A leadframe-based semiconductor package is revealed, primarily comprising a chip, a plurality of leads of a leadframe, a multi-layer tape, and an encapsulant. The multi-layer tape is attached to the chip and includes an adhesive layer disposed on a dielectric core layer. The internal leads of the leads are partially embedded in the adhesive layer in a manner not to directly contact the dielectric core layer. A bonding interface with a U-shaped profile is formed between the adhesive layer and each internal lead to increase the adhesions of the leads so that the internal leads will not be shifted nor delaminated during molding processes. The concentrated stresses exerted on the internal leads disposed at the corners of the packages will be released and reduced.