Electronic processing unit with printed circuit boards arranged one above the other

Abstract

Electronic computing unit (2), comprising a housing (4), a main circuit board (5) with at least one integrated computing circuit (7) and at least one further circuit board (6), wherein the further circuit board (6) and the main circuit board (5) are arranged stacked one above the other, and wherein a circuit board connector (8) is provided which is arranged spatially and in a signal-transmitting manner between the main circuit board (5) and the further circuit board (6), wherein both the main circuit board (5) and the further circuit board (6) each have interfaces (9, 10) on opposite flat sides (27, 28) for connection to a circuit board connector (8).

Description

The invention relates to an electronic computing unit with printed circuit boards stacked one above the other. The invention further relates to a system having such a computing unit and a cooling system for cooling the computing unit.In known computing units, in particular high-performance computers ("HPC" for short), the layout of the printed circuit boards ("PCB" for short) is usually adapted specifically to the respective cooling strategy. This may be either liquid cooling ("liquid cooling") or air cooling ("air cooling"). However, the cooling strategy has direct effects on the placement of components of the computing unit, the alignment of plug connectors and the mechanical integration of the components into a housing. The housings themselves likewise differ in their design depending on the type of cooling provided, which leads to different configurations in the mechanical fastening and in the air or liquid guidance. As a result, different circuit board designs are produced in the prior art depending on the cooling variant, which leads to higher development expenditure, higher costs and longer development times.The object of the present invention is to provide an electronic computing unit which can be used with a uniform printed circuit board design in both air-, liquid- and chassis-cooled systems. The object is achieved by the respective subject matter of claim 1 and claim 12.According to a first aspect, an electronic computing unit comprises a housing, a main printed circuit board having at least one integrated computing circuit and at least one further printed circuit board, wherein the further printed circuit board and the main printed circuit board are arranged stacked one above the other, and wherein a printed circuit board plug connector is provided which is arranged spatially and signal-transmittingly between the main printed circuit board and the further printed circuit board, wherein both the main printed circuit board and the further printed circuit board each have interfaces on opposite planar sides for connection to a printed circuit board plug connector.The two printed circuit boards mentioned each have at least one interface on both planar sides, such that the printed circuit boards can be mounted in the housing in any desired vertical sequence and can be connected in a signal-transmitting manner to a printed circuit board plug connector (also referred to as board-to-board plug connector).The electronic computing unit is a module for processing data, which consists of a plurality of electronic components. It typically serves as a control, regulating or processing unit in technical systems, in particular in vehicles. The computing unit is preferably a high-performance computer.The main printed circuit board (also referred to as a main PCB) is the central printed circuit board of the computing unit, on which at least one integrated computing circuit is located. It is the functional core and is designed electrically and mechanically to operate in various cooling environments. The further printed circuit board (also referred to as "extended PCB") is an additional board which is installed together with the main printed circuit board in the housing of the computing unit. It can perform supplementary functions and is electrically connected to the main circuit board via a printed circuit board plug connector. A printed circuit board connector (also a board-to-board connector) is an electrical connecting element which connects two printed circuit boards to one another. It enables a signal-transmitting coupling between the printed circuit boards arranged one above the other or stacked one above the other, without these having to lie directly on top of one another. It is conceivable for the electronic computing unit to have a main printed circuit board and two or more further printed circuit boards. In principle, it is also conceivable for the computing unit also to have more than one main printed circuit board.The main circuit board and the further circuit board each have standardized fastening points which make mounting on both sides possible in the housing independently of the installation sequence. The attachment points may be positioned symmetrically or offset.A PCB (printed circuit board) is a carrier medium for electronic components with conductive conductor tracks for electrical connection. A plurality of PCBs are used in the computing unit.An interface is a physical and electrical contact point for connection to other components, in this case in particular to a plug connector or a plug connector. It enables the data exchange between the printed circuit board and other units inside or outside the computing unit. The interfaces of the respective