Heat sink

Abstract

Provided is a heat sink having improved heat-dissipating efficiency and high manufacturability. A heat sink (100) of the present invention comprises a base (1) including a surface on which a plurality of heat-dissipating fins (2) are provided spaced apart from each other. Each of the plurality of heat-dissipating fins (2) comprises: a first inclined fin portion (21) provided on one side of a reference line AX extending longitudinally on the surface, the first inclined fin portion (21) being inclined at a first angle θ1 with respect to the reference line AX; a second inclined fin portion (22) provided on the other side of the reference line AX on the surface and being inclined at a second angle θ2 with respect to the reference line AX; and a linking fin portion (23) linking mutually opposing ends of the first inclined fin portion (21) and the second inclined fin portion (22).

Description

Technical Field

[0001] The present invention relates to a heat sink.

Background Art

[0002] Patent Document 1 discloses a heat sink capable of improving heat dissipation efficiency. Specifically, Patent Document 1 discloses a heat sink including a plate-shaped base plate extending vertically upward from a substrate, and a plurality of heat radiation fins arranged in parallel at a predetermined interval on both surfaces of the base plate. The plurality of heat radiation fins are arranged in a plurality of rows along the vertical direction on each surface of the base plate and are inclined with respect to the vertical direction (see FIG. 4(a) in particular). Here, a space extending in the vertical direction is provided between the heat radiation fins constituting the left column and the heat radiation fins constituting the right column.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when manufacturing a heat sink provided with a space extending in the vertical direction between the heat radiation fins constituting the left column and the heat radiation fins constituting the right column as in Patent Document 1, there is a problem that the manufacturability of the heat sink is reduced. For example, when manufacturing a heat sink provided with a space extending in the vertical direction between the heat radiation fins constituting the left column and the heat radiation fins constituting the right column as in Patent Document 1 by casting, the flow of the molten metal (in particular, the flow of the molten metal with respect to each of the heat radiation fins constituting the left column and the heat radiation fins constituting the right column) deteriorates, resulting in reduced manufacturability.

[0005] In view of such problems, an object of the present disclosure is to provide a heat sink with improved heat dissipation efficiency and high manufacturability.

Means for Solving the Problems

[0006] The heat sink of the present disclosure includes a base including a surface on which a plurality of heat dissipation fins are provided at intervals from each other, each of the plurality of heat dissipation fins includes a first inclined fin portion provided on one side of a reference line extending in the longitudinal direction of the surface and inclined at a first angle with respect to the reference line, a second inclined fin portion provided on the other side of the surface with respect to the reference line and inclined at a second angle with respect to the reference line, and a connecting fin portion connecting the ends of the first inclined fin portion and the ends of the second inclined fin portion facing each other.

Effects of the Invention

[0007] According to the present disclosure, a heat sink with improved heat dissipation efficiency and high manufacturability can be provided.

Brief Description of the Drawings

[0008]

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MODE FOR CARRYING OUT THE INVENTION

[0009] Hereinafter, specific embodiments to which the present disclosure is applied will be described in detail with reference to the drawings. In each drawing, the same reference numerals are assigned to the same elements, and for the sake of clarity of explanation, duplicate explanations are omitted as necessary.

[0010] (First Embodiment) Using FIG. 1, the configuration of the heat sink 100 according to the first embodiment will be described. FIG. 1 is a front view showing an example of the configuration of the heat sink 100. Of course, the right-handed xyz orthogonal coordinates shown in FIG. 1 and the like are for convenience in explaining the positional relationship of the components. Usually, the xy plane is the base 1 plane described later, the positive z-axis direction is the height direction of the heat dissipation fins 2 described later, and is common among the drawings.

[0011] The heat sink 100 includes a base 1 including a surface on which a plurality of heat dissipation fins 2 are provided at intervals. Each of the plurality of heat dissipation fins 2 has a first diagonal fin portion 21 provided on one side with respect to a reference line AX extending in the vertical direction (y direction) of the surface and inclined at a first angle θ1 with respect to the reference line AX, and a second diagonal fin portion 22 provided on the other side with respect to the reference line AX of the surface and inclined at a second angle θ2 with respect to the reference line AX, and a connecting fin portion 23 connecting the end portions of the first diagonal fin portion 21 and the second diagonal fin portion 22 facing each other.

