Heat dissipation structure and electronic device

Abstract

To dissipate heat efficiently even at high temperatures.SOLUTION: A heat dissipation structure includes a housing that supports a heat generating element mounted on a vehicle, and a radiator 40 that dissipates heat generated by the heat generating element. The housing 30 includes a top plate 31 with a first inclined portion 312 that is inclined so as to guide condensation water generated and dripped by vehicle's air conditioning equipment 100 to the radiator 40, and the radiator 40 is arranged exposed to a side wall 33 of the housing 30 and has a storage portion 45 that stores the condensation water guided to the radiator 40.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] It is known that electronic components such as control circuits mounted on the circuit board of electronic devices generate heat, and therefore the electronic components are provided with a heat dissipation structure (for example, Patent Document 1). In the technology described in Patent Document 1, heat is dissipated by attaching a heat sink (heat dissipator) to the housing of the electronic device mounted on the vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-253230 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there have been many midsummer days and extremely hot days, and such weather conditions also cause the space in which the electronic devices of the vehicle are installed to become hot. The technology of Patent Document 1 allows the heat generated by the electronic components to be dissipated by a heat sink attached to the housing of the electronic device. However, it does not assume that the space of the vehicle in which the electronic device is installed will become hot, and there is a possibility that the heat cannot be dissipated efficiently.

[0005] In view of the above problems, an object of the present disclosure is to provide a heat dissipation structure and an electronic device that can efficiently dissipate heat even at high temperatures. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the objective, the heat dissipation structure of the present disclosure includes a housing that supports a heat generating element mounted on a vehicle, and a radiator that dissipates heat generated by the heat generating element, the housing has a top plate having a first inclined portion that is inclined so as to guide condensation water generated and dripped by the air conditioning equipment to the radiator, and the radiator is arranged exposed on a side wall of the housing and has a storage portion that stores the condensation water guided to the radiator.

[0007] In order to solve the above-mentioned problems and achieve the object, an electronic device according to the present disclosure includes a substrate and the above-mentioned heat dissipation structure. Effect of the Invention

[0008] According to the present invention, heat can be efficiently dissipated even at high temperatures. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing an electronic device having a heat dissipation structure according to an embodiment. [Diagram 2] FIG. 2 is a perspective view of the housing according to the present embodiment. [Diagram 3] FIG. 3 is a cross-sectional view of the housing according to this embodiment taken along line AA. [Figure 4] FIG. 4 is a perspective view of the hood of the housing according to the present embodiment. [Diagram 5] FIG. 5 is a cross section of the housing according to this embodiment taken along line BB, and is a cross section of the canopy portion. [Figure 6] FIG. 6 is a front view of a heat sink according to another example of this embodiment. [Figure 7] FIG. 7 is a front view of a heat sink according to another example of this embodiment. [Figure 8] FIG. 8 is a front view of a heat sink according to another example of this embodiment. [Figure 9] FIG. 9 is a front view of a heat sink according to another example of this embodiment. [Figure 10] FIG. 10 is a front view of a heat sink according to another example of this embodiment. [Figure 11] FIG. 11 is a perspective view of a housing according to another example of this embodiment. [Figure 12] FIG. 12 is a perspective view of a housing according to another example of this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to this embodiment. In addition, the components of this embodiment include those that are replaceable and easy for a person skilled in the art, or those that are substantially the same.

[0011] [Embodiment] <Electronic equipment> FIG. 1 is a schematic diagram showing an electronic device having a heat dissipation structure according to an embodiment. FIG. 1 shows the inside of a dashboard of a vehicle as viewed from the front to the back of the page. The electronic device 1 is, for example, an AV (Audio Visual) integrated car navigation system or car audio. In the embodiment, the up-down direction is the Z direction, the left-right direction is the X direction, and the front-rear direction is the Y direction. The up direction is the Z1 direction, the down direction is the Z2 direction, the front direction is the Y2 direction, the rear direction is the Y1 direction, the left direction is the X1 direction, and the right direction is the X2 direction. In addition, a plane that combines the up-down direction (Z direction) and the front-rear direction (Y direction) is called a vertical plane, and a plane that combines the left-right direction (X direction) and the front-rear direction (Y direction) is called a horizontal plane. Furthermore, the left-right direction (X direction) is also called a horizontal direction. In this embodiment, the inside of the dashboard refers to a space on the opposite side to the interior of the vehicle, which is partitioned by a dashboard provided in the interior of the vehicle.

[0012] The electronic device 1 is mounted on a vehicle. More specifically, the electronic device 1 is mounted below an air conditioner 100 mounted on the vehicle. The electronic device 1 and the air conditioner 100 are disposed inside a dashboard. The electronic device 1 includes a substrate 2 and a heat dissipation structure 10.

