Electronic apparatus and heat sink

Abstract

To solve a problem in a heat radiation in a heat sink where a front surface area and a volume have to be increased in order to increase a heat radiation efficiency, but the size is limited, and thus, an improvement of the heat radiation efficiency from a different viewpoint is demanded.SOLUTION: An electronic apparatus that performs a heat exhaust by air cooling comprises: a heat generation element installed into a housing of the electronic apparatus; a heat sink provided to an upper part so as to be in contact with the heat generation element; and a fan blowing air to the heat sink, and exhausting the air to the outside of the housing. The heat sink includes a fin group formed of a plurality of fins arranged so as to be extended to an exhaust side where the air is exhausted to the outside of the housing from a suction side where the air is sucked by the fan. The plurality of fins are arranged in nearly parallel excluding a neighbor of an outlet of the exhaust side, and the plurality of fins passing a high temperature part that becomes a high temperature by the heat generation element are arranged so that an interval is expanded at the neighbor of the outlet of the exhaust side as compared with the other fins.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a cooling structure and a heat sink for an electronic device. [Background technology]

[0002] Conventionally, research has been conducted into improving the cooling efficiency of heat sinks in order to improve heat dissipation efficiency. For example, Patent Document 1 describes a heat sink that has a first region with high fin density and a second region with low fin density, thereby increasing the flow rate of air passing through the fins and improving thermal efficiency. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-110640 A Summary of the Invention [Problem to be solved by the invention]

[0004] In order to increase the heat dissipation efficiency of a heat sink, it is necessary to increase the surface area and volume. However, since there is a limit to the size, there is a need to improve the heat dissipation efficiency from a different perspective. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, the present invention is an electronic device that dissipates heat by air cooling, comprising a heat-generating element installed within a housing of the electronic device, a heat sink provided on the upper part so as to be in contact with the heat-generating element, and a fan that blows air into the heat sink and exhausts it outside the housing, wherein the heat sink has a fin group consisting of a plurality of fins arranged to extend from an intake side where air is drawn in by the fan to an exhaust side where air is exhausted outside the housing, the plurality of fins are arranged approximately parallel to each other except in the vicinity of the exhaust side outlet, and among the plurality of fins, the plurality of fins that pass through a high temperature portion that becomes hot due to the heat-generating element are arranged so that the spacing between them is wider near the exhaust side outlet than the other fins. Effect of the Invention

[0006] According to the present invention, it is possible to provide an electronic device and a heat sink with improved heat dissipation efficiency by changing the shape of the heat dissipation fins. [Brief description of the drawings]

[0007] [Figure 1] 1 is a perspective view of an in-vehicle device according to a first embodiment as viewed from above and to the right. [Diagram 2] 2 is a perspective view of the in-vehicle device according to the first embodiment as viewed from below and rear left. FIG. [Diagram 3] FIG. 2 is a perspective view of the housing with the up case and the front case removed. [Figure 4] 4 is a cross-sectional view taken along line IV-IV in FIG. 1. [Diagram 5] FIG. 4 is a top view of FIG. [Figure 6] 6 is an enlarged view of the vicinity of the exhaust side outlet of the heat sink in FIG. 5. FIG. [Figure 7] FIG. 11 is a perspective view of a housing according to a second embodiment with an up case and a front case removed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [1. Configuration of Electronic Device According to First Embodiment] A first embodiment of the present invention will be described below with reference to the drawings.

[0009] FIG. 1 is a perspective view of an in-vehicle device 1 according to the first embodiment as viewed from above and to the right. In this embodiment, an in-car device 1 will be described as an example of an electronic device. In this embodiment, the in-car device 1 will be described as being basically installed on a horizontal plane. In this embodiment, the following will be used as a basis for front, rear, left and right of the in-car device 1. That is, the front side of the in-car device 1 will be described as corresponding to the lower left side in FIG. 1, and the rear side of the in-car device 1 will be described as corresponding to the upper right side in FIG. 1. In addition, the left side of the in-car device 1 will be described as corresponding to the upper left side in FIG. 1, and the right side of the in-car device 1 will be described as corresponding to the lower right side in FIG. 1.

