JPH10190327A - Manufacture of dielectric resonator and dielectric filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cost, to miniaturize a device and to facilitate the adjustment of a characteristic by removing a conductor film by means of a laser beam, sand blast and a router, for example, so that a band-like terminal conductor connected to a conductor film in a through hole is obtained in a first end face and a part of an outer peripheral face. SOLUTION: The laser beam is selectively projected on the conductor film on a dielectric 1 and a conductor film removal area 6 is provided. The conductor film removal area 6 is formed so that the band-like conductor 7 is generated for the first end face 2 and first and third sides 4a and 4c in the outer peripheral face 4. The conductor film except for the terminal conductor 7 becomes an outer conductor 9 on the first end face 2 and the outer peripheral face 4. When the terminal conductor 7 is completely separated from the outer conductor 9 by the conductor film removal area 6, the device can be used as a dielectric resonator. When a target frequency characteristic is to be obtained, a part 11 of the terminal conductor 7 or a part 12 of the outer conductor 9 is removed by the laser beam and the target frequency characteristic is obtained.

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 dielectric resonator and a dielectric filter used in a mobile communication device or the like.

[0002]

2. Description of the Related Art A conventional typical TEM mode coaxial dielectric resonator for forming a band-pass filter or a band-stop filter includes a cylindrical dielectric having a through-hole and an inner hole provided in the through-hole. A conductor, an outer conductor provided on the outer peripheral surface of the dielectric, a short-circuit conductor connecting the inner conductor and the outer conductor at one end of the dielectric, and a through-hole from the other end (open end) of the dielectric. And a terminal member inserted into the inner conductor and connected to the inner conductor.

[0003]

However, the above-described conventional dielectric resonator has disadvantages in that not only the cost is increased but also the size is increased because independent terminal members are used. ing. When a metal terminal is used, the connection between the metal terminal and the inner conductor of the resonator is performed by soldering.
It is difficult to confirm the solder connection, which may cause a problem in reliability. In addition, there is a possibility that cracks may occur due to the difference in the coefficient of thermal expansion between the solder, the inner conductor, and the dielectric, which poses a problem in reliability. Further, the dielectric resonator has a disadvantage that it is difficult to accurately obtain a target resonance frequency because porcelain is used as a dielectric. Note that a dielectric filter in which a plurality of dielectric resonators are formed by one dielectric also has the above-described disadvantages.

Accordingly, an object of the present invention is to provide a method of manufacturing a dielectric resonator and a dielectric filter which can be reduced in cost and size or facilitate adjustment of characteristics.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and to achieve the above object, the present invention provides first and second end surfaces, an outer peripheral surface, and a structure extending from the first end surface to the second end surface. A dielectric having a through hole is prepared, and a conductive film is formed on all exposed surfaces of the first and second end surfaces, the outer peripheral surface, and the through hole of the dielectric, and the first end surface and the outer periphery are formed. For example, a laser beam, a sand blast, or the like so that a strip-shaped terminal conductor connected to the conductor film in the through hole is obtained on a part of the surface.
The present invention relates to a method for manufacturing a dielectric resonator, wherein the conductor film is removed by a router or the like. In addition,
It is desirable to adjust a frequency characteristic by removing a part of the terminal conductor. Preferably, the conductor film is removed by a laser beam, and the dielectric is subjected to a heat treatment after the conductor film is removed by a laser beam or after a part of the terminal conductor is removed. Claim 4
As shown in (1), a band-shaped terminal conductor is provided on a part of the first end face and the outer peripheral face of the dielectric, and the frequency can be adjusted by removing this part. Further, it is desirable that the removal of the terminal conductor of claim 4 be performed by a laser beam. The method according to claims 1 and 4 is also applied to each resonator in a dielectric filter having at least first and second through holes for resonance in one dielectric as shown in claims 6 and 7. be able to.

[0006]

According to the first to third and sixth aspects of the present invention, a terminal film is formed on the entire exposed surface of the dielectric and the terminal conductor is formed by removing the conductive film. Therefore, the cost of the dielectric resonator or the dielectric filter (composite dielectric resonator) can be reduced. Further, since the terminals are formed of the conductive film, the size of the dielectric resonator or the dielectric filter can be reduced. According to the third aspect of the present invention, it becomes possible to recover the characteristics of the dielectric material deteriorated by the irradiation of the laser beam by the heat treatment. According to the second, fourth, fifth and seventh aspects of the invention, the strip-shaped terminal conductor functions equivalently as an inductance, and has a stray capacitance (floating capacitance) between the terminal conductor and the ground, that is, the outer conductor. As the inductance of the terminal conductor increases, the resonance frequency f0 decreases. Conversely, as the inductance of the terminal conductor decreases, the resonance frequency f0 increases. Also, when the stray capacitance of the terminal conductor increases, the resonance frequency f0 decreases, and when the stray capacitance of the terminal conductor decreases, the resonance frequency f0 increases. Therefore, according to the second, fourth, fifth, and seventh aspects of the present invention, not only the terminal configuration is simplified, but also the frequency can be easily adjusted. According to the seventh aspect of the present invention, the frequency of each dielectric resonator is adjusted by removing a part of the first and second terminal conductors, and the frequency characteristic of the dielectric filter is also adjusted. Becomes possible.

