Hi,
Is it possible to solder by hand a chip in LFCSP package. Like the ADUC7020?
sure,
for small series prototype chip soldering you can do as follows:
you need small stencil with the chip pad pattern to print the paste on the PCB pads, use 0.15 mm thick stencil for these fine pitch devices as there is no need for much solder paste on the pads to prevent bridging
then good vacuum pen with paddle switch and X/Y ARM to may position accurate the chip over the pads as if you try to place by hand your arm will probably shiver when you drop the part and it will not go to the correct position.
then use hot air gun to blow hot air above the chip to solder it - tip place drop of solder paste near the chip as indicator when the temperature is enough to melt the paste and stop the air when the paste drop make solder ball.
also it’s good this to be the first component on the board as when heating it you may de-solder the components near it.
Tsvetan
10x for the reply.
I have another question. I’ve received some samples from ADI(ADuC7025 in chip scale pack) and on the enclosure there is that very scary notice:
" If these samples are to be subjected to solder reflow or other high temperature process they must be baked for 24 hours at 125 degrees Celsius prior to board mount. Failure to comply may result in crack and/or delamination of critical interfaces within the package"
So is this baking really needed or it is just a recommendation??? 
What is your experience?
baking is needed to remove the moisture from your chip package
the package absorbs moisture and when you heat the chip the steam may cause micro-cracks the package (google for “IC pop corn effect”)
we usually bake for 8-10 hours (overnight) at 80-90C which works fine with our reflow oven later
Tsvetan
And what about that “Exposed pad” on the bottom of the chip. What is actually “exposed” on it?
you just need some colophony,and than use neat alcohol clean it.
this type package like intersil’s isl6441,nRF2401A,ADuC7020,eg.