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
Electronics Forum | Fri Jul 05 11:45:47 EDT 2002 | stefwitt
I have seen the U-shaped aperture on a customer site, being used with success. However, the problems with the stencil and the �loose� tabs where reportedly a reason to search for different aperture designs. Before this company could test their ideas
Electronics Forum | Mon Jul 16 21:25:26 EDT 2001 | davef
Sure, use of U-shape apertures is another way to reduce the amount of paste that you apply. That and similar schemes mentioned in the article are not a function of the flux used. We have used U-shaped apertures for MELF and mini-MELF. They are sug
Electronics Forum | Tue Mar 18 11:51:24 EST 2003 | slthomas
I like this answer! Part geometry, part mass, land pattern, print accuracy, reflow profile, placment accuracy, and aperture shape all play a role. If you use a homeplate to reduce solder balling, have high profile/low mass parts AND place more to
Electronics Forum | Fri Sep 15 10:00:15 EDT 2006 | Joe C.
Hello Everyone, Does anyone have any experience with an SMT right angle LED from Panasonic, part number LNJ123W8PRZ. In our experience the pattern design from the vendor was not very effective (the part swam around on the pads & flipped backwards dur
Electronics Forum | Thu Jul 26 12:04:16 EDT 2018 | wendymm
RS-274X file contains the complete description of a PCB layer image without requiring any external files. It has all the imaging operators needed for a PCB image. Any aperture shape can be defined as well as positive and negative objects. Maybe that
Electronics Forum | Wed Jul 03 07:29:05 EDT 2002 | jax
Where did you find this article about "U-shape" apertures? I believe it is simply talking about rounded corners on the inside of a normal square aperture. ( resembling a filled in U ). It kinda follows the same ideas behind the home-plate design, wit
