Electronics Forum | Thu Oct 15 14:23:31 EDT 1998 | Earl Moon
| I have a problem with measling on our PCB's. We saw it on our FR4 PCB's at final assembly yesterday. Is this a defect from the board vendor or something we did in our assembly process when building the PCA's (thru hole). Could the wave solder ma
Electronics Forum | Fri Jan 20 11:44:40 EST 2006 | Mike Dolbow Atotalgps.com
I have seen 100% Matte Tin plating and a lot of Sn/Ag/Cu plating for gull wing parts. This is the most common type of plating. Also in a lead free process you will see that the very end Toe of the part will not flow. This is due to the metal being cu
Electronics Forum | Tue May 26 15:27:36 EDT 1998 | Dave F
| | | I'm reviewing my board fab spec. It calls for a minimum SnPb thickness of 50 microinches on HASL PWB's. I've looked at other specs that call out anything from 30 to 80 microinches, and others that just say the copper pad must be covered and s
Electronics Forum | Wed Mar 14 09:07:34 EST 2001 | blnorman
We just ran a study to try to determine this. We exposed the paste to 85% humidity to simulate worst case manufacturing. At various times we removed the paste from the chamber and tested it for tack, solder balling, wetting (copper coupon), and vis
Electronics Forum | Mon Dec 20 21:01:12 EST 2004 | davef
Bare inconel is NOT ment to take solder, because * Nickel develops a tenacious oxide layer that is very difficult to remove since the nature of the oxide is very dense, coherent, etc. * Chromium is difficult to solder. * Iron is difficult to solder.
Electronics Forum | Tue Jun 29 18:35:59 EDT 1999 | JohnW
| | Could somebody tell me what means Leaching, ie: "Leaching of terminal end face exposing the ceramic"? | | | Roberto: Leaching, according to the SMTnet Library of Terms: | | Leaching. Dissolution of a metal coating into liquid solder. Nickel ba
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 | Thu Sep 30 16:28:51 EDT 2010 | 18424
Hello All, looking for some help from you guru's. I have several Enig boards with solderability problems. Components ranging from 0402's to ssop's. Using AIM W/S leaded solder paste, profile is beautiful and has been for years running the same produc
Electronics Forum | Fri Sep 28 02:48:46 EDT 2018 | teresat2
Principle A layer of photosensitive material (photosensitive oil or dry film) is applied to the copper foil on the board surface, and PCB manufacturer should be use the position is exposed by black film, This applies to most PCB factories, especially
Electronics Forum | Tue Mar 28 08:29:04 EST 2006 | davef
Pad design - Standard IPC 20 pitch QFP Thermal pad design - Layout the thermal pad 0mm to 0.15mm larger per side (0mm to 0.30mm larger overall) than the exposed die pad on the package. �Larger than�, as opposed to the same size, is preferred. Obvio
