Electronics Forum | Fri Dec 10 09:47:52 EST 1999 | Larry
What does everyone use for stencil apertures on D Paks? What's the best way to keep them from floating during reflow?
Electronics Forum | Wed Aug 25 21:51:13 EDT 1999 | Jason Tomlinson
| Does anyone have any information on stencil aperture/pad ratios for noclean solder paste. In the past I have experienced severe solder ball problems when using the same size apertures from aqueous products as I do with the No-clean products. Cons
Electronics Forum | Fri Apr 11 05:51:20 EDT 2008 | janz
w/4t=0.8 Regards Jan
Electronics Forum | Wed Apr 16 02:46:55 EDT 2008 | andrzej
Thanks Jan for hints
Electronics Forum | Fri Apr 11 06:22:04 EDT 2008 | andrzej
Hi Andrzej, > > We are using for BGA (0.8 pitch) > square apertures size 0.4 mm (rounded corners r = > t) and stencil thickness t=5 mils. So area > ration-_ w/4t=0.8 > > Regards Jan Hello Jan, I understand that you have the same pad dimensio
Electronics Forum | Fri May 17 14:12:17 EDT 2002 | dason_c
Not now, Valor may under develop the module for its Trilogy 5000 with the stencil aperture based on the rules which you set. Also, check with IRI stencil (Alpha), they have a s/w and based on using ODB++ file and not Gerber. Rgds.
Electronics Forum | Wed Aug 25 19:44:35 EDT 1999 | Dave F
| Does anyone have any information on stencil aperture/pad ratios for noclean solder paste. In the past I have experienced severe solder ball problems when using the same size apertures from aqueous products as I do with the No-clean products. Cons
Electronics Forum | Fri Sep 17 14:30:06 EDT 2004 | russ
You are right, playing with apertures is how to ensure release. Making a stencil thinner or thicker is "playing with apertures" It all relates to aspect and area ratio calculations and what you need to do based upon the numbers you get. Russ
Electronics Forum | Mon Feb 18 11:31:02 EST 2008 | davef
Print paste through the new stencil with a piece of mylar [or other clear plastic sheet about the thickness of paper] between the board and the stencil. Dispose of the mylar according to local practice after confirming proper aperturation of the sten
Electronics Forum | Tue Jul 19 11:21:50 EDT 2005 | russ
You may want to try reducing the large center aperture on your stencil to 50-70% of the area of the pad. This is what we do with QFNs and it may be applicable in this case also.
