Electronic System with Hybrid Cooling System

Abstract

The present invention relates to an electronic system having a hybrid cooling system. An electronic system is described, which includes: a first board and a first processing unit, wherein the first processing unit includes a first semiconductor chip disposed on a first surface of the first board; a first cooling unit facing the first surface of the first board and configured to cool the first semiconductor chip; a second processing unit and at least one additional board, wherein the second processing unit includes additional semiconductor chips disposed on a first surface of the at least one additional board; and a second cooling unit facing the first surface of the at least one additional board and configured to cool the additional semiconductor chips. The first board and the at least one additional board are spaced apart from each other. The first cooling unit is a passive cooling unit, and the second cooling unit is an active cooling unit.

Description

Technical Field

[0001] The present application relates to the field of cooling systems for electronic devices. Background Art

[0002] An electronic control unit (ECU) is an embedded system in automotive electronics. The ECU controls one or more of the electrical systems or electrical subsystems in a vehicle. A vehicle motor can include up to 80 ECUs. As the integration level of the electrical systems in a vehicle increases, the space for arranging ECUs in the vehicle becomes smaller. Therefore, it is necessary to design the ECUs in a compact manner while ensuring that they remain robust, that is, they can perform at least some of the functions of the ECUs even when a failure occurs in the main system. The main system includes a plurality of semiconductor chips arranged on at least a first board. To introduce redundancy in the system, a second board can be arranged, which operates independently of the main board and can perform at least some of the functions of the main board when the main board fails.

[0003] An electronic controller can include a plurality of processing units that must be cooled, such as a microcontroller or a system-on-chip (SoC).

[0004] It is necessary to effectively cool an electronic system so that it can operate properly. Summary of the Invention

[0005] According to one example, the present disclosure relates to an electronic system, the electronic system comprising: a first board and a first processing unit, wherein the first processing unit includes at least one first semiconductor chip arranged on a first surface of the first board; a first cooling unit, the first cooling unit facing the first surface of the first board and configured to cool the at least one first semiconductor chip; a second processing unit and at least one additional board, wherein the second processing unit includes at least one additional semiconductor chip arranged on a first surface of the at least one additional board; and a second cooling unit, the second cooling unit facing the first surface of the at least one additional board and configured to cool the at least one additional semiconductor chip. The first board and the at least one additional board are spaced apart from each other. In addition, the first cooling unit is a passive cooling unit, and the second cooling unit is an active cooling unit.

[0006] In this type of electronic system, the first board having the first processing unit and the second board having the second processing unit are thermally separated and have separate cooling units. The main function can be implemented in the second processing unit cooled by the second cooling unit, and the redundant fault operation function can be implemented in the first processing unit cooled by the first cooling unit. The first cooling unit and the second cooling unit are independent, where the passive first cooling unit operates even when the active second cooling unit fails. Thus, within a single electronic system, even when the main system implemented by the second processing unit fails, the backup system implemented by the first processing unit can be kept running. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The embodiments described herein can be better understood with reference to the following description and the drawings. The components in the drawings are not necessarily drawn to scale, but rather focus on illustrating the principles of the embodiments. Further, in the drawings, the same reference numerals denote corresponding parts.

[0008] Figure 1 is a schematic diagram illustrating an electronic system according to one example;

[0009] Figure 2 is a schematic diagram illustrating an electronic system according to another example;

[0010] Figure 3 is a schematic diagram illustrating an electronic system according to another example;

[0011] Figure 4 is a schematic diagram illustrating an electronic system according to another example;

[0012] Figure 5 is Figure 2 an exploded perspective view of the electronic system;

[0013] Figure 6A and Figure 6B more detailed perspective views of the electronic system ( Figure 6A ) and cross-sectional views ( Figure 6B ). DETAILED DESCRIPTION

[0014] Figure 1 Illustrates an example of an electronic system. The system includes a first board 1, at least one additional board 4A, a first cooling unit 3, and a second cooling unit 6. The system further includes a first processing unit having at least one first semiconductor chip 2 disposed on a first surface 11 of the first board 1, and a second processing unit having at least one additional semiconductor chip 5A disposed on a first surface 41A of the at least one additional board 4A. In Figure 1In the example shown, the electronic system includes an additional board 4A (which is also referred to hereinafter as the second board 4A). At least one additional semiconductor chip 5A disposed on the second board 4A is also referred to hereinafter as the second semiconductor chip 5A.

