JP2550537Y2 - Dielectric filter - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric filter in which a dielectric resonator is accommodated in a metal case. It relates to a structure that can be avoided.

[0002]

2. Description of the Related Art As an example of a dielectric filter using a plurality of dielectric coaxial resonators, there is a conventional structure shown in FIG. The dielectric filter 30 is configured by disposing a coupling substrate 32 on a pair of dielectric coaxial resonators 31, 31, connecting input / output terminals 33, 33 to the coupling substrate 32, and inserting the coupling substrate 32 into a metal case 34. Have been. Capacitor electrodes 32a, 32a are provided at both ends of the coupling substrate 32, respectively.
Are formed, and these capacitor electrodes 32a, 32
One end of the input / output terminal 33 penetrates and is connected to a. Capacitor electrodes 32b, 32b are formed in the center of the coupling substrate 32, and the coupling terminals 35 of the dielectric resonators 31 are provided on the respective capacitor electrodes 32b.
Are connected through. The metal case 34
The upper surface and the lower surface of the dielectric resonator 31 are in contact with both side walls 34a.
Are electrically and mechanically connected by the solder filled therein. Further, a locking piece 34 is provided on the front edge of each side wall 34a.
The connecting board 32 is in contact with each of the locking pieces 34c. To assemble the dielectric filter 30, the input / output terminals 3
3 and the coupling terminal 35 of the dielectric substrate 31 are inserted, and the coupling substrate 32 is positioned by being brought into contact with the locking piece 34c of the metal case 34, and the input / output terminal 33 and the coupling terminal 35 of the coupling substrate 32 are connected. Part and solder hole 3 of metal case 34
Solder cream is applied to 4b, and reflow soldering is performed in this state.

[0003]

However, in the above-mentioned conventional dielectric filter, when input / output terminals and coupling terminals are inserted into the coupling substrate, a metal case is mounted, or reflow soldering is performed. There is a problem that the positions of the input / output terminals and the coupling substrate are easily shifted, and in some cases, the characteristics are deteriorated.

The present invention has been made in view of the above-mentioned conventional situation, and has as its object to provide a dielectric filter which can prevent a position shift of an input / output terminal or a coupling substrate and can avoid deterioration of characteristics.

[0005]

According to a first aspect of the present invention, a substrate 2 is connected to dielectric resonators R1 to R3, and input / output terminals 3 and 3 are connected to the substrate 2 and housed in a case 4. In the dielectric filter 1 formed as described above, a resin base 10 having left and right side walls 10c and 10d is inserted and arranged in the case 4, and the fixing portion 1 is fixed to a bottom wall 10a of the resin base 10.
4 and 14, and the left and right side walls 10c,
10d, insertion grooves 13, 13 for connecting the fixing portions 14, 14 to the outside are formed, and the input / output terminals 3, 3 are inserted from the insertion grooves 13, 13 to be fitted to the fixing portions 14, 14. A holding portion 15, formed on the resin base 10,
The input / output terminals 3, 3 are clamped and fixed by inserting and fixing the substrate 2 between the dielectric resonators R1, R2 and R3.
3 is characterized in that the coupling terminal 6a of the dielectric resonator is connected to the substrate 2 when the substrate 3 is inserted into the case 4.

Here, when the resin base is inserted into the case, the edge of the resin base hits the opening edge of the case and it takes time to insert the resin base, or the corner of the resin base is inserted into the inner corner of the case. The rattling may occur. Therefore, the invention of claim 2 is characterized in that a chamfered portion is formed on a corner edge of the resin base.

[0007]

