Heatsink Assembly

Abstract

In one example, the disclosed heat sink assembly includes a heat sink having a plurality of ribs integrally molded by extrusion along its internal longitudinal direction, the spaces between the ribs forming flow paths, and first and second surfaces open at both longitudinal ends; and a pair of end plugs that close the first and second surfaces at both ends of the heat sink, respectively. The ribs of the heat sink include a center rib that is closed at one end on the first surface side of the pair of end plugs and open at the other end on the second surface side, and side ribs that are positioned on at least one side of the center rib and have both ends open on the first and second surfaces.

Description

[Technical Field]

[0001] The present invention relates to a heat sink assembly that is attached to the bottom of a battery pack that includes a plurality of secondary batteries and promotes heat dissipation from the battery pack.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0069307, filed May 30, 2023, and Korean Patent Application No. 10-2024-0067688, filed May 24, 2024, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference. [Background technology]

[0003] Unlike primary batteries, secondary batteries are rechargeable and have the potential to be small and have large capacities, and as such, they have been the subject of much research and development in recent years. Demand for secondary batteries as an energy source is rapidly increasing due to the increasing technological development and demand for mobile devices, as well as the emergence of electric vehicles and energy storage systems in response to modern demands for environmental protection.

[0004] Secondary batteries are classified into coin-type batteries, cylindrical batteries, prismatic batteries, and pouch-type batteries depending on the shape of the battery case. The electrode assembly installed inside the battery case of a secondary battery is a power generating element that can be charged and discharged and is made up of a laminated structure of electrodes and a separator.

[0005] Since secondary batteries are required to be used continuously for a long period of time, it is necessary to effectively control the heat generated during the charging and discharging process.If the secondary battery is not cooled smoothly, a positive feedback chain reaction will occur in which a rise in temperature causes an increase in current, and the increase in current causes another rise in temperature, ultimately leading to a catastrophic state of thermal runaway.

[0006] Heat sinks (also called cooling plates) through which a refrigerant flows are widely used to effectively dissipate heat generated by secondary batteries. Heat sinks are attached to the bottom of a group of multiple secondary batteries, such as a battery pack containing multiple secondary batteries, and perform a cooling function by absorbing heat generated inside the pack with a refrigerant and dissipating it to the outside.

[0007] Heat sinks can be divided into brazed and extruded heat sinks depending on their structure or manufacturing method. Brazed heat sinks are made by brazing two plates together to form flow channels, which allows for greater freedom in flow channel design, but has the disadvantage of reduced structural rigidity due to the material's reduced physical properties. In contrast, extruded heat sinks, which are manufactured as a continuous body through extrusion molding, have the advantage of structural rigidity, but can only form linear flow channels, resulting in a large number of ports, which means connecting pipes take up space. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention aims to provide a heat sink assembly that is an extruded heat sink but does not require a separate pipe for forming a flow path, occupies less space, and has a simplified flow path configuration that reduces the number of parts, thereby improving differential pressure.

[0009] However, the technical problems that the present invention aims to solve are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below. [Means for solving the problem]

[0010] The present invention relates to a heat sink assembly, which in one example includes a heat sink having a plurality of ribs integrally formed by extrusion along its internal longitudinal direction, with the spaces between the ribs forming flow paths and first and second surfaces open at both longitudinal ends, and a pair of end plugs that close the first and second surfaces at both ends of the heat sink, respectively. The ribs of the heat sink include a center rib that is closed at one end on the first surface side of the pair of end plugs and open at the other end on the second surface side, and side ribs that are positioned on at least one side of the center rib and have both ends open on the first and second surfaces.

[0011] In one embodiment of the present invention, based on the center rib on the first surface side, one end of which is closed relative to the end plug, an inlet port may be arranged on one side along the width direction, and an outlet port may be arranged on the other side.

[0012] A plurality of side ribs may be provided, and one end of each of the side ribs on the first surface side may move away from the first surface as it approaches the center rib, and the other end of each of the side ribs on the second surface side may move closer to the second surface as it approaches the center rib.

[0013] The side ribs may be provided in a plurality on both sides in the width direction of the center rib.

[0014] Meanwhile, in one embodiment of the present invention, the pair of end plugs may be joined to the first and second surfaces of the heat sink by welding, respectively.

