Lead has traditionally been the base metal of solder but, due to its toxicity, is nearly phased out by legislation such as the European RoHS Directive (2002/95/EC) and the WEEE Directive (2012/19/EU).
The present most common replacement of lead as solder metal is an alloy of Tin, Silver and Copper. This mix is, however, prone to the formation of brittle intermetallic compounds which is a major technical challenge in power-electronics products with high operating temperature.So, there is strong demand for solder metals which are more resistant to cracking over a product’s lifetime when
operating in a harsh environment, and which also can contribute to reduction in energy and materials required for the product manufacture.
A group of international researchers has reportedly developed a new formula for solder that could help to reduce cracking and premature degradation in vulnerable electronics for exposed applications, e.g. subject to high
temperatures and/or vibration such as in electric vehicles.
The new alloy formula includes nanoparticles and other microalloying elements that enhance the properties and the reliability of solder joints.
The research leading to the new potential solder formula was conducted by a British university in partnership with researchers in Japan and Malaysia and was funded by a British program intended to promote collaborative research in the field of climate change.
The motive for the present project has primarily been the growing need of reliability for long term survivability of
electrical vehicles, where the weakest link in the many electronics devices are usually the solder interconnects.
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