Heat sink with pin fins and a non-straight constant volume flow path

Abstract

The heat sink includes a heat sink body that defines a fluid passage and houses the flow of a cooling fluid. The heat sink body includes a passage bottom surface and passage walls extending from the passage bottom surface to define the fluid passage, and the passage walls have a plurality of wall segments that form a non-straight passage wall profile. An array of pin fins is located inside the fluid passage and extends from the passage bottom surface, and the passage walls are positioned to surround the array of pin fins. The plurality of wall segments may be configured as semi-circular wall segments adjacent to each other that form a wavy passage wall profile, and / or the pin fins may be cylindrical pin fins having a circular cross-sectional shape, although other combinations of shapes may be used. The passage walls and the array of pin fins are positioned such that a constant flow area exists for the flow of the cooling fluid across each row and column of the array of pin fins.

Description

Technical Field

[0001] Related Applications This application claims the benefit of U.S. Provisional Application No. 63 / 347,666, filed on June 1, 2022, and U.S. Provisional Application No. 63 / 396,329, filed on August 9, 2022, the contents of both of which are incorporated herein by reference.

[0002] Field of the Invention This application generally relates to fluid-cooled heat sinks that can be used for cooling electronic circuit components, and more particularly, to fluid-cooled heat sinks for use in small footprint applications, such as electronic motor controllers.

Background Art

[0003] Electronic controllers require a cooling solution to dissipate heat generated by the operation of electronic circuit components, such as electronic transistors. Without such cooling, heat can damage the electronic circuit components, resulting in failure of the electronic controller. Heat dissipation is particularly difficult in applications where the electronic controller has a relatively small footprint. For example, an electronic motor controller needs to be compactly sized for incorporation within a motor structure. The small footprint available for heat transfer and dissipation creates challenges in achieving sufficient cooling required for such small footprint electronic controllers.

[0004] In a conventional configuration, a fluid-cooled heat sink is thermally assembled to an electronic device package that includes an electronic circuit component that generates heat. The heat sink includes a body that defines a fluid passage having an inlet and an outlet through which a cooling fluid flows. The cooling fluid may be water, a working fluid, or another suitable fluid suitable for heat transfer. The cooling fluid flow is caused to flow into the inlet of the heat sink body, and as the fluid flows through the fluid passage from the inlet to the outlet, the fluid absorbs the heat generated by the electronic component. As a result, such heat is removed from the heat sink body by the outlet fluid flow.

[0005] Many conventional configurations use a straight wall configuration for the fluid passage through the heat sink body, thereby providing a low resistance flow path. However, such a straight wall configuration has drawbacks. The straight wall configuration causes most or a significant non-uniform portion of the fluid to flow near the straight wall section of the fluid passage, thereby providing a sub-optimal heat transfer path for the fluid. Also, conventional straight passage heat sinks do not have sufficient surface area inside the fluid passage to achieve the heat transfer required for small footprint applications, such as electronic motor controllers. Further, conventional straight passage heat sinks cannot cause an even distribution and turbulence of the fluid inside the heat sink fluid passage, and as a result of such lack of evenness and turbulence, non-uniform heat transfer occurs that is not effective in achieving sufficient cooling. To achieve the target heat transfer for sufficient cooling, more complex fluid passage designs have been proposed, but such complex heat sink designs increase the manufacturing cost of the heat sink and are not suitable for small footprint applications. SUMMARY OF THE INVENTION

[0006] This application describes an improved fluid-cooled heat sink design that is particularly suitable for small footprint applications, such as cooling of electronic motor controllers. The fluid-cooled heat sink includes a heat sink body that defines a fluid passage having a non-straight passage wall profile, in combination with an array of protruding pin fins located within at least a portion of the fluid passage. In an exemplary embodiment, the fluid-cooled heat sink includes a fluid passage configured with a semi-circular corrugated wall passage profile having a plurality of adjacent semi-circular wall segments, in combination with an array of cylindrical pin fins each having a circular cross-sectional shape. With such a configuration, an even flow distribution is achieved with a high level of turbulent flow, as compared to conventional configurations, thereby achieving excellent heat transfer efficiency with a small footprint.

[0007] A cylindrical heat sink with a semi-circular corrugated passage wall contour provides effective cooling for electronic motor controllers and other applications, particularly electronic circuit components in small footprint applications. In an exemplary embodiment, the passage wall contour of the heat sink fluid passage is configured as adjacent semi-circular wall segments surrounding an array of cylindrical pin fins having a circular cross-sectional shape. The shape and position of the passage wall contour relative to the pin fins are defined such that the cross-sectional space (area) between the wall and the pin fins is the same as the space between each of the pin fins, resulting in a constant flow area across each portion of the pin fin array. This configuration helps to equally distribute the fluid across the cross-section of the heat sink, eliminating the problem of a larger portion of the flow flowing closer to the passage wall. Thus, due to the passage wall contour shape, the flow path will have a constant volume or a constant area for each section of the flow element. The uniform arrangement of the pin fins in combination with the semi-circular corrugated passage wall contour further provides optimal fluid distribution inside the fluid passage, increasing the surface area in contact with the cooling fluid for better heat transfer, thereby allowing for a smaller footprint for the heat sink. The pin fins and the fluid passage wall segments may have another suitable regular shape as long as the flow cross-sectional area surrounding each pin fin is uniform. For example, diamond, oval, square, hexagonal or other regularly shaped pin fins and / or passage wall segments may be used.