[0015] In one example, the pair of end plugs are friction stir welded to the upper and lower surfaces of the first and second surfaces of the heat sink, wherein the weld depths of the friction stir welds on the upper and lower surfaces can overlap each other.

[0016] Alternatively, the pair of end plugs may be friction stir welded to the upper or lower surfaces of the first and second surfaces of the heat sink, respectively, and the welding depth of the friction stir weld may start from the upper or lower surface, penetrate through the end plugs, and reach at least a portion of the upper or lower surface.

[0017] The heat sink may have different thicknesses formed by the upper and lower surfaces relative to the flow path on the first and second surfaces.

[0018] The welding depth of the friction stir welding on the first and second surfaces of the heat sink can start from either the upper or lower surface, which has a thinner thickness relative to the flow path, and penetrate through the end plug to at least a portion of the other surface, which has a thicker thickness.

[0019] In another example, the pair of end plugs may be friction stir welded to the upper and lower surfaces of the first and second surfaces of the heat sink, and additional auxiliary welds may be formed on the side surfaces of the pair of end plugs and the first and second surfaces.

[0020] The auxiliary weld is formed in a region where the welding depths of the friction stir welding on the upper and lower surfaces do not overlap each other.

[0021] The welding depth of the friction stir welding on the upper and lower surfaces is connected by the auxiliary weld.

[0022] In some embodiments, the auxiliary weld may be formed on a work surface that exposes the weld depth of the friction stir welds on the upper and lower surfaces, interconnecting the weld depths of the friction stir welds on the upper and lower surfaces that do not overlap each other.

[0023] In another example, the pair of end plugs may be joined to the first and second surfaces of the heat sink by friction stir welding along the width direction of the front faces of the end plugs.

[0024] In such a case, the welding depth of the friction stir welding extends over the top, bottom and side surfaces of the first and second surfaces of the heat sink. [Effects of the Invention]

[0025] The heat sink assembly of the present invention having the above-described configuration has excellent structural rigidity because the heat sink is manufactured as a continuous body by extrusion molding, and at the same time, a center rib and side ribs are formed by machining both longitudinal ends of the ribs formed integrally with the heat sink, and a pair of end plugs are attached to both ends, thereby forming a cooling flow path divided into an inlet and an outlet.

[0026] As a result, the heat sink assembly of the present invention is based on an extruded heat sink, which has the advantage of structural rigidity, but does not require a separate pipe for forming a flow path, occupies less space, and has a simplified flow path configuration that reduces the number of parts, thereby improving differential pressure.

[0027] However, the technical effects that can be obtained by the present invention are not limited to the effects described above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0028] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical concept of the present invention, and therefore the present invention should not be interpreted as being limited solely to the matters depicted in such drawings. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a view showing a heat sink assembly according to an embodiment of the present invention; [Figure 2] FIG. 2 is an exploded perspective view of the heat sink assembly. [Figure 3]10 is a diagram showing in detail the structure of a rib formed integrally inside a heat sink; [Figure 4] 4 is a diagram showing the flow of a coolant in a heat sink assembly. [Figure 5] 1 is a diagram showing an embodiment of a welding structure between a heat sink and an end plug. [Figure 6] 1 is a view showing an embodiment of a unidirectional welded structure between a heat sink and an end plug. [Figure 7] 1 is a view showing an embodiment of a unidirectional welded structure between a heat sink and an end plug. [Figure 8] 10 is a view showing another embodiment of a welding structure between a heat sink and an end plug. [Figure 9] 10 is a view showing another embodiment of a welding structure between a heat sink and an end plug. [Figure 10] 1 is a view showing an example in which a heat sink assembly according to the present invention is applied to a pack case; DETAILED DESCRIPTION OF THE INVENTION

[0030] Because the present invention can be modified in various ways and can have various embodiments, specific embodiments will be described in detail below.

[0031] However, this is not intended to limit the invention to any particular embodiment, but rather to be understood as including all modifications, equivalents, or alternatives falling within the spirit and scope of the invention.

