JPH0983287A - Support structure for piezoelectric vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the support structure for the piezoelectric vibrator with excellent shock resistance by adopting the support structure in which a stress resulting from a shock due to dropping or the like exerted to the piezoelectric vibrator hardly has an adverse effect onto a piezoelectric substrate. SOLUTION: Lead terminals 2, 2 are sealed to a base 1 via a glass air-tightly with insulation. Support plates 3A, 3A to support a piezoelectric substrate 4 are provided above the lead terminals 2, 2. The piezoelectric substrate is inserted to a slit of the supports for mounting. Then the piezoelectric substrate is adhered to a thin part of support upper parts 32A, 32A with a conductive adhesives 6. Thick support lower parts 31A, 31A are fitted to the lead terminals. When a shock is exerted to the support members of the piezoelectric vibrator, a mechanical displacement differs from the thick part of the support upper part and the thick part of the support lower part. Then concentration of a stress onto part of the piezoelectric vibrator is relaxed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric vibrator and a piezoelectric filter using a piezoelectric plate made of quartz or the like, and more particularly to a support structure for a piezoelectric plate.

[0002]

2. Description of the Related Art A conventional structure for supporting a piezoelectric vibrator will be described with reference to the drawings. FIG. 9 is a front view showing a conventional embodiment, and FIG.
0 is a side view of FIG. The lead terminals 2 and 2 are hermetically and insulated and sealed to the base 1 via glass, and a slit 33 (only one is shown) is formed on the inner leads of the lead terminals 2 and 2 by a method such as spot welding. Plated supports 3, 3 are attached. The piezoelectric plate 4 is inserted and mounted in the slits 33 (only one of which is shown) of the supports 3 and 3, and electro-mechanical connection is made by the conductive bonding material 6. The piezoelectric plate 4 is, for example, an AT-cut rectangular crystal plate, and excitation electrodes 5 (the back surface is not shown) are formed on the front and back surfaces thereof. Then, a cap (not shown) is put on the base 1 and hermetically sealed to produce a final piezoelectric vibrator.

[0003]

However, the above-mentioned structure has a problem in terms of impact resistance, and is caused by the pressing force at the time of resistance welding when sealing the cap, or after sealing. Mechanical stress is transmitted from the supporter to the piezoelectric plate due to an impact from the outside, and the piezoelectric plate is distorted, which may cause variations in the resonance frequency and the CI value with respect to the initial value and deteriorate them. Further, stress may be concentrated on the joint portion of the piezoelectric plate by the conductive joint material when a strong external impact is applied such as dropping, and the piezoelectric plate may be broken at the joint portion.

The present invention provides a support structure for a piezoelectric vibrator having excellent shock resistance by adopting a supporting structure in which the stress is less likely to adversely affect the piezoelectric plate or the like when a shock due to dropping or the like is applied to the piezoelectric vibrator. The purpose is to

[0005]

Therefore, the support structure for a piezoelectric vibrator of the present invention has a base having a plurality of lead terminals, and a plate-shaped support for supporting the piezoelectric plate is provided above the plurality of lead terminals. Is provided, the piezoelectric plate is inserted into the slit of the support to provide electromechanical connection with a conductive bonding material, and the support is provided in a piezoelectric vibrator support structure in which the base is capped and hermetically sealed. The upper part of the support including at least a part of the slit is formed thinner than the lower part of the support, and the piezoelectric plate is electromechanically bonded to the thin part of the support.

Thus, when an impact force is applied to the support member of the piezoelectric vibrator, the mechanical displacement amount can be made different between the thin portion above the support and the thick portion below the support. Then, stress concentration on a part of the piezoelectric vibrator can be relaxed.

