Quartz crystal single-ended clamped-hinge tuning fork temperature-sensitive resonator

Abstract

A quartz crystal single-end fixed support tuning fork type temperature sensitive resonator comprises a fixed support structure (11), a stress isolation structure (12), a vibration damping structure (13), a resonant tuning fork (14), a first metal electrode (21), a second metal electrode (22), a third metal electrode (23), a fourth metal electrode (24), a fifth metal electrode (31), a sixth metal electrode (32), a seventh metal electrode (33), and an eighth metal electrode (34). The resonant tuning fork (14) is connected to an external alternating voltage, and the resonant tuning fork (14) bends and vibrates, and the vibration damping structure (13) attenuates the vibration. The resonant tuning fork (14) senses external temperature changes, and when the external temperature changes, the vibration frequency of the two changes to complete temperature measurement. The present application uses a vibration damping structure and a stress isolation structure, reduces the loss of resonant energy, avoids the shift of resonant mode, and improves the accuracy and stability of the resonator temperature measurement.

Description

Technical Field

[0001] This invention relates to a temperature-sensitive resonator, and more particularly to a quartz crystal single-ended fixed-braced tuning fork type temperature-sensitive resonator. Background Technology

[0002] In aerospace systems, especially for long-term temperature measurement, quartz temperature sensors with high stability, high precision, low power consumption, and strong resistance to radiation and electromagnetic interference can accurately, quickly, and conveniently measure and transmit various temperature indicators in complex and harsh special space environments.

[0003] Currently, commonly used quartz temperature sensing elements employ thickness shear mode resonators, which suffer from high resonant frequencies, high power consumption in the oscillation circuit, large size, large heat capacity, and long response time. In contrast, quartz temperature sensing elements utilize bending vibration mode resonators, i.e., single-ended fixed-support tuning fork temperature resonators, which offer advantages such as wide temperature measurement range, small size, good linearity, fast response speed, high resolution, and high accuracy.

[0004] However, current quartz crystal single-ended fixed-support tuning fork temperature resonators have three main problems: First, they do not consider the vibration damping of the tuning fork, meaning there is no vibration damping structure designed between the tuning fork and the fixed support structure, leading to energy loss, a decrease in the quality factor (Q value), and system instability. Second, they do not adequately isolate external forces acting on the fixed support structure, meaning there is no stress isolation structure designed between the tuning fork and the fixed support structure, causing the resonant frequency of the tuning fork to shift, preventing it from operating in the normal bending vibration mode and resulting in temperature measurement failure. Third, the driving efficiency of the electrodes is low, meaning the electrode topology distribution is unreasonable. Summary of the Invention

[0005] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a novel quartz crystal single-ended fixed tuning fork temperature resonator, which greatly improves the accuracy, stability and reliability of temperature measurement by using a vibration damping structure and a stress isolation structure.

[0006] The technical solution of this invention is: a quartz crystal single-ended fixed-support tuning fork type temperature-sensitive resonator, comprising a fixed-support structure, a stress isolation structure, a vibration damping structure, a first resonant tuning fork, a second resonant tuning fork, a first metal electrode, a second metal electrode, a third metal electrode, a fourth metal electrode, a fifth metal electrode, a sixth metal electrode, a seventh metal electrode, and an eighth metal electrode. The first and second resonant tuning forks have identical structural shapes.

[0007] One end of the stress isolation structure is perpendicularly connected to the fixed support structure, and the other end is perpendicularly connected to one end of the vibration damping structure. The first and second resonant tuning forks are both perpendicularly connected to the other end of the vibration damping structure. The first and second metal electrodes are evenly distributed on both sides of the upper surfaces of the fixed support structure, the stress isolation structure, and the vibration damping structure, and are not interconnected. The first and second metal electrodes are alternately distributed on the upper surfaces of the first and second resonant tuning forks. The third and fourth metal electrodes are evenly distributed on both sides of the lower surface of the vibration damping structure and are not interconnected. The third and fourth metal electrodes are alternately distributed on the lower surface of the first and second resonant tuning forks. On one side, the fifth and sixth metal electrodes are evenly distributed on both sides of the first resonant tuning fork, and the seventh and eighth metal electrodes are evenly distributed on both sides of the second resonant tuning fork. The first, third, fifth, and sixth metal electrodes are connected, and the second, fourth, seventh, and eighth metal electrodes are connected. The first and second metal electrodes are connected to an external AC voltage. The resonant tuning fork bends and vibrates, and the vibration attenuation structure attenuates the vibration of the resonant tuning fork. The first and second resonant tuning forks sense changes in external temperature. When the external temperature changes, the vibration frequency of the first and second resonant tuning forks changes to complete the temperature measurement.

