JPH0831767B2 - Contour-slip crystal unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] First, the background of the present invention will be described. In the field of consumer equipment and communication equipment, miniaturization and high precision are being actively promoted. The crystal unit used for is also miniaturized, especially the surface mount type crystal unit has a frequency of 1.5M
It has been required at Hz to 4.2MHz. The present invention has been made in view of this. That is, the crystal unit of the present invention is a crystal unit used as a reference signal source for various devices such as consumer devices and communication devices. The vibrating section and the supporting section are formed by an etching method, and the contour is suitable for the surface mounting type. Related to slip crystal oscillators.

[Outline of Invention]

The present invention proposes a new shape and size of the supporting part and the vibrating part of the contour slip quartz crystal resonator in which the vibrating part and the supporting part are integrally formed by an etching method. Specifically, the contour sliding vibration of the vibrating part is proposed. Accordingly, the supporting portion (bending portion) exhibiting bending vibration is given a dimensional condition that does not suppress the contour sliding vibration, and good electrical characteristics are obtained.

Further, the direction connecting the support portions at both ends of the vibrating portion is the Z'direction of the crystal axis of the crystal, and the support portions are supported by the ceramic pedestal having a value close to the linear expansion coefficient in the axial direction. . All plane shapes are symmetrical with respect to the center line connecting the supporting portions.

Furthermore, because it is molded by etching and the above-mentioned support structure, sufficient performance can be obtained even if it is extremely small, and the resonance frequency of contour slip can be as high as 1.5 to 4.2 MHz, and the corresponding vibration part The shape is square,
The size of each side is 0.72 to 2.02 mm. With such a structure, a crystal resonator of a contour slip mode having a small loss resistance, an excellent impact resistance and an excellent temperature characteristic was obtained.

[Conventional technology]

A conventional contour-slip crystal oscillator is formed by machining, and the oscillator is usually supported by two thin lead wires at the center of a square plate. Therefore, it is difficult to miniaturize, it is weak against impact, there are many vibration leaks due to the supporting point, the loss resistance R ₁ is small, and a contour sliding crystal unit with a high Q value cannot be obtained. was there.
In addition, the conventional contour-slip crystal oscillator manufactured by machining has a size that can be mass-produced in view of the oscillator supporting method described above. .

[Problems to be Solved by the Invention]

The present invention addresses the above problem and applies a method of integrally forming a vibrating portion and a supporting portion of a crystal unit by an etching method. In this method, a GT cut quartz vibration in which two longitudinal vibration modes are combined is applied. An example for a child is disclosed (Japanese Patent Publication No. 58-47883, Japanese Patent Publication No. 53-132988, Japanese Patent Publication No. 61-44408), and US Patent (435091).
8,4447753,4484382,4633124) and the like, and is known to be suitable for the crystal oscillator type method. Therefore,
In the present invention, the conventionally well-known etching method is applied to the contour sliding mode crystal oscillator of the present invention to overcome the above-mentioned drawbacks caused by machining. or,
The shape of the contour slip quartz crystal oscillator of the present invention is similar to the oscillator shape of the above-mentioned patent, but its vibration mode is fundamentally different, and the idea of determining the oscillator shape / dimension is basically different. It is intended to solve the problem with a new shape and size.

[Means for solving the problem]

In order to solve the above-mentioned problems, the present invention is a contour slip quartz crystal oscillator in which a vibrating portion and a supporting portion are integrally formed by an etching method, and the bending portion of the supporting portion is connected at the center of the side of the vibrating portion. Since the width W of the bending portion connected to the vibrating portion is 0.67L with respect to the length L of the bending portion, the supporting portions are provided at both ends of the vibrating portion in the z'-axis direction, and the vibrating portion has a substantially square shape. The size of each side is 0.72 mm to 2.02 mm, and the problem is solved by supporting and fixing at both ends of the supporting portion.

[Action]

Quartz is a physically and chemically stable substance as a background of the present invention. Therefore, a so-called crystal oscillator formed from the crystal obtains an oscillator having a small loss resistance and a high Q value. be able to. However, the reason why such excellent characteristics are obtained is that it is obtained only when a vibrator shape design with small vibration leakage is made.
This is the viewpoint of the present invention.

〔Example〕

Prior to the embodiments, the principle of the present invention will be described.

