You maybe interested to know The National Physical Laboratory is currently investigating a number of component related issues associated with lead-free process implementation. 

Last year we completed our second project looking at noble metal coatings (Au/Pd/Ni combinations). Details of reports are available on our website  : http://www.npl.co.uk/npl/ei/index.html. 

We are currently running a follow-on multipartner programme looking at plated lead free component finishes. This evaluation covers Sn, SnAg and SnBi platings and involves 5 plating chemistry suppliers, 15 chemistries in all, one component manufacturer, one OEM, one materials supplier, the European Space Agency and ourselves. Aspects of finishes being investigated include processability, solderability, plating ductility and propensity to tin whisker. We are currently looking at a technique which can develop tin whiskers in some coatings within 7 days of testing. We expect to report our findings around September.

Further projects to start in the next 12 months include an evaluation of component durability and the effects that increased processing temperatures may have on the long-term reliability of temperature sensitive components.

We are also developing a code of practice for temperature profiling during soldering. This project is a collaboration between four profiling equipment manufacturers, three OEMs, an oven manufacturer and ourselves. It is aimed at improving the accuracy of oven and wave soldering profiles as well as assisting OEMs to reduce the delta T across their assemblies during soldering and therefore reduce the maximum temperatures to which components might be exposed. 

The web site is kept updated so please keep an eye open for updates on the progress of the various projects.


Dr Christopher Hunt
Web:       www.npl.co.uk/npl/ei/
National Physical Laboratory
Centre for Materials Measurement Technology
Building 15
Queens Road
Teddington
Middlesex
United Kingdom TW11 0LW

Tel +44 (0) 208-943 7027 direct or switchboard 0208-977 3222 ext 7027 
Fax: +44 (0) 208-614 0428
E-mail:     [log in to unmask]

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