Cooling module and electronic device

Abstract

To improve cooling performance.SOLUTION: A cooling module mounted on an electronic device, the cooling module comprising: a heat pipe; a first heat sink including a plurality of first fins between which air flows, the first heat sink being connected to the heat pipe; and a fan including a discharge port, the discharge port being disposed to face the first heat sink, the fan includes a fan housing provided with the discharge port on one side surface, an impeller configured to rotate in the fan housing, a main flow path provided around the impeller in the fan housing, a sub-flow path branched from the main flow path in the fan housing and partitioned from the main flow path by a partition wall, and a second heat sink provided in the sub-flow path and thermally connected to a position different from a first connection portion of the heat pipe to the first heat sink.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a cooling module equipped with a fan and an electronic device equipped with the cooling module. [Background technology]

[0002] Electronic devices such as notebook PCs are equipped with a heat-generating element such as a CPU. Such electronic devices are equipped with a cooling module inside the housing, which absorbs heat generated by the heat-generating element and dissipates it to the outside. For example, Patent Document 1 discloses a configuration in which a heat pipe connects the CPU, which is a heat-generating element, to a heat sink placed opposite the outlet of a fan. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7097477 Summary of the Invention [Problem to be solved by the invention]

[0004] The heat sink has a plurality of fins arranged in parallel at equal intervals along the width direction of the outlet of the fan. Air discharged from the outlet cools the heat sink by passing through the gaps between the fins.

[0005] However, the space inside the housing of such electronic devices is limited due to the need to make the housing thinner and more compact. This makes it difficult to install a large heat sink that is large enough to accommodate the fan's airflow, and it may not be possible to ensure sufficient heat exchange performance. If the heat sink does not dissipate heat sufficiently, the cooling capacity of the cooling module will be limited, which can lead to a decrease in performance of the CPU, etc.

[0006] The present invention has been made in consideration of the above-mentioned problems of the conventional technology, and has an object to provide a cooling module that can improve cooling performance and an electronic device equipped with the cooling module. [Means for solving the problem]

[0007] A cooling module according to a first aspect of the present invention is a cooling module mounted on an electronic device, and comprises: a heat pipe; a first heat sink connected to the heat pipe and having a plurality of first fins through which air flows between them; and a fan having an outlet that is positioned opposite the first heat sink, wherein the fan comprises a fan housing having the outlet on one side thereof, an impeller that rotates within the fan housing, a main flow path arranged around the impeller within the fan housing, a sub-flow path that branches off from the main flow path within the fan housing and is separated from the main flow path by a partition wall, and a second heat sink that is arranged in the sub-flow path and thermally connected to a position different from the first connection part of the heat pipe to the first heat sink.

[0008] An electronic device according to a second aspect of the present invention comprises a cooling module having a housing, a heat generating element provided within the housing, a first heat sink having a plurality of first fins through which air flows between them, a fan having an outlet arranged opposite the first heat sink, and a heat pipe having one end thermally connected to the heat generating element and the other end connected to the first heat sink, wherein the fan has a fan housing having the outlet provided on one side, an impeller rotating within the fan housing, a main flow path provided around the impeller within the fan housing, a sub-flow path branching from the main flow path within the fan housing and separated from the main flow path by a partition wall, and a second heat sink provided in the sub-flow path and thermally connected to a position different from the first connection part of the heat pipe to the first heat sink. [Effects of the Invention]

[0009] According to the above aspect of the present invention, the cooling performance can be improved. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic plan view of an electronic device according to an embodiment, viewed from above. [Figure 2] FIG. 2 is a plan view schematically showing the internal structure of the housing. [Figure 3] FIG. 3 is a schematic configuration diagram of the cooling module as viewed from the bottom side. [Figure 4] FIG. 4 is a schematic configuration diagram of the cooling module shown in FIG. 3 as viewed from above. [Figure 5] FIG. 5 is a perspective view of the fan of the cooling module and its surroundings. [Figure 6] FIG. 6 is an exploded perspective view of the fan and its surroundings shown in FIG. [Figure 7] FIG. 7 is a schematic plan cross-sectional view of the fan of the cooling module and its surrounding area. [Figure 8] FIG. 8 is a schematic plan cross-sectional view of a fan and its surroundings of a cooling module according to a first modified example. [Figure 9] FIG. 9 is an exploded perspective view of a fan and its surroundings of a cooling module according to a second modified example. [Figure 10] FIG. 10 is a schematic plan cross-sectional view of a fan and its surroundings in a cooling module according to a third modified example. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cooling module and an electronic device according to preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0012] FIG. 1 is a schematic plan view of an electronic device 10 according to one embodiment, viewed from above. As shown in FIG. 1, the electronic device 10 according to this embodiment is a clamshell notebook PC. The electronic device 10 has a configuration in which a cover 11 and a housing 12 are connected by a hinge 14 so that they can rotate relative to each other. In this embodiment, the electronic device 10 is a notebook PC, but the electronic device may be other than a notebook PC, such as a tablet PC, a smartphone, or a portable game console.

