Cooling structure of the computing unit

Abstract

To enable an IC chip to be cooled effectively in a limited space of an arithmetic unit.SOLUTION: The invention relates to a cooling structure of an arithmetic unit 1 including a substrate 3 provided with an IC chip 6 and a housing 2. The cooling structure has: a coolant jacket 4 having a metallic cooling wall 4d which faces the substrate 3 through a gap 5a; and an outside air intake port 9 and an outside air discharge port 10 which are open at the housing 2 and circulate outside air in the gap 5a. The IC chip 6 is arranged in the gap 5a while contacting with the cooling wall 4d through a conduction member 7. Multiple projections 4e are provided on the cooling wall 4d facing the gap 5a.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The disclosed technology relates to a cooling structure for a computing unit that includes a substrate on which a plurality of electronic components including an IC chip are mounted. [Background technology]

[0002] In recent years, advances in computer and communication technologies have led to a remarkable shift to electrification of automobiles. The number of automobiles that run on electricity, such as hybrid and electric vehicles, is on the rise. Furthermore, the number of high-performance electrical components installed in automobiles, such as cameras and sensors, is also increasing. Accordingly, automobiles are increasingly being equipped with high-performance computing units that can process the vast amounts of data obtained from these components in a short period of time.

[0003] Furthermore, by enabling the onboard computing unit to send and receive data to and from external systems via a network, it is becoming possible to use the computing unit to provide a wide variety of services and support not only when the car is being driven, but also when the car is not being driven.

[0004] In the future, it is expected that the data handled by in-vehicle computing units will become even larger, and that the content of that data will increase, including video, audio, etc. Accordingly, it is expected that the performance of electronic components such as IC chips installed in computing units will also improve in line with the amount of data.

[0005] Regarding the disclosed technology, Patent Document 1 discloses a cooling structure in which an air passage for blowing air by a fan is provided inside a sealed electronic device housing, a heat-conducting member with high thermal conductivity and a large surface area is attached to a heat-generating member, and part of the heat-conducting member is arranged in the air passage. Heat generated by the heat-generating member is dissipated into the air passage through the heat-conducting member. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-251916 Summary of the Invention [Problem to be solved by the invention]

[0007] The more powerful an IC chip is, the more heat it generates during processing, so the cooling power of the IC chip must also be increased accordingly.

[0008] In contrast, electrical equipment installed in automobiles, including the on-board computing unit, is powered by a battery with limited power. Therefore, the cooling of the computing unit, which only has an auxiliary function, requires power saving. It is preferable to cool the IC chip with the necessary and sufficient power consumption according to the heat generation amount.

[0009] The cooling structure of Patent Document 1 uses air cooling to cool heat-generating components. Therefore, the cooling effect decreases when the ambient temperature is high, such as in summer. Running the fan at full capacity may prevent abnormal temperatures in the heat-generating components, but it consumes battery power. From the perspective of power saving, there is room for improvement in the cooling structure of Patent Document 1.

[0010] Furthermore, in the case of an in-vehicle computing unit, the installation space is limited, so the in-vehicle computing unit must be thin and compact, and therefore must be able to be cooled efficiently even in such a limited space.

[0011] The purpose of the disclosed technology is to enable the IC chip to be cooled effectively by efficiently utilizing the limited space in the computing unit. [Means for solving the problem]

[0012] The disclosed technology relates to a cooling structure for a computing unit that includes a substrate on which a plurality of electronic components including an IC chip are provided, and a housing that houses the substrate.

[0013] The cooling structure of the computing unit includes a cooling water jacket having a metal cooling wall facing the board across a gap, and an outside air intake and an outside air exhaust opening that open in the housing to circulate outside air through the gap. The IC chip is placed in the gap in contact with the cooling wall via a heat conductive member, and a plurality of protrusions are provided on the cooling wall facing the gap.

[0014] In other words, according to the cooling structure of this computing unit, the IC chip, which dissipates heat during operation, is placed in the gap between the substrate and the cooling wall, in contact with the metal cooling wall of the cooling water jacket through which cooling water flows, i.e., the cooling wall with excellent thermal conductivity, via a heat conductive member, i.e., a member with excellent thermal conductivity.