[0008] The above-described configuration of arranging pin fins and non-straight fluid passage wall segments enables, as compared with conventional configurations, the heat sink to be compact while still achieving the required cooling with less pressure drop. The pin fins may be arranged in different sets of rows and columns having different numbers of pin fins, and may also be arranged with different pin fin diameters or different pin fin shapes to enhance the heat transfer ability of the heat sink. The pin fins and the non-straight heat sink fluid passage walls may be fabricated using sand casting or pressure die casting, which helps to reduce the cost of fabrication and provides a simple configuration with effective heat transfer.

[0009] An array of pin fins is arranged in a plurality of rows and columns located inside the fluid passage and extending from the bottom surface of the passage, and the passage walls are positioned to surround the array of pin fins. The passage walls and the array of pin fins are positioned such that there is a constant flow area for the flow of the cooling fluid across each of the rows and columns of the plurality of rows and columns. The shortest distance between adjacent pin fins is constant or the same throughout the array of rows and columns of pin fins. Similarly, for the pin fins positioned adjacent to the passage wall, the shortest distance between such a pin fin positioned adjacent to the passage wall and the passage wall is the same as the shortest distance between adjacent pin fins within the rows and columns of the array of pin fins. In such a configuration, there is a constant flow area for the flow of the cooling fluid across each of the rows and columns of the plurality of rows and columns in the array of pin fins.

[0010] Accordingly, an aspect of the present invention is an improved heat sink having a non-straight fluid passage wall profile and an array of pin fins within the fluid passage, thereby providing more effective heat transfer with a small footprint. In an exemplary embodiment, the heat sink includes a heat sink body having a first port and a second port, the heat sink body defining a fluid passage between the first port and the second port to accommodate a flow of cooling fluid between the first port and the second port. The heat sink body includes a passage bottom surface and a passage wall extending from the passage bottom surface to define the fluid passage, the passage wall having a plurality of wall segments that form a non-straight passage wall profile. An array of pin fins arranged in a plurality of rows and columns is located within the fluid passage and extends from the passage bottom surface, and the passage wall is positioned to surround the array of pin fins. The passage wall and the array of pin fins are positioned such that a constant flow area exists for the flow of cooling fluid across each row and column of the plurality of rows and columns.

[0011] In an exemplary embodiment, the plurality of wall segments are configured as adjacent semi-circular wall segments that form a wavy passage wall profile, and / or the pin fins are cylindrical pin fins having a circular cross-sectional shape.

[0012] In an exemplary embodiment, the pin fins in the array have a uniform arrangement, whereby each pin fin in the array is spaced equidistant from adjacent pin fins and / or spaced equidistant from the passage wall.

[0013] In an exemplary embodiment, the pin fins are rods having a diamond-shaped cross-sectional shape.

[0014] In an exemplary embodiment, the pin fins are rods having an elliptical cross-sectional shape.

[0015] In an exemplary embodiment, each of the plurality of wall segments has a shape corresponding to the cross-sectional shape of the pin fin.

[0016] In an exemplary embodiment, each of the plurality of wall segments has a shape different from the shape corresponding to the cross-sectional shape of the pin fin.

[0017] In an exemplary embodiment, the plurality of wall segments includes semi-circular wall segments adjacent to each other that form a corrugated passage wall contour, and the pin fin is a rod pin fin having a rhombic cross-sectional shape.

[0018] In an exemplary embodiment, the plurality of wall segments includes semi-rhombic wall segments adjacent to each other that form a rhombic passage wall contour, and the pin fin is a rod pin fin having a rhombic cross-sectional shape.

[0019] In an exemplary embodiment, the plurality of wall segments includes semi-elliptical wall segments adjacent to each other that form an elliptical corrugated passage wall contour, and the pin fin is a rod pin fin having an elliptical cross-sectional shape.

[0020] In an exemplary embodiment, the pin fins are arranged in different sets of rows and columns each having a different number of pin fins.

[0021] In an exemplary embodiment, the passage wall and the pin fin extend perpendicularly from the passage bottom surface.

[0022] In an exemplary embodiment, the passage wall includes a first wall section and a second wall section facing the first wall section, and the plurality of wall segments includes wall segments facing each other located in the first wall section and the second wall section, respectively.

[0023] In an exemplary embodiment, the first port and the second port are located on the same side of the heat sink body, the fluid passage includes a first passage portion and a second passage portion through which the cooling fluid flows in opposite directions to each other, the first passage portion and the second passage portion are connected by a passage bridge, and otherwise are separated by a central body portion of the heat sink body.

[0024] In an exemplary embodiment, the first port and the second port are located on opposite sides of the heat sink body.

[0025] In an exemplary embodiment, the shortest distance between adjacent pin fins is constant throughout the rows and columns of the pin fin array, and for the pin fins positioned adjacent to the passage wall, the shortest distance between the pin fins positioned adjacent to the passage wall and the passage wall is the same as the shortest distance between adjacent pin fins within the rows and columns of the pin fin array.

[0026] In an exemplary embodiment, the heat sink further includes a cover plate that is fixed to the outer surface of the heat sink body and covers the extent of the fluid passage.

