Abstract: A thin flip chip package structure comprises a substrate, a chip and a heat dissipation paste, wherein the substrate comprises an insulating layer and a trace layer. The insulating layer comprises a first insulating portion and a second insulating portion, the first insulating portion comprises a first upward surface, a first downward surface, a first thickness and a recess formed on the first downward surface, wherein the recess comprises a bottom surface. The second insulating portion comprises a second upward surface, a second downward surface and a second thickness larger than the first thickness. The trace layer is at least formed on the second insulating portion, the chip disposed on top of the substrate is electrically connected with the trace layer and comprises a plurality of bumps, and the heat dissipation paste is disposed at the recess.