Electronics Forum | Fri Jun 07 10:46:16 EDT 2019 | gregoryyork
The Single Solder ball stuck to the mask may indicate undercured as well. The issue is not so much the mild No Clean flux but the potentially major active HASL flux or Silver Process chemistries causing issues. This has been through flow solder hasnt
Electronics Forum | Tue Sep 14 14:52:22 EDT 2004 | Carol
During processing, the solder in the vias reflows and forms solder balls. PCBs have solder in random PBGA vias from the board manufacturer.The manufacturer says this is a result of the HASL process and is unavoidable. We use HASL finish, multilayer,
Electronics Forum | Mon Sep 28 09:35:28 EDT 1998 | Clive Heke
I have had some field failures returned recently, the boards had flux contamination under the components in a sensitive area, Nothing really visible until the component was removed, and the board had no evidence of rework of any type. Is it possib
Electronics Forum | Wed Feb 05 17:37:40 EST 2003 | mk
Investigate "Solid Solder Deposition"
Electronics Forum | Wed Feb 05 10:31:38 EST 2003 | bpan
Hello Everyone, Is anyone out there building smt boards that have plated through vias directly located through the pads. We are seeing some of these designs and the soldering is very poor because the solder is flowing through the via. We think that w
Electronics Forum | Wed Feb 05 19:43:34 EST 2003 | iman
If by the Powers Ta Be (customer/designer), you can't change the PCB design, negotiate for the PCB fab house, to block the via holes with their (green?) solder mask some customers/designers want to have via holes to be present in the PCB pad, due to
Electronics Forum | Tue Jul 22 20:38:28 EDT 2003 | Paul T.
Have the PCB fabricator use a conductive paste to fill the vias and then finish by plateing over the via. Make sure it's coplanar to the side they're on, usually secondary side for discretes. PT
Electronics Forum | Tue Feb 11 13:12:25 EST 2003 | Jim Mills
Use a PCB fab house that is capable of "Conductive Via Filling" is the way to do it right. A conductive epoxy is used to fill the drilled via PRIOR to final plating. After final plating, the surface of the "Filled Via" will appear to be the same as t
Electronics Forum | Mon Feb 10 06:49:06 EST 2003 | bg
Specify a .1 mm diameter FHS with tolerance of +.3 -.1 using a .15 mm stencil.
Electronics Forum | Mon Feb 10 15:39:20 EST 2003 | bpan
Thanks for all the info guys. Dont think that the problem is a thermal one and I believe the guys designing the board just need to design them out. I have directed the customers we get the boards from to read this posted question so that they could s
