Heat sink and electronic apparatus

Abstract

The present invention improves cooling efficiency. A heat sink 1 includes: a base 2 to which a plate-like one surface 21a is attached along an outer surface of a right plate 102f which is a standing wall part of a body section 102 of an electronic apparatus 101; a plurality of fins 3 that are arranged side-by-side along a plate-like other surface 21b of the base 2; and passages parts 4 formed continuously, between the fins 3, along the other surface 21b of the base 2. In a state where the base 2 is attached to the right plate 102f, one end 4a of each of the passages 4 is provided so as to be open downward along the vertical direction, and the fins 3 are formed so that the other end 4b of all the passages 4 is positioned on the upper side with respect to the one end 4a, and the other end 4b is open along the horizontal direction.

Description

Heat sinks and electronic devices

[0001] The present invention relates to a heat sink and an electronic device.

[0002] For example, Patent Document 1 discloses a heat sink. This heat sink aims to suppress a decrease in the amount of heat exchange between the air present in the gaps between the fins and the fin surface, regardless of whether one side of the fin base extends horizontally or vertically. To this end, the heat sink includes a square or rectangular fin base having a first surface connected to a heat generating element, a second surface opposite the heat generating element side of the first surface, a first side extending horizontally or vertically, a second side having one end abutting one end of the first side, a third side having one end abutting the other end of the first side, and a fourth side having one end abutting the other end of the second side and the other end abutting the other end of the third side. Furthermore, the heat sink includes a plurality of fins provided on the second surface, spaced apart from one another, each extending from the first side toward the second side.

[0003] Japanese Patent Application Laid-Open No. 2019-092337

[0004] For example, some electronic devices are mounted in vehicles and fixed inside the dashboard of the vehicle with metal fittings. Other electronic devices are placed on shelves, for example. In some cases, such electronic devices are cooled by providing a heat sink on the outer surface of the vertical wall. A typical heat sink has one side of a plate-shaped base attached to the outer surface of the vertical wall, and linear fins arranged in parallel on the other side of the base opposite the one side. When using such a heat sink for cooling, it is preferable to arrange the fins so that they extend vertically, and to promote the rise of air heated by heat transferred to the fins between the fins due to buoyancy.

[0005] However, as mentioned above, in the case of electronic devices that are mounted in a vehicle and fixed inside the dashboard or placed on a shelf, there is a dashboard top plate or shelf above, so heat released to the upper side may become trapped in the gap between the top plate or shelf and not be able to escape, which may reduce cooling efficiency.

[0006] Here, for example, even if the heat sink described in Patent Document 1 is attached to the outer surface of the vertical wall of an electronic device, due to its intended characteristic configuration, there is a possibility that heat will remain in the gap between the top plate or shelf plate and the upper side, just like with a general heat sink.

[0007] The present disclosure aims to provide a heat sink and an electronic device that can prevent heat from being trapped in a gap above the device and improve cooling efficiency.

[0008] In order to achieve the above-mentioned object, a heat sink according to one embodiment of the present disclosure includes a base having one plate-shaped surface attached along the outer surface of a vertical wall portion of an electronic device, a plurality of fins arranged in parallel along the other plate-shaped surface of the base, and a passage portion formed continuously between the fins along the other surface of the base, wherein the fins are formed so that when the base is attached to the vertical wall portion, one end of the passage portion is open downward in the vertical direction, and the other ends of all of the passage portions are positioned above the one end and open in the horizontal direction.

[0009] In order to achieve the above object, the above-described heat sink is applied to an electronic device according to one aspect of the present disclosure.

[0010] According to the present disclosure, cooling efficiency can be improved.

[0011] FIG. 1 is a perspective view of an electronic device to which a heat sink according to an embodiment is applied. FIG. 2 is a perspective view showing a heat sink according to embodiment 1. FIG. 3 is a side view showing a heat sink according to embodiment 1. FIG. 4 is a perspective view showing an operation of the heat sink according to embodiment 1. FIG. 5 is a perspective view showing an operation of a general heat sink. FIG. 6 is a perspective view showing an operation of a general heat sink. FIG. 7 is a side view showing another example of the heat sink according to embodiment 1. FIG. 8 is a side view showing another example of the heat sink according to embodiment 1. FIG. 9 is a side view showing another example of the heat sink according to embodiment 1. FIG. 10 is a side view showing another example of the heat sink according to embodiment 1. FIG. 11 is an explanatory diagram of a thermal boundary layer. FIG. 12 is a side view showing another example of the heat sink according to embodiment 1. FIG. 13 is a side view showing another example of the heat sink according to embodiment 1. FIG. 14 is a side view showing another example of the heat sink according to embodiment 1. FIG. 15 is a side view showing another example of the heat sink according to embodiment 1. FIG. 16 is a side view showing another example of the heat sink according to embodiment 1. FIG. 17 is a side view showing a heat sink according to embodiment 2. FIG. 18 is a side view showing another example of a heat sink according to embodiment 2. FIG. 19 is a side view showing another example of a heat sink according to embodiment 2. FIG. 20 is a side view showing another example of a heat sink according to embodiment 2. FIG. 21 is a side view showing another example of a heat sink according to embodiment 3. FIG. 22 is a side view showing model 1 of a heat sink according to an example. FIG. 23 is a perspective view showing model 1 of a heat sink according to an example. FIG. 24 is an analytical diagram of model 1 of a heat sink according to an example. FIG. 25 is an analytical diagram of model 1 of a heat sink according to an example. FIG. 26 is a side view showing model 2 of a heat sink according to an example. FIG. 27 is a perspective view showing model 2 of a heat sink according to an example. FIG. 28 is an analytical diagram of model 2 of a heat sink according to an example. FIG. 29 is an analytical diagram of model 2 of a heat sink according to an example. FIG. 30 is a side view showing model 3 of a heat sink according to an example. FIG. 31 is a perspective view showing model 3 of a heat sink according to an example. FIG. 32 is an analytical diagram of model 3 of a heat sink according to an example.FIG. 33 is an analysis diagram of model 3 of the heat sink according to the examples. FIG. 34 is a side view showing model 4 of the heat sink according to the examples. FIG. 35 is a perspective view showing model 4 of the heat sink according to the examples. FIG. 36 is an analysis diagram of model 4 of the heat sink according to the examples. FIG. 37 is an analysis diagram of model 4 of the heat sink according to the examples. FIG. 38 is a side view showing model 5 of the heat sink according to the examples. FIG. 39 is a perspective view showing model 5 of the heat sink according to the examples. FIG. 40 is an analysis diagram of model 5 of the heat sink according to the examples. FIG. 41 is a chart showing performance test results of the heat sink according to the examples. FIG. 42 is a chart showing evaluations of each model in the performance test of the heat sink according to the examples.

[0012] Hereinafter, modes for carrying out the present disclosure (hereinafter referred to as embodiments) will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the following embodiments. Furthermore, the components in the following embodiments include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the components disclosed in the following embodiments can be combined as appropriate.

[0013] 1 is a perspective view of an electronic device to which a heat sink according to an embodiment of the present invention is applied. The electronic device 101 according to the present embodiment is, for example, an audiovisual (AV)-integrated car navigation device mounted inside a vehicle. The electronic device according to the present embodiment also includes an electronic device placed on a shelf.

[0014] In the following description, the "front" refers to the side seen by the operator, and corresponds to the front side of the electronic device 101 shown in Figures 1 and 3. In the case of a car navigation device, since it is disposed at the front of the vehicle, the side facing the rear of the vehicle is the "front" side. In addition, in describing the electronic device and the display panel storage structure in this embodiment, the upper, lower, right, and left sides are defined as viewed from the front, and the side opposite the "front" side is the "rear" side.

[0015] As shown in FIG. 1, an electronic device 101 according to the embodiment includes a main body 102, a display unit 103, and a heating element 104.

[0016] The main body 102 has a structure in which the front, upper, lower, right, left, and rear sides are covered with sheet metal. Therefore, the main body 102 has a front plate 102a, a rear plate 102b, an upper plate 102c, a lower plate 102d, a left plate 102e, and a right plate 102f, which are outer casing members that form its outer shell, and is formed into a rectangular parallelepiped shape as a whole. The main body 102 is disposed inside a center cluster (also called a dashboard) 201 shown in FIG. 3 and is fixed with metal fittings (not shown) using screws or the like. The center cluster 201 is formed as a plate material.

[0017] When the main body 102 is fixed inside the center cluster 201, the front plate 102a, the rear plate 102b, the left plate 102e, and the right plate 102f are configured as standing walls that extend in the vertical direction (up and down direction), and the upper plate 102c and the lower plate 102d are configured as horizontal walls that connect the upper and lower ends of the standing walls. The upper plate 102c is configured as an upper horizontal wall that connects the upper ends of the standing walls, and the lower plate 102d is configured as a lower horizontal wall that connects the lower ends of the standing walls.

[0018] Therefore, as shown in Fig. 3, the main body 102 is fixed inside the center cluster 201, and the center cluster 201, which is a plate material, is disposed above the upper plate 102c, which is the upper lateral wall, with a gap S therebetween. Also, as shown in Fig. 3, the rear side of the main body 102 is an open area. Note that the center cluster 201 is structured to encase the main body 102, and in the drawing, a portion disposed above the main body 102 is shown simply as a flat plate.

[0019] The display unit 103 is installed on the front side of the main body 102 with its panel surface, which is its display surface, facing forward. The display unit 103 has, for example, a liquid crystal display (LCD) or an organic electroluminescence (EL) display. Although not explicitly shown in the drawings, the display unit 103 can also be configured as a touch panel. When the main body 102 is placed inside the center cluster 201, the display unit 103 is positioned so that it can be seen from outside the center cluster 201.

[0020] The heating element 104 is provided inside the main body 102. The heating element 104 may be, for example, a control device that controls the electronic device 101. The heating element 104 is fixed to the standing wall portion. In this embodiment, the heating element 104 has a flat fixing surface that follows the outer surface of the right plate 102f, which is the standing wall portion, and is fixed to a notched portion of the right plate 102f.

[0021] In the embodiment, the heat sink 1 is attached to the outer surface of the right plate 102f, which is a vertical wall portion to which the heating element 104 is fixed. The heat sink 1 is fixed in a manner that makes contact with the heating element 104. The heat sink 1 is formed of a metal material. The heat sink 1 is preferably formed of a metal material with relatively high thermal conductivity, such as aluminum alloy or copper. Note that electronic devices 101 equipped with the heating element 104 generally have power supply cords and connectors for connecting to other devices located on the rear plate 102b, which is the rear side of the main body 102, and it may not be possible to place a heat sink on the rear plate 102b. For this reason, in the embodiment, the heating element 201 is arranged along the right plate 102f, avoiding the rear plate 102b, and the heat sink 1 is fixed in contact with the fixing surface of the heating element 201.

[0022] [First Embodiment of Heat Sink] The heat sink 1 of the first embodiment will be described in detail below with reference to Fig. 2 to Fig. 4. Each figure shows the heat sink 1 attached to the right plate 102f, which is the upright wall portion.

[0023] The heat sink 1A shown in FIGS. 2 to 4 includes a base 2, fins 3, and a passage portion 4.

