Hi guys,
I'm designing a flyback power supply, and the transformers' copper goes up to about 90 deg. C. The efficiency is ~90%, which is good enough (though I will investigate on how to improve that), but that's still a few watts (around 5W I'm guessing) of thermal power to dissipate on a very small surface.
One quick fix is to add a heatsink to the offending area, as proposed in the attachment. Basically, a machined alluminum block would be thermally connected to the copper through the outer kapton tape and through a thermal pad material.
My questions are:
1. Is this a good idea? If not, why?
2. Will there be any stray currents created in the alluminum heatsink when it's this close to the winding? If so, how much of an effect will they have?
3. Are there any better solutions to the problem?
4. Is this a problem? 90.deg C is a lot, but the rest of the power supply (transistor, sense resistor) are relatively cool.
Thanks,
David