[0032] In the present invention, terms such as "comprise" and "have" are intended to specify the presence of features, numbers, steps, operations, components, parts or combinations thereof described in the specification, and may be understood as not precluding the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0033] Furthermore, in the present invention, when a layer, film, region, plate, or other portion is described as being "on" another portion, this includes not only the case where it is "directly on" the other portion, but also the case where there is another portion therebetween. Conversely, when a layer, film, region, plate, or other portion is described as being "under" the other portion, this includes not only the case where it is "directly under" the other portion, but also the case where there is another portion therebetween. Furthermore, in this application, being "located on" can include not only the case where it is located at the top, but also the case where it is located at the bottom.

[0034] The present invention relates to a heat sink assembly, which in one example includes a heat sink having a plurality of ribs integrally formed by extrusion along its internal longitudinal direction, with the spaces between the ribs forming flow paths and first and second surfaces open at both longitudinal ends, and a pair of end plugs that close the first and second surfaces at both ends of the heat sink, respectively. The ribs of the heat sink include a center rib that is closed at one end on the first surface side of the pair of end plugs and open at the other end on the second surface side, and side ribs that are positioned on at least one side of the center rib and have both ends open on the first and second surfaces.

[0035] The heat sink assembly of the present invention having the above-described configuration has excellent structural rigidity because the heat sink is manufactured as a continuous body by extrusion molding, and at the same time, a center rib and side ribs are formed by machining both longitudinal ends of the ribs formed integrally with the heat sink, and a pair of end plugs are attached to both ends, thereby forming a cooling flow path divided into an inlet and an outlet.

[0036] As a result, the heat sink assembly of the present invention is based on an extruded heat sink, which has the advantage of structural rigidity, but does not require a separate pipe for forming a flow path, occupies less space, and has a simplified flow path configuration that reduces the number of parts, thereby improving differential pressure.

[0037] Hereinafter, specific embodiments of the heat sink assembly 10 of the present invention will be described in detail with reference to the accompanying drawings. For reference, the directions of front, back, up, down, left, and right used in the following description to designate relative positions are intended to aid in understanding the invention, and unless otherwise specified, are based on the directions shown in the drawings.

[0038] (First embodiment) Fig. 1 is a view showing a heat sink assembly 10 according to an embodiment of the present invention, Fig. 2 is an exploded perspective view of the heat sink assembly 10, and Fig. 3 is a view showing in detail the structure of ribs 110 integrally formed inside the heat sink 100. The heat sink assembly 10 of the present invention will be described in detail with reference to the accompanying Figs. 1 to 3.

[0039] The heat sink assembly 10 of the present invention includes a heat sink 100 manufactured by extrusion molding and a pair of end plugs 200 .

[0040] The heat sink 100 has a configuration corresponding to a main body manufactured as a continuous body by extrusion molding, and a plurality of ribs 110 are integrally formed inside along the longitudinal direction L. The heat sink 100 can be prepared by cutting the extrusion molded product manufactured as a continuous body to a designed length.

[0041] The multiple ribs 110 are arranged at suitable intervals, and each space between the ribs 110 functions as a flow path 120 (refrigerant passage) through which the refrigerant flows. If the surfaces formed by both ends of the heat sink 100 in the longitudinal direction L are defined as a first surface 130 and a second surface 140, respectively, the first surface 130 and the second surface 140 are open. In other words, the ribs 110 formed inside the heat sink 100 can be observed and approached through the first surface 130 and the second surface 140.

[0042] Here, the longitudinal direction L is defined as the extrusion molding direction of the heat sink 100, i.e., the direction in which the ribs 110 extend, and the width direction W is defined as the direction perpendicular to the longitudinal direction L in which the multiple ribs 110 are spaced apart.

[0043] A pair of end plugs 200 are coupled to close the first and second faces 130, 140 of the heat sink 100 at both ends in the longitudinal direction L. The end plug 200 includes an insert 204 inserted into the heat sink 100 and a front face 202 that covers the first and second faces 130, 140 of the heat sink 100 after coupling. That is, the end plug 200 is generally shaped like the letter "T" when viewed in the width direction W. The front face 202 of the end plug 200 conforms to the outlines of the first and second faces 130, 140 of the heat sink 100, and the insert 204 fits snugly into the interior space of the heat sink 100. As will be described later, to ensure space for the insert 204 of the end plug 200 to be inserted, machining is performed to remove portions of both ends of the multiple ribs 110.

