Electronics Forum | Thu May 07 20:28:35 EDT 2009 | davef
From our notes, the following is a series of snips from: "Copper Dissolution in Tin" LJ Turbini, PhD, adjunct faculty member, University of Toronto, Materials Science and Engineering, SMT 2/07 As the solder becomes molten, copper from the board diff
Electronics Forum | Tue Dec 05 15:10:55 EST 2000 | Francois Monette
Victor, here are a few more elements of information to answer your question. Both the temperature and relative humidity on the manufacturing floor have a significant impact relative to the rate of diffusion of moisture inside a plastic package and t
Electronics Forum | Sat Mar 08 21:45:59 EST 2003 | MA/NY DDave
Hi The other thing the Ni does is to create a time barrier for the underlying copper (Cu) migration into the joint. Degradation still occurs yet it is slowed significantly. Diffusion Equations under, electonic current pressures across time, are inv
Electronics Forum | Tue Jan 13 20:52:21 EST 2004 | davef
Bismuth Solder alloys * Fatigue life is reduced when soldered to hot air solder leveled (HASL) boards. * Lead from Hot Air Leveling (HAL) coatings can diffuse through the grain boundaries of alloy. * Lead is bismuth alloys can form a eutectic composi
Electronics Forum | Tue Nov 29 22:32:51 EST 2005 | davef
The dissolution rate of nickel into tin is a lot slower than that of copper [into tin]. This results in a nickel-tin (Ni3Sn4) intermetallic that is only 0.25-0.75�m thin after a normal soldering process. The Ni-Sn intermetallic compound tends to be m
Electronics Forum | Thu Dec 15 12:10:07 EST 2005 | muse95
It should be the other way around. A Pb BGA ball will fully melt in a Pb free process, but a Pb free BGA ball will not fully melt in a Pb process, which means the Pb from the paste on the board will not fully diffuse through the ball. This leads to
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 | Tue Mar 25 12:08:53 EDT 2008 | ludee_circuits
My factory produces Printed Circuits Boards.Today, my customer says they encounter problem with solder ability issue. Some of the boards have difficulties during SMT solder flow. Could not stick to the pads and the components fell off. Those boards
Electronics Forum | Thu May 07 08:11:58 EDT 2009 | davef
We don't have a good answer for you, but we do have several thoughts on the issue: * First, tin in your solder or solderability protection is going to diffuse into the copper trace or pad on the board naturally. You can stop that by using a protectiv
Electronics Forum | Fri Sep 03 16:43:13 EDT 2021 | djenkins62
Hello Everyone, We are building devices to remove moisture from boards prior to rework where it does not require the use of ovens as stated in IPC-TM-650, Method 2.6.28. Instead of evaporation, we use moisture magnets to pull out the part......even
