Electronics Forum | Mon Nov 13 09:40:01 EST 2017 | philc
Just a few thoughts, as we use similar quite frequently without issues. Ensure correct support when pasting the board, especially if it is thin. Correct support when placing the part. Is it placed correctly by the machine? If it is very slightly of
Electronics Forum | Thu Feb 11 06:50:17 EST 2010 | CL
Good Morning Bryan, We are using Mirtec MV-3 AOI's with 4 megapixle cameras. We use them for 100% post reflow. We are checking, presence, polarity, value, solder, bridging,component height for BGA, QFN etc... and 1st piece validation for machine set
Electronics Forum | Fri Mar 26 11:31:34 EDT 2010 | rway
I have been using ICT for a number of years. It is still a viable resource for catching defects in the production process. AOI doesn't catch everything, such as bridging on QFN or J-lead devices (this will depend on the type of AOI and camera syste
Electronics Forum | Thu Oct 15 11:04:28 EDT 2009 | spitkis2
Thanks Jim. Pressing the QFN into paste was what I thought of, just wasn't sure if it would cause solder paste to be pressed outside the pad area and possibly bridge with an adjacent pad. Do you recall the ratio of paste coverage to the pad area?
Electronics Forum | Fri Feb 08 16:21:15 EST 2013 | spitkis2
Are you doing this to minimize solder paste splattering? Is this a value that you use for all QFN's (would the overall size of a QFN matter)? I was told reducing placement force with these components is recommended so just was wondering what is bein
Electronics Forum | Fri Nov 10 22:31:27 EST 2017 | myke03o
Hi, we are experiencing insufficient solder and bridging solder. Any recommendation on the inner pad (LGA) and stencil thickness. Any suggestion will be very helpful. link: http://www.latticesemi.com/~/media/LatticeSemi/Documents/ApplicationNotes/
Electronics Forum | Tue Jun 03 01:03:04 EDT 2008 | daxman
Hi, I think what you are describing is a half-etch QFN, which causes the 3 mil gap. In our process, we don't require solder to bridge this gap as it's internally connected to the bottom lead. I'm not sure if this is the question you're asking, but
Electronics Forum | Wed Aug 27 15:50:11 EDT 2014 | smtdoug
If at all possible, you definately want solder mask defined pads. Without it, you will struggle with solder bridging. This is especially important if you have a larger size board.
Electronics Forum | Mon Aug 14 13:51:37 EDT 2023 | calebcsmt
I'm actually currently in the process of discussing with stencil MFG regarding the apertures and reduction to see if perhaps it was not optimal for this fine pitch QFN, as just as you mentioned, we have similar products with similar QFNs that do not
Electronics Forum | Wed Nov 15 12:52:21 EST 2017 | georgetruitt
IMO – Look into nano-coatings for your stencil and radius all square apertures This should help out with solder paste releasing from the stencil helping with insufficient solder QFN LGA aperture design, try a stencil cut with a few different apertur
