[HN Gopher] Tin whiskers: What happens when they spontaneously e...
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Tin whiskers: What happens when they spontaneously erupt? (2018)
Author : forgotthepasswd
Score : 139 points
Date : 2022-03-10 16:21 UTC (6 hours ago)
(HTM) web link (www.microcontrollertips.com)
(TXT) w3m dump (www.microcontrollertips.com)
| atesti wrote:
| Does anybody from Germany know where I can still buy leaded
| solder? Unfortunately I forgot to order a lifetime supply while
| it was still available
| tejohnso wrote:
| This is very surprising to me. I had no idea that certain
| conductors had some kind of (stochastic, according to robomartin)
| built-in time delayed short circuit mechanism that will, without
| question, manifest itself given enough time.
|
| Like some kind of natural electronics prank.
| voakbasda wrote:
| If you were feeling particularly cynical, you might wonder
| whether this phenomenon has been incorporated into shipping
| products, such manufacturers would be assured that their goods
| would fail shortly after the warranty expired.
| dmitrygr wrote:
| Use lead solder, like NASA does: easier to use, and no whisker
| issues. Just wash your hands afterwards
| mmastrac wrote:
| Better to solve these issues long-term. Lead's external costs
| in full product lifecycles are just too high.
| dmitrygr wrote:
| As you read in TFA, there is no known solution, nor even a
| known cause for whiskers
| mmastrac wrote:
| No known cause or solution _yet_
| adrian_b wrote:
| It is extremely unlikely to ever find any solution to the
| tin whiskers problem, other than alloying tin with toxic
| elements, i.e. either lead or antimony.
|
| The reliability problem could be solved only by replacing
| soldering with another method of making electrical
| connections during PCB assembly, e.g. thermal/ultrasonic
| welding of copper on copper, metal deposition in vacuum
| etc.
|
| While replacing soldering is possible, any known
| alternative method would hugely increase the price for
| the assembly of electronic equipment.
|
| Soldering is not used because it is a good method for
| making electrical connections, but because it is
| extremely cheap, allowing many thousands of connections
| to be made simultaneously, during a pass of a PCB through
| a reflow oven, or over a soldering wave.
| hulitu wrote:
| > The reliability problem could be solved only by
| replacing soldering with another method of making
| electrical connections during PCB assembly, e.g.
| thermal/ultrasonic welding of copper on copper, metal
| deposition in vacuum etc.
|
| The whiskers are not related to soldering. Of course
| there are some soldering issues which facilitate whiskers
| but that's about it. Tin is a normal plating material so
| you can find whiskets in places which were not soldered.
| Animats wrote:
| _The reliability problem could be solved only by
| replacing soldering with another method of making
| electrical connections during PCB assembly, e.g. thermal
| /ultrasonic welding of copper on copper, metal deposition
| in vacuum etc._
|
| There's been some interest in laser welding for PCB
| assembly. But most modern components are not designed
| with the pins out where you can get at them with a laser
| beam. Laser welding is commonly used to weld the
| connections in automotive battery packs, so it does work.
| Animats wrote:
| If you can get the parts you need in SSOP or TSSOP
| packaging, with the pins visible from straight down,
| laser brazing might work.
|
| Brazing is done at higher temperatures than soldering,
| but with a laser, you can apply the heat to just the area
| of interest, and hopefully not cook the ICs. Laser
| soldering already exists, and there are laser cutters, so
| adapting one for laser brazing ought to be possible.
|
| The advantage of brazing is that you can use many more
| materials, most of which don't contain either tin or
| lead. Low-cost aluminum brazing rod or wire might work.
| Working temp around 700C. This is going to take careful
| heat management. Worth a try for aerospace applications.
| formerly_proven wrote:
| Okay, so here's what's what. Tin whiskers have been known
| for ~100 years. Originally solder was just tin. Lead was
| added specifically in the 30s or so to avoid tin whiskers
| [1] though nobody knows why that works. RoHS/lead-free
| has been around for ~20 years and there hasn't been a
| definitive solution.
