Seeing this guy slowly come unglued as he tried to build a kit plane, on his own, in < 30 days, is one of the few things that make PBS worth watching.
Tin whiskers can grow at up to nine millimeters per year. They grow in any atmosphere including a pure vacuum. They grow in any humidity condition. They just grow. And when they get long enough they either touch another joint, shorting out one or more connections, or they vaporize in a flash, creating a little plasma cloud that can carry for an instant hundreds of amps and literally blow your device to pieces.
Since 2006 we have been exclusively manufacturing soldered connections thousands of times more likely to create tin whiskers than older joints made with tin-lead solder. Because of the universal phase-in of the new solder technology and the fact that the solder technologies can’t reliably be mixed (old solders mess with new solder joints in the same device through simple outgassing) this means that it is practically impossible to use older, more reliable technology just for mission-critical (even life-critical) connections. So we’re all in this tin boat together.
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Why? so we’ll buy new ones! Duh!
CC
I was just talking to some HAMs about this over the last weekend. While lead core solder does exist, it’s increasingly difficult to find. Rosin core solder is decent for repairs, but for longevity, I don’t trust it.
I’ve got an old Kenwood transceiver with lead soldered everything, and it’s still going strong. Meanwhile, I’ve replaced caps on two Yaesu radios in the last 5 years.
Just like with handling firearms, you don’t go off having a meal or putting your fingers in your mouth after soldering. I hate how our government has grown to such nanny-state proportions that even something as simple and effective as lead has to be regulated out of everything from bullets to transformers. Stupid.
So do you have a solution that is better than gold?
Seeing this guy slowly come unglued as he tried to build a kit plane, on his own, in < 30 days, is one of the few things that make PBS worth watching.
Something to do with the laws of thermodynamics?
So, kind of like cotton candy?
Another reason why, in some cases, paper records are superior to electronic.
Examples: voting ballots, family photos, medical records.
Interesting post. While searching for a replacement for a failing iMac I noticed eBay has several ‘sellers’ who offer re-soldering of high failure rate graphics cards.
The smoke gets out?
Most high availability computing environments call for regular shut down and vacuum out of computer components for this very reason. Home users should do this once per year to extend the life of their equipment.
Nothing Gillette cannot solve with a proper infusion of R&D capital.
PFL
Why? It's none of your bismuth.
On all my surface mount designs I used SAC, Tin, solver, copper. There have been several instances where I had to spec PbSn, but at that time it would still be considered RoHS. SAC works fine under most conditions.
The main problem I had was things that relied on their solder connections as a mechanical mount point, such as DC-DC power supply modules, daughter boards and large pig tailed cable bundles soldered directly onto a PCB board.
Tin will crack and slag and if there is nickel in there, then you definitely can get whiskers. Plus the angle of repose is shallow which contributes cracking and conductivity problems.
A couple of good links from the NASA program I found on Ken Rockwell’s camera site:
Page 41 starts into detail at this pdf:
http://nepp.nasa.gov/whisker/reference/tech_papers/2011-kostic-pb-free.pdf
and this site:
http://nepp.nasa.gov/whisker/