[0027] In an exemplary embodiment, the heat sink body is a concave shelf portion that is formed as a step with respect to the outer surface, extends along the entire circumference of the edge of the passage wall on the side opposite to the passage bottom surface, and includes a concave shelf portion for attaching the cover plate.

[0028] Another aspect of the present invention is an operating assembly including the heat sink according to any one of the above embodiments, assembled to an electronic device package having an electronic component that generates heat. In an exemplary embodiment of this operating assembly, the heat sink includes a first outer surface and a second outer surface opposite to the first outer surface, the bottom surface of the passage is the inner surface of the heat sink body that transfers heat to the second outer surface, and the array of pin fins extends from the bottom surface of the passage into the fluid passage in a direction opposite to the second outer surface. A cover plate is fixed to the first outer surface of the heat sink body and covers the spread range of the fluid passage. The electronic device package is assembled to the second outer surface of the heat sink body, and the electronic component is positioned adjacent to the second outer surface of the heat sink body such that the heat generated by the electronic component is transferred to the fluid passage through the bottom surface of the passage and the pin fins.

[0029] These features and further features of the present invention should become apparent by reference to the following description and the accompanying drawings. The specification and drawings disclose in detail specific embodiments of the present invention as examples of several forms in which the principles of the present invention can be utilized, but of course, the scope of the present invention is not correspondingly limited. Rather, the present invention includes all changes, modifications and equivalents encompassed by the spirit and terms of the appended claims. Features described and / or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments and / or in combination with or instead of the features of other embodiments.

Brief Description of the Drawings

[0030]

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DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, embodiments of the present application will be described with reference to the drawings, and like reference numerals will be used throughout to refer to like elements. Of course, the drawings are not necessarily to scale.

[0032] FIG. 1 is a perspective view of an exemplary heat sink 10 according to an embodiment of the present application. FIG. 2 is a plan view of the exemplary heat sink 10 of FIG. 1. The heat sink 10 includes a heat sink body 12, and the heat sink body 12 defines a fluid passage 14 extending through the heat sink body 12. The heat sink body 12 includes a first port 16 and a second port 18 that are in fluid communication with the fluid passage 14. As will be described in more detail below, during operation, a cooling fluid flows through the fluid passage 14 between the first port 16 and the second port 18 to dissipate heat. In the clear illustration of FIG. 2, the first port 16 is an inlet port for the inflow of the cooling fluid, and the second port 18 is an outlet port for the outflow of the cooling fluid, but the inlet port and the outlet port may be interchanged with the illustration in FIG. 2. The material used to fabricate the heat sink 10 may be any material having a high thermal conductivity. Suitable examples include copper and aluminum, and aluminum is a particularly cost-effective material choice for many applications.

[0033] Regarding the definition of the fluid passage 14, the heat sink body includes a passage bottom surface 20 (which can be best recognized in the plan view of FIG. 2) and a passage wall 22 extending from the passage bottom surface 20. The passage wall 22 may extend perpendicularly from the passage bottom surface 20. The passage wall 22 has a non-straight passage wall contour in a direction parallel to the plane of the passage bottom surface 20. Looking at the enlarged portions in FIGS. 1 and 2, in the examples shown in FIGS. 1 and 2, the passage wall contour includes a first wall section 24 and a second wall section 26 facing the first wall section 24. In this example, the non-straight passage wall contour is configured as a semi-circular corrugated passage wall contour. In this case, each of the wall sections 24, 26 is configured as semi-circular wall segments 28 adjacent to each other, whereby the semi-circular wall segments 28 of the first wall section 24 are positioned facing the corresponding semi-circular wall segments 28 of the second wall section 26. Further, in the examples shown in FIGS. 1 and 2, in order to minimize the occupied area of the heat sink, the first port 16 and the second port 18 are located on the same side of the heat sink body 12. In such a configuration, the fluid passage 14 includes a first passage portion 30 and a second passage portion 32 that flow cooling fluid in opposite directions to each other. The first passage portion 30 and the second passage portion 32 are connected by a passage bridge 34 and are otherwise separated from each other by a central body portion 36 of the heat sink body 12.

[0034] The passage wall 22 is positioned to surround an array of pin fins 38 extending from the passage bottom surface 20. The pin fins 38 may extend perpendicularly from the passage bottom surface 20. In the examples of FIGS. 1 and 2, each of the pin fins 38 is a cylindrical pin fin having a circular cross-sectional shape extending perpendicularly from the passage bottom surface 20. The pin fins in the array may be evenly distributed, whereby each of the pin fins 38 in the array is spaced equidistant from the adjacent pin fins.

[0035] For example, a non-straight passage wall contour including semi-circular wall segments adjacent to each other increases turbulence inside the fluid passage, and thus improves heat transfer efficiency. An additional arrangement of pin fins combined with a semi-circular corrugated passage wall contour further provides optimal fluid distribution inside the fluid passage and increases the surface area in contact with the cooling fluid for better heat transfer. More generally, the shape and position of the passage wall contour with respect to the pin fins are defined such that the cross-sectional space (area) between the passage wall and the pin fins is the same as the space between each of the pin fins. This configuration helps to equally distribute the fluid across the cross-section of the heat sink and eliminates the problem of a larger portion of the flow flowing near the passage wall. Thus, due to the passage wall contour shape, the flow path will have a constant volume or a constant area in each section of this flow path. The aforementioned configuration of arranging the pin fins and the non-straight fluid passage wall segments enables the heat sink to be more compact while still achieving the required cooling with less pressure drop compared to conventional configurations. The pin fins may be arranged in different sets of rows and columns, each having a different number of pin fins, as can be seen in FIGS. 1 and 2 showing examples of alternating rows of three and four pin fins. The pin fins may also have different pin fin diameters in order to enhance the heat transfer ability of the heat sink. The pin fins and the non-straight heat sink fluid passage wall may be fabricated using sand casting or pressure die casting, which helps to reduce the manufacturing cost and provides a simple configuration with effective heat transfer in a small footprint.

