Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!fluke!strong
From: strong@tc.fluke.COM (Norm Strong)
Newsgroups: sci.electronics
Subject: Re: Which is a better conductor: gold or silver?
Message-ID: <10912@fluke.COM>
Date: 7 Sep 89 17:04:59 GMT
References: <14172@swan.ulowell.edu> <19729@louie.udel.EDU> <20483@cup.portal.com> <996@maestro.htsa.aha.nl> <1986@kodak.UUCP> <23544@quack <673@gorn.santa-cruz.ca.us>
Sender: news@tc.fluke.COM
Organization: John Fluke Mfg. Co., Inc., Everett, WA
Lines: 19
Keywords: gold, silver, palladium, plating

In article <673@gorn.santa-cruz.ca.us> logo@gorn.santa-cruz.ca.us (David Kiviat) writes:
}
}Hi! This discussion reminds me of a question I have had for many years
}since I worked in a final test department of a large chipmaker. The company
}decided they wanted to replace gold as the substrate (or was it the preform-
}I forget-it's been a long time) with silver. They put a lot of research into
}it and seemed to pull it off. The only problem I remember was that we had
}to centrifuge all those chips and a fairly high percentage of them went
}kabloey in the process. At the time we were told that despite the higher
}losses the cost savings made the change worthwhile.
} 
}My question is did this catch on in the industry or is using silver instead of
}gold to hold the die in place now a rare thing?

The usual die attach these days is conductive epoxy.  This works well
unless you intend to run lots of substrate current.
-- 

Norm   (strong@tc.fluke.com)