Assuming that 3G cell-phone service is still available, will a brand new 3G cell-phone left in the box unopened for years exhibit deterioration (or death) when finally opened?
(Any explanation of why I would like to know this would only give more ammunition to those who think I’m nuts.)
No, I very much doubt it. It’s going to be shielded from oxidation, radiation, and mold/mildew and other biological growth. I’d say it’d be pretty pristine after decades assuming that there weren’t any punctures in the packaging.
It may or may not be shielded from oxidation, depending on the packaging. For something intended to be used in an open atmosphere, I doubt that any money will be spent by the manufacturer to protect it from oxidation during the short time it’s expected to remain unopened.
It’s even more doubtful that it will be shielded from environmental radiation.
There have been historical problems with tin (and other metal) whiskers wrecking electronics after some time. The Wikipedia article says the problem was originally solved by adding lead to solder, and now that lead is being excluded, the problem is once again becoming a concern.
The electrical components by themselves will still be fine. The problem will be the battery. At the least, it will not hold a charge anymore. Depending on the type of battery it may leak corrosive fluid that will wreck the electronics.
Interesting. I would have expected that tin whiskers would be less likely if the device is never on, that the whiskers would tend to grow to be “pulled out” by out an electric field, but that link says otherwise:
Define “years”. I’m a little fuzzy on the details (it’s been about 25 years since I had a class on the physics of semiconductors) but there is an aging effect in semiconductors that will eventually cause the components to fail. This takes a while. It’s not going to have a noticeable effect in two or three years but over decades it could. You’ll have more problems in miniature electronics like what you find in a cell phone than you will in something like a stereo amplifier simply because the transistors in a stereo amplifier are a lot bigger and a small part of them can get damaged and not significantly affect their performance, where the same size fault in a cell phone could completely ruin the transistor.
Also, the electrolyte in some capacitors does not necessarily age all that well. This is more of a problem in those bigger “tin can” type capacitors than the small chip capacitors used in miniature things like cell phones.
I would also be very surprised if the packaging were airtight. I’d expect some oxidation problems in the long term. I don’t think they vacuum pack cell phones.
Cell phones are not shielded from radiation (for most of the common uses of the term “radiation”).
The firmware in the phone will degrade over time. The flash eprom chips themselves don’t go bad but they do lose track of their 1’s and 0’s. Technically re-flashing the firmware would fix it so it wouldn’t really be “broken” but that’s not something that a typical cell phone user can do and the phone wouldn’t work straight out of the box, which is what the OP is asking. This also doesn’t happen quickly. It’s a problem that occurs after decades, not months. Exposure to radiation like cosmic rays accelerates it, so a cell phone stored at a higher altitude will have more problems than one stored at or below sea level. A cell phone stored underground might be better shielded from radiation but also it might get more radiation exposure due to things like radon or naturally radioactive granite, etc.
I’m not sure what materials they use in the speakers and microphones these days, but I wouldn’t be surprised if they get brittle with age and fail easily. They might not be dead out of the box but they might die a very early death once you start using the phone.
ISTR that diffusion is a problem for ultra-small scale electronics, i.e. the distinct features of IC’s become progressively blurry over time as the atoms comprising them diffuse into the surrounding material. Maybe that’s the mechanism you’re thinking of? It’s not a problem for large-scale power electronics, e.g. the components in a stereo amplifier you mentioned, but when the size scales of electronic component features get to be on the order of tens of nanometers, perhaps diffusion could take a substantial bite out of those features in a relatively short amount of time.
Maybe someone more familiar with IC technology can confirm?
I regularly use electronic components that are decades old, since I pull them out of stuff people throw out, including parts often considered to deteriorate over time like electrolytic capacitors (if I suspect them, I open up one or two that I don’t really need, and if they are still juicy I figure that they are still good, I also use glue to hold the capacitors down, as well as provide an additional seal around the base; most of what I use are newer though since I prefer SMPS capacitors and 105C types). Ironically, exploded capacitors are much more common in newer equipment (typically those with some arcane Chinese name on them, like Fuhjyyu, due to defective electrolyte) Also, the last cell phone I took apart didn’t have any electrolytics, at least not the traditional wet type.
As for transistors and chips, I don’t think diffusion is a problem unless they get VERY hot, as in inoperative (hundreds to a thousand degrees C, as when they initially diffuse atoms into the chip). You might be thinking of electromigration, but this only happens when powered up.
As for lead-free solder, I haven’t had any problems with it (aside from a higher melting point, but with a soldering iron that’s only a problem with very large joints, like soldering a heatsink down, thus I save old solder from PCBs for that use, mixing it with some fresh solder). Of course, most of what I use are through-hole or larger SMT components and I liberally use hot melt glue over the connections (wired on a perfboard, so no PCB traces, the glue is mainly to hold wires in place; this also limits the operating temperature to 50C or so, so most of the parts run pretty cool).
Note also that the rate of aging is generally considered to double* with every 10C temperature increase, so a part that can operate for a decade at 50C will last far longer (80 years) if stored at 20C.
*This capacitor datasheet says every 5C increase halves the lifetime (at least from ripple current heating, which isn’t really different from other sources of heat); thus, going from 105C to 20C is 17 doublings (131,072 x 2,000-5,000 hours).
One thing I discovered in replacing a droid screen is that the latest cell phones are largely held together by adhesives which bind the various components together. They also make the phones extremely difficult to service or fix. The life span of the adhesives re integrity is going to be the main issue in how a sealed phone ages.
If the box were wrapped tightly in cellophane, would that wrapping on average increase, decrease or have no real effect on the life of the phone?
Definitely agree here. I’d be surprised if anyone makes vacuum packed cell phones. The added cost to manufacturer would be quite a bit, with no return on investment.
The reflash-ability of this would depend in the region of the loss. Many (most?) cell phones on the market today use a bootrom in the flash part to enable reflash. If that’s damaged, and there is no valid backup, you wouldn’t be able to reflash it.
Hmm. I was just hanging out with an audio engineer at the bar. I’ll have to ask him next time I see him.
That’s an interesting part of the problem. I also wonder how various piezio-electric components might behave over time.
(I also wonder how to spell piezio..)
-D/a
Losing data from flash memory may not be as big of a problem as you think; at least, it isn’t uncommon to see retention times of 100 years or more specified, and even when the more usual 10 years is specified, tests show that they can easily exceed a century if kept near room temperature (this being the very important part, see my last post about the 10C rule; note that the 10 year retention time applies at the maximum rated operating temperature, which if it is 85C and you store it at 25C, results in at least 6 doublings, or a 64-fold increase/640 years). As for how they can test that:
So it’s possible in as little as 24 hours to simulate centuries of aging at room temperature (based on this, the 10C rule is again very approximate, or 60 years at 55C would be only 480 years at 25C, not 1150). Whether actual memory lasts as long as calculated I can’t say but I don’t really worry about it myself, unless by “long-term” you mean like in a time capsule meant to be opened in a century or more, or put on a space probe as an example of human technology in the hopes that aliens intercept it.
Hilary Algar - As mentioned by others, wrapping it in shrink-wrap would probably have little effect since even if it were airtight, plastic is permeable, if only slightly (this being why food wrapped in airtight plastic still dries out, think also of balloons deflating themselves for the same reason).