[0012] Therefore, in the heat sink 100 according to the first embodiment, the heat dissipation efficiency can be improved, and the flow of molten metal during casting of the heat sink 100 is better than that in the case where the connecting fin portion 23 is absent, so that the manufacturability can be improved.

[0013] (Second Embodiment) First, the configuration of the heat sink 200 according to the second embodiment will be described with reference to FIGS. 2 and 3. The heat sink 200 is a specific example of the heat sink 100 according to the first embodiment. FIG. 2 is a perspective view showing an example of the configuration of the heat sink 200. FIG. 3 is a front view showing an example of the configuration of the heat sink 200.

[0014] As shown in FIGS. 2 and 3, the heat sink 200 includes a plate-like base 1 having one surface and the other surface opposite thereto and having a thickness in the z direction, and a plurality of heat dissipation fins 2 provided at intervals on one surface. The heat sink 200 (the base 1 and the heat dissipation fins 2) is an integral body manufactured by casting a metal material such as aluminum, for example. Note that the heat sink 200 (the base 1 and the heat dissipation fins 2) may be manufactured by performing cutting on an aluminum or copper-based metal material. Further, the heat sink 200 may be manufactured by press-fitting the separately manufactured base 1 and heat dissipation fins 2. Here, the metal material used for casting / cutting / press-fitting is not limited to the above-described metal materials.

[0015] Each of the plurality of heat dissipation fins 2 includes a left diagonal fin portion (an example of the first diagonal fin portion of the present invention) 21, a right diagonal fin portion (an example of the second diagonal fin portion of the present invention) 22, and a connecting fin portion 23.

[0016] The left diagonal fin portion 21 is provided on the left side of a reference line AX extending in the vertical direction (y direction) on one surface, and is inclined at a first angle θ1 with respect to the reference line AX. The reference line AX passes through the center of the base 1 in the horizontal direction (x direction) and extends in the vertical direction (y direction). Here, the plurality of left diagonal fin portions 21 are arranged side by side in the vertical direction at a predetermined interval (pitch P, see FIG. 3). Further, the left diagonal fin portion 21 extends linearly along one surface (xy plane).

[0017] The right diagonal fin portion 22 is provided on the right side of a reference line AX extending in the vertical direction (y direction) on one surface, and is inclined at a second angle θ2 with respect to the reference line AX. Here, the plurality of right diagonal fin portions 22 are arranged side by side in the vertical direction at a predetermined interval (pitch P, see FIG. 3). Further, the right diagonal fin portion 22 extends linearly along one surface (xy plane).

[0018] The first angle θ1 and the second angle θ are each preferably an acute angle. Note that the first angle θ1 and the second angle θ may each be an obtuse angle. Also, the first angle θ1 and the second angle θ are preferably the same angle as each other. That is, it is desirable to arrange the left diagonal fin portion 21 and the right diagonal fin portion 22 symmetrically with respect to the reference line AX (left - right symmetry). In this way, no matter from which direction the natural wind supplied to the heat - dissipating fin 2 comes, the temperature of the base 1 can be lowered on average. Note that the left diagonal fin portion 21 and the right diagonal fin portion 22 may be arranged asymmetrically with respect to the reference line AX. For example, the reference line AX may pass through a position deviated from the center of the base 1 in the horizontal direction (x direction) and extend in the vertical direction (y direction). Also, the reference line AX is not limited to a straight line extending in the vertical direction, and may be a curve extending in the vertical direction (for example, an S - shaped curve) or the like. Also, the angle θ1 and the angle θ2 may be different from each other.

[0019] The connecting fin portion 23 connects (joins) the end portions of the left diagonal fin portion 21 and the right diagonal fin portion 22 that face each other. The connecting fin portion 23 is curved convexly downward in the vertical direction. Note that the direction in which the connecting fin portion 23 curves is not limited to downward in the vertical direction. For example, when both the first angle θ1 and the second angle θ are obtuse angles, the connecting fin portion 23 may be curved convexly upward in the vertical direction. The lowermost part of the curved connecting fin portion 23 exists on the reference line AX. The plurality of connecting fin portions 23 are arranged vertically at a predetermined interval (pitch P; see FIG. 3) from each other. Note that the connecting fin portion 23 is not limited to a shape that is curved convexly downward in the vertical direction, and may be, for example, a shape that opens in a V shape (V-shaped) upward in the vertical direction. However, as a flow path, it is desirable that the connecting fin portion 23 has a gently curved (curved convexly downward in the vertical direction) curved shape.

