Post by thread:[EE]:: Utterly superb book on "Electronic packagin

IEEE approved in depth electronic packaging course utterly superb PCBs and much much more http://www.prc.gatech.edu/academics/elpkg/ Section 3 is on PCBs - around 100 pages on this alone http://www.prc.gatech.edu/academics/elpkg/pdf/module3.pdf Section 6 - 30 or so pages on SMD http://www.prc.gatech.edu/academics/elpkg/pdf/module6.pdf Russell Source PRC at Georgia Tech and other centres - PRC director Prof Tummala seems to get around http://www.raotummala.com/ The Microsystems Packaging Research Center (PRC) is housed in the Manufacturing Research Center building on the Georgia Tech campus. Established in 1994 as a U.S. National Science Foundation Engineering Research Center, the Georgia Institute of Technology Microsystems Packaging Research Center (PRC) is the largest center worldwide dedicated to System-on-Package (SOP) and microsystems packaging technologies. It comprises 7 academic departments, over 500 students, 20 faculty, 15 researchers, and 50 companies from around the world. The PRC offers unique and interdisciplinary degree programs at the B.S., M.S., and Ph.D. levels as well as continuing education in SOP technologies. It also leads several conferences and workshops in packaging research and education. __________ Also available in a "real book look" form as a Google book for $ here (many but not all pages available free online) http://books.google.co.nz/books?id=P93ZrOWHlO0C&pg=PA82&lpg=PA82&dq=%22Electronic+products+are+now+integral+parts%22&source=web&ots=rjiJeS74xO&sig=WlxmLfgooBD7dh3Wka0jojPD_L8&hl=en#PPA2,M1

Hi Russell, Thanks for the link! One think really puzzles me, though. I was looking at "module 3" on PCBs and in a table he shows Gold as more conductive than Copper. This is incorrect AFAIK. Is it a typo, or does it have something to do with alloys? Sean On Fri, Feb 29, 2008 at 5:56 AM, Apptech <spam_OUTapptechTakeThisOuTparadise.net.nz> wrote: {Quote hidden}> IEEE approved in depth electronic packaging course utterly > superb PCBs > and much much more > > http://www.prc.gatech.edu/academics/elpkg/ > > Section 3 is on PCBs - around 100 pages on this alone > > http://www.prc.gatech.edu/academics/elpkg/pdf/module3.pdf > > Section 6 - 30 or so pages on SMD > > http://www.prc.gatech.edu/academics/elpkg/pdf/module6.pdf > > > Russell > > > > Source PRC at Georgia Tech and other centres - PRC director > Prof Tummala seems to get around > > http://www.raotummala.com/ > > The Microsystems Packaging Research Center (PRC) is housed > in the Manufacturing Research Center building on the Georgia > Tech campus. Established in 1994 as a U.S. National Science > Foundation Engineering Research Center, the Georgia > Institute of Technology Microsystems Packaging Research > Center (PRC) is the largest center worldwide dedicated to > System-on-Package (SOP) and microsystems packaging > technologies. It comprises 7 academic departments, over 500 > students, 20 faculty, 15 researchers, and 50 companies from > around the world. The PRC offers unique and > interdisciplinary degree programs at the B.S., M.S., and > Ph.D. levels as well as continuing education in SOP > technologies. It also leads several conferences and > workshops in packaging research and education. > > > > __________ > > Also available in a "real book look" form as a Google book > for $ here (many but not all pages available free online) > > http://books.google.co.nz/books?id=P93ZrOWHlO0C&pg=PA82&lpg=PA82&dq=%22Electronic+products+are+now+integral+parts%22&source=web&ots=rjiJeS74xO&sig=WlxmLfgooBD7dh3Wka0jojPD_L8&hl=en#PPA2,M1 > > > > > --

