attached to the metal lower case 121 to form a closed magnetic circuit.

As shown in FIG. 6, the dielectric multilayer substrate 110 includes a dielectric sheet 11 provided with a port electrode film P3, a ground electrode film 101a, and a resistor film 107 (terminating resistor R).
1. Dielectric sheets 112 and 114 provided with ground electrode films 101b and 101c, respectively, capacitor electrode film 10
Dielectric sheet 113 provided with 3a to 103c and dielectric sheet 1 provided with center electrode films 102c and 102b, respectively.
15, 116, the center electrode film 102a is provided on the upper surface, and the ground electrode film 101d and the port electrode film P1, are provided on the lower surface.
The dielectric sheet 117 is provided with P2.

Capacitor electrode films 103a, 103b, 1
03c constitutes matching capacitors C1, C2, C3 facing the ground electrode films 101b, 101c with the dielectric sheets 112, 113 interposed therebetween. The matching capacitors C1 to C3 and the terminating resistor R form an electric circuit together with the via holes 108 and the port electrode films P1 to P3 provided in the dielectric sheets 111 to 117. In addition,
In FIG. 6, the via holes 108 connected to the respective port electrode films P1 to P3 are shown connected by dotted lines.

In addition, three center electrode films 102a to 102
c are arranged so as to form an angle of approximately 120 degrees with each other. One end of each of the center electrode films 102a, 102b, 102c is connected to the port electrode film P via the via hole 108.
1, P2, P3, and the other end is electrically connected to the ground electrode films 101a to 101d through the via holes 108.

Here, as shown in FIG. 7, the resistor film 10
The film thickness T of the electrode film P3, 101a of the layer in which 7 is formed
2 is the remaining electrode film 101b-101d, 103a
˜103c, 102a to 102c, P1, P2 film thickness T
It is set to be thicker than 1. This allows
The heat generated in the resistor film 107 is efficiently transmitted through the electrode films P3, 101a connected to the resistor film 107 and radiated. Therefore, without increasing the number of resistors, the heat dissipation is improved and the temperature rise of the resistor film 107 is prevented. As a result, the power resistance can be improved without increasing the size of the isolator 100.

After the dielectric sheets 111 to 117 are laminated, they are integrally fired to form the multilayer substrate 1 as shown in FIG.
It is set to 10. The multilayer substrate 110 thus obtained has a terminating resistor R on the surface thereof and the matching capacitors C1 to C1 inside.
It has C3 and center electrode films 102a to 102c. The multilayer substrate 110 has an electrode film P formed on the bottom surface.
1, P2, 101d are respectively provided on the surface of the input / output substrate 123, an input terminal electrode 134, an output terminal electrode 135,
By soldering to the ground terminal electrode 136, it is electrically connected and fixed to the input / output board 123.

[Third Embodiment, FIG. 8] In the third embodiment,
A mobile phone will be described as an example of the communication device according to the present invention.

FIG. 8 is a block diagram of an electric circuit of the RF portion of the mobile phone 220. In FIG. 8, 222 is an antenna element, 223 is a duplexer, 231 is a transmission side isolator, 232 is a transmission side amplifier, 233 is a transmission side interstage band pass filter, 234 is a transmission side mixer, 235 is a reception side amplifier, and 236 is Bandpass filter for receiving side interstage, 2
37 is a receiving side mixer, 238 is a voltage controlled oscillator (VC
O) and 239 are local band pass filters.

Here, as the transmission side isolator 231, the lumped constant type isolators 1 and 100 of the first and second embodiments can be used. By mounting the isolators 1 and 100, a mobile phone with improved electrical characteristics can be realized.

[Other Embodiments] The present invention is not limited to the above embodiments, but can be modified into various configurations within the scope of the gist of the present invention. For example, in the second embodiment, the center electrode and the matching capacitor may be formed on the magnetic multilayer substrate. When the center electrode and the matching capacitor are formed on the magnetic multilayer substrate, a multilayer substrate having a structure in which ferrite and the center electrode are integrated is obtained. In addition, the thickness of the resistor film may not be the same as the thickness of the electrode film of the layer in which the resistor film is formed.