|
| [1] (and because Pb63Sn37 or the inexplicably more
| popular Pb60Sn40 are eutectic and near-eutectic,
| respectively, which is nice for wire dipping and related
| sports)
| iancmceachern wrote:
| Yeah, and we're not allowed to even put it in products
| anymore by law (RoHs, reach, etc)
| Steltek wrote:
| On the contrary, I am not NASA. I'm not even a consumer
| electronics company. I'm a hobbyist at home, soldering things
| at my desk or table. Lead-free is the least of my problems when
| building something and I don't believe "just wash your hands"
| is sufficient for cleaning my workspace (or kitchen table?) of
| possible lead contamination.
| alar44 wrote:
| It definitely is enough. I don't know where the myth that
| looking at lead kills you started, but unless you are eating
| it or breathing it in (soldering is not hot enough to
| vaporize lead) there's nothing to worry about.
| JaggedNZ wrote:
| Fellow hobbyist here. Actually your biggest health risk is
| industrial asthma from flux fumes. I know professionals who
| have spent a good fraction of there lives soldering with no
| lead poisoning issues. Lead needs to be consumed or inhaled
| for it to be an issue. The guy I meet who did have lead
| poisoning, large bore rifle shooting coach, from spending to
| much time at the "wrong end" of the rifle range. Lots of lead
| dust there.
| Flozzin wrote:
| I wouldn't recommend this. If you do use lead soldering, make
| sure you don't breathe in any fumes.
| foldr wrote:
| The trick is not to end up inhaling or eating the solder in
| its solid state. This is actually quite difficult to avoid,
| as cleaning the tip of your iron will create lots of tiny
| solder balls that fly everywhere and can persist in your
| environment.
|
| Personally I would say that in hobbyist electronics tin
| whiskers are the least of your concerns when it comes to the
| reliability of the devices you're making. I wouldn't risk
| using leaded solder even if the risk is low.
| mrob wrote:
| Agreed. This, not lead fumes, is the real danger of leaded
| solder. You can't hand solder reliably without cleaning the
| iron, but both of the common cleaning techniques (damp
| sponge and brass wool) inevitably break the soldier into
| tiny balls, which bounce and roll all over the place. They
| can get caught in clothes, and from there they might end up
| getting into food. With the safe dose for lead being zero,
| I don't think it's worth the risk.
| trhway wrote:
| During my elementary school years (beginning of 198x
| USSR) the lead was a go to material for a lot of things -
| using campfires we melted the lead out of Navy cables and
| batteries (from the Navy dumps), no gloves, no masks, and
| made a lot of things out of it - toy action
| figures/soldiers for example, weights and weighted hooks
| for fishing, bullets for DYI guns, gear for some games,
| etc. (I'm a drop-out from PhD. program at a top Russian
| Math school - didn't see money in it and thus went into
| programming, so i guess the few IQ points i lost due to
| lead (i score usually about 130) is what caused such poor
| judgement :)
| foldr wrote:
| None of those activities pose the same risks as soldering
| using leaded solder, for the reasons given above. (You
| are unlikely to end up ingesting significant quantities
| of the lead.)
|
| It's probably worth emphasizing that this is risk with
| home soldering, where you're likely to eat and solder in
| relatively close proximity, and without being completely
| rigorous about changing your clothes and cleaning.
| the-dude wrote:
| The boiling point of lead is 1749 degC (3180 degF).
| turminal wrote:
| That by itself does not imply fumes cannot form at lower
| temperatures.
| the-dude wrote:
| Great. If we follow this line, standing next to a roll of
| solder is just as dangerous. No need to fire up the iron.
|
| If lead was so easily dissolved into air, wouldn't we
| have had massive issues in electronics factories? I don't
| recall ever reading such a thing ( as opposed to
| _painters madness_ for example ). Not a native speaker,
| probably doesn 't translate too well.
