Electronics Forum | Mon Feb 18 02:08:06 EST 2008 | lococost
4 days seems a lot. You could be losing flux activation causing poor wetting on the enig. Check your suppliers data sheets for paste life. If it was contamination on the PCB, you'ld expect other components to solder badly as well. Try using a bra
Electronics Forum | Sun Feb 24 10:15:41 EST 2008 | teamcanada
Issue cross talk \Stencil thickness recommendation? 3-4-5 mil Using manufactures recommended paste layout Water soluable vs No clean Paste. Any recommended publications? Only one found so far is Fairchild, recommend NC due to potential cleaning issue
Electronics Forum | Thu Jan 21 18:11:24 EST 2010 | colormaker
I have a strange problem with 1208 resistors flipping off placed position. I have the same reflow settings that I have used for years with the same solder paste. PAste is only a few months old and it was used just 1 week ago without problems. Some re
Electronics Forum | Mon May 24 13:11:12 EDT 2010 | deanm
A guideline that I use agrees with MikeS: For 20mil pitch, apertures should be 9-10mil with a stencil thickness of 5-6mils to achieve an acceptable aspect ratio of 1.7. Just be sure you are using a mesh Type 3 or 4 solder paste. Otherwise, larger par
Electronics Forum | Tue Jun 15 19:14:51 EDT 2010 | hegemon
You also need to consider the total metal load in your dispensable paste. You'll need a slightly higher flux content and less metal, say around 87% total metal, in a 4 or 5 mesh size. We had to have some special mixes made in order to do fine pitch
Electronics Forum | Thu Sep 02 12:27:27 EDT 2010 | frankmurch
Voiding is tricky, but some pastes have flux residue that can escape others don’t. It is normally called out. So I would change pastes. If you do not want to do that, try a slightly longer time above eutectic (give the flux a little more time to get
Electronics Forum | Fri Sep 17 16:44:56 EDT 2010 | rdubya
If your pads are long enough you shouldn't have a problem, the pins on the connector are curved up(away from pcb)and will plow solder paste to the end of the pad then it will wick back up the pin during reflow. if you have a second stencil for the bo
Electronics Forum | Tue Nov 02 08:36:51 EDT 2010 | rgduval
Michelle, Our experience with no-clean solder pastes has been that water washing a mis-print is a bad idea. We've found that DI water does not do a sufficient job removing the no-clean paste (the same goes for stencils). Instead, we have washed no
Electronics Forum | Sun Oct 21 22:17:19 EDT 2012 | eadthem
We have had this issue on several parts in the past, typically we use a grid of squares of solder paste on large flow areas, This helps reduce but not eliminate all voiding. I would be very interested in hearing what you come up with. O and what is
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
