CN105094252A - Cooling module - Google Patents

Abstract

The invention provides a heat dissipation module which comprises a fan and a heat pipe. The fan includes an impeller, a motor, and a casing including an air outlet, a heat sink, a side wall portion, and a contact portion in thermal contact with the heat pipe, the casing being located in a region surrounded by the air outlet and the side wall portion in a plan view, at least a part of the contact portion being made of metal, the contact portion extending along an arrangement direction of the plurality of fins, overlapping the heat sink in a plan view, and having a heat diffusion member in thermal contact with the heat pipe and a region of the casing other than the contact portion.

Description

Cooling module

technical field

The invention relates to a heat dissipation module, which is preferably mounted on electronic equipment such as notebook computers.

Background technique

In small and high-performance electronic devices such as notebook computers, the CPU and the like inside the case generate a large amount of heat. Therefore, countermeasures against fever are important. As one method of countermeasures against heat generation, a blower fan is installed inside the casing to discharge heat.

For example, Japanese Laid-Open Publication No. 2009-150561 discloses a heat sink that adjusts heat dissipation by arranging a plurality of heat pipes with different heat generation values. The heat sink includes first heat pipes 3-1 and 3-2 composed of a plurality of heat pipes, a second heat pipe 5 composed of at least one heat pipe, and a plurality of cooling fins 6 arranged in parallel. One end of the main heat pipes in the first heat pipes 3-1, 3-2 made of multiple heat pipes is in thermal contact with all the heat sinks 6, and one end of the second heat pipe 5 made of at least one heat pipe is only in contact with the heat sink. Parts of the plurality of heat sinks 6 are in thermal contact.

However, in the heat sink disclosed in Japanese Laid-Open Publication No. 2009-150561, the heat pipe 13 is arranged and connected so as to traverse at least a part of the fin group. Cooling fin group is provided with cooling wind by fan 18, carries out forced cooling. At this time, the heat sink group is further transferred heat through the heat pipe 13 due to the heat dissipation. Through this action, heat dissipation of the heat source is achieved. That is, the higher the extent to which the cooling fin group is forcibly cooled by the fan 18, the higher the heat dissipation degree of the heat source. On the other hand, only a part of the fin group as the object of heat dissipation is in thermal contact with the heat pipe 13 , so the heat transfer efficiency from the heat pipe 13 is not high. That is, even if the heat sink group is forcibly cooled, the thermal resistance increases. In other words, the entire area of the heat sink group cannot be effectively utilized. In addition, the metal plate 19 connected to the heat pipe 13 is also the forced cooling object of the fan 18, and its contact with the heat pipe is only a part, and the heat transfer efficiency is not high.

Contents of the invention

The first exemplary aspect of the present invention is a heat dissipation module, which is characterized in that the heat dissipation module includes: a fan; and a heat pipe, one end of which is in thermal contact with a heat source, and the other end of which is in thermal contact with the fan, and the fan includes: an impeller having a plurality of blades circumferentially arranged around a central axis extending in an up-down direction; a motor rotating the impeller; and a casing housing the impeller and the motor, the casing including : an exhaust port, which penetrates radially outward; a radiator, which has a plurality of cooling fins arranged along the exhaust port; a side wall portion, which covers the outer periphery of the impeller; and a contact portion, which is connected to the The heat pipe is in thermal contact, the casing is located in the area surrounded by the exhaust port and the side wall when viewed from above, at least a part of the contact part is made of metal, and the contact part is along a plurality of The heat dissipation fins extend in an array direction and overlap with the heat sink in a plan view, and the heat dissipation module has a heat diffusion member that is in contact with the heat pipe and the area on the housing except for the contact portion. These two parts are in thermal contact.

According to the first exemplary aspect of the present invention, it is possible to reduce the thermal resistance from the heat source to the forced cooling object (radiator or housing) of the fan.

On the basis of the heat dissipation module described in the first aspect, an exemplary second aspect of the present invention is characterized in that:

The casing has a suction port, and the suction port is located in an area of the casing that faces the impeller in the axial direction, and the thermal diffusivity member is located on the outside of the suction port and closer to the area surrounded by the exhaust port and the side wall. inside position.

On the basis of the heat dissipation module described in the first aspect, an exemplary third aspect of the present invention is characterized in that:

The radially outer end of the heat diffusive component is in contact with the heat pipe, the radially inner end of the thermal diffusive component is in contact with the casing, and the radially outer end of the thermal diffusive component is located radially inner than the center of the heat pipe in the width direction.

