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.
© 2003 Optical Society of America
Original Manuscript: October 2, 2002
Revised Manuscript: March 26, 2003
Published: July 1, 2003
Hiromoto Tamura, Ryousuke Kojima, and Hiroaki Usui, "Preparation of plastic spherical microlenses by use of a fluoropolymer stencil and oil-bath heating," Appl. Opt. 42, 4008-4015 (2003)