[0036] Accordingly, the array of pin fins is arranged in a plurality of rows and columns located inside the fluid passage and extending from the passage bottom surface, and the passage wall is positioned to surround the array of pin fins. The passage wall and the array of pin fins are positioned such that there is a constant flow area for the flow of the cooling fluid across each of the plurality of rows and columns.

[0037] Figure 2A is a diagram showing an enlarged portion of a heat sink indicating a variation in the configuration of FIG. 2, and further, a diagram showing the concept of a constant flow area across the heat sink. As can be seen in FIG. 2A, the shortest distance between adjacent pin fins as indicated by the arrows is constant or the same throughout the array of rows and columns of pin fins. Similarly, for pin fins positioned adjacent to the passage wall, for example, the pin fins positioned adjacent to the first wall section 24 of the passage wall 22 shown in FIG. 2A, as further indicated by the arrows, the shortest distance between such pin fins positioned adjacent to the passage wall and the passage wall is the same as the shortest distance between adjacent pin fins within the rows and columns of the pin fin array. In such a configuration, using circular-based shaped pin fins and the passage wall contour, there is a constant flow area for the flow of the cooling fluid across each of the rows and columns among the plurality of rows and columns in the pin fin array.

[0038] FIG. 3 is a perspective view of an exemplary heat sink 10 of FIG. 1, and further shows an additional cover plate 40 and a seal 43. The heat sink body 12 has a first outer surface 42 and a concave shelf 44 formed by a step 46 with respect to the first outer surface 42. The concave shelf 44 extends along the entire circumference of the edge of the passage wall 22 on the side opposite to the passage bottom surface 20. The concave shelf 44 is shaped to attach the cover plate 40, whereby the cover plate 40 covers the spread range of the fluid passage 14, and when the cover plate 40 is attached inside the concave shelf 44, it is in the same plane as the first outer surface 42. When properly positioned, the cover plate 40 is fixed to the concave shelf 44. The cover plate 40 and the concave shelf 44 may have aligned fastening holes 47, 49 for attaching a fastening element 50, which may be bolts, screws or another suitable fastener, respectively. As another example, the cover plate 40 may be fixed to the concave shelf 44 using an adhesive or similar material that adheres or bonds the cover plate to the concave shelf. To prevent leakage of fluid from the heat sink, there may be a seal 43, such as an O-ring seal, that seals the contact surface between the concave shelf 44 and the cover 40. The concave shelf 44 has a groove 45 for accommodating the O-ring seal 43.

[0039] FIG. 4 is a perspective view of an exemplary heat sink 10 in combination with an electronic device package 52 in which the heat sink 10 is assembled to form an operating assembly 54. FIG. 5 is a side view of an operating assembly 54 including the combination of the heat sink 10 and the electronic device package 52 of FIG. 4. FIG. 6 is a cross-sectional view of an operating package 54 including the combination of the heat sink and the electronic device package of FIGS. 4 and 5, and further shows pin fins positioned relative to the electronic device package. The electronic device package includes one or more electronic circuit components that generate heat during use. As described above, one exemplary application is an electronic controller for an electric motor, and this electronic controller includes one or more electronic circuit components that generate heat, such as transistors. As will be detailed further below, the heat sink serves to dissipate the heat generated by the electronic circuit components. Further, although the heat sink 10 is described mainly in relation to dissipating heat from electronic components, the heat sink is not limited to use with electronic components and may be used in any other application where it is necessary to remove heat from a system.

[0040] The electronic device package 52 is assembled to a second outer surface 56 of the heat sink body 12, and this second outer surface 56 is positioned opposite the first outer surface 42 and the cover plate 40. The electronic device package 52 is assembled to the heat sink 10 at the second outer surface 56 using a fastener 58 that may be a bolt, a screw, or another suitable fastener. The electronic device package 52 includes a support board 60 to which one or more electronic circuit components 62 that generate heat (see particularly FIGS. 5 and 6) are attached. As described above, an exemplary application is an electronic controller including transistors as one or more electronic circuit components 62 that generate heat, but as described above, the heat sink 10 may be used to dissipate heat from any suitable heat-generating device.

[0041] Referring particularly to the cross-sectional view of FIG. 6, the second outer surface 56 and the passage bottom surface 20 are opposite surfaces of the outer portion of the heat sink body 12. In such a configuration, the passage bottom surface 20 is the inner surface of the heat sink body that transfers heat to the second outer surface 56. The pin fins 38 extend from the passage bottom surface 20 into the fluid passage 14 in a direction opposite to the second outer surface 56. The electronic device package 52 is fixed to the outer surface 56 of the heat sink body 12, and the heat-generating electronic circuit components 62 are positioned or positioned adjacent to the second outer surface 56 of the heat sink body 12.

