Electronics Forum | Tue Mar 15 22:04:56 EST 2005 | KEN
The hasl joint looks fuller (and is easier to inspect)because it has more solder volume. Think about it. Your pre-plating your board with solder (before you add more solder). I doubt your getting 0.3 mils of hasl.....probably more like 1.3 to 3.0
Electronics Forum | Tue Sep 25 15:48:34 EDT 2001 | mparker
Scavenge all the old solder off the board and the chip. Micro screen paste to the chip. As far as thickness, check your aspect ratio to determine the spec. Eliminate just one variable at a time to get to the root cause. Start by not using the tacky
Electronics Forum | Fri Jul 10 13:55:16 EDT 1998 | Bob Willis
After reflow the paste on a copper pad should spread out from its original print dimensions it should ideally not prior to reflow as that is a hot slump. The better the solderability of the OSP or the higher the activity of the flux will greter flow
Electronics Forum | Fri Jan 24 16:54:24 EST 2014 | davef
Yeh, I worked at Wang Computer factory in a reclaimed fabric mill with wooden floors. One of the causes of grapping is flux loss. In their paper, Briggs and Laskey talk about flux loss due to spreading and suggest: * Graping is much less prevalent i
Electronics Forum | Fri Sep 28 16:51:41 EDT 2001 | pcmarch
I have had success by applying the paste flux with my finger, using a finger cot and spreading it on the PCB. This seems to put it on more consistently than using a brush.
Electronics Forum | Mon Jul 10 07:46:51 EDT 2006 | ronalds
You are right, RSS profile is not the correct description. I am using a profile which heats up quickly to let the flux spread. Next linear up to activate the flux and prevent thermoshock. My experience is however, that small changes in this profile
Electronics Forum | Thu Feb 26 13:29:36 EST 2015 | swiese242
Use the appropriate heat for that part. You can then use techspray flux remover with a brush. Spray the brush, and not the board, to reduce spreading the flux. Acetone or alcohol are less expensive and may work as well.
Electronics Forum | Sun Feb 13 01:35:55 EST 2000 | Dean
Without further information my first guess would be lack of flux to "cut through" the ENTEK layer. Question: In X-ray is the suspect ball of equal diameter when compared to adjacent balls? If no then the volume of solder is different which would po
Electronics Forum | Thu Jul 09 11:13:00 EDT 1998 | justin medernach
| IS IT BETTER FOR SOLDER PASTE TO SPREAD OUT AS FAR AS POSSIBLE ON BARE COPPER, OR FOR IT TO KEEP THE SHAPE OF THE PRINT? I'VE BEEN DOING SOME SOLDER PASTE EVALUATIONS, AND I'M TRYING TO EVALUATE THE RESULTS. I'M NOT SURE THAT BECAUSE A PASTE MAY
Electronics Forum | Thu Jun 02 22:26:46 EDT 2016 | slouis2014
i have tried to design the stencil as attached, but the void is more than 35%. do you have any idea what is the ideal diameter for the stencil aperture for the solder to spread and the flux to be released out of the component simultaneously. thanks a
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