On the basis of the heat dissipation module described in the third aspect, an exemplary fourth aspect of the present invention is characterized in that:

The outer surface in the radial direction of the heat diffusing member is in contact with the inner surface of the heat pipe, and the lower surface in the axial direction of the heat diffusing member is in contact with the upper surface of the casing.

On the basis of the heat dissipation module described in the third aspect, an exemplary fifth aspect of the present invention is characterized in that:

The axial thickness of the heat diffusing member is thinner than the axial thickness of the heat pipe.

On the basis of the heat dissipation module described in the first aspect, an exemplary sixth aspect of the present invention is characterized in that:

The heat pipe includes: an outer portion disposed radially outward with respect to an outer edge of the casing; and an inner portion disposed radially inner with respect to the outer edge of the casing, and in the inner portion, the radially outer region and the thermal diffusivity parts in contact.

On the basis of the heat dissipation module described in the sixth aspect, an exemplary seventh aspect of the present invention is characterized in that:

The inner portion has a bent portion that is in thermal contact with the heat diffusing member.

On the basis of the heat dissipation module described in the first aspect, an exemplary eighth aspect of the present invention is characterized in that:

The contact area of the heat diffusing member and the case is larger than the contact area of the heat diffusing member and the heat pipe.

On the basis of the heat dissipation module described in the first aspect, an exemplary ninth aspect of the present invention is characterized in that:

The heat diffusing member extends in a circumferential direction centering on the central axis on the radially outer side of the impeller.

On the basis of the heat dissipation module described in the first aspect, an exemplary tenth aspect of the present invention is characterized in that:

The heat diffusing member is located on the upstream side in the rotation direction from the heat pipe.

On the basis of the heat dissipation module described in the first aspect, an exemplary eleventh aspect of the present invention is characterized in that:

The heat diffusing member is a heat diffusing graphite sheet.

On the basis of the heat dissipation module described in any one of the first to eleventh aspects of the invention, the twelfth aspect of the present invention is characterized in that:

The casing includes an upper plate portion covering the upper side of the impeller.

On the basis of the heat dissipation module described in the twelfth aspect, an exemplary thirteenth aspect of the present invention is characterized in that:

The heat pipe is in thermal contact with the upper surface of the upper plate portion.

On the basis of the heat dissipation module described in any one of the first to eleventh aspects of the invention, the fourteenth aspect of the present invention is characterized in that:

The casing includes a lower plate portion that covers the lower side of the impeller and supports the motor.

Based on the heat dissipation module described in the fourteenth aspect, an exemplary fifteenth aspect of the present invention is characterized in that:

The heat pipes are in thermal contact with the lower surface of the lower plate portion.

On the basis of the heat dissipation module described in any one of the first to eleventh aspects of the invention, the sixteenth aspect of the present invention is characterized in that:

The heat pipe is in thermal contact with the side wall portion.

On the basis of the heat dissipation module described in any one of the first to eleventh aspects of the invention, the seventeenth aspect of the present invention is characterized in that:

The enclosure has:

an upper plate portion covering an upper side of the impeller; and

a lower plate portion covering the lower side of the impeller and supporting the motor,

The heat sink is positioned radially outward of the upper plate portion or the lower plate portion, and the heat pipe is in thermal contact with the heat sink.

The above and other features, elements, steps, features and advantages of the present invention can be more clearly understood from the following detailed description of preferred embodiments of the present invention with reference to the accompanying drawings.

Description of drawings

FIG. 1 is a cross-sectional view of a heat dissipation module according to a first embodiment.

Fig. 2 is a plan view of the heat dissipation module according to the first embodiment.

Fig. 3 is an enlarged view of the vicinity of the radiator according to the first embodiment.

Fig. 4 is a bottom view of the heat dissipation module according to the second embodiment.

5 is a perspective view of a heat dissipation module according to a third embodiment.

6 is a plan view of a heat dissipation module according to a fourth embodiment.

Detailed ways

In this specification, the axial upper side parallel to the central axis of the fan 1 of the cooling module 100 in FIG. 1 is simply referred to as "upper side", and the lower side is simply referred to as "lower side". The up-down direction in this manual does not indicate the up-down direction when assembled into the actual device. In addition, the circumferential direction around the central axis is simply referred to as "circumferential direction", and the radial direction around the central axis is simply referred to as "radial direction".

