We present a cost-efficient parallel optical transceiver module based on a 1×4 VCSEL array, a 1×4 PD array, and a 12-wide multimode fiber ribbon for very-short-reach application. A passive alignment technique using through-silicon-hole (TSH) has been developed to realize high-efficient butt-coupling between optoelectronic arrays and multimode fibers. In this paper, the detail optical coupling structure, misalignment tolerance, micro-assembly process, and measurement results are mainly discussed. Finally, lensed multimode fibers formed by chemical etching are proposed, which exhibit a great potential for further improvement of coupling performance.