JP5556120B2 - Non-reciprocal circuit element - Google Patents

Description

  The present invention relates to the structure of non-reciprocal elements such as isolators and circulators that are employed as high-frequency components in the microwave band of automobile phones, mobile phones, and the like.

  Non-reciprocal circuit elements such as isolators and circulators have a function of passing high-frequency signals only in the transmission direction and preventing transmission in the reverse direction. For example, an isolator is mounted on a motherboard together with a power amplifier and the like, and is an important microwave circuit component used to prevent instability of operation of the power amplifier due to a reflected wave caused by mismatching of the microwave circuit, and to prevent destruction.

  The nonreciprocal circuit element has a port portion used for connection of an input terminal, an output terminal, a dummy resistor, and the like. It is mounted on the motherboard together with a power amplifier as a microwave circuit component. In this case, the soldering of the nonreciprocal circuit element to the motherboard is achieved by significantly mounting productivity by mechanically mounting the nonreciprocal circuit element supplied in a tape-and-reel format with a mounter. Improvements are being made.

  In many cases, the port portion is usually formed of a thin copper plate having a thickness of 0.1 to 0.25 mm. The port portion is bent and soldered to a mounting substrate. However, such a thin copper plate has a problem that it is easily deformed by the action of external force, the terminal is deformed, and a gap is formed between the wiring of the mother board and a soldering failure is likely to occur.

For such a problem, Patent Document 1 proposes to use a terminal support member having rigidity and a terminal member (hereinafter sometimes referred to as a tab terminal) provided at an end of the terminal support member. . FIG. 6 is an external perspective view of the non-reciprocal circuit element, and FIG. 7 is an exploded perspective view showing a configuration of a lower case (storage container in the present invention) and a terminal support member.
Between the upper case 250 and the lower case 201, a permanent magnet, a plate-like ferrite, a central conductor, a ground plate, a terminal support member 501 and the like are disposed so as to overlap each other. The terminal support member 501 includes three arm portions 202 and extends from the side opening of the lower case 201, and a terminal member 502 is disposed on the distal end side of each arm portion 202. FIG. 8 is a cross-sectional view showing the configuration of the terminal member 502. A cylindrical contact lead 301 made of a conductive material and a dielectric material 302 covering the periphery of the body portion are provided, and the dielectric material 302 ensures insulation from the lower case 201 and the terminal support member 501.
The lead portion 401 of the central conductor extends from the side opening to the top side 306 of the cylindrical contact lead 301 of the terminal member 502 and is electrically connected. The bottom side 305 of the cylindrical contact lead 301 is the lower case. 201 is configured to be substantially flush with the bottom surface 24 of 201.

Patent Document 2 discloses that a terminal support member having rigidity is configured as an insulator. FIG. 9 is a perspective view showing an example of a non-reciprocal circuit device using the configuration, and FIG. 10 is an exploded perspective view showing the internal structure. Since the terminal support member 18 is made of a material having high bending strength such as glass epoxy resin or liquid crystal polymer, there is almost no deformation even when an external force is applied. A through hole 19 is provided at the end of the arm of the terminal support member 18, and the terminal member (tab terminal) 5 is formed in the through hole 22 and the through hole 19 formed at the end of the lead portion 20 of the center conductor 40. It is inserted and fixed by soldering. In FIG. 13 and FIG. 14, the same reference numerals are given to the parts common to the non-reciprocal circuit device of the present invention described later.
In any case, by connecting the lead portion of the central conductor to the wiring of the mother board via the terminal member supported by the terminal support member, even if an external force acts on the terminal member, the flatness can be easily broken. And good electrical connection is possible.

JP-A-10-294606 JP 2003-124711 A

However, there are some problems caused by the rigidity of the terminal support member. According to the configuration of the prior art, the flatness of the bottom surface of the lower case and the terminal member can be accurately formed, and deformation after the formation is prevented, but a separate terminal support member is required, and the parts cost Increases assembly man-hours.
In addition, the impedance of each input / output terminal is shifted, and there is a problem that it is difficult to adjust when the desired electrical characteristics cannot be obtained.
Therefore, in the present invention, even when an external force is applied to the terminal member, the flatness thereof is not easily lost, and a good electrical connection is possible. Even when the impedance of each input / output terminal is shifted, the adjustment is easy. An object of the present invention is to provide a non- reciprocal circuit device.