[0013] The cover 11 is a thin, flat, box-shaped housing. The cover 11 is equipped with a display 16. The display 16 is, for example, an organic EL display or a liquid crystal display.

[0014] The housing 12 is a thin, flat box. A keyboard device 18 and a touchpad 19 face the top surface (surface 12a) of the housing 12. Hereinafter, the housing 12 and each of the components mounted thereon will be described based on the posture of an operator operating the keyboard device 18, with the width direction (left and right) of the housing 12 referred to as the X1 and X2 directions, the depth direction (front and back) of the housing 12 referred to as the Y1 and Y2 directions, and the thickness direction (top and bottom) of the housing 12 referred to as the Z1 and Z2 directions. The X1 and X2 directions may be collectively referred to as the X direction, and the Y1, Y2 directions and the Z1, Z2 directions may similarly be referred to as the Y direction and the Z direction. These directions are defined for convenience of explanation and may naturally change depending on the usage state or installation posture of the electronic device 10, etc.

[0015] The housing 12 is composed of a housing member 20 that forms the top surface and four peripheral side surfaces, and a cover material 21 that forms the bottom surface. The housing member 20 is formed by forming standing walls 20B on the four peripheral edges of a cover plate 20A that forms the surface 12a of the housing 12. Therefore, the housing member 20 has a roughly bathtub shape with an open bottom surface. The cover material 21 has a roughly flat plate shape and serves as a lid that closes the bottom opening of the housing member 20. The housing member 20 and the cover material 21 are overlapped in the thickness direction and are detachably connected to each other. The standing walls 20B may be formed on the cover material 21. In this case, the housing member 20 may be composed of only the cover plate 20A.

[0016] The hinge 14 is installed in a recessed hinge placement groove 12b formed in the rear edge of the housing 12, and connects the housing 12 and the cover 11. The hinge 14 has a structure in which, for example, hinge shafts serving as rotation axes are supported at both longitudinal ends of the hinge housing 14a. The hinge 14 of this embodiment is configured in a so-called one-bar shape, with the hinge housing 14a extending along the longitudinal direction of the hinge placement groove 12b. The hinge 14 descends diagonally rearward while the hinge housing 14b rotates integrally with the cover 11. The hinge 14 has a structure that increases the rotation angle of the cover 11 in this way, a so-called drop-down structure. The hinge 14 may have a structure other than that described above.

[0017] Fig. 2 is a plan view schematically showing the internal structure of the housing 12. Fig. 2 is a view of the inside of the housing member 20 from the bottom side with the cover material 21 removed.

[0018] 2, the housing 12 accommodates a cooling module 24, a motherboard 25, and a battery device 26. The housing 12 also accommodates various electronic components, mechanical components, and the like.

[0019] The motherboard (substrate) 25 is a circuit board that serves as the main board of the electronic device 10. The motherboard 25 is disposed near the Y2 side of the housing 12 and extends in the X direction. The battery device 26 is a rechargeable battery that serves as the power source for the electronic device 10. The battery device 26 is disposed near the Y1 side of the motherboard 25 and extends in the X direction.

[0020] The motherboard 25 of this embodiment is equipped with a CPU (Central Processing Unit) 25a. In addition to the CPU 25a, the motherboard 25 can also be equipped with various electronic components such as a GPU (Graphics Processing Unit), memory, and a communication module.

[0021] The motherboard 25 has, for example, an upper surface (first surface 25A) that serves as an attachment surface to the housing member 20, and a lower surface (second surface 25B) that serves as a mounting surface for the CPU 25a and the like.

[0022] Next, an example of the configuration of the cooling module 24 will be described.

[0023] The CPU 25a is a heat generating element that generates the largest amount of heat among the electronic components mounted in the housing 12. The cooling module 24 can absorb and diffuse the heat generated by the CPU 25a and discharge it to the outside of the housing 12. The cooling module 24 may be configured to cool a heat generating element other than the CPU 25a, such as a GPU.

