High performance cooling device

• US 6,505,680 B1
• Filed: 07/27/2001
• Issued: 01/14/2003
• Est. Priority Date: 07/27/2001
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Hegde, Shankar
• Primary Examiner(s): Bennett, Henry
• Assistant Examiner(s): Duong, Tho V
• Application Number:
  US09/916,932
• Publication Number:
  US 20030019609A1
• Time in Patent Office: 536 Days
• Field of Search: 165/80.3, 165/121, 165/125, 165/185, 361/697, 361/709, 361/710, 257/722, 174/16.3
• US Class Current: 165/80.3
• CPC Class Codes: H01L 23/467 by flowing gases, e.g. air H01L23/473 takes precedence
• 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

A low-cost, fan assisted cooling device is disclosed. The cooling device includes a narrow bottom and broad top shape to optimize a material versus performance ratio. A plurality of vanes surround a central heat mass and an inside surface of the vanes define a chamber that surrounds the heat mass. A portion of each vane is split into a plurality of fins and both the vanes and the fins have a surface area that increase in a radially outward direction from an axis of the heat mass. The heat mass includes a boss that is surrounded by a groove. Both the boss and the grove have arcuate surface profiles. The vanes, the fins, the boss, and the groove efficiently dissipate heat when a fan or the like forces air into the chamber thereby producing air flows in three different directions. In a first direction, the air flows out of the chamber through the vanes. In a second direction, a low pressure region in the chamber induces air from outside the chamber to flow through the fins. In a third direction, the low pressure region induces an airflow over the groove and boss. Openings between the vanes are angled and offset from an orientation of the fans blades to minimize the airflow shock losses thereby reducing fan noise. The vanes and the fins can be homogeneously formed with the heat mass.

Claims

1. A cooling device for dissipating heat from a component, comprising:

a heat mass including a boss having a convex arcuate surface profile and a groove surrounding the boss and having a concave arcuate surface profile, the groove and the boss are symmetrically positioned about an axis of the heat mass;

a heat conductive base in contact with the heat mass and including a mounting surface adapted to contact the component;

a plurality of vanes in contact with the heat mass and spaced apart to define a primary slot therebetween and extending to the heat mass, the vanes have a surface area that increases in a radially outward direction from the axis,

the vanes including a top face, an aerodynamically profiled inner wall including a first portion extending from the groove and terminating at a second portion that extends to the top face, the inner walls of the vanes defining a chamber that surrounds the groove, an outer wall having a surface profile that widens from a bottom of the heat mass to the top face and includes therebetween a smooth curved portion, a draft portion, and a smooth radially outward portion, and

the vanes including at least one secondary slot extending through a portion of each vane to define a plurality of fins in each vane; and

wherein an air flow entering the chamber exits through the primary slots and a bottom portion of the secondary slots in an exhaust flow that dissipates heat from the vanes and the fins, the exhaust flow creates a low pressure region within the chamber that induces an intake flow into the chamber through the secondary slots and a top portion of the primary slots thereby dissipating heat from the fins and the vanes, and the low pressure region induces a surface flow along the first and second portions of the inner wall so that the surface flow passes over the groove and the boss to dissipate heat from the heat mass.

2. The cooling device as set forth in claim 1 wherein the heat mass, the base, and the vanes are homogeneously formed.

3. The cooling device as set forth in claim 1 wherein the mounting surface is substantially perpendicular to the axis.

4. The cooling device as set forth in claim 1 wherein the mounting surface further comprises:

a plurality of projections that extend outward of the mounting surface; and

a thermal interface material in contact with the mounting surface and positioned between the projections, and

wherein the projections are adapted to protect the thermal interface material from damage when the base is in contact with the component.

5. The cooling device as set forth in claim 1 and further comprising at least one fan positioned adjacent to the top face and positioned over the chamber so that an air flow generated by the fan produces the air flow into the chamber.

6. The cooling device as set forth in claim 5 and further comprising a mounting ring adapted to abut against the smooth radially outward portion and including a plurality of mounting fixtures adapted to receive a fastener that connects the fan with the mounting ring such that the fan is fixedly connected with the top face.

7. The cooling device as set forth in claim 6 wherein at least a portion of the top face is a substantially planar portion and the fan is seated on the substantially planar portion when the fan is connected with the top face.

8. The cooling device as set forth in claim 1 wherein the vanes are tangentially oriented to a predetermined diameter of a circle centered about the axis.

9. The cooling device as set forth in claim 8 where in the predetermined diameter is from about 3.0 millimeters to about 12.0 millimeters.

10. The cooling device as set forth in claim 1 wherein the vanes are inclined at an angle with respect to the axis.

11. The cooling device as set forth in claim 10 wherein the angle at which the vanes are inclined is from about 5.0 degrees to about 25.0 degrees.

