JP6741993B2 - Heat dissipation device - Google Patents

Description

The present disclosure relates to a heat dissipation device that radiates heat from a heating element of an electronic device.

Conventionally, there is a heat dissipation device that cools a CPU (Central Processing Unit) of a personal computer or the like (see, for example, Patent Document 1). This heat dissipation device has a heat sink arranged on the CPU and a cooling fan arranged on the heat sink.

JP, 2014-183284, A

The heat dissipation device can improve the cooling performance by enlarging the heat sink and increasing the rotation speed of the fan.

However, there is a problem that if the heat sink is made large, the entire device becomes large, and if the number of rotations of the fan is increased, noise becomes large.

The non-limiting examples of the present disclosure contribute to the provision of a heat dissipation device having a small size and high cooling performance.

A heat dissipation device according to an aspect of the present disclosure includes a heat dissipation part that dissipates heat of a heat generating body, and a fan provided on a surface of the heat dissipation part opposite to a surface on which the heat generating body is located. The part is formed by stacking a plurality of plate-shaped heat dissipation plates, and a comb-shaped fin part extending radially in the in-plane direction is formed around each of the heat dissipation plates.

Note that these comprehensive or specific aspects may be realized by a system, a method, an integrated circuit, a computer program, or a recording medium, and any of the system, the apparatus, the method, the integrated circuit, the computer program, and the recording medium may be realized. It may be realized by any combination.

According to one aspect of the present disclosure, a small size and high cooling performance can be realized.

Further advantages and effects of one aspect of the present disclosure will be apparent from the specification and the drawings. Such advantages and/or effects are provided by the features described in several embodiments and in the specification and drawings, respectively, but not necessarily all to obtain one or more of the same features. There is no.

Perspective view showing an example of a heat dissipation device Side view showing an example of a heat dissipation device Sectional view of the heat dissipation device of FIG. Exploded perspective view showing an example of a heat dissipation device Perspective view showing an example of a heat sink Perspective view showing an example of a heat sink The figure explaining an example of the manufacturing method of a heat dissipation device. The figure explaining an example of the manufacturing method of a heat dissipation device. The figure explaining an example of the manufacturing method of a heat dissipation device. The figure explaining an example of the manufacturing method of a heat dissipation device. Perspective view showing a part of the heat sink Perspective view showing a part of the heat sink

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, more detailed description than necessary may be omitted. For example, detailed description of well-known matters and repeated description of substantially the same configuration may be omitted. This is for avoiding unnecessary redundancy in the following description and for facilitating understanding by those skilled in the art.

It should be noted that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the claimed subject matter by them.

Vehicles are equipped with various electronic devices. For example, an automobile has an ECU (Engine Control Unit), a HUD (Head-Up Display), an ADAS (Advanced Driver-Assistance Systems), a digital meter cluster, a drive circuit of an LED (Light Emitting Diode) of a headlamp, or a car navigation system. Equipped with electronic devices.

These electronic devices have a heating element such as a CPU or SOC (System-On-a-Chip). In order to suppress malfunction of electronic devices, heat dissipation of the CPU or SOC by the heat dissipation device is important.

Electronic devices mounted in automobiles are required to be small in size and quiet in some places, for example. For example, since the digital meter cluster is arranged in front of the driver, it is important to suppress the fan noise so that the driver does not hear the fan noise of the heat dissipation device. In other words, it is important for the heat dissipation device to be small in size and to be able to sufficiently dissipate heat from the heating element without rotating the fan at high speed.

FIG. 1 is a perspective view showing an example of the heat dissipation device 10. As shown in FIG. 1, the heat dissipation device 10 includes a heat dissipation unit 11, a frame 12, and a fan 13. The heat dissipation part 11, the frame 12, and the fan 13 are integrated. Hereinafter, the x, y, and z axes of the three axes shown in FIG. 1 are set for the heat dissipation device 10. Further, the +z axis direction is the upper side and the −z axis direction is the lower side.

The heat dissipation part 11 has, for example, a quadrangular prism shape. As will be described below, the heat dissipation unit 11 is configured by laminating a plurality of plate-shaped heat dissipation plates (for example, see the heat dissipation unit 11 and the heat dissipation plates 11a to 11f in FIG. 4).