[0024] Fig. 3 is a schematic diagram of the cooling module 24 as viewed from the bottom side (Z2 side). Fig. 4 is a schematic diagram of the cooling module 24 as viewed from the top side (Z1 side) shown in Fig. 3.

[0025] As shown in FIGS. 2 to 4, the cooling module 24 of this embodiment includes a heat pipe 28, a first heat sink 30, a fan 32, and a metal plate .

[0026] The heat pipe 28 is a pipe-type heat transport device. The heat pipe 28 is made by flattening a metal pipe to form an elliptical cross section, and sealing a working fluid in the sealed space inside. Examples of the working fluid include water, alternative chlorofluorocarbons, acetone, and butane.

[0027] One end 28a of the heat pipe 28 serves as a heat receiving portion that is thermally connected to the CPU 25a. A heat receiving plate 36 made of, for example, a copper plate can be interposed between the one end 28a and the CPU 25a. The other end 28b of the heat pipe 28 serves as a heat dissipation portion that is thermally connected to the first heat sink 30. The other end 28b is fixed to the surface (Z2 side) of the first heat sink 30 by, for example, soldering. This allows the heat pipe 28 to efficiently receive heat from the CPU 25a and transport it to the first heat sink 30. The heat pipe 28 of this embodiment also exchanges heat with a second heat sink 54 installed within the fan 32 (see FIG. 5), as will be described in detail below.

[0028] The first heat sink 30 has a structure in which multiple fins (first fins) 30a formed from thin metal plates are arranged at equal intervals in the longitudinal direction (Y direction). Each fin 30a stands in the Z direction and extends in the X direction. A gap is formed between adjacent fins 30a, 30a, through which air sent from the fan 32 passes. Each fin 30a is formed of a metal with high thermal conductivity, such as aluminum or copper. The first heat sink 30 is disposed opposite an outlet 42 provided on a side surface 40a on the Y2 side of the fan 32. The housing 12 has an exhaust port 38 formed in the standing wall 20B on the X1 side facing the first heat sink 30.

[0029] The fan 32 is a centrifugal fan that rotates an impeller 41 housed in a fan housing 40 using a motor (see FIG. 7). The fan 32 has an outlet 42 on a side surface (one side surface) 40a on the X1 side of the fan housing 40. The outlet 42 is adjacent to and faces the first heat sink 30. The fan 32 has an intake 43 on at least the Z2-side end surface 40c of the upper and lower end surfaces 40b, 40c of the fan housing 40 facing the Z direction. The intake 43 can also be provided on the Z1-side end surface 40b. The end surfaces 40b, 40c are surfaces that are perpendicular to the side surface 40a and perpendicular to the axial direction of the rotation shaft of the impeller 41. The intake 43 draws in outside air from an intake port formed, for example, in the cover material 21 that forms the bottom surface (lower surface) of the housing 12.

[0030] The metal plate 34 is a thin plate made of a metal with high thermal conductivity, such as copper or aluminum. The metal plate 34 is positioned adjacent to the X2 side of the fan 32 and covers the second surface 25B of the motherboard 25. This allows the metal plate 34 to function as a heat diffusion member that absorbs and diffuses heat from the CPU 25a and other heat-generating elements mounted on the motherboard 25. The metal plate 34 has a cutout 34a that allows, for example, a heat pipe 28 to pass through in the thickness direction (Z direction). One end 28a of the heat pipe 28 is connected to the heat receiving plate 36 through the cutout 34a. A strip-shaped leaf spring 46 extending in the X direction is attached to the periphery of the portion where the metal plate 34 vertically overlaps the heat receiving plate 36. A pair of leaf springs 46 are provided in the Y direction. The leaf spring 46 is a component that presses the heat receiving plate 36 and one end 28a of the heat pipe 28 connected thereto against the CPU 25a.

[0031] Next, a more specific example of the configuration of the fan 32 and its surroundings will be described.

[0032] Fig. 5 is a perspective view of the fan 32 of the cooling module 24 and its surrounding area. Fig. 6 is an exploded perspective view of the fan 32 and its surrounding area shown in Fig. 5. The impeller 41 is not shown in Figs. 5 and 6. Fig. 5 shows an exploded view of the cover plate 49. Fig. 7 is a schematic plan cross-sectional view of the fan 32 of the cooling module 24 and its surrounding area. The air inlet 43 is not shown in Fig. 7.

[0033] As shown in FIGS. 5 to 7, the fan housing 40 has a sidewall member that forms the outer peripheral side surface, and cover plates 49 and that close openings on the top and bottom surfaces of the sidewall member .