[0020] In the heat sink 200 described above, the pitch P (see FIG. 3), the first angle θ1 (see FIG. 3), the second angle θ2 (see FIG. 3), and the height H (see FIG. 2) of the radiation fins 2 can be obtained as follows, for example, using thermal analysis software. First, the longitudinal and lateral lengths of the base 1 (see the reference numerals L1 and L2 in FIG. 3) are determined first. Next, the pitch P, the first angle θ1, the second angle θ2, and the height H of the radiation fins 2 are adjusted, and the performance (heat dissipation efficiency, etc.) of the heat sink after the adjustment is confirmed each time it is adjusted. Thereby, the optimal pitch P, the first angle θ1, the second angle θ2, and the height H of the radiation fins 2, that is, the ones with the highest performance (heat dissipation efficiency, etc.) can be obtained.

[0021] Subsequently, the operation of the heat sink 200 according to the second embodiment will be described with reference to FIGS. 4, 5, and 6. FIG. 4 is a diagram showing the relationship between the heat sink 200 and the object to be cooled 3. As shown in FIG. 4, the heat sink 200 dissipates the heat transferred from the object to be cooled 3 into the air. Specifically, the heat sink 200 is attached to the object to be cooled in a state where the object to be cooled 3 (heat source) is in contact with the other surface of the base 1 on the side opposite to the surface where the plurality of heat dissipation fins 2 are provided. Then, the heat sink 200 cools the object to be cooled 3 by using the air W (natural wind, indicated by the solid line arrow) in the atmosphere that has flowed into the space between the plurality of heat dissipation fins 2 of the base 1 in the heat sink 200. Although the air W is illustrated as flowing in a direction perpendicular to the surface of the base 1 in this figure, the direction of the air W is not limited to the perpendicular direction.

[0022] FIG. 5 is a diagram showing an example of installation of the heat sink 200 on the device to be the object to be cooled 3. As shown in FIG. 5, the housing 4 is, for example, a housing (which generates heat when the wireless base station operates) that constitutes a wireless base station of a mobile phone (for example, an antenna-integrated outdoor base station for 5G), and is the object to be cooled 3. When the heat sink 200 (heat dissipation fins 2) is installed on the housing 4, the heat transferred from the housing 4 through the base 1 (the other surface) is dissipated into the air. At this time, the heat sink 200 is attached to the housing 4 to be cooled in a state where one of the six surfaces of the housing 4 is in contact with the other surface of the base 1 on the side opposite to the surface where the plurality of heat dissipation fins 2 are provided. Note that this is not limited to the above example, and the heat sink 200 may be attached to each of a plurality of surfaces among the six surfaces of the housing 4. Also, the number of surfaces of the housing 4 is not limited to six.

[0023] FIG. 6 is a diagram showing the flow path of the air W flowing into the heat sink 200. As shown in FIG. 6, air W (natural wind, indicated by the solid line arrow) flows into the heat sink 200. Then, after the air W hits the base 1 of the heat sink 200, the air W is discharged from the inside to the outside of the base 1 through between the plurality of heat radiating fins 2. Specifically, the air W that has flowed into between the left diagonal fin portions 21 is discharged from the inside to the outside of the base 1 through between the left diagonal fin portions 21. On the other hand, the air W that has flowed into between the right diagonal fin portions 22 is discharged from the inside to the outside of the base 1 through between the right diagonal fin portions 22. By doing so, the heat sink 200 dissipates the heat of the object to be cooled 3 using the air passing between the left diagonal fin portions 21 or the right diagonal fin portions 22.

[0024] Subsequently, with reference to FIGS. 7 and 8, the effect of the heat sink 200 according to the second embodiment will be described. FIG. 7 is a diagram showing the temperature change of the air flowing into the heat sink 1000 according to the comparative example. On the other hand, FIG. 8 is a diagram showing the change in the air temperature in the heat sink 200 according to the second embodiment. In FIGS. 7 and 8, the temperature of the air is illustrated by hatching as the individual temperature (° C.).

