JPS631459Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a piezoelectric vibrator that can be used as a filter or the like, and more particularly to a piezoelectric vibrator that can reduce spurious vibrations (unnecessary vibrations).

In an energy confinement type piezoelectric resonator, it is important to suppress unnecessary vibrations other than the main vibration.
For this reason, in the past, unnecessary vibrations were mainly suppressed by reducing the area of the excitation electrode provided on the piezoelectric plate, adjusting the hoop shape, etc. However, it is desirable to suppress unnecessary vibrations while allowing miniaturization.

Therefore, an object of the present invention is to provide a piezoelectric vibrator that can suppress unnecessary vibrations while being miniaturized.

To achieve the above object, the present invention includes a piezoelectric plate having a rectangular planar shape, a plurality of excitation electrodes provided on the piezoelectric plate, and a connection to one of the plurality of excitation electrodes via an internal wiring conductor. and a first external connection conductor portion provided broadly along substantially the entire length of the first side of the piezoelectric plate, and an internal wiring conductor provided to another one of the plurality of excitation electrodes. a second external connection conductor portion that is connected to the piezoelectric plate through the piezoelectric plate and is provided broadly along substantially the entire length of a second side opposite to the first side of the piezoelectric plate; a first terminal pin connected to the first external connection conductor part with a conductive adhesive while extending in the same direction as the conductor part; and a first terminal pin extending in the same direction as the second external connection conductor part; The present invention relates to a piezoelectric vibrator configured to include at least a second terminal pin coupled to a second external connection conductor portion with a conductive adhesive, and an insulating base that holds at least the first and second terminal pins. It is something.

In the above idea, a wide external connection conductor part is provided along almost the entire length of the first side and the second side opposite to this of a square piezoelectric plate, and the terminal pins are connected to each part using a conductive adhesive. Therefore, the effect of suppressing unnecessary vibration is greater than that of the conventional structure in which connecting conductor portions are partially provided.

Embodiments of the present invention will be described below with reference to the drawings.

A piezoelectric plate 1 of an energy confinement type piezoelectric resonator according to an embodiment of the present invention is made of lead zirconate-lead titanate porcelain (PZT porcelain) as shown in the front view of FIG. 1 and the back view of FIG. It is formed into a rectangular shape, in which first and second thickness longitudinal vibration three-terminal filters 2 and 3, shown surrounded by dotted lines, are formed. The first filter 2 includes first and second electrodes 5 and 6 for excitation formed on one surface 4 of the piezoelectric plate 1 and a third electrode 7 formed on the other surface 8. . Further, the second filter 3 has one surface 4
Fourth and fifth electrodes 9, 1 for excitation formed in
0 and a sixth electrode 11 formed on the other surface 8. Note that each of the filters 2 and 3 is polarized in the thickness direction of the piezoelectric plate 1.

The first electrode 5 of the first filter 2 is connected to a wide first external connection conductor 13 via a narrow first internal wiring conductor 12. Note that the first external connection conductor 13 is connected to the first side 1 of the piezoelectric plate 1.
It is formed into a belt shape extending in the same direction as a.

Further, the second electrode 6 is connected to one capacitor electrode 15 via a second internal wiring conductor 14, and further connected to a fourth electrode 9 via a third internal wiring conductor 16.
It is connected to the. Moreover, the first and second electrodes 5,
As is clear from FIG.
It is connected to the second capacitor electrode/second external connection conductor portion 18 via the second capacitor electrode/second external connection conductor portion 18 . The second external connection conductor section 18 extends in the same direction as the first external connection conductor section 13 in a band shape, and a portion thereof faces one of the capacitor electrodes 15. A sixth electrode 11 is also connected to this second external connection conductor portion 18 by a fifth internal wiring conductor 19 .

Further, the fifth electrode 10 on one surface 4 is the sixth electrode 10.
It is connected to a wide third external connection conductor portion 21 by an internal wiring conductor 20 . Note that the third external connection conductor portion 21 is formed in a band shape and extends in the same direction as the second side 1b of the piezoelectric plate 1.

The piezoelectric resonator terminal member 22 having a stem type structure shown in FIGS. 3 to 5 includes an insulating base 23 made of synthetic resin,
It consists of first, second and third terminal pins 24, 25 and 26 held therein. The piezoelectric plate 1 is attached to the terminal member 22 as shown in FIGS. 6 to 8. That is, the first and third terminal pins 24 and 26 face the first and third external connection conductor parts 13 and 21 on one surface 4, and the second terminal pin 25 faces the first and third external connection conductor parts 13 and 21 on the other surface 8. 3 external connection conductor part 18
It is mounted so as to face the 3 terminal pins 2
4, 25, and 26 are arranged in advance so that the piezoelectric plate 1 can be inserted, so that the piezoelectric plate 1 can be inserted into the two terminal pins 24, 26 from the horizontal or vertical direction.
and one terminal pin 25, the upper surface 27 of the base 23 and the three terminal pins 24, 25, 2
6, it is temporarily fixed or held. Therefore, silver-containing conductive paint was applied to the first, second, and third
attached to the external connection conductor portions 13, 18, 21 of
Thereafter, by drying and curing at 130° C. to 140° C. for 30 to 40 minutes, the first, second, and third terminal pins 24, 2 are bonded with the conductive adhesive 28 as shown in FIG.
5 and 26 are electrically and mechanically coupled to the first, second, and third external connection conductor portions 13, 18, and 21. The second terminal pin 25 is formed slightly shorter than the other pins in order to increase the amount of solder attached to the conductor portion 18.

