JP2006237366A - Heat sink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a heat sink capable of improving heat dissipation ability and uniformly cooling an electronic machine placed in the heat sink. <P>SOLUTION: The heat sink includes a base plate 3, a pair of opposite side plates 4 provided perpendicularly to the base plate 3, a plurality of platelike fins 5 provided on the base plate 3 in parallel with the side plates 4 between the pair of side plates 4, an upper plate 6 provided on the side plate 4 opposite to the base plate 3, an axial fan 7 having a diameter smaller than a distance between the fins 5 provided at both ends and placed in contact with the upper plate 6 between the base plate 3 and the upper plate 6, and a ventilation flue passing under the axial fan 7 for connecting from one of side plates 4 to the other side plate 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat sink for cooling an electronic device such as a power module.

  In a conventional heat sink, a fan is provided inside the heat sink body in order to reduce the size of the heat sink (for example, Patent Document 1).

JP-A-10-303348 (paragraph number 0011, FIG. 2).

  In order to increase the heat dissipation capability per unit volume of the heat sink, it is necessary to reduce the fan volume in the entire heat sink and increase the volume of the fins that are heat dissipation portions. However, in the case of a heat sink in which fans are installed, as shown in FIG. 10, if the distance Gf between the fins installed at both ends is longer than the diameter d of the fan, the region outside the fans in the row direction of the fins However, there is a problem that the air does not flow and the heat dissipation capability of the heat sink cannot be increased. In addition, when an axial fan is used, there is a problem in that the electronic equipment installed on the heat sink cannot be uniformly cooled because air does not flow easily and the amount of heat radiation is small immediately below the center of the axial fan.

  The present invention is for solving the above-described problems, and provides a heat sink that can increase the heat dissipation capability and can uniformly cool an electronic device installed on the heat sink.

A heat sink according to the present invention includes a base plate, a pair of opposing side plates installed perpendicular to the base plate, and a plurality of plate-like fins installed on the base plate in parallel with the side plates between the pair of side plates. The side plate has a diameter smaller than the distance between the upper plate installed opposite to the base plate and the fins installed at both ends, and is installed in contact with the upper plate between the base plate and the upper plate. An axial fan,
A ventilation path that passes through the lower part of the axial flow fan and connects from one side plate to the other side plate is provided.

  According to the present invention, the heat dissipation capability can be increased, and the electronic device installed on the heat sink can be uniformly cooled.

Embodiment 1 FIG.
FIG. 1 is a perspective view of a heat sink and electronic equipment installed on the heat sink in Embodiment 1 of the present invention.

  As shown in FIG. 1, in the heat sink 1, a pair of side plates 4 facing each other perpendicularly to the base plate 3 are installed at both ends of the base plate 3, and between the pair of side plates 4, parallel to the side plate 4. A plurality of plate-like fins 5 are installed on the base plate 3. An upper plate 6 is installed on the side plate 4 so as to face the base plate 3. An axial fan 7 is installed between the upper plate 6 and the base plate 3 in the center of the upper plate 6 via a housing 11 and sucked from an inlet 9 provided on the upper portion of the axial fan 7. The air is sent to the fin 5, the side plate 4 and the base plate 3. The base plate 3, the side plates 4, the fins 5 and the upper plate 6 are preferably made of a metal having a high thermal conductivity such as aluminum or copper. The electronic device 2 that is a heating element is installed on the surface opposite to the surface on which the fins 5 of the base plate 3 are installed.

  The detailed structure of the heat sink 1 will be described. FIG. 2A is a cross-sectional view of the heat sink taken along the line AA, that is, a cross-sectional view in a direction parallel to the side plate. FIG. 2B is a cross-sectional view of the heat sink taken along the line BB, that is, a cross-sectional view in a direction perpendicular to the side plate.

  As shown in FIG. 2, in the heat sink 1, the fins 5 are also installed outside the axial fan 7 in the row direction, and the diameter d of the axial fan 7 is between the fins 5 installed at both ends. Is smaller than the distance Gf. The ventilation path 8 passes through the lower part of the axial flow fan 7, connects from one side plate 4 to the other side plate 4 in a direction perpendicular to the side plate 4, and is installed outside the axial flow fan 7 in the row direction of the fins 5. The arranged fins 5 are also arranged to send air. The air sent to the fin 5, the side plate 4, and the base plate 3 is discharged from the air outlets 10 provided at both ends of the fin 5.

  As shown in FIG. 2A, each fin 5 is divided into two regions with respect to its height Hf. A region (−Lf / 2 ≦ L) where the distance from a portion C (L = 0) that includes the rotating shaft 12 of the axial fan 7 and intersects with a plane perpendicular to the side plate 4 is less than half the width Lf of the axial fan 7 ≦ Lf / 2) is defined as region D. Further, a region where the distance from the portion C that includes the rotation axis 12 of the axial fan 7 and intersects the plane perpendicular to the side plate 4 is separated from half of the width Lf of the axial fan 7 (L <−Lf / 2, Lf). / 2 <L) is defined as region E.

  Here, the width Lf of the axial fan 7 is the width of the housing 11 in a direction parallel to the side plate 4. The axial fan 7 is not necessarily housed in the housing 11. When the axial fan 7 is not housed in the housing 11, the width Lf of the axial fan 7 corresponds to the radius (d / 2) of the axial fan 7 when the blades of the axial fan 7 and the fins 5 hit each other. It is the length which added the clearance gap provided so that it may not exist.

  The height Hf of each fin 5 is the lowest in a portion C that intersects with a plane perpendicular to the side plate 4 including the rotating shaft 12 of the axial fan 7, and becomes higher in the region D as the distance from the portion C increases. In the region E, the height Hf of each fin 5 is equal to the distance between the base plate 3 and the upper plate 6 and is constant.

  On the other hand, in the ventilation path 8, the shape of the ventilation cross section parallel to the side plate 4 is a triangle, and the height Hw from the bottom of the ventilation path 8 to the upper plate 6 includes the rotating shaft 12 of the axial fan 7 and the side plate. The portion C intersecting with the surface perpendicular to 4 is the highest, changes in the direction parallel to the side plate 4, and becomes lower as the distance from the portion C increases.

  Heat generated by the electronic device 2 is transmitted to the fins 5 and the side plates 4 through the base plate 3. The air sucked into the axial fan 7 from the inlet 9 passes through the ventilation path 8 and is sent to all the fins 5 installed between the two side plates 4 as shown by the dotted arrows in FIG. At the same time, it is also sent to the side plate 4 having the role of releasing heat from the electronic device 2 in the same manner as the fin 5. When the air flows between the adjacent fins 5 and between the fins 5 and the side plates 4, the air takes heat from the fins 5, the side plates 4 and the base plate 3 and is discharged from the outlet 10, and the electronic device 2 is cooled. The

  Here, since the height Hf of each fin 5 increases as the distance from the portion C increases, the air sent by the axial fan 7 moves toward the portion C as indicated by an arrow in FIG. Air flows easily under the center of the axial fan.

  As described above, in the heat sink 1 shown in the first embodiment, the ventilation path 8 that passes through the lower part of the axial fan and connects from one side plate 4 to the other side plate 4 is provided. In the direction, air can also be sent to the fins 5 installed on both sides of the axial fan 7, and the heat dissipation capability of the heat sink 1 can be increased.

  Further, the height Hf of each fin 5 is the lowest at the portion C that intersects the plane perpendicular to the side plate 4 including the rotation shaft 12 of the axial fan 7, and increases in the region D as the distance from the portion C increases. Yes. That is, the height Hw from the bottom portion to the upper plate 6 in the ventilation cross section parallel to the side plate 4 of the ventilation path 8 is the highest at the portion C including the rotating shaft 12 of the axial fan 7 and intersecting the plane perpendicular to the side plate 4. Higher and lower as the distance from part C increases. For this reason, it becomes easy for air to flow directly under the center of the axial flow fan 7 in which air does not easily flow, and the electronic device 2 installed on the heat sink 1 can be cooled uniformly.

  In the heat sink 1 of the first embodiment, as shown in FIG. 2 (a), the shape of the ventilation cross section of the ventilation path 8 is a triangle, but the shape of the ventilation cross section is not limited to this, and a trapezoidal shape is also possible. Good. FIG. 3 is a cross-sectional view in a direction parallel to the side plate of the heat sink.

  In the heat sink 1 shown in FIG. 3, the shape of the ventilation cross section parallel to the side plate 4 of the ventilation path 8 is a trapezoid. Accordingly, the height Hf of each fin 5 is constant at the same height as the portion C in the vicinity of the portion C (L = 0), and the region D excluding the vicinity of the portion C (−Lf / 2 ≦ In L ≦ Lf / 2), the distance from the portion C increases. As described above, in the vicinity of the portion C, even if the height is constant at the same height as the portion C, the air easily flows under the center of the axial flow fan 7 where the air does not easily flow. 2 can be cooled uniformly.

  Moreover, in the heat sink 1 of this Embodiment 1, as shown in FIG. 2, although the shape of each fin 5 is the same, it may differ. FIG. 4 is a cross-sectional view in a direction perpendicular to the side plate 4 of the heat sink 1. 5A is a cross-sectional view taken along line AA of the heat sink 1 shown in FIG. 4, FIG. 5B is a cross-sectional view taken along line XX of the heat sink 1 shown in FIG. 4, and FIG. It is YY sectional drawing of the heat sink 1 shown in FIG.

  In FIG. 4 and FIG. 5, the fin height Hf of the portion C including the rotational axis 12 of the axial fan 7 and intersecting the plane perpendicular to the side plate 4 is the rotational axis of the axial fan 7 in the row direction of the fins 5. The higher the distance from 12, the higher. In the heat sink 1 shown in FIGS. 4 and 5, the height Hf of each fin 5 is the lowest in the portion C, and the region D is still higher as the distance from the portion C increases.

  As described above, even when the shapes of the individual fins 5 are different, the ventilation path 8 that passes through the lower part of the axial fan and connects from one side plate 4 to the other side plate 4 is provided. Thus, air can also be sent to the fins 5 installed on both sides of the axial fan 7 in the row direction of 5, and the heat dissipation capability of the heat sink 1 can be increased.

  Further, the height Hf of each fin 5 is the lowest at the portion C that intersects the plane perpendicular to the side plate 4 including the rotation shaft 12 of the axial fan 7, and increases in the region D as the distance from the portion C increases. Yes. That is, the height Hw from the bottom to the upper plate 6 in the ventilation cross section parallel to the side plate 4 of the ventilation path 8 is the highest in the portion C and decreases as the distance from the portion C increases. For this reason, it becomes easy for air to flow directly under the center of the axial flow fan 7 in which air does not easily flow, and the electronic device 2 installed on the heat sink 1 can be cooled uniformly.

Embodiment 2. FIG.
A modified example of the heat sink 1 shown in the first embodiment is shown in the second embodiment. FIG. 6 is a cross-sectional view in a direction parallel to the side plate of the heat sink in the second embodiment.

  In the heat sink 1 shown in the first embodiment, the height of each fin 5 increases linearly as the distance from the portion C (L = 0) increases in the region D (−Lf / 2 ≦ L ≦ Lf / 2). It has become. The heat sink 1 shown in FIG. 5 is different from the heat sink 1 shown in Embodiment 1 in that the height Hf of each fin 5 is curvilinearly higher in the region D as it is away from the portion C. .

  Therefore, in the ventilation path 8, the shape of the ventilation cross section parallel to the side plate 4 is semi-elliptical, and the height Hw from the bottom of the ventilation path 8 to the upper plate 6 is the rotational axis 12 of the axial fan 7. The portion C that intersects with the plane perpendicular to the side plate 4 is the highest, changes in a direction parallel to the side plate 4, and becomes lower in a curve as the distance from the portion C increases.

  Other configurations and functions are the same as those of the heat sink 1 shown in the first embodiment, and the heights Hf of the individual fins 5 are the same in the point where the portion C is the lowest.

  As described above, in the heat sink 1 shown in the second embodiment, the height Hf of each fin 5 intersects with a plane perpendicular to the side plate 4 including the rotating shaft 12 of the axial fan 7 in the region D. As the distance from the portion C increases, the curve becomes higher. That is, the height Hw from the bottom portion to the upper plate 6 in the ventilation cross section parallel to the side plate 4 of the ventilation path 8 is separated from the portion C that includes the rotating shaft 12 of the axial fan 7 and intersects the plane perpendicular to the side plate 4. Is curvilinearly lower. For this reason, similarly to the heat sink 1 shown in Embodiment 1, the electronic device 2 installed in the heat sink 1 can be cooled uniformly.

Embodiment 3 FIG.
FIG. 7 is a cross-sectional view in a direction parallel to the side plate of the heat sink shown in the third embodiment.

  In the heat sink 1 shown in the first embodiment, the height Hf of each fin 5 is the distance between the base plate 3 and the upper plate 6 in the region E (L <−Lf / 2, Lf / 2 <L). It was equal and constant. On the other hand, in the heat sink 1 shown in the third embodiment, the height Hf of each fin 5 is higher in the region E as the distance from the portion C (L = 0) increases. This is different from the heat sink 1 shown in FIG. That is, in the heat sink 1 shown in the third embodiment, the height Hf of each fin 5 increases as the end of the fin 5 is approached. Other configurations and functions are the same as those of the heat sink 1 shown in the first embodiment.

  The air sent from the axial fan 7 is once squeezed at the outlet of the axial fan 7 and then gradually spreads along the fins 6 as shown by the dotted arrows in FIG. However, in the upper part of the region E of the fins 5, the air flow rate is slow and hardly contributes to the heat dissipation effect.

  Therefore, in the heat sink 1 shown in the third embodiment, the fins 5 are not installed above the region E. Therefore, the height Hf of each fin 5 is also higher in the region E as it gets away from the portion C, that is, as it gets closer to the end of the fin 5. For this reason, the weight of the heat sink 1 can be reduced and the manufacturing cost can be reduced without reducing the heat dissipation effect.

  In order to prevent air from flowing between the fins 5 and between the fins 5 and the side plates 4 as shown in FIG. The housing 11 of the fan 7 and the fin 5 are installed so as to contact each other.

  In the heat sink 1 shown in FIG. 7, in the region E, the height Hf of each fin 5 increases linearly as the distance from the portion C increases, that is, as the end of the fin 5 approaches. FIG. 8 is a cross-sectional view in a direction parallel to the side plate of the heat sink. As shown in FIG. 8, the height Hf of each fin 5 may be increased in a curve as the distance from the portion C increases, that is, as the end of the fin 5 is approached. Even when the height Hf of each fin 5 increases from the portion C, that is, as it approaches the end of the fin 5 in a curvilinear manner, the weight of the heat sink 1 is reduced without reducing the heat dissipation effect. In addition, the manufacturing cost can be reduced.

Embodiment 4 FIG.
FIG. 9 is a cross-sectional view in a direction parallel to the side plate of the heat sink shown in the fourth embodiment.

