On-vehicle device

Abstract

To provide an on-vehicle device that enhances the moldability of a cooling fin and improves the productivity of a heat dissipation member.SOLUTION: An on-vehicle electronic apparatus (on-vehicle device) 10 comprises: a housing 11; a plate-shaped heat sink (heat dissipation member) 15 which is provided inside the housing and comes into contact with the upper surface of an SoC (electronic component) 13 to dissipate heat generated by the SoC; a cooling fin 31 that detachably comes into contact with a region including at least a region on an upper surface of the SoC on the upper surface of the heat sink to enhance heat dissipation of the heat sink; and a centrifugal fan (cooling fan) 20 that blows cooling air along the heat sink between multiple fins constituting the cooling fin.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to an in-vehicle device. [Background technology]

[0002] In order to cool the heat generated by a microprocessor, a cooling device has been disclosed in which a heat sink with multiple fins is placed above the microprocessor and air from a blower fan is passed between the fins to dissipate heat from the microprocessor (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-96766 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the cooling device disclosed in Patent Document 1, the fins are molded integrally within the cylindrical portion that constitutes the heat sink, making it difficult to mold the fins thin.

[0005] An object of the present disclosure is to provide an in-vehicle device that is capable of increasing the formability of cooling fins and improving the productivity of heat dissipation members. [Means for solving the problem]

[0006] The in-vehicle device of the present disclosure comprises a housing, a plate-shaped heat dissipation member provided inside the housing and abutting an upper surface of an electronic component to dissipate heat generated by the electronic component, a cooling fin that detachably abuts an area on the upper surface side of the heat dissipation member that includes at least an area of ​​the upper surface of the electronic component to promote heat dissipation from the heat dissipation member, and a cooling fan that blows cooling air along the heat dissipation member between multiple fins that constitute the cooling fin. Effect of the Invention

[0007] According to the in-vehicle device according to the present disclosure, the formability of the cooling fins can be improved, and the productivity of the heat dissipation member can be improved. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic exploded perspective view of an in-vehicle electronic device. [Diagram 2] FIG. 2 is a first diagram showing a main structure of the heat sink. [Diagram 3] FIG. 3 is a second diagram showing the structure of the main part of the heat sink. [Figure 4] FIG. 4 is a diagram illustrating an example of a schematic structure of a centrifugal fan. [Diagram 5] FIG. 5 is a first diagram showing a main structure of the in-vehicle electronic device. [Figure 6] FIG. 6 is a second diagram showing the structure of the main part of the in-vehicle electronic device. [Figure 7] FIG. 7 is a third diagram showing the structure of the main part of the in-vehicle electronic device. [Figure 8] FIG. 8 is a first diagram showing an example of a method for connecting circuit boards. [Figure 9] FIG. 9 is a second diagram showing an example of a method for connecting circuit boards. [Figure 10] FIG. 10 is a third diagram showing an example of a method for connecting circuit boards. [Figure 11] FIG. 11 is a first diagram showing an example of the top surface shape of the upper chassis. [Figure 12] FIG. 12 is a second diagram showing an example of the top surface shape of the upper chassis. [Figure 13] FIG. 13 is a third diagram showing an example of the top surface shape of the upper chassis. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (Embodiment) Hereinafter, embodiments of an in-vehicle electronic device according to the present disclosure will be described with reference to the drawings.

[0010] (Overview of in-vehicle electronic devices) A schematic configuration of an in-vehicle electronic device 10 will be described with reference to Fig. 1. Fig. 1 is a schematic exploded perspective view of the in-vehicle electronic device.

[0011] The in-vehicle electronic device 10 is a device that is mounted on a vehicle and performs various electronic controls such as navigation system control, audio system control, engine control, ADAS (Advanced Driver-Assistance Systems) control, etc. The in-vehicle electronic device 10 is an example of an in-vehicle device in the present disclosure.

[0012] The in-vehicle electronic device 10 includes the main components shown in FIG.

