JPS58225715A - Thickness sliding crystal oscillator - Google Patents

Abstract

PURPOSE:To obtain a thickness sliding crystal oscillator which has electrically and mechanically excellent characteristics and superior productivity, by forming projection parts from the axial end parts of electrodes for fixation toward the center parts of plate surfaces. CONSTITUTION:An oscillator 11 is obtained by forming an AT-cut crystal blank piece rectangularly so that the lengthwise direction coincides with an X axis and the breadthwise direction coincides with a Z' axis, and then polished with abrasives so that the outward surface is curved. Then, the main electrodes 12 are provided at the center parts of both side plate surfaces and the electrodes 13 for fixation are provided at the lengthwise end parts. The main electrodes 12 have connection parts 12a extending from the breadthwise side parts to the lengthwise end parts, and the connection parts 12a and electrodes 13 for fixation are made conductive through an adhesive. The electrodes 13 for fixation are formed at the corners of the plate surfaces and have projection parts 13a projecting toward the center parts of the plate surfaces.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thickness-slip crystal oscillator, and particularly relates to an improved VC holding structure and electrode shape. It becomes a neutral point that does not occur. Therefore, even if this lower end is directly attached to the base, the vibration characteristics are hardly impaired.

On the other hand, in a thickness-slip crystal resonator, the displacement during vibration extends to the peripheral edge, so if it is held too tightly even at the peripheral edge, the vibration characteristics will be seriously impaired. In the conventional holding structure for a thickness-sliding crystal resonator, a highly elastic pin is implanted in the base, and the tip of this pin is formed into a clip shape to hold the crystal piece on both sides, and conductive adhesive is used to hold the crystal piece. It is used in conjunction with the agent to hold the sea urchin peel. Therefore, the tip of the pin [the process of forming it into a predetermined shape? However, the strength of the conductive adhesive has problems with vibration resistance and impact resistance.For this reason, even in thickness-sliding crystal resonators, tuning fork-shaped crystal vibrators are difficult to use. As with the child, it is desirable to attach it directly to the tip of the holding rod installed in the base, etc. with a downward arrow. However, in this soldering process, the characteristics of the attached thickness-slip crystal resonator vary widely, making it impossible to put it to practical use.

That is, the electrodes of this type of crystal resonator are formed by attaching silver, gold, and other metals to the surface of a crystal piece by means of vapor deposition. - Power solder generally melts after cocooning at 240°C, but the tin that is present in the solder easily spreads to the surface of the metal electrode at temperatures as low as 85°C. When a component such as solder spreads on the surface of the electrode in this way, the CI (crystal impedance) value changes appropriately by controlling the extent of this spread. In other words, the crystal oscillator is attached to the support rod.[The characteristics of the crystal oscillator will depend on the conditions in which the solder spreads when soldering.

Therefore, as shown in the front and side views of Figures Jg1 (a) and (b), thickness shear vibration [excitation Turuo w
11 poles are provided, a fixing electrode 1b is provided at the longitudinal end, and a pair of supports are installed in the base 2 as shown in the front view shown in FIGS. 2(a) and 2(b), and as shown in the top view 1 The tip of the rod 3 is held by attaching it to the fixed electrode Jb, and a conductive adhesive 4 is applied between the fixed electrode 1b and the main electrode 1a.
It is considered that the material is coated with a coating to make it electrically conductive.

With this construction, the main electrode 1a can be led out through the conductive adhesive 4, the fixing electrode 1b, the solder 5 soldered thereto, and the support rod 3. In addition, since the vibrator 1t is held by soldering to the support rod 3, sufficient mechanical and electrical performance can be obtained. In addition, since the Eri vibrator 1r can be held at any end, workability is also good. Bevel processing on a tapered surface, barrel processing that rotates or vibrates with an abrasive material, etc.? There is something that can be done0.In this way, if the thickness of the end part of the vibrator is formed to be thinner than the center part, the vibration distribution of the vibration due to the thickness can be concentrated in the center part of the plate surface0. The effect of confining vibration energy is to suppress parasitic vibrations in the longitudinal direction and hold them at the ends of the longitudinal direction, resulting in a decrease in resonance sharpness? It can be prevented. However, in this ↓ vibrator, it has become clear that the shape and position of the fixed electrode have a significant influence on the vibration characteristics.The present invention was made in view of the above circumstances, and the A main electrode is provided in the center, a fixed electrode is provided at the end, a support rod T is soldered to this fixed electrode, and held between the main electrode and the fixed electrode. What electrode shape can provide good electrical and mechanical properties when electrically connected with conductive adhesive and processed to have the edges thinner than the center? [Providing thickness-slip crystal oscillator] This is the purpose.

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 3 and 4. In other words, the inventors particularly determined the position and shape of the fixed electrode, and the C of the support rod t and the soldering end.
Measurements were made regarding changes in I value. As a result, for example, in an AT cant thickness-shear crystal resonator, the a-th factor (a
).

It was confirmed that there were changes as shown in (b).

