Three-dimensional die stacks with inter-device and intra-device optical interconnect

• US 20090103855A1
• Filed: 10/23/2007
• Published: 04/23/2009
• Est. Priority Date: 10/23/2007
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Binkert, Nathan, Davis, Al, Jouppi, Norm, Beausoleil, Raymond
• Granted Patent: US 8,064,739 B2
• Time in Patent Office: Days
• US Class Current: 385/14
• CPC Class Codes: G02B 6/43 Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation

Abstract

Examples of a computer system packaged in a three-dimensional stack of dies are described. The package includes an electrical die and an optical die coupled to and stacked with the electrical die. The electrical die includes circuitry to process and communicate electrical signals, and the optical die includes structures to transport optical signals. The electrical die has a smaller area than the optical die so that the optical die includes an exposed mezzanine which is configured with optical input/output ports. Additionally, the packaging can be configured to provide structural support against insertion forces for external optical connections.

Claims

1. An apparatus comprising a three-dimensional stack of dies, the apparatus comprising:

an electrical die comprising circuitry to process and communicate electrical signals;

an optical die coupled to and stacked with the electrical die, said optical die comprising structures to transport and modulate optical signals; and

an exposed optical mezzanine of the optical die which is configured with optical input/output ports.

2. The apparatus of claim 1, further comprising:

a cooling device attached to said electrical die on a side opposing to said optical die; and

packaging configured to provide structural support against insertion forces when optical fibers are interconnected to ports on the optical die.

3. The apparatus of claim 1, wherein the electrical die has a smaller area than the optical die, and wherein the exposed optical mezzanine is on a side of the optical die facing the electrical die.

4. The apparatus of claim 1, further comprising:

one or more base die coupled to and stacked with the optical die on a side opposing said electrical die, wherein said base die(s) comprise electrical and/or optical dies.

5. The apparatus of claim 4, wherein the base die include at least one memory die.

6. The apparatus of claim 4, wherein the base die has a smaller area than the optical die such that the exposed optical mezzanine is on a side of the optical die facing the base die.

7. The apparatus of claim 1, further comprising:

a sidewall structure to form a cavity into which said electrical and optical dies are positioned.

8. The apparatus of claim 1, further comprising holographic lenses coupled to the exposed optical mezzanine and configured to interconnect signals from optical fibers to the optical input/output ports.

9. The apparatus of claim 1, wherein the exposed optical mezzanine further includes at least one input for laser power from an external laser.

10. The apparatus of claim 9, wherein the external laser is attached to the exposed optical mezzanine.

11. The apparatus of claim 9, wherein the external laser is coupled to the exposed optical mezzanine by way of optical fiber.

12. The apparatus of claim 1, further comprising electrical vias configured to go through at least the optical die.

24. The apparatus of claim 1, further comprising:

a diamond layer for heat dissipation stacked between the optical die and the electrical die.

13. An optical die comprising:

an optical waveguide structure;

interface structures to interface between an attached electrical die and the optical waveguide structure, wherein the attached electrical die is bonded to a front side of the optical die;

at least one exposed mezzanine area on the front side of the optical die.

14. The optical die of claim 13, wherein the exposed area(s) include optical input/output bonds.

15. The optical die of claim 13, wherein the exposed area(s) include at least one laser power input.

16. The optical die of claim 13, further comprising through-vias which electrically connect the first side of the optical die to an opposite side of the optical die.

17. The optical die of claim 13, wherein there are at least two exposed areas on opposite sides of the front side of the optical die.

18. A packaging method for forming a three-dimensional stack of dies including electrical and photonic dies, the packaging method comprising bonding an electrical die comprising circuitry to process and communicate electrical signals to an optical die comprising structures to transport and modulate optical signals, wherein a mezzanine area on the optical die is exposed with optical input/output ports.

19. An apparatus having a three-dimensional stack of semiconductor dies comprising:

an electrical die comprising at least analog electronics circuitry; and

an optical die comprising structures to transport and modulate optical signals and coupled to the electrical die by way of a face-to-face bond; and

a mezzanine area on the optical die which is exposed with input/output ports for receiving and sending the optical signals.

20. The apparatus of claim 19, further comprising:

a cooling device; and

at least one additional electrical die stacked between said electrical die and said cooling device.

21. The apparatus of claim 20, wherein said electrical die or dies include at least one processor core and a memory controller.

22. The apparatus of claim 21, further comprising at least one memory die in the stack and electrical through-vias interconnecting the at least one memory die to said memory controller.

23. The apparatus of claim 19, further comprising:

at least one additional optical die in the stack.

25. The apparatus of claim 19, further comprising:

a diamond layer for heat dissipation stacked between the optical die and the electrical die.