Electronics Forum | Tue Oct 27 16:22:00 EDT 2009 | davef
It's not the first thing we think of in looking at your picture. First off, the lack of copper in the region of the red oval makes us think of a plating defect. We don't expect that moisture out-gassing through the barrel wall to show-up on opposite
Electronics Forum | Fri Nov 16 08:22:03 EST 2007 | ck_the_flip
For those of you who've completely switched to Pb-Free or who're running in a mixed environment, are you also buying or specifying the "RoHS PCBs" - the ones with * Greater Tg (glass transition temperature) * Thru-holes with limited drill hits and
Electronics Forum | Thu Apr 18 16:52:15 EDT 2002 | davef
General comments are: * First place I would look is the supplier of the pins that you are trying to install. Most suppliers that sell press fit components have done a good deal of work to qualify the component and will have all the specifications yo
Electronics Forum | Thu Aug 17 17:36:08 EDT 2006 | slthomas
I don't have any data (haven't tried this), but it doesn't take much thought to see that determining the risks associated with simultaneously applying compressive and rotational forces to the end of the barrel, not to mention chewing up the copper, i
Electronics Forum | Wed Nov 05 18:39:06 EST 2008 | joeherz
Hello, We have recently installed a selective soldering machine and are seeing some voiding/cratering in random locations. We have done some basic experimenting with fluxing parameters, preheat and dwell times but haven't been able to eliminate it.
Electronics Forum | Fri Feb 22 14:22:07 EST 2008 | stevek
Are you using nocleans, especially when you get to SMT? Years ago, I had OA wave flux get into vias that were plugged from the top under parts. It is really difficult to clean small, high aspect ratio vias. Cross sections showed that the copper in
Electronics Forum | Tue Apr 28 07:22:46 EDT 2020 | stephendo
Are you watching for copper dissolution? At one place I was asked to check why we had no barrels with some PTH locations. It was being dissolved in the solder fountain during rework.
Electronics Forum | Mon Apr 02 20:47:22 EDT 2001 | davef
Cuppla questions for ya ... Where are the shorts [above the mask or between the mask and the laminate]? On the board, what material is between the copper traces and the mask? What type of solder mask(s) used by your suppliers? What are they using
Electronics Forum | Mon Mar 07 20:27:07 EST 2005 | KEN
Oh silver and its...improved solderability over tin / copper. BS if you ask me. Look to your flux and thermal profile for wetting spread. Ask yourself just how much "wetting spread" do you need to fill a barrel? I have the same 100% barrel fill
Electronics Forum | Sat Nov 08 09:10:16 EST 2008 | davef
SN100 was designed for selective soldering and producing low levels of voiding. But thin barrel plating is a common cause of voids in wave and selective soldered connections, as you say. As a result, you checked the plating thickness and it was accep