Nope, gold is more conductive than copper. So is silver. However, they are also much more expensive. -Adam On 3/3/08, Sean Breheny <.....shb7KILLspam@spam@cornell.edu> wrote: {Quote hidden}> Hi Russell, > > Thanks for the link! > > One think really puzzles me, though. I was looking at "module 3" on > PCBs and in a table he shows Gold as more conductive than Copper. This > is incorrect AFAIK. Is it a typo, or does it have something to do with > alloys? > > Sean > > > > > On Fri, Feb 29, 2008 at 5:56 AM, Apptech <apptechKILLspamparadise.net.nz> wrote: > > IEEE approved in depth electronic packaging course utterly > > superb PCBs > > and much much more > > > > http://www.prc.gatech.edu/academics/elpkg/ > > > > Section 3 is on PCBs - around 100 pages on this alone > > > > www.prc.gatech.edu/academics/elpkg/pdf/module3.pdf > > > > Section 6 - 30 or so pages on SMD > > > > www.prc.gatech.edu/academics/elpkg/pdf/module6.pdf > > > > > > Russell > > > > > > > > Source PRC at Georgia Tech and other centres - PRC director > > Prof Tummala seems to get around > > > > http://www.raotummala.com/ > > > > The Microsystems Packaging Research Center (PRC) is housed > > in the Manufacturing Research Center building on the Georgia > > Tech campus. Established in 1994 as a U.S. National Science > > Foundation Engineering Research Center, the Georgia > > Institute of Technology Microsystems Packaging Research > > Center (PRC) is the largest center worldwide dedicated to > > System-on-Package (SOP) and microsystems packaging > > technologies. It comprises 7 academic departments, over 500 > > students, 20 faculty, 15 researchers, and 50 companies from > > around the world. The PRC offers unique and > > interdisciplinary degree programs at the B.S., M.S., and > > Ph.D. levels as well as continuing education in SOP > > technologies. It also leads several conferences and > > workshops in packaging research and education. > > > > > > > > __________ > > > > Also available in a "real book look" form as a Google book > > for $ here (many but not all pages available free online) > > > > books.google.co.nz/books?id=P93ZrOWHlO0C&pg=PA82&lpg=PA82&dq=%22Electronic+products+are+now+integral+parts%22&source=web&ots=rjiJeS74xO&sig=WlxmLfgooBD7dh3Wka0jojPD_L8&hl=en#PPA2,M1 > > > > > > > > > > --

Nope! I was wrong! Gold is less conductive than copper, and silver is more conductive than copper. Gold is useful in that it doesn't oxidise easily - it's fairly stable. It's soft, though, so usually gold alloys are used for plating contacts that need frequent insertions. http://environmentalchemistry.com/yogi/periodic/electrical.html -Adam On 3/3/08, M. Adam Davis <.....stienmanKILLspam.....gmail.com> wrote: {Quote hidden}> Nope, gold is more conductive than copper. So is silver. However, > they are also much more expensive. > > -Adam > > On 3/3/08, Sean Breheny <EraseMEshb7spam_OUTTakeThisOuTcornell.edu> wrote: > > Hi Russell, > > > > Thanks for the link! > > > > One think really puzzles me, though. I was looking at "module 3" on > > PCBs and in a table he shows Gold as more conductive than Copper. This > > is incorrect AFAIK. Is it a typo, or does it have something to do with > > alloys? > > > > Sean > > > > > > > > > > On Fri, Feb 29, 2008 at 5:56 AM, Apptech <apptechspam_OUTparadise.net.nz> wrote: > > > IEEE approved in depth electronic packaging course utterly > > > superb PCBs > > > and much much more > > > > > > http://www.prc.gatech.edu/academics/elpkg/ > > > > > > Section 3 is on PCBs - around 100 pages on this alone > > > > > > www.prc.gatech.edu/academics/elpkg/pdf/module3.pdf > > > > > > Section 6 - 30 or so pages on SMD > > > > > > www.prc.gatech.edu/academics/elpkg/pdf/module6.pdf > > > > > > > > > Russell > > > > > > > > > > > > Source PRC at Georgia Tech and other centres - PRC director > > > Prof Tummala seems to get around > > > > > > http://www.raotummala.com/ > > > > > > The Microsystems Packaging Research Center (PRC) is housed > > > in the Manufacturing Research Center building on the Georgia > > > Tech campus. Established in 1994 as a U.S. National Science > > > Foundation Engineering Research Center, the Georgia > > > Institute of Technology Microsystems Packaging Research > > > Center (PRC) is the largest center worldwide dedicated to > > > System-on-Package (SOP) and microsystems packaging > > > technologies. It comprises 7 academic departments, over 500 > > > students, 20 faculty, 15 researchers, and 50 companies from > > > around the world. The PRC offers unique and > > > interdisciplinary degree programs at the B.S., M.S., and > > > Ph.D. levels as well as continuing education in SOP > > > technologies. It also leads several conferences and > > > workshops in packaging research and education. > > > > > > > > > > > > __________ > > > > > > Also available in a "real book look" form as a Google book > > > for $ here (many but not all pages available free online) > > > > > > books.google.co.nz/books?id=P93ZrOWHlO0C&pg=PA82&lpg=PA82&dq=%22Electronic+products+are+now+integral+parts%22&source=web&ots=rjiJeS74xO&sig=WlxmLfgooBD7dh3Wka0jojPD_L8&hl=en#PPA2,M1 > > > > > > > > > > > > > > > -- >

M. Adam Davis wrote: > Nope! I was wrong! > > Gold is less conductive than copper, and silver is more conductive than copper. > > Gold is useful in that it doesn't oxidise easily - it's fairly stable. > It's soft, though, so usually gold alloys are used for plating > contacts that need frequent insertions. Some field results suggest the opposite may be true in some cases. Inserting mating connectors (depending on the type of connector) often wipes away oxide build up. Meanwhile, frequent insertion cycles often removes gold plating. But if left in place, golds resistance to oxidation works well. Witness for example Apple II socketed mother boards that would fail after 2 to 3 weeks and then be revived after lifting and re-seating the chips. The sockets were tin plated. Here, they should have been gold plated or better yet, chips soldered directly in place.