The heat radiating section 11 is arranged on the upper surface of a heat generating element that generates heat (for example, see the heat radiating section 11 and the heat generating element 21 in FIG. 2 ). The heat radiating unit 11 radiates the heat generated from the heating element. The heat radiating section 11 and the heat generating element may be in contact with each other, or, for example, grease or the like is applied between the heat radiating section 11 and the heat generating element so that the heat of the heat generating element is smoothly transferred to the heat radiating section 11. May be. In the following, "contact" may include the case where grease or the like is applied between objects.

The frame 12 is provided on the surface of the heat dissipation portion 11 opposite to the surface on which the heating element is located. The periphery of the frame 12 has the same shape as the periphery of the heat dissipation portion 11, and has, for example, a quadrangular prism shape.

The fan 13 is provided in the frame 12. The fan 13 is provided in the frame 12 so that the rotation axis is located at the center of the frame 12. The fan 13 is rotated by a motor.

FIG. 2 is a side view showing an example of the heat dissipation device 10. 2, the same parts as those in FIG. 1 are designated by the same reference numerals. The heating element 21 is shown in FIG.

As shown in FIG. 2, the heat dissipation device 10 is arranged such that the lower surface of the heat dissipation portion 11 is located on the upper surface of the heating element 21. The heating element 21 is an electronic component that generates heat, such as a CPU or SOC. The heat of the heating element 21 is absorbed and radiated by the heat radiating portion 11. The frame 12 and the fan 13 housed in the frame 12 are provided on the surface of the heat dissipation portion 11 opposite to the surface on which the heating element 21 is located.

FIG. 3 is a cross-sectional view of the heat dissipation device 10 of FIG. 3, the same components as those in FIG. 1 are designated by the same reference numerals. The fan 13 is housed in the frame 12.

The fan 13 has a motor 13a and blades 13b. The motor 13a is, for example, a hydrodynamic bearing motor.

The blade 13b is connected to the rotating shaft of the motor 13a. The blade 13b is located above the heat dissipation unit 11. The blades 13b rotate as the rotation shaft of the motor 13a rotates. When the blades 13b rotate, the air above the fan 13 is sent to the heat dissipation unit 11. As a result, the heat radiating portion 11 is cooled, and the heating element is also cooled.

FIG. 4 is an exploded perspective view showing an example of the heat dissipation device 10. 4, the same parts as those in FIG. 1 are designated by the same reference numerals.

As shown in FIG. 4, the frame 12 has a cover 12a. The cover 12a has, for example, a circular opening for taking in air that cools the heat radiating unit 11 and the heating element. The diameter of the opening of the cover 12a may be, for example, the same as (including substantially the same as, hereinafter, the same) as the diameter of the fan 13, or may be larger than the diameter of the fan 13.

The heat dissipation part 11 has heat dissipation plates 11a to 11f. The heat sinks 11a to 11f are stacked. For example, grease or the like may be applied between the laminated heat dissipation plates 11a to 11f so that heat can be transferred smoothly.

The heat sinks 11a to 11f are rectangular plate-shaped members. The material of the heat sinks 11a to 11f is a material having high thermal conductivity, such as aluminum or copper. For example, the heat sinks 11a to 11f may be formed of A1050 or C1020 of Japanese Industrial Standard.

Further, the heat dissipation plates 11a to 11f may be laminated not only by one material but also by combining different materials. For example, the materials applied to the heat dissipation plates 11a to 11f may be alternated. Specifically, the heat sink 11a may be aluminum, the heat sink 11b may be copper, the heat sink 11c may be aluminum, the heat sink 11d may be copper, the heat sink 11e may be aluminum, and the heat sink 11f may be copper.

FIG. 5 is a perspective view showing an example of the heat dissipation plate 11a. As shown in FIG. 5, the heat dissipation plate 11a includes a core plate portion 31, extension plate portions 32a to 32d, and a fin portion 33.

The core plate portion 31 is a flat area and has a rectangular shape. The heating element is arranged on the core plate portion 31. In other words, the heating element is brought into contact with the core plate portion 31. The shape and size of the core plate portion 31 may be formed according to the shape and size of the heating element, for example.