printed circuit board can be arranged offset to one another, wherein the first interface of the main printed circuit board and the first interface of the further printed circuit board are each arranged in alignment with one another, and wherein the second interface of the main printed circuit board and the second interface of the further printed circuit board are arranged in alignment with one another, in order to be able to realize any desired installation sequence. The plug connector is designed in accordance with the arrangement of the interfaces facing each other.Alternatively, the interfaces of the printed circuit boards directed towards one another are arranged in alignment with one another in the case of a variable vertical installation sequence. In this context, "alignment" means that two interfaces on different printed circuit boards are geometrically exactly opposite one another, regardless of the vertical sequence in which the printed circuit boards were mounted. This ensures a reliable connection through the plug connector.It is likewise conceivable for the first and second interfaces of the respective printed circuit board to differ in their size and / or shape.The integrated computing circuit is the central electronic component on the main printed circuit board, which takes over the data processing. It can be embodied, for example, as a system-on-chip (SoC) or system-in-package (SiP).The housing is the outer casing of the computing unit, which provides mechanical protection and enables the mounting and cooling of the contained components. It has interfaces for external connections and devices for integrating ventilation or liquid cooling systems. In addition, the housing may have shape elements and portions that allow the circuit boards to be prepositioned and evenly spaced apart regardless of their mounting order.The variable vertical installation sequence describes the possibility of freely selecting the sequence of the printed circuit boards mounted vertically one above the other in the housing. As a result, the assembly of the computing unit can be flexibly adapted to different cooling and installation concepts.The term "stacked one above the other" does not necessarily mean that the elements lie directly on top of one another and contact one another directly, but that they are located in a vertical staggered arrangement. The elements are instead oriented parallel and arranged spatially spaced apart from one another. Only the electrical coupling takes place via the plug connector. Accordingly, a space for accommodating a plug connector is provided between the main board and the circuit board.The main circuit board and the further circuit board are each completely mechanically and electrically compatible and can be operated in air- as well as liquid-cooled environments without a layout change being required on the circuit boards. The printed circuit boards can thus be integrated into a housing which can be cooled with different cooling types. For this purpose, the housing has standardized interfaces for fan modules or fluid connections. It can also have an opening which enables a thermal connection to a thermally conductive external component, for example a vehicle chassis.The same main circuit board and the further circuit board can be used for different cooling variants, in particular for air cooling variants, for liquid cooling variants and for chassis cooling.In a first installation variant, the main printed circuit board is mounted in the upper region of the housing, with the computing circuit pointing downward. The further printed circuit board is located underneath, wherein the two printed circuit boards are electrically connected to one another via a centrally arranged plug connector. In this configuration, the cooling of the computing circuit can take place, for example, via a liquid cooling plate. In this sense, the housing preferably has a cooling plate with channels for guiding a cooling medium, wherein the arithmetic circuit of the main circuit board comes to rest on the cooling plate. The cooling plate is preferably arranged spatially between the further printed circuit board and the main printed circuit board and has an aperture for the passage of the printed circuit board plug connector, wherein the main printed circuit board is mounted in the housing in such a way that the computing circuit is arranged on a side of the main printed circuit board facing the further printed circuit board. This allows a space-saving arrangement of the cooling structure and effective heat dissipation.In a second installation variant, the printed circuit boards can be mounted in the reverse sequence, such that the computing circuit is arranged below the at least one further printed circuit board. In this sense, the main circuit board is mounted in the housing in such a way that the computing circuit is arranged on the side of the main circuit board facing away from the further circuit board. The positioning of the further printed circuit board can remain the same. This mounting situation can be advantageous if, for example, air cooling is to take place by fans arranged from above. To this end, fans for air cooling the computing unit can be arranged on the housing. Thereby, active air cooling of the arithmetic circuit can be ensured. According to one embodiment, the housing has a cooling structure on which the computing circuit of the main printed circuit board comes to rest. Because the computing