High-Density Interconnect Modules with Innovative Thermal Management

May 15, 2019 by Scott McMahan

Molex showed its new BiPass thermal management configuration cooling for QSFP-DD (quad small form-factor pluggable double density) interconnect modules up to 20W with a 15°C change from the ambient temperature.

First unveiled at DesignCon 2019, the Molex QSFP-DD thermal solution can cool a range of 15W to 20W QSFP-DD transceiver modules in different configurations. The BiPass solution allows the cooling of higher wattage modules, and Molex expects the cooling solution to help designers on the path toward 112Gbps.

As the industry is preparing for next-generation copper and optical QSFP-DD transceivers, thermal management strategies are crucial. During a demonstration, Molex showed a SFP-DD belly-to-belly SMT configuration, QSFP-DD belly-to-belly BiPass configuration, Q 2x1 QSFP-DD stacked configuration, and 1x2 QFSP-DD BiPass in a vertical orientation with dual heat sinks.

In 15W operation, all configurations were able to cool at less than 25C delta T rise. The BiPass solution routes high-speed signals via the Temp-Flex twinax cables enabling increased channel margin compared to PCB alone. It allows for a second heat sink on the bottom of the cage to make contact with the module, offering additional cooling.

"If you need to be able to cool a 15W module, there are a number of different solutions available today," said Chris Kapuscinski, global product manager, Molex. "We now have the ability to cool higher wattage modules. The BiPass solution has the opportunity to save designers money as well as be a key enabler as we move forward with 112 Gbps PAM-4 implementations."

The BiPass solution allows bypassing of the lossy printed circuit board by utilizing Temp-Flex high-speed twinax. This bypassing results in lower insertion loss when going from an ASIC in a router or switch to another server within a rack.

Advances in heat sink technologies are enabling highly efficient, reliable and resilient thermal management strategies allowing higher density in both copper and optical connectivity.

The resulting improvement in signal integrity performance and lower insertion loss allows the use of passive copper throughout the design.

"As demand for faster data rates grow, data center technology is evolving quickly, and thermal management technology must keep up. The BiPass solution allows for better temperature control of a system using advanced materials, the latest tools and cutting-edge technologies without compromising performance," added Kapuscinski.