[0042] During operation, a cooling fluid (e.g., water, a working fluid, or another suitable cooling fluid) reaches the first port 16 and is caused to flow into the fluid passage 14, and the cooling fluid flows through the fluid passage 14 and reaches the second port 18. When one or more electronic circuit components 62 operate, the heat generated by this electronic circuit component is heat-transferred into the heat sink body 12 through the outer surface 56 at the position of the electronic circuit component. Heat is transferred to the fluid passage 14 through the passage wall 22 and through the pin fins 38. The cooling fluid flowing around the pin fins absorbs the heat, and this heat is removed from the heat sink by the outflow of the cooling fluid through the second port 18. As described above, for example, a configuration of a non-straight passage wall profile including semi-circular wall segments of waveforms adjacent to each other increases turbulent flow inside the fluid passage, and thus improves heat transfer efficiency. The additional arrangement of the pin fins combined with the non-straight passage wall profile further provides optimal fluid distribution inside the fluid passage and increases the surface area in contact with the cooling fluid for better heat transfer. The distribution provides an even arrangement of the pin fins in an array arranged in regular rows and / or columns and / or in an even distribution arrangement, whereby each pin fin in the array is spaced equidistant from adjacent pin fins and / or spaced equidistant from the passage wall. In such a configuration, there is a constant flow area for the flow of the cooling fluid across each row and column of the plurality of rows and columns in the array of pin fins.

[0043] The pin fins and the fluid passage wall segments may have another suitable regular shape as long as the flow cross-sectional area surrounding each pin fin is uniform. Rhombus, square, hexagon, ellipse, or other regularly shaped pin fins and / or passage wall segments may be used. As described above, the shape and position of the passage wall contour with respect to the pin fins are defined such that the cross-sectional space (area) between the passage wall and the pin fins is the same as the space between each of the pin fins. This configuration helps to equally distribute the fluid across the cross-section of the heat sink and eliminates the problem of a larger portion of the flow flowing near the passage wall. Thus, due to the passage wall contour shape, the flow path will have a constant volume or a constant area for each section of the flow elements.

[0044] Thus, any suitable combination of a passage wall contour and a pin fin cross-sectional shape that meets such criteria may be used. For example, FIG. 7 is a perspective view showing another exemplary heat sink 100 according to an embodiment of the present application, and FIG. 8 is a plan view showing the exemplary heat sink 100 of FIG. 7. The configuration of the heat sink 100 is similar to that of the heat sink 10 in FIGS. 1 to 6, except that the heat sink 100 uses a configuration of pin fins of different shapes. Thus, the heat sink 100 includes a heat sink body 112, and the heat sink body 112 defines a fluid passage 114 extending through the heat sink body 112. The heat sink body 112 includes a first port 116 and a second port 118 that are in fluid communication with the fluid passage 114 for the flow of the cooling fluid. In the previous embodiment, the first port and the second port were located on the same side of the heat sink body. In the variations of FIGS. 7 and 8, the first port 116 and the second port 118 are located on opposite sides of the heat sink body 112, and the cooling fluid travels through the heat sink body from the first port 116 to the second port 118 (or vice versa).

[0045] With respect to the definition of the fluid passage 114, the heat sink body 112 includes a passage bottom surface 120 (which can be best recognized in the plan view of FIG. 8) and a passage wall 122 extending from the passage bottom surface 120. The passage wall 122 may extend perpendicularly from the passage bottom surface 120. Similar to the previous embodiment, in the examples of FIGS. 7 and 8, the passage wall 122 has a non-straight passage wall contour in a direction parallel to the plane of the passage bottom surface 120. This non-straight passage wall contour is configured as a semi-circular corrugated passage wall contour. In this case, each of the mutually opposed wall sections 124, 126 is configured as semi-circular wall segments 128 adjacent to each other. As a result, the semi-circular wall segments 128 of the first wall section 124 are positioned opposite to the corresponding semi-circular wall segments 128 of the second wall section 126.

[0046] The passage wall 122 is positioned to surround an array of pin fins 138 extending from the passage bottom surface 120. The pin fins 138 may extend perpendicularly from the passage bottom surface 120. In the examples of FIGS. 7 and 8, each of the pin fins 138 is a rod pin fin having a rhombic cross-sectional shape extending perpendicularly from the passage bottom surface 120. The pin fins in the array may be evenly distributed, whereby each of the pin fins 138 in the array is spaced equidistant from the adjacent pin fins and / or equidistant from the passage wall. The arrays of pin fins may be arranged in rows with different numbers of pin fins. In one embodiment, the wall segments forming the passage wall contour each have a shape corresponding to the cross-sectional shape of the pin fins, that is, the semi-circular wall segment shape is combined with circular cross-sectional pin fins as shown in FIGS. 1 and 2, or the semi-rhombic wall segment shape is combined with rhombic cross-sectional pin fins. Alternatively, in another embodiment, the wall segments forming the passage wall contour each have a shape different from the shape corresponding to the cross-sectional shape of the pin fins, that is, the semi-circular wall segment shape is combined with rhombic cross-sectional pin fins as shown in FIGS. 7 and 8.

