Heat sink with heat pipe

Abstract

To realize downsizing and improvement of heat dissipation performance in a heat sink with a heat pipe.SOLUTION: A base 70 has a front surface 70S1 on which a heat source is provided, and a rear surface 70S2 on a side opposite to the front surface 70S1. A plurality of fins 72 protrude from the rear surface 70S2 of the base 70. A heat pipe 80 has: an evaporation unit in thermal contact with the base 70; and a condensation unit 80C disposed at a position apart from the evaporation unit. A fin 82 with a heat pipe is provided at the condensation unit 80C of the heat pipe 80. The plurality of fins 72 are arranged in a horizontal direction. The plurality of fins 72 are vertically arranged. At least a part of the condensation unit 80C of the heat pipe 80 is arranged just above the fin 72.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a heat sink with a heat pipe.

Background Art

[0002] As a conventional technique, the technique described in Japanese Unexamined Patent Application Publication No. 2014-64467 (Patent Document 1) is exemplified. The above document discloses a heat pipe for cooling a semiconductor element.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A heat sink with a heat pipe has excellent heat dissipation performance compared to a general air-cooled heat sink. However, in order to dissipate the heat received by the heat pipe to the air, it is necessary to increase the heat dissipation area of the fins, so it is necessary to use a large amount of space inside the device.

[0005] In the present disclosure, a heat sink with a heat pipe that can achieve miniaturization of the device and improvement of heat dissipation performance is proposed.

Means for Solving the Problems

[0006] According to the present disclosure, a heat sink with a heat pipe is proposed, which includes a heat source, a base portion, a plurality of fin portions, a heat pipe, and a fin portion with a heat pipe. The base portion has a surface on which the heat source is provided and a back surface opposite to the surface. The plurality of fin portions protrude from the back surface of the base portion. The heat pipe has an evaporation portion that is thermally in contact with the base portion and a condensation portion that is disposed at a position separated from the evaporation portion. The fin portion with a heat pipe is provided on the condensation portion of the heat pipe. The plurality of fin portions are arranged side by side in the horizontal direction. The plurality of fin portions are arranged vertically. At least a part of the condensation portion of the heat pipe is disposed directly above the fin portion.

[0007] Here, "thermally in contact" means a state in which heat is directly transferred between two members and the heat transfer efficiency is sufficiently high. This is not limited to the case where these members are in direct mechanical contact with each other by abutting. For example, when two members are integrated by soldering, welding, etc., or when they are indirectly in contact with a highly thermally conductive substance interposed therebetween, they are also included in the state of being thermally in contact. This definition is the same for the following embodiments.

Advantages of the Invention

[0008] According to the heat sink with a heat pipe according to the present disclosure, miniaturization of the device and improvement of heat dissipation performance can be achieved.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments will be described with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated. In the drawings, for convenience of explanation, the configuration may be omitted or simplified in some cases. It is also initially planned that any configurations are extracted from the embodiments and combined arbitrarily.

[0011] Figure 1 is a circuit diagram of a power conversion unit. In Figure 1, a circuit diagram of an inverter unit 5 is shown as a representative example of the power conversion unit. The inverter unit 5 converts DC power into AC power. As shown in Figure 1, the inverter unit 5 includes a DC positive bus bar PL, a DC negative bus bar NL, a capacitor unit 1, an inverter 4, and a fuse 6.

[0012] The capacitor unit 1 is connected between the DC positive bus bar PL and the DC negative bus bar NL. The capacitor unit 1 is electrically connected in parallel with the inverter 4 and smoothes the output voltage of the inverter 4. The capacitor unit 1 includes a plurality of DC smoothing electrolytic capacitors.

[0013] The inverter 4 includes a plurality of power modules 40 connected in parallel between a DC positive bus bar PL and a DC negative bus bar NL. Each power module 40 has two IGBTs (Insulated Gate Bipolar Transistors) 401 connected in series between DC input nodes P and N, and two anti-parallel diodes (hereinafter referred to as diodes) 402 respectively connected to the two IGBTs 401. In FIG. 1, the inverter 4 is described as a so-called two-level inverter, but it is not limited thereto, and for example, it may be a three-level inverter.

