Silicon chips on heat sinks

[Scdc5515]

Does anybody have experience processing the silicon chips on the backside of heat sinks? I processed a small group by first boiling and hydrochloric acid. There was a pretty good reaction and when it was done the filtrate was a beautiful clear purple. Negative test for precious metals or silver. Then I boiled the remainder of the material in Aqua regional. It rendered a beautiful bright green yellow filtrate. Again no positive test for precious metals or silver. Is there anyThing to extract from these chips?

 

[Yggdrasil]

Heat sinks are the copper or aluminum screwed or clamped to a processor.
The processor it self has a silicone die, sometimes with a heat spreader soldered/glued to it.
The heat spreader sometimes has a thin enig gold layer inside.
There have been multiple discussions if or not it is worth processing. Search the forum and you will find.

The silicone die it self has no a available PMs.

So please get your terminology right, it is hard to help you otherwise.