[0013] (Air conditioning equipment) Here, an overview of the air conditioner 100 will be described. The air conditioner 100 is mounted on a vehicle, and adjusts the temperature inside the vehicle cabin by an occupant operating an operation button (not shown) provided inside the vehicle cabin. For example, when an occupant operates a button so that the air conditioner 100 cools the vehicle cabin, the air conditioner 100 lowers the temperature inside the vehicle cabin by the cooling function. At this time, the air conditioner 100 circulates a refrigerant, which is an air conditioning gas. The refrigerant returns to the compressor again via the compressor, condenser, injector (expansion valve), heat exchanger (evaporator), etc. of the air conditioner 100. The refrigerant is compressed by the compressor to a high-temperature, high-pressure state (semi-liquid). The refrigerant in the high-temperature, high-pressure state is cooled by the condenser to a low-temperature, high-pressure liquid. The low-temperature, high-pressure refrigerant is atomized by the expansion valve and sprayed toward the evaporator. The evaporator vaporizes the refrigerant by the mist of refrigerant absorbing heat from the surrounding air. The evaporator cools by the refrigerant absorbing heat from the surrounding air. As the refrigerant absorbs heat from the surrounding air, the water vapor contained in the air becomes saturated and condenses on the surface of the cooled evaporator to become condensed water (water droplets). Some of the condensed water drips (falls) onto the housing 30 of the electronic device 1, and some is drained outside the vehicle. The blower fan located near the evaporator rotates to send air into the vehicle cabin. This cools the vehicle cabin. The refrigerant that passes through the evaporator becomes a low-temperature, low-pressure gas and returns to the compressor.

[0014] The air conditioner 100 includes a guide path 110 that guides a portion of the condensed water to the housing 30 of the electronic device 1. The guide path 110 is, for example, a duct. One end of the guide path 110 is connected to the evaporator, and the other end is located above the top plate 31 of the housing 30. Note that the guide path 110 is not limited to a duct.

[0015] (substrate) The substrate 2 is a plate-shaped printed circuit board. More specifically, the substrate 2 is configured by electrically connecting electronic components such as an integrated circuit (IC) 20, resistors, capacitors, and transistors arranged on a plate material made of an insulator. The substrate 2 outputs control signals to each part of the electronic device 1. The substrate 2 has wiring 2a that connects the substrate 2 and the integrated circuit 20. An electric signal generated on the substrate in the integrated circuit 20 flows through the wiring 2a. The substrate 2 is fixed to the bottom plate 32 of the housing 30 via the legs 2b with screws (not shown).

[0016] (Integrated Circuit) The integrated circuit 20 is configured such that a substrate on which heat-generating electronic components are mounted is housed in a thin rectangular box-shaped case 21. The integrated circuit 20 has a high temperature in the case 21 due to heat generated by the mounted electronic components. The case 21 has a main surface 21a, a main surface 21b facing the main surface 21a, and four side surfaces 21c, 21d, 21e, and 21f connecting the opposing ends of the main surface 21a and the main surface 21b. Wiring 2a protrudes toward the substrate 2 from the main surface 21b.

[0017] The integrated circuit 20 is, for example, a power IC. The integrated circuit 20 is, for example, an integrated circuit that is expected to generate heat of 100° C. or more, which is the boiling point of water.

[0018] (heat dissipation structure) The heat dissipation structure 10 dissipates heat generated by an integrated circuit 20, which is a heat generating body of the electronic device 1. The heat dissipation structure 10 includes a housing 30 and a heat sink 40.

[0019] (Housing) Fig. 2 is a perspective view of the housing according to this embodiment. Fig. 3 is a cross-sectional view of the housing according to this embodiment taken along line AA. For the sake of explanation, part of the housing 30 (part of the overhanging portion 50 shown in Fig. 4 described later) is not shown in Fig. 2.

[0020] The housing 30 is box-shaped and contains the board 2 and the wiring 2a. The housing 30 has the heat sink 40 arranged exposed. The housing 30 has a top plate 31, a bottom plate 32 facing the top plate 31, and three side walls 33, a side wall 34, and a rear panel 35 connecting the facing ends of the top plate 31 and the bottom plate 32. The housing 30 also has a display screen 36. A space 37 is formed in the housing 30 for arranging the heat sink 40. Since the space 37 is formed in the housing 30, a part of the housing 30 is recessed in an L-shape when viewed from above.

[0021] The top plate 31 is located on the upper surface of the housing 30, and a part of the condensation water generated by the air conditioner 100 drips (falls) onto the surface 311. The top plate 31 has a space 37 formed in a part thereof, and is inclined so as to guide the dripped condensation water to the radiator 40 arranged in the space 37. Specifically, the top plate 31 has a first inclined portion 312 on the inside of the horizontal plane, which guides the condensation water dripped onto the surface 311 of the top plate 31 to the radiator 40. The first inclined portion 312 is formed in an inclined surface shape inclined in the Z2 direction (downward) from the surface 311 of the top plate 31. Therefore, a step H is formed between the surface 311 of the top plate 31 and the surface of the first inclined portion 312. The first inclined portion 312 is inclined in the Z2 direction as it moves from the X2 direction to the X1 direction. The first inclined portion 312 may also be inclined in the Y1 direction. In this case, first inclined portion 312 inclines in the Z2 direction from the Y2 direction toward the Y1 direction. First inclined portion 312 forms narrow passage 313 whose width in the Y direction at the connection portion with second inclined portion 315 becomes the same as the width in the Y direction of storage portion 45 of heat sink 40. Note that the height of step H increases in the X1 direction as first inclined portion 312 inclines.

