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2011-11-18 by Russell Shaw
The stupidy of European government knows no bounds. Understanding and mitigating tin whiskers <http://www.eetimes.com/design/military-aerospace-design/4230652/Understanding-and-mitigating-tin-whiskers?pageNumber=0&Ecosystem=communications-design>
2011-11-18 by tda7000
Well, I already knew lead-free solder was stupid, but that article is a good read. The way I see it, lead-free = higher failure rate (and maybe not just from whiskers but probably also from higher soldering temperatures damaging components more) = more stuff thrown away = more in landfills and more pollution = pretty much the opposite of what RoHS is supposed to achieve! --- In Homebrew_PCBs@yahoogroups.com, Russell Shaw <rjshaw@...> wrote:
> > The stupidy of European government knows no bounds. > > Understanding and mitigating tin whiskers > > <http://www.eetimes.com/design/military-aerospace-design/4230652/Understanding-and-mitigating-tin-whiskers?pageNumber=0&Ecosystem=communications-design> >
2011-11-18 by Stefan Trethan
This is an old story, decades older than RoHS, some "consultant" probably just warmed it up to make a quick buck. The industry is well beyond this problem by using alloys instead of pure tin. The problems we have in modern equipment are due to bad design (over stressing of cheap components), and increasingly bad software (when have you last bought something software driven that doesn't have bugs?). Everyone who does repairs knows this. It's easy to blame the government because they are idiots, but it's just not the truth. The problem is us buying cheap, cheap stuff from china, and shipping it right back as junk, to be "recycled" by children who should be in school rather than in front of a pot of molten solder. Sure, RoHS doesn't really solve the problem, but neither does it cause it. ST
On Fri, Nov 18, 2011 at 10:30 AM, tda7000 <Tda7000@...> wrote: > > > Well, I already knew lead-free solder was stupid, but that article is a good read. > > The way I see it, lead-free = higher failure rate (and maybe not just from whiskers but probably also from higher soldering temperatures damaging components more) = more stuff thrown away = more in landfills and more pollution = pretty much the opposite of what RoHS is supposed to achieve! > > --- In Homebrew_PCBs@yahoogroups.com, Russell Shaw <rjshaw@...> wrote: >> >> The stupidy of European government knows no bounds. >> >> Understanding and mitigating tin whiskers >> >> <http://www.eetimes.com/design/military-aerospace-design/4230652/Understanding-and-mitigating-tin-whiskers?pageNumber=0&Ecosystem=communications-design> >> > > > > > ------------------------------------ > > Be sure to visit the group home and check for new Links, Files, and Photos: > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links > > > >
2011-11-18 by Russell Shaw
On 18/11/11 22:53, Stefan Trethan wrote: > This is an old story, decades older than RoHS, some "consultant" > probably just warmed it up to make a quick buck. > The industry is well beyond this problem by using alloys instead of pure tin. > > The problems we have in modern equipment are due to bad design (over > stressing of cheap components), and increasingly bad software (when > have you last bought something software driven that doesn't have > bugs?). Everyone who does repairs knows this. > > It's easy to blame the government because they are idiots, but it's > just not the truth. The problem is us buying cheap, cheap stuff from > china, and shipping it right back as junk, to be "recycled" by > children who should be in school rather than in front of a pot of > molten solder. Sure, RoHS doesn't really solve the problem, but > neither does it cause it. I hand-solder controllers for farm machinery and the last thing anyone wants is a blown controller in the middle of harvesting a million dollar crop. The problem is compounded by the temperature and vibration extremes. Same goes for anything else mission critical. Luckily, i still use lead-tin solder and am far away from europe (the further the better).
