JPH11205016A - Manufacture of isolator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the manufacture of an isolator, capable of taking prescribed isolation without regard to the positional error of the intersection of a center electrode in manufacturing process. SOLUTION: This method manufactures an isolator consisting of a magnetic body, first and second center electrodes 21 and 22 close to this magnetic body and crossing with each other, a magnet for impressing a DC magnetic field and a case housing them. In this case, the intersection of a first center line 21a, passing through the center of the width direction of a first center electrode 21 and a second center line 22a passing through the center of the width direction of a second center electrode 22 is set to be deviated from a center line 30, which is nearly parallel with both of a line passing through one tip 21b of the electrode 21 and one tip 22b of the electrode 22 and a line passing through the other tip 21c of the electrode 21 and the other tip 22c of the electrode 22 and passes through the center point of the magnetic body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a two-port isolator used in a high frequency band such as a mobile communication device.

[0002]

2. Description of the Related Art An isolator conventionally used in a mobile communication circuit or the like will be described with reference to FIG. However, the figure is a schematic diagram focusing on a ferrite molded body.

[0003] In a conventional isolator, a center conductor is printed on a ferrite sheet, and the center conductor is used to print the center electrodes 121 and 1.
Construct 22. The center electrodes 121 and 122 are stacked so as to form an angle of about 90 degrees with each other, and fired to form a ferrite molded body 120. The ferrite molded body 120 is arranged at a predetermined position on a substrate on which a circuit is formed by printing electrodes on a resin or the like.

One end 121b of the first center electrode 121 exposed on the side surface of the ferrite molded body 120 is used as an input terminal, and the other end 121c is used as an input terminal.
Is connected to earth. Similarly, one end 122b of the second center electrode 122 is connected to the output terminal, and the other end 122c is connected to the ground.

[0005] A chip resistor 115 is arranged between one end 121b, which is the input side of the first center electrode 121, and one end 122b, which is the output side of the second center electrode 122, on the circuit. Further, one end 121b of the first center electrode 121 and one end 122b of the second center electrode 122
, A chip capacitor 116 is arranged and connected to each other on the circuit.

As described above, the ferrite molded body 120, the resistor 115
The substrate on which the capacitors 116 are arranged is housed in a metal case. At this time, a magnet is similarly accommodated above the ferrite molded body 120 in the metal case, and a DC magnetic field is applied to the ferrite molded body 120. A closed loop of the magnetic field is formed by the metal case.

The isolator thus formed is matched so as to have a high isolation of 30 dB or more at a desired frequency by adjusting the lengths of the center electrodes 121 and 122 and the capacity of the capacitor 116. The isolator thus formed has a function that a signal input from an input terminal is output to an output terminal but does not allow a signal in the opposite direction to pass.

[0008]

In the above-described isolator, as shown in FIG. 10, a first center line 121a passing through the center in the width direction of the first center electrode 121 and a center passing through the center in the width direction of the second center electrode 122 are used. The intersection 128 of the second center line 122a was located on the center line 130 viewed from above the ferrite molded body 120.
At this time, the values of the matching circuits such as the capacitor 116 and the resistor 115 were designed on the condition that the intersection point 128 was on the center line 130. Here, the center line 130 is the first center electrode 121
And a line connecting the one end 121b on the input terminal side of the second center electrode 122 and the one end 122b on the output side of the second center electrode 122, and the other end 121c on the ground side of the first center electrode 121, and the other end on the ground side of the second center electrode 122. 122
This is a line that is substantially parallel to the line connecting to c and passes through the center point of the ferrite molded body 120.

However, when the center electrodes 121 and 122 are printed on a ferrite sheet, or when the ferrite molded body 120 is manufactured, such as when the ferrite sheets are laminated, the intersection point 128 deviates from an intended position. This cannot be avoided with current technology. And the error is ±
It is about 70 μm.

FIG. 3 shows the relationship between the degree of deviation of the intersection 128 between the first center line 121a and the second center line 122a from the center line 130 and the isolation. In this case, the isolator is a calcium-vanadium-garnet-structured magnetic material (hereinafter, referred to as a “vertical (vertical) length 1.6 mm) in a direction parallel to the center line 130 (horizontal length) of 2.4 mm. , CV
G) printed on a rectangular ferrite sheet consisting of palladium / silver and having a width of 0.5 mm, and laminated at a crossing angle of 90 °.
120 is used. And a 51Ω chip resistor to resistor 115,
A 5.5 pF chip capacitor is used for the capacitor 116.

As shown in FIG. 3, when the intersection 128 of the first center line 121a and the second center line 122a deviates more than 30 μm to the ground side, the isolation required for the function of the isolator of 30 dB or more cannot be obtained. Therefore, if the matching circuit is adjusted by assuming that the intersection point 128 of the first center line 121a and the second center line 122a is on the center line 130, an error of ± 70 μm in the manufacturing process of the ferrite molded body 120 will cause an error of 30 dB.
The intersection may be shifted in a range where the above isolation cannot be obtained. As described above, in the conventional isolator, there is a problem that a defective product in which desired isolation cannot be obtained occurs.

When the angle of intersection between the first center electrode 121 and the second center electrode 122 is changed to change the adjustment of the matching circuit such as the resistor 115 and the capacitor 116, the first center line 121a and the second center line 122a are changed. FIG. 5 shows the relationship between the degree of deviation of the intersection point 128 from the center line 130 and the isolation.

