通过热应力分析改善AOTF键合层附着力

针对声光可调滤光器(AOTF)压电换能器和声光晶体键合后出现附着力差的问题开展分析,根据热应力理论计算AOTF键合层各层的热应力分布情况,提出通过增加过渡层改善键合层应力特性。当过渡层Au膜厚为200nm时,理论上键合层和声光晶体间的热应力减小到-0.613 MPa,能够保证膜层的附着强度。测试结果显示,添加过渡层后频率响应的3dB带宽增加,衍射效率提高了2%~4%。

Improvement of the Adhesion of AOTF's Bonding Layer by Thermal Stress Analysis

Aiming at the problem of poor adhesion after the bonding of piezoelectric transducer of AOTF and the acousto optic crystal, a method of adding a transition metal layer to improve the stress characteristics of the banding layer was presented through calculating the thermal stress distribution of the bonding layer of AOTF based on the thermal stress theory. When the thickness of the transition layer of Au film reached to 200 nm, the theory thermal stress between the bonding layer and acousto optic crystal was reduced to -0.613 MPa and the adhesion strength of the coatings could be ensured. The test results showed that the 3 dB bandwidth of the frequency response increased with the addition of the transition layer, and the diffraction efficiency was increased by 2%~4%.