Further, there is a base having a plurality of lead terminals, a plate-shaped support for supporting the piezoelectric plate is provided above the plurality of lead terminals, and the piezoelectric plate is inserted into the slit of the support to make the conductive material. In a support structure of a piezoelectric vibrator in which electromechanical connection is performed by a bonding material, the base is covered with a cap and hermetically sealed, the support has a bent portion formed in at least a slit portion, and
The lower part of the support is formed wider than the upper part of the support, and its width change is formed discontinuously, and the piezoelectric plate is electromechanically formed in the narrow part above the bent part of the support. Joined to.

As a result, when an impact force acts on the support member of the piezoelectric vibrator, the mechanical displacement amount can be made different between the upper side and the lower side of the bent portion, and the narrow portion of the support upper portion and the support can be changed. The amount of mechanical displacement can be different from that of the wide portion at the bottom. Then, stress concentration on a part of the piezoelectric vibrator can be relaxed. In addition, the wide portion of the lower portion of the support makes the mechanical impact from the lead terminals less likely to be affected.

Further, there is a base having a plurality of lead terminals, and a plate-shaped support for supporting the piezoelectric plate is provided above the plurality of lead terminals, and the piezoelectric plate is inserted into the slit of the support so as to be conductive. In a support structure of a piezoelectric vibrator in which electromechanical connection is performed by a bonding material, the base is covered with a cap and hermetically sealed, the support has a bent portion formed in at least a slit portion, and
The upper part of the support is formed thin and narrow with respect to the lower part of the support, and its width change is formed discontinuously, and the piezoelectric plate is formed in the thin narrow part above the bent part of the support. Electrically and mechanically bonded.

As a result, when an impact force is applied to the support member of the piezoelectric vibrator, the mechanical displacement amount can be made different between the thin portion at the upper portion of the support and the thick portion at the lower portion of the support. The mechanical displacement amount can be made different between the upper side and the lower side, and the mechanical displacement amount can be made different between the narrow portion of the upper support and the wide portion of the lower support. Then, the stress concentration on a part of the piezoelectric vibrator can be further alleviated. In addition, the wide portion of the lower portion of the support makes the mechanical impact from the lead terminals less likely to be affected.

Next, an example of experimental data will be shown. As a common matter of the experiment, a fundamental wave oscillation and a frequency of 20.945 MHz
In the crystal oscillator of (1), nickel was used as the support material, and an epoxy resin-based bonding material was used as the conductive bonding material. Then, using the support structure of the present invention as shown in FIG. 3 (10 samples) and the conventional support structure as shown in FIG. 9 (10 samples), 12
Dropped from a height of 0 cm. This falling direction is 13
By adding 0 g, the direction was changed to three directions, that is, the vertical direction, the horizontal direction, and the height direction, to drop, and all three directions were dropped to complete one cycle. At this time, the frequency deviation characteristic and the CI value deviation characteristic for each cycle were measured and the impact resistance was compared. FIG. 11 is a graph showing the frequency deviation characteristic of the crystal plate according to the conventional example, and FIG. 12 is a graph showing the CI value deviation characteristic of the crystal plate according to the conventional example. 13 is a graph showing a frequency deviation characteristic of the crystal plate according to the embodiment of the present invention, and FIG. 14 is a graph showing a CI value deviation characteristic of the crystal plate according to the embodiment of the present invention. Note that FIG. 15 is a graph comparing the average value of the frequency deviation characteristics between the related art and the present invention, and FIG. 16 is a graph comparing the average value of the CI value deviation characteristics between the related art and the present invention. As is clear from these figures, it can be seen that the present invention has less variation in characteristics and improved impact resistance as compared with the prior art.

