JP2003209408A - Non-reciprocal circuit element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-reciprocal circuit element in which further height reduction and miniaturization can be realized without short-circuiting a capacitor or central conductor assembly. <P>SOLUTION: Insulating coatings 3d and 2b are formed in respective areas facing the lateral sides of capacitors 7a and 7b by the inner walls of a lower yoke 3 and an upper yoke 2, and the lateral sides of the capacitors 7a and 7b are abutted to the inner walls of the lower yoke 3 and the upper yoke 2 via the insulating coatings 3d and 2b. On the inner bottom board of the lower yoke 3, a positioning pattern 3e for positioning the capacitors 7a and 7b and a central conductor assembly 6 is formed from the insulating coatings. Input/ output terminals 11a and 11b are composed of elastic sheet metals and integrally formed on a spacer 10. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-reciprocal circuit device that uses a magnetic material to give directionality to signal transmission, and more specifically to a non-reciprocal circuit called isolator or circulator used in mobile communication equipment. Regarding circuit elements.

[0002]

2. Description of the Related Art Conventionally, nonreciprocal circuit devices such as isolators and circulators have been used in terminals of mobile communication devices such as mobile phones and car phones used in the microwave band and UHF band. These isolators and circulators are used for the purpose of preventing damage to the amplifier inside the terminal, and have the function of reducing insertion loss in the signal transmission direction and increasing reverse loss in the reverse direction. is there.

As a conventional isolator 60, for example, as shown in FIG. 16, a lower yoke 6 made of a magnetic material is used.
1, a resin case 62 is integrally formed, and in this resin case 62, a capacitor 63, a chip resistor 64 as a terminating resistor, and a ferrite plate 65 are arranged so that three center conductors 66 are insulated from each other. Center conductor assembly 67
There is a configuration that is arranged. A magnet 68 for applying a DC magnetic field to the ferrite plate 65 is arranged on the central conductor assembly 67, and an upper yoke 69 made of a magnetic material is arranged on the opening surface of the resin case 62. The closed magnetic circuit is constituted by 69 and the lower yoke 61.

Here, the ground terminal 70 is the lower yoke 6
It is provided in a state of being electrically connected to 1. On the other hand, one end of the input / output terminal 71 is exposed to the outside while being insulated from the lower yoke 61, and is held by the resin case 62.

A plurality of penetrating portions 62a are formed at predetermined positions on the inner bottom surface of the resin case 62, and the penetrating portions 62a are formed.
And a groove portion 61a is formed on the inner bottom surface of the lower yoke 61,
The capacitor 63, the chip resistor 64, and the center conductor assembly 67 are housed in the groove 61a. This positions the capacitor 63, the chip resistor 64, and the center conductor assembly 67. Thus, the resin case 62 holds the input / output terminal 71, the capacitor 63, the chip resistor 64,
It also has a role of positioning the central conductor assembly 67 and the like.

[0006]

However, in the above isolator 60, the resin case 62 is insert-molded in the lower yoke 61, and the thickness of the resin case 62 is considerably thicker than that of the lower yoke 61. Specifically, the isolator 60 has a thickness d of several hundreds μm, and the height h is required to form the positioning through portion 62a. There was a limit to miniaturization. In particular, in recent years, with the demand for further miniaturization of mobile communication devices, there is an urgent need to design the size of the isolator 60 itself to, for example, 4 × 4 mm square or less. The existence is becoming a factor to prevent further miniaturization of the isolator 60.

Further, as an isolator, there has been proposed a structure in which a capacitor and a central conductor assembly are directly mounted on a lower yoke without using this resin case, but the capacitor and the central conductor assembly are proposed. Since there is no resin case for positioning, the capacitor and the central conductor assembly may be displaced during the manufacturing process. In that case, for example, the side wall of the capacitor may come into contact with the inner side walls of the lower yoke and the upper yoke to short-circuit the capacitor, and the function of the capacitor may not be fulfilled. In particular, the lower yoke is made of a material having a low conductivity in which a plating film such as Ag is formed on Fe or the like, and therefore, when the capacitor comes into contact with the inner side wall of the lower yoke, a short circuit is likely to occur.

Therefore, the present invention has been proposed in view of such a conventional situation, and eliminates the resin case which has been a limitation in miniaturization, and prevents the capacitor and the center conductor assembly from being short-circuited. It is an object of the present invention to provide a non-reciprocal circuit device capable of achieving further height reduction and size reduction.

[0009]

A non-reciprocal circuit device according to the present invention completed to achieve the above-mentioned object includes a magnetic yoke made of a metal case and a capacitor mounted on the inner bottom surface of the magnetic yoke. And a central conductor assembly mounted on the inner bottom surface of the magnetic yoke and having a plurality of central conductors crossed on a magnetic substrate in an electrically insulated state, and a magnetic substance housed in the magnetic yoke. The substrate is provided with a magnet for applying a DC magnetic field to the substrate, an input terminal and an output terminal that are electrically connected to the center conductor and the capacitor, and each end of which is drawn out from the magnetic yoke. An insulating coating is formed in a region facing at least one of the side surfaces, and the side surface abuts via the insulating coating. According to the present invention having such a configuration, at least one of the capacitor and the central conductor assembly abuts on the inner wall of the magnetic yoke via the insulating coating, so that the capacitor and the central conductor assembly can be assembled without using a thick resin case. While making it possible to prevent three-dimensional shorts,
The capacitor and the central conductor assembly can be arranged in the magnetic yoke as close to each other as possible, and the size can be reduced.

At this time, it is preferable that a positioning pattern for positioning at least one of the capacitor and the center conductor assembly is formed of an insulating coating on the inner bottom plate of the magnetic yoke. With this configuration, the capacitor and the center conductor assembly can be reliably positioned by the thin insulating film without using a thick resin case, and the non-reciprocal circuit device can be made low in height. .

Here, the above insulating film has a heat resistant temperature of 2
It is preferably made of a material having a temperature of 00 ° C. or higher. This makes it possible to sufficiently withstand the heating of the insulating coating even when it is placed in the reflow step when the capacitor or the like is mounted by soldering.