[0047] In such a combination of passage wall / pin fin shapes, similar to the previous embodiments, the shortest distance between adjacent pin fins is constant or the same throughout the array of rows and columns of pin fins. Similarly, for the pin fins positioned adjacent to the passage wall, the shortest distance between such pin fins positioned adjacent to the passage wall and the passage wall is the same as the shortest distance between adjacent pin fins within the rows and columns of the pin fin array. In such a configuration, diamond-based shaped pin fins and a semi-circular passage wall contour are used to provide a constant flow area for the flow of cooling fluid across each of the plurality of rows and columns in the pin fin array.

[0048] FIG. 9 is a perspective view showing an exemplary heat sink 100 of FIG. 7 and further shows an additional cover plate 140. In this example, the heat sink body 112 has a first outer surface 142 shaped to attach the cover plate 140, whereby the cover plate 140 covers the extent of the fluid passage 114. In this example, the cover plate 140 is directly fastened or secured substantially over the entire extent of the outer surface 142 (i.e., unlike the previous embodiments, in this embodiment, no recessed shelf is used). The cover plate 140 and the outer surface 142 may have aligned fastening holes 146, 148 for attaching a fastening element 150, which may be bolts, screws or another suitable fastener, respectively. As another example, the cover plate 140 may be secured to the outer surface 142 using an adhesive or similar material that bonds or couples the cover plate to the heat sink body. When assembled with the cover plate, the heat sink 100 may be secured to an electronic device package as described above in connection with FIGS. 4 - 6, thereby removing or dissipating heat generated by one or more electronic components of the electronic device package.

[0049] As another example of different shaped configurations of the combination of the pin fins and the passage wall contour, FIGS. 10 and 11 are views showing a perspective view of another exemplary heat sink 200 according to an embodiment of the present application, and FIG. 11 is a view showing a plan view of the exemplary heat sink 200 of FIG. 10. The heat sink 200 includes a heat sink body 212, and the heat sink body 212 defines a fluid passage 214 that extends through the heat sink body 212. The heat sink body 212 includes a first port 216 and a second port 218 that are in fluid communication with the fluid passage 214 for the flow of the cooling fluid. Also in the variations of FIGS. 10 and 11, the first port 216 and the second port 218 are located on opposite sides of the heat sink body 212, and the cooling fluid travels from the first port 216 to the second port 218 (or vice versa) through the heat sink body.

[0050] Regarding the definition of the fluid passage 214, the heat sink body 212 includes a passage bottom surface 220 (which can be best recognized in the plan view of FIG. 11) and a passage wall 222 that extends from the passage bottom surface 220. The passage wall 222 may extend perpendicularly from the passage bottom surface 220. In the examples of FIGS. 10 and 11, the passage wall 222 has a non-straight passage wall contour in a direction parallel to the plane of the passage bottom surface 220, and this non-straight passage wall contour is configured as a semi-rhombic passage wall contour. In this case, each of the mutually opposed wall sections 224, 226 is configured as a semi-rhombic wall segment 228 adjacent to each other, whereby the semi-rhombic wall segments 228 of the first wall section 224 are positioned opposite to the corresponding semi-rhombic wall segments 228 of the second wall section 226.

[0051] The passage wall 222 is positioned to surround an array of pin fins 238 extending from the passage bottom surface 220. The pin fins 238 may extend perpendicularly from the passage bottom surface 220. In the examples of FIGS. 10 and 11, each of the pin fins 238 is a rod pin fin having a rhombic cross-sectional shape that extends perpendicularly from the passage bottom surface 220. The pin fins in the array may be evenly distributed, such that each pin fin 238 in the array is spaced equidistant from adjacent pin fins and / or equidistant from the passage wall.

[0052] Accordingly, similar to the previous embodiments, the array of pin fins is disposed in a plurality of rows and columns located within the fluid passage and extending from the passage bottom surface, and the passage wall is positioned to surround the array of pin fins. The passage wall and the array of pin fins are positioned such that a constant flow area exists for the flow of the cooling fluid across each row and column of the plurality of rows and columns. FIG. 12 is a view showing a portion of the heat sink of FIG. 11 and further shows the concept of a constant flow area for the passage wall / pin fin shape combination of FIGS. 10 and 11. As can be seen in FIG. 12, the shortest distance between adjacent pin fins is constant or the same throughout the array of rows and columns of pin fins. Similarly, for the pin fins positioned adjacent to the passage wall, such as the pin fins positioned adjacent to the first wall section 224 of the passage wall 222 shown in FIG. 12, the shortest distance between such pin fins positioned adjacent to the passage wall and the passage wall is the same as the shortest distance between adjacent pin fins within the rows and columns of the array of pin fins. In such a configuration, a constant flow area exists for the flow of the cooling fluid across each row and column of the plurality of rows and columns in the array of pin fins using the pin fins shaped based on a rhombus and the passage wall contour.

[0053] FIG. 13 is a perspective view of an exemplary heat sink 200 of FIG. 10 and further shows an additional cover plate 240. In this example, the heat sink body 212 has a first outer surface 242 shaped to attach the cover plate 240, whereby the cover plate 240 covers the extent of the fluid passage 214. Also in this example, the cover plate 240 is directly fastened or secured substantially over the entire extent of the outer surface 242. The cover plate 240 and the outer surface 242 may have aligned fastening holes 246, 248 for attaching a fastening element 250, which may be bolts, screws or another suitable fastener, respectively. As another example, the cover plate 240 may be secured to the outer surface 242 using an adhesive or similar material that adheres or bonds this cover plate to the heat sink body. When assembled with the cover plate, the heat sink 200 may be secured to the electronic device package as described above in connection with FIGS. 4 - 6, whereby heat generated by one or more electronic components of this electronic device package can be removed or dissipated.

