JPH02119402A - Dielectric resonator and its manufacture - Google Patents

Abstract

PURPOSE:To reduce the cost of a dielectric resonator by using a conductive particle or piece with low cost so as to connect a terminal of a capacitor to an inner conductor film. CONSTITUTION:Cream solder (paste solder) is injected to a resonance throughhole 4 and heated in a constant temperature oven. Thus, the cream solder is molten and the solder is intruded between copper particles 21, between the copper particle 21 and the metallic cap 14, a lead wire 16 and between the copper particle 21 and the inner conductor film 5, and the 2nd terminal consisting of the metallic cap 14 and of the lead wire 16 and the inner conductor film are coupled electrically and mechanically. Thus, the limitation of the dimension of the conductive particle 21 or chip is reduced and the cost of the conductive particle 21 or chip is remarkable reduced in comparison with that of a conventional connection component.

Description

[Detailed Description of the Invention] [Industrial Application] The present invention is applicable to, for example, a car telephone, a personal radio, =1-
The present invention relates to a dielectric resonator that can be used in communication equipment such as mobile telephones.

1 "Prior Art" A rod-shaped lead terminal and a cylindrical resin dielectric material surrounding it are inserted into a through hole of a ceramic dielectric material constituting a 174-wavelength distributed constant type dielectric resonator for use in a communication TS device, etc. For example, Japanese Utility Model Application Publication No. 58-54102 discloses a method of inserting a unit consisting of the above and obtaining an input coupling capacity between the lead terminal and the inner conductor (inner peripheral electrode) on the wall surface of the through hole. According to this structure, coupling capacitance can be obtained with a simple configuration.

However, based on the target capacitance, -2°5% ~
Errors exceeding the tolerance of about 2.5% can easily occur.
The manufacturing yield was poor at about 70%, which caused an increase in costs. In addition, the variations in capacitance are as follows (1) to (4)
This is thought to be caused by the accumulation of

(1) Due to variations in diameter, wall thickness, and length of the cylindrical resin dielectric.

(2) This is due to variations in the diameter of the resonance through-hole in the ceramic dielectric.

(3) This is caused by variations in the thickness of the inner conductor film of the resonance through-hole.

(4) This is due to variations in the adhesion of the cylindrical m-fat dielectric to the resonance through-hole.

In order to solve the above-mentioned problems, the applicant of the present invention proposed a structure in which individual capacitors are used as coupling capacitors in Japanese Patent Application No. 158425/1982 and Japanese Patent Application No. 6253/1988.

[Problems to be Solved by the Invention] Conventionally, when connecting a capacitor electrode to the inner conductor film of a through hole, special connecting parts were used, making it difficult to assemble the capacitor electrode easily. It has also been proposed to process the lead wires of the capacitor and solder them to the inner conductor film, but it is difficult to process the lead wires into the desired shape.

Therefore, a first object of the present invention is to provide a dielectric resonator that is easy to assemble and can reduce costs.

A second object of the present invention is to provide a method for efficiently manufacturing dielectric resonators.

[Means for Solving the Problems] The invention that achieves the above first object is based on at least one
a dielectric block having resonance through holes, an inner conductor film provided on the wall surface of the through hole, an outer conductor film provided on the outer peripheral surface of the dielectric block, and first and second terminals. , at least a portion of the first terminal is disposed outside the resonance through hole, and the second terminal is inserted into the resonance through hole and connected to the inner conductor film. In the dielectric resonator comprising a capacitor for use in a dielectric resonator, a plurality of conductive particles or pieces are interposed between the second terminal and the inner conductor film, and a plurality of conductive particles or pieces are interposed between each other and the inner conductor film. The invention relates to a dielectric resonator in which solder is interposed between the conductive particles or pieces and the second terminal and between the conductive particles or pieces and the inner conductor film.

Further, the invention for achieving the above-mentioned second object relates to a method of achieving a connection by inserting conductive particles or pieces and solder between the second terminal and the inner conductor film and heating them. It is something.

[Function] The conductive particles or pieces in the above invention have the function of bridging the second terminal and the inner conductor film, and also have the function of blocking unnecessary flow of solder. Therefore, even if the distance between the second terminal and the inner conductor film is relatively large, the two can be reliably connected. Also, because there are fewer restrictions on the dimensions of the conductive particles or strips, the cost of the conductive particles or strips can be significantly lowered compared to conventional connection parts.