[0024] The base 2 is formed in a plate shape. The base 2 has a plate-shaped one side 21a and a plate-shaped other side 21b. In the drawings, the one side 21a is shown facing left, and the other side 21b is shown facing right. The one side 21a and the other side 21b of the base 2 of the heat sink 1A are formed in a rectangular shape, and have four ends (sides). Specifically, in the drawings, the base 2 has a front end (front side) 22a facing the front, a rear end (rear side) 22b facing the rear, an upper end (upper side) 22c facing upward, and a lower end (lower side) 22d facing downward. The base 2 is attached to a fixing surface where the heating element 104 appears in a cutout portion of the right plate 102f, which is a vertical wall portion. The base 2 is attached so that the one side 21a contacts the fixing surface of the heating element 104. The area of ​​one surface 21 a of the base 2 is larger than the area of ​​the surface on which the heating element 104 is fixed.

[0025] The fins 3 are arranged on the other surface 21b of the base 2. The fins 3 are arranged on the other surface 21b of the base 2 facing away from the right plate 102f, which is the upright wall portion to which the heating element 104 is fixed. In the heat sink 1A, the fins 3 include a first fin 31 and a second fin 32.

[0026] The first fin 31 is formed in a plate shape and is arranged to rise from the other surface 21b of the base 2. In the illustration, it is arranged to extend toward the right, away from the other surface 21b of the base 2. The first fin 31 is formed continuously from one end 3a to the other end 3b along the other surface 21b of the base 2. The one end 3a faces downward. The other end 3b faces rearward. The first fin 31 is formed continuously from the lower side to the rear side. One end 3a of the first fin 31 is arranged at the lower end 22d of the base 2, and the other end 3b is arranged at the rear end 22b of the base 2. Furthermore, the first fin 31 has an edge 3c that rises from the other surface 21b of the base 2, extending from the one end 3a to the other end 3b, and is positioned equidistant from the other surface 21b of the base 2. That is, the first fin 31 is formed as a long plate having a rectangular shape when unfolded, with one end of the long plate designated as one end 3a and the other end of the long plate designated as the other end 3b, and is fixed to the other surface 21b of the base 2. The first fin 31 is formed to be curved so that the portion from the one end 3a to the other end 3b bulges upward. In the embodiment, the first fin 31 is formed to be curved in an arc shape so that the portion from the one end 3a to the other end 3b bulges upward. A plurality of first fins 31 are arranged side by side at intervals along the other surface 21b of the base 2. The first fins 31 are arranged so that the intervals between adjacent first fins 31 along the other surface 21b of the base 2 are uniform and equal from the one end 3a to the other end 3b.

[0027] The second fin 32 is disposed on the outer side of the curve relative to the multiple first fins 31. The second fin 32 is formed in a plate shape and is disposed upright from the other surface 21b of the base 2. In the drawing, the second fin 32 is disposed extending toward the right, away from the other surface 21b of the base 2. The second fin 32 is formed continuously from one end 3a to the other end 3b along the other surface 21b of the base 2. The one end 3a faces the front side. The other end 3b faces the rear side. The second fin 32 is formed continuously from the front side to the rear side. One end 3a of the second fin 32 is disposed at the front end 22a of the base 2, and the other end 3b is disposed at the rear end 22b of the base 2. Furthermore, the second fin 32 has an edge 3c that rises from the other surface 21b of the base 2, extending from the one end 3a to the other end 3b, and is positioned equidistant from the other surface 21b of the base 2. That is, the second fin 32 is formed as a rectangular long plate when unfolded, with one end of the long plate designated as one end 3a and the other end of the long plate designated as the other end 3b, and is fixed to the other surface 21b of the base 2. The second fin 32 is curved so that the portion from the one end 3a to the other end 3b bulges upward. In this embodiment, the second fin 32 is curved in an arc shape so that the portion from the one end 3a to the other end 3b bulges upward. Multiple second fins 32, together with the first fin 31, are arranged side by side at intervals along the other surface 21b of the base 2. The second fins 32 and the first fins 31 are arranged so that the spacing between adjacent second fins 32 and first fins 31 is uniform and equal from the one end 3a to the other end 3b along the other surface 21b of the base 2. The second fin 32 is not an essential component.

[0028] The passage 4 is formed continuously along the other surface 21b of the base 2 between adjacent first fins 31 and second fins 32 along the other surface 21b of the base 2. The passage 4 is formed to be open toward the right side in the figure at the position of an edge 3c where the multiple first fins 31 and second fins 32 rise from the other surface 21b of the base 2.

[0029] The passages 4 provided between the multiple first fins 31 are formed continuously from one end 4a to the other end 4b along the other surface 21b of the base 2. One end 4a of the passages 4 is open at the position of one end 3a of the first fin 31, and the other end 4b is open at the position of the other end 3b of the first fin 31. The one end 4a is open downward along the vertical direction. The other end 4b is open rearward along the horizontal direction. Therefore, the passages 4 provided between the multiple first fins 31 are formed continuously from the one end 4a to the other end 4b from the lower side to the rear side. The passages 4 provided between the multiple first fins 31 are open at one end 4a at the lower end 22d of the base 2 and at the other end 4b at the rear end 22b of the base 2. Furthermore, the passages 4 provided between the multiple first fins 31 are continuous from one end 4a to the other end 4b at an equal distance from the other surface 21b of the base 2 because the edges 3c of the first fins 31 are equidistant from the other surface 21b of the base 2 from one end 3a to the other end 3b. Furthermore, the passages 4 provided between the multiple first fins 31 are curved so that the first fins 31 bulge upward from one end 3a to the other end 3b, so the passages 4 are curved so that the first fins 31 bulge upward from one end 4a to the other end 4b. The curve is formed in an arc shape. The passages 4 provided between the multiple first fins 31 are uniform and equally spaced from one end 4a to the other end 4b.

[0030] The passage 4 associated with the second fin 32 is formed continuously from one end 4a to the other end 4b along the other surface 21b of the base 2. One end 4a of the passage 4 opens at the position of one end 3a of the second fin 32, and the other end 4b opens at the position of the other end 3b of the second fin 32. Because the second fin 32 and the first fin 31 are curved, the one end 4a opens downward and toward the front in the vertical direction. The other end 4b opens toward the rear in the horizontal direction. Therefore, the passage 4 associated with the second fin 32 is formed continuously from the one end 4a to the other end 4b, extending downward and from the front to the rear. The passage 4 associated with the second fin 32 is formed continuously from the one end 4a to the other end 4b, extending downward and from the front to the rear. One end 4a of the passage 4 associated with the second fin 32 opens at the front end 22a of the base 2, and the other end 4b opens at the rear end 22b of the base 2. Furthermore, the passage 4 provided in association with the second fin 32 is continuous from one end 4a to the other end 4b at an equal distance from the other surface 21b of the base 2 because the edge 3c of the first fin 31 is equidistant from the other surface 21b of the base 2 from one end 3a to the other end 3b. Furthermore, the passage 4 provided in association with the second fin 32 is curved so that the first fin 31 bulges upward from the one end 3a to the other end 3b, so the passage 4 is curved so that the first fin 31 bulges upward from the one end 3a to the other end 3b. The curve is formed in an arc shape. The passage 4 provided in association with the second fin 32 is not necessarily a required component.

[0031] 3, the heat sink 1A configured in this manner has the base 2 fixed to the outer surface of the right plate 102f, which is a vertical wall portion of the main body 102 of the electronic device 101. Specifically, the heat sink 1A is fixed such that the rear end 22b of the base 2 is at the rear end of the right plate 102f of the main body 102 of the electronic device 101 and along the rear plate 102b. The electronic device 101 to which the heat sink 1A is fixed is then fixed inside the center cluster 201, with the center cluster 201, which is a plate material, positioned above the top plate 102c of the main body 102 with a gap S between them.

[0032] In this heat sink 1A, heat generated by a heat generating element 104 of electronic device 101 is transferred to base 2, and then from base 2 to fins 3. As shown in Figures 3 and 4, in heat sink 1A, the heat transferred to fins 3 causes air A1 to flow upward in passage 4 between fins 3 from one end 4a located on the lower side toward the other end 4b located on the upper side, and is released to the rear side toward which the other end 4b faces, behind rear plate 102b of main body 102 of electronic device 101.

[0033] As shown in FIG. 4 , when the heat sink 1A is heated on the outside of the fins 3 (the right side in this embodiment), a flow of air A2 rises from the bottom to the top. As described above, the heat sink 1A allows air A1 to flow from the lower end 4a toward the upper end 4b, thereby assisting the flow by drawing in air A2 at the lower end 4a. Meanwhile, as described above, the heat sink 1A releases air A1 toward the rear side, toward which the other end 4b faces, creating a flow in a different direction from air A2, thereby suppressing the upward flow of air A1. As a result, the heat sink 1A reduces the amount of heat dissipated into the gap S above the center cluster 201, which is a plate material above the main body 102 of the electronic device 101, while allowing heat to be dissipated to the open area behind the main body 102. As a result, the heat sink 1A prevents heat from accumulating in the gap S above the electronic device 101, thereby improving cooling efficiency.

[0034] 5 and 6 show general heat sinks 1X and 1Z. The heat sinks 1X and 1Z differ from the heat sink 1A in the shape of the fins 3, and the same parts are denoted by the same reference numerals and their description will be omitted.

[0035] The heat sinks 1X and 1Z have straight fins 3 arranged side by side at equal intervals on a rectangular plate-shaped base 2. The heat sink 1X shown in Fig. 5 is fixed to the electronic device so that the fins 3 are aligned vertically. The heat sink 1Z shown in Fig. 6 is fixed to the electronic device so that the fins 3 are aligned horizontally.

[0036] In the heat sink 1X shown in FIG. 5 , heat transferred to the fins 3 causes air A1 to flow upward in the passage 4 between the fins 3 from the lower end 4a to the upper end 4b, and then to be released upward toward the other end 4b. In the heat sink 1X, heat transferred to the fins 3 generates a flow of air A2 rising from the bottom to the top outside the fins 3 (on the right side in this embodiment). Because air A1 flows from the lower end 4a to the upper end 4b, the heat sink 1X assists the flow by entraining air A2 at both the lower end 4a and the upper end 4b. As a result, the heat sink 1X cannot suppress the amount of heat dissipation into the gap S above the center cluster 201, which is a plate material above the main body 102 of the electronic device 101. As a result, the heat sink 1X traps heat in the gap S above the electronic device 101, failing to improve cooling efficiency.

[0037] In addition, in the heat sink 1Z shown in FIG. 6 , heat transferred to the fins 3 causes air A1 to flow through the passage 4 between the fins 3 toward the front and rear ends 4a and 4b, respectively, and then to be released forward and backward. In the heat sink 1Z, air A2 flows upward from the bottom to the top due to heat transferred to the fins 3 on the outside (right side in this embodiment) of the fins 3. Because air A1 flows forward and backward in the heat sink 1Z, there is little tendency for air A2 to be drawn in. Therefore, while the heat sink 1Z can reduce the amount of heat dissipated into the gap S above the center cluster 201, which is a plate material above the main body 102 of the electronic device 101, the direction in which air A1 is released is not determined. As a result, although the heat sink 1Z can reduce the accumulation of heat in the gap S above the electronic device 101, it cannot improve cooling efficiency.

[0038] In this way, the heat sink 1A of the embodiment is excellent in that it can prevent heat from remaining in the gap S above the electronic device 101 and improve cooling efficiency.

