JPS63184410A - Applied vibrator device - Google Patents

Abstract

PURPOSE:To realize the reduction in the number of packages by forming two end face reflecting type vibrators by at least once on the same piezoelectric substrate. CONSTITUTION:Vibrators 20, 30 are arranged in parallel on the piezoelectric substrate 40 so that parallel electrodes 21a, 22a and 31a, 32a arrange in parallel with each other. Slots 23, 33 of a prescribed depth are formed to the surface in contact with each other. The side wall of the slots 23, 33 acts like a reflection end face to reflect the surface sliding wave. Thus, in applying a proper high frequency voltage to interdigital electrodes 21, 22 and 31, 32, a surface sliding wave propagated in a direction orthogonal to the parallel electrodes 21a, 22a and 31a, 32a is generated and the surface sliding wave is reflected on the reflecting face to obtain the resonance characteristic. Thus, two or over of end face reflecting type vibrators are formed on the substrate by once.

Description

[Detailed Description of the Invention] [Summary] Regarding a resonator application device using an end-reflection type surface shear wave resonator, for the purpose of miniaturizing the device and reducing the number of mounting steps, at least two end-reflection type surface shear wave resonators are used. The structure is such that the elements are formed on the same piezoelectric substrate.

[Industrial application field]

The present invention relates to a vibrator application device using an end-reflection type surface shear wave vibrator.

The above-mentioned end face reflection type surface shear wave vibrator reflects a surface shear wave of a specific frequency on the end face of a piezoelectric substrate to resonate.
It has the effect of increasing its amplitude. This type of oscillator has the characteristics of a simple structure, small size and light weight, and stability in high frequency bands, and is applied to, for example, FM modulators of wireless microphones and filters for timing extraction. These devices have recently attracted attention as resonator-applied devices.

[Conventional technology]

A filter is an example of the above-mentioned resonator application device.
Its general circuit configuration is shown in FIG.

This filter has two end-reflection type surface shear wave transducers (hereinafter abbreviated as transducers) 1.2 connected in series.
It is constructed by connecting a capacitor C as a coupling capacitance, and has a terminating resistor Ri on its input side and an output side, respectively.
RO is connected.

Although the vibrators 1 and 2 have the same structure, they are formed on separate substrates, and the specific structure of one of them (vibrator 1) is shown in FIG. This vibrator 1 has a plurality of parallel electrodes 11a, 12a, and common electrodes 11b, 1, respectively.
A pair of interdigital electrodes 11 and 12 connected to 2b,
The substrates 13 are formed oppositely on the surface of the piezoelectric substrate 13 so as to engage with each other, and further parallel to the parallel electrodes 11a and 12a.
The free cross section of is taken as the reflective end surfaces 13a and 13b of the surface shear wave. In such a configuration, by applying an appropriate high frequency voltage to the interdigital electrodes 11.12, a surface shear wave is generated, and the reflective end faces 13a, 13b are
It is reflected by and acquires resonance characteristics. This surface shear wave is displaced in a direction parallel to the parallel electrodes 11a and 12a (direction of arrow A) and propagates in a direction perpendicular to the parallel electrodes 11a and 12a, so the reflective end surface 13a
, 13b, there is no conversion to other modes, and it is reflected as a surface shear wave. Moreover, the energy distribution of this surface shear wave in the substrate thickness direction is concentrated within a predetermined depth t, as shown by diagonal lines on the reflective end face 13b.

Note that FIG. 10 shows the filter characteristics (relationship between insertion loss and frequency) of the filter (FIG. 8) using the vibrator 1.2 having the above configuration. The figure shows that the filter can pass a predetermined frequency band.

[Problem that the invention seeks to solve]

As shown in FIG. 9, a conventional vibrator is made by forming one vibrator on one piezoelectric substrate.

Therefore, if you try to create a filter with the circuit configuration shown in Figure 8, for example, you will have to separately mount the vibrators 1 and 2 formed on separate boards, which will reduce the overall size. In addition to being disadvantageous, there is a problem in that the manufacturing cost increases due to the increase in the number of mounting steps.

Such problems are not limited to the above filter, but apply to all conventional vibrator-applied devices that use a plurality of vibrators.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to realize miniaturization and reduction in the number of mounting steps in a vibrator application device that uses a plurality of vibrators.

