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nVent/Schroff Calmark High Thermal Card-Loks available from Foremost

nVent/Schroff Calmark High Thermal Card-Loks available from Foremost

Foremost Electronics, the engineering-led Essex based importer and specialist distributor of electromechanical components, can now supply the nVent/Schroff Calmark range of innovative Sawtooth “HTS” Card-Loks which meet the dual requirements of high clamp force PCB retainers for use in rugged environments as well as high thermal performance for the latest high-power data-processing systems. To develop these market leading products nVent/SCHROFF has worked with leading engineers in the industry to develop innovative board retention and cooling products to satisfy requirements for SWaP and Second Level Maintenance.

Increasing cooling demands in systems are being driven by greater data processing loads, higher clock cycles and increasing board density. The nVent/Schroff Calmark High Thermal Sawtooth card locks dissipate enough heat to meet increased cooling demands and avoid costly redesigns. The provide lower junction resistance that results in a 15% improvement of thermal performance when compared to traditional five segment card locks which are limited to only three heat paths.

The 260HTS, 265HTS and 280HTS Card-Loks are drop-in replacements for the standard Card-Lok series with the same profile, expansion and mounting options. They can provide up to 90% more clamping force than similarly sized clamping blocks and meet SWaP (reducing size and weight while effectively handling increasing power) requirements in conduction-cooled systems.

Heat in a conventional five segment Card-Lok must travel thought two segments to get to the cold wall. The sawtooth designed profiles of the nVent/Schroff HTS series provide heat transfer across the length of the Card-Lok with a continuous and uniform surface. This provides a shorter path for the heat to travel directly from the PCB to the cold wall. To further increase thermal performance the HTS Card-Lok can be machined into the enclosure frame, eliminating another thermal interface. This design can result in up to a 40% improvement in module thermal resistance depending on configuration.

Standard COTS and modified Card-Loks are available to meet a wide arrange of requirements and include designs for second level maintenance including torque limiting and tool-less card locks. With their small and lightweight designs typical applications include industrial systems, defence, space flight, communications, computers and intelligence surveillance.

Historically greater clamp force has only been available with larger profile card locks which require more space in the enclosure, are heavier and consume valuable board space. The innovative new nVent/Schroff high clamp force design features 30⁰ wedge angles versus the 45⁰ wedge angles on conventional card lock designs. The shallower angle provides greater normal force between the wedges resulting in enhanced clamp performance. The high clamp force provides on average more than 3X the amount of clamp force compared to similarly sized card locks. The new high clamp force retainers have been designed to be drop-in replacements for most applications currently using standard clamp locks.

Emma Kempster, Key Account Manager, of Foremost Electronics, comments;” With continued demands for systems to become ever more compact, managing heat dissipation is a major design consideration. The new nVent/Schroff Calmark High Thermal Card-Loks offer designers not only excellent thermal performance but also excellent PCB retention for systems in harsh environments and portable equipment.”

For more information on nVent/Schroff Calmark range of innovative Sawtooth “HTS” Card-Loks call +44 (0)1371 811171, email or visit

Posted by Michelle White