[0014] The load 2 is driven by three-phase AC power output from nodes U, V, and W connected to the connection points of the two IGBTs 401 of the power module 40. The load 2 is, for example, a motor.

[0015] The fuse 6 is electrically connected to at least one of between the DC input node P of the power module 40 and the DC positive bus bar PL and between the DC input node N of the power module 40 and the DC negative bus bar NL. The fuse 6 is provided for short-circuit protection when the IGBT 401 or the diode 402 is short-circuited for some reason.

[0016] The power module 40 generates heat due to the loss during the switching operation of the IGBT 401. The power module 40 corresponds to an example of a heat source that generates heat. In order to cool the power module 40, the heat sink 100 with a heat pipe of the embodiment described later is used.

[0017] Figure 2 is a schematic cross-sectional view showing an example of the internal configuration of the power conversion device. As shown in Figure 2, the housing 3 has a vertically long box shape. Inside the housing 3, a plurality of electrical devices 38A to 38D are accommodated. The electrical devices 38A to 38D may be, for example, a capacitor unit 1 (Figure 1), a transformer, a reactor, a control unit, a circuit breaker unit, etc., or other types of electrical devices. The arrangement of the electrical devices 38A to 38D shown in Figure 2 is an example, and the electrical devices 38A to 38D may be arranged at other positions inside the housing 3.

[0018] In Figure 2, the left-right direction in the figure is the front-back direction of the power conversion device, and the left side in the figure is the front side of the power conversion device. An air inlet 31 is formed on the front surface of the housing 3. The air outside the housing 3 passes through the air inlet 31 and is taken into the housing 3. An exhaust port 32 is formed on the upper surface of the housing 3. The air inside the housing 3 passes through the exhaust port 32 and is discharged to the outside of the housing 3.

[0019] The partition 34 is arranged to extend in the vertical direction inside the housing 3, and partitions the internal space of the housing 3 in the front-back direction. In the example shown in Figure 2, the electrical devices 38A and 38B are accommodated in the space partitioned in front of the partition 34, and the electrical devices 38C and 38D are accommodated in the space partitioned behind the partition 34.

[0020] A cover 36 is provided behind the partition 34. A duct passage 37 extending in the vertical direction is formed between the partition 34 and the cover 36 in the front-back direction of the power conversion device. A part of the air flowing into the housing 3 from the air inlet 31 flows upward in the duct passage 37 and flows toward the exhaust port 32.

[0021] In the duct passage 37, a fin portion 72 and a fin portion 82 with a heat pipe that constitute a heat sink 100 with a heat pipe are arranged. A base portion 70 that constitutes a heat sink 100 with a heat pipe is attached to the front surface of the partition 34. The power module 40 shown in Figure 1 is mounted on the front surface of the base portion 70 and is in thermal contact with the base portion 70.

[0022] The base portion 70 and the power module 40 mounted on the front surface of the base portion 70 are disposed in front of the partition body 34. The fin portion 72 and the fin portion 82 with a heat pipe are disposed behind the partition body 34. The heat pipe 80 that constitutes the heat sink 100 with a heat pipe is disposed across the front and rear of the partition body 34. A part of the heat pipe 80 is disposed in the duct passage 37.

[0023] The cover 36 separates the duct passage 37 in which the fin portion 72 and the fin portion 82 with a heat pipe are disposed from the space in which the electrical devices 38C and 38D are disposed. The cover 36 suppresses the air whose temperature has risen due to receiving the heat dissipation of the electrical devices 38C and 38D from flowing into the duct passage 37. The cover 36 suppresses the radiant heat of the electrical devices 38C and 38D from being transmitted to the fin portion 72 and the fin portion 82 with a heat pipe. Since the cover 36 separates the electrical devices 38C and 38D from the power module 40, it is possible to replace the power module 40 with the electrical devices 38C and 38D energized during the maintenance of the power conversion device.

