Electronics Forum | Tue Feb 23 12:56:03 EST 2010 | vleasher
Is there any harm in washing SMT soldered with NoClean paste? The PCA has some large thru-hole connectors that we would prefer to do as water soluble on out selective solder but the SMT consists of LGA's and other low parts that we would not be able
Electronics Forum | Tue Nov 28 17:43:03 EST 2006 | IRAS
I'm looking to gain some knowledge on potential causes of solderballs on LGA's and advice on how to eliminate them. we all seeing some solderballs on only the edges of the LGA. Any inputs will be greatful.
Electronics Forum | Wed Jun 03 16:10:54 EDT 2009 | mattkehoe
Here is a little different spin on re-working/hand placing LGA's.. http://www.sipad.com/download/LGA%20Rework%20Document.pdf
Electronics Forum | Wed May 20 17:00:56 EDT 2009 | dyoungquist
We just placed a 56 pin QFN, 1 per board, on 10 boards and had zero defects. A good paste job, proper placement and a correct oven profile are the keys. If these are set up correctly, on larger runs your defects won't be zero but they should be le
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 | Fri May 22 08:04:30 EDT 2009 | stevezeva
Have any of you ever worked with Actel's QFN 180? A three row I/O QFN? Actel has a published paper on design and assembly guidelines, but we're finding that they are pretty much generic, and don't really work as well as they lead you to believe. ht
Electronics Forum | Tue May 26 15:39:16 EDT 2009 | mikesewell
Amkor's MLF guidelines are very similar to Actels. 1 to 1 on the stencil to part pad on the I/O pads, 75% with a grid windowpane, 0.125 mm/5 mil stencil. For example, the Actel area ratio for a 0.3 mm sq. pad and 0.125 mm stencil is 0.6 which seems
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 May 26 14:39:40 EDT 2009 | boloxis
QFN or MLFs are mainstream now, QFNs already evloved to much more complex versions now like matrix pins, stacked dice and flipchip versions. IPC 610D already includes them, just make sure the pins have solder plating, the PWB pads have soldermask in
Electronics Forum | Fri Jul 15 12:41:56 EDT 2005 | russ
You are not wrong in monitoring the Product (your really not monitoring the process). This methodology is valuable if your process is unstable (SPC is used to stabilize process). There is value in "real time" inspection of a process's product as lon