| mcguire wrote:
| " _Results showed that the mean PbB concentration of the
| exposed workers (6.12 +4.61 ug /dl) was significantly
| higher than that of the unexposed workers (4.63+3.91
| ug/dl ) (z = 4.96; p = 0.001). There was a significant
| association between the blood lead concentrations with
| the exposure to lead (2 = 437.72; p = 0.001)._" (https://
| www.researchgate.net/publication/271077842_Occupatio...)
|
| " _Epidemiological and experimental studies indicate that
| chronic exposure resulting in blood lead levels (BLL) as
| low as 10 ug /dL in adults are associated with impaired
| kidney function, high blood pressure, nervous system and
| neurobehavioral effects, cognitive dysfunction later in
| life, and subtle cognitive effects attributed to prenatal
| exposure. Pregnant women need to be especially concerned
| with reducing BLL since this can have serious impact on
| the developing fetus._"
| (https://www.osha.gov/lead/health-effects)
| amatecha wrote:
| is that because they inhaled it in fumes, or because they
| touched it? or something else?
| the_jeremy wrote:
| Mad Hatter[0] is a good example in English.
|
| [0]: https://en.wikipedia.org/wiki/Erethism
| kadoban wrote:
| Or you could just look at the actual material property
| that matters, which I believe is called vapor pressure.
| xmodem wrote:
| The boiling point of water is 100 degC, and yet my shower
| seems to produce an awful lot of steam despite not being
| anywhere close to that.
| [deleted]
| at_a_remove wrote:
| You have confused steam with small water droplets, akin
| to what emerges from an ultrasonic mister. If it were
| steam, you would be shrieking and then dead.
| kimixa wrote:
| I thought everyone did the experiment of leaving a saucer
| of water out and seeing it evaporates over time, despite
| being significantly lower than 100c.
|
| And "Steam" is wooly term for high enough density of
| water vapor that you see condensation - often caused by
| higher temperatures in the majority of cases people
| experience it in day to day life. So it doesn't really
| have a precise definition. At what temperature point does
| "mist" become "steam?" What %age of the volume of air
| needs to be water vapor? If you lowered the pressure
| water "boils" at a lower temperature - is that still
| steam?
| deathanatos wrote:
| But it's still water, and it's still moving up and about
| of its own accord in the local air which is the point.
| That it isn't _technically_ steam doesn 't disprove the
| point the person you're responding to is trying to
| make...
|
| The commenter's point isn't that the lead has technically
| been boiled, it's that, if we analogize to "steam" in a
| shower, I don't have to reach water's boiling point
| before I'm breathing in water. Does that translate to
| lead: i.e., even if I'm below lead's boiling point, could
| I be nonetheless breathing in lead vapor, or something
| like that? (I don't know the answer here, which would
| push me towards lead-free solder. I.e., I don't know if
| the precautions I'd take with lead would actually
| suffice.)
| jpindar wrote:
| No, soldering doesn't send streams of liquid solder
| through the air. And if an occasional drip of solder does
| splash, it is so heavy, and has so much surface tension,
| that it doesn't go far and doesn't stay in the air like
| water droplets do.
| B1FF_PSUVM wrote:
| Good point. Also, steam is invisible. What we see - e.g.
| from a boiling kettle - is condensation.
| myself248 wrote:
| Or just get your blood lead level measured.
|
| A few months ago, I happened to be at the doctor getting some
| other stuff checked out, and the week prior to the
| appointment I had done a ton of soldering, like two 12-hour
| days bashing out a whole batch of boards, both paste reflow
| and hand-PTH work, with a fair bit of sucker rework, and of
| course after that the lab needed a good tidying so I emptied
| all the suckers and tip cleaners as part of that. All tin-
| lead solder.
|
| Zero gloves, and I only wore a mask part of the first day
| (when there were other people around). And actually the
| several weeks leading up to that also saw a lot of SMT rework
| and other up-to-by-elbows-in-solder sort of activity.
|
| So I figured, that's kind of a worst-case for my lead
| exposure, hey Doc, can I get my blood lead level checked?
| Sure why not, it's one extra vial on top of the bloodwork
| already being ordered!