[0013] The in-vehicle electronic device 10 includes a housing 11 and a plurality of circuit boards 12a and 12b contained in the housing 11. The plurality of circuit boards 12a and 12b are stacked in the height direction (the Z-axis direction in FIG. 1) and are connected to each other by board-to-board connectors (BtoB connectors). The board-to-board connectors will be described in detail later (see FIG. 8 and FIG. 9).

[0014] The housing 11 is formed by screwing together an upper chassis 11a, a lower chassis 11b, a rear chassis 11c, and a front chassis 11d. A recess is formed on the top surface of the upper chassis 11a to allow water droplets to escape in order to prevent water from entering the housing 11 due to condensation formed in the vehicle cabin. This will be described in detail later (see Figs. 11, 12, and 13).

[0015] A system on a chip (SoC) 13 is mounted on the circuit board 12b. The SoC 13 is a single semiconductor chip on which many or all of the functions required for the operation of a system are mounted. The SoC 13 includes, for example, a processor function such as a CPU or GPU, a memory function, a communication interface function, and the like. The SoC 13 has the advantage of enabling electronic devices to be made smaller, lighter, and faster, but generates a lot of heat during operation and therefore requires cooling. The SoC 13 is an example of an electronic component in this disclosure.

[0016] A bracket 70 is mounted between the circuit board 12a and the circuit board 12b. The bracket 70 is fastened to the circuit board 12a and also fastened to the circuit board 12b. This suppresses vibrations between the circuit boards 12a and 12b that occur when the vehicle is traveling, for example. The bracket 70 also provides electrical continuity between the ground lines of the circuit boards 12a and 12b, thereby matching the ground potentials between the different circuit boards.

[0017] A heat sink 15 is provided above the circuit board 12b (on the positive side of the Z axis) so as to abut against the SoC 13. The heat sink 15 is made of a material with high thermal conductivity, for example, an aluminum plate, and dissipates heat generated by the SoC 13 into the housing 11.

[0018] Above the SoC 13, the cooling fins 30 are removably installed with the heat sink 15 in between. The cooling fins 30 have a number of fins aligned along the X-axis. Since the cooling fins 30 are removable, in an in-vehicle electronic device 10 in which the amount of heat generated by the SoC 13 is small, the necessary heat dissipation can be achieved by the heat sink 15 alone, without the need for the cooling fins 30. The cooling fins 30 are manufactured by extruding aluminum, for example.

[0019] A centrifugal fan 20 is installed on the negative side of the cooling fins 30 along the X-axis. The cooling fins 30 suck in air inside the housing 11 from the positive side of the Z-axis and blow it out toward the multiple fins of the cooling fins 30. The flow of the blown air passes between the multiple fins of the cooling fins 30, thereby removing heat generated by the SoC 13. In other words, the flow of air blown out by the centrifugal fan 20 acts as a cooling wind. The centrifugal fan 20 is an example of a cooling fan in this disclosure.

[0020] A bracket 40 is installed above the cooling fins 30 (on the positive side of the Z axis) so as to cover the tip side of the cooling fins 30. The bracket 40 guides the cooling air blown out by the centrifugal fan 20 through the multiple fins of the cooling fins 30 to the axial fan 50 described below. The bracket 40 is an example of an air guide member in the present disclosure.

[0021] An axial fan 50 is installed on the side surface of the upper chassis 11a on the positive side of the X-axis. The axial fan 50 exhausts the cooling air that has passed through the cooling fins 30 to the outside of the housing 11. The axial fan 50 is an example of an exhaust fan in this disclosure. The air guide path from the centrifugal fan 20 to the axial fan 50 will be described in detail later (see FIG. 7).

[0022] (Main structure of heat sink) The structure of the main part of the heat sink 15 will be described with reference to Figures 2 and 3. Figure 2 is a first diagram showing the structure of the main part of the heat sink. Figure 3 is a second diagram showing the structure of the main part of the heat sink.

