Electronics Forum | Wed Mar 01 17:13:15 EST 2000 | Dave F
Sorin: Formulas for calculating heat dissipation of traces don�t seem to provide practical results. But there are some wonderful tables and graphs that will meet you needs. You may need to do some finagling when calculating vias and through holes,
Electronics Forum | Mon Jan 07 20:37:15 EST 2002 | davef
For soldered areas, we like to keep gold thickness substantially below the maximum you propose. Search the fine SMTnet Archives for our discussions on the topic of acceptable levels of gold with solder connections. Let�s fix this �no one seems be s
Electronics Forum | Tue Jun 04 17:10:13 EDT 2002 | davef
First, �flash gold� is very loose language. It means different things to different people. �Flash� gold is a thin coat of immersion gold. Imm gold self-limits at ~0.3um[12uin]. And fabs put-down �flash� prior to electroplating thicker gold for wi
Electronics Forum | Wed Jun 26 09:10:21 EDT 2002 | davef
I want to suggest: * IPC-2221, Generic Standard On Printed Board Design * IPC-222X, Sectional Design Standard For Printed Board For Y Printed Boards ... but I just thumbed through both quickly and saw nothing, I really didn't spend as much time as I
Electronics Forum | Tue May 13 06:57:10 EDT 2003 | davef
Your vendor site is totally correct. 2Ag is an excellent solder, but it does nothing to prevent tin and gold from reacting chemically. An earlier poster is correct gold goes into solution in liquid solder very fast, less than a second. Gold and ti
Electronics Forum | Mon Aug 16 20:32:10 EDT 2004 | davef
First, we didn't say "electrolytic soft gold with a minimum thickness of 5-8 of Au". We said, "'electrolytic soft gold' thickness 5 to 8uin". FOCUS. ;-) Second, we're unaware of an industry accepted specification that you can reference. IPC-2221
Electronics Forum | Tue Mar 22 20:33:24 EST 2005 | davef
Q1. What are you guys doing for filled/tented/plugged vias on the BGA site? A2. 2221A, 4.5.1 tells you the vias have to be tented on both sides. Q2. What type of issues can this cause if using no filled/tented/plugged vias on the BGA site? A2. BGA
Electronics Forum | Tue Nov 07 22:41:48 EST 2006 | davef
You are correct that hand soldering ceramic capacitors often causes them to crack. They do not take thermal shock well. You might be able to reduce the amount of cracking by following the rework repair guidelines discussed in the fine SMTnet Archiv
Electronics Forum | Thu Jul 12 21:58:10 EDT 2007 | davef
Bill 1 Systems for BGA, Flip Chip, CSP and Bump measurement are: * UBM [550 Weddell Dr, Suite 3, Sunnyvale, CA 94089; 800-731-1220 f408-541-0153 contact@ubmusa.com ubmusa.com] ScanView, AutoScan and LaserScan. * Integrated Packaging Assembly; 2221 Ol
Electronics Forum | Tue Sep 18 07:52:29 EDT 2007 | davef
Does the change from supplier to supplier as a result of: * Board definition? * Differences in processing at fabs? 3 Specification Fir Tree General Technical Specification 3a Design/Layout: * IPC-2221 * IPC-2222 3b PCB Fab: * IPC-6011 * IPC-6012 * I
