摄动热电机三参量有限元对DSAW声波力学的研究

Compensating Influences on DPSAW Waves and SMS Stresses Using The Perturbed Thermo-Electro-Mechanical Multivariant FEM

压电石英声表面波(PSAW)装置结构的实际扰动压电声表面波(DPSAW)特性受电极几何材料参数的扰动影响,而温度又将进一步影响DPSAW基频和波速。除了电极影响外,该文还考虑高阶温度系数的影响。由于对带热带电极各向异性分层压电材料结构,还没有或很难获得理论解,该文首次利用高效高精度三参量摄动热-机-电有限单元方法,即声元和应力元法,力图为计算热压电/力学奠定理论基础,优化电极厚度。精确计算了在一定温度下各阶温度系数对SAW谐振器波速波频的影响,以利于温度/电极耦合补偿设计。简单模拟计算热表面贴片封装应力(SMS)变形,得到了一系列不同温度下有用的计算值。自由表面SAW理论解和室温试验数据与数值计算结果一致,验证了该热压电有限元理论的可靠性。

The velocities of piezoelectric surface acoustic waves(PSAW) together with central and two lower/upper limit frequencies in a stopband of various SAW devices, are disturbed by both electrode geometries and environmental temperaturesAs theoretical solutions are hard to get or unavailable so far for thermal multilayered piezoelectriccontrolled anisotropic DPSAW problems subjected to Alelectrode disturbance,this paper takes advantage of an effective perturbed thermoelectromechanical finite element method(FEM)like acoustic element and stress element methods, for the first time, opening up the possibilities for multiperiodical analysis, so as to accurately compute and study the mixed and coupled effects associated with electrode thickness and temperature gradients on PSAW speeds and thermal surface mount stresses(SMS), which is helpful to both optimization of electrode heights and temperature compensating design of the PSAW devices including resonators, sensors and filters