JPH0253313A - Vibrator - Google Patents

Abstract

PURPOSE:To facilitate the handling and to improve the characteristic by providing a vibration base and a couple of plates with an electrode made of the same material as that of the base formed thereto and sealing an inactive gas to a gap between both the plates and the vibration base. CONSTITUTION:The vibrator is provided with a couple of plates 12, 13 made of the same material as that of the crystal base 11 and opposite electrodes 14, 15 are formed in advance to the plates 12, 13 by the vacuum deposition method or the sputtering method or the like. The electrodes 14, 15 are prolonged up to the outer circumference of the plates 12, 13 to attain electric connection with an external device. Moreover, the crystal base 11 having a vibration part 11a is clipped between a couple of the plates 12, 13 under an inactive gas atmosphere such as nitrogen gas (N2) or the like and the base is sealed airtightly by a glass flit 16 or the like. Thus, the inactive gas is sealed in the gap between the crystal base 11 and the plates 12, 13. Then the handling at the mount of the vibrator is facilitated and the aging characteristic is improved.

Description

[Detailed Description of the Invention] [Summary] The purpose of this invention is to provide a high-frequency oscillation resonator that is easy to handle during manufacturing and mounting and has good aging characteristics, and has a thin wall in the center. A vibrating substrate formed with a vibrating portion, and a pair of plates made of the same material as the vibrating substrate and having electrodes formed in advance on the surface facing the vibrating portion of the vibrating substrate, and the vibrating substrate is sandwiched between the two plates. By airtightly sealing both plates and the vibrating substrate, an inert gas is filled in the gap between the two plates and the vibrating substrate.

[Industrial application field]

The present invention relates to the structure of a vibrator that is effective for use as a fundamental wave oscillator of a high frequency oscillator.

[Prior art and problems to be solved by the invention] In a vibrator using a vibrating substrate such as an AT-cut crystal substrate, a higher frequency can be obtained by decreasing the thickness of the vibrating part of the vibrating substrate. In order to obtain this, it is necessary to reduce the thickness of the vibrating part to about 16 μm, which makes handling during subsequent electrode formation and mounting extremely difficult.

4 and 5 show an example of a conventional vibrator for a high frequency oscillator, and FIG. 6 shows another example of a conventional vibrator for a high frequency oscillator.

Referring to these figures, the vibrator is equipped with an AT-cut crystal substrate 1, and an extremely thin vibrating section 1a is located in the center of the substrate.
is formed. In order to form the vibrating part 1a, the fifth
In the illustrated example, recesses are formed on both sides of the crystal substrate 10,
In the example shown in FIG. 6, a recess is formed on one side of the crystal substrate 1. Electrodes are then provided on the crystal substrate 1 on which the vibrating portion 1a has been formed, but conventionally, electrodes 2.3 were formed directly on the surface of the crystal substrate 1 by vacuum evaporation, sputtering, etc., as shown in the figure. , crystal substrate 1 during electrode formation
Extreme care was required when handling. Especially when using the sputtering method, the crystal substrate 1 is
Since the crystal substrate 1 is exposed to high temperatures, there has been a problem in that the vibrating portion 1a of the crystal substrate 1 is easily destroyed due to thermal distortion. Furthermore,
Even in the completed vibrator, the extremely thin vibrating portion 1a is exposed to the outside, so great care must be taken when mounting the vibrator on an oscillation circuit board and handling it thereafter. In addition, since electrodes 2 and 3 are exposed to the outside, electrode 2
．． There has been a problem in that the frequency characteristics fluctuate due to the oxidation of No. 3.

Therefore, an object of the present invention is to provide a high-frequency oscillation resonator that is easy to handle during manufacturing and mounting and has good aging characteristics.

[Means to solve the problem]

A vibrator according to the present invention includes a vibrating substrate having a thin vibrating portion formed in the center thereof, and a pair of plates made of the same material as the vibrating substrate and having electrodes formed in advance on the surface facing the vibrating portion of the vibrating substrate. The vibrating substrate is sandwiched between the two plates and installed in an airtight manner, thereby filling the gap between the two plates and the vibrating substrate with an inert gas.

[For production]

In the vibrator having the above configuration, opposing electrodes are formed in advance on a pair of plates that sandwich the vibrating substrate, but since there is no need to form a thin wall part on the plates like the vibrating part of the vibrating substrate, when forming the electrodes, The plate is easy to handle, and there is no risk of thermal distortion or damage due to high temperatures during sputtering.

In addition, the vibrating board, which has a thin vibrating section, is sandwiched between a pair of plates made of the same material and protected from the outside, increasing the structural strength of the completed vibrator and making it easier to handle when mounting the vibrator. Become.

Furthermore, by sealing the vibrating substrate and the plate, an inert gas is filled in the gap between the vibrating substrate and the plate, so there is no risk of internal oxidation of the electrodes, and the aging characteristics of the vibrator are improved.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

11 and 2 show a first embodiment of the present invention. Referring to these figures, the vibrator includes an AT-cut crystal substrate 11 as a vibrating substrate in which a thin vibrating portion 11a is formed in the center.

The thickness of the outer periphery of the crystal substrate 11 is usually 30 to 50 μm, which is the limit value for mechanical polishing. Also, for example, 100M
In the case of a Hz vibrator, the thickness of the vibrating portion 11a at the center of the crystal substrate 11 is approximately 16 μm. A dry etching method or a different etching method is usually used to form such an extremely thin vibrating portion 11a. In this example,
Recesses are formed on both sides of the crystal substrate 110 to form the vibrating portion 11a.