[0007]

First Embodiment Next, a dielectric resonator according to a first embodiment of the present invention and a method of manufacturing the same will be described with reference to FIGS. When manufacturing the dielectric resonator, first, the ceramic dielectric 1 shown in FIG. 1 is prepared. The dielectric 1 has first and second end surfaces 2 and 3 and four side surfaces 4a, 4b, 4c and 4d.
And a through hole 5 for resonance extending from the first end face 2 to the second end face 3.

Next, a metal conductive paste (silver paste) is applied and baked on the entire exposed surfaces of the dielectric 1, that is, the surfaces of the first and second end surfaces 2, 3 and the outer peripheral surface 4 and the through holes 5. To form a conductive film.

Next, a laser beam is selectively projected onto the conductor film on the dielectric 1 to remove the conductor film removal region 6 shown in FIGS.
Is provided. In FIG. 2, the conductor film is shown ignoring the thickness, and the conductor film removal region 6 is dotted to distinguish the conductor film removal region 6 from the conductor film region. The conductor film removal region 6 is formed such that a strip-shaped terminal conductor 7 is formed on the first and third side surfaces 4a and 4c of the first end surface 2 and the outer peripheral surface 4. The terminal conductor 7 is connected to the inner conductor 8 in the through hole 5. The conductor film other than the terminal conductor 7 on the first end face 2 and the outer peripheral face 4 becomes the outer conductor 9. In addition, the conductor film on the second end face 3 becomes the short-circuit conductor 10, and the inner conductor 8 and the outer conductor 9
And connect.

When the terminal conductor 7 and the outer conductor 9 are completely separated from each other by the conductor film removing region 6, the terminal conductor 7 can be used as a dielectric resonator. Therefore, the frequency characteristic of the dielectric resonator is measured by a known resonance frequency measuring device, and when it is desired to obtain a target frequency characteristic, as shown in FIG. Part 1 of outer conductor 9
2 is removed by a laser beam to obtain a target frequency characteristic.

The dielectric resonator shown in FIGS. 2 and 3 can be represented by an equivalent circuit shown in FIG. The first inductance L1 and the first capacitance C1 in FIG. 4 indicate a coaxial dielectric resonator main body based on the inner conductor 8 and the outer conductor 9,
L2 represents the equivalent inductance of the band-shaped terminal conductor 7, and the second capacitance C2 represents the terminal conductor 7
Shows the stray capacitance between the capacitor and the outer conductor 9 or ground. The second inductance L2 of the equivalent circuit of FIG.
Increases, the resonance frequency decreases. Conversely, when L2 decreases, the resonance frequency increases. Also, when the second capacitance C2 increases, the resonance frequency decreases, and when C2 decreases, the resonance frequency increases. Therefore, the dielectric resonator is configured so that the resonance frequency before the adjustment is lower than the target resonance frequency, and thereafter, a part 1 of the terminal conductor 7 is formed.
Removing 1 increases the inductance L2, and removing a portion 12 of the outer conductor 9 reduces the stray capacitance C2, making it possible to adjust the resonance frequency.

Next, the dielectric 1 after the terminal conductor 7 is formed
Is subjected to a heat treatment at 600 ° C. for 30 minutes. As a result, the Q characteristic of the dielectric 1 deteriorated by the emission of the laser beam is recovered. This heat treatment may be performed before the part 11 of the terminal conductor 7 and the part 12 of the outer conductor 9 are removed by a laser beam, that is, after the formation of the conductor film removal region 6.

This embodiment has the following advantages. (A) A conductor film is formed on the entire exposed surface of the dielectric 1, a conductor film removal region 6 is formed by a laser beam, and a terminal conductor 7 is formed.
Therefore, the terminal conductor 7 can be easily obtained. (B) Since the frequency is adjusted by providing at least one of the part 11 of the terminal conductor 7 and the part 12 of the outer conductor 9 by trimming subsequent to the formation of the conductor film removal area 6, the frequency adjustment can be easily achieved. it can. (C) Since a part of the terminal conductor 7 is also provided on the outer peripheral surface 4, a surface-mounted dielectric resonator can be provided. That is, the outer conductor 9 can be connected to the ground conductor layer 14 of the circuit board 13 indicated by the broken line in FIG. 3 by solder 16, and the terminal conductor 7 can be connected to another conductor layer 15 by solder 17.

