Contamination effects from component finishes in lead-free soldering

Circuit World

ISSN: 0305-6120

Article publication date: 1 June 2004




(2004), "Contamination effects from component finishes in lead-free soldering", Circuit World, Vol. 30 No. 2.



Emerald Group Publishing Limited

Copyright © 2004, Emerald Group Publishing Limited

Contamination effects from component finishes in lead-free soldering

Contamination effects from component finishes in lead-free soldering

Keywords: National Physical Laboratory, Lead-free soldering

The National Physical Laboratory is seeking partners to investigate the impact of unknown component alloy finish during the lead-free transition period and its impact on reliability.

At present, there is an issue with mixed alloys occurring with component finishes and with the solder alloy used in attachment. Ideally, the metals used should all be either tin-lead based or all completely lead-free. Achieving this distinction is difficult at present, with the uncertainty that exists between the component manufacturers and distribution as to what components are actually being shipped. Known reliability problems can occur by the unfortunate combination of certain component finishes and alloys. Particularly worrisome is a small percentage of lead in nominally lead-free systems.

To clarify this position and identify where the risks lay the NPL is launching a collaborative project with industry to investigate the reliability of a range of components manufactured with tin- lead and lead-free alloys.

A number of test assemblies will be manufactured and these assemblies will be subsequently thermal cycled to assess their reliability, and an assessment in the form of a report produced.

Further details can be found at: or please contact: Dr Chris Hunt, National Physical Laboratory, Teddington, UK. E-mail:

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