A heat dissipating device comprises a plurality of fins. An upper side and a lower side of each fin is folded with folding sheets. Each of two sides of each sheet is protruded with a buckling ear. The buckling ear is formed by a triangular sheet and a support plate. The support plate is connected to one apex of the triangular sheet and the folding sheet. A hole is formed on the folding sheet and is located behind the buckling ear. The shape of the hole is corresponding to that of the buckling ear. A tenon is formed at two lateral walls of the hole and a middle section of the tenon is protruded with a semi-round section. Further, the buckling ear may have a T shape or the triangular sheet can be replaced by a round sheet.