Stacked multi-die packages with impedance control
AssigneeTessera Research LLC
InventorBelgacem Haba
Life of this patent
Estimating the term…
Abstract
A microelectronic assembly may include microelectronic devices arranged in a stack and having device contacts exposed at respective front surfaces. Signal conductors having substantial portions extending above the front surface of the respective microelectronic devices connect the device contacts with signal contacts of an underlying interconnection element. A rear surface of a microelectronic device of the stack overlying an adjacent microelectronic device of the stack is spaced a predetermined distance above and extends at least generally parallel to the substantial portions of the signal conductors connected to the adjacent device, such that a desired impedance may be achieved for the signal conductors connected to the adjacent device.
Claims52
A microelectronic assembly comprising:
- a plurality of microelectronic devices arranged to form a stack of microelectronic devices, wherein adjacent first and second microelectronic devices in the stack each have device contacts exposed at a front surface, and have a rear surface remote from the front surface;
- an interconnection element underlying the second microelectronic device, the interconnection element having a plurality of signal contacts;
- and
- first and second signal conductors respectively connecting the device contacts of the first and second devices with the signal contacts, the first and second signal conductors having substantial portions extending above the front surfaces of the respective first and second microelectronic devices,
- wherein the rear surface of the first microelectronic device is spaced a predetermined first distance above and extends at least generally parallel to the substantial portions of the second signal conductors, such that a desired impedance is achieved for the second signal conductors.
A method of fabricating a microelectronic assembly comprising:
- arranging a plurality of microelectronic devices in a stack including a first microelectronic device mounted above an adjacent second microelectronic device, wherein the first and second microelectronic devices in the stack have device contacts exposed at a front surface and have a rear surface remote from the front surface;
- and
- connecting the device contacts of the first and second devices with signal contacts of an interconnection element underlying the second microelectronic device using respective first and second signal conductors, the second signal conductors being connected to the signal contacts before the first signal conductors are connected to the signal contacts, the first and second signal conductors having substantial portions extending above the front surfaces of the respective first and second microelectronic devices, and
- wherein the rear surface of the first microelectronic device is spaced a predetermined first distance above and extends at least generally parallel to the substantial portions of the second signal conductors, such that a desired impedance is achieved for the second signal conductors.
A method of fabricating a microelectronic assembly comprising:
- arranging a plurality of microelectronic devices in a stack over an interconnection element, wherein adjacent first and second microelectronic devices in the stack have device contacts exposed at a front surface and have a rear surface remote from the front surface, wherein the interconnection element underlies the second microelectronic device, wherein the device contacts of the first and second devices are connected with signal contacts of the interconnection element by respective first and second signal conductors, the second signal conductors being connected to the signal contacts before the first signal conductors are connected to the signal contacts, the first and second signal conductors having substantial portions extending above the front surfaces of the respective first and second microelectronic devices,
- wherein the rear surface of the first microelectronic device is spaced a predetermined first distance above and extends at least generally parallel to the substantial portions of the second signal conductors, such that a desired impedance is achieved for the second signal conductors and empty spaces are defined between the first and second microelectronic devices;
- and
- injecting dielectric material into the empty spaces between the first and second microelectronic devices.
Dependencies are inferred from the claim text.