Electronics Forum | Tue Feb 12 17:57:42 EST 2008 | chef
I must ask the silly question- are you sure you deposited the correct amount of paste? Depending on aperature design-the voiding could come from a stencil that has its holes partially built up with old paste. If paste volume is guaranteed, then what
Electronics Forum | Wed May 24 16:01:08 EDT 2006 | samir
GEB, Datasheets are usually just guidelines and most App. Engineers from paste companies will tell you that as well. You don't have to "copy exact" what they say, but rather set your oven to what gets you and your type of boards the best results. P
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 | Fri Jun 20 18:32:55 EDT 2008 | hegemon
Back when I used to do a lot of these style devices we ran into the same problem you are describing. Use a pattern for the center pad area and keep the total coverage to about 68% of the pad area. Diagonal Stripes, tic tac toe, cloverleaf, dot array
Electronics Forum | Fri Dec 11 08:56:08 EST 2020 | SMTA-64304223
One of the common causes of solder ballin is also outgassing from the boards have your tested the board for outgassing? Bob Willis
Electronics Forum | Thu Mar 15 11:12:45 EST 2001 | slthomas
solder, but flux -> adhesive. Hmmmmm.... Are the chemists working hard to reduce the consequences of these possibilities? And as to Dave's comment about long term reliability issues due to outgassing from the adhesive, double-hmmmmmmm....... Ther
Electronics Forum | Tue Aug 06 17:43:10 EDT 2013 | davef
I agree with SOB. First, someone is thinking too much and has too much idle time. And second, controlling volatiles from routine fluxing should be much more concerning than volatiles from out-gassing from delamination. In most plants, delamination is
Electronics Forum | Tue Apr 07 14:37:14 EDT 1998 | Chrys
Be careful about the material you choose. All the materials out there are basically glass-filled epoxy composites, but they are different blends with different fillers. Some of them have carbon in the matrix to make them ESD safe, but it also short
Electronics Forum | Fri Nov 17 17:34:26 EST 2006 | realchunks
OK, why are you hand fluxing? You may want to take the time to use your real fluxer. Yeah, it's a bit messy but you can control the amount of flux you're putting on the board. And with water based fluxes, this is critical. If you are stuck to han
Electronics Forum | Mon Jun 13 10:28:29 EDT 2005 | andymackie
I've had a lot of experience with solder spatter. It's usually related to moisture (humidity) uptake by the paste, or outgassing from plating: particularly Au/Ni. Solder spatter from the plating will change from board-vendor to board-vendor. I shoul
