Electronics Forum | Sun Sep 30 09:50:18 EDT 2012 | rgduval
We believe that Dave's analysis above is mostly accurate. Run a board with no components, and check for voids. We'd also like a little more information, though, to clarify. What type of component is experiencing the voiding? You describe the void
Electronics Forum | Thu Oct 25 13:35:47 EDT 2012 | davef
Here's a paper that may help http://www.ipcoutlook.org/pdf/assembly_challenges_bottom_terminated_ipc.pdf Temperature Impact * Profile didn’t have a significant impact on voiding. * Voids slightly increased with higher temperature. Reflow Atmosp
Electronics Forum | Fri Jan 03 10:26:15 EST 2020 | emeto
Some of the voids are questioned and they might easily be over 25%.
Electronics Forum | Fri Jan 03 13:36:01 EST 2020 | emeto
We use low voiding formula from Indium.
Electronics Forum | Sun Jan 05 20:10:16 EST 2020 | sssamw
Yes, you may need tell us how the PCB designed, how it re-flow(even it's Indium voiding formula), how stencil is. The void ratio means area ratio, not diameter ratio, so you need calculate it. If you have high ratio void, show its picture.
Electronics Forum | Tue Dec 31 11:48:36 EST 2019 | emeto
Hello experts, I have a 50mmx50mm LGA on a PCBA. I Would like to decrease voiding in these joints and I wanted to hear about your techniques to decrease voiding. Stencil is currently 5mil. SAC305. ENIG finish.
Electronics Forum | Fri Jan 03 02:03:58 EST 2020 | sssamw
What's your target for voiding? I cannot see it violate 25% of solder joint area. Process setting and PCB design can impact the voiding, many factors, such as PCB pad, stencil aperture and thickness, re-flow profile, solder paste, etc.
Electronics Forum | Fri Jan 03 12:48:23 EST 2020 | cyber_wolf
Besides correct stencil design, solder paste chemistry can have a profound effect on voiding. People will tell you reflow profiles. I have never in my career seen a reflow profile have any effect on voiding unless it is grossly off.
Electronics Forum | Mon Sep 17 14:45:57 EDT 2012 | kkay
We are experiencing voiding on one of our lead-free assemblies on every part. The voiding only occurs underneath the parts and not in the solder fillet (see pic). We have tried baking, curing, washing, multiple pastes and everything else we can think
Electronics Forum | Tue Sep 25 12:00:21 EDT 2012 | kkay
Thanks for fixing the picture. What you are looking at is a pad that the part was pried off of after reflow. The right side of the pad shows a good solder joint and underneath the part is where the voids occur. The outter solder joints show no voids