[0022] The top plate 31 also includes a second inclined portion 315. The second inclined portion 315 is a plate-shaped member that guides the condensation water that has fallen onto the housing 30 from the narrow passage 313 to the storage portion 45 of the heat sink 40. The second inclined portion 315 is formed in an eave-like shape that protrudes toward the storage portion 45. The second inclined portion 315 is connected to the narrow passage 313. The second inclined portion 315 is inclined in the Z2 direction toward the storage portion 45 of the heat sink 40. The second inclined portion 315 is inclined in the Z2 direction as it moves from the X2 direction to the X1 direction. The width of the second inclined portion 315 in the X direction is shorter than the width L2 of the heat sink 40. It is preferable that the length of the second inclined portion 315 in the Y direction is approximately the same as the width L1 of the heat sink 40. For the sake of explanation, the top plate 31 shown in FIG. 2 does not show the portion located in the Z1 direction of the space portion 37.

[0023] The bottom plate 32 faces the top plate 31 and supports the side walls 33 and 34 and the rear panel 35. The bottom plate 32 has a cutout at an end in the X1 direction and an end in the Y1 direction. The cutout portion of the bottom plate 32 becomes part of the space 37. For example, the leg portion 2b that fixes the substrate 2 is fixed to the bottom plate 32.

[0024] The side wall 33 has a part that is L-shaped in top view. The side wall 33 has a side wall 331 that is wider than the width L2 of the heat sink 40 in the horizontal plane. The side wall 33 is recessed in the Y2 direction by the width of the side wall 331. That is, the side wall 33 has the side wall 331 and a recessed wall 332 that is a side wall recessed in the Y2 direction. The wall part 43 of the heat sink 40 contacts the side wall 331 in the assembled state. The space between the Y1 direction of the side wall 331 and the X1 direction of the recessed wall 332 is the space part 37. The recessed wall 332 supports the integrated circuit 20 that is a heat generating body, and the heat sink 40 is disposed therein. The recessed wall 332 supports the integrated circuit 20 such that a part of the integrated circuit 20 is exposed from the recessed wall 332. The recessed wall 332 may support the integrated circuit 20 such that the entire integrated circuit 20 is exposed. The recess walls 332 may support the integrated circuit 20 with the integrated circuit 20 entirely contained within the housing 30 .

[0025] The recessed wall 332 of the side wall 33 has the heat sink 40 fixed to the space 37 below the second inclined portion 315 by the screws S1 and S2. The recessed wall 332 may have the second inclined portion 315 formed at the upper end of the side wall 33 to which the heat sink 40 is fixed.

[0026] The side wall 34 has a rectangular shape and is disposed opposite the side wall 33 .

[0027] The rear panel 35 is located on the rear side of the housing 30. The rear panel 35 has a space 37 formed in a part thereof.

[0028] The display screen 36 is positioned opposite the rear panel 35. The display screen 36 is supported by the top panel 31, the bottom panel 32, and the side walls 33 and 34. The display screen 36 displays images such as route directions and song titles based on the electrical signals generated by the integrated circuit 20.

[0029] The space 37 is formed in a part of the housing 30. The space 37 is formed in the Y2 direction from the end of the top plate 31 where X1 and Y1 intersect at right angles (the left rear end of the top plate 31 in FIG. 2). The space 37 is formed penetrating along the Z direction. The heat sink 40 is disposed in the space 37. The space 37 may be large enough to accommodate the heat sink 40. The space 37 is formed with a width in the Y direction equal to the width L1 of the heat sink 40 in FIG. 2. The space 37 is formed with a width in the X direction wider than the width L2 of the heat sink 40. For example, the space 37 is formed by recessing the end in the Y1 direction of the side wall 33 to the same extent as the width L1 of the heat sink 40 in the Y2 direction and recessing the end in the X1 direction wider than the width L2 of the heat sink 40 in the X2 direction. As a result, an L-shaped recess is formed in the top plate 31, the bottom plate 32, and the rear panel 35 corresponding to the recess in the side wall 33. In other words, the space 37 is formed penetrating the top plate 31, the bottom plate 32, the side wall 33, and the rear panel 35 in the Z direction.

