Electronics Forum | Tue Dec 31 17:05:20 EST 2019 | slthomas
Assuming you've already looked at optimizing your profile and stencil design, have you looked at metal load in the paste? I hadn't, but just read that increased metal load (associated with reduced powder size, i.e., moving from T3 to T4) has been sh
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 | Wed Oct 17 09:55:48 EDT 2012 | anvil1021
Has anyone ever experienced void increase while using N2? Thanks for the Help!! anvil
Electronics Forum | Mon Jan 22 22:37:27 EST 2001 | davef
50 ppm oxygen was on half joints reflowed in air. 3d Human factors PCB pad cleanliness: Handling of bare board pads creates excessive voiding. Print rejection: Cleaning of OSP pads with acetone or isopropanol increases voiding.
Electronics Forum | Wed Apr 16 11:20:31 EDT 2003 | russ
What was the original complaint? when you say solder wicked onto top of capacitor do you mean it was dewetted from the board and only on the cap? What type of device showed voiding? how bad was it 20%,50%? I have found that the paste type seems to
Electronics Forum | Thu Oct 11 13:10:04 EDT 2012 | anvil1021
We are experimenting with void control in reflow and have had pretty good luck for the most part in attaining Class lll IPC spec. but we have seen a sudden increase in voiding on a specific product and I was wondering if anyone has seen this extreme
Electronics Forum | Thu Nov 21 21:22:15 EST 2019 | sssamw
=50% area soldered. If you need less void the the grounding area, you can increase solder paste area/volume.
Electronics Forum | Thu Oct 18 11:08:22 EDT 2012 | scottp
Since we follow IPC Class III, I've done experiments turning N2 on and off and measuring void level with both SnPb and SAC305 solder. In both cases there was a statistically significant, measurable increase in voids with N2, but it wasn't significan
Electronics Forum | Wed Aug 09 11:59:19 EDT 2017 | dleeper
As you already know, it depends on the paste. There isn't really a rule of thumb, but less time exposed it better. The issue is the flux exposure to the air and ambient conditions. The flux can evaporate or absorb moisture from the air. If the paste
Electronics Forum | Mon Dec 27 19:10:58 EST 2021 | ppcbs
The component should float into place provided you have the correct amount of solder paste. Perform a solderability test on the pads. We have come across new components with oxidation that prevents wetting. This will cause components to not self ali
