JPS5935209B2 - Crystal oscillator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a crystal resonator, particularly a small crystal resonator for watches, which is hermetically sealed by cold welding. The purpose is to provide a vibrator with reduced

Furthermore, due to the above-mentioned reason, it is possible to downsize the vibrator. Conventionally, crystal resonators with special consideration given to aging characteristics have an airtight sealing structure using cold welding.

However, as shown in the plan view of FIG. 1A and the cross-sectional view of FIG.
a-1, lb-1, the material of the cold welding part 2 is pushed away, and a large amount of material flows toward the inside of the sealing body, causing bulges in the flat parts 1a-2, Ib-2, etc. of the sealing body. Because deformation and stress generated around the airtight terminal 4 that keeps the electrical lead terminal 3 insulated and airtight may cause cracking of the airtight terminal or peeling of the adhesive part of the airtight terminal, a compressive force is applied to the airtight terminal as shown in the figure. , it is necessary to take measures such as increasing the distance L between the airtight terminal and the sealing body parts 1a-3 and lb-3 (hereinafter referred to as the sealing body side surface) connected to the flange, and due to structural limitations and This was an impediment to miniaturization. The present invention provides a small crystal oscillator that eliminates such difficult curves.

Embodiments of the present invention will be described below with reference to the drawings. The tuning fork type crystal resonator of the flat package according to the present invention shown in the plan view of FIG. 2A and the sectional view of FIG. As shown in the figure, the compressive deformation of the cold welding portion 6 is maximized on the inside of the sealing body and decreases toward the outside of the sealing body as shown in the figure, thereby increasing the amount of material displaced by cold welding. is allowed to flow toward the sealing body side, thereby suppressing the flow to the inside of the sealing body.

Furthermore, by making the side surfaces 5a-2 and 5b-2 of the sealing body thinner by machining the sealing body side surfaces 5a-2 and 5b-2, the strain caused by the material flowing into the sealing body is absorbed by the side surfaces of the sealing body, and the flat surface portion 5a-2 of the sealing body is absorbed by the side surfaces of the sealing body. 3 and 5b-3 is almost eliminated, and the stress applied to the bonded portion 1a between the sealing body flat portion 5a-3 and the airtight terminal T is significantly reduced. After cold welding,
The outer circumferences of the flanges 5a-1 and 5b-1 are cut off (
The same procedure will be applied to other embodiments below). Third
FIG. 4 is a partially enlarged view of the embodiment of FIG. 2B. Figure 3 is a diagram of the action during cold welding of the flange, showing how welding starts from the inside of the sealing body and gradually moves outward.The arrows in the diagram indicate the compression. It is shown that the material in the cold welding part flows outward due to the shear H applied to the material in the direction toward the outside of the sealing body. Note that the two-dot chain line 8 indicates a press die for cold welding, and the cold welding portion 6 is compressed by the composite force N of the force H and the vertical compression force v by the inclined portion of the press die 8. FIG. 4 is an enlarged view of the sealing body side parts 5a-2 and 5b-2, where M is a bending moment applied near the intersection with the sealing body flat parts 5a-3 and 5b-3, and the sealing is performed by cold welding. If the amount of material flowing into the body is constant, approximately MOct3(t;
thickness of the side surface of the sealing body), and the side surface of the sealing body 5a-2, 5b
-2 by reducing the thickness of the sealing rest surface portion 5a-3,
The deformation of 5b-3 is greatly reduced. However, Figure 3,
The effects shown in FIG.
Since the deformation of 5b-3 is completely negligible, a structure is adopted in which shearing force is applied to the adhesive part 7 of the hermetic terminal 6 as shown in FIG. The present invention greatly contributes to miniaturization while increasing the degree of freedom in structural design, such as by being able to shorten the distance. FIG. 5 is a sectional view of a main part near the side surface of the sealing body of a crystal resonator in a flat package according to another embodiment of the present invention, and FIG. -1, 9b-1 is partially thinned, a Kovar plate 10 is bonded to the mounting part 9c of the copper sealing body 9a, an airtight terminal 11 is bonded on the Kovar plate 10, and the area around the airtight terminal 11 is strengthened. The safety against deformation is further increased.

FIG. 6 is a cross-sectional view of a main part of a crystal resonator showing still another embodiment of the present invention, which has a structure in which the airtight terminal 12 is closer to the side surface 13 of the sealing body than the crystal resonator shown in FIG. It's getting better. Further, the present invention is also effective when applied to a multi-cavity cold welding method. The multi-crystal welding method referred to here is a method in which cold welding is performed on a large number of molds at the same time, and as shown in FIG. This method involves completing all processes up to just before welding, such as trimming, and then stacking the other sealed body and performing cold welding to complete the crystal resonator, which is then separated into individual pieces. Since there is a plate connecting the sealing bodies, in the conventional technology, the amount of material flowing into the sealing body is larger than when cold welding is performed individually, and therefore the flat surface of the sealing body is more likely to be deformed. The number of problems will increase and become a serious problem. With the structure according to the present invention as described above, as is clear from the explanations in FIGS. 2A, 2B, 3 and 4, almost the same effect as when cold welding is performed individually can be obtained. . The present invention has been described above with respect to a rectangular flat package crystal resonator.
Naturally, the present invention can also be applied to other crystal resonators vacuum-sealed by cold welding.

[Brief explanation of the drawing]

Figure 1A is a plan view of a conventional crystal resonator, and Figure 1B is a top view of a conventional crystal resonator.
2A is a plan view of the crystal resonator of the present invention, FIG. 2B is a sectional view of FIG. 2A, FIG. 3 is a partially enlarged sectional view of FIG. The figure is a partially enlarged sectional view of FIG. 2B, FIG. 5 is a sectional view of a main part of a crystal resonator showing another embodiment of the present invention, and FIG. 6 is a crystal oscillator showing still another embodiment of the present invention. FIG. 7 is a sectional view of the main parts of the crystal resonator, and FIG. 7 is a perspective view of the crystal unit being manufactured by a multi-piece manufacturing method suitable for the crystal resonator of the present invention. 1a, 1b, 5a, 5b, 9a, 9b... sealed body, 1a-1, 1b-1, 5a-1, 5b-1...
...Flange, 4, 7, 11, 12...Airtight terminal.

Claims (1)

[Scope of Claims] 1. A sealed body to which an airtight terminal is added, the flanges of the sealed body are joined by cold welding, and a crystal piece is vacuum-sealed in a crystal resonator. Alternatively, a crystal resonator characterized in that at least a part of the sealing body part connected to the flange is made thinner than the thickness around the airtight terminal. 2 In a crystal resonator formed by a sealed body to which an airtight terminal is added, the flanges of the sealed body are joined by cold welding, and a crystal piece is vacuum-sealed, the cold welded portion is placed near the inner side of the sealed body. 2. The crystal resonator according to claim 1, further comprising an inclined portion that maximizes the compressive deformation rate.