Method and structure for cooling a dual chip module with one high power chip

• US 20050068739A1
• Filed: 09/26/2003
• Published: 03/31/2005
• Est. Priority Date: 09/26/2003
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Toy, Hilton T., Arvelo, Amilcar R., Sikka, Kamal Kumar
• Granted Patent: US 7,031,162 B2
• Time in Patent Office: Days
• US Class Current: 361/718
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 23/3675 characterised by the shape of the housing
• 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 23/433 Auxiliary members in containers characterised by their shape, e.g. pistons
• CPC Class Codes: H01L 24/31 Structure, shape, material or disposition of the layer connectors after the connecting process
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/16152 Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/16251 Connecting to an item not being a semiconductor or solid-state body, e.g. cap-to-substrate

Abstract

Disclosed is a cooling structure which has individual spreaders or caps mounted on the chips. The thickness of the high power spreader or cap exceeds the thickness of the lower power spreaders to ensure that the high power spreader achieves the highest plane and mates to a heat sink with the smallest interface gap. The variable and higher gaps between the lower power spreaders and the heat sink base are accommodated by compressible thermal pad or grease materials.

Claims

1. A cooling structure for an integrated circuit structure having multiple integrated circuit chips, said cooling structure comprising:

a plurality of heat spreaders, wherein the lower side of each of said heat spreaders is connected to the top of a corresponding one of said integrated circuit chips; and

a heat dissipating structure connected to the upper sides of said heat spreaders through a thermally conductive material,

wherein said thermally conductive material is positioned in gaps between the upper sides of said heat spreaders and the bottom of said heat dissipating structure, and

wherein the smallest of said gaps exists between the top of the heat spreader that is connected to the integrated circuit chip that produces the most thermal energy, relative to the other integrated circuit chips, and the bottom of said heat dissipating structure.

2. The structure in claim 1, wherein said heat spreaders have different thicknesses.

3. The structure in claim 1, wherein said heat spreaders have different coefficients of thermal conductivity.

4. The structure in claim 1, further comprising of a thermal adhesive connecting said heat spreaders to said integrated circuit chips.

5. The structure in claim 1, wherein said thermally conductive material comprises a plurality of thermally conductive materials having different coefficients of thermal conductivity.

6. The structure in claim 1, wherein said thermally conductive material comprises one of a thermal grease and a phase change material.

7. The structure in claim 1, wherein said integrated circuit chips comprise at least one higher power chip and at least one lower power chip, wherein, during operation, said higher power chip generates more thermal energy than said lower power chip.

8. A cooling structure for an integrated circuit structure, said cooling structure comprising:

a chip carrier comprising multiple integrated circuit chips;

a cap connected to said chip carrier and to the top of the integrated circuit chip that produces the most thermal energy, relative to the other integrated circuit chips;

a plurality of heat spreaders, wherein the lower side of each of said heat spreaders is connected to the top of a corresponding integrated circuit chip of said other integrated circuit chips; and

a heat dissipating structure connected to the upper sides of said heat spreaders and said cap through a thermally conductive material,

wherein said thermally conductive material is positioned in gaps, wherein said gaps exist between the tops of said heat spreaders and the bottom of heat dissipating structure, and between the upper side of said cap and the bottom of said heat dissipating structure, and

wherein the smallest of said gaps exists between the upper side of said cap and the bottom of said heat dissipating structure.

9. The structure in claim 8, wherein said cap includes a piston.

10. The structure in claim 8, wherein said heat spreaders have different thicknesses than said cap.

11. The structure in claim 8, wherein said heat spreaders have different coefficients of thermal conductivity than said cap.

12. The structure in claim 8, further comprising a thermal adhesive connecting said heat spreaders to said integrated circuit chips.

13. The structure in claim 8, wherein said thermally conductive material comprises one of a thermal grease and a phase change material.

14. The structure in claim 8, wherein said integrated circuit chips comprise at least one higher power chip and at least one lower power chip, wherein, during operation, said higher power chip generates more thermal energy than said lower power chip.

15. A cooling structure for an integrated circuit structure having multiple integrated circuit chips, said cooling structure comprising:

a heat spreader connected to the integrated circuit chip that produces the most thermal energy, relative to the other integrated circuit chips; and

a heat dissipating structure connected to the upper side of said heat spreader and to the upper sides of said other integrated circuit chips,

wherein thermally conductive material is positioned in gaps, wherein said gaps exist between the upper side of said heat spreader and the bottom of said heat dissipating structure, and between the upper sides of said integrated circuit chips and the bottom of said heat dissipating structure, and

wherein the smallest of said gaps exists between the upper side of said heat spreader and the bottom of said heat dissipating structure.

16. The structure in claim 15, wherein said heat dissipating structure including a recess for accommodating said heat spreader.

17. The structure in claim 15, further comprising a thermal adhesive connecting said heat spreader to said integrated circuit chip that produces the most thermal energy.

18. The structure in claim 15, wherein said thermally conductive material comprises a plurality of thermally conductive materials having different coefficients of thermal conductivity.

20. The structure in claim 15, wherein said thermally conductive material comprises one of a thermal grease and a phase change material.

21. The structure in claim 15, wherein said integrated circuit chips comprise at least one higher power chip and at least one lower power chip, wherein, during operation, said higher power chip generates more thermal energy than said lower power chip.

22. A cooling structure for an integrated circuit structure, said cooling structure comprising:

a chip carrier comprising multiple integrated circuit chips;

a heat dissipating structure connected to the upper sides of said integrated circuit chips through a thermally conductive material,

wherein said thermally conductive material is positioned in gaps between the upper sides of said integrated circuit chips and the bottom of said heat dissipating structure, and

wherein said heat dissipating structure is shaped such that the smallest of said gaps exists between the top of the integrated circuit chip that produces the most thermal energy, relative to the other integrated circuit chips, and the bottom of said heat dissipating structure.

23. The structure in claim 22, wherein said heat dissipating structure has a protrusion positioned adjacent said integrated circuit chip that produces the most thermal energy to allow the smallest of said gaps to exist between said top of said integrated circuit chip that produces the most thermal energy and said bottom of said heat dissipating structure.

24. The structure in claim 22, wherein said thermally conductive material comprises a thermally conductive adhesive.

25. The structure in claim 22, wherein said thermally conductive material comprises a plurality of thermally conductive materials having different coefficients of thermal conductivity.

26. The structure in claim 22, wherein said integrated circuit chips comprise at least one higher power chip and at least one lower power chip, wherein, during operation, said higher power chip generates more thermal energy than said lower power chip.