[0008] The aforementioned fixed support structure, stress isolation structure, and vibration damping structure are all cuboid structures.

[0009] The stress isolation structure has a length greater than or equal to twice the length of the vibration attenuation structure, and a width greater than or equal to the sum of the widths of the first and second resonant tuning forks.

[0010] The first and second metal electrodes are deposited on both sides of the upper surface of the fixed structure, the upper surface of the stress isolation structure, and the upper surface of the vibration damping structure by sputtering and evaporation. The first and second metal electrodes are deposited on the upper surfaces of the first and second resonant tuning forks by sputtering and evaporation and are staggered. The third and fourth metal electrodes are deposited on both sides of the lower surface of the vibration damping structure by sputtering and evaporation. The third and fourth metal electrodes are deposited on the lower surfaces of the first and second resonant tuning forks by sputtering and evaporation and are staggered. The fifth and sixth metal electrodes are deposited on both sides of the first resonant tuning fork by sputtering and evaporation. The seventh and eighth metal electrodes are deposited on both sides of the second resonant tuning fork by sputtering and evaporation.

[0011] The quartz crystal is cut into (ZYw)θ shapes.

[0012] The advantages of this invention compared to the prior art are:

[0013] (1) Compared with the prior art, the temperature-sensitive resonator of the present invention effectively reduces the loss of resonant energy by using a vibration damping structure, thereby greatly improving the accuracy and stability of temperature measurement;

[0014] (2) Compared with the prior art, the temperature-sensitive resonator of the present invention fully isolates the external forces acting on the resonant tuning fork by using a stress isolation structure, keeps the resonant frequency stable, and does not shift the working mode, thereby improving the reliability of temperature measurement;

[0015] (3) Compared with the prior art, the temperature-sensitive resonator of the present invention has a three-dimensional driving electrode formed on the upper surface, lower surface and side surface of the resonant tuning fork, which has extremely high driving efficiency, can obtain the optimal electromechanical coupling effect, effectively maintain the fundamental frequency resonance stability of the resonant tuning fork, and thus ensure the stability of temperature measurement. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the three-dimensional structure of a quartz crystal single-ended fixed-support tuning fork type temperature-sensitive resonator according to the present invention.

[0017] Figure 2 This is a schematic diagram of the planar structure of a quartz crystal single-ended fixed-support tuning fork temperature resonator according to the present invention.

[0018] Figure 3 This is a schematic diagram of the resonator of the present invention and the electrode distribution on its upper surface;

[0019] Figure 4 This is a schematic diagram of the resonator of the present invention and the electrode distribution on its lower surface;

[0020] Figure 5 For the resonator of this invention along Figure 2 A cross-sectional view of the A-A' axis. Detailed Implementation

[0021] This invention proposes a quartz crystal single-ended fixed-support tuning fork type temperature-sensitive resonator. The temperature-sensitive resonator uses a quartz crystal with a (ZYw)θ cut and an overall single-ended fixed-support tuning fork structure design. By applying an AC voltage to the metal electrode, the resonant tuning fork is driven to a resonant working state. The temperature characteristic measurement is realized by utilizing the principle that the resonant frequency of the tuning fork changes with the external temperature. The invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] The three-dimensional structure of the temperature-sensitive resonator of this invention is as follows: Figure 1 As shown, the temperature-sensitive resonator is a tuning fork structure, including a fixed support structure 11, a stress isolation structure 12, a vibration damping structure 13, and a resonant tuning fork 14, as well as metal electrodes 21 distributed on the upper and lower surfaces of the resonator (see details). Figure 3 ), metal electrode 22 (see details) Figure 3 ), metal electrode 23 (see details) Figure 4 ), metal electrode 24 (see details) Figure 4 Metal electrodes 31, 32, 33, and 34 are distributed on the side of the resonant tuning fork 14. The length direction of the resonant tuning fork 14 is along the Y-axis direction of the quartz wafer, and the width direction is along the X-axis direction of the quartz wafer. The coordinate system used in the method of the present invention is the coordinate system of the quartz wafer itself.

