JPH09102703A - Dielectric filter - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] An object of the present invention is to provide a dielectric filter that can be used for environmental tests and the like. A component connecting portion (15a) provided on a ground conductor (13) of a mounting board (11) is individually and independently provided to each dielectric resonator (18), and the component connecting portion (15a) is provided on the bottom surface of the dielectric resonator (18). It is smaller inward than the outer peripheral edge.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a dielectric filter used in various communication devices.

[0002]

2. Description of the Related Art A conventional dielectric filter will be described below with reference to the drawings.

The dielectric filter shown in FIG. 5 is constructed as shown in FIG. Reference numeral 1 is a mounting substrate, on the top surface of which a ground conductor 2 and circuit-forming conductors 3a and 3b were provided.

Reference numeral 5 is a dielectric resonator, and this dielectric resonator 5 is connected to the circuit-forming conductors 3a and 3b via a metal fitting 6 and a plate capacitor 7 in the input / output section 5a. At the same time, the bottom surface of the dielectric resonator 5 was mounted on the ground conductor 2 by using solder.

Reference numeral 8 is a coil, and this coil 8 connects between the circuit-forming conductors 3a and 3b.

Reference numeral 9 is a cover made of metal, and the side surface of the cover 9 is soldered to the ground conductor 2 and the upper surface is soldered to the dielectric resonator 5.

[0007]

As shown in FIG. 7, the dielectric filter constructed as described above is one in which the dielectric resonator 5 is reflow-mounted using the solder 9 on the mounting substrate 1. Thus, the melted solder 9 wraps around the entire bottom surface of the dielectric resonator 5, and the end of the electrode 10 on the outer peripheral side surface of the dielectric resonator 5 is also connected to the ground conductor 2. Further, as shown in FIG. 8, the melted solder 9 also enters between the adjacent dielectric resonators 5, and the solder 9 is absorbed between the dielectric resonators 5 by a capillary phenomenon to cause an electrode 10 on the outer peripheral side surface of the dielectric resonator 5. The electrode 10 wraps around to the end, and the end of the electrode 10 is also connected to the adjacent dielectric resonator 5.

If the end of the electrode 10 provided on the outer peripheral side surface of the dielectric resonator 5 is connected to another component as described above, the force is applied to the dielectric filter from the outside by an environmental test or the like. Is added to the end of the electrode 10 on the outer peripheral side surface of the dielectric resonator 5, the electrode 10 peels off, the frequency of the dielectric resonator 5 changes, and the characteristics of the dielectric filter change. .

SUMMARY OF THE INVENTION Therefore, the present invention aims to solve the above problems and prevent the characteristic change of the dielectric filter.

[0010]

In order to achieve this object, the present invention provides a component connecting portion to which a dielectric resonator of a mounting board is connected individually and independently to each dielectric resonator. The dielectric resonator is made smaller inward than the outer peripheral edge of the bottom surface thereof, thereby preventing characteristic changes.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the dielectric filter according to the first aspect of the present invention, since the individual component mounting portions do not reach the outer peripheral edge of the bottom surface of each dielectric resonator, the outer periphery of the dielectric resonator is reduced. Even if the electrode end provided on the and other parts are not connected and, as a result, external force is applied to the dielectric filter,
The force is not applied to the electrode end provided on the outer periphery of the dielectric resonator, and this electrode end can be prevented from peeling off, and the frequency of the dielectric resonator can be changed and the characteristics of the dielectric filter can be prevented from changing. It is something that can be done.

A dielectric filter according to an embodiment of the present invention will be described below with reference to the drawings.

The dielectric filter according to one embodiment of the present invention is constructed as shown in FIGS.

Reference numeral 11 is a mounting substrate, and circuit-forming conductors 15a and 15b having a ground conductor 13 and an input / output terminal portion 14 are provided on the upper surface of a glass epoxy substrate 12. The lower surface is provided with a ground conductor (not shown) connected to the ground conductor 13 and input / output conductors (not shown) connected to the circuit-forming conductors 15a and 15b, respectively.

Further, on the mounting board 11, component connecting portions 16a, 16b, 16c, 1 for connecting respective components described later are provided.
An electrode protective film 17 is provided except for 6d.

Reference numeral 18 is a dielectric resonator having a through hole 18a.
The dielectric block 18b having the outer peripheral electrode 18c and the inner electrode 18d having one end connected to the outer peripheral electrode 18c are provided in the through hole 18a.
In this dielectric resonator 18, the outer peripheral electrode 18c is mounted on the component connecting portion 16a provided on the mounting substrate 11 by using solder, and the internal electrode 18d in the through hole 18a is a metal connection fitting. It is connected via 19 and the plate capacitor 20 to the component connecting portion 16b provided on the circuit-forming conductors 15a and 15b.