[0030] (heat sink) The heat sink 40 dissipates heat generated by the integrated circuit 20. The heat sink 40 evaporates condensation water generated by the air conditioner 100. As shown in FIG. 2, the heat sink 40 is disposed outside the housing 30. The heat sink 40 is disposed in the space 37 of the housing 30 and exposed from the housing 30. The heat sink 40 is made of a material having a higher thermal conductivity than the case 21 and the housing 30. The heat sink 40 is formed of, for example, an aluminum material. When the temperature of the heat sink 40 is lower than that of the case 21, the heat generated by the integrated circuit 20 is conducted to the heat sink 40. When the temperature of the heat sink 40 is higher than that of the air outside the housing 30, the heat sink 40 is constantly air-cooled by the air outside the housing 30. Therefore, even when the temperature of the heat sink 40 is higher than that of the housing 30, heat is not easily conducted to the housing 30.

[0031] The heat sink 40 has a U-shaped cross section in top view. More specifically, the heat sink 40 has a base 41 in contact with the housing 30, a wall portion 42 arranged from one end of the base 41 in a plane perpendicular to the base 41, and a wall portion 43 arranged opposite the wall portion 42 and arranged from the other end of the base 41 in a plane perpendicular to the base 41. The heat sink 40 has a plate member 44 (storage portion 45) extending in the Y direction in the plane perpendicular to the base 41. The heat sink 40 has a visor portion 50 on the upper portion of the heat sink 40.

[0032] The base 41 is formed in a rectangular shape. The base 41 is arranged outside the housing 30 in parallel with the side wall 33 of the housing 30. The back surface of the base 41 is in close contact with the main surface 21a of the case 21. The base 41 is in close contact with the main surface 21a of the case 21 by fastening the base 41 to the recessed wall 332 of the side wall 33 with the screws S1 and S2. When the temperature of the base 41 is lower than that of the main surface 21a of the case 21, heat is conducted from the main surface 21a of the case 21. Therefore, since the base 41 is in close contact with the main surface 21a, a part of the base 41 becomes hot. The heat conducted to the base 41 is conducted to the wall portion 42, the wall portion 43, and the storage portion 45.

[0033] The wall portion 42 is disposed at one end of the base 41 at a right angle along a vertical plane on the X1 direction side. The wall portion 42 has an inner wall portion 421 parallel to the wall portion 42 at a position spaced apart from the wall portion 42. More specifically, the wall portion 42 has the inner wall portion 421 at one end of the narrow passage 313. Since the plate member 44 of the base 41 extends in the Y direction, the inner wall portion 421 extends from the plate member 44 in the Z1 direction and the Z2 direction. In other words, it can be said that the inner wall portion 421 extends in the up-down direction from the plate member 44 at a position spaced apart from the wall portion 42. The inner wall portion 421 conducts heat conducted to the base 41.

[0034] The wall portion 43 is disposed at the other end of the base 41 at a right angle along the vertical plane on the X1 direction side. The wall portion 43 has an inner wall portion 431 parallel to the wall portion 43 at a position separated from the wall portion 43. More specifically, the wall portion 43 has the inner wall portion 431 at the other end of the narrow passage 313. Since the plate member 44 of the base 41 extends in the Y direction, the inner wall portion 421 extends from the plate member 44 in the Z1 direction and Z2 direction. In other words, it can be said that the inner wall portion 431 extends in the vertical direction from the plate member 44 at a position separated from the wall portion 43. The inner wall portion 431 conducts the heat conducted to the base 41.

[0035] Plate member 44 protrudes in the X1 direction and extends in the Y direction. Storage portion 45 is a box-shaped portion surrounded by base 41, inner wall portion 421, inner wall portion 431, and blocking portion 452, and has plate member 44 as a bottom plate. Storage portion 45 stores condensation water guided to heat radiator 40. Storage portion 45 has hole 451 for draining condensation water that has not been completely evaporated in heat radiator 40. Storage portion 45 includes blocking portion 452 and drainage channel 453.

[0036] The damming portion 452 is a member that blocks the condensation water stored in the storage portion 45 so that it does not fall from the storage portion 45 due to vibration of the vehicle or the like. The damming portion 452 is provided between the inner wall portion 421 and the inner wall portion 431. More specifically, the damming portion 452 is provided at the end of the storage portion 45 opposite the base 41 and parallel to the base 41. The length (height) of the damming portion 452 in the Z1 direction is shorter than the length (height) of the inner wall portion 421 and the inner wall portion 431 from the storage portion 45 in the Z1 direction.

[0037] Drainage channel 453 drains condensation water that has not completely evaporated in radiator 40. Drainage channel 453 drains condensation water that has not completely evaporated after being stored in storage section 45, for example. Drainage channel 453 is, for example, a pipe line, and protrudes from hole 451 of storage section 45 in the Z2 direction.