[0025] As shown in FIG. 7, on one surface of the base 1001 of the heat sink 1000 according to the comparative example, a plurality of heat radiation fins 1002 are provided in parallel rows in the lateral direction (x direction) of the base 1001. For example, the heat sink 1000 is installed on a cooling target 3 (not shown) such that the surface of the base 1001 on the lower side in the vertical direction (lower side in the y direction) faces the ground side. In the heat sink 1000 that employs natural air cooling, it is widely known that the length of the heat radiation fins 1002 is not simply better if it is long, but there is an optimal value. In recent years, mobile base stations and the like are integrated devices with built-in antennas, so they are affected by the substrate size and tend to be vertically long. Accordingly, the length L3 of the heat radiation fins 1002 tends to be vertically long. Therefore, when the cold air W that has entered the inlet of the heat sink 1000 passes between the heat radiation fins 1002, the distance that the cold air W passes through the heat radiation fins 1002 becomes long, so the cold air W is gradually warmed, and hot air stays at the upper part of the heat sink 1000. By doing so, the heat radiation efficiency of the heat sink 1000 deteriorates.

[0026] On the other hand, as shown in FIG. 8, in the heat sink 200 according to the second embodiment, the heat radiation fins 2 are formed in a shape inclined at angles θ1 and θ2 with respect to the reference line AX. By doing so, the length L4 (see FIG. 8) of each heat radiation fin 2 of the heat sink 200 is shorter than the length L3 (see FIG. 7) of the heat radiation fins 1002 of the heat sink 1000. Therefore, in the heat sink 200, the distance that the cold air W that has entered the inlet passes between the heat radiation fins 2 is shorter than the distance that the cold air W that has entered the inlet of the heat sink 1000 passes between the heat radiation fins 1002. Therefore, the air W is discharged to the outside before it is fully warmed between the heat radiation fins 2 (between the left diagonal fin portions 21 and between the right diagonal fin portions 22). In the heat sink 200, the heat radiation efficiency is improved compared with the heat sink 1000. That is, efficient natural air cooling becomes possible. Further, in the heat sink 200, since the heat radiation efficiency is improved compared with the heat sink 1000, miniaturization and weight reduction can be achieved.

[0027] In addition, for the heat sink 200, manufacturability is improved. For example, when the heat sink 200 is manufactured by casting, the manufacturability is improved. This is because the ends of the left diagonal fin portion 21 and the ends of the right diagonal fin portion 22 facing each other are connected (joined) by the connecting fin portion 23. Therefore, compared with the case where the left diagonal fin portion and the right diagonal fin portion are not connected (see Patent Document 1 above), when the heat sink 200 is manufactured by casting, the circulation of hot water (particularly, the circulation of hot water around the heat radiation fins 2) is improved. Further, when the heat sink 200 is manufactured by performing cutting on a metal material such as aluminum or copper, there is no need to divide the center to form a space between the left diagonal fin portion and the right diagonal fin portion as in Patent Document 1 above. Therefore, manufacturing costs such as processing costs required for the division can be reduced.

[0028] (Modification of the Second Embodiment) Subsequently, with reference to FIGS. 9 and 10, the configuration of the heat sink 200A according to the modification of the second embodiment will be described. FIG. 9 is a perspective view showing an example of the configuration of the heat sink 200A. FIG. 10 is a front view showing an example of the configuration of the heat sink 200A. In the second embodiment, an example in which the left diagonal fin portion 21 and the right diagonal fin portion 22 (see FIG. 3 etc.) extend linearly along one surface has been described, but the present invention is not limited to this. For example, in consideration of design, as shown in FIGS. 9 and 10, at least one of the left diagonal fin portion 21 and the right diagonal fin portion 22 may extend in a curved shape along one surface.

[0029] (Third Embodiment) Subsequently, with reference to FIG. 11, the configuration of the heat sink 300 according to the third embodiment will be described. When the heat sink 200 according to the second embodiment is installed in an outdoor environment, water may accumulate in the connecting fin portion 23 due to the influence of rain and snow. To suppress this, as shown in FIG. 11, in the heat sink 300 according to the third embodiment, a notch (groove) 231 penetrating in the vertical direction (y direction) that functions as a drain port is provided in the connecting fin portion 23 (for example, the lowermost part of the connecting fin portion 23) of the heat radiation fin 2 in the heat sink 200 according to the second embodiment. The notch 231 is provided in a state where the base portion of the connecting fin portion 23 (the portion near the base 1A of the connecting fin portion 23) is left. Note that the notch 231 is not limited to being provided in a state where the base portion of the connecting fin portion 23 is left, and may be provided so as to penetrate in the vertical direction while leaving a part of the connecting fin portion 23. Further, the notch 231 may not be provided in a state where the base portion of the connecting fin portion 23 is left.