[0010] The in-vehicle device 1 is an electronic device mounted on a vehicle, such as an infotainment device, an audio device, or a navigation device. The in-vehicle device 1 includes a housing 2 that defines the exterior shape. The housing 2 is formed from an appropriate material, such as metal or resin, with a shape (a rectangular parallelepiped shape in the illustrated example) and dimensions that fit into an installation space in the vehicle. The installation space may be, for example, a storage recess provided in the dashboard of the vehicle, but if there is no display unit or operation panel, the installation space may be embedded in an invisible location inside the dashboard of the vehicle. The size of this installation space may be, but is not limited to, the 1DIN or 2DIN size standard of the German Industrial Standard.

[0011] FIG. 3 is a perspective view of the in-vehicle device 1 with the top case 4 and the front cover 5 removed. The in-vehicle device 1 has a bottom case 3 disposed below, circuit boards 6, 7 attached to the bottom case 3, heat sinks 8, 9 installed on the circuit boards 6, 7, and a fan unit 10 disposed above the lower heat sink 8. The top case 4 is attached to the bottom case 3 from above, and covers the circuit boards 6, 7, heat sinks 8, 9, and fan unit 10. The front cover 5 covers the front surfaces of the bottom case 3 and the top case 4.

[0012] The bottom case (first member) 3 has a shallow box shape with an open top. The bottom case 3 has a rectangular flat bottom plate portion (bottom plate) 30 (see FIG. 4), and a front plate portion 31, a rear plate portion 32, a left plate portion 33, and a right plate portion 34 corresponding to side plate portions provided on the front, rear, left, and right sides of the bottom plate portion 30.

[0013] The top case (second member) 4 is in the shape of a deep box with an open bottom. As shown in Fig. 1, the top case 4 of this embodiment has a rectangular flat top plate portion (top plate) 40 and side plates provided on the front, rear, left and right sides of the top plate portion 40. The side plates are composed of a front plate portion 41, a rear plate portion (side plate) 42, a left plate portion 43, and a right plate portion 44.

[0014] The front cover (third member) 5 covers the front plate portion 31 of the bottom case 3 and the front plate portion 41 of the top case 4. The front cover 5 has a front plate portion 51 corresponding to the front side plate portion, and a top plate connection portion 50 bent rearward from the upper end of the front plate portion 51.

[0015] The bottom case 3, the top case 4, the front cover 5, and the rear cover 52 (see FIG. 2) form a hollow housing 2. That is, the front plate 31, the rear plate 32, the left plate 33, and the right plate 34 of the bottom case 3 are connected to the front plate 41 (see FIG. 4), the rear plate 42, the left plate 43, and the right plate 44 of the top case 4, respectively. The front plate 51 and the top plate connection part 50 of the front cover 5 are connected to the front plate 31 of the bottom case 3 and the front plate 41 of the top case 4, and the top plate 40 of the top case 4, respectively.

[0016] The front plate portion 31, the front plate portion 41, and the front plate portion 51 form the front side plate of the housing 2. The rear plate portion 32, the rear plate portion 42, and the rear cover 52 form the rear side plate of the housing 2. The left plate portion 33 and the left plate portion 43 form the left side plate of the housing 2. The right plate portion 34 and the right plate portion 44 form the right side plate of the housing 2. The top plate of the housing 2 is formed by the top plate portion 40 and the top plate connection portion 50. The bottom plate of the housing 2 is formed by the bottom plate portion 30.

[0017] 2 is a perspective view of the in-vehicle device 1 as viewed from below and rear to the left. An intake hole 35 is formed in the bottom plate of the housing 2, i.e., the bottom plate portion 30 of the bottom case 3. The intake hole 35 is composed of a plurality of round holes. The intake hole 35 is formed in a position facing the heat generating element 61 (see FIG. 4) of the lower circuit board 6. Connectors 73, 74, 75, and 77 are exposed at the rear side of the housing 2, and except for these portions, the inside is covered by the rear plate portion 42 of the top case 4 and the rear cover 52.

[0018] A plurality of heat dissipation holes 2a are formed in the top plate of the housing 2, i.e., the top plate portion 40 of the top case 4. The heat dissipation holes 2a are formed on the outer periphery of the top plate portion 40. The heat dissipation holes 2a are formed at the rear end portion. The heat dissipation holes 2a are formed in the shape of elongated holes extending in the front-rear direction. A plurality of heat dissipation holes 2a are formed in the left-right direction to constitute an overall heat dissipation port. In this embodiment, the heat dissipation holes 2a are formed from the top plate portion 40 to the rear plate portion 42 of the top case 4. That is, in this embodiment, the heat dissipation holes 2a are formed in the top plate portion 40 and the rear plate portion 42 of the top case 4.

