Electronics Forum | Thu May 06 13:06:36 EDT 2010 | dwonch
Unfortunately nothing ground breaking to report. The board shops analysis (SEM/EDS)showed high levels of carbon and oxygen, likely indicating an organic based contaminate. They are still stumped on where it is coming from. We recieved some boards y
Electronics Forum | Tue Nov 25 05:20:20 EST 2014 | grimus
Could be. I am making overprint to achieve proper amount of solder paste inside hole. Now I am trying to reduce maximum overprint and compensate it with step - up stencil. This could reduce effect that some particles of solder paste are not gathering
Electronics Forum | Thu Jul 21 19:53:20 EDT 2011 | isd_jwendell
Using AIM N.C. paste, just ran 10 panels to test after applying Rain-X to the stencil (pre-clean with IPA). Printing and release were slightly better (maybe my imagination), but not a large difference. Stencil remained cleaner longer. I could not tel
Electronics Forum | Sat Dec 01 13:43:51 EST 2012 | anvil1021
Do you mean the Paste Layer of the Gerber files? If so then you can check for aspect and area ratio of the component apertures (which is determined by the thickness of the stencil) there is an IPC specification for this and it is IPC-7525A I believ
Electronics Forum | Fri Aug 02 10:06:37 EDT 2019 | davef
I don't get it. The liquidus of 80Pb/20Sn is like 280*C. Your reflow temperature got nowhere near that value. Where did that material go? Is it folded back under the component? Disappeared? Was it ever there? Ask someone while analysis tools to hel
Electronics Forum | Thu Mar 29 01:22:57 EST 2001 | chinaman
Hello everybody, Two questions came up during an audit (old topics once more): 1. we are not checking the solder paste volume/pad height after printing - others are using an AOI, but is it really necessary? We just do visual inspection randomly. We
Electronics Forum | Fri Jan 14 10:11:45 EST 2000 | John Thorup
I'll have to go along with Wolfgang as having a good experiance with frameless. We have been using a system from IIT in California for about a year. I was sceptical at first because of this system's X only tensioning but it does work. We use mostl
Electronics Forum | Wed May 27 10:19:43 EDT 1998 | Jerry
We have no problems but orientation does matter. Orient with longest side of component body perpendicuar to wave. In other words the same preference as with through hole DIPS. Idea is the same as for through hole, that the surface tension will ten
Electronics Forum | Wed May 20 12:01:16 EDT 1998 | Chrys
Have you tried the new Accu-Frame from PNC? It tensions on all four sides using an operator-INdependent mechanical scheme. It seems pretty slick. They're failry new, and don't have a frame for the MPM's last time I checked, so I haven't tried it m
Electronics Forum | Fri May 31 12:50:42 EDT 2013 | spoiltforchoice
Is this a "thermal balance" issue? In the 2nd image you have a group of pads blobbed together as one giant pad. IMHO this is a bad idea, QFN's rely heavily on the magic of your paste and good PCB design to get good alignment. When your solder paste i