In order to mechanically protect the piezoelectric resonator constructed in this way, paraffin is attached to the first and second filters 2 and 3, and after drying, a porous synthetic resin coating layer 29 is applied. Form. That is, after being coated with a liquid synthetic resin, it is naturally dried for 15 to 24 hours, and then a curing treatment is performed at 130°C to 150°C for 40 to 60 minutes. This heat treatment evaporates the paraffin and absorbs it into the pores of the synthetic resin coating layer 29, creating spaces 30 as shown in FIG.

For example, the piezoelectric resonator configured as described above has a first
It is used in a four-terminal circuit as shown in Figure 0. 1st
The characteristic curve a shown by a solid line in FIG. 1 is obtained by connecting the piezoelectric resonators shown in FIG. 9 as shown in FIG. The characteristic curve b indicated by the dotted line in FIG.
Instead of extending from one end of the piezoelectric plate 1 to the other, the vertical width of the piezoelectric plate is increased and an external connection conductor is provided only in a limited area at the bottom, and the terminal pin is connected here. It is a frequency characteristic curve of a conventional filter.

As is clear from the above, the piezoelectric resonator of this embodiment has the following advantages.

(a) The first filter 1 is the first external connection conductor part 1
3 and the first terminal pin 24 and the second external connection conductor part 15 and the second terminal pin 25, and the second filter 2 is arranged between the second external connection conductor part 15 and the second terminal pin 25. Since the terminal pin 25 of FIG. Excellent filter frequency characteristics as shown by curve a can be obtained.

(b) Two piezoelectric filters 2 and 3 on one piezoelectric plate 1
Despite the fact that a wide second external connection conductor section 18 is provided in the center, and the second terminal pin 25 is fixed thereto with an adhesive 28, it is difficult to connect the two. works to separate,
Excellent filter characteristics can be obtained.

(c) Since the terminal pins 24, 25, 26, etc. have the function of suppressing spurious vibrations, there is no need to increase the area of the piezoelectric plate 1, and it is possible to downsize the piezoelectric plate 1.

(d) Three terminal pins 24, 25, 26 on the base 23
and these terminal pins 24, 25, 26
Since the structure is such that the piezoelectric plates 1 are arranged between the two, assembly is facilitated. Furthermore, damage to the piezoelectric plate 1 is reduced.

(e) Since the piezoelectric plate 1 is placed on the base 23, not only the piezoelectric plate 1 is stably held, but also the base 2
3 can also be expected to suppress unnecessary vibrations.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and can be further modified. For example, two filters 2 and 3 can be mounted on a common piezoelectric plate 1. Piezoelectric plate 1 without providing
It is also applicable to the case where one piezoelectric filter is configured. Further, it is also applicable to a case where a vibrator is constituted by only a pair of excitation electrodes facing each other. Also 3
It is also applicable when one or more filters are formed on the same piezoelectric plate. Furthermore, polarization may be applied to the entire piezoelectric plate 1 without being limited to the filter portion.

[Brief explanation of the drawing]

Fig. 1 is a front view showing a piezoelectric plate of a piezoelectric resonator according to an embodiment of the present invention, Fig. 2 is a rear view of this piezoelectric plate, and Fig. 3 is a terminal member of the piezoelectric resonator of this embodiment. 4 is a front view of this terminal member, FIG. 5 is a right side view of this terminal member, FIG. 6 is a plan view showing the resonator with a piezoelectric plate attached to the terminal member, and FIG. 7 is a plan view of the terminal member. is a front view of the resonator in Figure 6, and Figure 8 is a front view of the resonator in Figure 6.
The figure is a right side view of the resonator in Figure 7, Figure 9 is a sectional view of the completed resonator taken along the - line in Figure 7, and Figure 10 is the electrical connection of the resonator. FIG. 11 is a characteristic diagram showing the frequency characteristics of the resonator with the maximum output set to 0 dB. In the symbols used in the drawings, 1 is a piezoelectric plate, 2 is a first filter, 3 is a second filter, 5 is a first electrode, 6 is a second electrode, and 7 is a third electrode.
13 is a first external connection conductor part, 15 is one capacitor electrode, 18 is a second external connection conductor part, 21 is a third external connection conductor part, 22 is a terminal member, and 23 is an insulating base , 24 is the first terminal pin, 2
5 is the second terminal pin, 26 is the third terminal pin, 2
8 is a conductive adhesive.

Claims (1)

[Claims for Utility Model Registration] A piezoelectric plate having a rectangular planar shape, a plurality of excitation electrodes provided on the piezoelectric plate, and a plurality of excitation electrodes connected to one of the plurality of excitation electrodes via an internal wiring conductor. and the first piezoelectric plate
a first external connection conductor section provided broadly along substantially the entire length of a side of the piezoelectric plate; a second external connection conductor section that is provided wide along substantially the entire length of a second side opposite to the first side; and a second external connection conductor section that extends in the same direction as the first external connection conductor section. a first terminal pin connected to the first external connection conductor part with a conductive adhesive; and a first terminal pin connected to the second external connection conductor part with a conductive adhesive while extending in the same direction as the second external connection conductor part. A piezoelectric vibrator comprising at least the following: a second terminal pin that has a second terminal pin; and an insulating base that holds at least the first and second terminal pins.