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Shelf life of assembled electronics

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PlainName:

--- Quote ---Second what others have said about purely touchscreen interfaces.  Great for a mobile phone but not for a car, not until we get true full self driving!
--- End quote ---

Not even then - there would still be the problem of jolts and random accelerations preventing accurate operation of a purely touch interface.

ebastler:

--- Quote from: pcm81 on December 01, 2022, 03:04:52 am ---Everything stated above makes sense to me, but there are also additional factors like solder, oxidation etc.
[...]
Naturally an assembly of components, like pcb, cannot have longer lifespan or shelf life than the individual components used on it; however it would seem like the assembly should have shorter lifespan than shortest lifespan of individual components, since assembly is an item of higher complexity and may be more prone to faults or additive behavior of faults.

That's why i was curious if anyone did any research into lifespan of assemblies.

--- End quote ---

Your concern seems to be that the ingredients used to assemble a circuit board (PCB substrate, traces, solder) are shorter-lived than the actual components? I don't think that is an issue in practice, and certainly not if the complete device is stored under conditions which are favorable for precision opto-mechanical assemblies: Moderate temperatures, limited humidity, no permanent vibrations.

A lot of the feedback you received above is based on actual experience -- people do use and repair old computers, test and measurement equipment, audio electronics etc. Some components are more prone to failure than others, as discussed above; but I don't recall ever seeing, or reading about, PCBs disintegrating or traces just corroding away on their own. (Unless a battery or electrolytic capacitor has spilled their corrosive guts...)

Solder joints may deteriorate into "cold joints" or develop cracks if parts run very hot, expand and shrink a lot under temperature cycles, or are subjected to mechanical vibrations without being properly supported. Again, none of these should occur in a precision (and low-power) device like a photography camera.

Cameras for very low-light use, e.g. in astronomy or high-end microscopy, use actively deep-cooled image sensors, and are somewhat likely to suffer from problems in that area sooner or later. The high temperature differences between operation and storage will cause mechanical stress on solder joints, and also on the seal of the (often evacuated) chamber which encloses the sensor.

Edit: Oh, and contact surfaces which are exposed to the environment can be a weak spot of course: IC sockets, connectors to internal or external wiring, contacts inside switches. That's where oxidation can bite... .

pcm81:


--- Quote from: Siwastaja on December 01, 2022, 12:09:33 pm ---I call bullshit about Berni's comments about the flash.

If the camera designers are not total morons (which they could be, though, in which case I will stand corrected), for the firmware, they use the kind of flash which
1) is NOT unreliable, and does NOT hide the unreliability by ECC. Might not have ECC at all.
2) has data retention of at least 50 years or so guaranteed by manufacturer, and this is at elevated temperature.

This is usually internal to the microcontroller(s), sometimes external, with size in hundreds of kilobytes to maybe a few megabytes.

--- End quote ---
Read all replies above and wanted to address this one specifically, because it talks about camera gear. Just dropped 3K on lightly used Nikon D5 with 25K shutter actuations. In comparison i have 16K shutter actuations on my D800, which i got in 2013 and it is still in mint condition. D800 is rated by nikon at 200K shutter actuations and D5 at 400K. So naturally came to realization that my cameras will eventually die of old age, not due to me using them beyond their operational lifespan. Hence this thread. Lots of companies do testing for MTBF vs cycles or OP time, but i have not ever seen a spec for electronic assembly shelf life, especially when it is with intermittent use, hence allowing for basic self maintenance to occur such as refreshing charge in non-volatile memory etc.

james_s:

--- Quote from: PlainName on December 02, 2022, 11:42:35 am ---
--- Quote ---Second what others have said about purely touchscreen interfaces.  Great for a mobile phone but not for a car, not until we get true full self driving!
--- End quote ---

Not even then - there would still be the problem of jolts and random accelerations preventing accurate operation of a purely touch interface.

--- End quote ---

They don't work well in the cold either, I suspect it's when the air is dry. Or if you have gloves on which I sometimes do in the winter. Winter is also a time that I suspect will cause a lot of "self driving" tech to utterly fail. How does a Tesla which uses only cameras tell where the road is when there's a coating of snow over it and the entire road is solid white as happened here the other day? How does any self driving car know that the road is likely to be covered in black ice and slow down preemptively?

PlainName:

--- Quote ---How does a Tesla which uses only cameras tell where the road is when there's a coating of snow over it and the entire road is solid white
--- End quote ---

Doesn't matter - it's got no choice which ditch it's going to end up in after all :)

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