JP7746804B2 - Cooling structure of the computing unit - Google Patents

Description

The disclosed technology relates to a cooling structure for a computing unit that includes a substrate on which multiple electronic components, including IC chips, are mounted.

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

Furthermore, by enabling on-board computing units to send and receive data with external systems via networks, it is becoming possible to use the computing units not only when the car is being driven, but also when the car is not being driven, to provide a wide variety of services and support.

In the future, it is expected that the data handled by onboard computing units will become even larger, and that data content will increase to include more video, audio, and other content. Accordingly, the performance of electronic components such as IC chips installed in computing units is also expected to improve in line with the amount of data.

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

Japanese Patent Application Laid-Open No. 2005-251916

The more powerful an IC chip is, the more heat it generates during processing. Therefore, the cooling strength of the IC chip must also be increased accordingly.

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 energy conservation. It is preferable to cool the IC chip with the necessary and sufficient power consumption according to the amount of heat generated.

The cooling structure in Patent Document 1 uses air cooling to cool heat-generating components. Therefore, the cooling effect is reduced 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 in Patent Document 1.

In addition, the space available for installing an on-board computing unit is limited. For this reason, on-board computing units must be thin and compact. Therefore, on-board computing units must be able to be cooled efficiently even in such a limited space.

The purpose of the disclosed technology is to enable effective cooling of IC chips by efficiently utilizing the limited space in the computing unit.

The disclosed technology relates to a cooling structure for a computing unit that includes a substrate on which multiple electronic components, including IC chips, are mounted, and a housing that houses the substrate.

The cooling structure of the computing unit includes a cooling water jacket with a metal cooling wall that faces the board across a gap, and an outside air intake and an outside air exhaust that open into the housing and allow outside air to circulate through the gap. The IC chip is placed in the gap in contact with the cooling wall via a thermally conductive member, and multiple protrusions are provided on the cooling wall facing the gap.

In other words, with this computing unit's cooling structure, 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., a cooling wall with excellent thermal conductivity, via a heat-conducting member, i.e., a member with excellent thermal conductivity.

The cooling wall has multiple protrusions on the part facing the gap, and the gap is configured to allow outside air to flow through the outside air intake and exhaust openings in the housing.

Since the IC chip is thermally connected to the cooling wall, heat generated by the IC chip can be efficiently dissipated via the cooling wall to the cooling water jacket and the cooling water inside it, regardless of whether cooling water is flowing inside the cooling water jacket, thereby cooling the IC chip.

If the cooling water inside the cooling water jacket is flowing, the IC chip can be water-cooled, allowing for more effective cooling of the IC chip.

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 has been enlarged by the protrusions. Therefore, when 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.

In other words, with this computing unit's cooling structure, 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.

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.

The cooling structure of the computing unit may also have multiple protrusions arranged near the IC chip.

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.

Furthermore, multiple protrusions may be arranged around the entire periphery of the IC chip.

This increases the surface area of the cooling wall facing the gap all around the IC chip. This allows the heat from the IC chip to be dissipated in all directions without being biased. This means the IC chip can be cooled even more effectively.

It is preferable that the size of the gap is less than twice the thickness of the IC chip.

In other words, if the gap is made slightly larger than the IC chip, the surface of the IC chip can be essentially directly attached to the cooling wall. This allows the heat from the IC chip to be efficiently dissipated to the cooling wall. Furthermore, since the cooling structure is thinner, it is suitable for thin, compact computing units.

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.

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

The cooling structure of the computing unit may also be such that 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, and the outside air intake and the outside air exhaust allow the outside air to circulate below the second surface as well as through the gap.

IC chips are small electronic components. 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 made smaller. 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. This means that the IC chip and other electronic components can be air-cooled.

The cooling structure for the computing unit may also include a fan that draws in outside air through the outside air intake and expels it through the outside air exhaust port.

This allows the fan to be operated as needed to air-cool the IC chip. Furthermore, since the fan can be operated instantly, the IC chip can be cooled quickly in response to cooling demands.

