Abstract: An integrated heat spreader (IHS) lid over a semiconductor die connected to a substrate forms a cavity. A bead of foaming material may be placed within the IHS cavity. During an IHS cure and reflow process the foaming material will expand and fill the IHS cavity and the foam's shape conforms to the various surface features present, encapsulating a thermal interface material (TIM) material, and increasing contact area of the foam sealant.