JPH0537537Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tubular piezoelectric vibrator having lead terminals at both ends.

[Prior art]

Conventionally, small piezoelectric resonators such as crystal resonators generally have two lead terminals protruding in parallel from one side of an airtight container. Since such a vibrator supports a long and thin piezoelectric vibrating piece at one end, it is easily destroyed by a drop impact.
Also, when attaching to a printed circuit board, bend the lead terminals 90 degrees and lay them horizontally before attaching them.
The airtight container must be glued to the printed circuit board,
This has the disadvantage of increasing implementation costs.

To overcome this drawback, a structure in which both ends of a piezoelectric vibrating piece are supported has been proposed in Japanese Patent Application Laid-Open No. 58-219809 and Japanese Utility Model Application Publication No. 55-13462.
However, in the former case, as shown in FIG.
and lead wires 5, 6 are joined via retaining springs 7, 8 formed by bending them into a U-shape, and the latter is a lead wire made of a thin wire, as shown in FIG. It is connected to the crystal piece through an elastic part formed by bending the wire 9 twice.

In general, piezoelectric vibrators are used in environments that span a wide temperature range and are subject to external vibrations and shocks, so they are not affected by thermal expansion stress caused by the expansion and contraction of piezoelectric vibrating pieces or airtight containers, and impact forces caused by external shocks. It is inevitable that you will receive it. Therefore, it is necessary to design the frequency change caused by these influences to be as small as possible.

[Problem that the invention attempts to solve]

However, in the former Japanese Patent Application Laid-open No. 58-219809, the crystal piece is supported by a spring member bent into a U-shape, so the tension and compression forces conflictingly with each other at the bent portion of the spring member. The bending deformation range of the bending portion is limited to a relatively local area and is therefore small. Therefore, the mitigation effect for thermal expansion stress and impact force is small, and it is difficult to absorb stress caused by impact force acting in the axial direction of the vibrating element and the stress caused by displacement due to thermal expansion. You can't have a child.

Furthermore, although the configuration shown in FIG. 8 described in the latter Japanese Unexamined Utility Model Publication No. 55-13462 differs in that it is folded twice, it has almost the same problem as the aforementioned Japanese Unexamined Patent Publication No. 58-219809. That is, even though it is bent twice, the bent spring portion also relaxes the stress, so the effect of alleviating thermal expansion stress and impact force is small as in the former conventional example. Furthermore, in the case of Fig. 8, since there are two bent parts, the size of the support part in the longitudinal direction of the vibrating element becomes large.
This has been a major obstacle in miniaturizing crystal oscillators.

The purpose of the present invention is to support the piezoelectric vibrating piece with a support member capable of elastic deformation sufficient to absorb the impact force applied in the strong direction of the piezoelectric vibrating piece, thermal expansion deformation, and the accompanying stress. The present invention provides a piezoelectric vibrator that is less susceptible to impact forces.

[Means for solving problems]

In order to achieve the above object, the present invention provides a piezoelectric vibrator in which a rectangular piezoelectric vibrating piece is supported by an elastic support member, a lead member connected to the elastic support member is led outside, and the piezoelectric vibrator is hermetically sealed in an airtight container. The elastic support member is formed with a length shorter than one turn in a plane substantially perpendicular to the vibrating element fixing part and the lead member, and the elastic support member is formed to have a length shorter than one turn in a plane substantially perpendicular to the vibrating element fixing part and the reed member, and the elastic supporting member has a length shorter than one turn in a plane substantially perpendicular to the vibrating element fixing part and the reed member. This tubular piezoelectric vibrator is composed of a torsionally deforming part that is torsionally deformed, and an arm part that connects the fixed part and the torsionally deformable part and converts the longitudinal deformation of the vibrating element into rotational motion.

〔Example〕

FIG. 1 is a front view showing a partial cross section of a tubular piezoelectric vibrator that is an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line A-A, and FIG. 11 is a right side view of the main part of FIG. 2.

