JPH10270970A - Crystal oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crystal oscillator with less residual distortion by suppressing a difference between the coefficient of the thermal expansion of a pedestal and the coefficient of the thermal expansion of a GT cut-type crystal oscillation bar to be not more than a specified value. SOLUTION: The pedestal 10, the oscillation bar 20 and a plug 30 are provided. The oscillation bar 20 is joined with the pedestal 10 through a fine terminal part 21. Furthermore, the pedestal 10 is connected with the plug 30 having a lead 40. The coefficient of the thermal expansion of ceramic in the pedestal 10 is about 10 ppm/ deg.C and it shows a value which is considerably approximated to about 11 ppm/ deg.C which is the coefficient of the thermal expansion of the oscillation bar of AT cut. The coefficient of the thermal expansion of the crystal oscillation bar of GT cut is about 13 ppm/ deg.C and it has the difference of about 3 ppm/ deg.C with the coefficient of the thermal expansion of the pedestal. It becomes a smaller value compared to about 8 ppm/ deg.C being the difference with the coefficient of the thermal expansion of a former pedestal. Thus, the residual strain of the crystal oscillator using the thin bar can be reduced and thus the superior crystal oscillator with less fluctuation of the frequency characteristic can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a portable information device, a PHS
The present invention relates to a quartz oscillator used for the same and the like and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, alumina ceramic has been used as a base for supporting a vibrator piece.

[0003]

Since alumina ceramic has a different thermal expansion coefficient from that of quartz, there are disadvantages such as cracking of the quartz piece due to reflow and heat shock in the manufacturing process and deterioration of vibration characteristics. . In particular, G
The T-cut quartz-crystal vibrating piece had a large difference in thermal expansion coefficient from that of alumina ceramic and tended to increase residual stress.

[0004]

Accordingly, in the present invention,
A pedestal having a thermal expansion coefficient close to that of the crystal unit was used. By reducing the difference in the coefficient of thermal expansion, a quartz resonator having less residual distortion and less variation in frequency characteristics can be obtained.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a crystal resonator having a small residual distortion can be obtained by suppressing the difference between the thermal expansion coefficient of the pedestal and the thermal expansion coefficient of the crystal blank to 10 ppm or less.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment in which the invention of the present application is applied to a heat-resistant tube type crystal resonator, which comprises a pedestal 10, a vibrator piece 20 and a plug 30. ing. Further, the pedestal 10 is connected to a plug 30 having a lead 40.

FIG. 2 shows a comparison between the thermal expansion coefficient of the vibrator piece and the thermal expansion coefficient of the pedestal. The thermal expansion coefficient 1 of the ceramic of the present invention is about 10 ppm / .degree.
Shows a value very close to about 11 ppm / ° C. Also, the thermal expansion coefficient 3 of the GT-cut vibrator piece is about 13 ppm / ° C., which is about 3 ppm / ° C. different from the thermal expansion coefficient of the base of the present invention.
The value was smaller than a difference of about 8 ppm / ° C. from the thermal expansion coefficient 4 of the conventional pedestal.

FIG. 3 is a view showing another embodiment of the present invention, in which a vibrator piece 20 is arranged in a surface mounting case 50 via a pedestal 10 having a similar thermal expansion coefficient.

[0009]

According to the present invention, the residual stress of a crystal unit using a thin crystal unit can be reduced.
As a result, it is possible to obtain an excellent quartz oscillator having little variation in frequency characteristics.

[Brief description of the drawings]

FIG. 1 is a diagram of a crystal vibration unit of the present invention.

FIG. 2 is a view of a crystal vibrating unit of the present invention.

FIG. 3 is a diagram showing a coefficient of thermal expansion.

[Explanation of symbols]

 10 Pedestal 20 Transducer piece 30 Plug 40 Lead

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[Procedure amendment]

[Submission date] April 20, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

Claims (1)

[Claims] 1. A crystal resonator comprising a GT cut type crystal resonator element and a pedestal having a linear thermal expansion coefficient of 5 PPM / ° C. or less between the resonator element connected to the resonator element.