JPH03252202A - Non-reciprocal circuit element - Google Patents

Abstract

PURPOSE:To miniaturize parts and to reduce the number of parts and the man- hour of assembling to reduce the cost by making a case of an insulating resin and forming electrode films, which lead a center conductor to the outside, on the case by coating. CONSTITUTION:A terminal part 21 and a ground part 22 are formed on outside surfaces of second and third side walls 2b and 2c of a case 1 as one body, and a terminal part 23 is formed on the outside surface of a fourth side wall 2d as one body. An input/output electrode film 20 is formed from the outside surface of the terminal part 21 to the inner peripheral surface of a through hole 18a and the upper face of a step part 17. The input/output electrode film 20 is formed on the outside surface extended to a slit part 19 and the bottom of the slit part 19. A ground electrode film 24 is formed on the outside surface of a ground part 22 and is connected to a shield electrode film 25, and a bottom wall 2e constitutes a shield part. Since the case 2 is made of an insulating resin and the center conductor is led to the outside by electrode films 20 and 24 formed by coating, a short-circuit preventing space between elements can be omitted to miniaturize parts.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to non-reciprocal circuit elements, such as circulator isolators, which are employed as high-frequency components in the microwave band, and in particular, to miniaturization and weight reduction of the components. In addition, it relates to a structure that reduces costs by reducing the number of parts and assembly man-hours. [Prior art] Generally, circulators and isolators have almost no attenuation in the signal transmission direction, and no attenuation in the opposite direction. It has a function that increases the size of the device, and is used, for example, in transmitting circuits of mobile communication devices such as mobile phones and car phones. Conventionally, such an isolator has a structure shown in FIG. 9. This isolator 40 has a ferrite assembly 44 in which a pair of ferrites 43 and 43 are opposed to a plurality of center conductors 42 arranged inside a magnetic metal case 41, and a matching circuit on the inner surface of the assembly 44. A pair of dielectric substrates 45.4 on which capacitor electrodes are formed.
5 central holes 45a, located inside 45a! A pair of permanent magnets 47, 47 are brought into contact with each ground electrode formed on the outer surface of each dielectric substrate 45 via a shield plate 46, 46, respectively. In addition, each of the central conductors 42
One end of a rectangular output terminal 48 is connected to the external lead-out portion 42a, and the other end of each terminal 48 projects outward from the opening 41a of the case 41. The connection end portion of the output terminal 48 is embedded in a rectangular frame-shaped resin block 49 disposed along the inner peripheral edge of the case 41. The block 49 determines the position of each terminal 48, and at the same time, the terminal 48 is connected to the case 41 and the shield plate 46.
This is to avoid short-circuiting due to contact with the

Here, when the isolator or circulator is used in a mobile phone, for example, it is necessary to make the parts smaller and lighter due to the application, and in order to further stimulate demand, the parts need to be made lower in price. is requested.

[Problem that the invention seeks to solve]

However, the above-mentioned conventional isolator has a problem in that there is a limit to its size and weight reduction due to its structure, and it cannot sufficiently meet the demand for lower prices.

That is, since the resin block 49 needs to be strong enough to withstand the external force applied to the terminal, it must be set to a certain size, which increases the space for arrangement within the case, and as a result, parts Become larger.

In addition, since a metal case is used, it is necessary to provide space between each circuit element and the case to avoid damage caused by contact with each circuit element. This makes it difficult to reduce the weight of the metal case, and also makes it difficult to reduce the weight of the metal case.

Furthermore, the assembly work of the conventional isolator described above involves positioning and arranging a large number of separately formed component elements inside the case, which increases the number of assembly steps and makes assembly difficult, resulting in high costs. rises.

The object of the present invention has been made in view of the above-mentioned conventional situation, and it is an object of the present invention to provide a non-reciprocal circuit element that can realize miniaturization and weight reduction of parts, and can reduce cost by reducing the number of parts per assembly man-hour. It is an object.

[Means for solving problems]

The present invention includes a plurality of electrically insulated central conductors arranged in a cross-shaped manner within a case, a pair of ferrites interposed between the central conductors, and each central conductor led out of the case. The non-reciprocal circuit element configured as above is characterized in that the case is made of an insulating resin, and the case is covered with an electrode film that leads each of the center conductors to the outside of the case.

