The defense industry thought it was off the hook when the RoHS directive was released. The military was exempt from compliance, which meant engineers would not have to struggle with tin whiskers – those tiny metal hairs that form easily on pure tin and can break off and short out a component. The exemption also meant the military would not have to defy the directive outright as leaders had threatened.
But there is a new wicket that is almost as tricky as tin whiskers: component obsolescence. Over the past two decades, the military has been buying an increasing percentage of its components on the commercial market rather than springing for the pricier mil-spec (military specification) parts. Mil-spec parts are highly reliable in the most extreme conditions. But military specifications gave us the $700 hammer, so defense procurement specialists turned to commercial products for the savings.
With RoHS, however, those commercial parts are going green. The military won’t buy the green versions of the commercial parts for fear of tin whiskers. And while many of the commercial parts suppliers insist they will continue to produce leaded parts for the military market, those parts will be produced for a significantly smaller market and will likely rise in price if they continue to be available at all. “I doubt there will be a big enough market for leaded products for suppliers to sustain production,” says Pat Wastal, SVP and director of the IP&E business group at component distributor, Avnet Inc.
A good portion of those leaded commercial parts will soon go obsolete. Even if suppliers continue to produce the leaded versions, you can bet those components will not progress with new technology the way the high-volume green parts will. The current generation will likely be produced for a few months, then dropped as the next generation of technology goes all green. So the military will probably have to return to the costly mil-spec components. “The military went to commercial parts to save money, but if they want to assure leaded product going forward, it will have to be mil-spec,” says Wastal.
Component experts believe that commercial parts that contain lead will be phased out over time. “This is a dimmer switch more than an on-off switch,” says Peter Lachapelle, VP of content and SRM at i2 Technologies, a supply chain company that tracks components. “Some of the leaded product will be available three to 12 months after the July 1, 2006 RoHS deadline, but that’s probably it.”
Lachapelle believes there will initially be an oversupply of leaded parts. “There will be an initial imbalance of inventory. The military will take what it needs and the rest of the parts will become disposable.” He expects the remaining leaded parts to be liquidated at severe discounts to manufacturers that don’t sell into the European market. After that, few commercial leaded parts will remain. “The military will be challenged to find economically viable leaded parts,” says Lachapelle. “The price point will not be as low because the production economies of scale won’t be there.”