[0015] The cooling wall has a plurality of protrusions on the portion facing the gap, and the gap is configured so that outside air can flow through the outside air intake and outside air exhaust openings in the housing.

[0016] Therefore, since the IC chip is thermally connected to the cooling wall, the heat generated by the IC chip can be efficiently dissipated to the cooling water jacket and the cooling water therein via the cooling wall, regardless of whether the cooling water inside the cooling water jacket is flowing or not, thereby cooling the IC chip.

[0017] If the cooling water inside the cooling water jacket is flowing, the IC chip can be water-cooled, and therefore the IC chip can be cooled more effectively.

[0018] The outside air that flows through the gap not only flows in contact with the IC chip, but also flows along the cooling wall whose surface area is enlarged by the protrusions. Therefore, when the outside air flows through the gap, it can cool the IC chip through direct heat exchange with the outside air and indirect heat exchange with the outside air via the cooling wall, i.e., air cooling.

[0019] That is, with this cooling structure for the computing unit, the IC chip can be cooled by water cooling, air cooling, or both. Because the cooling method can be selected depending on the level of cooling demands of the IC chip, the IC chip can be cooled with the necessary and sufficient power consumption according to the amount of heat generated by the IC chip.

[0020] Furthermore, the cooling structure of this computing unit cools the IC chip using the cooling water jacket itself and the gap between the cooling water jacket and the substrate, making it possible to efficiently utilize the limited space in the computing unit and suitable for a thin, compact computing unit.

[0021] The cooling structure of the computing unit may also be such that a plurality of the protrusions are arranged near the IC chip.

[0022] This increases the surface area of ​​the cooling wall facing the gap near the IC chip, allowing the IC chip to be cooled more effectively.

[0023] Furthermore, a plurality of the protrusions may be arranged around the entire periphery of the IC chip.

[0024] This increases the surface area of ​​the cooling wall facing the gap all around the IC chip, allowing the heat from the IC chip to be dissipated in all directions without being concentrated in one direction, resulting in even more effective cooling of the IC chip.

[0025] The size of the gap is preferably smaller than twice the thickness of the IC chip.

[0026] In other words, if the gap is slightly larger than the IC chip, the surface of the IC chip can be attached substantially directly to the cooling wall. Therefore, the heat of the IC chip can be efficiently dissipated to the cooling wall. Moreover, since the thickness of the cooling structure is thin, it is suitable for thin and compact computing units.

[0027] The cooling structure of the computing unit may also be such that the cooling water jacket has a thin plate shape, a cooling water flow path is formed inside the cooling water jacket so as to extend along the substrate, and the cooling water flow path is adjacent to the gap via the cooling wall.

[0028] This reduces the thickness of the cooling structure, making it suitable for a thin, compact computing unit. Moreover, the IC chip can be cooled efficiently with a small amount of cooling water. The IC chip can be effectively water-cooled.

[0029] The cooling structure of the computing unit may also be such that the plurality of electronic components include non-chip electronic components installed on a second surface of the substrate facing the opposite side of the gap, and the outside air intake and the outside air exhaust allow the outside air to circulate below the second surface as well as the gap.

[0030] An IC chip is a thin electronic component. A board usually has multiple electronic components mounted on it. If an electronic component larger than the IC chip is mounted on the second surface of the board, facing the opposite side of the gap, the gap can be reduced. If outside air is also circulated below the second surface, the heat from the electronic components mounted on the second surface can also be dissipated to the outside air. In other words, the IC chip and other electronic components can be air-cooled.

[0031] The cooling structure for the computing unit may further include a fan that takes in outside air through the outside air intake and discharges it through the outside air exhaust port.