FIG. 3 is a diagram modeling the oscillator for explaining the principle of the contour slip quartz crystal oscillator of the present invention. The oscillator 1 is composed of a vibrating part 2 and a supporting part 3, and the supporting part 3 is composed of at least a bending part 4 and a mount part 5, and the supporting part is considered to be fixed under the boundary condition of one end support. You can Further, when the vibrating portion 2 is represented by a length x ₀ , a width z ₀ , and a thickness y ₀ , and the bending portion 4 of the supporting portion 3 is represented by a length L and a width W, the electrodes 6, 6 When an electric field is applied to 7, the vibrating portion 2 of the vibrator 1 causes a displacement of the contour slip as shown by the broken line, and at that time, the bent portion 4 of the supporting portion 3 is also displaced as shown by the broken line. Needless to say, when the opposite electric field is applied to the vibrating portion 2, the expansion and contraction displacements occur in opposite directions. That is, in the present invention, the displacement of the contour of the vibrating portion 2 is changed to the supporting portion 3
By converting to the bending mode of, the degree of freedom of the vibration is not suppressed. And, in reality, there is a dimension that does not suppress vibration. The shape and size are determined by the strain energy of the bending portion 4 of the vibrating portion 2 and the supporting portion 3.
That is, if the strain energy of the vibrating portion 2 is U ₁ and the strain energy of the bending portion is U ₂ , then U ₁ and U ₂ are expressed by the following equations.

However, stress T ₅ , strain S ₅ , Young's modulus E, moment of inertia of area I, displacement u, volumes V ₁ , V ₂ , and coordinates Z are shown.

Further, the relationship that does not suppress the vibration of the contour slip quartz crystal resonator is as follows from the equations (1) and (2).

U ₁ > U ₂ (3) From this, the dimensions L and W of the bent portion 4 are determined. For example, when the frequency f of the vibrator of the present invention is f = 1.84 MHz, the dimensions of the vibrating portion are length x ₀ = z ₀ = 1.65 mm, plate thickness y ₀ = 50 μm (however, plate thickness y ₀ has almost no effect on frequency. But not etch
y ₀ = 50 μm because of the workability of the ing process and the elimination of spurious vibration. At this time, if the width dimension W of the bent portion of the supporting portion is smaller than 0.67L, the vibration of the vibrating portion 2 is not suppressed, so that the loss resistance R ₁ ≈10
It was possible to obtain a contour-slip crystal oscillator having a small Q value of 0Ω and a Q value of about 150,000 and excellent electrical characteristics. The above example is for the case where the frequency is f = 1.84MHz, but when the frequency is f = 1.5MHz to 4.2MHz, the width dimension and length dimension (x ₀ = z ₀ ) of the vibrating part are formed to form a square. 2.02 mm to 0.72 on each side
The size is very small (mm), and the dimension including the supporting part is 5 mm or less. At the same time, a crystal unit strong against impact was obtained because it was mounted on ceramics or the like at both ends of the support. or,
The reason for providing the support portion of the contour-slip crystal oscillator of the present invention in the z′-axis direction is that the linear expansion coefficient of the ceramic pedestal and the linear expansion coefficient of the crystal oscillator are relatively close to each other, and the influence on the frequency with respect to temperature is affected. A crystal oscillator with a stable contour can be obtained, which can be made as small as possible. Further, the cut angle θ giving the zero temperature coefficient is obtained by rotating the Y plate about θ = 37 ° about the X axis.

Next, vibration leakage will be described. As can be seen in the description of the modeled diagram of FIG. 3, the vibration energy of the vibrating part 2 is transmitted to the support part 3. Therefore, it suffices to reduce the energy loss in the bent portion 4 of the supporting portion 3, and the mode of the supporting portion 3 is converted into the bending mode. Therefore, if the mass of the mounted portion of the supporting portion is infinitely large. , Support 3
The energy at the bent portion 4 of the will not leak. This does not hold in any case of the resonator resonance system,
It holds in the symmetry of vibration. In other words, the above can be said in the case of a resonance system in which resonance of the vibrator is easily caused and stable vibration is obtained. In the present invention, one resonance system is formed by the support portions that are connected at the center portions of the sides of the vibrating portion and that are symmetrically provided at both ends of the vibrating portion. This can cause a symmetric mode,
Vibration with stable frequency can be obtained. As described above, the present invention makes the vibration of the vibrating section free by selecting the shape that is converted from the vibrating section 2 into the bending mode of the support section 3, that is, the ratio of the width and the length of the bending section, and Increase the mass of the part that connects with the part that deforms in the bending mode,
Furthermore, by providing two support portions symmetrically at the center of the support piece of the vibrating portion, the freedom of the vibrating portion is ensured.

Next, the results obtained by the present invention will be specifically described. FIG. 1 is a plan view and a top view of an embodiment of a contour slip quartz crystal oscillator according to the present invention. The oscillator 1 is composed of a vibrating section 2 and a supporting section 3, and electrodes 6 and 6 are provided on the upper and lower surfaces of the oscillator 1. 7 are arranged and integrally formed by an etching method. The vibrating portion has sides 10, while the supporting portion has the bent portion 4, the second frame 9, the first frame 11, the third frame 12, and the hole 8.
And a mount portion 5. More specifically, the supporting portion 3 is provided with the bent portion 4, and when the width is W and the length is L, W is smaller than 0.67L. The reason for this is to enable free vibration without suppressing the vibration of the vibrating section 2. Further, a mount portion 5 is provided at the end of the bent portion 4 in order to reduce vibration leakage, and the mount portion 5 is fixed with solder, a conductive adhesive, or the like. At this time, since the supporting portion 3 is provided in the z'-axis direction, the linear expansion coefficient values of both are almost the same even when mounted on ceramics, and even if the temperature changes, stress does not act on the vibrator, and it is stable. The frequency characteristics are shown. Also, the bent portion 4
Are connected at the center of the side of the vibrating part 2 with a length x ₀ . It is possible to further reduce vibration leakage.

