基于云纹干涉法的封装结构应变测量技术研究

Research on strain measurement of package structure based on moiréinterferometry

随着高密度、高集成度封装技术的发展,封装结构的可靠性问题备受关注.本文基于云纹干涉法和Twyman/Green干涉法,结合四步相移技术,建立了一套高精度三维光学测量方法,能够实现封装结构在力、热载荷下离面和面内的变形测量.进一步采用多项式拟合后求导的方法,提升了传统差分法求应变的测量精度.最后,通过标准试验件三点弯曲实验,验证了方法的测量精度,并通过该方法实现了典型球栅阵列(Ball Grid Array,BGA)封装结构在热载荷下的变形测量,测量结果与有限元仿真结果相比具有较好的一致性.本文基于光测力学方法获得了封装结构在力、热等载荷下的变形场和应变场,从而对提升封装结构的可靠性具有重要意义.

With the development of high density and high integration packaging technology,the reliability of packaging structure has attracted much attention.In this paper,a compact and high sensitivity 3D optical testing method is constructed by effective combination of Moiréinterferometry with Twyman/Green interferometry and by implementing phase shifting technique.In order to further improve the stain accuracy,the discrete deformation field obtained by the phase shifting technology is fitted with polynomial,and then the derivation is realized.The measurement accuracy of the method is verified by the three-point bending experiment of the standard test piece,and the deformation of the typical Ball Grid Array(BGA)package structure under thermal load is finally measured.The deformation and strain information of package structure under thermal and force loads can be obtained by the method,which is of great significance to improve the reliability of package structure.