Design for reliability of polysiloxane-based electrical-optical circuit boards.

Based on the standards for optical components in telecommunications (Telcordia) and general printed circuit boards (Institute of Printed Circuits and International Electro Technical Commission), three environmental stability verification tests are concluded for polysiloxane-based electrical-optical circuit boards (EOCBs). In terms of defined test models, the respective acceleration factors are determined. Combining the acceleration factors and proposed reliability objective of 400 failures in time (FITs) (one FIT is equal to one device failure in 10(9) device hours of operation) at the 90% confidence level, EOCB test sample size to each acceleration test are deduced, and a corresponding amount of samples are prepared for mechanical and optical stabilities verification. In addition to the good mechanical stability the results exhibit, the packaged EOCBs have low and stable optical loss values (<0.1 dB/cm) and numerical aperture even at extreme environmental conditions. Furthermore, a total failure rate of 400 FITs is predicted for 14.4 yr of operation at 25 degrees C and moderate humidity conditions (20% relative humidity).