Electronics Forum | Tue Dec 05 04:30:02 EST 2017 | jan_pedersen
You find good information in IPC-4554 that includes recommended total Sn thickness and recommended free Sn. It refers to how much usable Sn is needed to meet coating durability categories defined in J-STD-003. As example, if you need 6 months shelf l
Electronics Forum | Tue Jul 14 07:23:50 EDT 2020 | researchmfg
There is a misunderstanding that people think the IMC layer grows the thicker the stronger soldering strength. The IMC layer can be grown and distributed evenly at the interface location will be good enough. Once the IMC layer grows too thick and ove
Electronics Forum | Wed May 03 20:24:22 EDT 2000 | Dave F
MF: I know of nothing that addresses your question directly. Let me suggest: * Technical types at your solder supplier should be able to help. * "Effect Of Intermetallic Compounds On The Thermal Fatigue Of Surface Mount Solder Joints" PL Tu, et a
Electronics Forum | Fri Jan 19 17:43:30 EST 2001 | davef
Intermetalic Layer (IL). A compound formed at the interface of two different metals, whose atoms have an extremely high natural attraction for each other, so high, that they do not bond to other elements by any other means. Also, intermetalic compo
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 | Mon Jun 12 22:00:51 EDT 2000 | Dave F
Could be. What are your profiles? 2) Au finish fail => Could be, but that the connections can be made with hand soldering makes this a low probability cause, assuming the activity of the flux used in hand soldering is not significantly different fr
Electronics Forum | Mon Nov 25 09:06:15 EST 2002 | jax
You might want to check the tin thickness. I believe you have a minimum of .65 microns in order to achieve a good solder joint through 3 thermal passes. In an immersion tin process, the ability to solder is time and temperature dependant. As the int
Electronics Forum | Tue May 24 19:35:36 EDT 2005 | davef
Certainly, most often, the focus of pot analysis is directed at controlling impurities. Maintaining proper level of tin is important, also. When the portion of tin decreases: * Liquidous temperature increases. * Ability to wet decreases. * Solder c
Electronics Forum | Thu Sep 16 18:07:16 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 reco
Electronics Forum | Tue Aug 31 20:51:20 EDT 1999 | Raeto Zryd
Dear fellow process engineers, Some solder joints "trough hole component" have cracked. I suspect that in the market some technician tryed to straighten some components (LED) and has applied enough force to actually brake the joint. The joints were