[0024] FIG. 3 is a perspective view of the heat sink 100 with a heat pipe. FIG. 4 is a front view of the heat sink 100 with a heat pipe. FIG. 5 is a left side view of the heat sink 100 with a heat pipe. FIG. 6 is a right side view of the heat sink 100 with a heat pipe. FIG. 7 is a top view of the heat sink 100 with a heat pipe. FIG. 8 is a bottom view of the heat sink 100 with a heat pipe. FIGS. 4 to 8 respectively show the heat sink 100 with a heat pipe as viewed from the directions of arrow IV, arrow V, arrow VI, arrow VII, and arrow VIII shown in FIG. 3.

[0025] As also shown in FIG. 2, the heat sink 100 with a heat pipe mainly includes a base portion 70, a fin portion 72, a heat pipe 80, and a fin portion 82 with a heat pipe.

[0026] The base portion 70 has a rectangular plate-like outer shape. The base portion 70 is arranged vertically. The base portion 70 has a front surface 70S1 and a back surface 70S2 on the side opposite to the front surface 70S1. The front surface 70S1 and the back surface 70S2 extend parallel to each other. A power module 40 (see FIG. 1. Not shown in FIGS. 4 to 8) is mounted on the front surface 70S1 of the base portion 70. Referring also to FIG. 2, the front surface 70S1 of the base portion 70 is arranged facing the front of the power conversion device. The back surface 70S2 of the base portion 70 is arranged facing the back of the power conversion device.

[0027] The base portion 70 has an upper edge 70UE and a lower edge 70LE. The upper edge 70UE and the lower edge 70LE extend in the horizontal direction. The upper edge 70UE and the lower edge 70LE extend orthogonally to the front surface 70S1 and the back surface 70S2. The upper edge 70UE is arranged facing upward. The lower edge 70LE is arranged facing downward.

[0028] A plurality of fin portions 72 are provided on the back surface 70S2 of the base portion 70. The plurality of fin portions 72 protrude horizontally from the back surface 70S2 of the base portion 70. The plurality of fin portions 72 protrude from the back surface 70S2 of the base portion 70 toward the rear side of the power conversion device. The fin portion 72 is orthogonal to the back surface 70S2 of the base portion 70. The base portion 70 is arranged vertically, and the fin portion 72 protrudes laterally from the base portion 70.

[0029] Each of the plurality of fin portions 72 is composed of a flat plate. Typically, each fin portion 72 has a rectangular plate-like outer shape. The plurality of fin portions 72 are arranged side by side in the horizontal direction. Each of the plurality of fin portions 72 is arranged vertically. Each fin portion 72 extends in the vertical direction. Each fin portion 72 is arranged in a row with a gap 74 opened between adjacent fin portions 72.

[0030] The fin portion 72 has a root portion 72R connected to the base portion 70, a tip portion 72T farthest from the base portion 70, an upper edge portion 72UE, and a lower edge portion 72LE. The upper edge portion 72UE and the lower edge portion 72LE extend linearly. The upper edge portion 72UE and the lower edge portion 72LE extend in the front-rear direction of the power conversion device. The upper edge portion 72UE and the lower edge portion 72LE are orthogonal to the back surface 70S2 of the base portion 70. The root portion 72R extends linearly along the back surface 70S2 of the base portion 70. The tip portion 72T extends linearly parallel to the back surface 70S2 of the base portion 70. The root portion 72R and the tip portion 72T extend in the vertical direction. The root portion 72R and the tip portion 72T are orthogonal to the upper edge portion 72UE and the lower edge portion 72LE.

[0031] The lower edge 70LE of the base portion 70 and the lower edge portion 72LE of the fin portion 72 extend on the same plane. The upper edge portion 72UE of the fin portion 72 is located below the upper edge 70UE of the base portion 70.

[0032] Each of the plurality of fin portions 72 is in thermal contact with the base portion 70. Each of the plurality of fin portions 72 is in thermal contact with the power module 40 mounted on the base portion 70 via the base portion 70. The heat generated by the power module 40 is transmitted to each of the plurality of fin portions 72 via the base portion 70. Heat is transmitted from the fin portion 72 to the air, and the base portion 70 is cooled.

