Electronics Forum | Tue Apr 27 07:50:09 EDT 2021 | jeremy_leaf
@KWalker I think that could be the case. Though I read somewhere a while back that nickel oxidation can be quite tough to remove, even with flux. Am I wrong about that?
Electronics Forum | Tue Apr 13 11:41:18 EDT 2021 | jeremy_leaf
I have a SAC305 preform with which I am attempting to bond a gold coated component to an ENIG coated PCB pad. I've specified 2 microinches of gold for the ENIG. It worked previously but now with a new batch of boards, I am having an issue where the p
Electronics Forum | Fri Oct 14 09:58:13 EDT 2005 | patrickbruneel
Here's what I believe is happening. The main difference between the HASL boards and the gold plated boards is that HASL boards are pre-soldered. HASL boards need very little flux activity to get good hole fill and the machine settings have a wide pro
Electronics Forum | Mon Apr 26 17:09:05 EDT 2021 | kwalker
Sounds like you are getting oxidation of the nickel under the gold layer. If the gold is porous it will allow the nickel underneath to oxidize, which is the dark dull layer you are seeing, and why when you apply flux it solders just fine - the flux i
Electronics Forum | Wed Apr 14 19:47:13 EDT 2021 | solderingpro
Sounds like you may have already found the issue: inconsistency from your supplier. Seeing as Gold really doesnt oxidize and you're using an inert environment (N2 I suspect), I would turn my attention to the supplier. You said yourself, the "Shine
Electronics Forum | Mon Oct 12 08:07:45 EDT 1998 | Earl Moon
| I have datas to substain that a not wetting PCB ( the HAL oxided or not uniform in thickness )if soldered in reflow, it shows voids with X-Ray inspection.The voids are in side all the joints not only on the solder pads levell. | | Is there a techn
Electronics Forum | Mon Aug 30 16:10:10 EDT 1999 | Dave F
| I have looked through the IPC web page and surfed to frustration. Can somebody give me a lead? | Brian: We don't use an etched board. We use a special stencil, described below and print on bare copper laminate. 3 Solder Wetting Test. Recogniz
Electronics Forum | Fri Mar 30 06:56:17 EDT 2007 | realchunks
Hi Chris, Mini stencils are a pain to line up and then holding it still while trying to print is almost impossible. We used to use tacky flux but found the Stencil Quik gizzmo from Best works the best. Give it a try. http://www.solder.net/stencil
Electronics Forum | Thu Mar 29 13:15:18 EDT 2007 | adrian_nishimoto
We always apply solder paste to either the PCB pads or the BGA balls. I have found that only using liquid or tacky flux does not always ensure proper wetting of the pads. Also The BGA sits closer to the PCB making cleaning and endoscopic inspection
Electronics Forum | Wed Nov 21 06:07:20 EST 2018 | robl
Hi Prem, Voiding has lots of causes, but boiling off flux to quickly really doesn't help, so maybe a more gentle profile. Also you do not need to print a solid block of paste, you can print a window pain style pad to help the flux escape. Also, th