|
| And the results came back below the test's detectable level.
|
| So as far as I'm concerned, if that didn't do it, I don't
| think I have anything to worry about. Now, I'm sort of a
| germophobe and I never eat with my hands, so this doesn't
| necessarily generalize, but as far as skin absorption or
| vapor inhalation, I've gone from "not very worried" to
| "abjectly unconcerned" after getting that result.
|
| I would encourage everyone to get their level measured and
| have actual data to make decisions with. Superstition does
| not become us.
| semi-extrinsic wrote:
| The vapor pressure of lead at 300 degC is around 10^-6 Pa. In
| laymans' terms, there is zero evaporation of lead happening
| during soldering. Ice at -40degC evaporates (sublimates) 10
| million times faster.
|
| The fumes from soldering are from the flux or rosin, and that
| is just as dangerous if you are using lead free solder.
| Always use adequate ventilation and/or filtration to avoid
| inhaling fumes.
| adrian_b wrote:
| Besides lead, there is a second element which greatly reduces
| the risk of tin whiskers, when alloyed to tin: antimony.
|
| However the proposals of replacing the tin-lead alloys withe
| tin-antimony alloys have been rejected due to the fear that
| antimony is also toxic.
|
| While antimony in high doses is indeed quite toxic, it is less
| dangerous as a pollutant than lead, because it does not have
| the same tendency for very long time accumulation in animal
| bodies and such a strong effect on the nervous system.
| 1970-01-01 wrote:
| Much more info here:
|
| https://nepp.nasa.gov/whisker/
| jwilk wrote:
| > _as fast as 15 nanometer per second to 1 mm per year_
|
| That doesn't sound right. 15 nm/s is ~47 cm/year.
| coryrc wrote:
| They break off if they get too long and will run out of
| material at some point.
| greggsy wrote:
| I don't think it's a steady growth rate.
| RicoElectrico wrote:
| > No one has been able to eliminate whiskering, as the phenomenon
| is not yet fully understood.
|
| It's the kind of stuff we should be embarrassed not to
| understand. I get that understanding living things can be tricky
| due to complexity and issues with controlling conditions, but a
| lump of metal? Whatever we find out will at least save us money
| in damaged devices, and hopefully drive some progress in
| metallurgy as well.
|
| We had an era in semiconductor manufacturing when despite the
| relative simplicity the process was not understood/controlled
| fully, which took the toll on yield. E.g. CMOS was super fussy
| due to difficulties in creating gate oxide - impurities in air
| like halogens made the yield seasonal [1]. But now I assume that
| if any problems arise, they're due to bona-fide complexity.
|
| [1] https://news.ycombinator.com/item?id=28178612
| [deleted]
| [deleted]
| [deleted]
| robomartin wrote:
| > It's the kind of stuff we should be embarrassed not to
| understand.
|
| We understand it. Onset is stochastic. Mitigation is impossible
| given current regulations in consumer-land. Read my longer
| comment for further details.
|
| EDIT: What I mean by "we understand it" is that we know that
| lead-free solder chemistry leads to tin whisker growth. When I
| was taking a deep dive into this many years back, the
| researchers I was working with at NASA told me "Growth onset
| can be 0 days to 3 years after manufacturing. Your guess is as
| good as mine.". And, BTW, you can have growth start in a few
| days in one corner of the PCB and a few months later elsewhere.
| It's a complex relationship of materials properties.
|
| We know that tin whisker growth in lead-free solder is as much
| of a reality as gravity is between two celestial bodies. In
| other words, it will happen. We simply have no way to predict
| when or how quickly they will grow. It might just be too
| complex to compute/predict given the variables involved.
| gowld wrote:
| That sounds like not understanding it.
| robomartin wrote:
| Not quite. We understand that we can't build an anti-
| gravity device and don't even know how to go about thinking
| of one. Understanding that something is impossible (or
| likely impossible) is understanding. We might not like the
| answers (I sure didn't at the time) yet they are a based on
| knowledge and decades of research by some of the smartest
| scientists I have ever met.