[0039] Other examples of the heat sink 1 of the first embodiment will be described below with reference to Figures 7 to 16. The other examples of the heat sinks 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, and 1N differ from the heat sink 1A mainly in the shape of the fins 3, and the same parts are denoted by the same reference numerals and will not be described again.

[0040] The heat sink 1B shown in FIG. 7 has only the first fins 31, which are formed linearly.

[0041] The first fin 31 is formed continuously from one end 3a to the other end 3b along the other surface 21b of the base 2. The one end 3a faces downward. The other end 3b faces rearward. The first fin 31 is formed diagonally and continuously from the lower side to the rearward side. The first fin 31 has one end 3a located at the lower end 22d of the base 2 and the other end 3b located at the rear end 22b of the base 2. The first fin 31 has an edge 3c extending from the other surface 21b of the base 2, extending from the one end 3a to the other end 3b, and is equidistant from the other surface 21b of the base 2. That is, the first fin 31 is formed as a rectangular plate, and is fixed to the other surface 21b of the base 2 with one end 3a as the one end and the other end 3b as the other end. The first fin 31 is formed diagonally and linearly from the one end 3a to the other end 3b. A plurality of first fins 31 are arranged in parallel at intervals along the other surface 21 b of the base 2. The first fins 31 are arranged at uniform and equal intervals along the other surface 21 b of the base 2 from one end 3 a to the other end 3 b.

[0042] The passages 4 provided between the multiple first fins 31 are formed continuously from one end 4a to the other end 4b along the other surface 21b of the base 2. One end 4a of the passages 4 is open at the position of one end 3a of the first fin 31, and the other end 4b is open at the position of the other end 3b of the first fin 31. The one end 4a opens downward along the vertical direction. The other end 4b opens rearward along the horizontal direction. Therefore, the passages 4 provided between the multiple first fins 31 are formed continuously diagonally from the one end 4a to the other end 4b from the lower side to the rear side. The passages 4 provided between the multiple first fins 31 are formed continuously diagonally from the one end 4a to the other end 4b. The one end 4a of the passages 4 provided between the multiple first fins 31 is open at the lower end 22d of the base 2, and the other end 4b is open at the rear end 22b of the base 2. Furthermore, the passages 4 provided between the multiple first fins 31 are continuous at an equal distance from the other surface 21 b of the base 2 from one end 4a to the other end 4b because the edges 3c of the first fins 31 are equidistant from the other surface 21 b of the base 2 from one end 3a to the other end 3b. Furthermore, the passages 4 provided between the multiple first fins 31 are formed in an obliquely linear manner from one end 4a to the other end 4b because the first fins 31 are formed in an obliquely linear manner from one end 3a to the other end 3b. The passages 4 provided between the multiple first fins 31 are uniform and equally spaced from one end 4a to the other end 4b.

[0043] In this heat sink 1B, heat generated by a heat generating element 104 of the electronic device 101 is transferred to the base 2 and then from the base 2 to the fins 3. In the heat sink 1B, the heat transferred to the fins 3 causes air A1 to flow upward in the passage 4 between the fins 3 from one end 4a located on the lower side to the other end 4b located on the upper side, and is released to the rear side toward which the other end 4b faces, behind the rear plate 102b of the main body 102 of the electronic device 101. As a result, like the heat sink 1A, the heat sink 1B can prevent heat from being trapped in the gap S above the electronic device 101, improving cooling efficiency.

[0044] The heat sink 1C shown in FIG. 8 has only the first fins 31, which are formed to be bent.

[0045] The first fin 31 is formed continuously from one end 3a to the other end 3b along the other surface 21b of the base 2. The one end 3a faces downward. The other end 3b faces rearward. The first fin 31 is formed continuously from the lower side to the upper side, bent, and rearward. The first fin 31 has one end 3a located at the lower end 22d of the base 2 and the other end 3b located at the rear end 22b of the base 2. The first fin 31 has an edge 3c extending from the other surface 21b of the base 2, extending from the one end 3a to the other end 3b, and is equidistant from the other surface 21b of the base 2. That is, when unfolded, the first fin 31 is formed as a rectangular elongated plate, and is fixed to the other surface 21b of the base 2 with one end 3a as the one end and the other end 3b as the other end. Furthermore, the first fins 31 are formed to be curved from one end 3 a to the other end 3 b. A plurality of first fins 31 are arranged in parallel at intervals along the other surface 21 b of the base 2. The first fins 31 are arranged at uniform, equal intervals between adjacent fins along the other surface 21 b of the base 2 from one end 3 a to the other end 3 b.

[0046] The passages 4 provided between the multiple first fins 31 are formed continuously from one end 4a to the other end 4b along the other surface 21b of the base 2. One end 4a of the passages 4 is open at the position of one end 3a of the first fin 31, and the other end 4b is open at the position of the other end 3b of the first fin 31. The one end 4a is open downward along the vertical direction. The other end 4b is open rearward along the horizontal direction. Therefore, the passages 4 provided between the multiple first fins 31 are formed continuously from the one end 4a to the other end 4b, bending from the lower side to the upper side and extending rearward. The passages 4 provided between the multiple first fins 31 are open at one end 4a at the lower end 22d of the base 2 and at the other end 4b at the rear end 22b of the base 2. Furthermore, the passages 4 provided between the multiple first fins 31 are continuous at an equal distance from the other surface 21b of the base 2 from one end 4a to the other end 4b because the edge 3c of the first fin 31 is equidistant from the other surface 21b of the base 2 from one end 3a to the other end 3b. Furthermore, the passages 4 provided between the multiple first fins 31 are curved from one end 4a to the other end 4b because the first fins 31 are curved from one end 3a to the other end 3b. The passages 4 provided between the multiple first fins 31 are uniform and equally spaced from one end 4a to the other end 4b.

[0047] In this heat sink 1C, heat generated by the heat generating element 104 of the electronic device 101 is transferred to the base 2 and then from the base 2 to the fins 3. In the heat sink 1C, the heat transferred to the fins 3 causes air A1 to flow upward in the passages 4 between the fins 3 from one end 4a located on the lower side to the other end 4b located on the upper side, and is then released to the rear side toward which the other end 4b faces, behind the rear plate 102b of the main body 102 of the electronic device 101. As a result, like the heat sink 1A, the heat sink 1C can prevent heat from being trapped in the gap S above the electronic device 101, improving cooling efficiency. Furthermore, since the passages 4 are formed on the entire surface of the base 2 of the heat sink 1C, the heat received by the base 2 is transferred to the air in all of the passages 4, reducing waste in the movement of hot air to the rear side.

[0048] A heat sink 1D shown in FIG. 9 has only first fins 31, which are curved like the heat sink 1A.

[0049] The first fin 31 is formed continuously from one end 3a to the other end 3b along the other surface 21b of the base 2. The one end 3a faces downward. The other end 3b faces rearward. The first fin 31 is formed continuously from the lower side to the upper and rear sides. One end 3a of the first fin 31 is located at the lower end 22d of the base 2, and the other end 3b is located at the rear end 22b of the base 2. Furthermore, the first fin 31 has an edge 3c rising from the other surface 21b of the base 2, extending from the one end 3a to the other end 3b, and is positioned equidistant from the other surface 21b of the base 2. That is, when unfolded, the first fin 31 is formed as a rectangular elongated plate, and is fixed to the other surface 21b of the base 2 with one end 3a as the one end and the other end 3b as the other end. Furthermore, the first fin 31 is formed to bulge upward and curve in an arc shape from one end 3a to the other end 3b. A plurality of first fins 31 are arranged side by side at intervals B along the other surface 21b of the base 2. The intervals B between adjacent first fins 31 along the other surface 21b of the base 2 are uniform from one end 3a to the other end 3b. In the heat sink 1D, the first fins 31 are arranged such that the intervals B become larger as they move toward the outside (upper side) of the arc.

[0050] The passages 4 provided between the multiple first fins 31 are formed continuously from one end 4a to the other end 4b along the other surface 21b of the base 2. One end 4a of the passages 4 is open at the position of one end 3a of the first fin 31, and the other end 4b is open at the position of the other end 3b of the first fin 31. The one end 4a is open downward along the vertical direction. The other end 4b is open rearward along the horizontal direction. Therefore, the passages 4 provided between the multiple first fins 31 are formed continuously from the one end 4a to the other end 4b from the lower side to the rear side. The passages 4 provided between the multiple first fins 31 are open at one end 4a at the lower end 22d of the base 2 and at the other end 4b at the rear end 22b of the base 2. Furthermore, the passages 4 provided between the multiple first fins 31 are continuous from one end 4a to the other end 4b at an equal distance from the other surface 21b of the base 2 because the edges 3c of the first fins 31 are equidistant from the other surface 21b of the base 2 from one end 3a to the other end 3b. Furthermore, the passages 4 provided between the multiple first fins 31 are formed so that the first fins 31 bulge upward and curve in an arc from one end 4a to the other end 4b because the first fins 31 bulge upward and curve in an arc from one end 4a to the other end 4b. The passages 4 provided between the multiple first fins 31 have a uniform spacing B from one end 4a to the other end 4b. Furthermore, the passages 4 provided between the multiple first fins 31 are arranged so that the spacing B increases toward the outside (upper side) of the arc.

[0051] In this heat sink 1D, heat generated by a heat generating element 104 of the electronic device 101 is transferred to the base 2 and then from the base 2 to the fins 3. In the heat sink 1D, the heat transferred to the fins 3 causes air A1 to flow upward in the passage 4 between the fins 3 from one end 4a located on the lower side to the other end 4b located on the upper side, and is released to the rear side toward which the other end 4b faces, behind the rear plate 102b of the main body 102 of the electronic device 101. As a result, like the heat sink 1A, the heat sink 1D can prevent heat from remaining in the gap S above the electronic device 101, thereby improving cooling efficiency.

[0052] Furthermore, the heat sink 1D is positioned so that the spacing B increases as the passage portion 4 moves toward the outside (upper side) of the arc. This prevents the temperature boundary layer around the fins 3 from interfering with each other, even though the temperature boundary layer around the fins 3 increases at the upper side where the temperature of the heat transmitted to the base 2 is higher, thereby promoting the flow (convection) of air A1.

[0053] 10, the fins 3 include a first fin 31, a second fin 32, and a third fin 33. The heat sink 1N shown in FIG. 10 has a third fin 33 in addition to the heat sink 1A described above.

[0054] The third fin 33 is disposed on the outer side of the curve relative to the multiple second fins 32. The third fin 33 is formed in a plate shape and is disposed upright from the other surface 21b of the base 2. In the drawing, the third fin 33 is disposed extending toward the right, away from the other surface 21b of the base 2. The third fin 33 is formed continuously from one end 3a to the other end 3b along the other surface 21b of the base 2. The one end 3a faces downward. The other end 3b faces rearward. The third fin 33 is formed continuously from the lower side to the rear side. One end 3a of the third fin 33 is disposed at the lower end 22d of the base 2, and the other end 3b is disposed at the rear end 22b of the base 2. Furthermore, the third fin 33 has an edge 3c that rises from the other surface 21b of the base 2, extending from the one end 3a to the other end 3b, and is positioned equidistant from the other surface 21b of the base 2. That is, the third fin 33 is formed as a rectangular long plate when unfolded, with one end of the long plate designated as one end 3a and the other end of the long plate designated as the other end 3b, and is fixed to the other surface 21b of the base 2. The third fin 33 is formed linearly along the vertical direction from the one end 3a to the other end 3b, and is curved so as to bulge upward from there to the other end 3b. In this embodiment, the third fin 33 is curved in an arc shape so as to bulge upward from the other end 3b to the other end 3b. The third fin 33 is provided as a single fin and is arranged to surround the front and upper sides of the first fin 31 and the second fin 32. Multiple third fins 33 are arranged side by side at intervals along the other surface 21b of the base 2, together with the first fin 31 and the second fin 32. The fins 31, 32, 33 are arranged at equal intervals along the other surface 21b of the base 2 from one end 3a to the other end 3b.