Here, as a method for forming an electrode film for leading to the outside on the above-mentioned case, it can be realized by employing an electroless plating method, a photoetching method, a sputtering method, or the like. For example, when forming electrodes by the electroless plating method described above, a resin material to which plating adheres and a resin material to which plating does not adhere are used. First, a case portion having a shape corresponding to the part on which the electrode film is to be formed is plated. Injection molding is performed using a resin material that will adhere, and this molded product is placed in a mold with a shape that corresponds to the remaining case part, and a resin material that does not adhere to the metal plate is injected into the cough mold, and injection molding is performed. The case is formed by two-step injection molding. After this, by subjecting the case to an electroless plating process, the electrode film can be formed only on the necessary portions.

[Effect]

According to the non-reciprocal circuit element according to the present invention, the case is formed of an insulating resin and the electrode film for leading to the outside is formed on the case. Therefore, the conventional terminal block can be made unnecessary, and the necessary arrangement within the case can be made accordingly. Space can be reduced and size can be reduced. Further, since the number of parts can be reduced by eliminating the need for the terminal block, and the assembly work of mounting the block in the case can be omitted, the cost can be reduced by that much and the price can be lowered.

Furthermore, since the case is made of insulating resin, it will not cause a short circuit even if it comes into contact with each circuit element, so the space for preventing a sheet, which is conventionally necessary, can be omitted, and from this point of view, the device can be made smaller. Furthermore, since the resin case is lighter than the conventional metal case, the overall weight can be reduced accordingly.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 to 8 are diagrams for explaining a nonreciprocal circuit element according to an embodiment of the present invention. In this embodiment, a case where it is applicable to a lumped constant type circulator will be explained as an example.

In the figure, 1 is a lumped constant type circulator of this embodiment. This circulator l has a center conductor board 3 disposed inside a box-shaped case 2, a pair of ferrites 4.4 are brought into contact with both main surfaces of the center conductor board 3, and the ferrites 4.4 are surrounded by a pair of ferrites 4.4. So first. Second dielectric substrate5.
A pair of permanent magnets 7.7 are arranged to face the center conductor substrate 3 with both dielectric substrates 5 and 6 in between, and the permanent magnets 7.7 It is configured to apply a direct current magnetic field.

Further, a rectangular plate-shaped magnetic metal yoke 26 is provided on the upper surface of the case 2, and a disk-shaped magnetic metal yoke 26 is provided on the lower surface of the case 2.
6 are arranged respectively, and the yoke 26 is connected to the case 2.
The opening is closed to form a magnetic closed circuit. Note that a shield plate 27 is disposed between the upper permanent magnet 7 and the first dielectric substrate 5.

As shown in FIG. 8, the center conductor substrate 3 has three pairs of center electrodes 9 (indicated by solid lines) formed on one principal surface 8a of an insulating substrate 8 made of a high dielectric constant material. The remaining portion of each center conductor 9 (indicated by a broken line) is formed on the other main surface 8b, and the opposing portion of the center conductor 9 on each main surface is formed as a through-hole electrode 9.
The central conductors 9 are electrically insulated and intersect at intervals of 120 degrees, and the ferrite 4 is in contact with the intersecting portions. Further, on the lead-out end side portions of each central conductor 9 on both main surfaces 8a and 8b, lead-out electrode films 1 facing each other with the substrate 8 in between are provided.
02 to 10C are formed, and the lead-out electrode films 10a to 10C are formed.
The lead-out ends of each of the central conductors 9 are connected to 10c. Further, on the tip side portion of each center conductor 9 on both main surfaces 8a and 8b, there is a ground electrode film 1)a facing each other with the substrate 8 in between.
~1) C is formed, and each earth electrode film 1)2~
1) The tip of the center conductor 9 is connected to C.

In addition, each of the lead-out electrodes l1) 103-
The IOCs and the earth electrode films 1) a to IICs are electrically connected to each other by the through-hole electrodes 12.
．． Insertion holes 5a, 6a are provided in the center of the second dielectric substrate 5.6.
are formed, and each of the ferrites 4 is inserted into the insertion holes 5a, 5a. Each of the above dielectric substrates5.
Three matching circuit capacitor electrode films 14 are formed on the opposing surfaces of the capacitors 6, respectively, and each electrode film 14 is connected to the lead-out electrode films 10a to 10c of the central conductor 9.