FIG. 2 is a plan view and a top view of another embodiment of the contour slip quartz crystal oscillator of the present invention. Electrodes 6 and 7 are provided on the upper and lower surfaces of the oscillator 1, and the oscillator 1 and the support 3 are provided. And is integrally formed by an etching method. The support portion 3 is provided with a bent portion 4 and a mount portion 5, and the width W and the length L thereof are set to W ≦ 0.67L. The reason for this is first
The reason is the same as that described in the illustrated embodiment. Further, a hole 8 is provided between the bent portion 4 and the mount portion 5 so that the vibration of the bent portion 4 is not further transmitted to the mount portion 5. As a result, a contour slip quartz crystal resonator having a small vibration leak even when mounted by the mount portion 5 and a small loss resistance R ₁ can be obtained. Further, the bent portion 4 is connected at the center of the side of the vibrating portion 2 with a length x ₀ . That is, since the left and right are symmetrically symmetrical with respect to the straight line connecting the centers of the mount parts 5 and 5, the vibration leakage can be further reduced. In addition, since the mount portions 5 of the support portion 3 provided at both ends of the square-shaped vibrating portion 2 are fixedly held at both ends by solder or conductive adhesive, stress dispersion is performed against impact and shock resistance A strong crystal oscillator can be obtained.

〔The invention's effect〕

As described above, the present invention has the following remarkable effects by proposing the contour-slip quartz crystal resonator in which the vibrating portion and the supporting portion are integrally formed by the etching method.

Since the vibration can be freely made by devising and improving the formation dimension of the support portion, a crystal resonator having a small loss resistance and a high Q value can be obtained.

Since the vibrating portion and the supporting portion are integrally formed by the etching method, the size can be reduced.

At the same time, since it is supported and fixed by the mount portion of the support portion, it has excellent impact resistance.

Since the support part is connected to the central part of the vibrating part side, vibration leakage is small and loss resistance R ₁ is small.

Since it is fixed to a pedestal such as ceramics by a mount that does not affect vibration, vibration leakage is reduced.

Since the vibrator has a small thickness and is supported and fixed at both ends, a thin surface mount type crystal unit is possible.

[Brief description of drawings]

FIG. 1 is a plan view and a top view of an embodiment of the shape of a contour slip quartz crystal oscillator of the present invention. FIG. 2 is a plan view and a top view of another embodiment of the shape of the contour slip quartz crystal resonator of the present invention. FIG. 3 is a model diagram for explaining the principle of the contour slip quartz crystal resonator of the present invention. 1 ... Transducer, 2 ... Vibrating part 3 ... Supporting part, 4 ... Bending part 5 ... Mounting part, 6,7 ... Electrode 8 ... Hole, L ... Bending part length W ... Width of bending part, x ₀ ...... Width of vibrating part z ₀ ...... Length of vibrating part, y ₀ …… Thickness of vibrator x …… Electrical axis y ′ …… Mechanical axis after coordinate rotation z ′ …… Optical axis after coordinate rotation 9 ... 2nd frame 11 ... 1st frame 12 ... 3rd frame

Claims (1)

[Claims] 1. Electrodes are arranged on the upper and lower surfaces of a vibrator including a vibrating part and a pair of supporting parts, the vibrator is integrally formed by an etching method, and the supporting part includes a bending part 4, a first frame 11, A pair of second frame 9, third frame 12, hole 8
The first frame, the second frame, and the third frame constitute a hole 8, and one end of the bent portion 4 is attached to the vibrating portion 2 at a substantially central portion of the side length of the vibrating portion 2. The other end of the bent portion 4 is connected to the first frame 11, both ends of the first frame are connected to one end of the second frame 9, and the other end of the second frame is connected to the third frame 12. A contour slide crystal unit connected to each end and a mount part 5 connected to a third frame, wherein the bending part 4 is provided perpendicularly to the side 10 of the vibrating part and the first frame 11. The width W of the bent portion is smaller than 0.67 with respect to the length L of the bent portion, the vibrating portion is substantially square, and the dimension of each side is 0.72 mm ~.
2. The contour slip quartz crystal resonator, wherein the supporting portion is 2.02 mm, and the supporting portion is provided at both ends of the vibrating portion in the z′-axis direction, and is supported and fixed at both end portions of the supporting portion.