WO2017056689A1

WO2017056689A1 - Non-reversible circuit element, front end circuit and communication device

Info

Publication number: WO2017056689A1
Application number: PCT/JP2016/072603
Authority: WO
Inventors: 聖吾日野
Original assignee: 株式会社村田製作所
Priority date: 2015-09-29
Filing date: 2016-08-02
Publication date: 2017-04-06

Abstract

The objective of the present invention is to improve the filling ratio of a resin material around a magnetic rotor in order to reduce the likelihood of a non-reversible circuit element becoming deformed even if the non-reversible circuit element is subjected to stress. This non-reversible circuit element is provided with: a magnetic rotor (10) in which a plurality of central conductors are disposed in ferrite (20), and which has a mounting surface, a top surface and side surfaces; a permanent magnet (25) which surrounds the side surfaces of the magnetic rotor (10); yokes (51) and (52) disposed respectively on the mounting surface side and the top surface side of the magnetic rotor (10); and a resin material (60) which fills a space formed by the magnetic rotor (10), the permanent magnet (25) and the yokes (51) and (52). At least one slit (27) is provided in the permanent magnet (25).

Description

Non-reciprocal circuit element, front-end circuit and communication device

The present invention relates to a nonreciprocal circuit element, in particular, a nonreciprocal circuit element such as a circulator or an isolator used in a microwave band, a front end circuit including the nonreciprocal circuit element, and a communication device including the front end circuit.

Non-reciprocal circuit elements such as circulators and isolators have a characteristic of transmitting a signal only in a predetermined specific direction and not transmitting in a reverse direction. Using this characteristic, for example, a circulator is used in a front-end circuit of a mobile communication device such as a mobile phone.

Patent Document 1 includes a magnetic rotor made of ferrite in which a central conductor is arranged, a permanent magnet surrounding a side surface portion of the magnetic rotor, and yokes arranged on the mounting surface side and the top surface side of the magnetic rotor. A non-reciprocal circuit device is described.

JP-A-8-51306

In the non-reciprocal circuit element of the above-mentioned prior art, when the molten resin material is injected around the magnetic rotor, there is no gap through which air escapes at the injection destination, and voids are generated, and the filling rate of the resin material may deteriorate. There is sex. When the filling rate is deteriorated, there is a problem that when the stress is applied to the nonreciprocal circuit element, the nonreciprocal circuit element is easily deformed, and the characteristics and the like are deteriorated.

Accordingly, an object of the present invention is to improve the filling rate of the resin material around the magnetic rotor and to prevent deformation due to stress, and a front end circuit including the nonreciprocal circuit element And providing a communication device.

The nonreciprocal circuit device according to the first aspect of the present invention is
A plurality of central conductors are arranged in the ferrite, a magnetic rotor having a mounting surface, a top surface, and side surfaces
A permanent magnet surrounding the side of the magnetic rotor;
Yokes respectively disposed on the mounting surface side and the top surface side of the magnetic rotor;
A resin material filled in a space formed by the magnetic rotor, the permanent magnet and the yoke;
In a non-reciprocal circuit device comprising:
At least one slit is provided in the permanent magnet;
It is characterized by.

A front end circuit according to a second embodiment of the present invention includes the nonreciprocal circuit element. Furthermore, a communication device according to a third aspect of the present invention includes the front end circuit.

In the non-reciprocal circuit element, since at least one slit is provided in the permanent magnet surrounding the side surface of the magnetic rotor, when filling the molten resin material around the magnetic rotor, air is passed through the slit. Escaping, the generation of voids is suppressed, and a decrease in the filling rate of the resin material is prevented. Since the filling rate of the resin material does not decrease, the nonreciprocal circuit element is hardly deformed even when stress is applied to the nonreciprocal circuit element.

In the present invention, it is not always necessary to completely surround the side surface of the magnetic rotor with the permanent magnet, and a part thereof may be opened by a slit as in the following embodiments.

According to the present invention, in the nonreciprocal circuit element, by increasing the filling rate of the resin material around the magnetic rotor, the nonreciprocal circuit element is hardly deformed even when stress is applied to the nonreciprocal circuit element. .