[0012]

Next, a first embodiment of the present invention will be described with reference to the drawings. 1 is a front view showing a first embodiment of the present invention, and FIG. 2 is a side view of FIG. The supports 3A and 3A are made of, for example, Cu-Ni-Zn alloy, SUS,
A piezoelectric plate, which is made of a metal plate such as nickel-white and has lower support portions 31A and 31A for connecting to the lead terminals 2 and 2 and upper support portions 32A and 32A for joining to the piezoelectric plate 4, which will be described later. Is formed with a slit 33A (only one is shown). Then, the upper portion of the support is formed into a thin shape by half etching (in the case of the first embodiment, the upper portion is located above the center of the support). These supports can be formed by, for example, pressing and etching, or only etching. In addition, the base 1 has lead terminals 2 and 2 hermetically sealed via glass and insulated, and supports 3A and 3A are attached to the inner leads of the lead terminals 2 and 2 by a method such as laser welding. They are installed facing each other. Then, the piezoelectric plate 4 is inserted and mounted in the slit 33A (only one is shown) of the support, and the thin mechanical portions of the support upper portions 32A and 32A are electrically and mechanically connected by the conductive bonding material 6. The piezoelectric plate 4 is made of, for example, an AT-cut rectangular crystal plate, and its front and back surfaces are provided with an excitation electrode 5 whose main component is, for example, silver or gold by a method such as vapor deposition (the back surface is not shown). Are formed. Then, the base 1 is covered with a cap (not shown), and hermetically sealed by, for example, resistance welding or cold pressure welding. In this way, the thin support upper part is joined to the piezoelectric plate, and the thick support lower part is attached with the lead terminals.Therefore, the mechanical displacement amount differs between the upper support part and the lower support part. The stress concentration on a part of the oscillator can be relaxed. FIG.
As shown in FIG. 7, the widths of the slit lateral portions 321A and 322A of the support to which the conductive bonding material is applied are substantially the same on the left and right, so that there is no bias in the strain of the support and the stress distribution of the conductive bonding material. It can be said to be preferable.

Next, a second embodiment will be described with reference to the drawings. FIG. 3 is a front view showing a second embodiment of the present invention, and FIG. 4 is a side view of FIG. Support 3B,
3B is made of a metal plate such as Cu-Ni-Zn alloy, SUS, nickel silver, etc., and support lower parts 31B and 31B for connecting the lead terminals 2 and 2 and a support upper part 32B for connecting the piezoelectric plate 4 to each other. , 32B, and a slit 33B (only one of which is shown) for inserting a piezoelectric plate, which will be described later, and bent portions 34B, 34B protruding outward are formed. The lower portion of the support is formed with a wide triangular portion which is discontinuous with the upper portion of the support and gradually widens. These supports can be formed by, for example, pressing. In addition, the base 1 has lead terminals 2 and 2 hermetically sealed and insulated via glass, and the supports 3B and 3B are attached to the inner leads of the lead terminals 2 and 2 by a method such as spot welding. They are installed facing each other. Then, the slit 33B for supporting the piezoelectric plate 4
(Only one of them is shown in the figure) and is mounted, and electro-mechanical connection is made by the conductive bonding material 6 in the narrow portion above the bent portions 34B, 34B. In addition, the piezoelectric plate 4
Is made of, for example, an AT-cut rectangular crystal plate, and excitation electrodes 5 (the back surface is not shown) whose main component is, for example, silver or gold are formed on the front and back surfaces by a method such as vapor deposition. . Then, the base 1 is covered with a cap (not shown) and hermetically sealed by, for example, resistance welding or cold pressure welding. In this way, the upper part of the support is joined to the piezoelectric plate at the upper part of the bent part, and the lead terminal is attached at the lower part of the wide support. The amount of displacement can be made different to alleviate the stress concentration on a part of the piezoelectric vibrator. Also, FIG.
As shown in FIG. 7, the slit lateral portions 321B and 322B of the support to which the conductive bonding material is applied have substantially the same width on the left and right, so that there is no bias in the strain of the support and the stress distribution of the conductive bonding material. It can be said to be preferable.

