表面结构对集成式石英谐振器性能的影响

Effect of Surface Structure on Properties of Integrate Quartz Resonator

在研究石英晶体谐振器力敏特性与加力方位角关系及晶体薄片内波的传播特性的基础上,设计制作了基于同一晶体基片上的集成式四电极谐振器。研究了这种结构的谐振器的力敏特性与加力方位、谐振频率稳定性与基片表面和边沿结构的关系。实验结果表明,谐振器的力敏特性与加力方位密切相关;对晶体基片表面进行抛光处理,能有效地消除表面缺陷对谐振器振动状态的影响,提高谐振频率的稳定性;对晶体基片边沿进行倒边处理,能缩短谐振波波幅在边沿区衰减的空间距离,抑制了谐振器振动能量沿晶片边沿的散失,使谐振器频率稳定性得到进一步提高。经表面抛光及边沿倒边处理后,谐振器频率波动的平均值分别下降到处理前的42%和30%。

Based on the research of the relations between the force frequency characterizations and the stress azimuth as well as the propagation of wave in slice of quartz crystal oscillators, a four electrode resonator is designed and fabricated in the same crystal wafer. We have studied the resonator of this structure about the relations of the force frequency characterizations and stress azimuth, stability of resonance frequency and surface and border struc- ture. The experimental result indicated that there are close correlation between the force frequency characterizations and stress azimuth of the resonator, the polishing surface of crystal wafer can be used to eliminate its influence on the resonator vibration state effectively which is caused by the surface defect, and to enhance the stability of resonance frequency. Meanwhile, It also can be used to reduce the space length of the resonant wave amplitude which weakens in the border area, and it can be used to suppress the loss of resonator vibration energy along chip border, and enable the stability of resonator frequency to improved further by beveling the crystal wafer border. After polishing the crystal wafer surface and beveling the crystal wafer border, the average value of the resonator frequency fluctuation can be reduced by drop to 42% and 30% respectively in comparison with before processing.