Patent Application
20210372710
Example embodiments relate generally to the field of heat transfer and, more particularly, to multi-thermal characteristic heat sink fins.
During operation of electronic systems, the heat generated by processors must be dissipated quickly and efficiently to keep operating temperatures within manufacturer recommended ranges, under, at times, challenging operating conditions. As these electronic systems increase in functionality and applicability so does operating speed of the processors used therein; with an increase in operating speeds and an increase in the number of processors employed, power requirements of the electronic systems also increase, which in turn, increases cooling requirements.
Several techniques have been developed for extracting heat from processors in electronic systems. One such technique is an air-cooling system, wherein a heat exchanger is in thermal contact with a processor, transporting heat away from the processor, and then air flowing over the heat exchanger removes heat therefrom. One type of heat exchanger is a heat sink.
Heat sinks are devices that are attached directly to a heat source, such as a processor, to enhance heat dissipation therefrom. In general, heat sink fins, heat pipes, and fans, individually, or in any combination, may also form a part of the heat sink to facilitate air flow over the part of the heat sink in thermal contact with the processor to remove heat therefrom. For heat sinks formed at least, with heat sink fins and heat pipes, a material choice between aluminum or copper heat sinks is often required, depending upon application and specification requirements and operating environment. While copper heat sinks may be optimal for certain heat extracting solutions, copper is heavier and more expensive than aluminum. However, for aluminum heat sinks, heat spreading and thermal performance may be sacrificed.
Generally, when aluminum is utilized with copper in a heat sink, a complex system of thermal interface materials with mechanical attachments is required, whereby, the system increases thermal resistance. When thermal interface materials are not utilized, galvanic corrosion issues may be created. For metallurgically and permanently joining copper with aluminum, thermal resistance is decreased, but, expense increases.
In an embodiment, a multi-thermal characteristic heat sink fin, configured for at least a heat pipe to be slidably engaged therewith, comprising a first heat spreading plate, a second heat spreading plate, and a primary heat spreading plate is provided. The first, second, and primary heat spreading plates have at least a first opening, a second opening, and a primary opening, respectively. The primary heat spreading plate further has a heat pipe fixing hub, extending from a perimeter of the primary opening.
The primary heat spreading plate is mounted between the first and second heat spreading plates and the heat pipe fixing hub extends through the first opening. The at least a heat pipe is slidably engaged to the multi-thermal characteristic heat sink fin via the first, second, and primary openings, respectively.
A material of the primary heat spreading plate has a first thermal characteristic, and a material of the first heat spreading plate and a material of the second heat spreading plate, respectively, have a second thermal characteristic different from that of the first thermal characteristic.
In some embodiments, the second heat spreading plate further comprises at least a rivet shaft, and the first heat spreading plate further comprises at least a rivet fixing hole corresponding to the at least a rivet shaft. The primary heat spreading plate is mounted between the first and second heat spreading plates via the heat pipe fixing hub extending through the first opening and the at least a rivet shaft retained in the at least a rivet fixing hole.
In some embodiments, in addition to the second heat spreading plate further comprising at least a rivet shaft, and the first heat spreading plate further comprising at least a rivet fixing hole, the primary heat spreading plate further comprises a first contact surface and at least two pairs of opposite fixing folds near furthest opposing ends thereof, the at least two pairs of opposite fixing folds extend outward and perpendicular from the first contact surface, and the first heat spreading plate further comprises at least two pairs of opposite first fixing fold passageways near furthest opposing ends thereof, corresponding to the at least two pairs of opposite fixing folds. The primary heat spreading plate is mounted between the first and second heat spreading plates via the heat pipe fixing hub extending through the first opening, the at least a rivet shaft retained in the at least a rivet fixing hole, and the at least two pairs of opposite fixing folds extending outward over the at least two pairs of opposite first fixing fold passageways, respectively.
In some embodiments, the first heat spreading plate further comprises an accommodating side having a recessed surface surrounded and defined by an elevated rim, and the second heat spreading plate further comprises an inner surface having a rim area on a perimeter therearound, corresponding to the elevated rim. The primary heat spreading plate is mounted and enclosed within the recessed surface and elevated rim, preventing debris and contaminants from entering therein.