[0044] As shown in FIG. 3, the plurality of ribs 110 forming the flow passages 120 inside the heat sink 100 can be divided into a center rib 112 and side ribs 114 depending on their relative positions (contact or non-contact) with the end plug 200.

[0045] The center rib 112 corresponds to a rib 110 that is connected to a pair of end plugs 200 and has one end on the first surface 130 side closed and the other end on the second surface 140 side open. In other words, the center rib 112 divides the space inside the heat sink 100 into two spaces that are disconnected at the first surface 130 but communicate at the second surface 140. Although the center rib 112 is located in the center in FIG. 3 , the center rib 112 does not necessarily need to divide the space inside the heat sink 100 evenly. The center rib 112 should be understood as a rib 110 that serves as a reference for the structure of the entire flow path 120, dividing the internal space of the heat sink 100 so that it continues only to one side of the second surface 140.

[0046] The side ribs 114 refer to the remaining ribs 110 arranged on at least one side in the width direction W with respect to the center rib 112. Unlike the center rib 112, the side ribs 114 have both ends on the first surface 130 and second surface 140 sides open to the pair of end plugs 200. Therefore, the side ribs 114 arranged on either side of the center rib 112 in the width direction W communicate with each other at both ends on the first surface 130 and second surface 140 sides.

[0047] 3 shows multiple side ribs 114 on both sides of the center rib 112 in the width direction W, this is merely an example, and the side ribs 114 can be arranged in various ways. For example, although not shown in the drawing, one or more side ribs 114 may be arranged on only one side of the center rib 112, or multiple side ribs 114 may be arranged on one side while only one side is arranged on the other side. Furthermore, the spacing between the side ribs 114 does not necessarily have to be uniform.

[0048] The structure of the center rib 112 and the side ribs 114, particularly the distance from the first surface 130 and the second surface 140 or the full length of each rib 110, is created to a designed dimension by machining (such as cutting) performed through the first surface 130 and the second surface 140 based on the depth to which the insert 204 of the end plug 200 is inserted. For example, the distance from the first surface 130 of the center rib 112 can be cut to correspond to the length of the insert 204 of the end plug 200, thereby allowing one end of the center rib 112 to be closed on the first surface 130 side.

[0049] In this embodiment of the present invention, an inlet port 210 is disposed on one side of the center rib 112 on the first surface 130, one end of which is closed by the end plug 200, and an outlet port 220 is disposed on the other side along the width direction W. As described above, the center rib 112 divides the interior space of the heat sink 100 into two spaces that are disconnected at the first surface 130 but communicate at the second surface 140. Therefore, by separately disposing the inlet port 210 and the outlet port 220 on both sides of the center rib 112 in the width direction W near the first surface 130, a "U"-shaped flow of refrigerant is created inside the heat sink 100. In FIG. 4, the flow of refrigerant within the heat sink assembly 10 is indicated by arrows.

[0050] When a plurality of side ribs 114 are provided, the relative positions of the side ribs 114 in the longitudinal direction L may be varied while maintaining the same or similar overall length to promote the flow of refrigerant flowing in through the inlet port 210 and out through the outlet port 220. Referring to FIG. 4 , the side ribs 114 may be arranged such that, based on the width direction W, one end of each side rib 114 on the first surface 130 gradually moves away from the first surface 130 as it approaches the center rib 112, while the other end of each side rib 114 on the second surface 140 moves closer to the second surface 140 as it approaches the center rib 112. This relative arrangement of the side ribs 114 reduces the pressure difference of the refrigerant flowing in through the inlet port 210 and out through the outlet port 220, improving the uniformity of the flow rate distribution in each flow path 120.

[0051] (Second embodiment) In the first embodiment, a structure of a heat sink assembly 10 was described that uses an extruded heat sink 100 but does not require a separate pipe to form the flow path 120. The heat sink assembly 10 of the present invention is fabricated by hermetically coupling a pair of end plugs 200 to the open first and second surfaces 130, 140 of the heat sink 100, respectively. In the second embodiment, various structures for effectively hermetically coupling the end plugs 200 to the heat sink 100 will be described.

[0052] The pair of end plugs 200 that seal the open first and second surfaces 130 and 140 of the heat sink 100, respectively, can be connected in various ways, such as by fitting, sealing members, or welding. However, when considering factors such as thermal expansion and contraction due to heat dissipation, airtight stability, durability, and productivity, it is preferable to connect them by welding.

