JP2005159967A - Structure for supporting piezoelectric vibrator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure for supporting a piezoelectric vibrator wherein a frequency is stabilized, by reducing a torsion force by adding laterally symmetrical stresses from a support plate to a piezoelectric raw plate. <P>SOLUTION: In the structure for supporting the piezoelectric vibrator supported by the support plate where the piezoelectric raw plate is fixed with two metal terminals air-tightly passing through a metal base in order to solve the problem, an injection port of a bonding is provided on an outer side surface of thickness of the support plate, and a recessed portion which is communicated to the injection port abutted to the piezoelectric raw plate at two points in the center, is provided on an inner side surface of thickness of the support plate at the side of the piezoelectric raw plate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

     The present invention relates to a support structure for a piezoelectric element plate in a piezoelectric vibrator having two metal terminals.

     With the rapid growth of the mobile communication market in recent years, the demand for communication equipment has increased dramatically. As a result, piezoelectric vibrators that are used as a source of frequency as a reference in communication equipment are used in the surrounding environment. However, in the present situation, it is required to secure a more stable operation of the specified frequency output even under use in more severe environmental conditions.

Among the piezoelectric vibrators, OCXO (Oven
There are roughly two types of crystal plate holding structures for highly stable crystal units used in Controlled Crystal Oscillators. As shown in FIG. 3, a plate support holding structure mold using a metal such as solder as a bonding material between the crystal element plate and the support plate, and a bonding material between the crystal element plate and the support plate as shown in FIG. Two types of slit support plate holding structure using an adhesive.

     One of the factors that influence the aging characteristics, which is one of the important characteristics of these highly stable crystal units, is the stress from the support plate, which is the holder of the crystal base plate, to the crystal base plate, and especially the twisting force. When added from the support plate to the crystal base plate, there is a problem that the characteristics of the highly stable crystal resonator are greatly affected.

     Further, when manufacturing a piezoelectric vibrator having this shape, the weld pressure deforms the metal base during welding, and the stress accompanying the deformation is held inside the piezoelectric vibrator through the metal terminal and the support plate. There is a problem that it is transmitted to the piezoelectric element plate, and as a result, the specified frequency may change.

     In addition, in the past, since the shape of the support plate bonded to the piezoelectric element plate via the conductive adhesive is a flat plate shape, the support plate is flat and connected to the piezoelectric element plate by a bonding material such as solder. As a result, the bonding position and area vary, and asymmetric stress is generated from the two left and right support plates facing each other, and the twisting force is applied from the support plate to the piezoelectric element plate, thereby adversely affecting the piezoelectric element plate. is there.

Japanese Patent Application No. 7-240656

     The applicant has not found any prior art documents related to the present invention other than the prior art documents specified by the prior art document information described above by the time of filing of the present application.

     The present invention has been made under the technical background as described above. Therefore, the object of the present invention is to reduce the stress applied to the piezoelectric element plate from the support and to obtain the symmetry of the stress. To provide a support structure for a piezoelectric vibrator having a stable frequency by reducing stress such as twisting force applied to the piezoelectric element plate even during welding.

     In order to achieve the above object, the present invention provides a piezoelectric vibrator supporting structure in which a piezoelectric element plate is supported by a support plate fixed to two metal terminals hermetically penetrating a metal base. An injection port for the bonding material is provided on the outer surface of the plate thickness, and a concave portion that communicates at the center with the injection port that contacts the piezoelectric element plate at two points is provided on the inner surface of the support plate on the piezoelectric element plate side. Features.

     By using the support structure of the piezoelectric vibrator according to the present invention, the stress applied from the support plate to the piezoelectric base plate has symmetry, and the weld pressure applied to the metal base applied during the welding process in manufacturing the piezoelectric vibrator is metal. The piezoelectric vibrator is stable by eliminating the problem of deforming the base and changing the specified value of the frequency due to the deformation, and improving the vibration resistance and impact resistance applied from the outside of the piezoelectric vibrator. A high frequency can be maintained.

     Further, not only the piezoelectric vibrator alone of this embodiment but also the piezoelectric oscillator constituting the piezoelectric vibrator of the present invention has the effect of remarkably reducing the change in characteristics such as the frequency as described above. As a result, the manufacturing yield of the piezoelectric oscillator can be improved.

     In addition, the stress from the support plate applied to the piezoelectric element plate is fixed in a certain direction with respect to the two support parts of the piezoelectric element plate facing each other because the bonding material is similarly accommodated in the two support parts facing the piezoelectric element plate. In particular, the twisting force applied to the piezoelectric element plate from the support plate is suppressed, and as a result, the fluctuation of the aging characteristic of the highly stable piezoelectric vibrator using the support plate of the present invention is reduced, and a plurality of piezoelectric elements There is an effect that variation in aging characteristics between the vibrators is also reduced.