[0055] The passages 4 provided between the multiple first fins 31 are formed continuously from one end 4a to the other end 4b along the other surface 21b of the base 2. One end 4a of the passages 4 is open at the position of one end 3a of the first fin 31, and the other end 4b is open at the position of the other end 3b of the first fin 31. The one end 4a is open downward along the vertical direction. The other end 4b is open rearward along the horizontal direction. Therefore, the passages 4 provided between the multiple first fins 31 are formed continuously from the one end 4a to the other end 4b from the lower side to the rear side. The passages 4 provided between the multiple first fins 31 are open at one end 4a at the lower end 22d of the base 2 and at the other end 4b at the rear end 22b of the base 2. Furthermore, the passages 4 provided between the multiple first fins 31 are continuous from one end 4a to the other end 4b at an equal distance from the other surface 21b of the base 2 because the edges 3c of the first fins 31 are equidistant from the other surface 21b of the base 2 from one end 3a to the other end 3b. Furthermore, the passages 4 provided between the multiple first fins 31 are curved so that the first fins 31 bulge upward from one end 3a to the other end 3b, so the passages 4 are curved so that the first fins 31 bulge upward from one end 4a to the other end 4b. The curve is formed in an arc shape. The passages 4 provided between the multiple first fins 31 are uniform and equally spaced from one end 4a to the other end 4b.

[0056] The passage 4 associated with the second fin 32 is formed continuously from one end 4a to the other end 4b along the other surface 21b of the base 2. One end 4a of the passage 4 opens at the position of one end 3a of the second fin 32, and the other end 4b opens at the position of the other end 3b of the second fin 32. Because the second fin 32 and the first fin 31 are curved, the one end 4a opens downward and toward the front in the vertical direction. The other end 4b opens toward the rear in the horizontal direction. Therefore, the passage 4 associated with the second fin 32 is formed continuously from the one end 4a to the other end 4b, extending downward and from the front to the rear. The passage 4 associated with the second fin 32 is formed continuously from the one end 4a to the other end 4b, extending downward and from the front to the rear. One end 4a of the passage 4 associated with the second fin 32 opens at the front end 22a of the base 2, and the other end 4b opens at the rear end 22b of the base 2. Furthermore, the passage 4 provided in relation to the second fin 32 is continuous from one end 4a to the other end 4b at an equal distance from the other surface 21b of the base 2, because the edge 3c of the first fin 31 is located equidistant from the other surface 21b of the base 2 from one end 3a to the other end 3b. Furthermore, the passage 4 provided in relation to the second fin 32 is curved so that the section from one end 4a to the other end 4b bulges upward, because the first fin 31 is curved so that the section from one end 3a to the other end 3b bulges upward. The curve is formed in an arc shape.

[0057] The passage 4 associated with the third fin 32 is formed continuously from one end 4a to the other end 4b along the other surface 21b of the base 2. One end 4a of the passage 4 is open at the position of one end 3a of the third fin 33, and the other end 4b is open at the position of the other end 3b of the third fin 33. The third fin 33 is formed linearly along the vertical direction from the one end 3a to partway along the third fin 33, and is therefore arranged to cover the front side of the one end 4a of the passage 4 formed by all of the second fins 32 in that portion. Furthermore, the third fin 33 is formed in an arc shape from partway along the third fin 33 to the other end 3b, and is therefore arranged in an arc shape along the outside of the second fins 32 in that portion. That is, the passage portion 4 provided in relation to the third fin 32 has one end 4a that opens downward along the vertical direction and the other end 4b that opens rearward along the horizontal direction so that the passage portions 4 related to all the second fins 32 are arranged inside the passage portion 4, with all the second fins 32 arranged between them and the outermost first fin 31. Therefore, the passage portion 4 provided in relation to the third fin 33 is formed continuously from the one end 4a to the other end 4b from the lower side to the rear side. The passage portion 4 provided in relation to the third fin 33 has one end 4a that opens at the lower end 22d of the base 2 and the other end 4b that opens at the rear end 22b of the base 2. Furthermore, the passage 4 associated with the third fin 33 is continuous from one end 4a to the other end 4b at an equal distance from the other surface 21b of the base 2 because the edges 3c of each fin 31, 32, and 33 are equidistant from the other surface 21b of the base 2 from one end 3a to the other end 3b. The passage 4 associated with the third fin 33 is formed vertically in a straight line from the one end 3a to the middle of the third fin 33. The passage 4 associated with the third fin 33 is also formed vertically in this portion. The passage 4 associated with the third fin 33 is also curved so that the third fin 33 bulges upward from the middle of the third fin 33 to the other end 3b. The curve is an arc.

[0058] In this heat sink 1N, heat generated by the heat generating element 104 of the electronic device 101 is transferred to the base 2 and then from the base 2 to the fins 3. As shown in Fig. 10, in the heat sink 1N, the heat transferred to the fins 3 causes air A1 to flow upward in the passage 4 between the fins 3 from one end 4a located on the lower side to the other end 4b located on the upper side, and is released to the rear side toward which the other end 4b faces, that is, behind the rear plate 102b of the main body 102 of the electronic device 101. As a result, like the heat sink 1A, the heat sink 1N can prevent heat from being trapped in the gap S above the electronic device 101, thereby improving cooling efficiency.

[0059] Moreover, in the heat sink 1N, one end 4a of the passages 4 provided in relation to the third fins 32 is open downward and the other end 4b is open rearward so that the passages 4 related to all the second fins 32 are located inside the passages 4, with all the second fins 32 being located between the third fins 32 and the outermost first fins 31. Therefore, the heat sink 1N can cause the air A1 in the passages 4 related to all the second fins 32 to flow from the bottom to the rear.

[0060] Here, the thermal boundary layer will be explained with reference to Figure 11. Figure 11 shows the fins 3 as viewed from the edge 3c toward the base 2. When the fins 3 generate heat, the heat is transferred to the air in contact with the fins 3 by thermal conduction, causing the temperature of the air to rise. As a result, the heated air in contact with the fins 3 forms a thermal boundary layer around the fins 3, as indicated by the dashed line. The heated air then becomes lighter and, due to buoyancy, convects and rises. In the heat sink 1 of this embodiment, the fins 3 are arranged from the bottom to the top, so the heated air around them rises along the fins 3. As the heated air rises, its volume increases as it goes higher, and the thermal boundary layer becomes thicker, as indicated by the arrows.

[0061] The heat flow rate [W] due to air convection at this time is calculated as follows: ２ Heat flow rate [W] = convection surface area [m ２ ]×convection heat transfer coefficient [W / m ２K] × (surface temperature - fluid temperature [K]) ... Equation 1 The thickness δ of the thermal boundary layer shown in Figure 11 is expressed by the following Equation 2: Heat flow rate [W] = partial surface area S [m ２ ] × (heat transfer coefficient λa [W / m ２ K] / thickness of thermal boundary layer δ [m] × coefficient) × (surface temperature Tw − fluid temperature T∞ [K]) ... Equation 2

[0062] From these relationships, in order to reduce the influence of the thermal boundary layer and promote the flow of air A1 (convective heat transfer), it is important to prevent interference between the thermal boundary layers. This promotes the flow of air A1 and increases the efficiency of heat dissipation, which makes the thermal boundary layer thinner, further promoting the flow of air A1 and improving cooling efficiency.

[0063] From this perspective, by arranging the passage section 4 so that the spacing B increases as it goes towards the outside (upper side) of the arc, as in the heat sink 1D, interference between the temperature boundary layers of adjacent fins 3 can be prevented, and cooling efficiency can be further improved.

[0064] A heat sink 1E shown in FIG. 12 has only first fins 31, which are curved like the heat sink 1A.

[0065] The first fin 31 is formed continuously from one end 3a to the other end 3b along the other surface 21b of the base 2. The one end 3a faces downward. The other end 3b faces rearward. The first fin 31 is formed continuously from the lower side to the upper and rear sides. One end 3a of the first fin 31 is located at the lower end 22d of the base 2, and the other end 3b is located at the rear end 22b of the base 2. Furthermore, the first fin 31 has an edge 3c rising from the other surface 21b of the base 2, extending from the one end 3a to the other end 3b, and is positioned equidistant from the other surface 21b of the base 2. That is, when unfolded, the first fin 31 is formed as a rectangular elongated plate, and is fixed to the other surface 21b of the base 2 with one end 3a as the one end and the other end 3b as the other end. Each first fin 31 is curved and bulges upward from its one end 3a to its other end 3b. A plurality of first fins 31 are arranged side by side at intervals B along the other surface 21b of the base 2. In the heat sink 1E, the first fins 31 are arranged such that the spacing between adjacent first fins 31 gradually changes such that the spacing B1 between their one ends 3a is greater than the spacing B2 between their other ends 3b.

[0066] The passages 4 provided between the multiple first fins 31 are formed continuously from one end 4a to the other end 4b along the other surface 21b of the base 2. One end 4a of the passages 4 is open at the position of one end 3a of the first fin 31, and the other end 4b is open at the position of the other end 3b of the first fin 31. The one end 4a is open downward along the vertical direction. The other end 4b is open rearward along the horizontal direction. Therefore, the passages 4 provided between the multiple first fins 31 are formed continuously from the one end 4a to the other end 4b from the lower side to the rear side. The passages 4 provided between the multiple first fins 31 are open at one end 4a at the lower end 22d of the base 2 and at the other end 4b at the rear end 22b of the base 2. Furthermore, the passages 4 provided between the multiple first fins 31 are continuous at an equal distance from the other surface 21 b of the base 2 from one end 4a to the other end 4b because the edges 3c of the first fins 31 are equidistant from the other surface 21 b of the base 2 from one end 3a to the other end 3b. Furthermore, the passages 4 provided between the multiple first fins 31 are formed so that the first fins 31 bulge upward and curve between the one end 3a and the other end 3b, and therefore the passages 4 provided between the multiple first fins 31 are formed so that the distance between the one end 4a and the other end 4b gradually increases from the distance B1 to the distance B2 from the one end 4a to the other end 4b.

[0067] In this heat sink 1E, heat generated by the heat generating element 104 of the electronic device 101 is transferred to the base 2 and then from the base 2 to the fins 3. In the heat sink 1E, the heat transferred to the fins 3 causes air A1 to flow upward in the passage 4 between the fins 3 from one end 4a located on the lower side to the other end 4b located on the upper side, and is released to the rear side toward which the other end 4b faces, behind the rear plate 102b of the main body 102 of the electronic device 101. As a result, like the heat sink 1A, the heat sink 1E can prevent heat from remaining in the gap S above the electronic device 101, thereby improving cooling efficiency.