The disclosed technology enables IC chips to be cooled effectively.

1 is a schematic diagram showing a cooling structure of a computing unit to which the disclosed technology is applied; 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. 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. 3 is a schematic cross-sectional view taken along the arrow line AA in FIG. 2. 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. FIG. 2 is a schematic perspective view showing the main part of a specific example of an arithmetic unit. 10 is a flowchart showing a specific example of cooling of a computing unit.

Embodiments of the disclosed technology will be described below. However, the following description is essentially merely an example. For convenience, the up/down, left/right, and front/back directions used in the description will follow the directions shown in each figure.

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

The computing unit 1 has a low-profile metal housing 2. Inside this housing 2 is a printed circuit board 3 with various electronic components mounted on both sides. The housing 2 has a thin, rectangular parallelepiped appearance, corresponding to the printed circuit board 3's rectangular surface.

A thin, plate-shaped metal cooling water jacket 4 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, extending 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 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 outlet 4c.

That is, a vehicle 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 activated, the coolant circulates through the coolant circulation path 100c.

Coolant heated by the engine or other devices passes through the radiator 100a, where it is cooled by heat exchange with the outside air. The coolant then returns to the engine, cooling it. The coolant flow path 4a is connected to the coolant circulation path 100c, and when the water pump 100b is activated, cooled coolant flows into the coolant flow path 4a.

Then, on the other flat side (bottom side) inside the housing 2, a storage space 5 is defined that extends along the flat surface and has a narrow vertical width. The printed circuit boards 3 are housed in this storage space 5 in a predetermined arrangement.

An MMP6 (multimedia processor) is installed in the center of the first surface (top surface) of printed circuit board 3. In Figure 1, only one MMP6 is shown on the first surface of printed circuit board 3. The MMP6 is a thin electronic component (i.e., an IC chip) equipped with an integrated circuit, and is installed on printed circuit board 3 with its underside in close contact with the top of the first surface of printed circuit board 3.

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

MMP6 processes large amounts of data at high speed. As a result, MMP6 generates a large amount of heat when in operation. Therefore, MMP6 needs to be cooled to maintain an appropriate temperature when in operation.

The printed circuit board 3 is installed with its first surface facing the cooling water jacket 4, across a gap 5a from 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 with the cooling wall 4d via this thermal grease 7 (surface contact).

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 MMP 6 itself is small in thickness, 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.

On the second surface (bottom surface) of the substrate, facing the opposite side of the gap 5a, are mounted multiple electronic components (non-chip electronic components 8), such as capacitors and transistors, whose height from the substrate to their top end is greater than that of the MMP 6. Therefore, most electronic components are located on the second surface of the substrate.

Incidentally, while 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. Furthermore, an electronic component (chip-type electronic component) whose height from the substrate to its top edge is shorter than that of the MMP6 may also be installed.

An outside air intake 9 and an outside air exhaust 10 are located on the opposing front and rear sides of the housing 2, on the sides facing the storage space 5. The outside air intake 9 is located on one side, and the outside air exhaust 10 is located on the other side. Both the outside air intake 9 and the outside air exhaust 10 are positioned so that they face both above (gap 5a) and below (large space 5b) the printed circuit board 3 in the storage space 5.

A fan 11 is installed in the outside air intake 9. When the fan 11 is activated, outside air flows into the housing 2 from the outside air intake 9. As shown by the dashed arrows in Figure 1, the outside air that has flowed into the housing 2 is divided into both the gap 5a and the storage space 5 and flows toward the outside air exhaust 10, from which it is exhausted to the outside of the housing 2.

Across the cooling wall 4d, excluding the area where the MMP6 comes into contact, multiple fins 4e (an example of a protrusion) are provided. Each fin 4e has a thin plate shape extending in the direction of outside air flow (front-to-back direction), and is arranged approximately parallel to the left and right at regular intervals. Therefore, 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 less than the thickness of the MMP6.

