JPH0591029U - Piezoelectric oscillator - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] Providing a piezoelectric ceramic resonator with a simple structure that ensures reliable connection between the piezoelectric ceramic diaphragm and the lead terminals and that does not hinder the vibration of the piezoelectric element. To do. [Structure] A rectangular piezoelectric element 6 having a facing electrode in the central portion and electrodeless portions formed on opposite surfaces of both ends is provided with a conductive adhesive on a terminal portion 3 of a terminal block 2 in which lead terminals 1 are implanted. Alternatively, the case 7 is electrically and mechanically connected and fixed using the solder 4, and the case 7 is fixed to the terminal block 2. In addition, since it is easy to superimpose a plurality of piezoelectric elements 6 on the terminal portion of the terminal block, by connecting piezoelectric elements of the same frequency in parallel with one piezoelectric ceramic vibrator, good trap attenuation characteristics and high performance can be obtained. Piezoelectric oscillator
Further, it is possible to provide a piezoelectric ceramic vibrator having a plurality of trap functions by connecting piezoelectric elements of different frequencies in parallel with one piezoelectric ceramic vibrator.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention mainly relates to a piezoelectric ceramic oscillator such as a ceramic filter and a ceramic trap using a piezoelectric ceramic diaphragm used for extracting and removing a high frequency band signal from a video device such as a television receiver and a video tape recorder. Is.

[0002]

[Prior Art]

 Conventionally, some prior arts have been filed as piezoelectric ceramic vibrators for high frequency bands. Of these, as typical ones, Japanese Patent Application No. 51-172072, Japanese Patent Application No. 52-384, There are Japanese Patent Application No. 54-142100 and Japanese Patent Application No. 56-70042, and conventional examples thereof will be described with reference to FIG.

FIG. 5 is a cross-sectional view showing a conventional piezoelectric ceramic oscillator, showing a square plate piezoelectric ceramic diaphragm 15 provided with an upper surface electrode 13 and a lower surface electrode 14 which are formed so as to face each other. The lower surface electrode 14 is electrically and mechanically connected and fixed to the first lead wire 17 by a rectangular flat plate 16 that makes surface contact with the entire surface of the lower surface electrode 14. The upper electrode 13 is supported by a whisker 19 having a spring property which is electrically and mechanically connected and fixed to the second lead wire 18 so that the vibration of the rectangular plate piezoelectric ceramic diaphragm 15 is not killed. It is supported by point contact by means of, and is sealed by a glass container 20 so as to support and protect the square plate piezoelectric ceramic vibrating plate 15 and the first and second lead wires 17 and 18.

[0004]

[Problems to be solved by the device]

 However, in the above-described conventional configuration, when the contact pressure between the square plate piezoelectric ceramic diaphragm 15 and the whiskers 19 is high, the vibration of the square plate piezoelectric ceramic diaphragm 15 is killed and the performance deteriorates. If the contact pressure is low, vibration and shock from the outside will cause the square plate piezoelectric ceramic diaphragm 15 to move internally and electrical connection will not be established, resulting in an open failure, or the end surface of the square plate piezoelectric ceramic diaphragm 15 will become a glass container 20. There was a problem that the vibrations were killed by contact with the inner surface of the and the performance deteriorated, and in severe cases, the characteristics did not appear.

In addition, when used in video equipment, one piezoelectric ceramic resonator does not have trapping performance, and it is necessary to connect a plurality of piezoelectric ceramic resonators of the same frequency in parallel to a printed circuit board or to use traps of different frequencies. In such cases, multiple piezoelectric ceramic oscillators with different frequencies were connected in parallel to the printed circuit board. For this reason, there are problems that the printed circuit board cannot be downsized and that the number of man-hours for inserting the component is increased.

[0006] In order to solve this problem, the above-mentioned Japanese Patent Application No. 56-70042, which is a prior art, was also examined, but the problem of the contact pressure between the square plate piezoelectric ceramic diaphragm 15 and the whisker 19 remains and the performance remains. Are unstable, or to obtain the same performance, it is necessary to make the size of the piezoelectric ceramic diaphragm 15 the same, which makes it impossible to unify the members such as changing the size of the glass container 20. There was a problem with mass productivity.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a high-quality piezoelectric ceramic oscillator having a simple structure, good mass productivity, and high reliability. ..