[0032] This allows the fan to be operated as needed to cool the IC chip. Moreover, since the fan can be operated instantly, the IC chip can be cooled quickly in response to cooling demands. [Effects of the Invention]

[0033] The disclosed technology enables IC chips to be cooled effectively. [Brief explanation of the drawings]

[0034] [Figure 1] 1 is a schematic diagram showing a cooling structure of a computing unit to which the disclosed technology is applied; [Figure 2] 1 shows a specific example of a computing unit. The upper figure is a top view of the computing unit, and the lower figure is a left side view thereof. [Figure 3] 1 shows a specific example of a computing unit. The upper figure is a front view of the computing unit, and the lower figure is a rear view. [Figure 4] FIG. 3 is a schematic cross-sectional view taken along the arrow line AA in FIG. 2. [Figure 5] The upper diagram is a schematic cross-sectional view taken along the arrow line BB in FIG. 2, and the lower diagram is a schematic cross-sectional view taken along the arrow line CC in FIG. [Figure 6] FIG. 2 is a schematic perspective view showing the main part of a specific example of an arithmetic unit. [Figure 7] 10 is a flowchart showing a specific example of cooling of a computing unit. DETAILED DESCRIPTION OF THE INVENTION

[0035] Hereinafter, embodiments of the disclosed technology will be described. However, the following description is essentially merely exemplary. For convenience, the up / down, left / right, and front / rear directions used in the description will follow the directions shown in each drawing.

[0036] <Cooling structure of computing unit 1> 1 is a schematic diagram showing the cooling structure of a computing unit 1 to which the disclosed technology is applied. This computing unit 1 is configured for in-vehicle use and is installed inside the automobile (in a location accessible from the passenger compartment).

[0037] The computing unit 1 has a low metal housing 2. A printed circuit board 3 with various electronic components mounted on both sides is housed inside the housing 2. The housing 2 has a thin rectangular parallelepiped appearance corresponding to the printed circuit board 3 having a rectangular surface.

[0038] A metal cooling water jacket 4 in the shape of a thin plate is provided on one flat surface (top surface) of the thin housing 2. A cooling water flow path 4a is formed inside the cooling water jacket 4 and extends along the flat surface. An inlet 4b for introducing cooling water and an outlet 4c for discharging cooling water are provided on the front side surface of the cooling water jacket 4. Cooling water is distributed and supplied to the cooling water flow path 4a from a cooling water circulation path 100c installed in the automobile via the inlet 4b and the outlet 4c.

[0039] That is, an automobile is provided with a coolant circulation mechanism 100 that circulates coolant to cool, for example, the engine, motor, transmission, etc. The coolant circulation mechanism 100 is composed of a radiator 100a, a water pump 100b, a coolant circulation path 100c, etc. When the water pump 100b is operated, the coolant circulates through the coolant circulation path 100c.

[0040] Coolant heated by the engine or the like passes through the radiator 100a and is cooled by heat exchange with the outside air. The coolant returns to the engine or the like, thereby cooling the engine or the like. The coolant flow path 4a is connected to the coolant circulation path 100c, and is configured so that cooled coolant flows into the coolant flow path 4a when the water pump 100b is operated.

[0041] An accommodation space 5 having a narrow vertical width and extending along the plane is defined on the other flat surface (bottom surface) inside the housing 2. The printed circuit boards 3 are accommodated in this accommodation space 5 in a predetermined arrangement.

[0042] An MMP 6 (multimedia processor) is installed in the center of the first surface (top surface) of the printed circuit board 3. In Fig. 1, only one MMP 6 is shown on the first surface of the printed circuit board 3. The MMP 6 is a thin electronic component (i.e., an IC chip) equipped with an integrated circuit, and is installed on the printed circuit board 3 with its underside in close contact with the top of the first surface of the printed circuit board 3.

[0043] The MMP6 is a high-performance processor suited to processing video data, including video and audio. The MMP6 mainly processes information related to services. For example, the MMP6 performs information processing such as recording video of the interior and exterior of a vehicle captured by an onboard camera while driving, linking it to information such as the date and time of capture and the location of the vehicle.

[0044] The MMP6 processes large amounts of data at high speed. As a result, the MMP6 generates a large amount of heat when in operation. Therefore, cooling the MMP6 is necessary to maintain an appropriate temperature when in operation.

[0045] The printed circuit board 3 is installed with its first surface facing the cooling water jacket 4, across a gap 5a, and facing a flat wall (cooling wall 4d) located inside the cooling water jacket 4. Thermal grease 7 (thermal conductive material) with excellent thermal conductivity is applied to the top surface of the MMP 6, and the entire top surface of the MMP 6 is in close contact (surface contact) with the cooling wall 4d via this thermal grease 7.

[0046] Therefore, the size G of the gap 5a between the printed circuit board 3 and the cooling surface is slightly larger than the thickness of the MMP 6. Since the thickness of the MMP 6 itself is small, the size G of the gap 5a is also small. The size G of the gap 5a is at least smaller than twice the thickness of the MMP 6.

[0047] On the second surface (bottom surface) of the substrate facing the opposite side of the gap 5a, there are mounted a plurality of electronic components (non-chip electronic components 8) such as capacitors and transistors, whose height from the substrate to their upper ends is greater than that of the MMP 6. Therefore, many of the electronic components are arranged on the second surface of the substrate.

[0048] Incidentally, although this embodiment shows a case where the MMP6 is installed alone on the first surface of the substrate, an IC chip with a thickness similar to that of the MMP6 may also be installed on the first surface of the substrate. Also, an electronic component (chip-type electronic component) whose height from the substrate to its top end is shorter than that of the MMP6 may also be installed.

[0049] Of the opposing front and rear side surfaces of the housing 2, an outside air intake 9 and an outside air exhaust 10 are open on the portions facing the storage space 5. The outside air intake 9 is provided on one side surface, and the outside air exhaust 10 is provided on the other side surface. Both the outside air intake 9 and the outside air exhaust 10 are positioned so as to face both above (gap 5a) and below (large space 5b) the printed circuit board 3 in the storage space 5.

[0050] A fan 11 is installed in the outside air intake 9. When the fan 11 is operated, outside air flows into the housing 2 from the outside air intake 9. The outside air that has flowed into the housing 2 flows toward the outside air exhaust port 10 while being divided into both the gap 5a and the storage space 5, as shown by the dashed arrows in FIG. 1 , and is then discharged from the outside air exhaust port 10 to the outside of the housing 2.

[0051] A plurality of fins 4e (an example of protrusions) are provided on the cooling wall 4d in an area excluding the contact portion of the MMP6. Each fin 4e has a thin plate shape extending along the flow direction of the outside air (front-rear direction) and is arranged approximately parallel at regular intervals in the left-right direction. Therefore, the outside air flowing through the gap 5a flows between these fins 4e. The amount by which the fins 4e protrude from the cooling wall 4d is equal to or less than the thickness of the MMP6.

[0052] (Effect of cooling structure) The entire upper surface of the MMP 6 is substantially directly attached to the cooling wall 4d of the cooling water jacket 4. The cooling wall 4d is made of metal and has excellent thermal conductivity. Moreover, the cooling wall 4d is provided with multiple fins 4e, which greatly increases its surface area.

[0053] Furthermore, a cooling water flow path 4a extends inside the cooling water jacket 4, separated only by a cooling wall 4d. The cooling water flow path 4a is filled with cooling water having a large heat capacity, regardless of whether the water pump 100b is operating or not.

[0054] Therefore, the heat generated in the MMP6 can be rapidly transferred to the cooling wall 4d and the cooling water as shown by the dashed arrows in FIG. 1, and can be dissipated efficiently.

[0055] Arranging multiple fins 4e near the MMP 6 can more effectively cool the MMP 6. Arranging multiple fins 4e around the entire periphery of the MMP 6 can dissipate heat from the MMP 6 in all directions without uneven distribution.

[0056] You can choose from three cooling methods: air cooling, water cooling, and air-water cooling (air cooling + water cooling).

[0057] Air cooling is achieved by operating the fan 11, which cools the MMP 6 through heat exchange with the outside air circulating inside the housing 2. Because the MMP 6 is located in the gap 5a through which the outside air flows, air cooling allows the MMP 6 to be directly cooled through heat exchange with the outside air. Most of the cooling surface faces the gap 5a, and many fins 4e are installed there. Therefore, the temperature of the cooling wall 4d drops due to heat exchange with the outside air, promoting heat transfer from the MMP 6 via the cooling wall 4d.

[0058] The outside air that flows into the housing 2 by the operation of the fan 11 also flows into the large space 5b. Many non-chip electronic components 8, such as capacitors and transistors, are arranged in the large space 5b. Therefore, air cooling can also dissipate the heat generated by these non-chip electronic components 8.

[0059] The fan 11 starts operating immediately when its motor is energized, so air cooling has excellent responsiveness.

[0060] Water cooling is achieved by heat exchange with the cooling water circulated through the cooling water flow path 4a. The MMP6 is adjacent to the cooling water flow path 4a via only the cooling wall 4d. By water cooling, the MMP6 absorbs heat from the flowing cooling water, allowing the MMP6 to be cooled powerfully. Furthermore, the cooling water jacket 4 has a thin plate shape. Therefore, heat can easily flow through the cooling water jacket 4, promoting heat transfer. The MMP6 can be cooled effectively.

[0061] However, water cooling depends on the operation of the water pump 100b. If the car is in a state where it can be driven, for example, if the ignition is on (IG on) and the engine is running, the water pump 100b is operating, and the MMP6 can be water-cooled.

[0062] On the other hand, if the vehicle is not drivable, for example, if the ignition is turned off (IG off) and the engine is stopped, the water pump 100b is not operating, and therefore, unless the water pump 100b is operated, the MMP 6 cannot be water-cooled. In order to water-cool the MMP 6, the water pump 100b must be operated.

[0063] Air-water cooling is simultaneous cooling using air and water. In air-water cooling, the fan 11 and the water pump 100b are activated. Therefore, the MMP 6 is cooled more powerfully.

[0064] In this way, with this cooling structure for the computing unit 1, the cooling means can be selected depending on the level of the cooling demands of the MMP 6. The cooling means can also be selected depending on the cooling situation of the MMP 6. For example, when the IG is on and there is spare cooling capacity in the cooling water circulation mechanism 100, selecting water cooling can reduce power consumption.

[0065] On the other hand, when the IG is off, the water pump 100b must be operated to perform water cooling. Therefore, performing water cooling when the IG is off increases power consumption and takes a long time before water cooling can be performed. On the other hand, with air cooling, the fan 11 rotates instantly when the fan motor is energized, allowing for immediate cooling and reducing power consumption compared to the water pump 100b. Also, even if air-water cooling is selected when the water pump 100b is stopped, the period until water cooling starts can be supplemented by air cooling.

[0066] In this way, the cooling structure of this computing unit 1 not only has excellent cooling capacity for the MMP 6, but also allows for selection of multiple cooling means with different cooling capacities depending on the situation, making it possible to cool the MMP 6 with the necessary and sufficient power consumption according to the amount of heat generated by the MMP 6. Therefore, the MMP 6 can be cooled effectively while suppressing power consumption.

[0067] Furthermore, this cooling structure is configured with thin air-cooling and water-cooling structures layered on top of the printed circuit board 3, making it applicable to a thin computing unit 1. Therefore, it is suitable for an in-vehicle computing unit 1.

[0068] <Example of an arithmetic unit> 2 to 5 show specific examples of the arithmetic unit 1 to which the disclosed technology is applied.

[0069] The upper view of Fig. 2 is a top view of the arithmetic unit 1, and the lower view of Fig. 2 is a left side view thereof. The upper view of Fig. 3 is a front view of the arithmetic unit 1, and the lower view of Fig. 3 is a rear view thereof. Fig. 4 is a schematic cross-sectional view taken along the arrow line AA in Fig. 2. The upper view of Fig. 5 is a schematic cross-sectional view taken along the arrow line BB in Fig. 2, and the lower view of Fig. 5 is a schematic cross-sectional view taken along the arrow line CC in Fig. 2. The symbols used for the various components in the previous explanations are also used in this explanation.

[0070] As shown in Fig. 2, the housing 2 of this computing unit 1 is constructed by placing a rectangular box-shaped metal case 21 on a plate-shaped mounting base 20. A pair of mounting brackets 20a, 20a are provided on each of the front and rear edges of the mounting base 20. The computing unit 1 is attached to the automobile by bolting these mounting brackets 20a.

[0071] A pair of connectors 22, 22 protrude from the left side surface of the metal case 21. Connectors for communication and power are connected to these connectors 22, 22. In this way, the arithmetic unit 1 is electrically connected.

[0072] A pair of connection ports constituting the inlet 4b and the outlet 4c protrude from the front surface of the metal case 21. Paths (such as hoses) branching from the cooling water circulation path 100c are connected to these connection ports.