(Effects 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 a plurality of fins 4e, which greatly increases its surface area.

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

Therefore, the heat generated by the MMP6 can be quickly transferred to the cooling wall 4d and the cooling water, as shown by the dashed arrows in Figure 1, allowing for efficient heat dissipation.

By arranging multiple fins 4e near the MMP6, the MMP6 can be cooled more effectively. By arranging multiple fins 4e all around the MMP6, the heat from the MMP6 can be dissipated in all directions without being concentrated unevenly.

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

Air cooling operates 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, where numerous fins 4e are installed. 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.

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

The fan 11 starts operating immediately when its motor is energized. Therefore, air cooling has excellent responsiveness.

Water cooling is achieved by heat exchange with the cooling water circulated through the cooling water flow path 4a. The MMP 6 is adjacent to the cooling water flow path 4a via only the cooling wall 4d. Water cooling allows the MMP 6 to absorb heat from the flowing cooling water, thereby effectively cooling the MMP 6. Furthermore, the cooling water jacket 4 has a thin plate shape. Therefore, heat flows easily through the cooling water jacket 4, promoting heat transfer. The MMP 6 can be cooled effectively.

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

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 the MMP 6 cannot be water-cooled unless the water pump 100b is operated. In order to water-cool the MMP 6, the water pump 100b must be operated.

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

In this way, with this cooling structure for the computing unit 1, the cooling means can be selected depending on the level of cooling demands from the MMP 6. Furthermore, the cooling means can be selected depending on the cooling situation of the MMP 6. For example, when the IG is on and the cooling water circulation mechanism 100 has spare cooling capacity, water cooling can be selected, thereby reducing power consumption.

On the other hand, when the ignition is off, the water pump 100b must be operated to perform water cooling. Therefore, performing water cooling when the ignition is off consumes more power and it 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. Furthermore, even if air-water cooling is selected when the water pump 100b is stopped, the period until water cooling starts up can be supplemented by air cooling.

As such, the cooling structure of this computing unit 1 not only provides excellent cooling capacity for the MMP 6, but also allows for the selection of multiple cooling methods with different cooling capacities depending on the situation, allowing for cooling 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.

Furthermore, this cooling structure is constructed with thin air-cooled and water-cooled structures layered around the printed circuit board 3, making it suitable for use in thin computing units 1. Therefore, it is ideal for use in computing units 1 for vehicles.

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

The upper view in Figure 2 is a top view of the computing unit 1, and the lower view in Figure 2 is its left side view. The upper view in Figure 3 is a front view of the computing unit 1, and the lower view in Figure 3 is its rear view. Figure 4 is a schematic cross-sectional view taken along the arrow line A-A in Figure 2. The upper view in Figure 5 is a schematic cross-sectional view taken along the arrow line B-B in Figure 2, and the lower view in Figure 5 is a schematic cross-sectional view taken along the arrow line C-C in Figure 2. The reference numerals for each component used in the previous explanation will be used in this explanation as well.

As shown in Figure 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 vehicle by bolting these mounting brackets 20a.

A pair of connectors 22, 22 protrude from the left side of the metal case 21. Connectors for communication and power are connected to these connectors 22, 22. This electrically connects the computing unit 1.

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

As shown in Figure 3 (top diagram), a circular outside air intake 9 equipped with a fan 11 opens in the lower left-right center section on the front surface of the metal case 21. As shown in Figure 3 (bottom diagram), a circular outside air exhaust vent 10 opens in the lower left-right center section on the rear surface of the metal case 21, facing the outside air intake 9 from front to back.

As shown in Figures 4 and 5, a metal 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, spreading along the printed circuit board 3 and partitioned in a serpentine manner. This allows the cooling water to flow in a serpentine manner along the printed circuit board 3, as indicated by the dashed arrow in Figure 2.

As shown in Figures 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 its first surface faces the cooling wall 4d with a small gap 5a between them.

