Tubular heat sink for memory module and memory module incorporating the same

Abstract

The present application relates to a tubular heat sink for a memory module and a memory module incorporating the tubular heat sink. For example, a memory module may have: a printed circuit board PCB having an edge connector; a plurality of memory devices disposed on a surface of the PCB; and a tubular heat sink disposed along an edge of the PCB opposite the edge connector. The tubular heat sink may include a tubular portion open at both ends thereof to allow a cooling gas to flow therethrough; and two planar elements extending in parallel away from the tubular portion and configured to provide a friction fit with the memory module. Each of the planar elements may be configured to transfer thermal energy from the memory module to the tubular portion.

Description

Technical Field

[0001] The present disclosure relates generally to semiconductor memory modules, and more particularly, to tubular heat sinks for memory modules and memory modules incorporating tubular heat sinks. Background Art

[0002] Semiconductor memory is often provided in memory modules such as dual in-line memory modules for use in system applications. According to industry standards, these modules share a common physical form factor (e.g., size, pins, connector shape). As memory devices have larger capacity and faster performance, the heat generated poses a challenge to memory module design. It is necessary to transfer heat from the memory device (and other heat generating components, such as registered clock drivers (RCDs), other semiconductor devices, integrated circuit components, etc.) to a heat dissipation structure that can be cooled by, for example, forced air cooling. Since the size of the memory module is limited by industry standard specifications such as the JEDEC specifications for dual in-line memory modules (DIMMs, such as DDR4 and DDR5 RDIMMs and LRDIMMs), the available space for this thermal structure is limited and the implementation of thermal management solutions is often unsatisfactory. Summary of the invention

[0003] In one aspect, the present application provides an apparatus comprising: a printed circuit board (PCB) having an edge connector; a plurality of memory devices disposed on a surface of the PCB; and a tubular heat sink disposed along an edge of the PCB opposite the edge connector.

[0004] In another aspect, the present application provides a dual in-line memory module (DIMM) comprising: a printed circuit board (PCB) having an edge connector; a first plurality of DRAM devices disposed on a first surface of the PCB; a second plurality of DRAM devices disposed on a second surface of the PCB; and a tubular heat sink disposed along an edge of the PCB opposite to the edge connector, the tubular heat sink having thermal connections to the first and second plurality of DRAM devices.

[0005] In another aspect, the present application provides a tubular heat sink comprising: a tubular portion open at both ends thereof to allow cooling gas to flow therethrough; and two planar elements extending in parallel away from the tubular portion and configured to provide a friction fit with the memory module, wherein each of the planar elements is configured to transfer heat energy from the memory module to the tubular portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1is a simplified side view of a memory module including a tubular heat sink in accordance with an embodiment of the present technology.

[0007] Figures 2A-2C is an end view of a memory module including a tubular heat sink according to various embodiments of the present technology.

[0008] Figure 3 is an end view of a memory module including a tubular heat sink according to another embodiment of the present technology.

[0009] Figure 4 is an end view of a memory module including a tubular heat sink in accordance with an embodiment of the present technology. DETAILED DESCRIPTION

[0010] As discussed above, thermal management of memory modules presents challenges, particularly in light of the space constraints of industry standard module sizes and the high heat generated by higher capacity and higher bandwidth memory devices. For example, a memory module may include a printed circuit board (PCB) with an edge connector, a plurality of memory devices (e.g., DRAM devices), and a registered clock driver (RCD). In order to transfer thermal energy from the memory devices and the RCD during operation, various thermally conductive structures may be provided. For example, a heat sink may be disposed on the memory module. The heat sink may include a metal or other thermally conductive structure configured to increase the surface area available for heat dissipation / allowing heat exchange with a cooling gas (e.g., on a surface area that is larger than the surface area of ​​the outer surface of the memory device and other heat generating components). The heat sink may include a planar element that interfaces (e.g., makes thermal contact) with the outer surface of the memory device to transfer heat from the memory device to the heat sink, and an upper portion of the planar element that engages. The heat sink may be held on the memory module by a friction fit, a thermal adhesive, or by other methods known to those skilled in the art.