[0034] The sidewall member 48 is a thin, plate-like member made of, for example, metal or resin and curved in a generally C-shape. The sidewall member 48 surrounds the outer periphery of the fan housing 40 except for the side surface 40a which becomes the outlet 42. The cover plates 49, 50 are thin, plate-like members made of, for example, metal such as stainless steel. The cover plate 49 is a lid that closes the opening on the Z1 side of the sidewall member 48 and forms the end surface 40b. The cover plate 50 is a lid that closes the opening on the Z2 side of the sidewall member 48 and forms the end surface 40c. The suction port 43 is formed in the cover plate 50.

[0035] As shown in FIG. 7, a main flow path 51 and a sub-flow path 52 are provided inside the fan housing 40.

[0036] The main flow path 51 is an air flow path provided around the impeller 41. The main flow path 51 corresponds to a flow path provided inside a general centrifugal fan. The impeller 41 rotates counterclockwise in FIG. 7. The arrows indicated by dashed dotted lines in FIG. 7 schematically show the air flow. The sidewall member 48 has a tongue portion 48a protruding from the inner circumferential surface on the side opposite the sub-flow path 52 (Y1 side). The main flow path 51 is a flow path that circulates external air A1 introduced from the suction port 43 from the vicinity of the tongue portion 48a at the most upstream position to the discharge port 42 at the most downstream position. The air A1 is finally discharged to the outside from the discharge port 42. The tongue portion 48a is not shown in FIGS. 5 and 6, and the same is true in FIG. 9.

[0037] The sub-flow passage 52 is an air passage that branches off from the main flow passage 51 inside the fan housing 40 and is separated from the main flow passage 51 by a partition wall 52a. The sub-flow passage 52 is formed between the partition wall 52a and an inner circumferential surface 48b of the side wall member 48 on the opposite side (Y2 side) from the tongue portion 48a. The discharge port 42 extends in the Y direction so as to straddle from the main flow passage 51 to the sub-flow passage 52, and the first heat sink 30 also extends in the Y direction. The sub-flow passage 52 may have a branch port (inlet) 52b that opens to a position upstream of the discharge port 42 in the flow direction of air A2 in the main flow passage 51. The outlet of the sub-flow passage 52 is the discharge port 42. The partition wall 52a is provided to protrude from the discharge port 42 in the direction opposite to the flow direction of air A1 in the main flow passage 51 (approximately the X1 direction). A tip 52a1 of the partition wall 52a forms one edge of the branch port 52b. That is, the branch port 52b of the sub-flow passage 52 is a gap formed between the tip 52a1 and the inner circumferential surface of the side wall member 48 located opposite the tip 52a1.

[0038] The sub-flow path 52 extends from the branch port 52b toward the discharge port 42 along the side surface 40d of the fan housing 40 that forms the inner circumferential surface 48b. As a result, the sub-flow path 52 allows a portion of the air A1 introduced from the branch port 52b (air A2) to flow to the discharge port 42 and be discharged to the outside from the discharge port 42. In other words, the sub-flow path 52 is a duct flow path that bypasses the main flow path 51 within the fan housing 40.

[0039] The sub-flow passage 52 is provided with a second heat sink 54 .

[0040] The second heat sink 54 is a component that exchanges heat between the air A2 flowing through the sub-flow path 52 and the heat pipe 28. The second heat sink 54 has a structure in which multiple fins (second fins) 54a formed from thin metal plates are arranged. In this embodiment, the second heat sink 54 has two fins 54a. Each fin 54a stands in the Z direction and extends along the flow direction of the air A2 in the sub-flow path 52. A gap is formed between the fins 54a, allowing the air A2 sent from the fan 32 to pass through. A gap is also formed between the fin 54a on the Y2 side and the inner circumferential surface 48b allowing the air A2 to pass through. The number of fins 54a may be one, or three or more. In the configuration example shown in FIG. 7, one fin 54a of the second heat sink 54 forms the partition wall 52a. In other words, the partition wall 52a is formed by the fin 54a.

[0041] In the second heat sink 54 of this embodiment, one end surface (the Z2 side end surface) of the two fins 54a, 54a can be integrally formed with the bottom plate 54b. That is, the second heat sink 54 can be formed from a sheet metal member having a trough shape with a generally U-shaped cross section. This allows the second heat sink 54 to be easily fixed to the inner surface 50b of the cover plate 50 via the bottom plate 54b. The second heat sink 54 is fixed to the inner surface 50b by, for example, soldering. The fins 54a and the bottom plate 54b are formed from a metal with high thermal conductivity, such as aluminum or copper.