[0015] The system according to Figure 1 includes a plurality of first semiconductor chips 2 located on the first surface 11 of the first board and a plurality of second semiconductor chips 5A located on the first surface 41A of the second board 4A. However, this is just an example. Basically, the number of the first semiconductor chips 2 on the first board 1 depends on how many first semiconductor chips 2 are required to perform the desired functions of the first processing unit, and the number of the second semiconductor chips 5A on the second board 4A depends on how many second semiconductor chips 5A are required to perform the desired functions of the second processing unit. The first processing can be configured to perform a first set of functions, and the second processing can be configured to perform a second set of functions. According to one example, the first set is a subset of the second set.

[0016] The first cooling unit 3 is configured to cool at least one of the first semiconductor chips 2 on the first board 1, and the second cooling unit 6 is configured to cool at least one of the second semiconductor chips 5A on the second board 4A. In this example, the first cooling unit 3 and the second cooling unit 6 are spaced apart from each other in a first direction x, which is also referred to hereinafter as the vertical direction.

[0017] The first board 1 can be a PCB (printed circuit board). The first surface 11 of the first board 1 faces the first cooling unit 3. The second board 4A can also be a PCB. The first surface 41A of the second board 4A faces the second cooling unit 6.

[0018] In Figure 1 the example shown, the first board and the second board 4A are spaced apart from each other in a second direction y perpendicular to the first direction x. This second direction is also referred to hereinafter as the lateral direction or the horizontal direction. In addition, both the first board 1 and the second board 4A are arranged between the first cooling unit 3 and the second cooling unit 6 in the vertical direction x. Since the first surface 11 of the first board 1 faces the first cooling unit 3 and the first surface 41A of the second board 4A faces the second cooling unit 6, the first surface 11 of the first board 1 and the first surface 41A of the second board 4A face opposite directions. That is, the first surface 41A of the second board 4A is flipped 180 degrees relative to the first surface 11 of the first board 1.

[0019] According to one example, the second processing unit on the second board 4A is configured to perform the main functions of the main system. For example, the second board 4A can be configured to control a driving assistance system in a vehicle. The first processing unit on the first board 1 can be a fail-operational unit that is configured to perform only a subset of the main functions and take over when the main system fails. Thus, the first processing unit on the first board 1 is at least partially redundant with respect to the second processing unit on the second board 4A. The first processing unit on the first board 1 can be regarded as a standby unit with reduced functionality and can operate independently of the second processing on the second board 4A. The semiconductor chips 2, 5A can be any kind of integrated circuit, such as a system-on-chip (SoC) or a microcontroller.

[0020] In Figure 1 the example shown, the first board 1 and the second board 4A are arranged spaced apart from each other in the second direction y. In this way, the first board 1 and the second board 4A are thermally separated.

[0021] The first cooling unit 3 is a passive cooling unit that is configured to cool the first semiconductor chip 2 of the first plate 1 by natural convection or radiation. Passive cooling is a cooling technique that does not involve external devices (such as pumps or fans) and thus does not use any additional energy. Instead, passive cooling utilizes the architectural design of the object to be cooled, typically relying on a heat sink and a heat spreader, to enhance heat transfer only through natural convection and radiation. Passive cooling has the advantages of energy conservation and cost-effectiveness. In the depicted example, the first cooling unit 3 includes a cooling plate 31 that is in thermal contact with the first semiconductor chip 2 and faces the first surface 11 of the first plate 1. The cooling plate 31 extends along the second direction y and may cover the first plate 1 and the second plate 4A. The cooling unit may also include a plurality of cooling ribs 32 that protrude from the surface of the cooling plate 31 facing away from the first plate 1, such that heat generated by the semiconductor chip 2 can be carried away from the first plate 1 via the cooling plate 31 and the cooling ribs 32. In this way, the first plate 1 can be cooled by the first cooling unit 3 at any time without circulating fluid in an active manner and independently of the second plate 4A. The cooling plate 31 may be made of a metallic material such as aluminum. The cooling ribs 32 are plates that protrude in a direction perpendicular to the outer surface of the cooling plate 31 and are arranged parallel to each other and with a constant gap therebetween. The cooling ribs 32 may be arranged only on the portion of the cooling plate 31 that is disposed above the first plate 1. The cooling ribs 32 increase the surface area of the cooling plate 31. In other examples, other metallic components may be added to the cooling plate 31 to increase the heat exchange surface area. The advantage of passive cooling is that cooling is always carried out independently of the environment and operating conditions. The efficiency of passive cooling is not as good as that of active cooling, in which fluid is circulated actively to transfer heat. However, since the first plate 1 only has reduced functionality relative to the main board 4A, the passive cooling unit 3 is able to ensure sufficient cooling of the semiconductor chip 2. In other examples, the first cooling unit is an active cooling unit that is independent of the second cooling unit 6.