[0073] As shown in Fig. 3 (upper diagram), a circular outside air intake 9 equipped with a fan 11 opens at a lower center position in the left-right direction on the front surface of metal case 21. As shown in Fig. 3 (lower diagram), a circular outside air exhaust port 10 opens at a lower center position in the left-right direction on the rear surface of metal case 21 so as to face outside air intake 9 in the front-rear direction.

[0074] As shown in Figures 4 and 5, a metallic cooling water jacket 4 is installed on top of the metal case 21. As shown in Figure 2, a cooling water flow path 4a is formed inside the jacket 4, which extends along the printed circuit board 3 and is partitioned in a meandering manner. This allows the cooling water to flow in a meandering manner along the printed circuit board 3, as shown by the dashed arrow in Figure 2.

[0075] 4 and 5, a storage space 5 for storing the printed circuit board 3 is provided in the lower part of the metal case 21 (below the cooling water jacket 4). As described above, the printed circuit board 3 is screwed to the cooling water jacket 4 so that the first surface faces the cooling wall 4d with a small gap 5a between them.

[0076] 6, the MMP 6 is located in the gap 5a and is in close surface contact with the cooling wall 4d via a thin layer of thermal grease 7. A plurality of fins 4e are provided on the cooling wall 4d in an area excluding the area in contact with the MMP 6. Each fin 4e has a thin plate shape extending in the front-rear direction and is arranged approximately parallel to the cooling wall 4d at regular intervals in the left-right direction.

[0077] 4 and 5, non-chip electronic components 8, such as capacitors, mounted on the second surface of printed circuit board 3 are located in large space 5b extending below printed circuit board 3. As shown in Fig. 5, outside air intake 9 is arranged so as to face both gap 5a and large space 5b. Outside air exhaust 10 is also arranged so as to face both gap 5a and large space 5b.

[0078] Therefore, when the fan 11 is operated, outside air flows into the gap 5a as shown by the arrow in Figure 6. The outside air passes between the fins 4e and flows along the cooling wall 4d. The outside air also flows in contact with the MMP 6. Therefore, the heat generated by the MMP 6 is dissipated directly into the outside air.

[0079] The cooling wall 4d facing the gap 5a has an expanded surface area due to multiple fins 4e. The gap 5a is adjacent to the cooling water flow path 4a via the cooling wall 4d. Therefore, heat from the MMP 6 can be quickly dissipated to the outside air and cooling water through heat transfer via the cooling wall 4d. The MMP 6 can be effectively cooled in a limited, narrow space. Operation of the fan 11 causes outside air to flow into the large gap 5b. Heat generated by the non-chip electronic components 8 can also be cooled by dissipating heat to the outside air.

[0080] Even if the fan 11 is not operating, if water cooling is performed, cooled cooling water will flow at a relatively high flow rate, as shown by the white arrows in Figure 6. The MMP 6 is powerfully cooled by heat transfer via the cooling wall 4d. If the fan 11 is operating in conjunction with water cooling, the MMP 6 is cooled even more powerfully.

[0081] <Example of cooling for computing units> Figure 7 shows a specific example (flowchart) of the cooling of the arithmetic unit 1. Although not shown in the figure, the arithmetic unit 1 is provided with a controller for controlling its cooling.

[0082] As described above, in this arithmetic unit 1, any one of three cooling means, namely air cooling, water cooling, and air-water cooling (air cooling + water cooling), can be selected according to the magnitude of the cooling requirement of MMP6. Therefore, the controller can select a cooling means according to the cooling requirement of MMP6. The cooling requirement of MMP6 can be determined, for example, from the temperature of MMP6.

[0083] During the operation of the vehicle, the cooling water is circulating. Therefore, when water cooling is performed using the remaining capacity of its cooling ability, air cooling is not selected alone. In this specific example, it is assumed that the time when the water pump 100b is not operating and the IG is off.

[0084] In advance, selection reference values for cooling requirements (C1 and C2, C1 < C2) are set in the controller. When the cooling requirement of MMP6 is small, that is, when the cooling requirement is less than C1 (Yes in step S1), the controller operates the fan 11 to perform air cooling (step S2). MMP6 can be appropriately and quickly cooled with low power consumption.

