柔性器件基底预应变和各参数对蛇形结构延展性的影响  

Effect of substrate prestrain and parameters on serpentine structure stretchability for flexible device

作　　者：李学通[1] 仝洪月 赵越[1] 杜凤山[1] 

机构地区：[1]燕山大学机械工程学院066004秦皇岛

出　　处：《应用力学学报》2015年第2期251-255,353,共5页Chinese Journal of Applied Mechanics

基　　金：河北省自然科学基金(E2011203090);燕山大学青年教师自主研究课题资助项目(13LGA002)

摘　　要：为了提高柔性电子器件在大变形过程中的可变形性,防止失效破坏,本文以完全粘结的蛇形结构为例,利用ABAQUS有限元软件建立了金属薄膜交联导体-基底的三维有限元模型,研究了金属导体在基底预应变作用下的延展性,计算出导体和基底的不同材料和几何参数(基底厚度ts(500μm^3000μm)、导体宽度wm(1μm^4μm)、导体厚度tm(0.25μm^6μm)、长间距比α(0~3))下蛇形结构的弹性延伸率(εs)大小,并利用Origin软件得出了各参数与弹性延伸率的关系曲线。结果表明:弹性延伸率随着基底弹性模量、金属厚度的增加而减小,随着导体弹性模量的增大而增大,当金属厚度tm<0.45μm时,弹性延伸率超过100%,导体延伸率受基底厚度、金属宽度影响较小;当长间距比α<1时延伸率随着α的增大而增大,α>1时基本保持不变。根据这些结果可进一步优化系统结构,使系统获得最大延展性。数值模拟结果也说明了基底预应变能显著提高蛇形交联导体的弹性延伸率。To improve the deformability of electronic devices in large deformation and prevent the failure damage, a metal film interconnect-substrate FEM model is established by ABAQUS software to investigate the stretchability of metal with the prestrained substrate for the case of fully bonded serpentine structure. The stretchability of serpentine structure with different materials and geometrical parameters, such as substrate thickness ts(500~3000μm), metal width wm(1~4μm), metal thickness tm(0.3~6μm) and length/spacing ration α(0~3) are obtained. Curves between parameters and the elastic stretchability(εs) are given by using the ORIGIN software. Results show that the stretchability decreases with the increase of substrate modulus and metal thickness, increases with the increase of metal modulus, and it surpasses 100% for the case of the metal thickness tm<0.45μm. It is also can be concluded that the stretchability is not sensitive to the substrate thickness and metal width. For the case of length/spacing ration α<1, the stretchability increases with the increase of α, and remains constant for α>1. The structure system can be further optimized according to these curves and obtain the optimal stretchability value. Numerical simulation results also illustrate that the substrate prestrain can significantly enhance the stretchability of serpentine interconnects.

关 键 词：柔性电子器件 蛇形交联导体 有限元分析 预应变 延展性 

分 类 号：O34[理学—固体力学]