Electronics Forum | Fri Sep 21 14:03:45 EDT 2001 | jschake
I have observed solder balling for all aperture sizes tested. Solder balling levels appear to be better correlated against the amount of solder paste that is underneath the 0201 component terminations after placement rather than comparing this to th
Electronics Forum | Thu Sep 30 06:47:51 EDT 1999 | park kyung sam
| My stencil thickness is 6 mil and we got qfp's with fine pitch. | how many percent should i reduce my stencil aperture using a 6 mil stencil for 0.5 mm pitch and 0.4 mm pitch ? | | thanks | we have placed 16 mil components for 3 years. why don't
Electronics Forum | Wed Feb 18 14:45:33 EST 2004 | Mauro Pinheiro
I'm looking for a shareware software that I could use for specifying stencils (we are stencil users not manufacturers). I would like to enter some preliminary spec in a software form, such as: the smallest pad geometry on pcb (possibly selected from
Electronics Forum | Wed Apr 27 20:55:10 EDT 2005 | KEN
One thing that may have been over looked: Not all solder pastes are created equal. Period. The best way to avoid these situations is to characterize you material (and your process). The fact is you could try every aperture shape under the sun....a
Electronics Forum | Mon Jul 20 13:47:04 EDT 1998 | MMurphy
:On a dense board, a great way to reduce solderballing is to either; print paste 1:1 with pad size using a 5mil foil, reduce aperture openings by 10% of pad size or change aperture shape to "Home Plate" design. If none of these work on their own you
Electronics Forum | Mon Jul 20 19:31:00 EDT 1998 | Eric
| | :On a dense board, a great way to reduce solderballing is to either; print paste 1:1 with pad size using a 5mil foil, reduce aperture openings by 10% of pad size or change aperture shape to "Home Plate" design. If none of these work on their ow
Electronics Forum | Mon Jan 03 10:17:00 EST 2000 | Mark D.
Does anyone know of a good technical reference source that deals with the screen printing of surface mount adhesives? I'm looking for help in adhesive selection and guidelines for designing aperture sizes/shapes for typical B/S wavesolderable SMT com
Electronics Forum | Wed Feb 16 09:19:22 EST 2000 | MARK ALDER
Please check Circuit Assembly March 1998, article "Solder balls and aperture shapes" and August 1999 "Guiding stencil design". They can be contacted at www.circuitassembly.com The main cause of mid chip solder balls is the volume of paste that is p
Electronics Forum | Tue Apr 26 18:23:30 EDT 2005 | russ
How does your machine recognize the part? Does it use vision for ball inspection or a just a body scan? What is the aperture size on the stencil? Have you calculated the area ratio? What is the aperture shape? What type of paste are you using? is
Electronics Forum | Thu Jul 17 15:12:18 EDT 2008 | slthomas
To quote a regular here, "Are you sure your washer is set up correctly?" :P He's a WS junkie. This is a really common problem and is discussed here often. Mid chip solder balls (solder beads) are almost always the result of too much paste being dep
