Electronics Forum | Wed Dec 24 11:23:22 EST 2008 | childs
I can't seem to locate any information/concerns about moisture entrapment in IC packages on the promary side in a double sided SMT assembly using water soluable solder paste when soldering the second side. A typical process would assemble/reflow/cle
Electronics Forum | Thu Jun 28 17:05:46 EDT 2012 | davef
Here’s what we seem to know: * There’s a problem with voiding in the solder connections of SMT capacitors * A void is an open area caused by air or process fluid that is trapped within a solder connection * Voids are an allowable condition as long as
Electronics Forum | Fri Jun 29 14:13:05 EDT 2001 | markhoch
Just a quick thought on solder balls "or beads" caused when using NC paste. I found a spec (12.4.10 in IPC-A-610C) that says solder beads are acceptable if they are entrapped in NC flux residue and can not be dislodged in the normal service environme
Electronics Forum | Mon Oct 18 11:48:57 EDT 1999 | Dave F
No, but answer me this? 1 What type of BGA? 2 What's the wave process, materials and temps? Are you waving the BGA or top-side flowing it? 3 If the BGA is plastic, what are you doing to prevent/remove entrapped moisture before solder processing?
Electronics Forum | Tue Jul 06 12:21:38 EDT 1999 | Kelly Morris
I've heard that use of VOC free flux with wavesolder fixtures can be challenging due to entrapment of water in the fixture. Is anyone out there successfully running VOC free with wave fixtures & did you experience problems? If so, how did you resol
Electronics Forum | Tue Nov 27 14:24:13 EST 2001 | mparker
Short term fixes can be: have the vias "plugged" with solder by the fab house. This works if your fab is HASL finish. Tent the vias with solder mask, top side only. You may get a flux entrapment issue in the vias with this manner. Long term fix can
Electronics Forum | Wed Mar 27 18:23:01 EST 2002 | kmorris
Does anyone have experience doing conformal coating over Plastic BGA in High-Rel PCB assembly? Is underfill necessary to avoid problems with entrapped air, etc? Our application is a 17x17mm BGA, 256 I/O. We are assembling with a water soluable pas
Electronics Forum | Thu Jul 03 15:03:39 EDT 2003 | Jim Nunns
My design group wants to change our route keep out around all SMT parts to 5 mil even under the parts with zero standoff. Are others in the industry routing under parts that have no standoff? My fear is that we will get shorting if the mask is scaped
Electronics Forum | Tue Dec 14 13:26:19 EST 2004 | Peter
I have a question regarding post cured property of SMT adhesive. If after component placement, the epoxy dot gets compressed and bridges between the 2 pads, what would the impact on the circuitry? Would it pose risk for flux entrapment? Could the cu
Electronics Forum | Fri Jan 21 16:50:33 EST 2005 | Board House
I work for a board house and our proceedure for this process is the following, We cover the via pads leaving the hole open and then apply the surface finish and then go back and Cover the Via with a second operation. By doing this you do not entrap
