JP2592280B2 - Vertical crystal oscillator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a vertical quartz crystal resonator covering about 1 MHz and a middle frequency band. In particular, it relates to the vibrator shape.

[Summary of the Invention]

An object of the present invention is to provide a vertical quartz crystal resonator having very little vibration leakage and having excellent impact resistance. Quartz is a physically and chemically very stable substance. Therefore, a so-called crystal resonator formed therefrom can obtain a resonator having a small loss resistance and a high Q value. However, such excellent characteristics can be obtained only when the shape of the vibrator with small vibration leakage is designed. In the present invention, the energy of the vibrating part can be taken into the vibrating part by devising and improving the shape of the supporting part of the vertical crystal resonator in which the vibrating part and the supporting part are integrally formed by the etching method, and And impact resistance can be improved. That is, an object of the present invention is to obtain a vertical quartz crystal resonator having small vibration leakage and excellent impact resistance.

[Conventional technology]

The conventional vertical quartz crystal unit in which the vibrating part and the supporting part are integrally formed by the etching method has a uniform width of the supporting part frame,
In addition, since they are formed in the same direction and their ends are mounted, the energy of the vibrating part is transmitted to the mounting part, which causes vibration leakage. Therefore, it was not possible to obtain a small longitudinal quartz crystal resonator loss resistance R _1. In addition, since the vibrating portion does not have a degree of freedom with respect to impact, a large impact is directly applied to the vibrating portion, causing problems such as breakage.

[Problems to be solved by the invention]

Therefore, there are drawbacks such as have been associated with such increasing the amplification factor of the amplifier increases the consumption current with the rise of the loss resistance R _1, when placed in the device when severe,
There has been a large problem that vibration leakage is large and oscillation stops. Therefore, the present invention proposes a vertical crystal resonator having a very small vibration leakage. That is, it provides a very small shape of vibration leakage. On the other hand, with respect to impact resistance, the present invention provides a shape that avoids stress concentration on the vibrator due to impact.

[Means for solving the problem]

FIG. 1 is a simplified diagram for explaining the principle of the vertical quartz crystal resonator of the present invention. The vibrator 1 includes a vibrating part 2 and a supporting part 3
It can be considered that the support portion 3 is fixed under the condition that one end is fixed and the other end is supported. The vibrating part 2 is represented by a length L ₁ , a width W ₁ , and a thickness T, and the support part 3 is represented by a length L ₂ , a width W ₂
When the vibrating part 2 of the vibrator 1 undergoes elongation displacement as shown by the arrow A, the support part 3 naturally generates a bending mode inward as shown by the arrow B. Here, a portion where the bending mode occurs is indicated by a bent portion 5. Conversely, vibrating part 2
When the bending is reduced, the bending portion 5 of the supporting portion 3 generates a bending mode outward. That is, in the present invention, the displacement of the vibration section 2 in the width direction is converted into the bending mode of the support section 3 so that the degree of freedom of the vibration is not suppressed. Actually, there is a dimension that does not suppress vibration. The shape and size are determined by the strain energy of the vibrating part 2. That is, the distortion energy of the vibrating part 2 is U ₁ , and the distortion energy of the bending part is U
₂ to the U _1, U ₂ is expressed by the following equation.

Where stress T ₂ , strain S ₂ , Young's modulus E, second moment of area
I, displacement v, volumes V ₁ , V ₂ , and coordinates x are shown. In addition, the relationship that does not suppress the vibration of the vertical quartz-crystal vibrator satisfies the following relationship from Expressions (1) and (2).

U ₁ > U ₂ (3) Accordingly, the dimensions L ₂ and W ₂ of the bent portion 5 are determined. For example, when the frequency of the vibration part of the present invention is ₁ MHz, the length L ₁ = 2.6 mm, W ₁ = 80 μm, and T = 160 μm, the dimensional ratio W ₂ / L ₂ of the bent part of the support part is It may be 0.16 μm or less. By determining the dimensions in this way, it is possible to obtain a vertical quartz crystal resonator having a small loss resistance and a high Q value.
Next, vibration leakage will be described. As can be seen from the simplified diagram of FIG. 1, the vibration energy of the vibration part 2 is transmitted to the support part 3 via the bridge part 4. Therefore, the support 3
It is sufficient to reduce the energy loss in the support part 3
Is converted into a bending mode, so that if the mass of the fixed portion at one end, that is, the fixed portion is infinitely large, the energy of the support portion 3 will not leak.
Similarly, energy leakage can be eliminated by making the support portion 3 having the condition of supporting the other end free. In other words, the present invention relates to the support portion 3 transmitted from the vibrating portion 2.
Shape, ie, the ratio of width W to length L
By selecting W / L, the vibration of the vibrating part is free,
In addition, the object of the present invention is achieved by increasing the mass of the portion connected to the portion that bends and making it free.

