Electronics Forum | Tue Jun 04 17:21:22 EDT 2002 | jasonfang
I found solderballs are around chip components (on one side of middle area), I checked gerber data, solder paste of aperture on the stencil for these chip components have 5% reduction to solder land on PCB, shape of solder land are square, not home p
Electronics Forum | Tue Jun 04 17:05:52 EDT 2002 | davef
Solder balls floating around on the air currents of a reflow oven. I sincerely doubt it. Could the solder on your gold fingers be from: * Excess placement force during P&P? * Ejactula from solder deposits during rapid preheat ramp rates? * Ejactula
Electronics Forum | Wed Jun 05 12:22:45 EDT 2002 | Bob
No. Placement force is fine. Also boards have been inspected prior to reflow using microscope with no evidance of misplaced solder balls. The ramp rate has been reduced to acceptable limits, typically .8 - 1.5 degrees per sec. Outgassing from eithe
Electronics Forum | Thu Jun 06 16:26:36 EDT 2002 | Bob
Thanks for all the input. It is pretty much what we have checked for, microscopic analisys before printing, assembly and reflow, but like we all seem to agree one ball of solder is hard to find. The boards are full QWERTY keypads with a few LED's a
Electronics Forum | Thu Jun 20 04:53:13 EDT 2002 | hany_khoga
Thanks Dave but unluckily my sweet BGA�s are surrounded by plastic connectors with hundreds of pins. Also my PCB�s are 4-layers so just thinking of doing what you suggest means ruining them for me. To be honest I tried bypassing the baking issue bef
Electronics Forum | Mon Jul 01 21:03:15 EDT 2002 | ianchan
Dason: Hi mate, Could you help clarify this abit? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ we found component weight will reduce more than 50% of the moisture weight after place in the cabinet with 55C and less than 5 % for 48 hours ~~~~~~~~~~~~~~~~~~~~~
Electronics Forum | Mon Jun 24 19:15:13 EDT 2002 | Chris C
Do I really need a Vapour Phase Oven or a Nitrogen Oven when soldering PBGA's if my PCB has only 2 to 3 BGA's (ball pitch of 0.5mm to 1.27mm) ? Is the quality of soldering when using an 8-Zone Convective Oven is not acceptable? I have been bombarded
Electronics Forum | Tue Jun 25 15:42:39 EDT 2002 | Daan Terstegge
Hi Steve, To my opinion your peak temperature is a little low. If you are sure that the BGA (especially the balls under it) reaches this 205 degrees then it should be OK, but if you measured somewhere else on the board then it's probably better to r
Electronics Forum | Mon Jul 15 09:41:11 EDT 2002 | soupatech
I am experimenting with 2 types, FG256 17x17mm and FG456 23x23mm both with a 1mm pitch and .5mm ball. They both have a full array. As for as the x-ray, we are looking into pruchasing some used equipment but will mostly send them out for testing until
Electronics Forum | Wed Jul 17 12:07:48 EDT 2002 | dragonslayr
DaveF is correct in directing you to the archives. This problem type has been discussed many times, it is quite common. Questions to ask yourself and provide us with answers are: It always happens or random? All assemblies or just one? solder paste
