热冲击对石英晶体谐振器稳定性的影响研究  

The Study on the Influence of Thermal Shock for Stability of Quartz Crystal Resonators

作　　者：尹小三 徐俊俊 YIN Xiaosan;XU Junjun(TXC(Ningbo)Corporation,Ningbo 315800,China)

机构地区：[1]台晶(宁波)电子有限公司,浙江宁波315800

出　　处：《压电与声光》2020年第5期607-610,共4页Piezoelectrics & Acoustooptics

基　　金：宁波市科技创新2025重大专项基金资助项目(2019B10122)。

摘　　要：分析并研究了瞬时热冲击之一的回流焊对石英晶体谐振器频率稳定性的影响,综合已有研究经验和回流焊后频率的可恢复性,推断薄膜应力是回流焊后频率稳定性的主要影响因子。通过试验发现,薄膜溅射功率降至200 W或薄膜热退火温度升至350℃可有效改善回流焊后谐振器的频率稳定性,回流焊后频率变化量降低(4~5)×10^-6。采用显微拉曼光谱仪对回流焊前、后的石英晶片进行分析发现,其在回流焊后的拉曼特征峰明显往高频移动,推断是由于薄膜热膨胀引起的张应力增大而致石英晶片内压应力增加约8 MPa;随冷却时间延长,薄膜收缩而致石英晶片内压应力减小,频率逐渐恢复。结果表明,薄膜应力变化是回流焊对谐振器频率稳定性的影响机理。The influence of reflow soldering,one of the instantaneous thermal shocks,on the frequency stability of quartz crystal resonators is analyzed and studied.Based on the existing research experience and the frequency recoverability after reflow soldering,it is deduced that the film stress is the main influence factor of frequency stability after reflow soldering.Through experiments,it is found that the frequency stability of resonators after reflow soldering can be effectively improved when the sputtering power of the thin film is reduced to 200 W or the annealing temperature of the thin film is increased to 350℃,and the frequency deviation after reflow soldering decreases by about(4~5)×10^-6.The micro Raman spectrometer is used to analyze quartz wafers before and after reflow soldering,and it is found that the Raman characteristic peak of quartz wafers shift obviously toward the high frequency after reflow soldering.It is inferred that the compressive stress of the quartz wafers increase by about 8 MPa because of the increase of the tensile stress of thin film caused by its thermal expansion.With the increase of the cooling time,the thin films shrink and the pressure stress of quartz wafers decreases and the frequency gradually recovers.The results show that the change of film stress is the mechanism of reflow soldering on the frequency stability of resonators.

关 键 词：石英晶体谐振器 热冲击 回流焊 频率稳定性 薄膜应力 影响机理 

分 类 号：TN752[电子电信—电路与系统] O321[理学—一般力学与力学基础]