circuit is arranged on the side facing away from the further printed circuit board, access to the cooling structure is facilitated and the cooling performance is optimized. Thus, efficient heat dissipation from the computing circuit is enabled.Identical printed circuit boards and plug connections can be used in both installation variants, which allows flexible and cost-effective adaptation to different vehicle architectures and cooling systems. The mirrorability during installation reduces the diversity of variants and simplifies the logistics and production of the computing unit.According to a further embodiment, the housing has an opening which is configured such that the computing circuit of the main printed circuit board can come to bear against a thermally conductive component of a vehicle or of another system. Accordingly, the housing is designed to be open toward one side, so that the computing circuit can be thermally connected to an external component. This allows integration into existing cooling structures of a vehicle. In particular, chassis cooling can be realized and separate air or liquid cooling can be dispensed with. Chassis cooling is a passive cooling method in which the computing circuit is coupled directly to a thermally conductive structural component, for example the vehicle chassis. This allows robust and quiet cooling without additional active components. This type of cooling is space-saving, noise-free and particularly robust.The main circuit board and the further circuit board preferably each have at least one further interface for connection to vehicle or other system components. This improves system integration and enables modular system architecture. An additional electrical connection on the main or further printed circuit board is to be understood as a further interface, which serves for connecting external vehicle or system components, for example via plug connectors or cables. "Vehicle or other system components" are external electronic or mechanical units with which the computing unit can cooperate, such as sensors, control units, communication modules or energy supply systems in the vehicle or in other applications.According to a preferred embodiment, the positioning of the further interfaces on the main printed circuit board and / or the further printed circuit board is selected such that the installation sequence of the printed circuit boards within the housing is variable. Furthermore, the installation sequence can be variable for possibly different housing variants. The further interfaces are arranged on the main printed circuit board and / or the further printed circuit board in such a way that they remain accessible independently of the vertical position of the respective board in the housing. As a result, the sequence in which the printed circuit boards are mounted in the housing can be freely selected without the electrical connection to external components being impaired. This increases the flexibility in assembly and allows the use of the same circuit boards in different system configurations.According to a further embodiment, each further interface comprises a plug which is passed through a recess of the housing. This allows a simple external connection. The plug is the component of the further interface which establishes the physical and electrical connection to an external component. The plug can be designed as a standardized plug connector for cables or printed circuit boards. The recess is a specific opening or recess in the housing of the computing unit, through which the mentioned plug or another component can be passed in order to enable external connections.According to a further aspect, a system for carrying out arithmetic-intensive functions, such as complex or extensive data processing tasks, comprises an electronic arithmetic unit described herein and a cooling system, wherein the cooling system is designed as an air cooling system having at least one fan and / or as a liquid cooling system having at least one cooling plate with channels for guiding a cooling medium. The computing unit is arranged in thermal contact with the respective cooling system, so that the waste heat arising during the data processing can be efficiently dissipated-regardless of whether air, liquid or chassis cooling is involved. By being able to install the printed circuit boards flexibly in the housing, an adaptation of the system to various thermal requirements is made possible.The system may be used in, for example, an automated driving vehicle control apparatus. The computing unit can process high-resolution sensor data in real time and execute AI-based decision algorithms, for example.Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. Identical or similar elements are provided with the same reference numerals. It shows FIG. 1 is a highly schematic illustration of a system for performing compute-intensive functions in accordance with a preferred embodiment; FIG. 2 shows a schematic sectional illustration of an electronic computing unit of the system according to FIG. 1 ; FIG. 3 shows a schematic sectional illustration of the electronic computing unit according to a second embodiment; and FIG. 4 shows a schematic sectional illustration of the electronic computing unit according to a third embodiment.FIGS. 1 to 4 show different embodiments of a system 1 for executing computation-intensive functions. The system 1 can be used in a vehicle-not shown here. As shown in FIG. 1, the system 1 comprises an electronic computing unit 2 and a cooling system 3. The cooling system 3 is thermally coupled to the arithmetic unit 2 and, depending on the embodiment, can be designed as an air cooling system, liquid cooling system or chassis cooling system, as will be described below.The computing unit 2 comprises, according to FIGS. 2 to 4, a housing 4 in which, by way of example, a main printed circuit board 5 and a further printed circuit board 6 are arranged stacked one above the other. The main printed circuit board 5 carries an integrated computing circuit 7, which can preferably be embodied as a system-on-a-chip or system-in-package. A printed circuit board plug connector 8 is arranged between the main printed circuit board 5 and the further printed circuit board 6, said printed circuit board plug connector producing a signal-transmitting connection between aligned interfaces 9, 10 of the printed circuit boards 5, 6.Both the main circuit board 5 and the further circuit board 6 have the aforementioned interfaces 9, 10 on their opposite flat sides 27, 28, respectively, so that the vertical installation sequence in the housing 4 is variable. Regardless of the stacking sequence of the printed circuit boards 5, 6, the interfaces 9, 10 are always positioned such that they are aligned and can be electrically connected via the plug connector 8. For simplification, the flat sides of the printed circuit boards 5, 6 are provided with the reference numerals 27 and 28 only in FIG. 2.The printed circuit boards 5, 6 can be fixed, for example screwed, in the housing 4 via standardized fastening points. For this purpose, the housing 4 has shaped sections 22, 23 for defining predefined relative distances in the vertical direction between the printed circuit boards 5, 6.In FIGS. 1 and 2, the cooling system 3, which is illustrated in a highly schematic manner, is designed as a liquid cooling system and in thermal contact with the arithmetic unit 2. the housing 4 in this embodiment has a cooling plate 12 with channels for guiding a cooling medium, in particular a cooling liquid. According to FIG. 1 in conjunction with FIG. 2, the cooling plate 12 is connected to an inlet 11 and an outlet 13. The pump 19 delivers the cooling medium from a reservoir 20 via the inlet 11 into the channels of the cooling plate 12, after which it flows via the outlet 13 back into the reservoir 20 shown in FIG. 1.The cooling plate 12 is arranged between the main printed circuit board 5 arranged at the bottom in the lower region of the housing 4 and the further printed circuit board 6 lying above it and has an aperture 14 for the printed circuit board plug connector 8 to pass through. In this example, the computing circuit 7 is arranged on the side of the main circuit board 5 facing the further circuit board 6 and thermally abuts the cooling plate 12. By this arrangement, the generated heat can be efficiently dissipated to the liquid cooling system.FIG. 3 shows a second embodiment of the computing unit 2, in which the main printed circuit board 5 and further printed circuit board 6 are stacked one above the other in the opposite sequence into the housing 4. The computing circuit 7 is now located on the side facing away from the further printed circuit board 6. In this embodiment, the cooling system 3 is designed as an air cooling system with a fan 15 installed in an opening 21 of the housing 4, which fan is arranged in the upper region of the housing 4. Optionally, a plurality of fans may be provided in different positions. The housing 4 also has a cooling structure 16, for example in the form of cooling ribs or a heat-conducting plate, on which the arithmetic circuit 7 comes to rest. The cooling structure 16 reinforces the cooling effect. The reverse installation direction achieves optimum air conduction across the arithmetic circuit 7.FIG. 4 shows a third embodiment of the computing unit 2, in which the same main printed circuit board 5 and further printed circuit board 6 are used for chassis cooling. The installation sequence is analogous to FIG. 3 : The housing 4 has an opening 17 on the side of the computing circuit 7, through which the computing circuit 7 is directed outwards. A heat-conducting component 18 can be guided through the opening 17 as far as into the housing 4, so that the computing circuit 7 can come to bear directly on the heat-conducting component 18, for example on the chassis or a heat sink of the vehicle. Thus, the thermally conductive member 18 may be a vehicle member that can thermally interact with the computing circuit 7 of the computing unit 2 to effectively dissipate heat from the computing circuit 7. Active fans or liquid guides can be dispensed with in this variant.The cooling is effected purely passively via the thermal connection of the main printed circuit board 5 to the external structure.In all embodiments, the main printed circuit board 5 and the further printed circuit board 6 are of identical construction and are completely compatible mechanically and electrically. The symmetrically arranged interfaces 9, 10 and the aligned plug connectors 8 enable variable, mirror-image and modular assembly. The uniform use of the printed circuit boards 5, 6 independently of the cooling system reduces the diversity of variants and significantly reduces the development and production costs.Furthermore, in all exemplary embodiments, the main printed circuit board 5 and the further printed circuit board 6 are