US Patent 9607863 Integrated circuit package with vacant cavity

Integrated circuit packages with cavity are disclosed. A disclosed integrated circuit package includes a first die. A second die may be coupled to the first die by attaching the first die to a top surface of the second die. A blocking element such as a barrier structure may be formed that surrounds the second die. A cavity may be formed between the blocking element and the first die that encloses the second die. The barrier structure may help prevent underfill material from entering the cavity during underfill deposition processes. A heat spreading lid may cover the first die, second die and package substrate.