[0068] Furthermore, the heat sink 1E is arranged with the passage sections 4 spaced at varying intervals so that the spacing B2 at one end 4b is larger than the spacing B1 at the other end 4a. This prevents the temperature boundary layers around the fins 3 from interfering with each other, even though the temperature boundary layer around the fins 3 becomes larger at the upper side where the temperature of the heat transmitted to the base 2 is higher, and promotes the flow (convection) of air A1, thereby further improving cooling efficiency.

[0069] The heat sink 1F shown in FIG. 13 has only first fins 31, which are bent in the same manner as the heat sink 1C.

[0070] The first fin 31 is formed continuously from one end 3a to the other end 3b along the other surface 21b of the base 2. The one end 3a faces downward. The other end 3b faces rearward. The first fin 31 is formed continuously from the lower side to the upper side, bent, and rearward. The first fin 31 has one end 3a located at the lower end 22d of the base 2 and the other end 3b located at the rear end 22b of the base 2. The first fin 31 has an edge 3c extending from the other surface 21b of the base 2, extending from the one end 3a to the other end 3b, and is equidistant from the other surface 21b of the base 2. That is, when unfolded, the first fin 31 is formed as a rectangular elongated plate, and is fixed to the other surface 21b of the base 2 with one end 3a as the one end and the other end 3b as the other end. Furthermore, each first fin 31 is formed to bend from one end 3a to the other end 3b. A plurality of first fins 31 are arranged side by side at intervals along the other surface 21b of the base 2. In the heat sink 1F, the first fins 31 are arranged such that the spacing B1 between adjacent first fins 31 at one end 3a is greater than the spacing B2 at the other end 3b. The spacing B1 at one end 3a is uniform up to the bent portion, and changes from this bent portion to the spacing B2 at the other end 3b.

[0071] The passages 4 provided between the multiple first fins 31 are formed continuously from one end 4a to the other end 4b along the other surface 21b of the base 2. One end 4a of the passages 4 is open at the position of one end 3a of the first fin 31, and the other end 4b is open at the position of the other end 3b of the first fin 31. The one end 4a is open downward along the vertical direction. The other end 4b is open rearward along the horizontal direction. Therefore, the passages 4 provided between the multiple first fins 31 are formed continuously from the one end 4a to the other end 4b, bending from the lower side to the upper side and extending rearward. The passages 4 provided between the multiple first fins 31 are open at one end 4a at the lower end 22d of the base 2 and at the other end 4b at the rear end 22b of the base 2. Furthermore, the passages 4 provided between the multiple first fins 31 are continuous from one end 4a to the other end 4b at an equal distance from the other surface 21b of the base 2 because the edges 3c of the first fins 31 are equidistant from the other surface 21b of the base 2 from one end 3a to the other end 3b. Furthermore, the passages 4 provided between the multiple first fins 31 are curved from one end 4a to the other end 4b because the first fins 31 are curved from one end 3a to the other end 3b. The passages 4 provided between the multiple first fins 31 are arranged so that the interval B1 increases to the interval B2 from one end 4a to the other end 4b.

[0072] In this heat sink 1F, heat generated by the heat generating element 104 of the electronic device 101 is transferred to the base 2 and then from the base 2 to the fins 3. In the heat sink 1E, the heat transferred to the fins 3 causes air A1 to flow upward in the passage 4 between the fins 3 from one end 4a located on the lower side to the other end 4b located on the upper side, and is released to the rear side toward which the other end 4b faces, behind the rear plate 102b of the main body 102 of the electronic device 101. As a result, like the heat sink 1A, the heat sink 1E can prevent heat from remaining in the gap S above the electronic device 101, thereby improving cooling efficiency.

[0073] Furthermore, the heat sink 1F is arranged with the passage sections 4 spaced at varying intervals so that the spacing B2 at one end 4b is larger than the spacing B1 at the other end 4a. This prevents the temperature boundary layers around the fins 3 from interfering with each other, even though the temperature boundary layer around the fins 3 becomes larger at the upper side where the temperature of the heat transmitted to the base 2 is higher, and promotes the flow (convection) of air A1, thereby further improving cooling efficiency.

[0074] The heat sink 1G shown in FIG. 14 has only first fins 31, which are curved like the heat sink 1A.

[0075] The first fin 31 is formed continuously from one end 3a to the other end 3b along the other surface 21b of the base 2. The one end 3a faces downward. The other end 3b faces rearward. The first fin 31 is formed continuously from the lower side to the rearward side. The first fin 31 has one end 3a located at the lower end 22d of the base 2 and the other end 3b located at the rear end 22b of the base 2. The first fin 31 has an edge 3c extending from the other surface 21b of the base 2, extending from the one end 3a to the other end 3b, and is equidistant from the other surface 21b of the base 2. That is, the first fin 31 is formed as a rectangular elongated plate when unfolded, and is fixed to the other surface 21b of the base 2 with one end 3a as the one end and the other end 3b as the other end. The first fin 31 is formed to bulge upward and curve from the one end 3a to the other end 3b. A plurality of first fins 31 are arranged side by side at intervals B along the other surface 21 b of the base 2. The first fins 31 are arranged at uniform, equal intervals along the other surface 21 b of the base 2 from one end 3 a to the other end 3 b.

[0076] The passages 4 provided between the multiple first fins 31 are formed continuously from one end 4a to the other end 4b along the other surface 21b of the base 2. One end 4a of the passages 4 is open at the position of one end 3a of the first fin 31, and the other end 4b is open at the position of the other end 3b of the first fin 31. The one end 4a is open downward along the vertical direction. The other end 4b is open rearward along the horizontal direction. Therefore, the passages 4 provided between the multiple first fins 31 are formed continuously from the one end 4a to the other end 4b from the lower side to the rear side. The passages 4 provided between the multiple first fins 31 are open at one end 4a at the lower end 22d of the base 2 and at the other end 4b at the rear end 22b of the base 2. Furthermore, the passages 4 provided between the multiple first fins 31 are continuous at an equal distance from the other surface 21 b of the base 2 from one end 4a to the other end 4b because the edges 3c of the first fins 31 are equidistant from the other surface 21 b of the base 2 from one end 3a to the other end 3b. Furthermore, the passages 4 provided between the multiple first fins 31 are formed so that the first fins 31 bulge and curve upward from one end 3a to the other end 3b, so that the passages 4 provided between the multiple first fins 31 are formed so that the first fins 31 bulge and curve upward from one end 4a to the other end 4b. The passages 4 provided between the multiple first fins 31 are uniform and equally spaced from one end 4a to the other end 4b.

[0077] In the heat sink 1G, within the range of the other surface 21b of the base 2, the other ends 3b of each first fin 31 forming the other ends 4b of the passage portions 4 differ in position relative to the vertical line L. Specifically, the heat sink 1G is formed so that the rear end 22b of the base 2 is inclined at an acute angle relative to the vertical line L. The other ends 3b of each first fin 31 are aligned with the rear end 22b of the base 2. Therefore, within the range of the other surface 21b of the base 2, each first fin 31 is positioned so that the other ends 3b gradually become shorter from below to above with respect to the vertical line L based on the first fin 31 at the lowest position.

[0078] In this heat sink 1G, heat generated by a heat generating element 104 of the electronic device 101 is transferred to the base 2 and then from the base 2 to the fins 3. In the heat sink 1G, the heat transferred to the fins 3 causes air A1 to flow upward in the passage 4 between the fins 3 from one end 4a located on the lower side to the other end 4b located on the upper side, and is released to the rear side toward which the other end 4b faces, behind the rear plate 102b of the main body 102 of the electronic device 101. As a result, like the heat sink 1A, the heat sink 1G can prevent heat from remaining in the gap S above the electronic device 101, thereby improving cooling efficiency.

[0079] Moreover, in the heat sink 1G, each first fin 31 is arranged within the other surface 21b of the base 2 so that the other end 3b gradually becomes shorter from the bottom to the top with respect to a vertical line L based on the lowest first fin 31, so that heat released from the passages 4 between each first fin 31 rises without being obstructed by the upper first fin 31. As a result, the heat sink 1G can dissipate heat over a wider range, further improving cooling efficiency.

[0080] 15 has the same basic configuration as the heat sink 1G, but within the other surface 21b of the base 2, the other ends 3b of each first fin 31 forming the other ends 4b of the passage portions 4 are positioned differently relative to the vertical line L. The heat sink 1H is formed so that the rear end 22b of the base 2 is inclined at an obtuse angle relative to the vertical line L. The other ends 3b of each first fin 31 are aligned with the rear end 22b of the base 2. Therefore, within the other surface 21b of the base 2, each first fin 31 is positioned so that the other ends 3b gradually become longer from below to above with respect to the vertical line L based on the first fin 31 at the lowest position.

[0081] In this heat sink 1H, heat generated by the heat generating element 104 of the electronic device 101 is transferred to the base 2 and then from the base 2 to the fins 3. In the heat sink 1H, the heat transferred to the fins 3 causes air A1 to flow upward in the passage 4 between the fins 3 from one end 4a located on the lower side to the other end 4b located on the upper side, and is released to the rear side toward which the other end 4b faces, behind the rear plate 102b of the main body 102 of the electronic device 101. As a result, like the heat sink 1A, the heat sink 1H can prevent heat from remaining in the gap S above the electronic device 101, thereby improving cooling efficiency.

[0082] Moreover, in the heat sink 1H, each first fin 31 is arranged within the other surface 21b of the base 2 so that the other end 3b gradually becomes longer from below to above with respect to a vertical line L based on the lowest first fin 31, and therefore the heat released from the passage 4 between each first fin 31 is prevented from rising upward by the upper first fin 31, and the heat can be released further behind the vertical line L. As a result, the heat sink 1G can prevent heat from being released into the gap S above the main body 102 of the electronic device 101, further improving cooling efficiency.

[0083] 16 has the same basic configuration as the heat sink 1G, but within the range of the other surface 21b of the base 2, the other ends 3b of each first fin 31 forming the other end 4b of the passage portion 4 are positioned differently relative to the vertical line L. The heat sink 1I is formed so that the rear end 22b of the base 2 is inclined at an obtuse angle relative to the vertical line L. The other ends 3b of each first fin 31 are positioned unevenly relative to the vertical line L within the range of the other surface 21b of the base 2.

[0084] In this heat sink 1I, heat generated by the heat generating element 104 of the electronic device 101 is transferred to the base 2 and then from the base 2 to the fins 3. In the heat sink 1I, the heat transferred to the fins 3 causes air A1 to flow upward in the passage 4 between the fins 3 from one end 4a located on the lower side to the other end 4b located on the upper side, and is released to the rear side toward which the other end 4b faces, behind the rear plate 102b of the main body 102 of the electronic device 101. As a result, like the heat sink 1A, the heat sink 1I can prevent heat from remaining in the gap S above the electronic device 101, thereby improving cooling efficiency.

