Electronics Forum | Wed Jan 10 09:57:08 EST 2007 | realchunks
Shields can carry a large thermal mass. If you ever tried removing one in repair, you'd find out how hard they can be. Also, they do deflect air flow. So in a convection oven, your air flow will be turbulent, which also will affect your reflow.
Electronics Forum | Thu Jan 11 09:23:32 EST 2007 | mscalzo3
BE, Flux coating helps as there is no solvent to volatize. Also, we offer vacuum-cast preforms that will eliminate the possibility of the voids comimg from the alloy itself. I can email a PDF of some profiles, all I need your email address. You c
Electronics Forum | Wed Jan 17 17:09:43 EST 2007 | russ
appears to be incomplete reflow on a couple of balls or they were moved during a cooldown. it also seems as though there is a deviation in ball size due to inconsistant paste application possibly. I would stop applying paste and just reflow that pa
Electronics Forum | Tue Jan 23 17:16:07 EST 2007 | darby
Check out the web sites of the major solder manufacturers. From a quick glance most of the pastes around that temperature range have problems with Zn content and may not be available as pastes???? Depending on your application, some of the lower melt
Electronics Forum | Thu Jan 25 04:11:09 EST 2007 | aj
Tricky stuff. I would expect to hit between 210-215 peak temp on Lead process. What sort of profile are you using? I would imagine a good soak zone would be critical- I have never had BGAs on bottomside so cant really advise any further,i will be in
Electronics Forum | Tue Feb 20 14:35:47 EST 2007 | ehess
FRank, are the BGA's in question a no-lead part? This usually results inthe paste flowing to make the electrical contact and not the ball, so I assume they could possibly crack easier than a leaded part. We have been receiveing almost all our BGA's
Electronics Forum | Thu Jan 25 15:58:49 EST 2007 | slthomas
Does the t/c read the actual skyrocketing temperature (you could confirm with a profiler if you wanted to leave it running while it's setting itself on fire) or something much lower than reality, driving the heaters harder? I would probably start sw
Electronics Forum | Thu Jan 25 13:20:17 EST 2007 | slthomas
Are you running a lead free process? If not, have you identified these as lead free components? If so, have you increased the temps in your profile to accomodate that? After that, I'd look for a AgPd (silver/palladium) or some other such PITA platin
Electronics Forum | Thu Jan 25 17:14:44 EST 2007 | slthomas
Good luck with that. ;) More likely you'll have to adjust your profiles. In our case with the palladium terminations we had to touch them up. There were other parts on the board that couldn't take more than 5 seconds at ~235 C� (don't remember for s
Electronics Forum | Mon Feb 12 13:01:09 EST 2007 | campos
Hi all,, I running SMQ230 solder paste with a time above = 40sec with peak temperature = 239 degrees .. the complete reflow takes almost 6 min with a slope (150to190) close to .60 degrees/sec .. may I have some concern about that or it's ok?? tks..
