Quad flat no-lead package and method for forming the same

A Quad Flat No-Lead Package is proposed, comprising a die-mounting base; a plurality of electrical connecting pads disposed at the periphery of the die-mounting base, wherein the bottom surfaces of the die-mounting base and the electrical connecting pads are covered by a copper layer; a die mounted on the die-mounting base; a plurality of bonding wires each respectively connecting the die with the electrical connecting pads; an encapsulant for encapsulating the die-mounting base, electrical connecting pads, the die and bonding wires while exposing the copper layer on the bottom surfaces of the die-mounting base and the electrical connecting pads therefrom; ; a dielectric layer formed on the bottom surface of the encapsulant and with a plurality of openings being exposed from the copper layer, wherein the copper layer has a good bonding with the dielectric layer that helps prevent solder material in a reflow process from permeating into the die-mounting base and the protruding of solder material on the interfa