It is an equivalent circuit diagram which shows the nonreciprocal circuit element (3 port type circulator) which is 1st Example. It is a disassembled perspective view of the circulator shown in FIG. FIG. 3 is an exploded perspective view of the magnetic rotor shown in FIG. 2. A part of manufacturing process of the circulator shown in FIG. 1 is shown, (A) is a plan view of the parent substrate viewed from the mounting surface side, and (B) is a side view thereof. It is sectional drawing of a magnetic rotor, (A), (B) shows the example of this invention, (C) shows a prior art example. A part of manufacturing structure of the nonreciprocal circuit device (3 port type circulator) which is 2nd Example is shown, (A) is the top view which looked at the main board | substrate from the mounting surface side, (B) is the side view. . The arrangement | positioning of the slit provided in the permanent magnet is shown, (A) is 1st Example, (B) is 2nd Example. It is a block diagram which shows a front end circuit and a communication apparatus (mobile phone).

Hereinafter, embodiments of the non-reciprocal circuit device, the front-end circuit, and the communication device will be described with reference to the accompanying drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same member and the overlapping description is abbreviate | omitted.

(Refer to the first embodiment of the non-reciprocal circuit device, FIG.
The nonreciprocal circuit device 1 according to the first embodiment is a lumped constant type three-port circulator having the equivalent circuit shown in FIG. That is, the first central conductor 21 (L1), the second central conductor 22 (L2) and the third central conductor 21 are applied to the rectangular microwave ferrite 20 to which the DC magnetic field A is applied by the permanent magnet 25 (see FIGS. 2 and 4). The center conductors 23 (L3) are arranged in an insulated state so as to intersect with each other at a predetermined angle, one end of the first center conductor 21 is the first port P1, the one end of the second center conductor 22 is the second port P2, and the third center. One end of the conductor 23 is a third port P3.

Furthermore, the other end of each of the

center conductors

21, 22, and 23 is connected to GND (ground). Capacitance elements C1, C2, and C3 are connected in parallel to the

central conductors

21, 22, and 23, respectively. A capacitive element Cs1 is connected between the first port P1 and the transmission terminal TX, a capacitive element Cs2 is connected between the second port P2 and the reception terminal RX, and the third port P3 and the antenna ANT A capacitive element Cs3 is connected between the two. The capacitive elements C1, C2, and C3 are for adjusting the resonance frequency, and the capacitive elements Cs1, Cs2, and Cs3 are for matching impedance.

Specifically, the nonreciprocal circuit element (3-port circulator) 1 composed of the above-described equivalent circuit includes a center conductor forming portion 24 (portions where the

center conductors

21, 22, and 23 are disposed) as shown in FIG. The magnetic rotor 10 including the ferrite 20 having a magnetic field, the substantially frame-shaped permanent magnet 25 surrounding the side surface of the magnetic rotor 10, the yoke 51 disposed on the mounting surface side of the magnetic rotor 10, and the top surface side. The yoke 52 and the resin material 60 are used. The resin material 60 is filled in a space formed by the magnetic rotor 10, the permanent magnet 25, and the

yokes

51 and 52. The details of the resin material 60 will be described later.

Here, as shown in FIG. 1, one end (port P1) of the first center conductor 21 is an external connection electrode 41, the other end is an external connection electrode 42, and one end (port P2) of the second center conductor 22 is The external connection electrode 43, the other end is an external connection electrode 44, one end (port P3) of the third central conductor 23 is an external connection electrode 45, and the other end is an external connection electrode 46. When the nonreciprocal circuit device 1 is incorporated in a transmission / reception circuit unit (front end circuit) such as a mobile phone, the first port P1 (electrode 41) is connected to the transmission side (TX) and the second port P2 (electrode) 43) is connected to the receiving side (RX), and the third port P3 (electrode 45) is connected to the antenna side (ANT).

The operation of the nonreciprocal circuit element 1 (3-port circulator) in the front-end circuit is as follows. That is, the high frequency signal input from the first port P1 (transmission circuit) is output from the third port P3 (ANT), and the high frequency signal input from the third port P3 (ANT) is the second port P2 (reception circuit). ). The high frequency signal of the second port P2 is not attenuated by the front end circuit and transmitted to the first port P1.