[0085] When the cooling requirement of MMP6 is medium, that is, when the cooling requirement is C or more and less than C2 (Yes in step S3), the controller circulates the cooling water by operating the water pump 100b to perform water cooling (step S4). MMP6 can be appropriately cooled with power consumption according to the cooling requirement.

[0086] When the cooling requirement of MMP6 is large, that is, when the cooling requirement is C2 or more (Yes in step S5), the controller operates the fan and the water pump 100b to perform air-water cooling (step S6). Even when the heat generation amount is large, MMP6 can be appropriately cooled.

[0087] In this way, the cooling structure of this computing unit 1 allows selection of multiple cooling means with different cooling capacities according to the cooling requirements of the MMP 6, making it possible to cool with the necessary and sufficient power consumption according to the amount of heat generated by the MMP 6. Therefore, the MMP 6 can be cooled effectively while suppressing power consumption.

[0088] The cooling means may be selected depending on the situation when the MMP6 is cooled, or may be selected depending on both the cooling demand for the MMP6 and the situation when the MMP6 is cooled.

[0089] The disclosed technology is not limited to the above-described embodiment, but also includes various other configurations.

[0090] For example, although the embodiment has been described with reference to an MMP6 as an example of an IC chip, the IC chip is not limited to the MMP6, and the disclosed technology can be applied to any IC chip that generates a large amount of heat.

[0091] The fan 11 is not essential. Air cooling may be achieved by using the wind generated by running the vehicle, or by using an air flow obtained by an on-board fan.

[0092] In the embodiment, the protrusions are exemplified as aligned fins 4e, but the shape and arrangement of the protrusions can be changed as appropriate depending on the specifications. For example, even if the protrusions are fins, they may be arranged in a staggered manner in the front-to-rear direction, and the protrusions may have a rod-like cross section that is circular, rectangular, polygonal, streamlined, or the like. [Explanation of symbols]

[0093] 1 arithmetic unit 2. Case 3 Printed circuit board 4 Cooling water jacket 4a Cooling water flow path 4b entrance 4c outlet 4d cooling wall 4e Fins (protrusions) 5. Storage space 5a Gap 5b Significant space 6 MMP (IC chip) 7 Thermal grease (heat conduction material) 8. Non-chip electronic components 9. Fresh air intake 10. Outside air outlet 11 Fan

Claims

1. A cooling structure for an in-vehicle computing unit including a substrate on which a plurality of electronic components including an IC chip are mounted, and a housing for accommodating the substrate, a cooling water jacket having a metal cooling wall facing the substrate across a gap and having a plurality of protrusions facing the gap; an outside air intake port and an outside air exhaust port that open to the housing and allow outside air to flow through the gap; a water pump that causes cooling water to flow inside the cooling water jacket; a fan that takes in outside air through the outside air intake and discharges it through the outside air exhaust port; and the IC chip is disposed in the gap in a state of contacting the cooling wall via a heat conductive member, The cooling structure for a computing unit allows selection of one of three cooling means: air cooling by operating the fan, water cooling by operating the water pump, and air-water cooling by operating the fan and the water pump.

2. 2. The cooling structure for a computing unit according to claim 1, A cooling structure for a computing unit, wherein a plurality of the protrusions are arranged in the vicinity of the IC chip.

3. 3. The cooling structure for a computing unit according to claim 2, A cooling structure for a computing unit, wherein a plurality of the protrusions are arranged around the entire periphery of the IC chip.

4. The cooling structure for a computing unit according to any one of claims 1 to 3, The cooling structure for a computing unit, wherein the size of the gap is smaller than twice the thickness of the IC chip.

5. The cooling structure for a computing unit according to any one of claims 1 to 4, The cooling water jacket has a thin plate shape, a cooling water flow path is formed inside the cooling water jacket so as to extend along the substrate, The cooling structure for a computing unit, wherein the cooling water flow path is adjacent to the gap via the cooling wall.

6. The cooling structure for a computing unit according to any one of claims 1 to 5, the plurality of electronic components include non-chip electronic components mounted on a second surface of the substrate facing the opposite side of the gap; The cooling structure for a computing unit, wherein the outside air intake and the outside air exhaust port allow the outside air to circulate below the second surface as well as the gap.

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