[Means for solving problems]

The present invention is a vibrator application device having at least a plurality of vibrators (edge-reflection type surface shear wave vibrators), in which at least two of the vibrators are formed on the same piezoelectric substrate.

[Effect]

If two or more vibrators are formed on one piezoelectric substrate, there is no need to separately mount two or more vibrators formed on separate substrates as in the past, and two or more vibrators can be mounted at one time. oscillator can be implemented. Therefore, the number of mounting steps can be reduced, and manufacturing costs can also be reduced.

Furthermore, since two or more vibrators are integrated on one substrate, less mounting space is required, and the overall device size can therefore be reduced.

〔Example〕

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

FIG. 1 ta+ is a plan view showing the configuration of a filter according to an embodiment of the present invention, and FIG. 1 fbl is a sectional view taken along the line BB.

In this embodiment, two oscillators (edge reflection type surface shear wave oscillators) 20 and 30 are connected to parallel electrodes 21a and 22a.
; 31a and 32a are formed side by side on one piezoelectric substrate 40 so as to be parallel to each other. Furthermore, grooves 23.33 of a predetermined depth are formed on the surfaces of the parts of the two vibrators 20.30 that contact each other. Since the energy distribution of the surface shear waves is concentrated on the surface as indicated by diagonal lines in FIG. 9, the side walls of the grooves 23, 33 act as reflective end faces for reflecting the surface shear waves. Note that, in the vibrator 20.30, the plurality of parallel electrodes 21a, 22a; 31a, 32a described above are connected to the respective common electrodes 21b, 22b; A pair of interdigital electrodes 21.22; 31.32 connected to the piezoelectric substrate 40
are formed facing each other so as to interlock with each other.

All of the vibrators 20.30 having the above configuration exhibit the same function, and the respective interdigital electrodes 21.22i31.3
2 by applying an appropriate high frequency voltage to the parallel electrodes 21a, 22a; 31a.

A surface shear wave is generated that propagates in a direction perpendicular to the groove 32a, and this surface shear wave is generated by
(sidewalls), and resonance characteristics can be obtained.

Further, a capacitor C as a coupling capacitance is provided between the common electrode 22b of the vibrator 20 and the common electrode 32b of the vibrator 30.
is connected. With such a connection, a filter having the same circuit configuration as that shown in FIG. 8 can be obtained.

Note that the grooves 23 and 33 may be shared as one groove. In this way, both side walls of the one groove become reflective end faces of the vibrator 20 and 300, respectively.

Next, FIG. 2 is a plan view showing the configuration of a filter according to another embodiment of the present invention.

In this embodiment, two vibrators 50 and 60 are formed side by side on one piezoelectric substrate 70 so that their common electrodes 51b, 52b, 61b, and 62b are parallel to each other, and the common electrodes 50 and 60 are arranged adjacent to each other. A feature is that 52b and 62b are formed as one shared common electrode. The above-mentioned vibrator 50.60 is also the vibrator 20.30 shown in FIG.
Similarly, the respective common electrodes 51b and 52b described above
, 61b, 62b and a plurality of parallel electrodes 51a, 52a;
Interdigital electrode 51.52.6 consisting of 61a and 62a
It has a value of 1.62.

The same resonance characteristics as the vibrator 20.30 can also be obtained with the vibrator 50.60 having the above configuration.

Further, a capacitor C as a coupling capacitance is connected to the shared common electrode 52b (62b). By connecting in this manner, a filter having the same circuit configuration as that shown in FIG. 8 can be obtained, similar to the previous embodiment.

Next, a method for manufacturing the vibrators 50 and 60 will be briefly described.

First, the surface of a piezoelectric substrate 70 made of, for example, 40° rot Y-L 1 Taos (lithium tantalate) is polished to a mirror finish, and then, for example, NiCr (chromium) and Au (gold) are applied.
are sequentially and uniformly deposited to a predetermined thickness. Thereafter, the interdigital electrodes 51 are formed on the piezoelectric substrate 70 by etching and patterning using a photolithography technique.
Form 52.61.62. In this way, two vibrators 50 and 60 are integrally formed on the same substrate.

In addition, as shown in FIG. 3, two such vibrators 5
0.60 can be formed on a single wafer-shaped piezoelectric substrate 80, and by doing so, batch processing becomes possible.