[0008]

[Means for Solving the Problems]

 In order to solve this problem, the piezoelectric ceramic vibrator of the present invention has a titanic acid oscillator having electrodes formed such that electrodeless portions are provided on one end of the upper surface and the lower surface of the other end, and the central portions face each other. A rectangular piezoelectric ceramic vibrating plate containing lead as its main component (hereinafter referred to as a piezoelectric element) and lead wires for electrically and mechanically joining and fixing both ends of this piezoelectric element together with a base substrate using a conductive adhesive or solder. It consists of a terminal block that is planted, a bottomed case that fits around the outer periphery of the terminal block and forms a space above the piezoelectric element, and has an open end, and a sealing resin that closes the opening of this case. It is a thing.

[0009]

With this configuration, not only the terminal block and the piezoelectric element are securely connected, but also the space formed between the piezoelectric element and the case is securely ensured, so that vibration or impact from the outside Thus, it is possible to provide a high-quality piezoelectric ceramic oscillator that does not cause open defects and characteristic defects.

Further, since it is possible to easily stack a plurality of piezoelectric elements on the terminal portion of the terminal block without adding new members, it is possible to connect piezoelectric elements of the same frequency with one piezoelectric ceramic vibrator. It is possible to provide a high-performance piezoelectric ceramic oscillator, and by connecting piezoelectric elements of different frequencies, it is possible to provide a piezoelectric ceramic oscillator having a plurality of trap functions.

[0011]

【Example】

 Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially cutaway perspective view showing the structure of a piezoelectric ceramic vibrator according to a first embodiment of the present invention. In FIG. 1, the terminal portion 3 of a terminal block 2 in which a lead terminal 1 is planted is shown. The base substrate 5 and the piezoelectric element 6 are electrically and mechanically connected and fixed with a conductive adhesive or solder 4, the case 7 is covered on the upper side of the terminal block 3, and the open side of the case 7 is made of epoxy resin or the like. It is configured by sealing with the sealing resin 8.

The piezoelectric element 6 contains PbO and TiO ₂ as main components, and PbO / TiO ₂ is less than 0. 97 to 0.95, a piezoelectric ceramic composition containing TiO ₂ as 100 and 1.0 to 2.0 mol% of La ₂ O ₃ added in combination has an electromechanical coupling coefficient of thickness longitudinal vibration of 40 to 50. %, The electromechanical coupling coefficient of length vibration is 10% or less, the mechanical quality coefficient is 700 to 1200, and the relative dielectric constant is 150 to 240 (the same as those disclosed in Japanese Patent Application No. 46-64534 or A high frequency piezoelectric material (according to this) was used.

FIG. 2 is a comparison characteristic diagram of the trap performance when the piezoelectric ceramic resonator according to the first embodiment of the present invention is combined with a surface wave filter and the same performance using a conventional piezoelectric ceramic resonator. Therefore, when the piezoelectric ceramic resonator of the present invention is used, the amount of attenuation is large at the desired frequency, and one piezoelectric ceramic resonator can achieve the performance of two traps of the conventional piezoelectric ceramic resonator. It has.

Second Embodiment Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is a partially cutaway perspective view showing the structure of a piezoelectric ceramic vibrator according to a second embodiment of the present invention. In FIG. 3, the piezoelectric elements 9 and 10 having the same natural vibration frequency are used as lead terminals. It is configured such that the terminal portion 3 of the terminal block 2 in which 1 is implanted is electrically and mechanically connected and fixed so as to be overlapped with a conductive adhesive or solder 4. The other structure is the same as that of the first embodiment of the present invention. With such a configuration, a larger amount of attenuation can be stably obtained at a desired frequency.