In the method invention of claim 2, since the connection is completed by simply adding and heating the conductive particles or pieces and solder simultaneously or separately, work such as positioning the connecting parts is unnecessary, and the assembly work time is reduced. can be significantly shortened.

[First Embodiment] Next, a 174-wavelength distributed constant type dielectric resonator according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4.

This dielectric filter includes a cylindrical dielectric block 1 made of barium titanate ceramic.

The dielectric block 1 is provided with one resonance through hole 4 extending from one end surface 2 to the other end surface 3. An inner conductor film 5 is provided on the wall surface of the resonance through hole 4, an outer conductor film 7 is provided on the outer peripheral surface 6, that is, the side surface, and the other end surface 3 connects the inner conductor M5 and the outer conductor 11 [7]. The end face conductor WA8 is provided so as to. The inner conductor 11g5, the outer conductor film 7, and the end face conductor film 8 are made by applying and baking silver paste.

Note that one end surface 2 is an open end surface.

As shown in FIG. 3, the coupling capacitor 9 disposed in the resonance through hole 4 has a cylindrical capacitor ceramic dielectric 10 and a portion of the inner peripheral surface, one end surface, and outer peripheral surface of this dielectric 10. A first @ electrode 11 provided, a second electrode [12 provided on the outer peripheral surface], a first metal cap 13 coupled to the first electrode 11, and a second electrode [r12 coupled to The second
metal cap 14 and first and second metal caps 1
The first metal cap 13 and the first lead wire 15 function as a first terminal, and the first metal cap 13 and the first lead wire 15 function as a first terminal, and The cap 14 and the second lead wire 16 are configured to function as a second terminal. In this embodiment, in order to stably attach the capacitor 9 to the through hole 4,
An insulating cover 17 made of synthetic resin is provided. Hereinafter, the combination of the capacitor 9 and the insulating cover 17 will be referred to as a capacitor assembly 18.

Since the capacitor 9 is an inexpensive, general-purpose axial lead type cylindrical ceramic capacitor, one with a desired capacity can be obtained very easily. Furthermore, even if a capacitor with the desired capacity is not available, the first and/or second t-pole 1
The capacity can be adjusted by partially polishing 1.12.

The covering 17 has a flange 19 and a protrusion 20 therefrom. The protrusion 20 is formed in a cylindrical shape and is fitted into the resonance through hole 4. The flange 19 is in contact with one end surface 2 of the dielectric block 1 and determines the insertion depth of the protrusion 2o.

When manufacturing this dielectric resonator, a dielectric block 1 having an inner conductor film 5, an outer conductor film 7, and an end face conductor film 8 is prepared, as well as a capacitor assembly 18 shown in FIG. 3.

Next, a portion of the capacitor assembly 18 is inserted into the through hole 4 so that the second lead wire 16 side is inserted. That is,
The protrusion 20 is inserted into the through hole 4.

As a result, one entrance of the through hole 4 is closed.

Next, the second lead wire 16 is on top, and the first lead wire 1
Dielectric block 1 and assembly 18 so that 5 is on the bottom
Turn it upside down. Of course, if it is upside down from the beginning, there is no need to turn it upside down.Next, several copper particles 21 with external dimensions of about 0°2 to 1.0flI11 are introduced into the resonance through hole 4. .

Since the copper particles 21 are sufficiently smaller than the resonance through-hole 4, they can be inserted into the resonance through-hole 4 very easily. Further, there is no need to specifically position the copper particles 21 with respect to the second terminal consisting of the metal cap 14 and the lead wire 16.

Next, cream solder (paste solder) is injected into the resonance through hole 4 and heated in a constant temperature bath. As a result, the cream solder melts and enters between the copper particles 21, between the copper particles 21 and the metal cap 14 and the lead wire 16, and between the copper particles 21 and the inner conductor PLA5, and the solder 22
and the copper particles 21 electrically and mechanically connect the second terminal consisting of the metal cap 14 and the lead wire 16 to the inner conductor WA5.

When the dielectric resonator shown in FIG. 1 is mounted on a circuit board, the outer conductor film 7 is connected to the ground, and the lead wire 15 is connected to the signal transmission path. Therefore, this dielectric resonator can be represented by an equivalent circuit consisting of a capacitor c1, an inductance L1, and a coupling capacitor Ca shown in FIG.

