微透镜阵列热压精密成型需要时间保温, 生产效率较低。因此, 提出在模芯加热表面的微沟槽阵列上对聚合物导光板进行热压, 使工件热变形的微米尺度表面层流入微沟槽空间内, 快速形成微拱形透镜阵列, 而保证工件主体不变形。目的是实现高效率和低能耗的微光学透镜阵列热压成型加工。首先, 针对导光板表面的微阵列结构和尺寸分析其微光学性能; 然后, 使用微磨削技术在模芯表面加工出高精度和光滑的微沟槽阵列结构; 最后, 研究微拱形阵列的快速精密成型工艺及微光学应用。微光学分析显示, 微阵列的高度和分布密度对出光面的光照度影响较大。热压工艺实验结果表明, 采用深度为104 μm和角度为121°的微沟槽阵列模芯, 在12 MPa的压力和110 ℃的温度下, 可以在3s内将高度为50 μm的3D微拱形阵列导光板快速精密热压成型。本文方法制作的87 mm×84 mm的导光板, 与市面具有2D点阵且高度为8.2 μm的丝网印刷导光板相比, 光照度提高了21%, 光照均匀度提高了27%。本文研究将促进微光学精准设计和制造在LED照明产业的应用。

The precision hot embossing of microlens array needs heat preservation time, leading to poor efficiency. Hence, a rapid hot embossing of micro-arch array on polymer light guide plate (LGP) is proposed using a heated microgrooved die core. It only performs a thermal deformation for micro-scale surface layer flowing inside microgroove spaces without changing macro workpiece sizes. The objective is to develop the hot embossing process of microlens array of micro-optics with high machining efficiency and low energy-consumption. First, the micro-optics performances of LGP are analyzed with regard to the shape and size of micro-arch array; then the micro-grinding is employed to machine precision and smooth microgroove array on steel die core; finally, the rapid and accurate forming process of micro-arch array and its micro-optics application are studied. The micro-optics analyses show that the height and distribution density of micro-arch array greatly influence the micro-optics performance. The hot embossing experiments show that by using a microgroove array die core with an average groove depth of 104 μm and an average groove angle of 121°, the 50-μm-height 3D micro-arch array may be precisely formed in 3 s in the case of 12 MPa in loading pressure and 110 ℃ in loading temperature. Compared with the general screen-printing 2D micro-dot array with 8.2-μm-height, the LGP patterned with micro-arch array increases the LGP irradiance intensity by 21% and its uniformity by 27%, respectively. It contributes to the micro-optics precision design and fabrication applied for LED lighting industry.