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Originally Posted by jaydee
A 1" die is not a 1" IHS. A IHS does not make heat. You have a die under the IHS, the IHS is not going to spread the heat from that die perfectly to all parts of the IHS. The heat will be concentrated in the area the die is under the IHS. If JoeC wants to mimic a CPU with a IHS he needs to make the die the same size as the CPU's die and then put a IHS on top of it. The extra TIM layer of the IHS adds another PITA to deal with.
It dosn't matter how accurate the data is if it applies to nothing.
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I really do not understand why people make it so complicated.
you have a thermal cascade with the die to grease to IHS and then from the package to IHS.
It is simple to measure that resistance, (case temp vs diode) then calculate how much copper area you need to approximate a case temp C/W = make and test it.
Die simulator/IHS simulator.......whats wrong with that? Just another relative way to look at data
You will have more delta temp variation in small die area changes then you will to large area dies. Going from 1' to 2 in. might yield a few 10th's of a degree. going from 1cm to 2cm would probably net you a couple of degrees C
1 cm and 1 in. dies are common in a number of papers I have read. So are .5 and .75 in. Choose your poison for quick mental HTC calcs
Looking only at die temps without an IHS is only part of the picture and will bias any test result if that is the only tool you use, a case C/W is just part of the total cascade as is the on die C/W.