Electronics Forum | Mon Apr 16 09:13:16 EDT 2007 | pjc
Tombstone head and a graveyard mind. I would not recommend 1:1 due to solderpaste beed out opportunities. Have you tried the inverted home-plate? Here are some good links on tombstoning and how to eliminate it: http://www.aimsolder.com/technical_ar
Electronics Forum | Tue Apr 21 16:33:06 EDT 2009 | llaerum
Home plate design is great for avoiding beads and tombstoning in some cases, but it will not help you when the spacing is too far apart. It will make it worse. You need a good even screen and accurate placement.
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 | Wed Jul 22 11:27:25 EDT 1998 | Russ Miculich
I agree with the response and strongly recommend that you use the "home plate" design to reduce solder ball entrapment, and that the under cut for the 0402's in particular be 80% of the pad size. Solder slump is typically about 1.2 to 1 so spread wi
Electronics Forum | Mon Sep 17 15:27:51 EDT 2001 | jschake
Challenges: The basic defects that impact assembly yield are bridging, satellite solder balls, and opens (i.e. tombstones / draw bridges). There are many variables with the stencil printing process that can impact these; several of them are listed
Electronics Forum | Fri Jun 22 10:56:07 EDT 2007 | ed_faranda
5mil works great. Just make sure that you screen alignment is dead on. We're using a SAC305 with a home plate design. I ran a test a couple of months back and found that the home plate design works the best with 0402s.
Electronics Forum | Wed Nov 29 14:49:38 EST 2006 | MS
Any recommendation to reduce solder beads next to 0402, 0603 and 0805 caps and res? What about home plate vs. bow tie stencil aperture design?
Electronics Forum | Fri May 01 22:32:38 EDT 1998 | Jon Medernach
A pad design shaped like Home Plate will eliminate the problem, You can get info from Create Group at Panasonic FA They have the patent on this style pad and the most experience working with the 0402 and now have qualified the 0201 Caps from Murata
Electronics Forum | Thu Jun 22 11:42:29 EDT 2000 | Chrys Shea
Sal, Silly question: Were the parts skewed before they went into the oven? I've chased down a few similar reflow problems in my lifetime, only to find out it was a pick and place problem. Wrong nozzle size, bad nozzle, feeder not advancing all
Electronics Forum | Wed Jun 30 17:52:06 EDT 1999 | JohnW
| | | | | | | | | | | | | | | | snip | | | | | | | | | | | | | | | | | John and Dave, | | | | | | | | | | | | | | | | | | Again, I don't work with larger chip devices with this issue. The company I now work with developed a strategy, based on cons