[0085] Furthermore, in the heat sink 1I, the other ends 3b of the first fins 31 are unevenly arranged with respect to the vertical line L within the other surface 21b of the base 2, so that heat released from the passages 4 between the first fins 31 rises without being obstructed by the upper first fins 31 and is suppressed from rising upward by the upper first fins 31. As a result, the heat sink 1I has the effect of dissipating heat over a wider area and suppressing heat dissipation into the gap S above the main body 102 of the electronic device 101, thereby further improving cooling efficiency. Furthermore, by shortening the first fins 31 within the other surface 21b of the base 2 as described above, the flow paths between the long first fins 31 widen from the other ends 3b of the short first fins 31 toward the outlet side, i.e., the other end 4b of the passages 4, thereby optimizing the interference interval of the thermal boundary layer. On the other hand, by narrowing the intervals between the fins 31 on the inlet side, i.e., one end 4a of the passages 4, to ensure the number of fins, cooling efficiency can be further improved.

[0086] The heat sink 1 of embodiment 1 is characterized by including a base 2 having a plate-shaped one surface 21a attached along the outer surface of the right plate 102f, which is the vertical wall portion of the main body 102 of the electronic device 101; fins 3 arranged in parallel along the plate-shaped other surface 21b of the base 2; and passage portions 4 formed continuously along the other surface 21b of the base 2 between the fins 3, and the fins 3 are formed so that, when the base 2 is attached to the right plate 102f, one end 4a of the passage portions 4 is open downward in the vertical direction, and the other end 4b of all the passage portions 4 is positioned above the one end 4a and is open in the horizontal direction.

[0087] With this heat sink 1, air A1 flows upward in the passage 4 between the fins 3 from one end 4a located on the lower side to the other end 4b located on the upper side, and is discharged to the rear side along the horizontal direction in which the other end 4b faces, behind the rear plate 102b of the main body 102 of the electronic device 101. As a result, the heat sink 1 prevents heat from being trapped in the gap S above the electronic device 101, thereby improving cooling efficiency.

[0088] In the heat sink 1 of the first embodiment, the distance between adjacent fins 3 is varied so that one end 4b of the passage 4 is larger than the other end 4a.

[0089] This heat sink 1 prevents interference between the temperature boundary layers of adjacent fins 3, promotes the flow (convection) of the air A1, and further improves the cooling efficiency.

[0090] Furthermore, in the heat sink 1 of the first embodiment, each fin 3 is curved so that the passage portion 4 bulges upward.

[0091] According to this heat sink 1, by curving the passage portion 4, the length of the passage portion 4 can be extended within the range of the other surface 21b of the base 2 compared to a straight passage portion 4, thereby increasing the amount of heat transferred from the base 2 to the fins 3 and further improving the cooling efficiency.

[0092] In the heat sink 1 of the first embodiment, the other ends 3b of the fins 3 that form the other ends 4b of the passages 4 are located at different positions relative to the vertical line L within the other surface 21b of the base 2.

[0093] According to this heat sink 1, heat released from the passages 4 between the fins 3 rises without being obstructed by the upper fins 3, and is prevented from rising upward by the upper fins 3. As a result, the heat sink 1 has the effect of dissipating heat over a wider range and of preventing heat from being dissipated into the gap S above the main body 102 of the electronic device 101, thereby further improving cooling efficiency.

[0094] Moreover, the electronic device 101 of the first embodiment is applied with the heat sink 1 described above.

[0095] According to this electronic device 101, it is possible to prevent heat from remaining in the gap S above the electronic device 101, thereby improving the cooling efficiency.

[0096] The above-described first embodiment encompasses the following inventions. [Invention 1] A heat sink including a base having one plate-shaped surface attached along the outer surface of a vertical wall of an electronic device; a plurality of fins arranged in parallel along the other plate-shaped surface of the base; and passages formed continuously between the fins along the other surface of the base, wherein, when the base is attached to the vertical wall, one end of each passage is open downward in the vertical direction and the other end of each passage is located above the one end and is open in the horizontal direction. [Invention 2] The heat sink according to Invention 1, wherein the fins are arranged with varying spacing between adjacent fins so that the other end of each passage is larger than the one end. [Invention 3] The heat sink according to Invention 1 or 2, wherein each fin is curved so that the passage bulges upward. [Invention 4] The heat sink according to any one of Inventions 1 to 3, wherein, within the other surface of the base, the end of each fin forming the other end of each passage is positioned at a different position relative to a vertical line. [Invention 5] The device includes: an equipment body in which a heating element is provided on the inner surface of a predetermined vertical wall portion and a plate material is placed on the upper side of an upper horizontal wall portion to which the upper ends of the vertical wall portion are connected; and the heat sink according to any one of Inventions 1 to 4.

[0097] [Second Embodiment of Heat Sink] Hereinafter, details of a heat sink 1 according to a second embodiment will be described with reference to Fig. 17 to Fig. 20. Each figure shows a state in which the heat sink 1 is attached to the right plate 102f, which is a standing wall portion.

[0098] The heat sinks 1J, 1K, 1L, and 1M of the second embodiment differ from the heat sink 1 of the first embodiment mainly in the shape of the fins 3, and the same parts are denoted by the same reference numerals and description thereof will be omitted.

[0099] The heat sinks 1J, 1K, 1L, and 1M shown in FIGS. 17 to 20 only have first fins 31, and these first fins 31 are formed to be curved like the heat sink 1A.

[0100] The first fin 31 is formed continuously from one end 3a to the other end 3b along the other surface 21b of the base 2. The one end 3a faces downward. The other end 3b faces rearward. The first fin 31 is formed continuously from the lower side to the upper and rear sides. The first fin 31 has one end 3a located at the lower end 22d of the base 2 and the other end 3b located at the rear end 22b of the base 2. The first fin 31 has an edge 3c extending from the other surface 21b of the base 2, extending from the one end 3a to the other end 3b, and is equidistant from the other surface 21b of the base 2. That is, when unfolded, the first fin 31 is formed as a rectangular elongated plate, and is fixed to the other surface 21b of the base 2 with one end 3a as the one end and the other end 3b as the other end. The first fins 31 are formed so as to bulge upward and curve between one end 3 a and the other end 3 b. A plurality of the first fins 31 are arranged side by side at intervals B along the other surface 21 b of the base 2. The first fins 31 are arranged at uniform, equal intervals between adjacent fins along the other surface 21 b of the base 2 from one end 3 a to the other end 3 b.

[0101] The passages 4 provided between the multiple first fins 31 are formed continuously from one end 4a to the other end 4b along the other surface 21b of the base 2. One end 4a of the passages 4 is open at the position of one end 3a of the first fin 31, and the other end 4b is open at the position of the other end 3b of the first fin 31. The one end 4a opens downward along the vertical direction. The other end 4b opens rearward along the horizontal direction. Therefore, the passages 4 provided between the multiple first fins 31 are formed continuously from the one end 4a to the other end 4b from the lower side to the rear side. The passages 4 provided between the multiple first fins 31 are formed continuously from the one end 4a to the other end 4b. The one end 4a of the passages 4 provided between the multiple first fins 31 is open at the lower end 22d of the base 2, and the other end 4b is open at the rear end 22b of the base 2. Furthermore, the passages 4 provided between the multiple first fins 31 are continuous at an equal distance from the other surface 21 b of the base 2 from one end 4a to the other end 4b because the edges 3c of the first fins 31 are equidistant from the other surface 21 b of the base 2 from one end 3a to the other end 3b. Furthermore, the passages 4 provided between the multiple first fins 31 are formed so that the first fins 31 bulge and curve upward from one end 3a to the other end 3b, so that the passages 4 provided between the multiple first fins 31 are formed so that the first fins 31 bulge and curve upward from one end 4a to the other end 4b. The passages 4 provided between the multiple first fins 31 are uniform and equally spaced from one end 4a to the other end 4b.

[0102] 17 , the first fins 31 have extensions 3d such that the other ends 3b extend horizontally from the rear end 22b of the base 2 to outside the range (rear side) of the other surface 21b of the base 2. The extensions 3d are provided to extend horizontally. In the heatsink 1J, the first fins 31 have the other ends 3b that extend outside the range of the other surface 21b of the base 2 due to the extensions 3d, aligned at the same position with respect to the vertical line L. Therefore, in the heatsink 1J, the first fins 31 that form the other ends 4b of the passages 4 are formed to extend horizontally from the rear end 22b of the base 2 to the rear side, outside the range of the other surface 21b of the base 2.

[0103] In this heat sink 1J, heat generated by the heat generating element 104 of the electronic device 101 is transferred to the base 2 and then from the base 2 to the fins 3. In the heat sink 1J, the heat transferred to the fins 3 causes air A1 to flow upward in the passage 4 between the fins 3 from one end 4a located on the lower side to the other end 4b located on the upper side, and is released to the rear side toward which the other end 4b faces, behind the rear plate 102b of the main body 102 of the electronic device 101. As a result, like the heat sink 1A, the heat sink 1J can prevent heat from remaining in the gap S above the electronic device 101, thereby improving cooling efficiency.

[0104] Moreover, in the heat sink 1J, the other end 3b of each first fin 31, which forms the other end 4b of the passage 4, extends horizontally outside the range of the other surface 21b of the base 2. This allows heat released from the passage 4 between the first fins 31 to be guided outside the range of the other surface 21b of the base 2. Furthermore, in the heat sink 1J, the other end 3b of each first fin 31, which protrudes rearward from the rear end 22b of the base 2, is exposed at the portion where it was joined to the other surface 21b of the base 2. This allows heat to be transferred from the heat-generating element 201 and dissipated at a position away from the high-temperature base 2. In addition, the heat sink 1J can also dissipate heat from the exposed end surface away from the base 2. As a result, the heat sink 1J has an increased space for heat dissipation and can dissipate heat over a wider area, thereby further improving cooling efficiency.

[0105] 18 , the first fin 31 has an extension 3d such that the other end 3b extends horizontally from the rear end 22b of the base 2 to outside the range (rear side) of the other surface 21b of the base 2. The extension 3d is provided to extend horizontally. In the heat sink 1K, the first fin 31 is arranged such that the other end 3b, which extends outside the range (rear side) of the other surface 21b of the base 2 by the extension 3d (from the rear end 22b of the base 2) by the extension 3d, gradually becomes shorter from below to above with respect to a vertical line L based on the first fin 31 at the lowest position.

[0106] In this heat sink 1K, heat generated by the heat generating element 104 of the electronic device 101 is transferred to the base 2 and then from the base 2 to the fins 3. In the heat sink 1K, the heat transferred to the fins 3 causes air A1 to flow upward in the passage 4 between the fins 3 from one end 4a located on the lower side to the other end 4b located on the upper side, and is released to the rear side toward which the other end 4b faces, behind the rear plate 102b of the main body 102 of the electronic device 101. As a result, like the heat sink 1A, the heat sink 1K can prevent heat from remaining in the gap S above the electronic device 101, thereby improving cooling efficiency.

[0107] Moreover, in the heat sink 1K, the other end 3b of each first fin 31, which forms the other end 4b of the passage 4, extends horizontally outside the range of the other surface 21b of the base 2, so that heat released from the passage 4 between the first fins 31 is guided outside the range of the other surface 21b of the base 2. Furthermore, in the heat sink 1K, the other end 3b of the first fin 31, which protrudes rearward from the rear end 22b of the base 2, is exposed at the portion where it was joined to the other surface 21b of the base 2. Therefore, heat is transferred from the heat-generating element 201 and can be dissipated at a position away from the high-temperature base 2. In addition, the heat sink 1K can also dissipate heat from the exposed end surface away from the base 2. As a result, the heat sink 1K has more space for heat dissipation and can dissipate heat over a wider area, thereby further improving cooling efficiency.