[0011] In many systems where space is at a premium (e.g., server racks), the clearance above the top of the memory module may be very small, leaving little room for heat exchange structures exposed to the flow of cooling gas. As a result, the performance of conventional heat sinks may be limited. Several embodiments of the present technology can provide improved thermal management of memory modules by providing a reduced height printed circuit board (PCB) for the memory module and a tubular heat sink opposite the edge connector of the module without exceeding the module height restrictions imposed by industry standards. For example, some embodiments of the present technology are directed to a memory module, which includes a PCB with an edge connector; a plurality of memory devices disposed on a surface of the PCB; and a tubular heat sink disposed along an edge of the PCB opposite the edge connector. Other embodiments of the present technology are directed to a tubular heat sink for a memory module, which includes a tubular portion, the tubular portion being open at both ends thereof to allow cooling gas to flow therethrough; and two planar elements extending parallel away from the tubular portion and configured to provide a friction fit with the memory module, wherein each of the planar elements is configured to transfer thermal energy from the memory module to the tubular portion.

[0012] Figure 1 1 is a simplified side view of a memory module including a tubular heat sink according to an embodiment of the present technology. The memory module 100 includes a PCB 101 with an edge connector 102, a plurality of memory devices 103 (e.g., DRAM devices), and an RCD 104. In order to provide more space for the tubular heat sink 110, the PCB 101 may have a reduced height when compared to conventional memory modules. For example, in an embodiment where the memory module 100 is a DDR4 RDIMM instead of a 31 mm high conventional PCB, the PCB 101 may have a height of less than 27 mm to leave room for the 4 mm high tubular heat sink 110. In other embodiments, tubular heat sinks and memory modules with different sizes may also be used (e.g., the height of the heat sink is greater or less than 4 mm, and / or the memory module meets other industry standard specifications). The tubular heat sink 110 is disposed along the upper edge of the PCB 101 (e.g., opposite the edge connector 102) and is configured to provide efficient heat exchange with cooling gas directed along the long axis of the memory module 100. Figure 2A An end view of the memory module 100 is illustrated, wherein it can be seen that the end 111 of the tubular heat sink 110 is open so that cooling gas can pass through the interior portion of the tubular heat sink 110 .

[0013] According to one embodiment of the present technology, the tubular heat sink 110 may have a constant cross-section (eg, Figure 2AThe tubular heat sink 110 may be formed in other ways known to those skilled in the art (e.g., folded planar metal structures, etc.). Suitable metals for extruded thermally conductive heat sinks may include copper, aluminum, silver, gold, alloys thereof, etc. In other embodiments of the present technology, the tubular heat sink 110 may be formed in other ways known to those skilled in the art (e.g., folded planar metal structures, etc.).

[0014] Although for the convenience of Figure 1 and 2A , a tubular heat sink 110 is shown without a visible thermal connection to the memory device 103 or the RCD 104, but various methods of providing a thermal connection between the tubular heat sink 110 and the heat generating components of the memory module may be employed in accordance with aspects of the present technology. For example, Figure 2B A memory module in an embodiment of the present technology is described, wherein a shield 112 is disposed around the tubular portion 110 of the tubular heat sink 110 and extends to the memory devices on either side of the memory module. The shield may include a metal or other thermally conductive material that provides thermal connection to both the tubular heat sink 110 (e.g., its tubular portion) and the heat generating components of the memory module (e.g., the memory device 103, the RCD 104, etc.). For example, the shield may include a generally planar structure bent into a "U" shaped cross-section, thereby providing extensive thermal contact between the outer surface of the tubular portion of the tubular heat sink 110 and the outermost planar surface of the heat generating components. Alternatively, the cross-sectional shape of the shield 112 may be provided by metal extrusion, or other metal manufacturing and forming techniques known to those skilled in the art. The shield 112 may be attached to the memory module via a friction fit (e.g., having spring tension in its upper portion, thereby providing friction between the planar element of the shield 112 and the memory device 103).