[0019] Drainage holes 2b are formed in the side surface of the housing 2 in a position corresponding to the lower side of the heat dissipation holes 2a. In this embodiment, the drainage holes 2b are formed in the rear side panel of the housing 2. The drainage holes 2b are openings that extend horizontally. The drainage holes 2b are formed to be longer in the left-right direction than the formation range of the heat dissipation holes 2a. In this embodiment, a lower edge portion 42a that is recessed upward is formed in the rear panel portion 42 of the top case 4. The drainage hole 2b is formed by the surrounding shape of the lower edge portion 42a of the rear panel portion 42 and a tip end 102 in the extension direction of a water receiving portion 100 described later.

[0020] Connector holes 2c are formed in the side surface of the housing 2 in a position corresponding to the lower side of the heat dissipation holes 2a. In this embodiment, a plurality of connector holes 2c are appropriately formed in the rear side plate of the housing 2. The connector holes 2c are formed lower than the drainage holes 2b. In this embodiment, some of the connector holes 2c and the drainage holes 2b form an integral opening shape.

[0021] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. Circuit boards 6 and 7 are arranged inside the housing 2. The circuit boards 6 and 7 are, for example, printed circuit boards. The circuit boards 6 and 7 are arranged vertically with a gap therebetween. The circuit boards 6 and 7 are fixed to the bottom case 3 or the top case 4. The lower circuit board 6 has a board 60 installed over substantially the entire surface of the bottom plate portion 30 as shown in FIG. 3. The upper circuit board 7 has a board 70 formed in a shape that avoids the fan unit 10. The boards 60 and 70 are mounted with electric and electronic components 61, 62, 71, 72, 76 and connectors 73, 74, 75, 77 required for the in-vehicle device 1 as shown in FIGS. 3 to 5. Many other components for realizing various functions of the in-vehicle device 1 are arranged on the mounting surface of the boards 60 and 70.

[0022] These components include heat generating elements 61 and 71, which generate more heat than other components and require heat dissipation for stable operation. Examples of the heat generating elements 61 and 71 include processors such as MPUs (Micro Processing Units) and CPUs (Central Processing Units), and various integrated circuits such as SoCs (System-on-a-Chips) and PICs (Peripheral Interface Controllers). In this embodiment, the heat generating element 61 is an SoC. The heat generating element 71 is a PIC.

[0023] The upper board 60 and the lower board 70 are electrically connected by a harness 62 . Appropriate connectors 73, 74, 75, and 77 (see FIGS. 2 and 4) are provided at the rear ends of the boards 60 and 70. External terminals extending from external devices are removably connected to the connectors 73, 74, 75, and 77. The connectors 73, 74, 75, and 77 protrude to the outside of the housing 2 through the connector holes 2c.

[0024] Heat sinks 8 and 9 are attached to the heating elements 61 and 71, respectively. The lower surfaces of the heat sinks 8 and 9 are attached to the upper surfaces of the heating elements 61 and 71 via thermally conductive grease or a thermally conductive sheet. As a result, the heat sinks 8 and 9 receive heat from the heating elements 61 and 71. The thermally conductive grease or the thermally conductive sheet may be omitted. The heat sinks 8 and 9 absorb the heat from the heating elements 61 and 71 and release the heat to the surrounding air. As a result, the heat sinks 8 and 9 release the heat generated by the heating elements 61 and 71 by air cooling. The heat sinks 8 and 9 are formed of a highly thermally conductive material such as aluminum, copper, or an alloy containing these. In this embodiment, an aluminum plate is used for the heat sink 8, and aluminum die casting is used for the heat sink 9.

[0025] The lower heat sink 8 is formed into an L-shape in cross section as shown in Fig. 4. The heat sink 8 has a plate-shaped main body 80 that has a thickness in the up-down direction and extends in the front-rear direction, and a plate-shaped bent portion 81 that bends upward from the front end of the main body 80. The lower surface of the main body 80 of the heat sink 8 is in close contact with the upper surface of the heating element 61.