[0053] 5 is a diagram showing one embodiment of a welded structure between a heat sink 100 and an end plug 200. In the illustrated example, a pair of end plugs 200 are friction stir welded to the upper surface 101 and the lower surface 102 of the first surface 130 and the second surface 140 of the heat sink 100, respectively. Friction stir welding is performed across the entire width of the heat sink 100, and in particular, the weld depth 300 of the friction stir welds on the upper surface 101 and the lower surface 102 overlap each other. Because the weld depth 300 on the upper surface 101 and the lower surface 102 overlap, not only are the upper and lower surfaces of the end plug 200 sealed to the upper surface 101 and the lower surface 102 of the heat sink 100, respectively, but sealing is also completed on both sides of the heat sink 100 in the width direction W. In other words, the side of the insert 204 of the end plug 200 and the side of the heat sink 100 in the width direction W are joined to each other by the weld depth 300, where they overlap vertically. In this manner, in the embodiment of FIG. 5, a sealed structure is completed by welding surrounding all four sides of the first surface 130 or the second surface 140 by two friction stir welding operations performed sequentially on the upper surface 101 and the lower surface 102 of the heat sink 100.

[0054] Fig. 6 is a diagram showing a modified embodiment of the welding structure of the heat sink 100 and the end plug 200. While the embodiment of Fig. 5 can be called, for example, a two-way welding structure in which the end plug 200 is joined to the upper surface 101 and the lower surface 102 of the heat sink 100 by friction stir welding, the embodiment of Fig. 6 shows a one-way welding structure in which the end plug 200 is joined to either the upper surface 101 or the lower surface 102 of the heat sink 100 by a single friction stir welding operation.

[0055] The unidirectional welding structure of Fig. 6 is an embodiment applicable when a sufficiently deep weld depth 300 can be formed by friction stir welding. Here, a sufficiently deep weld depth 300 means a weld depth 300 that allows friction stir welding starting from the upper surface 101 or the lower surface 102 of the heat sink 100 to penetrate through the insert 204 of the end plug 200 sandwiched therebetween and reach at least a partial region of the lower surface 102 or the upper surface 101. Fig. 6 exemplarily illustrates a case where friction stir welding is performed on the upper surface 101 of the heat sink 100, and the meaning of a sufficiently deep weld depth 300 can be clearly understood by referring to Fig. 6.

[0056] An advantage of the unidirectional welding structure shown in Figure 6 is that the joining of the end plug 200 and the sealing of the heat sink 100 can be completed by a single friction stir welding operation performed on either the top surface 101 or the bottom surface 102 of the heat sink 100. According to the embodiment of Figure 6, the heat sink 100 is sealed on the top, bottom, and both sides of the end plug 200, similar to the embodiment of Figure 5. As such, if the welding equipment for friction stir welding has the capability to form a sufficiently deep weld depth 300, the productivity of the heat sink assembly 10 can be improved by applying the unidirectional welding structure shown in Figure 6.

[0057] FIG. 7 illustrates another application example of the unidirectional welding structure of FIG. 6, which allows application even when the welding equipment for friction stir welding is somewhat insufficient. Referring to FIG. 7, the thicknesses of the upper surface 101 and the lower surface 102 of the flow passage 120 of the heat sink 100 are different from each other, and friction stir welding is performed on the thinner surface of the heat sink 100, allowing the weld depth 300 to penetrate through the insert 204 of the end plug 200 and reach at least a portion of the other surface. Based on FIG. 7, the thickness of the upper surface 101 of the heat sink 100 is thinner than the thickness of the lower surface 102, and friction stir welding is performed on the upper surface 101 of the heat sink 100. The shape of the end plug 200 also needs to be changed, such as the size of the front surface 202 and the position of the insert 204, to accommodate the asymmetrical thickness structure of the upper and lower surfaces of the heat sink 100.

[0058] The embodiment of Figure 7 has the effect of exceeding the performance limits of friction stir welding equipment and expanding the applicability range of unidirectional welded structures. That is, by designing the structure of the heat sink 100 asymmetrically from the top to bottom in terms of thickness, a sufficiently deep weld depth 300 can be ensured to form a unidirectional welded structure. For reference, the structural rigidity of one side of the thin heat sink 100 (the top side as viewed in the drawing) must be fully considered during design, and if necessary, a supplementary structure (e.g., a rib structure, etc.) that improves rigidity may be added, although this is not shown in the drawing.