In this case, the first center line 121a and the second center line 12
If the intersection 128 of 2a is shifted more than 30 μm to the input / output side,
The isolation of 30dB or more required for the function of the isolator cannot be obtained. Therefore, the first center line
When the matching circuit is adjusted by setting the intersection 128 of the 121a and the second center line 122a on the center line 130, the ferrite molded body 120
Due to an error of ± 70 μm in the manufacturing process, the intersection may be shifted in a range where isolation of 30 dB or more cannot be obtained. Also in this case, there is a problem that a defective product in which desired isolation cannot be obtained occurs in the manufactured isolator.

[0014] In the above-described isolator, the length from the one end 121b of the first center electrode 121 to the intersection point 128 and L _1,
The length from one end 122b of the second center electrode 122 to the intersection 128 is L
_2, and the length from the other end 121c of the first center electrode 121 to the intersection point 128 and L _3, the intersection from the other end 122c of the second center electrode 122 12
A length of up to 8 when formed into a L _4, L ₁ = L ₂ and L ₃ = L ₄
In a relationship. At this time, in the example shown in FIG.
In the range of osθ <(L ₁ −L ₃ ) / 2 (μm), isolation of 30 dB or more cannot be obtained, and in the example shown in FIG.
In a range of 0 / cos θ <(L ₃ −L ₁ ) / 2 (μm), isolation of 30 dB or more cannot be obtained.

The above-mentioned problem also occurs in an isolator of a type in which metal foil center electrodes are overlapped on a ferrite via an insulating sheet so as to intersect each other, or in a distributed constant type isolator.

The isolator of the present invention has been made in view of the above-mentioned problems, and has as its object to solve these problems and to provide a method of manufacturing an isolator capable of stably obtaining an isolation of 30 dB or more. .

[0017]

According to a first aspect of the present invention, there is provided a method of manufacturing an isolator, comprising the steps of:
A second center electrode, a magnet for applying a DC magnetic field, one end of the first center electrode is connected to an input terminal, the other end is connected to ground, one end of the second center electrode is an output terminal, and the other end is grounded. A case that houses the resistor connected between one end of the first center electrode and one end of the second center electrode, the magnetic body, the center electrode, the magnet, and the resistor. In the method for manufacturing an isolator, a first center line passing through the center in the width direction of the first center electrode, and an intersection of a second center line passing through the center in the width direction of the second center electrode, The center point of the magnetic body is substantially parallel to both a line passing through one end of one center electrode and one end of the second center electrode and a line passing through the other end of the first center electrode and the other end of the second center electrode. The manufacturing method is set so as to be shifted from the center line passing through the center.

Further, according to the method of manufacturing an isolator according to claim 2, the first center line passing through the center in the width direction of the first center electrode and the second center passing through the center in the width direction of the second center electrode. A manufacturing method is used in which an intersection with a line is set so as to be shifted from the center line to one end of the first center electrode and one end of the second center electrode.

Further, according to the method of manufacturing an isolator according to claim 3, the first center line passing through the center in the width direction of the first center electrode and the second center line passing through the center in the width direction of the second center electrode. A manufacturing method is used in which an intersection with the center line is set to be shifted from the center line to the other end of the first center electrode and the other end of the second center electrode.

Further, according to the method for manufacturing an isolator according to claim 4, a line passing through one end of the first center electrode and one end of the second center electrode, the other end of the first center electrode, and the second A range of a shift between the center line passing through the center point of the magnetic body and the intersection, which is substantially parallel to both lines passing through the other end of the center electrode, is twice the distance from the center line to the first center electrode. k (μm), (-0.01875k + 70) ~
(0.125k-70) (μm) (However, 974 ≦ k ≦ 3733 (μm))
The manufacturing method is set so that

Further, according to the method for manufacturing an isolator according to claim 5, a line passing through one end of the first center electrode and one end of the second center electrode, the other end of the first center electrode, and the second Using a manufacturing method which is substantially parallel to both lines passing through the other end of the center electrode and which is set so that the range of deviation between the center line passing through the center point of the magnetic body and the intersection is 40 to 130 (μm). I have.

Further, according to the method for manufacturing an isolator according to the sixth aspect, the magnetic material, the first and second center electrodes which are close to and intersect with the magnetic material, and the magnet for applying a DC magnetic field. One end of the first center electrode is connected to an input terminal, the other end is connected to ground, one end of the second center electrode is connected to an output terminal, and the other end is connected to ground. In a method for manufacturing an isolator including a resistor connected between one end of two center electrodes, the magnetic body, the center electrode, the magnet, and a case accommodating the resistor, the first center electrode includes from the intersection of the second center line passing through the widthwise center of the first centerline and the second center electrode passing through the center in the width direction, a length of up to one end of the first central electrode is L _1, the intersection a length of up to one end of the second center electrode and L ₂ from When L ₁ = the relationship L _2, the length of the to the other end of the first center electrode and L ₃ from the intersection point,
The length from the intersection to the other end of the second center electrode is L ₄
Then, a manufacturing method is used in which L ₃ = L ₄ and L ₁ ≠ L ₃ .

