Monday, June 29, 2009

Are Environmental concerns killing our electronics?

Technology continues to advance at an ever-increasing pace and usually, were better off as a result.

However, there seem to be a growing number of instances where our attempts to improve our lot are having unexpected side-effects.

One example of this which might very well have a nasty effect on the electronics and computer industries is the switch away from lead-based solder.

Yes, the shiny gray metal alloy that for years has been used to attach all those various components to printed circuit boards has undergone a subtle change in recent years - and it's all down to a fear of lead.

Lead, as most people will know, is a soft, malleable and very heavy metal with quite a low melting point (as far as metals go). This low melting point and relatively good electrical conductivity meant that an alloy of tin and lead made the ideal "glue" for connecting wires inside electronic devices.

When the printed circuit was introduced back in the 1960s, there was no lead-phobia. In fact, houses were regularly decorated with lead-based paints, the glaze on kitchenware frequently contained a small percentage of lead and our cars belched clouds of the stuff into the atmosphere thanks to the octane-improving effects it had in petrol.

Roll forward a few decades however, and lead had become a villain.

Everywhere you looked, lead was being shunned as awareness grew of the subtle and devastating effects that it could have on health and the environment at large.

As a result of this, the ROHs directive was introduced and lead-use fell under its umbrella.

One of the first victims of this "lead-be-gone" campaign was a subtle change to the solder used in our computers and other electronics. The toxic lead was dumped, replaced with a cocktail of other metals including bismuth, silver, indium, zinc and others.

Unfortunately, in ditching the lead, these new solders have created what some believe is a disaster waiting to happen.

The issues are manifold but the key one is that of tin-whiskers, think crystals of tin that, over time, grow inexorably out of soldered joints, sometimes to the point where they create a short circuit by reaching adjacent components or circuit-board pads.

Some of the strongest concern comes from within the aerospace community, where a single tin-whisker could bring down an aircraft worth hundreds of millions of dollars.

What's more, the problem isn't something that can easily be weeded-out at production time or even in post-production testing. The tin-whiskers can take years to form to the point where they become apparent or cause problems. The computer that works perfectly today may fail completely tomorrow -- and without any warning.

Although work continues on addressing the issues created by the use of lead-free solders, it appears we're still a long way from coming up with a replacement that is as good as the old stuff.

Some pragmatists in the industry are still lobbying for a return to lead-based solders, claiming that the best way to preserve the environment while also retaining previous levels of solder-joint reliability, is to focus on effective recycling rather than dumping of waste electronics.

The case argued by these people is backed up by the realisation that, even at its peak, the total amount of lead used in solder accounted for just 0.5% of all the lead consumed world-wide. What's more, only 50% of such solder is used for electronics, the balance going into structural soldering such as plumbing etc.

So, if you've got the feeling that your new consumer electronic devices simply aren't as reliable as the old ones were - perhaps you can blame the solder they're now forced to use.

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