[0015] In alternative embodiments, the tubular heat sink may be provided with an integrated planar element for providing thermal connection to a heat generating device on the memory module. Figure 2C 1 is an end view of a memory module 100 including a tubular heat sink according to an embodiment of the present technology. The tubular heat sink includes a tubular portion 113a (e.g., having a substantially straight cross-section and an open end) and an integrated planar element, such as a planar element 113b, which is configured to provide a thermal path between the heat generating element of the memory module and the tubular portion 113a. According to one aspect of the present technology, the cross-sectional shape of the tubular portion 113a and the integrated planar element 113b can be provided by metal extrusion or other metal manufacturing and forming techniques known to those skilled in the art. According to one aspect of the present technology, the integrated planar element 113b can allow the tubular heat sink to be attached to the memory module via a friction fit. In other embodiments, the tubular heat sink can be attached to the memory module by other methods (e.g., thermal adhesive, solder connection, etc. between the planar element 113b and the heat generating component).

[0016] Although in the foregoing example embodiments, tubular heat sinks have been illustrated and described with reference to straight cross-section tubular portions, in other embodiments of the present technology, other tubular cross-sectional profiles may be used. For example, Figure 3 A memory module 300 including a tubular heat sink according to another embodiment of the present technology is illustrated, wherein the tubular heat sink has a tubular portion 313a with an elliptical cross-section. The tubular heat sink may further include an integrated planar element, such as planar element 313b, for providing a thermal path between the heat generating element of the memory module and the tubular portion 313a of the heat sink.

[0017] Although in the foregoing example embodiments, the tubular heat sink has been illustrated and described by a planar element for contacting the heat generating device of the memory module, in other embodiments of the present technology, other methods may be used to provide a thermal path between the heat generating device on the memory module and the tubular heat sink at its upper edge. For example, Figure 4 is an end view of a memory module including a tubular heat sink according to an embodiment of the present technology, wherein the memory module includes an integrated heat distribution layer 406 between a substrate 401 of the module and a heat generating component (e.g., a memory device 403). The heat distribution layer 406 may include a thermally conductive material (e.g., graphene, metal, etc.) in contact with the memory device 403 and configured to transfer thermal energy from the memory device to the tubular heat sink. The tubular heat sink includes a tubular portion 413a (e.g., having a straight cross-sectional shape and an open end to allow a cooling gas to flow therethrough) and a planar element 413b for providing a thermal connection between the heat distribution layer 406 and the tubular portion 413a. The planar element 413b may be an integrated planar element (e.g., such as Figure 4 ), or alternatively may be provided by a shield surrounding the tubular portion 413a and extending to the heat distribution layer 406 (eg, as described in more detail above).

[0018] Although in the foregoing example embodiments, memory modules have been described and illustrated with respect to DIMMs, in other embodiments of the present technology, other memory module formats may also employ tubular heat sinks as described in more detail above. Furthermore, although DIMMs have been described and illustrated with a particular number of memory devices and dedicated RCD dies, in other embodiments, other numbers of memory dies may be included, and RCD dies (and / or other integrated circuit dies, such as memory controllers, processors, etc.) may or may not be included in the memory module.

[0019] Although in the foregoing example embodiments, memory modules having memory dies disposed on both sides of the memory module have been described and illustrated, in other embodiments, a tubular heat sink may be provided on a memory module having an integrated circuit die on only one side. In such an embodiment, the tubular heat sink may be thermally connected to the integrated circuit die through a single planar element or via a thermally conductive layer or the like inside the module.

[0020] It should be noted that the methods described above describe possible implementations, and that the operations and steps may be rearranged or otherwise modified, and other implementations are possible. Furthermore, embodiments from two or more of the methods described may be combined.