[0030] When the heat sink 300 is attached to the cooling target 3 in the orientation shown in FIG. 11, water reaches the connecting fin portion 23 (for example, the lowermost part of the connecting fin portion 23) through between the left diagonal fin portions 21 or between the right diagonal fin portions 22. Then, the water that has reached the connecting fin portion 23 is drained through the notch 231 provided in the connecting fin portion 23. Thereby, it is possible to suppress water from accumulating on the heat radiation fin 2 (mainly the connecting fin portion 23).

[0031] Further, in the heat sink 300, since the notch 231 is provided in a state where a part (for example, the base portion) of the connecting fin portion 23 is left, it is possible to achieve both good flow of molten metal when casting the heat sink 300 (the base 1 and the heat radiation fin 2) and the function of suppressing water from accumulating on the heat radiation fin 2.

[0032] Note that the present invention is not limited to the above-described embodiments, and can be appropriately modified without departing from the gist. For example, in each of the above embodiments, an example in which the heat sink of the present invention is applied to natural air cooling has been described, but the present invention is not limited to this, and the heat sink of the present invention may be applied to forced air cooling. For example, the heat sink of the present invention may be used in an indoor device equipped with a fan (electric fan) for forced air cooling or the like.

[0033] Further, the shape of the base 1 of the heat sink 200 is not limited to a plate shape as long as it includes a surface on which a plurality of heat radiation fins 2 are provided at intervals from each other. The shape of the base 1 may be, for example, a triangular prism shape, a quadrangular prism shape, or the like.

[0034] Also, the surface of the base 1 of the heat sink 200 that contacts the object to be cooled 3 is not limited to a flat surface, and may be a curved surface, or may be a surface including a flat surface and a curved surface. Further, in the heat sink 200, the object to be cooled 3 may be prevented from contacting the base 1.

[0035] As described above, the present invention has been described with reference to the embodiments, but the present invention is not limited thereto. Various changes that can be understood by those skilled in the art within the scope of the invention can be made to the configuration and details of the present invention.

[0036] This application claims priority based on Japanese Patent Application No. 2021-146390 filed on September 8, 2021, and incorporates the entire disclosure thereof herein.

Explanation of Reference Numerals

[0037] 1, 1A Base 2, 2A Heat Radiation Fin 3 Object to be Cooled 4 Housing 21, 21A First Diagonal Fin Portion 22, 22A Second Diagonal Fin Portion 23, 23A Connecting Fin Portion 231 Notch 100, 200, 200A, 300 Heat Sink 1000 Heat Sink 1001 Base 1002 Heat Radiation Fin

Claims

1. A heat sink comprising a base including a surface on which a plurality of heat radiating fins are provided at intervals from each other, wherein each of the plurality of heat radiating fins includes, a first obliquely extending fin portion provided on one side of a reference line extending in the longitudinal direction of the surface and inclined at a first angle with respect to the reference line, a second obliquely extending fin portion provided on the other side of the surface with respect to the reference line and inclined at a second angle with respect to the reference line, and a connecting fin portion connecting ends of the first obliquely extending fin portion and the second obliquely extending fin portion facing each other, wherein a notch portion penetrating in the longitudinal direction is provided in the connecting fin portion, leaving a root portion of the connecting fin portion, a heat sink.

2. The heat sink according to claim 1, wherein the first angle and the second angle are each an acute angle.

3. The heat sink according to claim 2, wherein the first angle and the second angle are the same angle as each other.

4. The heat sink according to claim 2 or 3, wherein the reference line passes through the center of the base in the lateral direction and extends in the longitudinal direction.

5. The connecting fin portion is curved convexly downward in the longitudinal direction, the heat sink according to claim 2.

6. At least one of the first obliquely extending fin portion and the second obliquely extending fin portion extends linearly, the heat sink according to claim 1.

7. At least one of the first obliquely extending fin portion and the second obliquely extending fin portion extends in a curved shape, the heat sink according to claim 1.

8. The base further includes a surface that contacts a cooling target, and the plurality of heat radiating fins dissipate heat transferred from the cooling target through the surface that contacts the cooling target. the heat sink according to claim 1.

9. The base and the plurality of heat radiating fins are an integral body manufactured by casting, the heat sink according to claim 1.

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