ERA's Reliability and Failure Analysis group is putting together a 'High Reliability Electronics Qualification Task Force' and invites companies such as Contract Electronic Manufacturers (CEMs) and product suppliers to participate in the project. The Task Force is urgently needed to provide data on the long-term reliability of electronics assembled with lead-free solders and in particular:

	qualification of high reliability and high performance lead free assembly processes
	pragmatic, industry-focussed assessment of lead-free electronics design

The customers of many high technology, low-volume CEMs must transfer their Printed Circuit Board (PCB) assembly to lead-free designs under legislative and market pressure. Although certain types of electronics assembly (eg. military products) are currently exempt from the Restriction of Hazardous Substances (RoHS) Directive, CEMs will not want to run separate production lines and most will therefore migrate to lead-free production.

Lead-free products have been on the market for several years but have mainly used solders containing bismuth or zinc, with melting points close to 200°C. It is now clear that the most likely lead-free solders for wide scale use are those melting at around 220°C. The effect of this change on both components and assembly requires a re-qualification of the whole production process. Companies making high specification products are asking CEMs to qualify their lead-free production technology for a 10 to 20 year product life. At present there is considerable reluctance to start down the lead-free route because of the lack of data on the long-term reliability of products using lead-free solders.

There are many technical problems to be considered. Earlier projects have shown that lead-free soldering of joints for electronic components onto PCBs can be produced consistently. The components used in these projects have often been integrated circuits as they provide large numbers of small closely spaced connections as well as a few passive components. The effect of the high temperature excursion during lead-free soldering on the long-term performance of active components has been investigated but very little work on the long-term performance of passive components has been carried out. One of the problems is that only accelerated testing has been used but it is not known how this can be extrapolated to obtain real life predictions.

	the immediate effect of the high temperature lead-free assembly process on certain temperature-sensitive components (including the PCB itself)
	the long-term life of all components after passing through a high temperature assembly process
	the effect that a specific mix of PCB components has on overall reliability

Participants in the project will be able to reduce the technical and commercial risk of moving to lead-free designs by demonstrating the reliability of lead-free assembly, whilst building important supply-chain relationships with other project participants.

For further information, please contact chris.robertson@era.co.uk

About ERA Technology
ERA Technology works at the leading edge of many advanced technologies. The business was founded in 1920 and today provides specialist, high value-added, technology-based services including design and development, testing, assessment and expert advice.

The company has built an international reputation for technical expertise through constant innovation at the leading edge of technology. ERA provides technology-based services across industries such as communications, aerospace, defence, IT, manufacturing, transport, electronics and energy.

ERA Technology is a Chelton Group company, part of Cobham plc.