[0026] A fan unit 10 is disposed above the lower heat sink 8. The fan unit 10 has a fan 110 and an air duct 120 that supports the fan 110. The air duct 120 is fixed to the inner surface of the top panel portion 40. The fan 110 is fixed to the lower surface of the air duct 120.

[0027] In this embodiment, an axial flow fan is used as the fan 110. The fan 110 has a rectangular ring-shaped fan casing 110a, a fan motor 110b supported on the inner periphery of the fan casing 110a, and blades (not shown) rotatably supported by the fan motor 110b. The fan casing 110a is fixed to the lower surface of the air duct 120 by fasteners such as bolts. The fan 110 rotates around a motor shaft of the fan motor 110b extending in the vertical direction as the center of rotation. The fan 110 sucks in air from below and blows it upward. The type of the fan 110 may be other than an axial flow fan, such as a sirocco fan.

[0028] The air duct 120 guides air blown by the fan 110 to the heat sink 9. The air duct 120 has a plate-like main body 121 having a thickness in the vertical direction. The main body 121 is flat and extends at an angle to the left as it progresses rearward (see FIG. 3). A ventilation hole 121a penetrating in the vertical direction is formed at the front end of the main body 121. The fan 110 is fixed to the underside of the main body 121 in correspondence with the ventilation hole 121a. The fan 110 is disposed so as to cover the ventilation hole 121a. As a result, the fan 110 faces the main body 80 of the heat sink 8.

[0029] At this time, the bottom surface of the fan casing 110a is located lower than the upper end of the bent portion 81 of the heat sink 8. The bottom surface of the fan casing 110a is located lower than the upper substrate 70. This makes it easier for the fan 110 to send air flowing above the main body 80 of the heat sink 8 into the air duct 120 through the ventilation opening 121a.

[0030] A duct wall 122 (see FIG. 3) is formed on the upper surface of the main body 121 in a shape that stands up from the upper surface. In a plan view, the duct wall 122 has a front wall 123 extending in a semicircular arc shape along the left front side of the ventilation opening 121a, a left wall 124 extending left rear from the left end of the front wall 123, and a right wall 125 extending left rear from the right end of the front wall 123. On the upper surface of the main body 121, the front side, left side, and right side of the ventilation opening 121a are surrounded by the front wall 123, the left wall 124, and the right wall 125 of the duct wall 122. The left wall 124 and the right wall 125 extend rearward with a predetermined interval between them. An approximately U-shaped upper opening 122a that is open to the rear is formed by the surrounding shapes of the upper end of the front side wall 123, the upper end of the left side wall 124, and the upper end of the right side wall 125. The upper end of the duct wall 122 is configured to abut against or be close to the top plate portion 40. An approximately U-shaped rear opening 122b that is open upward is formed by the surrounding shapes of the rear end of the main body portion 121, the rear end of the left side wall 124, and the rear end of the right side wall 125.

[0031] A plurality of fixing parts 126 are formed on the outer periphery of the upper part of the duct wall 122 (see FIG. 3). The fixing parts 126 are fixed to the top plate part 40 of the top case 4. At this time, the upper opening 122a is closed by the top plate part 40, and the upper part of the rear opening 122b is also closed. That is, an air flow path 120S (see FIG. 4) is formed by the space surrounded by the duct wall 122 and the top plate part 40. In the air duct 120, air flowing in from the ventilation opening 121a flows through the flow path 120S and flows out from the rear opening 122b.

[0032] The front wall 123 has a lower portion 123a extending upward and an upper portion 123b that slopes left and rear as it advances upward from the upper end of the lower portion 123a. The sloped shape of the upper portion 123b makes it easier for the air flowing upward from the ventilation opening 121a to be guided left and rear without decreasing its flow speed.

[0033] A heat sink 9 is disposed behind the rear opening 122b of the air duct 120. The heat sink 9 extends from the air duct 120 toward the heat dissipation holes 2a. The heat sink 9 integrally includes a heat dissipation section 90 located above the heat generating element 71, and a water receiving section 100 connected to the heat dissipation section 90 and located below the heat dissipation holes 2a.

