Electronic apparatus for vehicle

Abstract

To prolong the life of a flash memory soldered to a circuit board of an electronic apparatus for a vehicle, while suppressing increase of cost or space.SOLUTION: An electronic apparatus (a data relay device 1) for a vehicle includes: a housing 10; a circuit board 11 stored in the housing 10, a flash memory 32 and a CPU 30 being soldered to each other in the circuit board 11 and the CPU 30 generating more heat than the flash memory 32 ; and a heat release member 12 made of metal and having a heat release unit 17 separate from the circuit board 11 and a first extension unit 18 extending from the heat release unit 17 and in contact with a CPU 30, the flash memory 32 not being in contact with the heat release member 12.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The technology disclosed in this specification relates to an in-vehicle electronic device. [Background technology]

[0002] Electronic devices that include a housing and a circuit board housed in the housing may require some kind of heat countermeasure (see, for example, Patent Document 1). The electronic device described in Patent Document 1 configures an air tunnel by disposing a frame made of a sponge-like material between the top plate and the shield case, and guides air inside the shield case that is guided by a fan to a heat dissipation hole opened in the top plate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-323878 A Summary of the Invention [Problem to be solved by the invention]

[0004] Some electronic devices are mounted on vehicles. Electronic devices mounted on vehicles (hereinafter referred to as in-vehicle electronic devices) may have a flash memory mounted on the circuit board. When mounting a flash memory on a circuit board, it is possible to mount the flash memory by inserting it into a connector provided on the circuit board. However, in the case of in-vehicle electronic devices, there is a concern that the flash memory may come off the connector due to vibrations of the vehicle, so it is generally fixed to the circuit board by soldering.

[0005] It is known that the higher the temperature of flash memory, the shorter its lifespan becomes. If the flash memory is inserted into a connector, it is easy to replace it even if it reaches the end of its lifespan, but in the case of in-vehicle electronic devices, the flash memory is soldered in place, so it is not easy to replace. For this reason, in the case of in-vehicle electronic devices, it is desirable to extend the life of flash memory by implementing heat countermeasures so as to eliminate the need to replace the flash memory. In this case, it is possible to install a fan inside the housing as in the electronic device described in the above-mentioned Patent Document 1, but in general, in-vehicle electronic devices are often not equipped with fans due to cost, space, and other considerations. Since it is difficult to generate air flow inside a vehicle, it is also difficult to cool the flash memory using the air flow inside the vehicle.

[0006] This specification discloses a technique for extending the life of a flash memory soldered to a circuit board included in an in-vehicle electronic device while suppressing increases in cost and space. [Means for solving the problem]

[0007] The in-vehicle electronic device of the present disclosure is an in-vehicle electronic device comprising: a housing; a circuit board housed in the housing, the circuit board having a flash memory and a first electronic component that generates more heat than the flash memory soldered thereto; and a metallic heat dissipation member having a heat dissipation portion spaced apart from the circuit board and a first extension portion extending from the heat dissipation portion and in contact with the first electronic component, wherein the flash memory is not in contact with the heat dissipation member. Effect of the Invention

[0008] According to the present disclosure, it is possible to extend the life of a flash memory soldered to a circuit board included in an in-vehicle electronic device while suppressing increases in cost and space. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a data relay device according to the first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the data relay device. [Diagram 3] FIG. 3 is a perspective view of the circuit board. [Figure 4]FIG. 4 is a perspective view of the heat dissipation member as viewed from below. [Diagram 5] FIG. 5 is a cross-sectional view of the data relay device according to the second embodiment. [Figure 6] FIG. 6 is a cross-sectional view of a data relay device according to the third embodiment. [Figure 7] FIG. 7 is a cross-sectional view of an in-vehicle electronic device according to a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [Description of the embodiments of the present disclosure] First, embodiments of the present disclosure will be listed and described.

[0011] (1) An in-vehicle electronic device according to the present disclosure comprises a housing; a circuit board housed in the housing, the circuit board having a flash memory and a first electronic component that generates more heat than the flash memory soldered thereto; and a metallic heat dissipation member having a heat dissipation portion spaced apart from the circuit board and a first extension portion extending from the heat dissipation portion and in contact with the first electronic component, wherein the flash memory is not in contact with the heat dissipation member.

