JPS5854718A - Crystal oscillator - Google Patents

Abstract

PURPOSE:To attain mass-production, by arranging a surface electrode for its free end surfaces so as to perform profile slip oscillation and gradually decreasing the amplitude toward the fixed terminal, and making supporting easy. CONSTITUTION:Surface electrode films 2 and 3 are arranged so as to produce the profile slip oscillation which is the same as the oscillation mode known as that of a DT-cross section oscillation plate can be performed, as shown by two-dot chain lines, only at the vicinity of the upper end of a rod shape crystal oscillator 1 having almost square or rectangular cross section. The electrodes 2 and 3 are made not to form excitation electric field to the lower end and are electrically bonded to the projection in the package of terminal pins 4 and 5 through an insulation glass of a hermetic terminal 6 around the lower end of the rod 1 to fix the quartz rod 1 in cantilever.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a crystal resonator having a novel vibration mode based on the idea of so-called edge modes.

BACKGROUND ART Tuning fork-type or lens-type AT plates have conventionally been used as crystal resonators that are ultra-small, have relatively flat frequency-temperature characteristics, and are easy to manufacture, and have been mainly used in quartz watches and the like. However, in the tuning fork type 1C, the oscillation frequency is a little too low, so the fine adjustment of the output frequency using a frequency divider with a variable frequency division ratio becomes too rough, which is inconvenient, and the natural frequency of the left and right branches of the tuning fork becomes too low. Even if there is a slight deviation in the degree of coincidence due to a manufacturing error, characteristics tend to deteriorate, which is one of the factors that lowers the yield in mass production. On the other hand, the frequency-temperature characteristic of the AT plate resonator is difficult to compensate for: it is a cubic curve and is extremely sensitive to the cutting angle, and there are so-called secondary vibrations, making it difficult to match the characteristics, and lens processing However, since a large number of vibrating elements cannot be applied simultaneously within a crystal block or wafer, the cost inevitably increases.

The present invention was made with the aim of creating a vibrator that eliminates the drawbacks of these conventional products and has the advantages. This is not necessary, and a resonator with relatively excellent temperature characteristics and a moderately high frequency can be obtained. This will be explained below based on the drawings.

FIG. 1 shows the inside of a container of a vibrator according to an embodiment of the present invention.
FIG. 3 is a perspective view showing the structure including support.

1 is a rod-shaped crystal vibrating body with a cross section of approximately square or l)+1 shape, and only the vicinity of its upper end, as shown by the two-dot chain line, has a cross section that is known as the so-called I) vibration mode performed by a T-cut diaphragm. It is designed to cause vibrations in the throat without the same ringing. For this purpose, surface electrode films 2 and 6 are provided so as to generate an effective electric field only at the upper end.

The electrodes 2 and B are routed toward the lower end so as not to create an excitation electric field as much as possible, and near the lower end of the rod 1, ... Glue conductively to the protruding part, for example, with a pad, or directly to the terminal B, and apply conductive paste to pins 4.5!・Fix the connection lever and the crystal frame 1 in a cantilevered manner.

The entire device is hermetically housed in a cylindrical container, but this is not shown.

FIG. 2 shows an example of the cutting direction with respect to the crystal axis of the crystal frame 1, and the direction of the end face coincides with the direction of the d-shaped DT plate. Alternatively, it can be said that it is shifted perpendicularly to the AT plate by +i. There is a very high possibility that the temperature coefficient of frequency becomes zero at a cutting angle in this vicinity. The excitation electrode is desirably arranged so that the y-direction component of the electric field it creates is the largest, and moreover, it is concentrated as much as possible in local areas where the vibration distortion is large (medium heat on each side of the tip). This embodiment does not take such careful consideration.

Figure 3 shows the state in which the crystal frame 1 is being cut out from the Glock 7 of the crystal moon using a wire saw or blade saw, and 8 is a wire. As shown in the figure, the crystal block 7 is cut into a lattice shape using 2][o] and placed into a large number of crystal frames (divided into 2 rims).

Each of the figures in FIG. 1I shows a side profile of another embodiment of the crystal frame 1. Both of them increase the effect of confining vibrational energy to the upper end.They are located in the longitudinal direction of the rod and have a cross-sectional shape that changes to create an 'IQ E' (lz- The purpose is to make the natural frequencies of the pawl vibrations different and to minimize the propagation of vibrations at the bottom end.

Figure 4 (a) shows the height including +7J in the middle of the height, which can be easily formed by swinging the wire no to the left and right during processing. , Fig. 4(b) to (e)
is a part of a rectangular persimmon whose cross section has been narrowed down.
During machining, tilt the wire saw (cutting direction), or grind to change the thickness of the plate with one side of the grid cut, and then stack the plates to create a wire cutting line, or It is made by aligning and gluing the rods cut into rectangular parallelepipeds again and grinding each side one by one (the same process as the ankle weight of a watch).

FIG. 4(f) is an example in which a hole is formed on the side surface to change the cross section. In addition, in these profile processing, when the side length of the crystal frame is, for example, 2 μm or less, a large number of pieces are simultaneously cut out from the crystal wafer by etching, the scales and the electrode film are completed, and then the pieces are separated from the wafer by being folded. It is highly likely that the phenomenon is similar to that of the current crystal thin tuning fork vibrating piece. The cross-sectional change may be provided not only on a pair of opposing side surfaces but also on all four side surfaces. The natural frequency of the vibrator in this mode is approximately a few megahertz. Also, since the vibrations are balanced in each cross section like a DT plate, there is no need to adjust the shape to a complicated shape like a tuning fork.

As is clear from the above, the present invention makes it possible to construct a vibrator with a simple shape and easy support, making it suitable for mass production at low manufacturing costs, and with a moderately high frequency and excellent temperature characteristics. There is an effect that can be obtained. Of course, the 1t6 cutting angle, the detailed shape of the rod-shaped vibrator, the arrangement structure of the electrode film, and the shape of the supporting brim container are not limited to those shown in the drawings.

[Brief explanation of the drawing]

Fig. 1 is an illustration of the first embodiment of the present invention, Fig. 2 is an explanatory drawing showing an example of the cutting direction of the crystal plate, and Fig. 3 is an old drawing showing an outline of the processing method of the crystal frame. , each figure in FIG. 4 shows the profile of the crystal frame in each other embodiment of the present invention.
It is a front view. 1. Crystal frame, 2.3. Excitation electrode.

Claims (1)

[Claims] One end of a rod made of a crystal material is fixed, a surface electrode is arranged so that the free end surface of the rod makes a circular sliding vibration, and the amplitude decreases toward the fixed end. crystal oscillator.