[Second Embodiment] Next, a dielectric filter according to a second embodiment of the present invention will be described with reference to FIGS. 5 to 8. However, in FIGS. 5 to 8, parts that are substantially the same as those in FIGS. 1 to 4 are designated by the same reference numerals, and their explanations will be omitted. This dielectric filter is a combination of two dielectric resonators. Therefore, two resonance through holes 4 are provided extending from one end surface 2 to the other end surface 3 of the dielectric block 1, and one coupling through hole 23 is provided between them.

An inner conductor film 5 is provided on the wall surface of each resonance through hole 4, and an outer conductor 11! is provided on the outer peripheral surface 6 between the pair of end surfaces 2.3, that is, the 41111 surface. j, 7 are provided, and an end surface conductor film 8 is provided on the other end surface 3 so as to connect the inner conductor film 5 and the outer conductor film 7. The inner conductor film 5, the outer conductor IIA7, and the end face conductor film 8 are made by applying and baking silver paste. Note that one end surface 2 is an open end surface.

A coupling capacitor 9 is inserted into each of the two resonance through holes 4. The configuration of the coupling capacitor 9 is shown in Figure 1~
3, copper particles 21 are placed between the second terminal consisting of the lower metal cap 14 and the lead wire 16 and the inner conductor film 5 in the same manner as in FIG. Connection between each other has been achieved.

The pair of capacitors 9 are interconnected by an insulating cover 17a. A metal shield member 24 is further integrated into the insulating cover 17a.

When manufacturing this dielectric filter, the dielectric block 1 having each of the conductive films 5, 7, and 8 shown in FIG. An integrated assembly 25 is prepared, two capacitors 9 are inserted into two resonance through holes 4 at the same time, and copper particles 21 and solder 22 are inserted in the same manner as in the first embodiment.
Electrical connection to the inner conductor film 5 is achieved by this.

The shield member 24 has a portion 24a that covers the upper part of the coupling hole 23 and portions 24b and 24c that cover a pair of side walls, and is generally U-shaped in cross section.

When connecting the completed dielectric filter to an electrical circuit,
One of the pair of lead wires 15 is used as an input lead terminal, the other is used as an output lead terminal, and the shield member 24 is connected to ground.

FIG. 8 shows an equivalent circuit of a dielectric filter. A first resonant circuit consisting of the capacitor C1 and the inductance L1 is formed based on the inner conductor film 5 of one of the pair of through holes 4, the grounded outer conductor film 7, and the end face conductor film 8, and the capacitor C2 A second resonant circuit consisting of an inductance L2 and an inductance L2 is formed based on the other inner conductor film 5 of the pair of through holes 4, the grounded outer conductor film 7, and the end face conductor film 8.
The two resonant circuits are coupled by a dielectric impedance Z1. Note that the input coupling capacitance Ca corresponds to one of the pair of capacitors 9, and the output coupling capacitance Cb corresponds to the other of the pair of capacitors 9.

In this embodiment as well, exactly the same effects as in the first embodiment can be obtained.

[Third Embodiment] Next, a dielectric filter according to a third embodiment of the present invention will be described with reference to FIG. However, the capacitor 9 and the inner conductor film 5
Since the configuration other than the connection configuration with the second embodiment is the same as that of the second embodiment, the common parts are given the same reference numerals and the explanation thereof will be omitted.

In this embodiment, a mixture of copper particles with an average particle size of about 1 µm and cream solder at a ratio of about 1:1 (weight ratio) is injected into the resonance through hole 4, and heated in a constant temperature bath to form fine copper particles 21a. The metal cap 14 and the inner conductor film 5 are bonded together by solder 22.

Even in this manner, the coupling of the capacitor 9 to the inner conductor film 5 can be easily achieved as in the first and second embodiments.

[Modifications] The present invention is not limited to the above-described embodiments, and, for example, the following modifications are possible.

(1) Instead of putting the mixture of copper particles and cream solder into the resonance through-hole 4 as in the third embodiment, the fine copper particles 21a are first put into the resonance through-hole 4, and then the cream solder is put into the resonance through-hole 4. Solder may be added and then heated.