FIG. 4 shows an example of an actual mounting state when the filter shown in FIG. 2 is constructed using the two vibrators 50 and 60 integrally formed on the same substrate in this manner.

In the figure, a vibrator 50 is placed on a ceramic substrate 90.
．． Thick conductor films 91, 92, 9 are placed in advance at positions corresponding to the respective arrangement positions of common electrodes 51b, 52b (62b), 61b of 60 and both electrodes (both terminals) of individual capacitor C°.
3.94 is formed, and an integrated vibrator 50 is placed on top of it.
．． 60 and capacitor C', and then the common electrode 51
b, 52b (62b), 61b and the conductor thick film 91
．． 92 and 93 are connected by conductive resin or wire bonding 100.

FIG. 5 shows two vibrators 5 integrally formed on the same substrate.
2 shows another example of an actual mounting state when the filter shown in FIG. 2 is configured using 0.60.

In the figure, a vibrator 50 is placed on a ceramic substrate 95.
．． 60 common electrodes 51b and 60 common electrodes 51b and 60 common electrodes 52b (60
After forming the thick film capacitor C11 corresponding to the arrangement position of 2b) and placing the integrated vibrator 50.60 on it, the common electrodes 51b, 61b, the conductor thick film 96.97, and the common electrode 52b are placed. (62b) and thick film capacitor C”
The terminal is connected to one electrode (terminal) using conductive resin or wire bonding 100.

However, the thick film capacitor CIT consists of a lower thick film electrode (lower terminal) 98a, a dielectric layer 98b, and an upper thick film electrode (upper terminal) 98C, and the upper thick film electrode 98c is connected to the common electrode 52b (62b). However, the lower thick film electrode 98a is formed integrally with a conductor thick film 99 for external connection.

As described above, in each of the above embodiments, since the two vibrators are formed on one piezoelectric substrate, there is no need to separately mount the two vibrators as in the past.
Two oscillators can be mounted at once in just one step. Therefore, the number of mounting steps can be reduced, and manufacturing costs can also be reduced. Also, since two resonators are integrated on one board, less mounting space is required.
Therefore, it is also possible to downsize the entire filter.

In particular, the embodiment shown in FIG. 2 can be made more compact than the embodiment shown in FIG. 1, and the number of processing steps can be reduced. Moreover, since multiple sets can be made on one wafer in the orientation shown in Figure 3, the width of each vibrator can be formed uniformly, thereby reducing variations in the frequency characteristics of each vibrator. You can also do it.

Next, for reference, the filter characteristics of the embodiment shown in FIG. 2 (FIG. 4) are shown in FIG. Note that here, the piezoelectric substrate 7
0 to 40°RO with dimensions 5mmX1.5mmX0.4mm
t Y-L i Ta O8 board is used, and the thickness is 500 (7) Nicr for the interdigital electrode 51.52.61.62.
A vapor-deposited film with a thickness of 2,000 layers of Au was used.

Further, the dimensions of the interdigital electrodes 51 and 52 are as shown in FIG.
crm, intersection width 700 μm, mutual spacing S 21.5 μm
It was set as m. This dimension is the same for the interdigital electrodes 61,62. The frequency characteristics of amplitude and phase were measured using a measurement system in which the coupling capacitance C was 39 pF and the termination resistance Ri=Ro=92Ω.

It has been found that the above filter characteristics are equivalent to those of conventional vibrators of the same type, and that there is no deterioration in frequency characteristics caused by forming two vibrators on the same substrate.

In the above embodiment, two vibrators were formed on one substrate, but three or more vibrators may be formed.

Furthermore, the vibrator-applied device of the present invention is not limited to filters, but can be applied to devices in various fields using two or more vibrators, and each vibrator can be electrically connected between the vibrators. It is free to electrically connect various elements such as C and R to each vibrator.

〔Effect of the invention〕

According to the vibrator application device of the present invention, two or more vibrators are formed on one piezoelectric substrate, so that two or more vibrators can be
It is possible to mount more than one vibrator, thus reducing the number of mounting steps and making it possible to lower prices. At the same time, since less mounting space is required, it is possible to downsize the entire device.

