JPS6330812B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a piezoelectric ceramic filter that is easy to assemble and can obtain arbitrary filter performance by combining ceramic resonant elements.

As a conventional example, an example of a combination of two ceramic resonant elements will be described with reference to FIGS. 1 and 2. In Figure 1a, two vibrating parts are formed on a single ceramic substrate 1, and conductive parts 2, 2', 2'' are provided on the front and back sides by vapor deposition, plating, etc. so that the vibration can be extracted. Fig. 1 b
It looks like this, and is a combination of two ceramic resonant elements. Figures 2a and b show external lead wires 3, 3', and
3" with solder or conductive adhesive 4, 4', 4"
A piezoelectric ceramic filter is shown in which the piezoelectric ceramic filter is connected to a container 5 made of resin or the like and covered with a lid 6 made of resin or the like. Keep your body in. In this case, since the external lead wire is directly connected to the ceramic resonant element, external stress on the lead wire is applied directly to the ceramic resonant element, causing cracks and cracks, resulting in weak mechanical strength. Furthermore, if several sets of vibrating parts are provided on a single ceramic substrate depending on the filter performance, the ceramic substrate will become larger and its mechanical strength will further weaken, and ceramic resonant elements with different shapes must be created depending on the performance. No. Furthermore, when placing the ceramic resonant element in the container, the ceramic resonant element must be kept floating so as not to come into contact with the inside of the container until the lid is attached, which is a time-consuming process.

The present invention was devised to eliminate the above-mentioned drawbacks of the conventional technology, and one embodiment thereof will be described below as a third embodiment.
This will be explained with reference to FIGS.

First, FIG. 3a shows a ceramic substrate in which conductive parts 8 and 8' are provided on the front and back sides of a rectangular ceramic substrate 7 by vapor deposition, plating, etc., so that the conductive parts 8 and 8' face each other at the center, reach opposite ends of the front and back, and can extract vibrations. Resonant element A is expressed in electrical symbols as shown in FIG. 3b. As shown in FIG. 4a, this resonant element A is printed, plated, etched, etc. to match the conductive parts 10 and 1 for vibration extraction of the resonant element A.
The conductive parts 8 and 8' of the resonant element A are connected to the conductive parts 10 and
10' with solder or conductive adhesive 11 and 1, respectively.
Fix by connecting at 1'. The insulating substrate 9 to which the resonant element A is connected and fixed is placed in a container 12 made of resin or the like having an end surface that the peripheral edge of the insulating substrate 9 comes into contact with, as shown in FIG. 5a. A frame 13 made of resin or the like as shown in FIG. The insulating substrate 9 to which the resonant element constituting the filter body is connected and fixed is placed thereon and fixed with adhesive, and then the same container 12 is placed thereon and fixed with adhesive as shown in FIG. 5d. In other words, two sets of filter bodies are placed in frame 1.
3 and conductive parts 1 at both ends.
It is fixed with adhesive so that 0 and 10' are exposed.
The one shown in FIG. 5d has conductive parts (not shown) for connecting the conductive parts 10 and 10' of the insulating substrate 9 protruding from both ends, and a lead wire connected to the conductive part. A piezoelectric ceramic filter shown in FIG. 6 is obtained by gluing lids 15, 15' having lids 14, 14' to both ends.

According to the present invention, mechanical strength is improved because stress from the external lead wire is transmitted to the resonant element via the insulating substrate. In addition, even when combining many resonant elements to obtain a desired filter performance, it is easy to stack the insulating substrates connected to the resonant elements in a frame, and prepare a lid for wiring the conductive parts on the end faces. Can be done. Furthermore, it is possible to provide a piezoelectric ceramic filter having the advantage that the ceramic resonant element only needs to have one type of shape, and the resonant element can be easily mass-produced.

[Brief explanation of the drawing]

Fig. 1a is a perspective view of a ceramic resonant element used in a conventional example, Fig. 1b is a diagram showing its electrical signal representation, Fig. 2a is a cross-sectional view showing a conventional piezoelectric ceramic filter assembly structure, and Fig. 2b is a perspective view of a ceramic resonant element used in a conventional example. 3A is a perspective view of the ceramic resonant element used in the present invention, FIG. 3B is a representation of the electric signal, and FIG. FIG.
is a perspective view of an insulating substrate with an element mounted thereon connected and fixed to the container, c is a perspective view of a frame used in the present invention, and d is a perspective view of the completed piezoelectric ceramic filter according to the present invention. FIG. 6 is a perspective view of a piezoelectric ceramic filter constructed according to the present invention. A... Ceramic resonant element, 8, 8'... Conductive part for vibration extraction, 9... Insulating substrate, 10, 10'
... Conductive part, 12 ... Container, 13 ... Frame, 14,
14'... External lead wire, 15, 15'...
lid.

Claims (1)

[Claims] 1. The ceramic resonant element is connected and fixed on an insulating substrate on which the conductive part connected to the conductive part for vibration extraction of the ceramic resonant element is provided so as to reach the end face, and the insulating substrate is connected so that the peripheral edge of the insulating substrate is in contact with the conductive part of the ceramic resonant element. At least two sets of the filter bodies are stacked together via a frame having an end surface that the peripheral edge of the insulating substrate contacts, and the insulating substrate is attached to both ends of the filter body. A piezoelectric device is formed by adhering and fixing the conductive part so that the conductive part is exposed, and further adhering a lid having an external lead wire connected to the conductive part of the insulating substrate to both ends of the insulating substrate where the conductive part is exposed. Porcelain filter.