Electronics Forum | Sat Aug 15 13:26:05 EDT 1998 | Bob Willis
| Electrical Eng. is looking for 5 micrograms per sq centimeter. After the board has been cleaned. Is this possible on a fully assembled bd? The European standard often quoted is 1.5 mg/cm which ia achievable on a board assembly please remember one
Electronics Forum | Mon Mar 11 11:11:38 EST 2002 | slthomas
Tahnk you for posting the charts. > > They look > very useful, but I have a silly question: In > reflow problems _ What is "leaching" ? Dissolution of the component metallisation into the liquid solder. _ > What is "Halo effect" ? "...a
Electronics Forum | Thu May 09 15:30:57 EDT 2002 | TomN
I'd be a more than a little cautious about doing this. Had a somewhat different application once and found out that as the solution was cleaning/etching the surface, it also leached (thru the lead frame) into the body of the part. What we thought w
Electronics Forum | Tue Jun 04 16:12:41 EDT 2002 | Bob
The original profile had a higher ramp rate, and the apertures were 100%. The ramp rate is now much gentler and the addition of a small soak area around 160 � 170 degrees should burn off any excess flux. Appertures are now smaller and we get no leac
Electronics Forum | Thu Aug 29 17:51:43 EDT 2002 | nifhail
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 h
Electronics Forum | Wed Aug 27 09:45:22 EDT 2003 | caldon
My initial thought (Quick and not to in depth)made me think of the solder joint integrity. I would fear solder contamination if the metal making up the plating would leach (or its elements) into the solder joint. I strongly suggest if you were to go
Electronics Forum | Thu Jan 15 09:40:47 EST 2004 | davef
Search the fine SMTnet Archives. For instance: http://www.smtnet.com/forums/Index.cfm?CFApp=1&Message_ID=24429 Do not get your hopes up about finding something to support your "leaching out of silver theory", though. * AgxSn IMC are disbursed ro
Electronics Forum | Fri Mar 26 17:12:17 EST 2004 | ben
I have recently encountered a new pcb design with a very high density of components on either side of the pcb. One of the suggested "fixes" is to use the smt pads as vias i.e. the via will be drilled thorough the centre of the smt pad. My concern i
Electronics Forum | Thu Apr 08 04:52:24 EDT 2004 | Dougie
We are concerned about the issues you mentioned and more, however we have no option but to change over due to legislation. A high percentage of our market share is in Europe and Japan, who of course have already embraced the no-lead change. We simply
Electronics Forum | Tue Nov 21 09:46:19 EST 2006 | jax
I assume you are talking about Sn62Pb36Ag2 solder. You should not see any added concerns when subjecting Sn62 to multiple reflow cycles as compared to Sn63. As compared to Sn63Pb37: Reduced leaching issues Increased Wetting due to lo
