JPH08172307A - Dielectric coaxial resonator and its production - Google Patents

Abstract

PURPOSE: To remove variance of characteristics of resonators, to reduce the size and cost of the resonator and to attain easy manufacturing. CONSTITUTION: A dielectric 5 is provided.with an inner conductor 21 and an outer conductor 22. A terminal conductor line 1 made conductive to the conductor 21 and insulated from the conductor 22 is formed on the terminal part 51 of the dielectric 5. The line 1 is connected to one end part of the conductor 5 e.g. and formed like a groove. It is preferable to continuously form the line 1 by the same material as the conductor 21. The line 1 is formed so as to be extended from the conductor 21 on the end part 51 of the dielectric 5 in the direction to the substrate mounting face 59 of the conductor 22. The aperture end of the line 1 is recessed or projected from the substrate mounting face 59 of the conductor 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric coaxial resonator, and more particularly to a connection structure between its inner conductor and an external circuit.

[0002]

2. Description of the Related Art Generally, a dielectric coaxial resonator has a structure in which an inner conductor 92 and an outer conductor 93 are provided on a ceramic dielectric 91 having a through hole 90 as shown in FIGS. There is. The inner conductor 92 is formed on the inner wall of the through hole 90, and the outer conductor 93 is formed on the outer surface of the ceramic dielectric 91. The outer conductor 93 is grounded to the ground electrode 96 on the substrate 95 by the solder 94. The inner conductor 92 is connected to the metal terminal pin 97 mounted in the through hole 90. Further, the terminal pin 97 is joined to the external circuit 98 on the substrate 95 by the solder 99.

A method of mounting the terminal pin 97 is shown in FIG.
There is a direct fitting method utilizing the elasticity of metal shown in (for example, Japanese Utility Model Laid-Open No. 62-86708). In this method, one end of the terminal pin 97 is provided with a slit 970 in the longitudinal direction.
And a protrusion 971 on the outer periphery of the through hole 9
It is to be inserted into 0 and mounted. Also,
As another mounting method, there is a solder joining method of joining the terminal pin to the inner conductor with solder.

[0004]

However, in connecting the inner conductor 92 and the external circuit 98 of the conventional dielectric coaxial resonator 9 described above, there are the following problems. That is, in the case of the direct fitting method, it is necessary to precisely process the terminal pin 97 and insert it to a predetermined position. Also, in the case of the solder joining method, the terminal pin 97 has to be soldered to a predetermined position on the inner conductor 92 having a small diameter.

Such work of processing, inserting, and soldering the terminal pins not only causes variations in the characteristics of the resonator due to the depth of insertion of the terminal pins, the amount of solder, etc.
Increase manufacturing costs. Furthermore, the inner conductor of the dielectric coaxial resonator may be mechanically or thermally damaged, and the characteristics of the resonator may be impaired.

On the other hand, miniaturization of dielectric coaxial resonators has been steadily progressing in accordance with the trend of miniaturization of electronic parts. The smaller the dielectric coaxial resonator 9 becomes, the more difficult the mounting work of the terminal pin 97 becomes. Further, since the terminal pin 97 is located between the ceramic dielectric 91 and the external circuit 98, a three-dimensional space for arranging the terminal pin is required, which makes it difficult to achieve high-density mounting and miniaturization of the board.

In view of the above conventional problems, the present invention is intended to provide a low-cost dielectric coaxial resonator which is free from variations in the characteristics of the resonator, can be miniaturized, and is easy to manufacture, and a manufacturing method thereof. is there.

[0008]

According to the present invention, there is provided a dielectric coaxial resonator comprising an inner conductor and an outer conductor provided in a dielectric body, wherein an end portion of the dielectric body is electrically connected to the inner conductor and is connected to the outer conductor. Is a dielectric coaxial resonator comprising an insulated conductor line for terminals.

What is most noticeable in the present invention is that a conductor line for a terminal, which is electrically connected to the inner conductor and insulated from the outer conductor, is provided at the end of the dielectric.

The terminal conductor line is connected to one end of the inner conductor and is formed in a groove shape or a plane shape, for example. The groove-shaped conductor line for terminal is formed, for example, by the method described later. The flat terminal conductor line is formed by printing or printing, for example.

