What we can obviously learn from this experience is that the manufacturers in the EU and all those who want to supply electronics products to Europe after the qualifying date have to be very cautious. We are now quickly approaching WEEE (waste of electronics equipment) registration which takes effect soon in August, requiring every country to have a reclamation system in place by then. And after this, with no break to lean back and relax, RoHS (reduction of hazardous substances), the most challenging project in our industry, is just three quarters away. In other words: time has almost run out.
So, what can be done now? The basics of transition should be completed, but RoHS legislation is still in flux, and some ideas of exemptions as well as other extended producer responsibility directives also currently under debate. We can observe that not everything has been finally said and settled in this matter. Watching this industry and its tendencies, we still can expect some more improvements. One example for this is the tin-whisker case, small needle-like crystals growing from electroplated tin. They can be over 1mm in length and therefore cause short circuits on soldered IC terminations. The old tin-lead plating is free from whisker formation, but RoHS will ban lead from most electronic products. The accepted Pb-free material for lead-frame plating is tin. If we would exempt fine-pitch components (pins spaced with centers 0.5mm or less) from the ban, and use about 15% lead in the plating, it would stop whiskering. But tin is not the only alternative to leadframe plating. Some companies are moving to environment-friendly nickel-palladium-gold plating for its RoHS-compliant parts.
The extremely slow mechanism of tin-whisker formation is not yet understood, but bending and scraping the tin is known to promote the effect. Another exemption initiative deals with the flexible ribbon-cable-type PCBs that are used as connections between board assemblies. Also here, researchers found out that 5 to 10% of lead in the tin or the other plating alloy NiPdAu will suppress the whisker effect. These are just two examples which have come up – watch out for more exemptions.
Yes, we should keep our eyes open, and it’s worthwhile to look for non-hazardous solutions. The RoHS/WEEE thing is just one tile of the entire mosaic we are forming. Everybody in this industry should keep in mind that we only have this one environment, this one planet – and we are responsible for it. This is no esoteric fooling around, but rather just plain truth.
