Fabrication of Multiscale-Structure Wafer-Level Microlens Array Mold

Abstract

The design and manufacture of cost-effective miniaturized optics at wafer level, usingadvanced semiconductor-like techniques, enables the production of reduced form-factor cameramodules for optical devices. However, suppressing the Fresnel reflection of wafer-level microlensesis a major challenge. Moth-eye nanostructures not only satisfy the antireflection requirementof microlens arrays, but also overcome the problem of coating fracture. This novel fabricationprocess, based on a precision wafer-level microlens array mold, is designed to meet the demandfor small form factors, high resolution, and cost effectiveness. In this study, three different kinds ofaluminum material, namely 6061-T6 aluminum alloy, high-purity polycrystalline aluminum, and purenanocrystalline aluminum were used to fabricate microlens array molds with uniform nanostructures.Of these three materials, the pure nanocrystalline aluminum microlens array mold exhibited auniform nanostructure and met the optical requirements. This study lays a solid foundation for theindustrial acceptation of novel and functional multiscale-structure wafer-level microlens arrays andprovides a practical method for the low-cost manufacture of large, high-quality wafer-level molds.

Design and Fabrication of Wafer-Level Microlens Array with Moth-Eye Antireflective Nanostructures

“…The microlens surface could be spherical, aspheric, or free-form in shape [36,37,38]. Secondly, the metal mold was treated using a chemical approach to create an even layer of V-shaped nanopores on the hard mold [39]. Next, a UV-curable resin-based nanoimprint process was used to transfer the hybrid structures on the metal mold to a glass wafer substrate, generating the wafer lens array with nanostructured surfaces.…”

Special Issue on “Micro/Nano Manufacturing”

“…The Special Issue contains 13 papers covering the topics listed above [6][7][8][9][10][11][12][13][14][15][16][17][18]. The treated micro fabrication technologies range from established processes like elliptical vibration cutting to novel process chains such as the formation of nanoparticle arrays by hot embossing and sputtering.…”