In some embodiments, a thermal spreading resistance of the first thermal characteristic material is less than a thermal spreading resistance of the second thermal characteristic material. In some embodiments, a weight per square centimeter of the first thermal characteristic material is greater than a weight per square centimeter of the second thermal characteristic material. In some embodiments the first thermal characteristic material is made of copper or copper alloy. In some embodiments, the second thermal characteristic material is made of aluminum or copper alloy.
In some embodiments, a shape of the at least a primary opening, at least a first opening, and at least a second opening is cylindrical, respectively, and corresponds to a shape of the at least a heat pipe. In some embodiments, a shape of the multi-thermal characteristic heat sink fin is quadrangular shape. In some embodiments, a shape of the primary heat spreading plate is a stretched octagonal shape resembling a rectangle.
In some embodiments, an amount of the at least a primary opening, at least a first opening, and at least a second opening is five. In some embodiments, an amount of the at least a primary opening, at least a first opening, and at least a second opening is greater than five. In some embodiments, an amount of the at least a primary opening, at least a first opening, and at least a second opening is less than five.
In some embodiments, an amount of the multi-thermal characteristic heat sink fin is more than one. The heat pipe fixing hub of each of the multi-thermal characteristic heat sink fins is mounted on the at least a heat pipe, forming parallel air passages therebetween via a length of the at least two pairs of opposite fixing folds and a length of the heat pipe fixing hub, forming a heat sink.
Unless specified otherwise, the accompanying drawings illustrate aspects of the innovative subject matter described herein. Referring to the drawings, wherein like reference numerals indicate similar parts throughout the several views, several examples of heatsink fins incorporating aspects of the presently disclosed principles are illustrated by way of example, and not by way of limitation.
The following describes various principles related to heatsink fins by way of reference to specific examples of heatsink fins, and heat exchanger systems, including arrangements and examples of heat pipes, and fans embodying innovative concepts. More particularly, but not exclusively, such innovative principles are described in relation to selected examples of heatsink fins, and heat exchanger systems and well-known functions or constructions are not described in detail for purposes of succinctness and clarity. Nonetheless, one or more of the disclosed principles can be incorporated in various other embodiments of heatsink fins, and heat exchanger systems to achieve any of a variety of desired outcomes, characteristics, and/or performance criteria.
Thus, heatsink fins, and heat exchanger systems having attributes that are different from those specific examples discussed herein can embody one or more of the innovative principles, and can be used in applications not described herein in detail. Accordingly, embodiments of heatsink fins, and heat exchanger systems not described herein in detail also fall within the scope of this disclosure, as will be appreciated by those of ordinary skill in the relevant art following a review of this disclosure.
Example embodiments as disclosed herein are directed to multi-thermal characteristic heat sink fins. In an embodiment, a multi-thermal characteristic heat sink fin comprises a first heat spreading/containment plate, a second heat spreading/containment plate, and a primary heat spreading plate. A plurality of multi-thermal characteristic heat sink fins is assembled together to form a heat sink, wherein the heat sink further has a plurality of heat pipes assembled through the plurality of multi-thermal characteristic heat sink fins, and a base plate, assembled to the plurality of heat pipes and in contact with a heat source. The primary heat spreading plate is sandwiched and enclosed within the first and second heat spreading/containment plates, hindering debris, contaminants, and moisture from entering the surface interfaces therebetween, which would increase galvanic corrosion issues. The material of the heat pipes and primary heat spreading plate is different from that of the first and second heat spreading/containment plates. However, no heat treatment process of two or more different materials is required for assembly of the plurality of multi-thermal characteristic heat sink fins and plurality of heat pipes thereto.