[0012] The effect of the in-vehicle electronic device described in (1) above will be described with reference to a comparative example shown in Fig. 7. In-vehicle electronic device 401 according to the comparative example includes a metal heat dissipation member 412. Heat dissipation member 412 includes a heat dissipation section 417 spaced apart from circuit board 411, and an extension section 418 extending from heat dissipation section 417 and in contact with electronic component 430. Electronic component 430 is a component that generates more heat than flash memory 432. In in-vehicle electronic device 401 according to the comparative example, extension section 418 further extends from heat dissipation section 417 toward flash memory 432, and extension section 418 is in contact with flash memory 432.

[0013] In the in-vehicle electronic device 401 according to the comparative example, the heat of the electronic component 430 and the heat of the flash memory 432 are averaged by the heat dissipation member 412. In other words, the temperature burden is shared between the electronic component 430 and the flash memory 432, so that it is possible to prevent the temperature of the electronic component 430 from rising significantly. In this case, there is a problem that the temperature of the electronic component 430 falls, but the temperature of the flash memory 432 rises.

[0014] In contrast, in the in-vehicle electronic device described in (1) above, the first electronic component contacts the heat dissipation member via the first extension portion, while the flash memory does not contact the heat dissipation member, so that the temperature rise of the flash memory can be suppressed compared to when the first electronic component and the flash memory are in contact with the heat dissipation member to equalize the temperatures. Therefore, the flash memory soldered to the circuit board provided in the in-vehicle electronic device can have a longer life while suppressing increases in cost and space.

[0015] (2) In the in-vehicle electronic device described in (1) above, the flash memory may be covered with a sheet-like insulating material.

[0016] According to the in-vehicle electronic device described in (2) above, the flash memory is covered with a sheet-like heat insulating material, so that it is possible to suppress an increase in the temperature of the flash memory due to radiant heat from the first extension portion.

[0017] (3) In the in-vehicle electronic device described in (1) or (2) above, a sheet-like heat insulating material may be wound around an outer peripheral surface of the first extension portion.

[0018] If the first extension is not wrapped with a heat insulating material, the temperature of the flash memory may increase due to radiant heat from the first extension. According to the in-vehicle electronic device described in (3) above, since the outer peripheral surface of the first extension portion is wrapped with a heat insulating material, it is possible to suppress an increase in temperature of the flash memory due to radiant heat from the first extension portion.

[0019] (4) In the in-vehicle electronic device described in (1) or (2) above, a sheet-shaped heat insulating material may be disposed between the heat dissipation portion and the circuit board.

[0020] If a sheet-like insulating material is not placed between the heat dissipation section and the circuit board, the heat from the heat dissipation section will cause the temperature inside the housing to rise, which may in turn cause the temperature of the flash memory to rise. According to the in-vehicle electronic device described in (4) above, since the sheet-shaped heat insulating material is disposed between the heat dissipation unit and the circuit board, the temperature inside the housing is less likely to rise, which makes it possible to further suppress the temperature rise of the flash memory.

[0021] (5) In the in-vehicle electronic device described in (1) or (2) above, the first electronic component may be an integrated circuit for arithmetic processing.

[0022] Generally, integrated circuits (ICs) used for arithmetic processing become very hot. According to the in-vehicle electronic device described in (5) above, the integrated circuit for arithmetic processing is in contact with the heat dissipation member, whereas the flash memory is not in contact with the heat dissipation member, so that the temperature rise of the flash memory can be suppressed.

[0023] (6) In the in-vehicle electronic device described above in (5), the integrated circuit for arithmetic processing may be an integrated circuit for Ethernet communication that performs arithmetic processing for Ethernet communication. Generally, integrated circuits used for Ethernet communication become very hot. According to the in-vehicle electronic device described in (6) above, the integrated circuit for Ethernet communication is in contact with the heat dissipation member, whereas the flash memory is not in contact with the heat dissipation member, so that the temperature rise of the flash memory can be suppressed.

[0024] (7) In the in-vehicle electronic device described in (1) or (2) above, a second electronic component that generates less heat than the first electronic component is soldered to the circuit board, and the heat dissipation member may have a second extension portion extending from the heat dissipation portion and in contact with the second electronic component.

[0025] According to the in-vehicle electronic device described in (7) above, the second electronic component, which generates less heat than the first electronic component, is in contact with the heat dissipation member via the second extension portion. Therefore, the temperature is equalized between the first electronic component and the second electronic component, thereby preventing the temperature of the first electronic component from rising significantly. [Details of the embodiment of the present disclosure] The present disclosure will be described below with reference to the embodiments. The present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0026] <Embodiment 1> The first embodiment will be described with reference to Figures 1 to 4. In the following description, the up-down direction, the front-rear direction, and the left-right direction are based on the up-down direction, the front-rear direction, and the left-right direction shown in Figure 1.

