Bourns hot-dips trimmers to eliminate tin whiskers
By Margery Conner, Technical Editor -- EDN, February 12, 2009
Tin whiskers—electrically conductive, crystalline structures that grow from surfaces on which tin is the final finish—have been the bane of electronic products since 2007. During that year, a European ROHS (restriction-of-hazardous-substances) directive essentially banned the use of lead in many electronic devices. However, the lead-free tin solder replacement is prone to whiskers, which can cause short circuits, interference, and unreliability. To virtually eliminate tin whiskers in its trimmers, Bourns’ line of ROHS-compliant cermet-wire-terminal trimming potentiometers now uses a new, hot-dipped-tin process. Although the process costs more than the matte-finished leads the company previously used, Bourns is not passing the additional cost on to customers, seeing it as an opportunity to gain market share.
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"During that year, a European ROHS (restriction-of-hazardous-substances) directive essentially BANNED the use of lead in many electronic devices BECAUSE tin whiskers can cause short circuits, interference, and unreliability. "
Is that WHY they did it????
Dave Dixon - 2009-16-2 08:22:00 PST -
"During that year, a European ROHS (restriction-of-hazardous-substances) directive essentially banned the use of lead in many electronic devices because tin whiskers can cause short circuits, interference, and unreliability."
That's a non sequitur; the tin whiskers are a _result_ of the lead ban. Don't get me started on the supposed reasons for the ban, which I don't feel has been worth all of the resources poured into accommodating it, not to mention the unintended consequences (increased tin mining, higher solder temperatures (energy costs/global warming), etc.)
Ron Bauerle - 2009-13-2 10:32:00 PST