In an embodiment, the first contact surface 129 of the primary heat spreading plate 150 is assembled to the recessed surface 126 and surrounding rim 128 of the accommodating side 129 of the first heat spreading/containment plate 120 via flushed fit therein. The thickness of the primary heat spreading plate 150 is generally equal to the depth of the recessed surface 126 and height of the elevated rim 128. The plurality of heat pipe fixing hubs 153 protrude through the plurality of first heat pipe openings 122, whereby the outer surface of the plurality of heat pipe fixing hubs 153 is flush with the perimeter of the plurality of first heat pipe openings 122, respectively. The at least one pair of opposite fixing folds 157, protrude through a plane of the at least one pair of opposite first fixing fold passageways 127, whereby an inner surface of the at least one pair of opposite fixing folds 157 is flush with a side edge of the at least one pair of opposite first fixing fold passageways 127. The flushed fit of the primary heat spreading plate 150 within the recessed surface 126 and surrounding rim 128, and flushed fit between the plurality of heat pipe fixing hubs 153 and plurality of first heat pipe openings 122 and at least one pair of opposite fixing folds 157 and at least one pair of opposite first fixing fold passageways 127, secures the primary heat spreading plate 150 to the first heat spreading/containment plate 120. Next, the inner surface 186 of the second heat spreading/containment plate 180 is assembled and fixed to the second contact surface 159 of the primary heat spreading plate 150 and rim 128 of the first heat spreading/containment plate 120 via the plurality of rivet shafts 184 of the second heat spreading/containment plate 180, retained in, corresponding plurality of rivet fixing holes 124 of the first heat spreading/containment plate 120 via interference fit.
In some embodiments, the thickness of the primary heat spreading plate 150, first heat spreading/containment plate 120, and second heat spreading/containment plate 180 may vary depending upon application and specification requirements, such as the size of the heat source and operating temperature generated therefrom, the dimensions and material of the base plate, the size and number of the plurality of heat pipes, and number of multi-thermal characteristic heat sink fins 100.
In some embodiments, the thickness of the at least one pair of opposite fixing folds 157, and plurality of heat pipe fixing hubs 153 may vary depending upon application and specification requirements as stated previously.
In some embodiments, the height of the at least one pair of opposite fixing folds 157, and plurality of heat pipe fixing hubs 153 may vary depending upon application and specification requirements as stated previously.
In some embodiments, the height of the plurality of rivet shafts 184 of the second heat spreading/containment plate 180 is slightly less than the thickness of the primary heat spreading plate 150 and elevated rim 128; however, the embodiments are not limited thereto. As long as the plurality of rivet shafts 184 may be securely retained in the corresponding plurality of rivet fixing holes 124 of the first heat spreading/containment plate 120.
In an embodiment, the material of the primary heat spreading plate 150 has a first thermal characteristic and the material of the first and second heat spreading/containment plates 120, 180 has a second thermal characteristic, different from that of the first thermal characteristic material. Portions of the second heat spreading/containment plate 180 in contact with the first heat spreading/containment plate 180 comprise at least one pair of opposite plurality of rivet shafts 184, retained in, corresponding at least one pair of opposite plurality of rivet fixing holes 124 of the first heat spreading/containment plate 120. Portions of the second heat spreading/containment plate 180 not in contact with the first heat spreading/containment plate 180 comprise centrally disposed plurality of rivet shafts 184, retained in, corresponding centrally disposed plurality of rivet fixing holes 124 of the first heat spreading/containment plate 120, through centrally disposed plurality of rivet holes 154 of the primary heat spreading plate 150. Fixed assembly of the multi-thermal characteristic heat sink fin 100 is achieved between the first and second heat spreading/containment plates 120, 180, made of the same thermal characteristic material.
The at least one pair of opposite fixing folds 157 and plurality of heat pipe fixing hubs 153 of the primary heat spreading plate 150, respectively, are exposed surface areas. However, the remaining surface areas of the primary heat spreading plate 150, such as the first and second contact surfaces 156, 159, are encompassed within the first and second heat spreading/containment plates 120, 180, hindering debris, contaminants, and moisture from entering the surface interfaces between the primary heat spreading plate 150 (first and second contact surfaces 156, 159 of the primary heat spreading plate 150) and first and second heat spreading/containment plates 120, 180 (accommodating side 129 of the first heat spreading/containment plate 120 and inner surface 186 of the second heat spreading/containment plate 180), hindering galvanic corrosion issues from occurring at the interface between the primary heat spreading plate 150 made of a material having a first thermal characteristic and the first and second heat spreading/containment plates 120, 180 made of a material having a second thermal characteristic.
In an embodiment, a plurality of multi-thermal characteristic heat sink fins 100 are assembled together, whereby the outer first side 126 of the first heat spreading/containment plate 120 is facing the outer second side 189 of the second heat spreading/containment plate 180 via contact with the at least one pair of opposite fixing folds 157. In some embodiments, a plurality of heat pipes are assembled to the plurality of multi-thermal characteristic heat sink fins via the plurality of heat pipe fixing hubs 153 of the primary heat spreading plates 150, respectively, forming a heat sink, whereby the plurality of heat pipes are also assembled to a base plate in thermal contact with a heat source, such as a processor.