(2) Instead of the copper particles 21, as shown in FIG.
Conductive particles 21b, which are made of porcelain particles 26 made of the same material as the dielectric block 1 and provided with a copper plating layer 27, are put into the resonance through hole 4, and then cream solder is injected,
Soldering may also be performed by heating. Furthermore, instead of the copper particles 21, other solderable metal particles such as iron may be used.

(3) Instead of cream solder, solder particles or solder pieces may be put into the resonance through hole 4 and melted and soldered.

(4) As shown in FIG. 11, the capacitor 9 is provided with a pair of electrodes 11a and 12a on a cylindrical dielectric body 10a, and a metal cap 13.14 and lead wires 15.16 as terminal members.
may be provided.

5) The cover 17 can be omitted. If this creates a large gap between the inner conductor WA5 and the metal cap 14, a removable jig corresponding to the covering 17 should be inserted into the resonance through-hole 4, or a The inlet on the open end surface 2 side may be closed and conductive particles and solder may be introduced. When the gap between the inner conductor film 5 and the metal cap 14 is narrow, the copper particles 21 and the solder 22 remain at desired locations without using a jig.

(6) In the embodiment, since a general-purpose capacitor 9 is used, the lead wire 16 is led out at the bottom.
It may be removed if necessary.

(7) Three or more resonance through holes 4 in the dielectric block 1
It is also applicable when providing a. In this case, a capacitor 9 is installed in the resonance through hole 4 of the input stage and the output stage.

(8) It is also applicable to the case where the end face conductor film 8 is omitted and a distributed constant dielectric resonator with 172 wavelengths is configured.

[Effects of the Invention] As is clear from the above, according to the present invention, the terminals of the capacitor are connected to the inner conductor film using low-cost conductive particles or pieces, so the cost of the dielectric resonator is reduced. can be achieved. Furthermore, since conductive particles or pieces with a large degree of freedom are used for the resonance through-hole, it is possible to easily connect the capacitor terminal to the resonance through-hole.

[Brief explanation of the drawing]

1 is a sectional view of a dielectric resonator according to a first embodiment of the present invention taken along line I-I in FIG. 2; FIG. 2 is a plan view of the dielectric resonator in FIG. 1; 4 is an equivalent circuit diagram of the dielectric resonator of FIG. 1, and FIG. 5 is a dielectric filter according to the second embodiment of the present invention. 6 is a plan view of the dielectric filter shown in FIG. 5, FIG. 7 is a perspective view showing a dielectric block equipped with each conductor film shown in FIG. 5, and FIG. is an equivalent circuit diagram of the dielectric filter shown in FIG. 5, FIG. 9 is a sectional view showing the dielectric filter of the third embodiment, FIG. 10 is a sectional view showing conductive particles of a modified example, and FIG. FIG. 7 is a cross-sectional view showing a modified capacitor. 1... Dielectric block, 4... Resonance through hole, 5...
...Inner conductor film, 7...Outer conductor film, 9...Capacitor, 13.14...Metal cap, 15.16...Lead wire, 21...Copper particles, 22...Solder .

Claims (1)

[Scope of Claims] [1] A dielectric block having at least one resonance through hole, an inner conductor film provided on the wall surface of the through hole, and an outer conductor film provided on the outer peripheral surface of the dielectric block. It has a conductor film, and first and second terminals, at least a portion of the first terminal is disposed outside the resonance through hole, and the second terminal is inserted into the resonance through hole. and a coupling capacitor connected to the inner conductor film, wherein a plurality of conductive particles or pieces are interposed between the second terminal and the inner conductor film; Solder is interposed between a plurality of conductive particles or pieces, between the conductive particles or pieces and the second terminal, and between the conductive particles or pieces and the inner conductor film. Features dielectric resonator. [2] A dielectric block having at least one resonance through-hole, an inner conductor film provided on the wall of the through-hole, and an outer conductor film provided on the outer peripheral surface of the dielectric block; and a second terminal, at least a portion of the first terminal is disposed outside the resonance through hole, and the second terminal is inserted into the resonance through hole and connected to the inner conductor film. A method for manufacturing a dielectric resonator comprising a coupling capacitor connected thereto, comprising the steps of: introducing conductive particles or pieces between the second terminal and the inner conductor film, and also adding solder; , melting the solder to connect the conductive particles or pieces, between the conductive particles or pieces and the second terminal, and between the conductive particles or pieces and the inner conductor film. A method for manufacturing a dielectric resonator, comprising the steps of: