Thanks, gentlemen. All points well taken, and some hit pretty close to home. Our pick-and-place programmer assures me that coplanarity isn't the issue because the machine won't (or can't) place parts beyond an acceptable criteria. It's an Amistar 5530L, and apparently one of it's sensing functions screens for coplanarity. I know nothing beyond that, but that will come with time. If you know he's wrong, please let me know.
The stencil is a brand new design for us, 5 mil, 1:1 apertures/pads, traps, and is much better than our previous stencil w/respect to release. I don't think the stencil is the problem because, although we've changed stencils and get much better performance print wise, the results out of reflow are the same.
I'm more inclined to think it's the profile, especially since I've spent some time with it today. I think the oven was profiled with a bare board, w/taped down tc's. I ran soldered-to-lead-bottom profiles today and the max. temp reached on 3 out of the 4 locations didn't pass 210C, and one was below 200C. After I played with the heat ranges I got it to look much better but I'm concerned about to much heat in the reflow chamber. Is going from a setting of 200 in zone 5 to 270 in zone 6 (reflow) to much of a jump? That's what I need to get to a decent max. temp. without exceeding the reflow temp for too long. Now much can I shock these components by doing that? I haven't looked into the manufacturers specs. for max. temp. but I guess that's a good place to start...
So much to do, so little time.....and knowledge.....but that's probably becoming painfully obvious to you. Thanks for any and all assistance, guys.
Steve
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