Electronics Forum | Tue Jan 30 20:47:32 EST 2007 | davef
Inspection criteria [B Willis] Solder-paste application * Fine-pitch printing Satisfactory solder-paste should: ** Be aligned with all pads ** Conform to the stencil's pad-aperture size ** Have a smooth, flat void-free surface Acceptable solder paste
Electronics Forum | Thu Jul 02 16:01:57 EDT 2009 | ewchong
thanks kpm. agree the cause of those pads lifting. all of them were no connects so they cannot be the cause of the electrical failure. when the bga was removed, all the solder balls on the pcb turned into conical shape due to the separation, except
Electronics Forum | Wed Aug 26 18:58:07 EDT 2009 | rossi
I am not sure that it is the pillow problem. With the pillow problem you tend to see residual solder on the pad and voids where this solder pulled from on the ball. What we are seeing is a very thin flat layer of solder on the pad and a flat surface
Electronics Forum | Tue Nov 03 18:09:17 EST 2009 | gregoryyork
I think most have summed up the first pictures also is the drillng looking like it is misregistered as well. Better to do a solvent test to determine resist cure not the old stuff the newer chemicals show under cure problem much better. Try your st
Electronics Forum | Sun Dec 19 23:22:11 EST 2010 | Jacki
Hi Rem Woo, ur board is such long one,7'. Our PCB is only 2' long but 3.5kg weight b4 solder. We use wave machine to solder it and PCB was sit on the pallet. all PCB side lengths are pressed by clamps. PCB was flat just after wave, however there was
Electronics Forum | Tue Sep 13 12:00:57 EDT 2011 | swag
Flex circuits are assemblies that can be bent or twisted into shapes after assembly (flexible). When heald in panels for SMT assembly, it's difficult to get repeated x/y offsets so you need to consider fiducal placement in your design for placment m
Electronics Forum | Mon Aug 13 09:49:35 EDT 2012 | rjlatz
I just got back from a visit to our PCBA manufacturer. We have good flowthrough on the PTH, but solder skips and bridges on the SMT SO IC's. We have correct orientation and robber pads, but the results are still the same. I noticed the wave shape is
Electronics Forum | Thu Jun 27 17:32:35 EDT 2013 | tpost
We recently had a question come up regarding the amount of solder on a flat underside termination ( we referenced Flat Lug Lead in IPC 610). Judging by the photo you can see on the Left is a target solder joint, but on the right is one which had rewo
Electronics Forum | Wed Mar 22 12:53:43 EST 2000 | David Spilker
Be careful if you use Ni/Au. The "black pad" phenomenum can be crippling. We moved from Ni/Au to OSP because of it. I also don't want to return to the lack of flatness of HASL.
Electronics Forum | Fri Nov 10 12:22:12 EST 2000 | casi
I'm interested in probes for wafer testing made in verted. I need to tested wafers with pad with flat gold bumps ( 17um ) with pitch = 70um. I'm also interested in every web site related on gold bumps testing. Thanks a lot !!! Casi
