Patent ID: 7800238

Claim:
A system of stacked microelectronic dies, comprising: a first microelectronic die having a back-side surface, a surface depression in the back-side surface, and a first metal contact located within the surface depression; a second microelectronic die having a front-side surface and a second metal contact located at the front-side surface and aligned with the first metal contact; and a die-to-die interconnect coupling the first metal contact with the second metal contact, the die-to-die interconnect including a flowable metal material that at least partially fills the surface depression; wherein the surface depression comprises a first surface depression, the die-to-die interconnect comprises a first die-to-die interconnect, and the flowable metal material comprises a first flowable metal material, and wherein the first die further includes a second surface depression having a second flowable metal material that at least partially fills the second surface depression, the second flowable metal material being associated with a second die-to-die interconnect and being electrically isolated from the first flowable metal material, and wherein the first metal contact does not project beyond a plane defined by the back-side surface of the first microelectronic die.