Polymer interconnects

Over the past five years, the Photonics Systems Group in the Engineering Department has collaborated with Dow Corning through their participation in the Centre for Advanced Photonics and Electronics (CAPE) and the Cambridge Integrated Knowledge Centre (CIKC). Led by Professor Ian White and Professor Richard Penty, the project’s goal has been to achieve highly manufacturable but very high-speed (>10 gigabits per second) communication systems, such as required between high-end computers.

To accomplish this, the efficiency of high-speed data interconnects on electronic circuit boards must be increased without also increasing manufacturing costs. The material chosen to realise this goal is siloxane, which is capable of withstanding high operating and process temperatures, and yet components can be manufactured under conditions similar to those used to manufacture standard printed circuit boards.

Siloxane materials have been developed by Dow Corning, a global leader in silicon-based technology and innovation. The company wished to see their materials come closer to the marketplace through the realisation of high-performance technology demonstrators, as Dr Terry Clapp from Dow Corning explained: ‘Systems proof of the materials and process required a team of exceptional skill and knowledge of the contemporary state of communication technology and we identified that in Professor Ian White’s and Professor Richard Penty’s activities in CAPE.’

As well as contributing materials expertise, Dow Corning transferred the technology for waveguide processing to the University to allow independent demonstration of device fabrication. The Photonics Systems Group has in turn provided waveguide and device designs, mask layout, and device and systems test.

Commenting on the success of the relationship, Professor Penty said: ‘Working with the materials expertise from Dow Corning has allowed us to develop state-of-the-art polymer components and systems in a way we wouldn’t have been able to do on our own.’ A computer backplane to interconnect multiple computer blade servers has now been built with a total data capacity in the terabit range and a signal loss that is a world-record low.