JP2534049Y2 - Dielectric filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a dielectric filter in which a plurality of dielectric resonators are capacitively coupled to each other via a coupling substrate on which, for example, a capacitor electrode is formed. More particularly, the present invention relates to a structure in which the connection strength of input / output terminals is improved to prevent the terminals from being peeled off by an external force.

[Conventional technology]

Conventionally, as an example of a dielectric filter using a plurality of dielectric coaxial resonators, there is one having a structure shown in FIGS. The dielectric filter 1 includes a plurality of dielectric coaxial resonators 2 housed in a metal case 3 including a grounding case plate 3a and a case cover 3b. Each of the dielectric coaxial resonators 2 has a through hole 5 formed in the axis of a rectangular parallelepiped dielectric block 4, and an inner peripheral surface of the through hole 5 and an open end surface of an outer surface of the dielectric block 4. The structure is such that the electrode film 4b is formed to cover portions other than 4a. A cylindrical coupling terminal 6 is press-fitted into the through-hole 5 of each of the dielectric blocks 4, and a part of the coupling terminal 6 protrudes outward from the open end face 4a. Further, a strip-shaped coupling dielectric substrate 7 is provided on the open end face 4a of each dielectric block 4 with a gap provided between the dielectric block 4 and the ground plate 3a. Capacitor electrodes 8a to 8d are formed on the upper surface of the dielectric substrate 7, and each of the capacitor electrodes 8a to 8d
The protruding portion of the coupling terminal 6 is connected by soldering. Thus, the dielectric coaxial resonators 2 are capacitively coupled to each other by the capacitor electrodes 8a to 8d. Also,
Terminal connecting electrodes 9 are provided at both ends of the lower surface of the dielectric substrate 7.
a and 9b are formed. One end of each of the input and output terminals 10 and 10 is connected to each of the electrodes 9a and 9b.
Is protruded outward from the opening 3c of the case cover 3b. Further, the case plate 3a and the case cover 3b are
The solder 11 filled in the solder holes 3d is electrically and mechanically connected to the electrode film 4b on the outer surface of the dielectric block 4.

Here, in the dielectric filter 1, it is necessary to support the dielectric substrate 7 in a floating state so that the capacitor electrodes 8 a to 8 d and the input / output terminals 10 of the dielectric substrate 7 do not contact the case 3. is there. For this reason, the conventional case plate
A strip-shaped insulating spacer 12 is disposed between the dielectric substrate 3a and the dielectric substrate 7, and both are bonded and fixed with an adhesive 13.

[Problems to be solved by the invention]

However, in the above-described conventional dielectric filter 1, the input and output terminals 10, 10 are connected to the floating dielectric substrate 7, so that when any external force is applied to the input and output terminals 10, the input and output terminals 10, 10 are separated. However, there is a problem that disconnection is easily caused. For this purpose, after the input and output terminals 10 are soldered,
As shown in the figure, an adhesive 14 may be applied to the input / output terminals 10 to reinforce them. However, even if the adhesive 14 is applied, there is a problem that the external force is weak to the downward direction, and the productivity is lowered by the number of steps for applying the adhesive 14.

The present invention has been made in view of the above conventional situation,
It is an object of the present invention to provide a dielectric filter capable of improving the connection strength of input / output terminals and preventing peeling due to external force.

[Means for solving the problem]

