Perforated Thermal Interface Construction

Abstract

The perforated thermal interface construct includes a thermal interface material (TIM) structure, the TIM structure including a TIM sheet including a plurality of perforations, each of the plurality of perforations including a cavity and displaced material, the displaced material from each of the plurality of perforations protruding away from the TIM sheet.

Description

[Technical field]

[0001] The technical field of the invention is data processing, and more specifically, methods and systems for perforated thermal interface construction. [Background technology]

[0002] The development of the EDVAC computer system in 1948 is often cited as the beginning of the computer age. Since that time, computer systems have evolved into extremely complex devices. Today's computers are significantly more advanced than earlier systems such as the EDVAC. A computer system typically includes a combination of hardware and software components, application programs, operating systems, processors, buses, memory, and input / output devices. As advances in semiconductor processing and computer architectures have enabled computers to become increasingly more powerful, computer software has become more advanced to take advantage of the more powerful hardware, resulting in today's computer systems being significantly more powerful than they were just a few years ago.

[0003] These advances in computer systems have created a need for more efficient thermal management within these complex systems. To obtain the best performance from certain components, particularly the central processing unit and graphics processing unit, heat must be quickly and efficiently removed from these components and nearby areas. Some of these components may have or develop irregular, non-flat surfaces, resulting in gaps between the component and the heat exchanger. Without good thermal contact between the component and the heat exchanger, heat cannot be efficiently removed from the system. Summary of the Invention

[0004] The perforated thermal interface construct may include a thermal interface material (TIM) structure, the TIM structure including a TIM sheet including a plurality of perforations, each of the plurality of perforations including a cavity and displaced material, the displaced material from each of the plurality of perforations protruding away from the TIM sheet.

[0005] Advantages provided by such embodiments for perforated thermal interface constructions include filling gaps in irregular, non-planar surfaces between heat generating components and heat exchangers or spreader plates. The perforations provide highly compressible thermal contact at lower loads between the heat generating components and the heat exchangers or spreader plates without using a different TIM across a single surface.

[0006] In an optional embodiment, the TIM structure includes additional viscous TIM disposed in at least one cavity and guided away from the TIM sheet by the displaced material, which provides the advantage that the additional TIM material fills the perforations to provide additional thermal contact.

[0007] In any embodiment, the displaced material from each of the plurality of perforations protrudes above and below the TIM sheet, which provides the advantage of increased gap-filling capability without additional TIM.

[0008] In any embodiment, the material displaced from at least one of the plurality of perforations adheres to at least two sides of the cavity, which provides the advantage of creating greater thermal contact without an additional TIM.

[0009] In any embodiment, the plurality of perforations includes cavities of at least two different sizes, which provides the advantage of tailoring the perforations to the requirements of the gap to be filled by creating a perforation size appropriate to the size of the gap even within the same TIM sheet.

[0010] In any embodiment, at least one portion of the TIM sheet has no perforations, which provides the advantage of using a single TIM sheet where only a portion of the distance between the heat generating component and the heat exchanger or spreader plate requires only the width of the non-perforated TIM sheet, while still using the same TIM sheet for thermal contact in gaps between the same elements.

[0011] The perforated thermal interface construction may include a system that includes a heat-generating electronic component including a non-planar surface; a heat exchanger located along the non-planar surface on the electronic component, where a gap exists between the heat exchanger and the electronic component, the gap being a portion of the non-planar surface of the electronic component that is a greater distance away from the heat exchanger than at least one other portion of the non-planar surface of the electronic component; and a thermal interface material (TIM) sheet disposed between the electronic component and the heat exchanger, the TIM sheet including a plurality of perforations positioned in the gap between the heat exchanger and the electronic component, each of the plurality of perforations including a cavity and displaced material protruding away from the TIM sheet.

[0012] Advantages provided by such embodiments for perforated thermal interface constructs include filling gaps in irregular, non-flat surfaces between the heat generating component and the heat exchanger. The perforations provide a highly compressible thermal contact between the heat generating component and the heat exchanger at lower loads without using a different TIM across a single surface.