The thickness of the insulating coating is preferably 3 μm or more and 100 μm or less. If the thickness of the insulating coating is less than 3 μm, holes are likely to be formed in the insulating coating,
The short-circuit prevention function cannot be achieved. On the other hand, if the thickness of the insulating coating is larger than 100 μm, the size of the non-reciprocal circuit device will be hindered.

Further, in the nonreciprocal circuit device having the above-mentioned structure, a spacer member made of an insulating material housed in the magnetic yoke and arranged on the capacitor and the center conductor assembly is provided, and the spacer member is provided with an input terminal and an output terminal. A pair of terminal electrode parts that are integrally molded and that correspond to each of the input terminal and the output terminal are provided on the capacitor, and a plurality of center conductors are connected to the input terminal, and a center conductor that is connected to the output terminal. It is preferable that the other end of each of the input terminal and the output terminal is electrically connected to the corresponding terminal electrode portion on the capacitor through the corresponding center conductor. With this configuration, the input terminal and the output terminal can be held by the spacer member arranged on the capacitor and the center conductor assembly without using a thick resin case, and the non-reciprocal circuit device can be downsized. Can be achieved.

At this time, the input terminal and the output terminal are made of a metal plate having elasticity, and the spacer member is placed on the capacitor against the elasticity of the input terminal and the output terminal. More preferably, the other end is pressed against the corresponding terminal electrode portion on the capacitor via the corresponding center conductor. With this configuration, the input terminal and the output terminal can be reliably and firmly contacted with the terminal electrodes on the capacitor without holding the input / output terminal by the resin case.

Further, it is preferable that the spacer member is provided with a magnet housing portion for housing a magnet. This makes it possible to sufficiently reduce the height of the nonreciprocal circuit device even if the spacer member for holding the input / output terminals is provided.

The spacer member has a heat resistant temperature of 20.
It is preferably composed of an engineering plastic of 0 ° C. or higher. This makes it possible for the spacer member to sufficiently withstand the heating even if it is placed in the reflow step when the capacitor or the like is mounted by soldering.

Further, the central conductor may be provided with a claw portion that engages with the magnetic yoke. As a result, the claw portion engages with the magnetic yoke, so that the central conductor assembly can be reliably positioned without displacement.

It is more preferable that the magnetic substrate in the central conductor assembly has a rectangular shape. This allows
Since the length of the center conductor wound around the magnetic substrate can be made as long as possible, the inductance of the center conductor can be increased, and the low frequency can be applied. In addition, since the rectangular magnetic substrate can reduce the dead space during mounting as compared with the circular ferrite plate, it can be made smaller.

As the nonreciprocal circuit device according to the present invention completed to achieve the above-mentioned object, a magnetic yoke made of a metal case, a capacitor mounted on the inner bottom surface of the magnetic yoke, and a magnetic A central conductor assembly, which is placed on the inner bottom surface of the yoke and has a plurality of central conductors that are electrically insulated from each other and crosses over the magnetic substrate, and a DC conductor on the magnetic substrate that is housed in the magnetic yoke. At least one of the capacitor and the center conductor assembly is provided on the inner bottom surface of the magnetic yoke. A positioning pattern for positioning any one may be formed of an insulating coating. According to the present invention having such a configuration, the capacitor and the center conductor assembly can be reliably positioned by using the thin insulating film without using a thick resin case, and the nonreciprocal circuit device can be downsized. You can

Here, the insulating coating is preferably made of a material having a heat resistance of 200 ° C. or higher. This makes it possible to sufficiently withstand the heating of the insulating coating even when it is placed in the reflow step when the capacitor or the like is mounted by soldering.

The thickness of the insulating thin film is preferably 3 μm or more and 100 μm or less. If the thickness of the insulating thin film is smaller than 3 μm, holes are likely to be formed in the insulating film,
The short-circuit prevention function cannot be achieved. On the other hand, if the thickness of the insulating thin film is larger than 100 μm, the size of the nonreciprocal circuit device will be hindered.

Further, in the nonreciprocal circuit device having the above-mentioned structure, a spacer member made of an insulating material housed in the magnetic yoke and arranged on the capacitor and the center conductor assembly is provided, and the spacer member is provided with an input terminal and an output terminal. A pair of terminal electrode parts that are integrally molded and that correspond to each of the input terminal and the output terminal are provided on the capacitor, and a plurality of center conductors are connected to the input terminal, and a center conductor that is connected to the output terminal. It is preferable that the other end of each of the input terminal and the output terminal is electrically connected to the corresponding terminal electrode portion on the capacitor through the corresponding center conductor. With this configuration, the input terminal and the output terminal can be held by the spacer member arranged on the capacitor and the center conductor assembly without using a thick resin case, and the size can be reduced.

At this time, the input terminal and the output terminal are made of elastic metal plates, and the spacer member is placed on the capacitor against the elastic force of the input terminal and the output terminal, so that the input terminal and the output terminal are More preferably, each other end is pressed against a corresponding terminal electrode portion on the capacitor via a corresponding center conductor. With this configuration, the input terminal and the output terminal can be reliably and firmly contacted with the electrodes of the capacitor without holding the input / output terminal by the resin case.

Further, the central conductor may be provided with a claw portion which engages with the magnetic yoke. As a result, the claw portion engages with the magnetic yoke, so that the central conductor assembly can be reliably positioned without displacement.

