Electronics Forum | Wed Aug 05 20:48:50 EDT 1998 | Ron Costa
I'm currently running a double sided paste smt board loaded with 0603's, on the secondary side. Many of the 0603 devices tombstone during reflow if the parts are not perfectly centered on the pads. Is this caused by the .008 foil thickness? Has anyon
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
Electronics Forum | Fri Jan 14 11:16:45 EST 2005 | Dan Gosselin
I have heard of people using a round pad or Home plate design to decrease the incidence of tombstoning on 0402's Anyone have any practical experience on this or is everyone just using the IPC 782 recommended land pattern (28mil x 33mil rectangle pad
Electronics Forum | Fri Mar 04 10:04:14 EST 2005 | jbrower
We use Alpha UP-78 (Older paste formula) and it works well for what we do. We standardized our stencils at 5mil with a 10% reduction on IC apetures and a home plate design on passive components. Additionally we use laser cut electro-polished stenci
Electronics Forum | Wed Jul 13 14:56:53 EDT 2005 | jdengler
I read the Cookson/Alpha paper "Optimizing stencil design for Lead-free SMT processing". I interpreted it to mean that if you had a mid chip solder ball (MCSB) problem the "radiused inverted home plate of 20/60/20 style" had the greatest impact on r
Electronics Forum | Tue Aug 17 12:27:48 EDT 2010 | namruht
That reminds me...We already have home plate apertures on our stencil. Try number 2...I tried an overall reduction based on the copper layer of 10% and used oval apertures. I hope that you guys can suggest something that I am over looking. I know tha
Electronics Forum | Tue Aug 17 13:36:17 EDT 2010 | hegemon
Since you have home plated the apts and done solder reduction, I would take a look at your soldering profile. We have run into this before when running no-clean and found that reducing the initial ramp rate to the flux activation was a help in the
Electronics Forum | Fri Dec 20 15:38:53 EST 2013 | island2013
Aperature layout on your stencil could be a root cause as well. Home plate design aperatures have cleared this issue up for me in the past. If it's a clean product, running through the wash may get rid of quite a few of them. Also check your IPC s
Electronics Forum | Wed Apr 29 08:24:55 EDT 2009 | davef
Commonly when we see solder balling, we think "too much paste." As a result, we pinch the apertures or change the shape to a "home plate." We don't think that's what's going on here. But what if this component has a thicker solder plating on its ter
Electronics Forum | Mon Jan 17 08:09:05 EST 2000 | Mark Anderson
As stated previous, the following elements all have a effect on solder beading. Solder Paste, stencil apertures(reduction of home plate), stencil thickness, printing parameters, placement height, reflow preheat and soaking slope and dwell, manufactur
