1. Field of Invention
Aspects of the invention relate to a heat sink assembly, e.g., for holding parts together used in transferring heat from an electronic component heat source, such as an integrated circuit or other electronic component, to a heat sink.
2. Related Art
Heat sink assemblies are widely used to dissipate or otherwise transfer heat from an electronic component, such as an integrated circuit, computer processor, printed circuit board, or other electronic component. Proper cooling of electronic components, particularly computer-related components, can be important for a variety of well-known reasons, such as preventing damage to components due to overheating, maintaining suitably high processing speed or other circuit component operation, and so on. U.S. Patent Application Publications 2010/0200206 and 2010/0018670 describe various embodiments of heat sink assemblies used to cool electronic components.
In some aspects of the invention, a first retaining device used to hold a heat sink (such as a finned metal block) and heat source (such as a computer processor) together may include a frame that defines an opening to receive at least a portion of the heat sink and/or the heat source. The frame may be arranged to be fully assembled with the heat sink and a retainer element (which is arranged to bias the heat sink into contact with the heat source), and be capable of engagement with the heat source in the fully assembled condition. Moreover, after the full assembly is engaged with the heat source, the frame may allow for partial disassembly, if needed. For example, the frame may remain engaged with the heat source while the heat sink is removed and exchanged for another heat sink, or a thermal coupling is verified, if desired. In some embodiments, the heat sink may be larger than the frame in at least one dimension, but not interfere with engagement of the fully assembled heat sink, frame and retainer element arrangement with the heat source. These features may provide significant advantages, such as allowing a manufacturer the ability to fully assemble a heat sink, frame and retainer element ready for engagement with a heat source, and then engage the completed assembly with the heat source. This can help reduce the likelihood that improper components are assembled together. After engagement with the heat source, if there is some need to verify the engagement, check a solder connection at the heat source, change the heat sink, etc., this can be easily done, since the frame may remain engaged with the heat source while the retainer element is removed and the heat sink disengaged from the heat source and removed from the frame as needed.
In one aspect of the invention, a heat sink assembly includes a heat sink having a base with a contact plate. The heat sink may include other heat dissipating or heat transferring features, such as one or more fins extending from the base, a channel for conducting cooling liquid, one or more heat pipes thermally coupled to the contact plate, etc. A portion of the contact plate may be arranged to contact and receive heat from a heat source, e.g., a thermal grease may help to conductively couple a portion of the contact plate with the heat source to receive heat. A frame used to engage the heat sink with the heat source may have four sides defining an opening in which the portion of the contact plate of the heat sink is received. Two of the frame sides that are opposed to each other may include one or more holding features, such as inwardly extending tabs or protrusions, to engage with the heat source and secure the frame to the heat source. In one embodiment, the tabs may engage the heat source in a space between a ball grid array substrate and a circuit board that is joined to the ball grid array substrate by an array of solder balls, although other engagement arrangements are possible. The two opposed sides may each include a feature to engage with a tool used to flex the two sides so as to move the one or more holding features on the two opposed sides away from each other. For example, the two opposed sides may include one or more slots formed in a top of the frame side that can receive a tool used to flex the frame. The frame may be flexed so as to move the heat source-engaging tabs away from each other so a portion of the heat source can be received into the opening of the frame. Upon release of the flexing force, the frame may return to its undeformed shape, causing the tabs to engage the heat source. A top of the four sides of the frame may define a flat, continuous surface around the frame, and a bottom of the four sides may define a discontinuous surface around the frame, e.g., one or more legs or other features may extend downwardly from a bottom of the frame and contact the heat source. A retainer element may be arranged to engage the frame and heat sink with the portion of the contact plate received in the opening to urge the heat sink to move downwardly relative to the frame. For example, the retainer element may include a spring plate or wire arranged to resiliently bias the heat sink to move into the frame opening so that the heat sink is biased into contact with an engaged heat source.
The frame may be arranged to receive the portion of the contact plate in a direction from a top of the opening to a bottom of the opening, i.e., in a top-down direction, and the heat sink, frame and retainer element may be arranged for assembly together with the portion of the contact plate received in the opening of the frame and the retainer element engaged with the frame such that the assembled heat sink, frame and retainer element are engagable with a heat source. That is, the fully assembled heat sink, frame and retainer element may be engaged together to a heat source in a single operation. Since the contact plate of the heat sink is received into the frame opening in a top-down direction, the heat sink is removable from the frame even while the frame is engaged with a heat source. This allows for disassembly if needed, but also accommodates heat sink base sizes that are larger than the frame.