Further, in the nonreciprocal circuit device according to the present invention completed to achieve the above-mentioned object, a capacitor and a plurality of center conductors are electrically insulated from each other and crossed over a magnetic substrate. A central conductor assembly, a magnet for applying a direct current magnetic field to the magnetic substrate, a spacer member made of an insulating material disposed on the capacitor and the central conductor assembly, a capacitor, a central conductor assembly, a magnet, and A capacitor is provided with a magnetic yoke made of a metal case for accommodating the spacer member, an input terminal and an output terminal which are integrally molded with the spacer member and are electrically connected to the central conductor and the capacitor, and one ends of which are drawn out from the magnetic yoke to the outside. A center conductor having a pair of terminal electrode portions corresponding to the input terminal and the output terminal, respectively, and a plurality of center conductors connected to the input terminal; and an output terminal. A center conductor to be connected, wherein the input terminal and the output terminal are made of elastic metal plates, and the spacer member is placed on the capacitor against the elastic force of the input terminal and the output terminal. Thus, the other ends of the input terminal and the output terminal may be pressed against the corresponding terminal electrode portions on the capacitor via the corresponding center conductors. According to the present invention having such a configuration, the input terminal and the output terminal can be held by the spacer member arranged on the capacitor and the center conductor assembly without using a thick resin case, and the size can be reduced. be able to. Moreover, the input terminal and the output terminal are made of elastic metal plates, and the other ends of the input terminal and the output terminal are pressed against the terminal electrodes on the capacitor, so that the input / output terminals are held by the resin case. Even without it, the input terminal and the output terminal can be surely and firmly contacted with the terminal electrodes on the capacitor.

At this time, it is preferable that the spacer member is provided with a magnet housing portion for housing a magnet. Thereby, even if a spacer member for holding the input / output terminals is provided,
It is possible to sufficiently reduce the height of the non-reciprocal circuit device.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION A non-reciprocal circuit device according to an embodiment of the present invention will be described below in detail with reference to the drawings, taking a case where it is applied to an isolator as an example. Figure 1
FIG. 3 is an exploded perspective view showing the isolator 1 according to the embodiment of the present invention.

The isolator 1 according to this embodiment has a function of reducing insertion loss in the signal transmission direction and increasing the reverse loss of reflected waves. Specifically, it is used in the microwave band and the UHF band. It is arranged between a power amplifier and an antenna in a terminal of a mobile communication device such as a mobile phone and a car phone, which prevents backflow of an unnecessary signal to the power amplifier and prevents damage to the power amplifier.

In the isolator 1, as shown in FIG. 1, three central conductors 4 are insulated from each other on a ferrite plate 5 in a yoke forming a closed magnetic circuit by joining an upper yoke 2 and a lower yoke 3. A central conductor assembly 6 arranged in a crossed state, capacitors 7a and 7b arranged around the central conductor assembly 6 and a chip resistor 8 as a terminating resistor, and a magnet 9 for applying a DC magnetic field to the ferrite plate 5. And a spacer 10 holding the magnet 9 are housed respectively.

FIG. 2A shows a plan view of the lower yoke 3.
FIG. 2B shows a sectional view of the lower yoke 3 taken along the straight line q in FIG. 2A. FIG. 3 is a plan view showing a state where the center conductor assembly 6, the capacitors 7a and 7b, and the chip resistor 8 are mounted on the lower yoke 3.

The lower yoke 3 is made of a metal plate having a ferromagnetism such as soft iron, and as shown in FIG. 2, side walls 3b are bent and formed on the two opposite sides of the bottom plate 3a.
Then, the other 2 which is not provided with the side wall 3b of the bottom plate 3a
A pair of ground terminals 3c are integrally formed on the sides. A conductive layer such as Ag plating is preferably formed on the front and back surfaces of the lower yoke 3.

In particular, on the inner wall 3b of the lower yoke 3, as shown in FIG. 2, an insulating thin film 3d is formed in a region facing the capacitors 7a and 7b and the chip resistor 8, and as shown in FIG. , The capacitors 7a and 7b and the chip resistor 8 are connected to the inner wall 3 of the lower yoke 3 through the insulating thin film 3d.
abut b. With such an insulating thin film 3d, it is possible to prevent short-circuiting of the capacitors 7a and 7b and the chip resistor 8 without using a conventional thick resin case, and at the same time, the capacitors 7a and 7b, the chip resistor 8 and the center conductor assembly 6 are provided. Can be arranged in the yoke as close as possible, so that the isolator 1 can be downsized.

Here, the insulating thin film 3 for preventing this short circuit
The film thickness of d is preferably 3 μm or more and 100 μm or less.
If the insulating thin film 3d is smaller than 3 μm, holes are likely to be formed in the insulating thin film 3d, and the short-circuit preventing function cannot be achieved. If the insulating thin film 3d is larger than 100 μm, miniaturization of the isolator 1 will be hindered.

As shown in FIGS. 1 and 2, a positioning pattern 3e for positioning the capacitors 7a and 7b, the chip resistor 8 and the center conductor assembly 6 is provided on the bottom plate 3a of the lower yoke 3. It is formed by.
Specifically, as shown in FIG. 2A, the positioning pattern 3e has a sickle-shaped or square-shaped positioning pattern 3e1 for positioning both ends and corners of the capacitors 7a and 7b, and a triangular cross-section for positioning one end of the chip resistor 8. Positioning pattern 3e2. Then, the central conductor assembly 6 is also positioned on one side surface of the positioning patterns 3e1 and 3e2 at the same time.

With such a positioning pattern 3e,
As shown in FIG. 3, it is possible to reliably use the capacitor 7a, as shown in FIG. 3, by using a thin insulating thin film without using a conventional thick resin case.
7b, the chip resistor 8 and the central conductor assembly 6 can be positioned, and the height and size of the isolator 1 can be reduced.

Here, the film thickness of the insulating thin film forming the positioning pattern 3e is preferably 3 μm or more and 100 μm or less, and more preferably 10 μm or more.
If the insulating thin film 3d is smaller than 3 μm, holes are easily formed in the insulating thin film, and the insulating thin film does not function as a positioning pattern. If the insulating thin film is larger than 100 μm, it hinders downsizing of the isolator 1. In order for the positioning pattern 3e to function as a more accurate positioning pattern, the film thickness is 1
It is preferably 0 μm or more.

