STTR Phase I: Fully Embedded Optical Interconnect Layers Based on Molded Polymer Lightwave Components for Large Field Size Printed Circuit Boards

This Small Business Technology Transfer (STTR) Phase I project aims at developing a commercially viable optical interconnect technology. Conventional optical interconnect technologies suffer from planar optical waveguides with small dimensions in the vertical direction, which leads to alignment difficulties, laser coupling efficiency reduction, and deteriorated packaging reliability. These optical interconnect technologies also fail to provide transmission over a large field size, and the insertion of optical interconnects is incompatible with electronic device packaging. In this program, it is proposed to develop a fully embedded optical interconnection layer within the three dimensional (3D) electrical interconnect layers using molded optical waveguides in conjunction with thin film lasers and thin film photodetectors (both ~ 10 micron in thickness). The selection of polymer based molded waveguides solves two pending problems, the small field size of the interconnects and the shallow depth of the waveguides. The proposers intend to demonstrate up to 24"x36" molded waveguide films having waveguide dimensions of 50 microns by 50 microns, which make the alignment, and therefore packaging, of laser diodes and photodetectors highly reliable. Such a waveguide depth is not economically feasible using any other waveguide technologies. Commercially, using current communication devices, future data transmission demands at the printed circuit board and system level will be difficult to achieve with current copper interconnect technology due to issues regarding signal attenuation, electromagnetic interference, and parasitic noise. The state of the art electrical interconnect technology is anticipated to hit a deadlock between 2008 and 2012 at speeds above 10Gb/s. The proposed research provides a unique solution that reliably incorporates the optical interconnects into printed circuit board (PCB) fabrication and integration. The result of this research program will lay a solid foundation for a future PCB industry, which is critical for the United States to lead the market for the years to come.