The extending plate portions 32a to 32d are flat regions, and extend from four corners of the quadrangular core plate portion 31 in four directions outward (radially extending).

The fin portion 33 is formed around the core plate portion 31 and around the extension plate portions 32a to 32d. The fin portion 33 extends outward from the periphery of the core plate portion 31 and the periphery of the extension plate portions 32a to 32d in the in-plane direction (direction perpendicular to the normal to the heat dissipation plate 11a).

The fin portion 33 may be formed by pressing, for example. Further, the fin portion 33 may be formed by laser processing, for example. When the fin portion 33 is formed by laser processing, for example, a square flat plate is prepared, and a groove is formed from one side of the prepared flat plate to a side opposite to the side by the laser to form the fin portion 33. Form.

For example, a groove is formed by laser from the side indicated by arrow A11 in FIG. 5 toward the side indicated by arrow A12. The length of the groove is the same near the center of the side, and is shortened as it approaches the end of the side. This is performed on each side of the rectangular flat plate. Thus, the heat dissipation plate 11a having the core plate portion 31, the extension plate portions 32a to 32d, and the fin portion 33 as shown in FIG. 5 is formed.

The core plate portion 31 receives the heat of the heating element. The received heat is transmitted to the extension plate portions 32a to 32d. The heat received by the core plate portion 31 and the heat transmitted to the extension plate portions 32a to 32d are radiated by the fin portions 33 radially extending from the core plate portion 31 and the extension plate portions 32a to 32d. Then, the fin portion 33 is air-cooled by the fan 13.

Although the heat sink 11a has been described with reference to FIG. 5, the heat sink 11b also has the same shape and size as the heat sink 11a.

FIG. 6 is a perspective view showing an example of the heat dissipation plate 11f. 6, the same components as those in FIG. 5 are designated by the same reference numerals. The heat radiating plate 11f is different from the heat radiating plate 11a shown in FIG. 5 in that the heat radiating plate 11f has a circular opening 41 in the central portion (including a substantially central portion;

The opening 41 is formed at the center of the heat dissipation plate 11f. The extending plate portions 32a to 32d extend outward in four directions from the area around the opening 41.

The fan 41 and a part of the frame 12 are housed in the opening 41. For example, as shown by an arrow A1 in FIG. 3, the fan 13 and part of the frame 12 are housed in the opening 41.

The fin portion 33 shown in FIG. 6 may be formed by, for example, press working similarly to the fin portion 33 shown in FIG. Further, the fin portion 33 may be formed by laser processing, for example. For example, when the fin portion 33 is formed by laser processing, a quadrangular flat plate is prepared, and a groove is formed from one side of the prepared flat plate to a side opposite to that side by the laser to form the fin portion 33. Form.

Although FIG. 6 illustrates the heat dissipation plate 11f, the heat dissipation plates 11c to 11e also have the same shape and size as the heat dissipation plate 11f. Thus, the height of the heat dissipation device 10 can be suppressed by providing openings in the heat dissipation plates 11c to 11f and accommodating part of the frame 12 and the fan 13.

The heat sinks 11a to 11f are stacked. The heat dissipation plate 11a in contact with the heating element has a core plate part and an extension plate part, and the heat dissipation plate 11b arranged on the heat dissipation plate 11a also has a core plate part and an extension plate part. The core plate portion and the extension plate portion of the heat radiating plate 11b are laminated so as to overlap with the core plate portion and the extension plate portion of the heat radiating plate 11a in a plan view (viewed from the +z axis direction).

The heat radiating plates 11c to 11f arranged on the heat radiating plate 11b have an opening and an extending plate part. The opening of the heat dissipation plate 11c is stacked so as to overlap with the core plate part of the heat dissipation plate 11b, and the extension plate part of the heat dissipation plate 11c is laminated so as to overlap the extension plate part of the heat dissipation plate 11b. Further, the heat radiating plates 11c to 11f are laminated so that the respective opening portions and the extending plate portions overlap each other. That is, the extending plate portions of the heat radiating plates 11c to 11f having the openings are formed at positions overlapping the extending plate portions of the heat radiating plates 11a and 11b having the core plate portions in a plan view.

Thus, the heat received by the heat radiating plate 11a from the heating element is transmitted to the heat radiating plate 11b via the core plate portion and the extension plate portion. The heat transferred to the heat dissipation plate 11b is transferred to the respective extension plate parts of the heat dissipation plates 11c to 11f via the extension plate part of the heat dissipation plate 11b. Then, the heat transmitted to the heat radiating plates 11a to 11f is radiated by the fin portions included in each of the heat radiating plates 11a to 11f. The fins of the radiator plates 11a to 11f are air-cooled by the fan 13.

The heat dissipation plates 11a to 11f are stacked so that their fin portions also overlap each other in a plan view. Therefore, the heat received by the heat radiating plate 11a from the heat generating body is transmitted to each of the heat radiating plates 11b to 11f through the fin portion.

7A to 7D are diagrams illustrating an example of a method of manufacturing the heat dissipation device 10. 7A to 7D, the same parts as those in FIG. 4 are designated by the same reference numerals.

As shown in FIG. 7A, the cover 12a of the heat dissipation device 10, the fan 13, the frame 12, and the heat dissipation plates 11a to 11f are in a disjointed state. From the state shown in FIG. 7A, as shown in FIG. 7B, heat dissipation plates 11 a to 11 f are stacked, and the stacked heat dissipation plates 11 a to 11 f (heat dissipation part 11) are fixed to the frame 12.

The center of the bottom of the frame 12 has a recess for accommodating the bottom of the fan 13, as shown by an arrow A21 in FIG. 7A. The center of the bottom of the frame 12 is housed in an opening (see, for example, the opening 41 in FIG. 6) provided in the heat dissipation plates 11c to 11f (see, for example, the arrow A1 in FIG. 3).

The heat dissipation part 11 (heat dissipation plates 11a to 11f) may be fixed to the frame 12 with screws, for example. For example, the screw tip of the screw may be passed through a hole (not shown) provided in the heat dissipation portion 11 and inserted into the screw hole provided in the frame 12 to fix the heat dissipation portion 11 to the frame 12.

Further, the heat dissipation plates 11a to 11f may be fixed (integrated) by, for example, caulking. The heat radiating plates 11a to 11f fixed by crimping may be fixed to the frame 12 with screws.

In order to improve heat conduction, for example, grease or the like may be applied between the laminated heat dissipation plates 11a to 11f.

When the heat dissipation unit 11 and the frame 12 are integrated, the fan 13 is housed and fixed in the frame 12, as shown in FIG. 7C. The bottom portion of the fan 13 (the portion indicated by the arrow A22 in FIG. 7B) is housed in the recessed portion in the center of the bottom portion of the frame 12 (see, for example, arrow A1 in FIG. 3). In other words, the bottom of the fan 13 is housed in the openings of the heat radiating plates 11c to 11f together with the center of the bottom of the frame 12.

When the fan 13 is fixed to the frame 12, the cover 12a is fixed to the frame 12 as shown in FIG. 7D. For example, the cover 12a is fixed to the frame 12 with screws.

8A and 8B are perspective views showing a part of the heat dissipation unit 11. 8A and 8B, the same components as those in FIGS. 4 to 6 are designated by the same reference numerals.

As described above, the extension plate portions and the fin portions of the heat dissipation plates 11a to 11f have the same shape and are formed at the same positions. Therefore, when the heat radiating plates 11a to 11f are stacked, as shown in FIGS. 8A and 8B, the extending plate portions and the fin portions of the heat radiating plates 11a to 11f are aligned at the same position in the vertical direction.

The positions of the fins of the heat radiating plates 11a to 11f were changed and the amount of heat radiated by the heat radiating device 10 was examined. For example, the amount of heat radiated by the heat dissipation device 10 was examined by shifting the vertically adjacent fins little by little in the left-right direction. As a result, a good amount of heat dissipation was obtained when the positions of the fin portions of the heat dissipation plates 11a to 11f were aligned at the same position in the vertical direction (that is, the state shown in FIGS. 8A and 8B).

