Electronics Forum | Tue Dec 31 02:10:04 EST 2019 | sssamw
It looks like solder dross there or flux residue that not activated well. Your speed is 43cm/60s, wave width contact is 2cm, so dwell time is 2x43/60=1.43s, it's short also.
Electronics Forum | Sat Jan 18 12:44:35 EST 2020 | anteiv
We made much better contact of wave with board. There was not enough solder in bath. We increased it so wave height is higher with same pump power And now board is pushing dirty wave to the other side and board is much cleaner!
Electronics Forum | Fri Dec 27 14:22:00 EST 2019 | ameenullakhan
Hi , Thanks..., Its "not wetting the pads sufficiently" We have tried with RTS , Our paste is ROL0 based chemistry. Which solder have you changed. Regards, Ameen
Electronics Forum | Mon Dec 30 23:37:47 EST 2019 | agoesfirmanto
Hello All, I am a SMT Engineer from Indonesia, I am facing the problem of soldering balls in only one IC location, in other areas there are none. solder ball defect almost 30%. I have done several actions but failed to reduce the solder ball. 1.
Electronics Forum | Tue Dec 31 09:24:22 EST 2019 | SMTA-Davandran
You may try reduction on stencil aperture on the particular IC location. Reduction on width and extend outer length may help to minimise solder ball issue. However, please look into stencil foil thickness to meet AR.
Electronics Forum | Fri Jan 03 11:37:24 EST 2020 | emeto
Sometimes might be internal change with personnel. Issue is actually there, but if no one questions it-it is not an issue. With 7mil stencil there is a good chance to have solder balls. So were they registered or were they fixed/cleaned?
Electronics Forum | Sat Feb 06 07:14:40 EST 2021 | agoesfirmanto
Dear Sirs, very sorry being late reply after a year. Thank you very much for your advices, you are absolutely correct after reduce grounding pad size. No more solder ball issue. Thank you very much. highly appreciate all of your supports. Best re
Electronics Forum | Sat Feb 06 07:17:47 EST 2021 | agoesfirmanto
Hello Pak Zack. very sorry late reply Thank you for your sharing. Solder ball issue already solved. Best regards, Agoes
Electronics Forum | Fri Jan 03 02:03:58 EST 2020 | sssamw
What's your target for voiding? I cannot see it violate 25% of solder joint area. Process setting and PCB design can impact the voiding, many factors, such as PCB pad, stencil aperture and thickness, re-flow profile, solder paste, etc.
Electronics Forum | Wed Feb 12 07:25:47 EST 2020 | dontfeedphils
If you have control of the solder alloy you're able to use on the product, you could run a lower temp solder on the second side and try to avoid the first side entering reflow.