  The present invention is provided with a conductive tab terminal connected to an end portion of a lead portion of a central conductor extending from the storage container by arranging a plate-shaped ferrite, a central conductor, and a permanent magnet on the storage container. The lead portion extends radially in three directions at a predetermined angular interval centered on the common conductor portion of the central conductor that is overlapped with the plate-like ferrite, and the outer edge side portion of the plate-like ferrite. The non-reciprocal circuit device is characterized in that the lead portion is fixed to the storage container with an adhesive in the storage container.

It is preferable that the adhesive is provided in a paste form and has appropriate elasticity after curing. For example, it is preferable to have a viscosity that can be supplied by a dispenser (liquid dispensing device). However, if the viscosity is low, the adhesive may leak out, which may make handling difficult. Therefore, the viscosity of the adhesive is preferably 100 Pa · s or more. As such an adhesive, a silicone rubber adhesive is preferably used.
The adhesive is filled between the lead portion of the center conductor and the inner bottom surface of the storage container. Since the storage container functions as the ground of the nonreciprocal circuit, a grounding capacitor is formed by the parasitic capacitance generated between the lead part and the storage container or the ground plate disposed on the inner bottom surface of the storage container, and the impedance is adjusted. I can do it. The capacitance value can be adjusted by the amount of adhesive filled between the lead portion and the ground. Further, since the lead portion is fixed to the storage container by the curing of the adhesive, even if an external force acts on the terminal member, the flatness is not easily lost.

  The central conductor includes a lead portion extending in three directions from the common conductor portion with the common conductor portion resonating in the TM110 mode as a central portion. When a high-frequency current is passed through the center conductor, a high-frequency magnetic field surrounding the center conductor is generated in the plate-shaped ferrite, and a rotating magnetic field is generated in the plate-shaped ferrite by a permanent magnet, so that the input high-frequency magnetic field passes through the plate-shaped ferrite. In this case, the plane of polarization rotates, and the light is output only to a predetermined lead portion, so that the circuit has irreversibility.

  The central conductor is preferably made of a metal material having a spring property. For example, it is preferably formed from a thin plate made of phosphor bronze and having a thickness of 100 to 250 μm. This is etched or punched out with a mold to form a central conductor. Phosphor bronze is widely used as a highly reliable spring material because of its excellent strength and spring characteristics, and is excellent in stress corrosion cracking resistance. By using such phosphor bronze as the central conductor, the lead portion has both strength and springiness. Phosphor bronze tends to have a contradictory electrical resistivity with respect to strength and springiness. Depending on the electrical resistivity of the metal material having springiness to be used, it is desirable to plate a metal having a good conductivity such as Au, Ag or Cu on the surface.

A through hole is formed at the end of the lead portion, and a conductive tab terminal is inserted and fixed by an electrical connection member such as solder. The conductive tab terminal in the present invention preferably has a substantially cylindrical shape having a flat bottom surface, a truncated cone shape, and a push pin shape, and is an iron-based, copper-based, silver-based, or gold-based metal, Alternatively, any of these alloys is preferably used. Depending on the electric resistivity of the metal material to be used, it is desirable that the surface is plated with a metal having good conductivity such as Au, Ag, or Cu.
Further, the shape of the bottom side connected to the wiring of the mother board is allowed to be spherical or needle-shaped as long as it is difficult to process and does not cause a problem due to a decrease in the connection area.

  Since the tab terminal is inserted through the through hole formed at the end of the lead part, in addition to a simple columnar shape, it has a truncated cone shape, or a step is provided in the middle, with a thin shaft part and a thick shaft part. It is more preferable that the push pin is configured. In either case, insertion is restricted by the diameter of the through hole formed at the end of the lead portion. For this reason, the tab terminal is not inserted more than necessary into the through hole of the lead part, and the height of the tab terminal appearing on the motherboard side from the lead part is uniquely determined by the step or inclination, and the tab terminal and the mother boat Can be made substantially parallel. By setting the motherboard side of the tab terminal to the thick shaft side, the fixing area can be increased to increase the strength.

According to the present invention, even when an external force is applied to the terminal member, the flatness thereof is not easily lost, and a good electrical connection is possible. Even when the impedance of each input / output terminal is shifted, the adjustment is possible. An easy non- reciprocal circuit device can be provided.

