Fabrication of a 2.5 Gbps × 4 channel optical micro-module for O-PCB application

We report on the fabrication of a polymer-based 2.5 Gbps × 4 channel optical interconnecting micro-module for optical printed circuit board (O-PCB) application. An optical waveguide array is used for optical transmission from vertical surface emitting laser (VCSEL) array to photodiode (PD) array and the built-in 45° waveguide mirrors are used for vertical coupling. The optical waveguide array and the 45° mirrors are fabricated by UV imprint process in one-step. We fabricate microlensed VCSELs by micro-inkjetting method, which reduced radiation angle of VCSEL from 18° to 15° for better light coupling. We use solder ball array and pin array for alignment between O-PCB and the electrical sub-boards with alignment mismatch below 10 μm in x, y and z axis. The fabricated optical interconnection module transmits data at the rate of 2.5 Gbps per channel.