It is preferable that the terminal conductor line is formed so as to extend from the inner conductor at an end portion of the dielectric body in the direction of the board mounting surface of the outer conductor (FIG. 3). As a result, the terminal conductor line can be directly joined to the external circuit on the board by a soldering method or the like.
Therefore, it is easy to attach to the board without using terminal pins as in the conventional case.

It is preferable that the terminal conductor line is continuously formed of the same material as the inner conductor. As a result, the terminal conductor line and the inner conductor can be integrally formed, which facilitates manufacturing. The terminal conductor line and the outer conductor can be insulated by interposing an exposed dielectric between them.

The opening end of the terminal conductor line, that is, the opening portion on the side opposite to the inner conductor side can be opened to a recessed surface which is recessed from the board mounting surface of the outer conductor (FIG. 3). The step between the substrate mounting surface and the recessed surface is 0.05 to 2.
It is preferably 0 mm. If the thickness is less than 0.05 mm, the conductor electrode film may remain on the recessed surface, and the terminal conductor line and the outer conductor may not be insulated. on the other hand,
If it exceeds 2.0 mm, it may be difficult to bond it to an external circuit. Further, the opening end of the conductor line for terminal can be opened on a protruding surface of the outer conductor protruding from the board mounting surface (FIG. 8). The step between the board mounting surface and the projecting surface is preferably small in view of stability when mounted on the board, but if it is 0.5 mm or less, there is no problem.

The width of the terminal conductor line is 0.2 mm.
It is preferable that it is above. If it is less than 0.2 mm, the conductor line for the terminal may be broken in the middle.
In addition, it may be difficult to connect to the outer conductor. On the other hand, the width of this conductor line for terminals is smaller than the outer diameter of the dielectric coaxial resonator, and it is sufficient if it is insulated from the outer conductor.
From the standpoint of ease of manufacture, this width is preferably 0.8 mm or more smaller than the outer diameter of the dielectric coaxial resonator.

Next, as a method of manufacturing the dielectric coaxial resonator, for example, a through hole is formed in the dielectric, and
A groove communicating with the open end of the through hole is provided on one end surface of the dielectric, and then a conductor electrode film is provided on the entire surface of the dielectric including the through hole, the groove, and the outer surface, and the inside of the through hole is provided. Forming an inner conductor and an outer conductor on the outer surface, and then cutting and removing one end face of the dielectric having the groove to a depth larger than the thickness of the conductor electrode film, and opening the groove. By cutting and removing a portion between the end and the outer conductor to a thickness larger than that of the conductor electrode film, a terminal conductor line that is electrically connected to the inner conductor and insulated from the outer conductor is provided in the groove. There is a method for manufacturing a dielectric coaxial resonator, which is characterized in that the dielectric coaxial resonator is formed.

The depth of the groove formed on the one end surface of the dielectric is set to be deeper than the cutting thickness at the time of cutting in the subsequent step. In cutting and removing between the open end of the groove and the outer conductor, for example, after forming the conductor electrode film, the outer conductor in the vicinity of one end face of the dielectric is notched deeper than the thickness of the conductor electrode film. (Embodiment 1) Alternatively, a protruding portion is provided in advance on the outer conductor near one end surface of the dielectric, and the protruding portion is cut and removed after the conductor electrode film is formed (Embodiment 2). As a result, the terminal conductor line insulated from the outer conductor can be easily formed.

[0017]

In the dielectric coaxial resonator of the present invention, the conductor line for the terminal, which is electrically connected to the inner conductor, is formed at the end of the dielectric. This conductor line for terminals plays a role as a terminal by connecting one end thereof to an external circuit by soldering or the like. Therefore, unlike the conventional case, the terminal conductor line can be directly joined to an external circuit by a soldering method or the like without being inserted into the inner conductor and via a long terminal pin.

Since it is not necessary to use terminal pins,
The installation work is also unnecessary. Furthermore, a three-dimensional space for mounting the terminal pins is not required, and the dielectric coaxial resonator can be downsized. In addition, there is no mechanical or thermal effect on the inner conductor when the terminal pin is attached. Therefore,
It is possible to reduce variations in the characteristics of the dielectric coaxial resonator.

Further, since the terminal conductor line is formed integrally with the dielectric coaxial resonator itself as described above, it is highly reliable in terms of heat resistance and vibration resistance as an element. Therefore, the dielectric coaxial resonator of the present invention can be used in various applications such as a dielectric filter and a voltage controlled oscillator, and a high frequency device using these can be miniaturized and improved in performance. .

Next, in the method of manufacturing a dielectric coaxial resonator of the present invention, a groove is formed on one end face of the dielectric, a conductor electrode film is formed, and then the one end face is cut and removed.
The conductor electrode film naturally remains in the groove. Therefore, it is easy to form the terminal conductor line. Further, by forming the conductor electrode film, the inner conductor, the outer conductor, and the terminal conductor line are integrally formed of the same material. Therefore, it is possible to easily manufacture an excellent dielectric coaxial resonator as described above,
The manufacturing cost can be reduced.

According to the present invention, there is no variation in characteristics,
It is possible to provide a low-cost dielectric coaxial resonator that can be miniaturized and is easy to manufacture, and a manufacturing method thereof.

[0022]

【Example】

Example 1 FIG. 1 shows a dielectric coaxial resonator according to an example of the present invention.
This will be described with reference to FIG. Dielectric coaxial resonator 8 of this example
As shown in FIG. 1, the dielectric 5 has an inner conductor 21 and an outer conductor 22. The end portion 51 of the dielectric 5 is provided with a groove-shaped conductor line 1 for terminals which is electrically connected to the inner conductor 21 and insulated from the outer conductor 22.

The terminal conductor line 1 extends from the inner conductor 21 toward the board mounting surface 59 of the outer conductor 22. The terminal conductor line 1 and the outer conductor 22 are insulated by exposing the dielectric 5 between them as shown in FIG. As shown in FIGS. 1 and 3, this exposed surface is formed in a recessed surface 52 which is recessed with respect to the board mounting surface 59 of the outer conductor 22.

The dielectric 5 is a high frequency dielectric ceramic containing titanium oxide and barium oxide as main components. The shape of the dielectric 5 is a prism having a square cross section. The dielectric 5 is provided with a cylindrical through hole 50, and the inner conductor 21 is formed on the inner wall thereof. As shown in FIG. 3, the inner conductor 21 is joined to the external circuit 62 provided on the substrate 6 by the solder 7 via the terminal conductor line 1. The outer conductor 22 is formed on the outer surface of the dielectric 5. The board mounting surface 59 of the outer conductor 22 is soldered to the ground circuit 61 provided on the board 6.

As shown in FIG. 3, the groove-shaped conductor line 1 for terminals has a depth L ₀ of 0.4 mm, and as shown in FIG. 2, its width W is 1.0 mm. As shown in FIG. 3, the step difference t ₁ between the recessed surface 52 and the substrate mounting surface 59 is 0.3.
mm. The length L ₁ of the recessed surface 52 between the end portion 51 of the dielectric 5 and the substrate mounting surface 59 is 1.0 m.
m. Further, the dielectric 5 is a rectangular parallelepiped, its cross section is a square with one side of 4.0 mm, and its length L
Is 8.8 mm. The diameter of the through hole 50 provided in the dielectric 5 is 1.2 mm. The dielectric constant of the dielectric 5 is 9
0.

Next, a method of manufacturing the dielectric coaxial resonator will be described with reference to FIGS. First, as shown in FIG. 4 and FIG. 5, using the above-mentioned high frequency dielectric ceramics, a rectangular prism-shaped dielectric 5 having a square cross section is formed.
To manufacture. Further, a through hole 50 is formed along the axial direction of the dielectric body 5, and the through hole 5 is formed on one end surface 510 of the dielectric body 5.
A groove 55 having a depth larger than the depth L ₀ is formed between 0 and the outer surface of the dielectric 5. Next, the dielectric 5 is fired.

Next, as shown in FIG. 6, the through hole 5
0, the groove 55, and the entire surface of the dielectric 5 including the outer surface,
The conductor electrode film 2 having a thickness of about 0.02 mm is provided by the dipping method or the plating method. As a result, the inner conductor 21 is formed in the through hole 50 and the outer conductor 22 is formed on the outer surface.

Next, as shown in FIG. 6, one end face 510 of the dielectric 5 provided with the groove 55 is made to have a thickness L ₃ which is larger than the thickness of the conductor electrode film 2 at the arrow C1 by a horizontal axis surface grinder. Remove by cutting. Further, in the direction of arrow C2 in FIG. 6, the outer conductor 22 is cut and removed between the opening end of the groove 55 and the outer conductor 22 by a cutting grinder to a thickness larger than the thickness of the conductor electrode film 2. A recessed surface 52 that is recessed by a step t ₂ is formed. As a result, as shown in FIG. 3, the terminal conductor line 1 that is electrically connected to the inner conductor 21 and insulated from the outer conductor 22 is formed in the groove 55, and the dielectric coaxial resonator 8 is obtained.

