JPS631460Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite piezoelectric vibrator that can be used as a filter or the like, and more particularly to a composite piezoelectric vibrator that can be miniaturized.

When a plurality of vibrators are formed on one piezoelectric plate, it is necessary to prevent mutual interference between one vibrator and the other vibrator. For this reason, one vibrator is generally kept sufficiently separated from the other vibrator. Therefore, the external dimensions of the vibrator have inevitably increased.

Therefore, an object of the present invention is to provide a composite piezoelectric vibrator that can be miniaturized.

To achieve the above object, the present invention includes a piezoelectric plate, a first vibrator provided in a first region of the piezoelectric plate, and a second vibrator provided in a second region of the piezoelectric plate. and a region between the first region and the second region of the piezoelectric plate that is elastically sandwiched between the first and second vibrators. The present invention relates to a composite piezoelectric vibrator that includes at least a lead-out conductor that is electrically connected to a common connection conductor portion with the vibrator.

According to the present invention, since the region between the first vibrator and the second vibrator is elastically sandwiched between the lead-out conductors, the propagation of unnecessary vibrations is significantly restricted in this sandwiched portion. Therefore, it is possible to make the distance between the first vibrator and the second vibrator relatively small, thereby making it possible to downsize the device.

Hereinafter, an energy confinement type piezoelectric resonator according to an embodiment of the present invention will be described with reference to the drawings.

As shown in Figures 1 and 2, lead zirconate
A piezoelectric plate 1 made of lead titanate-based porcelain (PZT-based porcelain) is formed into a rectangular shape, and has a first plate surrounded by a dotted line.
It has a first region 2 for forming a vibrator and a second region 3 for forming a second vibrator. The piezoelectric vibrator in the first region 2 has first and second electrodes 5 and 6 for excitation, which are illustrated with hatching formed on one surface 4 of the piezoelectric plate 1, and the other electrode. and a third electrode 7 formed on the surface 8. Further, the second vibrator formed in the second region 3 has fourth and fifth excitation electrodes 9 and 10 formed on one surface 4 and a sixth electrode formed on the other surface 8. The electrode 11 is provided. still,
The first and second regions 2 and 3 are polarized in the thickness direction of the piezoelectric plate 1.

The first electrode 5 in the first region 2 is connected to the wide first internal wiring conductor 12 via the narrow first internal wiring conductor 12.
It is connected to the external connection conductor section 13 of. The first
The external connection conductor portion 13 is formed in a band shape and extends in the same direction as the side 1a of the piezoelectric plate 1. Further, the second electrode 6 is connected to the first capacitor electrode 16 via a second internal wiring conductor 14 and a third internal wiring conductor 15, and is further connected to a fourth internal wiring conductor 17.
and the fifth internal wiring conductor 18 to the fourth electrode 9 . Further, the fourth electrode 9 is connected to the second capacitor electrode 20 via the sixth internal wiring conductor 19. Further, the fifth electrode 10 is connected to a wide second external connection conductor portion 22 by a seventh internal wiring conductor 21 . The second external connection conductor portion 22 is formed in a band shape and extends in the same direction as the second side 1b of the piezoelectric plate 1.

A third electrode 7 formed on the other surface 8 so as to face the first and second electrodes 5 and 6, respectively, is connected to the second electrode 7.
As is clear from the figure, it is connected to the third external connection conductor section 24 via the eighth internal wiring conductor 23. Note that the third external connection conductor section 24 extends in the same direction as the first external connection conductor section 13 in a band shape. The sixth electrode 11 is also connected to the third external connection conductor portion 24 through a ninth internal wiring conductor 25 . Further, this third external connection conductor portion 24 includes a
The first capacitor back electrode 27 is connected through the ten internal wiring conductors 26, and the second capacitor back electrode 2 is further connected through the eleventh internal wiring conductor 28.
9 is connected. In addition, in order to prevent a capacitor from being formed anywhere other than between the first capacitor electrode 16 and the first capacitor back electrode 27 and between the second capacitor electrode 20 and the second capacitor back electrode 29, The internal wiring conductor on the front surface in FIG. 1 and the internal wiring conductor on the back surface in FIG. 2 are designed so as not to face each other as much as possible.

In order to connect lead members to the first, second, and third external connection conductor portions 13, 22, and 24 of the piezoelectric plate 1 as described above, a lead frame 30 shown in FIG. 3 is used.
and the first, second, and third lead-out conductors 31 and 3 provided on this lead frame 30.
The piezoelectric plate 1 is held between 2 and 33. 1st, 2nd,
The third lead-out conductors 31, 32, and 33 each have an elastic clamping portion 34. That is, as shown in FIG. 4, the elastic clamping portion 34 is formed by bonding a pair of elastic plates 35 and 36 made of phosphor bronze and opening the tip portions into two prongs. Note that one elastic plate 35 at the tip of the first and second lead-out conductors 31 and 32 is connected to the first and second lead-out conductors 31 and 32 as shown in FIGS.
The other elastic plate 36 is press-contacted directly to the piezoelectric plate 1, respectively. Further, one elastic plate 35 of the third lead-out conductor 33 that functions as a ground terminal or a common terminal is directly pressed against the piezoelectric plate 1, and the other elastic plate 36 is pressed against the third external connection conductor portion 24. ing. In addition, the first, second, and third lead-out conductors 31, 32,
Since the tip of 33 is open, the first and second lead-out conductors 31 and 32 are connected to the electrode 1 for forming a capacitor.
6, 20, 27, and 29, and the third lead-out conductor 33 does not contact the fourth internal wiring conductor 17.