[0054] As another example of different shaped configurations of the combination of pin fins and passage wall contours, FIG. 14 is a perspective view of another exemplary heat sink 300 according to an embodiment of the present application, and FIG. 15 is a plan view of the exemplary heat sink 300 of FIG. 14. The heat sink 300 includes a heat sink body 312 that defines a fluid passage 314 extending therethrough. The heat sink body 312 includes a first port 316 and a second port 318 that are in fluid communication with the fluid passage 314 for the flow of a cooling fluid. Also in the variations of FIGS. 14 and 15, the first port 316 and the second port 318 are located on opposite sides of the heat sink body 312, and the cooling fluid travels through the heat sink body from the first port 316 to the second port 318 (or vice versa).

[0055] Regarding the definition of the fluid passage 314, the heat sink body 312 includes a passage bottom surface 320 (which can be best recognized in the plan view of FIG. 15) and a passage wall 322 extending from this passage bottom surface 320. This passage wall 322 may extend perpendicularly from the passage bottom surface 320. In the examples of FIGS. 14 and 15, the passage wall 322 has a non-straight passage wall contour in a direction parallel to the plane of the passage bottom surface 320. This non-straight passage wall contour is configured as a semi-elliptical passage wall contour. In this case, each of the mutually opposed wall sections 324, 326 is configured as semi-elliptical wall segments 328 adjacent to each other. As a result, the semi-elliptical wall segments 328 of the first wall section 324 are positioned opposite to the corresponding semi-elliptical wall segments 328 of the second wall section 326.

[0056] The passage wall 322 is positioned so as to surround an array of pin fins 338 extending from the passage bottom surface 320. The pin fins 338 may extend perpendicularly from the passage bottom surface 320. In the examples of FIGS. 14 and 15, each of the pin fins 338 is a rod pin fin having an elliptical cross-sectional shape extending perpendicularly from the passage bottom surface 320. The pin fins in the array may be evenly distributed, whereby each of the pin fins 338 in the array is spaced equidistant from adjacent pin fins and / or spaced equidistant from the passage wall.

[0057] Thus, similar to the previous embodiment, the pin fin array is arranged in a plurality of rows and columns located inside the fluid passage and extending from the bottom surface of the passage, and the passage walls are positioned to surround the pin fin array. The passage walls and the pin fin array are positioned such that a constant flow area exists for the flow of the cooling fluid across each row and column of the plurality of rows and columns. FIG. 16 is a view showing a part of the heat sink of FIG. 15, and further, is a view showing the concept of a constant flow area for the combination of the passage wall / pin fin shapes of FIGS. 14 and 15. As can be seen in FIG. 16, the shortest distance between adjacent pin fins is constant or the same throughout the array of rows and columns of pin fins. Similarly, for the pin fins positioned adjacent to the passage wall, for example, the pin fins positioned adjacent to the first wall section 324 of the passage wall 322 shown in FIG. 16, the shortest distance between such pin fins positioned adjacent to the passage wall and the passage wall is the same as the shortest distance between adjacent pin fins within the rows and columns of the pin fin array. In such a configuration, elliptically shaped pin fins and wall sections are used to provide a constant flow area for the flow of the cooling fluid across each row and column of the plurality of rows and columns in the pin fin array.

[0058] FIG. 17 is a perspective view of an exemplary heat sink 300 of FIG. 14 and further shows an additional cover plate 340. In this example, the heat sink body 312 has a first outer surface 342 shaped to attach the cover plate 340, whereby the cover plate 340 covers the extent of the fluid passage 314. Also in this example, the cover plate 340 is directly fastened or secured substantially over the entire extent of the outer surface 342. The cover plate 340 and the outer surface 342 may have aligned fastening holes 346, 348 for attaching a fastening element 350, which may be bolts, screws or another suitable fastener, respectively. As another example, the cover plate 340 may be secured to the outer surface 342 using an adhesive or similar material that adheres or bonds the cover plate to the heat sink body. When assembled with the cover plate, as described above in connection with FIGS. 4 - 6, the heat sink 300 may be secured to an electronic device package, thereby removing or dissipating heat generated by one or more electronic components of the electronic device package.

[0059] Although the invention has been shown and described with respect to certain embodiments or embodiments, it will be apparent to those skilled in the art upon reading and understanding this specification and the accompanying drawings that equivalent changes and modifications will occur to them. In particular, with respect to the various functions realized by the elements (parts, assemblies, devices, compositions, etc.) described above, the terms used to describe such elements (including references to "means") are intended to correspond to any element that performs the specified function of the described element (i.e., is functionally equivalent), even if not structurally equivalent to the disclosed structure that realizes the function in one or more exemplary embodiments of the invention illustrated herein. Further, although certain features of the invention have been described above with respect to only one or more of the numerous exemplary embodiments illustrated, such features may be combined with one or more other features of another embodiment, if desired and advantageous for any given or particular application.