[0023] A schematic diagram of the planar structure of the temperature-sensitive resonator of this invention is shown below. Figure 2 As shown, the fixed support structure 11, stress equalization structure 12, vibration damping structure 13, and resonant tuning fork 14 are sequentially connected to each other. The fixed support structure 11 is a cuboid structure with two pads on the upper surface for temperature measurement frequency signal output, and the lower surface and sides for fixation. The stress isolation structure 12 is a cuboid structure, the length of which should be greater than or equal to twice the length of the vibration damping structure 13, and its width should be greater than or equal to the sum of the widths of the two tuning fork fingers. The vibration damping structure 13 is a cuboid structure, and the longer its length, the better the damping effect. The resonant tuning fork 14 is composed of two cuboid tuning fork fingers, and its length and width are determined by the operating frequency of the resonator.

[0024] The vibration damping structure 13 is used to dampen the vibration of the resonant tuning fork 14, preventing the vibration from being transmitted to the stress isolation structure 12 and the fixed support structure 11. This structural design can effectively reduce the loss of resonant energy and improve the Q value of the temperature-sensitive resonator. The stress isolation structure 12 fully isolates the external forces acting on the fixed support structure 11 from being transmitted to the resonant tuning fork 14, avoiding the shift of the working mode, maintaining the stability of the vibration frequency of the resonant tuning fork 14, and greatly improving the accuracy, stability and reliability of temperature measurement.

[0025] The electrode topology distribution structure of the present invention is as follows: Figure 3 , Figure 4 and Figure 5 As shown, the upper surface metal electrodes of the resonator consist of metal electrodes 21 and 22, which are staggered and parallel to the resonator, and include two pads for easy gold wire bonding to output the temperature measurement frequency signal. The lower surface metal electrodes of the resonator vibration damping structure 13 consist of metal electrodes 23 and 24, with an electrode distribution almost identical to that of the upper surface, but without the two pads. The metal electrodes distributed on both sides of the resonant tuning fork 14 consist of metal electrodes 31, 32, 33, and 34. The aforementioned surface metal electrodes and side metal electrodes are deposited on the surface and sides of the resonant tuning fork using microelectronic processes such as sputtering and evaporation. Figure 5The electrode topology shown maintains the connectivity of metal electrodes 21, 23, 31, and 32, as well as metal electrodes 22, 24, 33, and 34, causing the resonant tuning fork 14 to be wrapped by three-dimensional electrodes, resulting in extremely high excitation efficiency and optimal electromechanical coupling effect.

[0026] The resonant frequency of a quartz crystal single-ended fixed-support tuning fork temperature resonator exhibits a unidirectional change within its operating temperature range. This phenomenon is essentially due to the thermal expansion and contraction of the quartz structure and the alteration of its physical parameters with temperature. When an AC voltage is applied to metal electrodes 21 (metal electrodes 21, 23, 31, and 32 are connected) and 22 (metal electrodes 22, 24, 33, and 34 are connected), the resonant tuning fork 14, based on the piezoelectric effect of the quartz crystal, is in a bending vibration mode. The vibration damping structure 13 attenuates the vibration of the resonant tuning fork 14, reducing energy loss. If the external temperature changes, the temperature of the quartz crystal changes through heat transfer, affecting the vibration of the resonant tuning fork 14 and consequently causing a change in the resonator's frequency. The stress isolation structure 12 isolates the influence of external forces on the vibration of the resonant tuning fork 14, preventing a shift in the operating mode. Utilizing the principle that the resonant frequency changes with external temperature, temperature characteristic measurement is achieved.

