JPH11308011A - Dielectric filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate dislocation of a metallic case, to hold mechanical intensity upon performing electrical connection equivalent to the conventional case as reducing mounting area and to enable miniaturization of a dielectric filter by inserting a projecting part provided at a metallic plate, to which a bending work is performed in the L-shape into a through-hole provided at a grounding pattern. SOLUTION: A chip capacitor 3 as an electrical connection element to connect plural coaxial dielectric resonators 6, and dielectric resonators 6 is mounted on a printed circuit board 1 for constituting a circuit. In addition, since electromagnetic fault, etc., to the outside are considered in this state, the metallic case 8 to which the bending work is performed in the L-shape is allowed to cover in the direction of an arrow 12 to perform electromagnetic shielding from the electromagnetic fault, etc., to the outside. In this case, the metallic case 8 is electrically and mechanically soldered and connected with an external conductor 13 on the Ag-melalized upper surface of the dielectric resonator 6 the projecting part 10 of which is inserted into the through hole 5 provided at the earth pattern 2 of the printed circuit board 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric filter for a high frequency band of several hundred MHz to several GHz used for a mobile communication device or the like.

[0002]

2. Description of the Related Art Generally, electronic components used in an electronic device are close to each other, so that interference or the like due to radiated noise may occur, which may hinder normal operation of the electronic device.

For this reason, a dielectric filter used in a mobile communication device is designed to avoid electromagnetic interference to the outside and further protect the device from external electromagnetic interference as shown in FIG. The earth pattern 2 of the substrate 1 and the outer conductor of the dielectric resonator 6 and the box-shaped metal case 9 are electrically and mechanically soldered and covered.

[0004]

However, with the recent trend of miniaturization and height reduction of electronic parts, miniaturization of dielectric filters is inevitably required, and the mounting area is reduced. The metal case 9 having the horizontal outward bending portion 11 for connection requires a large mounting area. Further, when the metal case is connected to the printed wiring board by soldering, there is a problem that the metal case is displaced.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a metal case that has no positional displacement, reduces the mounting area, maintains the same electrical connection as before, and maintains mechanical strength.
An object of the present invention is to provide a dielectric filter that can be reduced in size.

[0006]

According to the present invention, a plurality of coaxial dielectric resonators mounted on a printed circuit board for circuit configuration, and an electric coupling element for coupling the dielectric resonators are provided. And a dielectric filter comprising a metal case that electrically and mechanically connects the outer conductor of the dielectric resonator and the ground pattern of the printed wiring board, wherein the metal case is bent into an L shape. A dielectric filter having a structure in which a protrusion is provided at one end of a metal plate and wherein the protrusion is inserted into a through hole provided in a ground pattern of the printed wiring board is obtained.

The dielectric filter according to the present invention uses a metal case formed in a conventional box shape having no horizontal outward bent portion for solder connection, so that the dielectric filter can be configured in a small mounting space. Can be. That is, the size of the dielectric filter can be reduced.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a dielectric filter according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an exploded perspective view of a dielectric filter according to the present invention. In FIG. 1, a plurality of coaxial dielectric resonators 6 and a chip capacitor 3 as an electric coupling element for coupling the dielectric resonators are mounted on a printed wiring board 1 for circuit configuration.

Further, in this state, there is a concern that electromagnetic interference or the like to the outside may occur. Therefore, in order to electromagnetically shield these, an L-shaped bent metal case 8 is covered in the direction of arrow 12.

At this time, the metal case 8 is
Is electrically and mechanically soldered to the outer conductor 13 on the upper surface of the dielectric resonator 6 which is inserted into the through hole 5 provided in the ground pattern 2 of the printed wiring board 1 and has been subjected to Ag metallization. .

The printed wiring board 1 has a plurality of through holes 5, and the metal case 8 has a plurality of projections (projections that can be inserted into the through holes) 10 having a width equal to or less than the diameter of the through holes 5. This is because the positioning is easily performed by inserting the protrusion 10 into the through hole 5 and soldering is performed without displacement.

[0013]

As described above, according to the present invention,
It is possible to realize a dielectric filter capable of maintaining electrical and mechanical strength and reducing its size while reducing the mounting area.

Further, by providing the through-holes of the printed wiring board and the projections of the metal case, the positioning can be easily performed, and the problem of misalignment of the metal case during the passage in the reflow furnace at the time of manufacturing, which has been a problem, is prevented. Can be prevented.

Further, the metal case of the dielectric filter of the present invention has fewer bent portions and is easier to process than the conventional metal case, so that the cost can be reduced by reducing the number of steps.

[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 an exploded perspective view of a conventional dielectric filter.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 printed wiring board 2 ground pattern 3 chip capacitor 4 input / output terminal 5 through hole 6 (coaxial) dielectric resonator 7 terminal pin 8 metal case (of the present invention) 9 (conventional) metal case 10 protrusion 11 Oriented bending part 12 Arrow 13 Outer conductor

Claims (1)

[Claims] 1. A semiconductor device comprising: a plurality of coaxial dielectric resonators mounted on a printed wiring board for circuit configuration; and an electric coupling element for coupling the dielectric resonators. In a dielectric filter comprising a metal case for electrically and mechanically connecting a conductor and a ground pattern of a printed wiring board, the metal case is provided with a protruding portion at one end of an L-shaped bent metal plate. A dielectric filter having a structure, wherein the protrusion is inserted into a through hole provided in a ground pattern of the printed wiring board.