Editorial

From time to time Circuit World is intentionally published as a themed issue with a focus on a particular topic or subject matter. A recent example was the issue covering buried passives and the last issue had a section featuring the work of the Innovative Electronics Manufacturing Research Centre. These issues were deliberately compiled to have such a focus but the same cannot be said for this issue, which has almost by chance developed into a themed issue simply by a coincidence in the close thematic relationship of the papers that have been submitted and selected for publication.

I am pleased, therefore, that this issue has a focus on the influence of environmental issues on materials choices in printed circuit board (PCB)fabrication. The issue begins with a paper outlining the impact of the various emerging regulations and market trends in lead- and halogen-free electronics; a topic that continues to provide challenges for PCB manufacturers around the world. There then follow a series of papers detailing studies of the material and reliability issues that have to be addressed when PCB laminate suppliers and manufacturers move to meet the requirements of the new regulations and the performance demands of their customers. The influence of new materials, material choices and the need for process optimisation on subsequent reliability should not be underestimated. The issue then continues with details of a new lead-free solderable silver finish that offers an interesting alternative to the traditional tin-lead HASL finishes, as well as other established silver finishes. Finally, and to complete the loop, this issue concludes with a review of recently completed work that addressed new technologies for recycling end-of-life electronics including PCBs.

One of the papers included in this issue is by Per Johander and his colleagues at the IVF in Gothenburg. Per initially presented an earlier version of this paper at the RAPRA International Conference on Polymers in Electronics that took place in Munich in January this year. Circuit World was a sponsor of this event and offered a prize for the best paper in the conference proceedings. Per's paper was the winner of this award and I am delighted that we have the opportunity to include the latest version of his paper in this issue.

I hope that you enjoy this issue of Circuit World and, as always, I welcome feedback, comments and suggestions by e-mail at: martingoosey@aol.com

Martin Goosey