Insulating thin film 3d for preventing short circuits,
The insulating thin film forming the positioning pattern 3e is 200 ° C.
It is made of a resin material having the above heat resistance. In particular,
Highly heat-resistant thermoplastic engineering plastics such as polyimide, liquid crystal polymer, and polyphenylene sulfide are included. By using such a material, when the capacitors 7a, 7b, etc. are placed on the lower yoke 3 via cream solder and soldered by the reflow process,
It is possible to sufficiently withstand the heating in the reflow step.

FIG. 4 is a plan view showing the ferrite plate 5, and FIG. 5 is a plan view showing the center conductor 4 in a developed state.
The ferrite plate 5 has a square shape as shown in FIG.
A pair of long sides 5a facing each other, a pair of short sides 5b facing each other, and an inclined side 5 connecting the long sides 5a and the short sides 5b.
It consists of c and. In this way, by using the rectangular plate as the ferrite plate 5, the length of the central conductor 4 wound around the ferrite plate 5 can be made as long as possible.
The inductance of the central conductor 4 can be increased,
It can be applied to lower frequencies. Further, since the square ferrite plate 5 can reduce the dead space during mounting as compared with the circular ferrite plate, it can be made smaller.

As the ferrite plate 5, for example, Y
An IG (yttrium / iron / garnet) -based magnetic material or the like can be used. Also, part of Y in YIG is G
It is also possible to use d, Ca, V or the like in which a part of Fe is replaced by Al, Ga or the like. In this embodiment,
Although the ferrite plate 5 is used, the material is not limited to the ferrite plate, and may be made of any magnetic material as long as the material functions as a nonreciprocal circuit element with respect to the DC magnetic field from the magnet 9.

Here, in the ferrite plate 5, as shown in FIG. 4, the angle formed by the long side 5a and the inclined side 5c is 10 ° to 3 °.
It is preferably 0 °. By setting the inclination angle of the inclined side 5c within this range, the inclined side 5c serves as a receiving surface for the bent portion of the center conductors 4c and 4d, and the center conductor 4 is accurately positioned and bent while preventing the center conductors 4c and 4d from floating. It will be possible.

As shown in the development view of FIG. 5, the central conductor 4 extends from the common electrode 4a having substantially the same shape as the rectangular ferrite plate 5 and the long side and the slanted side of the common electrode 4a, respectively. First central conductor 4b, second central conductor 4c
And a third central conductor 4d. These central conductors 4
Slits 4b1, 4c1 and 4d1 are formed in the centers of b, 4c and 4d along the longitudinal direction, and each slit is divided into a pair.

The center conductor 4 is formed by punching a sheet-like plate material made of a metal material such as copper, gold or silver into a shape as shown in FIG. 5 by a press machine, or by means such as etching. In the center conductor 4, the common electrode 4a is arranged on the inner bottom plate 3a of the lower yoke 3, the ferrite plate 5 is arranged on the common electrode 4a, and then the center conductors 4b, 4c of the center conductor 4 are formed. The center conductor assembly 6 as shown in FIG. 1 is formed by bending 4d through the side surfaces of the ferrite plate 5.

More specifically, the first central conductor 4b is bent at a right angle through the long side 5a of the ferrite plate 5, as shown in FIG.
As shown in, the ferrite plate 5 is arranged in a V shape on the surface. The second and third center conductors 4c and 4d are shown in FIG.
3 is bent along diagonal lines L1 and L2 of the ferrite plate 5, and as shown in FIG. 3, the ferrite plate 5 is overlapped on the surface of the ferrite plate 5 at an inclination angle of 120 ° in a plan view. At this time, an insulating sheet Z shown in FIG. 9 which will be described later is interposed between the conductors of the center conductors 4b, 4c, 4d, and the center conductors 4b, 4c, 4d are individually overlapped in an electrically insulated state. To be

In the central conductor assembly 6 composed of the central conductors 4 as described above, the central conductors 4b, which longitudinally cut the ferrite plate 5 in the direction of the short sides 5b, are V-shaped, so that the central conductors 4 are formed.
The substantial line length of b can be made long, and the length can be made as long as possible with the long central conductors 4c and 4d that cross the diagonal of the ferrite plate 5, and the inductance can be increased to reduce the frequency and further reduce the size. Can be adapted to Further, in the center conductor assembly 6, the three center conductors 4b, 4c, 4d are arranged so as not to overlap at one location,
The thickness can be reduced and the height can be reduced.

Further, as shown in FIG. 5, the central conductor 4 has claw portions 4e which engage with the upper yoke 2 on both sides of the short side.
Is provided and, as shown in FIG. 1, these claw portions 4e are bent so as to stand upright. Such a claw portion 4e engages with the inner side wall of the upper yoke 2, so that the central conductor assembly 6 is formed.
Can be reliably positioned without misalignment. The claw portions 4e may be provided at any position on the central conductor 4 and the number thereof is not limited.

The capacitor 7a is, for example, a single plate type capacitor, and as shown in FIGS. 1 and 3, the terminal electrode portion 7a1 is formed on the inner bottom plate 3a of the lower yoke 3 in a state where the central conductor assembly 6 is surrounded. It is soldered and grounded via a ground electrode provided on the opposite side of 7a2. Capacitor 7a
As shown in FIG. 3, terminal electrode portions 7a1 and 7a2 are provided on both ends on the hot end side, and second and third central conductors 4c and 4 are provided on the terminal electrode portions 7a1 and 7a2.
The tip of d is connected. Then, the tip ends of the second and third center conductors 4c and 4d are electrically connected to the later-described input / output terminals 11a and 11b provided on the spacer 10. The capacitor 7b is the first capacitor 7a.
And electrodes are formed on both surfaces, and the tip of the first center conductor 4b is connected to the hot end side electrode. Then, like the capacitor 7a, the capacitor 7b is soldered onto the inner bottom plate 3a of the lower yoke 3 via the ground electrode which is the cold end side electrode.

As shown in FIG. 3, the chip resistor 8 is arranged side by side with the capacitor 7b, and is soldered on the inner bottom plate 3a of the lower yoke 3 so as to surround the central conductor assembly 6 together with the capacitors 7a and 7b. Grounded. Then, the tip of the first central conductor 4b is connected to the upper surface of the chip resistor 8.