FIG. 1 is a cross-sectional view of a heat dissipation module 100 according to an exemplary first embodiment of the present invention. FIG. 2 is a plan view of the heat dissipation module 100 according to the first exemplary embodiment of the present invention. The heat dissipation module 100 includes a fan 1 that blows air in a predetermined direction, and a heat pipe 5 that has one end in thermal contact with a heat source 6 described below and the other end in thermal contact with the fan 1 . Fan 1 is a centrifugal fan. The heat dissipation module 100 is mounted, for example, in a notebook computer (hereinafter referred to as a “notebook PC”), and is used for cooling the devices inside the case of the notebook PC.

The fan 1 includes a motor 2 , a casing 3 and an impeller 4 . The impeller 4 has a plurality of blades 41 arranged in the circumferential direction around a central axis J1 extending in the vertical direction. The motor 2 rotates the impeller 4 around the central axis J1. The casing 3 accommodates the motor 2 and the impeller 4 .

The motor 2 is an outer rotor type. The motor 2 includes a stationary part 21 as a fixed assembly, a rotating part 22 as a rotating assembly, and a sleeve 23 as a bearing. The sleeve 23 has a substantially cylindrical shape centered on the central axis J1. The rotating part 22 is supported by the sleeve 23 so as to be rotatable about the central axis J1 relative to the stationary part 21 .

The stationary part 21 includes a stator 210 and a bearing holding part 24 . The bearing holder 24 accommodates the sleeve 23 . The bearing holding portion 24 has a substantially cylindrical shape centered on the central axis J1 and is formed of resin. The bearing holding portion 24 protrudes upward from substantially the center of a lower plate portion 32 described below. The bearing holding portion 24 is fixed in a hole portion (not shown) provided in the lower plate portion 32 . A lower end portion of the bearing holding portion 24 and a portion around a hole portion (not shown) are fastened by insert molding.

The stator 210 has a ring shape centered on the central axis J1 and is attached to the outer surface of the bearing holding portion 24 . Stator 210 includes a stator core (not shown) and a plurality of coils (not shown).

The rotating part 22 includes a shaft 221 , a rotor magnet 223 and a cup part 224 . The cup portion 224 has a covered substantially cylindrical shape centered on the central axis J1 and is opened downward. The shaft 221 is arranged around the central axis J1 and its upper end is fixed to the cup portion 224 . The rotor magnet 223 has a substantially cylindrical shape centered on the central axis J1 and is fixed to the inner surface of the cup portion 224 .

The shaft 221 is inserted into the sleeve 23 . The sleeve 23 is formed of an oil-impregnated porous metal body, and is inserted into and fixed to the bearing holding portion 24 . In addition, as a bearing mechanism, for example, a ball bearing may be used.

The casing 3 includes an upper plate portion 31 , a lower plate portion 32 , a side wall portion 33 and a heat sink 34 . The upper plate portion 31 covers the upper side of the impeller 4 . The lower plate portion 32 covers the lower side of the impeller 4 . The lower plate portion 32 supports the motor 2 . The side wall portion 33 covers the side of the impeller 4 . A wind tunnel (not shown) surrounding the impeller 4 is constituted by the upper plate portion 31 , the side wall portion 33 , and the lower plate portion 32 .

The upper plate portion 31 and the lower plate portion 32 are formed in a thin plate shape from metal such as aluminum alloy or stainless steel. The side wall portion 33 is made of aluminum alloy by die-casting or resin molding. The lower end portion of the side wall portion 33 and the peripheral edge portion of the lower plate portion 32 are fastened by screwing or the like. The upper plate portion 31 is fixed to the upper end portion of the side wall portion 33 by caulking or the like. The casing 3 has a suction port 35 located in a region of the casing 3 axially opposite to the impeller 4 . More specifically, the upper plate portion 31 has an air inlet 35 in a region facing the impeller 4 in the axial direction. The suction port 35 is located above the impeller 4 . An exhaust port 36 is formed on the side of the impeller 4 by the upper plate portion 31 , the side wall portion 33 and the lower plate portion 32 . The exhaust port 36 penetrates the casing 3 toward the radially outer side. A heat pipe 5 described below is installed on the upper surface of the upper plate portion 31 of the cabinet 3 , and the installation location is a contact portion 37 that is in thermal contact with the heat pipe 5 . At least a part of the contact portion 37 is formed of metal. Part of the contact portion 37 overlaps the heat sink 34 in plan view.

