高深宽比微细结构紫外光固化-脱模工艺建模与分析

Numerical Analysis of the UV Curing and Demolding Process for High Aspect Ratio Micro Structure

针对高深宽比结构的脱模问题,利用压缩试验获得了材料的力学性能,并用Ogden模型对其进行描述,建立了卷对卷紫外光(UV)固化-脱模工艺过程的有限元模型.分析了光照时长、残余层厚度、微结构深宽比以及结构间隙等参数对脱模最大应力的影响规律.结果表明:在结构深宽比为4∶1时,界面粘接力是导致脱模缺陷的主要原因;光照时长越长,残余层厚度越薄;微结构深宽比越小以及结构间隙越大,固化-脱模应力越小、越有利于脱模.

Focusing on the demolding issues of high aspect ratio structures,this paper attempts to explain the reasons behind this problem.Firstly,the material properties of the cured resist was measured,and Ogden model was used to describe its behavior.Then,a roll to roll UV curing and demolding numerical model was constructed and analyzed.It was found that the adhesive forces between mold and structures is the major cause of maximum stress in cured resist when aspect ratio is set to 4∶1.Moreover,a longer curing time,a thinner residual layer thickness,a smaller structure aspect ratio and a bigger structure gap can lead to smaller maximum stress during the curing and demolding process.