In other words, Fig. 3(a) is a graph showing the relationship between the longitudinal position of the crystal oscillator of the fixing electrode and the CI value, and Fig. 3(b) is a graph showing the relationship between the widthwise position of the fixing electrode and the Cl value. This is a graph showing the relationship with the value. That is, as is clear from this result, the closer the longitudinal position of the fixing electrode is to the end, the smaller the change in CI value is, and the closer it gets to the center, the more the amount of change in CI value increases exponentially. In addition, the position of the fixed electrode in the width direction, for example in the 2' axis direction in AT cut, the closer to the end, the less the change in CI value will be, and as it gets closer to the center
The amount of change in the I value increases.

Therefore, it is generally desirable to provide the fixing electrode t at the end corner of the vibrator.

Therefore, the inventors investigated the relationship between the shape and vibration characteristics of fixed electrodes [provided at the corners of the vibrator plate surface]. The best characteristics were obtained when the fixing electrode was provided on the protrusion that protruded toward the center, as shown in the front and side views.

That is, in Figures 4(a) and (b), 11 is A
This is a vibrator made by forming a T-cut piece of crystal wood into a rectangular shape with the longitudinal direction being the X axis and the width direction being the 2' axis, and then polished with an abrasive to form a curved surface. 12 is a main electrode provided at the center of both side plate surfaces, 13 is a fixed electrode provided at the end in the longitudinal direction, and 0 is a main electrode 12.
The fixing electrodes 13 are formed symmetrically with respect to the center of the plate surface, and 12 fixing electrodes λt are provided at each end of the vibrator 11 to hold any end portion regardless of the direction. thing? Note that the main electrode 12 extends from the side in the width direction to the end in the longitudinal direction at a connecting portion 12hk, and between this connecting portion 1271 and the fixing electrode 13? The connection is made using conductive adhesive. Further, the fixed electrodes 131 are formed at the corners of the cutting board surface, and the protruding portions 13a extend toward the center of the board surface. is forming. If the protrusion 13a is provided in this structure, better characteristics can be obtained than in the case where the protrusion 13a is not provided.Also, as shown in FIG. 'f When soldering, there is a gap between the curved surface of the i part of the vibrator 1 and the support rod 14.
If they invade and hold together, then both over a large area? Note that the support rod 14 is held on a base (not shown), etc., and a conductive adhesive is applied between the main electrode IJj'f, the connection portion 12 & and the fixing electrode 13 at a distance of Vcm. Of course, the vibrator 11 can be led out to the outside through the support rod 14. Alternatively, the vibrator 11 may be housed in a container (not shown) and hermetically sealed with an inert gas or the like.

With a configuration like this ↓, even if you solder the support rod 1411 to the fixing electrode 13 during assembly, this fixing electrode 13 (
C. Solder does not spread to the main electrodes 12 that are spaced apart from each other by a predetermined distance. And this soldering! Since the solder particles adhering to the vibration characteristics are spread only to the fixing electrodes 130 at the corners of the plate surface of the vibrator 1), which have relatively little influence on the vibration characteristics, there is almost no variation in characteristics. Furthermore, if you attach the fixing electrode 13 and support rod 14, t
It can be mechanically and electrically firmly joined, and the protrusion 13hk is provided on the fixed electrode 13 to increase the area of the fixed electrode 130 with a concave area that does not adversely affect the characteristics, and it also has good vibration resistance and impact resistance. Good, long-term, stable performance can be obtained.

As described in detail above, the present invention provides an AT-cut rectangular vibrator in which a main electrode is provided at the center of the front and back plates, a fixing electrode is provided at the end corner, and a support rod is attached to the fixing electrode. Is there a soldering between the main electrode and the fixed electrode? In those that are connected using conductive adhesive, a protrusion is formed from the widthwise end of the fixing electrode toward the center of the plate surface. Good characteristics? Thickness-slip crystal resonator with excellent productivity?
can be provided.

[Brief explanation of the drawing]

1s1 Figures (a) and (b) show the oscillator r according to the principle of the present invention.
Figure 2 (a) and (b) are the front view and plan view showing the assembled state of the vibrator shown in Figure 81, and Figure 3 (a) and (b) i. Graph showing the Europeanization of the position of the fixing electrode and the CI value, Figure 4 (a), (
b), (0) 1 is a front view showing a vibrator 1 according to an embodiment of the present invention, and a side view is a diagram showing a machining attachment state LI. Ω1... vibrator, 12... main electrode , 13... Fixing electrode, 14... Support rod, 16... Solder. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 21J(a) (b)
(a) (b) Figure 3 (a) (b) Toy direction-X
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":"IkoFigure 4 (a) (b) (C) -70=

Claims (1)

[Scope of Claims] In an AT-cut rectangular vibrator with the vertical direction lx axis and the width direction tz' axis, a main electrode is formed at the center of the front and back plate surfaces of the vibrator, and a main electrode is formed on the front and back plate surfaces of the vibrator. Fixed electrodes formed at the corners of the ends and soldered to the fixed electrodes of the above vibrator? A support rod that holds the main electrode and leads out the main electrode via a conductive adhesive attached between the main electrode and the fixed electrode, and a direction from the widthwise end of the fixed electrode to the center of the plate surface. A protrusion that extends to [a thickness-sliding crystal oscillator].