  In the heat sink 1 shown in the third embodiment, an axial fan 7 is installed at substantially the center in the direction parallel to the side plate 4. As shown in FIG. 9, the heat sink 1 shown in the fourth embodiment is different from the heat sink 1 shown in the third embodiment in that an axial fan 7 is installed at an end in a direction parallel to the side plate 4. ing. Further, the heat sink 1 shown in the fourth embodiment is a side surface of the base plate 3, and a sealing plate 14 is installed perpendicularly to the base plate 3 at one of the end portions of the fins 5. 10 is different from the heat sink 1 shown in the third embodiment in that only the end of the fin 5 on the side opposite to the sealing plate 14 is provided.

  In FIG. 9, the height Hf of each fin 5 is the lowest at the end (L = 0) in contact with the sealing plate 14 and increases toward the end on the air outlet 10 side. For this reason, the height Hw from the bottom of the ventilation path 8 to the upper plate 6 is the highest at the end portion in contact with the blocking plate 14, changes in the direction parallel to the side plate 4, and the end in contact with the blocking plate 14. It becomes lower as it gets away from the department.

  Here, the air flow sent from the axial flow fan 7 is once throttled at the outlet of the axial flow fan 7 as shown by the dotted arrows in FIG. However, the upper part of the region E (L> Lf / 2) has a low air flow rate and hardly contributes to the heat dissipation effect.

  Therefore, in the heat sink 1 shown in the fourth embodiment, the fin 5 is not provided above the region E. Accordingly, the height Hf of each fin 5 is higher in the region E as it is away from the end in contact with the blocking plate 14, that is, as it is closer to the end of the fin 5. For this reason, the weight of the heat sink 1 can be reduced and the manufacturing cost can be reduced without reducing the heat dissipation effect.

  As shown in FIG. 9, in order to prevent air from flowing between the adjacent fins 5 and between the fins 5 and the side plates 4 without flowing through the spaces 13 between the fins 5 and the upper plate 6, The housing 11 of the axial fan 7 is installed in contact with the fins 5.

1 is a perspective view of a heat sink and an electronic device showing Embodiment 1 of the present invention. It is sectional drawing of the heat sink which shows Embodiment 1 of this invention. It is sectional drawing of the heat sink which shows Embodiment 1 of this invention. It is sectional drawing of the heat sink which shows Embodiment 1 of this invention. It is sectional drawing of the heat sink which shows Embodiment 1 of this invention. It is sectional drawing of the heat sink which shows Embodiment 2 of this invention. It is sectional drawing of the heat sink which shows Embodiment 3 of this invention. It is sectional drawing of the heat sink which shows Embodiment 3 of this invention. It is sectional drawing of the heat sink which shows Embodiment 4 of this invention. It is sectional drawing of the conventional heat sink.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat sink, 2 Electronic equipment, 3 Base plate, 4 Side plate, 5 Fin, 6 Upper plate, 7 Axial fan, 8 Ventilation path, 9 Inlet, 10 Outlet, 11 Housing, 12 Rotating shaft, 13 Space, 14 Sealing plate

Claims (5)

A base plate,
A pair of opposing side plates installed perpendicular to the base plate;
A plurality of plate-like fins installed on the base plate in parallel with the side plate between the pair of side plates;
An upper plate installed opposite to the base plate on the side plate;
An axial fan having a diameter smaller than the distance between the fins installed at both ends, and installed in contact with the upper plate between the base plate and the upper plate;
A heat sink comprising a ventilation path that passes through a lower portion of the axial fan and connects from one side plate to the other side plate. The height from the bottom of the ventilation path to the upper plate in the ventilation cross section parallel to the side plate is highest at a portion that includes the axis of rotation of the axial fan and intersects a plane perpendicular to the side plate. heatsink. The heat sink according to claim 1 or 2, wherein the height from the bottom of the ventilation path to the upper plate in the ventilation cross section parallel to the side plate changes in a direction parallel to the side plate. 2. The heat sink according to claim 1, wherein the height of each fin is lowest at a portion intersecting with a plane perpendicular to the side plate including the rotational axis of the axial fan. The heat sink according to claim 1 or 4, wherein the height of each fin increases as it approaches the end of the fin.

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