Electronics Forum | Fri Jul 23 05:14:40 EDT 2004 | greg york
Hi Thomas Ever considered that this maybe HASL flux left on PCB as this is extremely hygroscopic and has heat transfer fluids that cannot be baked out unless you go to a temperature of around 600C. One way of testing is to leave iron tip on joint an
Electronics Forum | Mon Jan 10 11:08:39 EST 2005 | mrgman9999
We are having a problem with popcorning of a plastic BGA that has been under careful humidity control. We have had problems in the past and some have been related to too much trapped internal solvents from the die attach epoxy. We did a life time b
Electronics Forum | Mon Aug 01 18:50:46 EDT 2005 | crishan
Hi Cecil, We using conformal coating in our manufacturing area, we did use to use Humiseal, others have been Bectron and Peters. We recentalt switched all lacquering to Peters, since it is lead free and it is a lot friendly than Humiseal. To answer
Electronics Forum | Fri Jun 09 05:18:07 EDT 2006 | Rob
Hi Shawn, that you're baking the components makes me think that they are either old, or have been sitting around for a while (or none of the above & you are really dilligent!) Whilst baking will sort out the MSD issues (such as popcorning) it will
Electronics Forum | Tue Jul 18 18:53:23 EDT 2006 | Mike F
Is it showing up after wave or reflow soldering, or after hand soldering? If the delamination or blister bridges between traces you have the potential for a short circuit between those traces. A delamination might be repairable, but in most cases i
Electronics Forum | Mon Aug 14 18:03:49 EDT 2006 | GS
Sure the bake need to be done after BGA replacement? Normally the board need to be backed before BGA replacement (not only)in order to avoid PCB delamination due to moisture entrapped during his life staing on field. Oven Temperature from 90 to 125
Electronics Forum | Thu Nov 16 11:45:15 EST 2006 | markb
I still think the best bet is probably an SMT pre-bake operation to ensure that there is no moisture in the board. Vapor pressure is usually the leading cause for delamination, so removing the source should significantly help out. Unfortuantely, pr
Electronics Forum | Wed Apr 04 19:10:20 EDT 2007 | rgduval
Pete, Top-side temp might be an issue. What's the easiest way to check it? I seem to recall some thermal decals that we used to use a couple of jobs ago. I spoke with the flex manufacturer, and they recommended 4 hours at 250 degrees pre-process
Electronics Forum | Fri Jul 13 08:54:18 EDT 2007 | rgduval
Has your board house reviewed the PCB layer stack? Make sure that the layers are balanced in copper weight, etc? Have you tried pre-baking the boards? We just had an issue with some boards warping that have never warped before for us. It happened
Electronics Forum | Tue Jul 31 15:33:30 EDT 2007 | gregs110
I have seen a few threads about delamination issues on IS410 laminate in RoHS applications. I have recently been running into a rash of issues on 4 different part numbers with a single PWB source. All the parts have been built fine in the past with
