Electronics Forum | Fri Mar 14 08:38:15 EDT 2008 | davef
Pastes from different suppliers have different hot slump characteristics
Electronics Forum | Mon Aug 23 03:12:57 EDT 2010 | grahamcooper22
Possible route causes of bridging on fine pitch ICs are; too much paste (stencil aperture wrong), poor print quality (paste smudges during printing), pcb pads not flat depending on the solderable coating, paste has poor cold slump properties, too muc
Electronics Forum | Fri Jul 21 13:34:54 EDT 2006 | fredericksr
hot/cold slump, print misregistration
Electronics Forum | Wed Nov 19 10:47:37 EST 2014 | grahamcooper22
Probably not all the overpinted paste is flowing onto the joint. You may need a paste with great coalescence properties so it all flows together, and doesn't leave any on the resist. Does the paste drip out the through hole too ? If so it suggests it
Electronics Forum | Wed Dec 11 06:34:24 EST 2019 | ameenullakhan
Hi Everyone, Reducing the top heaters around 10 deg each at last 3 zones of reflow oven. Helped us in achieved little lesser temperature at top connection of the CCGA. And we didn't face any bent. Bridging : Reducing the stencil aperture , has wor
Electronics Forum | Wed Aug 21 13:28:20 EDT 2019 | ameenullakhan
And what is the solder paste selection recommendation for the same. 1. Water soluble ( organic based flux solder based ) 2. No clean ( rosin or resin based solder paste ) customer is suggesting water soluble chemistry , which is having lot hot an
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 | Wed Mar 24 23:12:48 EDT 2021 | grahamcooper22
0.66 area aspect ratio...so for example...if the device is 0.5mm pitch QFP, the pcb pad may be 12 thou wide..make the aperture 9 to 10 thou wide...and reduce it's length by 10 % overall compared to the pcb pad.... Depending on device pitch, select ap
Electronics Forum | Tue Sep 18 16:48:55 EDT 2001 | jschake
Why do you think that assembling the BGA, QFP, and fine pitch parts will solve your bridging problem? I would think doing this may cause you more grief by having these more massive components being reflowed upside down fall off during the second pas
Electronics Forum | Tue Nov 28 21:16:17 EST 2006 | davef
J Rose at EMPF says: The introduction of no-clean solder fluxes in electronics manufacturing has given rise to greater levels of solder balling simply because the opportunity to remove them in the wash process does not exist. They are typically cause
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