Electronics Forum | Sun Dec 13 08:49:15 EST 1998 | Ron Costa
Has anyone had any experience with using this alternative plating process? Some board houses are pushing toward this plating. Is there any long term data on this process? Any problems experienced with smt and thru-hole? I've heard tin whiskers to be
Electronics Forum | Wed Aug 09 08:06:07 EDT 2006 | davef
See "IPC-4554 Specification for Immersion Tin Plating for Printed Circuit Boards" 3.2.1 Immersion Tin Thickness. The most common reason for solderability issues with the white tin surface coating during multiple thermal excursions is a thin white ti
Electronics Forum | Mon Dec 14 10:53:10 EST 1998 | Earl Moon
| Has anyone had any experience with using this alternative plating process? Some board houses are pushing toward this plating. Is there any long term data on this process? Any problems experienced with smt and thru-hole? I've heard tin whiskers to b
Electronics Forum | Fri Dec 16 08:16:41 EST 2005 | davef
Heat cycles deplete the pure tin layer. Each solder cycle reduces the tin thickness by ~0.1 micron (4 uin). So, if you start with a thin imm tin coating you'll have problems after multiple heat cycles. Steve Wentz says, "In almost every case I've
Electronics Forum | Tue Dec 13 14:55:12 EST 2005 | muse95
Your response is from the point of view of using a Bismuth solder with Pb plated leads. Samir's point of view is from Bismuth in the plating on the leads being used with a Pb solder. There is a very large difference in the amount of Bi that will en
Electronics Forum | Mon Dec 12 14:04:33 EST 2005 | craigj
Hi All was wondering is there anything I should be aware of or look out for if using parts with SnBi (Pb free) lead plating with Sn/Pb/Ag solder paste? I was always lead to believe that mixng lead and bismuth caused problems or are the bismuth levels
Electronics Forum | Mon Dec 12 15:57:58 EST 2005 | Samir Nagaheenanajar
4% of the alloy), there is a ternerary phase (not sure if i spelled that right) where the melting point of the alloy is MUCH less than, say, SAC305's. Sn-Bi has also been associated with...... none other than Tin Whiskers. There are some in the in
Electronics Forum | Tue Dec 13 09:15:56 EST 2005 | Samir Nagaheenanajar
5% Bi results in less plasticity * Formation of low temperature (ternerary phases) not detected. I don't advocate the use of Bismuth, per se, but rather I'm just relaying info. that I learned this from a Lead-Free seminar that I attended at Riyadh
Electronics Forum | Mon Dec 12 21:38:05 EST 2005 | davef
Effect of lead on bismuth solders * Lead from hot air leveling (HAL) coatings can diffuse through the grain boundaries of the alloy. * Lead can form a eutectic composition of Bi52Pb32Sn16 in the grain boundaries. * Melting point of this eutectic all
Electronics Forum | Wed Sep 01 08:27:38 EDT 2004 | davef
Zinc from the brass [Cu3Zn2] diffuses into the tin causing solderability problems. Just 0.001% of Zn in your solder can render it fit for the scrap heap. So, you need a barrier plate between the brass and the tin. Copper or nickel-plating is commonl
