Electronics Forum | Thu May 29 17:19:51 EDT 2008 | dyoungquist
On 0402s we use 20x25 mil pads with a 15 mil gap between the pads on the pcb with ENIG finish, 5 mil stencil with a 1:1 aperture (20x25 mil) and SAC305 lead free solder paste. We very rarely see any tombstoning on 0402s using this setup.
Electronics Forum | Thu May 29 15:00:49 EDT 2008 | slthomas
We've found that reverse homeplate reduces tombstoning significantly for us on 0603 and 0402 (the latter of which we hardly ever see).
Electronics Forum | Thu May 29 14:35:37 EDT 2008 | rdmundo
Gents, We've been using a round 1:1 aperture for a 5 mils thickness on our stencil design on 0402 and recently, IPC guidelines recommend oblong, homeplate or reverse homeplate. I believed the PCB pad for 0402's area within the recommended size/dimen
Electronics Forum | Fri Apr 12 15:10:00 EDT 2002 | jsherrow
IMHO it's caused by three things: 1) placement 2) placement 3) placement
Electronics Forum | Sat Apr 18 05:09:08 EDT 2009 | alfred
I have a solution.... contact me by mail Vapor phase gives a solution to that problem
Electronics Forum | Fri Apr 24 07:55:12 EDT 2009 | davef
TOMBSTONING OF 0402 AND 0201 COMPONENTS: "A STUDY EXAMINING THE EFFECTS OF VARIOUS PROCESS AND DESIGN PARAMETERS ON ULTRA-SMALL PASSIVE DEVICES" Michael Yuen, Heather Benedict, Kris Havlovitz, and Tim Pitsch, Plexus Electronic Assembly Corporation, N
Electronics Forum | Fri Apr 17 10:21:20 EDT 2009 | padawanlinuxero
have you try to change the stencil apertures to another figure like the one that look like a baseball home? I was having that problem and some solder beads and with that I was able to decrease the tombstones
Electronics Forum | Sat Apr 18 09:44:46 EDT 2009 | davef
Low tombstone pastes have been around for 8-10 years. Talk to your paste supplier about suggestions of the "latest and greatest." Usually these pastes: * Are a blend of alloys with slightly different melting points * Have a mid-level activity flux *
Electronics Forum | Sat Apr 18 17:42:07 EDT 2009 | billwestiet
I like this suggestion the best as a "band aid", check out some of the low tombstoning solder pastes. I've seen these work.
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.