In the present invention, a plurality of resonators 2, 2
The coupling substrate 7 is disposed with a gap provided between the coupling substrate 7 and the grounding case 3a, and the capacitive coupling electrodes 8a to 8d formed on one main surface of the coupling substrate 7 are provided. A dielectric filter is formed by connecting the resonators 2, inputting the connection electrodes 9a, 9b formed on the other main surface of the coupling substrate 7 and connecting one end of the output terminals 10, 10. 1, the coupling substrate 7 is formed in a strip shape, and one main surface and the other main surface of the substrate 7 are arranged so as to be parallel to a plane including the axis of the resonators 2, 2,. A strip-shaped insulating spacer 20 having substantially the same length as the substrate 7 is interposed between the grounding case 3a and the coupling substrate 7, and one main surface and the other main surface of the insulating spacer 20 are bonded. By connecting to the other main surface of the coupling substrate 7 and the inner surface of the grounding case 3a with an agent 23, the spacer 20
The coupling substrate 7 is fixed to the grounding case 3a through the above, the input and output terminals 10 and 10 are formed in a strip shape, and the electrode 21 formed on one main surface of the insulating spacer 20 is connected to the coupling substrate 7 and the electrode 9a formed on the other main surface of the input / output terminal 1
The two input / output terminals are sandwiched and fixed at one end, and the input / output terminals are protruded outwardly between the insulating spacer 20 and the coupling substrate 7.

[Action]

According to the dielectric filter of the present invention, the gap between the grounding case and the coupling substrate is filled with the spacer, whereby the coupling substrate is fixed to the grounding case via the spacer, and the input and output terminals are provided. Is fixed between the spacer and the coupling substrate, and is projected outward through the space between the spacer and the coupling substrate. Therefore, even if an external force is applied to the input and output terminals, there is no separation. The connection strength can be improved as compared with a structure in which the input and output terminals are connected to the floating coupling substrate.

〔Example〕

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 are views for explaining a dielectric filter according to an embodiment of the present invention, in which the same reference numerals as those in FIGS. 5 and 6 denote the same or corresponding parts. Since the basic structure of the dielectric filter of this embodiment is substantially the same as that shown in FIGS. 5 and 6, the description will be made with reference to FIG.

In the dielectric filter 1 of the present embodiment, four dielectric coaxial resonators 2 are accommodated in a metal case 3 and a dielectric substrate 7 is provided with a gap between the dielectric substrate 7 and a case plate 3 a of the case 3. It is arranged and configured. A coupling terminal 6 press-fitted into the through-hole 5 of the dielectric coaxial resonator 2 is connected to each of the capacitor electrodes 8a to 8d formed on the upper surface of the dielectric substrate 7 by soldering. Further, terminal connection electrodes 9a and 9b are formed at both ends of the lower surface of the dielectric substrate 7 so as to face the capacitor electrodes 8a and 8d at the both ends, and input and output are provided to the electrodes 9a and 9b. One ends of the terminals 10, 10 are connected by soldering. The other ends of the input and output terminals 10, 10 protrude outward from the opening 3c of the case cover 3b, and the basic structure is substantially the same as the conventional one.

Further, an insulating spacer 20, which is a feature of the present embodiment, is disposed between the case plate 3a and the dielectric substrate 7.
The spacer 20 is a plate-like member having substantially the same length and width as the dielectric substrate 7, and the thickness of the spacer 20 is set to a size to fill a gap between the case plate 3a and the dielectric substrate 7. ing. The spacer 20, the dielectric substrate 7, and the case plate 3a are fixed to each other with an adhesive 23, whereby the dielectric substrate 7 is fixed to the case plate 3a via the spacer 20.

In addition, connection electrodes 21 and 21 are formed in portions of the spacer 20 that are in contact with the upper and lower terminals 10 and 10, and the electrodes 21 are soldered to the input and output terminals 10. As a result, the input and output terminals 10 are connected to the dielectric substrate 7 and the spacer.
It is pinched by 20.

 Next, the operation and effect of this embodiment will be described.

According to the dielectric filter 1 of the present embodiment, the spacer 20 is disposed between the case plate 3a and the dielectric substrate 7 to fill the gap therebetween, and the dielectric substrate 7 is connected to the case plate via the spacer 20. 3a, connection electrodes 21 are formed at both ends of the spacer 20, and the input and output terminals 10 are soldered to the electrodes 21 to connect the input and output terminals 10 to the spacer 20 and the dielectric substrate 7. Because of this, the input and output terminals 10 can be prevented from peeling due to external force such as pulling, and the connection strength can be improved.