[0034] A pair of outer walls 111, 112 (see FIG. 3) are formed in the width direction on the upper surface of the heat sink 9, i.e., the upper surface 91 of the heat dissipation portion 90 and the upper surface 101 of the water receiving portion 100. The outer walls 111, 112 extend from the air duct 120 toward the heat dissipation hole 2a. The outer walls 111, 112, together with the upper surfaces 91, 101 of the heat dissipation portion 90 and the water receiving portion 100, form a recessed shape that is open upward.

[0035] The outer wall portions 111, 112 of the water receiving portion 100 are formed outside the heat dissipation holes 2a in the left-right direction. The outer wall portions 111, 112 are formed at a height that makes them abut against or close to the top plate portion 40. An air flow path 9S is formed by a space surrounded by the upper surfaces 91, 101 of the heat dissipation portion 90 and the water receiving portion 100, the outer wall portions 111, 112, and the top plate portion 40. In the heat sink 9, air flowing out from the rear opening 122b of the air duct 120 flows through the flow path 9S and is discharged to the outside of the housing 2 through the heat dissipation holes 2a and the drainage holes 2b.

[0036] Hereinafter, when the heat sink 9 is referred to as an intake side, it means the air duct 12 side of the heat sink 9. On the other hand, when the heat sink 9 is referred to as an exhaust side, it means the heat radiation hole 2a side of the heat sink 9.

[0037] 4, the heat dissipation section 90 has a block-shaped base section 92. The base section 92 extends from the air duct 120 toward the heat dissipation hole 2a. A heat receiving section 93 formed in a rectangular column shape is formed on the lower surface of the base section 92. The lower surface of the heat receiving section 93 is in close contact with the upper surface of the heating element 71.

[0038] A duct connection portion 94 is formed at the intake side end of the base portion 92. The duct connection portion 94 protrudes downward from the base portion 92 and then protrudes forward. The duct connection portion 94 extends below the air duct 120.

[0039] The upper surface of the base portion 92, i.e., the upper surface 91 of the heat dissipation portion 90, has an intake side upper surface 91a that slopes upward as it progresses toward the exhaust side. In other words, the distance between the intake side upper surface 91a and the top plate portion 40 narrows as it progresses toward the exhaust side. The intake side end of the intake side upper surface 91a is formed at the same height as the upper surface of the main body portion 121 of the air duct 120. The intake side end of the intake side upper surface 91a may be lower than the upper surface of the main body portion 121. This makes it easier for air discharged from the air duct 120 to move to the upper surface 91 of the heat dissipation portion 90.

[0040] On the exhaust side of the intake side upper surface 91a, a midstream upper surface 91b is formed, extending along the top plate portion 40. The midstream upper surface 91b is located above the heat receiving portion 93. On the exhaust side of the midstream upper surface 91b, an exhaust side upper surface 91c is formed, which slopes upward as it proceeds toward the exhaust side.

[0041] A connector avoidance portion 95 is formed at the exhaust side end of the base portion 92. The connector avoidance portion 95 is cut out in an L shape. The connector avoidance portion 95 accommodates the connector 74 (see FIGS. 2 and 4).

[0042] Fig. 5 is a top view of Fig. 3. In this embodiment, heating element 71 (see Fig. 4) is provided closer to the intake side of heat sink 9 in the front-rear direction and closer to outer wall portion 111 of the heat sink in the left-right direction when viewed from above housing 2. A position on top surface 91 of the heat sink corresponding to the upper part of heating element 71 is subjected to heat from heating element 71 to form high temperature portion 105, which is the highest temperature part of top surface 91. The heat sink is formed with a plurality of heat dissipation fins (fins) 96 standing on the upper surface 91. The plurality of fins constitute a fin group of the present invention. The heat dissipation fins 96 are formed between the outer wall portions 111, 112. The heat dissipation fins 96 extend in linear, substantially parallel fashion in a plan view from the intake side to the exhaust side of the heat sink 9, except for the vicinity of the exhaust side outlet, and are arranged at regular intervals in the left-right direction.