The resonance frequency of the dielectric coaxial resonator 8 is
Was 900MH _Z. This resonance frequency is determined by the length L of the dielectric coaxial resonator as in the conventional open-ended λ / 4 coaxial resonator. When the unloaded Q value of the dielectric coaxial resonator was measured, it was 410, which was almost the same as the conventional one. In addition, when the characteristics of the resonator manufactured by the above manufacturing method within the lot were evaluated, the characteristics of the resonator showed very little variation.

Next, the function and effect of this example will be described.
In the dielectric coaxial resonator 8 of this example, as shown in FIG. 3, the terminal conductor line 1 that is electrically connected to the inner conductor 21 is formed at the end 51 of the dielectric 5. The terminal conductor line 1 plays a role as a terminal by connecting one end thereof to the external circuit 62 with the solder 7. Therefore, the terminal conductor line 1 can be directly joined to the external circuit 61 by a soldering method or the like without using a terminal pin as in the conventional case. Further, since the open end of the terminal conductor line 1 is open toward the board mounting surface 59, the external circuit 62 on the board can be directly joined by the solder 7.

Further, since it is not necessary to use the terminal pins as in the conventional case, the attaching work is also unnecessary. Further, the three-dimensional space for attaching the terminal pins is not required, and the dielectric coaxial resonator 8 can be downsized. Further, there is no mechanical or thermal influence on the inner conductor 21 due to the mounting of the terminal pins, and it is possible to reduce variations in the characteristics of the dielectric coaxial resonator. Further, since the terminal conductor line 1 is formed integrally with the dielectric coaxial resonator itself as described above, it has high reliability with respect to heat resistance and vibration resistance as an element.

Next, in the method of manufacturing the dielectric coaxial resonator of this example, as shown in FIG. 6, a groove 55 is formed in one end surface of the dielectric 5 and the conductor electrode film 2 is formed. The end face is cut and removed. Therefore, the conductor electrode film 2 naturally remains in the groove 55. Therefore, the formation of the terminal conductor line 1 is easy.

Further, the inner conductor 2 is formed by forming the conductor electrode film.
1, the outer conductor 22 and the terminal conductor line 1 are integrally formed of the same material. Therefore, the excellent dielectric coaxial resonator as described above can be easily manufactured, and the manufacturing cost can be reduced. In this example, the dielectric 5 has a square cross-section, but the shape is not limited to this, and the cross-section may be columnar such as circular, polygonal, or rectangular.

Embodiment 2 In the dielectric coaxial resonator of this embodiment, as shown in FIG. 7, the opening end of the terminal conductor line 1 is opened to the protruding surface 53 protruding from the board mounting surface 59 of the outer conductor 22. are doing.
As shown in FIG. 8, the protrusion thickness t ₂ of the protrusion surface 53 is 0.
It is 2 mm. The protrusion thickness t ₂ does not hinder the stability of the dielectric coaxial resonator when mounted on the substrate.

The groove-shaped terminal conductor line 1 has a depth L ₀ of 0.5 mm and a width W of 1.5 mm as shown in FIG. In addition, as shown in FIG.
The length L ₁ of the protruding surface 53 between the end portion 51 of the dielectric 5 and the substrate mounting surface 59 is 2.0 mm. The dielectric 5 is a rectangular parallelepiped, and its cross section is a square having one side of 6.0 mm, and its length L is 10.0 mm.
The diameter of the through hole 50 provided in the dielectric 5 is 1.8 mm. The dielectric constant of the dielectric 5 is 90.

Next, in manufacturing the dielectric coaxial resonator 81, first, as shown in FIG. 10, a die having a two-step lower punch is used to form a projecting portion 530 on a prism having a square cross section. The dielectric 5 is manufactured. Protruding part 53
0 is formed on the board mounting surface 59 near the one end surface 510 of the dielectric 5.