[0023] 2 shows the structure of a portion of heat sink 15 that contacts the bottom surface of cooling fin 30. Heat sink 15 has flat area 26 formed on the back surface side of planar proximity area 19 (see FIG. 3) that contacts the top surface of SoC 13. Protrusions 16a, 16b, and 16c that protrude toward the positive side of the Z axis are formed around flat area 26 so as to surround flat area 26. Protrusions 16a, 16b, and 16c are formed so that the protrusion amounts from flat area 26 are equal.

[0024] When the cooling fin 30 is attached above the heat sink 15 (on the positive side of the Z axis), the protrusions 16a, 16b, and 16c come into contact with the bottom surface of the cooling fin 30, thereby forming a minute gap between the upper surface of the heat sink 15 and the bottom surface of the cooling fin 30. A GAP filler 60a, which will be described later, is filled into this minute gap. The GAP filler 60a will be described in detail later (see FIG. 5).

[0025] At least two of the protrusions 16a, 16b, and 16c sandwiching the flat area 26 are formed with screw holes for screwing the heat sink 15 and the cooling fin 30. In the case of Fig. 2, the screw holes are formed in the protrusions 16a and 16b.

[0026] At the end of the heat sink 15, abutment portions 17a and 17b are formed which are bent toward the negative side of the Z axis. Also, at the heat sink 15, abutment portion 17c which protrudes toward the negative side of the Z axis is formed. Abutment portions 17a, 17b, and 17c are formed around the periphery of the flat area 26 so as to surround the flat area 26. Also, abutment portions 17a, 17b, and 17c are formed so that the protruding amounts from the bottom surface of the heat sink 15 are equal.

[0027] Abutment portion 17a, abutment portion 17b, and abutment portion 17c abut against the upper surface of circuit board 12b when heat sink 15 is attached to circuit board 12b. Then, a minute gap is formed between the upper surface of SoC 13 mounted on circuit board 12b and the bottom surface of heat sink 15. GAP filler 60b, which will be described later, is filled into this minute gap. GAP filler 60b will be described in detail later (see FIG. 5).

[0028] Furthermore, at the corner of the heat sink 15 on the positive side of the X-axis, a wall portion 18 is formed by bending the end of the heat sink 15 upward (toward the positive side of the Z-axis). The wall portion 18 controls the flow of cooling air that has passed through the cooling fins 30. The function of the wall portion 18 will be described in detail later (see FIG. 7).

[0029] Fig. 3 shows the structure of a portion of heat sink 15 that is adjacent to the top surface of SoC 13. That is, Fig. 3 is a view of Fig. 2 as seen from the rear surface side (the negative side of the Z axis).

[0030] 1, circuit board 12b is placed on the back surface side of heat sink 15. The top surface of SoC 13 mounted on circuit board 12b is disposed adjacent to proximity region 19 shown in FIG.

[0031] As described above, the abutment portions 17a, 17b, and 17c formed on the back side of the heat sink 15 abut against the upper surface of the circuit board 12b. Then, a minute gap is formed between the upper surface of the SoC 13 mounted on the circuit board 12b and the bottom surface of the heat sink 15, i.e., the proximity region 19. This minute gap is filled with a GAP filler 60b, which will be described later. The GAP filler 60b will be described in detail later (see FIG. 5).

[0032] (Schematic structure of a centrifugal fan) The general structure of the centrifugal fan 20 will be described with reference to Fig. 4. Fig. 4 is a diagram showing an example of the general structure of a centrifugal fan.

[0033] The centrifugal fan 20 has a structure in which a motor 23 and blades 24 are built into a housing 21. The blades 24 are driven to rotate on an XY plane by the rotational driving force of the motor 23.

[0034] Housing 21 is formed with air intake port 22 and air outlet 25. Air intake port 22 takes in air from inside casing 11 into housing 21 by rotation of blades 24. Air outlet 25 blows the air taken in from air intake port 22 toward the positive side of the X-axis. The air blown from air outlet 25 acts as cooling air that cools cooling fins 30.