In FIGS. 1 and 2, the piezoelectric vibrating piece 11 is
Made of AT-cut crystal piece, its surface has Ag,
A thin film electrode 11a made of Au, Al, etc. is deposited. An elastic support member 12 is fixed to both ends of the piezoelectric vibrating piece 11, a lead member 13 is provided in connection with the elastic support member 12, and the piezoelectric vibrating piece 11 is hermetically sealed in an airtight container 14 made of glass or the like. has been done. The lead member 13 is guided to the outside while being hermetically sealed by the hermetic sealing portion 14a.

As shown in FIG. 2, the elastic support member 12 includes a vibrating element fixing portion 12a, a linear arm portion 12b connected to the vibrating element fixing portion 12a, and a torsionally deforming portion 12c connected to the arm portion 12b. It consists of Referring to FIGS. 10 and 11, when the piezoelectric vibrating piece 11 is deformed in the longitudinal axis direction due to thermal deformation, for example, the arm portion 12b is connected to the torsionally deformed portion 12c in response to the deformation. It rotates in the direction of arrow A using the installed part as a fulcrum. This arm part 1
The rotation of the piezoelectric vibrating piece 11 causes the torsionally deforming portion 12c to be torsionally deformed in the direction of the arrow B, thereby absorbing the deformation of the piezoelectric vibrating piece 11 in the longitudinal direction. Since this torsional deformation is evenly distributed over the length dimension a (shown in FIG. 10) of the torsional deformation portion 12c, there is little stress concentration, and a sufficiently large torsional elastic deformation is possible, resulting in excellent thermal deformation stress and impact. It has a force absorption effect. Further, the arm torsion deformation portion 12c is connected to the lead member 13 and has a length shorter than one turn in a plane substantially perpendicular to the lead member 13, and the arm portion 12b is connected to the connecting point with the vibrating element fixing edge 2a. 12d is the torsional deformation part 1
Direction as far away from 2c as possible, i.e. approximately 90
It is formed by bending it in the direction of degrees.

If the elastic support member 12 shown in this embodiment is used, even if the piezoelectric vibrating piece 11 expands or contracts due to the influence of temperature changes, the torsionally deformed portion 12 will be
c is torsionally deformed and moves the vibrating element fixing portion 12a in the longitudinal axis direction. Moreover, the structure of this embodiment that uses torsional deformation is different from the conventional example described above that uses bending deformation, and is capable of large elastic deformation in principle and dimension.
Even if force due to thermal deformation stress or impact is applied to 1, the force can be relaxed and the adverse effect on the vibrator characteristics can be made extremely small. In addition, while the conventional device has a bending elastic portion in the plane that includes the lead portion, in this example, the torsional elastic deformation portion is formed in a plane perpendicular to the lead portion, so that it This can contribute to miniaturization of the vibrator.

FIG. 3 illustrates another embodiment of the elastic support member used in the present invention. FIG. 3A shows a torsional deformation portion 12c corresponding to the torsional deformation portion 12c in FIG.
3B shows a torsion deformation portion 16c corresponding to the torsion deformation portion 15c in FIG. 3A being elongated to obtain a large elastic deformation. Furthermore, in FIG. 3C, an arm portion 17b corresponding to the arm portion 16b in FIG. 3B is bent in an arc shape, and the arm portion and the torsion deformation portion form a central angle of 135°.
In Fig. 3D, the arc shape 18b has a central angle of 135 degrees. Either of these elastic support members has the advantage that a large elastic effect can be obtained and that they are easy to process.

FIG. 4 is a partially cutaway sectional view showing an embodiment using another airtight container, and the configurations of the piezoelectric vibrating piece 21, elastic support member 22, and lead member 23 are the same as those in FIG. The airtight container is composed of a sealing tube 24 made of ceramic or metal and an airtight sealing part 25 made of low melting point glass. The end portion where the cross section is not shown has the same configuration as the portion where the cross section is shown.