[0021] Specific details of several embodiments of semiconductor devices are described below. The term "semiconductor device" generally refers to a solid-state device that includes semiconductor material. A semiconductor device may include, for example, a semiconductor substrate, a wafer, or a die singulated from a wafer or substrate. Throughout this disclosure, semiconductor devices are generally described in the context of semiconductor dies; however, semiconductor devices are not limited to semiconductor dies.

[0022] The term "semiconductor device package" may refer to an arrangement in which one or more semiconductor devices are incorporated into a common package. A semiconductor package may include a housing or shell that partially or completely encapsulates at least one semiconductor device. A semiconductor device package may also include an interposer substrate that carries one or more semiconductor devices and is attached to or otherwise incorporated into the shell. The term "semiconductor device assembly" may refer to an assembly of one or more semiconductor devices, semiconductor device packages, and / or substrates (e.g., interposer, support, or other suitable substrates). A semiconductor device assembly may be manufactured, for example, in discrete package form, strip or matrix form, and / or wafer panel form. As used herein, the terms "vertical", "lateral", "upper", and "lower" may refer to the relative direction or position of features in a semiconductor device or device assembly in view of the orientation shown in the figure. For example, "upper" or "uppermost" may refer to a feature that is positioned closer to or closest to the top of the page than another feature or a portion of the same feature, respectively. However, these terms should be broadly construed to include semiconductor devices having other orientations, such as inverted or tilted orientations, where top / bottom, above / below, over / below, up / down, and left / right may be interchanged depending on the orientation.

[0023] The devices including memory devices discussed herein may be formed on a semiconductor substrate or die, such as silicon, germanium, silicon-germanium alloys, gallium arsenide, gallium nitride, etc. In some cases, the substrate is a semiconductor wafer. In other cases, the substrate may be a silicon-on-insulator (SOI) substrate, such as silicon-on-glass (SOG) or silicon-on-sapphire (SOP), or an epitaxial layer of semiconductor material on another substrate. The conductivity of the substrate or a sub-region of the substrate may be controlled by doping using various chemical species including, but not limited to, phosphorus, boron, or arsenic. Doping may be performed during the initial formation or growth of the substrate, by ion implantation, or by any other doping means.

[0024] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. Other examples and implementations are within the scope of the present disclosure and the appended claims. Features implementing the functions may also be physically located at various locations, including being distributed so that parts of the functions are implemented at different physical locations.

[0025] As used herein, including in the claims, "or" used in a list of items (e.g., a list of items beginning with a phrase such as "at least one of" or "one or more of") indicates an inclusive list, such that a list of at least one of, for example, A, B, or C means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). In addition, as used herein, the phrase "based on" should not be construed as referring to a closed set of conditions. For example, an exemplary step described as "based on condition A" may be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted similarly to the phrase "based at least in part on."

[0026] It will be appreciated from the foregoing that specific embodiments of the present invention have been described herein for illustrative purposes, but various modifications may be made without departing from the scope of the present invention. On the contrary, in the above description, numerous specific details are discussed to provide a thorough and illustrative description of embodiments of the present invention. However, those skilled in the relevant art will recognize that the present disclosure may be practiced without one or more of the specific details. In other cases, well-known structures or operations typically associated with memory systems and devices are not shown or described in detail to avoid confusing other aspects of the technology. In general, it should be understood that various other devices, systems, and methods other than those specific embodiments disclosed herein may be within the scope of the present invention.

Claims

1. A device comprising: A printed circuit board PCB having an edge connector; a plurality of memory devices disposed on a surface of the PCB; and a tubular heat sink disposed along an edge of the PCB opposite the edge connector, wherein the tubular radiator is open at both ends to allow forced air flow through the tubular radiator, wherein the tubular heat sink has a surface area greater than the combined surface area of ​​the plurality of memory devices, wherein the tubular heat sink is attached to at least one edge of the PCB thermally coupled to the plurality of memory devices by a solder connection, and The attached combination of the tubular heat sink and the PCB has a height that is less than the mounting height within the server rack, and the clearance distance thereof represents a limited space that exposes the heat exchange structure to the forced air flow.

