Electronics Forum | Fri Aug 18 07:42:11 EDT 2006 | amol_kane
Hi Russ, Can you please clarify on what you mean by "after wash they should be gone since it is water soluble,".....the flux would be water soluble or otherwise, how does that relate to solder balls being removed by cleaning?...i can see them being r
Electronics Forum | Wed Oct 04 13:58:38 EDT 2006 | cw
hi Dave.F and All, I need to reflow SCA solder balls on Sn/Pb paste, i get a pretty OK solder wetting and collapse apperance, however, i am seeing voids everywhere, some of them is greater than 25-30%, which has exceeded IPC standard. Please advise.
Electronics Forum | Wed Oct 04 14:14:49 EDT 2006 | russ
Change mfgrs of paste OR better yet use pbfree paste, If you are collapsing the balls on the BGA then you are possibly overheating the paste/flux quite a bit. most lead pastes do not like much more than 230 C. I am assuming that you have a decent p
Electronics Forum | Wed Oct 04 14:48:49 EDT 2006 | cw
My soak at 150C - 180C for approx. 85sec to 100sec. I believe this is sufficient. I can't change my paste because customer wants to use SnPb paste with SAC solder balls. They claimed that they have sucessful result with other CM. I need to know if
Electronics Forum | Wed Oct 04 16:14:17 EDT 2006 | inds
what is your peak temp.. if you try to go too high say 225-230 deg C there is a fair chance of seeing voids.. depending on your ball size and paste volume you can get a good collapse at temps below 225deg C...
Electronics Forum | Wed Jan 17 17:09:43 EST 2007 | russ
appears to be incomplete reflow on a couple of balls or they were moved during a cooldown. it also seems as though there is a deviation in ball size due to inconsistant paste application possibly. I would stop applying paste and just reflow that pa
Electronics Forum | Fri Jun 15 11:34:49 EDT 2007 | cman
What is the board finish? Did you profile built assy and get the temps on the board with a t/c in the board? DId you drill the BGA and get the t/c at the ball? When the parts came off the board did all of hte solder come off the pads and stay with th
Electronics Forum | Mon Aug 13 11:05:18 EDT 2007 | saaitk
Would I be correct in assuming that the solder used to attach the BGA ball to the device body should have a higher liquidous point that the solder used to attach the device to the board. If the peak reflow temp for SnPb is around 225 deg should the b
Electronics Forum | Fri Aug 24 11:03:15 EDT 2007 | hussman
I agree with Joris. But to add to his comment, the type of finish also has a direct affect to your wave solder process. Going from a gloss finish to a matte finish may help a lot. As for humidity affecting your wave - I doubt it. I use a water
Electronics Forum | Wed Jan 09 13:03:22 EST 2008 | patrickbruneel
Matte solder mask greatly reduces the potential for solder balls, and since you altered the machine parameters with no improvement it might be flux related. Do you use a VOC free (water based) or alcohol based no-clean flux? Do you use machine settin