Specifically, as shown in FIG. 3, the magnetic rotor 10 includes

insulator layers

11, 12, 13, and 14 having glass as a main component on the top surface side and the mounting surface side of the rectangular microwave ferrite 20. In addition, a plurality of through-hole conductors and a plurality of electrodes for connecting various conductors provided on the top surface side and the mounting surface side in a coil shape are also formed on the ferrite 20. .

Specifically, the

conductors

21a, 21b, and 21c forming the first central conductor 21 (L1) are formed on the insulator layer 12, and the conductors 21d and 21e are formed between the insulator layer 13 and the ferrite 20. An end portion of the conductor 21a is an external lead portion 41a, and an end portion of the conductor 21c is an external lead portion 42a. The other end of the conductor 21a is connected to one end of the conductor 21d via the conductor 21f, and the other end of the conductor 21d is connected to one end of the conductor 21b via the conductor 21g. The other end of the conductor 21b is connected to one end of a conductor 21e via a conductor 21h, and the other end of the conductor 21e is connected to one end of a conductor 21c via a conductor 21i.

The conductors 22a, 22b, and 22c forming the second central conductor 22 (L2) are formed between the insulator layer 11 and the ferrite 20, and the conductors 22d and 22e are formed on the lower surface of the insulator layer 14. An end portion of the conductor 22a is an external lead portion 43a, and an end portion of the conductor 22c is an external lead portion 44a. The other end of the conductor 22a is connected to one end of the conductor 22d via the conductor 22f, and the other end of the conductor 22d is connected to one end of the conductor 22b via the conductor 22g. The other end of the conductor 22b is connected to one end of a conductor 22e via a conductor 22h, and the other end of the conductor 22e is connected to one end of a conductor 22c via a conductor 22i.

The conductors 23a, 23b and 23c forming the third central conductor 23 (L3) are formed between the insulator layers 11 and 12, and the conductors 23d and 23e are formed between the insulator layers 13 and 14. An end portion of the conductor 23a is an external lead portion 46a, and an end portion of the conductor 23c is an external lead portion 45a. The other end of the conductor 23a is connected to one end of the conductor 23d through the conductor 23f, and the other end of the conductor 23d is connected to one end of the conductor 23b through the conductor 23g. The other end of the conductor 23b is connected to one end of a conductor 23e through a conductor 23h, and the other end of the conductor 23e is connected to one end of a conductor 23c through a conductor 23i.

The external connection electrode 41 is formed by an external lead portion 41a which is an end portion of the conductor 21a and an electrode connected thereto. The external connection electrode 42 is formed by an external lead portion 42a, which is an end portion of the conductor 21c, and an electrode connected thereto. The external connection electrode 43 is formed by an external lead portion 43a which is an end portion of the conductor 22a and an electrode connected thereto. The external connection electrode 44 is formed by an external lead portion 44a, which is an end portion of the conductor 22c, and an electrode connected thereto. The external connection electrode 45 is formed by an external lead portion 45a, which is an end portion of the conductor 23c, and an electrode connected thereto. The external connection electrode 46 is formed by an external lead portion 46a which is an end portion of the conductor 23a and an electrode connected thereto.

The

central conductors

21, 22, and 23 can be formed as a thin film conductor such as Ag or Cu, a thick film conductor, or a conductor foil, and it is preferable to use a photosensitive metal paste. The insulator layers 11 to 14 are preferably made of a material having high insulation resistance such as photosensitive glass or polyimide. The conductor layer and the insulating layer can be formed by photolithography, etching, printing, or the like. The external connection electrodes 41 to 46 and the through-hole conductors are preferably formed by applying and baking a conductive electrode material (paste) mainly composed of Ag and Cu, and forming a Ni plating layer on the surface thereof. Further, a plating layer of Au, Sn, Ag, Cu or the like is formed. It is not limited to plating, but may be a sputtering process or the like. On the other hand, the capacitive elements C1, C2, C3, etc. use chip parts.