     Embodiments of the present invention will be described below with reference to the accompanying drawings. In addition, the same code | symbol in each figure shall show the same object.

     FIG. 1 is a schematic side view of a support plate 4 which is a support structure of a piezoelectric vibrator 5 of the present invention, and a schematic front view 1 and a front view 2. In the case of the support plate 4 in the front view 2, the width of the concave portion 9 on the support plate 4 on the piezoelectric element plate 1 side is narrower than the entire width of the support plate 4. These drawings partially show one side of the supporting portions of two opposing piezoelectric element plates that hold the piezoelectric element plate 1. In the support plate 4 of the present invention, a concave portion 9 filled with a bonding material 6 for bonding the piezoelectric element plate 1 and the support plate 4 and an injection port 7 for injecting the paste-like bonding material 6 into the concave portion 9 are provided. Have. The concave portion 9 on the piezoelectric element plate 1 side of the support plate 4 of the present invention is at least as long as the injection port 7, and a conductive adhesive 12, Au—Sn paste, or the like is used for the bonding material 6 to be injected. . The support plate 4 is made of pure nickel or the like.

     FIG. 2 is a schematic view of the crystal base plate 1 viewed from the main surface direction showing a state in which the crystal base plate 1 is held via the conductive adhesive 12 using the support plate 4 that is the support structure of the piezoelectric vibrator 1 of the present invention. It is a figure of this, and its side surface schematic diagram. When a fixed amount of a paste such as a conductive adhesive 12 is injected from the injection port 7 using a dispenser or the like and solidified by the support plate 4 which is the support structure of the present invention, the conductivity of the quartz base plate 1 and the support plate 4 The bonding surface by the adhesive 12 has a certain area, position, and thickness because the conductive adhesive 12 is accommodated in the concave portion 9 that contacts the side surface of the piezoelectric base plate 1. Similarly, the conductive adhesive 12 is provided in the concave portion 9 that abuts against the side surface of the piezoelectric element plate 1 in the same manner with respect to the support parts of the two piezoelectric element elements that face the left and right sides of the quartz element element 1 that is the piezoelectric element plate 1. Therefore, the stress from the support plate applied to the crystal element plate becomes constant in the support portions of the two opposing piezoelectric element plates, and in particular, the twisting force applied from the support plate 4 to the crystal element plate 1 is suppressed. As a result, it is possible to reduce the variation in the aging characteristics of the highly stable crystal resonator using the support plate 4 of the present invention and to reduce the variation in the aging characteristics of the plurality of crystal resonators.

     FIG. 3 is a schematic view seen from the main surface direction of the crystal base plate 1 showing how the crystal base plate 1 is held using a conventional plate support.

     FIG. 4 is a schematic view seen from the main surface direction of the crystal base plate 1 showing a state in which the crystal base plate 1 is held using a conventional slit support plate.

     FIG. 5 is a schematic view seen from the side of the crystal base plate 1 showing how the crystal base plate 1 is held via the conductive adhesive 12 using a conventional slit support plate. In the conventional support plate 4 as shown in FIGS. 3 and 4, the bonding surface between the crystal base plate 1 and the support plate 4 does not have a constant area, position, and thickness.

FIG. 3 is a schematic side view of a support plate which is a support structure of a piezoelectric vibrator of the present invention, and a schematic front view and a front view. In the case of the support plate of FIG. 2, the width of the concave portion on the piezoelectric element plate side of the support plate is narrower than the entire width of the support plate. Schematic schematic view from the main surface direction of a quartz base plate showing a state of holding the quartz base plate via a conductive adhesive using a support plate that is a support structure of a piezoelectric vibrator of the present invention, and a schematic side view thereof FIG. It is the schematic seen from the main surface direction of the crystal base plate which shows a mode that a crystal base plate is hold | maintained using the conventional plate support plate. It is the schematic seen from the main surface direction of the crystal base plate which shows a mode that a crystal base plate is hold | maintained using the conventional slit support plate. It is the schematic seen from the side surface direction of the crystal base plate which shows a mode that a crystal base plate is hold | maintained via a conductive adhesive using the conventional slit support plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piezoelectric base plate 2 Metal base 3 Metal terminal 4 Support board 5 Piezoelectric vibrator 6 Bonding material 7 Inlet 8 Inlet length 9 Recess 10 Electrode 11 Solder 12 Conductive adhesive 13 Slit

Claims (1)

In the support structure of the piezoelectric vibrator in which the piezoelectric element plate is supported by a support plate fixed to two metal terminals hermetically penetrating the metal base,
An inlet for bonding material is provided on the outer surface of the support plate in the thickness direction, and the inner surface of the support plate on the side of the piezoelectric element plate on the thickness side of the support plate is centered on the inlet that contacts the piezoelectric element plate at two points. A support structure for a piezoelectric vibrator having a concave portion that communicates therewith.

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