微细光束固化的蒙特卡罗建模

Monte Carlo Simulation Model of Micro Light Beam Solidification

光固化是光束与光敏树脂之间的光化学反应,其作用过程对光固化加工分辨率有着直接影响。基于光子输运理论,利用蒙特卡罗方法追踪光子在树脂中的运动轨迹,对曝光光束入射、传输过程进行抽样,建立了微细光束固化模型;利用遗传算法并结合光固化实验重构获得了树脂材料的光学参数;利用该固化模型,模拟计算了微细会聚紫外光束(λ=365nm)单点曝光固化过程和固化单元点的形状和大小,分析了不同曝光量对固化结果的影响规律,计算结果与实验结果一致。研究表明,该模型可以有效地对微细光束与光敏树脂作用的复杂过程进行仿真,并能对不同入射光和曝光工艺条件下的固化物进行模拟计算,为微细光固化机理的研究和工艺优化提供了基础。

Light solidification is a photochemical reaction between the light beam and photosensitive resin, and has a direction relation with light solidification micro-machining resolution. First of all, the movement trajectory of photon in the resin was traced by Monte Carlo simulation. By sampling the exposure photon in the incident and transmission processes, micro light beam solidification model was constructed based on photon transportation theory. Secondly, optical parameters of the resin were reconstructed by combining the genetic algorithm and the curing results of experiment. Finally, the simulated calculation of single-point curing process （λ=365 nm）, shape and size of solidified points was carried out, and the as-obtained curing rule was analyzed in different exposure energy. The simulation results agree well with the experimental results under same exposure parameters. Thus the model can effectively simulate the complicated process of the reaction between the micro beam light and the resin, predict the curing result with different curing conditions and provide a foundation for studying micro solidification mechanisms, and optimizing the technique.