In this embodiment, an isolator is taken as an example of the non-reciprocal circuit element, but when the non-reciprocal circuit element of the present invention is applied to a circulator, another input / output is newly used without using the chip resistor 8. It suffices if a terminal is provided.
Further, the capacitors 7a and 7b and the chip resistor 8 may be arranged so that the ground electrode is connected to the inner side wall 3b of the lower yoke 3 and that the capacitors 7a and 7b stand vertically to the surface of the ferrite plate 5. At this time, the insulating coating 3d is provided on the inner bottom plate 3a of the lower yoke 3 at the portion where the side surfaces of the capacitors 7a and 7b contact, and at least the capacitors 7a and 7b on the inner side wall 3b and the ground electrode of the chip resistor 8 are connected. The insulating coating 3d is not provided on the portion to be covered. With this configuration,
The size of the isolator 1 can be further reduced.

FIG. 6 is an enlarged perspective view of the magnet 9 and the spacer 10 that houses the magnet 9. The spacer 10 is formed with a circular storage recess 10a for storing the magnet 9 on the upper yoke 2 side and a through hole 10b provided on the inner bottom surface of the storage recess 10a, and is formed from the magnet 9 stored in the storage recess 10a. A direct current magnetic field acts on the ferrite plate 5 of the central conductor assembly 6 through the through hole 10b. The magnet 9
May have a rectangular shape or another angular shape, and in that case, the storage recess 10 is provided in accordance with the shape of the magnet 9. Legs 10c are provided at the four corners of the spacer 10, and the spacer 10 is placed on the capacitors 7a and 7b and the chip resistor 8 via the legs 10c as shown in FIG. By mounting the spacer 10 in this manner, the spacer 10 presses the capacitors 7a and 7b and the chip resistor 8, so that the terminal electrode portion 7a1 of the capacitor 7 is pressed.
7a2 and the chip resistor 8 and the central conductors 4b, 4c, 4d can firmly contact each other, and the central conductors 4b, 4c, 4d are prevented from floating.

The spacer 10 is made of a resin material having a heat resistant temperature of 200 ° C. or higher. Specific examples thereof include highly heat-resistant thermoplastic engineering plastics such as polyimide, liquid crystal polymer, and polyphenylene sulfide. By using such a material, the capacitors 7a, 7
When b, etc. is placed on the lower yoke 3 via the cream solder and further the spacer 10 is placed on the capacitors 7a, 7b and carried into the reflow process, it should be able to sufficiently withstand the heating in the reflow process. You can

As shown in FIG. 6, the leg portion 10c of the spacer 10 has an input terminal 11a whose one end is pulled out of the yoke.
The output terminal 11b and the output terminal 11b are integrally formed. Here, FIG. 7 is an enlarged cross-sectional view showing a state in which the input terminal 11a is provided on the spacer 10 by cutting along the straight line n in FIG. FIG. 8 is an enlarged cross-sectional view showing the vicinity of the input terminal 11a in the isolator 1 with the spacer 10 and the upper yoke 2 placed thereon, taken along the line n in FIG. Specifically, as shown in the enlarged cross-sectional view of FIG. 7, the input terminal 11 a is the leg portion 10 of the spacer 10.
The leg portion 10c of the spacer 10 is flush with the bottom surface of c.
It is buried in. Then, as shown in the direction of the arrow in FIG. 7, the spacer 10 is placed on the capacitors 7a and 7b, so that the lower surface 11a1 of the other end of the input terminal 11a.
Contacts the tip of the second central conductor 4c on the terminal electrode portion 7a1 and electrically connects them.

As described above, the input terminal 11a and the output terminal 1 are provided on the spacer 10 without using the conventional thick resin case.
By integrally molding 1b, input / output terminals 11a and 11b
Can be held by the spacer 10, and the isolator 1
The width can be reduced in size. Moreover, by providing the spacer 10 with the storage recess 10a for storing the magnet 9, it is possible to reduce the height of the isolator 1.

Further, in the conventional isolator, the input / output terminal is made of the same material as the lower yoke, and is insert-molded in the resin case together with the lower yoke while being magnetically independent of the lower yoke. Since the lower yoke and the input / output terminal were formed of the ferromagnetic material, the input / output terminal might disturb the bias magnetic field from the magnet. However, by forming the input / output terminals 11a and 11b integrally with the spacer 10 as in the present embodiment, the input / output terminal 1
1a and 11b are made of C, which is different from the constituent material of the lower yoke 3.
Since it can be formed of a non-magnetic conductive material such as u,
The bias magnetic field is not disturbed, and as a result, the insertion loss can be reduced. In particular, when the ferrite plate 5 has a square shape, one end of the input / output terminal is arranged closer to the ferrite plate 5 than when it has a circular shape, and thus there is a large possibility that the input terminal disturbs the bias magnetic field in the past. But
With the configuration of the present embodiment, it is possible to reliably avoid the situation where the input / output terminals 11a and 11b disturb the bias magnetic field even if the ferrite plate 5 has a square shape.

As shown in FIG. 1, the upper yoke 2 is made of a material similar to that of the lower yoke 3, and is formed by bending both side walls from the upper plate. Notches 2a are provided to allow the terminals 11a and 11b to escape.

Particularly, on the inner wall of the upper yoke 2, an insulating thin film 2b is formed in a region facing the capacitors 7a, 7b and the chip resistor 8, and the capacitors 7a, 7b and the chip resistor 8 are connected via the insulating thin film 2b. The upper yoke 2 is brought into contact with the inner wall of the upper yoke 2. With such an insulating thin film 2b, it is possible to prevent short-circuiting of the capacitors 7a, 7b and the chip resistor 8 without using a conventional thick resin case, and at the same time, the capacitors 7a, 7b, the chip resistor 8 and the center conductor assembly 6 are provided. Can be arranged in the yoke as close as possible, so that the isolator 1 can be downsized.