2011-11-18 by Dylan Smith
On Sat, Nov 19, 2011 at 12:03:24AM +1100, Russell Shaw wrote: > Same goes for anything else mission critical. Luckily, i still use lead-tin > solder and am far away from europe (the further the better). You can still buy leaded solder in Europe. Farnell sells big reels of the stuff. Europe's actually very nice. You should visit one day :-)
2011-11-18 by Russell Shaw
On 19/11/11 01:03, Dylan Smith wrote: > On Sat, Nov 19, 2011 at 12:03:24AM +1100, Russell Shaw wrote: >> Same goes for anything else mission critical. Luckily, i still use lead-tin >> solder and am far away from europe (the further the better). > > You can still buy leaded solder in Europe. Farnell sells big reels of the > stuff. > > Europe's actually very nice. You should visit one day :-) I've wanted to go to Russia and check out the space scene among other things like seeing what electronic components and surplus they have.
2011-11-18 by Anders Sponton
Russia is definitively NOT Europe! But we got our own space scene... Anders, Sweden, lurker ________________________________ Från: Russell Shaw <rjshaw@...> Till: Homebrew_PCBs@yahoogroups.com Skickat: fredag, 18 november 2011 15:48 Ämne: Re: [Homebrew_PCBs] Re: Tin Whiskers On 19/11/11 01:03, Dylan Smith wrote: > On Sat, Nov 19, 2011 at 12:03:24AM +1100, Russell Shaw wrote: >> Same goes for anything else mission critical. Luckily, i still use lead-tin >> solder and am far away from europe (the further the better). > > You can still buy leaded solder in Europe. Farnell sells big reels of the > stuff. > > Europe's actually very nice. You should visit one day :-) I've wanted to go to Russia and check out the space scene among other things like seeing what electronic components and surplus they have. [Non-text portions of this message have been removed]
2011-11-18 by Stefan Trethan
You know how it is on American maps, they go from Japan on the left to France on the right, Russia isn't even on them so how would they know where it is. ;-) ST
On Fri, Nov 18, 2011 at 4:21 PM, Anders Sponton <anders.sponton@...> wrote: > Russia is definitively NOT Europe! But we got our own space scene... > > Anders, Sweden, lurker > > > > ________________________________ > Från: Russell Shaw <rjshaw@...> > Till: Homebrew_PCBs@yahoogroups.com > Skickat: fredag, 18 november 2011 15:48 > Ämne: Re: [Homebrew_PCBs] Re: Tin Whiskers > > > > On 19/11/11 01:03, Dylan Smith wrote: >> On Sat, Nov 19, 2011 at 12:03:24AM +1100, Russell Shaw wrote: >>> Same goes for anything else mission critical. Luckily, i still use lead-tin >>> solder and am far away from europe (the further the better). >> >> You can still buy leaded solder in Europe. Farnell sells big reels of the >> stuff. >> >> Europe's actually very nice. You should visit one day :-) > > I've wanted to go to Russia and check out the space scene among other things > like seeing what electronic components and surplus they have. > > > > [Non-text portions of this message have been removed] > > > > ------------------------------------ > > Be sure to visit the group home and check for new Links, Files, and Photos: > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links > > > >
2011-11-18 by Peter Loron
As Anders said, Russia is not Europe, but it is definitely worth visiting (been there 4 times). There are exemptions in the RoHS regs for aerospace, military and other high-reliability uses. As was said, though, for most "normal" applications the early problems with lead-free solder have been fixed through improved solder alloys and soldering processes. -Pete
On Nov 18, 2011, at 6:48 AM, Russell Shaw wrote: > On 19/11/11 01:03, Dylan Smith wrote: >> On Sat, Nov 19, 2011 at 12:03:24AM +1100, Russell Shaw wrote: >>> Same goes for anything else mission critical. Luckily, i still use lead-tin >>> solder and am far away from europe (the further the better). >> >> You can still buy leaded solder in Europe. Farnell sells big reels of the >> stuff. >> >> Europe's actually very nice. You should visit one day :-) > > I've wanted to go to Russia and check out the space scene among other things > like seeing what electronic components and surplus they have. > > > ------------------------------------ > > Be sure to visit the group home and check for new Links, Files, and Photos: > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links > > >