[0059] Figure 8 is a view showing another embodiment of the welded structure of the heat sink 100 and the end plugs 200. The embodiment of Figure 8 is the same as the embodiment of Figure 5 in that the pair of end plugs 200 are joined to the upper surface 101 and the lower surface 102 of the first surface 130 and the second surface 140 of the heat sink 100 by friction stir welding, but differs in that additional auxiliary welds 310 are formed on the side surfaces of the pair of end plugs 200 and the first surface 130 and the second surface 140.

[0060] The embodiment of Fig. 8 is intended to strengthen or complement the sealing structure on the side surface in the width direction W of the heat sink 100. In the embodiment of Fig. 5, it is necessary for the weld depth 300 of the friction stir welding on the upper surface 101 and the lower surface 102 to overlap each other, but the welding structure of Fig. 8 can be applied to address cases where it is difficult to ensure a sufficient weld depth 300 in friction stir welding due to performance limitations of the friction stir welding equipment, the possibility of deviation in welding quality due to deterioration of the welding tool over time, or the characteristics of the base material.

[0061] Therefore, the auxiliary weld 310 is basically formed in an area where the welding depth 300 of the friction stir welding on the upper surface 101 and the lower surface 102 do not overlap with each other. As a result, the welding depth 300 of the friction stir welding on the upper surface 101 and the lower surface 102 is completely connected by the auxiliary weld 310, and a tightly sealed structure is completed on both sides of the heat sink 100 in the width direction W.

[0062] 8, auxiliary weld 310 may be formed on machined surface 320 that exposes friction stir weld depth 300 on upper surface 101 and lower surface 102, and interconnects non-overlapping friction stir weld depths 300 on upper surface 101 and lower surface 102. Machined surface 320 is created at a depth that exposes insert 204 of end plug 200, and machined surface 320 may be formed into a curved or flat surface by, for example, milling.

[0063] 9 is a diagram showing another embodiment of the welded structure of the heat sink 100 and the end plug 200. The embodiment of FIG. 9 differs from the embodiments of FIGS. 5 and 8 in the welding direction relative to the end plug 200. In the embodiment of FIG. 9, the end plug 200 is joined to the first surface 130 and the second surface 140 of the heat sink 100 by friction stir welding along the width direction W of the front surface 202 of the end plug 200. That is, as shown in FIG. 9, friction stir welding is performed via the front surface 202 of the end plug 200 rather than the upper surface 101 and lower surface 102 of the heat sink 100.

[0064] 9, as shown in the cross-sectional view, the weld depth 300 of the friction stir weld extends across the top surface 101, bottom surface 102, and side surfaces of the first surface 130 and second surface 140 of the heat sink 100. Because the weld depth 300 extends across the top surface 101, bottom surface 102, and side surfaces of the heat sink 100, the entire joining surface with the end plug 200 is sealed. The embodiment of FIG. 9 has the advantage that sealing of the first surface 130 or second surface 140 of the heat sink 100 is completed by a single friction stir welding operation with the front surface 202 of the end plug 200.

[0065] (Third embodiment) FIG. 10 shows an example in which the heat sink assembly 10 of the present invention, which has been described in detail above, is applied to a pack case 400.

[0066] 10, a heat sink assembly 10 is coupled to the outer side (bottom surface) of a bottom plate 410 of a pack case 400. The illustrated pack case 400 has a structure in which a plurality of battery modules (not shown) are mounted in two rows along the longitudinal direction L, and is configured so that one heat sink assembly 10 is disposed in each row corresponding to the battery modules. However, this is just one example, and it is also possible for one heat sink assembly 10 to be coupled to the entire bottom surface of the pack case 400.

[0067] The two heat sink assemblies 10 are mirror-symmetrical with respect to the arrangement of the inlet ports 210 and outlet ports 220 and the structure of the flow paths 120 with respect to the center of the longitudinal direction L of the pack case 400. In the illustrated embodiment, a pair of inlet ports 210 is located at the center of the width direction W of the pack case 400, and a pair of outlet ports are located farther away on the outside. By the refrigerant absorbing heat from the center of the width direction W, cooling of the inner battery cells, which are disadvantageous in terms of heat dissipation, is effectively performed.

