Electronics Forum | Wed Jul 13 19:47:06 EDT 2005 | Darby
This works for me with ENIG finish and a SAC305 NC paste Reduce all pads by -2mil on all sides ie 0.050" x 0.050" becomes 0.046" x 0.046" EXCEPT Anything smaller than 30mil; -1.5mil Anything smaller than 20mil; -1mil Anything smaller than 15mil;
Electronics Forum | Fri Jul 15 18:21:55 EDT 2005 | dggjr
We have Kester 256 no-clean spec'd as an alternate paste. I bring some 256 in occasionally to make sure it still works as a backup. The last batch I brought in was bridging like crazy. Scraped it off the stencil, put our regular Alpha back down an
Electronics Forum | Thu Jul 14 16:07:16 EDT 2005 | saragorcos
Here is a link to a specific article about cleaning no-clean assemblies: http://www.residues.com/pdfs/Clean_No_Clean.pdf Our facility does a lot of contract cleaning and cleanliness testing for various companies around the world, and that study s
Electronics Forum | Fri Jul 15 08:32:40 EDT 2005 | stepheniii
Now is when you find out if you have a good sales rep for your solder. I've seen solder reps eventually get around to responding. And I've seen some that would be in the plant that day to help you out. I even know a couple who would give advice even
Electronics Forum | Thu Jul 14 11:52:16 EDT 2005 | davef
Sure you can use SPC charting on the wave setup parameters to warn of impending problems. Examples of useful points of analysis are: * Dwell * Temperature * Pot analysis Certainly there's a range of other process controls that could be monitored.
Electronics Forum | Fri Jul 15 03:29:52 EDT 2005 | dougs
thomas, why isn't it process control, you cant just think that because you've set up your machine properly ( pot temp, wave height, pre-heat etc etc )that everything is going to be ok, there are other factors that you wont find with wave riders or
Electronics Forum | Fri Jul 15 08:20:44 EDT 2005 | stepheniii
And why do you want to control the process? To prevent defects, I would think. Actually orginally the way I first saw SPC was to reduce inspection. If you are using SPC for plating thickness, you don't have to measure every piece to be confident the
Electronics Forum | Fri Jul 15 10:56:19 EDT 2005 | pr
As Russ said, you do a DOE beforehand. BUT Maybe we are missing something, we do SPC after the wave (1/5) to catch defect trends and fix them with a minimum of inspection. If you are running a 2,000 piece pull, are you that confident that your origin
Electronics Forum | Fri Jul 15 12:41:56 EDT 2005 | russ
You are not wrong in monitoring the Product (your really not monitoring the process). This methodology is valuable if your process is unstable (SPC is used to stabilize process). There is value in "real time" inspection of a process's product as lon
Electronics Forum | Mon Jul 18 18:36:01 EDT 2005 | slthomas
"thomas, why isn't it process control," Minute detail, really. Defects aren't a measurement of process parameters, they're the result of them (and a few other things that have been mentioned). SPC measures process parameters. It is preemptive, and
