naa a22 4500 510803199 CHVBK 20180411083404.0 cr unu---uuuuu 180411e20131201xx s 000 0 eng 10.1007/s11664-013-2732-7 doi (NATIONALLICENCE)springer-10.1007/s11664-013-2732-7 Influence of Photolithography on the Cross-Sectional Shape of Polysiloxane as an Optical Waveguide Material on Printed Circuit Boards [Elektronische Daten] [Kam-chuen Yung, Chung-pang Lee, Ching-hong Wong, Siu-lim Tam, Siu-kwong Pang, Tai-man Yue] Optical waveguide cross-sectional shapes that deviate from rectangles or squares may cause significant loss of signal. In this study, a photolithography approach was adopted to fabricate waveguides on printed circuit boards, using photo-imageable polysiloxane as a waveguide material. The effects of I-line ultraviolet (UV) lamp exposure, 355-nm Nd:YAG laser direct imaging, and 248-nm excimer laser direct imaging on the cross-sectional shape of waveguides were investigated. For I-line UV lamp exposure, increasing the exposure time could cause changes in the tilt angle of the waveguides from negative (inverted trapezoid) to positive (trapezoid). To obtain rectangular waveguides, the optimum I-line UV lamp exposure time was found to be around 150s. From the results for 355-nm Nd:YAG laser direct imaging, the width and tilt angle of the waveguides varied with the energy density of the laser beam irradiating the core materials, being controlled by the repetition rate and focus. Lowering the laser energy density could produce waveguides with small widths and tilt angles. Excimer laser direct imaging at 248nm was found to be unsuitable for waveguide patterning since the core materials could not be cured at this wavelength. TMS, 2013 Optical printed circuit boards nationallicence optical waveguides nationallicence photolithography nationallicence cross-sectional shape nationallicence polysiloxane nationallicence Yung Kam-chuen Department of Industrial and Systems Engineering, PCB Technology Centre, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong aut Lee Chung-pang Department of Industrial and Systems Engineering, PCB Technology Centre, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong aut Wong Ching-hong Department of Industrial and Systems Engineering, PCB Technology Centre, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong aut Tam Siu-lim Department of Industrial and Systems Engineering, PCB Technology Centre, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong aut Pang Siu-kwong Department of Industrial and Systems Engineering, PCB Technology Centre, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong aut Yue Tai-man Department of Industrial and Systems Engineering, PCB Technology Centre, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong aut Journal of Electronic Materials Springer US; http://www.springer-ny.com 42/12(2013-12-01), 3494-3501 0361-5235 42:12<3494 2013 42 11664 https://doi.org/10.1007/s11664-013-2732-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11664-013-2732-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yung Kam-chuen Department of Industrial and Systems Engineering, PCB Technology Centre, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong aut NATIONALLICENCE 700 1- Lee Chung-pang Department of Industrial and Systems Engineering, PCB Technology Centre, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong aut NATIONALLICENCE 700 1- Wong Ching-hong Department of Industrial and Systems Engineering, PCB Technology Centre, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong aut NATIONALLICENCE 700 1- Tam Siu-lim Department of Industrial and Systems Engineering, PCB Technology Centre, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong aut NATIONALLICENCE 700 1- Pang Siu-kwong Department of Industrial and Systems Engineering, PCB Technology Centre, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong aut NATIONALLICENCE 700 1- Yue Tai-man Department of Industrial and Systems Engineering, PCB Technology Centre, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong aut NATIONALLICENCE 773 0- Journal of Electronic Materials Springer US; http://www.springer-ny.com 42/12(2013-12-01), 3494-3501 0361-5235 42:12<3494 2013 42 11664 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer