Electronics Forum | Thu Sep 26 20:25:06 EDT 2002 | davef
When we DOE a board, we use the following independent print variables: * Print pressure * Print speed * Separation speed * Aperture orientation * Squeegee hardness
Electronics Forum | Thu Oct 03 18:45:56 EDT 2002 | davef
Get started with an "On-Board Forum" [blue bar an inch down from the top of the page] moderated by Jeff Schake at DEK that was a discussion focused on stencil printing issues with 0201 technology. Chris: Are you putting 0201 on flex? If so, sounds
Electronics Forum | Sat Oct 12 05:05:09 EDT 2002 | Kenture
I run 0201 on a 5 mils stencil with openting of 15X12 and did not have any issue. The major concern is the placement and CP643 did very good job. Type 3 solder pastes was used. Good luck.
Electronics Forum | Mon Dec 16 13:33:09 EST 2002 | pjc
square apertures provide better paste release than round in most applications. See IPC 7525 Stencil Design Guidelines
Electronics Forum | Wed Sep 01 11:09:45 EDT 2004 | burgosa
We are considering the CyberOptics SE300 for solder paste inspection at post-stencil print. Does anyone have experience with this AOI machine? How it works with small apertures like 0201's and uBGA's? Comments are welcome. Thanks
Electronics Forum | Thu Dec 08 09:47:46 EST 2005 | slthomas
I'm with Grant on the .005" foil thickness. The key is to keep your aspect ratio (aperture width/foil thickness) over 1.5, laser cut, and I like trapezoidal aps. too.
Electronics Forum | Fri Dec 09 04:38:11 EST 2005 | Rob
Madam, that's rather forward! By zipper pattern do you mean offsetting the apertures on every other ultra fine pitch qfp pad? Thanks, Rob. (we don't roll in England, we amble)
Electronics Forum | Mon Mar 27 22:20:04 EST 2006 | davef
Mike The air 'contained' in the aperture would prefer to escape between the board and the bottom of the stencil rather than through your paste while you're printing over it.
Electronics Forum | Thu Nov 04 19:04:49 EDT 2010 | eadthem
It would depend on the solder paste but the stuff we use is heavy enough that it wont go airborne. and theres really no other way to clean the apertures on a 0402 or similar part.
Electronics Forum | Mon May 20 15:58:55 EDT 2013 | sevenzero
Did you try a thinner stencil? More pressure and speed in the printer? What size is the QFN? Maybe the aperture needs to have a + in the center?
.gif)
