Electronics Forum | Thu Oct 15 11:04:28 EDT 2009 | spitkis2
Thanks Jim. Pressing the QFN into paste was what I thought of, just wasn't sure if it would cause solder paste to be pressed outside the pad area and possibly bridge with an adjacent pad. Do you recall the ratio of paste coverage to the pad area?
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 | Fri Oct 09 00:57:05 EDT 2009 | jjmag921612000
SteveO, I had personal experience with this using a Panasonic MPAV2B. It took a while, but I believe the end result was to have some additional "Z" travel to press the QFN into the paste. Also, the design of the paste on the ground was key to keep t
Electronics Forum | Thu Mar 22 16:06:22 EST 2001 | dblsixes
Our next plan of attack is to dog-bone the solder aperature. By reducing the width of the solder paste at the heel, we hope to slow the flow up the leg of the pin while the temperature of the pad catches up. We have boards that were HASL ...
Electronics Forum | Thu Mar 22 21:53:49 EST 2001 | davef
Don't mess with the doggie stuff until you get longer pads [and then you won't have to mess with it] because you'll just ruin your lead definition with more paste and still not have the heel fillet you desire.
Electronics Forum | Tue Jan 14 10:48:07 EST 2020 | dontfeedphils
I've worked with these quite a bit in the past as well. As the previous poster mentioned, we ran either 4/5 mil thick stencil with a pretty standard RTS profile in a 10 zone convention oven without issue.
Electronics Forum | Tue Jan 14 19:41:32 EST 2020 | avillaro2020
Hi Evtimov, Thanks for your response. Yes, the vapour phase is suppose to handle big and heavy boards, at least thats the intention. Well our thin board is like around 3mm which is not really thin. In our application the thicker the boards means more
Electronics Forum | Mon Jan 13 17:39:49 EST 2020 | avillaro2020
Hi, I need help on how to address the solder wicking on the samtec searay connector after reflow resulting to open solder joints on thick and thermal heavy PCB (4.4mm and 6.3mm). I increased my solder paste thickness to 8 mils, the connector is manua