Electronics Forum | Wed Jun 03 13:56:09 EDT 2009 | mika
less total area of voids, which mean a much more strength in the joint and much easier to solder such a cooling pad grounded via vias, with this approach! The same goes for big cooling pads of let say Power transistors without any via etc. Always re
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 | Thu Jul 20 17:43:57 EDT 2023 | smtusa
There are alot of simple time air release dispensers from China but are pretty slow for production use. They are accurate. Mydata was making more money in jet printing so they discontinued their glue station. I think both companies are seeking a p
Electronics Forum | Thu Aug 10 13:16:17 EDT 2000 | Bob Willis
Here is some thing that I wrote a while back on solder beading. First what is a Solder Bead? The term solder bead is used to differentiate it from solder balls. A solder bead is a solder ball but its location is normally constant unlike solder bal
Electronics Forum | Wed Mar 17 13:42:31 EDT 2010 | davef
Primary causes to consider are: * Poor thermal recipe during paste reflow * Failed solder paste
Electronics Forum | Fri Feb 15 12:29:35 EST 2013 | mikesewell
What foil thickness? Type 3 or 4 paste? Have you checked your area ratio(s)? You could overprint or drop your foil thickness by one mil to improve the ratio and paste transfer. As always you can search the fine SMTnet archives for more info.
Electronics Forum | Fri Aug 20 09:40:56 EDT 2010 | namruht
kpm, We were afraid of that, so we have tried several variations with paste usage. New paste, transfered paste from another line, and a new tube from another date code. I think the problem is profile, board design or humidity. I just have to starti
Electronics Forum | Mon Jan 09 05:14:56 EST 2006 | abhinavajmera
Hi all, I want to know the possible causes of poor paste release in stencil printing process if the same brand and part number of solder paste that has been used successfully is being used with a set of process parameters which worked before. Other t
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 | Thu Jan 20 13:56:51 EST 2022 | stivais
For me it seems that the board is already assembled & soldered. Before assembling the board had been (poorly) washed (misprint perhaps) and the spots are just melted solder paste. Aren't those solder balls in the grooves between the pads and solder