Further, according to the method of manufacturing an isolator according to claim 7, the first center line passing through the center in the width direction of the first center electrode and the second center line passing through the center in the width direction of the second center electrode. The length L ₁ from the intersection with the center line to one end of the first center electrode and the length L ₃ from the intersection to the other end of the first center electrode have a relationship of L ₁ <L _3. The manufacturing method is set as follows.

Further, according to the method of manufacturing an isolator according to claim 8, the first center line passing through the center in the width direction of the first center electrode and the second center line passing through the center in the width direction of the second center electrode. from the intersection of the center line until the end of the first center electrode and the length L _1, and the length L ₃ from the intersection point to the other end of the first center electrode, a relationship of L _1> L ₃ The manufacturing method is set as follows.

Further, according to the method for manufacturing an isolator according to the ninth aspect, the first center line passing through the center in the width direction of the first center electrode and the second center line passing through the center in the width direction of the second center electrode. from the intersection of the center line until the end of the first center electrode and the length L _1, the length L ₃ from the intersection point to the other end of the first center _{electrode, L 1 + L 3 = h} (μm) Where (−0.01875 h cos θ + 70) ≦ | L ₁ −L ₃ | / 2
≤ (0.125hcosθ-70) (μm) (However, (974 /
(cos θ) ≦ h ≦ (3733 / cos θ) (μm)).

Further, according to the method of manufacturing an isolator according to claim 10, the first center line passing through the center in the width direction of the first center electrode and the second center line passing through the center in the width direction of the second center electrode. The length L ₁ from the intersection with the center line to one end of the first center electrode and the length L ₃ from the intersection to the other end of the first center electrode are 40 / cos θ ≦ | L ₁ -L ₃ | / 2 ≦ 130 /
The manufacturing method is set so as to satisfy cos θ (μm).

Further, according to the method for manufacturing an isolator according to the eleventh aspect, a manufacturing method is used in which the first center electrode and the second center electrode are composed of a plurality of layers of center conductors.

Further, according to the method for manufacturing an isolator according to the twelfth aspect, a plurality of first center conductor center lines passing through the center in the width direction of the plurality of layers of center conductors constituting the first center electrode, Among a plurality of center conductor intersections with a plurality of second center conductor center lines passing through the center in the width direction of the plurality of layers of center conductors constituting the second center electrode, at least one center conductor intersection is defined by the center line. More shifted to one end of the first center electrode and one end of the second center electrode,
A manufacturing method is used in which at least one center conductor intersection is set to be shifted from the center line to the other end of the first center electrode and the other end of the second center electrode.

Further, according to the method for manufacturing an isolator according to the thirteenth aspect, the range of deviation of the center conductor intersection from the center line is twice the distance from the center line to the first center electrode. Is k (μm), (−0.01875
k + 70) to (0.125k-70) (μm) (However, 974 ≦ k ≦ 373
3 (μm)).

Further, according to the method for manufacturing an isolator according to the fourteenth aspect, a manufacturing method is used in which the range of deviation of the center conductor intersection from the center line is 40 to 130 (μm). ing.

Further, according to the method for manufacturing an isolator according to the fifteenth aspect, a plurality of first center conductor center lines passing through the center in the width direction of the plurality of layers of center conductors constituting the first center electrode, A plurality of center conductor intersections with a plurality of second center conductor center lines passing through the center in the width direction of each of the plurality of layers of center conductors constituting the second center electrode; a length between the one end and l _1, the length from each of the central conductors intersecting point to one end of each second central conductor and l _2, from each of the central conductors intersecting point to the other end of the first center conductor The length of l ₃
When the length from each of the center conductor intersections to the other end of the second center conductor is l ₄ , l ₁ = l ₂ and l ₃ =
a l _4, and using the manufacturing method of at least about one layer <the relation l _3, l ₁ for at least another one layer> l ₁ set to a relationship of l _3.

Further, according to the method of manufacturing an isolator according to the sixteenth aspect, the plurality of first center conductor center lines passing through the center in the width direction of each of the plurality of layers of center conductors constituting the first center electrode are provided. A plurality of center conductor intersections with a plurality of second center conductor center lines respectively passing through the center in the width direction of the plurality of layers of center conductors constituting the second center electrode, and the first center conductor is provided from each of the center conductor intersections Length to one end of
₁ , at least one of the layers having a relationship of l ₁ <l ₃ and l ₁ > l _{3 in} a length l ₃ from each of the center conductor intersections to the other end of the first center conductor. At least one of the layers in the relationship is l ₁ + l ₃ = h (μm)
Where (−0.01875h cos θ + 70) ≦ | l ₁ −l ₃ |
/2≦(0.125hcosθ-70) (μm) (However, (974 / co
(sθ) ≦ h ≦ (3733 / cos θ) (μm)).

Further, according to the method for manufacturing an isolator according to claim 17, the plurality of first center conductor center lines passing through the center in the width direction of the plurality of layers of center conductors constituting the first center electrode, and A plurality of center conductor intersections with a plurality of second center conductor center lines respectively passing through the center in the width direction of the plurality of layers of center conductors constituting the second center electrode, and the first center conductor is provided from each of the center conductor intersections Length to one end of
₁ , at least one of the layers having a relationship of l ₁ <l ₃ and l ₁ > l _{3 in} a length l ₃ from each of the center conductor intersections to the other end of the first center conductor. At least one of the layers in the relationship is 40 / cos θ ≦ | l ₁ −l
₃ | / 2 ≦ 130 / cos θ (μm) is used.