[0022] The second cooling unit 6 is an active cooling unit configured to cool the second semiconductor chip 5A via a fluid (such as air or water) that circulates in an active manner. Active cooling is a cooling technique that relies on external devices to enhance heat transfer. Typically, a device (which can be a fan or a pump) forces a fluid (such as a gas or a liquid) to circulate, thereby increasing fluid flow and heat transfer. Active cooling can generally produce much higher heat transfer than passive cooling, but the disadvantages are high cost and power consumption. The second cooling unit 6 includes a cooling plate 61 that is in thermal contact with the semiconductor chip 5A and thus faces the first surface 41A of the second plate 4A. The cooling unit 6 also includes at least one tube 62 through which a cooling fluid that can be moved by a fan or a pump can enter and leave the cooling plate 61. The circulating fluid transfers the heat generated by the semiconductor chip 5A to a central heat exchange system (not shown), enabling the second plate 4A to be cooled in an active manner. In the depicted example, the first plate 1 and the second plate 4A are arranged between the cooling plate 31 of the first cooling unit 3 and the cooling plate 61 of the second cooling unit 6. According to one example (as shown), the cooling unit 6 does not extend beyond the second plate 4A in the second direction y, specifically, does not extend to the first plate 1. In this way, a very compact structure can be obtained.

[0023] The first plate 1 is cooled only by the passive first cooling unit 3, while the second plate 4A is cooled only by the active second cooling unit 6. If the active cooling fails, the second plate 4A can no longer be properly cooled and the second processing unit (which may be the main processing unit) fails. However, since the first plate 1 (which may be a backup plate) is cooled independently of the second plate 4A by the passive cooling unit 3, the first processing unit remains operational and can at least partially take over, such that at least some of the functions of the main unit can still be performed. In this way, a very robust electronic system can be achieved.

[0024] Referring to the above, the first cooling unit 3 is in thermal contact with at least one first semiconductor chip 2 on the first plate 1, and the second cooling unit 6 is in thermal contact with at least one second semiconductor chip 5A on the second plate 4A. This can include direct contact between the cooling plates 31, 61 of the respective cooling units 3, 6 and the respective semiconductor chips 2, 5A, or a thermal paste is disposed between the cooling plates 31, 61 and the respective semiconductor chips 2, 5A. Each of the semiconductor chips 2, 5A can include a semiconductor die and a semiconductor package that encapsulates the die, wherein the cooling plates 31, 61 and / or the thermal paste are in contact with the respective semiconductor packages.

[0025] The first plate 1 and the second plate 4A may be arranged in a sealed housing 7 (shown in dotted lines). The housing may be made of aluminum to ensure good thermal conductivity. As shown, the cooling plate 31 of the first cooling unit 3 may form part of the housing 7. In this case, the cooling ribs 32 are arranged on the outside of the housing 7 and allow the at least one first semiconductor chip 2 to be cooled by natural convection and radiation in order to keep the first processing unit operational even if a failure of the second processing unit occurs. Reference Figure 1 , the cooling plate 61 of the second cooling unit may form another part of the housing.

[0026] Figure 6A and Figure 6B In stereogram ( Figure 6A ) and cross-section diagram ( Figure 6B ) shows Figure 1 Possible implementation of an electronic system of the type shown. Figure 6A , the housing 7 may include a first opening 91 for electrical connection with the first plate 1 and a second opening 92 for electrical connection with the second plate 4A. The second cooling unit 6 may include at least one pipe 62 having an inlet and an outlet for circulation of a cooling fluid.

[0027] In addition, if Figure 6B As can be seen, the cooling plate 31 of the first cooling unit 3 can be part of the housing 7 that encapsulates the first board 1 and the second board 4A. The first board 1 can be mechanically attached to the cooling plate 31 of the first cooling unit 3 by screws 81, and the second board can be mechanically attached to the cooling plate 61 of the second cooling unit 6 by screws 82. At least one first semiconductor chip 2 of the first board 1 can be thermally coupled to the cooling plate 31 of the first cooling unit 3 by thermally conductive paste 41, and the semiconductor chip 5A of the second board 4A can be thermally coupled to the cooling plate 61 of the second cooling unit 6 by thermally conductive paste 42. In this way, the first board 1 and the second board 4A can be independent of each other in a logical, thermal and electrical manner.