The heat sink 34 is composed of a plurality of fins 341 . The plurality of cooling fins 341 is formed by, for example, arranging a plurality of cooling fins in a substantially U-shape including an upper surface portion, a vertical surface portion, and a bottom surface portion, arranged side by side. With the fins formed by juxtaposition, the upper surface portion, the bottom surface portion, the vertical surface portion, and the adjacent vertical surface portions form a passage with a rectangular cross section. The wind generated by the fan 1 passes through the passage described above. The exhaust port 36 is constituted by the radial outer ends of the plurality of cooling fins 341 , the upper plate portion 31 and the lower plate portion 32 . In addition, the contact portion 37 of the casing 3 extends along the arrangement direction of the plurality of cooling fins 341 .

The impeller 4 includes a plurality of blades 41 . The plurality of blades 41 are arranged in a ring around the central axis J1 on the outside of the cup portion 224 . The radial inner end of each blade 41 is fixed to the outer surface of the cup portion 224 . By supplying the current to the stationary portion 21 , torque is generated between the rotor magnet 223 and the stator 210 around the central axis J1 . Thereby, the impeller 4 rotates together with the rotating part 22 centering on the central axis J1. By the rotation of the impeller 4 , air is sucked into the casing 3 through the air inlet 35 and sent out through the air outlet 36 .

FIG. 2 is a plan view of the heat dissipation module 100 according to the first exemplary embodiment of the present invention. The direction of rotation of the fan 1 is indicated in the figure by arrows. One end of the heat pipe 5 is in thermal contact with the heat source 6 and the other end is in thermal contact with the fan 1 . The heat pipe 5 has a flat cross section. The other end of the heat pipe 5 is installed on the upper surface of the upper plate portion 31 of the casing 3 along the exhaust port 36 . FIG. 3 is an enlarged view of the vicinity of the radiator 34 according to the first embodiment. As shown in FIG. 3 , the other end of the heat pipe 5 is in thermal contact with the radiator 34 via the upper plate portion 31 . In other words, the heat pipe 5 overlaps with the heat sink 34 in plan view. In addition, although one heat pipe is thermally connected in FIG. 2 , two heat pipes may be arranged in parallel with a predetermined gap in plan view. In addition, when the heat dissipation module 100 has two heat pipes, in plan view, one heat pipe may be in thermal contact with the area overlapping the radiator 34 on the upper plate portion 31, and the other heat pipe may be in thermal contact with the radiator 34 on the upper plate portion 31. 34 non-overlapping areas for thermal contact.

The heat diffusing member 7 is in thermal contact with both the heat pipe 5 and the region of the cabinet 3 except for the contact portion 37 . If the heat diffusing member 7 is in contact with the heat pipe 5 and the housing 3 in the area of the contact portion 37 , since the heat pipe 5 and the heat diffusing member 7 are overlapped in the axial direction, the axial thickness of the heat dissipation module 100 will increase. Therefore, the heat diffusing member 7 is in thermal contact with the side surface of the heat pipe 5 . In addition, the heat diffusing member 7 is in thermal contact with the upper plate portion 31 of the casing 3 . The upper plate portion 31 is formed with a contact portion 37 that is in thermal contact with the heat pipe 5 , and the heat diffusing member 7 is in thermal contact at a portion other than the contact portion 37 . In addition, the heat diffusing member 7 is a member that is particularly planar and promotes thermal diffusion, and it is possible to use metal sheets such as copper foil or plate-shaped copper and aluminum foil with thermal conductivity, graphite sheets, and high thermal conductivity ceramic sheets such as boron nitride sheets. and so on. In this embodiment, a heat diffusible graphite sheet is used. In addition, when the plate-shaped copper is fixed to the upper plate portion 31, it may be fixed by soldering.

By adopting such a structure, the heat generated by the heat source 6 is thermally transferred to the cabinet 3 via the heat pipe 5 . At this time, the heat pipe 5 is arranged in the vicinity of the exhaust port 36 so as to traverse the air flow path toward the exhaust port 36 . That is, the heat pipe 5 is arranged in an area where the wind speed is relatively high. In areas with higher wind speeds, the casing 3 is more forcibly cooled than in other areas. When the casing 3 is forcibly cooled, heat is further supplied to the casing 3 through the heat pipe 5, and the temperature of the heat source 6 decreases. The inside of the casing 3 becomes an air flow path, and is forcibly cooled regardless of the wind speed. On the other hand, the heat transferred from the heat pipe 5 only passes through the contact portion between the heat pipe 5 and the casing 3 , so the heat transfer efficiency is poor. The thermal diffusibility member 7 can ensure that the heat is transferred by the heat pipe 5 via the thermal diffusibility member 7 (thermal diffusibility graphite sheet) by thermally contacting the two parts of the heat pipe 5 and the area except the contact portion 37 on the casing 3. The path to the casing 3 enables heat to be transferred to more areas of the casing 3 that are forcibly cooled. That is, the thermal resistance from the heat source 6 to the case 3 can be reduced.

The arrangement of the heat diffusing member 7 will be described in detail. The heat diffusing member 7 is located outside the air inlet 35 and inside the area surrounded by the air outlet 36 and the side wall portion 33 . In addition, the heat diffusing member 7 is disposed at a position overlapping the air flow path in the axial direction. Since the effect of the air passage for forcibly cooling the cabinet 3 is higher than that of other regions, heat transfer from the heat source 6 can be efficiently performed through the heat diffusing member 7 . The more the thermal diffusing member 7 is used, the higher the cost, but on the other hand, the cooling performance is slightly improved. By employing this configuration, the thermal diffusivity member 7 can improve cooling characteristics with a minimum usage amount.

As shown in FIG. 2 , the radially outer end of the heat diffusing member 7 is in contact with the heat pipe 5 , and the radially inner end of the heat diffusing member 7 is in contact with the casing 3 . The radially outer end of the heat diffusing member 7 is located radially inward from the center of the heat pipe 5 in the width direction. In the present embodiment, the outer surface of the thermal diffusing member 7 contacts the inner surface of the heat pipe 5 in the radial direction, and the lower surface of the thermal diffusing member 7 contacts the upper surface of the casing 3 in the axial direction. When the cross-sectional shape of the heat pipe 5 is circular, the heat diffusing member 7 and the heat pipe 5 are only in contact with the outer surface of the heat pipe 5 on the inner surface of the heat diffusing member 7, and the heat pipe 5 will not be in contact with the heat diffusing member 7 on the axis. Overlap upwards. Therefore, the upper end of the heat diffusing member 7 is not positioned above the upper end of the heat pipe 5 . Therefore, it is possible to reduce the thickness of the heat dissipation module 100 . And, even when the cross-sectional shape of the heat pipe 5 is an ellipse, the heat diffusing member 7 and the heat pipe 5 are only in contact with the outer surface of the heat pipe 5 on the inner surface of the heat diffusing member 7, and the heat pipe 5 is not in contact with the heat diffusing member 7. The parts 7 overlap in the axial direction. Therefore, the upper end of the heat diffusing member 7 is not positioned above the upper end of the heat pipe 5 . Therefore, it is possible to reduce the thickness of the heat dissipation module 100 . When the cross-sectional shape of the heat pipe 5 is that the upper end surface and the lower end surface are flat, and the two side surfaces in the width direction are curved, the heat diffusing member 7 and the heat pipe 5 are only formed between the inner surface of the heat diffusing member 7 and the heat pipe 5. The outer surfaces are in contact, so that the heat pipe 5 does not axially overlap the heat diffusing member 7 . Even in this case, the upper end of the heat diffusing member 7 is not positioned above the upper end of the heat pipe 5 in the axial direction. Therefore, it is possible to reduce the thickness of the heat dissipation module 100 . That is, although the heat pipe 5 has various cross-sectional shapes, it is preferable that the radially outer end of the heat diffusing member 7 contacts the side surface of the other end of the heat pipe 5 . In addition, the radially outer end of the heat diffusing member 7 does not necessarily have to only be in contact with the side surfaces in the width direction of the heat pipe 5, and the radially outer end of the heat diffusing member 7 may be located above the heat pipe 5, and the radially outer end of the heat diffusing member 7 may be positioned above the heat pipe 5, and in the axial direction , the heat diffusing member 7 overlaps the heat pipe 5 .

