HEAT SINK INCLUDING PEDESTAL

Abstract: A heat sink (12) comprised of fins (14), a body (34) and a pedestal (36) located on a center portion of the body (34).

Description: HEAT SINK INCLUDING PEDESTAL BACKGROUND OF THE INVENTION The present invention relates to heat sinks. More particularly, the present invention relates to heat sinks which provide appropriate dissipation of heat from devices such as electrical components. Heat sinks have previously been provided to dissipate heat from electrical components. The electrical component typically has a flat top surface on which the heat sink is placed. Heat produced by the electrical component is efficiently dissipated using the heat sink since the heat sinks typically have a flat surface on the bottom extending over the entire surface of and which rests on the flat top surface of the electrical component. However, the electrical component can become excessively warped due to manufacturing process problems and/or due to thermal changes. The warping of the electrical component is typically concave on the top surface to form a dish-like surface. However, due to the excessive warping of the top surface of the electrical component, an unacceptable gap is formed between the top surface of the electrical component and the bottom surface of the heat sink, since the top surface of the electrical component is warped and the bottom surface of the heat sink is flat. Additionally, if the gap is larger than the thermal interface characteristics can support, the cooling solution fails. That is, large gaps can result between the electrical component and the heat sink due to thermal interface coverage (for example, due to grease voids) in manufacturing processes and excessive thermal interface loss. The thermal interface efficiency, such as grease, requires minimizing the thickness of the gap between the electrical component and the heat sink. SUMMARY OF THE INVENTION The present invention relates to a heat sink including a pedestal. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates a heat sink positioned to dissipate heat from an electrical device. Figure 2 illustrates a heat sink including a pedestal to dissipate heat from an electrical device according to an exemplary embodiment of the present invention. Figure 3 illustrates a bottom view of the heat sink illustrated in Figure 2 according to an exemplary embodiment of the present invention. Figure 4 illustrates values for sizes of various portions of a heat sink according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION Figure 1 illustrates an electrical component 10 and a heat sink 12 provided on electrical component 10. Electrical component 10 can be any electrical device which produces heat. In one embodiment, electrical component 10 can be a Pentium ® Pro processor made by Intel Corporation. Alternatively, electrical component 10 can be any processor made by Intel Corporation or any other processor. Heat sink 12 includes a plurality of fins 14 which are arranged to dissipate heat away from electrical component 10. A bottom edge 16 of heat sink 12 is flat so that it is arranged on a top surface 18 of electrical component 10. The top surface of component 10 is typically initially flat. However, the top surface 18 of electrical component 10 can be excessively warped due to component manufacturing processes and/or due to thermal changes. This warping causes top surface 18 to be formed in a concave dish-like surface as illustrated in Figure 1. Due to the warping of top surface 18, a gap 20 forms between top surface 18 of electrical component 10 and bottom edge 16 of heat sink 12. An example of an unacceptable gap limit may be, for example 10 mil (0.01 inches). An example of an acceptable gap limit is a range of 2-7 mil (where 2 mil is the target and 7 mil is the absolute maximum allowed). Another example of an acceptable gap limit is a range of 5-7 mil (where 5 mil is the target and 7 mil is the absolute maximum allowed). Other acceptable and unacceptable gap limit values may be used in implementing embodiments of the present invention according to particular preferences in particular embodiments or with particular electrical components. As the size of the gap 20 extends beyond the acceptable gap limit, heat conductivity from electrical component 10 to heat sink 12 is reduced. Figure 2 illustrates an electrical component 30 and a heat sink 32 provided on electrical component 30. Electrical component 30 can be any electrical device which produces heat. In one embodiment, electrical component 30 can be a Pentium ® Pro processor made by Intel Corporation. Alternatively, electrical component 30 can be any processor made by Intel Corporation or any other processor. Heat sink 32 includes a body 34 and a pedestal 36. Body 34 includes a plurality of fins 38 which are arranged to dissipate heat away from electrical component 30. According to an embodiment of the present invention, body 34 and pedestal 36 of heat sink 32 may be made of various grades of aluminum such as cast aluminum or extruded aluminum. According to embodiments of the present invention, body 34 and pedestal 36 of heat sink 32 may be made of any material, particularly materials which provide good heat dissipation. According to embodiments of the present invention, body 34 and pedestal 36 may be made of the same material or may be made of different materials. A bottom edge 40 of body 34 is arranged on top of pedestal 36. A top surface 38 of component 30 is typically initially flat. However, the top surface electrical component manufacturing process and/or due to thermal