| hulitu wrote:
| There are parts of the process which we do not underestand.
| Testing is expensive especially at this level and nobody
| wants to pay for things which _could_ happen.
| semi-extrinsic wrote:
| A lot of the challenge here AFAIK is that the process needs to
| be understood at the molecular level, where we measure time in
| picoseconds (10^-12), while this process takes something like
| 10^6 seconds. The disparity is an absolutely astronomical
| factor of 10^18.
| ChuckMcM wrote:
| It really is an amazing phenomena. Effectively atoms of tin are
| moving from the tin out to the end of the whisker. We spent a
| week talking about whiskering(sp?) in my materials science class
| at USC because it was such a big deal in the EE world.
|
| Prior to that class my world view was that only electrons could
| travel through metal, only to find that metal can travel through
| metal too!
|
| Locally at NASA Ames they had an experiment where they had a
| bunch of different assemblies being exposed to various conditions
| (high electric fields, non-ionizing radiation, etc) and one of
| the things they were measuring was the production of whiskers and
| other changes in material properties (strength, toughness, Etc.).
| Always amazing what we know and what we don't know about what we
| know.
| zdragnar wrote:
| > that metal can travel through metal too!
|
| I recommend watching clips of mercury amalgamations forming
| (nile red has some great videos on youtube).
|
| There is something about it that is both disturbing and
| beautiful to me.
| cjameskeller wrote:
| That was a welcome rabbit hole. Thank you!
| rootusrootus wrote:
| > Effectively atoms of tin are moving from the tin out to the
| end of the whisker.
|
| Don't tin whiskers get built from the base up, though? So the
| tip was the first thing built, and just gets pushed farther
| away.
| prutschman wrote:
| Could potting prevent this, or can the whiskers "push through"
| epoxy?
| dr_orpheus wrote:
| Yes? In my experience (some spacecraft electronics stuff) this
| is also on the list of things where we think conformal
| coating/potting helps prevent tin whiskers. But there are still
| instances where Tin whiskers have grown and pushed through
| conformal coating on a PCB.
|
| Edit: Go look at the more detailed response from robomartin
| robomartin wrote:
| No. Can't prevent it. Yes, they can push through epoxy or
| buckle under it (which isn't a solution). Read my longer answer
| for details. These things are a nightmare.
| jccooper wrote:
| Yes; satellite boards tend to have conformal coatings, it helps
| but it's not a complete solution. (The coatings also help avoid
| shorts from junk floating around, and launch vibration.)
| Because of the inherent unreliability and difficulty in
| replacement, they also try really hard to avoid lead-free
| solder requirements.
| Damogran6 wrote:
| State of Colorado Datacenters got them. The response to them were
| weird...if any machine were in any of the affected areas, they
| were persona non grata...they could never leave those datacenters
| as functional server.
|
| It DID lever some money for an awesome off-site backup
| datacenter...which was eventually our only datacenter for
| 'reasons'.
|
| In our case, I think one of the datacenter's raised floors got
| carpeted (don't judge, it predated me, I was equally baffled) and
| a grounding issue caused a voltage drift causing the tin to
| migrate...
| walrus01 wrote:
| raised floors in general are a nightmare for
| grounding/bonding/differences in potential between racks, the
| steel floor structure, the building, and electrical conduits.
|
| there's a reason why almost nobody builds them new from a
| clean-sheet-of-paper design anymore for serious datacenter
| applications or ISP/telecom purposes, which are racks/cabinet
| on concrete slab and everything overhead now.
|
| it's _much_ easier to ground /bond everything together using
| some very fat copper cables run along ladder rack overhead, and
| bond all the racks to that.
| robomartin wrote:
| I have dealt with the tin whisker problem in the context of
| aerospace applications (both space-borne and terrestrial flight),
| including extensive consulting with subject matter experts from
| NASA.
|
| The bottom line is quite simple:
|
| Tin whisker growth onset is a stochastic process. We cannot
| predict when it will start and we cannot prevent it.