The magnetic rotor 10 having the above configuration is disposed in a substantially frame-shaped permanent magnet 25, a yoke 51 is disposed on the mounting surface side, a yoke 52 is disposed on the top surface side, and sealed with a resin material 60. By being stopped, the nonreciprocal circuit element 1 is obtained. The

yokes

51 and 52 are preferably made of a magnetic material such as a cold-rolled steel plate, and may be a single metal of Fe, Ni, Co or an alloy containing these as a main component. An Ag or Au plating layer may be formed on the surfaces of the

yokes

51 and 52 in order to reduce high frequency loss. A structure in which the side surface of the magnetic rotor 10 is surrounded by the permanent magnet 25 and the upper and lower surfaces are sandwiched between the

yokes

51 and 52 is referred to as a ferrite-magnet assembly in this specification.

Incidentally, as shown in FIG. 2, a plurality of hatched

electrodes

51a, 51b, 51c, 51d are formed on the mounting surface side yoke 51 in an insulated state, and the electrode 41 (first port P1). Is connected to the electrode 51a, the electrode 43 (second port P2) is connected to the electrode 51b, and the electrode 45 (third port P3) is connected to the electrode 51c. The

electrodes

42, 44, 46 (GND) are connected to the electrode 51d. That is, the electrodes 41 to 46 of the magnetic rotor 10 are connected to a transmission circuit, a reception circuit, and an antenna via

electrodes

51a, 51b, 51c, and 51d that are divided in an electrically insulated state.

As shown in FIG. 4, the nonreciprocal circuit element (circulator) 1 has one magnetic rotor 10 disposed in each section of a parent substrate 25 </ b> A serving as a permanent magnet 25 on a parent substrate 52 </ b> A serving as a yoke 52. Then, after sealing with the resin material 60, it is manufactured by covering with a parent substrate 51A to be the yoke 51 and cutting along the alternate long and short dash lines X and Y. Through holes 26 are formed in a matrix on the parent substrate 25A, and slits 27 are formed on each of a plurality of sides (four sides in this embodiment) in plan view. The slit 27 may be formed on at least one of the four sides.

In the magnetic rotor 10, the electrodes 41 to 46 are fixed to the electrodes 51 a to 51 d of the yoke 51 with solder inside the through hole 26. In this state, when the molten resin material 60 is filled from above (the top surface side), the resin material 60 is filled into the through hole 26 and also into the slit 27. That is, the resin material 60 is filled in the space surrounded by the magnetic rotor 10, the permanent magnet 25, and the yoke 51, and further filled in the slit 27 (see FIG. 5A). Since air escapes through the slits 27 at the time of filling, the molten resin material 60 is almost completely filled into the space. A parent substrate 52 </ b> A serving as a top surface side yoke 52 is attached to the upper surfaces of the resin material 60 and the permanent magnet 25 via an adhesive 29. Then, the cutting by the alternate long and short dash lines X and Y is performed by integrating the permanent magnet 25 and the

yokes

51 and 52 together.

Incidentally, when the slit 27 is not formed in the permanent magnet 25, when the resin material 60 is filled, there is no air escape, so as shown in FIG. Voids 28 are generated, and the resin filling rate decreases. The slit 27 may be formed in at least one of the sides constituting the through hole 26. However, as shown in FIG. 5B, a void 28 is formed on the side where the slit 27 is not formed. There is a risk of formation. Although what is shown in FIG. 5 (B) is not necessarily the best, the reduction of the filling rate is prevented compared with the comparative example of FIG. 5 (C).

When the filling rate of the resin material 60 is reduced, the non-reciprocal circuit element is likely to be deformed when stress is applied to the non-reciprocal circuit element, which may deteriorate the characteristics. However, in the nonreciprocal circuit element 1 according to the first embodiment, since the filling rate of the resin material 60 is prevented, the nonreciprocal circuit element 1 is deformed even when stress is applied to the nonreciprocal circuit element 1. It becomes difficult.

(Refer to the second embodiment of the non-reciprocal circuit device, FIG. 6)
The nonreciprocal circuit device according to the second embodiment has the same basic configuration and manufacturing method as the first embodiment. The difference is that, as shown in FIG. 6, in the parent substrate 25 </ b> A of the permanent magnet 25, slits 27 are formed in X shapes at the corners of a plurality of sides (specifically, four sides). Also in the second embodiment, since the air escapes through the slits 27 when the resin material 60 is filled, the generation of voids 28 is prevented and the filling rate of the resin material 60 is prevented from being lowered. In addition, the slit 27 should just be provided in the at least 1 corner.

