An integrated circuit assembly that includes a substrate; a member formed on the substrate; a first die mounted to the substrate within an opening in the member such that there is space between the first die and the member and the member surrounds the first die, and wherein the first die does not extend above an upper surface of the member; an underfill between the first the die and the substrate, wherein the underfill at least partially fills the space between the die and member; and a second die mounted to the first die and the member, wherein the second die is mounted to the member on all sides of the opening.