A new and innovative interconnection technology applicable for printed circuit boards is presented. This technology is widely compatible with the existing design and manufacturing processes and technologies for conventional multilayer pc boards and it combines electrical and optical interconnects on pc board level. It provides the potential for on-board bandwidth of several Gb/s and closes the bottleneck caused by the limited performance of electrical interconnection technology. After giving an overview on the most important basic technologies and first available results and engineering samples, the focus of this paper is on the development of appropriate modeling methodologies and simulation algorithms necessary for designing and optimizing optical on-board interconnects within the conventional electrical pc board environment.Index Terms-Board-integrated multimode waveguides, design and modeling of optical multimode interconnects, electrical-optical printed circuit boards, modeling of laser-diodes and photodiodes, optical interconnection technology.