In this embodiment, the insulating coatings 3d and 2b for preventing short circuits are provided on the inner side walls of both the lower yoke 3 and the upper yoke 2, but the present invention is not limited to this, and the lower yoke 3 is not limited to this. Further, even if the insulating coating is formed on the inner wall of at least one of the upper yoke 2 and at least one of the capacitors 7a and 7b, the chip resistor 8 and the central conductor assembly 6, the insulating coating is formed as compared with the conventional case. Has the effect of miniaturization. However, when the insulating coatings 3d and 2b are formed on both the lower yoke 3 and the upper yoke 2 facing the capacitors 7a and 7b and the chip resistor 8 as in the present embodiment, the capacitors 7a and 7b and the chip resistor 8 are formed. The center conductor assembly 6 can be arranged closest to each other, which is very advantageous in terms of downsizing.

Further, in the present embodiment, the insulating film for preventing short circuit is formed on the inner wall surfaces of the lower yoke 3 and the upper yoke 2 in the regions facing the capacitors 7a, 7b and the chip resistor 8. Not limited to, for example,
In the case of an isolator in which the center conductor assembly is arranged so as to be in close proximity to the inner wall of the lower yoke, an insulating film for preventing short circuit is formed on the region of the inner wall of the lower yoke facing the center conductor assembly. The central conductor assembly may be brought into contact with the inner wall of the lower yoke via the insulating film.

FIG. 9 is a sectional view of the isolator 1 shown in FIG. 1 taken along the line m in FIG. Figure 10
FIG. 4 is a sectional view of the isolator 1 shown in FIG. 1 taken along a straight line n in FIG. 3. As shown in FIGS. 9 and 10, the upper yoke 2 covers the central conductor assembly 6, the capacitors 7a and 7b, and the chip resistor 8 via a spacer 10 and is attached to the lower yoke 3 by solder (not shown) and closed. Configure a magnetic circuit.

Next, another example of the spacer and the input / output terminal in the isolator 1 of this embodiment will be described. FIG. 11 is an enlarged cross-sectional view of the spacer 20 provided with the input terminal 21a taken along the line n in FIG. Further, FIG. 12 is an enlarged cross-sectional view of the vicinity of the input terminal 21a where the spacer 20 and the upper yoke 2 are placed, taken along line n in FIG. Here, the lower yoke 3, the center conductor assembly 6, the capacitors 7a and 7b,
Since the chip resistor 8 and the magnet 9 have the same configurations as those in the above-described embodiment, the description thereof will be omitted.

The spacer 20 is provided with a recess 20a for accommodating the input terminal 21a, and a protrusion 20c for supporting the input terminal 21a is integrally extended to the outer edge of the leg portion 20b. The input terminal 21a is formed by bending an elastic metal plate into an L shape, penetrates the spacer 20, has one end supported by the protrusion 20c, and is drawn out to the outside as shown in FIG. The other end projects toward the recess 20 a of the spacer 20. At this time, the input terminal 21a
A clearance C is formed between the other end and the recess 20 a of the spacer 20.

Then, as shown in the arrow direction in FIG. 11, the spacer 20 is placed on the capacitors 7a and 7b against the elasticity of the input terminal 21a, so that as shown in FIG. One end of 21a is exposed to the outside from the notch 2a of the upper yoke 2, and the input terminal 21a
The other end is stored in the recess 20a and pressed against the tip of the second center conductor 4c on the terminal electrode portion 7a1. In this way, the input terminal 21a is connected to the capacitor 7 by the protrusion 20c.
The input terminal 21a can be firmly brought into contact with the second center conductor 4c and the terminal electrode portion 7a1 of the capacitor 7a in a state of being reliably insulated from a and the lower yoke 3, and the center conductor 4c can be prevented from floating. Become. The output terminal has the same structure as the input terminal, and the spacer 20 has the same structure as the recess 20a and the protrusion 20c.
It is preferable to provide a concave portion for accommodating the output terminal and a protruding portion for supporting the output terminal.

Next, another example of the spacer and the input / output terminal in the isolator 1 of this embodiment will be described. In FIG. 13, the spacer 30 has an input terminal 31a.
FIG. 4 is an enlarged cross-sectional view taken along the line n in FIG. Here, the lower yoke 3, the central conductor assembly 6, the capacitors 7a and 7b, the chip resistor 8 and the magnet 9 have the same configurations as those in the above-described embodiment, and therefore the description thereof is omitted. .

The input terminal 31a is formed by bending an elastic metal plate into an L-shape, penetrates the spacer 30, and has one end thereof extending from the cutout portion 2a of the upper yoke 2 to the outside, as shown in FIG. While being pulled out, the other end projects from the inner wall of the leg portion 30a of the spacer 30. And
The portion of the leg portion 30a protruding from the inner wall is further bent to form an L-shaped connecting piece 31b.

Then, the spacer 30 is placed on the capacitor 7a against the elasticity of the connection piece 31b of the input terminal 31a, so that the input terminal 31a is
Connection piece 31b is pressed against the tip of the second central conductor 4c on the terminal electrode portion 7a1. In this way, the input terminal 31
a can be firmly brought into contact with the second center conductor 4c and the terminal electrode portion 7a1 of the capacitor 7a.
It is possible to prevent the floating.

The output terminal has the same structure as the input terminal. Further, in the embodiment of the spacer 30 shown in FIG. 13, it is not necessary to provide the protruding portion 20c as in the embodiment of the spacer 20 shown in FIG. 12, so that the isolator can be further downsized.

Next, an outline of the operation of the isolator 1 constructed as above will be described. FIG. 14 is an electrical equivalent circuit diagram of the isolator 1. In the isolator 1, a bias magnetic field is applied to the ferrite plate 5 of the central conductor assembly 6 by the magnet 9, and the signal input from the port P1 is transmitted to the port P2 side as shown in FIG. On the other hand, a signal from the port P2 side is attenuated and absorbed by the chip resistor 8 as a terminating resistor arranged on the port P3 side, and a component toward the port P1 side is extremely attenuated.