Ru engaged to an embodiment of the present invention mounted on the motherboard is a perspective view of a nonreciprocal circuit device. In one embodiment of the present invention is an exploded perspective view of the nonreciprocal circuit element engaging Ru. It is a plan view of the center conductor for use in an embodiment in the non-reciprocal circuit element engaging Ru of the present invention. It is a perspective view of a tab terminal used in the non-reciprocal circuit element engaging Ru to an embodiment of the present invention. It is a partially enlarged view showing a mounting state to the motherboard of the engagement Ru nonreciprocal circuit device in an embodiment of the present invention. Is a perspective view showing an example of a conventional nonreciprocal circuit device. Is a partially exploded perspective view showing the structure of a conventional nonreciprocal circuit device. It is a partially enlarged view showing a mounting state to the motherboard of a conventional non-reciprocal circuit device. It is a perspective view showing another example of a conventional nonreciprocal circuit device. It is an exploded perspective view showing another example of a conventional nonreciprocal circuit device.

Examples isolator with a termination resistor, the non-reciprocal circuit element engaging Ru to an embodiment of the present invention will be described in detail with reference to the drawings. Figure 1 is a perspective view of a nonreciprocal circuit device of the surface mount type according to an embodiment of the present invention mounted on the motherboard, 2, non-reciprocal circuit surface mount type according to an embodiment of the present invention It is a disassembled perspective view of an element.
The nonreciprocal circuit device includes a storage container (lower case) 10 having openings 13 in three directions, and an extension 12 projecting from the outer periphery of the storage container 10 is formed in one of the openings 13. A central conductor 40 is disposed inside the container 10, a part of the lead portion 20 extends outside from the opening 13, and is connected to the tab terminal 5 at the end of the extension portion. The lead portion 20 not connected to the tab terminal 5 is connected to the absorption resistor R disposed on the extension portion 12. A plurality of housing members including the center conductor 40 are disposed in the housing container (lower case) 10. From the inner bottom surface side, the lower ground plate 63, the plate-like ferrite 30 b, the center conductor 40, the plate-like ferrite 30 a, and the shield plate 60. The lower iron plate 65, the permanent magnet 3, and the upper iron plate 70 are stacked and accommodated in this order. Further, the cover 15 is put on, and the storage container 10 and the cover 15 are fixed by brazing with solder or the like, or caulking, welding, etc., and the pressing force generated by the fixing acts on the storage member, and they are also combined. Fixed.

  A silicone rubber adhesive is applied between the lead portion 20 and the storage container 10 from the three openings 13 by a dispenser (quantitative discharge device). The adhesive is cured by a dryer in a state where no external force acts on the lead portion 20 and the tab terminal 5. Curing is performed at a temperature that does not degrade the performance of the adhesive, but the conditions are preferably a temperature of 100 ° C. to 200 ° C. and a holding time of about 30 minutes to 2 hours.

FIG. 3 is a plan view of the central conductor 40 used in the surface mount type nonreciprocal circuit device of this embodiment. The lead portion 20 extends from the central common conductor portion 45 in three directions at angles θa, θb, and θc, and is bent at an angle θd on the way. If the impedance at the input and output ends is the same as a basic design, the angles θa, θb, and θc are 120 °, respectively. However, in the isolator, the terminal resistor R that is added includes a lot of reactance components at the operating frequency. If this occurs, an impedance shift occurs and the electrical characteristics are degraded. Therefore, in order to compensate for this, the angle between the lead portion 20 connected to the termination resistor R and the other lead portion 20 may be set to 100 ° to 120 °. In this case, the angle between the other lead portions 20 through which high-frequency signals are input and output is 120 ° to 160 °.
The thickness of the center conductor 40 may be a thickness that allows the lead portion 20 to have springiness, and is preferably 50 μm to 250 μm if it is a phosphor bronze thin plate. As the thickness of the central conductor 40 increases, the space formed between the plate-like ferrites 30a and 30b increases, and the leakage magnetic flux that does not contribute to the operation as a nonreciprocal circuit element increases.
Further, the width of the lead portion may be set to a width that does not easily deform due to twisting or external force from the lateral direction, and is preferably 2 mm to 5 mm if it is made of a phosphor bronze thin plate.

  An example of the shape of the tab terminal 5 is shown in FIGS. It is formed in a cylindrical shape (a), a truncated cone shape (b), or push pin shapes (c), (d). In the case of a push pin shape, the center of the thin axis and the thick axis may not be concentric. Of course, the center can be different. It is preferable that they are concentric from the viewpoint of ease of processing, and the thin shaft side may be formed into a cylinder or a truncated cone shape, and the thick shaft side may be formed into a polygonal shape.

  FIG. 5 is a partially enlarged cross-sectional view when the tab terminal 5 is inserted into the through hole 22 at the end of the lead portion 20 and fixed by soldering, and then placed on the mounting member 204 and connected to the wiring 205. The lead portion 20 is fixed and supported by a silicone rubber adhesive up to the vicinity of the tab terminal 5. For this reason, the bottom surface 11 of the storage container 10 and the bottom surface 6 of the tab terminal 5 can be formed on substantially the same surface, and even if an external force acts on the terminal member, its flatness is not easily broken.