Next, as shown in FIG. 11, the protruding portion 53
0, through hole 50, groove 55, and outer surface including dielectric 5
The conductor electrode film 2 is formed on the entire surface of. As a result, the inner conductor 21 is formed on the inner wall of the through hole 55 and the outer conductor 2 is formed on the outer surface.
Form 2

Next, one end face 510 of the dielectric 5 is cut and removed in the direction of arrow C _{3 in} FIG. 11 to a thickness L ₃ larger than the thickness of the conductor electrode film 2 by a horizontal axis surface grinder. As a result, as shown in FIG. 8, the end 5 where the dielectric 5 is exposed is exposed.
1 is formed. Further, in the direction of arrow C _{4 in} FIG. 11, the protruding portion 530 is cut and removed to a thickness t ₃ larger than the thickness of the conductor electrode film 2 by a cutting grinder. As a result, as shown in FIGS. 8 and 9, the protruding surface 53 where the dielectric 5 is exposed is formed, and the terminal conductor line 1 that is electrically connected to the inner conductor 21 and insulated from the outer conductor 22 is formed.
The dielectric coaxial resonator 81 is obtained.

Further, the resonance frequency of the dielectric coaxial resonator 81 is 800MHz _Z, the unloaded Q value was 530. Others are the same as in the first embodiment. Also in this example, the same effect as that of the first embodiment can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a dielectric coaxial resonator according to a first embodiment.

FIG. 2 is a bottom view of the dielectric coaxial resonator according to the first embodiment.

FIG. 3 is a sectional view of the dielectric coaxial resonator mounted on the substrate according to the first embodiment.

FIG. 4 is a perspective view of a dielectric in the method of manufacturing the dielectric coaxial resonator according to the first embodiment.

FIG. 5 is a bottom view of the dielectric in the method of manufacturing the dielectric coaxial resonator according to the first embodiment.

FIG. 6 is a partially cutaway bottom view of the dielectric body on which the conductor electrode film is formed in the method of manufacturing the dielectric coaxial resonator according to the first embodiment.

FIG. 7 is a perspective view of a dielectric coaxial resonator according to a second embodiment.

FIG. 8 is a sectional view of a dielectric coaxial resonator according to a second embodiment.

FIG. 9 is a bottom view of the dielectric coaxial resonator according to the second embodiment.

FIG. 10 is a side view of the dielectric in the method of manufacturing the dielectric coaxial resonator according to the second embodiment.

FIG. 11 is a partially cutaway side view of a dielectric body on which a conductor electrode film is formed in the method of manufacturing the dielectric coaxial resonator according to the second embodiment.

FIG. 12 is a perspective view of a conventional dielectric coaxial resonator mounted on a substrate.

FIG. 13 is a sectional view of a dielectric coaxial resonator showing an example of a method of mounting a terminal pin in a conventional example.

[Explanation of symbols]

 1. . . Terminal conductor line, 2. . . Conductor electrode film, 21. . . Inner conductor, 22. . . Outer conductor, 5. . . Dielectric, 50. . . Through hole, 51. . . End, 52. . . Recessed surface, 53. . . Protruding surface, 55. . . Groove, 59. . . Board mounting surface, 8, 81. . . Dielectric coaxial resonator,

Claims (5)

[Claims] 1. A dielectric coaxial resonator having an inner conductor and an outer conductor provided in a dielectric, wherein a terminal electrically connected to the inner conductor and insulated from the outer conductor is provided at an end of the dielectric. A dielectric coaxial resonator comprising a conductor line for use. 2. The dielectric coaxial resonator according to claim 1, wherein the terminal conductor line is connected to one end of the inner conductor and is formed in a groove shape. 3. The dielectric coaxial resonator according to claim 1, wherein the terminal conductor line is continuously formed of the same material as the inner conductor. 4. The method according to claim 1, wherein
The dielectric coaxial resonator, wherein the terminal conductor line is formed so as to extend from the inner conductor at an end portion of the dielectric body in a direction of a board mounting surface of the outer conductor. 5. A dielectric is provided with a through hole, and a groove communicating with an opening end of the through hole is provided on one end surface of the dielectric, and then the dielectric including the through hole, the groove and the outer surface is provided. The conductor electrode film is provided on the entire surface, the inner conductor is formed in the through hole, and the outer conductor is formed on the outer surface. The inner conductor is electrically connected to the groove by cutting and removing to a large depth and by cutting and removing between the opening end of the groove and the outer conductor to a thickness larger than the thickness of the conductor electrode film. A method for manufacturing a dielectric coaxial resonator, characterized in that a conductor line for a terminal, which is insulated from the outer conductor, is formed.