基于PDMS薄膜的微透镜制作方法

A Fabrication Method for Micro-Lenses Based on the PDMS Membrane

提出了一种基于聚二甲基硅氧烷(PDMS)薄膜的软模压印制作微透镜的方法。首先,采用具有钝化层的普通硅片作为基底加工出PDMS薄膜;然后,将薄膜粘于刻有对应孔径的硅模板上,薄膜在负压作用下产生凹陷,滴入快速固化的光固化树脂,固化后得到反向的模具作为制备微透镜结构的母板;最后,通过两次复制模具的方法,在PDMS上得到和母板一致的微透镜。实验测试了微透镜的厚度、焦距和成像效果,结果表明所得微透镜具有良好的表面形貌和聚光效果。这种制作方法可以极大地缩短微透镜的加工时间,并降低成本,为制作微透镜提供了一种简捷的方法。

A soft embossing process based on the polydimethylsiloxane （PDMS） membrane was proposed to fabricate micro-lens. Firstly, the PDMS membrane was fabricated on a silicon wafer with a passivation layer as the substrate. After the membrane was stuck on the silicon wafer tem- plate engraved with the corresponding aperture, the negative pressure was applied on the cavity to make the concave deform. Then, the rapidly cured photocurable resin was added to obtain the reversed mould which was served as the motherboard for the micro lens structure. Finally, the PDMS micro lenses which were the same as the motherboard were made by the second replica. The thickness, focal length and imaging effect were tested. And the results indicate that the mi- cro-lens has a good surface morphology and concentrating effect. This method can greatly reduce the process time and the cost of the micro-lens, and provide a simple fabricating way for the mi- cro-lens.