2011-11-18 by Anders Sponton
Yepp, I know, it´s the WORLD map. (But the Americans produce a lot of good stuff, like Fenders, Gibsons, Rickenbackers and such). Anders, Sweden, lurker ________________________________ Från: Stefan Trethan <stefan_trethan@...> Till: Homebrew_PCBs@yahoogroups.com Skickat: fredag, 18 november 2011 18:44 Ämne: Re: [Homebrew_PCBs] Re: Tin Whiskers You know how it is on American maps, they go from Japan on the left to France on the right, Russia isn't even on them so how would they know where it is. ;-) ST On Fri, Nov 18, 2011 at 4:21 PM, Anders Sponton <anders.sponton@...> wrote: > Russia is definitively NOT Europe! But we got our own space scene... > > Anders, Sweden, lurker > > > > ________________________________ > Från: Russell Shaw <rjshaw@....au> > Till: Homebrew_PCBs@yahoogroups.com > Skickat: fredag, 18 november 2011 15:48 > Ämne: Re: [Homebrew_PCBs] Re: Tin Whiskers > > > > On 19/11/11 01:03, Dylan Smith wrote: >> On Sat, Nov 19, 2011 at 12:03:24AM +1100, Russell Shaw wrote: >>> Same goes for anything else mission critical. Luckily, i still use lead-tin >>> solder and am far away from europe (the further the better). >> >> You can still buy leaded solder in Europe. Farnell sells big reels of the >> stuff. >> >> Europe's actually very nice. You should visit one day :-) > > I've wanted to go to Russia and check out the space scene among other things > like seeing what electronic components and surplus they have. > > > > [Non-text portions of this message have been removed] > > > > ------------------------------------ > > Be sure to visit the group home and check for new Links, Files, and Photos: > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links > > > > [Non-text portions of this message have been removed]
2011-11-18 by Derek
Unfortunately we need to follow the regulations to create the products. I read the article yesterday and was quite impressed - they still do not know the cause of the whisker growth. What was interesting is that the growth has been known since the 1940's. The chart of using various solders based on the situation is a good reference. And the point that lead, in general, is non-soluble; so where vapors could be generated or wiped off and into one's mouth, etc, lead is restricted - paint and gasoline are examples. But withing packaged semiconductors and on coated PC boards, tough to get the "lead out". :-) Derek Koonce DDK Interactive Consulting Services
On 11/18/2011 1:10 AM, Russell Shaw wrote: > > The stupidy of European government knows no bounds. > > Understanding and mitigating tin whiskers > > <http://www.eetimes.com/design/military-aerospace-design/4230652/Understanding-and-mitigating-tin-whiskers?pageNumber=0&Ecosystem=communications-design > <http://www.eetimes.com/design/military-aerospace-design/4230652/Understanding-and-mitigating-tin-whiskers?pageNumber=0&Ecosystem=communications-design>> > >
2011-11-18 by a_utrobin
Hi, Russel. Welcom to Russia! If you need an oficial private invitation, please write me personally. I live in St.Petersburg (Russia). And this IS a Europe! But I think it is more simple to get tourist visa. BTW: our market of electronic components are from world wide, but according to customs rules it is more expensive then in origin. And we have some russian own components, your never listen. BBTW: we still use leaded solder in Russia for amateur practise and in special requirements to reliability. Good luck! Alexander. --- In Homebrew_PCBs@yahoogroups.com, Russell Shaw <rjshaw@...> wrote: > I've wanted to go to Russia and check out the space scene among other things > like seeing what electronic components and surplus they have.
