Please wait a minute...
浙江大学学报(工学版)
J4  2012, Vol. 46 Issue (6): 1143-1147    DOI: 10.3785/j.issn.1008-973X.2012.06.027
    
Multi-layer encapsulation and stretchability analysis for
noncoplanar film-substrate structure
LI Zheng-wei, TAO Wei-ming
Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, China
Download:   PDF(0KB) HTML
Export: BibTeX | EndNote (RIS)      

Abstract  

In order to reduce the stretchability degradation of the non-coplanar film/substrate structure in flexible electronics caused by encapsulation, a multi-layer encapsulation design was proposed and the stretchability was investigated. This design was achieved by adopting polydimethylsiloxane (PDMS) with different mechanical properties near the upper and lower bridge surfaces. By simplifying the structure of bridge, upper and lower encapsulation layers to tensile-bending composite beam, the influences of thickness, elastic modulus and other related parameters of the layers on the overall stretchability were analyzed by finite element method (FEM). The results show that the upper encapsulation layer with high thickness or/and low elastic modulus is benefit to improve the stretchability. Meanwhile, the stretchability can be considerably improved when the lower layer's modulus is moderately higher than that of the basic encapsulation material and the thickness is suitable. Nevertheless, the stretchability may decrease significantly when the lower layer's modulus is too high or the thickness is too large.

Published: 24 July 2012
CLC:  O 346  
  O 343  
Service
E-mail this article
Add to my bookshelf
Add to citation manager
E-mail Alert
RSS
Articles by authors
Cite this article:

LI Zheng-wei, TAO Wei-ming. Multi-layer encapsulation and stretchability analysis for
noncoplanar film-substrate structure. J4, 2012, 46(6): 1143-1147.

URL:

http://www.zjujournals.com/eng/10.3785/j.issn.1008-973X.2012.06.027     OR     http://www.zjujournals.com/eng/Y2012/V46/I6/1143


非共面薄膜-基底结构多层封装及延展性分析

为减小柔性电子中非共面薄膜基底结构因封装而导致的延展性下降,提出一种多层封装结构形式,并对其延展性进行了研究. 通过对薄膜上下表面附近采用不同力学特性的聚二甲基硅氧烷(PDMS),形成层状封装结构. 在将薄膜及其上下封装层简化为复合梁的拉弯组合变形问题的基础上,采用有限元法计算了上下封装层的厚度、弹性模量等相关参数对结构整体延展性的影响.计算结果表明：上封装层弹性模量减小、厚度增加有利于改善延展性；下封装层的弹性模量适度高于基本封装材料且厚度合适的情况下可较大幅度提高结构延展性,而若弹性模量过高或厚度过大则可导致延展性的大幅下降.该多层封装结构设计和分析结果对于优化柔性电子器件结构具有参考和指导意义.

［1］ 许巍,卢天健.柔性电子系统及其力学性能［J］.力学进展,2008,38（2）: 137-150.
XU WEI, LU Tianjian. Flexible electronics system and their mechanical properties ［J］.Advance in Mechanics, 2008,38（2）: 137-150.
［2］ LI T, HUANG Z, SUO Z, et al. Stretchability of thin metal films on elastomer substrates ［J］. Applied Physics Letters, 2004, 86(15): 3435-3437.
［3］ LU N, WANG X, SUO Z, et al. Metal films on polymer substrates stretched beyond 50% ［J］. Applied Physics Letters, 2007, 91(22): 221901.
［4］ GONZALEZ M, HSU Y, VANDEVELDE B, et al. Design and performance of metal conductors for stretchable electronic circuits［J］. Circuit Word, 2009, 35(1): 22-29.
［5］ GONZALEZ M, AXISA F, BULCKE M, et al. Design of metal interconnects for stretchable electronic circuits ［J］.Microelectronics Reliability,2008,48(6): 825-832.
［6］ KHANG Y, JIANG H, HUANG Y, et al. A stretchable form of single crystal silicon for high performance electronics on rubber substrate ［J］. Science, 2006, 311(57/58): 208-212.
［7］ KIM D, SONG J, CHOI W, et al. Materials and noncoplanar mesh designs for integrated circuits with linear elastic responses to extreme mechanical deformations ［J］. Proceedings of the National Academy of Sciences of the United States of America, 2008, 105(48): 18675-18680.
［8］ WANG Y, FENG X. Dynamic behaviors of controllably buckled thin films ［J］. Applied Physics Letters, 2009, 95(23): 231915.
［9］ FENG X, MEITL M, BOWEN A, et al. Competing fracture in kinetically controlled transfer printing ［J］. Langmuir, 2007, 23(25): 12555-12560.
［10］ KIM D, LIU Z, KIM Y, et al. Optimized Structural Designs for Stretchable Silicon Integrated Circuits ［J］. Small, 2009, 5(24): 2841-2847.
［11］ JIANG H,SUN Y,ROGERS J, et al. Postbuckling analysis for the precisely controlled buckling of thin film encapsulated by elastomeric substrates［J］. International Journal of Solids and Structures, 2008, 45(7): 2014-2013.
[1] YANG Xin-Wang, BI Guo-Li, ZHANG Xue, et al. Path iterative method for laser-controlled crack propagation and its convergence[J]. J4, 2009, 43(11): 2043-2047.