Just theorizing here but if its more conductive than gold or aluminum then it is going to have less I2R heat loss from the resistive side so it runs cooler – a big issue with IC’s and computer power usage.
________________________________ From: Ken Javor [mailto:[email protected]] Sent: Tuesday, August 31, 2010 9:10 AM To: [email protected] Subject: Re: [PSES] Use of Cu bond wire instead of Au bond wire ??? Can’t speak to the longevity issue, but Cu is more conductive than Au. Also seems like there was a trend awhile back from Al to Cu for that reason: conductivity. As traces get smaller in cross-section, the extra conductivity counts. Ken Javor Phone: (256) 650-5261 ________________________________ From: "N.Shani" <[email protected]> List-Post: [email protected] List-Post: [email protected] List-Post: [email protected] Date: Tue, 31 Aug 2010 11:59:20 -0400 To: EMC PSTC <[email protected]> Subject: Use of Cu bond wire instead of Au bond wire ??? Hello all, not directly EMC affecting, rather (long term) reliability concern: we received a PCN from one of our semiconductor suppliers that effective immediately they will change the bond wire from gold to copper, following industry trend. My immediate reaction was: What? Then, why? Is cost the only issue? (and this brings me to the perennial issue of Pb-free assemblies and how long will they last). Is anyone on this list aware of this sea change? I recall, from many moons ago, that gold was deemed superior to anything else for most semiconductor application. Aluminum (OK, Aluminium) was reserved for RF devices, but gold ruled everything else (better conductivity, good plasticity or whatever term needs to be used, etc). Then, we started seeing copper as chip metalization of choice instead of aluminum (conductivity?) or gold (cost?) - which made sense since it was encapsulated in silicon dioxide. Now we are going to have copper wire bonds. These are as low as 0.5 mil (12 um) in diameter... they'll corrode in no time. Will appreciate your feedback/thoughts on this. Thanks, Naftali Shani Ottawa, ON - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]>