[0108] Moreover, the heat sink 1K is arranged so that the other end 3b of each first fin 31, which extends outside the range of the other surface 21b of the base 2 (rearward from the rear end 22b of the base 2) by the extension 3d, gradually becomes shorter from the bottom to the top with respect to a vertical line L based on the lowest first fin 31, so that heat released from the passage 4 between each first fin 31 rises without being obstructed by the upper first fin 31. As a result, the heat sink 1K can dissipate heat over a wider range, further improving cooling efficiency.

[0109] 19 , the first fin 31 has an extension 3d such that the other end 3b extends horizontally from the rear end 22b of the base 2 to outside the range (rear side) of the other surface 21b of the base 2. The extension 3d is provided to extend horizontally. In the heat sink 1L, the first fin 31 is arranged such that the other end 3b, which extends outside the range (rear side) of the other surface 21b of the base 2 by the extension 3d (from the rear end 22b of the base 2) by the extension 3d, gradually becomes longer from below to above with respect to a vertical line L based on the first fin 31 at the lowest position.

[0110] In this heat sink 1L, heat generated by the heat generating element 104 of the electronic device 101 is transferred to the base 2 and then from the base 2 to the fins 3. In the heat sink 1L, the heat transferred to the fins 3 causes air A1 to flow upward in the passage 4 between the fins 3 from one end 4a located on the lower side to the other end 4b located on the upper side, and is released to the rear side toward which the other end 4b faces, behind the rear plate 102b of the main body 102 of the electronic device 101. As a result, like the heat sink 1A, the heat sink 1L can prevent heat from remaining in the gap S above the electronic device 101, improving cooling efficiency.

[0111] Furthermore, in the heat sink 1L, the other end 3b of each first fin 31, which forms the other end 4b of the passage 4, extends horizontally outside the range of the other surface 21b of the base 2, so that heat released from the passage 4 between the first fins 31 is guided outside the range of the other surface 21b of the base 2. Furthermore, in the heat sink 1L, the other end 3b of the first fin 31, which protrudes rearward from the rear end 22b of the base 2, is exposed at the portion where it was joined to the other surface 21b of the base 2. Therefore, heat is transferred from the heat-generating element 201 and can be dissipated at a position away from the high-temperature base 2. In addition, the heat sink 1L can also dissipate heat from the exposed end surface away from the base 2. As a result, the heat sink 1L has more space for heat dissipation and can dissipate heat over a wider area, thereby further improving cooling efficiency.

[0112] Moreover, the heat sink 1L is arranged such that the other end 3b of each first fin 31, which extends outside the range of the other surface 21b of the base 2 (rearward from the rear end 22b of the base 2) by the extension 3d, gradually becomes longer from below to above with respect to the vertical line L based on the lowest first fin 31, so that the heat released from the passage 4 between each first fin 31 is prevented from rising upward by the upper first fin 31. As a result, the heat sink 1L can prevent heat from being dissipated into the gap S above the main body 102 of the electronic device 101, thereby further improving cooling efficiency.

[0113] 20 , the first fin 31 has an extension 3d such that the other end 3b extends horizontally from the rear end 22b of the base 2 to outside the range (rear side) of the other surface 21b of the base 2. The extension 3d is provided to extend horizontally. In the heat sink 1M, the other end 3b of the first fin 31 extends outside the range (rear side) of the other surface 21b of the base 2 due to the extension 3d, and is positioned unevenly with respect to the vertical line L.

[0114] In this heat sink 1M, heat generated by the heat generating element 104 of the electronic device 101 is transferred to the base 2 and then from the base 2 to the fins 3. In the heat sink 1M, the heat transferred to the fins 3 causes air A1 to flow upward in the passage 4 between the fins 3 from one end 4a located on the lower side to the other end 4b located on the upper side, and is released to the rear side toward which the other end 4b faces, behind the rear plate 102b of the main body 102 of the electronic device 101. As a result, like the heat sink 1A, the heat sink 1M can prevent heat from remaining in the gap S above the electronic device 101, improving cooling efficiency.

[0115] Moreover, in the heat sink 1M, the other end 3b of each first fin 31 forming the other end 4b of the passage 4 extends horizontally outside the range of the other surface 21b of the base 2, so that heat released from the passage 4 between each first fin 31 is guided to outside the range of the other surface 21b of the base 2. As a result, the heat sink 1M can dissipate heat over a wider range, thereby further improving cooling efficiency.

[0116] Moreover, in the heat sink 1M, the other ends 3b of each first fin 31 that extend outside the range of the other surface 21b of the base 2 (rearward from the rear end 22b of the base 2) due to the extensions 3d are unevenly arranged with respect to the vertical line L, so that heat released from the passages 4 between the first fins 31 rises without being obstructed by the upper first fins 31, or is suppressed from rising upward by the upper first fins 31. As a result, the heat sink 1M has the effect of being able to dissipate heat over a wider range and the effect of being able to suppress heat dissipation into the gap S above the main body 102 of the electronic device 101, thereby further improving cooling efficiency.

[0117] The heat sink 1 of embodiment 2 is characterized by including a base 2 having a plate-shaped one side 21a attached along the outer surface of a right plate 102f, which is a vertical wall portion of the main body 102 of the electronic device 101; fins 3 arranged in parallel along the plate-shaped other side 21b of the base 2; and passage portions 4 formed continuously along the other side 21b of the base 2 between the fins 3. When the base 2 is attached to the right plate 102f, the fins 3 are formed so that one end 4a of the passage portions 4 is open downward in the vertical direction, and the other end 4b of all the passage portions 4 is positioned above the one end 4a and is open in the horizontal direction, and the other end 3b of each fin 3 on the other end 4b side of the passage portion 4 is formed to extend horizontally outside the range of the other side 21b of the base 2.

[0118] With this heat sink 1, air A1 flows upward in the passage 4 between the fins 3 from one end 4a located on the lower side to the other end 4b located on the upper side, and is discharged to the rear side along the horizontal direction in which the other end 4b faces, behind the rear plate 102b of the main body 102 of the electronic device 101. As a result, the heat sink 1 prevents heat from being trapped in the gap S above the electronic device 101, thereby improving cooling efficiency.

[0119] Moreover, with this heat sink 1, the other end 3b of each fin 3 forming the other end 4b of the passage 4 extends horizontally outside the range of the other surface 21b of the base 2, so that heat released from the passage 4 between the fins 3 is guided to outside the range of the other surface 21b of the base 2. As a result, the heat sink 1 can dissipate heat over a wider range, further improving cooling efficiency.

[0120] In addition, in the heat sink 1 of embodiment 2, each fin 3 is arranged so that the other end 3b extended outside the range of the other surface 21b of the base 2 becomes gradually shorter from the bottom to the top with respect to the vertical line L based on the lowest fin 3.

[0121] With this heat sink 1, heat released from the passages 4 between the fins 3 rises without being obstructed by the upper fins 3. As a result, the heat sink 1 can dissipate heat over a wider range, further improving cooling efficiency.

[0122] In addition, in the heat sink 1 of embodiment 2, each fin 3 is arranged so that the other end 3b, which extends outside the range of the other surface 21b of the base 2, gradually becomes longer from the bottom to the top relative to the vertical line L based on the lowest fin 3.

[0123] According to this heat sink 1, the heat released from the passages 4 between the fins 3 is prevented from rising upward by the upper fins 3. As a result, the heat sink 1 can prevent heat from being released into the gap S above the main body 102 of the electronic device 101, thereby further improving cooling efficiency.

[0124] In the heat sink 1 of the second embodiment, the other end portions 3 b of the fins 3 that extend outside the range of the other surface 21 b of the base 2 are arranged unevenly with respect to the vertical line L.

[0125] According to this heat sink 1, heat released from the passages 4 between the fins 3 rises without being obstructed by the upper fins 3, and is prevented from rising upward by the upper fins 3. As a result, the heat sink 1 has the effect of dissipating heat over a wider range and the effect of preventing heat from being dissipated into the gap S above the main body 102 of the electronic device 101, thereby further improving cooling efficiency.

[0126] Moreover, the electronic device 101 of the second embodiment is applied with the heat sink 1 described above.

[0127] According to this electronic device 101, it is possible to prevent heat from being trapped in the gap S above the electronic device, thereby improving the cooling efficiency, and also to dissipate heat over a wider range, thereby further improving the cooling efficiency.

[0128] The heat sink 1 of the second embodiment can include the features of the heat sink 1 of the first embodiment, and can achieve the effects of the features of the heat sink 1 of the first embodiment.

[0129] The above-described embodiment 2 encompasses the following inventions. [Invention 1] A heat sink comprising: a base having one plate-shaped surface attached along the outer surface of a vertical wall of an electronic device; a plurality of fins arranged in a row along the other plate-shaped surface of the base; and passages formed continuously between the fins along the other surface of the base, wherein, when the base is attached to the vertical wall, the fins are formed so that one end of each passage is open downward in the vertical direction and the other end of each passage is located above the one end and is open in the horizontal direction, and an end of each fin on the other end side of the passage is formed to extend horizontally outside the range of the other surface of the base. [Invention 2] The heat sink according to Invention 1, wherein each fin is arranged so that the end extending outside the range of the other surface of the base gradually becomes shorter from below to above with respect to a vertical line based on the lowest fin. [Invention 3] The heat sink according to Invention 1, wherein the end of each of the fins extending outside the range of the other side of the base is arranged so that it gradually becomes longer from below to above with respect to a vertical line based on the fin at the lowest position. [Invention 4] The heat sink according to Invention 1, wherein the end of each of the fins extending outside the range of the other side of the base is arranged unevenly with respect to the vertical line. [Invention 5] A heat sink comprising: an equipment main body in which a heating element is provided on the inner surface of a predetermined vertical wall portion, and a plate material is arranged above an upper horizontal wall portion to which the upper ends of the vertical wall portion are connected; and the heat sink according to any one of Inventions 1 to 4.

[0130] [Heat Sink Embodiment 3] Hereinafter, details of the heat sink 1 according to the third embodiment will be described with reference to Fig. 21. Fig. 21 shows the heat sink 1 attached to the right plate 102f, which is the upright wall portion.

[0131] The heat sink 1P of the third embodiment has the same shape of the fins 3 as the heat sink 1K of the second embodiment, and the same reference numerals are used and the description thereof will be omitted.

[0132] In the heat sink 1P, the base 2 is formed such that the rear end 22b includes the extension 3d of the first fin 31 and has an extension 22e that extends to the other end 2b, as compared to the heat sink 1K. Therefore, the extension 22e of the base 2, together with the extension 3d of the first fin 31, is arranged to protrude rearward beyond the rear plate 102b of the main body 102 of the electronic device 101. In the heat sinks 1J, 1K, 1L, and 1M described above, only the extension 3d of the first fin 31 is arranged to protrude rearward beyond the rear plate 102b of the main body 102 of the electronic device 101.

