Electronics Forum | Sun Jan 30 03:06:50 EST 2000 | Roni H.
Hi, The major reason is that the flux is still "wet", you should fix the temp. profile (specialy preheat zone) so the evaporation of flux carriers will be better (anyway not to much !). Recommended: 1st preheat zone heating to ~70C , 2nd&3rd prehea
Electronics Forum | Tue Jul 28 02:28:48 EDT 1998 | Bob Willis
The causes for solder on gold are: Paste wash offs Dirty stencils Dirty under stencil cleaning cloths/no solvent Poor handling The most common reason is wash offs when there is a couple of balls left on the tabs and they reflow. With correct profile
Electronics Forum | Wed Oct 03 12:02:04 EDT 2001 | kjwaskow
We are getting solder blobs forming in open areas of the BGA, between the center array and outer array. THe ceter array balls are starved of solder, so they are presumably the source. The theory we hold is possible moisture causing the solder to mo
Electronics Forum | Mon Nov 12 16:10:46 EST 2001 | davef
There is no doubt that we reflowed topside BGA on our wave solder machine. We run our wave pot at 450�F and that�s plenty hot enough to reflow solder on topside SMT components. When the solder balls on the BGA melt, the package is over 200�C, trust
Electronics Forum | Tue Nov 27 15:25:51 EST 2001 | Ken Lester
Options that may help. Do you use a Vibratory Wave if so try reducing. The solder temperature shouldn't be to high. I would suggest 485F but is process dependant. Try slowing the preheat cycle this also may help. because this is variable I would try
Electronics Forum | Thu Jun 19 12:47:47 EDT 2003 | russ
I would believe that the connector spec is for the max temp that it can withstand while the paste is the max temp that you need to achieve. Solder balls are usually from excessive ramp rates in the oven. I would contact the connector mfg. and see wh
Electronics Forum | Sat Jul 31 08:52:15 EDT 2004 | g2garyg2
I am soldering with a softbeam laser and often get a flux/solder build up at the end of the feed tube. Seems better when we use Senju wire but this is very costly. It seems like we have tried everything to resolve this. Would appreciate assistance on
Electronics Forum | Thu Aug 12 08:03:54 EDT 2004 | Rafal M.
We used fluxes: Cobar 94-QMB (no bismuth), RF800, Cobar94RXZ-M, with foam and spray fluxers: MBO clean alloy SN63PB37.experienced with changing preheatting, speed of covoyer single and double wave., we tried every combination. I think the problem is
Electronics Forum | Tue Nov 02 08:01:13 EST 2004 | mattkehoe
Isn't that a good reason to use more paste? With just the paste from the balls, do you really get as good a solder joint as with a standard amount of solder paste added? What about voids? Do they go away by not using paste? I am talking about initial
Electronics Forum | Fri Jan 21 19:30:11 EST 2005 | Dreamsniper
Hi T2, The purpose of this is that we want to make our rework robust. Whenever we rework BGA's we have solder getting trapped into those 1 sided tented vias and bet yah...they are hard to desolder! And during BGA resoldering these trapped solder will