provided with further interfaces 24, 25 in order to couple these respectively to associated vehicle components or other system components. The interfaces 24, 25 can be designed in the form of plug receptacles which are arranged in recesses 26 of the housing 4. The recesses 26 are designed such that external cables and / or printed circuit boards can be connected to the computing unit 2 via the respective further interface 24, 25 independently of the stacking sequence of the printed circuit boards 5, 6.The embodiments shown show how different cooling concepts-air, liquid or chassis cooling-can be realized with a single printed circuit board design. The flexible installation sequence, the mounting on both sides and the aligned interfaces 9, 10 enable an application-specific adaptation without having to carry out changes to the layout of the printed circuit boards 5, 6. This reduces development times, manufacturing effort and costs and at the same time simplifies integration into different vehicle architectures.List of reference characters1 System 2 Computing unit 3 Cooling system 4 Housing 5 Main printed circuit board 6 Further printed circuit board 7 Computing circuit 8 Printed circuit board plug connector 9 Interface 10 Interface 11 Inlet 12 Cooling plate 13 Outlet 14 Aperture 15 Fan 16 Cooling structure 17 Opening 18 Thermally conductive component 19 Pump 20 Reservoir 21 Opening 22 Molding section 23 Molding section 24 Further interface 25 Further interface 26 Recess 27 Planar side of the printed circuit board 28 Planar side of the printed circuit board

Claims

Electronic computing unit (2) comprising a housing (4), a main printed circuit board (5) with at least one integrated computing circuit (7) and at least one further printed circuit board (6), wherein the further printed circuit board (6) and the main printed circuit board (5) are arranged stacked one above the other, and wherein a printed circuit board plug connector (8) is provided, which is arranged spatially and signal-transmittingly between the main printed circuit board (5) and the further printed circuit board (6), wherein both the main printed circuit board (5) and the further printed circuit board (6) each have interfaces (9, 10) on opposite planar sides (27, 28) for connection to a printed circuit board plug connector (8).The arithmetic unit (2) according to claim 1, characterized in that the interfaces (9, 10) of the printed circuit boards (5, 6) directed towards one another are arranged aligned with one another in the case of a variable vertical installation sequence.The arithmetic unit (2) according to claim 1 or claim 2, characterized in that a fan (15) for air cooling the arithmetic unit (2) is arranged on the housing (4).Computing unit (2) according to Claim 3, characterized in that the housing (4) has a cooling structure (16), on which the computing circuit (7) of the main printed circuit board (5) comes to rest.Computing unit (2) according to Claim 4, characterized in that the main printed circuit board (5) is mounted in the housing (4) in such a way that the computing circuit (7) is arranged on the side of the main printed circuit board (5) facing away from the further printed circuit board (6).The arithmetic unit (2) according to claim 1 or claim 2, characterized in that the housing (4) has a cooling plate (12) with channels for guiding a cooling medium, wherein the arithmetic circuit (7) of the main printed circuit board (5) comes to rest against the cooling plate (12).The computing unit (2) according to claim 6, characterized in that the cooling plate (12) is arranged spatially between the further printed circuit board (6) and the main printed circuit board (5) and has an aperture (14) for passing through the printed circuit board plug connector (8), wherein the main printed circuit board (5) is mounted in the housing (4) such that the computing circuit (7) is arranged on a side of the main printed circuit board (5) facing the further printed circuit board (6).Computing unit (2) according to Claim 1 or Claim 2, characterized in that the housing (4) has an opening (17) which is configured such that the computing circuit (7) of the main printed circuit board (5) can come to bear against a thermally conductive component of a vehicle or of another system.The computing unit (2) according to one of the preceding claims, characterized in that the main printed circuit board (5) and the further printed circuit board (6) each have at least one further interface (24, 25) for connection to vehicle or other system components.The computing unit (2) according to claim 9, characterized in that the positioning of the further interfaces (24, 25) on the main printed circuit board (5) and / or the further printed circuit board (6) is selected such that the installation sequence of the printed circuit boards (5, 6) within the housing (4) is variable.Computing unit (2) according to Claim 10, characterized in that each of the further interfaces (24, 25) comprises a plug which is passed through a recess (26) of the housing (4).System (1) for carrying out arithmetic-intensive functions, comprising an electronic arithmetic unit (2) according to one of the preceding claims and a cooling system (3), wherein the cooling system (3) is designed as an air cooling system with at least one fan (15) and / or as a liquid cooling system with at least one cooling plate (12) with channels for guiding a cooling medium.

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