Electronics Forum | Tue Jun 02 15:01:57 EDT 2015 | tombstonesmt
What is the reduction in aperture size for your stencil versus pad? Or are they at 100%?
Electronics Forum | Thu Jul 02 10:52:45 EDT 2009 | dyoungquist
For 0402s we use type 3 paste. We have .006 and .005 stencils. The .006 works okay but .005 seems to give us slightly better results. We use a 1:1 ratio for the aperture to match the pad, round pad not needed. With accurate placement and a correc
Electronics Forum | Wed Apr 15 17:16:00 EDT 2009 | rmitchell
Hi, I am trying to reduce some 0402 cap tombstones. The main cause is the pad spacing is a little too far apart and the parts are as tall as they are wide .5mm I am stuck with the pad spacing for a while. All other parts are soldering well, even 0
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 | Wed Sep 22 22:56:44 EDT 2004 | davef
Talk to 10 people and you get 10 recommendations for pad layout. So far, here's number 3 [after IPC and AVX]. We suggest: * Use the IPC recommended standard. * Change from that standard when someone gives you a documented reason to change.
Electronics Forum | Tue Jun 02 17:32:53 EDT 2015 | jldowsey
Les, Some of the answers to design or stencil aperture/placement machine depend upon what is the current spacing between your components which you didn't specify. Chip components such as 0402's and 0201's typically have very small reductions in pas
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 | Thu Apr 16 09:54:12 EDT 2009 | davef
We know virtually nothing about your process, but here's some guesses: * Turn-off the nitrogen * Change from Sn63 to Sn62 * Change to a low-tombstone paste * Change the thermal recipe: slower ramp, longer soak * Do a better job of placing components
Electronics Forum | Tue Jun 02 13:42:44 EDT 2015 | ldempsey
Hello all, Some background. We have JUKI machines (FX2, KE2000's and KE3000's) We're looking into an issue with 0402's in close proximity to each other. The paste gets mashed into the paste from adjacent parts. Some have suggested I deviate from
Electronics Forum | Fri Apr 17 10:44:29 EDT 2009 | rmitchell
Hi, follow up, Thanks to everyone that responded. We finished the build, the sun burst thru the clouds and the birds sang. Well that was a slight exageration. Sorry for lack of detail on the original post, I was frazzled. Since the 0201's were p