As a result, as shown enlarged in Figure 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 number of fins 4e are provided on the cooling wall 4d in the area excluding the area in contact with the MMP 6. Each fin 4e has a thin plate shape extending in the front-to-rear direction and is arranged approximately parallel to each other at a fixed interval in the left-to-right direction.

As shown in Figures 4 and 5, non-chip electronic components 8, such as capacitors, mounted on the second surface of the printed circuit board 3 are located in the large space 5b extending below the printed circuit board 3. As shown in Figure 5, the outside air intake 9 is positioned so that it faces both the gap 5a and the large space 5b. The outside air exhaust 10 is similarly positioned so that it faces both the gap 5a and the large space 5b.

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.

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. When the fan 11 is operated, outside air also flows into the large gap 5b. Heat generated by the non-chip electronic components 8 can also be cooled by dissipating it to the outside air.

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.

<Example of cooling of computing units>
7 shows a specific example (flowchart) of cooling the arithmetic unit 1. Although not shown, the arithmetic unit 1 is equipped with a controller for controlling the cooling.

As described above, this computing unit 1 can select one of three cooling methods: air cooling, water cooling, and air-water cooling (air cooling + water cooling), depending on the cooling requirement of the MMP 6. Therefore, the controller can select the cooling method depending on the cooling requirement of the MMP 6. The cooling requirement of the MMP 6 can be determined, for example, from the temperature of the MMP 6.

Coolant water circulates while the vehicle is in operation. Therefore, if water cooling is being performed using the remaining cooling capacity, air cooling alone will not be selected. In this specific example, we consider a situation where the ignition is off and the water pump 100b is not operating.

The controller has preset cooling requirement selection criteria (C1 and C2, where C1<C2). If the cooling requirement of the MMP 6 is small, that is, if the cooling requirement is less than C1 (Yes in step S1), the controller operates the fan 11 to perform air cooling (step S2). This allows the MMP 6 to be cooled appropriately and quickly with little power consumption.

If the cooling demand for MMP6 is moderate, that is, if the cooling demand is equal to or greater than C1 but less than C2 (Yes in step S3), the controller operates the water pump 100b to circulate the coolant and perform water cooling (step S4). MMP6 can be appropriately cooled with power consumption according to the cooling demand.

If the cooling demand for the MMP 6 is large, that is, if the cooling demand is C2 or greater (Yes in step S5), the controller operates the fan 11 and water pump 100b to perform air-water cooling (step S6). Even if the amount of heat generated is large, the MMP 6 can be cooled appropriately.

In this way, the cooling structure of this computing unit 1 allows for the selection of multiple cooling means with different cooling capacities depending on the cooling requirements of the MMP 6, allowing for cooling 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.

The cooling method may be selected depending on the situation when cooling the MMP6, or may be selected depending on both the cooling request for the MMP6 and the situation when cooling the MMP6.

The disclosed technology is not limited to the above-described embodiments, but also includes various other configurations.

For example, in the embodiment, an MMP6 is used as an example of an IC chip, but the IC chip is not limited to an MMP6. The disclosed technology can be applied to any IC chip that generates a lot of heat.

The fan 11 is not required. Air cooling can be achieved by using the wind generated by the vehicle's on-board fan, or the air flow generated by the vehicle's on-board fan.

In the embodiment, aligned fins 4e are used as the protrusions, but the shape and arrangement of the protrusions can be modified 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-shaped cross section that is circular, rectangular, polygonal, streamlined, or the like.

REFERENCE SIGNS LIST 1 arithmetic unit 2 housing 3 printed circuit board 4 cooling water jacket 4a cooling water flow path 4b inlet 4c outlet 4d cooling wall 4e fins (protrusions)
5 Storage space 5a Gap 5b Large space 6 MMP (IC chip)
7. Thermal grease (heat conduction material)
8 Non-chip type electronic component 9 Outside air intake 10 Outside air exhaust 11 Fan

Claims (6)

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. 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. 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. 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. 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. 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 .