RoHS compliant industrial connectors do not compromise on corrosion resistance, EMC behaviour and appearance

The key to Hypertac's ability to implement RoHS ahead of schedule was the principle of continuous improvement embodied within the ISO 14001 Environmental Management System. Working on this principle, Hypertac started intensive investigations to identify substitutes for the six banned substances ­ and in particular hexavalent chromium ­ long before the European RoHS Directive was passed on 27th January 2003.

The RoHS directive restricts the use of certain toxic metals like lead, mercury, cadmium and hexavalent chromium (chromium VI), and the use of some flame retardant additives in plastic in particular Polybrominated biphenyls (PBEs) and polybrominated diphenyl ether (PBDEs).

Hypertac's internal environmental rules already prohibited the use of the majority of these materials: hexavalent chromium, however, posed a real challenge. Chromium occurs in a number of oxidation states, the most common being +2, +3, and +6. While chromium (III) is an essential trace element
required in humans for a healthy metabolism, chromium (VI) can irritate the skin, nose and throat and can cause lung cancer.

Hexavalent chromium was, however, commonly employed in connectors deployed in harsh environments, as a surface coating to provide corrosion protection. Since no readily available alternative existed at the time, in April 2000 Hypertac GmbH started an investigation programme to identify technically
equivalent but environmentally safe substitutes. The programme included investigations into alternative materials, and into a number of different processing and surface treatment methods. The most promising solutions were thoroughly analysed and evaluated in close collaboration with Hypertac¹s
suppliers and customers.

Plating with chromium (III)Passivation treatments alternative to Chromium VI, combined with specialised surface preparation and post-processing techniques, was the breakthrough that made compliance with RoHS possible, while providing a paintable surface and retaining adequate corrosion
protection and electrical conductivity. Hypertac checked the effectiveness of the new process via a Test Validation Programme including salt spray durability tests following DIN 50021 SS and life cycle corrosion tests.