Electronics Forum | Wed Sep 10 12:56:09 EDT 2003 | davef
Intermetallic compounds [IMC]: * Form during the alloying process of some metals. In soldering these are Sn, Ni, Ag, Cu, Au. * Do not accept solder. * Increase in depth in logarithmic proportion to both time and temperature. [So during the solder
Electronics Forum | Thu Apr 09 00:35:06 EDT 2009 | padawanlinuxero
Hello! I am in a little problem, theres a problem in one of the components, is a new component that we are working with the leads are tin coated, and after we solder in the reflow oven, with lead solder, we took them to do a some test and on a cros
Electronics Forum | Sat Apr 11 09:56:31 EDT 2009 | davef
You're correct. You should expect to see an intermetallic layer in a proper solder connection. Try leaving the component at temperature for a longer period. Growth of intermetallic compounds on Cu surfaces [Klein Wassink]: d = 10^3(exp(-5*10^3/T)t^1
Electronics Forum | Tue Sep 09 18:07:18 EDT 2003 | davef
We would be very wary of allowing 50 uinches, because this will likely result in reduced shelf life due to intermetallic growth. As a guesstimate, at least 10 uinches of that 50 uinches, and maybe more, is already intermetallic when you receive the b
Electronics Forum | Fri Sep 12 09:10:23 EDT 2003 | Norm Morikawa
Around 1989 I had this probelmm with a SMT CCA that would not solder in one area consistently. I had it cross sectioned by the bare board supplier and found that under their metallurgical microscope the thickness of this HASL bare board could not be
Electronics Forum | Fri Sep 28 16:49:48 EDT 2007 | davef
good * No IMC => bad Intermetallic growths are diffusion limited, and therefore the thickness of the intermetallic is given by: z^2 = (Do)(t)exp[-Q/RT] Where Do (m^2 s-1) is the diffusion coefficient, T(�K) is the temperature, Q (J mol-1) is the act
Electronics Forum | Fri Sep 28 07:42:07 EDT 2007 | zanolli
We have the need to verify that proper intermetallic layer between a 100% Sn plated contact and the solder joint is being formed. Never having done this before: Is there any specifications, etc. that we can use as acceptability criteria?
Electronics Forum | Mon Jul 06 20:32:34 EDT 1998 | Chiakl
Hi there, I am looking for some informations concerning the shear or pull strength of a typical TQFP 20 mils leads in relationship with the Copper/Tin intermetalic layer thickness. Could anyone help? Thank in advandce. rgs, chiakl
Electronics Forum | Thu Jul 09 21:04:50 EDT 1998 | Dave F
| Hi there, | I am looking for some informations concerning the shear or pull strength of a typical TQFP 20 mils leads in relationship with the Copper/Tin intermetalic layer thickness. Could anyone help? | | Thank in advandce. | rgs, | chiakl Chiakl
Electronics Forum | Tue Aug 03 17:13:41 EDT 2010 | bradlanger
Craig, If it is LF Hasl it sounds like it applied too thin exposing the intermetallic layer wich is not solderable. We call out a minimum thickness of 80 microinches and have good results. We have had shops in the past that did not control the Hasl
