Smart bi-metallic heat spreader

• US 6,278,607 B1
• Filed: 08/06/1998
• Issued: 08/21/2001
• Est. Priority Date: 08/06/1998
• Status: Expired due to Term

• Current Assignee: Dell USA LP (Dell Technologies Inc.)
• Original Assignee: Dell USA LP (Dell Technologies Inc.)
• Inventors: Moss, David, Moore, Andrew
• Primary Examiner(s): Tolin, Gerald
• Assistant Examiner(s): CHANG, YEAN HSI
• Application Number:
  US09/129,930
• Time in Patent Office: 1,111 Days
• Field of Search: 361/687, 361/688, 361/690, 361/702-704, 361/709-711, 174/16.3, 165/80.3, 165/185
• US Class Current: 361/679.54
• CPC Class Codes: G06F 1/203 for portable computers, e.g. for laptops

Abstract

A variable area heat sink has a first heat sink area and a second heat sink area. A bridge is connected to the first heat sink area and includes a bi-metallic portion operable to connect and disconnect with the second heat sink area in response to a temperature change in the bridge which is sufficient to distort the bi-metallic portion from a first shape to a second shape. The first heat sink area may be installed in a computer chassis adjacent a first heat producing component. The second heat sink area may be installed in the chassis adjacent a second heat producing component. The combination of heat sink areas may be enlarged or reduced in size due to the coupling or uncoupling.

Claims

1. A variable are a heat sink comprising:

a first heat sink area;

a second heat sink area separated from the first heat sink area;

a third heat sink area separated from the first and second heat sink areas;

a first thermally responsive bridge thermally coupling the first heat sink area and the second heat sink area, the first bridge including a first metallic member adhered to an adjacent second metallic member, the first bridge thermally decoupling the first and second heat sink areas in response to the first, second and third heat sink areas having a combined first temperature higher than the temperature of the first heat sink area; and

a second thermally responsive bridge thermally coupling the second heat sink area and the third heat sink area, the second bridge including a first metallic member adhered to an adjacent second metallic member, the second bridge thermally decoupling the second and third heat sink areas in response to the second and third heat sink areas having a combined second temperature, greater than the first temperature.

2. The heat sink as defined in claim 1 wherein the first metallic member is adhered to the second metallic member by a shear carrier adhesive so that the first and second metallic members cannot shift laterally with respect to each other.

3. The heat sink as defined in claim 1 wherein the first metallic member is formed of aluminum and the second metallic member is formed of copper.

4. The heat sink as defined in claim 1 wherein the bridge distorts from a first shape to a second shape in response to a temperature change in the bridge.

5. A variable area heat sink comprising:

a first heat sink area;

a second heat sink area thermally coupled to the first heat sink area;

a third heat sink area thermally coupled to the second heat sink areas;

first means for thermally decoupling the first heat sink area and the second heat sink area in response to the first, second and third heat sink areas having a combined first temperature higher than the temperature of the first heat sink area, the first means including a bridge having a first metallic member adhered to an adjacent second metallic member; and

second means for thermally decoupling the second heat sink area and the third heat sink area in response to the second and third heat sink areas having a combined second temperature, greater than the first temperature, the second means including a bridge having a first metallic member adhered to an adjacent second metallic member.

6. The heat sink as defined in claim 5 wherein the first metallic member is adhered to the second metallic member by a shear carrier adhesive so that the first and second metallic members cannot shift laterally with respect to each other.

7. The heat sink as defined in claim 5 wherein the first metallic member is formed of aluminum and the second metallic member is formed of copper.

8. A computer comprising:

a chassis;

a first heat producing component mounted in the chassis adjacent a first heat sink area;

a second heat producing component mounted in the chassis adjacent a second heat sink area separated from the first heat sink area;

a third heat sink area adjacent to and separated from the first and second heat sink areas;

a first bridge operable to thermally decouple the first heat sink area and the second heat sink area in response to the first, second and third heat sink areas having a combined first temperature higher than the temperature of the first heat sink area; and

a second bridge operable to thermally decouple the second heat sink area and the third heat sink area in response to the second and third heat sink areas having a combined second temperature, greater than the first temperature.

9. The computer system as defined in claim 8 wherein the first metallic member is adhered to the second metallic member by a shear carrier adhesive so that the first and second metallic members cannot shift laterally with respect to each other.

10. The computer system as defined in claim 8 wherein the first metallic member is formed of aluminum and the second metallic member is formed of copper.

11. The computer system as defined in claim 8 wherein the bridge distorts from a first shape to a second shape in response to a temperature change in the bridge.

12. A computer system comprising:

a microprocessor;

an input coupled to provide input to the microprocessor;

a mass storage coupled to the microprocessor;

a video controller coupled to the microprocessor;

a memory coupled to provide storage to facilitate execution of computer programs by the microprocessor;

a chassis for housing the computer system;

a first heat producing component mounted in the chassis adjacent a first heat sink area;

a second heat producing component mounted in the chassis adjacent a second heat sink area separated from the first heat sink area;

a third heat sink area adjacent to and separated from the first and second heat sink areas;

a first thermally responsive bridge thermally coupling the first heat sink area and the second heat sink area, the first bridge including a first metallic member adhered to an adjacent second metallic member, the first bridge thermally decoupling the first and second heat sink areas in response to the first, second and third heat sink areas having a combined first temperature higher than the temperature of the first heat sink area; and

a second thermally responsive bridge thermally coupling the second heat sink area and the third heat sink area, the second bridge including a first metallic member adhered to an adjacent second metallic member, the second bridge thermally decoupling the second and third heat sink areas in response to the second and third heat sink areas having a combined second temperature, greater than the first temperature.

13. The computer system as defined in claim 12 wherein the first metallic member is adhered to the second metallic member by a shear carrier adhesive so that the first and second metallic members cannot shift laterally with respect to each other.

14. The computer system as defined in claim 12 wherein the first metallic member is formed of aluminum and the second metallic member is formed of copper.

15. The computer system as defined in claim 12 wherein the bridge distorts from a first shape to a second shape in response to a temperature change in the bridge.