Hello if I have 15 chips to dissipate 1W each (thus 15W in total), by math calculation, which of the next three possibilities is better:
1) using a unique shared heatsink @1.7K/W with 0.5mm thermal pad @1.5W/mK
2) using a unique shared heatsink @1.7K/W with 1.5mm thermal pad @8W/mK
3) using 15 heatsinks @25.6K/W each with 0.1mm thick thermal glue @0.9W/mK
By feeling the three performances appear pretty similar: one shared heatsink @1.7K/W seems slight better than the sum of the 15 heatsinks, but the thermal glue is slight better than the 8W/mK thermal pad.
Can we prove the three cases by exact calculation and formulas using MKS metric system please?
I need the thermal resistance model in term of K/W of each of the three mentioned cases (heatsink plus heat transfer material).
I think that calculation are independent from the surface area as it is just the sum of the top of each chip package and it is the same in all the three cases. In any case I give you: area of the top of the chip is 60mm^2 each.
Ambient temperature is fixed. No fans.
This is a real case. Thanks!
(by now don't consider compression ot the pad: I know it is not fully linear with the conducibility: if you have time considering an extra case of a 30% of reduction of the thickness of the pad due to the screws...)