Electronics Forum | Thu Jul 15 11:17:03 EDT 2010 | davef
Things don't disappear completely. If something caused nickel corrosion, the nickel corrosion by-product would be in place of the nickel. Is it possible that ... There never was any nickel? We know that the nickel will diffuse into the copper. Th
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 Apr 19 15:48:28 EDT 2002 | davef
I don�t know much about zinc either. I can tell you that zinc forms no intermetallics with lead. So, I�m not so sure that �diffusion� is the correct term. Of the following: * Hwang "Modern Solder Technology For � * Wassink "Soldering In Electronic
Electronics Forum | Mon Sep 10 15:49:28 EDT 2007 | mun4o
Hi, the solder on the pad is not molt.Temperature of the leads is about 220*C( I change this T from 214 to 232) but result is same - solder is granular and not diffuse.I think the T on leads is not enough high,bu I can't increase because the max T on
Electronics Forum | Sat May 02 23:31:06 EDT 2009 | kareal
Thanks davef. The defect always occurred during UHAST reliability, but not find in reflow. The key is that there is tin diffuse to copper trace under solder mask. is it a "normal" board defect and what is the potential risk for device? thanks!
Electronics Forum | Fri May 08 04:39:32 EDT 2009 | kareal
Hi Davef, I want to explain that the tin diffusion in my project is not on solder bump/Pad region. It is on copper trace between bumps. so it is very wondering for me.
Electronics Forum | Mon Mar 29 16:33:29 EDT 2010 | mikesewell
SAC 305 liquidus is 219 C. A hybrid profile is often recommended with a peak of 230 C (reflow the SAC and not kill the Pb parts) with an extended liquidus of 60-90 sec to get good alloy diffusion. Or if the design (parts & pwb) can tolerate it go P
Electronics Forum | Thu Nov 10 21:33:17 EST 2022 | stephendo
So if you stored them in a nitrogen cabinet then you would reduce the O2 diffusion as well as keep moisture out of the boards.
Electronics Forum | Wed Sep 15 17:53:53 EDT 2004 | aaronrobinson
My question is how does heat alone (125DegC for 48hours) diffuse the water vapour in a component, I figure the amount of water vapour in grams per cubic cm will be the same regardless of temp...yes with temp the RH changes but once the component rea
Electronics Forum | Wed May 03 20:19:31 EDT 2000 | Dave F
Sal: Sorry, sometimes (more often than I�d like to admit) I�m a bit dense. But first � Leaching. Dissolution of a metal coating into liquid solder. Leaching applies to liquid solder and is applied inaccurately to metallurgical effects, like diff