[0038] (Eaves) Fig. 4 is a perspective view of the eaves portion of the housing according to this embodiment. Fig. 5 is a cross-sectional view of the housing according to this embodiment taken along line BB, and a cross-sectional view of the eaves portion. As shown in Figs. 4 and 5, the eaves portion 50 is provided on the upper part of the heat sink 40 from the side wall 33 of the housing 30 toward the X2 direction. The eaves portion 50 is integrally molded with the top plate 31, and is provided so as to cover the upper part of the heat sink 40. The eaves portion 50 re-condenses the steam St of the condensed water evaporated in the heat sink 40, returning it to water (water droplets).

[0039] As shown in FIG. 5, the eaves portion 50 has an inverted U-shaped cross section in a side view. The eaves portion 50 extends in the Y direction. The eaves portion 50 is formed by bending a portion of the top plate 31. The eaves portion 50 is made of a material that condenses steam St. Therefore, when steam St comes into contact with the eaves portion 50, the eaves portion 50 condenses the steam St to generate water (water droplets). The eaves portion 50 includes a contact portion 51 and induction portions 52 and 53.

[0040] The contact portion 51 has a rectangular shape and extends parallel to the side wall 33 of the housing 30. The contact portion 51 extends parallel to the upper end of the heat sink 40 from the side wall 33 to a position partway along the second inclined portion 315. The contact portion 51 comes into contact with the steam St of condensed water evaporated in the heat sink 40.

[0041] The induction portion 52 protrudes in the Z2 direction (downward) from one end of the contact portion 51 in the X direction. The induction portion 52 preferably protrudes in the Z2 direction to the upper end of the heat radiator 40. The induction portion 52 guides the steam St generated by the heat radiator 40 to the contact portion 51.

[0042] The guiding portion 53 protrudes in the Z2 direction (downward) from the other end of the contact portion 51 in the X direction. The length of the guiding portion 53 in the Z2 direction is shorter than the length of the guiding portion 55 in the Z2 direction. The tip of the guiding portion 53 in the Z2 direction is located above the second inclined portion 315. The guiding portion 53 guides water droplets to the second inclined portion 315.

[0043] 1, the eaves portion 50 may be located above the top plate 31. In this case, for example, the eaves portion 50 has a support column 501 that supports the eaves portion 50. The support column 501 is provided, for example, on the top plate 31 of the housing 30. The support column 501 is provided on the outer surface 311 on both ends of the narrow passage 313, extends in the Z1 direction, and supports the eaves portion 50.

[0044] (action) When the air conditioner 100 is in operation, some of the condensation water generated from the air conditioner 100 passes through the guide path 110 of the air conditioner 100 and drips onto the top plate 31 of the housing 30. The condensation water dripping onto the top plate 31 is guided to the second inclined portion 315 according to the inclination of the first inclined portion 312. The condensation water guided to the second inclined portion 315 is guided to the radiator 40 according to the inclination of the second inclined portion 315. In this way, the condensation water generated from the air conditioner 100 is guided to the radiator 40 via the housing 30. The radiator 40 radiates heat generated by the integrated circuit 20. The radiator 40 becomes hot due to the heat generated by the integrated circuit 20, so that the condensation water evaporates and becomes steam St.

[0045] The steam St rises in the space 37 and is recondensed at the eaves portion 50, causing the water (water droplets) to drip down. The dripped water remains in the storage portion 45 of the radiator 40. The water remaining in the storage portion 45 evaporates again and becomes the steam St. In this manner, the water droplets are circulated.

[0046] Condensed water that remains in reservoir 45 of radiator 40 and does not completely evaporate flows through drainage channel 453 protruding from reservoir 45.

[0047] As described above, according to this embodiment, the housing 30 supporting the integrated circuit 20 is disposed in the Z2 direction (downward) of the air conditioner 100. The air conditioner 100 is provided with the guide path 110, and the top plate 31 of the housing 30 has a first inclined portion 312 that is inclined so as to guide a part of the condensation water generated from the air conditioner 100 to the radiator 40. In the housing 30, the radiator 40 is in close contact with the recessed wall 332 of the side wall 33. This allows the condensation water generated from the air conditioner 100 to be guided to the radiator 40 via the housing 30. The radiator 40 can lower the temperature of the radiator 40 by turning the guided condensation water into steam St, and can efficiently radiate the heat generated by the integrated circuit 20.

[0048] Furthermore, according to this embodiment, the radiator 40 has an eave portion 50 on the upper portion of the radiator 40. Therefore, the radiator 40 not only evaporates the condensed water guided to the radiator 40, but also re-condenses the evaporated steam St at the eave portion 50 to generate water (water droplets). The water droplets generated at the eave portion 50 drip back onto the radiator 40. In other words, the radiator 40 evaporates the condensed water generated by the air conditioner 100 and re-condenses it at the eave portion 50, thereby circulating the water droplets.