In order to assemble the dielectric filter according to the first aspect of the present invention, first, the input / output terminals 3, 3 are inserted from the insertion grooves 13, 13 of the left and right side walls 10c, 10d of the resin base 10, and the fixing portion 14 is formed. , 14, the substrate 2 is inserted and fixed between the holding portions 15, 15, the input / output terminals 3, 3 are clamped and fixed by the substrate 2, and the resin base 10 is inserted and arranged in the case 4. Next, the dielectric resonators R1 to R3 are connected to the substrate 2. Thus, in the present invention, the resin base 1
Since the coupling board 2 and the input / output terminals 3 can be mechanically fixed to the position 0 beforehand, it is possible to prevent a positional shift when each conventional component is assembled. Further, since the coupling board 2 and the input / output terminals 3 are fixed to the resin base 10, the components do not shift even when reflow soldering is performed, and as a result, deterioration of characteristics can be avoided. In the invention of claim 2,
Since the chamfered portion 17 is formed at the corner edge of the resin base 10, the time required for inserting the chamfered portion 17 into the case 4 can be improved,
In addition, the adhesion to the case 4 can be improved, and the workability during assembly can be improved accordingly, and the reliability for quality can be improved.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to 3 illustrate a dielectric filter according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a dielectric filter of the present embodiment, in which a coupling substrate 2 is disposed on three-stage dielectric coaxial resonators R1 to R3, and input / output terminals 3, 3 are connected to the coupling substrate 2. And is housed in a metal case 4. Each of the dielectric coaxial resonators R1 to R3 has a through hole 5a formed in the axis of the rectangular parallelepiped dielectric block 5, and the inner peripheral surface of the through hole 5a and the open end surface 5b of the dielectric block 5 are connected to each other. Except for the outer surface, a conductive film is coated and formed. In addition, each of the through holes 5a
A cylindrical coupling terminal 6 is press-fitted therein, and a connection piece 6a of the coupling terminal 6 protrudes outward from the open-side end face 5b.

On the upper surface of the coupling substrate 2, capacitor electrodes C1 to C3 are formed in a pattern. Each of the capacitor electrodes C1 to C3 has a connection piece 6a of the coupling terminal 6.
Is connected. On both ends of the lower surface of the coupling substrate 2, input / output electrodes 7, 7 facing the capacitor electrodes C1, C3 are formed, and each of the input / output electrodes 7 has one end of the input / output terminal 3. 3a, 3a are connected. The input / output terminal 3 is formed by bending in a stepped manner, and has a hole 3b for absorbing an excess amount of solder cream at one end 3a, and the other end 3c is formed from the case 4 above. It protrudes outward. Thus, the filter 1 in which the respective dielectric coaxial substrates R1 to R3 are coupled with each other with capacitance and also with external circuits with capacitance.
Is configured.

The metal case 4 has an upper wall 4a and a bottom wall 4b.
Are integrally formed by a front wall 4c, and a substantially H-shaped opening 9 is formed in the upper wall 4a. The opening 9 can be coated with solder cream or coaxially. This is a working opening for adjusting the resonators R1 to R3. A fixing piece 4d and a ground terminal 4e are integrally formed at the left and right edges of the bottom wall 4b of the metal case 4, and are further formed at the rear of the left and right edges of the bottom wall 4b. The positioning piece 4f is formed by bending at the upper part. A plurality of small holes 9a, 9b are formed in the front, center, and rear portions of the bottom wall 4b. The small holes 9a are used for fixing a resin base, which will be described later. Is to absorb the excess of the solder cream and to confirm soldering.

Reference numeral 10 denotes a resin base of the present embodiment, which comprises a bottom wall 10a, a front wall 10b, and left and right side walls 1
0c and 10c are integrally formed. A slit 11 is formed at the center of the front wall 10b, and a V-shaped groove 12 following the slit 11 is formed at the center of the bottom wall 10a. This is because when the number of dielectric resonators is increased to four or more, the width of the coupling substrate becomes large. Therefore, the resin base 10 is cut off from the groove 12 and divided into two parts. It is for correspondence. Further, each of the side walls 10
A relief 16 is formed at the lower edge of c and 10d.

An insertion groove 13 through which one end 3a of the input / output terminal 3 is inserted is cut out at a substantially central portion of each of the side walls 10c and 10d, and a bottom wall below the insertion groove 13 is formed. A fixing portion 14 into which the one end portion 3a is inserted is recessed on 10a. Further, holding portions 15 are respectively provided at both inner end portions of the front wall 10b and at rear end portions of the corner portions of the side walls 10c and 10d facing the front wall 10b.
The front end face and the rear end face of the coupling board 2 are in contact with each holding portion 15.

A chamfer 17 is formed at the upper edge and the lower edge of the front wall 10b of the resin base 10, so that the chamfer 17 and the inner corner of the metal case 4 are provided between the chamfer 17 and the inner corner. A gap is formed. Here, although not shown, a projection is formed on the lower surface of the bottom wall 10a of the resin base 10 to fit into each small hole 9a of the bottom wall 4b of the metal case 4.