The axial thickness of the heat diffusing member 7 is thinner than the axial thickness of the heat pipe 5 at the contact portion 37 . Recently, along with the thinning of electronic devices such as notebook computers, the heat dissipation module 100 is also required to be thinned. The cooling characteristics of the heat dissipation module 100 require a balance between the improvement of the heat transfer characteristics from the heat source 6 to the casing 3 and the improvement of the air volume characteristics of the fan 1 . The thicker the heat pipe 5 is, the higher the heat transfer characteristic is. On the other hand, if the heat pipe 5 is thickened, the axial dimension of the radiator 34 becomes smaller, and the heat dissipation area becomes smaller. Also, due to the arrangement of the heat pipes 5, the axial length of the blades 41 of the fan 1 becomes smaller, or the wind tunnel portion of the fan 1 becomes smaller. That is, the air volume of the fan 1 decreases. The heat pipe 5 needs to be filled with working fluid inside and has a certain thickness. On the other hand, the thermal diffusibility member 7 obtains heat conduction action due to the physical properties of the material, and facilitates thinning. By making the axial thickness of the heat pipe 5 thicker than that of the heat diffusing member 7 , heat can be efficiently transferred using the heat pipe 5 . That is, by preventing the heat diffusing member 7 from protruding from the heat pipe 5 in the axial direction, the heat pipe 5 can not interfere with the axial dimension of the fan 1 or can keep the obstruction to a minimum. Therefore, the heat pipe 5 can reduce adverse effects on the radiator 34 and the fan 1 , and can achieve thinning of the heat dissipation module 100 while balancing heat transfer characteristics and air volume characteristics to improve cooling characteristics.

The heat pipe 5 includes an outer portion 51 arranged radially outward with respect to the outer edge of the casing 3 and an inner portion 52 arranged radially inner with respect to the outer edge of the casing 3. In the inner portion 52, the radially outer The region is in contact with the heat diffusing member 7 . The radially outer region of the inner portion 52 of the heat pipe 5 corresponds to the high wind velocity region or the exhaust port 36 in the wind tunnel portion in the fan 1 . Therefore, since the cabinet 3 is a region that is easily forcibly cooled, the cooling efficiency of the heat source 6 is improved by bringing the heat diffusing member 7 into contact with the heat pipe 5 and the cabinet 3 in this region.

The inner portion 52 has a bent portion 53 that is in thermal contact with the heat diffusing member 7 . The structure of the heat pipe 5 is a hollow tube, and a capillary structure is disposed in the tube, and the tube is filled with working fluid. The heat pipe 5 has a straight rod shape at the time of initial processing, and is bent by processing to form a bent portion 53 . Through the bending process, the inner peripheral surface and the outer peripheral surface of the hollow tube are deformed together. As a result, the gap between the inner capillary structures at the bent portion 53 is narrowed. Therefore, it becomes difficult for the working fluid to move compared with other parts. That is, since the bent portion 53 acts as a heat transfer bottleneck, the other end side of the heat pipe 5 is in a state where heat is less likely to be transferred than the bent portion 53 . The bent portion 53 is radiated by being in contact with the heat diffusing member 7 . Therefore, the heat transfer efficiency is improved in the region of the heat pipe 5 on the one end side of the bent portion 53 .

The contact area of the heat diffusing member 7 and the cabinet 3 is larger than the contact area of the heat diffusing member 7 and the heat pipe 5 . The main purpose of the heat diffusing member 7 is to expand the heat transfer area to the casing 3 . The heat pipe 5 is circular or elliptical. On the other hand, the contact portion 37 of the heat pipe 5 on the casing 3 has no contact or is difficult to contact with the side of the heat pipe 5 . By being in contact with the heat pipe 5 and the case 3 respectively, the heat diffusing member 7 not only secures a heat transfer path from the heat pipe 5 but also enables heat transfer to a wide area of the case 3 . That is, heat is transferred to a wide area for forced cooling, and the thermal resistance from the heat source 6 to the casing 3 can be reduced.

The heat diffusing member 7 extends radially outside of the impeller 4 in the circumferential direction centering on the central axis J1. As the fan 1 rotates, the air flows outward in the radial direction, and the air flows in the direction of the vector sum of the tangential direction component of the blade 41 and the centrifugal direction component supplied to the air. These air flows flow in the circumferential direction inside the casing 3 . In addition, the radially outer side of the blade 41 becomes an air flow path, which is also affected by the centrifugal force, and the flow velocity of the radially outer flow path is faster than that of the inner flow path. The casing 3 is further forced to cool in areas of high flow velocity. Therefore, on the outside in the radial direction of the impeller 4, the heat diffusing member 7 is disposed so as to extend in the circumferential direction, so that heat can be transferred to a region to be further forcibly cooled.