[0035] (Main structure of in-vehicle electronic devices) The structure of the main parts of the on-vehicle electronic device 10 will be described with reference to Figures 5, 6, and 7. Figure 5 is a first diagram showing the structure of the main parts of the on-vehicle electronic device. Figure 6 is a second diagram showing the structure of the main parts of the on-vehicle electronic device. Figure 7 is a third diagram showing the structure of the main parts of the on-vehicle electronic device.

[0036] FIG. 5 shows a schematic structure of the in-vehicle electronic device 10 in a YZ cross section taken at a position including the SoC 13. As shown in FIG.

[0037] GAP filler 60b is filled in the space between the upper surface of SoC 13 mounted on circuit board 12b and heat sink 15. GAP filler 60b has thermal conductivity and conducts heat generated in SoC 13 to release the heat to heat sink 15. GAP filler 60b is an example of a resin member in this disclosure.

[0038] A space is formed between the top surface of SoC 13 and the bottom surface of heat sink 15 by abutment portions 17a and 17b formed on heat sink 15, and therefore GAP filler 60b is filled uniformly.

[0039] A cooling fin 30 is removably attached to the upper surface side of the heat sink 15. Specifically, the cooling fin 30 is screwed at a protrusion 16a and a protrusion 16b formed on the heat sink 15. Since the protrusion 16a and the protrusion 16b have the same protrusion amount, a space is formed between the upper surface of the heat sink 15 and the bottom surface of the cooling fin 30. A GAP filler 60a is filled in this space over the range where the SoC 13 is mounted. The GAP filler 60a has thermal conductivity similar to the above-mentioned GAP filler 60b. The GAP filler 60b promotes cooling of the heat sink 15 by conducting heat from the heat sink 15 to the cooling fin 30.

[0040] The cooling fin 30 includes a plurality of fins 31 that stand parallel to one another at equal intervals along the XZ plane. A bracket 40 is installed above the heat sink 15 so as to cover the tip side of the fins 31. A small gap is provided between the tip of the fin 31 and the bracket 40.

[0041] Between the fins 31, the cooling air blown by the centrifugal fan 20 flows from the negative side of the X-axis to the positive side of the X-axis. At this time, the tip side of the fin 31 is covered by the bracket 40, so an exhaust duct is formed. As described above, a small gap exists between the tip side of the fin 31 and the bracket 40, but the bracket 40 and the heat sink 15 are in close contact with each other, so the exhaust duct structure is secured. As a result, the cooling air from the centrifugal fan 20 is efficiently guided to the space between the fins 31, and the flow rate of the cooling air is improved by restricting the space through which the cooling air flows. Therefore, the cooling of the fins 31 is promoted. In addition, since the bracket 40 and the heat sink 15 are in close contact with each other, heat conduction from the heat sink 15 to the bracket 40 occurs, so that the cooling effect of the heat sink 15 can be expected.

[0042] FIG. 6 shows a schematic structure of the in-vehicle electronic device 10 in an XZ cross section taken at a position including the SoC 13 and the centrifugal fan 20. As shown in FIG.

[0043] The space between the top surface of circuit board 12b and the bottom surface of heat sink 15 is supported by abutment portion 17c in addition to abutment portions 17 and 17b described above. Therefore, even if circuit board 12b is warped, a uniform space for filling GAP filler 60b is formed between SoC 13 and heat sink 15 above SoC 13.

[0044] Moreover, the bracket 40 described above extends to the position of the upper surface of the centrifugal fan 20. Therefore, the cooling air blown from the centrifugal fan 20 advances inside the area surrounded by the bracket 40 and the heat sink 15 toward the positive side of the X-axis. By forming an air guide duct that limits the air guide range of the cooling air in this way, the cooling air can be guided along the upper surface of the heat sink 15 and between the multiple fins 31 of the cooling fins 30, improving the cooling efficiency. In addition, since there is no leakage of the cooling air, the blowing noise generated by the operation of the centrifugal fan 20 can be reduced.

