QFN : Quad Flat No Leads:These connect IC's to PCB's without through-holes.
The figure shows with lead frame and wire bonding. Flat no-lead packages include an exposed thermal pad to improve heat transfer out of the IC (into the PCB). Hand soldering is not possible with this package
QFP: Quad Flat PackageA surface mounted IC, pins extending for all the 4 sides. Socketing such packages is rare and through-hole mounting is not possible.
LQFP: Low Profile Quad Flat Package (1.4mm)
TQFP: Thin Quad Flat Package (1.0 mm)Has shorter leads than the LQFP. To be used in a space constrained designs.
Helps in solving increased board density.