An integrated circuit package in which pins are replaced by flat contacts on each of the four sides of the chip on its underside. These are simply bonded to a conductor on the circuit board surface. The centre of the QFN chip underside is also filled with a metal pad that provides a direct thermal connection from the chip to an external heat sink in the circuit board. QFN packages suit high-performance applications in which heat management is important. A thin quad-flat no-leads package (TQFN) is a QFN with a maximum body thickness of 0.8 mm. See also dual in-line package; leadless chip carrier; pin grid array.