-2
\$\begingroup\$

I am currently part of a Research and development Engineering Team (which I am newbie) and we are trying to find a solution on how to extend the normal operating temperature of the chip. The IC that we are using is dsPIC33FJ128MC706 of Microchip which its highest operating temperature is 150°C. We somehow aim to let the chip work at a temperature of 180°C. Is this possible or is it just wishful thinking?

\$\endgroup\$
9
  • \$\begingroup\$ The temperature the manufacturer specifies is the one they guarantee it operates at. If you try enough chips, then you will find one that works at 180, if you try even more you will find some that work at that temperature for a little longer time \$\endgroup\$
    – PlasmaHH
    Commented Jul 7, 2017 at 10:11
  • \$\begingroup\$ The manufacturer cannot guarantee that it will work beyond the stated maximum and you'll be breaking the warranty. You really shouldn't do this. Rather you should find ways to keep your IC cool. Why not a fan or a watercooler? \$\endgroup\$
    – Bradman175
    Commented Jul 7, 2017 at 10:12
  • 7
    \$\begingroup\$ 150 °C is the absolute maximum storage temperature. The absolute maximum ambient operating temperature is 85 °C. So, wishful thinking. Also, if you wanted to operate it at an ambient temperature of 180 °C you would have to use tiny tiny nuts and bolts for the electrical connections as solder would be either partially or completely molten, and just think how fiddly it would be to screw those together. \$\endgroup\$ Commented Jul 7, 2017 at 10:25
  • 2
    \$\begingroup\$ It is most likely a bad design that you want to make your microcontroller work in 180°C heat. \$\endgroup\$ Commented Jul 7, 2017 at 11:18
  • 1
    \$\begingroup\$ First of all, having operational electronics working at 180 degrees C sounds very fishy. I cannot really see what kind of application that would need this, some kind of space probe you intend to send into the sun? Lets for the sake of discussion imagine that the spec makes sense. You have a highly specialized project... what MCU do you pick? An obsolete general-purpose DSP with industrial temp spec, not even automotive qualified... The person who wrote the spec probably needs to be fired. I would consider to hire electrical engineers for this project instead. \$\endgroup\$
    – Lundin
    Commented Jul 7, 2017 at 13:36

4 Answers 4

6
\$\begingroup\$

If you want the chip to operate in ambient temperature of 150'C then you will need some form of active cooling for the chip. If you are looking at increasing operating temperature of the actual chip, I imagine that is quite difficult and there is probably a lot research going into this topic from various manufacturers.

However with the question you pose, I believe you are referring to storage temperatures of 150'C. There may be a little misunderstanding. The operating temperatures are much lower which make your problem worse.

With a quick look at the datasheet. Absolute Maximum Ratings(1)

Ambient temperature under bias ............................ -40°C to +85°C

Storage temperature ............................ -65°C to +150°C

http://ww1.microchip.com/downloads/en/DeviceDoc/70287C.pdf pg 275

\$\endgroup\$
2
  • \$\begingroup\$ Hi R.Joshi, This is not the Datasheet of the Chip I'm referring to. Here is the spec: Operating Range: Up to 40MIPS operation (at 3.0-3.6V) Industrial temperature range (-40°C to +85°C) Extended temperature range (-40°C to +125°C) High temperature range (-40°C to +150°C) microchip.com/wwwproducts/en/dsPIC33FJ128MC706A \$\endgroup\$
    – GeneOrator
    Commented Jul 10, 2017 at 1:28
  • \$\begingroup\$ is there a thermal compound than can easily cooled down and does not worn -out/burn out at high temperatures like 150°C or 180­°? I tried google but no luck. \$\endgroup\$
    – GeneOrator
    Commented Jul 10, 2017 at 1:55
3
\$\begingroup\$

The maximum operating temperature has two principal limitations. One is whether the design will work, considering that bias currents increase and base voltages shift. The second is how long the chip will survive against the various degradation processes that are enabled or accelerated by high temperatures.

The first is quite easy to check. Increase the temperature of the device and see when it stops working.

The second has to be estimated. All silicon processes are broadly similar in that their wear-out is accelerated by temperature. The factors for different processes might be slightly different, however the general trend is the same. There is an exponential decrease in life with incresaing temperature.

Take this paper for instance from TI. They say that for a particular device, operating at 125C rather than 105C results in a 5-fold reduction in lifetime.

If the same factor applied to your device, over the temperature range, 85C max specified temperature to 180C target temperature, then the lifetime reduction would be in the order of 625-fold. However, I suspect the factor increases at higher temperatures, as we activate different mechanisms like diffusion.

\$\endgroup\$
1
  • 1
    \$\begingroup\$ The maximum allowed power dissipation also decreases. You might not be able to run many high current sourcing or sinking pins. You might not be able to run at the maximum speed. \$\endgroup\$
    – Jeroen3
    Commented Jul 7, 2017 at 11:42
2
\$\begingroup\$

Some applications require high temperatures, so manufacturers usually have one or two chips that will fit your needs, for example this one works till 210°C:

http://www.ti.com/product/sm320f28335-ht

Microchip probably has some too. Of course, you'll need special solder, ceramic boards and other exotic unobtainium stuff, so the $300 price tag on the chip should be just a drop in the bucket in the end...

TL/DR: Unless you're making something really exotic like a borehole sensor for oil drilling, there are probably other, cheaper, better solutions.

\$\endgroup\$
-1
\$\begingroup\$

The IC that we are using is dsPIC33FJ128MC706 of Microchip which its highest operating temperature is 150°C.

chips working at that kind of temperature are very rare and i'm sure quite expensive. you may want to re-read the datasheet to be (super) sure.

We somehow aim to let the chip work at a temperature of 180°C. Is this possible or is it just wishful thinking?

you can answer Microchip; or you can simply test. I would be surprised if it didn't work if the chip was indeed specified for 150c working temperature.

Otherwise, it would be quite difficult to make most chips work at that kind of temperature.

A more realistic solution is to provide better cooling.

\$\endgroup\$
1
  • \$\begingroup\$ Hi dannyf, Thanks. I'm somehow more interested to your point of view. Here's the Spec of the IC, Operating Range: Up to 40MIPS operation (at 3.0-3.6V) Industrial temperature range (-40°C to +85°C) Extended temperature range (-40°C to +125°C) High temperature range (-40°C to +150°C) microchip.com/wwwproducts/en/dsPIC33FJ128MC706A Question, if for example its specs can operate at 150°C, is it possible to extend its operating Temp? I believe also that Manufacturers are setting extendable heat tolerances to the device they are making. \$\endgroup\$
    – GeneOrator
    Commented Jul 10, 2017 at 1:45

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.