Integrated vapor chamber heat sink and spreader and an embedded direct heat pipe attachment

• US 6,661,660 B2
• Filed: 10/04/2001
• Issued: 12/09/2003
• Est. Priority Date: 12/22/2000
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Chrysler, Gregory M., Prasher, Ravi, Frutschy, Kristopher, Sathe, Ajit V., Watwe, Abhay A., Ofman, Leo
• Primary Examiner(s): CHERVINSKY, BORIS LEO
• Application Number:
  US09/970,954
• Publication Number:
  US 20020080584A1
• Time in Patent Office: 796 Days
• Field of Search: 361/687, 361/699, 361/700, 361/710-712, 361/704, 361/705, 257/707, 257/714, 257/715, 257/718, 257/719, 257/727, 165/80.3, 165/80.4, 165/104.33, 174/15.2, 174/16.3
• US Class Current: 361/700
• CPC Class Codes: H01L 23/427 Cooling by change of state, e.g. use of heat pipes by liquefied gas H01L23/445
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

Two types of thermal management devices for efficiently dissipating heat generated by high performance electronic devices, such as microprocessors for desktop and server computers producing a power of near 200 Watts and high power electronic devices that are small and thin, such as those used in telephones, radios, laptop computers, and handheld devices. An integrated heat sink and spreader for cooling an item has a vapor chamber heat sink with a thinner first wall and a thicker second wall. The thicker second wall is engageable with the item in efficient heat transferring relationship. A plurality of heat-radiating fins are attached to the thinner first wall. An embedded direct heat pipe attachment includes a heat pipe embedded in a spreader plate that is in direct heat transferring contact with an item through a thin, uniform layer of thermal interface material.

Claims

1. An arrangement for pressing a heat-generating item against a substrate while ensuring that a compressible and easily damaged heat pipe capable of being thermally coupled to the heat-generating item is not damaged, comprising:

an essentially incompressible heat-spreading plate having a first surface engageable with the heat-generating item and a second surface opposed to the first surface;

a groove formed in the first surface of the heat-spreading plate for receiving a first end portion of the heat pipe, the groove having a depth which is substantially the same as or slightly greater than the thickness of the heat pipe, so that a force applied to the second surface of the heat-spreading plate to press the heat-generating item against the substrate has limited compressive effect on the heat pipe; and

a spring plate having a first side to receive a force and a second side, parallel to the first side, to apply the force to the second surface of the heat-spreading plate to press the heat-generating item against the substrate, the force directed substantially at the center of the heat-generating item, wherein a protrusion extends outward from the second side for applying and directing the force.

2. The arrangement as in claim 1, further comprising:

a heat sink attached to a second end portion of the heat pipe.

3. The arrangement as in claim 1, further comprising:

means for bonding the first end portion of the heat pipe into the groove so that an exposed surface of the heat pipe is substantially even with the first surface of the heat-spreading plate and capable of being thermally coupled to the heat-generating item.

4. The arrangement as in claim 3, further comprising:

thermal interface material interposeable between the exposed surface of the heat pipe and the heat-generating item, the thermal interface material being capable of thermally coupling the heat pipe to the heat-generating item.

5. The arrangement as in claim 4, wherein

said spring plate presses the thermal interface material into a layer of substantially uniform thickness.

6. An embedded direct heat pipe attachment for providing low thermal resistance for cooling a heat-generating component in a mobile electronic device, comprising:

a heat pipe having at least one exposed surface, the exposed surface being substantially flat and capable of being thermally coupled to the heat-generating component;

thermal interface material thermally coupling the heat pipe to the heat-generating component;

a spreader plate having an upper surface and a lower surface, the upper surface being substantially flat and the lower surface being substantially flat except where it defines a recess capable of receiving all but the exposed surface of the heat pipe;

bonding means between the recess and the heat pipe for bonding the heat pipe to the spreader plate so that the exposed surface is substantially level with the lower surface of the spreader plate; and

wherein the heat pipe includes a first end portion, a surface opposite the exposed surface, a first side of end portion and a second side opposite the first side, the bonding means applied to the first end portion only on the first and second sides of the first end portion.

7. The embedded direct heat pipe attachment as in claim 6, wherein

the bonding means is selected from the group consisting of solder and epoxy.

8. The embedded direct heat pipe attachment as in claim 6, wherein

the heat pipe is a remote heat exchanger which includes a second end portion opposite the first end portion, and

the embedded direct heat pipe attachment further comprises:

a heat sink thermally coupled to the second end portion.

9. An electronic assembly, comprising:

a substrate;

a die having a top and mounted on the substrate;

a heat pipe;

a spreader plate defining a recess capable of receiving the heat pipe;

a subassembly including the heat pipe bonded into the recess of the spreader plate so that the subassembly is capable of being thermally coupled directly to the die;

thermal interface material for thermally coupling the die to the subassembly so that the heat pipe is in direct thermal contact with the die; and

a plate to apply and direct a point load substantially at the center of the subassembly on a side of the spreader plate opposite to the side having the recess.

10. The electronic assembly as in claim 9, wherein

the total height of the electronic assembly is minimized.

11. The electronic assembly as in claim 9, wherein

the spreader plate spreads the pressure from the point load so that the heat pipe is not deformed and the thermal interface material is pressed into a very thin layer of substantially uniform thickness.

12. The electronic assembly as in claim 11, wherein

the subassembly is thermally coupled to the die so that about 80% of the heat from the die is conducted away from the die by the heat pipe and about 20% of the heat from the die is conducted away from the die by the spreader plate.

13. The electronic assembly as in claim 9, wherein

a thermal resistance at the point where the heat pipe and the die engage one another is less than about 0.8 degrees celsius per Watt.

14. The electronic assembly as in claim 13, wherein

a uniform power dissipation capacity is about 27 Watts, when a heat pipe to ambient thermal resistance is about 1.1 degrees celsius per Watt, a temperature at the die is about 100 degrees celsius, and an ambient temperature is about 50 degrees celsius.

15. A method of assembling an embedded direct heat pipe attachment, comprising:

bonding a heat pipe into a slot in a spreader plate to create a subassembly;

mounting a die on a substrate;

placing a thermal interface material on at least one of a top surface of the die and a bottom surface of the subassembly;

placing the bottom surface of the subassembly over the top surface of the die; and

applying a force to a top surface of the subassembly using a spring plate to press the subassembly against the die.

16. The method as in claim 15, further comprising:

machining a surface of the thermal interface material to create a flat before placing the bottom surface of the subassembly over the top surface of the die.

17. The method as in claim 15, wherein:

applying a force includes applying a point load substantially at the center of the top surface of the subassembly.