The heat diffusing member 7 is located on the upstream side of the heat pipe 5 in the rotation direction. Since the air flow is heat-transferred by the heat pipe 5 , the temperature rises on the downstream side in the rotation direction of the heat pipe 5 . That is, the temperature of the air flow is lower on the upstream side in the rotation direction of the heat pipe 5 than on the downstream side. The heat diffusing member 7 transfers the heat from the downstream side of the rotation direction to the upstream side of the rotation direction, thereby enhancing the effect of forced cooling of the side with the lower temperature of the air flow. With this structure, the heat of the heat source 6 is efficiently absorbed. cool down.

FIG. 4 is a plan view of a heat dissipation module 100A according to a second exemplary embodiment of the present invention. The basic structure of the second embodiment is the same as that of the heat dissipation module 100 of the first embodiment. The description of the second embodiment is only a part different from the first embodiment. In the first embodiment, there is a contact portion 37 for bringing the other end of the heat pipe 5 into contact with the upper plate portion 31 of the cabinet 3. The lower surface of the lower plate portion 32A contacts a contact portion 37A along the exhaust port 36A. The other end of the heat pipe 5A is in thermal contact with the heat sink 34A through the lower plate portion 32A. In the second embodiment, the lower surface of the heat diffusing member 7A can be in contact with the upper surface of the heat pipe 5 in the region of the contact portion 37A. That is, the heat diffusing member 7A may overlap the heat pipe 5A in plan view. The position where the contact portion 37A is provided depends on the installation relationship between the electronic device and the heat dissipation module 100A or the arrangement of the heat source 6A, and the effect of this embodiment is the same as that of the first embodiment.

FIG. 5 is a perspective view of a heat dissipation module 100B according to a third exemplary embodiment of the present invention. The basic structure of the third embodiment is the same as that of the heat dissipation module 100 of the first embodiment. The description about the third embodiment is only the part different from the first embodiment. In this embodiment, the heat pipe 5B is in thermal contact with the side wall portion 33B. More specifically, the heat pipe 5B is in thermal contact with the radially outer peripheral surface of the side wall portion 33B. The inner peripheral surface of the side wall portion 33B is a surface constituting a wind tunnel portion, and is a region where the wind speed of the air flow generated by the rotation of the impeller (not shown) is relatively high. That is, the side wall portion 33B is easily forcibly cooled by the air flow generated by the rotation of the impeller (not shown). Therefore, the heat transfer efficiency from the heat source (not shown) to the casing 3B is good.

FIG. 6 is a plan view of a heat dissipation module 100C according to a fourth exemplary embodiment of the present invention. The basic structure of the fourth embodiment is the same as that of the heat dissipation module 100 of the first embodiment. The description about the fourth embodiment is only the part different from the first embodiment. The heat sink 34C is located radially outward of the upper plate portion 31C or the lower plate portion (figure omitted), and the heat pipe 5C is in thermal contact with the heat sink 34C. In the embodiment, the radiator 34C is located radially outward from the upper plate portion 31C. Although the heat sink 34C is arranged on the upper end surface of the lower plate portion, it is not shown here. As described above, the radiator 34C may be positioned radially outward from the lower plate portion. In addition, the heat sink 34C may be arranged radially outward from both the upper plate portion 31C and the lower plate portion. The heat sink 34C has a contact portion 37C that makes thermal contact with the heat pipe 5C. That is, the heat pipe 5C is in direct contact with the heat sink 34C. With this structure, the heat transferred by the heat pipe 5C is directly transferred to the radiator 34C without passing through the upper plate portion 31C or the lower plate portion. Therefore, the heat generated by the heat source 6C is efficiently transferred to the heat sink 34C, and the heat dissipation module 100C can exhibit high cooling performance.

In the present embodiment, the heat diffusing member 7C is in contact with the housing 3C except for the contact portion 37C, and is in contact with the heat pipe 5C. At this time, the contact portion 37C also includes the upper surface of the heat sink 34C, improving heat transfer from the heat source 6C to the cabinet 3C. When described in more detail, the contact portion 37C also includes a part of the upper surface of the upper plate portion 31C, and can improve heat transfer characteristics.