2011-11-18 by Boman33
Anders & Peter, I suggest that you check your maps again. For example here: http://www.worldatlas.com/webimage/countrys/europe/eucaps.htm Russia, not Soviet Union, is part of Europe although many people do not think about it that way. Since I am originally from Sweden, here is a tidbit: The Swedish Vikings used to be called the Russ. They traveled extensively in what is now Russia all the way down to the Mediterranean and for example, Kiev was a Viking trade center. That is how Russia got its name. Anders: what part of Sweden are you from? I am from Karlstad. Bertho ============================ From: Anders Sponton Sent: Friday, November 18, 2011 10:21 Russia is definitively NOT Europe! But we got our own space scene... Anders, Sweden, lurker [Non-text portions of this message have been removed]
2011-11-19 by Anders Sponton
Middle part, north of Stockholm. Anders, Sweden ________________________________ Från: Boman33 <boman33@...> Till: Homebrew_PCBs@yahoogroups.com Skickat: fredag, 18 november 2011 21:20 Ämne: RE: [Homebrew_PCBs] Re: Tin Whiskers Anders & Peter, I suggest that you check your maps again. For example here: http://www.worldatlas.com/webimage/countrys/europe/eucaps.htm Russia, not Soviet Union, is part of Europe although many people do not think about it that way. Since I am originally from Sweden, here is a tidbit: The Swedish Vikings used to be called the Russ. They traveled extensively in what is now Russia all the way down to the Mediterranean and for example, Kiev was a Viking trade center. That is how Russia got its name. Anders: what part of Sweden are you from? I am from Karlstad. Bertho ============================ From: Anders Sponton Sent: Friday, November 18, 2011 10:21 Russia is definitively NOT Europe! But we got our own space scene... Anders, Sweden, lurker [Non-text portions of this message have been removed] [Non-text portions of this message have been removed]
2011-11-19 by mitch2054
Hi Derek, I ran some more searches to find a less-outdated link. Here's some notes: http://portal.groupkos.com/index.php?title=Tin_Whiskers Physics Today -- May 18, 2009 "Using Laue diffraction measurements made at the Advanced Photon Source at Argonne National Laboratory in Illinois, the researchers noted that at the CuSn interface, Cu6Sn5 develops along the tin grain boundaries and is most pronounced directly beneath a whisker's root. That observation, coupled with residual strain measurements, led the team to propose the following mechanism: Deep penetration of Cu6Sn5 into the 3-\u03bcm-thick tin layer induces in-plane compressive strains near the CuSn interface and in-plane tensile strains nearer the surface. Out-of-plane and in-plane strain gradientsnot the strains themselvesthen provide the driving force that leads to whisker growth by transporting Sn atoms to the whisker nucleation site as a strain-relief mechanism. (M. Sobiech et al., Appl. Phys. Lett., in press.)" It sounds like the whisker grows like a wart, with atoms adding from the metal surface that are migrating due to the asymmetric strain of an alloy blending to a non-alloy. Metal-creep over an alloy-bubble at the surface. AZdon --- In Homebrew_PCBs@yahoogroups.com, Derek <derek@...> wrote:
> > Unfortunately we need to follow the regulations to create the products. > I read the article yesterday and was quite impressed - they still do not > know the cause of the whisker growth. What was interesting is that the > growth has been known since the 1940's. The chart of using various > solders based on the situation is a good reference. And the point that > lead, in general, is non-soluble; so where vapors could be generated or > wiped off and into one's mouth, etc, lead is restricted - paint and > gasoline are examples. But withing packaged semiconductors and on coated > PC boards, tough to get the "lead out". :-) > > Derek Koonce > DDK Interactive Consulting Services > > > > On 11/18/2011 1:10 AM, Russell Shaw wrote: > > > > The stupidy of European government knows no bounds. > > > > Understanding and mitigating tin whiskers > > > > <http://www.eetimes.com/design/military-aerospace-design/4230652/Understanding-and-mitigating-tin-whiskers?pageNumber=0&Ecosystem=communications-design > > <http://www.eetimes.com/design/military-aerospace-design/4230652/Understanding-and-mitigating-tin-whiskers?pageNumber=0&Ecosystem=communications-design>> > > > > >
2011-11-20 by Derek