[0042] The second heat sink 54 is thermally connected to the heat pipe 28. The heat pipe 28 is thermally connected to the second heat sink 54 at a location different from the other end 28b, which is the connection portion to the first heat sink 30. Hereinafter, the other end 28b may be referred to as the "first connection portion 28b." The heat pipe 28 bends from the first connection portion 28b, which extends in the Y direction, to the X2 direction, and the portion extending substantially in the X direction along the side surface 40d is arranged to overlap the sub-flow passage 52 vertically. The heat pipe 28 is connected to the outer surface (end surface 40c) of the cover plate 50, which closes one side (Z2-side opening) of the sub-flow passage 52. This thermally connects the heat pipe 28 to the second heat sink 54 via the cover plate 50. The heat pipe 28 is fixed to the outer surface of the cover plate 50 by, for example, soldering. Hereinafter, the portion of the heat pipe 28 connected to the end surface 40c, i.e., the portion thermally connected to the second heat sink 54, will be referred to as the "second connection portion 28c."

[0043] The cover plate 50 may have a step 50a at the portion where the second connection portion 28c is connected (see FIGS. 5 and 6). The step 50a is a surface where the cover plate 50 is lowered by one step toward the inner surface 50b (Z1 side). The step 50a reduces the thickness of the fan housing 40, which would otherwise increase due to the stacking of the heat pipes 28.

[0044] 7, in the cooling module 24, the pitch P2 between the fins 54a, 54a of the second heat sink 54 can be larger than the pitch P1 between the fins 30a, 30a of the first heat sink 30. The fins 54a of the second heat sink 54 can have a length along the air flow direction longer than the fins 30a of the first heat sink 30.

[0045] Next, the cooling action of the cooling module 24 will be described.

[0046] In the electronic device 10, heat generated by a heat generating element such as the CPU 25a is absorbed at one end 28a of the heat pipe 28 and transported with high efficiency toward the other end 28b. The heat transported through the heat pipe 28 is transferred to the second heat sink 54 at the second connecting portion 28c, and then to the first heat sink 30 at the first connecting portion 28b.

[0047] The fan 32 draws in outside air through the air inlet 43 and discharges it to the air outlet 42 by the rotation of the impeller 41. The air A1 flowing through the main flow path 51 passes through the air outlet 42 and the first heat sink 30. At that time, the air A1 absorbs heat transferred from the first connection portion 28b to the first heat sink 30, and is discharged to the outside of the housing 12 through the air outlet 38.

[0048] A portion of the air A1 flows from the branch port 52b into the sub-flow path 52. The air A2 flowing through the sub-flow path 52 passes through the second heat sink 54. At this time, the air A2 absorbs heat transferred from the second connection portion 28c to the second heat sink 54, and passes through the outlet port 42 and the exhaust port 38 to be discharged to the outside of the housing 12. Note that the air A2 that has passed through the outlet port 42 also passes through the first heat sink 30, and therefore can also cool the first heat sink 30.

[0049] As described above, the cooling module 24 of this embodiment includes a heat pipe 28, a first heat sink 30 having a plurality of fins 30a through which air flows between them and connected to the heat pipe 28, and a fan 32 having an outlet 42 disposed opposite the first heat sink 30. The fan 32 includes a fan housing 40, an impeller 41, a main flow path 51 provided around the impeller 41, and a sub-flow path 52 branching from the main flow path 51 and separated from the main flow path 51 by a partition wall 52a. A second heat sink 54 is provided in the sub-flow path 52 and thermally connected to a position (second connection portion 28c) of the heat pipe 28 different from the first connection portion 28b.

[0050] Therefore, the cooling module 24 can cool the first heat sink 30 with the air A1 flowing through the main flow path 51 of the fan 32. Here, the heat pipe 28 is thermally connected to the second heat sink 54 in the sub-flow path 52 at a position other than the first connection portion 28b to the first heat sink 30 (second connection portion 28c). Therefore, the cooling module 24 can further cool the second heat sink 54 with the air A2 flowing through the sub-flow path 52 of the fan 32. As a result, the cooling module 24 can receive heat transported by the heat pipe 28 at the multiple heat sinks 30, 54 and efficiently cool each of them with the air flowing through the flow paths 51, 52. This improves the cooling performance of the cooling module 24, and also improves the performance of the electronic device 10.