According to the above configuration and method, a deviation of the intersection of ± 70 μm occurs in a process of manufacturing a ferrite molded body such as when printing a center electrode on a ferrite sheet or when laminating the ferrite sheet. However, the isolator of the present invention can reliably provide isolation of 30 dB or more.

Further, according to the present invention, the first and second center electrodes are composed of a plurality of stacked center conductors, so that the ferrite molded body has an input / output of the center line. It has a center conductor intersection on both sides. Therefore, the crossing angle of the center electrode formed by the center conductor and the matching circuit such as a resistor and a capacitor may be adjusted so that the center conductor crossing point is shifted to the input / output side / ground side, which side. . Therefore, the intersection of the first center line passing through the center in the width direction of the first center electrode of the ferrite molded body and the second center line passing through the center in the width direction of the second center electrode is shifted to which side. Marking or the like shown is unnecessary.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An isolator according to an embodiment of the present invention will be described below with reference to FIG. FIG. 1 is an exploded perspective view showing an isolator 10 of the present invention. As shown in FIG. 1, an isolator 10 of the present invention includes a ferrite molded body 20, a chip resistor 15, a chip capacitor
16, an upper case 11 and a lower case 12, and a magnet 13.

The ferrite molded body 20 is 2.4 mm wide and 1.6 mm long.
A single center conductor made of palladium / silver having a width of 0.5 mm is printed on a rectangular sheet-shaped CVG having a width of 1 mm, and a first center electrode and a second center electrode formed of one or a plurality of center conductors are formed. The ferrite sheets are stacked so as to cross each other at a crossing angle of 90 °. Then, firing is performed to form a ferrite molded body 20.

A circuit pattern is formed on a substrate 14 made of resin, and a ferrite molded body 20 is arranged at a predetermined position. One end of the first center electrode is connected to the input terminal, and the other end is connected to ground. One end of the second center electrode is connected to the output terminal, and the other end is connected to the ground. A chip resistor 15 of 51 Ω is mounted between one end of the first center electrode and one end of the second center electrode on the circuit, and a chip capacitor of 5.5 pF is provided for each of the first center electrode and the second center electrode. 16 has been implemented to be connected. The other end of the first center electrode, the other end of the second center electrode, and the other end of the chip capacitor 16 are connected to ground.

Thus, the ferrite molded body 20, the resistor 15,
The board 14 on which the capacitor 16 is mounted is housed in the lower case 12 and the upper case 11 made of metal. At that time, the magnet 13 is similarly accommodated in the upper part of the ferrite molded body 20, and a DC magnetic field is applied to the ferrite molded body 20. And a metal case
The closed loop of the magnetic field is constructed by 11 and 12.

The isolator 10 thus formed is used for a circuit such as mobile communication means, and a signal input from the input terminal side passes to the output terminal side, and a signal from the output terminal side does not pass to the input terminal side. It has the function of

Next, a method of manufacturing the isolator according to the present invention will be described. First, a predetermined amount of a magnetic powder mainly composed of calcium oxide and vanadium oxide is prepared, and 900 to
The material is calcined at 1200 ° C. to produce a calcined powder of a microwave magnetic material. Next, after crushing the calcined powder with an organic solvent,
It is dispersed in an organic solvent together with a polyvinyl alcohol-based binder to prepare a slurry. Further, the slurry is formed into a magnetic green sheet for microwaves having a uniform thickness of several tens of μm by a doctor blade method, and is punched into a predetermined size.

Next, a center conductor is formed on the sheet by screen printing and firing an electrode made of palladium and silver.

After laminating the magnetic green sheets for microwaves produced by the above steps, they are pressed and fired at 1200 to 1550 ° C. at the same time to obtain a ferrite molded body 20.

The ferrite compact 20 thus formed
Is connected by soldering and mounted on a substrate 14 on which circuit electrodes are formed on a resin by screen printing or the like. Similarly, on the substrate 14, a chip capacitor is provided at a predetermined position.
16 and the chip resistor 15 are soldered.

The substrate 14 is housed in a metal upper case 11 in which a magnet 13 is fitted and fixed, and a metal lower case 12.

As the magnetic material, yttrium, iron,
A garnet structure may be used, and an extrusion method may be used instead of the doctor blade method. Further, in this manufacturing method, the surface mounting type is used for the input / output terminals, but a metal foil may be used for the input / output terminals.

Further, a method of setting the center electrode intersection position in the isolator of the present invention will be described with reference to FIG. As shown in FIG. 2, a first center line 21a passing through the center in the width direction of the first center electrode 21,
The intersection point 28 with the second center line 22a passing through the center in the width direction of the second center electrode 22 is shifted by 100 μm from the center line 30 to one end 21b of the first center electrode 21 and one end 22b of the second center electrode 22. The value of the matching circuit is set so as to be arranged on the line. That is, the values of the matching circuits such as the capacitor 16 and the resistor 15 are designed in advance under the condition that the intersection 28 is located at a position shifted from the center line 30 by 100 μm. The center line 30 is a line connecting one end 21b of the first center electrode 21 and one end 22b of the second center electrode 22 and a line connecting the other end 21c of the first center electrode 21 and the other end 22c of the second center electrode 22. And passes through the center point of the ferrite molded body 20. By doing so, the ferrite molded body 20 such as center conductor printing and ferrite sheet lamination can be formed.
Even if a deviation of ± 70 μm that cannot be avoided in the manufacturing process occurs, the deviation from the center line 30 is in the range of 30 to 170 (μm). If the range of the deviation is 30 to 170 (μm), the isolation is 30 dB or more in all the manufactured isolators as shown in FIG.

