Patent ID: 8258013

Claim:
An integrated circuit package assembly, comprising: a substrate; a semiconductor die having opposing first and second surfaces and mounted on the substrate with the first surface facing the substrate; a heat-spreader including: a central region thermally coupled to the second surface of the semiconductor die; a flange region mounted on the substrate; a side wall region between the central and flange regions, wherein a cavity is formed between the heat-spreader, the substrate, and the semiconductor die; and at least one vent located in the flange region of the heat-spreader; a duct formed in the substrate, wherein the duct has a first end at the least one vent and extends to a second end at the cavity; and a membrane disposed at one of the first or second ends of the duct, wherein the membrane allows gaseous matter to flow from the cavity through the vent and prevents liquid from flowing through the vent and into the cavity.