[0014]

Second Embodiment Next, a dielectric resonator according to a second embodiment will be described with reference to FIG. However, FIG. 5 and FIG.
12 to 12 are denoted by the same reference numerals as those in FIGS. 1 to 3, and description thereof will be omitted. In the dielectric resonator shown in FIG. 5, the terminal conductor 7 extends only on the third side surface 4c side of the dielectric 1, and is not provided on the first side surface 4a side.
Except for this, the dielectric resonator is formed similarly to the dielectric resonator of the first embodiment. Therefore, the second embodiment has the same advantages as the first embodiment.

[0015]

Third Embodiment A dielectric resonator according to a third embodiment shown in FIGS. 6 to 9 is provided with a groove 18 on one end face 2 of a dielectric 1.
The terminal conductor 7 is provided in the groove 18, and the other portions are formed substantially the same as in the first embodiment. When manufacturing the dielectric resonator of the third embodiment, the through holes 5
A dielectric 1 having a groove and a groove 18 is prepared, a conductive film is formed on the entire exposed surface of the dielectric 1 based on the conductive paste in the same manner as in the first embodiment, and then the groove on the first end face 2 is formed. The conductor film other than 18 is removed by polishing, and thereafter, the conductor film removal region 6 as shown in FIG. 6 is formed on the first and third side surfaces 4a and 4c based on the projection of the laser beam. At least one of the part 11 of the terminal conductor 7 and the part 12 of the outer conductor 9 are removed with a laser beam to adjust the frequency. Thereafter, heat treatment is performed on the dielectric 1 to complete the dielectric resonator. The third embodiment has the same advantages as the first embodiment. Besides, since the terminal conductor 7 is formed in the groove 18, the terminal conductor 7 is prevented from being damaged, and the reliability of the electrical connection is improved. It also has the advantage of becoming

[0016]

Fourth Embodiment A dielectric resonator according to a fourth embodiment shown in FIG. 10 has terminal conductors 7 and outer conductors 9 formed on the basis of printing of a conductor paste. It is formed as in the example. Also in this embodiment, the frequency adjustment is achieved by removing at least one of the part 11 of the terminal conductor 7 and the part 12 of the outer conductor 9 with a laser beam. Therefore, the fourth embodiment has the same advantages in frequency adjustment as the first embodiment.

[0017]

Fifth Embodiment FIG. 11 shows in principle a dielectric filter, that is, a composite dielectric resonator according to a fifth embodiment. In FIG. 11, the terminal conductor 7 and the outer conductor 9 are shown ignoring the thickness, and the exposed surface of the dielectric 1 is dotted. Since the dielectric filter of FIG. 11 has a two-stage configuration, the first and second through-holes 5a and 5b are formed so as to extend from the first end face 2 to the second end face 3 of the dielectric 1. Are provided with respective inner conductors. A coupling hole 19 is provided between the first and second through holes 5a and 5b. Grooves 18a and 18b are provided like the groove 18 of the third embodiment so as to pass through the first and second through holes 5a and 5b, and the first and second terminal conductors 7a and 7b are provided here. ing. The first and second terminal conductors 7a, 7b also extend on the first and third side surfaces 4a, 4c of the dielectric 1. Adjustment of the frequency of each dielectric resonator in this embodiment also
This is achieved by removing at least one of the part 11 of the terminal conductors 7a and 7b and the part 12 of the outer conductor 9 with a laser beam. Therefore, there is an advantage related to frequency adjustment as in the first embodiment. Further, the advantages relating to the grooves 18a and 18b are provided similarly to the third embodiment.

[0018]

[Modifications] The present invention is not limited to the above-described embodiment, and for example, the following modifications are possible. (1) Instead of extending the terminal conductor 7 to the first and third side surfaces 4a and 4c in the third embodiment, the first end surface 2 and the first and third side surfaces 4a as shown in FIG. , 4c, a chamfered portion 20 may be provided, and the terminal conductor 7 may be provided here. Also, the terminal conductors 7a and 7b of the dielectric filter of FIG. 11 can be formed to extend to the chamfered portions similarly to the terminal conductor 7 of FIG. When formed as shown in FIG. 12, the first and third side surfaces 4a and 4a of the dielectric 1 are formed.
The conductor film of c can be easily removed. (2) Although the dielectric resonator of each of the embodiments has the short-circuit conductor 10 and is formed in a quarter-wavelength type, the dielectric resonator can be a half-wavelength type by omitting the short-circuit conductor 10. (3) The shape of the grooves 18, 18a, 18b can be changed to another shape such as a V-shaped groove or a semicircular groove. (4) The terminal conductor 7a of the dielectric filter shown in FIG.
7b can be formed by removing the conductive film with a laser beam as in the first embodiment. (5) The formation of the terminal conductor 7 by removing the conductor film and the partial removal of the terminal conductor 7 for frequency adjustment can be performed by sandblasting, a router, or the like without being limited to laser beams.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a dielectric of a dielectric resonator according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing the dielectric resonator of the first embodiment.

