Embedded liquid pump and microchannel cooling system

• US 6,785,134 B2
• Filed: 01/06/2003
• Issued: 08/31/2004
• Est. Priority Date: 01/06/2003
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Maveety, James G., Garner, Michael C., Chrysler, Gregory M.
• Primary Examiner(s): CHERVINSKY, BORIS LEO
• Application Number:
  US10/337,955
• Publication Number:
  US 20040130874A1
• Time in Patent Office: 603 Days
• Field of Search: 361/695, 361/700, 361/719-721, 174/15.1, 174/15.2, 257/714, 257/715, 165/80.4
• US Class Current: 361/699
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 23/42 Fillings or auxiliary members in containers or encapsulations selected or arranged to facilitate heating or cooling
• CPC Class Codes: H01L 23/473 by flowing liquids H01L23/4332, H01L23/4338 take precedence
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA

Abstract

Apparatus and methods in accordance with the present invention provide self-contained, closed-loop microchannel/electrokinetic pump cooling systems that can be integrated into the microelectronic die and the integrated heat sink to provide microelectronic die cooling. Microchannel/electrokinetic pump cooling systems utilize active cooling technology to reduce thermal gradients and operating temperature of a microelectronic die. This system disclosed here will enhance heat dissipation and provide immediate cooling of localized hot spots within the microelectronic die. This will have the effect of reducing the microelectronic die temperature or spreading the heat internally within the microelectronic die depending on the layout of the microchannels.

Claims

1. An apparatus comprising:

a substrate comprising an integrated heat spreader including microchannels in fluid communication with an electrokinetic pump housed within the integrated heat spreader,

the electrokinetic pump including

a fluid;

a reservoir, formed integral with the integrated heat spreader, in fluid communication with the microchannels; and

a plurality of electrodes adapted to provide a pressure differential by electrolysis of the fluid; and

a microelectronic die including internal die microchannels, the die microchannels in fluid communication with the microchannels within the integrated heat spreader.

2. A method for actively cooling a microelectronic die, comprising:

providing a substrate comprising an integrated heat spreader including substrate microchannels in fluid communication with an electrokinetic pump housed within the integrated heat spreader,

the electrokinetic pump including a fluid;

a reservoir, formed integral with the integrated heat spreader, in fluid communication with the substrate microchannels; and

a plurality of electrodes;

providing the plurality of electrodes with a voltage sufficient to electrolyze the fluid to drive the fluid through the substrate microchannels by a pressure differential caused by electrolysis of the fluid; and

forming internal die microchannels within the microelectronic die, the die microchannels in fluid communication with the substrate microchannels.

3. An apparatus comprising:

a microelectronic die including a high heat flux area and internal die microchannels;

a fluid disposed within the die microchannels, to at least facilitate heat transfer away from the high heat flux areas;

and a substrate including microchannels in fluid communication with the internal die microchannels.

4. The apparatus of claim 3, wherein the internal die microchannels exhibit increased spacing density in the high heat flux area.

5. The apparatus of claim 3, wherein the fluid at least facilitates heat transfer away from the high heat flux area through an evaporation/condensation cycle.

6. The apparatus of claim 3, further comprising:

a pump being in fluid communication with the die microchannels, to at least facilitate fluid motion through the die microchannels.

7. The apparatus of claim 6, wherein the pump comprises an electrokinetic pump.

8. The apparatus of claim 6, wherein:

the pump is disposed within the substrate, and

the substrate microchannels being in fluid communication with the die microchannels.

9. The apparatus of claim 8, wherein the pump comprises an electrokinetic pump including

a fluid;

a reservoir in fluid communication with the substrate microchannels; and

a plurality of electrodes adapted to provide a pressure differential by electrolysis of the fluid.

10. The apparatus of claim 3, wherein the substrate comprises an integrated heat spreader.

11. A method of heat transfer comprising:

operating a microelectronic die resulting in a high heat flux area;

transferring, at least a portion of the heat from the high heat flux area to a low heat flux area in a substrate by flowing a fluid through internal die microchannels disposed within the microelectronic die;

and through substrate microchannels in fluid communication with informal die microchannels.

12. The method of claim 11, wherein the flowing of the fluid is at least facilitated by a pressure differential created by a pump.

13. The method of claim 11, wherein the substrate includes an integrated heat spreader.

14. The method of claim 13, wherein the pump comprises an electrokinetic pump.

15. The method of claim 14, wherein the electrokinetic pump is disposed within the integrated heat spreader and includes a fluid, a plurality of electrodes, and a reservoir in fluid communication with the substrate microchannels.

16. The method of claim 15, wherein the pressure differential is at least facilitated by the electrodes providing a voltage sufficient to electrolyze the fluid.