12. The cooling device as set forth in claim 10 wherein the angle at which the vanes are inclined comprises a first angle from about 10.0 degrees to about 25.0 degrees, the first angle measured along the smooth radially outward portion, and a second angle from about 5.0 degrees to about 18.0 degrees measured along the smooth curved portion.

13. The cooling device as set forth in claim 1 wherein the arcuate surface profile of the boss is a profile selected from the group consisting of a sphere, a cone, and a frustum of a cone.

14. The cooling device as set forth in claim 1 wherein the arcuate surface profile of the groove is a semi-circular profile.

15. The cooling device as set forth in claim 1 wherein the primary slot further includes a first arcuate profile along the heat mass and the first arcuate profile is a portion of an arc having a radius from about 38.0 millimeters to about 45.0 millimeters.

16. The cooling device as set forth in claim 1 wherein the secondary slot extends to the heat mass and the secondary slot further includes a second arcuate profile along the heat mass and the second arcuate profile is a portion of an arc having a radius from about 31.0 millimeters to about 38.0 millimeters.

17. The cooling device as set forth in claim 1 wherein the first portion of the inner wall is a sloped surface and the second portion of the inner wall is a concave arcuate surface.

18. The cooling device as set forth in claim 1 wherein the base further comprises:

a cylindrical neck inset from the base and defining an attachment groove between the base and the heat mass; and

a pair of flats substantially perpendicular to the mounting surface and positioned in parallel opposition to each other.

19. The cooling device as set forth in claim 1 and further comprising:

a shroudless fan including a space frame for supporting the fan and for positioning the fan adjacent to the top face and over the chamber so that an air flow generated by the fan produces the air flow into the chamber,

the space frame including a plurality of arms that span the top face, the arms include fingers at an end thereof, and the fingers are adapted to clamp the space frame to the smooth radially outward portion of the outer wall.

20. A system for dissipating heat, comprising:

a cooling device including;

a heat mass including a boss having a convex arcuate surface profile and a groove surrounding the boss and having a concave arcuate surface profile, the groove and the boss are symmetrically positioned about an axis of the heat mass,

a heat conductive base in contact with the heat mass and including a mounting surface adapted to contact the component,

a plurality of vanes in contact with the heat mass and spaced apart to define a primary slot therebetween and extending to the heat mass, the vanes have a surface area that increases in a radially outward direction from the axis,

the vanes including a top face, an aerodynamically profiled inner wall including a first portion extending from the groove and terminating at a second portion that extends to the top face, the inner walls of the vanes defining a chamber that surrounds the groove, an outer wall having a surface profile that widens from a bottom of the heat mass to the top face and includes therebetween a smooth curved portion, a draft portion, and a smooth radially outward portion, and

the vanes including at least one secondary slot extending through a portion of each vane to define a plurality of fins in each vane, and

wherein an air flow entering the chamber exits through the primary slots in an exhaust flow that dissipates heat from the vanes and the fins, the exhaust flow creates a low pressure region within the chamber that induces an intake flow into the chamber through the secondary slots thereby dissipating heat from the fins, and the low pressure region induces a surface flow along the first and second portions of the inner wall so that the surface flow passes over the groove and the boss to dissipate heat from the heat mass;

a fan for generating the air flow into the chamber, the fan connected with the top face;

a component including a component face; and

a base mount for urging the mounting surface and the component face into contact with each other so that heat generated by the component is thermally communicated into the cooling device.

21. The system as set forth in claim 20 wherein the component is carried by a support unit selected from the group consisting of a socket, a substrate, and a PC board, and the base mount is removably connected with the support unit.

22. The system as set forth in claim 20 wherein the mounting surface further comprises:

a plurality of projections that extend outward of the mounting surface; and

a thermal interface material in contact with the mounting surface and the component face and positioned between the projections, and

wherein the projections are adapted to protect the thermal interface material from damage when the mounting surface is in contact with the component face.

23. The system as set forth in claim 20 wherein the base further comprises:

a cylindrical neck inset from the base and defining an attachment groove between the base and the heat mass; and

a pair of flats substantially perpendicular to the mounting surface and positioned in parallel opposition to each other.

24. The system as set forth in claim 23 wherein the mounting surface further comprises:

a plurality of projections that extend outward of the mounting surface; and

a thermal interface material in contact with the mounting surface and the component face and positioned between the projections, and

wherein the projections are adapted to protect the thermal interface material from damage when the mounting surface is in contact with the component face.

25. The system as set forth in claim 20 wherein the fan is a shroudless fan including a space frame for supporting the fan and for positioning the fan adjacent to the top face and over the chamber so that the air flow generated by the fan produces the air flow into the chamber,

the space frame including a plurality of arms that span the top face, the arms include fingers at an end thereof, and the fingers are adapted to clamp the space frame to the smooth radially outward portion of the outer wall.