In this paper, we presented fabrication of nickel based metal mold with 45 degrees tilted surfaces on both ends of the channel waveguide through electroplating process. To obtain a precise 45 degrees tilted angle, a 50microm thick SU-8 layer was UV exposed under de-ionized water, with repeatable error control of 0.5 degrees . The polymeric waveguide array with 45 degrees micro-mirrors, which is formed by a UV imprinting method with the fabricated metallic mold, shows total insertion losses around 4dB, propagation loss around 0.18dB/cm and 75% coupling efficiency.