FIG. 3 is a central longitudinal sectional view of the dielectric resonator of FIG. 2;

FIG. 4 is an equivalent circuit diagram of the dielectric resonator shown in FIG. 2;

FIG. 5 is a front view showing a dielectric resonator according to a second embodiment.

FIG. 6 is a perspective view showing a dielectric resonator according to a third embodiment.

FIG. 7 is a front view of the dielectric resonator shown in FIG. 6;

8 is a plan view of the dielectric resonator shown in FIG.

FIG. 9 is a sectional view taken along line AA of FIG. 8;

FIG. 10 is a front view showing a dielectric resonator according to a fourth embodiment.

FIG. 11 is a perspective view showing a dielectric filter according to a fifth embodiment.

FIG. 12 is a cross-sectional view illustrating a dielectric resonator according to a modification.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dielectric 7 Terminal conductor 8 Inner conductor 9 Outer conductor

Claims (7)

[Claims] A first end face, a second end face, an outer peripheral face, and the first end face;
A dielectric having a through-hole extending from the end face of the dielectric material to the second end face, and forming a conductive film on all exposed surfaces of the first and second end faces, the outer peripheral face, and the through-hole of the dielectric substance And removing the conductor film so that a strip-shaped terminal conductor connected to the conductor film in the through-hole is obtained on the first end face and a part of the outer peripheral face. Manufacturing method. 2. The method for manufacturing a dielectric resonator according to claim 1, wherein after removing said conductive film, a part of said terminal conductor is removed to adjust the frequency of said dielectric resonator. . 3. The method according to claim 1, wherein the conductor film is removed by a laser beam, and the dielectric is subjected to a heat treatment after the conductor film is removed by a laser beam or after a part of the terminal conductor is removed by a laser beam. The method for manufacturing a dielectric resonator according to claim 1, wherein: 4. The first and second end surfaces, the outer peripheral surface, and the first and second end surfaces.
A dielectric having a through-hole extending from the end face of the first end face to the second end face; an inner conductor provided in the through-hole; an outer conductor provided on the outer peripheral face; A dielectric resonator having a band-shaped part and a terminal conductor connected to the inner conductor is prepared, and the frequency of the dielectric resonator is adjusted by removing a part of the terminal conductor. A method for producing a dielectric resonator having a desired frequency characteristic. 5. The first and second end faces, the outer peripheral face, and the first and second end faces.
A dielectric having a through-hole extending from the end face of the first end face to the second end face, an inner conductor provided in the through-hole, an outer conductor provided on the outer peripheral face, the first end face and the outer peripheral face Prepare a dielectric resonator having a band-shaped part of the terminal conductor and a terminal conductor connected to the inner conductor, and remove the part of the terminal conductor with a laser beam to reduce the frequency of the dielectric resonator. A method for manufacturing a dielectric resonator, comprising: adjusting a dielectric resonator having a desired frequency characteristic. 6. The first and second end faces, the outer peripheral face, and the first and second end faces.
A dielectric having at least first and second through-holes extending from the end face of the dielectric to the second end face, the first and second end faces of the dielectric, the outer peripheral face, and the first and second A conductive film is formed on the entire exposed surface of the first and second through-holes, and a first and a band-shaped first and second peripheral surfaces are connected to the conductive films in the first and second through-holes. Second
A method for manufacturing a dielectric filter, comprising: removing the conductor film so as to obtain the terminal conductor described above. 7. The first and second end surfaces, the outer peripheral surface, and the first and second end surfaces.
A dielectric having first and second through-holes extending from the end surface of the first to the second end surface, first and second inner conductors respectively provided in the first and second through-holes, An outer conductor provided on the outer peripheral surface, and a strip-shaped conductor connected to the first and second inner conductors of the first and second through holes and provided on a part of the first end surface and the outer peripheral surface. First and second
And a part of the first and second terminal conductors of the first and second dielectric resonators constituting the dielectric filter are removed. A method of manufacturing a dielectric filter, comprising: adjusting the frequencies of the first and second dielectric resonators to obtain the dielectric filter having desired frequency characteristics.