Those companies that still need components that are not compliant with the Restriction of Hazardous Substances (RoHS) directive may find those parts have become harder to find and more expensive.

With the July 1 RoHS deadline almost here, most component suppliers have already switched to lead-free parts. While this is good news for those companies shipping consumer electronics to Europe, the change comes with difficulties for those in the exempt industries of defense and aerospace.

For many years, defense and aerospace manufacturers – exempt from RoHS – have been buying off-the-shelf consumer components, which are less expensive than the high-reliability military components. Consumer components are produced in large volume, which had kept prices low. But now that much of that component market has shifted to lead-free versions, many component suppliers are beginning to shut down their production of non-compliant parts.

Just recently, executives from Avnet reported price increases and extended lead times on non-compliant parts. Those executives have also noted an increase in end-of-life notices for non-compliant parts. This trend was long predicted, as it will become economically difficult for component suppliers to maintain two production lines, one with compliant product and one with non-compliant product.

“Suppliers don’t want to run two lines,” noted Eric Karofsky, senior research analyst at AMR Research Inc. in Boston. “This will become a big issue for the industry because there is still a market need for those non-compliant legacy components.”

Some design engineers in the defense and aerospace industries are already feeling the shortages of non-compliant parts. The problem is aggravated by the fact that these engineers are skeptical about the long-term viability of parts that contain no lead, so non-compliant versions of the parts they need may not be an option. An engineer from Lockheed Martin who spoke to Electronic News on the condition of anonymity said that he will not design a pure-tin component into a system because of concerns over tin whiskers, which can grow over time under stress on solder and coatings. “I will not allow a pure Sn [tin] part to be used,” said the engineer. “A mitigation to stop tin whiskers must be provided if pure Sn is used.”

While this engineer has not seen price increases or extended lead times yet for non-compliant components, he noted an increase in end-of-life notices on leaded product. “We’re using different part types because established parts are going obsolete,” said the engineer. “The new devices are being offered only in RoHS-compliant versions.”

He noted that some of the companies that produce high-reliability parts indicate they intend to continue producing non-compliant parts for the exempt industries. “The companies which have divisions dedicated to high-reliability components have said they will not go RoHS on some of the device types, while others say they will go RoHS but will have a non-pure tin option, as well.” The non-pure tin option means a solder that mixes tin with silver, nickel or another material designed to reduce the risk of tin whiskers growth on lead-free devices.

The engineer remains skeptical that component manufacturers can produces a non-lead product that is free from the risk of whisker growth. “The roadmap is not available yet on how to get a reliable solder that is PB [lead] free,” he said.

By: DocMemory
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