|
| Once they start growing it is almost impossible to contain them.
| They will poke through conformal coatings such as parylene and
| arathane. If they don't, they will buckle (coil-up) under the
| coating.
|
| While buckling sounds like a desirable outcome, this could lead
| to shorting of adjacent contacts in todays fine pitch integrated
| circuits and components.
|
| Growth rate can be in the order of 10 mm per year. This means
| that adjacent leads of something as mundane as a SOIC-16 package
| can be shorted by a tin whisker in 28 days or less.
|
| The take away is: There's nothing we can do about tin whiskers
| that is 100% guaranteed to prevent growth or slow it down by a
| non-trivial amount. The only path that prevents their growth is
| to use lead-based solder. This is why, as an example, we would do
| such things as send out BGA's with RoHS compliant solder balls to
| be re-balled with leaded solder.
|
| Time for a bit of a rant: All my work in this area led me to look
| at the RoHS initiative as yet another example of something that,
| while well intentioned, it will likely have precisely the
| opposite effect from what was intended.
|
| The fact that lead-free solder is susceptible to tin whisker
| growth means that 100% of all consumer electronic products are
| ticking time bombs when it comes to failures. This means that all
| kinds of consumer, commercial and industrial electronic products
| will fail over time in ways we might not be able to explain. The
| reason for this is that nobody does deep forensics when products
| fail. There is no reporting from the likes of Apple, Samsung, LG,
| Visio, Sony and myriad other manufacturers on failure rates and
| causes. In fact, they might not even have this data as consumer,
| commercial and industrial users simply replace the devices as
| they fail and move on.
|
| In other words, it is likely RoHS has caused --or will cause--
| massively more garbage in landfills. As a simple data point, my
| 40 year old HP-41 calculator still works perfectly fine. It is
| impossible to imagine a RoHS-compliant calculator not ending up
| in a landfill way earlier than 40 years.
|
| There was a bit of a movement to roll back RoHS around the time
| it was being enacted. Going up against many nations and
| politicians using "save the planet" to get elected proved
| impossible for those who rightly brought-up that the transition
| to lead-free solder required far more research before we fully
| understood the potential consequences.
|
| It wasn't about not wanting to go lead-free, it was about making
| the move when the science and math indicated that it would not
| create the massive problem we now likely have on our hands. The
| data on electronics waste due to tin whiskers is probably
| impossible to find. It might not even exist. Which is a tragedy.
|
| If you want to learn more about this, here are a couple of good
| links:
|
| https://nepp.nasa.gov/whisker./background/index.htm
|
| https://nepp.nasa.gov/whisker/reference/tech_papers/kadesch2...
|
| https://www.google.com/search?q=tin+whisker&hl=en&tbm=isch
|
| https://web.calce.umd.edu/tin-whiskers/
| xmodem wrote:
| Do you happen to know if tin whiskers have anything to do with
| passing current? (in other words, will a device that's in
| constant use develop them faster than a physically identical
| device that's switched off and in storage)
| hulitu wrote:
| Yes. Voltage has a big effect on whiskers.
| londons_explore wrote:
| Passing current means thermal cycling...
|
| And thermal cycling definitely accelerates whisker formation.
| twofornone wrote:
| Are there any easy ways to clean up a PCB that's developed
| whiskers? And once a whisker erupts on a given PCB, does that
| generally indicate that others are likely to form on that board
| in short order?
| oceanplexian wrote:
| Well actually, there is a way, but you might kill said PCB.
|
| Heat everything up in an oven, the solder will reflow, and
| you might temporarily fix the board. It's a similar idea to
| the Towel/Xbox 360 fix. I can attest to having successfully
| saved lots of random electronics this way.
|
| All of this started with the eco-friendly alternatives to
| lead solder, I have a lot of old computer hardware and
| motherboards, and the hardware from the early 2000s is the
| least reliable, whereas most game consoles, motherboards,
| etc. from the 80s and 90s works flawlessly. To this day I
| swear by the leaded stuff for personal use, it flows better,
| doesn't crack, and is superior in every way.