Next, a third embodiment will be described with reference to the drawings. 5 is a front view showing a third embodiment of the present invention, and FIG. 6 is a side view of FIG. Support 3C,
3C is made of a metal plate such as Cu-Ni-Zn alloy, SUS, nickel silver, etc., and support lower portions 31C and 31C for connecting the lead terminals 2 and 2 and a support upper portion 32C for connecting the piezoelectric plate 4 to each other. , 32C, and a slit 33C (only one is shown) for inserting a piezoelectric plate, which will be described later, and bent portions 34C, 34C protruding outward. The support upper part is formed to be thin by half etching (in the case of the third embodiment, it is located above the support center) and the support lower part is discontinuous and gradually widened with respect to the support upper part. A wide portion having a shape is formed. These supports can be formed by, for example, pressing and etching. Also,
In the base 1, the lead terminals 2 and 2 are hermetically sealed and insulated via glass, and the supports 3C and 3C face the inner leads of the lead terminals 2 and 2 by a method such as laser welding. And is installed. Then, the piezoelectric plate 4 is inserted into and mounted on the supports 3C and 3C slits 33C (only one is shown), and the electromechanical structure is formed by the conductive bonding material 6 in the thin and narrow portions above the bent portions 34C and 34C. Connection is made. The piezoelectric plate 4 is made of, for example, an AT-cut rectangular crystal plate, and its front and back surfaces are provided with an excitation electrode 5 whose main component is, for example, silver or gold by a method such as vapor deposition (the back surface is not shown). Are formed. Then, the base 1 is covered with a cap (not shown) and hermetically sealed by, for example, resistance welding or cold pressure welding. In this way, the thin and narrow support upper part is joined to the piezoelectric plate on the upper side of the bent part, and the lead terminal is attached to the thick and wide support lower part. The amount of mechanical displacement is different between the lower part and the stress concentration on a part of the piezoelectric vibrator can be relaxed. Further, as shown in FIG. 6, the lateral slits 321C and 322C of the support to which the conductive bonding material is applied have substantially the same width on the left and right, so that the strain of the support and the stress distribution of the conductive bonding material are biased. It can be said that it is even more preferable.

In the first to third embodiments of the present invention, there is a thin region from the middle of the support to the upper end.
Alternatively, the upper part of the support and the lower part of the support are distinguished by the presence or absence of a wide area from the middle of the support (requirement that the width change of the support is discontinuous) to the lower end.

In the second and third embodiments of the present invention,
The wide portion of the lower portion of the support has a triangular shape or a trapezoidal shape as an example, but the wide portion is not limited to these shapes, and may have a shape as shown in FIG. 7, for example. In addition, in the first and third embodiments of the present invention, the thin region is located above the vicinity of the central portion of the support, but it is not limited to these regions. For example, in the thin region as shown in FIG. It may be. The support of the present invention can employ not only the combinations and configurations disclosed in the above embodiments, but also various combinations and configurations shown in FIGS. 7 and 8. Further, although the quartz crystal diaphragm is used as the piezoelectric plate in each of the above embodiments, other single crystal piezoelectric bodies such as lithium tantalate or piezoelectric ceramics may be used. Although the AT-cut thickness-shear vibration is exemplified as the vibration mode, it can be applied to piezoelectric vibrators of other vibration modes. Further, the present invention can be applied not only to the crystal resonator but also to a crystal filter.

[0017]

According to the present invention, when an impact force is applied to the support member of the piezoelectric vibrator, the mechanical displacement amount can be made different between the thin portion of the upper support and the thick portion of the lower support. The buffer works. Thereby, stress concentration on a part of the piezoelectric vibrator can be relaxed. Therefore, when a shock due to a drop or the like is applied to the piezoelectric vibrator, the supporting structure is such that the stress does not adversely affect the piezoelectric plate and the like, and it is possible to provide a supporting structure for the piezoelectric vibrator having excellent shock resistance.

