JPS6346604B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a compositely made crystal tuning fork.

Conventionally, a tuning fork made in a composite manner is known, and this is assembled by laminating a thin plate-like crystal vibrating leg 1 to a bonding body 2, as shown in FIG.

The disadvantage of the conventional method is that there is a thick coupling plate between the two vibrating legs, making it impossible to make it smaller and thinner.

Because each member is pasted with adhesive, the effective leg length is unstable due to assembly errors, resulting in large frequency variations.

Because the adhesive, which is unsuitable as a material for a vibrator, is present in the part of the leg where the vibrational distortion is large (the base of the leg on the combined body side), the frequency stability is poor (a sufficiently high Q value cannot be obtained, Or the fluctuations due to long-term aging of the frequency become large.)

Conventionally, as shown in Figure 2, in order to improve the temperature characteristics specific to a quartz crystal tuning fork, the vibrating legs are formed into a Y-shape, and each leg is cut at a different angle with respect to the crystal axis. Attempts have been made to obtain the average properties expected from the cutting angle of each leg when vibrated. However, although the vibrating legs of a quartz crystal tuning fork should originally be parallel to each other, the Y-shape had a large unbalance of vibration, and did not function well as a tuning fork.

The present invention eliminates each of the disadvantages of the conventional examples and combines the advantages thereof. Furthermore, the present invention has excellent impact resistance and can be manufactured in a small size. Therefore, the present invention is a crystal tuning fork vibrator that is particularly suitable as a crystal resonator for wristwatches. The purpose is to have a child.

Embodiments of the present invention will be described below based on the drawings.

FIG. 3 shows the components of an embodiment of the present invention, in which 10 is a vibrating leg, and 11 is a base, both of which are cut into a substantially L-shape from a single crystal plate by etching or the like. θ ₂ is the cutting angle with respect to the crystal axis. FIG. 4 similarly shows other component elements, in which the vibrating leg 12 and the base 13 are cut out in an inverted L shape. By making the cutting angle θ ₁ different from θ ₂ , the temperature characteristics of both legs can be made different based on the same concept as the conventional example shown in FIG. FIG. 5 is a diagram showing the completed assembly of the embodiment of the present invention, in which the above-mentioned two elements are joined together by adhesive parts 14 and 15 provided on the opposing surfaces of each base so that the legs do not overlap. Indicates the condition. The adhesive parts 14 and 15 are joined by forming a metal part and a solder layer on the base part 11 and the base part 13 by vapor deposition or the like on a part of the base part that is, for example, 1/2 or more of the area of the base part, and then bonding them by heating or by applying an adhesive or the like. It is made strong and stable by adhering it.

A feature of this structure is that the bending stress of the legs is dispersed without stress concentration at the base. Naturally, excitation electrodes are provided on each leg, and these terminals are collected on the surface of one element through conductive paste or solder used for joining, and are connected to an external circuit through the support system of the tuning fork. Although this point is not particularly shown in the drawings, it can be implemented within the scope of the prior art. FIG. 6 is a diagram showing a crystal wafer for manufacturing the crystal tuning fork of the present invention in multiple pieces, and 16 and 17 are wafer frames in which each element shown in FIG. 3 or 4 is placed, respectively. A large number of them are aligned and formed integrally by etching. Next, an excitation electrode (not shown) and adhesive parts 14, 15 are simultaneously formed with each element connected. Each wafer is positioned and stacked, all bonded parts are bonded simultaneously, and each tuning fork is then separated to obtain the finished tuning fork shown in FIG. 5 in a mass-produced manner.

To summarize the various effects obtained by the present invention, since there are no slits that cause stress concentration, the vibrating legs are less likely to break and have excellent impact resistance.

If each element is formed by etching, the shape accuracy will be good and there will be less variation in frequency.

The frequency is stable because the adhesive is used only at the base and has little to do with vibration.

The base is simply overlapped and bonded, and there are no other connecting members, and the volume and thickness are sufficiently small, making it suitable for use as a small vibrator for a wristwatch.

Since the temperature characteristics of each leg can be freely selected, the composite temperature characteristics can be improved.

Suitable for mass production with multiple pieces.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a conventional composite type crystal tuning fork, Fig. 2 is a plan view of another conventional crystal tuning fork and an explanatory diagram of the cutting angle, and Figs. 3 and 4 are examples of the present invention. FIG. 5 is an assembled plan view showing an embodiment of the present invention, and FIG. 6 is a diagram showing a case where wafers are processed using a multi-piece method for crystal tuning forks. FIG. 3 is a partial plan view of a crystal wafer. 10, 12... vibrating leg, 11, 13... base,
14, 15...Joint part.

Claims (1)

[Scope of Claims] 1. One vibrating leg and base are formed by a thin crystal plate into a substantially L-shape, and a plurality of the thin crystal plates are formed so that the directions of the L-shape are opposite to each other, and When viewed from a direction perpendicular to A laminated crystal tuning fork vibrator characterized in that it has a substantially planar shape of a tuning fork when viewed from the same direction. 2. A laminated crystal tuning fork vibrator according to claim 1, wherein the plurality of crystal thin plates are cut out at different angles with respect to the crystal axis.