| robomartin wrote:
| All else being equal, once growth starts it is likely to
| start everywhere on that board. This is a probabilistic
| assumption based on the likelihood of all of the solder on
| that board being from the same batch and having been applied
| with the same process parameters. The same cannot be said of
| the device leads, where each manufacturer and batch could
| very well be different.
|
| It's quite a nightmare, particularly when you are trying to
| figure out if this stuff can kill people you want to send
| into space. The only real mitigation is lead-based solder and
| coatings on components.
|
| Cleaning? That can be both dangerous and highly ineffective.
| The whiskers are very strong due to their molecular scale.
| Mechanical brushing might fracture longer whiskers. Then you
| have the problem of ensuring that they don't go under devices
| or in-between contacts. The process would likely have to be
| repeated many times and include both manual and automated
| optical inspection as well as x-ray imaging (which might not
| be able to detect fine whiskers). And then there's the
| reality that you probably don't want to inhale these things
| at all.
|
| So, off to the landfill we go. It is likely better to build a
| new board than to try to clean one. I can't even begin to
| compute the delta in carbon footprint between making a board
| with lead-based solder that will last decades and the
| "clean/green" RoHS board that is sure to end-up in a landfill
| (cleaning/fixing it is bound to have a massively larger
| carbon footprint that making a new board).
| HPsquared wrote:
| Is this why space electronics often use wire-wound
| connections? Maybe welding the contacts together instead of
| soldering?
|
| I assume for the really critical components, you'd need to
| avoid solder completely.
| sydbarrett74 wrote:
| Unfortunately, all consumer electronics companies have
| this fetish for making products ever smaller and thinner.
| It dovetails with their profit motive: make things less
| reliable so we all have to buy more frequently.
| Ottolay wrote:
| RoHS does not just restrict lead. It also restricts use of
| mercury, cadmium, and several toxic compounds.
| Steltek wrote:
| > In other words, it is likely RoHS has caused --or will
| cause-- massively more garbage in landfills. As a simple data
| point, my 40 year old HP-41 calculator still works perfectly
| fine. It is impossible to imagine a RoHS-compliant calculator
| not ending up in a landfill way earlier than 40 years.
|
| Environmentalists can only wish that people were disposing of
| their electronics because of tin whiskers. Long lived consumer
| electronics needs a cultural overhaul more than it needs leaded
| solder.
| ghostly_s wrote:
| I did not know these whiskers had been implicated in the Toyota
| unintended acceleration scandal:
| https://nepp.nasa.gov/whisker/reference/tech_papers/2011-NAS...
| dilyevsky wrote:
| Miniaturization trend definitely doesn't help here either...
| stefan_ wrote:
| The _Restriction of Hazardous Substances Directive_ (RoHS) is
| not about preventing garbage in landfills, and frankly it 's
| been 18 years and the sky is not falling.
| MisterTea wrote:
| Yes but the parent is not stating that. They are stating that
| a "save the environment" effort is not very environmentally
| friendly if it makes more waste.
| _Microft wrote:
| They are assuming that these devices would be used long
| enough for tin whiskers to become a problem. I seriously
| doubt that RoHS will be causing more waste - because at the
| point that devices become unusuable, they are on in the
| trash anyways for completely unrelated reasons (think:
| bezel to large to be popular, plastic backshell instead of
| metal or glass, device is too thick, device is too heavy,
| ...).
| hulitu wrote:
| Tin whiskers continue to grow even after you device is in
| the landfill. You basically have a dust of tin which goes
| into landfil.
| mmastrac wrote:
| Saving the environment by reducing actively, acutely
| hazardous materials and saving the environment via reducing
| landfill/carbon emissions are completely different goals.
|
| As others have pointed out in this thread, reducing
| landfill waste from electronics is a much more complex
| problem and just adding leaded solder will not solve it.
| nomel wrote:
| That assumes waste reduction is the goal, rather than lead
| reduction. With toxic, intelligence reducing [1], materials
| like lead, maybe some extra waste is a perfectly good trade
| off.
