TCP (Tape Carrier Package) and COF (Chip On Flex or Chip On Film) are both IC packaging technology. It utilizes flexible printed circuit film as the medium for packaging IC chips. The microchip or die is directly mounted on and electrically connected to a flexible circuit built on a flexible substrate instead of the usual printed circuit board. The bonding is performed on the gold bumps on the chip and the inner lead on the circuit film by use of heat and pressure.