[0043] FIG. 6 is an enlarged view of the vicinity of the exhaust side outlet of the heat sink in FIG. 5. The vicinity of the exhaust side outlet of the heat dissipation fin 96 is formed so as to bend from the straight line from the intake side to the exhaust side. The fins 96 are arranged so that the left-right intervals in the vicinity of the exhaust side outlet are wider as the fins pass through the high temperature part 105 of the base part 92. The bends in the vicinity of the exhaust side outlet of the heat dissipation fin 96 are formed so that the fins pass through the high temperature part are smaller. The cross section of the heat dissipation fin 96 is approximately trapezoidal, tapering upward. The heat dissipation fin 96 extends so as to incline to the left as it proceeds rearward. In FIG. 4, the heat dissipation fins 96 are illustrated so as to be spaced apart in the front-rear direction in order to show a cross section intersecting the inclined heat dissipation fin 96.

[0044] [2. Functions of electronic devices] Next, the operation of the first embodiment will be described. When the in-vehicle device 1 is operated and the fan 110 is operated, an air flow A (see FIG. 4) is generated that moves from the intake hole of the bottom case 3 toward the heat dissipation hole 2a, the drainage hole 2b, etc. of the top case 4. That is, the air taken in from the intake hole moves along the underside of the lower circuit board 6, detouring the outer periphery of the lower circuit board 6 toward the fan unit 10. The air moving toward the fan unit 10 cools the heat sink 8 below.

[0045] The air that has cooled the heat sink 8 is taken in by the fan 110 of the fan unit 10 and sent into the flow path 120S of the air duct 120. The air sent into the flow path 120S is guided to the upper surface 91 of the heat sink 9 above, and flows along the heat dissipation fins 96. In the process, the air passing through is heated by the heat dissipation part 90 and becomes hot. The hot air is discharged from the heat dissipation holes 2a and the drainage holes 2b. In this embodiment, the heat dissipation fins 96 are bent near the exhaust outlet and the fins on the high temperature section 105 are arranged so that the intervals between them are wider near the exhaust outlet, which generates a Venturi effect and increases the wind speed of the air flowing through the high temperature section, where the flow path is narrower than near the outlet, thereby efficiently dissipating heat from the high temperature section. The Venturi effect is a phenomenon in which when the cross-sectional area of ​​a fluid flow path is partially narrowed, the flow speed of the fluid increases and low pressure areas are created, and is derived from Bernoulli's theorem when the flow rate is constant.

[0046] [3. Effects] As described above, in this embodiment, an electronic device that dissipates heat by air cooling comprises a heat generating element installed within a housing of the electronic device, a heat sink provided on the upper part so as to be in contact with the heat generating element, and a fan that blows air into the heat sink and exhausts it outside the housing, the heat sink has a group of fins installed to extend from the intake side that draws in air from the fan to the exhaust side that exhausts air outside the housing, the group of fins are arranged in parallel except near the exhaust side outlet, and among the multiple fins, the multiple fins that pass through the high temperature portion that becomes hot due to the heat generating element are arranged so that they are spaced apart more widely near the exhaust side outlet than the other fins. According to this configuration, by changing the shape of the heat dissipation fins, i.e., by widening the interval between the exhaust side outlets of the fins that pass through the high temperature part, a Venturi effect is generated, and the wind speed of the air passing through the heat dissipation part, which has a narrower flow path than the vicinity of the outlet, can be increased, and the heat dissipation efficiency of the heat generating element can be improved. Also, even if the position where the heat generating element contacts the heat sink changes, it is possible to accommodate various variations simply by adjusting the interval between the fins near the exhaust side outlet.

[0047] In the present embodiment, the heat generating element is disposed near the intake side of the heat sink when viewed from above, and the exhaust side ends of the fins are bent. The bend of the fins passing through the high temperature portion is smaller than the bend of the other fins. According to this configuration, by appropriately bending the exhaust side ends of the fins to adjust their spacing, i.e., by reducing the bending of the fins that pass through the high temperature section, the spacing between the exhaust side outlets of the fins is widened, creating a Venturi effect and increasing the speed of the airflow passing through the high temperature section, where the flow path is narrower than near the outlet, thereby enabling efficient cooling.

[0048] [4. Configuration of Electronic Device According to Second Embodiment] Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. In the description of the second embodiment, components having the same functions as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted.

[0049] FIG. 7 is a perspective view of a housing according to the second embodiment with the up case and the front case removed. The heat sink 209 according to the second embodiment dissipates heat not only from the first heat generating element 71 on the upper substrate, but also from the second heat generating element 72 which generates less heat than the first heat generating element 71. The heat sink 209 is integrally provided with a contact member 210 that comes into contact with the second heat generating element 72 .