[0027] A data relay device 1 as an in-vehicle electronic device according to the first embodiment will be described with reference to Fig. 1. The data relay device 1 is a device that relays data between a plurality of in-vehicle networks having different communication protocols. The data relay device 1 is called, for example, a CGW-ECU (Central Gateway - Electronic Control Unit). Examples of the multiple in-vehicle networks include a Controller Area Network (CAN), a Local Interconnect Network (LIN), an in-vehicle Ethernet, etc. At least an in-vehicle Ethernet is connected to the data relay device 1 according to the first embodiment.

[0028] As shown in Fig. 1, the data relay device 1 is generally box-shaped. As shown in Fig. 2, the data relay device 1 includes a housing 10, a circuit board 11 housed in the housing 10, and a heat dissipation member 12. The housing 10 is made of resin and has a box-shaped case portion 13 that is open at the top, and a lid portion 14 that is fixed to the top of the case portion 13. The case portion 13 has a bottom wall portion 15 that is rectangular when viewed from above, and a side wall portion 16 that rises in an annular shape from the outer periphery of the bottom wall portion 15.

[0029] An example of the circuit board 11 will be described with reference to Figures 2 and 3. As shown in Figure 2, the circuit board 11 is housed in the housing 10 in a position parallel to the bottom wall portion 15. As shown in Figure 3, a CPU 30, a RAM (random access memory) 31, and a flash memory 32 are mounted by soldering on the upper surface of the circuit board 11. Other components are also mounted on the circuit board 11, but these are omitted. The CPU 30 is an example of a first electronic component that generates more heat than a flash memory, an integrated circuit for arithmetic processing, and an integrated circuit for Ethernet communication. The RAM 31 is an example of a second electronic component that generates less heat than the first electronic component.

[0030] The CPU 30 is a CPU for Ethernet communication that performs calculation processing for Ethernet communication. Generally, in-vehicle Ethernet has a high communication speed, so the CPU 30 for Ethernet communication performs a large amount of calculation processing per unit time. Therefore, the CPU 30 for Ethernet communication generally generates more heat than the flash memory 32. The RAM 31 is a main storage device for the CPU 30 to execute various programs.

[0031] The flash memory 32 is a rewritable non-volatile semiconductor memory. Various programs and data executed by the CPU 30 are stored in the flash memory 32. Examples of the flash memory 32 include a NAND type flash ROM and a NOR type flash ROM. The NAND type flash ROM also includes an eMMC (embedded Multi Media Card).

[0032] The heat dissipation member 12 will be described with reference to Fig. 2. The heat dissipation member 12 is fixed to the lid portion 14 of the housing 10 with screws, bolts, or the like. The heat dissipation member 12 is made of a metal such as aluminum or copper, and has a heat dissipation portion 17 spaced apart from the circuit board 11, and a first extension portion 18 extending from the heat dissipation portion 17. The heat dissipation portion 17 has a flat board portion 19 and a plurality of heat dissipation fins 20 formed integrally with the board portion 19. The plurality of heat dissipation fins 20 rise up parallel to one another from the upper surface of the board portion 19.

[0033] 2 and 4, the first extension 18 is provided at a position overlapping with the CPU 30 when viewed from above. As shown in Fig. 2, an opening 21 is formed in the lid 14 of the housing 10 at a position corresponding to the first extension 18. The first extension 18 passes through the opening 21 in the lid 14 and is inserted into the inside of the housing 10, and its lower surface is in contact with the upper surface of the CPU 30. Therefore, heat from the CPU 30 is transferred to the heat dissipation section 17 via the first extension 18.

[0034] A sheet-like heat insulating material 22 is wound around the outer peripheral surface of the first stretched portion 18. The heat insulating material 22 is, for example, flexible aerogel. The sheet-like heat insulating material 22 is not limited to flexible aerogel as long as it has heat insulating properties, and can be appropriately selected.

[0035] A sheet-like heat insulating material 23 is disposed between the heat dissipation section 17 and the circuit board 11. The heat insulating material 23 is attached to the lower surface of the substrate section 19 of the heat dissipation section 17 (specifically, a portion of the lower surface of the substrate section 19 where the first extension section 18 is not formed). The heat insulating material 23 may be attached to the upper surface of the lid section 14 instead of the lower surface of the substrate section 19. Alternatively, the heat insulating material 23 may not be attached to either the lower surface of the substrate section 19 or the upper surface of the lid section 14, but may simply be sandwiched between the lower surface of the substrate section 19 and the upper surface of the lid section 14. The heat insulating material 22 wrapped around the first extension section 18 and the heat insulating material 23 attached to the lower surface of the substrate section 19 may be of different types.