[0028] Figure 2 A second example of an electronic system is illustrated. Figure 2 The electronic system is based on Figure 1 of electronic systems, and in accordance with Figure 1 The main difference between the electronic systems is that Figure 2 The electronic system further includes a third board 4B having a plurality of third semiconductor chips 5B on the first surface 41B. The third board 4B is spaced apart from the first board 1 and the second board 4A in the first direction x, and is arranged such that the second cooling unit 6 is arranged between the first board 1 and the second board 4A and the third board 4B.

[0029] exist Figure 2In the example shown, the first surface 41B of the third plate 4B faces the active second cooling unit 6, and the third semiconductor chip 5B is in thermal contact with the second cooling unit 6 such that the third semiconductor chip 5B can be cooled by the fluid circulating through the active cooling plate 61. The first surface 41B of the third plate 4B faces the first surface 41A of the second plate 4A, and at least one semiconductor chip 5A on the second plate 4A and at least one semiconductor chip 5B on the third plate 4B are in thermal contact with the second cooling plate 61 on opposite sides of the second cooling plate 61.

[0030] Unlike Figure 1 the example shown, the active cooling plate 61 according to Figure 2 extends along the second direction y such that it covers the first plate 1 and the second plate 4A on one side and the entire third plate 4B on the other side. Thus, the second cooling unit can cool all the third semiconductor chips 5B arranged on the third plate 4B. The third plate 4B is larger than the second plate 4A in the second direction y such that a larger number of third semiconductor chips 5B can be arranged on the third plate 4B compared to the number of second semiconductor chips 5A on the second plate 4A. The third plate 4B is arranged within the same sealed housing 7 as the first plate 1 and the second plate 4A.

[0031] Like the second plate 4A, the third plate 4B can be a PCB. According to one example, at least one third semiconductor chip 5B on the third plate 4B is part of a second processing unit. The semiconductor chips of the second processing unit are thus arranged on two different plates 4A, 4B cooled by the same active second cooling unit 6. Thus, a larger number of semiconductor chips for the second processing unit (main system) can be arranged within the same housing without an additional cooling system.

[0032] Figure 5 The exploded view of the electronic system according to Figure 2 is illustrated in a perspective view. The heat generated by the various semiconductor chips 2, 5A, 5B is indicated by arrows. As can be seen from Figure 5As can be seen, the heat of the first semiconductor chip 2 of the first board 1 is transferred to the passive cooling plate 31 and the cooling ribs 32 of the first cooling unit 3. The heat of the second semiconductor chip 5A of the second board 4A and the third semiconductor chip 5B of the third board 4B is transferred to the active cooling plate 61 of the second cooling unit 6. If the active second cooling unit 6 fails (for example, when the fan or pump that moves the cooling fluid stops working), the heat generated by the second semiconductor chip 5A and the third semiconductor chip 5B can no longer be dissipated, such that there is a risk of the second processing unit failing. However, the heat generated by the first semiconductor chip 2 will still be transferred to the first cooling unit 3 and dissipated through natural convection and radiation, such that the first processing unit will continue to operate and can take over some of the functions that the second processing unit can no longer perform. Such a hybrid cooling system including the first cooling unit 3 and the second cooling unit 6 and the thermal independence between the second board 4A and the third board 4B on the one hand and the first board 1 on the other hand ensure a very robust system that can operate even when the second cooling unit 6 of the main system fails.

[0033] Figure 3 Another example of an electronic system is illustrated. The electronic system according to Figure 3 differs from the electronic system according to Figure 2 in that the electronic system according to Figure 3 does not include the second board 4A. The third board 4B is configured to perform the first function of the main system alone. Only the third board 4B is cooled by the active second cooling unit 6. The first board 1 and the third board 4B are arranged on opposite sides of the second cooling unit 6 and are thus spaced apart from each other in the first direction x. Compared with the system according to Figure 1 the thermal isolation between the first processing unit and the second processing unit is improved.