The isolator according to this embodiment is arranged such that the first center electrode 21a and the second center line 22a
A length of up to one end 21b of the 21 as L _1, the length from the intersection 28 to the end 22b of the second central electrode 22 and L _2, the length from the intersection point 28 to the other end 21c of the first center electrode 21 and L _3, when the length from the intersection point 28 to the other end 22c of the second center electrode 22 was set to L _4,
L ₁ = a relationship of L ₂ and L ₃ = L _4. Shifting the intersection 28 from the center line 30 toward the one end 21b of the first center electrode 21 and the one end 22b of the second center electrode 22 by 100 μm means (L ₃
−L ₁ ) / 2 = 100 × 2 ^1/2 (μm) This is the same as the setting, and under these conditions, 30 dB or more isolation can always be obtained even if an error occurs in the manufacturing process. You can see that.

Next, a second embodiment of the present invention will be described. Since the configuration of the isolator is the same as that of the first embodiment, the ferrite molded body 20a will be described, and the same parts as those of the first embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 4, the intersection point 28 is arranged on the side of the other end 21c of the first center electrode 21 and the other end 22c of the second center electrode 22 on a line shifted from the center line 30 by 100 μm. The value of the matching circuit is set. That is, the capacitor 16 and the resistor
For the values of matching circuits such as 15, the intersection 28 must be
It is designed on condition that it is shifted by 100 μm from the position. In this way, even if there is an unavoidable deviation of ± 70 μm in the manufacturing process of the ferrite molded body 20a such as center conductor printing and ferrite sheet lamination, the deviation is 30 to
The range is 170 (μm). The shift range is 30 to 170 (μ
If m), as shown in FIG. 5, the isolation is 30 dB or more in all the manufactured isolators.

The isolator according to this embodiment is configured such that the first center electrode 21a and the second center line 22a
A length of up to one end 21b of the 21 as L _1, the length from the intersection 28 to the end 22a of the second central electrode 22 and L _2, the length from the intersection point 28 to the other end 21c of the first center electrode 21 and L _3, when the length from the intersection point 28 to the other end 22c of the second center electrode 22 was set to L _4,
L ₁ = a relationship of L ₂ and L ₃ = L _4. Shifting the intersection 28 from the center line 30 toward the other end 21b of the first center electrode 21 and the other end 22b of the second center electrode 22 by 100 μm means (L ₁
−L ₃ ) / 2 = 100 × 2 ^1/2 (μm) This is the same as setting, and under these conditions, 30 dB or more isolation can always be obtained even if an error occurs in the manufacturing process. You can see that.

In the first and second embodiments, one end of the ferrite molded body may be marked. Thereby, it is possible to clarify where the intersection 28 between the first center line 21a and the second center line 22a is shifted.

Next, a third embodiment of the present invention will be described with reference to FIGS. Since the configuration of the isolator is the same as that of the first embodiment, the ferrite molded body 40 will be described, and the same parts as those of the first embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

As shown in FIG. 7, in this embodiment, the ferrite molded body 40 has a four-layer laminated structure. That is, the center conductors 41, 42, 43, and 44 are formed and laminated on the plurality of ferrite sheets 31, 32, 33, and. Of the central conductors 41, 42, 43, 44, the central conductors 41, 43 constitute a first central electrode, and the central conductors 42, 44 constitute a second central electrode. Further, as shown in FIG. 6, the center conductor center line 41 of the center conductor 41 printed on the first ferrite sheet 31 is provided.
a and the center conductor center line 42a of the center conductor 42 printed on the second layer
The center conductor intersection 29a with the center line 30 of the ferrite sheet
100 μm on the side connected to the input and output terminals
The value of the matching circuit is set in advance so as to be arranged at a shifted position. Similarly, the third layer ferrite sheet
The center conductor intersection point 29b between the center conductor center line 43a of the center conductor 43 printed on 33 and the center conductor center line 44a of the center conductor 44 printed on the fourth layer is connected to the ground from the center line 30 of the ferrite sheet. The value of the matching circuit is set in advance so as to be arranged at a position shifted by 100 μm to the side of the matching circuit.

As a result, the isolation of 30 dB or more can always be obtained, and the ferrite molded body 40 can be arranged in any direction with the center line 30 as the axis of symmetry. Therefore, it is not necessary to provide a marking or the like for indicating the direction, and the manufacturing cost is reduced.