FIG. 5 shows an embodiment using still another airtight container of the present invention, and FIG. 6 is a sectional view taken along line BB in FIG. The configurations of the piezoelectric vibrating piece 31, the elastic support member 32, and the lead member 33 are the same as those shown in FIG. A lead member 33 is inserted through the small hole 34 and soldered or brazed 36.
The structure is firmly fixed. An airtight terminal 35, which hermetically seals the lead member 33, is press-fitted into the other end of the sealed tube 34. The airtight terminal 35 is a metal frame with a sealing glass embedded therein.

As the elastic support member 32, various shapes shown in FIG. 3 can be used. An insulating sheet 37 is wrapped around the outer peripheral surface of the sealed tube 34.

In the embodiments shown in FIGS. 4 to 6, the external dimensions of the airtight container can be reduced, and they are easier to manufacture than the glass container shown in FIG. It also has the advantage of being difficult.

FIG. 9 shows an embodiment using yet another airtight container of the present invention, the internal structure of which is the same as that shown in FIG. , 42 are fixed, the portion of the lead member protruding to the outside of the airtight container is cut off, and the end thereof is electrically connected at the connection point 43. A structure in which a metallized layer is provided instead of the metal cap 42 and the lead member is electrically connected to this layer is also possible.

Note that the structure of the present invention is applicable not only to the AT-cut crystal resonator described in the embodiment but also to other piezoelectric resonators.

[Effect of idea]

The present invention includes an elastic support member, a vibrating element fixing part, and
A configuration including an arm section connected to the arm section, and a torsion deformation section that is connected to the arm section and rotates and torsionally deforms the arm section in response to the deformation of the piezoelectric vibrating piece in the longitudinal axis direction. By doing so, elastic deformation larger than bending deformation can be obtained, so thermal expansion stress and impact force in the longitudinal axis direction can be sufficiently alleviated, and the temperature characteristics and impact characteristics can be made extremely good. Also,
Since the torsional deformation part is formed in a plane perpendicular to the lead part, the dimension in the longitudinal axis direction can be reduced.
By reducing the external size and simplifying assembly, it is possible to obtain a tubular piezoelectric vibrator that can be made smaller and reduce manufacturing costs.

[Brief explanation of the drawing]

Fig. 1 is a front view showing a partial cross section of one embodiment of the present invention, Fig. 2 is a sectional view taken along line AA in Fig. 1, and Fig. 3 is an elastic material used in another embodiment of the present invention. The side view of the support member, FIG. 4, FIG. 5, and FIG. 9 respectively relate to an embodiment using another airtight container of the present invention, FIG. 4 is a partially cutaway sectional view, and FIG. 5 is a sectional view. figure,
9 is a front view, FIG. 6 is a sectional view taken along line BB in FIG. 5, and FIGS. 7 and 8 are related to the prior art, respectively.
FIG. 7 is a sectional view, and FIG. 8 is a partially cutaway sectional view. Also, Figure 10 is a front view of the main part of Figure 2,
FIG. 1 is a side view of the main part of FIG. 2. 11, 21, 31...Piezoelectric vibrating piece, 11a...
Electrode, 12, 22, 32... Elastic support member, 12
a... Vibration piece fixing part, 12b... Arm part, 12c...
...Torsional deformation portion, 14a, 25...Airtight sealing portion.

Claims (1)

[Scope of utility model registration request] An elastic support member is fixed to the end of a rectangular piezoelectric vibrating piece, a lead member is provided in connection with the elastic support member, and the piezoelectric vibrating piece and the elastic support member are placed in an airtight container while leading out the lead member to the outside. In the tubular piezoelectric vibrator, the elastic support member includes a fixing portion that fixes an end of the piezoelectric vibrating piece, and a length shorter than one turn in a plane substantially perpendicular to the lead member. a torsionally deformable portion that is formed with a cylindrical shape and that is torsionally deformed in response to the deformation of the piezoelectric vibrating piece in the longitudinal direction; A tubular piezoelectric vibrator is characterized in that it is comprised of an arm portion that changes rotational motion into rotational motion.