JPS5848814Y2 - ceramic filter - Google Patents

Description

[Detailed description of the invention] The present invention relates to a ceramic filter in which a box-shaped terminal plate containing a ceramic resonator sandwiched between electrode plates is housed in a case, and the opening of the case is sealed with resin. It is.

The structure of a conventional ceramic filter of this type will be explained with reference to FIG.

In FIG. 1, reference numeral 1 denotes a terminal plate made of resin for housing electronic components, and is formed in the shape of a box with one side open.

2 is a resin box-shaped case fitted to cover the opening of the terminal plate 1, 3 and 4 are electrode plates each having a protrusion, and the ceramic resonator 5 is held between the electrode plates 3 and 4. has been done.

6 is a cushioning material interposed between the electrode plate 3 and the inner wall surface of the terminal plate 1; 7 is a resin such as epoxy that is filled in the lower part of the terminal plate 1 and seals the opening of the case 2.

Incidentally, FIG. 2 is a wiring diagram of the ceramic resonator constituting the above-mentioned ceramic filter.

However, the conventional ceramic filter described above has a slight slope due to the conditions of the molding die during molding of the terminal plate 1 and case 2. In order to spread the plates apart, the electrode plates 3 and 4 are tilted as shown in FIG.
The vibration of the ceramic resonator 5 was suppressed and the characteristics were affected.

The present invention consists of the ceramic resonator 5 and the electrode plates 3 and 4 as described above.
An embodiment of the present invention will be described below with reference to FIGS. 4 and 5, with the same numbers assigned to the same parts as in FIG. 1.

FIG. 4 shows a case 10 of the ceramic filter of the present invention, and the inner wall dimension a of the upper part of the case 10 is the same or smaller than the outer wall dimension of the opening of the terminal plate 1, and the lower end of the case 10 is open. An inclined surface 11 is formed toward the hole.

When the case 10 as described above is used, it is possible to suppress the expansion of the entrance of the terminal plate 1 as shown in Fig. 5, and the electronic components housed in the terminal plate 1 can stand up straight, thereby preventing ceramic resonance. The peripheral part of the ceramic resonator 5 no longer comes into contact with the electrode plates 3 and 4, so there is no influence on the characteristics, and the peripheral part of the ceramic resonator 5 does not come into contact with the electrode plates 3 and 4 due to external vibration.
4, there is no variation in insertion loss, and there is no adverse effect on in-band ripple, selectivity, etc.

In addition, as shown in FIG. 4, if the sloped surface 11 is provided so that the inner dimension of one opening of the case is wider than the dimension of the inner part, the workability when covering the terminal plate 1 will be improved, and this This shape provides a draft angle for taking out the molded product during resin molding of the terminal plate 1, which improves the workability of molding.

Further, even if the case 10 is made of metal or has no draft angle, the effect on the characteristics of the ceramic filter remains the same.

Further, when the terminal plate 1 has a draft angle, it is more effective if the inner dimension of the case is smaller than the outer dimension of the opening of the terminal plate.

The present invention has the above-mentioned structure.According to the present invention, there is no contact with the ceramic resonator due to the inclination of the electrode plate, which eliminates deterioration of the filter characteristics, and has the advantage of improving the workability of assembly. It is something that you have.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional ceramic filter, Figure 2 is a wiring diagram of the ceramic resonator that makes up the ceramic filter, and Figure 3 is a cross-section of a conventional ceramic filter when the terminal plate and case are sloped. Figure 4 is a sectional view of a case of a ceramic filter according to an embodiment of the present invention.
FIG. 5 is a sectional view of a ceramic filter according to an embodiment of the present invention. 1...Terminal board, 3, 4...Electrode plate, 5
... Ceramic resonator, 6 ... Cushion material, 7 ... Resin, 10 ... Case.

Claims (1)

[Scope of utility model registration request] It comprises a box-shaped terminal plate that houses a ceramic resonator sandwiched between electrode plates, and a box-shaped case fitted to cover the opening of the terminal plate, and the opening of the case is covered with resin. In the ceramic filter to be sealed, the inner wall size at the back of the case is formed to be equal to or smaller than the outer wall size of the opening of the terminal plate, and the inner wall of the case is provided with an inclined surface on the opening side.