[0051] For example, a fan installed in a typical notebook PC discharges air from its outlet at a velocity of approximately 1 to 2 m / s toward a heat sink with fins approximately 1 cm long. Applying this to the electronic device 10 of this embodiment, air A1 discharged from the main flow path 51 through the outlet 42 passes through the first heat sink 30 at a velocity of approximately 1 to 2 m / s. Meanwhile, the size of the first heat sink 30 must fit within the internal space of the housing 12, which must be thin and compact. Therefore, the X-direction length and number of fins 30a of the first heat sink 30 are limited, making it difficult to ensure a size large enough to accommodate the wind velocity (air volume) of the fan 32. As a result, there is a limit to the improvement in the heat exchange efficiency between the air discharged from the outlet 42 and the first connecting portion 28b of the first heat sink 30. Therefore, it is difficult for the heat transported by the heat pipe 28 to be transferred to the first heat sink 30 via the first connecting portion 28b and to be sufficiently dissipated. In this regard, the cooling module 24 connects the second connection portion 28c, which is located at a different position from the first connection portion 28b to the first heat sink 30, to the second heat sink 54, and exchanges heat between this and the air A2 flowing through the sub-flow path 52. This increases the heat exchange efficiency and amount of heat exchanged between the heat pipe 28 and the heat sinks 30, 54 in the cooling module 24, improving cooling performance.

[0052] However, the sub-flow passage 52 has a larger ventilation resistance than the main flow passage 51 because the second heat sink 54 is installed therein. Normally, air (wind) flows around areas where there is ventilation resistance. For this reason, simply installing the second heat sink 54 in the main flow passage 51 would result in almost no air flowing through the second heat sink 54, and the heat exchange efficiency of the second heat sink 54 would not be improved. Therefore, the cooling module 24 separates the main flow passage 51 and the sub-flow passage 52 with a separator (partition wall 52a). As a result, the air A1 flowing through the main flow passage 51 is forcibly introduced into the sub-flow passage 52 from the branch port 52b upstream of the discharge port 42. As a result, the cooling module 24 can ensure the flow of air A2 through the sub-flow passage 52, thereby improving the heat exchange efficiency of the second heat sink 54.

[0053] In the cooling module 24, the pitch P2 between the fins 54a, 54a is preferably larger than the pitch P1 between the fins 30a, 30a. This allows the second heat sink 54 to reduce the ventilation resistance of the air A2 and promote the inflow of air into the sub-flow paths 52. The fins 54a of the second heat sink 54 preferably have a longer length along the air flow direction than the fins 30a of the first heat sink 30. This allows the second heat sink 54 to limit the number of fins 54a or increase the pitch P2 while still ensuring a sufficient heat exchange surface area with the air A2.

[0054] In the cooling module 24, the heat pipe 28 may have a first connection portion 28b extending along the longitudinal direction of the first heat sink 30 and a second connection portion 28c bending from the first connection portion 28b and extending along the side surface 40d intersecting with the side surface 40a of the fan housing 40, and arranged to overlap the sub-flow passage 52. That is, as shown in FIG. 2, the electronic device 10 of this embodiment has an exhaust port 38 in the vertical wall 20B of the side of the housing 12, and the first heat sink 30 faces this exhaust port 38. Therefore, when the heat pipe 28 travels from the CPU 25a located near the center of the housing 12 to the first heat sink 30, it must bend approximately 90 degrees between the second connection portion 28c and the first connection portion 28b. That is, if the second connection portion 28c is not overlapped with the fan housing 40, dead space will be created below the second connection portion 28c (on the Z1 side). The cooling module 24 is configured to utilize the dead space below the heat pipe 28 to exchange heat between the heat pipe 28 and the second heat sink 54. This allows the cooling module 24 to increase its cooling capacity without substantially increasing the space it occupies within the housing 12. It goes without saying that the connection structure between the second heat sink 54 and the second connection portion 28c can also be used for a heat pipe 28 that does not bend between the first connection portion 28b and the second connection portion 28c.

[0055] The partition wall 52a can be formed by the fins 54a of the second heat sink 54. In this case, it is not necessary to provide a separate partition wall 52a inside the fan housing 40, which reduces component costs and improves the manufacturing efficiency of the fan 32.

[0056] Figure 8 is a schematic plan cross-sectional view of the fan 32 and its surroundings of the cooling module 24A according to the first modified example. In Figure 8, the same reference symbols as those shown in Figures 1 to 7 indicate the same or similar configurations, and therefore, as they have the same or similar functions and effects, detailed descriptions thereof will be omitted, and the same applies hereinafter.