In the above embodiment, the thickness of the electrode film of the layer provided with the resistor film is set to be thicker than the thickness of the electrode films of the remaining layers, but the thickness is not necessarily limited to this. . The thickness of the electrode film of the layer provided with the resistor film and connected to the resistor film may be set to be thicker than the thickness of the remaining electrode films. Thereby, only the film thickness of the electrode film directly connected to the resistor film can be increased, the amount of the electrode film paste used can be suppressed, and the manufacturing cost can be reduced.

[0043]

As is apparent from the above description, according to the present invention, the thickness of the electrode film of the layer provided with the resistor film,
Since the thickness of the electrode film which is the layer provided with the resistor film and which is connected to the resistor film is increased, the heat generated in the resistor film is applied to the electrode connected to the resistor film. Heat is efficiently transmitted through the film. Therefore, it is possible to obtain a non-reciprocal circuit device and a communication device capable of handling high power without increasing the size.

The thickness of the thick electrode film is approximately n times the thickness of the remaining thin electrode film (where n ≧ 2.
By setting n: an integer), a thick electrode film can be easily formed without changing the electrode film paste by a simple process of overcoating twice or more.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of a non-reciprocal circuit device according to the present invention.

FIG. 2 is an exploded perspective view of the multilayer substrate shown in FIG.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is an electrical equivalent circuit diagram of the nonreciprocal circuit device shown in FIG.

FIG. 5 is an exploded perspective view showing a second embodiment of a non-reciprocal circuit device according to the present invention.

FIG. 6 is an exploded perspective view of the multilayer substrate shown in FIG.

7 is a sectional view taken along line VII-VII in FIG.

FIG. 8 is an electric circuit block diagram of a communication device according to the present invention.

[Explanation of symbols]

1, 100 ... Lumped constant type isolator 4, 125 ... Metal upper case 8, 121 ... Metal lower case 9, 124 ... Permanent magnet 13 ... Center electrode assembly 17 ... Circuit electrode film 20, 122 ... Ferrite 21 ... 23 ... Center electrodes 30, 110 ... Multilayer substrates 41-46, 111-117 ... Dielectric sheets 71a-73a, 71b-73b, 103a-103c
Capacitor electrode films 74, 101a to 101d ... Ground electrode films 75, 107 ... Resistor films 102a to 102c ... Central electrode film 220 ... Mobile phones C1 to C3 ... Matching capacitors R ... Termination resistors P1 to P3 ... Port electrode films

Claims (6)

[Claims] 1. A permanent magnet, a ferrite to which a DC magnetic field is applied by the permanent magnet, a plurality of center electrodes arranged on a main surface of the ferrite, a resistor film, an electrode film, and an insulating layer at least laminated. A multi-layer substrate configured by, the multi-layer substrate, a resistor formed of the resistor film,
At least a matching capacitor composed of the electrode film is provided, and in the multilayer substrate, the thickness of the electrode film of the layer provided with the resistor film is smaller than the thickness of the electrode film of the remaining layers. Non-reciprocal circuit device characterized by being thick. 2. A permanent magnet, a ferrite to which a direct current magnetic field is applied by the permanent magnet, a plurality of center electrodes arranged on the main surface of the ferrite, a resistor film, an electrode film, and an insulating layer at least laminated. A multi-layer substrate configured by, the multi-layer substrate, a resistor formed of the resistor film,
At least a matching capacitor composed of the electrode film is provided, and in the multilayer substrate, an electrode film of a layer in which the resistor film is provided and the electrode film connected to the resistor film. A non-reciprocal circuit device having a thickness greater than that of the remaining electrode film. 3. The nonreciprocal circuit device according to claim 1, wherein the resistor film is provided inside the multilayer substrate. 4. The film thickness of the thick electrode film is approximately n times the film thickness of the remaining thin electrode film (where n ≧ 2.
n: an integer) 4.
The nonreciprocal circuit device according to any one of 1. 5. The film thickness of the thick electrode film is approximately twice the film thickness of the remaining thin electrode film, according to any one of claims 1 to 3. Non-reciprocal circuit element. 6. A communication apparatus comprising the nonreciprocal circuit device according to claim 1. Description: