Unsung Hero of the Industrial World

Unsung Hero of the Industrial World – the usefulness of X-Ray Fluorescence X-ray measurement using the X-ray fluorescence method has been important in industry for many years. It has been used for the measurement of coatings, more recently in identifying the banned elements in the RoHS directive and now in gold assay. Coating measurement became important with the use of gold on printed circuit boards and connectors. The normal electromagnetic and eddy current techniques do not work with gold coatings and the destructive methods were unpopular as the item was damaged and toxic chemicals were involved. As the coating – gold - was valuable, the higher cost of the instruments could be justified and the cost recovered in savings in a short period. X-ray systems are able to measure very thin coatings in the nanometre range and they also could measure several different layers in one measurement. With the advent of more complex coatings, they were developed to measure the alloy composition of the layers and can measure the thickness and composition of under layers in complex coating systems. The coatings were often expensive palladium-nickel under gold in the electronics industry and the more corrosion resistant nickel-zinc coatings in the automotive industries. Plating companies also can use these systems to analyse the plating solutions in their baths and determine if more chemicals are needed in a few seconds, rather than the hours sometimes taken by other wet chemistry methods. The recent introduction of the RoHS directive has seen these systems develop into analysers with the much improved performance required to find the few parts per million allowed for lead, cadmium, mercury bromine etc in the directive. The systems can even be used to analyse for the banned substances in plastics, where complex matrices of chlorine and other elements make this an exacting task. The removal of lead from the electronic solders used in commercial equipment has presented a problem for the aerospace and military industries. They are exempt from this aspect of the regulation at present as leaded solders are well proven for extreme environments and they do not wish to risk failure in life and death situations. Commercial components are now mostly lead free and sourcing leaded components has become difficult and in some cases risky. This is highlighted in the cost saving initiatives in the military, such as COTS (Commercial Off The Shelf) purchasing policies. Companies in these industries now often have to screen their components with X-Ray instruments to ensure they have the lead they require. This brings us full circle to gold again. All the (good quality) jewellery sold in the UK must be Hallmarked and there are Assay Offices around the country (London, Birmingham, Sheffield and Edinburgh) where this certification takes place. For many hundreds of years this was achieved by Fire Assay, where an item was heated with lead and treated with chemicals to remove all metals except the non reactive gold, which was then weighed. This process, although accurate, was time consuming, expensive and used a good deal of energy. Using an X-ray analyser, the analysis can be made in a few minutes and as well as measuring the gold, the copper, silver and other metals are all quantified in one measurement. There are also regulations banning nickel in jewellery and this also can be determined by X-ray analysis. As the analysers are so powerful now, some assay offices are now providing a more comprehensive analysis service for RoHS as well as nickel and of course gold. If you’re an electronics company, an aerospace or military organisation, an assaying office or an industrial company with a need for material coating thickness and analysis, please visit the dedicated microsite www.fischer-material-analysis.co.uk, where there is a question facility and a de

For more information on Unsung Hero of the Industrial World talk to Fischer Instrumentation