[Brief explanation of the drawing]

1 is a plan view and a sectional view thereof showing the structure of a filter according to an embodiment of the present invention, FIG. 2 is a plan view showing the structure of a filter according to another embodiment of the present invention, and FIG. 4 is a perspective view of a mounting example of the filter shown in FIG. 2, and FIG. 5 is a perspective view of the filter shown in FIG. 2. 6 is a plan view showing specific dimensions of the transducer interdigital electrode used to measure the filter characteristics of the filter shown in FIG. 2, and FIG. Figure 2 is a graph of the filter characteristics of the filter, Figure 8 is a circuit diagram showing the general configuration of a filter using two oscillators, and Figure 9 is a perspective view showing the specific structure of a conventional oscillator. 10 is a graph of the filter characteristics of the filter shown in FIG. shaped electrode, 21a, 22a, 31a, 32a,
51a, 52a, 61a, 62a are parallel electrodes, 21b, 22b, 31b, 32b, 51b, 52b, 6
1b and 62b are common electrodes, 23.33 are grooves, 40 and 70 are piezoelectric substrates, 100 is conductive resin or wire bonding, and C' and CIT are capacitors. Agent Patent Attorney Sada Igata - -1st page of Jyo-D (Contents! No changes made ¥2 A1 Teko/J Fi Sho's 4 Shi0 Taishin (Oda1*
5 Figure

Claims (1)

[Scope of Claims] 1) In a vibrator application device having at least a plurality of edge reflection type surface shear wave vibrators, at least two of the edge reflection type surface shear wave vibrators (20, 30; 5
0, 60) formed on the same piezoelectric substrate (40; 70). 2) The vibrator application device according to claim 1, wherein the end face reflection type surface shear wave vibrators are electrically connected. 3) The vibrator application device according to claim 1 or 2, wherein the end face reflection type surface shear wave vibrator is electrically connected to L, C, and R elements. 4) At least two edge-reflection surface shear wave transducers formed on the same piezoelectric substrate include a pair of interdigitated electrodes (2
1, 22; 31, 32; 51, 52; 61, 62) and
Claims 1 to 3 include reflective end surfaces formed on both sides of the piezoelectric substrate to reflect surface shear waves generated from the interdigital electrodes.
The vibrator application device according to any one of the items. 5) The interdigital electrodes include a plurality of parallel electrodes (21a, 22a; 31a, 32a; 51a,
52a; 61a, 62a) is connected to one common electrode (21b, 22b; 31b, 32b; 51b, 52
5. The vibrator application device according to claim 4, wherein the vibrator application device is connected to the vibrator (b, 61b, 62b). 6) At least two end-reflection type surface shear wave vibrators (50, 60) formed on the same piezoelectric substrate are arranged such that their respective common electrodes (51b, 52b, 61b, 62b) are parallel to each other. 6. The vibrator application device according to claim 5, wherein the common electrodes (52b, 62b) arranged side by side and adjacent to each other are formed as one shared common electrode. 7) At least two edge-reflection type surface shear wave vibrators (20, 30) formed on the same piezoelectric substrate have respective parallel electrodes (21a, 22a, 31a, 32a).
are arranged parallel to each other, and
A groove (
23, 33) are formed. The vibrator application device according to claim 5. 8) Two edge-reflection surface shear wave transducers (50, 60) and a capacitor (C) formed on the same piezoelectric substrate.
') and conductor thick films (91, 92, 93) in predetermined positions.
, 94), and each electrode of the vibrator and the capacitor is connected to a predetermined location of the conductor thick film, and the shared common 7. The vibrator application device according to claim 6, wherein one terminal of the capacitor is connected to an electrode. 9) Two end-reflection type surface shear wave transducers (50, 60) formed on the same piezoelectric substrate are placed in advance at predetermined positions with a thick film capacitor (C'') and a conductor thick film (96, 97, 9
9) is mounted on a ceramic substrate (95) formed with
The vibration according to claim 6, characterized in that the electrode of the vibrator is connected to a predetermined location of the thick conductor film, and the shared common electrode is connected to one terminal of the capacitor. Child application device. 10) The vibrator application device according to claim 8 or 9, wherein the connection between the thick conductor film and each of the electrodes is performed using a conductive resin or wire bonding (100). 11) The piezoelectric substrate is 40°rotY-LiTaO_3
The vibrator application device according to any one of claims 1 to 10, which is a plate. 12) Claims 2 to 1, wherein the interdigital electrode is a vapor deposited film of NiCr and Au.
The vibrator application device according to any one of Item 1.