[0027] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A quartz crystal single-ended fixed-end tuning fork type temperature-sensitive resonator, characterized in that... The structure includes a fixed support structure (11), a stress isolation structure (12), a vibration damping structure (13), a first resonant tuning fork, a second resonant tuning fork, a first metal electrode (21), a second metal electrode (22), a third metal electrode (23), a fourth metal electrode (24), a fifth metal electrode (31), a sixth metal electrode (32), a seventh metal electrode (33), and an eighth metal electrode (34). The first and second resonant tuning forks have identical structural shapes. One end of the stress isolation structure (12) is perpendicularly connected to the fixed support structure (11), and the other end is perpendicularly connected to one end of the vibration damping structure (13). The first resonant tuning fork and the second resonant tuning fork are both perpendicularly connected to the other end of the vibration damping structure (13). The first metal electrode (21) and the second metal electrode (22) are evenly distributed on both sides of the upper surface of the fixed support structure (11), the upper surface of the stress isolation structure (12), and the upper surface of the vibration damping structure (13), and are not connected to each other. The first metal electrode (21) and the second metal electrode (22) are staggered on the upper surfaces of the first and second resonant tuning forks. The third metal electrode (23) and the fourth metal electrode (24) are evenly distributed on both sides of the lower surface of the vibration damping structure (13) and are not connected to each other. The third metal electrode (23) and the fourth metal electrode (24) are staggered on the lower surfaces of the first and second resonant tuning forks. The fifth metal electrode (31) The sixth metal electrode (32) is evenly distributed on both sides of the first resonant tuning fork, and the seventh metal electrode (33) and the eighth metal electrode (34) are evenly distributed on both sides of the second resonant tuning fork. The first metal electrode (21), the third metal electrode (23), the fifth metal electrode (31), and the sixth metal electrode (32) are connected. The second metal electrode (22), the fourth metal electrode (24), the seventh metal electrode (33), and the eighth metal electrode (34) are connected. The first metal electrode (21) and the second metal electrode (22) are connected to an external AC voltage. The resonant tuning fork bends and vibrates. The vibration attenuation structure (13) attenuates the vibration of the resonant tuning fork. The first resonant tuning fork and the second resonant tuning fork sense changes in external temperature. When the external temperature changes, the vibration frequency of the first resonant tuning fork and the second resonant tuning fork changes to complete the temperature measurement. The stress isolation structure (12) is a cuboid structure, and the vibration attenuation structure (13) is a cuboid structure.

2. The quartz crystal single-ended fixed-end tuning fork type temperature-sensitive resonator according to claim 1, characterized in that: The fixed support structure (11) is a cuboid structure.

3. A quartz crystal single-ended fixed-end tuning fork type temperature-sensitive resonator according to claim 1 or 2, characterized in that: The stress isolation structure (12) has a length greater than or equal to twice the length of the vibration damping structure (13), and a width greater than or equal to the sum of the widths of the first resonant tuning fork and the second resonant tuning fork.

4. A quartz crystal single-ended fixed-end tuning fork type temperature-sensitive resonator according to claim 1, characterized in that: The first metal electrode (21) and the second metal electrode (22) are deposited on both sides of the upper surface of the fixed support structure (11), both sides of the upper surface of the stress isolation structure (12), and both sides of the upper surface of the vibration damping structure (13) by sputtering and evaporation. The first metal electrode (21) and the second metal electrode (22) are deposited on the upper surfaces of the first and second resonant tuning forks by sputtering and evaporation and are staggered. The third metal electrode (23) and the fourth metal electrode (24) are deposited on both sides of the lower surface of the vibration damping structure (13) by sputtering and evaporation. The third metal electrode (23) and the fourth metal electrode (24) are deposited on the lower surfaces of the first and second resonant tuning forks by sputtering and evaporation and are staggered. The fifth metal electrode (31) and the sixth metal electrode (32) are deposited on both sides of the first resonant tuning fork by sputtering and evaporation. The seventh metal electrode (33) and the eighth metal electrode (34) are deposited on both sides of the second resonant tuning fork by sputtering and evaporation.

5. A quartz crystal single-ended fixed-end tuning fork type temperature-sensitive resonator according to claim 1 or 2, characterized in that: The quartz crystal is cut into (ZYw)θ shapes.

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