[0013] The perforated thermal interface construction may include a method that includes placing a thermal interface material (TIM) sheet between an upper forming plate and a lower forming plate, where the upper forming plate includes a plurality of forming plate cavities and the lower forming plate includes a plurality of forming plate perforation nails; and pressing the upper forming plate against the lower forming plate to create a plurality of perforations in the TIM sheet, where each of the plurality of perforations includes a cavity and displaced material, and where the displaced material from each of the plurality of perforations protrudes away from the TIM sheet.

[0014] Advantages provided by such embodiments for perforated thermal interface constructs include an efficient method for creating TIM sheets to fill gaps in irregular, non-flat surfaces between heat generating components and heat exchangers.

[0015] The foregoing and other objects, features, and advantages of the present invention will become apparent from the following more particular description of illustrative embodiments of the invention, as illustrated in the accompanying drawings, in which like reference numerals generally represent like parts of the illustrative embodiments of the invention. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 illustrates an example of a thermal interface material (TIM) sheet as a perforated thermal interface construct according to an embodiment of the present invention. [Diagram 2] 13A-13C are additional diagrams illustrating portions of an example TIM sheet as a perforated thermal interface construct according to an embodiment of the present invention. [Diagram 3] 1A-1C illustrate examples of systems having perforated thermal interface constructs in accordance with embodiments of the present invention. [Figure 4] FIG. 13 illustrates an example of a TIM sheet pattern as a perforated thermal interface construct according to an embodiment of the present invention. [Diagram 5] 13A-13C show additional examples of TIM sheet patterns as perforated thermal interface constructs in accordance with embodiments of the present invention. [Figure 6] FIG. 1 illustrates an example of a system for creating a TIM sheet as a perforated thermal interface construct according to an embodiment of the present invention. [Figure 7] 1 is a flow diagram illustrating an exemplary method for making a perforated thermal interface construct in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Exemplary methods, apparatus, and products for perforated thermal interface constructions according to the present invention are described with reference to the accompanying drawings, beginning with Figure 1. Figure 1 shows a diagram illustrating an example of a thermal interface material (TIM) sheet as a perforated thermal interface construction according to an embodiment of the present invention. As shown in Figure 1, the TIM sheet (100) includes a plurality of perforations. Each perforation includes a perforation cavity (102) and displaced material (104).

[0018] The TIM sheet (100) is a single continuous sheet or pad of thermally conductive material. The TIM sheet may be a single material type, such as, for example, a graphite TIM sheet. Alternatively, the TIM sheet may be a composite material, such as, for example, a silicone and acrylate matrix TIM sheet. The TIM sheet (100) may include carbon particles, platelet fibers, nanotubes, metal particles, or ceramic metal oxide particles, including, but not limited to, thermally conductive ceramic particles, such as, for example, aluminum nitride, boron nitride, zinc oxide, and aluminum oxide. Additionally, the TIM sheet may be compressible in that the thickness of the TIM sheet may decrease when pressure is applied to the TIM sheet.

[0019] The displaced material (104) is the TIM sheet material that is displaced (i.e., moved) during the creation of the perforations and perforation cavities (102). The displaced material (104) is moved away from the TIM sheet (100). In the example of Figure 1, the displaced material (104) is moved in a direction substantially perpendicular to the plane created by the TIM sheet. Additionally, as shown in this example, the displaced material of each perforation is moved in the same direction (e.g., above the TIM sheet).

[0020] The perforated TIM sheet (100) shown in Figure 1 has the advantage of filling the gaps of irregular, non-flat surfaces between a heat generating component and a heat exchanger or spreader plate. The perforations provide a highly compressible thermal contact at lower loads between the heat generating component and the heat exchanger or spreader plate without using a different TIM across a single surface.

[0021] Perforating the TIM sheet (100) in different ways may result in different physical relationships between the cavity (102) and the transferred material (104). The transferred material (104) may be attached to a single side of the cavity (102) and resemble a rectangular, triangular, or circular door with a single hinge attaching the door to the cavity (102). Similarly, the transferred material (104) may be attached to two sides of the cavity (102) and resemble a rectangular, triangular, or circular double door with hinges on both sides of the cavity (102). As another example, the transferred material (104) may be a group of triangles, each of which may be attached to a portion of the cavity (102). In a perforated TIM sheet (100), the material migrated from at least one of the multiple perforations adheres to at least two sides of the cavity, which has the advantage of creating greater thermal contact with elements above and below the perforated TIM sheet (compared to a non-perforated TIM) without the need for additional TIM.