[0045] The height hb of the fins 31 of the cooling fins 30 is formed to be higher than the height ha of the air outlet 25 of the centrifugal fan 20. By adopting such a configuration, it is possible to reduce the ventilation resistance of the cooling air blown from the air outlet 25. For example, if the height hb of the fins 31 is formed to be lower than the height ha of the air outlet 25 of the centrifugal fan 20 and the upper surface of the centrifugal fan 20 and the tips of the fins 31 are covered by the bracket 40, the air guide range of the cooling air blown from the air outlet 25 is narrowed. In such a case, the narrowing of the air guide range generates ventilation resistance, and the cooling efficiency may be reduced.

[0046] FIG. 7 is a diagram of the in-vehicle electronic device 10 viewed from directly above the centrifugal fan 20 and the cooling fins 30. As shown in FIG.

[0047] Cooling air W blown from air outlet 25 of centrifugal fan 20 travels along the upper surface of heat sink 15 toward the positive side of the X-axis and passes between fins 31 of cooling fins 30. The bottom surface of cooling fin 30 abuts against protrusions 16a, 16b, and 16c formed on the upper surface of heat sink 15, and is fixed to heat sink 15 with screws at the positions of protrusions 16a and 16b.

[0048] The cooling air W that has passed between the fins 31 of the cooling fins 30 is discharged to the outside of the housing 11 by the rotation of an axial flow fan 50 attached to an upper chassis 11a (see FIG. 1) that constitutes the housing 11.

[0049] At this time, it is desirable that the distance d between the air outlet 25 of the centrifugal fan 20 and the fins 31 of the cooling fins 30 is equal to or greater than half the blade diameter D, which is the diameter of the blades 24 (see FIG. 4) of the centrifugal fan 20, i.e., d≧D / 2. This is because the cooling air W blown from the air outlet 25 of the centrifugal fan 20 requires a certain distance before its traveling direction becomes stable.

[0050] The axial flow fan 50 includes a fan 52 that is rotated by a motor 51 inside an outer frame member that is open on both the side where the cooling air W is sucked in and the side where the cooling air W is exhausted. The axial flow fan 50 sucks in the cooling air W that has passed between the fins 31 of the cooling fins 30 by the rotation of the fan 52, and exhausts it to the outside of the housing 11.

[0051] In order to improve the cooling efficiency, it is desirable that the air outlet 25 of the centrifugal fan 20, the fins 31 of the cooling fins 30, and the axial fan 50 are arranged in a straight line. However, depending on the structure of the circuit board 12b and the installation state of the input / output terminals attached inside the housing 11, the desirable arrangement may not be realized. For example, in the case of FIG. 7, the center of the air outlet 25 of the centrifugal fan 20 and the center of the fins 31 of the cooling fins 30 are aligned, but the central axis of the axial fan 50 is offset to the positive side of the Y axis. Therefore, in the example of FIG. 7, the wall portion 18 is formed at the end of the heat sink 15 on the positive side of the X axis and the negative side of the Y axis to control the flow of the cooling air W. Specifically, the cooling air W flowing on the negative side of the Y axis passes through the fins 31 of the cooling fins 30, hits the wall portion 18, and changes its traveling direction to the positive side of the Y axis. This reduces leakage of the cooling air W, and the cooling air W can be guided to the axial fan 50 without leakage. The installation position and shape of the wall portion 18 are appropriately designed according to the structure of the circuit board 12b, the installation state of the input / output terminals and the like attached inside the housing 11, and the like.

[0052] (Connection structure between circuit boards) A connection structure between circuit board 12a and circuit board 12b will be described with reference to Figures 8, 9, and 10. Figure 8 is a first diagram showing an example of a method for connecting circuit boards. Figure 9 is a second diagram showing an example of a method for connecting circuit boards. Figure 10 is a third diagram showing an example of a method for connecting circuit boards.

[0053] Board-to-board connector 73a mounted on circuit board 12a and board-to-board connector 73b mounted on circuit board 12b are connected with a connector passing portion 74 formed in bracket 70 sandwiched therebetween.