conditions. This warping causes top surface 38 to be formed in a concave dish-like surface as illustrated in Figure 2 similar to the warping of top surface 18 of electrical component 10 illustrated in Figure 1. Due to the warping of top surface 38, a gap 42 forms between top surface 38 of electrical component 10 and a bottom edge of pedestal 36. Even if the top surface 38 warps an excessive amount, the gap 42 will not represent a value greater than an acceptable gap limit. An example of an unacceptable gap limit may be, for example 10 mil (0.01 inches). An example of an acceptable gap limit is a range of 2-7 mil (where 2 mil is the target and 7 mil is the absolute maximum). Another example of an acceptable gap limit is a range of 5-7 mil (where 5 mil is the target and 7 mil is the absolute maximum). Due to the arrangement of the pedestal 36 of the heat sink 32, the gap 42 is reduced to the acceptable gap limit. Other acceptable and unacceptable gap limit values may be used in implementing embodiments of the present invention according to particular preferences in particular embodiments or with particular electrical components. Figure 3 illustrates a bottom view of the heat sink 32 illustrated in Figure 2. In the embodiment illustrated in Figure 3 pedestal 36 is arranged in a center portion of the bottom edge 40 of body 34 of heat sink 32. The pedestal 36 of heat sink 32 is illustrated as being arranged in a center portion of the bottom edge 40 of body 34. Due to its size and shape, pedestal 36 extends below surface 40 into the space between surface 40 and warped surface 38 so that the size of gap 42 does not become larger than an acceptable gap limit value. For example, the maximum value of the size of gap 42 may be 5 mil (0.005 inches) or less or may be 7 mil or less, or may be 2 mil or less. In an embodiment of the present invention as illustrated in Figure 4, a length 52 of the body 34 of the heat sink 32 is approximately in a range of 3.195 inches to 3.205 inches, or approximately 3.2 inches (or approximately 3.2 inches maximum), or approximately 2.66 inches or approximately 3 inches (or approximately 3 inches maximum), and a width 54 of the body 34 of heat sink 32 is approximately in a range of 2.5 inches to 3.0 inches, or approximately 2.46 inches, or approximately 3 inches (or approximately a maximum of 3 inches), a length 56 of the pedestal 36 is approximately 2.1 inches (or approximately 2.1 inches maximum) and a width 58 of pedestal 36 is approximately 1.3 inches (or approximately 1.3 inches maximum), a distance 60 between an edge of body 34 and an edge of pedestal 36 is approximately 0.27 inches, and a flatness (not illustrated) of pedestal 36 is approximately 1 mil per linear inch. A radius of the corners 62 of pedestal 36 is approximately 0.3 inches. An approximate depth of the pedestal 36 in an embodiment of the present invention is approximately 30 thousandths (or 0.03 inches). An approximate value of the surface area of the bottom of pedestal 36 is approximately 2.65 square inches or approximately 2.73 square inches, or approximately 2.7 square inches, or approximately in a range of 2.6 square inches to 2.8 square inches. Pedestal 36 is approximately positioned in a center of bottom edge 40 of body 34. Additionally, in an alternative embodiment of the present invention the bottom of pedestal 36 is not approximately flat but is curved or otherwise shaped in a manner to advantageously follow the warped top surface 38 of electrical component 30 to further reduce the gap between the electrical component and the pedestal of the heat sink. The approximate measurements illustrated in Figure 4 and described in connection thereto are particularly advantageous for a Pentium ® Pro processor heat sink. However, a heat sink having these approximate measurements could also be used for a heat sink used to dissipate heat from another processor or another electrical component other than a Pentium ® Pro processor according to embodiments of the present invention. The size and shape of pedestal 36 can be advantageously modified based on different particular electrical components 30 from which heat is being dissipated. In an exemplary embodiment of the present invention, the pedestal 36 is arranged in a center portion of the bottom surface 40 of the body 34 of the heat sink 32. In another embodiment of the present invention, the pedestal 36 can be formed of a plurality of legs (for example, two legs or four legs) extending from the bottom surface 40 of body 34 in a manner such that the gap between the pedestal legs and the warped top surface of the electrical component is minimized. According to other embodiments of the present invention, the pedestal 36 is formed in any shape, size or position relative to the body of the heat sink such that a gap between the heat sink and the electrical component occurring due to warping or other deformation of the surface of the electrical component can be minimized. For example, the bottom of the pedestal may be curved to ensure greater contact between the bottom edge of the pedestal and the warped surface of the electrical component. In an additional embodiment of the present invention, a fan or a plurality of fans may be provided on top of heat sink 32 to further enable heat dissipation. Although the electrical component has been described herein as being a Pentium ® Pro processor or any other processor, it is noted that the heat sink according to embodiments of the present invention may be used to dissipate heat from any electrical component or any other device from which it is desired to dissipate heat.