The isolator according to this embodiment is arranged such that the center conductor intersection point 29a between the first center conductor center line 41a of the first layer and the second center conductor center line 42a of the second layer is connected to one end of the first center conductor 41.
A length of up to 41b and l _1, the length of the central conductor intersections 29a to one end 42b of the second central conductor 42 and l _2, the central conductor intersections
A length of up to the other end 41c of the first central conductor 41 and l ₃ from 29a, when the length from the center conductor intersections 29a to the other end 42c of the second central conductor 42, and a l _4, l ₁ = l ₂ and l ₃ = l ₄ . Further, the length from the center conductor intersection 29b of the first center conductor center line 43a of the third layer and the second center conductor center line 44a of the fourth layer to one end 43b of the first center conductor 43 is l- ₁ , The length from the center conductor intersection 29b to one end 44b of the second center conductor 44 is l- ₂ , the length from the center conductor intersection 29b to the other end 43c of the first center conductor 43 is l- ₃ , and the center conductor intersection is When the length from 29b to the other end 44c of the second center conductor 44 is l- ₄ , l
_-1 = l- ₂ and l- ₃ = l- ₄ . To shift the center conductor intersection 29a by 100 μm from the center line 30 to the side connected to the input terminal / output terminal means (l ₃ −l ₁ ).
/ 2 = 100 × 2 ^1/2 is the same as set to satisfy ([mu] m), that shifted 100μm center conductor intersections 29b from the center line 30 on the side connected to the ground, (l _{- 1} −
This is the same as setting so that l ₋₃ ) / 2 = 100 × 2 ^1/2 (μm). Therefore, it is understood that under this condition, even if an error occurs in the manufacturing process, isolation of 30 dB or more can always be obtained.

It should be noted that the numerical values used in the above embodiment are just examples, and the present invention is not limited to this, and various combinations are possible according to desired characteristics. For example, the effects of the present invention can be obtained by appropriately combining a crossing angle of about 85 ° to 105 °, a resistance of 47 to 68Ω, and a capacitor of 4 to 8 pF. This is illustrated in FIG.
This will be described below with reference to FIGS.

FIG. 8 shows the relationship between the S ₁₂ -S ₂₁ phase difference of the isolator and the isolation. FIG. 9 shows the relationship between the intersection of the first center line and the second center line to one end of the first center electrode. When the length is L ₁ and the length from the intersection to the other end of the first center electrode is L ₃ , the ratio (in%) of L ₁ to (L ₁ + L ₃ ) and S ₁₂ -S ₂₁ phase difference FIG. 9 is a diagram showing a result of a simulation with respect to the relationship.

As shown in FIG. 8, the S ₁₂ -S ₂₁ phase difference is 1
In the range from 70 ° to 190 °, the isolator can achieve more than 30dB of isolation. Therefore, as long as the S ₁₂ -S ₂₁ phase difference falls within the range of 170 ° to 190 ° in FIG. 9, the isolator can achieve an isolation of 30 dB or more. That is, (L ₁ +
L ₃₎ the ratio of L ₁ with respect is that the take is more than 30dB isolation in the range of 37.5% of 51.875%.

When this condition is expressed as L ₁ + L ₃ = h (μm), -0.01875 h cos θ + 70 ≦ | L ₁ -L ₃ | / 2
≦ 0.125 h cos θ−70 (μm). However, since there is a manufacturing error of ± 70 μm from the set position of intersection 28, 30 d
At least 140 isolation ranges above B
(974 / cosθ)
≦ h (μm). In addition, the range where 30 dB or more of isolation can be obtained on one side when viewed from the center line 30 is as follows.
From the condition that it is smaller than 70 μm, h ≦ (3733 / cos
θ) (μm).

This will be considered by applying the above-described embodiment. In the above embodiment, h = 1600 × 2 ^1/2 (μ
m), the isolation range of 30 dB or more is -0.01875 h cos θ + 70 ≦ | L ₁ −L ₃ | /2≦0.1
In the conditional expression 25h cos θ-70 (μm), h = 1600 × 2 ^1/2 (μ
m), substituting cos θ = 1 ／ ^1/2 , 40 ≦ | L ₁ −L ₃ |
/ 2 ≦ 130 (μm). In comparison with FIGS. 3 and 5, it can be seen that this range is indeed compatible with the range in which the isolation of 30 dB or more can be obtained as shown from the experimental values of FIGS.

The above condition is that, if k (μm) is twice the distance from the center line to one end of the first center electrode, the range of the intersection between the center line and the intersection is (−0.01875 k + 70) to
This means that 30 dB or more of isolation can be obtained when the distance is (0.125k-70) (μm). However, 974 ≤
k ≦ 3733 (μm).

This will also be considered by applying the above-described embodiment. In the above-described embodiment, since the vertical length of the ferrite molded body is 1.6 mm, that is, k = 1600 (μm),
When k = 1600 (μm) is substituted into the conditional expression of −0.01875 + 70 to 0.125−70 (μm), the range of the deviation between the center line and the intersection where the isolation of 30 dB or more can be obtained is 40 to 130 (μm). According to FIGS. 3 and 5, this range is
Certainly, it can be seen that it is compatible with the range in which the isolation of 30 dB or more can be obtained as shown from the experimental values in FIGS.

The method for manufacturing an isolator of the present invention
An isolator of the type in which the center electrodes of metal foil are stacked on ferrite via an insulating sheet so as to cross each other,
The same can be applied to a distributed constant type isolator.

[0065]

As described above, according to the present invention, the intersection of the first center line passing through the center in the width direction of the first center electrode and the second center line passing through the center in the width direction of the second center electrode is determined. It was set to be shifted from the center line in accordance with matching circuits such as capacitors and resistors. By doing so, it is possible to manufacture an isolator capable of achieving an isolation of 30 dB or more despite the deviation of the intersection of ± 70 μm in the manufacturing process. Accordingly, the non-defective product rate is increased, and the production cost is reduced.