[0050] The fin spacing passing through the high temperature portion 105 of the first heating element 71 is set larger near the exhaust outlet than the fin spacing passing through the high temperature portion (not shown) of the second heating element 72. This makes it possible to increase the speed of air flowing through the fins in the high temperature portion 105 of the heat generating element 71 which generates more heat than the high temperature portion (not shown) of the second heat generating element 72 .

[0051] [5. Effects] In this embodiment, a second heat generating element that generates less heat than the first heat generating element is provided inside the housing, and a heat sink is provided so as to be in contact with the first heat generating element and the second heat generating element. The spacing between the fins passing through the high temperature portion of the first heat generating element is set larger near the exhaust side outlet than the spacing between the fins passing through the high temperature portion of the second heat generating element. According to this configuration, a plurality of heating elements may be provided, and the fins passing through the higher temperature heating elements are spaced apart from each other near the exhaust side outlet, i.e., a larger Venturi effect is generated, thereby increasing the flow rate of the airflow and allowing efficient cooling. That is, the speed of the air flowing through the fins at the high temperature part of the first heating element, which generates more heat, can be increased compared to the speed of the air flowing through the fins at the high temperature part of the second heating element, thereby improving the heat dissipation efficiency of the heating element. Since the second heating element is also in contact with the heat sink via a contact member, the second heating element can be cooled by the air flowing through the heat sink, which is less heated by the first heating element. In addition, even if the positional relationship between the first heating element and the second heating element and the heat sink changes, various variations can be accommodated by simply adjusting the spacing of the fins near the exhaust side outlet.

[0052] [6. Other embodiments] The above-described embodiment merely shows one aspect of the present invention, and any modification and application are possible within the scope of the present invention.

[0053] In the above embodiment, the configuration for increasing the wind speed of the airflow by changing the shape of the fins has been described. However, this shape change does not have to be to the fins. In other words, by changing the shape of the top case, the heat sink embankment, or the air duct, it is possible to form a shape that narrows the airflow path regardless of the left and right direction, and the wind speed can be increased. [Explanation of symbols]

[0054] 9. Heat sink 90 Heat radiation part 96 Heat dissipation fin 105 High temperature parts caused by heating elements

Claims

1. An electronic device that dissipates heat by air cooling, A heating element installed in a housing of the electronic device; A heat sink provided on the upper portion so as to contact the heat generating element; a fan that blows air to the heat sink and exhausts it to the outside of the housing; the heat sink has a fin group including a plurality of fins arranged to extend from an intake side where air is drawn in by the fan to an exhaust side where air is exhausted to the outside of the housing, The plurality of fins are arranged approximately parallel to each other except in the vicinity of the exhaust side outlet, and among the plurality of fins, the plurality of fins passing through a high temperature portion that becomes hot due to the heat generating element are arranged so that the intervals between the fins are wider in the vicinity of the exhaust side outlet than the other fins.

1. An electronic device comprising:

2. The fin group is bent in the vicinity of the exhaust side outlet, and the plurality of fins passing through the high temperature portion are formed with a smaller bend than the other fins.

2. The electronic device according to claim 1 .

3. a second heating element that generates less heat than the heating element is provided in the housing; the heat sink is provided in contact with the heat generating element and the second heat generating element, a distance between the fins passing through a high temperature portion caused by the heat generating element is greater in the vicinity of the exhaust side outlet than a distance between the fins passing through a high temperature portion caused by the second heat generating element; 2. The electronic device according to claim 1 .

4. A heat sink having a contact surface with a heat generating element and a fin group consisting of a plurality of fins arranged along a flow of air passing through the upper portion, the plurality of fins are arranged approximately parallel to each other except for the vicinity of the exhaust side outlet so as to guide air from the intake side to the exhaust side, Among the plurality of fins, a plurality of fins passing above the contact surface are arranged such that the intervals between the fins are increased in the vicinity of the exhaust side outlet. A heat sink characterized by:

5. The fin group is bent in the vicinity of the exhaust side outlet, and the plurality of fins passing through the high temperature portion are formed with a smaller bend than the other fins.

5. The heat sink of claim 4.

Images