[0036] The heat dissipation section 17 does not have an extension provided at a position overlapping the flash memory 32 when viewed from above. Therefore, the flash memory 32 is not in contact with the heat dissipation member 12. 2 and 3, the flash memory 32 is covered from above with a sheet-shaped insulating material 24. When viewed from above, the insulating material 24 has a shape that is slightly larger than the shape of the flash memory 32. The type of insulating material 24 may also be different from the insulating materials 22 and 23.

[0037] (2) Effects of the embodiment According to the data relay device 1 of the first embodiment, the CPU 30 contacts the heat dissipation member 12 via the first extension portion 18, while the flash memory 32 does not contact the heat dissipation member 12, so that the temperature rise of the flash memory 32 can be suppressed compared to the case where the CPU 30 and the flash memory 32 are brought into contact with the heat dissipation member 12 to equalize the temperature. Therefore, the flash memory 32 soldered to the circuit board 11 provided in the data relay device 1 can have a longer life while suppressing increases in cost and space.

[0038] According to the data relay device 1, the flash memory 32 is covered with the sheet-like heat insulating material 24, so that an increase in the temperature of the flash memory 32 due to radiant heat from the first extension portion 18 can be suppressed.

[0039] According to the data relay device 1, since the heat insulating material 22 is wound around the outer peripheral surface of the first extension portion 18, an increase in temperature of the flash memory 32 due to radiant heat from the first extension portion 18 can be suppressed.

[0040] According to the data relay device 1, the sheet-shaped heat insulating material 23 is disposed between the heat dissipation unit 17 and the circuit board 11, so that the temperature inside the housing 10 is less likely to rise. This makes it possible to further suppress the rise in temperature of the flash memory 32.

[0041] In the data relay device 1, the first electronic component that generates more heat than the flash memory 32 is the CPU 30. In the data relay device 1, the CPU 30 is in contact with the heat dissipation member 12, whereas the flash memory 32 is not in contact with the heat dissipation member 12, so that an increase in the temperature of the flash memory 32 can be suppressed.

[0042] In the data relay device 1, the CPU 30 is a CPU for Ethernet communication. In the data relay device 1, the CPU 30 for Ethernet communication is in contact with the heat dissipation member 12, while the flash memory 32 is not in contact with the heat dissipation member 12, so that the rise in temperature of the flash memory 32 can be suppressed.

[0043] <Embodiment 2> A data relay device 201 according to the second embodiment will be described with reference to Fig. 5. The heat dissipation member 212 of the data relay device 201 has a second extension portion 218 extending from the heat dissipation portion 17. The lower surface of the second extension portion 218 is in contact with the RAM 31. A sheet-like heat insulating material 22 is also wound around the outer peripheral surface of the second extension portion 218. The data relay device 201 according to the second embodiment is substantially the same as the data relay device 1 according to the first embodiment in other respects.

[0044] According to the data relay device 201 of the second embodiment, the RAM 31, which generates less heat than the CPU 30, is in contact with the second extension portion 218, and therefore the temperature is equalized between the CPU 30 and the RAM 31, thereby preventing the temperature of the CPU 30 from rising significantly. In general, the lifespan of the RAM 31 is unlikely to be shortened even if it becomes hot, so that the lifespan of the RAM 31 is unlikely to be shortened even if the temperature of the RAM 31 rises due to the equalization.

[0045] <Embodiment 3> A data relay device 301 according to the third embodiment will be described with reference to Fig. 6. The data relay device 301 does not include the cover part 14 of the first embodiment. The data relay device 301 according to the third embodiment is substantially the same as the data relay device 1 according to the first embodiment in other respects.

[0046] According to the data relay device 1 of the third embodiment, since the cover part 14 is not provided, the configuration of the data relay device 1 can be simplified.

[0047] <Other embodiments> The technology disclosed in this specification is not limited to the embodiments described above and in the drawings, and for example, the following embodiments are also included in the technical scope disclosed in this specification.

[0048] (1) In the above embodiment, the data relay device 1 (CGW-ECU) is exemplified as an in-vehicle electronic device, but the in-vehicle electronic device is not limited to this. For example, the in-vehicle electronic device may be an ECU for engine control, an ECU for gear shift control, or an ECU for brake control. The in-vehicle electronic device may be an electronic device other than an ECU.