Reference numeral 21 is a coil which connects between the component connecting portions 16c provided on the circuit-forming conductors 15a and 15b.

Reference numeral 22 is a cover made of metal, and a soldering window 22a and an adjustment window 22b are provided on the upper surface. The side surface of the cover 22 is soldered to the component connecting portion 16d provided on the mounting substrate 11, and the soldering window 22a is connected to the outer peripheral electrode 18c of the dielectric resonator 18, It serves as a shield that blocks external influences on the body filter.

The component connecting portion 16a provided on the mounting substrate 11 is provided inwardly smaller than the outer peripheral edge of the bottom surface of each dielectric resonator 18. By providing the component connecting portion 16a in this way, the side surface of the outer peripheral electrode 18c of the dielectric resonator 18 is not directly connected to the ground conductor 13 by the solder 23 as shown in FIG. Is not applied to the side surface of the outer peripheral electrode 18c of the dielectric resonator 18, and as shown in FIG. 3, the component mounting portion 16a on which the dielectric resonator 18 is mounted is Since each dielectric resonator 18 is partitioned by an electrode protective film so as to be independent of each other, it is possible to prevent the solder from flowing between the adjacent dielectric resonators 18, which also applies force to the side surface of the outer peripheral electrode 18c. Is less likely to be added.

Further, the cover 22 is attached to the dielectric resonator 18
When soldering and, the soldering window 22a of the cover 22 and the center of each dielectric resonator 18 are individually and independently connected by solder 24 as shown in FIG. It is possible to prevent the solder 24 from flowing between the resonators 18.

The dielectric filter having the above structure is
The solder 23 for mounting the dielectric resonator 18 on the mounting substrate 11 does not connect the side surface of the outer peripheral electrode 18c of the dielectric resonator 18 to the mounting substrate 11, and further the soldering window of the cover 22 is used. 22a and the center of each dielectric resonator 18 are individually and independently connected by the solder 24, so that the solder can be prevented from flowing between the adjacent dielectric resonators 18, and as a result, an environmental test can be performed. Even when a force is externally applied to the dielectric filter due to, for example, the force is not applied to the side surface of the outer peripheral electrode 18c of the dielectric resonator 18, the outer peripheral electrode 18c is prevented from peeling off, and the dielectric resonator 18 It is possible to prevent the frequency from changing and the characteristics of the dielectric filter to change.

[0022]

As described above, according to the present invention, when the dielectric resonator is mounted on the mounting substrate, there is an electrode protective film,
Solder does not wrap around the electrode end provided on the outer periphery of the dielectric resonator, the electrode end provided on the outer periphery of the dielectric resonator is not connected to the mounting board, and it is not between the adjacent dielectric resonators. Since solder does not flow in, even if external force is applied to the dielectric filter as a result, the force is not applied to the electrode provided on the outer peripheral side surface of the dielectric resonator, which may cause the electrode to peel off. It is possible to prevent the frequency of the dielectric resonator from changing and the characteristics of the dielectric filter to change, and it is possible to cope with an environmental test or the like.

[Brief description of the drawings]

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

FIG. 2 is a front side sectional view of the dielectric filter.

FIG. 3 is a side sectional view of the same dielectric filter.

FIG. 4 is a plan view of the dielectric filter.

FIG. 5 is a perspective view of a conventional dielectric filter.

FIG. 6 is an exploded perspective view of the dielectric filter.

FIG. 7 is a front side sectional view of the dielectric filter.

FIG. 8 is a side sectional view of the same dielectric filter.

[Explanation of symbols]

 11 Mounting Substrate 13 Earth Conductors 14a, 14b Circuit Constituting Conductors 16a, 16b, 16c Connection Electrode 18 Dielectric Resonator 22 Cover

Claims (3)

[Claims] 1. A mounting board provided with a ground conductor and a circuit-forming conductor, and a mounting board mounted on a component connecting portion provided on the ground conductor, and an input / output end thereof is electrically connected to the circuit-forming conductor. Consists of a plurality of connected dielectric resonators, a mounting component electrically connected to the circuit-forming conductor, and a cover that covers the dielectric resonator and the mounting component on the mounting board and is connected to the ground conductor. The individual dielectric resonators are individually provided with the component connecting portions provided on the ground conductor, and the component connecting portions are made smaller inward than the outer peripheral end of the bottom surface of the dielectric resonator. Dielectric filter. 2. The electrode protective film is provided on the surface of the mounting substrate, and the electrode protective film non-forming portion is provided in the electrode protective film, and the non-electrode protective film non-forming portion is used as a component connecting portion. Dielectric filter. 3. The dielectric filter according to claim 1, wherein each of the dielectric resonators is independently soldered to the cover when connecting the plurality of dielectric resonators to the cover.