[0054] In the in-vehicle electronic device 10 of this embodiment, the board-to-board connectors 73a, 73b have many connection pins, for example, 200 pins. Therefore, in order to facilitate insertion and removal of the board-to-board connectors 73a, 73b during maintenance, etc., it is desirable to reduce the contact load applied to the connection portion of the connector. In the in-vehicle electronic device 10 of this embodiment, the contacts of the board-to-board connectors 73a, 73b are single contacts, which makes it easy to insert and remove the board-to-board connectors 73a, 73b.

[0055] However, by reducing the contact load on the connection parts of the board-to-board connectors 73a, 73b, micro-sliding may occur at the contacts of the board-to-board connectors 73a, 73b due to vibrations of the vehicle in which the in-vehicle electronic device 10 is installed, and this micro-sliding may cause wear of the contacts.

[0056] Therefore, in the in-vehicle electronic device 10 of this embodiment, as shown in FIG. 9, arm portions 71a and 71b formed in the bracket 70 near the inter-board connectors 73a and 73b are fastened to the circuit boards 12a and 12b, respectively, thereby preventing fluctuations in the inter-board distance between the circuit boards 12a and 12b due to vehicle vibrations.

[0057] 9 and 10, a part of the bracket 70 is cut out near the inter-board connectors 73a, 73b of the bracket 70 to form an arm 71a bent toward the circuit board 12a. Also, a part of the bracket 70 is cut out near the inter-board connectors 73a, 73b of the bracket 70 to form an arm 71b bent toward the circuit board 12b.

[0058] The tip of arm 71a is bent in a direction along circuit board 12a, and a screw hole 72a is opened at the tip. Then, circuit board 12a and arm 71a are fastened together by a screw 75a inserted through screw hole 72a.

[0059] The tip of arm 71b is bent in a direction along circuit board 12b, and a screw hole 72b is opened at the tip. Circuit board 12b and arm 71b are fastened together by a screw 75b inserted through screw hole 72b.

[0060] Such a fastening structure between the circuit boards prevents fluctuations in the inter-board distance between circuit boards 12a and 12b due to vehicle vibrations, thereby suppressing micro-sliding at the contact points of board-to-board connectors 73a, 73b.

[0061] (Top structure of the housing) The top surface structure of housing 11 will be described with reference to Fig. 11. Fig. 11 is a first diagram showing an example of the top surface shape of the upper chassis.

[0062] An upper chassis 11a constituting a part of the housing 11 of the in-vehicle electronic device 10 has a drainage groove 80 and a recess 81 formed therein.

[0063] The drain groove 80 is a concave groove formed along the width direction of the upper chassis 11a, with both ends in the width direction bent toward the rear side of the upper chassis 11a. In general, the housing 11 is installed in a vehicle in an inclined state so that the front side is higher than the rear side. Therefore, when water droplets are generated inside the vehicle, the generated water droplets fall on the surface of the upper chassis 11a and then slide down from the front side to the rear side of the upper chassis 11a. The drain groove 80 catches the water droplets that have slid down the upper chassis 11a and drains them below the housing 11 from both ends in the width direction of the upper chassis 11a. In this way, by forming the drain groove 80, it is possible to prevent various connection connectors exposed from the rear chassis 11c from being wetted by water droplets that have slid down the surface of the upper chassis 11a.

[0064] The recess 81 is a groove formed so that the rear side of the upper chassis 11a is located closer to both ends of the width direction of the upper chassis 11a than the front side of the upper chassis 11a. The recess 81 catches water droplets that slide down the surface of the upper chassis 11a and directs them to both ends of the width direction of the upper chassis 11a.

[0065] Water droplets that have passed through the rear end of the recess 81 flow down the portion of the drain groove 80 that is bent toward the rear side of the upper chassis 11a, and are then drained below the housing 11. That is, the water droplets are drained along the drain path F1. In this way, by providing the recess 81, the water droplets can be guided to both ends in the width direction of the upper chassis 11a at an earlier stage. This makes it possible to more reliably prevent the various connection connectors exposed from the rear chassis 11c from becoming wet.

