0
$\begingroup$

I am looking for a way to create prototype high temperature circuits capable of going up to 500 °C. I know one way is to generate the CAD file and send it to a PCB manufacturer. Another way is to get copper plated alumina wafers and just cnc/etch them myself.

I was wondering if there was a way to do this by adhering copper foil onto a high-temperature non-conductive wafer. It would not be as precise as having it PCB manufactured, but it would be 10 times cheaper and faster. The highest temperature capable foil that I found has been in the 200 °C range. Is there a high temperature capable adhesive that I can combine with regular copper foil? Is there a pre-made high temperature adhesive foil somewhere? Are there any other techniques that I am missing?

$\endgroup$
1
  • 1
    $\begingroup$ The "christmas tree" where components are just joined together by twisting wires to form the junctions - as long as the wires don't corrode due to the heat then should work for a prototype. $\endgroup$
    – Solar Mike
    Commented Dec 12, 2023 at 16:07

2 Answers 2

0
$\begingroup$

Another approach that may be practical for prototypes if your circuit design is not too tiny or complex is to make each separate element of the circuit in thin copper, either wire or sheet that is thick enough for practical hand work and mechanically fasten all of it together on a substrate sheet of Macor machineable ceramic (good to 1470F)with drilled holes in it that can accomodate machine screws or other methods like silver solder (which comes in various melting temperatures from around 1000 to 1300F so you can work in steps). Or you could use cheaper plain ceramics and drill the holes with diamond tools. Or find a friend that does ordinary pottery and have then make you a flat ceramic plate with the holes already in it. Do some research in this direction and real quick you will know more about it than I do.

$\endgroup$
0
$\begingroup$

Take a look at plasma sprayed alumina coatings that toward the end of the last century were used on turbine blades and some other less visible industrial applications. They have graduated to consumer grade cookware. I've had an aluminum griddle about 4 years and the coating is finally falling off the center where I have let it get to "red" heat too many times. That coating is black in color suggesting a titania fraction in the alumina mix. Some manufcturers are even now bragging about their "titanium" pots. If you understand how stone walls survive for centuries without any mortar you will understand how plasma spray ceramic coatings resemble microscopic stone walls and can endure huge thermal expansion of their metal "foundation" without cracking. My experience with this goes back almost 30 years. Do a patent search on my full name "Edwin Charles Weldon." BTW, I'm pretty old now and not in any position to engage in any consultant activities.
So I'd suggest you go find a new flat griddle from one of the many manufacturers, check the conductivity of the surface and have at it with a 4-1/2" angle grinder and a thin cutoff disc or a saw with small teeth and a good bimetal blade. (don't forget the safety goggles and a mask to block any bad dust. Ed Weldon

$\endgroup$

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.