[0057] The cooling module 24A shown in FIG. 8 differs from the cooling module 24 described above in that a partition wall 52a separating the main flow path 51 and the sub-flow path 52 is formed on the inner surface 50b of the cover plate 50. That is, the partition wall 52a can be formed as a separate member from the fins 54a of the second heat sink 54. The partition wall 52a of the cooling module 24A can be formed from a plate made of a metal such as stainless steel, aluminum, or copper and fixed to the inner surface 50b of the cover plate 50. In this way, the cooling module 24A has the partition wall 52a formed as a separate member from the second heat sink 54. This allows the entire surfaces of, for example, two fins 54a to be disposed within the sub-flow path 52 and utilized for heat exchange with the air A2, thereby improving the heat exchange efficiency of the second heat sink 54.

[0058] In the cooling module 24 (24A) described above, the second heat sink 54 can be fixed to the inner surface 50b of the metal cover plate 50 by soldering or the like. The second connection portion 28c of the heat pipe 28 can be fixed to the outer surface (end surface 40c) of the cover plate by soldering or the like. This allows the second heat sink 54 to receive heat from the heat pipe 28 more efficiently.

[0059] FIG. 9 is an exploded perspective view of a fan 32 and its surroundings of a cooling module 24B according to a second modification.

[0060] As shown in FIG. 9 , the cooling module 24B of the fan 32 is configured by, for example, cutting a portion of the cover plate 50 that forms the step portion 50a and closing this portion with a heat pipe 28. That is, in the cooling module 24B, one side (the Z2-side opening) of the sub-flow passage 52 is closed with the heat pipe 28. In this case, the second heat sink 54 can be fixed to the surface of the heat pipe 28 by soldering or the like. This allows the second heat sink 54 to directly receive heat from the heat pipe 28, further improving the efficiency of heat transfer between them. In the cooling module 24B, by replacing a portion of the cover plate 50 with the heat pipe 28, the thickness of the portion where the heat pipe 28 overlaps the fan housing 40 can be reduced. On the other hand, the cooling module 24 (24A) described above closes one side of the sub-flow passage 52 with the cover plate 50, which has the advantages of easily ensuring airtightness of the sub-flow passage 52 and high manufacturing efficiency.

[0061] FIG. 10 is a schematic plan cross-sectional view of a fan 32 and its surroundings of a cooling module 24C according to a third modified example.

[0062] In the cooling modules 24 (24A, 24B) described above, the branch port 52b of the sub-flow passage 52 is provided slightly upstream of the discharge port 42, which is the most downstream of the main flow passage 51. In contrast, the cooling module 24C shown in FIG. 10 is configured such that the branch port 52b of the sub-flow passage 52 is provided near the most upstream side of the main flow passage 51. The sub-flow passage 52 of the cooling module 24C is located approximately 180 degrees opposite the direction of rotation of the impeller 41 compared to the sub-flow passages 52 of the cooling module 24, etc. The partition wall 52a of the cooling module 24C is provided to protrude from the discharge port 42 toward the flow direction (approximately the X2 direction) of the air A1 in the main flow passage 51.

[0063] In this cooling module 24C, too, the first heat sink 30 can be cooled by the air A1 flowing through the main flow path 51, and the second heat sink 54 can be cooled by the air A2 flowing through the sub-flow path 52. This improves the cooling performance of the cooling module 24, and also improves the performance of the electronic device 10.

[0064] In the cooling module 24C, a tongue (first tongue) 56 is provided at the base end of the partition wall 52a, protruding toward the main flow path 51. The cooling module 24C may further include a tongue (second tongue) 57 located on the opposite side of the tongue 56 across the branch port 52b, protruding from the inner circumferential surface of the side wall member 48 into the main flow path. The tongue 56, like the tongue 48a shown in FIG. 7, indicates the most upstream portion of the main flow path 51 and is a member that closes the gap around the impeller 41 to start compressing the air A1. On the other hand, the tongue 57 is a member that more reliably introduces the air A1 into the branch port 52b of the sub-flow path 52, which has high ventilation resistance. The tongue 57 may be omitted.