The centrifugal fan according to the present invention can be used for cooling devices inside the casings of notebook computers or desktop computers, cooling other devices, supplying air to various objects, and the like. Also, it can be used for other purposes.

In addition, various elements appearing in the above-described embodiments or modified examples can be appropriately combined within a range that does not cause contradiction.

From the preferred embodiments of the present invention described above, it is considered that modifications and changes that do not depart from the scope and spirit of the present invention will be obvious to those skilled in the art. The scope of the invention is therefore to be determined solely by the claims.

Claims (17)

1. A cooling module, the cooling module comprising: fans; and a heat pipe having one end in thermal contact with a heat source and the other end in thermal contact with said fan, The heat dissipation module is characterized in that, The fan includes: an impeller having a plurality of blades circumferentially arranged around a central axis extending in an up-down direction; a motor that rotates the impeller; and a casing housing the impeller and the motor, The casing includes: an exhaust port penetrating towards the radially outer side; a heat sink having a plurality of fins arranged along the exhaust port; a side wall portion covering the periphery of the impeller; and a contact portion that makes thermal contact with the heat pipe, The casing is located in an area surrounded by the exhaust port and the side wall when viewed from above, At least a part of the contact portion is made of metal, the contact portion extends along the arrangement direction of the plurality of heat sinks, and overlaps with the heat sink when viewed from above, The heat dissipating module has a heat diffusing member that is in thermal contact with both the heat pipe and a region of the housing other than the contact portion. 2. The heat dissipation module according to claim 1, characterized in that, The casing has a suction port, and the suction port is located in an area of the casing opposite to the impeller in the axial direction, The heat diffusing member is located outside of the intake port and inside of a region surrounded by the exhaust port and the side wall. 3. The heat dissipation module according to claim 1, characterized in that, The radially outer end of the heat diffusing member is in contact with the heat pipe, the radially inner end of the heat diffusing member is in contact with the casing, The radially outer end of the heat diffusing member is located radially inward of the center of the heat pipe in the width direction. 4. The heat dissipation module according to claim 3, characterized in that, The radially outer surface of the heat diffusing member is in contact with the inner surface of the heat pipe, and the axially lower surface of the heat diffusing member is in contact with the upper surface of the housing. 5. The heat dissipation module according to claim 3, characterized in that, The axial thickness of the heat diffusing member is thinner than the axial thickness of the heat pipe. 6. The heat dissipation module according to claim 1, characterized in that, The heat pipe includes: an outer portion arranged on a radially outer side with respect to an outer edge of the casing; and relative to the outer edge of the casing, it is disposed on the inner side in the radial direction, In the inner portion, a radially outer region is in contact with the heat diffusing member. 7. The heat dissipation module according to claim 6, characterized in that, The inner portion has a bent portion that is in thermal contact with the heat diffusing member. 8. The heat dissipation module according to claim 1, characterized in that, A contact area of the thermal diffusing member with the housing is larger than a contact area of the thermal diffusing member with the heat pipe. 9. The heat dissipation module according to claim 1, characterized in that, The heat diffusing member extends radially outside of the impeller in a circumferential direction centering on the central axis. 10. The heat dissipation module according to claim 1, characterized in that, The heat diffusing member is located upstream in the rotation direction of the heat pipe. 11. The heat dissipation module according to claim 1, characterized in that, The heat-diffusing member is a heat-diffusing graphite sheet. 12. The heat dissipation module according to any one of claims 1 to 11, characterized in that, The casing includes an upper plate portion covering an upper side of the impeller. 13. The heat dissipation module according to claim 12, characterized in that, The heat pipe is in thermal contact with the upper surface of the upper plate portion. 14. The heat dissipation module according to any one of claims 1 to 11, characterized in that, The casing includes a lower plate portion covering a lower side of the impeller and supporting the motor. 15. The heat dissipation module according to claim 14, characterized in that, The heat pipe is in thermal contact with the lower surface of the lower plate portion. 16. The heat dissipation module according to any one of claims 1 to 11, characterized in that, The heat pipe is in thermal contact with the side wall portion. 17. The heat dissipation module according to any one of claims 1 to 11, characterized in that, The enclosure has: an upper plate portion covering an upper side of the impeller; and a lower plate portion covering the lower side of the impeller and supporting the motor, The heat sink is located radially outward of the upper plate portion or the lower plate portion, and the heat pipe is in thermal contact with the heat sink.