Electronics Forum | Tue Feb 18 22:15:04 EST 2003 | davef
Arturo, So, you're not shorting to a thermal pad. Given that you're shorting to outer balls, tell us about: * Location of the shorting among the outer balls. * Board construction. * BGA constuction. * Paste deposition. * Temperature measurements ta
Electronics Forum | Wed Feb 26 16:06:34 EST 2003 | slthomas
Something else I just thought of, and MikeK touched on it briefly, is what you'll be cleaning. If you need to be capable of removing both epoxy and solder paste, for instance, you need to look at chemistry and processes that will clean both, and the
Electronics Forum | Mon Mar 31 01:20:42 EST 2003 | Bryan Sheh
I agree that we should bake the pcb at higher temp and for longer time.for example...95--115c for at least 4 hours. also,keep the temp from 150--170c ,60-90 seconds while preheating. completely keep the moisture and volitales out of pcb and solder pa
Electronics Forum | Fri Mar 28 13:12:10 EST 2003 | barryg
We are going to be using a no-clean paste (smt)and no clean wave solder flux on a small pcb we will be doing here soon. As far as the wave process, should i purchase a new fluxer stone for the no-clean. Should I also purchse the recommended thinner o
Electronics Forum | Fri Apr 04 17:43:52 EST 2003 | Kris
Hi, Did you use this paste before with out any problem or is it occuring for the first time ? If you wash only once a double sided board the side that passes through two reflow will have hardened flux which will may not be washed in your normal wa
Electronics Forum | Mon Apr 07 17:08:09 EDT 2003 | jonfox
I remember an issue that we had with some SMD AEC's in the not too distant past. They had a thermal barrier that our reflow oven surpassed, not allowing us to run them through reflow. We ended up having to hand solder them in place post reflow. We
Electronics Forum | Fri Apr 18 10:45:34 EDT 2003 | tsongshe
I'm sure the parts and solder paste are well registered. these transistors are commonly to252 package,and sometimes to263 package.I 've a picture of these two diffrent kinds of pad patterns of to252,but i don't know how to post it here... Thanks ®ard
Electronics Forum | Wed Jul 23 08:21:55 EDT 2003 | James
Here we go again. I tried changing paste and that did nothing. Literally solder balled up and flew to the next pad. What would be a short term fix to use up all baards with white tin. Is there a fix if the board house did not manufacturer the boards
Electronics Forum | Thu Aug 07 16:52:49 EDT 2003 | craigj
We've been doing it for quite a while on some parts but are noticing that as more manufacturers are going lead free we are starting to see some issues. Particularily with pure tin on nickel. Have found that need to increase oven reflow temp and time
Electronics Forum | Thu Oct 16 00:08:31 EDT 2003 | Dean
Why would you have troubles if and when you switch? Isn't that the point of materials evaluation? Understanding the impact and material capability BEFORE "betting the farm on it". I would never stake my career on a solder paste without an Engineer
.gif)