An arrow A31 in FIG. 8B indicates the width of the fin portion 33. The arrow A32 in FIG. 8B indicates the fin pitch. The ratio between the width of the fin portion 33 and the pitch of the fin portion 33 is “1:1”.

The ratio of the width of the fin portion 33 and the pitch of the fin portion 33 was changed, and the heat radiation amount of the heat dissipation device 10 was examined. As a result, when the ratio between the width of the fin portion 33 and the pitch of the fin portion 33 is "1:1", a good heat radiation amount was obtained.

Assuming that the heat dissipation device 10 is applied to, for example, an electronic device mounted in an automobile, the size (length×width) of the outer shape of the heat dissipation plate is set to “45 mm×45 mm”. Further, the thickness when the heat dissipation plates are stacked (thickness of the heat dissipation part) is set to “3 mm”. Further, the ratio of the width of the fin portion and the pitch of the fin portion is set to "1:1". The rotation speed of the fan is set to "3000 to 4000 r/min".

Under these conditions, the heat resistance of the heat dissipation device 10 was measured while changing the number of heat dissipation plates, the thickness, and the width of the fin portion. When the number of heat radiating plates was "6", the thickness was "0.5 mm", and the width of the fin portion was "1.0 mm", a thermal resistance of "2.6 K/W" was obtained.

The number of heat radiating plates to be stacked may be "2 to 16". The thickness of the heat sink may be “2.0 mm or less”. The width of the fin portion may be “0.5 mm to 2.5 mm”. The rotation speed of the fan may be "1500 r/min to 8000 r/min" or "1500 r/min or more". Even in this case, the target thermal resistance of "2.7 K/W" or less was obtained.

As described above, the heat dissipation device 10 includes the heat dissipation unit 11 that dissipates the heat of the heat generation unit 21, and the fan 13 provided on the surface of the heat dissipation unit 11 opposite to the surface on which the heat generation unit 21 is located. The heat dissipation part 11 is formed by laminating a plurality of plate-shaped heat dissipation plates 11a to 11f, and a comb-shaped fin part 33 extending radially in the in-plane direction is formed around each of the heat dissipation plates 11a to 11f. Has been done. As a result, the heat dissipation device 10 is small and can realize high cooling performance. Further, in the heat dissipation device 10, due to the high cooling capacity of the heat dissipation unit 11, it is not necessary to increase the rotation speed of the fan 13, and noise can be suppressed.

Further, among the heat dissipation plates 11a to 11f, the heat dissipation plates 11a and 11b have a core plate portion 31 that receives the heat of the heat generating body 21 and extension plate portions 32a to 32d that radially extend from the core plate portion 31. The fin portions 33 of the heat dissipation plates 11a and 11b extend radially from the core plate portion 31 and the extension plate portions 32a to 32d. As a result, the heat dissipation device 10 is small and can realize high cooling performance. Further, in the heat dissipation device 10, due to the high cooling capacity of the heat dissipation unit 11, it is not necessary to increase the rotation speed of the fan 13, and noise can be suppressed.

In addition, among the heat dissipation plates 11a to 11f, the heat dissipation plates 11c to 11f have an opening 41 for accommodating the fan 13 formed in the center thereof, and the extension plate 32a extending radially from the area around the opening 41. The fin portions 33 of the heat radiating plates 11c to 11f have 32d and extend radially from the area around the opening 41 and the extending plate portions 32a to 32d. As a result, the heat dissipation device 10 is small and can realize high cooling performance. Further, in the heat dissipation device 10, due to the high cooling capacity of the heat dissipation unit 11, it is not necessary to increase the rotation speed of the fan 13, and noise can be suppressed.

Further, the extension plate portions 32a to 32d of the heat dissipation plates 11c to 11f are formed at positions overlapping the extension plate portions 32a to 32d of the heat dissipation plates 11a and 11b in a plan view. As a result, the heat dissipation device 10 is small and can realize high cooling performance. Further, in the heat dissipation device 10, due to the high cooling capacity of the heat dissipation unit 11, it is not necessary to increase the rotation speed of the fan 13, and noise can be suppressed.

