Electronics Forum | Fri Sep 17 07:33:56 EDT 2010 | scottp
Based on the last few pictures in the report, the root cause is lousy HASL. In fact, you don't have HASL - you've got SnCu intermetallic. Don't mess with your reflow profile, change paste, or monkey with anything else in your process. Have the boar
Electronics Forum | Fri Mar 26 15:48:31 EDT 2021 | grahamcooper22
Leaded HASL on small pads can be quite difficult to print on...the HASL tends to be domed rather than flat..and that can affect print quality...you really need a perfectly flat pcb pad to print paste on when you are assembling 0.5mm QFPs. If the pcb
Electronics Forum | Wed Aug 19 18:18:02 EDT 2009 | smt_guy
Thanks Sir Dave. Yeah my apologies. To clarify, we built the product PCB whcih has a Lead-Free HASL Finish using a Sn63/Pb37 Solder paste. My major concern regarding reliability is that my profile whish is between 215'C-225'C was insufficient to ref
Electronics Forum | Wed Nov 17 10:03:29 EST 2010 | scottp
Instead of a minimum thickness, we require no exposed copper or SnCu intermetallic. We've been having a lot of trouble lately with suppliers of SN100 HASL boards giving us pads with very irregular solder deposits with areas of exposed intermetallic.
Electronics Forum | Wed Apr 21 20:01:00 EDT 1999 | Dave F
Earl said, in essence: | Justin is absolutely right ... | | Again, Entek is not much more than a flux coating ... | | Metallic coatings protect best, as we all know - especially those electroplated. Those coatings chemical come in next to no coati
Electronics Forum | Wed Sep 03 11:52:58 EDT 2008 | stepheniii
But Vlad was talking tin and Davef gave intermetalic thicknesses which Vlad said needs to be avoided by having a few microns of tin. I'm not 100% sure but I suspect that DaveF is not convinced that Vlad knows what "intermetalic" means.
Electronics Forum | Tue Aug 03 17:13:41 EDT 2010 | bradlanger
Craig, If it is LF Hasl it sounds like it applied too thin exposing the intermetallic layer wich is not solderable. We call out a minimum thickness of 80 microinches and have good results. We have had shops in the past that did not control the Hasl
Electronics Forum | Wed Oct 06 04:11:35 EDT 2010 | grahamcooper22
I've done minimal research to this point and > understand my issue with solder on the double > sided boards is due to oxidation that occures on > the unpopulated pads when the board makes its > first trip through the reflow oven. > > We did run
Electronics Forum | Wed Jan 24 11:27:54 EST 2007 | bradlanger
We have been using SN100C lead free hasl for over a year now with good success. It is very solderable and has good shelf life. You do have to make sure the finish gets applied to the correct thickness. If the lead free hasl finish is not applied thic
Electronics Forum | Sun Apr 25 12:01:58 EDT 1999 | Earl Moon
| Earl said, in essence: | | | Justin is absolutely right ... | | | | Again, Entek is not much more than a flux coating ... | | | | Metallic coatings protect best, as we all know - especially those electroplated. Those coatings chemical come in ne
