metal whiskers

(redirected from Tin whiskers)

metal whiskers

Microscopic filaments of metal such as zinc and tin that "grow" out of coated metal surfaces. In particular, zinc whiskers can be dislodged from the metal tracks of raised flooring, migrate via heating and air conditioning ducts into electronic equipment and cause short circuits if they settle onto circuit board surfaces. For more information on metal whiskers, visit http://nepp.nasa.gov/whisker.


Zinc Whiskers
The bright filaments are zinc whiskers emerging out of a scratch in the zinc plating on the underside of a 10 year-old raised floor tile from a computer room. According to Peter Bush, consultant to the International Electronics Manufacturing Initiative (www.inemi.org), there were some two million whiskers on this tile. (Image courtesy of Peter Bush, State University of New York at Buffalo.)
References in periodicals archive ?
The UK's National Physical Laboratory has developed a test vehicle incorporating specially plated SOIC components mounted on PCBs that have a high propensity to develop tin whiskers.
Our study subjected over a dozen alloys to a multitude of tests related to electronic solders, and we learned a lot about the creation of tin whiskers.
Tin whiskers no longer lives in jeffs basement, it has morphed into a real, live brewery with a space of its own.
The editors said, 'Whether we're talking the International Space Station, a C-17, or a Humvee, tin whiskers can throw a monkey wrench into system functionality, and even result in loss of life.
1), (2), (3), (4) This change sparked concern since pure-Sn plating has a well-known reliability problem: the potential to spontaneously grow tin whiskers.
Some scientists say that tin whiskers tend to occur when there is less than 3 percent lead in the coatings of a component.
It's not necessarily going to be on the formation of tin whiskers, a subsystem's reduced operating temperature, the proliferation of counterfeit components or potentially lowered reliability, but rather on the information flow between the customer and the manufacturer.
Tin whiskers refers to needle-like crystalline structures of tin (Sn) that form and grow on surfaces that use pure or nearly-pure tin as a final finish.
The guidelines the group has developed are intended to minimize the risk of failures from tin whiskers.
Tin whiskers can grow from tin-based finishes on components and connectors in a lead-free solder joint (Figure 1).
There are exceptions for medical and the military (who incidentally face critical problems of ensuring that Pb is used on their assemblies--imagine tin whiskers growing quietly in some ICBM silo), and there are other areas still under discussion or requiring clarification.
Three tests have been proposed by the JEDEC Solid State Technology Association with guidance from the National Electronics Manufacturing Initiative (NEMI) to more effectively screen for the susceptibility to tin whiskers.