JP2014063887A - Heat sink - Google Patents

Abstract

An object of the present invention is to provide a heat sink that suppresses an increase in flow resistance of a gap between fins and improves heat dissipation performance.
A fin plate includes: a base plate that thermally couples an IGBT chip to a front surface, and a plurality of fin plates that are erected in parallel to a back surface of the base plate. Are provided with concave ridge portions 25 or ridge portions 26 extending substantially parallel to the rear surface 21B of the base plate 21 on the opposing surfaces 22A and 22B facing the adjacent fin plates 22.
[Selection] Figure 3

Description

  The present invention relates to a heat sink in which a plurality of fin plates are erected in parallel on a base plate.

Generally, a heat sink is known that includes a base plate having a heating element thermally connected to one surface and a plurality of fin plates erected in parallel to the other surface of the base plate. In this type of heat sink, it is desired to efficiently cool the heating element, and an attempt is being made to increase the surface area of the fin plate in contact with the cooling fluid.
For this reason, conventionally, a heat sink has been proposed which is made of an aluminum extruded material and has a corrugated portion that changes so that the cross-sectional shape corrugates in the extending direction of the fin plate (extrusion direction of the heat sink) (for example, , See Patent Document 1).

JP 2001-308232 A

  However, in the above-described configuration, by providing the corrugated portion on the fin plate, the surface area of the fin plate is enlarged, but each fin plate is irregularly waved, and the gap between adjacent fins is partially Narrowing occurs. For this reason, for example, when the cooling fluid is circulated through the gap between the fins, the narrowed portion becomes a bottleneck, and the flow resistance increases, which may hinder the cooling performance of the heat sink. .

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a heat sink that suppresses an increase in flow resistance of a gap between fins and improves cooling performance.

  To achieve the above object, the present invention comprises a base plate having a heating element thermally connected to one surface, and a plurality of fin plates erected in parallel on the other surface of the base plate. In the heat sink, the fin plate is provided with a concave portion or a convex portion extending substantially parallel to the other surface of the base plate on a surface facing the adjacent fin plate.

  In this configuration, the concave portion on one opposing surface may be provided at a position facing the convex portion on the other opposing surface. Moreover, the said recessed strip part and a protruding strip part may be provided alternately in the height direction of the said fin board. Moreover, it is good also as a structure by which the fluid for cooling distribute | circulates to the clearance gap between adjacent fin plates.

Moreover, the said fin board may be divided | segmented into plurality in the extension direction of the said recessed strip part and the said protruding strip part, respectively. In this case, the interval between the divided fin plates may be smaller than the thickness of the fin plates.
The fin plate may include a groove portion that extends in a height direction of the fin plate and divides at least the convex strip portion into a plurality of portions in the extending direction of the convex strip portion.
Moreover, the said recessed strip part or the said protruding strip part may be formed in the cross-sectional substantially triangular shape.

  According to the present invention, since the fin plate includes the concave or convex portion extending substantially parallel to the other surface of the base plate on the surface facing the adjacent fin plate, the surface area of each fin plate can be increased. At the same time, when the cooling fluid flows along the concave and convex portions, an increase in the flow resistance of the gap between the fin plate and the fin plate can be prevented, and thus the cooling performance can be improved.

It is a sectional side view of the power module using the heat sink concerning a 1st embodiment. It is a perspective view which shows a heat sink. It is a perspective view which shows the shape of a fin board. It is a side view of a fin board. It is a perspective view which shows the shape of the fin board of the heat sink concerning 2nd Embodiment. It is a side view of a fin board. It is a perspective view which shows the shape of the fin board of the heat sink concerning 3rd Embodiment. It is a top view of a fin board. It is a side view which shows the shape of the fin board of the heat sink concerning 4th Embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a side sectional view of a power module using a heat sink according to the first embodiment. The power module 100 is used for, for example, an inverter (power conversion device) that drives and controls a motor mounted on an electric vehicle or a hybrid vehicle.
The power module 100 includes an IGBT (Insulated Gate Bipolar Transistor) chip (heating element) 10 as a power semiconductor element, and a heat sink that is thermally connected to the IGBT chip 10 and cools the IGBT chip 10. 20, a water cooling jacket 30 in which the heat sink 20 is disposed, and a protective case 40 that is fixed to the water cooling jacket 30 and covers the IGBT chip 10 and the heat sink 20 described above.

The heat sink 20 includes a flat base plate 21, and the IGBT chip 10 is fixedly disposed on the surface (one surface) 21 </ b> A of the base plate 21 by brazing or the like. The heat sink 20 includes a plurality of fin plates 22 projecting in parallel downward from the back surface 21B on the back surface (the other surface) 21B of the base plate 21. The base plate 21 and the fin plate 22 are, for example, It is molded integrally with an aluminum alloy.
The heat sink 20 is fixed to the upper surface 31 of the water cooling jacket 30 formed of an aluminum alloy or the like by screws 32, and the fin plate 22 is inserted into a water tank 33 formed at a substantially central portion of the upper surface 31 of the water cooling jacket 30. Yes.
In this embodiment, the water cooling jacket 30 has a configuration in which cooling water is circulated and circulated from one end to the other end in the extending direction of the fin plate 22, and cooling water (cooling) is provided between the fin plates 22 and 22. It functions as the flow path 23 of the fluid 34). Thereby, the base plate 21 is water-cooled by the cooling water 34 flowing in the water tank 33 through the fin plate 22, and as a result, the IGBT chip 10 is cooled.

  The water cooling jacket 30 is formed with an O-ring storage groove 35 so as to surround the water tank 33, and an O-ring 36 is stored in the O-ring storage groove 35. The O-ring 36 is compressed by the base plate 21, and seals the water tank 33 in close contact with the back surface 21 </ b> B of the base plate 21 and the inner surface of the O-ring housing groove 35. Thereby, the cooling water in the water tank 33 is prevented from leaking outside.

  The protective case 40 has a top plate and a side plate, a box-shaped case body 41 having an open lower surface facing the heat sink 20, and a flange 42 formed at the opening end of the case body 41 in the circumferential direction. Is provided. The protective case 40 is fixed to the upper surface 31 of the water cooling jacket 30 with a screw 43 via a flange 42.

Next, the heat sink 20 will be described.
2 is a perspective view of the heat sink 20, FIG. 3 is a perspective view showing the shape of the fin plate 22, and FIG. 4 is a side view of the fin plate 22.
The heat sink 20 is formed by extrusion formation using an aluminum alloy, and the fin plate 22 extends along the extrusion direction of the heat sink 20 (X direction in the figure) as shown in FIG. The base plate 21 of the heat sink 20 is formed to be long in the extending direction X of the fin plate 22, and a plurality of rows of fin plates in a direction Y orthogonal to the extending direction X is provided at a substantially central portion of the base plate 21. 22 and 22 are formed side by side, and a flow path 23 is formed between the fin plates 22 and 22, respectively. Further, a screw through hole 24 for fixing the heat sink 20 to the water cooling jacket 30 is formed in the peripheral portion of the base plate 21.

Incidentally, in the heat sink 20 in which the cooling water flows along the flow path 23 between the fin plates 22 and 22, improvement of the cooling performance of the heat sink 20 is desired.
In this configuration, as shown in FIG. 3, the fin plate 22 is formed with a concave portion 25 and a convex portion 26 on the surface facing the other fin plate 22 adjacent to each other with the flow path 23 interposed therebetween. Yes. Each of the concave stripe portion 25 and the convex stripe portion 26 has a cross section in the extending direction X of the fin plate 22 formed in a substantially triangular shape, and extends substantially parallel to the back surface 21 </ b> B of the base plate 21. Further, the concave stripe portions 25 and the convex stripe portions 26 are alternately provided in the height direction of the fin plate 22 (Z direction in the figure).

  Specifically, as shown in FIG. 4, the fin plate 22 includes two facing surfaces 22A and 22B facing the other fin plates 22 adjacent to each other with the flow path 23 therebetween, and the facing surfaces 22A and 22B are provided with the facing surfaces 22A and 22B. A concave strip portion 25 and a convex strip portion 26 each having a substantially triangular cross section are formed across the lateral width of the fin plate 22. Thereby, since the surface area of each fin plate 22 can be increased, the amount of heat exchange with the cooling water can be increased correspondingly, and the cooling performance of the heat sink 20 can be improved.

Further, each fin plate 22 is formed so that the cross-sectional shape in the extending direction X of the fin plate 22 is substantially the same. For this reason, the heat sink 20 can be easily formed by extrusion, and when the cooling water flows along the concave strip portion 25 and the convex strip portion 26 of the fin plate 22, the opposing surface of the fin plate 22 extends in the extending direction X. Can be formed smoothly, and an increase in the flow resistance of the cooling water can be prevented.
Further, the fin plate 22 has a concave portion 25 and a convex portion 26 provided on one opposing surface 22A, and a concave portion 25 and a convex portion 26 provided on the other opposing surface 22B in the height direction. Different. That is, at the same height position of the fin plate 22, a substantially triangular recess 25 is formed on one facing surface 22 </ b> A, whereas a substantially triangular shape having a substantially same size is formed on the other facing surface 22 </ b> B. A shaped ridge 26 is formed. According to this configuration, since the fin plate 22 can be formed with substantially the same thickness D over the height direction, the fin plate 22 has a cross-sectional area perpendicular to the height direction at the proximal end and the distal end. Therefore, uniform heat conduction in the fin plate 22 can be realized.

Furthermore, in this embodiment, with respect to the fin plates 22 and 22 adjacent to each other with the flow path 23 interposed therebetween, the concave strip portion 25 and the convex strip portion 26 provided on one opposing surface 22A of the one fin plate 22 and this opposing The concave strip 25 and the convex strip 26 provided on the other facing surface 22B of the other fin plate 22 facing the surface 22A are different in the height direction.
That is, at the same height position in the adjacent fin plates 22 and 22, the concave stripe portion 25 is formed on one opposing surface 22A, and the convex stripe portion 26 is formed on the other opposing surface 22B. Similarly, a convex strip portion 26 is formed on one opposing surface 22A, and a concave strip portion 25 is formed on the other opposing surface 22B. According to this configuration, the distance P between the valley portion 25 </ b> A of the concave stripe portion 25 and the top portion 26 </ b> A of the convex stripe portion 26 can be formed substantially the same over the height direction of the fin plate 22.
For this reason, since the width of the flow path 23 formed between the fin plates 22 and 22 can be formed substantially the same over the height direction of the fin plate 22, the cooling water is supplied in the height direction of the flow path 23. It can flow substantially evenly, and the flow path resistance of the flow path 23 can be reduced. Therefore, the heat exchange efficiency between the fin plate 22 and the cooling water is increased, and the cooling performance of the heat sink 20 can be improved.

In the present embodiment, the fin plate 22 is divided into a plurality of pieces in the extending direction X of the fin plate 22 as shown in FIGS. 2 and 3. Specifically, the long fin plate formed in the extending direction X is divided by forming notches at predetermined intervals in the extending direction X by extrusion formation. According to this configuration, as shown in FIG. 3, the surface newly generated as a result of the division (the opposing surfaces of the fin plates 22 and 22 arranged side by side in the extending direction X) can also be used for heat exchange with the fluid. Therefore, the surface area of the heat sink 20 in contact with the cooling water can be increased.
Further, in the configuration in which the cooling water flows along the fin plate 22, generally, the temperature boundary layer is formed thicker from the front end portion of the fin plate 22 toward the downstream side in the cooling water flow direction (extending direction of the fin plate 22). Tend to be. On the other hand, in the present embodiment, the fin plate 22 is divided into a plurality of portions in the extending direction X of the fin plate 22, and therefore, in the gap 27 formed between the fin plates 22 and 22, Since the flow of the cooling water is disturbed, the temperature boundary layer can be prevented from developing downstream, and the cooling performance of the heat sink 20 can be improved.
In this case, it is desirable to form the distance L of the gap 27 between the fin plates 22 and 22 smaller than the thickness D of the fin plate 22. As described above, by providing the gap 27 between the fin plates 22 and 22, the cooling performance of the heat sink 20 can be improved. On the other hand, when the gap 27 is increased, the heat exchange area of the heat sink 20 is reduced accordingly. .
For this reason, by making the distance L of the gap 27 between the fin plates 22 and 22 smaller than the thickness D of the fin plate 22, the cooling performance of the heat sink 20 can be enhanced while ensuring a heat exchange area.
In the present embodiment, the fin plate 22 is completely divided by providing a notch from the tip of the fin plate 22 to the base end (end connected to the base plate). For example, you may connect a part from a front-end | tip to a base end like the state which connected the base end. According to this configuration, the heat sink 20 as a whole can increase the surface area in contact with the cooling water, can increase the rigidity of the fin plate 22, and can improve the strength of the heat sink 20 with respect to the flow direction of the cooling water.

[Second Embodiment]
Next, another embodiment of the heat sink will be described. The heat sink 120 of the second embodiment is different from that of the first embodiment in the shape of the fin plate. For this reason, in this 2nd Embodiment, only the point from which a structure differs is demonstrated, the same code | symbol is attached | subjected about the same structure and description is abbreviate | omitted.

FIG. 5 is a perspective view showing the shape of the fin plate 122 of the heat sink 120 according to the second embodiment, and FIG. 6 is a side view of the fin plate 122.
The fin plate 122 of the present embodiment is formed in a substantially rectangular cross-sectional shape, and semi-cylindrical ridges 126 are respectively provided at predetermined intervals in the height direction on the two opposing surfaces 122A and 122B of the fin plate 122. It is formed integrally with a gap. The opposed surfaces 122A and 122B that are recessed from the ridges 126 are exposed between the ridges 126 and 126 adjacent in the height direction. In the present embodiment, the surfaces are exposed between the ridges 126 and 126. The opposing surfaces 122 </ b> A and 122 </ b> B function as the concave portion 125.
Since the fin plate 122 has a simpler shape than the fin plate 22 described above, the heat sink 120 can be easily formed when the fin plate 122 is formed by extrusion.

[Third Embodiment]
FIG. 7 is a perspective view showing the shape of the fin plate 222 of the heat sink 220 according to the third embodiment, and FIG. 8 is a plan view of the fin plate 222.
The fin plate 222 of the present embodiment is formed so as to be longer in the width direction than the fin plate 122 described above, and a point that divides the ridges 226 provided on the opposing surfaces 222A and 222B of the fin plate 222. The configuration is different.

In the third embodiment, the fin plate 222 is formed in a single shape along the extending direction X of the fin plate 222, and the protruding strips are formed on the opposing surfaces 222A and 222B of the fin plate 222, respectively. 226 is integrally formed at a predetermined interval in the height direction. The opposed surfaces 222A and 222B that are recessed from the convex portions 226 are exposed between the convex portions 226 and 226 adjacent to each other in the height direction. In the present embodiment, the opposing surfaces 222A and 222B are exposed between the convex portions 226 and 226. The opposing surfaces 222 </ b> A and 222 </ b> B function as the concave strip 225.
In the present embodiment, the fin plate 222 includes a groove portion 227 that extends in the height direction of the fin plate 222 and divides the protruding portion 226 into a plurality of extending directions X of the protruding portion 226. The groove 227 is formed by, for example, cutting the opposing surfaces 222A and 222B of the fin plate 222 after the heat sink 220 is extruded. According to this configuration, the groove portion 227 partially removes the protruding portion 226 of the fin plate 222, so that a portion having the protruding portion 226 with respect to the flow direction of the cooling water and a portion without the protruding portion are formed. Disturbed. For this reason, even if it is a case where a cooling water is poured along the fin board 222, it can suppress that the said temperature boundary layer develops toward a downstream, and can improve the cooling performance of the heat sink 220. FIG. Furthermore, since the fin plate 222 is not divided into a plurality of pieces like the above-described fin plate 122, the strength of the heat sink 220 can be improved with respect to the flow direction of the cooling water.

In the present embodiment, the fin plate 222 is formed in a single shape along the extending direction X of the fin plate 222. However, the present invention is not limited to this, and the fin plate 222 is divided into a plurality of extending directions X. A groove may be formed for each fin plate. Moreover, in this embodiment, although the groove part 227 is set as the structure which divides | segments the protruding item | line part 226 into multiple in the extending direction X of the said protruding item | line part 226, it divides | segments the recessed item part 225 also in the extending direction X. Also good.
In the present embodiment, the groove 227 is provided from the tip of the fin plate 22 to the base end (end connected to the base plate), but the groove may be provided in a part from the tip to the base end. Of course.
Furthermore, it is needless to say that a groove portion may be provided in the fin plate 22 according to the first embodiment.

[Fourth Embodiment]
FIG. 9 is a side view showing the shape of the fin plate 322 of the heat sink 320 according to the fourth embodiment.
In the fin plate 322 of the present embodiment, the fin strips 322 and 322 adjacent to each other across the flow path 23 are provided with a concave strip portion 325 having a substantially triangular cross section provided on one facing surface 322A of one fin plate 322 and a convex portion. The strip portion 326 and the concave strip portion 325 and the convex strip portion 326 having a substantially triangular cross section provided on the other facing surface 322B of the other fin plate 322 facing the facing surface 322A are at the same height position. Forming. That is, it forms so that trough parts 325A of the concave strip part 325 formed in each opposing surface and the top parts of the convex strip part 326 may face each other.
According to this configuration, although the width of the flow path 23 is partially different in the height direction, since the same height direction circulates in the same width, it is possible to prevent an increase in the flow resistance of the cooling water. it can.
In the present embodiment, the fin plate 322 has a concave strip portion 325 and a convex strip portion 326 which are alternately arranged in the height direction in a substantially triangular cross section. For example, as in the shape of the fin plate 122 described above, semi-cylindrical ridges are integrally formed on the opposing surface of the substantially rectangular fin plate at predetermined intervals in the height direction. Of course, a thing may be used. Needless to say, the above-described groove portion 227 can be provided in the fin plate 322.

  As described above, according to the present embodiment, the base plate 21 in which the IGBT chip 10 is thermally connected to the front surface 21 </ b> A and the plurality of fin plates 22, 122, 222, which are erected in parallel with the back surface 21 </ b> B of the base plate 21. In the heat sink 20, 120, 220, 320 provided with 322, the fin plates 22, 122, 222, 322 are opposed surfaces 22 A, 22 B, 122 A, 122 B, 222 A facing the adjacent fin plates 22, 122, 222, 322. , 222B, 322A, 322B are provided with the concave strip portions 25, 125, 225, 325 and the convex strip portions 26, 126, 226, 326 extending substantially parallel to the back surface 21B of the base plate 21, so that the fin plates 22, 122 are provided. , 222, 322 and the surface area of 25, 125, 225, 325 and the ridges 26, 126, 226, 326 By cooling water flows, it can be prevented an increase in the flow resistance of the gap between the fin plate and the fin plate, therefore, it is possible to improve the cooling performance.

  Further, according to the present embodiment, for the adjacent fin plates 22, 122, 222, the concave strips 25, 125, 225 of one opposing surface 22A, 122A, 222A are the same as the other opposing surfaces 22B, 122B, 222B. Since the protrusions 26, 126, and 226 are provided at positions facing each other, the width of the flow path 23 formed between the fin plates is substantially the same across the height direction Z of the fin plates 22, 122, and 222. Therefore, the cooling water can be made to flow substantially evenly in the height direction of the flow path 23, and the flow resistance of the flow path 23 can be reduced. Therefore, the heat exchange efficiency between the fin plates 22, 122, 222 and the cooling water is increased, and the cooling performance of the heat sinks 20, 120, 220 can be improved.

  Further, according to the present embodiment, the concave stripe portions 25, 125, 225, 325 and the convex stripe portions 26, 126, 226, 326 are alternately provided in the height direction Z of the fin plates 22, 122, 222, 322. Therefore, the surface area of the fin plates 22, 122, 222, 322 can be easily increased.

  Further, according to the present embodiment, since the cooling water flows through the flow path 23 formed in the gap between the adjacent fin plates, the heat exchange efficiency between the cooling water and the fin plates is improved, and the heat sinks 20, 120 are provided. , 220 can be improved in cooling performance.

