Arduino at 85°C?

Hello,

For tests on components I want to put arduino mega2560 in an oven at 85 ° C for two months.
I need to know whether or not the arduino will fail?

Are they certified for 85 ° C and for how long?

Thank you

The ATMEGA itself is specified for 85°C (125°C abs max).
I would maybe be a little more careful with current through the LDO.

It is not industrial or military or medical grade. The official Arduino boards are good quality, but as far as I know they are not guaranteed for a certain temperature range.

How is it powered ?
If you power it with 12V, then the voltage regulator gets too hot.

ATmega2560 : According to the datasheet, it will keep the sketch for 20 years at 85°C.
Resistors : no problem.
logic chips : no problem.
Crystal : Can't stand cold, but high temperatures should be no problem.
Capacitors : That depends on the quality and the type of the capacitors. I don't know.

Do some pins of the Arduino board power something ?

I think it should work at 85°C, but two months is a long time. Can you make an automatic backup system ?

I'd be nervous about the caps surviving; there's also a ton of other "stuff" on most Arduino boards, and I'd be concerned that some random part buried in there wasn't rated for 85c. I'd have more faith in a standalone atmega328p (ie, perfboarduino) with no electrolytic caps, and without all the unnecessary baggage that a normal arduino board comes with.

It’s not so simple unfortunately. If the background temperature is 85c then, assuming the arduino is running the operating temperature will be higher. Without knowing the thermal parameters it is difficult to know how much higher, but I would say the semiconductor device junctions may be above what’s allowable. Further, the caps will be on the limit before correcting for changes during operation.

There is the mega328p processor that is rated at 105c, you could use that with the simplest possible circuit (crystal, two ceramic caps and a ceramic bootstrap cap), it may last a few months in that hostile environment. Enable whatever power saving possible on that chip and do what you need on a timer or interrupt.

I need to know whether or not the arduino will fail?

Yes it will fail.

Just testing one won't tell you much. If you are serious about testing components then put a hundred in the oven. If the Mega is controlling the test then it should be in a cooler part of the oven. If the Mega is the test then buy 20 of them to test simultaneously.

aurelAirmems:
For tests on components I want to put arduino mega2560 in an oven at 85 ° C for two months.
I need to know whether or not the arduino will fail?

Are they certified for 85 ° C and for how long?

Why the heck do you want to do that.
Testing parts on the Arduino, or testing other parts with the Arduino.
I don't see how you can run this without wires to the outside of the oven anyway.
A Mega draws ~70mA, and that would be a mighty big battery for two months.
And how do you get the data out.

Educated guess: The 47uF electrolytic caps will fail first, and might leak all over the board.
They should survive 500-1000 hours@85C, but I doubt it.
The rest depends on current draw.
Parts that normally get warm will now get hotter than 85C.

Why a Mega. A Nano with fewer parts and no electrolytic caps might survive this a lot longer.
Leo..

I need to know whether or not the arduino will fail?

I doubt you will know without testing.

My experience at extreme temperatures is; staying at one temperature is not too hard on electronics unless you are already marginal on power dissipation and don't have enough voltage derating (for caps).

Thermal cycling is much more detrimental than a being at a constant temperature.

However you also have to consider humidity (if there is a moisture source). Humidity accelerated corrosion could be a problem within this time frame.

I also don't think 2 months is a terribly long time (again unless you are already marginal).

I would keep the input voltage low (to reduce the load on the regulator) and go for it.

As for whether or not you approach is well founded, I don't know your reasoning nor restrictions so I'll not comment.

aurelAirmems:
Hello,

For tests on components I want to put arduino mega2560 in an oven at 85 ° C for two months.
I need to know whether or not the arduino will fail?

Are they certified for 85 ° C and for how long?

Thank you

What components are you testing, the Mega or something else.
What is the reason for the tests?
Are you using the components in circuit while temperature testing?
I would doubt if the polarised caps are happy at that temp continuously, 85C is what most are rated at.
105C is the next level.

Thanks.. Tom.. :slight_smile:

MorganS:
Just testing one won't tell you much. If you are serious about testing components then put a hundred in the oven. If the Mega is controlling the test then it should be in a cooler part of the oven. If the Mega is the test then buy 20 of them to test simultaneously.

If it fails a single test will tell you that it will fail. If it doesn't fail, try more until you have a failure. Then at least you can fudge up some statistics. We can theorize all day long, but the test is what will decide.

Thank you for all your answers although I could not answer all.
I added a homemade card that tests components not the top of the arduino.
I have two different cards for two test modes. I will not say more.
I also have a scheild sd that records the measurements.
I feed the Arduino in 10V and my card requires him to consume about 200mA. So the temperature of the arduino certainly exceeds 85 ° C.
For now the arduino work at 85 ° C, I had put a few weeks.
For me the most practical is to put them with the components that we test.
However, in view of what you told me, I will have to take them out.
Unless, currently, a French company must offer me a custom box to cool the arduino in the oven.

To have.

And this, kids, is why I don't like shields. It is all fun and games for a beginner to stick a shield on an Arduino Mega and have some fun programming, but the minute you don't look, somebody makes a shield for component testing and puts a whole Mega in the oven for 2 month ...

You say it's a test - so why don't you just do the test at 85degC and then let us know the outcome. You'll get a definite answer then :smiley:

Hi,
I have a collection of blank shields.
protoshield.jpg
They are great for quick and dirty work solutions, or I use them like a connector to the Arduino with ribbon cable or what ever connected between the outside world and the shield.

Tom… :slight_smile: