Electronics Forum | Mon Apr 27 14:39:38 EDT 2015 | davef
Anirudh: When board fabs talk "surface finishing" they're talking about the solderability protection that you'd like on the solderable copper component mounting pads that you laid-out for each component: * Bare copper pads corrode very quickly * Corr
Electronics Forum | Thu Aug 29 06:48:01 EDT 2002 | yngwie
I have seen several Imm Ag pad on the assembled board which have a copper colorleaching through the silver plating This happened on the pad which was not deposited with paste during the assembly process. Don't know if it is a problem, but we only
Electronics Forum | Wed Nov 06 20:18:30 EST 2002 | davef
cvrgrrrl Your first thermal cycle with imm silver should be the easiest to solder. That you see copper indicates you did no soldering, got no wetting, produced no intermetallics, etc. Tell us again which components did not solder? Wuzzis "plug" t
Electronics Forum | Sat Sep 27 10:40:24 EDT 2008 | hussman
Hello all, Just had a problem where the solder paste does not want to stick to the pad, thru the stencil. We have run this board for years with no problem, and this new lot of boards is giving us problems. I know it's a board problem because they
Electronics Forum | Sun Jun 29 15:03:04 EDT 2008 | jensteele
I was referring to the HASL supplied by the supplier...specifically Lead Free HASL. I've been searching the web and I cannot find a thickness specification like we have for ENIG and Immersion Silver.
Electronics Forum | Thu Jul 08 23:46:21 EDT 2010 | rdoss
I have this same problems on the flex i use, most of which has an ENIG or immersion silver finish. About the only thing I know to do is have your supplier package it in a vaccume seeled bag to keep it from oxidizing. Otherwise you end up having to
Electronics Forum | Thu Sep 30 16:54:33 EDT 2010 | 18424
Enig have been one of the industries leading finishes with great solderabilty and shelf life, And now Immersion Silver is starting to get popular.
Electronics Forum | Wed Apr 26 03:32:29 EDT 2006 | saaitk
Hi all, Has anyone any experience they can share with regard to pad dissolution on PTH's on thick boards. We are using lead free SAC305 on both OSP and Immersion silver finishes and are experiencing difficulties when removing and replacing connector
Electronics Forum | Sat Aug 30 11:42:49 EDT 2008 | davef
Some immersion silver [IAg] products can go brown with aging. On a newly plated board, we expect you to see Ag, C, & O. The amount will vary according to supplier and thickness. Questions are: * How uniform is the brown coloration of the IAg on the
Electronics Forum | Thu Dec 07 07:36:15 EST 2006 | callckq
Hi Davef, The BGA pad is with ENIG finish, the PCB pad is with immersion silver and the solder paste is with SAC type. I already checked, the solder paste Cu is just 0.5%..Hence, I am guessing that copper migration is from PCB pad. No way it is fr