[0049] (2) In the above embodiment, the CPU 30 is exemplified as an integrated circuit for arithmetic processing, but the integrated circuit for arithmetic processing may be an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), or a microcomputer (so-called microcomputer). A microcomputer is an integrated circuit in which a CPU, RAM, flash memory, etc. are integrated into a single chip. Since the flash memory of a microcomputer generally has a small capacity, a large-capacity flash memory is often mounted on the circuit board 11 separately from the microcomputer. In this case, the microcomputer is brought into contact with the heat dissipation member 12, while the flash memory mounted separately from the microcomputer is not brought into contact with the heat dissipation member 12, thereby extending the life of the flash memory mounted separately from the microcomputer.

[0050] (3) In the above embodiment, the case was exemplified where the lower surface of the first extension portion 18 is in direct contact with the CPU 30. In contrast, the lower surface of the first extension portion 18 may be indirectly in contact with the CPU 30 via a thermal pad, thermally conductive grease, a thermally conductive adhesive (for example, a thermally conductive two-part adhesive), or the like.

[0051] (4) In the above embodiment, the heat dissipation section 17 has the substrate section 19 and the plurality of heat dissipation fins 20, but the heat dissipation section 17 does not have to have the heat dissipation fins 20. In other words, the heat dissipation section 17 may be composed of only the substrate section 19.

[0052] (5) In the above embodiment, the case where the housing 10 is made of resin is illustrated. However, the housing 10 may be made of metal.

[0053] (6) In the above embodiment, the RAM 31 is exemplified as the second electronic component, but the second electronic component is not limited to the RAM 31 as long as it is an electronic component that generates less heat than the first electronic component. For example, the second electronic component may be a power supply IC or a FET (Field Effect Transistor).

[0054] (7) In the above embodiment, the first extension portion 18 and the second extension portion 218 extend straight toward the circuit board 11, but they may extend while bending. [Explanation of symbols]

[0055] 1: Data relay device (an example of an in-vehicle electronic device) 10: Housing 11: Circuit Board 12: Heat dissipation material 13: Case part 14: Lid 15: Bottom wall 16: Side wall 17: Heat dissipation part 18: First extension 19: Circuit board 20: Heat sink fin 21: Aperture 22: Insulation 23: Insulation 24: Insulation 30: CPU (an example of a first electronic component, an integrated circuit for arithmetic processing, and an integrated circuit for Ethernet communication) 31: RAM (an example of a second electronic component) 32: Flash memory 201: Data relay device 212: Heat dissipation materials 218: Second extension 301: Data relay device 401: Automotive electronic equipment 411: Circuit Board 412: Heat dissipation materials 417: Heat radiation part 418: Extension part 430: Electronic Components 432: Flash memory

Claims

1. An in-vehicle electronic device, A housing and a circuit board housed in the housing, the circuit board having a flash memory and a first electronic component soldered thereto, the first electronic component generating more heat than the flash memory; a heat dissipation member made of metal, the heat dissipation member having a heat dissipation portion spaced apart from the circuit board and a first extension portion extending from the heat dissipation portion and in contact with the first electronic component; Equipped with The electronic device for vehicle mounting, wherein the flash memory is not in contact with the heat dissipation member.

2. 2. The in-vehicle electronic device according to claim 1, The electronic device for vehicle installation, wherein the flash memory is covered with a sheet-like heat insulating material.

3. 3. The in-vehicle electronic device according to claim 1, The electronic device for vehicle mounting, wherein a sheet-shaped insulating material is wrapped around an outer peripheral surface of the first extension portion.

4. 3. The in-vehicle electronic device according to claim 1, The electronic device for vehicle installation, further comprising: a sheet-shaped heat insulating material disposed between the heat dissipation portion and the circuit board.

5. 3. The in-vehicle electronic device according to claim 1, The electronic device for an automobile, wherein the first electronic component is an integrated circuit for arithmetic processing.

6. 6. The in-vehicle electronic device according to claim 5, The integrated circuit for arithmetic processing is an integrated circuit for Ethernet communication that performs arithmetic processing for Ethernet communication.

7. 3. The in-vehicle electronic device according to claim 1, a second electronic component that generates less heat than the first electronic component is soldered to the circuit board; The heat dissipation member has a second extension portion extending from the heat dissipation portion, the second extension portion being in contact with the second electronic component.

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