Electronics Forum | Mon Feb 19 18:57:49 EST 2001 | davef
Expanding on the limit of the portion of gold acceptable in a solder connection [mentioned in an earlier post]: The embrittlement culprit, AuSn4, is 29 weight percent gold. So even if one had 100% tin as the solder alloy and 10% gold were dissolved
Electronics Forum | Tue Sep 09 20:32:10 EDT 2003 | davef
The maximum ratio of gold weight to solder alloy weight can be calculated, to help prevent a problem from excessive gold-tin intermetallic compound (i.e., AuSn4). For the equation and its derivation, please refer to "The Use of Capillary Action Measu
Electronics Forum | Fri Feb 09 20:05:15 EST 2001 | benefid
The ENIG process will yield between 3-7 micro inches (110 - 275 microns) of gold over the nickel barrier. This thickness range is pretty much the limit as this is a self limiting displacement reaction process. Once all surface nickel ions are repl
Electronics Forum | Thu Jul 27 21:57:16 EDT 2000 | Dave F
Hi Doug: Responding to your questions: � If gold over nickel is self limiting ... You didn�t say whether you gold plating was electroless or immersion. Electroless is not is self limiting. It can plate up to 5 thou. Expect immersion plated gold to
Electronics Forum | Mon Sep 13 06:23:06 EDT 1999 | Earl Moon
| | We have a product, with various PWBs, with over 600 parts each one (We are a low Volume/high mix company with an average component placement per PCB between 250 to 300 parts). This PWBs have 7 to 10, 20 mils pitch parts. We are having problems wi
Electronics Forum | Thu Feb 15 19:41:38 EST 2001 | davef
What do you mean by "But after performing temperature cycle test, the former aging rate (from the shear strength ) seems faster than the latter."? Comments are: I can't recall having heard the term "precipitation hardness" [not that that means anyt
Electronics Forum | Fri Sep 17 06:01:12 EDT 1999 | Earl Moon
| | We have some SMT components with gold plated leads. They're actually LCC led packages. A good solder alloy to use would be Indium / Lead to reduce tin dissolution into the gold and avoid the resultant brittle intermetallic compound. However, a re
Electronics Forum | Tue Mar 21 20:25:30 EST 2000 | Dave F
John: What�s the matter? Free gold � good thing for you, bad thing for your supplier. :^) Pre-tinning of gold plated leads is important to: � Prevent gold embrittlement of the solder joint � Determine if the leads are solderable prior to assembly (
Electronics Forum | Fri Sep 17 09:54:40 EDT 1999 | Brian
| | | We have some SMT components with gold plated leads. They're actually LCC led packages. A good solder alloy to use would be Indium / Lead to reduce tin dissolution into the gold and avoid the resultant brittle intermetallic compound. However, a
