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Article #823Re: Which is a better conductor: gold or silver?
From: Mark Robert Thorson
Date: Sat, 15 Jul 1989 22:27
Date: Sat, 15 Jul 1989 22:27
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As John Berryhill said, gold is used for corrosion resistance on contact surfaces. It's not a very good conductor, as metals go. It's electrical resistance is not important because it's a thin layer. The other important feature of gold is its ductility. Integrated circuits in plastic packages use gold bond wires because the packages flex with temperature. This is one reason IC's in plastic packages are less reliable; the gold bond wire interacts with the aluminum bonding pad on the chip. Gold diffuses into the pad, and aluminum diffuses into the wire. This can create voids in the bond, and it creates a brittle gold-aluminum alloy. Military chips, on the other hand, use ceramic packages. These don't flex, so aluminum bond wires can be used.
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!portal!cup.portal.com!mmm From: mmm@cup.portal.com (Mark Robert Thorson) Newsgroups: sci.electronics Subject: Re: Which is a better conductor: gold or silver? Message-ID: <20483@cup.portal.com> Date: 15 Jul 89 22:27:25 GMT References: <14172@swan.ulowell.edu> <19729@louie.udel.EDU> Organization: The Portal System (TM) Lines: 13