Electronics Forum | Mon Feb 03 16:26:30 EST 2020 | stephendo
A few lifetimes ago I went to a seminar on reflow profiles. The speaker emphasized more than once that the cool down rate is important. Someone asked him about controlling the cool down rate and he acknowledged that you can't. And IIRC it was an ove
Electronics Forum | Fri Aug 10 04:19:05 EDT 2001 | wister
There are lots of voids at solder joint of chips,the thickness of multilayer pcb is 3.2mm,top side have lots of chip component and bottom side has several BGA and QFPs.For top side profile,the preheat time is about 100s,soak time is about 75s,time ov
Electronics Forum | Fri Nov 22 15:59:43 EST 2002 | GSW
What type of reflow profile are you using ? There is a void reduction profile recommeded by some paste manufacturers, Try that it might help. Did you check the components or the board and see if they have absorbed mositure ? try baking the boards and
Electronics Forum | Wed May 24 16:19:58 EDT 2006 | inds
John, there have been quite a few discussion on Mixed Assemblies in this forum.. do a search.. you will get whole lot of information.. in addition - IF you are using Lead-free reflow profile...make sure the rated temp for Sn-Pb components is not vi
Electronics Forum | Thu Oct 05 16:03:31 EDT 2006 | C.K. the Flip
I had horrible experiences with a certain brand on multiple types of BGA's (I choose not to mention the brand). The paste was nice and active, but almost to a fault when it came to BGA's. Finally, I arrived at a profile with a more agressive ramp u
Electronics Forum | Mon Aug 18 17:15:15 EDT 2008 | jlawson
This can be seen on leaded soldering also as well as LF (worse with LF). To reduce this you can look at your stencil and profile. Printing a cross-hatch deposit can reduce the voiding as it allow gasses to release when in reflow - thats the theory
Electronics Forum | Thu Jan 30 07:09:34 EST 2020 | jineshjpr
Hi All, I'm using 8 zone reflow for ROHS 0.2mm Thick PCB soldering, but Micro BGA shows voids more than 25%. Is there anybody can suggest for better solder profile. paste- aim m8, SAC 305, T4, Soaking (150-200) - tried 90s, 60s, 45s; TAL (>217)-
Electronics Forum | Fri Nov 13 08:27:43 EST 2009 | herman
Your customer is very unreasonable to demand void-free BGA SJs. Minor voiding is not a condition for rejection per IPC-A-610D, J-STD-001D, or even J-STD-001DS (Space addendum). Having said that, let me tell you that the voiding has little or nothing
Electronics Forum | Sun Apr 25 11:37:51 EDT 1999 | Earl Moon
| We are just starting to manufacture a PCB with a .039" fine-line PBGA. We are currently seeing voids, mainly in the center, that are as much as 45%. We also intermittently see the corner balls of the PBGA smaller than the center balls. We are using
Electronics Forum | Tue Nov 20 12:48:40 EST 2001 | tony_sauve
We recently experienced a problem w/voids (up to 65%) in uBGA solder joints. The only joints that have the problem correlated to pads which had blind 0.006" via's in them. The via's only extend down 2 layers, of the 18. 21 BGA's on the PCB, only expe
.gif)
