Electronics Forum | Fri Mar 03 13:51:17 EST 2006 | Chunks
We've looked at our stencil under magnification after hand cleaning. There is some paste left behind. Machine washing removes all of the paste. Your best bet is to clean like normal, then look at the aps under magnification. Adjust accordingly (a
Electronics Forum | Tue Mar 07 14:23:21 EST 2006 | billyd
I think it has a whole lot to do with the heat applied, and the paste type. It was a seriously populated, very thick board, so we had to go big with the heat just to make 240-ish. That produced voids maybe 45 or 50% of the ball size. We knew immediat
Electronics Forum | Thu Mar 09 16:29:35 EST 2006 | russ
Will the Pb part handle 240C? That is the first question that you need to answer. If it will then yes I would run the pbfree paste and profile. I assume that all other components are pbfree. If not, the same questions will need be asked as for th
Electronics Forum | Mon Mar 20 03:47:16 EST 2006 | Adrian
Hi guys, Has anyone ever had experiance with a Vision Master 150 ?, we have 2 onsite and I am trying to get accurate BGA paste height measurements from this machine, but both the machines are giving me results with huge variations, like +/- 0.2 thou
Electronics Forum | Thu May 18 09:18:33 EDT 2006 | Chunks
Hi dwelch123, 8 mils seems a bit thick to me. I would normally go 6 or 5 mil for fine pitch such as this. One other area to check is the the snap off. Are you using the slow snap off or just lowering the board right after print? If so you should
Electronics Forum | Thu May 18 10:20:55 EDT 2006 | slthomas
Russ asks good questions and I think Chunks pretty much nailed it. Aspect ratio (aperture width/stencil thickness) s/b 1.2 minimum (I like 1.5 if I can get it). If your aperture width = lead width (.008"), yours is 1. Tough to get consistent paste r
Electronics Forum | Tue Jul 11 12:59:26 EDT 2006 | mattkehoe@sipad.com
We are trying to apply solder to boards with 80 microinches of electro plated hard gold. No components involved, just print 63/37 paste and reflow. The results are very poor on some boards, not so bad on others? Pictures at http://www.sipad.net/thick
Electronics Forum | Fri Jul 28 09:40:11 EDT 2006 | pavel_murtishev
Good afternoon, 1. Yes, most of all I suspect the components. Could you explain what does mean "reflothermal recipe"? Ramp-to-spike? Ramp-soak-spike? Something special? Thanks. 2. Void is really huge. This voiding differs from "standard" voiding ef
Electronics Forum | Mon Aug 14 12:08:35 EDT 2006 | cuculi54986@yahoo.com
I agree with using the homeplate design on chips. Some Pb-free solder paste manufacturers recommend 1:1 apertures. This, in my experience, is not a good idea with any of the SAC305 pastes I've tried. I've been using the same stencil design guideli
Electronics Forum | Thu Aug 10 10:00:40 EDT 2006 | slthomas
Temp. and humidity levels are dependant upon your chemical (paste and adhesive) specifications. Ballpark I'd say 70�F and 40%-45% RH are good targets, as our paste spec. says optimal ranges are 70-77� and 30-70 RH. As far as air quality, if you bui
