Abstract
The present disclosure describes methods and structures for improved secondary side cooling of pluggable optical modules (POMs) mounted in a "belly-to-belly" configuration compliant with Multi-Source Agreement (MSA) standards. Traditional cooling solutions rely on airflow-based convection, which is limited due to low airflow in constrained spaces under modules. The disclosed methods uniquely incorporate conductive heat transfer mechanisms using compliant thermal interface materials, such as graphite-over-foam (GOF), soldered spring gaskets, and thermally conductive gap pads, directly contacting the underside of POMs. Enhanced PCB designs include open-bottom cages exposing module undersides to PCB copper planes, deliberate removal of soldermask to maximize copper exposure, and extensive use of grounded vias and ground planes for heat spreading. Heat is effectively transferred via these conductive pathways to fixed external heatsinks, which dissipate heat into forced airflow. Alternative implementations utilize cold plates or passive heat-spreader assemblies with embedded heat pipes, further expanding applicability across diverse high-power optical modules and cooling configurations.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Anonymous, "Secondary Side Cooling of Pluggable Optical Modules in a "Belly-to-Belly" Arrangement", Technical Disclosure Commons, (May 16, 2025)
https://www.tdcommons.org/dpubs_series/8132