Development of Manufacturing Technology of Optical Printed Circuit Board
The next generation of internet switches and high-end computers are expected to process aggregate data rates in the orders of Tbit/s. Consequently, the interconnections between the processing units will have to handle data rates in the order of 10-40 Gbit/s. Conventional electrical interconnection technology will suffer from high transmission losses and severe integrity problems at such data rates.
Optical PCBs interconnects are considered a preferred solution. The integration of optical waveguides in printed circuit boards has several advantages over the conventional PCBs. They are: increased data transmission rate, reduced physical size of electrical connection, reduced material cost and power consumption
Optical PCBs can be applied in telecommunications, photonic interconnection, Opto-Micromachine, etc.
For the past several years, researchers have focused on the material and processing technologies of waveguide fabrication. However, there is still no mature manufacturing technology for the mass production of optical PCBs. In the search for an alternative method, this research will address several technological gaps of optical PCB processing technology:
1. A photo-imaginable waveguide material to meet functional and processing requirements.
2. An imaging processing technology resulting in good dimensional integrity of waveguide layer.
3. Improved relibality for Optical PCBs.
For the past several years, researchers have focused on the material and processing technology of waveguide fabrication. However, there is still no mature manufacturing technology for the mass production of optical PCBs. In the search for an alternative method, this research will address several technological bottlenecks of optical PCB processing technology:
Several technological gaps are needed to be bridged if optical PCBs are to be manufactured using conventional PCB facilities:
- A photo-imaginable material making up waveguide core and cladding layer should be developed to meet functional and processing requirements. The waveguide core material should meet the functional requirement such as optical loss as well as processing requirement such as viscosity. On other hand, cladding material should be compatible with conventional PCB material (such as FR-4) to provide good adhesion between optical layer and electrical layer.
- The waveguide core layer must be in good dimensional integrity after developing. This requires a coating method that can provide excellent thickness distribution across the PCBs. Moreover, a photo imaging technique that can develop sharp and parallel waveguide core lines should also be developed.
- The fabricated waveguide layer will be subsequently laminated to a conventional electrical layer. As the material configuration of the two layers was different, the adhesion (and hence the reliability) of the final product is a concern.On the other hand, the waveguide material will be degraded if the lamination is too high. As a result, to develop the processing parameters of lamination is of paramount importance.
This project will address the above technology gaps
In this proposal, a new waveguide manufacturing technology will be researched. The technology is based on the spin coating of a polymeric waveguide material (polysiloxane) followed by laser direct imaging. The following deliverables should have been achieved by the end of this project:
1) a technology for processing Optical PCBs will have been developed
2) a database of processing parameters for access by local manufacturers will have been developed
Project Commencement Date:
01 October, 2011
Project Completion Date:
30 September, 2012
Dr. Winco K.C. Yung
Tel (852) 2766-6599
Project Team Member:
1.Dr. Winco K.C. Yung
2.Prof T.M. Yue
3.Mr. James Tam
4. Mr. C.P. Lee
5.Ms. Joanne Wong