In addition, the deviation of the intersection was set in the range of 40 μm to 130 μm in accordance with the matching circuit such as a capacitor and a resistor. By doing so, 2.4m in width that is commonly used
When a ferrite molded body having a length of 1.6 mm and a length of 1.6 mm is used, an isolator capable of reliably achieving an isolation of 30 dB or more can be manufactured despite the deviation of the intersection of ± 70 μm in the manufacturing process. Therefore, the non-defective product rate is further increased, which leads to a reduction in manufacturing cost.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an isolator of the present invention.

FIG. 2 is a schematic view focusing on the ferrite molded body of the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a relationship between a shift of an intersection and isolation.

FIG. 4 is a schematic view focusing on a ferrite compact of a second embodiment of the present invention.

FIG. 5 is a second diagram showing the relationship between the displacement of the intersection and the isolation.

FIG. 6 is a schematic view focusing on a ferrite compact of a third embodiment of the present invention.

FIG. 7 is an exploded perspective view of a ferrite molded body according to a third embodiment of the present invention.

FIG. 8 is a diagram illustrating a relationship between an S ₁₂ -S ₂₁ phase difference and isolation.

FIG. 9: Ratio of L ₁ to (L ₁ + L ₃ ) and S ₁₂ −S ₂₁
It is a figure showing the relationship with a phase difference.

FIG. 10 is a schematic view focusing on a ferrite molded body of a conventional isolator.

[Explanation of symbols]

 10 Isolator 11 Upper case 12 Lower case 13 Magnet 14 Substrate 15 Chip resistor 16 Chip capacitor 20,20a, 40 Ferrite molded body 21,22 Center electrode 28 Intersection 29a, 29b Center conductor intersection 30 Center line 31,32,33,34 Ferrite Sheet 41,42,43,44 Center conductor

Claims (17)