Claims: What Is Claimed Is: 1. A heat sink comprising: a body; and a pedestal. 2. A heat sink according to claim 1 , wherein the body includes a plurality of fins. 3. A heat sink according to claim 1 , wherein the heat sink is a processor heat sink. 4. A heat sink according to claim 3, wherein the heat sink is a Pentium ® Pro processor heat sink. 5. A heat sink according to claim 1 , wherein the pedestal extends on an edge of the body. 6. A heat sink according to claim 5, wherein the edge of the body is a bottom edge of the body. 7. A heat sink according to claim 5, wherein the pedestal extends on a center portion of the edge of the body. 8. A heat sink according to claim 1 , wherein the pedestal comprises a plurality of legs extending on an edge of the body. 9. A heat sink according to claim 1 , wherein the pedestal extends on a center portion of an edge of the body. 10. A heat sink according to claim 9, wherein a length of the pedestal is approximately in a range of 70% to 90% of a length of the body. 11. A heat sink according to claim 9, wherein a length of the pedestal is approximately 80% of a length of the body. 12. A heat sink according to claim 11 , wherein the length of the body is in a range of approximately 2.5 inches to 3.5 inches and the length of the pedestal is in a range of approximately 2.0 inches to 2.5 inches. 13. A heat sink according to claim 12, wherein the length of the body is approximately 2.66 inches and the length of the pedestal is approximately 2.1 inches. 14. A heat sink according to claim 9, wherein a surface area of a bottom of the pedestal is approximately 2.65 square inches. 15. A heat sink according to claim 14, wherein a surface area of a bottom of the body is approximately in a range of 6.0 inches to 6.5 inches. 16. A heat sink according to claim 1 , wherein the body and the pedestal of the heat sink are made of aluminum. 17. A heat sink according to claim 1 , wherein the pedestal extends to cover a maximum surface area of an electrical component. 18. A heat sink according to claim 1 , wherein the pedestal extends to cover a maximum area of a surface of an electrical component, wherein the surface of the electrical component is warped. 19. A heat sink according to claim 1 , wherein the pedestal extends to cover a maximum surface area of a non-flat surface of an electrical component, wherein the pedestal is designed in a shape to provide a maximum coverage over the non-flat surface of the electrical component. 20. An apparatus for dissipating heat from an electrical component, comprising a heat sink including a body and a pedestal. 21. An apparatus according to claim 20, further comprising a fan. 22. An apparatus according to claim 20, wherein the pedestal extends to cover a maximum surface area of the electrical component. 23. An apparatus according to claim 20, wherein the pedestal extends to cover a maximum area of a surface of the electrical component, wherein the surface of the electrical component is warped. 24. An apparatus according to claim 20, wherein the pedestal extends to cover a maximum surface area of a non-flat surface of the electrical component, wherein the pedestal is designed in a shape to provide a maximum coverage over the non-flat surface of the electrical component. 25. An apparatus according to claim 20, wherein the electrical component is a processor. 26. An apparatus according to claim 20, wherein the electrical component is a Pentium ® Pro processor. 27. An apparatus according to claim 20, wherein the pedestal extends on a center portion of an edge of the body. 28. An apparatus according to claim 20, wherein the pedestal extends over at least a portion of a surface of the electrical component. 29. An apparatus according to claim 20, wherein the pedestal extends over a center portion of a surface of the electrical component. 30. An apparatus according to claim 20, wherein the heat sink is made of aluminum.

Inventors: MCDONALD MICHAEL R, REMBOLD DALE, MCDONALD, MICHAEL, R., REMBOLD, DALE
Applicants: INTEL CORP, MCDONALD MICHAEL R, REMBOLD DALE, INTEL CORPORATION, MCDONALD, MICHAEL, R., REMBOLD, DALE
Application year: 1998
Main classification: F28F7
IPC codes: H01L23