[0068] The present invention has been described in more detail above through the drawings and embodiments, etc. However, the configurations described in the drawings or embodiments in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, and therefore, there may be various equivalents and modifications that can replace them at the time of filing this application. [Explanation of symbols]

[0069] 10: Heat sink assembly 100: Heat sink 101:Top surface 102: Bottom surface 110: Rib 112: Center rib 114: Side rib 120: Flow path 130: 1st page 140:Second side 200: End plug 202:Front 204: Insert 210: Inlet port 220: Exit port 300: Weld depth 310: Auxiliary welding section 320: Machining surface 400: Pack case 410: Bottom plate L: Longitudinal direction W: Width direction

Claims

1. a heat sink in which a plurality of ribs are integrally formed along an internal longitudinal direction by extrusion molding, spaces between the ribs form flow paths, and a first surface and a second surface at both ends in the longitudinal direction are open; a pair of end plugs closing first and second surfaces of the heat sink, respectively; The ribs of the heat sink are A heat sink assembly including a pair of end plugs, each of which has a center rib that is closed at one end on the first surface side and an open end at the other end on the second surface side, and a side rib that is positioned on at least one side of the center rib and has open ends on both the first surface side and the second surface side.

2. With reference to the center rib on the first surface side, one end of which is closed relative to the end plug, 2. The heat sink assembly of claim 1, wherein an inlet port is disposed on one side along the width direction and an outlet port is disposed on the other side.

3. The side ribs are provided in plural, 3. The heat sink assembly of claim 2, wherein one end of each of the side ribs on the first surface moves away from the first surface as it approaches the center rib, and the other end of each of the side ribs on the second surface moves closer to the second surface as it approaches the center rib.

4. The side ribs are The heat sink assembly of claim 3 , wherein a plurality of the ribs are provided on both sides of the center rib in the width direction.

5. The pair of end plugs are The heat sink assembly of claim 1 , wherein the first and second surfaces of the heat sink are respectively welded together.

6. The pair of end plugs are the first surface and the second surface are joined to the upper and lower surfaces of the heat sink by friction stir welding; The heat sink assembly of claim 5 , wherein the friction stir weld depths at the upper and lower surfaces overlap each other.

7. The pair of end plugs are the first surface and the second surface are joined to the upper surface or the lower surface of the heat sink by friction stir welding, 7. The heat sink assembly of claim 1, wherein the welding depth of the friction stir welding starts from the upper or lower surface, penetrates through the end plug, and reaches at least a portion of the lower or upper surface.

8. The heat sink is The heat sink assembly of claim 7 , wherein the first and second surfaces have different thicknesses that the upper and lower surfaces form with respect to the flow passage.

9. 9. The heat sink assembly of claim 8, wherein the welding depth of the friction stir welding on the first and second surfaces of the heat sink starts from one of the upper and lower surfaces, which has a thinner thickness relative to the flow path, and penetrates through the end plug to at least a portion of the other surface, which has a thicker thickness.

10. The pair of end plugs are the first surface and the second surface are joined to the upper and lower surfaces of the heat sink by friction stir welding; 6. The heat sink assembly according to claim 5, wherein additional auxiliary welds are formed on the pair of end plugs and on the side surfaces of the first and second surfaces.

11. The auxiliary weld is The heat sink assembly according to claim 10 , wherein the weld depths of the friction stir welds on the upper and lower surfaces are formed in regions where they do not overlap each other.

12. The heat sink assembly of claim 11 , wherein the friction stir weld depths at the upper and lower surfaces are connected by the auxiliary weld.

13. The auxiliary weld is The upper and lower surfaces are formed on a processed surface that exposes the welding depth of the friction stir welding, The heat sink assembly of claim 10 , wherein the friction stir welds at the upper and lower surfaces interconnect the weld depths so that they do not overlap.

14. The pair of end plugs are The heat sink assembly according to claim 5 , wherein the end plug is joined to the first and second surfaces of the heat sink by friction stir welding along the width direction of the front surface of the end plug.

15. The welding depth of the friction stir welding is The heat sink assembly of claim 14 , spanning a top, bottom, and side surface relative to the first and second surfaces of the heat sink.

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