The vibrator is a pair of plates 12 made of the same material as the crystal substrate 11.
．． 13, and counter electrodes 14 and 15 are formed in advance on the plates 12 and 13 by vacuum vaporization, sputtering, or the like. Electrodes 14.15 are connected to plate 12.
13 to enable electrical connection with the outside.

The crystal substrate 11 having the vibrating part 11a is filled with nitrogen gas (N2).
It is sandwiched between a pair of plates 12 and 13 in an inert gas atmosphere such as the like, and is hermetically sealed to each other by a glass foot 16 or the like. Therefore, the crystal substrate 11 and the plate 1
An inert gas is filled in the gap space between 2.13 and 2.13.

Regarding the vibrator having the above configuration, as mentioned above,
Opposing electrodes are formed in advance on the pair of plates 12 and 13 that sandwich the vibrating substrate 11, but since there is no need to form a thin wall portion on the plates 12 and 13 like the vibrating portion 11a of the vibrating substrate 11, when forming the electrodes, Handling of the plate N2.13 is easy, and there is no risk of thermal strain damage due to high temperatures during sputtering. In addition, since the vibrating board 11 having the thin vibrating part 11a is sandwiched between two pairs of plates 12 and 13 and protected from the outside, the structural strength of the completed vibrator is increased, and handling during mounting of the vibrator etc. becomes easier. Furthermore, since the pair of plates 12 and 13 are made of the same material as the crystal substrate 11, there is no possibility that the effects of distortion due to thermal expansion will be applied to the vibrating portion 11a. Furthermore, since the vibration substrate 11 and the plate 12.13 are sealed together, an inert gas is filled in the gap between the vibration substrate 11 and the plate N2.13, so there is no risk of internal oxidation of the electrode 14.15. This improves the aging characteristics of the vibrator.

FIG. 3 shows a second embodiment of the invention. In the figures, the same reference numerals are given to the same components as in the above embodiment. In this embodiment, the crystal substrate 11
A recess is formed only on one side of the crystal substrate 11 in order to form a vibrating part 11a having a predetermined thickness in the central part of the crystal substrate 11, and a recess is formed in the plate 13 on the opposite side to the recess of the crystal substrate 11.
A recess 13a facing a is formed. plate 1
A counter electrode 15 provided at 3 extends into the recess 13a. The other configurations are the same as those of the first embodiment. In this embodiment, the etching process of the vibrating part 11a of the crystal substrate 11 becomes easy, and the thickness of the vibrating part 11a can be easily controlled. On the other hand, although it is necessary to form the recesses 13a in the plate 13 by etching or the like, the thickness of the recesses 13a does not need to be made as thin as the vibrating part 11a. The plate 13 is easy to handle. Therefore, the same effects as in the above embodiment can be obtained.

Although the illustrated embodiment has been described above, the present invention is not limited to the above-mentioned embodiment H. For example, changes may be made to the pattern shape of the electrodes 14.15 and the arrangement on the plate 12.13. For example, plate 12.1
A through hole may be formed in the plate 12, 13 so that the end of the electrode 14, 15 can be led out from the outer end surface of the plate 12, 13.

〔Effect of the invention〕

As is clear from the above description, according to the configuration of the present invention, the opposing electrodes are formed in advance on a pair of plates that sandwich the vibrating substrate, but a thin wall portion like the vibrating part of the vibrating substrate is formed on the plates. Since this is not necessary, handling of the plate during electrode formation is easy, and there is no risk of thermal strain damage due to high temperatures during sputtering. In addition, - the vibrating board with a thin vibrating part is sandwiched between a pair of plates made of the same material and protected from the outside, increasing the structural strength of the completed vibrator and making it easier to handle when mounting the vibrator. become. Furthermore, by sealing the vibrating substrate and the plate, an inert gas is filled in the gap between the vibrating substrate and the plate, so there is no risk of internal oxidation of the electrodes. Therefore, it is possible to provide a high-frequency oscillation resonator that is easy to handle during manufacturing and mounting and has good aging characteristics.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a vibrator showing a first embodiment of the present invention, FIG. 2 is a perspective view of the vibrator shown in FIG. 1, and FIG. 3 is a cross-sectional view of a vibrator showing a second embodiment of the present invention. 4 is a perspective view of a conventional vibrator, FIG. 5 is a cross-sectional view of the vibrator shown in FIG. 4, and FIG. 6 is a cross-sectional view showing another conventional structure of the vibrator. DESCRIPTION OF SYMBOLS 11...Crystal substrate (vibration substrate), 11a...Vibration part, 12.13...Plate, 14.15...Counter electrode, 16...Glass frit, 12.] meter/plate 14. 15... Counter electrode 16... Glass frit 41 Perspective view of the vibrator shown in FIG. 2

Claims (1)

[Claims] 1. A vibrating substrate (11) with a thin vibrating portion (11a) formed in the center thereof, and electrodes (14, 15) made of the same material as the vibrating substrate and having electrodes (14, 15) formed in advance on the surface of the vibrating substrate facing the vibrating portion. A pair of plates (12, 13), both plates (
A vibrator in which an inert gas is filled in the gap space between both plates (12, 13) and the vibrating substrate (11) by sandwiching the vibrating substrate (11) between the two plates (12, 13) and sealing them airtight. .