(Example)
Hereinafter, the nonreciprocal circuit device according to the present invention will be described in detail. Since the entire configuration is the same as that of FIGS. 1 and 2 already described in the previous section, the description of the overlapping parts will be omitted. A lower ground plate 63 having a thickness of 0.1 mm was disposed on the inner bottom surface of the storage container 10 made of SPCC. In the storage container 10, a plating layer having a total thickness of 10 to 30 μm is formed in the order of lower Cu—intermediate part Ni—upper Au.
A plate-like ferrite 30 b is disposed on the lower ground plate 63. Further, a central conductor 40 is disposed thereon. The central conductor 40 is formed by etching phosphor bronze having a thickness of 150 μm. The lead part 20 extends at an angle of 120 °.

  A through hole 22 having a diameter of 0.6 mm is formed at the end of the lead portion 20 through which high-frequency signals are input and output. The tab terminal 5 formed in the shape of a push pin with a thin shaft side of φ0.50 mm and a thick shaft side of φ1.0 mm is inserted into the through hole 22, and the thin shaft side of the tab terminal 5 and the lead portion 20 are connected by solder. Has been. The length of the tab terminal 5 appearing at the lower portion of the lead portion 20 is formed such that its lower surface is about 0.1 m lower than the lower surface of the storage container 10.

A plate-like ferrite 30 a is disposed on the center conductor 40. As the plate-like ferrites 30a and 30b, garnet ferrite having a diameter of 17 mm and a thickness of 0.5 mm, a relative dielectric constant εr of 11, a saturation magnetization of 4πMs of 115 mT, and a dielectric loss tan δε of 2 × 10 ⁻⁴ was used.

On the plate-like ferrite 30a, a shield plate 60 having a thickness of 0.1 mm, a lower iron plate 65 made of SPCC having a thickness of 0.8 mm, a permanent magnet 3 having a diameter of 20 mm and a thickness of 5 mm, and an upper iron plate 70 having a thickness of 0.8 mm. Are stacked and accommodated in order. Further, a lid 15 made of SPCC and having a thickness of 0.2 mm was disposed, and the end of the lid 15 was caulked to the folded portion at the upper end of the storage container 10 and fixed together with the housing member.
The permanent magnet 3 was a La-Co substitution type ferrite magnet. As for the magnetic properties, the residual magnetic flux density (Br) is 430 to 450 mT, and the intrinsic coercive force (iHc) is 382 to 414 KA / m.

A silicone rubber adhesive was applied to the three openings 13 by a dispenser. It is a silicone rubber adhesive having a viscosity of 110 Pa · s, a relative dielectric constant of 3.5 at 1 MHz, a dielectric loss tangent of 5 × 10 ⁻³ , and a durometer A50. The lead part 20 and the storage container 10 were fixed by holding and curing at 150 ° C. for 30 minutes.

  The obtained surface mount type nonreciprocal circuit device was placed on a motherboard. In order to check the connection state with the tab terminal 5 of the surface mount type non-reciprocal circuit element, the wiring is placed without applying a connecting member such as solder, and in this state, between the wirings connected to the two lead portions 20 The resistance value was confirmed. As a result, it was confirmed that there was no difference in resistance value between the tab terminals of the surface mount type nonreciprocal circuit element and a good mounting state was obtained.

5 Tab terminal 10 Storage container 20 Lead part 30a, 30b Plate-like ferrite 40 Center conductor 300 Adhesive

Claims (3)

A nonreciprocal circuit comprising a conductive tab terminal connected to an end portion of a lead portion of a central conductor extending from the storage container, in which a plate-shaped ferrite, a central conductor, and a permanent magnet are arranged in a storage container. An element,
The lead portions extend radially in three directions at a predetermined angular interval centered on the common conductor portion of the central conductor that is overlapped with the plate-like ferrite, appear on the outer edge side of the plate-like ferrite, and extend to the outer edge of the storage container. broth,
The lead portion in accommodating container is fixed directly to the inner bottom surface of the container by an adhesive, a non-reciprocal circuit device, which comprises forming a capacitor for impedance adjustment between the container and the lead portion has .   The nonreciprocal circuit device according to claim 1, wherein the adhesive is a silicone rubber adhesive. Substantially cylindrical said tab terminal having a flat bottom surface, a truncated cone shape, a non-reciprocal circuit device according to claim 1 or 2, characterized in that a push-pin shape.

Images