Patent ID: 8357565

Claim:
A method of forming an integrated circuit package, the method comprising: providing a die having a central region and a periphery surrounding the central region; providing a substrate to which the die is to be mounted; attaching the die to the substrate using a plurality of bumps, the die being spaced from the substrate; providing an underfill material in the space between the die and the substrate, leaving a void containing no underfill material between the die and the substrate in the central region of the die, wherein providing the underfill material comprises introducing the underfill material simultaneously from around the entire periphery of the die and trapping a volume of gas such that the trapped gas prevents inward flow of the underfill material under the central region; curing the underfill material; and encapsulating the die, the substrate and the cured underfill material with an encapsulation material to form an encapsulating layer that is separated from the underfill material by a physical interface.