In an embodiment, the plurality of multi-thermal characteristic heat sink fins 100 are assembled together in a linear array, such that an air path is defined between neighboring multi-thermal characteristic heat sink fins 10. Heat exchange is achieved, whereby heat from the heat source is transferred to the base plate, and then to the heat pipe, and then to the plurality of multi-thermal characteristic heat sink fins 100. When copper is utilized as the first thermal characteristic material, and is the same material as the heat pipes, and aluminum is utilized as the second thermal characteristic material, high thermal performance is achieved by the copper heat pipe to copper primary heat spreading plate 150 heat transfer, whilst minimizing weight, expense and galvanic corrosions issues via the non-heat treatment process assembly of the primary heat spreading plate 150 to the first and second heat spreading/containment plates 120, 180 and encasement of the primary heat spreading plate 150 between the first and second heat spreading/containment plates 120, 180. Generally, the multi-thermal characteristic heat sink fins 100 can be manufactured by low cost processes such as stamping, cutting and folding. Those of ordinary skill in the art will readily appreciate that materials other than copper and aluminum may be utilized to achieve the multi-thermal characteristic heat sink fin 100 of the embodiments, so long as the heat spreading ability of the first thermal characteristic material is greater than the second thermal characteristic material, the expense of the second thermal characteristic material is greater than the expense of the first thermal characteristic material, and the weight of the first thermal characteristic material is greater than the second thermal characteristic material.
In some embodiments, the heat pipes are hermetically sealed chambers having a wicking structure and a working fluid therein. The plurality of heat pipes is generally cylindrical in shape; however, the embodiments are not limited thereto. It should be appreciated that the cross-section of the plurality of heat pipes may be square, rectangular, elliptical or other cross-sectional shape, and hollow, and a closed-system, depending upon application and specification requirements. Also, the plurality of heat pipes may be of any suitable size, depending upon application and specification requirements. Those of ordinary skill in the relevant art may readily appreciate that the size of the plurality of heat pipes may depend on the size of the heat source and operating temperature generated therefrom, dimensions and material of the base plate, number of heat pipes utilized, and size and number of multi-thermal characteristic heat sink fins 100 utilized, and the embodiments are not limited. As long as the size and number of heat pipes correspond to the plurality of first and second heat pipe openings 122, 182 and plurality of primary heat pipe openings 152 of the plurality of multi-thermal characteristic heat sink fins 100. In some embodiments, the material of the plurality of heat pipes is copper; however, those of skill in the relevant art may readily appreciate that the plurality of heat pipes may be made of other heat-dissipating material. As long as the material of the plurality of heat pipes is the same as that of the primary heat spreading plate 150.
In some embodiments, the size, thickness, shape, and mounting means of the base plate are adapted to the size, thickness, shape, and mounting assembly of the heat source, such as a processor. The mounting means may be any mounting means known to those of ordinary skill in the relevant art. The material of the base plate may be a monolithic metal, for example, aluminum, or other heat-dissipating material known to those of ordinary skill in the relevant art. The plurality of heat pipes is mounted to the base plate via mounting means known to those of ordinary skill in the relevant art.
In some embodiments, the heat sink having the plurality of multi-thermal characteristic heat sink fins 100, further comprises an active fan, known to those of ordinary skill in the relevant art. The fan comprises multiple fan blades and provides airflow over the multi-thermal characteristic heat sink fins 100 and a portion of the plurality of heat pipes during operation. The fan is positioned on one side of the plurality of multi-thermal characteristic heat sink fins 100 and orthogonal thereto, further increasing the heat-dissipating capacity of the heat sink.
