Lead Free Update: How connector makers plan to comply with RoHs mandate

Staff -- Purchasing, 2/17/2005

Here's how connector makers plan to comply with RoHs mandate.

Connector manufacturers are committed to complying with the upcoming ban on the use of lead in electronic products.

"About two years ago, most American manufacturers were saying it was not important," says Bob Hult, director of product technology for connector industry researcher Bishop and Associates Hult. "They were taking a sit back and watch attitude. They weren't interested. But they are committed to it now because most of their customers have committed to complying with the Restriction on the Use of Hazardous Substances (RoHS) legislation.

Tin lead is used in many connectors on the interface, but major connector manufacturers—including Tyco, Amphenol, Molex and FCI—have agreed to drop lead all together and use a pure tin interface.

"That seems like a simple solution, but the problem is a condition called tin 'whiskering' which occurs on pure tin surfaces," says Hult. (Whiskers are little crystals of pure tin that tend to grow quickly given the right conditions of temperature and humidity. Whiskers can short out adjacent contacts if they are close enough to them.)

With tin lead plating, whiskers are not a problem because the lead prevents whiskers form growing, says Hult. "Connector manufacturers have decided they can address the problem by making sure their connector-making processes are very controlled," says Hult. "By maintaining more control during the plating, connector makers believe they can minimize the issue."

To be sure, says Hult, "it will be more expensive for the connector maker. But it's hard to say (just yet) how it will affect prices," says Hult. "If manufacturers have to put in more plating lines or more accurate controls it could add to the cost of the connector."

Hult says when connector makers switch to lead-free, some will issue new part numbers while others will maintain the same part numbers and distinguish lead-free parts from leaded parts by date codes.