Interesting article AZdon. It talks about Cu6Sn5 being the start of the problem. I wonder if using a different nuclide would solve the issue. But then there is the purification of something like Cu7Sn6, that would raise up cost of manufacture. :-) Derek Koonce DDK Interactive Consulting Services --- In Homebrew_PCBs@yahoogroups.com, "mitch2054" <don@...> wrote:
> > Hi Derek, > > I ran some more searches to find a less-outdated link. > > Here's some notes: > > http://portal.groupkos.com/index.php?title=Tin_Whiskers > > Physics Today -- May 18, 2009 > > "Using Laue diffraction measurements made at the Advanced Photon Source at Argonne National Laboratory in Illinois, the researchers noted that at the CuSn interface, Cu6Sn5 develops along the tin grain boundaries and is most pronounced directly beneath a whisker's root. That observation, coupled with residual strain measurements, led the team to propose the following mechanism: Deep penetration of Cu6Sn5 into the 3-\u03bcm-thick tin layer induces in-plane compressive strains near the CuSn interface and in-plane tensile strains nearer the surface. Out-of-plane and in-plane strain gradientsnot the strains themselvesthen provide the driving force that leads to whisker growth by transporting Sn atoms to the whisker nucleation site as a strain-relief mechanism. (M. Sobiech et al., Appl. Phys. Lett., in press.)" > > It sounds like the whisker grows like a wart, with atoms adding from the metal surface that are migrating due to the asymmetric strain of an alloy blending to a non-alloy. Metal-creep over an alloy-bubble at the surface. > > AZdon > > --- In Homebrew_PCBs@yahoogroups.com, Derek <derek@> wrote: > > > > Unfortunately we need to follow the regulations to create the products. > > I read the article yesterday and was quite impressed - they still do not > > know the cause of the whisker growth. What was interesting is that the > > growth has been known since the 1940's. The chart of using various > > solders based on the situation is a good reference. And the point that > > lead, in general, is non-soluble; so where vapors could be generated or > > wiped off and into one's mouth, etc, lead is restricted - paint and > > gasoline are examples. But withing packaged semiconductors and on coated > > PC boards, tough to get the "lead out". :-) > > > > Derek Koonce > > DDK Interactive Consulting Services > > > > > > > > On 11/18/2011 1:10 AM, Russell Shaw wrote: > > > > > > The stupidy of European government knows no bounds. > > > > > > Understanding and mitigating tin whiskers > > > > > > <http://www.eetimes.com/design/military-aerospace-design/4230652/Understanding-and-mitigating-tin-whiskers?pageNumber=0&Ecosystem=communications-design > > > <http://www.eetimes.com/design/military-aerospace-design/4230652/Understanding-and-mitigating-tin-whiskers?pageNumber=0&Ecosystem=communications-design>> > > > > > > > > >
2011-11-21 by Peter Loron
Yes, geographically Russia considered a part of Europe. However the culture and mindset is different. Quite an interesting history for sure! -Pete
On Nov 18, 2011, at 12:20 PM, Boman33 wrote: > Anders & Peter, > > I suggest that you check your maps again. For example here: > > http://www.worldatlas.com/webimage/countrys/europe/eucaps.htm > > > > Russia, not Soviet Union, is part of Europe although many people do not think about it that way. > > > > Since I am originally from Sweden, here is a tidbit: The Swedish Vikings used to be called the Russ. They traveled extensively in what is now Russia all the way down to the Mediterranean and for example, Kiev was a Viking trade center. That is how Russia got its name. > > > > Anders: what part of Sweden are you from? I am from Karlstad. > > Bertho > > ============================ > > From: Anders Sponton Sent: Friday, November 18, 2011 10:21 > Russia is definitively NOT Europe! But we got our own space scene... > > Anders, Sweden, lurker > > > > > > [Non-text portions of this message have been removed] > > > > ------------------------------------ > > Be sure to visit the group home and check for new Links, Files, and Photos: > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links > > >
2012-01-11 by Russell Shaw
More tin whisker stuff. It's a largish download, but this report is definitely worth a look (especially the pictures): August 2011 "Lead-Free Electronics Reliability - An Update", A. Kostic, GEOINT Development Office, Aerospace Corporation, August 2011 http://nepp.nasa.gov/whisker/ Also worth a look: September 2011 H. Leidecker, L. Panashchenko, J. Brusse, "Electrical Failure of an Accelerator Pedal Position Sensor Caused by a Tin Whisker and Investigative Techniques Used for Whisker Detection", 5th International Tin Whisker Symposium, Sept. 2011 http://nepp.nasa.gov/whisker/