In some embodiments the shape of the primary heat spreading plate 150 is generally a stretched octagonal shape resembling a rectangle, with height and length dimensions varied, depending upon application and specification requirements. As long as the first and second contact surfaces 156, 159, are encompassed within the first and second heat spreading/containment plates 120, 180, hindering debris, contaminants, and moisture from entering the surface interfaces between the primary heat spreading plate 150 and first and second heat spreading/containment plates 120, 180, and the plurality of heat pipe fixing hubs 153 protrude through the plurality of first heat pipe openings 122, whereby the outer surface of the plurality of heat pipe fixing hubs 153 is flush with the perimeter of the plurality of first heat pipe openings 122, respectively, and the at least one pair of opposite fixing folds 157, protrude through a plane of the at least one pair of opposite first fixing fold passageways 127, whereby an inner surface of the at least one pair of opposite fixing folds 157 is flush with a side edge of the at least one pair of opposite first fixing fold passageways 127.
Although illustrated as being quadrangular; however the embodiments are not limited thereto. It should be appreciated that the shape of the multi-thermal characteristic heat sink fin 100 may be round, oval, or some other geometric shape, depending upon application and specification requirements and the embodiments are not limited thereto.
In some embodiments, the number of multi-thermal characteristic heat sink fins 100 in an assembled heat sink may vary, depending upon operating temperature of the heat source, weight limitations, the type of active fan utilized, if employed, and cost. In some embodiments, the number of multi-thermal characteristic heat sink fins 100 is varied, depending upon application and specification requirements as stated previously.
In some embodiments, the general shape of the plurality of primary heat pipe openings 152 and plurality of first and second heat pipe openings 122, 182 corresponds to the shape of the heat pipes. As an example and not to be limiting, the general shape of the plurality of primary heat pipe openings 152 and plurality of first and second heat pipe openings 122, 182 is cylindrical; however, the embodiments are not limited thereto and depend on the shape of the heat pipes.
In some embodiments, the plurality of primary heat pipe openings 152 is substantially the same as outer dimensions of heat pipes assembled therethrough. The plurality of first and second heat pipe openings 122, 182 is substantially the same and larger than the plurality of primary heat pipe openings 152 by generally the thickness of the heat pipe fixing hub 153. As an example, and not to be limiting, the diameter of the outer dimensions of the plurality of heat pipes may vary, the diameter of the first and second heat pipe openings 122, 182 may vary, and given a thickness of the heat pipe fixing hub 153, the diameter of the plurality of primary heat pipe openings 152 may vary, all depending upon application and specification requirements.
In some embodiments, the number of the plurality of primary heat pipe openings 152 and plurality of first and second heat pipe openings 122, 182 is 5; however the embodiments are not limited thereto. Those of ordinary skill in the art may readily appreciate that there may be more than or less than 5 plurality of primary heat pipe openings 152 and plurality of first and second heat pipe openings 122, 182, depending on application and specification requirements as previously stated.
When engaged through the plurality of primary heat pipe openings 152, the heat pipes are in physical contact with the plurality of primary heat pipe openings 152 and plurality of heat pipe fixing hubs 153. To achieve close contact, the plurality of primary heat pipe openings 152 and plurality of first and second heat pipe openings 122 comprise an expandable tail for snug fitting. In some embodiments, the heat pipes are slidably engaged with the multi-thermal characteristic heat sink fins 100 during assembly of a heat sink.
In the embodiments, multi-thermal characteristic heat sink fins 100, comprising a first heat spreading/containment plate 120, a second heat spreading/containment plate 180, and a primary heat spreading plate 150 are provided. The primary heat spreading plate 150 is sandwiched and enclosed within the first and second heat spreading/containment plates 120, 180 via the recessed surface 126 of the accommodating side 129 of the first heat spreading/containment plate 120, at least one pair of opposite fixing folds 157 and plurality of heat pipe fixing hubs 153 of the primary heat spreading plate 150, and plurality of rivet shafts 184 of the second heat spreading/containment plate 180, retained in, corresponding plurality of rivet fixing holes 124 of the first heat spreading/containment plate 120 via interference fit. A plurality of multi-thermal characteristic heat sink fins are assembled together, whereby the outer first side 126 of the first heat spreading/containment plate 120 is facing the outer second side 189 of the second heat spreading/containment plate 180 via contact with the at least one pair of opposite fixing folds 157. A plurality of heat pipes are assembled to the plurality of multi-thermal characteristic heat sink fins via the plurality of heat pipe fixing hubs 153 of the primary heat spreading plates 150, respectively, forming a heat sink, whereby the plurality of heat pipes are also assembled to a base plate in thermal contact with a heat source, such as a processor.