According to the second aspect, when an impact force is applied to the support member of the piezoelectric vibrator, the mechanical displacement amount can be made different between the upper side and the lower side of the bent portion, and the narrow portion of the support upper portion can be made. Since the mechanical displacement amount can be made different between the wide part of the lower part of the support and the lower part of the support, a cushioning function works. Thereby, stress concentration on a part of the piezoelectric vibrator can be relaxed. Therefore, when a shock due to a drop or the like is applied to the piezoelectric vibrator, the supporting structure is such that the stress does not adversely affect the piezoelectric plate and the like, and it is possible to provide a supporting structure for the piezoelectric vibrator having excellent shock resistance.

According to claim 3, when an impact force is applied to the support member of the piezoelectric vibrator, the mechanical displacement amount can be made different between the thin portion of the upper support and the thick portion of the lower support. The amount of mechanical displacement can be made different between the upper side and the lower side of the bent portion, and the mechanical displacement can be made different between the narrow portion of the upper support and the wide portion of the lower support, so that it can be buffered. The action works. This can further alleviate the stress concentration on a part of the piezoelectric vibrator. Therefore, when a shock due to a drop or the like is applied to the piezoelectric vibrator, the supporting structure is such that the stress does not adversely affect the piezoelectric plate and the like, and it is possible to provide a supporting structure for the piezoelectric vibrator having excellent shock resistance.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is a front view showing a second embodiment of the present invention.

FIG. 4 is a side view of FIG. 3;

FIG. 5 is a front view showing a third embodiment of the present invention.

FIG. 6 is a side view of FIG. 5;

FIG. 7 is a diagram showing an example of a wide support shape applied to an embodiment of the present invention.

FIG. 8 is a diagram showing an example of a support thick-walled shape applied to an embodiment of the present invention.

FIG. 9 is a plan view showing a conventional example.

FIG. 10 is a side view of FIG. 9.

FIG. 11 is a graph showing frequency deviation characteristics of a quartz plate according to a conventional example.

FIG. 12 is a graph showing CI value deviation characteristics of a quartz plate according to a conventional example.

FIG. 13 is a graph showing frequency deviation characteristics of a crystal plate according to an example of the present invention.

FIG. 14 is a graph showing a CI value deviation characteristic of a quartz plate according to an example of the present invention.

FIG. 15 is a graph comparing the average value of frequency deviation characteristics between a conventional method and the present invention.

FIG. 16 is a graph comparing the average value of the CI value deviation characteristics between the related art and the present invention.

[Explanation of symbols]

 1 ... Base 2 ... Lead terminal 3, 3A, 3B, 3C ... Support 4 ... Piezoelectric plate 5 ... Excitation electrode 6 ... Conductive bonding material

Claims (3)

[Claims] 1. A base having a plurality of lead terminals, a plate-shaped support for supporting a piezoelectric plate is provided above the plurality of lead terminals, and the piezoelectric plate is inserted into a slit of the support to make it conductive. In a support structure of a piezoelectric vibrator in which an electromechanical connection is performed by a bonding material, and the base is capped and hermetically sealed, the support has at least a part of a slit, and the support upper part has a thinner wall than the support lower part A support structure for a piezoelectric vibrator, wherein the support is formed and a piezoelectric plate is electrically and mechanically bonded at a thin portion of the support. 2. A base having a plurality of lead terminals is provided, and a plate-shaped support for supporting a piezoelectric plate is provided above the plurality of lead terminals, and the piezoelectric plate is inserted into a slit of the support so as to be conductive. In a support structure of a piezoelectric vibrator in which an electromechanical connection is performed by a bonding material, and the base is covered with a cap to hermetically seal, in the support, a bent portion is formed at least in a slit portion, and the support lower portion is The support is formed wider than the upper part, and its width change is formed discontinuously, and the piezoelectric plate is electromechanically bonded at the narrow part above the bent part of the support. Support structure for piezoelectric vibrators. 3. The support structure for a piezoelectric vibrator according to claim 2, wherein the support has an upper portion of the support including at least a part of a slit and is formed thinner than a lower portion of the support.