How Liquid Flow Through Modules Work Reliably in Rugged Environments

Overview

This two-page technical paper by nVent SCHROFF details their liquid cooling solution for rugged electronics, developed in alignment with the VITA 48.4 standard and SOSA technical guidelines. As modern military applications demand higher computing power within tight SWaP (size, weight, and power) constraints, traditional air and conduction cooling methods fail to adequately dissipate the significant heat generated by multicore processors operating at speeds up to 300 watts per slot. nVent SCHROFF addresses this challenge by implementing liquid flow-through cooling modules that ensure efficient thermal management without exposing circuit boards directly to liquid.

The VITA 48.4 standard underlies the liquid cooling approach: coolant circulates through cold plates or embedded channels within each module to absorb and remove heat from processors. Advantages include superior heat dissipation compared to air or conduction cooling and suitability for high-power computing and signal processing in harsh military and aerospace environments. Cooling capacity depends on coolant type, flow rate, and cold plate design.

nVent SCHROFF customizes the liquid flow path for each PCB using in-house thermal simulations to optimize heat transfer. The resulting design uses aluminum cooling plates with securely sealed covers via brazing, laser welding, or friction stir welding, preventing liquid contact with sensitive electronics. The 1-inch module pitch conforms to VITA 48.4 and SOSA 3U/6U form factors. Connectivity between module and liquid cooling infrastructure leverages VITA 48.4-compliant quick disconnects that are leak-proof and vibration-resistant, ensuring reliable fluid transfer even under extreme vehicle movements.

Recognizing that liquid cooling modules must also resist shock, vibration, and leakage, nVent SCHROFF integrates additional securing features. Their 311 Series Inserter/Extractor provides self-compensation for board tolerances and maintains positive pressure on connectors, enhancing mechanical and fluid connection stability. The company’s High Clamp (HC) Force Card-Loks, offering up to three times the clamping force compared to standard retainers, further protect PCBs from mechanical stresses.

In conclusion, nVent SCHROFF’s two decades of liquid cooling expertise, combined with adherence to VITA 48.4 and SOSA standards, enable delivery of rugged, highly reliable liquid-cooled modules. Their innovations—from custom flow paths and secure quick disconnects to advanced retention hardware—reduce the risk of failure in mission-critical military electronics operating in extreme environments, all while allowing easy integration into existing 48.4 chassis systems.