[0022] 1 shows only a single sized cavity (102), other embodiments may include two or more different sized cavities (102). Groups of cavities (102) may be of different sizes with different shapes of displaced material (104). Different sized cavities (102) provide the advantage of tailoring the perforations to the requirements of the gap to be filled by creating a perforation size appropriate to the size of the gap even within the same TIM sheet.

[0023] 1 shows the displaced material (104) from each perforation protruding above the TIM sheet (100), other embodiments may include displaced material (104) protruding above and below the TIM sheet (100). Creating perforations with displaced material (104) protruding above and below the TIM sheet (100) has the advantage of increasing the gap-filling capability of the TIM sheet (100) by having twice the height of the displaced material (104) to make thermal contact with electronic components and heat exchangers.

[0024] The perforations in the TIM sheet (100) may be made in a wide variety of patterns. Additionally, at least one portion of the TIM sheet (100) may not include perforations. Such a portion of the TIM sheet (100) may be used between elements that are in direct thermal contact or have a minimum gap size. The advantage of including a portion of the TIM sheet (100) that does not have perforations is that the functionality of a single TIM sheet (100) is increased, since the same TIM sheet (100) may be used for narrow and wider gaps.

[0025] Figure 2 shows an additional view of a portion of an example TIM sheet as a perforated thermal interface construct according to an embodiment of the present invention. Specifically, Figure 2 shows a close-up of a single perforation on the TIM sheet (100). As shown in Figure 2, the TIM sheet (100) includes a perforated cavity (102) with migrated material (104) on two sides of the cavity (102).

[0026] 2 also illustrates that the fibers, particles, or tubes may be oriented substantially parallel to the plane of the TIM sheet (100). This orientation causes the thermal conductivity along the TIM sheet (100) (i.e., in the direction of the fibers) to be different than the thermal conductivity perpendicular to the TIM sheet (100) (i.e., perpendicular to the direction of the fibers). For example, the thermal conductivity in the xy direction may be 1900 Watts per meter Kelvin (W / mK), while the thermal conductivity in the z direction may be 20 W / mK.

[0027] Creating perforations in the TIM sheet (100) changes the direction of thermal conductivity of the TIM sheet (100). Specifically, elements in thermal contact with the transferred material (104) will conduct heat towards the TIM sheet (100) more efficiently than elements in thermal contact with non-perforated portions of the TIM sheet because the direction of higher thermal conductivity has been changed by the perforations and transferred material (104).

[0028] Figure 3 shows a diagram illustrating an example of a system having a perforated thermal interface construct according to an embodiment of the present invention. As shown in Figure 3, the system includes a TIM sheet (100) between a heat exchanger (202) and an electronic component (204). The electronic component (204) is bent so that the edges of the electronic component (204) are lower than the center, creating gaps (206) on both sides. Within the gaps (206) are TIM perforations (208).

[0029] The electronic component (204) is an element that generates heat through its operation. The electronic component (204) may be a central processing unit or a graphics processing unit. The heat exchanger (202) is a mechanism, such as a cold plate, that transfers heat from the electronic component (204) to a fluid medium for dissipation. The heat exchanger (200) may be liquid-cooled or air-cooled.

[0030] As shown in Figure 3, TIM perforations (208) are created in the TIM sheet (100) at locations that correspond to the gaps (206) between the heat exchanger (202) and the electronic component (204). The migrated material in the perforations (208) is in thermal contact with the electronic component (204). Without the perforations (208), there would be no thermal contact between the electronic component (204) and the TIM sheet (100).

[0031] The portion of the TIM sheet (100) that does not have perforations is positioned at the portion of the electronic component (204) that is spaced from the heat exchanger (202) by a distance less than the gap (206). This provides the advantage of using a single TIM sheet where only a portion of the distance between the heat generating component and the heat exchanger or spreader plate requires the width of the non-perforated TIM sheet, while still using the same TIM sheet (100) for thermal contact in the gap (206) between the same elements.

[0032] The TIM sheet (100) may be accompanied by an additional viscous TIM (e.g., a thermal grease or paste containing a phase change material with conductive filler particle loading) disposed adjacent to the TIM sheet (100). When the viscous TIM and the TIM sheet (100) are compressed together, the perforations (208) guide the viscous TIM through the cavities and away from the TIM sheet (100) along with the displaced material. This provides the advantage that the additional TIM material fills the perforations to create additional thermal contact.

