5 ms·
<i>Why shouldn't it? Isn't it just hardware too?</i> In a mechanical hard drive, there are moving parts which can wear out due to friction, etc. SSDs are soli
by blincoln 8y ago
<i>Why shouldn't it? Isn't it just hardware too?</i>
In a mechanical hard drive, there are moving parts which can wear out due to friction, etc.
SSDs are solid-state, so it seems like at least theoretically, it should be possible to build one that keeps working for decades. e.g. I have solid-state hardware from the 70s and 80s which still functions.
I've always been a little mystified as to why SSDs' data areas wear out for that reason,[1] but that's a whole separate issue. The author of the article is writing about sudden failure of the device as a whole.
There are only two explanations I've ever heard for short lifetimes in electronics as a general industry.[2]
For devices manufactured after about 2000 there's tin whiskers,[3] which began to be a problem because of RoHS requirements. I'm not sure if that applies here, though.
If the device includes electrolytic capacitors, my understanding is that those generally have a finite lifetime as well, and it can be fairly short if they're poorly-made.
I'm not a hardware expert, though, so I'd be interested in hearing about other factors, and I'm sure the author of the article would too.
[1] I've seen lots of writeups of how wear-leveling works, etc., but never a good physical explanation of what is actually wearing out over time.
[2] Obviously there are other factors for specific devices, or specific designs. E.g. maybe parts of a specific device break over time due to thermal expansion and contraction if the device wasn't engineered to handle that properly.
[3] https://nepp.nasa.gov/whisker/background/ https://nepp.nasa.gov/whisker/background/
- pbhjpbhj 8y agoOn the subject of capacitor death. Is there a robotic device that can take in a circuit board and swap out all the [electrolytic] caps?
- sigstoat 8y agoi've never seen or heard of an automated board rework system. thinking about the steps and things i've had to do to manually rework boards, your machine would need not only be able to apply force to pull parts off of boards without damaging the board, but also be prepared to restore pads / through holes to usable states after desoldering parts, before new ones could go back in. there's a reason companies don't repair circuit boards in consumer electronics.
- pbhjpbhj 8y agoI've done it myself, save restoring pads -- to me it's just the sort of fiddly, finnickety thing that it seems like robots sold be good at. And, they're not going to burn their fingers or run out of hands to hold things!
- PeterisP 8y agoRobots are good at repetitive tasks and economy of scale. Doing a tricky action for ten thousand boards is something that robots are good at; doing a different tricky action on each of a hundred boards is not. It doesn't seem plausible to have a business case where you'd get be able to get a large quantity of identical boards (that are otherwise good!), replace caps on them, and be able to sell them for much more than you got them - i.e. that the boards haven't become obsolete in that time. If there's no mass production, there's not much use for automation.
- rasz 8y agoYes, and it mostly speaks Ukrainian, or Chinese.
- falcolas 8y agoOn 1): It's because each cell is essentially a consumable with a limited number of state transfers. It's similar in that way to how a solid state accellerometer still has a moving part inside it that can break or wear out over time. EDIT: More reasons and methods for failure of "solid state" circuits and systems: https://news.ycombinator.com/item?id=14765868 https://news.ycombinator.com/item?id=14765868
- blincoln 8y agoI understand that there is something that makes the cells stop working over time. blattimwind's reply is the first actual explanation I've ever seen of what that something might be.
- blattimwind 8y ago> I've seen lots of writeups of how wear-leveling works, etc., but never a good physical explanation of what is actually wearing out over time. SSDs are flash are basically EEPROMs. In an EEPROM one bit is stored in a dual-gate MOSFET. One Gate is a normal gate, the other is floating, i.e. it just is a small conductive island. The information is stored by (quite literally) shooting electrons through the insulation of the floating gate into it. They're then trapped on the gate; if you turn the second gate on, the transistor conducts iff the floating gate is also turned on. This shooting action happens to damage the insulation, which at some point is degraded enough that it can't keep the electrons trapped on the floating gate. Hence the electrons leave, together with your information. > For devices manufactured after about 2000 there's tin whiskers,[3] which began to be a problem because of RoHS requirements. The solder joints themselves usually don't form whiskers, which mostly grow on pure tin-plated surfaces, e.g. the pins of components (which previously used lead). Using lead-free solder is mostly co-incident with whisker risk, not the cause of the majority of problems.
- 0db532a0 8y agoThe electrons aren't shot through the insulation. They end up in the floating gate by quantum tunneling. The insulation by its name is non-conductive, and must be so that the electrons stay put. The degradation happens through general thermal wear.
- userbinator 8y agoThe exact wear mechanism doesn't really matter (you must be referring to "hot carrier injection") --- the point is that to record data, electrons are being forced through a material which gradually wears it out.
- 0db532a0 8y agoThat was also my point. I was just pointing out that the idea that electrons shoot through the insulation to end up in the floating gate was not true.
- 8y ago