Further, a ground electrode film 15 is formed on substantially the entire surface of the opposite surface of each of the dielectric substrates 5 and 6.
A part thereof surrounds the edges of the insertion holes 5a, 6a and extends toward the opposing surface, and the extended portion 15a is connected to the ground electrode films 1)a to IIC of the center conductor 9.

The case 2 of this embodiment is made of insulating resin. This case 2 has first to fourth side walls 2a.
~2d is integrally formed with a bottom wall 2e in the shape of a rectangular box, and a circular opening 16 is formed on the lower surface of the bottom wall 2e, and the lower permanent magnet is inserted into the opening 16. 7. A metal yoke 26 is inserted. Also, a second side wall 2a adjacent to the first side wall 2a on the upper surface of the bottom wall 2e is provided. Triangular step portions 17 are formed to bulge out at some of the corners of the third side walls 2b and 2c. Each chamfered edge of the second dielectric substrate 6 is engaged with the step portion 17, and the upper surface of the step portion 17 and the upper surface of the second dielectric substrate 6 are approximately on the same plane. It has become. In addition, a bottom wall 2 is provided at the corner of each side wall 2a to 2d in the case 2.
Through holes 13a and 18b are formed to penetrate through the lower surface of each through hole 13a and 18b, and the upper end of each through hole 18a and 18b has a stepped portion 17.e. It is located on the upper surface of the bottom wall 2e.

Further, a slit portion 19 extending downward and having a depth located approximately on the same plane as the step portion 17 is formed in the center portion of the fourth side wall 2d.

In addition, the second case of the above case 2. A terminal portion 21° and a ground portion 22 are provided at both lower ends of the outer surfaces of the third side walls 2b and 2C, respectively.
are integrally formed therein, and a terminal portion 23 is integrally formed at the lower end central portion of the outer surface of the fourth side wall 2d.

As shown in FIGS. 2 and 3, each of the terminal portions 2
An output electrode film 20 is formed from the outer surface of the through hole 18a to the inner peripheral surface of the through hole 18a and the upper surface of the stepped portion 17.

Further, on the outer surface of the terminal portion 23, the outer surface extending to the slit portion 19 of the fourth side wall 2d, and the bottom surface of the slit portion 19, there are people,
An output electrode film 20 is formed (see FIG. 3), and a ground electrode film 24 is formed on the outer surface of each of the ground portions 22 and the inner peripheral surface of the through hole 18b. are connected to a shield electrode film 25 formed on the entire upper and lower surfaces of the bottom wall 2e of the case 2.

Thereby, this bottom wall 2e constitutes a shield portion.

Here, the above person, the output electrode membrane 20. Earth electrode film 24.
The shield electrode film 25 is formed by selectively applying electroless plating. To perform this selective plating, the following method can be adopted. First, portions of the case 2 corresponding to the terminal portions 21, 23, the ground portion 22, the bottom wall 2e, and the through holes 18a, 18b are injection molded using a resin material to which plating is attached. Next, this molded product is placed in a mold corresponding to the overall shape of the case 2, and a resin material that does not cause plating is injected into the cough mold. The case 2 is formed by such two-step injection molding. After that, by subjecting the case 2 to an electroless plating process, each of the terminal parts 21 and 23 and the ground part 22 are
, pole films 20, 24, and 25 are formed at necessary locations on the bottom wall 2e, and through holes 18a and 18b.

In this way, the lead-out tm films 10a to 10a of each of the central conductors 9 are
The IOC is connected to each capacitor electrode film 14 by solder, and is also connected to the output electrode film 20 by solder, and is led out to each terminal portion 21.23. In addition, each of the central conductors 9
The earth electrode films 1) a to Ilc are connected to the earth electrode film 24 via the extension part 15a of the earth electrode 15,
It is led out to each ground portion 22. In addition, each terminal part 21
23 and the center conductor 9 by providing a matching circuit between the electrode films 10a to 10c. In the present invention, such a case is also referred to as being "derived."

Next, the effects of this embodiment will be explained.

