The optical interconnection using polymer waveguides on the optical and electronic printed circuit board was designed and fabricated for low optical propagation loss and high speed data rate. The ray tracing simulation for the tolerance study of optical interconnection and fabrication was carried by the LightTools commercial software. In order for the easy fabrication and high position accuracy, the polymer waveguides were forming 45° reflective mirrors using dicing approach and followed by the e-beam deposition for silver coated 90° beam turning. The interface coupling loss was discussed in different polishing grit sizes and dicing approaches. Upto 12.5 Gb/s transmission rate and 0.1 dB/cm optical propagation loss were demonstrated in the board-embedded flexible polymer waveguide. The Q factor of 7.4 at 12.5 Gb/s and additional optical loss of 0.3 dB were experimentally shown on the 2-mm bending radius and 180° curvature angle.