Electronics Forum | Fri May 14 16:49:17 EDT 2021 | winston_one
Agree with WiIIR and also can recommend to play with vaccum pump RPM . Slower vacuum increasing have help me to resolve one problem caused by the vacuum (it was solder splash from BGA balls, but the reason can be similar to your case). Also check i
Electronics Forum | Thu May 05 09:17:58 EDT 2005 | jimmiem
I tried soldering to several of the black pads and was successful, the solder stuck with no hesitation. so i guess this is not truly "black pad"? would that be a correct statement? What causes this blackening that looks like oxidation under the mic
Electronics Forum | Mon May 06 06:22:39 EDT 2019 | SMTA-Rogers
Hello! Do you have a better stencil design to reduce the large area of solder joint voids? Or is there a suggested way to set the reflow profile? Or are there other process improvements to make the solder joint at the LED pad less than 10% per void?
Electronics Forum | Tue May 07 10:36:38 EDT 2019 | slthomas
Probably just means you started out with an optimal profile. I suspect that not everyone does. ;) It seems like we did have some luck with profile adjustments in one instance with some QFN's with a large thermal pad. Like I said, though, the profi
Electronics Forum | Tue May 28 18:31:08 EDT 2019 | jlawson
Solder paste flux is main contributor, Lead termination chemical-oxide by products and PCB Plating-Chemicals. Reflow profile would have very limited if not no impact really unless is way off. Paste volume control and Stencil design plays a big part
Electronics Forum | Thu May 30 09:33:15 EDT 2019 | emeto
Contributors in order of importance: 1. PCB design - if you have large thermal pads, a grid of via holes should be created. Components with low profile will not let the gas to escape from the joint. The only way is going down. 2. Reduce paste volum
Electronics Forum | Mon Jan 10 19:13:46 EST 2000 | TNT
HELLO MIKE, THE PROBLEM WITH THE VIA BEING IN THE MIDDLE OF THE PAD CAN BE HANDLED. IF YOU ARE HAVING PROBLEMS WITH SOLDER FLOWING THROUGH AT REFLOW YOU MIGHT WANT TO CHECK YOUR VACUUM AT YOU SCREEN PRINTER. SOMETIMES THE VACUUM THAT HOLDS THE PCB
Electronics Forum | Wed Sep 30 13:10:49 EDT 2009 | spitkis2
Hi guys, Can someone please clarify whether adjustment of Z axis travel is a critical parameter during placement of QFN devices. If so, to within what tolerance? In other words, should a pick and place machine position a QFN down on the board so t
Electronics Forum | Wed Apr 20 10:28:34 EDT 2005 | James
Anyone know of a place to get the vacuum pads for the traverser of the LCS units? Assembleon want over $100 each for a ring of ESD foam! ! ! ! If I can't find a reasonable source I guess I will try to make them myself. James jseagle@zworld.com
Electronics Forum | Wed Apr 20 13:47:58 EDT 2005 | KEN
...those are ESD foam rings. ....and their $107 each. ...and I'm in the wrong business. How many a month do you use?