  In addition, according to the present embodiment, the fin plates 22, 122, 322 are divided into a plurality in the extending direction X of the concave strip portions 25, 125, 325 and the convex strip portions 26, 126, 326, respectively. Surfaces that come into contact with the cooling water as a whole as the heat sinks 20, 120, and 320 can also be used for heat exchange with the cooling water because the surfaces newly generated as a result of the division (the opposing surfaces of the fin plates arranged side by side in the extending direction X) can also be used. Can be increased. Further, in the gap 27 formed between the fin plates, the flow of the cooling water is disturbed, so that the temperature boundary layer can be prevented from developing downstream, and the cooling performance of the heat sinks 20, 120, 320 can be suppressed. Can be improved.

  Further, according to the present embodiment, the distance L of the gap 27 between the divided fin plates is formed smaller than the thickness D of the fin plates, so that the heat sink 20, 120, The cooling performance of 320 can be enhanced.

  Further, according to the present embodiment, the fin plate 222 includes the groove portion 227 that extends in the height direction Z of the fin plate 222 and divides the ridge portion 226 into a plurality of directions in the extending direction X of the ridge portion 226. Therefore, the groove portion 227 partially removes the protruding portion 226 of the fin plate 222, so that there is a portion where the protruding portion 226 is present and a portion where the protruding portion 226 is not present in the flow direction of the cooling water, and the flow is disturbed. For this reason, even if it is a case where a cooling water is poured along the fin board 222, it can suppress that the said temperature boundary layer develops toward a downstream, and can improve the cooling performance of the heat sink 220. FIG. Furthermore, since the fin plate 222 is not divided into a plurality of pieces like the above-described fin plate 122, the strength of the heat sink 220 can be improved with respect to the flow direction of the cooling water.

As mentioned above, although this invention was concretely demonstrated based on embodiment, this invention is not limited to the said embodiment, It can change in the range which does not deviate from the summary.
For example, in the present embodiment, the configuration in which the cooling water is caused to flow through the flow path 23 between the fin plates has been described. However, the present invention is not limited to this. It is good also as a structure which distribute | circulates air (fluid for cooling).
In the present embodiment, the fin plate has a configuration in which a plurality of concave portions and convex portions are alternately provided in the height direction. However, the fin plate may have a configuration in which only concave portions or convex portions are provided. . Moreover, the shape of a recessed line part and a protruding line part is not restricted to description of this embodiment.

10 IGBT chip (heating element)
20, 120, 220, 320 Heat sink 21 Base plate 21A Surface (one surface)
21B Back side (the other side)
22, 122, 222, 322 Fin plate 22A, 122A, 222A, 322A Opposing surface (one opposing surface)
22B, 122B, 222B, 322B facing surface (the other facing surface)
23 Channel 25, 125, 225, 325 Concave part 26, 126, 226, 326 Convex part 27 Gap

Claims (8)

In a heat sink comprising a base plate, to which a heating element is thermally connected to one surface, and a plurality of fin plates erected in parallel to the other surface of the base plate,
The heat sink according to claim 1, wherein the fin plate includes a concave or convex portion extending substantially parallel to the other surface of the base plate on a surface facing the adjacent fin plate.   2. The heat sink according to claim 1, wherein the concave portion of one opposing surface is provided at a position facing the convex portion of the other opposing surface.   The heat sink according to claim 1 or 2, wherein the concave stripes and the convex stripes are alternately provided in a height direction of the fin plate.   The heat sink according to any one of claims 1 to 3, wherein a cooling fluid flows in a gap between adjacent fin plates.   5. The heat sink according to claim 1, wherein each of the fin plates is divided into a plurality of portions in an extending direction of the concave stripe portion and the convex stripe portion.   The heat sink according to claim 5, wherein an interval between the divided fin plates is smaller than a thickness of the fin plates.   The said fin board is provided with the groove part which extends in the height direction of the said fin board, and divides | segments at least the said convex strip part into plurality in the extension direction of the said convex strip part. Heat sink described in.   The heat sink according to any one of claims 1 to 7, wherein the recess or the protrusion is formed in a substantially triangular shape in cross section.

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