Electronics Forum | Wed Jan 09 18:08:23 EST 2013 | hegemon
Not exactly normal, I don't think. Though I have seen similar in the CM world. I can't think of a way to remove that overplating, either. If you can't reject the boards outright, then you might be looking at some touch up work, should bridging hap
Electronics Forum | Thu Sep 12 11:26:11 EDT 2002 | scottefiske
CK, If joints have been validated prior to ICT (under BGA Scope), more often than not repeatable joint fractures are due to undo stress being placed on the component during ICT test. Verify ICT probes and fixture. If after proving out fixture/pin com
Electronics Forum | Wed Mar 17 14:59:53 EST 2004 | Claude_Couture
since there is a bit of humor in this thread, try drilling the pads from the opposite side of the pcb.
Electronics Forum | Mon Oct 13 19:04:47 EDT 2003 | davef
Aperture size should vary with the component [pitch]. That size should be the same a the pad size. So, generally pinching is not required. Indium discusses BGA apertures on their site [ http://www.indium.com ]
Electronics Forum | Fri Mar 19 10:06:22 EDT 2010 | karlo
Rework is typically done by heating the BGA to 170-180C to first scrape off the fillet. Then, heat to above reflow, and lift the BGA. Then, collapse the solder with heat and flux. Then, back down at 170-180C, scrape off the underfill from the boar
Electronics Forum | Tue May 13 08:26:29 EDT 2008 | davef
First, on your reflow temperature comment: The 183*C focus for reflow recipes for tin-lead solder is a falicy. If you held a recipe for tin-lead solder at 183*C peak, it would never reflow. Recipes for tin-lead solder need to be at liquidus plus 20*C
Electronics Forum | Mon Aug 16 16:37:08 EDT 2004 | davef
As we mentioned in an earlier response in this thread [Q5], you do NOT want to solder to hard gold. Hard gold is a wear surface. [That's IT, that's the LIST.] If you want to solder to gold, then either use: * IPC-4552 ENIG specification, mentioned
Electronics Forum | Wed Jun 13 20:38:23 EDT 2012 | kahrpr
It is possible that there is nickel contamination in the gold. Depending on your plating board vendors put nickel down first. The plating also could be to thin. Dave had a good suggestion in trying to solder the pad with a Iron that will tell a lot.
Electronics Forum | Thu Jun 14 04:24:32 EDT 2012 | brettrenishaw
Yes pads are still gold after the wave soldering process even if you wave solder a pcb several times. I have tried soldering using an iron and the solder takes to the pad as you would expect. This happens on all boards of this type and all boards are
Electronics Forum | Thu Jun 14 15:29:29 EDT 2012 | davef
That you can get good solder flow when hand soldering seems to indicate that the temperature of your solder pot is too low. Still, I'm uneasy that you see gold on the pads after passing the board across the solder pot. Gold is so thin with ENIG. So