[0066] Next, a first modified example of the water droplet drainage structure will be described with reference to Fig. 12. Fig. 12 is a second diagram showing an example of the top surface shape of the upper chassis.

[0067] 12, a recess 82 is formed in place of the recess 81 described above. The recess 82 is formed by making the angle between the recess 81 and the left and right side ends of the upper chassis 11a smaller and increasing the length of the recess 81. Furthermore, the rear side of the recess 82 in the upper chassis 11a is connected to the drain groove 80.

[0068] In Fig. 12, water droplets are drained along the drainage path F2. By forming the recess 82 in this way, the flow of water droplets caught in the recess 82 can be made faster. In addition, since the recess 82 and the drainage groove 80 are connected, water droplets that have flowed through the recess 82 can be quickly drained. This further improves the effect of preventing various connectors exposed from the rear chassis 11c from becoming wet.

[0069] Next, a second modified example of the water droplet drainage structure will be described with reference to Fig. 13. Fig. 13 is a third diagram showing an example of the top surface shape of the upper chassis.

[0070] In the upper chassis 11a shown in FIG. 13, a plurality of recesses 81a, 81b, and 81c having the same shape as the recess 81 described above are formed on both left and right ends of the upper chassis 11a.

[0071] In Fig. 13, water droplets caught in recess 81a are drained along drainage path F3. Water droplets caught in recess 81b are drained along drainage path F4. Water droplets caught in recess 81c are drained along drainage path F5. By forming a plurality of recesses 81a, 81b, 81c in this way, the probability of catching water droplets increases compared to the case where only one recess 81 is formed as shown in Fig. 11, and therefore the effect of preventing water from getting into various connection connectors exposed from the rear chassis 11c can be further improved.

[0072] (Effects of this embodiment) As described above, the in-vehicle electronic device 10 (in-vehicle device) of the present embodiment includes the housing 11, the plate-shaped heat sink 15 (heat dissipation member) that is provided inside the housing 11 and abuts against the upper surface of the SoC 13 (electronic component) to dissipate heat generated by the SoC 13, the cooling fin 30 that detachably abuts against an area on the upper surface side of the heat sink 15 including at least the area of ​​the upper surface of the SoC 13 to promote heat dissipation from the heat sink 15, and the centrifugal fan 20 (cooling fan) that blows cooling air along the heat sink 15 between the multiple fins 31 that constitute the cooling fin 30. Therefore, the cooling fin 30 can be manufactured separately from the heat sink 15, so that the moldability of the cooling fin 30 can be improved and the productivity of the heat sink 15 can be improved. In addition, since the cooling fin 30 and the heat sink 15 are separable, the presence or absence of the cooling fin 30 can be selected depending on the amount of heat dissipation from the SoC 13. This allows the heat sink 15 to be reused between multiple different in-vehicle electronic devices 10.

[0073] Moreover, the in-vehicle electronic device 10 (in-vehicle device) of this embodiment further includes a bracket 40 (air guide member) that is installed so as to cover the air outlet 25 of the centrifugal fan 20 (cooling fan) and the tip side of the fins 31 and guides the cooling air W blown by the centrifugal fan 20 between the multiple fins 31 of the cooling fins 30, and an axial flow fan 50 (exhaust fan) that exhausts the cooling air W that has passed through the cooling fins 30 to the outside of the housing 11. Therefore, the bracket 40 acts as an exhaust duct, and heat dissipation by the cooling fins 30 can be promoted.

[0074] In the in-vehicle electronic device 10 (in-vehicle device) of this embodiment, the height hb from the upper surface of the heat sink 15 (heat dissipation member) to the tip of the cooling fin 30 is higher than the height ha of the air outlet 25 of the centrifugal fan 20 (cooling fan). Therefore, the cooling air from the centrifugal fan 20 can be applied to the fin 31 efficiently.

