Electronics Forum | Tue Sep 01 22:41:13 EDT 1998 | Kelly
| Hi Kelly, | A couple of questions first. what type of BGA are these components? CBGA, PBGA, TBGA, etc. What is your aperture diameter on your stencil and what stencil thickness are you using? I think I can be of more help once I know the answer
Electronics Forum | Mon Jun 25 20:37:14 EDT 2001 | davef
You are 100% correctamundo that the pad on PCB should be the same as the pad on the BGA interposer, but let�s not expend that thinking to the aperture of your solder paste stencil, right away. Generally, paste on large pitch BGA is often 1:1, but as
Electronics Forum | Wed Sep 19 15:32:24 EDT 2001 | jschake
I�ll volunteer to answer this one for Jake. In order to prove the performance and capability of the stencil printing process, I think this level of inspection detail is required. However, in a production scenario where a known printing performance
Electronics Forum | Fri Jun 02 19:38:12 EDT 2000 | Ravi Bhat
Robert, I think I am late, but better be late than never. Did you get solution to your problem. If not, Can you give me the stencil aperture dimensions and aperture type ? I think I can give you some insight into this.
Electronics Forum | Tue Feb 08 10:33:26 EST 2005 | Dougs
have you had any reduction in aperture size though, we generally use a 6 mil stencil thickness with a 10% aperture size reduction for chip components and leaded components ( SOIC - QFP ) and a 1:1 ratio for BGA components without any problems.
Electronics Forum | Tue Apr 04 14:12:54 EDT 2006 | cyber_wolf
I did the apertures 1:1 using an Invar foil material. I will post and let you know how it works out. Thanks
Electronics Forum | Thu Nov 07 10:59:11 EST 2002 | pjc
IPC-7525 "Stencil Design Guidelines" is a good reference document to have. Here are notes from a Tessera, (a major mBGA mfg.), study- "Application Note Solder Stencil Requirement for mBGA" The stencil aperture is to be square, equal in size to the l
Electronics Forum | Fri Mar 12 11:53:47 EST 2004 | Dreamsniper
Thanks Dave...it's such a good site for reworking BGA's (reballing). But what about when it comes to re-attaching the BGA onto the PCB? We are using Flextac Stencils but I found out that the apertures of their stencil is bigger than our pads for the
Electronics Forum | Wed Jun 20 08:14:36 EDT 2007 | pavel_murtishev
Good afternoon, You should use overprint technique if you have any problems with paste volume (PIH technology and mixed designs, for instance). Otherwise, it is useless. Overprint has to be made in such way so that paste would have an ability to flo
Electronics Forum | Wed Jun 14 09:34:25 EDT 2017 | cyber_wolf
In my experience there is no need for wet wiping stencils. We run 0201'and micro BGA's daily with no issues. If you are having paste release issues, I would be looking at other things. Aperture area aspect ratio, aperture design, land design, sold