The isolator 1 having such an operation function is arranged between a power amplifier (not shown) and an antenna in a terminal of a mobile communication device (not shown) to prevent backflow of an unnecessary signal to the power amplifier. To prevent damage.

The central conductor assembly of the present invention has a V-shaped central conductor 4b as shown in FIG.
Not only that having three center conductors 41a, 41b, 4 as shown in the perspective view of FIG. 15 and the development view of FIG.
One conductor 41c of 1c is divided by a slit so that the interval becomes wider toward the center in the longitudinal direction.
It may be composed of c1 and 41c2. Here, the divided conductors 41c1 and 41c2 are not parallel to each other, or have a shape in which opposite sides are parallel to each other and are bent as shown in FIG. Then, as shown in FIG. 15, the central conductors 41a, 41b, 41c are bent through the corresponding sides of the ferrite plate 5 and arranged in a pantograph shape.

In the center conductor assembly 40 composed of such a center conductor 41, the substantial line length of the center conductor 41c can be made long, and the inductance can be increased to adapt to low frequencies. Further, in this center conductor assembly 40,
By making the three center conductors 41a, 41b, 41c not overlap at one place, the thickness can be reduced and the height can be reduced.

As shown in the perspective view of FIG. 17, as the center conductor assembly 50 in the present invention, three conventionally proposed center conductors 51a, 51b, 51c are rectangular ferrite plates 52. Needless to say, the structure may be bent along the side wall of the.

[0071]

As described in detail above, in the nonreciprocal circuit device according to the present invention, in the inner wall of the magnetic yoke, in the region facing at least one side surface of the capacitor and the central conductor assembly, An insulating coating is formed, and the side surface is in contact with the insulating coating via the insulating coating. According to the present invention having such a configuration, at least one of the capacitor and the central conductor assembly abuts on the inner wall of the magnetic yoke via the insulating coating, so that the capacitor and the central conductor assembly can be assembled without using a thick resin case. The capacitor and the central conductor assembly can be arranged in the magnetic yoke as close as possible while preventing a three-dimensional short circuit, and the size can be reduced.

Further, the nonreciprocal circuit device according to the present invention is characterized in that a positioning pattern for positioning at least one of the capacitor and the central conductor assembly is formed on the inner bottom surface of the magnetic yoke by an insulating coating. You can use According to the present invention having such a configuration, the capacitor and the center conductor assembly can be reliably positioned by using the thin insulating film without using a thick resin case, and the nonreciprocal circuit device can be downsized. You can

Further, the nonreciprocal circuit device according to the present invention is
The input terminal and the output terminal are integrally formed with the spacer member,
Moreover, these input / output terminals are made of elastic metal plates,
By placing the spacer member on the capacitor against the elastic force of the input terminal and the output terminal, each other end of the input terminal and the output terminal is pressed against the terminal electrode portion provided on the capacitor. You can do it. According to the present invention having such a configuration, without using a thick resin case,
The input terminal and the output terminal can be held by a spacer member arranged on the capacitor and the center conductor assembly,
It is possible to reduce the size of the non-reciprocal circuit device. Moreover,
The input and output terminals are made of elastic metal plates, and the other ends of the input and output terminals can be pressed against the electrode part of the capacitor. The terminal and the output terminal can be reliably and firmly contacted with the terminal electrode portion on the capacitor.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an isolator according to an embodiment of the present invention.

FIG. 2 is a plan view and a cross-sectional view of a lower yoke of the isolator according to the present embodiment.

FIG. 3 is a plan view showing a state in which a center conductor assembly, a capacitor and a chip resistor are mounted on a lower yoke in the isolator according to the present embodiment.

FIG. 4 is a plan view showing a ferrite plate in the isolator according to the present embodiment.

FIG. 5 is a development view showing the center conductor of the isolator according to the present embodiment in an expanded manner.

FIG. 6 is an enlarged perspective view showing an enlarged magnet and a spacer that houses the magnet in the isolator according to the present embodiment.

FIG. 7 is an enlarged cross-sectional view showing a state in which the spacer is provided with an input terminal in the isolator according to the present embodiment.

8 is an enlarged cross-sectional view showing the vicinity of an input terminal in a state where a spacer and an upper yoke are placed in the isolator shown in FIG.

FIG. 9 is a cross-sectional view of the isolator according to the present embodiment taken along the line m in FIG.

FIG. 10 is a cross-sectional view of the isolator according to the present embodiment taken along the line n in FIG.

FIG. 11 is an enlarged sectional view showing another embodiment of the spacer and the input terminal.

FIG. 12 is an enlarged cross-sectional view showing the vicinity of the input terminal with the spacer and the upper yoke placed on the isolator shown in FIG.

FIG. 13 is an enlarged sectional view showing still another embodiment of the spacer and the input terminal.

FIG. 14 is an electrical equivalent circuit diagram of the isolator according to the present embodiment.

FIG. 15 is a perspective view showing another embodiment of the center conductor assembly.

16 is a development view showing a central conductor in the central conductor assembly shown in FIG. 15. FIG.

FIG. 17 is a perspective view showing still another embodiment of the center conductor assembly.

FIG. 18 is an exploded perspective view showing a conventional isolator.

