Semiconductor package structure with a heat-dissipation stiffener and method of fabricating the same

摘要

A semiconductor package structure with a heat-dissipation stiffener and a method of fabricating the same are proposed. The proposed packaging technology includes a substrate; a thermally-conductive stiffener mounted over the front surface of the substrate, the stiffener being formed with a centrally-hollowed portion and an outward-extending passage; a semi-conductor chip mounted on the front surface of the substrate and within the centrally-hollowed portion of the stiffener; an underfill layer filled and cured in a gap between the semiconductor chip and the substrate; and a plurality of solder balls mounted on the back surface of the substrate. Alternatively, the passage can be formed in the front surface of the substrate. During fabrication process, the passage is used for the injection of a cleaning solvent into the gap between the semiconductor chip and the substrate so as to clean away remnant solder flux. The proposed packaging technology allows the cleaning solvent used in the solder flux cleaning process to be unobstructed by the stiffener so that the cleaning solvent can be more smoothly injected into the gap between the semiconductor chip and the substrate. This benefit allows the subsequently formed underfill layer to be substantially free of voids, allowing the finished package product to be more assured in quality and reliability.