Xie Dan, Chang Xuefeng, Shu Xiayun, Wang Jian, Mei Lifang, Luo Shanming
Opt Express. 2016 Dec 26;24(26):30264-30274. doi: 10.1364/OE.24.030264.
In this paper, we propose a replication method of thermoplastic polymer spherical lens array using a novel microforged mold. The SiN ceramic balls, with 3.5 mm diameter, 10 nm surface roughness and 84 nm deviation from spherical profile, were utilized as indentor to generate aluminum alloy lens array mold. Upon the optimization of technical parameters, such as heating and de-molding temperature, indentation force and holding time, a high quality spherical lens array mold was obtained. The mold was used to fabricate spherical PMMA lens array by hot embossing, which showed excellent characteristics on dimensional stability, surface features and optical performances. Especially for the requirements of deep sag height and low f/#, the microforging technique reveals superior performance for low cost and high quality manufacture of spherical lenses. Compared to the previous complicated tools which requires precise calibration, the self-alignment mode of the balls and cavities can easily guarantee positioning accuracy. Accordingly, the pre-milled spherical cavity deformed uniformly in the process of microforging due to the symmetrical distribution of contact pressure and reduced the error caused by deformation. We believe the proposed microforging technique is an ideal mass production approach to the fabrication of thermoplastic polymer spherical lens array.
在本文中，我们提出了一种使用新型微锻造模具复制热塑性聚合物球面透镜阵列的方法。直径为3.5毫米、表面粗糙度为10纳米且与球面轮廓偏差为84纳米的SiN陶瓷球被用作压头来制造铝合金透镜阵列模具。通过优化诸如加热和脱模温度、压痕力和保压时间等工艺参数，获得了高质量的球面透镜阵列模具。该模具用于通过热压印制造球面聚甲基丙烯酸甲酯（PMMA）透镜阵列，其在尺寸稳定性、表面特征和光学性能方面表现出色。特别是对于深矢高和低f/#的要求，微锻造技术在低成本和高质量制造球面透镜方面显示出卓越性能。与先前需要精确校准的复杂工具相比，球与型腔的自对准模式能够轻松保证定位精度。因此，由于接触压力的对称分布，预铣削的球形型腔在微锻造过程中均匀变形，并减少了由变形引起的误差。我们认为所提出的微锻造技术是制造热塑性聚合物球面透镜阵列的理想大规模生产方法。