|
| 1. https://news.ycombinator.com/item?id=30600539
| hulitu wrote:
| Last i checked tin was not an edible material. There is a
| small difference between having tin dust, which you
| cannot contain, and having electronics containing lead
| which you can colect and store in a warehouse ( asuming
| you want to address the problem in the first place).
| cinntaile wrote:
| Are you saying that electronics devices continuously let
| out tin dust so we end up breathing in this stuff?
| stefan_ wrote:
| Uhm, that is exactly the point that I'm making? That the
| goal was never save the environment, but rather reduce the
| exposure to toxic-at-any-concentration things like _lead_?
|
| Hence why I quoted the program name.
| Steltek wrote:
| Devices are disposed of (becomes waste) long before they
| become broken from whiskers. That makes RoHS a net-win by
| reducing toxic materials from landfills full of phones with
| broken screens and kitschy doodads with broken plastic.
| adrian_b wrote:
| The sky is not falling in large part because the transition
| to lead-free solder was simultaneous with the transition to
| electronic devices that are not repaired and which frequently
| have a lifetime not much longer than their warranty time.
|
| Most current electronic devices are dumped much earlier than
| when they would fail due to the tin whiskers.
|
| Many consumer electronic devices made 50 years ago are still
| usable without any problems caused by the aging of the
| soldering or of the semiconductor devices (but old
| electrolytic capacitors may have to be replaced). The
| electronic devices that are made now do not have any chances
| of such a long lifetime, with the exception of a few devices
| made for special requirements, e.g. military/aerospace.
| zozbot234 wrote:
| Consumer electronics used to break down all the time 50
| years ago. Metal whiskers are not even close to being
| relevant when other factors impact reliability and
| durability to a far greater extent.
| hulitu wrote:
| They used to break down and they could and were repaired.
| Nowadays if something breaks it goes in the garbage can.
| I had an extension cable which died staying in the
| basement for a year. When i opened it to check the reason
| i was shocked. It looked like a spider net made of dust
| but this was metal.
| adrian_b wrote:
| Consumer electronics used to break down all the time, but
| in almost all cases that was due to manufacturing
| defects, which were much more frequent, because many
| operations that are now automated were still done
| manually then.
|
| The consumer devices which survived infant mortality,
| because they were free of manufacturing defects, had a
| negligible aging rate after that.
|
| Modern electronic devices have far fewer initial
| manufacturing defects, due to automated production, but
| all age much quicker, due to very small component sizes,
| lower safety factors, surface semiconductor devices (MOS
| transistors) instead of bulk semiconductor devices
| (bipolar transistors), lead-free soldering and other
| similar changes in technologies.
| squarefoot wrote:
| > Consumer electronics used to break down all the time 50
| years ago
|
| But they could be easily repaired.
| oceanplexian wrote:
| Once things started going to multi-layer PCBs it was the
| end of reparability. It's too bad because I have fond
| memories of fixing broken components on PC hardware and
| game consoles, even as someone who's not an expert and
| simply a hobbyist.
| alfor wrote:
| Does wisker form inside semiconductor also or do they use
| metals immune to that?
| hulitu wrote:
| Yes they do but slower. In the past gold was used for wires
| from terminal to pads. Gold as far as i know is not so
| subceptible to form whiskers. But gold is expensive and now
| they use copper instead of gold.
| [deleted]
| mmastrac wrote:
| After seeing the articles on ice spikes, I wonder if this is
| somehow a related phenomenon.
| thanatos519 wrote:
| Indeed. Maybe they are also related to bone spurs!
| jerf wrote:
| Remind me more of this, only in slow-mo:
| https://www.nature.com/articles/nature.2015.16771
| [deleted]
| FpUser wrote:
| Accepting RoHS was in my opinion one of the most idiotic
| environmental initiatives that was rammed through without much
| thinking about long term cost / benefit analysis.
| hulitu wrote:
| A repaired device is one less device sold new. At the end what
| matters is money.
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