Electronics Forum | Thu Jun 16 22:33:54 EDT 2005 | davef
Peter: Please explain: * You say, "The cooling phase is important to perform the strength of the solder joint." [We agree that fast cooling rates produce fine grain in solder and that fine grained solder connections are stronger than coarse grained.
Electronics Forum | Tue Apr 09 08:49:43 EDT 2002 | davef
Hey Bud. Allow me to 'turn' your point about 'grain structure' just a bit. Fast cooling rates / coarse grain structures was a bit of red herring in the early 80's. Faster cooling DOES produce finer grained solder connections. Accelerated testing of
Electronics Forum | Fri Mar 03 16:05:42 EST 2006 | Chris
Hi, Anyone ever perform a DOE on prepreg glass bundle direction or glass bundle grain and how or if it affects PCB warpage and chip component cracking at V-score depanel? Since most FR4 and prepreg has has 1.4 times more fiber bundles in one direct
Electronics Forum | Mon Mar 06 17:57:39 EST 2006 | slthomas
Not here, but I'd be interested in hearing what you found.
Electronics Forum | Mon Mar 01 09:11:29 EST 1999 | Brian C
| | | | I need some help to see if anyone knows of a vendor that makes a permanent marker that is in the Houston area that can write on a PCB the size of a grain of rice using white permanent ink...That's the amount of space we have to write our seri
Electronics Forum | Tue Feb 04 09:21:48 EST 2020 | nhusa
There are two areas that are important when discussing cooling rate. One is the rate thru the liquidus, where a fast rate produces small grains in the metal and a slow rate results in larger grains. Although smaller grains are stronger normal SM
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 | 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 | Thu Aug 24 13:21:57 EDT 2000 | Dave F
Please compare indium (In) / Tin (Sn) paste properties in terms of reflow profile, creep, grain structure, etc with other major no-lead solder formulations.
Electronics Forum | Mon Jul 23 20:23:19 EDT 2001 | davef
Flux charring * Cool-down too long => Coarse grain ps: Some would argue that potentially you'd get greater response in the process forum rather than the design forum
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