Intellectual Merit: The objective of this project is develop new packaging interconnections with embedded patterned substrate layers that allow engineers to manipulate dispersion, impedance, and higher order modes in high density and high data rate channels. The innovation is the addition of a patterned layer with sub-wavelength structures that sits between the ground and signal layers in a transmission line. Interconnects with such structures will achieve design flexibility and superior performance using well-known packaging materials and without vias. Another unique aspect is the design of patterned structures that are non-periodic since the pattern density (and thus impedance) change along the line. These lines will exhibit a graded permittivity along the length of a transmission line which can reduce dispersion by compensating for delay in the direction of propagation. The ability to ?engineer characteristic impedance? creates entirely new possibilities for high performance interconnects with appropriate field and impedance match. The research will include full-wave simulations that are verified by measurements on prototype structures. The goal is an increase is approximately 10GHz in signal bandwidth and a reduction of at least 25% of signal loss over present-day wired interconnects. The research project is based on transforming the electrical properties of transmission lines using well-known dielectric materials and fills in technology gaps of present methods. The dream outcome of this work is to realize a non-homogeneous permittivity, which has not been practically realized.
Broader Impacts: This work will bring value to US industry by providing a new approach to interconnects. We hope to achieve unique interconnect solutions that have features of both low permittivity for low dispersion and high-permittivty in terms of size shrinkage that uses reliable manufacturing processes. The framework developed in this work will be applicable to a wide variety of transmission lines. Results of the project including comparisons of simulations and experiments will be widely disseminated to the scientific community by papers and by providing results via a website. The project includes development of a workforce aware in issues such as signal integrity and design for manufacturability. A course in electronic packaging principles will be converted to an on-line format. Video-produced virtual field trips that take students into the simulation and circuit fabrication laboratories will be developed and offered in freshman engineering courses. These materials will also be used in recruiting highly qualified high school students taking courses for university credit.