[0065] It should be noted that the present invention is not limited to the above-described embodiment, and can be freely modified without departing from the spirit of the present invention. [Explanation of symbols]

[0066] 10 Electronic equipment 12. Case 20A, 49, 50 Cover Plate 24, 24A~24C Cooling Module 25 Motherboard 25a CPU 28 Heat Pipe 30 First heat sink 30a,54a fins 32 fans 40 Fan enclosure 41 Impeller 42 Discharge port 48a,56,57 Tongue 51 Main Channel 52 Sub-channel 52a Partition wall 52b Branch 54 Second heat sink

Claims

1. A cooling module mounted on an electronic device, A heat pipe and a first heat sink having a plurality of first fins between which air flows and connected to the heat pipe; a fan having an outlet, the outlet being disposed opposite the first heat sink; Equipped with The fan is a fan housing having the outlet on one side thereof; an impeller rotating within the fan housing; a main flow path provided around the impeller in the fan housing; a sub-flow path branched from the main flow path within the fan housing and separated from the main flow path by a partition wall; a second heat sink provided in the sub-flow path and thermally connected to a position of the heat pipe different from a first connection portion of the heat pipe with respect to the first heat sink; have A cooling module characterized by:

2. 10. The cooling module of claim 1, The heat pipe is the first connection portion extending along the longitudinal direction of the first heat sink; a second connection portion bent from the first connection portion, extending along a side surface of the fan housing that intersects with the one side surface, and arranged to overlap the sub-flow passage in the vertical direction, thereby being thermally connected to the second heat sink; have A cooling module characterized by:

3. 3. The cooling module according to claim 1, the second heat sink has a plurality of second fins extending along a flow direction of air in the sub-flow passage and through which air flows; The pitch between the second fins of the second heat sink is greater than the pitch between the first fins of the first heat sink. A cooling module characterized by:

4. 4. The cooling module of claim 3, The second fin has a length along the air flow direction that is longer than that of the first fin. A cooling module characterized by:

5. 3. The cooling module according to claim 1, the second heat sink has a plurality of second fins extending along a flow direction of air in the sub-flow passage and through which air flows; The partition wall is formed by the second fin. A cooling module characterized by:

6. 3. The cooling module according to claim 1, The partition wall is provided so as to protrude from the discharge port in a direction opposite to the air flow direction in the main flow path, and a tip end of the partition wall forms one edge of a branch port of the sub-flow path from the main flow path. A cooling module characterized by:

7. 3. The cooling module according to claim 1, The partition wall is provided so as to protrude from the discharge port in the direction of air flow in the main flow path, and a tip end of the partition wall forms one edge of the branch port of the sub-flow path. A cooling module characterized by:

8. 8. The cooling module of claim 7, The fan is a first tongue portion provided so as to protrude from a base end of the partition wall into the main flow path; a second tongue portion located on the opposite side of the first tongue portion with the branch port interposed therebetween, the second tongue portion being provided so as to protrude from an inner circumferential surface of the fan housing into the main flow path; have A cooling module characterized by:

9. 3. The cooling module according to claim 1, the fan housing has a metal cover plate that closes one side of the sub-flow passage, the second heat sink is fixed to an inner surface of the cover plate; The heat pipe is connected to the outer surface of the cover plate. A cooling module characterized by:

10. 3. The cooling module according to claim 1, one side of the sub-flow passage of the fan housing is closed by the heat pipe, The second heat sink is fixed to the heat pipe. A cooling module characterized by:

11. An electronic device, The housing and a heating element provided within the housing; a cooling module including a first heat sink having a plurality of first fins between which air flows, a fan having an outlet disposed opposite to the first heat sink, and a heat pipe having one end thermally connected to the heat generating element and the other end connected to the first heat sink; Equipped with The fan is a fan housing having the outlet on one side thereof; an impeller rotating within the fan housing; a main flow path provided around the impeller in the fan housing; a sub-flow path branched from the main flow path within the fan housing and separated from the main flow path by a partition wall; a second heat sink provided in the sub-flow path and thermally connected to a position of the heat pipe different from a first connection portion of the heat pipe with respect to the first heat sink; have An electronic device characterized by:

12. 12. The electronic device according to claim 11, the housing has an exhaust port facing the first heat sink, The heat pipe is the first connection portion extending along the longitudinal direction of the first heat sink; a second connection portion bent from the first connection portion, extending along a side surface of the fan housing that intersects with the one side surface, and arranged to overlap the sub-flow passage in the vertical direction, thereby being thermally connected to the second heat sink; have An electronic device characterized by:

13. 13. The electronic device according to claim 11 or 12, the second heat sink has a plurality of second fins extending along a flow direction of air in the sub-flow passage and through which air flows; The pitch between the second fins of the second heat sink is greater than the pitch between the first fins of the first heat sink. An electronic device characterized by:

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