[0075] In the in-vehicle electronic device 10 (in-vehicle device) of this embodiment, thermally conductive GAP fillers 60a, 60b (resin members) are filled between the top surface of the SoC 13 (electronic component) and the bottom surface of the heat sink 15 (heat dissipation member), and between the top surface of the heat sink 15 and the bottom surface of the cooling fin 30. This can promote heat dissipation from the SoC 13.

[0076] Furthermore, in the in-vehicle electronic device 10 (in-vehicle device) of this embodiment, the heat sink 15 (heat dissipation member) is installed with gaps filled with GAP fillers 60a, 60b (resin members) between the top surface of the SoC 13 (electronic component) and the bottom surface of the heat sink 15, and between the top surface of the heat sink 15 and the bottom surface of the cooling fin 30. Therefore, regardless of the surface condition of each member or the warping state of each member, gaps filled with GAP fillers 60a, 60b can be formed between the members. This can promote heat dissipation from the SoC 13.

[0077] Although the embodiment of the present invention has been described above, the above-mentioned embodiment is presented as an example and is not intended to limit the scope of the present invention. This new embodiment can be embodied in various other forms. In addition, various omissions, substitutions, and modifications can be made without departing from the gist of the invention. In addition, this embodiment is included in the scope and gist of the invention, and is included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0078] 10 In-vehicle electronic equipment (in-vehicle equipment) 11. Cabinet 11a Upper Chassis 11b Lower chassis 11c rear chassis 11d Front chassis 12a, 12b Circuit board 13 SoC (electronic components) 15 Heat sink (heat dissipation material) 16a,16b,16c protrusion 17a,17b,17c Abutment part 18 Wall 19 Proximity Zone 20 Centrifugal fan (cooling fan) 21 Housing 22 Air intake 23 Motor 24 Blades 25 Ventilation vent 26 Planar area 30 Cooling fins 31 Finn 40 Bracket (air guide member) 50 Axial fan (exhaust fan) 51 Motor 52 Fans 60a, 60b GAP filler (resin material) 70 Bracket 71a,71b Arms 72a, 72b screw holes 73a, 73b Board-to-board connector 74 Connector passage 75a,75b bis 80 Drain 81, 81a, 81b, 81c, 82 recess D Blade diameter d Distance F1, F2, F3, F4, F5 Drainage route W Cooling air ha,hb Height

Claims

1. A housing and Provided inside the housing, a plate-shaped heat dissipation member that contacts an upper surface of an electronic component and dissipates heat generated by the electronic component; a cooling fin that is detachably abutted against an area of ​​the upper surface of the heat dissipation member that includes at least an area of ​​the upper surface of the electronic component and that promotes heat dissipation from the heat dissipation member; a cooling fan configured to blow cooling air along the heat dissipation member between a plurality of fins constituting the cooling fin; An in-vehicle device comprising:

2. an air guide member that is installed so as to cover an air outlet of the cooling fan and a tip side of the fin and guides the cooling air blown by the cooling fan between a plurality of fins that the cooling fin includes; and an exhaust fan that exhausts the cooling air that has passed through the cooling fins to the outside of the housing. The in-vehicle device according to claim 1 .

3. The height from the upper surface of the heat dissipation member to the tip of the cooling fin is higher than the height of the air outlet of the cooling fan. The in-vehicle device according to claim 1 or 2.

4. A thermally conductive resin member is filled between the top surface of the electronic component and the bottom surface of the heat dissipation member, and between the top surface of the heat dissipation member and the bottom surface of the cooling fin. The in-vehicle device according to claim 1 or 2.

5. The heat dissipation member is the electronic component and the heat dissipation member are disposed with gaps between the top surface of the electronic component and the bottom surface of the heat dissipation member, and between the top surface of the heat dissipation member and the bottom surface of the cooling fin, into which the resin member is filled; The vehicle-mounted device according to claim 4.

Images