Electronics Forum | Wed Apr 09 16:24:30 EDT 2003 | ksfacinelli
Dave is there an easy way to calculate liquidous temp? or just a ball park for Hasl boards / BGA's. I placed a thermal couple with kapton tape over a BGA to get the approx profile. Thanks, Kevin
Electronics Forum | Wed May 14 12:42:16 EDT 2008 | rgduval
Dave, Realized I didn't respond to one of your questions. We pasted and reflowed one board, with no components. This board exhibited extreme dewetting on all pads. The board was LF-HASL, and the paste was Qualitek (which we've used for approximat
Electronics Forum | Wed Apr 30 12:26:10 EDT 2008 | dphilbrick
There must be discussions about this on SMTnet but I have yet to find them. I would like to hear from all you smart people about running LF and PB BGA�s on the same board using 63/37 solder. If you run your profile up to peak at around 225C +/- (nitr
Electronics Forum | Thu May 25 08:58:14 EDT 2006 | inds
aj, check out the link http://www.smtnet.com/forums/index.cfm?fuseaction=view_thread&CFapp=8&Thread_id=10387&mc=5 as Samir mentioned in that link, try keeping your peak temp within 220-225degC.. TAL 217 around 20-40 sec..depending on your ball d
Electronics Forum | Wed Feb 14 10:10:55 EST 2007 | rob_thomas
The challenge regarding the stencil was mostly due to the actual board layout and nothing having to do with the voids in the solder. It was my first encounter with 0.5 mm pitch on BGA and dealing with a LF solder paste with higher viscosity than tha
Electronics Forum | Thu Apr 20 22:46:26 EDT 2006 | samir
Amol, I thought I answered your question in another thread, dude! Anyway, to re-iterate. Yes, I was able to pull it off a hybrid profile. The LF BGA passed tensile testing, but no, it wasn't thermally cycled or stressed first to expose any latent
Electronics Forum | Wed Dec 22 09:56:12 EST 2004 | davef
For BGA: http://www.smta.org/knowledge/proceedings_abstract.cfm?PROCEEDING_ID=731 For 0402: http://www.xs4all.nl/~tersted/PDF_files/Plexus/tombstoning.pdf
Electronics Forum | Wed Apr 26 09:15:23 EDT 2006 | Carol Stirling
That would be correct. Some others call it `Head in Pillow'. The BGA balls are 63/37 and the board it's mounting to is HASL.
Electronics Forum | Fri Oct 15 17:11:45 EDT 2004 | HOSS
Matt, Had a similar problem with HASL that wasn't fluxed properly during fab. The appearance of the HASL looked dull and/or mottled (sp?). Solder was curled under on the edges where it should have been smoothly joined to the pad. Almost like a pu
Electronics Forum | Thu Dec 15 11:06:05 EST 2005 | Samir Nagaheenanajar
You might wanna try a small reduction in your stencil aperture. For example, for a 30-mil pad go 26-mil square aperture with 8 to 10-mil radius on your corners. Also, look at your designs. Is there enough resist between your pad and ball? Another