[Coco] OT: Gold Ceramic chip (circa 1973)

jdaggett at gate.net jdaggett at gate.net
Sat Jan 22 19:49:31 EST 2011


On 22 Jan 2011 at 9:39, Bruce W. Calkins wrote:

> FWIW; When his University scrapped their mainframe my brother bought it.  He 
> got his money back from the gold and his profit from the aluminum.  But that 
> was a 1960s mainframe.  By the 1970s gold content was minimal. 
> 
> 


That was my point. The amount of gold that was used in the outside packaging was minimal. 
In ICs today the greated amount of gold is in the wire bonds for ICs that still use that process. 
The wire from the IC to the package pins is 24 carrot gold. Very soft and nearly pure gold. 
During the 90's package technology started to move away from wire bonds and have gone 
toflip chip eutetic bonding . With the BGA packages there is almost no gold used anymore. 
With gold prices they way they are now that is a major cost savings. 

james





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