After the piezoelectric plate 1 is supported by the lead frame 30 as described above, silver-containing conductive paint is applied to the first, second, and third external connection conductor parts 13, 22, 24.
The conductive adhesive 37 is applied to the first, second, and third lead-out conductors 31, 32 by drying and curing at 130° C. to 140° C. for 30 to 40 minutes, as shown in FIG. , 33 are electrically and mechanically coupled to the first, second, and third external connection conductor portions 13, 22, and 24.

In order to mechanically protect the piezoelectric resonator constructed in this way, paraffin is attached to the first and second regions 2 and 3, and after drying, a porous synthetic resin coating layer 38 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. During this heat treatment, the paraffin is evaporated and absorbed into the pores of the synthetic resin coating layer 38, creating spaces 39 as shown in FIG.

The piezoelectric resonator configured as described above is, for example, the sixth
It is used as a four-terminal circuit as shown in the figure. The characteristic curve shown by the solid line in FIG. 7 is obtained by connecting the piezoelectric resonators shown in FIG. 5 as shown in FIG. 6 and determining the frequency characteristics with the gain at the maximum output being 0 dB.

The piezoelectric resonator of this embodiment has the following advantages.

(a) Since the first region 2 and the second region 3 are sandwiched elastically by the third lead-out conductor 33, propagation of unnecessary vibrations is suppressed. Therefore, the mutual spacing is smaller than that of conventional elements, and the element can be miniaturized.

(b) Also, the vertical width of piezoelectric plate 1 is approximately 2.5 mm, and the horizontal width is approximately 8.6 mm.
mm, thickness is approximately 0.2 mm, vertical width is electrode 5, 6,
Since the range is about 3 to 4 times the width of 9 and 10,
Unnecessary vertical vibrations of the piezoelectric plate 1 are suppressed. Therefore, the element of this embodiment has the same performance as a conventional element in which the vertical width of the piezoelectric plate 1 is about 6 mm and the piezoelectric plate 1 is coated with a synthetic resin.

(c) The first region 2 is arranged between the first external connection conductor section 13 and the first lead-out conductor 31 and the third external connection conductor section 24 and the third lead-out conductor 33, and The region 3 of No. 2 is arranged between the second external connection conductor section 22 and the second lead-out conductor 32, and the third external connection conductor section 24 and the third lead-out conductor 33, so that these Unnecessary vibrations (spurious vibrations) can be suppressed and excellent filter frequency characteristics as shown in FIG. 7 can be obtained.

(d) first, second and third lead-out conductors 31, 32,
33 has the function of suppressing spurious vibrations, there is no need to increase the area of the piezoelectric plate 1, and it becomes possible to downsize the piezoelectric plate 1.

(e) Since the piezoelectric plate 1 is elastically held by the first, second, and third lead-out conductors 31, 32, and 33, assembly is facilitated. Furthermore, damage to the piezoelectric plate 1 is reduced.

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. It can also be applied when forming. Furthermore, polarization may be applied to the entire piezoelectric plate 1 without being limited to the filter portion.

[Brief explanation of drawings]

Fig. 1 is an explanatory front view of a piezoelectric plate of a piezoelectric resonator according to an embodiment of the present invention, Fig. 2 is an explanatory rear view of this piezoelectric plate, and Fig. 3 is a piezoelectric plate held by a lead frame. Explanatory front view showing the state in which the
The figure is a sectional view taken along the - line in Fig. 3, Fig. 5 is a sectional view of the completed resonator corresponding to the - line in Fig. 3, Fig. 6 is an equivalent circuit diagram of the resonator, and Fig. 7 is a sectional view taken along the - line in Fig. 3. 5
FIG. 3 is a frequency-gain characteristic diagram of the resonator shown in the figure. In the symbols used in the drawings, 1 is a piezoelectric plate, 2 is a first region, 3 is a second region, 5 is a first electrode, 6 is a second electrode, 9 is a fourth electrode, 1
0 is the fifth electrode, 13 is the first external connection conductor part,
16 is a first capacitor electrode, 20 is a second capacitor electrode, 22 is a second external connection conductor portion, 24
31 is a first lead-out conductor, 32 is a second lead-out conductor, 33 is a third lead-out conductor, and 34 is an elastic clamping part.

Claims (1)

[Claims for Utility Model Registration] A piezoelectric plate, a first vibrator provided in a first region of the piezoelectric plate, a second vibrator provided in a second region of the piezoelectric plate, The piezoelectric plate is arranged so as to elastically sandwich at least a part of a region linearly connecting the excitation electrode of the first vibrator and the excitation electrode of the second vibrator, and A composite piezoelectric vibrator comprising at least a lead-out conductor electrically connected to a common connection conductor portion of a first vibrator and a second vibrator.