title: Preparation of plastic spherical microlenses by use of a fluoropolymer stencil and oil-bath heating.
abstract: A new method for fabricating plastic spherical microlenses was developed, which allowed self-alignment of lenses and self-organized formation of a spherical shape. First a low-surface-energy fluoropolymer thin film was deposited and patterned as a stencil. Then photosensitive phenol resin was patterned on it as the lens material. Finally the resin was annealed in an oil bath to form a sphere. The molten phenol resin spontaneously formed a sphere and positioned itself in the center of the fluoropolymer ring pattern as a result of the difference of surface free energy and the equivalently zero-gravity condition in the oil bath. When a light-emitting-diode printer head was loaded with spherical microlenses, its optical output increased by 1 order of magnitude.
authors.affiliation: Research and Development Center, Research and Development Laboratory, Stanley Electric Co., Ltd., Eda-nishi 1-3-1, Aoba-ku, Yokohama, Kanagawa 225-0014, Japan.
authors.forename: Hiromoto
authors.initials: H
authors.lastname: Tamura
authors.forename: Ryousuke
authors.initials: R
authors.lastname: Kojima
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Usui