[0033] The heat pipe 80 protrudes from the upper edge 70UE of the base portion 70 and extends upward, and is bent toward the back surface 70S2 side of the base portion 70. Thereby, at least a part of the condensation portion 80C of the heat pipe 80 is disposed directly above the fin portion 72. The condensation portion 80C of the heat pipe 80 extends obliquely with respect to the extending direction of the upper edge portion 72UE of the fin portion 72. The condensation portion 80C of the heat pipe 80 extends obliquely so as to go upward as it moves away from the base portion 70.

[0034] In the vertical direction, the distance between the condensation part 80C of the heat pipe 80 and the upper edge part 72UE of the fin part 72 is smaller at the base part 72R of the fin part 72 and larger at the tip part 72T of the fin part 72. In the vertical direction, the distance between the heat pipe 80 and the tip part 72T is made larger than the distance between the heat pipe 80 and the base part 72R.

[0035] Inside the heat pipe 80, a sealed and vacuum-decompressed space is formed. An appropriate amount of working fluid is injected into this space. The working fluid has the property (condensability) of being heated and evaporated and releasing heat to condense. The heat pipe 80 has an evaporation part that is in thermal contact with the base part 70 and a condensation part 80C that is arranged at a position separated from the evaporation part. In the embodiment, the evaporation part of the heat pipe 80 is embedded inside the base part 70 and is arranged so as not to be visible from the outside. The condensation part 80C is arranged at a position away from the base part 70 and is separated from the evaporation part inside the base part 70. The condensation part 80C extends obliquely upward as the distance from the evaporation part increases.

[0036] The power module 40, which is a heat source, is mounted on the base part 70, and the evaporation part of the heat pipe 80 receives heat from the heat source through the base part 70. When the liquid working fluid inside the heat pipe 80 is heated, the working fluid absorbs heat as latent heat. In the evaporation part, the working fluid evaporates and becomes gaseous. The vapor of the evaporated working fluid flows through the heat pipe 80 from the evaporation part toward the condensation part 80C, and thus heat is carried to the condensation part 80C. The vapor of the working fluid releases latent heat at the condensation part 80C and thus condenses into a liquid state. The liquid working fluid moves to the evaporation part by the action of gravity.

[0037] In this way, through the heat transfer by the vaporization and liquefaction of the working fluid, the heat generated by the power module 40 is transmitted to the condensation part 80C of the heat pipe 80. Heat is transferred from the condensation part 80C to the air, and the base part 70 is cooled.

[0038] A fin section 82 with a heat pipe is provided at a condensation section 80C of the heat pipe 80. The fin section 82 with a heat pipe is attached to the condensation section 80C and is in thermal contact with the condensation section 80C. The fin section 82 with a heat pipe has a plurality of flat fins. These plurality of fins are arranged with gaps in the extending direction of the condensation section 80C of the heat pipe 80. The heat pipe 80 penetrates through the plurality of fins of the fin section 82 with a heat pipe in the thickness direction of the fins.

[0039] The heat radiation area in the condensation section 80C is increased by the fin section 82 with a heat pipe. The fin section 82 with a heat pipe promotes heat radiation from the condensation section 80C to the air. The fin section 82 with a heat pipe increases the amount of heat transfer from the condensation section 80C of the heat pipe 80 to the air. Thereby, the heat transport capacity of the heat pipe 80 is improved, and the cooling performance for cooling the base portion 70 is improved.

[0040] The condensation section 80C of the heat pipe 80 is inclined with respect to the horizontal direction so as to go upward as it moves away from the base portion 70. Each fin of the fin section 82 with a heat pipe is provided around the heat pipe 80 so as to extend orthogonally to the extending direction of the heat pipe 80. Thereby, the fin section 82 with a heat pipe is inclined with respect to the vertical direction. Also, in a plan view, at least a part of the fin section 82 with a heat pipe overlaps with the fin section 72.

[0041] The heat sink 100 with a heat pipe having the configuration described above is disposed within the housing 3 of the power conversion device shown in FIG. 2. Air taken into the housing 3 from the air inlet 31 flows into the duct passage 37. The air receives heat radiation from the fin portion 72 disposed within the duct passage 37, and the temperature of the air rises. The air, whose temperature has risen and whose specific gravity has decreased, rises. The air reaches the condensation portion 80C of the heat pipe 80 disposed directly above the fin portion 72. Receiving heat radiation from the condensation portion 80C, the temperature of the air further rises, and the specific gravity of the air further decreases. The air rises and flows toward the exhaust port 32 formed on the upper surface of the housing 3, and is discharged to the outside of the housing 3 from the exhaust port 32.

[0042] Due to natural convection of the air within the duct passage 37, an air flow is generated around the fin portion 72 and the condensation portion 80C of the heat pipe 80, and a configuration is provided such that heat can be radiated from the fin portion 72 and the condensation portion 80C to the air. It is no longer necessary to provide the cooling fan and air filter that were conventionally required. Thereby, maintenance work for the cooling fan and air filter can be labor-saving, and running costs can be reduced. The noise of the cooling fan can be reduced, and quietness can be improved.

[0043] As shown in FIGS. 3 to 4 and 8, since the fin portion 72 is directly attached to the base portion 70 where the heat source is provided, heat transfer from the base portion 70 to the fin portion 72 is promoted. Heat is radiated from the fin portion 72 to the air, and the base portion 70 is further cooled by heat transport of the heat pipe 80, so the cooling performance for cooling the base portion 70 is enhanced. The heat dissipation performance of the heat sink 100 with a heat pipe can be improved. In addition to cooling the base portion 70 by heat transport of the heat pipe 80, the base portion 70 is cooled by the fin portion 72, so it becomes possible to miniaturize the heat pipe 80. Therefore, miniaturization of the entire device of the heat sink 100 with a heat pipe can be realized.

[0044] As shown in FIGS. 3, 6, and 8, a plurality of fin portions 72 protrude from the back surface 70S2 of the base portion 70, are arranged horizontally, and are vertically disposed. The air whose temperature has risen by receiving heat dissipation from the fin portions 72 can rise without being blocked by the base portion 70 and reach the condensation portion 80C of the heat pipe 80. Forming an upward air flow in the fin portions 72 and enhancing the effect of natural convection of the air assist in heat dissipation to the air in the condensation portion 80C. In this way, the heat dissipation performance of the heat sink 100 with a heat pipe can be improved.

[0045] As shown in FIGS. 3 to 4 and 7 to 8, since a part of the condensation portion 80C of the heat pipe 80 is disposed directly above the fin portions 72, the air whose temperature has risen by receiving heat dissipation in the fin portions 72 can surely flow to the periphery of the condensation portion 80C. Since the temperature of the air flowing around the condensation portion 80C is increased and the flow velocity of the air is increased, heat dissipation from the condensation portion 80C to the air is promoted. An acceleration distance is ensured until the air passing through the fin portions 72 reaches the condensation portion 80C, and the flow velocity of the air whose temperature has risen in the fin portions 72 can surely develop. In this way, the heat dissipation performance of the heat sink 100 with a heat pipe can be improved.

[0046] As shown in FIGS. 3 to 4, a fin portion 82 with a heat pipe is provided in the condensation portion 80C of the heat pipe 80. By providing the fin portion 82 with a heat pipe in the condensation portion 80C, heat dissipation from the condensation portion 80C to the air is promoted, and the working fluid of the heat pipe 80 can be quickly liquefied, so the heat transport capacity of the heat pipe 80 can be improved.

[0047] As shown in FIGS. 3 to 4 and FIGS. 7 to 8, in a plan view, a part of the fin portion 82 with a heat pipe overlaps with the fin portion 72, and at least a part of the fin portion 82 with a heat pipe is disposed directly above the fin portion 72. The air that has received heat dissipation in the fin portion 72 and has increased in temperature flows around the fin portion 82 with a heat pipe. Since the flow velocity of the air flowing around the fin portion 82 with a heat pipe is increased, heat dissipation from the fin portion 82 with a heat pipe to the air is promoted. In this way, it is possible to improve the heat dissipation performance of the heat sink 100 with a heat pipe.

[0048] As shown in FIG. 4, in the vertical direction, the distance between the heat pipe 80 and the tip portion 72T of the fin portion 72 is larger than the distance between the heat pipe 80 and the base portion 72R of the fin portion 72. The condensation portion 80C of the heat pipe 80 is disposed above the fin portion 72. The distance by which the heat pipe 80 separates from the upper edge portion 72UE of the fin portion 72 at the tip portion 72T of the fin portion 72 is larger than the distance by which the heat pipe 80 separates from the upper edge portion 72UE of the fin portion 72 at the base portion 72R of the fin portion 72 that is connected to the base portion 70.

[0049] As a result, the heat pipe 80 is arranged to extend upward as it separates from the base portion 70 where the evaporation portion is provided. The vapor of the working fluid evaporated in the evaporation portion can move upward in the heat pipe 80 and quickly reach the condensation portion 80C. The liquid working fluid condensed in the condensation portion 80C can move downward in the heat pipe 80 and quickly reflux to the evaporation portion. Since the heat transport capacity of the heat pipe 80 can be improved, it is possible to improve the heat dissipation performance of the heat sink 100 with a heat pipe.

[0050] As shown in FIGS. 3, 6, and 8, each of the plurality of fin portions 72 is composed of a flat plate. A heat pipe penetrating the fin portion 72 is not provided. Since heat pipes are generally expensive, the heat dissipation performance of the heat sink 100 with a heat pipe can be improved with an inexpensive configuration. Since the pipe does not obstruct the flow of air passing through the fin portion 72 and the heat dissipation to the air in the fin portion 72 does not decrease, the heat dissipation performance in the fin portion 72 is improved.

[0051] Each of the plurality of fin portions 72 is arranged with a gap 74 therebetween. A part of the air that reaches the fin portion 72 flows into the gap 74. Since heat is dissipated to the air flowing through the gap 74 from the fin portions 72 on both sides of the gap 74, the temperature rise of the air is promoted. Since the fin portions 72 are arranged vertically and the lower and upper portions of the gap 74 are open, the flow of air passing through the gap 74 is suppressed from being obstructed by the fin portions 72. The heat dissipation performance in the fin portion 72 is improved, and the air whose temperature has risen more due to the heat dissipation from the fin portion 72 flows to the condensation portion 80C of the heat pipe 80, whereby the heat dissipation performance of the heat sink 100 with a heat pipe can be further improved.

[0052] Since it is configured to flow air by natural convection without providing a cooling fan, if the gap 74 is too small, it becomes difficult for air to flow into the gap 74, and heat dissipation to the air flowing through the gap 74 is inhibited. The dimension of the gap 74 is preferably determined such that air flowing by natural convection can easily flow into the gap 74. It is desirable to arrange the adjacent fin portions 72 so as to ensure such a gap 74.

[0053] As shown in FIGS. 3 and 4, the heat pipe 80 extends upward from the upper edge 70UE of the base portion 70 and is bent toward the back surface 70S2 side of the base portion 70. By forming the heat pipe 80 in such a shape, a configuration in which the condensation portion 80C of the heat pipe 80 is disposed directly above the fin portion 72 can be surely realized. The working fluid vaporized in the evaporation portion of the heat pipe 80 can be caused to rise in the heat pipe 80 and surely moved to the condensation portion 80C. The working fluid condensed in the condensation portion 80C of the heat pipe 80 can be caused to descend by the action of gravity and surely moved to the evaporation portion.

[0054] In the embodiment, an example in which the fin portion 82 with a heat pipe extends orthogonally to the extending direction of the heat pipe 80 and is inclined with respect to the vertical direction has been described. The arrangement of the fin portion 82 with a heat pipe with respect to the heat pipe 80 is not limited to this example. The fin portion 82 with a heat pipe may extend inclined with respect to the extending direction of the heat pipe 80. The fin portion 82 with a heat pipe may not be inclined with respect to the vertical direction.

[0055] Each fin of the fin portion 82 with a heat pipe may be arranged side by side along the heat pipe 80 and vertically, and may be arranged to extend in the vertical direction. In this case, when the fin portion 82 with a heat pipe and the fin portion 72 are viewed in plan, the fin portion 82 with a heat pipe and the fin portion 72 are arranged in a lattice pattern, and the air flow paths formed between the fins open to both the upper and lower sides. When the fin portion 82 with a heat pipe and the fin portion 72 are viewed from above, the entire flow path can be seen from the upper opening that serves as the air outlet from the air flow path formed between the fins to the lower opening that serves as the air inlet to the flow path. As a result, the resistance to the air flow is reduced, so that the air flow passing around the fin portion 72 and the fin portion 82 with a heat pipe can be further promoted.

Example

[0056] Hereinafter, examples will be described. For the heat sink with a heat pipe in the comparative example and the heat sink 100 with a heat pipe in the example, simulations were conducted to confirm the temperature distribution and the wind speed distribution. The heat sink 100 with a heat pipe in the example was assumed to have the configuration shown in FIGS. 3 to 8. The heat sink with a heat pipe in the comparative example was different from the example in that the fin portion did not protrude from the back surface of the base portion 70.

[0057] FIG. 9 is a three-dimensional view showing the temperature distribution of the heat sink with a heat pipe in the example and the comparative example. FIG. 10 is a cross-sectional view showing the temperature distribution of the heat sink with a heat pipe in the example and the comparative example. The temperature distribution indicates that the lighter the color, the lower the temperature, and the darker the color, the higher the temperature.

[0058] The analysis results of "(a) Front side of comparative example" and "(b) Back side of comparative example" in FIG. 9, and the analysis result of "(a) Comparative example" in FIG. 10 show the temperature distribution of the heat sink with a heat pipe in the comparative example. The analysis results of "(c) Front side of example" and "(d) Back side of example" in FIG. 9, and the analysis result of "(b) Example" in FIG. 10 show the temperature distribution of the heat sink 100 with a heat pipe in the example. The front side refers to the surface 70S1 side where the power module 40 is mounted on the base portion 70. The back side refers to the back surface 70S2 side of the base portion 70.

[0059] In the comparative example, the fin portion is not provided on the base portion 70, and the back surface of the base portion 70 cannot be used as a heat dissipation surface. In contrast, in the example, the fin portion 72 is provided on the back surface 70S2 of the base portion 70, and the structure is such that heat can be dissipated from the back surface 70S2 of the base portion 70. It was confirmed that in the example compared with the comparative example, the color of the base portion 70 is lighter and the temperature of the base portion 70 is lower. Thereby, it became clear that in the example, the heat dissipation performance of the heat sink 100 with a heat pipe for cooling the base portion 70 is further improved.

[0060] FIG. 11 is a cross-sectional view showing the air velocity distribution in the heat sink with a heat pipe in the examples and comparative examples. The analysis result of "(a) Comparative Example" in FIG. 11 shows the air velocity distribution in the heat sink with a heat pipe of the comparative example. The analysis result of "(b) Example" in FIG. 11 shows the air velocity distribution in the heat sink 100 with a heat pipe of the example. The velocity distribution indicates that the lighter the color, the smaller the velocity, and the darker the color, the larger the velocity.

[0061] In both the example and the comparative example, the flow velocity was sufficiently developed above the heat sink 100 with a heat pipe. However, in the example, the wind speed developed more downward, and an air flow with a large velocity was formed over a wider range. In the example, natural convection is generated by heating the air in the fin portion 72, and the air flow is further accelerated in the fin portion 82 with a heat pipe, so that the air velocity becomes large at a position closer to the heat sink 100 with a heat pipe. It is considered that heat can be radiated upward by the air flow with a large velocity, and active heat transport is performed, so that it is shown that the heat radiation performance of the heat sink 100 with a heat pipe is improved.

[0062] As shown in FIGS. 9 to 11, in the heat sink 100 with a heat pipe of the example, the length of the heat pipe 80 is shorter than that of the comparative example, the number of fins of the fin portion 82 with a heat pipe is reduced, and the volume occupied by the heat pipe 80 and the fin portion 82 with a heat pipe is smaller. It is shown that the heat sink 100 with a heat pipe of the example is miniaturized compared with the comparative example, space saving is realized, and the heat radiation performance is improved even when miniaturized.

[0063] <Supplementary Note> The above description includes the features described in the supplementary note below.

[0064] (Supplementary Note 1) A heat source, A base portion having a surface on which the heat source is provided and a back surface opposite to the surface, A plurality of fin portions protruding from the back surface, A heat pipe having an evaporation part that is in thermal contact with the base part, and a condensation part that is disposed at a position separated from the evaporation part, and a fin part with a heat pipe provided on the condensation part, wherein a plurality of the fin parts are arranged horizontally and disposed vertically, A heat sink with a heat pipe, at least a part of the condensation part of which is disposed directly above the fin part.

[0065] (Appendix 2) The heat sink with a heat pipe according to Appendix 1, wherein in a plan view, at least a part of the fin part with a heat pipe overlaps the fin part.

[0066] (Appendix 3) The fin part has a root part connected to the base part and a tip part farthest from the base part, The heat sink with a heat pipe according to Appendix 1 or Appendix 2, wherein the distance between the heat pipe and the tip part in the vertical direction is greater than the distance between the heat pipe and the root part.

[0067] (Appendix 4) Each of the plurality of fin parts is composed of a flat plate and arranged with a gap therebetween. The heat sink with a heat pipe according to any one of Appendices 1 to 3.

[0068] (Appendix 5) The heat sink with a heat pipe according to any one of Appendices 1 to 4, wherein the heat pipe extends upward from the upper edge of the base part and is bent toward the back surface side.

[0069] The embodiments and examples disclosed this time should be considered illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims be included.

Explanation of Reference Numerals

[0070] 3 housing, 5 inverter unit, 31 intake port, 32 exhaust port, 34 partition body, 36 cover, 37 duct passage, 38A to 38D electrical equipment, 40 power module, 70 base portion, 70LE lower edge, 70S1 surface, 70S2 back surface, 70UE upper edge, 72 fin portion, 72LE lower edge portion, 72R base portion, 72T tip portion, 72UE upper edge portion, 74 gap, 80 heat pipe, 80C condensation portion, 82 fin portion with heat pipe, 100 heat sink with heat pipe.

Claims

1. a heat source, a base portion having a surface on which the heat source is provided and a back surface opposite to the surface, a plurality of fin portions protruding from the back surface, a heat pipe having an evaporation portion in thermal contact with the base portion and a condensation portion disposed at a position spaced apart from the evaporation portion, and a fin portion with a heat pipe provided on the condensation portion, wherein the plurality of fin portions are arranged side by side in the horizontal direction and arranged vertically, a heat sink with a heat pipe, wherein at least a part of the condensation portion is disposed directly above the fin portion.

2. The heat sink with a heat pipe according to claim 1, wherein in a plan view, at least a part of the fin portion with a heat pipe overlaps the fin portion.

3. The fin portion has a root portion connected to the base portion and a tip portion farthest from the base portion, The heat sink with a heat pipe according to claim 1 or claim 2, wherein a distance between the heat pipe and the tip portion in the vertical direction is greater than a distance between the heat pipe and the root portion.

4. The heat sink with a heat pipe according to claim 1 or claim 2, wherein each of the plurality of fin portions is composed of a flat plate and arranged with a gap therebetween.

5. The heat sink with a heat pipe according to claim 1 or claim 2, wherein the heat pipe extends upward from an upper edge of the base portion and is bent toward the back surface side.

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