[Action]

As described above, by improving the shape and size of the supporting portion of the vertical quartz-crystal vibrator formed by the etching method, which is configured by the vibrating portion and the supporting portion of the present invention, a small Q value and a low loss resistance A vertical crystal resonator having the same can be obtained. At the same time, by analyzing the vibration mode of the support portion, a vertical quartz crystal resonator having small vibration leakage can be obtained.

〔Example〕

Next, the results obtained by the present invention will be specifically described. FIG. 2 shows an embodiment of a vertical quartz-crystal vibrator according to the present invention. A vibrator 1 is composed of a vibrating part 2 and a support part 3, and is integrally formed by an etching method.

The vibration unit 2 is driven by an external electric field (not shown).
At the same time, a longitudinal expansion and contraction movement is performed, and at the same time, a similar vibration is made in the vertical direction, that is, in the direction of the bridge portion 4. At this time, first, in order to freely excite the vibration in the longitudinal direction of the vibrating portion 2, it is important that the vibration in the direction of the bridge portion 4 be sufficiently free. 5. According to the ratio of the length L to the width W, that is, when the frequency is 1 MHz, if W / L is 0.16 or less, suppression of longitudinal vibration can be prevented. Next, vibration leakage will be described. The vibrator moves from the vibrating part 2 to the bridge part 4
Is formed integrally with the bent portion 5 by an etching method, and its end is connected to the frame 6. At this time, the bending portion 5 vibrates in the bending mode, but one end is connected to the frame 6 and the other end has a structure capable of freely vibrating so as to surround the vibrating portion 2, that is, one end is fixed and the other end is supported. It vibrates with the boundary condition. Therefore, if the mass of the frame 6 is increased, energy can be confined at the tip of the support portion 3, so that a vertical quartz-crystal vibrator with no vibration leakage can be obtained even if the frame 6 is fixed.
Next, the impact resistance will be described. In the embodiment of FIG. 2, the thickness in the direction perpendicular to the paper is as thick as about 160 μm, so that it is strong against impact. Rather, with respect to an impact in a direction parallel to the paper surface, stress concentrates on the connection portion 9 and causes a break. Therefore, the present invention provides a supporting portion shape in which stress concentration does not occur in the connecting portion 9. By providing the supporting portion 3 with the protruding portion 8, it is possible to reduce the tip amplitude of the bent portion at the time of impact. it can. As a result, stress concentration at the connection portion 9 is reduced, and the connection portion 9 is not broken.

〔The invention's effect〕

As described above, the present invention relates to a vertical quartz crystal resonator in which a vibrating portion and a supporting portion are integrally formed by an etching method.
By proposing a new vertical quartz crystal resonator, the following remarkable effects can be obtained.

By improving the shape and dimensions of the support portion, vibration can be made free, so that loss resistance is reduced.

By providing the protruding portion on the support portion, impact resistance can be improved.

The bent portion is connected to the frame in the direction opposite to the mount portion, and since the frame has a mass effect, vibration leakage is reduced.

Since the mounting is performed on one side, the manufacturing is easy and the size can be reduced.

[Brief description of the drawings]

FIG. 1 is a simplified plan view for explaining the principle of the vertical quartz crystal resonator of the present invention. FIG. 2 is a plan view showing an embodiment of the shape and dimensions of the vertical quartz crystal resonator of the present invention. DESCRIPTION OF SYMBOLS 1 ... Vibrator 2 ... Vibration part 3 ... Support part 4 ... Bridge part 5 ... Bend part 6 ... Frame 7 ... Mount part 8 ... Protrusion part 9 ... Connection part L ... Bend part Length W: Width of bent part

Claims (1)

(57) [Claims] 1. A vibrating portion that extends and contracts in a longitudinal direction, a pair of bridge portions connected to a central portion of the vibrating portion at one end in opposite directions, and connected to the other end of each of the bridge portions. A bent portion formed so as to surround the vibrating portion, a frame connected at a part of the outer periphery of the bent portion in a direction perpendicular to the length direction of the vibrating portion, at both ends and ends of the frame. A pair of support portions connected to and formed in parallel with the vibration portion, and a mount portion connected to the other end of each of the support portions, wherein the vibration portion, the bridge portion, the bending portion, In a vertical quartz crystal unit in which the frame, the support portion, and the mount portion are integrally formed by an etching method, each of the support portions is provided with a protruding portion in the vicinity of the bent portion. Features Vertical quartz oscillator for.