Third Embodiment A third embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 is a partially cutaway perspective view showing the structure of the piezoelectric ceramic vibrator according to the third embodiment of the present invention. In FIG. 4, the piezoelectric elements 11 and 12 having different natural vibration frequencies are connected to the lead terminal 1. The terminal portion 3 of the implanted terminal block 2 is electrically and mechanically connected and fixed so as to be superposed with a conductive adhesive or solder 4. The other structure is the same as that of the first embodiment of the present invention.

With this configuration, for example, when the piezoelectric ceramic vibrator according to the embodiment is used in combination with a surface wave filter, a desired attenuation amount cannot be obtained at the frequency at which the surface wave filter attenuates. In addition, by constructing one of the piezoelectric ceramic vibrators according to the embodiment so as to have an attenuation characteristic matched to the frequency to be attenuated by the surface wave filter, desired characteristics can be obtained. Further, it is possible to achieve the same in the case where it is desired to obtain the attenuation effect at a plurality of different frequencies.

[0020]

[Effect of the device]

 As described above, according to the present invention, not only is it possible to securely electrically and mechanically connect the terminal portion of the terminal block and the piezoelectric element, but it is also possible to connect the piezoelectric element to the piezoelectric element by connecting the case to the terminal block. Since the space is reliably formed between the piezoelectric ceramic oscillator and the case, it is possible to provide a high-quality piezoelectric ceramic oscillator that does not cause open defects and characteristic defects due to external vibration and impact.

Further, since it is possible to easily stack a plurality of piezoelectric elements on the terminal portion of the terminal block, by connecting piezoelectric elements of the same frequency in parallel with one piezoelectric ceramic oscillator, good trap attenuation characteristics can be obtained. It is possible to provide a high-performance piezoelectric ceramic oscillator, and it is possible to provide a piezoelectric ceramic oscillator having multiple trap functions by connecting piezoelectric elements of different frequencies in parallel with one piezoelectric ceramic oscillator. In addition, the printed circuit board of the video equipment can be downsized, and the number of man-hours for inserting components can be reduced.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing a structure of a piezoelectric ceramic vibrator according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a comparison between trap characteristics when the piezoelectric ceramic oscillator according to the embodiment is combined with a surface wave filter and the same characteristics when the conventional piezoelectric ceramic oscillator is used.

FIG. 3 is a partially cutaway perspective view showing a structure of a piezoelectric ceramic vibrator according to a second embodiment of the present invention.

FIG. 4 is a partially cutaway perspective view showing a structure of a piezoelectric ceramic vibrator according to a third embodiment of the present invention.

FIG. 5 is a sectional view showing the structure of a conventional piezoelectric ceramic vibrator.

[Explanation of symbols]

 1 lead terminal 2 terminal block 3 terminal part 4 conductive adhesive or solder 5 base substrate 6 piezoelectric element 7 case 8 sealing resin

Claims (4)

[Scope of utility model registration request] 1. A rectangular piezoelectric ceramic vibrating plate containing lead titanate as a main component and having electrodes formed so that electrodeless portions are provided on one end of the upper surface and on the lower surface of the other end, respectively, and the central portions face each other. And a terminal block with both ends of this piezoelectric ceramic vibrating plate attached to the base board electrically and mechanically with a conductive adhesive or solder, and a terminal block fitted on the outer periphery of the terminal block. A piezoelectric ceramic oscillator including a bottomed case having a space formed in the upper part of a plate and a sealing resin that closes the opening of the case. 2. The piezoelectric ceramic diaphragm has an electromechanical coupling coefficient of 40 to 50% for thickness longitudinal vibration, an electromechanical coupling coefficient of 10% or less for length vibration, a mechanical quality coefficient of 700 to 1200, and a relative dielectric constant. 3. The piezoelectric ceramic vibrator according to claim 1, wherein the third-order harmonic vibration of the piezoelectric ceramic having a thickness of 150 to 240 is utilized. 3. The piezoelectric ceramic vibrator according to claim 1, wherein a plurality of piezoelectric ceramic diaphragms having the same natural vibration frequency are joined in parallel. 4. The piezoelectric ceramic vibrator according to claim 1, wherein a plurality of piezoelectric ceramic diaphragms formed to have different natural vibration frequencies are joined in parallel.