The circulator 1 of this embodiment has a function of preventing backflow of signals, and is an essential component for mobile communication devices such as mobile phones and car phones.

According to this embodiment, the case 2 is formed of an insulating resin, and the terminal portions 21 and 23 are provided on the outer surface of the case 2.
Since the grounding section 20 and the grounding section 22 are integrally formed and are led out through the respective electrode films 20 and 24 covered therewith, the conventional terminal block can be made unnecessary and the size can be reduced accordingly. Furthermore, since the case 2 is made of insulating resin, it will not cause a short circuit even if it comes into contact with each circuit element, so the conventionally required silat prevention space can be omitted, and from this point of view as well, the device can be made smaller.

In addition, this embodiment eliminates the need for the conventional terminal block,
Furthermore, a bottom wall 2e is integrally formed in the case 2, and the bottom wall 2e
Since the shield electrode film 25 is formed and used as a shield part, the conventional shield plate can be made unnecessary and the number of parts can be reduced. Furthermore, since the assembly work of mounting the block and the shield plate in the case can be omitted, the cost of parts can be reduced and prices can be lowered.

Furthermore, since the case 2 can be made smaller in weight than a conventional metal case, it can contribute to weight reduction.

In addition, each person in this example has an output t8i film 20. Earth electrode film 24. Since the shield electrodes 1 and 25 are formed by electroless plating, good electrical conductivity can be obtained and thermal conductivity can be lowered compared to conventional metal terminals. This is because when reflow soldering the above component elements, it is difficult for solder heat to be transmitted to each component element, so that an adverse effect on the characteristics can be avoided and reliability regarding quality can be improved.

In the above example, the case 2 is formed by two-step injection molding using a resin material to which plating adheres and a resin material to which plating does not adhere, and an electroless plating process is performed on this case. Although described above, the method of forming the electrode film of the present invention is not necessarily limited to this, and may be formed by a photoetching method or the like.

In the above embodiments, ferrite and permanent magnets are used.

Although the case where two dielectric substrates are used is explained as an example, if the characteristics required by the present invention are not so high, the structure may be constructed using only one dielectric substrate.

Further, although the magnetic metal yoke is provided only on the upper and lower surfaces of the case 2, in the present invention, the case 2 may be housed within a magnetic metal case to constitute a magnetic shield.

Furthermore, although the above embodiment has been explained using a lumped constant type circulator as an example, the present invention can of course be applied to a distributed constant type circulator as well as an isolator. This can be realized by connecting one end of the resistor to the electrode film and connecting the other end to the ground to form two input/output terminal sections.

〔Effect of the invention〕

As described above, according to the non-reciprocal circuit element of the present invention, the case is formed of an insulating resin and the case is coated with an electrode film that leads the central conductor to the outside, making the component smaller and lighter. This has the effect of reducing costs by reducing the number of parts and assembly man-hours.

[Brief explanation of drawings]

1 to 8 are diagrams for explaining a circulator according to an embodiment of the present invention, in which FIG. 1 is a cross-sectional perspective view of the case, FIG. 2 is a cross-sectional view taken along the line ■■ in FIG. 4, Fig. 3 is a partial sectional view taken along the line ■-■ in Fig. 4, Fig. 4 is a plan view of the circulator, Fig. 5 is a sectional view taken along V-VMI in Fig. 4, and Fig. 6 is a -■- ■ Line sectional view, Figure 7 is an exploded perspective view of the circulator, Figure 8 is a perspective view of its central conductor board, Figure 9 is a perspective view of the circulator.
The figure is a sectional view showing a conventional isolator. In the figure, 1 is a circulator (irreciprocal circuit element),
2 is a case, 4 is a ferrite, 9 is a center conductor, 10a~
10c is a lead-out electrode film (leading part), and 20 is an input/output tm film.

Claims (1)

[Claims] (1) A plurality of electrically insulated center conductors arranged in a cross-shaped manner are placed inside the case, and a ferrite is placed opposite the crossing portions of the center conductors, and each of the above-mentioned center conductors is connected to the outside of the case. In the non-reciprocal circuit element configured to lead out each of the central conductors to the outside of the case, the case is formed of an insulating resin, and the case is coated with an electrode film that leads each of the center conductors to the outside of the case. Non-reciprocal circuit element.