We propose an optical and electrical hybrid LSI package with high bandwidth of 2.4 Tb/s and parallel multi-mode optical links at 1.3 μm using a polymer optical waveguide and our original optical I/O module. We report a silicate based organic-inorganic hybrid polymer optical circuit fabrication including waveguide, mirror and connector on electrical LSI package substrate. We also present about the propagation loss, bending loss and coupling loss at 1.3 μm using a MMF and a Si photonics transmitter. The propagation loss of the multimode polymer waveguide is 0.3 dB/cm at 1.3 μm. The minimum bending radian and value generated additional loss is 5 mm and 0.2 dB, respectively. The coupling loss of butt-coupling and mirror coupling from the polymer optical waveguide to the MMF is 0.4 dB and 1.2 dB, respectively. In addition, we measure the optical characteristics of LSI package substrate using our Si photonics transmitter integrated with vertical polymer waveguide. Owing to adoption of multi-mode transmission, large 1-dB alignment tolerances were obtained with efficient optical coupling.