Further, the width of the fin portion 33 and the pitch of the fin portion 33 are substantially the same. As a result, the heat dissipation device 10 is small and can realize high cooling performance. Further, in the heat dissipation device 10, due to the high cooling capacity of the heat dissipation unit 11, it is not necessary to increase the rotation speed of the fan 13, and noise can be suppressed.

The pitch of the fin portions 33 is smaller than the thickness of the heat dissipation portion 11 (thickness of the laminated heat dissipation plates 11a to 11f). As a result, the heat dissipation device 10 is small and can realize high cooling performance. Further, in the heat dissipation device 10, due to the high cooling capacity of the heat dissipation unit 11, it is not necessary to increase the rotation speed of the fan 13, and noise can be suppressed. Further, by stacking the heat dissipation plates 11a to 11f, the pitch of the fin portions 33 can be easily made smaller than the thickness of the heat dissipation portions 11.

In the above description, the heat radiating plates 11a and 11b have the core plate portion and the heat radiating plates 11c to 11f have the openings, but the present invention is not limited to this. For example, if the fan 13 does not have a protruding portion (for example, a portion indicated by an arrow A22 in FIG. 7B) at the bottom, the heat dissipation plates 11c to 11f do not have an opening portion but have a core plate portion. May be.

Further, although the fan 13 takes in the upper air and sends it to the heat radiating portion 11, the present invention is not limited to this. For example, the fan 13 may take in the air on the heating element 21 side and send it out above the frame 12.

Further, the shape around the heat dissipation portion 11 (heat dissipation plates 11a to 11f) and the frame 12 is not limited to the illustrated shape. For example, it may be circular or polygonal. Further, the shape of the openings formed in the heat dissipation plates 11c to 11f is not limited to the illustrated shape. For example, it may be polygonal or the like. Further, the shape of the opening of the cover 12a is not limited to the illustrated shape. For example, it may be polygonal or the like.

The present disclosure is useful, for example, as a heat dissipation device for a heating element such as a CPU or SOC of an electronic device mounted on a vehicle.

DESCRIPTION OF SYMBOLS 10 Heat dissipation device 11 Heat dissipation part 11a-11f Heat dissipation plate 12 Frame 12a Cover 13 Fan 13a Motor 13b Blade 21 Heating element 31 Core plate part 32a-32d Extension plate part 33 Fin part 41 Opening part

Claims (5)

A heat radiating portion that radiates the heat of the heating element,
A fan provided on the surface of the heat dissipation portion opposite to the surface on which the heating element is located;
Equipped with
The heat dissipation portion is formed by stacking a plurality of plate-shaped heat dissipation plates,
Wherein the respective periphery of the heat radiating plate, a comb-like fin portion extending radially in the plane direction is made form,
The thickness of each of the heat sinks is 2 mm or less,
The first radiator plate of the radiator plates is
A heat receiving area for receiving the heat of the heating element,
A first extending region radially extending from the heat receiving region;
Have
The fin portion of the first heat dissipation plate extends radially from the heat receiving region and the first extension region,
The width of the pitch of the fin portion is 0.5 mm to 2.5 mm,
The second radiator plate of the radiator plates is
An opening for accommodating the fan is formed in the central portion, and has a second extending region radially extending from a region around the opening,
Wherein the fins of the second heat sink, beauty Shin radially from a region around the opening and the second extending region,
The first extension region and the second extension region have the same shape,
The fin portion of the first heat dissipation plate and the fin portion of the second heat dissipation plate have the same shape,
In the first heat dissipation plate and the second heat dissipation plate, the first extension region and the second extension region are aligned at the same position in a plan view, and the fins of the first heat dissipation plate are provided. And the fin portion of the second heat dissipation plate are stacked so as to be aligned at the same position in a plan view.
Heat dissipation device. The number of the first heat radiating plate and the number of the second heat radiating plate are determined according to the height of the protrusion on the bottom surface of the fan.
The heat dissipation device according to claim 1. The width of the fin portion and the pitch of the fin portion are substantially the same,
The heat dissipation device according to claim 1 or 2. The fin portion pitch is smaller than the thickness of the heat dissipation portion,
The heat dissipation device according to any one of claims 1 to 3. Part of the plurality of heat sinks is formed of a material different from other heat sinks,
The heat dissipation device according to any one of claims 1 to 4.

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