Electronics Forum | Tue Jun 27 12:12:05 EDT 2006 | GMan
Yes it does seem like a plating issue and analysis is being done. Thank you for your inputs.
Electronics Forum | Wed Jun 28 02:29:48 EDT 2006 | Loco
Wow, great article there mike! Thanks for digging it up for us! Kind regards, Loco.
Electronics Forum | Tue Jun 05 14:38:55 EDT 2001 | pteerink
You would be better served to check your print quality as you run. Any problems caused by dirty stencils ( plugged aps etc ) would show up right away as a defect. Search the forum for more on this subject. I seem to recall the same subject coming up
Electronics Forum | Fri Nov 03 07:28:27 EST 2006 | davef
Via filling methods are: * Tenting * Plugging * Capping * Flooding Tented Via. A via covered with dry film soldermask; the via is not filled. When tenting from both sides there may be issues with trapped air that expands during mass soldering. Plug
Electronics Forum | Mon Jun 26 23:33:20 EDT 2006 | KEN
We saw this condition over 3 years ago. It sometimes is called "champagne bubbles". The intemetalic formation is interrupted due to the micro voiding reducing mechanical strength. I discovered this on lead free test vehicles for a major computer
Electronics Forum | Fri Mar 19 10:27:42 EDT 2010 | karlo
No clean pastes leave more flux residues. These can result in void formation and inhibtion of underfill curing. Selection of an underfill that is compatible with the flux residue is important. One company that has written about the effect of flux
Electronics Forum | Wed May 20 17:18:09 EDT 2009 | daxman
Just out of curiosity, how are you or anyone else determining a defect? Last I checked, IPC had no criteria yet for solder defects for QFN components. Has this changed? Biggest problems we see are voids which our x-ray shows a lot of. Our problems
Electronics Forum | Wed May 20 17:56:51 EDT 2009 | dyoungquist
I have attached a pdf showing the dimensions for the QFN we placed. First, The pins on the part are not only on the bottom side but also wrap around to come up each of the 4 sides of the part as shown in the side view in the attached pdf. This i
Electronics Forum | Tue Jun 27 16:29:28 EDT 2006 | Board House
There was a good artical on this in Assembly Magazine October 5, 2005 by Donald P. Cullen, Director of OEM and Assembly Applications, MacDermid Inc., Waterbury, CT Heres the Link http://www.assemblymag.com/CDA/Archives/56840a86f06c9010VgnVCM10000
Electronics Forum | Wed Jun 28 22:34:31 EDT 2006 | davef
Yes, it would. That you are asking this question makes us wonder if you would be better advised to contract with a independent FA laboratory to help you baseline your analysis. Among the fine labs to consider are: * Robisan Laboratory 6502 East 21