[0049] The lower end of the induction section 52 of the eaves section 50 reaches the upper end of the radiator 40. Therefore, the steam St evaporated by the heat of the radiator 40 condenses at the eaves section 50, turns into water droplets, and drips again into the storage section 45. Meanwhile, the air heated by the heat of the radiator 40 flows in the upward Z1 direction of the housing 30 through the gap between the lower end of the induction section 53 and the second inclined section 315. As a result, the heated air flows toward the lower part of the air conditioning duct, so that the amount of condensed water in the air conditioning duct can be increased, and the cooling efficiency can be further improved.

[0050] Moreover, according to this embodiment, the heat radiator 40 has the drainage channel 453 in the storage portion 45. Therefore, according to this embodiment, the condensation water that has not been completely evaporated in the heat radiator 40 can be drained.

[0051] Moreover, according to this embodiment, the electronic device 1 includes the above-mentioned heat dissipation structure 10. The electronic device 1 can efficiently dissipate heat by the heat sink 40 using condensation water generated from the air conditioner 100. Therefore, according to this embodiment, it is possible to prevent heat generated by the integrated circuit 20 of the electronic device 1 from being trapped in the housing 30.

[0052] [Other examples] Next, another example of the electronic device 1 having the heat dissipation structure 10 according to the embodiment will be described. FIGS. 6 to 10 are front views of a heat sink according to another example of the embodiment. FIG. 11 is a perspective view of a housing according to another example of the embodiment. FIG. 12 is a perspective view of a housing according to another example of the embodiment. In the following description, detailed description of components similar to those of the above embodiment will be omitted. The other example differs from the embodiment in that a groove 46A is formed in the base 41A of the heat sink 40A and that a fin 47A is provided in the storage section 45A of the heat sink 40A. In addition, the other example differs from the above embodiment in that a rib 60A is provided on the top plate 31 of the housing 30.

[0053] 6 to 10, the heat sink 40A has a plurality of grooves 46A formed therein. The heat sink 40A has a plurality of grooves 46A formed in a base 41A.

[0054] The heat sink 40A dissipates heat generated by the integrated circuit 20. The heat sink 40A evaporates condensation water generated by the air conditioner 100. The heat sink 40A is disposed outside the housing 30. The heat sink 40A is disposed in the space 37 of the housing 30 and exposed from the housing 30. The heat sink 40A is made of a material having a higher thermal conductivity than the case 21 and the housing 30. The heat sink 40A is formed of, for example, an aluminum material. When the temperature of the heat sink 40A is lower than that of the case 21, the heat generated by the integrated circuit 20 is conducted to the heat sink 40A. When the temperature of the heat sink 40A is higher than that of the air outside the housing 30, the heat sink 40A is constantly air-cooled by the air outside the housing 30, so that the heat sink 40A is less likely to conduct heat to the housing 30 even when the temperature of the heat sink 40A is higher than that of the housing 30.

[0055] The heat sink 40A has a U-shaped cross section in top view. More specifically, the heat sink 40A has a base 41A that contacts the housing 30, a wall portion 42 that is disposed in a plane perpendicular to the base 41A from one end of the base 41A, and a wall portion 43 that is disposed opposite the wall portion 42 and is disposed in a plane perpendicular to the base 41A from the other end of the base 41A. The heat sink 40A has a plate member 44 (storage portion 45A) in the plane perpendicular to the base 41A. The heat sink 40A has a visor portion 50 on the upper portion of the heat sink 40A.

[0056] The base 41A is formed in a rectangular shape. The base 41A is arranged outside the housing 30 in parallel with the side wall 33 of the housing 30. The back surface of the base 41A is in close contact with the main surface 21a of the case 21. The base 41A is in close contact with the main surface 21a by fastening the screws S1 and S2. When the temperature of the base 41A is lower than that of the main surface 21a of the case 21, heat is conducted from the main surface 21a of the case 21. Therefore, the base 41A is in close contact with the main surface 21a, and a part of the base 41A becomes hot. The heat conducted to the base 41A is conducted to the wall portion 42, the wall portion 43, and the storage portion 45. In addition, one end of the fin 47A is connected to the base 41A.

[0057] The groove 46A allows condensation water to flow to the base 41A in contact with the recessed wall 332 of the side wall 33. A plurality of grooves 46A are formed in the base 41A of the heat sink 40A. The grooves 46A suck up the condensation water guided to the heat sink 40A in the Z1 direction by capillary action. The grooves 46A may be provided on the Z2 direction side of the screw S1, or may extend to the upper end of the heat sink 40A. The grooves 46A may not be formed in two stages as shown in FIG. 6, but may be formed in a plurality of stages connected to one. The grooves 46A may be formed radially from the high temperature part of the base 41A with which the integrated circuit 20 of the heat sink 40A contacts, as shown in FIG. 8. This allows the grooves 46A to efficiently flow the condensation water guided to the heat sink 40A to the periphery of the high temperature part, thereby improving the evaporation efficiency.

[0058] In the example shown in Fig. 6 and Fig. 8, the groove 46A does not extend to the storage portion 45. In contrast, as shown in Fig. 7, Fig. 9, and Fig. 10, the groove 46A may extend to the storage portion 45. This allows the groove 46A to suck up the water stored in the storage portion 45 to the high temperature portion of the heat sink by capillary action, improving the cooling efficiency in the groove 46A. Although not shown, the groove 46A may be arranged in a lattice shape over the entire surface of the base 41A, and both the condensed water from the first inclined portion 312 of the top plate 31 and the water stored in the storage portion 45 can be quickly diffused to the heat sink surface and the high temperature portion by capillary action, improving the cooling efficiency.

[0059] In this way, by forming a plurality of grooves 46A in the base 41A of the heat sink 40A, the condensation water guided to the heat sink A flows through the grooves 46A by capillary action. That is, the condensation water comes into contact with a wide area of ​​the heat sink 40A. Therefore, as the condensation water flows through the grooves 46A, the contact area of ​​the condensation water with the heat sink 40A increases, and the evaporation efficiency can be improved.

[0060] 11, the heat sink 40A may have fins 47A. The heat sink 40A has the fins 47A in the storage portion 45A.

[0061] The reservoir 45A stores the condensation water guided to the heat radiator 40A. The reservoir 45A has a plurality of holes for draining the condensation water that has not been completely evaporated by the heat radiator 40A. The reservoir 45A includes a fin 47A, a blocking portion 452A, and a drainage channel 453A.

[0062] The fins 47A are arranged on the upper surface of the storage section 45A along the Y direction. The fins 47A are arranged parallel to the wall sections 42 and 43 of the heat sink 40A. One end of the fin 47A is connected to the base 41A, and the other end is connected to the blocking section 452. The fins 47A are formed in a rectangular shape. In the example shown in FIG. 11, three fins are provided. The fins 47A have a plurality of holes (not shown) between the fins 47A for draining condensation water that has not been completely evaporated in the heat sink 40A into the storage section 45A. Three or more fins 47A may be provided.

[0063] The damming portion 452A is a member that blocks the condensed water stored in the storage portion 45 from falling from the storage portion 45 due to vibration of the vehicle or the like. The damming portion 452A is provided between the inner wall portion 421 and the inner wall portion 431. More specifically, the damming portion 452A is provided at the end of the storage portion 45 opposite the base 41 and parallel to the base 41. The length (height) of the damming portion 452 in the Z1 direction is shorter than the length (height) of the inner wall portion 421 and the inner wall portion 431 from the storage portion 45 in the Z1 direction. The other end of the fin 47A is connected to the damming portion 452A.

[0064] Drainage channel 453A drains condensation water that has not been completely evaporated in radiator 40A. Drainage channel 453A drains condensation water that has been stored in storage section 45 and has not been completely evaporated. Drainage channel 453A is, for example, a pipe. One side of drainage channel 453A branches into four branch pipes and is connected to multiple holes in storage section 45, and the other side of drainage channel 453A is a single pipe formed by bundling the branch pipes. Drainage channel 453A protrudes in the Z2 direction from multiple holes in storage section 45A.

[0065] By providing fins 47A in reservoir 45A of radiator 40A in this manner, the contact area of ​​condensation water with radiator 40A increases, thereby improving the evaporation efficiency.

[0066] As shown in FIG. 12, a top plate 31A of a housing 30A may be provided with a rib 60A.

[0067] The housing 30A is box-shaped and contains the board 2 and the wiring 2a. The heat sink 40 is disposed in an exposed state in the housing 30A. The housing 30A has a top plate 31A, a bottom plate 32 facing the top plate 31A, and three side walls 33, a side wall 34, and a rear panel 35 connecting the facing ends of the top plate 31A and the bottom plate 32. The housing 30A also has a display screen 36 and a space 37 for disposing the heat sink 40.

[0068] The top plate 31A is located on the upper surface of the housing 30, and condensation water generated by the air conditioner 100 drips (falls) onto the surface 311A. The top plate 31A is formed with a space 37 in a part thereof, and is inclined so as to guide the dripped condensation water to the radiator 40 arranged in the space 37. Specifically, the top plate 31A has a first inclined portion 312A on the inside in the horizontal plane, which guides the condensation water dripped onto the surface 311A ​​of the top plate 31A to the radiator 40. The first inclined portion 312A is recessed in the Z2 direction (downward) from the surface 311A ​​of the top plate 31A. Therefore, a step H is formed between the surface 311A ​​of the top plate 31A and the surface of the first inclined portion 312A. The first inclined portion 312A is inclined in the X1 direction. The first inclined portion 312A may also be inclined in the Y1 direction. First inclined portion 312A is narrowed to form narrow passage 313 such that the width in the Y direction at the location where second inclined portion 315 is arranged is the same as the width in the Y direction of storage portion 45 of heat sink 40. Note that, as first inclined portion 312 is inclined, the height of step H increases in the X1 direction.

[0069] The rib 60A prevents the condensed water that has fallen onto the top plate 31A from flowing further from the top plate 31A to an unintended location or from falling due to vehicle vibration, a slope, or road conditions. The rib 60A is provided on the surface 311A ​​of the top plate 31A. More specifically, the rib 60A is provided on the inner edge or entire circumference of the surface 311A. In other words, the rib 60A is provided so as to separate the surface 311A ​​from the surface of the first inclined portion 312A. The rib 60A may be provided on the outer periphery or entire circumference of the top plate 31A. The first inclined portion 312A may be provided with a path that guides the condensed water that has fallen onto the first inclined portion 312A to the radiator 40. For example, the first inclined portion 312A may be provided with a guide path such as a straight or curved rib or groove.

[0070] In this way, condensation water dripping onto the top plate 31A can be guided to the radiator 40 more efficiently.

[0071] The heat dissipation structure 10 described above generates steam St by the radiator 40. This increases the humidity around the electronic device 1, which may affect the in-vehicle devices in the vehicle cabin or on the dashboard. Therefore, it is preferable to place the electronic device 1 in a separate space where it does not affect these devices.

[0072] <Effects> The heat dissipation structure 10 of this embodiment includes a housing 30 that supports a heat generating element mounted on a vehicle, and a radiator 40 that dissipates heat generated by the heat generating element, and the housing 30 has a top plate 31 having a first inclined portion 312 that is inclined so as to guide condensation water generated and dripping (falling) by the vehicle's air conditioning equipment 100 to the radiator 40, and the radiator 40 has a storage portion 45 that is exposed to the side wall 33 of the housing 30 and stores the condensation water guided to the radiator 40.

[0073] This allows efficient heat dissipation even at high temperatures.

[0074] The heat sink 40 of the heat dissipation structure 10 according to this embodiment further includes a eaves portion 50 on the upper portion of the heat sink 40, and the eaves portion 50 recondenses the steam St of the condensed water evaporated in the heat sink 40 back into water. This allows efficient heat dissipation even at high temperatures.

[0075] In the heat sink 40 of the heat dissipation structure 10 according to this embodiment, a groove 46A through which condensation water flows is formed in the base 41 that contacts the side wall 33. This allows efficient heat dissipation even under high temperatures.

[0076] The grooves 46A of the heat sink 40 of the heat dissipation structure 10 according to this embodiment are formed radially from the high temperature portion of the base 41 with which the integrated circuit 20 of the heat sink 40 comes into contact. This allows efficient heat dissipation even at high temperatures.

[0077] The electronic device 1 according to this embodiment includes a substrate 2 and any one of the heat dissipation structures 10 described above. This allows efficient heat dissipation even at high temperatures.

[0078] Each component of each device shown in the figure is a functional concept, and does not necessarily have to be physically configured as shown in the figure. In other words, the specific form of distribution and integration of each device is not limited to that shown in the figure, and all or part of them can be functionally or physically distributed and integrated in any unit according to various loads, usage conditions, etc. This distribution and integration configuration may be performed dynamically.

[0079] Although the embodiments of the present invention have been described above, the present invention is not limited to the contents of these embodiments. The above-described components include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the above-described components can be appropriately combined. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the above-described embodiments. [Explanation of symbols]

[0080] 1 Electronic equipment 20 Integrated circuits (heating elements) 21 cases 30, 30A housing 31, 31A Top plate 32 Bottom plate 33, 34, 331 side wall 35 Rear Panel 40, 40A Heatsink 41 Base 42, 43 Wall section 45, 45A Storage section 46A Groove 47A Fin 50 Eaves 51 Contact part 52, 53 Induction part 60A Rib 100 Air conditioning equipment 311, 311A ​​surface 312, 312A 1st slope 315 2nd slope part 452, 452A Damming section 453, 453A drainage channel St Steam

Claims

1. A housing for supporting a heating element mounted on a vehicle; a heat sink that dissipates heat generated by the heat generating element; Including, the housing includes a top plate having a first inclined portion inclined so as to guide condensation water generated and dripped by an air conditioning device of the vehicle to the radiator, The heat sink is disposed exposed to a side wall of the housing and includes a storage portion for storing the condensation water guided to the heat sink. Heat dissipation structure.

2. The heat sink further includes a visor portion on an upper portion of the heat sink, The eaves portion re-condenses the steam of the condensed water evaporated by the radiator back into water. The heat dissipation structure according to claim 1 .

3. The heat sink has a base in contact with the side wall, and a groove through which the condensation water flows is formed in the base. The heat dissipation structure according to claim 1 or 2.

4. The grooves are formed radially from a high temperature portion of a base with which the heat generating element of the heat sink comes into contact. The heat dissipation structure according to claim 3 .

5. A substrate; The heat dissipation structure according to claim 1 or 2, electronic equipment.

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