Electronics Forum | Thu Sep 14 11:56:47 EDT 2006 | russ
I think you have your pitch wrong but anyway, I have never had success with wave soldering anything less than 50 mil pitch. On a QFP I have had good luck on three sides of 25 mil but never all four sides and without defects. Mask 'em off and hand s
Electronics Forum | Tue Nov 01 09:00:07 EST 2005 | russ
Is an RQFP a Qfp with the center pad for heat dissipation? If so, you may be shifting when this center pad reflows and lifts the part.
Electronics Forum | Thu Jul 29 21:19:09 EDT 2004 | davef
You need: * Solder that is active enough to made those leads take solder * Reflow recipe that makes the most of the flux is the paste The flux in neither of your solder pastes is getting done.
Electronics Forum | Fri Jul 23 09:17:16 EDT 2004 | davef
The more we think about this, the more we think you should join the 20th century and upgrade from your good ol' WS609. We know this will be tough. We used the stuff for 10s of years.
Electronics Forum | Fri Jul 23 20:59:34 EDT 2004 | KEN
Ahmen bro. About 6 years ago I sent 12,000 dollars of this paste to the recycler because I calculated the cost of direct manufacturing defects would outweigh the cost of the paste!
Electronics Forum | Mon Oct 31 08:29:51 EST 2005 | chunks
Shifting? Please describe the "Shifting". I.E. is it centering, sliding to cause shorts..... Most 208s will self center. If it's causing shorts, first check your print to make sure it is on the pads. Next check placement. Another area to check
Electronics Forum | Tue Nov 01 12:29:35 EST 2005 | russ
I just noticed that you mention 2-5mm off, that is huge! It would seem to me that there is an external force here to move a part that far. Things such as a heavy air stream that for some reason is really hitting this part, something on the PCB unde
Electronics Forum | Mon Jul 19 08:55:54 EDT 2004 | dwanzek
Thanks, good input. The joints do seem to wet well, they pass solderability test we have done. The defect is apparent right after reflow, before wave solder. No we do not profiled with the oven loaded..... good idea. We run an ovenrider each shift an
Electronics Forum | Tue May 14 21:07:03 EDT 2002 | ianchan
Hi mates, Yes, the lighter mass is a valid reasoning. in addition to the "lighter (mass) than thou" point of view, 1) the first reason for mounting active Parts (eg. IC, QFP, LGA...) is to minimize the temperature exposure of the Parts to a single
Electronics Forum | Mon Jul 19 19:39:06 EDT 2004 | KEN
I once had a forced convection oven (insert brand here)...and the top 220VAC heater (reflow zone) had shorted to the frame ground, blowing the branch line fuses. THe machine had no idea the heater was out because the lower heater was heating the upp
