DigiTan said:
But how is that possible? Doesn't the soldering just push the chip off the pads? Maybe I should just tape it down or something.
"Push the chip off the pads"? - you're soldering it! - not bump starting a Jumbo jet!.
Simple step by step instructions!.
1) Place PCB on bench.
2) Brush pads with liquid flux (this GREATLY improves the ease of the job).
3) Carefully position chip in exactly the right place.
4) Place left index finger on top of chip and press lightly downwards, be careful NOT to move the chip - if you press perfectly vertically, there's no sideways force to make it move.
5) Using soldering iron with fine tip in right hand, with a SMALL amount of solder on the tip, gently touch one of the corner pins - the liquid flux should 'suck' the solder off the tip and perfectly coat the pin and pad.
6) Make sure the chip is still EXACTLY aligned, and do a similar touch on the opposite corner.
7) Remove left index finger - check it's still perfecty aligned.
8) Brush pins with more liquid flux, then solder each pin at a time.
9) Examine carefully with a magnifying glass to confirm all pins are soldered, and none are shorting out - the liquid flux helps to ensure BOTH of these.
10) Clean the flux residue off the board, using a suitable cleaner.
It's as easy as that - if you're left handed, reverse the left and right instructions above!.