Electronics Forum | Wed Sep 17 10:49:48 EDT 2003 | davef
We agree. Colin Lea showed that HASL less than 2 microns [80 uin] thick has limited shelf life and that shelf life gets worse as the HASL gets thinner. Unless you do not need shelf life, consider sticking with 100 to 500 uin. There is nothing wrong
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 | Tue Oct 23 09:09:27 EDT 2001 | Cemal Basaran
What is the reflow temperature you use to attach this package to your PCB.? I did extensive study on this package and compared it with other packages. I used our own Moire Interferometry, SEM, EDX studies. In my opinion the problem is TI does not man
Electronics Forum | Wed May 17 23:59:16 EDT 2006 | KEN
Repeatability data please. Please provide source. Can you provide the standard deviation and sample size please. Does this data represent all major angles? Was this data independently verified? Was this data collected using glass parts or p
Electronics Forum | Wed Feb 09 21:37:37 EST 2000 | Dave F
Rob: Someone's out there turning over stones, eh? Roller Tinning, Rolled Solder. In printed circuit fabrication, a surface coating of tin-lead, typically 1-2 microns thick, applied to preserve solderability. Still available from some fabricators
Electronics Forum | Thu Oct 25 16:48:29 EDT 2001 | Cemal Basaran
We can inspect and measure strain field in anything larger than 320nm with Laser techniques we have. We can do this measurements during fatigue testing. Of course thick intermetallic region as a solid region is a problem due to the fact that you ha
Electronics Forum | Mon Jun 30 08:55:31 EDT 2008 | davef
It will be tough to find a dimensional thickness specification for HASL. IPC-6012 Table 3-2, line "Fused tin-lead or solder coat - Coverage and Solderable" states the requirement that there has to be complete coverage of solder on the land, and it mu
Electronics Forum | Wed Sep 03 16:59:13 EDT 2008 | glennster
At a former employer we required HASL thicknes to be a minimum of 0.75 micron (30 microinches), as measured at the thinnest point on any given pad. This would generally assure a minimum 1 year solderability shelf life. Usually when we saw a soldera
Electronics Forum | Wed Oct 10 20:58:30 EDT 2001 | davef
Several points are: * There�s quite a bit of background on IMC in the fine SMTnet Archives. I�ll try not to duplicate it. * If you have a smooth and well-formed solder connection using fairly common materials, you assuredly will have IMC. Any evide
Electronics Forum | Tue Oct 23 20:27:06 EDT 2001 | davef
WOW!!! How do people get these coo toys? Comments are: * IPC-7530 is not a specification. It is merely a guideline. [IPC-7530 �Guidelines for Temperature Profiling for Mass Soldering (Reflow and Wave)�] * What makes you say a 20-micron intermetall