[0033] As the electronic component (204) flexes further over time, the perforated TIM sheet (100) may be replaced with a different TIM sheet containing a different pattern and / or configuration of perforations.

[0034] Figures 4 and 5 show examples of TIM sheet patterns as perforated thermal interface constructs according to embodiments of the present invention. Figure 4 shows a TIM sheet (100) in which a pattern of perforations is created at the corners of the TIM sheet (100). Figure 5 shows a TIM sheet (100) with an additional array of perforations in the center of the TIM sheet (100).

[0035] FIG. 6 illustrates an example of a system for creating a TIM sheet as a perforated thermal interface construct according to an embodiment of the present invention. Specifically, FIG. 6 illustrates a forming tool including an upper forming plate (602) and a lower forming plate (604). The upper forming plate (602) includes a group of forming plate cavities (606) that correspond to a group of forming plate perforation nails (608) in the lower forming plate (604). Although FIG. 6 illustrates the forming plate perforation nails (608) as being uniformly cylindrical, the forming plate perforation nails (608) may be of various shapes and sizes. Such variations may be used to create different types of transferred materials, such as those discussed above.

[0036] The TIM sheet (600) is positioned between an upper forming plate (602) and a lower forming plate (604). The upper forming plate (602) and the lower forming plate (604) are pressed together to drive the forming plate perforation nails (608) through the TIM sheet (600) and through corresponding forming plate cavities (606). The forming plate cavities (606) may shape displaced material of the cavities as the forming plate perforation nails (608) pass through. The system may optionally include forming plate perforation nails attached to the upper forming plate (602) toward the lower forming plate (604) with corresponding forming plate cavities in the lower forming plate (604). Such a system may be used to create perforations with displaced material protruding above and below the TIM sheet (600).

[0037] 7 shows a flow diagram illustrating an exemplary method for creating a perforated thermal interface construct according to an embodiment of the invention. The method of FIG. 7 includes disposing a thermal interface material (TIM) sheet between an upper forming plate and a lower forming plate (702), where the upper forming plate includes a plurality of forming plate cavities and the lower forming plate includes a plurality of forming plate perforation nails; and pressing the upper forming plate against the lower forming plate to create a plurality of perforations in the TIM sheet (704), where each of the plurality of perforations includes a cavity and displaced material, and where the displaced material from each of the plurality of perforations protrudes away from the TIM sheet.

[0038] It will be understood from the foregoing description that modifications and changes may be made to the various embodiments of the present invention without departing from the true spirit of the invention. The descriptions in this specification are for illustrative purposes only and should not be construed in a limiting sense. The scope of the present invention is limited only by the language of the following claims.

Claims

1. a heat-generating electronic component including a non-flat surface; a heat exchanger located along the non-planar surface on the heat-generating electronic component, wherein a gap exists between the heat exchanger and the heat-generating electronic component, the gap being a portion of the non-planar surface that is separated from the heat exchanger by a greater distance than at least one other portion of the non-planar surface of the heat-generating electronic component; a thermal interface material (TIM) sheet disposed between the heat-generating electronic component and the heat exchanger, the TIM sheet including a plurality of perforations located in the gap between the heat exchanger and the heat-generating electronic component, each of the plurality of perforations including a cavity and displaced material protruding away from the TIM sheet; Including, the system.

2. The system of claim 1 , further comprising a viscous TIM disposed in at least one cavity and guided away from the TIM sheet by the displaced material.

3. The system of claim 1 , wherein the TIM sheet has no perforations on portions of the non-planar surface of the heat-generating electronic component that are spaced from the heat exchanger by a distance less than the gap.

4. The system of claim 1 , wherein the plurality of perforations change a thermal conductivity direction of the TIM sheet.

5. The system of claim 1 , wherein the displaced material from each of the plurality of perforations protrudes above and below the TIM sheet.

6. The system of claim 1 , wherein the dislodged material from at least one of the plurality of perforations adheres to at least two sides of the cavity.

7. The system of claim 1 , wherein the plurality of perforations includes cavities of at least two different sizes.

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