[0034] Figure 4 Another example of an electronic system is illustrated. The electronic system according to Figure 4 differs from the electronic system according to Figure 3 in that the first board 1 extends in the second direction y over the entire length of the passive cooling plate 31 of the first cooling unit 3. The first board 1 also extends over the entire length of the active cooling plate 61 of the second cooling unit 6. In this way, compared with the shorter first board according to Figure 1 a larger number of first semiconductor chips 2 can be arranged on the first surface 11 of the first board 1. In order to be able to cool all the first semiconductor chips 2 of the first board 1, the cooling ribs 32 of the first cooling unit 3 are arranged over the entire cooling plate 31 in the second direction y.

[0035] The above electronic system can be used to implement the ECU of a vehicle, wherein the second processing unit can form a main processing unit (main unit), and the first processing unit can form a fail-operational unit, which is partially redundant with respect to the main unit and can operate independently of the main unit.

[0036] Although various embodiments have been illustrated and described with respect to one or more specific implementations, changes and / or modifications can be made to the illustrated examples without departing from the spirit and scope of the features and structures recited herein. In particular with respect to the various functions performed by the above-described components or structures (units, components, devices, circuits, systems, etc.), the terms used to describe such components (including references to "means") are intended to correspond, unless otherwise indicated, to any component or structure that performs the specified function of the described component (e.g., functionally equivalent), even if it is not structurally equivalent to the disclosed structure that performs the functions in the exemplary implementations illustrated herein.

Claims

1. An electronic system, the electronic system comprising: A first board (1); A first processing unit, wherein the first processing unit includes at least one first semiconductor chip (2) disposed on a first surface (11) of the first board (1); A first cooling unit (3), the first cooling unit facing the first surface (11) of the first board (1) and configured to cool the at least one first semiconductor chip (2); A second board (4A); A second processing unit, wherein the second processing unit includes at least one second semiconductor chip (5A) disposed on a second surface (41A) of the second board (4A), the second surface (41A) of the second board (4A) being opposite in direction to the first surface (11) of the first board (1); A second cooling unit (6), the second cooling unit facing the second surface (41A) of the second board (4A) and configured to cool the at least one second semiconductor chip (5A), Wherein the first cooling unit (3) and the second cooling unit (6) are spaced apart from each other in a first direction (x), the first direction being a vertical direction, and the first board (1) and the second board (4A) are spaced apart from each other in a second direction (y) perpendicular to the first direction (x), Wherein the first cooling unit (3) is a passive cooling unit, and Wherein the second cooling unit (6) is an active cooling unit.

2. The electronic system according to claim 1, wherein, The first board (1) and the second board (4A) are disposed between the first cooling unit (3) and the second cooling unit (6).

3. The electronic system according to claim 1, the electronic system further comprising a third board (4B), Among them, The third board (4B) includes at least one third semiconductor chip (5B) disposed on a first surface (41B) of the third board (4B), and Wherein the third board (4B) is spaced apart from the first board (1) in the first direction (x).

4. The electronic system according to claim 3, wherein, The second cooling unit (6) is disposed between the first board (1) and the third board (4B).

5. The electronic system according to claim 1, wherein, The first cooling unit (3) includes: A cooling plate (31), the cooling plate being in thermal contact with the at least one first semiconductor chip (2); and Cooling ribs (32), the cooling ribs protruding from a surface of the cooling plate (31) facing away from the first board (1).

6. The electronic system according to claim 1, wherein, The second cooling unit (6) includes: A cooling plate (61) in thermal contact with the at least one second semiconductor chip (5A); and At least one tube (62), the at least one tube being disposed inside the cooling plate of the second cooling unit (6) and configured to conduct a cooling liquid.

7. The electronic system according to claim 1, the electronic system further comprising: A housing (7), the housing encapsulating the first board (1) and the second board (4A).

8. The electronic system according to claim 7, wherein, At least one of the first cooling unit (3) and the second cooling unit (6) forms part of the housing.

9. The electronic system according to claim 1, wherein, The first processing unit is at least partially redundant with respect to the second processing unit.

10. The electronic system according to claim 9, wherein, The first processing unit is configured to execute a first set of functions, wherein the second processing unit is configured to execute a second set of functions independently of the first processing unit, and wherein the first set of functions is a subset of the second set of functions.

11. The electronic system according to claim 1, wherein, The first board (1) is a PCB.

12. The electronic system according to claim 1, wherein, The second board (4A) is a PCB.

13. The electronic system according to claim 1, wherein The second processing unit is configured to execute the main functions of the main system, and the second board (4A) is a backup board with reduced functions, and the second board is capable of operating independently of the main system.

Images