Ore.--A team of researchers from IBM and Dow Corning Electronics is claiming a
breakthrough that could enable silicone to supplant copper for creating
fast, energy efficient photonic interconnects on printed-circuit boards
(PCBs). The team demonstrated optical waveguides using a photonic
polymer at the Photonics West 2013 conference Monday (Feb. 4).
claims its collaboration with Dow Corning provides an integrated
approach to optical interconnects, similar to how metal PCB traces route
electrical signals around inside computers today. The polymer
waveguides are "highly flexible and resistant to high temperatures,"
said Bert-Jan Offrein, manager of the Photonics Research Group at IBM
Research (Zurich). Offrein said no curling or deformation was incurred
for bends as tights a 1 millimeter, and for extreme operating conditions
of 85 percent humidity and 185 degrees Fahrenheit.
makes uses of the same basic element as CMOS chips--silicon--but in a
flexible form that can transmit light around the bends and turns with
very little distortion. As a result, extremely fast and energy efficient
photonic interconnects can be fabricated that are capable of carrying
the exabytes of data needed for future data centers and supercomputers.
Peeters, a vice president at Dow Corning Electronic Solutions,
predicted that the new material will enable "silicone-based board-level
interconnects that quickly supersede conventional electronic signal
Flexible photonic waveguide made from Dow-Corning silicone material in IBM's Binnig and Roher Nanotechnology Center (Rueschlikon, Switzerland).
silicone polymer starts as liquid, like other optical materials such as
glass, but can be dispensed under normal atmospheric conditions,
solidifying in less than 45 minutes. The material also showed excellent
adhesion to conventional PCB materials like polyimide, had losses as
little as .03 dB per centimeter, was stable for over 2,000 hours at high
temperature/humidity, and survived 500 thermal cycles between -40 and
248 degrees Fahrenheit.
Photonics West presentation, "Stable and Easily Processable Optical
Silicones for Low-Loss Polymer Waveguide" was presented by Brandon
Swatowski, an application engineer at Dow Corning Electronics Solutions.
Photonics West is taking place this week in San Francisco.
If the waveguide is not isolated it is probably in touch with the polyimide FPCB. PI has higher RI than silicone. So to form a lossless waveguide during bending in smaller diameter you will need a low RI cladding to the silicone. Fluoropolymer is probably the only choice for silicone. Am I missing something?
1) silicone is a analogue of carbon based polymers - but the chain is of silicon atoms not carbon ones. There are many different silicones.
2) do they deposit the silicone in tracks or are they coating a whole board then etching it? I don't think 45 minute drying time is very practical if you have to deposit it as tracks, but as a board coating it might just work
With waveguides, loss-less bends can be made in case the index contrast is large enough compared to the bending radius of the bend. In the optical ray model, the total internal reflection condition is then still satisfied.
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