[Claims] 1. A magnetic body, first and second center electrodes close to and intersecting with the magnetic body, a magnet for applying a DC magnetic field, one end of the first center electrode is an input terminal, and the other end is Is connected to ground, one end of the second center electrode is an output terminal, and when the other end is connected to ground, a resistor connected between one end of the first center electrode and one end of the second center electrode. In the method for manufacturing an isolator including the magnetic body, the center electrode, the magnet, and a case accommodating the resistor, a first center line passing through a center in a width direction of the first center electrode;
The intersection with the second center line passing through the center in the width direction of the second center electrode, the line passing through one end of the first center electrode and one end of the second center electrode and the other end of the first center electrode and the A method of manufacturing an isolator, wherein the isolator is set so as to be substantially parallel to both lines passing through the other end of the second center electrode and deviated from a center line passing through a center point of the magnetic body. 2. An intersection between a first center line passing through the center in the width direction of the first center electrode and a second center line passing through the center in the width direction of the second center electrode is defined by the first line from the center line. 2. The method for manufacturing an isolator according to claim 1, wherein the isolator is set so as to be shifted to one end of the center electrode and one end of the second center electrode. 3. An intersection of a first center line passing through the center in the width direction of the first center electrode and a second center line passing through the center in the width direction of the second center electrode is defined by the first line from the center line. 2. The method for manufacturing an isolator according to claim 1, wherein the isolator is set so as to be shifted to the other end of the center electrode and the other end of the second center electrode. 4. A line substantially parallel to both a line passing through one end of the first center electrode and one end of the second center electrode and a line passing through the other end of the first center electrode and the other end of the second center electrode. The range of deviation between the center line passing through the center point of the magnetic body and the intersection point is twice the distance from the center line to the first center electrode by k.
Claim (1), wherein (μm) is set so that (−0.01875k + 70) to (0.125k−70) (μm) (where 974 ≦ k ≦ 3733 (μm)). 4. The method for manufacturing the isolator according to claim 2, or 3. 5. A line substantially parallel to both a line passing through one end of the first center electrode and one end of the second center electrode and a line passing through the other end of the first center electrode and the other end of the second center electrode. The range of deviation between the center line passing through the center point of the magnetic body and the intersection point is 40.
5. The method for manufacturing an isolator according to claim 1, wherein the distance is set to be about 130 (μm). 6. A magnetic body, first and second center electrodes which are close to and intersect with the magnetic body, a magnet for applying a DC magnetic field, one end of the first center electrode is an input terminal, and the other end is Is connected to ground, one end of the second center electrode is an output terminal, and when the other end is connected to ground, a resistor connected between one end of the first center electrode and one end of the second center electrode. A method of manufacturing an isolator including the magnetic body, the center electrode, the magnet, and a case accommodating the resistor; a first center line passing through a center in a width direction of the first center electrode; from the intersection of the second center line passing through the center in the width direction of the center electrode, a length of up to one end of the first central electrode is L _1, the length from the intersection to the end of the second center electrode L have a relationship of L ₁ = L ₂ when _2, the first center from the intersection L ₃ to a length of the pole at the other end
When the length from the intersection to the other end of the second center electrode is L ₄ , L ₃ = L ₄ , and L ₁ ≠ L _3. A method for manufacturing an isolator. 7. An intersecting point between a first center line passing through the center in the width direction of the first center electrode and a second center line passing through the center in the width direction of the second center electrode to one end of the first center electrode. 7. The method according to claim 6, wherein a length L ₁ and a length L ₃ from the intersection to the other end of the first center electrode are set to satisfy a relationship of L ₁ <L ₃ . Manufacturing method of isolator. 8. From the intersection of a first center line passing through the center in the width direction of the first center electrode and a second center line passing through the center in the width direction of the second center electrode, to one end of the first center electrode. 7. The method according to claim 6, wherein a length L ₁ and a length L ₃ from the intersection to the other end of the first center electrode are set to satisfy a relationship of L ₁ > L ₃ . Manufacturing method of isolator. 9. An intersection point between a first center line passing through the center in the width direction of the first center electrode and a second center line passing through the center in the width direction of the second center electrode to one end of the first center electrode. the length L _1, the length L ₃ from the intersection point to the other end of the first center electrode, when the _{L 1 + L 3 = h (} μm), (-0.01875hcosθ + 70) ≦ | L 1 - L ₃ | / 2 ≦ (0.125
hcos θ-70) (μm) (However, (974 / cos θ) ≦ h ≦ (3733 / cos θ) (μ
m), and θ is set so as to satisfy a half angle of an intersection angle between the first center line and the second center line, and the same hereinafter). 8. The method for manufacturing an isolator according to 8. 10. From the intersection of a first center line passing through the center in the width direction of the first center electrode and a second center line passing through the center in the width direction of the second center electrode, to one end of the first center electrode. the length L _1, the length L ₃ from the intersection point to the other end of the first center _{electrode, 40 / cosθ ≦ | L 1} -L 3 | / 2 ≦ 130 / cosθ (μm) to meet the 10. The method for manufacturing an isolator according to claim 6, wherein the value is set to: 11. The method for manufacturing an isolator according to claim 1, wherein said first center electrode and said second center electrode are composed of a plurality of layers of center conductors. 12. A plurality of first center conductor center lines passing through the center in the width direction of each of the plurality of layers of center conductors forming the first center electrode, and a plurality of layers of center conductors forming the second center electrode. Among a plurality of center conductor intersections with a plurality of second center conductor center lines each passing through the center in the width direction, at least one center conductor intersection is located at one end of the first center electrode and the second center electrode from the center line. At least one center conductor intersection is set so as to be shifted from the center line to the other end of the first center electrode and the other end of the second center electrode. Item 14. The method for manufacturing an isolator according to Item 11. 13. The range of deviation of the center conductor intersection from the center line, where k (μm) is twice the distance from the center line to the first center electrode, is (−0.01875k + 70) to (−0.01875k + 70). 13. The method for manufacturing an isolator according to claim 12, wherein the setting is made so that 0.125k-70) (μm) (where 974 ≦ k ≦ 3733 (μm)). 14. The method for manufacturing an isolator according to claim 12, wherein the range of deviation of said center conductor intersection from said center line is set to 40 to 130 (μm). . 15. A plurality of first center conductor center lines passing through respective widthwise centers of a plurality of layers of center conductors forming the first center electrode, and a plurality of layers of center conductors forming the second center electrode. a length between each of the plurality of central conductors intersecting point and said central conductor intersections of the plurality of second center conductor centerline, each passing through the center in the width direction and one end of each of the first central conductor and l _1, the central the length from the respective conductor intersections to one end of each second central conductor and l _2, a length of up to the other end of the first central conductor and l ₃ from each of the central conductors intersecting point,
When the length from each of the center conductor intersections to the other end of the second center conductor is l ₄ , l ₁ = l ₂ and l ₃ = l ₄ , and at least one layer has l ₁ <l ₃ 12. The method for manufacturing an isolator according to claim 11, wherein a relationship is established such that l ₁ > l ₃ for at least one other layer. 16. A plurality of first center conductor center lines passing through respective widthwise centers of a plurality of layers of center conductors forming the first center electrode and a plurality of layers of center conductors forming the second center electrode, respectively. It has a plurality of center conductor intersections with a plurality of second center conductor center lines passing through the center in the width direction, a length l ₁ from each of the center conductor intersections to one end of the first center conductor, and each of the center conductor intersections And at least one of the layers having a relationship of l ₁ <l ₃ , and at least one of the layers having a relationship of l ₁ > l ₃ in a length l ₃ from the first center conductor to the other end of the first center conductor. When one layer is defined as l ₁ + l ₃ = h (μm), (−0.01875 h cos θ + 70) ≦ | l ₁ −l ₃ | / 2 ≦ (0.125
hcos θ-70) (μm) (However, (974 / cos θ) ≦ h ≦ (3733 / cos θ) (μ
m)) is set so as to satisfy
16. The method for manufacturing an isolator according to 15. 17. A plurality of first center conductor center lines passing through respective widthwise centers of a plurality of layers of center conductors forming the first center electrode, and a plurality of layers of center conductors forming the second center electrode. A plurality of center conductor intersections with a plurality of second center conductor center lines passing through the center in the width direction, a length l ₁ from each of the center conductor intersections to one end of the first center conductor, and each of the center conductor intersections And at least one of the layers having a relationship of l ₁ <l ₃ , and at least one of the layers having a relationship of l ₁ > l ₃ in a length l ₃ from the first center conductor to the other end of the first center conductor. 17. The method for manufacturing an isolator according to claim 15, wherein one layer is set so as to satisfy 40 / cos θ ≦ | l ₁ −l ₃ | / 2 ≦ 130 / cos θ (μm).