The present invention relates to a thin film chip-on-chip package structure, which includes a flexible circuit substrate, a chip, a heat-dissipating cover, and an adhesive layer. The chip is disposed on the flexible circuit substrate and electrically connected to the flexible circuit substrate. The heat dissipation cover comprises a top and at least a side wall, wherein the top is disposed on the back surface of the chip, at least the side wall is connected to the top, and the heat dissipation cover does not touch the flexible circuit substrate. The glue layer is placed between the back of the chip and the top of the heat sink. At least the side of the heat dissipation cover is exposed with an adhesive layer. The heat dissipation cover of the present invention does not touch the flexible circuit substrate to allow a space for the flexible circuit substrate to be bent, so as to prevent the flexible circuit substrate from being displaced to the top of the heat dissipation cover when the flexible circuit substrate is bent.