[Explanation of symbols]

1 Isolator 2 Upper yoke 2b Insulation film 3 Lower yoke 3a Bottom plate 3b Side wall 3d insulating film 3e Positioning pattern 4 center conductor 4b First central conductor 4c Second central conductor 4d Third central conductor 5 Ferrite plate 6 Center conductor assembly 7a, 7b capacitors 8 chip resistance 9 magnets 10, 20, 30 spacer 10a storage recess 11a, 21a, 31a input terminals 11b output terminal 60 Isolator 61 Lower yoke 62 resin case 63 capacitor 64 chip resistance 65 Ferrite plate 67 Center conductor assembly 68 Magnet 69 Upper yoke

Claims (18)

[Claims] 1. A magnetic yoke formed of a metal case, a capacitor mounted on the inner bottom surface of the magnetic yoke, and a plurality of center conductors mounted on the inner bottom surface of the magnetic yoke and electrically insulated from each other. A central conductor assembly that is arranged so as to cross over the magnetic substrate, a magnet that is housed in the magnetic yoke and applies a DC magnetic field to the magnetic substrate, and that conducts to the central conductor and the capacitor. , An input terminal and an output terminal each of which is drawn out from the magnetic yoke to the outside, and an inner wall of the magnetic yoke faces at least one side surface of the capacitor and the central conductor assembly. A non-reciprocal circuit device, wherein an insulating coating is formed in the region, and the side surface contacts the insulating coating. 2. A positioning pattern for positioning at least one of the capacitor and the center conductor assembly is formed on the inner bottom surface of the magnetic yoke by an insulating coating. The described non-reciprocal circuit device. 3. The nonreciprocal circuit device according to claim 1, wherein the insulating coating is made of a material having a heat resistant temperature of 200 ° C. or higher. 4. The thickness of the insulating coating is 3 μm or more, 1
The non-reciprocal circuit device according to claim 1, wherein the non-reciprocal circuit device has a thickness of 00 μm or less. 5. A spacer member, which is housed in the magnetic yoke and is made of an insulating material, is disposed on the capacitor and the center conductor assembly, and the spacer member integrally includes the input terminal and the output terminal. Formed on the capacitor, a pair of terminal electrode portions are provided corresponding to each of the input terminal and the output terminal, the plurality of central conductors, a central conductor to be connected to the input terminal, A center conductor connected to the output terminal, and the other ends of the input terminal and the output terminal are electrically connected to the corresponding terminal electrode portions on the capacitor via the corresponding center conductor. The nonreciprocal circuit device according to any one of claims 1 to 4, wherein 6. The input terminal and the output terminal are made of an elastic metal plate, and the spacer member is placed on the capacitor against the elastic force of the input terminal and the output terminal. The nonreciprocal circuit device according to claim 5, wherein each of the other ends of the input terminal and the output terminal is pressed against the corresponding terminal electrode portion on the capacitor via the corresponding center conductor. 7. The nonreciprocal circuit device according to claim 5, wherein the spacer member is provided with a magnet housing portion for housing the magnet. 8. The upper temperature limit of the spacer member is 200.
The nonreciprocal circuit device according to any one of claims 5 to 7, wherein the nonreciprocal circuit device is made of an engineering plastic having a temperature of not less than ° C. 9. The claw portion that engages with the magnetic yoke is provided on the center conductor.
9. The nonreciprocal circuit device according to any one of 8 to 8. 10. The nonreciprocal circuit device according to claim 1, wherein the magnetic substrate has a rectangular shape. 11. A magnetic yoke formed of a metal case, a capacitor mounted on the inner bottom surface of the magnetic yoke, and a plurality of center conductors mounted on the inner bottom surface of the magnetic yoke and electrically insulated from each other. A central conductor assembly that is arranged so as to cross over the magnetic substrate, a magnet that is housed in the magnetic yoke and applies a DC magnetic field to the magnetic substrate, and that conducts to the central conductor and the capacitor. , A positioning terminal for positioning at least one of the capacitor and the central conductor assembly on an inner bottom surface of the magnetic yoke, each end having an input terminal and an output terminal drawn out from the magnetic yoke. A nonreciprocal circuit device having a pattern formed of an insulating film. 12. The nonreciprocal circuit device according to claim 11, wherein the insulating coating is made of a material having a heat resistance of 200 ° C. or higher. 13. The insulating coating has a thickness of 3 μm or more,
13. The nonreciprocal circuit device according to claim 11, which has a thickness of 100 μm or less. 14. A spacer member, which is housed in the magnetic yoke and is made of an insulating material, is provided on the capacitor and the central conductor assembly. The spacer member integrally includes the input terminal and the output terminal. Formed on the capacitor, a pair of terminal electrode portions are provided corresponding to each of the input terminal and the output terminal, the plurality of central conductors, a central conductor to be connected to the input terminal, A center conductor connected to the output terminal, and the other ends of the input terminal and the output terminal are electrically connected to the corresponding terminal electrode portions on the capacitor via the corresponding center conductor. The nonreciprocal circuit device according to claim 11, wherein 15. The input terminal and the output terminal are made of an elastic metal plate, and the spacer member is placed on the capacitor against the elastic force of the input terminal and the output terminal. 15. The nonreciprocal circuit device according to claim 14, wherein each of the other ends of the input terminal and the output terminal is pressed against the corresponding terminal electrode portion on the capacitor via the corresponding center conductor. 16. The nonreciprocal circuit device according to claim 11, wherein the center conductor is provided with a claw portion that engages with the magnetic yoke. 17. A capacitor, a central conductor assembly in which a plurality of central conductors are arranged so as to be electrically insulated from each other on a magnetic substrate, and a magnet for applying a DC magnetic field to the magnetic substrate. A spacer member made of an insulating material disposed on the capacitor and the central conductor assembly; a magnetic yoke made of a metal case accommodating the capacitor, the central conductor assembly, the magnet, and the spacer member; An input terminal and an output terminal, which are integrally molded with a member, are electrically connected to the central conductor and the capacitor, and have one end drawn out from the magnetic yoke to the outside; and the input terminal and the output terminal on the capacitor. A pair of terminal electrode portions is provided corresponding to each of the output terminals, and the plurality of center conductors include a center conductor connected to the input terminal and the output end. The input terminal and the output terminal are made of elastic metal plates, and the spacer member is placed on the capacitor against the elastic force of the input terminal and the output terminal. As a result, the other end of each of the input terminal and the output terminal is pressed against the corresponding terminal electrode portion on the capacitor via the corresponding center conductor. 18. The nonreciprocal circuit device according to claim 17, wherein the spacer member is provided with a magnet housing portion for housing the magnet.