2. The apparatus of claim 1, wherein the tubular heat sink comprises a metallic material.

3. The apparatus of claim 1, wherein the tubular heat sink has a straight tubular cross-section.

4. The apparatus of claim 1, wherein the tubular heat sink has an elliptical tubular cross-section.

5. The apparatus of claim 1, wherein a total height of the PCB and the tubular heat sink is less than or equal to 31 mm.

6. The apparatus of claim 1, further comprising a shroud surrounding the tubular heat sink and contacting the plurality of memory devices, the shroud configured to transfer thermal energy away from the memory devices.

7. The apparatus of claim 1, wherein the apparatus comprises a thermally conductive layer between the plurality of memory devices and the PCB, and wherein the tubular heat sink comprises at least one planar element contacting the thermally conductive layer and configured to transfer thermal energy away from the memory devices.

8. The apparatus of claim 1, wherein the tubular heat sink comprises at least one planar element contacting the plurality of memory devices and configured to transfer thermal energy away from the memory devices.

9. The apparatus of claim 1, wherein the apparatus is a dual in-line memory module (DIMM), and wherein the plurality of memory devices comprises a plurality of DRAM devices.

10. The apparatus of claim 1, wherein the solder connections provide the only thermal coupling connections between the plurality of memory devices and the tubular heat sink.

11. The apparatus of claim 1 , wherein the solder connection directly attaches the tubular heat sink to the PCB.

12. The apparatus of claim 1, wherein peripheral surfaces of the tubular heat sink and the plurality of memory devices are exposed to the forced air flow.

13. A dual in-line memory module DIMM, comprising: A printed circuit board PCB having an edge connector; a first plurality of DRAM devices disposed on a first surface of the PCB; a second plurality of DRAM devices disposed on a second surface of the PCB; and a tubular heat sink disposed along an edge of the PCB opposite the edge connector, the tubular heat sink having thermal connections to the first plurality of DRAM devices and the second plurality of DRAM devices, wherein the tubular radiator is open at both ends to allow forced air flow through the tubular radiator, wherein the tubular heat sink has a surface area greater than a combined surface area of ​​the first plurality of DRAM devices and the second plurality of DRAM devices, wherein the tubular heat sink is attached to at least one edge of the PCB thermally coupling the first plurality of DRAM devices and the second plurality of DRAM devices by a solder connection, and The attached combination of the tubular heat sink and the PCB has a height that is less than the mounting height within the server rack, and the clearance distance thereof represents a limited space that exposes the heat exchange structure to the forced air flow.

14. The DIMM of claim 13, wherein the thermal connection comprises a shroud surrounding the tubular heat sink and contacting the first and second pluralities of DRAM devices.

15. The DIMM of claim 13, wherein the thermal connection comprises first and second integrated planar elements, each extending from a tubular portion of the tubular heat sink to a corresponding one of the first and second pluralities of DRAM devices.

16. A tubular radiator, comprising: a tubular portion open at both ends thereof to allow forced air flow through the tubular radiator; and two planar elements extending in parallel away from the tubular portion and configured to provide a friction fit with the memory module, wherein each of the planar elements is configured to transfer thermal energy from the memory module to the tubular portion, wherein the tubular heat sink has a surface area greater than a surface area of ​​the memory module, wherein the tubular heat sink is attached to at least one edge of the memory module thermally coupled to the PCB by a solder connection, and The attached combination of the tubular heat sink and the PCB has a height that is less than the mounting height within the server rack, and the clearance distance thereof represents a limited space that exposes the heat exchange structure to the forced air flow.

17. The tubular heat sink of claim 16, further comprising a shroud surrounding the tubular portion and including the two planar elements.

18. The tubular heat sink of claim 16, wherein the two planar elements are integrally formed with the tubular portion via metal extrusion.

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