In one embodiment, the base of the heat sink may have a size that is larger than a size of the opening, e.g., the base of the heat sink may have a width, area or other dimension that is larger than a width, area or other dimension of the opening. In other embodiments, the heat sink may include fins, heat pipes or other features that extend laterally over one or more of the frame sides. This feature allows for a relatively large heat sink, but does not interfere with proper engagement of a fully assembled heat sink, frame and retainer element assembly with a heat source.
In one embodiment, the one or more holding features (e.g., tabs, protrusions, holes, grooves, etc.) are formed at a bottom end of a corresponding side of the frame, e.g., so that the opposed sides can be flexed to move the bottom ends of the opposed sides away from each other. If the frame includes one or more legs on its bottom, the legs may be arranged on sides of the frame that are adjacent to sides that include one or more holding features. Thus, for example, when the frame is placed onto the heat source during assembly and the sides are flexed to receive the heat source, the legs may contact the heat source so that when the sides are released, the holding features may be properly located to engage with corresponding holes, slots, tabs, etc., of the heat source.
In another aspect of the invention, a method for assembling a heat sink and an electrical component heat source includes providing a frame defining an opening and arranged to engage with a heat source and resist movement of the heat source relative to the frame in a z direction. The frame may also engage the heat source to resist movement of the heat source relative to the frame in x and/or y directions as well. The frame may be assembled with a heat sink by moving a contact plate of the heat sink into the opening of the frame in a top-down direction and engaging a retainer element with the frame to bias the heat sink to move into the opening. Thereafter, the opening defined by the frame may be enlarged by engaging opposed sides of the frame with a tool to receive a portion of a heat source while the frame, heat sink and retainer element are assembled together. With a portion of the heat source received in the enlarged portion of the opening, a size of the opening may be reduced to engage the frame with a portion of the heat source in the opening while the frame, heat sink and retainer element are assembled. Engagement of the frame with the portion of the heat source may cause the retainer element to resiliently bias the heat sink contact plate into thermal contact with a portion of the heat source, e.g., to press downwardly on the heat sink with a spring force to urge the heat sink into contact with the heat source.
As with the embodiments above, a base of the heat sink may have a size that is larger than a size of the opening. For example, the base of the heat sink may have a width that is larger than a width of the opening, yet still not interfere with mounting of the fully assembled assembly on the heat source. The opening of the frame may be enlarged by engaging a slot formed in a sidewall of the frame with a tool that is used to flex opposed sides of the frame so as to move holding features on the opposed sides away from each other.
These and other aspects of the invention will be apparent from the following description and claims.
Aspects of the invention are described below with reference to the following drawings in which like numerals reference like elements, and wherein:
It should be understood that aspects of the invention are described herein with reference to certain illustrative embodiments and the figures. The illustrative embodiments described herein are not necessarily intended to show all aspects of the invention, but rather are used to describe a few illustrative embodiments. Thus, aspects of the invention are not intended to be construed narrowly in view of the illustrative embodiments. In addition, it should be understood that aspects of the invention may be used alone or in any suitable combination with other aspects of the invention.
As discussed above, an embodiment of the invention includes a frame arranged to engage with a portion of a heat source, such as an integrated circuit, computer processor, ball grid array substrate, a printed circuit board, or other component, such that portions of the frame at least partially surround a part of the heat source. For example, the frame may have sides that define an opening and which can be elastically deformed, flexed or otherwise moved to enlarge a size of the opening defined by the frame, e.g., so that a portion of the heat source can be received into the opening. Once a portion of the heat source is received in the opening, the sides may be released, allowing the frame to return to its unflexed shape to engage the heat source and restrict the frame's movement relative to the heat source in x and/or y directions (which may be in a plane of the frame). The frame may also engage the heat source to restrict its movement in the z direction, e.g., so that the frame cannot move beyond a certain point in an upward direction relative to the heat source (which may be perpendicular to a plane of the frame).
The frame may receive a portion of a heat sink into the opening in a top-down direction, i.e., such that the heat sink portion is moved into the opening in a direction from a top of the frame toward the bottom. As a result, the heat sink may be larger than the frame, yet still be received into the frame opening. Moreover, the frame and heat sink may be made so that with the heat sink portion received into the opening, and a retainer element engaged with the frame to hold the heat sink in place, the fully assembled construction may be engaged with a heat source. Once the frame is engaged with the heat source, the retainer element engages with the frame and contacts the heat sink to bias the heat sink toward a heat source engaged by the frame. For example, the retainer element may apply a resilient bias on the heat sink in a downward direction toward the heat source. Since the frame may be restricted in upward movement relative to the heat source, the resilient bias on the heat sink may bias the heat source and heat sink together.
