In this paper, we studied the optimization of preparation for polymeric optical waveguide based bus structures with embedded 45 degree micro-mirrors by metallic hard mold method. The 45º facets on the metallic hard mold, which were used to create the 45 degree micro-mirrors, were studied by the atomic force microscopy (AFM). The surface roughness of the 45 degree facets was reduced from 70nm to be 2nm by a photopolymer coating step. High speed test on the waveguide shows the low loss and high Q-factor performance of the waveguide structures. A backplane bus with 10 Gbits/sec channel will be reported.