The material of the primary heat spreading plate 150 has a first thermal characteristic and is the same as the material of the plurality of heat pipes. The material of the first and second heat spreading/containment plates 120, 180 has a second thermal characteristic, different from that of the first thermal characteristic material. No heat treatment process of two or more different thermal characteristic materials is required for assembly of the plurality of multi-thermal characteristic heat sink fins and plurality of heat pipes, thereby decreasing galvanic corrosion issues.
The at least one pair of opposite fixing folds 157 and plurality of heat pipe fixing hubs 153 of the primary heat spreading plate 150, respectively, are exposed surface areas. However, the remaining surface areas of the primary heat spreading plate 150, such as the first and second contact surfaces 156, 159, are encompassed within the first and second heat spreading/containment plates 120, 180, hindering debris, contaminants, and moisture from entering the surface interfaces between the primary heat spreading plate 150 (first and second contact surfaces 156, 159 of the primary heat spreading plate 150) and first and second heat spreading/containment plates 120, 180 (accommodating side 129 of the first heat spreading/containment plate 120 and inner surface 186 of the second heat spreading/containment plate 180), thereby also decreasing galvanic corrosion issues.
When copper is utilized as the first thermal characteristic material and aluminum is utilized as the second thermal characteristic material, the embodiments of the multi-thermal characteristic heat sink fin 100 provide high thermal performance with minimized weight, expense and galvanic corrosion issues. Thermal contact is achieved between the plurality of heat pipes, and the primary heat spreading plate 150, both made of copper. Thermal contact is also achieved between the primary heat spreading plate 150 made of copper and the first and second heat spreading/containment plates 120, 180 made of aluminum, whereby, no heat treatment process of copper in contact with aluminum is required. The plurality of multi-thermal characteristic heat sink fins is assembled together via the plurality of at least one pair of opposite fixing folds, in direct contact with each other, made of copper, the plurality of heat pipe fixing hubs 153 in direct contact with the plurality of heat pipes, all made of copper, and the base plate and a portion of the elevated rims of the multi-thermal characteristic heat sink fins, both made of aluminum, or combinations thereof.
The presently disclosed inventive concepts are not intended to be limited to the embodiments shown herein, but are to be accorded their full scope consistent with the principles underlying the disclosed concepts herein. Directions and references to an element, such as “up,” “down,”, “upper,” “lower,” “horizontal,” “vertical,” “left,” “right,” and the like, do not imply absolute relationships, positions, and/or orientations. Terms of an element, such as “first” and “second” are not literal, but, distinguishing terms. As used herein, terms “comprises” or “comprising” encompass the notions of “including” and “having” and specify the presence of elements, operations, and/or groups or combinations thereof and do not imply preclusion of the presence or addition of one or more other elements, operations and/or groups or combinations thereof. Sequence of operations do not imply absoluteness unless specifically so stated. Reference to an element in the singular, such as by use of the article “a” or “an”, is not intended to mean “one and only one” unless specifically so stated, but rather “one or more”. As used herein, “and/or” means “and” or “or”, as well as “and” and “or.” As used herein, ranges and subranges mean all ranges including whole and/or fractional values therein and language which defines or modifies ranges and subranges, such as “at least,” “greater than,” “less than,” “no more than,” and the like, mean subranges and/or an upper or lower limit. All structural and functional equivalents to the elements of the various embodiments described throughout the disclosure that are known or later come to be known to those of ordinary skill in the relevant art are intended to be encompassed by the features described and claimed herein. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure may ultimately explicitly be recited in the claims. No element or concept disclosed herein or hereafter presented shall be construed under the provisions of 35 USC 112(f) unless the element or concept is expressly recited using the phrase “means for” or “step for”.
In view of the many possible embodiments to which the disclosed principles can be applied, we reserve the right to claim any and all combinations of features and acts described herein, including the right to claim all that comes within the scope and spirit of the foregoing description, as well as the combinations recited, literally and equivalently, in the following claims and any claims presented anytime throughout prosecution of this application or any application claiming benefit of or priority from this application.
The application claims the benefit of priority to U.S. provisional application No. 62/925,778, filed on Oct. 25, 2019, of which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62925778 | Oct 2019 | US |