The heat sink 3 in this illustrative embodiment includes a base with a contact plate 32 and a plurality of fins 31 that extend upwardly from the base. A lower surface of the contact plate 32 is arranged to make thermal contact with, or otherwise thermally communicate with an upper surface of the integrated circuit 42 so as to receive heat from the integrated circuit 42 and dissipate the heat via the fins 31. Of course, it should be understood that the heat sink 3 may include any suitable additional or alternate components, such as one or more heat pipes that are thermally coupled to the contact plate 32 or other collector block, a thermoelectric cooling device, a phase-change based or other thermal transfer medium, a liquid-based heat exchanger (e.g., including a channel in the contact plate 32 that carries a circulating liquid used to carry heat from the heat sink 3), and so on. In short, the heat sink 3 may include any suitable component to receive and transfer heat away from a heat source 4. The heat sink 3 in this embodiment may be formed in any suitable way, such as by casting, extruding, machining, forging, welding, or otherwise assembling portions made of any suitable material, such as conductive metals (aluminum, copper, steel, etc.), plastics, composites and/or combinations of any such materials.
The first retaining device 1 in this illustrative embodiment includes a frame clip with four sidewalls 15 that define an opening 18 arranged to receive a portion of the heat source 4 and the contact plate 32 of the heat sink 3. In one embodiment, the integrated circuit 42 and ball grid array substrate 43 may be received into the opening 18, and the sidewalls 15 may engage with edges of the ball grid array substrate 43 (e.g., by clamping, by engaging one or more tabs, grooves, hooks, teeth, wedges, barbs, or other holding features 14 with the substrate 43, etc.) to resist movement of the frame clip 1 relative to the heat source 4 in x and/or y directions as well as the z direction. (As can be seen in
In this embodiment, and as can be seen in
In accordance with an aspect of the invention, the frame clip, the heat sink and the retainer element may be completely assembled together and then attached to a heat source in the assembled condition. This feature may provide advantages, such as ensuring that the proper clip, heat sink and retainer element are used together with the corresponding heat source. For example, heat sink assemblies with associated frame clip and retainer element may be pre-assembled and packaged ready for attachment to a particular type of heat source. This way, a user can be ensured that the proper parts are associated with each other and are fully ready for attachment to a heat source, without any need to verify anything other than that the assembly as a whole is properly associated with the heat source. This is contrast to many heat sink assemblies that include frame clips which cannot be attached to a heat source while assembled with a heat sink and retainer.
In another aspect of the invention, the frame clip 1 includes a tool-engaging feature arranged to engage with a tool used to flex or bend the opposing sidewalls so as to spread tabs or other engagement features from each other to allow a portion of a heat source to be received in the opening 18 and engaged by the engagement features. In the embodiment of
In accordance with another aspect of the invention, the heat sink assembly may be attached to a heat source while fully assembled, even though the heat sink has a size which is larger than the frame clip opening. For example, as can be seen in
Another aspect of the invention is that the heat sink and frame clip are arranged such that the contact plate 32 of the heat sink 3 can be received into the opening 18 of the frame clip 1 in a top-down direction, i.e., in a direction along the z axis from a top of the frame clip 1 towards a bottom of the frame clip 1. Such an arrangement allows for simpler frame clip construction, and also helps avoid potential mechanical interference between the frame clip 1 and the heat sink 3. Moreover, assembly of the heat sink, frame clip and retainer element is made easier, e.g., because the assembly can be made by placing the frame clip on a surface, placing the heat sink over the frame clip with the contact plate in the opening 18, and then engaging the retainer element with the frame clip. There is no need to specifically align features of the heat sink and frame clip, other than positioning the contact plate in the opening. This is in contrast to many other arrangements in which the frame clip includes structures that extend into the opening 18 and interfere with the heat sink, requiring specific alignment of the heat sink and frame clip for assembly and/or requiring the heat sink to be inserted into the opening from the bottom of the frame clip.
Another aspect of the invention is that the frame clip may have a flat, continuous surface on a top face, and a discontinuous surface on the bottom face. The top face of the frame clip 1 can be seen in
As noted above, embodiments of the invention are not limited to any particular arrangement for the portions of the heat sink assembly 10. For example,
Having thus described several aspects of at least one embodiment of this invention, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description and drawings are by way of example only.
This application is a continuation of PCT/CN2013/084667, filed Sep. 30, 2013, which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
---|---|---|---|
Parent | PCT/CN2013/084667 | Sep 2013 | US |
Child | 15083474 | US |