I want to shoot it in about 20km altitude, but I have doubts about if the microcontroller still works under that low pressure. Does also anyone know the distance of the conducting paths?
... but I have doubts about if the microcontroller still works under that low pressure.
That would be new to me.
Decreased atmospherical schielding will increase bit errors rates, though.
Does also anyone know the distance of the conducting paths?
Not clear what you're asking there?
This is not a PCB design forum ...
Try to figure out exactly what challenges high altitude poses poses to your chip: low temperature, low pressure, radiation, ionization, ..... And then recreate similar environment on the ground to test your chip.
The device will be capsuled so temperature and radiation won't be a problem but I wonder if it survives the low pressure or will flash overs happen?
Semiconductor components are usually hermetically sealed anyway, so there is no relation to the surrounding pressure.
Otherwise, your application is similar to automotive conditions (roughly -30°C ... +50°C ambient temperature) or aeronautics (elevations > 10km), so similar measures would apply.
My company casts outdoor machinery electronic equipment in non-foaming PU lacquer.
Automotive temperature range is typically agreed to be -40C to 125C.
From first hand experience, -40C isn't the issue with automotives. Oil and batteries don't like getting cold, semiconductors, I've been told, just work better and better so they stop the testing at -40C.
Dear Daniel H
For which application usage : Spatial , inside a Zeppelin , Météo balloon ? Our STM32 are not rad hard qualified.
At below -40deg C our flash and overall digital should work if you increase VDD at 3.3 Minimum. Avoid operating at 1.8V. As exemple
But if it is just for fun, I’m interested to know if you do such test for us and share with the community ..
Low temperature, low blood pressure, and radiation are all not important at high altitude.Static ionization is your worst enemy.The stm microprocessors are very delicate devices, they do not tolerate spark hits of 2 kilovolts. Static voltage is collected on the parts of the probe itself, after which a breakdown occurs (spark). One small splash - and all your electronics turns into ballast.You need to protect the input signals of your PCB, and also apply a double screen with a weak connection.And yes, this is not an exciting activity.
I believe there will be no issue at high altitude except the Radiation as discussed.
to avoid issues with radiation, short tracks on the pcb, if you can afford it, use a 4/6 layer board use the out two layers as shield planes connected with say 1KR to the Ground terminal on the battery.
then use the 2/4 inner layers for routing, this will stop the radiation charging tracks.
otherwise a aluminum foil wrap around the whole unit, would be sufficient to stop all the radiation.
(connected by 1KR to the Ground terminal on the battery)
or a steel box except for the weight issue.
to avoid issues with radiation, short tracks on the pcb, ...
Radiation is mostly about internal MCU / semiconductor problems.
With small enough structural sizes, each alpha particle hit will distort internal states, i.e. flip RAM cell contents.
That means, albeit not physically damaged, it will do weird things up there.
Retrieving data ...