We are having some difficulty soldering a 240 pin Altera device. We use Alpha WS-609, a very generic profile for that solder paste, and a 6 mil stencil with laser cut apertures (1:1 ratio). This is a 20 mil pitch device (aperture size is 10 mils X 75 mils) and we are using HASL as the board finish. The manufacturer claims the lead frames are made from copper with an 85/15 tin lead finish. The results look suspiciously enough, like the results you might see if you were trying to solder to palladium (lifted leads sitting up on pillows, dull grainy joints). We suspect that because of our process time (25 minutes), the flux vehicle may be evaporating; we factory environment is consistently below 20% RH. Our experiments indicate that date code is not an issue and we have had parts tested for contaminants and only a slight black oxidation (whatever that means) was found Has anybody run into the same or similar problems? We are baffled.