Due to the progressing miniaturization and because of the better assembly there are IC miniature packages which have no connection wires but can be mounted directly on printed circuit boards via pads on the package bottom side.
Dual Flat No-Lead (DFN) is such an IC miniature package for SMT technology, Quad Flat No-Lead is another one. Within the package, the chip is connected to the pads on the IC bottom side via bonding wires.
Unlike QFN packages, which have the connection pads on all four sides, DFN packages have them on two opposite sides.
Dual flat no- lead packages are for electronic circuits such as voltage references, voltage transformers, or terminating resistors, to name a few. They come in sizes from 2 x 3 mm to 4 x 5 mm with 2 to 20 connection pads. The thickness of the DFN packages ranges from 0.4 mm to 0.9 mm. Compared to a shrink small outline package( SSOP), a DFN package requires only half the space.