Metal Whiskers: Small Problem, Big Impact

Metal Whiskers: Small Problem, Big Impact

Metal whiskers are microscopically small "hairs" that spontaneously grow from metal surfaces, often from tin or zinc. They can cause short circuits, malfunctions, or even complete system failure.

The problem isn't new -- tin whiskers were already spotted in vacuum tubes back in the 20th century -- but since the ban on lead in solder (RoHS, 2006) it's back in the spotlight. Because lead-free alloys are more susceptible to whisker formation.

That's exactly why soldering with lead is still permitted in certain sectors, such as aerospace, defence, and medical applications. Adding lead turns out to be one of the most effective methods to significantly slow down or even prevent whisker formation.

DeltaProto is going to actively investigate this.

We're starting by testing and comparing lead-free and leaded solder in our prototype and small-series PCBA's, to provide insight into the risks and solutions around whisker formation. This way, our customers can make better-informed choices for their specific application.

In short: an invisible but serious phenomenon that designers, manufacturers, and users need to take into account -- and that DeltaProto will now be researching.

Do you have tips and/or experiences? Let me know in the comments! (Sources: NASA, JEDEC, IPC publications, among others)

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