Investigations of Matrix-Exposure Lithography Using Stacked Linear Arrays of Squared Optical Fibers

Plastic optical fiber matrices with squared ends were investigated. Such fiber matrices are particularly required for printing two dimensional code marks by using them as new lithography tools combining with light emitting diodes. A large number of fibers with a diameter of 500 µm were packed in an oblong slit of a jig, and fiber ends were simultaneously transformed into square shapes by heating the jig on a hotplate. Next, three linear arrays, each composed of 10 fibers, were simply stacked and bound without coating any adhesives and/or opaque films. It was anticipated that light leaks from neighbored bright fibers degraded the printed pattern qualities. However, checker patterns were normally printed without influenced by neighbored bright fibers when the fiber ends were projected on a wafer through a 1/10 projection lens. Considering the advantages, a regularly arranged 10×10 fiber matrix was fabricated on trial for demonstrating the availability of the matrix required for developing a matrix-exposure lithography system.