>Witness for example Apple II socketed mother boards that would fail >after 2 to 3 weeks and then be revived after lifting and re-seating the >chips. The sockets were tin plated. Here, they should have been gold >plated or better yet, chips soldered directly in place. The Apple /// had an infamous problem where heat buildup caused the motherboard to slightly warp, causing contact problems with the socketed chips. The recommended procedure was to lift the computer a few inches and drop it on the desk, to re-seat the chips ;-) I actually had an Apple /// or two that I got second hand and repaired. I remember that virtually all of the chips were socketed, except for just a few, including a 555 or 556 timer. I'm not sure that they were soldered because a socket would cause electrical problems (well, more electrical problems than elsewhere on the motherboard) but they were at one edge of the mobo, and I think there was a clearance issue (with the keyboard perhaps, I can't remember). Why were the chips socketed? For ease of repair? I know the memory chips were socketed because you could add memory or upgrade from 4K to 16K DRAMs. -- --- Chris Smolinski Black Cat Systems http://www.blackcatsystems.com

Marcel Duchamp wrote: {Quote hidden}> M. Adam Davis wrote: > >> Nope! I was wrong! >> >> Gold is less conductive than copper, and silver is more conductive than copper. >> >> Gold is useful in that it doesn't oxidise easily - it's fairly stable. >> It's soft, though, so usually gold alloys are used for plating >> contacts that need frequent insertions. >> > > Some field results suggest the opposite may be true in some cases. > Inserting mating connectors (depending on the type of connector) often > wipes away oxide build up. > > Meanwhile, frequent insertion cycles often removes gold plating. But if > left in place, golds resistance to oxidation works well. > > Witness for example Apple II socketed mother boards that would fail > after 2 to 3 weeks and then be revived after lifting and re-seating the > chips. The sockets were tin plated. Here, they should have been gold > plated or better yet, chips soldered directly in place. > > I can assure you that gold-plated connectors hold up MUCH better than tin-plate or copper-only connections. The gold is so inert that gold-to-gold contact points last many times longer than the next best (rhodium or platinum to rhodium or platinum). No, gold is not a better conductor, just a more durable one. --Bob Axtell

> I can assure you that gold-plated connectors hold up MUCH > better than > tin-plate or copper-only > connections. The gold is so inert that gold-to-gold > contact points last > many times longer than the next > best (rhodium or platinum to rhodium or platinum). > No, gold is not a better conductor, just a more durable > one. As a general rule that's good advice (and as Bob said it that can be taken as a given :-) ). But do note that even gold is not without its problems. In some cases gold-gold has performed worse than gold-other. Certain memory-motherboard combos reflected this in the past (Intel memory from memory - but I'm not certain). Also gold is sometimes usefully alloyed with other material to improve it's durability in high insertion cycle applications. I'm sure that Bob can comment on and expand on these aspects. Russell

On Tue, 4 Mar 2008, Apptech wrote: {Quote hidden}> > I can assure you that gold-plated connectors hold up MUCH > > better than > > tin-plate or copper-only > > connections. The gold is so inert that gold-to-gold > > contact points last > > many times longer than the next > > best (rhodium or platinum to rhodium or platinum). > > > No, gold is not a better conductor, just a more durable > > one. > > As a general rule that's good advice (and as Bob said it > that can be taken as a given :-) ). > > But do note that even gold is not without its problems. > In some cases gold-gold has performed worse than gold-other. > > Certain memory-motherboard combos reflected this in the past > (Intel memory from memory - but I'm not certain). > > Also gold is sometimes usefully alloyed with other material > to improve it's durability in high insertion cycle > applications. > > I'm sure that Bob can comment on and expand on these > aspects. > Interesting. Does anyone know of any research into using silver/germanium alloys? I mention this alloy because it has a tendancy to stay "shinny". I don't know whow well it staves off tarnishing compared to other commonly used connector alloys, just that it does look very good as jewellery. BTW it's refered to as a Sterlin Silver and tradmarked as Argentium. Regards Sergio