Why do CPU die have colors

darkstar845

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Mar 29, 2010
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nehalem-core.jpg


i7-art-2.jpg


Are they color codes or they are unintentional?

They are made of millions of transistors but normal transistors are normally black or silver.
 

davidgermain

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Nov 18, 2005
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As light is refracted from the transistors its produces the different colours, but i am sure that the marketing people tweek it quite a bit.
Add a polarising filter on the camera lens and all sorts of things are possible.
a combination of all of these i think.
 
Actually I think it's just to graphically highlight the different sections of the CPU to make them easier to identify - L2 & L3 cache, cores, uncore, etc. That way someone can quickly guesstimate how much die area each portion uses.

However if you lift the IHS lid on your CPU and spot a disco ball twirling around with tiny lasers and a light show, and hear some faint rave music, then you have a real party CPU! :D
 
The colors on pictures like that are false colors that are super imposed to make the chip look pretty and help to distinguish various parts of the chip. If you were to look at the etched wafer you would see some colors caused by the light reflecting and refracting off the surface but it wouldn't be nearly as distinguished as those pictures are.


The "normal" black and silver transistors you are thinking of are actually covered in a molding compound to insulate them(and you from them), help with heat, and keep the silicon protected.
 
CPU's do reflect different colour light just like a CD does, although in the photos the effect is exaggerated.

Because the gaps between different reflective parts of the IC are very close together, a distance equivalent to only a few times the wavelength of visible light or less , the reflections will interfere with one another in interesting ways.

Light behaves like a wave, different colours have different wavelengths (blue short and red long) and the light waves reflecting from the surface between the gaps will interact with one another. In some directions the two waves will work together - constructively interfere, and in others they will work against one another - destructively interfere.
 


Light can behave like a wave or particle depending on the type of medium light travels through.
 
Light can behave like a wave or particle depending on the type of medium light travels through.
As Richard Feynman said "light can be viewed as either a particle in some cases or a wave, but if you treat it as a wave then you are always right" I am quoting him from one of his lectures from memory so the exact wording may not be correct but the sentiment is.