High-reliability flexible optical printed circuit board for opto-electric interconnections

Abstract

In this article, the optical interconnection loss in OEPCB was discussed for fabrication tolerance study. The LightTool simulator showed that the optical loss variation at mirror angles from 44 to 46 was less than 0.5 dB. The diamond-blade approach was applied and the 45 6 1 mirror was implemented. The waveguide interface coupling loss was also discussed by different waveguide terminal surface quality. The diamond-blade method could provide smooth surface and low coupling loss. A prototype OEPCB was fabricated and achieved the propagation loss of 0.1 dB/cm and mirror coupling loss of 0.8 dB. After one hundred thousand of 0 -180 bending fatigue tests, the propagation loss was increased lower than 0.2 dB. The eye diagrams with 10 Gbps signals at 2-mm bending radius was showing a high Q factor more than 10. As the flexible polymer waveguide optical loss on OEPCB was insensitive to the bending, a higher Q factor was possible for the higher bit rate. In summary, a prototype OEPCB combined with the optical flexible waveguide and electrical rigid PCB was demonstrated with its high speed optical interconnection applications. We also confirmed that a 4ch VCSEL array and a 4-ch PD array could successfully transmit light signals at the total speed of 40 Gbps.

Ultra-thin and low-power optical interconnect module based on a flexible optical printed circuit board

“…The fabrication process of the flexible optical waveguide and the flexible OPCB, as well as the optical characteristics and reliability properties of those parts have been previously discussed. 2,4,5 Thus, this paper focuses on details of the module packaging process and the experimental results of the OIM. Figure 3 shows the fabricated flexible OPCB, with the embedded flexible optical waveguide.…”

10 Gb/s Optical Interconnection on Flexible Optical Waveguide in Electronic Printed Circuit Board

“…For in-device optical interconnection, the optical polymer waveguide transmission is better than fiber because of its easy fab-rication, productivity and enabling high density integra-tion in folded-type mobile device requirements. Some research combines flexible optical polymer waveguide and print circuit board (PCB) to realize flexible data transmission and optical electrical integration [3,4]. In order to realize the board-to-board or chip-tochip inter-connection, the vertical coupling into optical waveguide had been studied, which included the 90º-bent fiber blocks [5], laser ablation processing [6], micro prisms [7], and dicing processing [3,4].…”

12.5‐Gb/s Highly Flexible 180° Polymer Waveguide on Optical and Electronic Printed Circuit Board

“…For in‐device optical interconnection, the optical polymer waveguide transmission is better than fiber because of its easy fabrication, productivity, and enabling high density integration requirements in folded‐type mobile devices. Some research combined flexible polymer waveguides and print circuit board (PCB) to realize flexible data transmission . In order to realize the board‐to‐board or chip‐to‐chip interconnection, several approaches from vertical coupling into optical waveguide were reported to illustrate 90° bent fiber blocks , laser ablation processing , X‐ray lithography , reactive ion etching , and dicing processing .…”

“…Some research combined flexible polymer waveguides and print circuit board (PCB) to realize flexible data transmission . In order to realize the board‐to‐board or chip‐to‐chip interconnection, several approaches from vertical coupling into optical waveguide were reported to illustrate 90° bent fiber blocks , laser ablation processing , X‐ray lithography , reactive ion etching , and dicing processing . Furthermore, a rapidly growing bandwidth demand for high‐speed data communication on multichannel polymeric waveguides was using a cube‐core structure as lens functions for vertical optical coupling between waveguides .…”