Signal Integrity Analysis in Immersion Liquid Cooling – Alibaba Cloud Server R&D Paper Accepted at DesignCon 2021

Recently, the DesignCon 2021 conference—often called the "Oscars" of high‑speed circuit design—was held in San Jose, USA, and the academic track announced that Alibaba Cloud's server R&D team had its paper "Signal Integrity Analysis in Immersion Liquid Cooling" accepted.

DesignCon is a premier forum that combines peer‑reviewed technical sessions with an exhibition, gathering global semiconductor and electronic‑design companies to showcase the latest advances in high‑speed signal modeling, simulation, testing, PCB design, packaging, materials, chips, and connectors.

With signal rates advancing from 8 Gbps to 112 Gbps, research on server board design, material selection, and manufacturing becomes increasingly critical for large‑scale server infrastructure, driving Alibaba Cloud to seek better materials, processes, and verification methods to ensure electrical performance and overall stability.

The accepted paper, the first to propose an analytical method for assessing how immersion liquid cooling impacts signal integrity, combines theoretical simulation with test validation. It reveals how different liquid media affect strip‑line, microstrip, high‑speed connectors, and cables on PCBs, identifies key influencing factors, and offers early‑stage design guidance to mitigate risks in massive deployments.

Industry forecasts estimate that China’s immersion‑liquid‑cooling data‑center market will exceed one trillion yuan by 2025, underscoring the growing importance of this technology for high‑density, high‑power servers and energy‑saving goals.

Alibaba built the world’s largest fully immersed liquid‑cooled data center in Hangzhou in 2020, achieving a PUE as low as 1.09. As liquid‑cooling expands, questions remain about its effects on signal integrity and whether traditional air‑cooled board and cable designs can be directly applied.

The Alibaba Cloud server R&D team continues to integrate fundamental research with product development, publishing over ten papers at top conferences such as ISCA, MICRO, and HPCA, and delivering innovations in fully immersed cooling, cloud‑native server architecture, heterogeneous acceleration, and edge computing to strengthen the digital‑economy infrastructure.