[0133] In this heat sink 1P, heat generated by the heat generating element 104 of the electronic device 101 is transferred to the base 2 and then from the base 2 to the fins 3. In the heat sink 1P, the heat transferred to the fins 3 causes air A1 to flow upward in the passage 4 between the fins 3 from one end 4a located on the lower side to the other end 4b located on the upper side, and is released to the rear side toward which the other end 4b faces, behind the rear plate 102b of the main body 102 of the electronic device 101. As a result, like the heat sink 1A, the heat sink 1P can prevent heat from remaining in the gap S above the electronic device 101, improving cooling efficiency.

[0134] Moreover, in the heat sink 1P, the other end 3b of each first fin 31 forming the other end 4b of the passage 4 is formed to extend along the horizontal direction, so that the heat released from the passage 4 between the first fins 31 is guided to outside the range of the other surface 21b of the base 2. Furthermore, in the heat sink 1P, the extension 22e (rear end 22b) of the base 2, together with the extension 3d (rear end 3b) of the first fin 31, is positioned to protrude rearward from the rear plate 102b of the main body 102 of the electronic device 101, so that the heat is guided rearward from the rear plate 102b of the main body 102.

[0135] Moreover, the heat sink 1P is arranged so that the other end 3b of each first fin 31 gradually becomes shorter from the bottom to the top with respect to a vertical line L based on the lowest first fin 31, so that heat released from the passages 4 between each first fin 31 rises without being obstructed by the upper first fins 31. As a result, the heat sink 1P can dissipate heat over a wider range when viewed along the vertical line L, thereby further improving cooling efficiency.

[0136] [Other configurations] In the heat sinks 1A to 1M described above, the rear end 22b of the base 2, together with the rear end 3b of the first fin 31, may be positioned to protrude rearward beyond the rear plate 102b of the main body 102 of the electronic device 101, as in the heat sink 1P.

[0137] The performance tests carried out on the heat sinks of the examples will be described below.

[0138] The performance test was carried out by simulation using the finite element method. Specifically, the performance test evaluated Models 1 to 5 based on the temperatures generated by the power ICs (ICs) shown in Figures 22, 26, 30, 34, and 38. A power IC is a general term for an integrated circuit incorporating a power semiconductor.

[0139] In the simulation, the main body 102 of the electronic device 101 is hollow, and a power IC (IC) is placed inside the main body 102, exposed from the main body 102, and the base 2 of each of the heat sink models 1 to 5 is brought into contact with the IC. In the simulation, the power IC is heated from room temperature (25°C) to saturation, generating 20 W of heat. The performance test results were compared and verified using the shapes of the heat sink models 1 to 5 as parameters, comparing the temperature rise of the power IC and the air flow conditions around the heat sink. The simulation analysis assumes natural convection, with turbulence not considered. The heat transfer paths are considered to be heat conduction and radiation.

[0140] The power IC (IC) is made of resin (beryllium), a common packaging material. The main body 102 of the electronic device 101 is made of resin (polycarbonate). By using resin for the main body 102, most of the heat from the power IC (IC) is transferred to the heat sink, which is closer to the evaluation of the heat sink alone.

[0141] Model 1 corresponds to the heat sink 1Z described above (see FIGS. 22 and 23). Model 2 corresponds to the heat sink 1X described above (see FIGS. 26 and 27). Model 3 corresponds to the heat sink 1K described above (see FIGS. 30 and 31). Model 4 corresponds to the heat sink 1J described above (see FIGS. 34 and 35). Model 5 corresponds to the heat sink 1P described above (see FIGS. 38 and 39). The heat sinks are made of aluminum.

[0142] For model 1, small lines in various directions in FIG. 24 represent the airflow around the heat sink, and the maximum flow velocity region in FIG. 25 represents the airflow around the heat sink. For model 2, small lines in various directions in FIG. 28 represent the airflow around the heat sink, and the maximum flow velocity region in FIG. 29 represents the airflow around the heat sink. For model 3, small lines in various directions in FIG. 32 represent the airflow around the heat sink, and the maximum flow velocity region in FIG. 33 represents the airflow around the heat sink. For model 4, small lines in various directions in FIG. 36 represent the airflow around the heat sink, and the maximum flow velocity region in FIG. 37 represents the airflow around the heat sink. For model 5, small lines in various directions in FIG. 40 represent the airflow around the heat sink. FIG. 41 shows the volume ratio (Model 1 is set as the reference 100%), the temperature (°C) reached at the contact surface of the power IC with the heat sink, a comparison of the temperatures reached by the power IC (Model 1 is set as the reference index 100), the maximum flow velocity (m / s) around the heat sink, and a comparison of the maximum flow velocity (Model 1 is set as the reference index 100).

[0143] The small line segments of various orientations shown in Figures 24, 28, 32, 36, and 40 indicate the air flow direction for each element in a finite element model in which the air domain is divided into a cubic grid. The maximum flow velocity regions shown in Figures 25, 29, 33, and 37 indicate the regions among the countless elements in the finite element model of air where the flow velocity is above a threshold. While a constant velocity surface is typically constructed as a curved surface in space, its complex three-dimensional shape makes it difficult to grasp the shape of the region on paper. To make this easier to understand, the region is divided vertically and displayed. Furthermore, the numerical scales of the flow velocity (maximum and minimum velocities) are uniformly displayed, allowing for comparison of results from different models. The black areas in Figures 29, 33, and 37 indicate the maximum flow velocity points in the maximum flow velocity region.

[0144] The evaluation results showed that compared to Models 1 and 2, Models 3 to 5 had a higher maximum flow velocity around the heat sink, which allowed the heat from the power IC to be discharged to the outside, lowering the temperature reached by the power IC.

[0145] In addition, in Model 1, the outlets (other ends 4b) of the passages 4 are aligned horizontally, allowing hot air to diffuse quickly in the space above the heat sink. In Models 3 to 5, the outlets (other ends 4b) of the passages 4 are aligned in the direction of gravity (vertical direction), and the fins overlap, causing the hot air to concentrate, maintain a high temperature, and rise at a high flow rate, enhancing the chimney effect. Furthermore, when the outlets (other ends 4b) of the passages 4 are formed in a stepped pattern due to differences in the lengths of the fin extensions, as in Models 3 and 5, the flow velocity distribution becomes denser and the width of the rising hot air becomes wider. This makes the air less susceptible to cooling from the outside air (thermal diffusion), less likely to lose buoyancy, further enhancing the chimney effect and allowing the air to rise at a higher flow rate.

[0146] Here, the heat dissipation from the heat sink is extremely weak because the air between the fins is drawn out by the negative pressure caused by the rising heated air near the other end 3b of the fins. Also, the air viscosity is high near the fins, so the air speed is extremely slow. On the other hand, the heated air rises due to buoyancy. When the heat source is below, there is less cold air obstructing the rising hot air, so the buoyancy increases due to the chimney effect. In other words, in Models 3 and 5, the high flow velocity of the rising air is due to the rise caused by the buoyancy of the heated air near the other end 3b of the fins.

[0147] FIG. 42 is a table showing the evaluation of each model in the performance test of the heat sink according to the embodiment.

[0148] In the performance test of the heat sink described above, when comparing Model 1 and Model 2, it was found that both Model 1 and Model 2 generated updrafts across the width of the heat sink, but over a relatively wide range. Model 2 was more likely to generate updrafts as the air between the fins flowed upward, and the maximum flow velocity in the air above was also greater.

[0149] In the heat sink performance tests, compared to Models 1 and 2, Models 3 to 5 generated an updraft in a relatively narrow range from the smallest to the largest protruding end of the fins when viewed from above. Model 3 had a higher flow velocity above the protruding fins than Model 2. Model 4 had a higher flow velocity above the protruding fins than Model 2. Model 4 had a smaller flow velocity and maximum flow velocity range than Model 3. Model 5 had a higher flow velocity above the protruding fins than Model 2. Model 5 had better cooling efficiency due to its enlarged base area. Furthermore, models 3 and 5, in which the protrusion amount of the fins gradually changes in the vertical direction, have a larger range of maximum flow velocity points within the maximum flow velocity range than Model 4, in which the protrusion amount of the fins is the same in the vertical direction, and therefore have better cooling efficiency.

[0150] The present disclosure can improve cooling efficiency.

[0151] 1(1A,1B,1C,1D,1E,1F,1G,1H,1I,1J,1K,1L,1M,1N,1P) ヒートシンク2 ベース21a One side 21b Other side 3 フィン(31 1フィン) 3a One end 3b Other end 3d Extension 4 Passage 4a One end 4b Other end 101 Electronic device 102 Main body 104 Heat emitting element L Vertical line

Claims

1. A base to which one plate-shaped surface is attached along the outer surface of the vertical wall of the electronic device, Multiple fins are arranged in parallel along the other plate-shaped surface of the base, A passage portion is formed continuously between the fins along the other surface of the base, Includes, With the base attached to the vertical wall, each fin is formed such that one end of the passage is open downward along the vertical direction, and all other ends of the passage are positioned above the one end and open along the horizontal direction. The ends of each of the fins on the other end side of the passage portion are formed to extend horizontally outside the range of the other surface of the base, Each of the fins is positioned such that the end portion extending beyond the range of the other surface of the base gradually becomes shorter from the bottom to the top with respect to a vertical line with respect to the lowest fin. heat sink.

2. A base to which one plate-shaped surface is attached along the outer surface of the vertical wall of the electronic device, Multiple fins are arranged in parallel along the other plate-shaped surface of the base, A passage portion is formed continuously between the fins along the other surface of the base, Includes, With the base attached to the vertical wall, each fin is formed such that one end of the passage is open downward along the vertical direction, and all other ends of the passage are positioned above the one end and open along the horizontal direction. The ends of each of the fins on the other end side of the passage portion are formed to extend horizontally outside the range of the other surface of the base, Each of the fins is positioned such that the end extending beyond the range of the other surface of the base gradually increases in length from the bottom to the top with respect to a vertical line with respect to the lowest fin. heat sink.

3. A base to which one plate-shaped surface is attached along the outer surface of the vertical wall of the electronic device, Multiple fins are arranged in parallel along the other plate-shaped surface of the base, A passage portion is formed continuously between the fins along the other surface of the base, Includes, With the base attached to the vertical wall, each fin is formed such that one end of the passage is open downward along the vertical direction, and all other ends of the passage are positioned above the one end and open along the horizontal direction. The ends of each of the fins on the other end side of the passage portion are formed to extend horizontally outside the range of the other surface of the base, Each of the fins has an end that extends beyond the range of the other surface of the base, which is arranged non-uniformly with respect to the vertical. heat sink.

4. A device body having a heating element provided on the inner surface of a predetermined vertical wall section, and a plate material positioned above the upper horizontal wall section to which the upper end of the vertical wall section is connected, A heat sink attached to the outer surface of the vertical wall portion of the main body of the device, Includes, The aforementioned heatsink is A base to which one plate-shaped surface is attached along the outer surface of the vertical wall portion, Multiple fins are arranged in parallel along the other plate-shaped surface of the base, A passage portion is formed continuously between the fins along the other surface of the base, Includes, With the base attached to the vertical wall, each fin is formed such that one end of the passage is open downward along the vertical direction, and all other ends of the passage are positioned above the one end and open along the horizontal direction. The ends of each of the fins on the other end side of the passage portion are formed to extend horizontally outside the range of the other surface of the base, Each of the fins is positioned such that the end portion extending beyond the range of the other surface of the base gradually becomes shorter from the bottom to the top with respect to a vertical line with respect to the lowest fin. electronic equipment.