(Magnetic flux density, see Fig. 7)
By the way, according to the inventor's simulation, the magnetic flux density of the DC magnetic field A applied from the permanent magnet 25 to the

central conductors

21, 22, 23 is 1100 gauss in the first embodiment, and in the second embodiment. 1140 Gauss. In this simulation, as shown in FIG. 2, a ferrite 20 having a regular square shape with a side dimension a of 1 mm is used, and the permanent magnet 25 is an inner shape b of 1.2 mm, an outer shape c of 2 mm, A slit having a height d of 0.4 mm, a slit 27 having a height e of 0.2 mm, and a width f of 0.1 mm was used. In order to cause the resin material 60 to flow inside the slit 27, the height e and the width f of the slit 27 are preferably 50 μm or more. Incidentally, as the resin material 60, an epoxy resin, a silicon resin, or the like can be suitably used.

The magnetic flux density of the second embodiment shown in FIG. 7B is higher than that of the first embodiment shown in FIG. 7A because the distance g between the central conductor forming portion 24 and the slit 27 is the first embodiment. This is because the second embodiment is larger than the example.

(Front end circuit and communication device, see FIG. 8)
FIG. 8 shows a front end circuit 70 including the nonreciprocal circuit device 1 and a communication device (mobile phone) 80 including the front end circuit 70. The front end circuit 70 is obtained by inserting the nonreciprocal circuit element 1 between a tuner 71 of an antenna ANT, a TX filter circuit 72, and an RX filter circuit 73. The

filter circuits

72 and 73 are a power amplifier 74 and a low noise amplifier 75, respectively. It is connected to the RFIC 81 via The front end circuit may include an antenna ANT and a tuner 71.

The communication device 80 includes an RFIC 81 and a BBIC 82 with respect to the front end circuit 70, a memory 83, an I / O 84, and a CPU 85 are connected to the BBIC 82, and a display 86 and the like are connected to the I / O 84.

(Other examples)
The nonreciprocal circuit element, the front end circuit, and the communication device according to the present invention are not limited to the above-described embodiments, and can be variously modified within the scope of the gist.

For example, the configuration, shape, number, etc. of the central conductor in the magnetic rotor are arbitrary. In particular, in the above-described embodiment, the magnetic rotor has a quadrangular shape in plan view, but may be a polygonal shape or a circular shape. The capacitive element may be composed of a conductor built in the circuit board, in addition to being mounted on the circuit board as a chip type. Further, when the application direction of the magnetic field to the ferrite 20 is reversed, the transmission path of the high frequency signal is switched.

As described above, the present invention is useful for non-reciprocal circuit elements, front-end circuits, and communication devices, and is particularly excellent in that the magnetic flux density applied to the magnetic rotor can be increased.

1 ... Non-reciprocal circuit element (circulator)
DESCRIPTION OF SYMBOLS 10 ... Magnetic rotor 20 ...

Ferrite

21, 22, 23 ... Center conductor 25 ... Permanent magnet 27 ...

Slit

51, 52 ... Yoke 60 ... Resin material 70 ... Front end circuit 80 ... Communication apparatus

Claims

A plurality of central conductors are arranged in the ferrite, a magnetic rotor having a mounting surface, a top surface, and side surfaces
A permanent magnet surrounding the side of the magnetic rotor;
Yokes respectively disposed on the mounting surface side and the top surface side of the magnetic rotor;
A resin material filled in a space formed by the magnetic rotor, the permanent magnet and the yoke;
In a non-reciprocal circuit device comprising:
At least one slit is provided in the permanent magnet;
A nonreciprocal circuit device characterized by the above.
The nonreciprocal circuit device according to claim 1, wherein the slit is provided on a mounting surface side.
3. The non-magnetic side according to claim 1, wherein the permanent magnet has a frame shape having a plurality of sides in a plan view, and the slit is provided on at least one side of the permanent magnet. 4. Reversible circuit element.
The permanent magnet has a frame shape having a plurality of sides and a corner formed by the sides in a plan view, and the slit is provided in at least one corner of the permanent magnet. The nonreciprocal circuit device according to claim 1 or 2.
A front end circuit comprising the nonreciprocal circuit device according to any one of claims 1 to 4.
A communication device comprising the front-end circuit according to claim 5.