Next, the operation and effect of this embodiment will be described. To assemble the dielectric filter 1 of this embodiment, one end 3a of the input / output terminal 3 is inserted into each of the insertion grooves 13 of the resin base 10.
And one end 3a is fitted into the fixing portion 14,
Thus, the input / output terminals 3 are positioned and fixed. next,
The front end face and the rear end face of the connection board 2 are pushed into the holding portions 15 of the resin base 10 while being in contact with each other, and pressed onto the bottom wall 10a. As a result, the coupling substrate 2 is positioned and fixed in the resin base 10, and the input / output electrodes 7 are brought into contact with one end 3 a of the input / output terminal 3. Next, the resin base 10 is inserted into the metal case 4, the front wall 10b of the resin base 10 is brought into contact with the inner surface of the front wall 4c of the metal case 4, and the resin base is inserted into each small hole 9a of the bottom wall 4b. The ten projections are fitted, thereby positioning and fixing. Next, the dielectric pieces R1 and R3 are placed on the bottom wall 4b of the metal case 4 so that the outer surfaces of the dielectric resonators R1 and R3 are in contact with the positioning pieces 4f, and the open end faces 5a of the resonators R1 to R3 are made of resin. The base plate 10 is brought into contact with the rear end face of the bottom wall 10a, and the connection piece 6a of each coupling terminal 6 is connected to each capacitor electrode C1.
To C3. Then, solder cream is applied to the connection terminals 6, the input / output terminals 3, the openings 9 and the small holes 9b of the metal case 4, and then reflow soldered.

As described above, according to the present embodiment, the one end 13a of the input / output terminal 3 and the coupling substrate 2 are positioned and fixed in advance to the fixing portion 14 of the resin base 10 and each holding portion 15,
Since the resin base 10 is inserted into the metal case 4 and fixed in position, misalignment during assembly or reflow soldering can be prevented, and deterioration of characteristics can be avoided. Further, in this embodiment, since the chamfered portions 17 are formed on the upper edge and the lower edge of the front wall 10b of the resin base 10, the corners of the resin base 10 may be caught when the metal base 4 is inserted. However, the workability during assembly can be improved accordingly.
Further, interference between the upper edge and the lower edge of the resin base 10 and the inner corner portion of the case 4 can be prevented.
0 can improve the adhesion to the metal case 4 and can prevent rattling to improve the reliability of quality.

Although the above embodiment has been described with reference to an example of a filter in which a coupling terminal is inserted into a dielectric coaxial resonator, the present invention can be applied to an integrally molded dielectric filter and a resin pin is inserted. Of course, it can be applied to a filter that does not.

[0017]

As described above, according to the dielectric filter of the present invention, the fixing portion into which the input / output terminals inserted from the insertion grooves in the left and right walls are fitted and the holding portion into which the substrate is inserted and fixed. Since the resin base is inserted into the case and the input / output terminals are sandwiched between the substrates, there is an effect that the displacement of each component can be prevented and the fluctuation of characteristics can be avoided. In addition, since the chamfered portion is formed at the corner of the resin base, the workability at the time of assembling can be improved and the play at the time of mounting can be prevented.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view illustrating a dielectric filter according to an embodiment of the present invention.

FIG. 2 is a side view of the dielectric filter of the embodiment.

FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 1, showing a state where input / output terminals and a coupling board are inserted into the resin base of the embodiment.

FIG. 4 is an exploded perspective view showing a conventional dielectric filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dielectric filter 2 Coupling board 3 I / O terminal 4 Metal case 10 Resin base 14 Fixed part 15 Holding part 17 Chamfered part R1-R3 Dielectric resonator

Claims (2)

(57) [Scope of request for utility model registration] 1. A connecting the substrate to the dielectric resonator, thereby connecting the input and output terminals on the substrate, in the dielectric filter formed by accommodated in a case, the left in the case, the right side wall
The resin base insert disposed with, the resin-based bottom wall
The fixing part is recessed at the left and right side walls.
An insertion groove is formed to allow the fixed section to communicate with the outside,
Insert the child from the insertion groove, fit it into the fixed part,
Insert the board between the holding parts formed on the resin base.
The input / output terminals are pinched and fixed by
When the dielectric resonator is inserted into the case, the dielectric resonance
A dielectric filter , wherein a coupling terminal of the container is connected to the substrate . 2. The dielectric filter according to claim 1, wherein a chamfer is formed at a corner of the resin base corresponding to an inner corner of the case.