I’m certain they meant 650F, which is around 345C. Still higher than I’d use — I try to stick as close to 300C for lead free as possible, since the higher you go, the quicker the solder on the tip oxidizes. 320C is a good temp for most boards. (At work, we aren’t even allowed to go above 360C, though I’ve frankly never had the need to do so.) At home, I usually use 270-280C for leaded, and 300-320C for lead free.
I also seriously doubt the Hakko (or any other soldering station, for that matter) goes up to 650C anyway!
I really better get weaker flux, or a non-spitting type. I have some MCU's to solder, and it tends to make a lot of little solder balls and gunk, that spatters. Thats at 650C on a legit Hakko
I never tried to solder a pin-less chip before, but my flux, (the solder is fine alone) has shorted a few things now I realize.
I suggest a gel flux. I use MG Chemicals no-clean gel at home, and Chip-Quik no-clean at work. The chip quik is exceptionally nice to work with, no clumpiness at all, and just smells sweet and nutty when heated. (Most modern fluxes are rather acrid.) I think it’s what I’ll get once my MG Chems runs out. It is, however, a smidgen more corrosive. (Even no-clean fluxes are corrosive - they must be heated up to a certain point for full activation, but the part people forget is that they must be heated beyond that to neutralize them. In a reflow oven that is guaranteed, but when hand soldering, almost guaranteed to not be the case. So be sure to clean.)
What do you mean that your flux creates solder balls?!? Flux doesn’t contain solder. Do you mean solder paste?!