Claims

1. A heat sink, wherein the heat sink includes a heat sink body having a first port and a second port, and the heat sink body defines a fluid passage between the first port and the second port to accommodate a flow of a cooling fluid between the first port and the second port, the heat sink body includes a passage bottom surface and a passage wall extending from the passage bottom surface for defining the fluid passage, and the passage wall includes a plurality of wall segments forming a non-straight passage wall contour, the heat sink includes an array of pin fins arranged in a plurality of rows and columns, located inside the fluid passage and extending from the passage bottom surface, and the passage wall is positioned to surround the array of pin fins, the passage wall and the array of pin fins are positioned such that a constant flow area exists for the flow of the cooling fluid across each row and column of the plurality of rows and columns, a heat sink.

2. The heat sink according to claim 1, wherein the plurality of wall segments include semi-circular wall segments adjacent to each other forming a corrugated passage wall contour.

3. The heat sink according to claim 1 or 2, wherein the pin fins are cylindrical pin fins having a circular cross-sectional shape.

4. The heat sink according to claim 1 or 2, wherein the pin fins are rods having a rhombic cross-sectional shape.

5. The heat sink according to claim 1, wherein each of the plurality of wall segments has a shape corresponding to the cross-sectional shape of the pin fins.

6. The heat sink according to claim 5, wherein the plurality of wall segments include semi-circular wall segments adjacent to each other forming a corrugated passage wall contour, and the pin fins are cylindrical pin fins having a circular cross-sectional shape.

7. The heat sink according to claim 5, wherein the plurality of wall segments include semi-rhombic wall segments adjacent to each other forming a rhombic passage wall contour, and the pin fins are rod pin fins having a rhombic cross-sectional shape.

8. The heat sink according to claim 5, wherein the plurality of wall segments include semi-elliptical wall segments adjacent to each other forming an elliptical passage wall contour, and the pin fins are rod pin fins having an elliptical cross-sectional shape.

9. The heat sink according to claim 1, wherein each of the plurality of wall segments has a shape different from the cross-sectional shape of the pin fin.

10. The heat sink according to claim 9, wherein the plurality of wall segments include semi-circular wall segments adjacent to each other that form a corrugated passage wall contour, and the pin fin is a rod pin fin having a rhombic cross-sectional shape.

11. The pin fins in the array have a uniform arrangement pattern, whereby each pin fin in the array is spaced equidistant from adjacent pin fins and / or spaced equidistant from the passage wall, according to any one of claims 1 to 10. The heat sink described in the item.

12. The heat sink according to any one of claims 1 to 11, wherein the pin fins are arranged in different sets of rows and columns each having a different number of pin fins.

13. The heat sink according to any one of claims 1 to 12, wherein the passage wall and the pin fin extend perpendicularly from the passage bottom surface.

14. The passage wall includes a first wall section and a second wall section facing the first wall section, and the plurality of wall segments each include opposing wall segments located in the first wall section and the second wall section, respectively. The heat sink according to any one of claims 1 to 13.

15. The first port and the second port are located on the same side of the heat sink body, and the fluid passage includes a first passage portion and a second passage portion through which the cooling fluid flows in opposite directions, and the first passage portion and the second passage portion are connected by a passage bridge and otherwise separated by a central body portion of the heat sink body, according to any one of claims 1 to 14. The heat sink described in the item.

16. The heat sink according to any one of claims 1 to 14, wherein the first port and the second port are located on opposite sides of the heat sink body.

17. The shortest distance between adjacent pin fins is constant throughout the rows and columns of the array of pin fins, and for the pin fins positioned adjacent to the passage wall, the shortest distance between the pin fin positioned adjacent to the passage wall and the passage wall is the same as the shortest distance between adjacent pin fins within the rows and columns of the array of pin fins. The heat sink according to any one of claims 1 to 16.

18. The heat sink according to any one of claims 1 to 17, further comprising a cover plate fixed to the outer surface of the heat sink body and covering the spread range of the fluid passage.

19. The heat sink body is a concave shelf portion, formed as a stepped portion with respect to the outer surface, extending along the entire circumference of the edge of the passage wall on the side opposite to the passage bottom surface, and including a concave shelf portion for attaching the cover plate. The heat sink according to claim 18.

20. An operating assembly, A heat sink according to any one of claims 1 to 17, including a first outer surface and a second outer surface opposite to the first outer surface, wherein the passage bottom surface is the inner surface of the heat sink body that transfers heat to the second outer surface, and the array of pin fins extends from the passage bottom surface into the fluid passage in a direction opposite to the second outer surface. A heat sink, A cover plate fixed to the first outer surface of the heat sink body and covering the spread range of the fluid passage, An electronic device package assembled to the second outer surface of the heat sink body, including electronic components that generate heat, and the electronic components are positioned adjacent to the second outer surface of the heat sink body such that the heat generated by the electronic components is transferred to the fluid passage through the passage bottom surface and the pin fins. An electronic device package Comprising an operating assembly.

21. The passage bottom surface and the second outer surface are opposite surfaces of the outer portion of the heat sink body. The operating assembly according to claim 20.

22. The heat sink body is a concave shelf portion, which is formed as a stepped portion with respect to the first outer surface, extends along the entire circumference of the edge of the passage wall on the side opposite to the passage bottom surface, and includes a concave shelf portion for attaching the cover plate, according to the operation assembly of claim 20 or 21.

Images