The connection between the connection electrode 21 of the spacer 20 and the input / output terminal 10 can be made at the same time as the connection of other electrodes and the like in the reflow step after the dielectric filter 1 is assembled. Therefore, a conventional adhesive is applied. The productivity can be improved as compared with the case.

In the above embodiment, the case where the input and output terminals 10 of the dielectric filter 1 are bent in a substantially L-shape and mounted on a printed circuit board is described as an example, but the present invention is shown in FIG. In this way, the input / output terminal 10 may be extended below the case plate 3a, and the extension may be penetrated through the printed circuit board for mounting, or as shown in FIGS. 4 (a) and 4 (b). Alternatively, the input / output terminal 10 may be projected forward of the case 3.

Further, in each of the above embodiments, the connection electrode 21 is formed on the spacer 20. However, the connection electrode 21 is not necessarily required. In other words, the connection electrode 21 is formed so that the input and output terminals 10 are sandwiched between the spacer 20 and the substrate 7. What is necessary is just to configure.

In the above embodiment, a filter using a dielectric coaxial resonator has been described as an example. However, the present invention is not limited to this, and can be applied to, for example, an integrally molded dielectric filter.

[Effect of the invention]

As described above, according to the dielectric filter according to the present invention,
A spacer is provided between the grounding case and the coupling substrate, and the substrate is fixed to the case, and the input and output terminals are clamped and fixed between the spacer and the coupling substrate. Since the projection is made to protrude, the connection strength of the input and output terminals can be improved, and there is an effect that separation due to external force can be prevented.

[Brief description of the drawings]

1 and 2 are views for explaining a dielectric filter according to an embodiment of the present invention. FIG. 1 is a partially sectional front view thereof, FIG. 2 is a perspective view showing a spacer thereof, and FIG. 3 is a front view showing a modification of the input and output terminals, FIG. 4 (a) is a front view showing another modification, FIG. 4 (b) is a side view thereof, and FIGS. 5 is an exploded perspective view, FIG. 6 is a partial cross-sectional front view, FIG. 7 is an equivalent circuit diagram, and FIG. 8 is a conventional dielectric filter. FIGS. 9 (a) and 9 (b) are a plan view, a bottom view, FIGS. 10 (a) and 10 (b) of a dielectric substrate, respectively, for explaining the problem of FIG. It is the front view and bottom view which show the connection part of the conventional input and output terminal, respectively. In the figure, 1 is a dielectric filter, 2 is a dielectric coaxial resonator, 3a is a case plate (grounding case), 7 is a dielectric substrate (coupling substrate), 8a to 8d are capacitor electrodes (coupling electrodes), 9a , 9b are connection electrodes, 10 is an input / output terminal, and 20 is a spacer.

Claims (1)

(57) [Scope of request for utility model registration] A plurality of resonators are disposed on a grounding case, and a coupling substrate is disposed with a gap provided between the resonators and the grounding case. The resonator is formed on one main surface of the coupling substrate. In the dielectric filter, each of the resonators is connected to each electrode for capacitive coupling, and one end of an input terminal and one end of an output terminal are connected to connection electrodes formed on the other main surface of the coupling substrate. The substrate is formed in a strip shape, and one main surface and another main surface of the substrate are arranged so as to be parallel to a plane including the axis of the resonator, and the substrate is provided between the grounding case and the coupling substrate. A strip-shaped insulating spacer having substantially the same length as the substrate is interposed, and one main surface and the other main surface of the insulating spacer are connected to the other main surface of the coupling substrate and the inner surface of the grounding case with an adhesive. By doing so, the coupling substrate is connected to the earth case via the spacer. The input and output terminals are strip-shaped, and the electrodes formed on one main surface of the insulating spacer and the electrodes formed on the other main surface of the coupling substrate are connected to one end of the input and output terminals. A dielectric filter wherein both main surfaces are sandwiched and fixed, and the input / output terminals are projected outwardly between the insulating spacer and the coupling substrate.