Electronics Forum | Tue Feb 29 21:53:46 EST 2000 | Kelvin Chow
Dear Robert, On PBGA assembly, BGA sphere shrinkage number depends to the following factors, a. BGA Sphere size (before reflow) b. Solder mask opening diameter As far as I know, no formular has been established yet. Most of my friends just collect
Electronics Forum | Wed Feb 28 07:40:26 EST 2007 | realchunks
Hi Roderick, Guess it depends on how you define "minor". If it is just a visual blemish in the mask, there will be no affect o the BGA. If it is through the resist there may be a chance of solder shorting, which will affect it, I doubt it but poss
Electronics Forum | Thu Oct 14 08:01:48 EDT 1999 | JohnW
Gee Dave That's the first time I've ever seen myself listed for a quote! Brian, what your saying is on the whole right, on the surface of it the mask, as long as it's cured properlay shouldn't make a difference but I have to say that I've found so f
Electronics Forum | Wed Jun 30 12:14:40 EDT 1999 | John Thorup
| | We are wave soldering some fabs with a lot of unmasked trace area along the edges. The trace area is solid copper covered with tin / lead, no masking, no components along the edges, same on solder side and component side (goofy board design). I
Electronics Forum | Tue Feb 27 22:40:28 EST 2007 | davef
IPC-A-600G, 2.9 Solder Resist [Solder Mask] [snip]"Solder resists are used to limit and control the application of solder to selected areas of the printed circuit board during assembly soldering operations and are sometimes used to reduce dendritic f
Electronics Forum | Fri Jul 02 10:06:17 EDT 1999 | John Thorup
| | | | We are wave soldering some fabs with a lot of unmasked trace area along the edges. The trace area is solid copper covered with tin / lead, no masking, no components along the edges, same on solder side and component side (goofy board design)
Electronics Forum | Fri Jul 02 09:54:02 EDT 1999 | John Thorup
| | | | We are wave soldering some fabs with a lot of unmasked trace area along the edges. The trace area is solid copper covered with tin / lead, no masking, no components along the edges, same on solder side and component side (goofy board design)
Electronics Forum | Tue Oct 06 17:36:20 EDT 2020 | hearsehauler
Have used stencils for low volume paste printing for 18 yrs. New job uses jet printing (MY500). But machine is limited to .33mm dot size. Parts used here have pad sizes that are .25mm or smaller, so paste touches between pads when printed. Thankfully
Electronics Forum | Tue Sep 14 14:52:22 EDT 2004 | Carol
During processing, the solder in the vias reflows and forms solder balls. PCBs have solder in random PBGA vias from the board manufacturer.The manufacturer says this is a result of the HASL process and is unavoidable. We use HASL finish, multilayer,
Electronics Forum | Fri Jul 02 05:28:13 EDT 1999 | Vinesh gandhi
| | | We are wave soldering some fabs with a lot of unmasked trace area along the edges. The trace area is solid copper covered with tin / lead, no masking, no components along the edges, same on solder side and component side (goofy board design).
