Electronics Forum | Sat Oct 06 05:33:47 EDT 2001 | spchua
I had recently encounter the "black and grey" pads problems for the BGA pad after the convection re-flow. The pads shows in in "black and grey" color and a litter solder in it, and it happen in ramdom, when applied heat and solder on the "black and g
Electronics Forum | Fri Apr 29 14:16:16 EDT 2011 | ppcbs
Below is the long explanation. This defect is most commonly found with BGA components, but can arrise with all components. I see it happening more now with lead free boards that are being assembled with a no clean flux. Best short term remedy is t
Electronics Forum | Fri Sep 07 16:29:52 EDT 2001 | mparker
That would be the elusive typo, check your keyboard, the "A" is right next to the "S". I believe she meant "SMT" boards. Wazzup Dave, your grey matter already shifted into weekend mode? Hoist a pint of Sierra Nevada, if you get that spill in your ne
Electronics Forum | Fri Apr 03 02:52:42 EST 1998 | Jacqueline Coia
At this moment in time we are using water soluble solder paste on our PCBs these are cleaned using water only, agitated with ultrasonics. After drying a white/grey residue is left around solder joints. Reflow profile is fine and a reliable wash proce
Electronics Forum | Mon Oct 22 09:32:27 EDT 2001 | Steve L
The solder joint appeared dull and there is dewetting on the PCB after Reflow. The leads of IC we used appeared dull grey before soldering. Dose anyone happen to know if there is a standard to verify the IC contamination and how to deal with the con
Electronics Forum | Tue May 20 07:55:27 EDT 2014 | andrzej
Hi, I am facing an issue with PB-free HAL on our boards (270 pcs of 800pcs lot). I look for a root couse for this issue and I guess it is strongly related with PCB manufacturing process. In attachment you can see PCB with dark pads. They turned grey
Electronics Forum | Tue Jun 12 20:36:00 EDT 2001 | ianchan
Hi mates, thanks for the interest on this topic, just to share info to clarify any queries : 1) am using light blue-grey materials for the Pallet 2) am using Hot Air Convection Reflow Oven 3) I suspect its due to the Pallet materials properties, t
Electronics Forum | Fri Apr 03 08:22:36 EST 1998 | Scott Cook
| At this moment in time we are using water soluble solder paste on our PCBs these are cleaned using water only, agitated with ultrasonics. After drying a white/grey residue is left around solder joints. Reflow profile is fine and a reliable wash pro
Electronics Forum | Wed Sep 05 07:07:25 EDT 2007 | mun4o
hi, I have a big problem with soldering uP QFP144 package.All components in PCB are small, only this chip is big and I can't make good temperature profile.Solder joints of other components are shining and with good wetting, but in QFP leads solder j
Electronics Forum | Sun Apr 05 18:59:15 EDT 1998 | Graham Naisbitt
Jaqueline There are so many variables in the electronic assembly manufacturing process involving more than 12 different chemistries, that it is impossible to easily identify and determine the nature and reason of such residues. GEC Hirst Research in
