A novel and rapid fabrication method for a high fill factor hexagonal microlens array using thermal reflow and repeating spin coating

作者：Lin Tsung Hung^*; Lin Meng Chen; Chao Ching Kong

来源：International Journal of Advanced Manufacturing Technology, 2017, 92(9-12): 3329-3336.

DOI：10.1007/s00170-017-0331-0

• Microlens array
• High fill factor
• PDMS microlens
• Micro plano-convex

This paper presents an innovative process for the fabrication of a high fill factor microlens array using thermal reflow and repeating spin coating. The repeated spin coating method creates a hexagonal microlens array after the thermal reflow processes as an alternative to the expensive gray-mask and longtime electroplating method. The first, the round base and hexagonally arranged array, precisely define the bottom shape of the liquid photoresist, and a tall hemispherical microlens array with a small radius of curvature is fabricated during the photoresist thermal reflow process. The second, the surplus photoresist, is then rotated at high velocity using a spinner. The micro-plano-convex microlens molds are then finished. The polydimethylsiloxane (PDMS) microlens array is fabricated using a replica molding process. The experimental results show that a high fill factor hexagonal PDMS microlens array is successfully fabricated. The fabricated microlens array has good surface roughness. The proposed fabrication method facilitates mass production and gives increased luminance efficiency and luminance power efficiency to produce a high fill factor microlens array that is suitable for use in the light-emitting diodes (LEDs) and organic light-emitting diodes (OLEDs).

• 出版日期2017-10