Optimized electronic multi-component assembly

Abstract

Electronic multi-component assembly (10), in particular for use in an electronic control unit, preferably for use in an electronic control unit for operating an electric compressor, comprising at least a printed circuit board (11), a metallic heat sink (6, 15, 16), and an electronic module (3), in particular an electronic module which generates waste heat during operation and must be cooled. According to the invention, the electronic module (3) is arranged directly on the heat sink (6, 15, 16) in a mounting plane, the printed circuit board (11) being arranged in the same mounting plane, the printed circuit board having a cutout (12) and being arranged such that the cutout (12) surrounds the electronic module (3).

Description

Technical field

[0001] The invention relates to an electronic multi-component assembly, in particular for use in an electronic control unit, preferably for use in an electronic control unit for operating a compressor, wherein waste heat from electrical components and / or from electronic modules comprising an electrical component must be specifically dissipated during operation. State of the art

[0002] In multi-component electronic assemblies, electrical conductors with low current carrying capacity are typically implemented as traces on printed circuit boards. For electrically conductive connections with high current carrying capacity, such as from terminals to power electronic components, stamped grids are used. These components are often made of copper alloys and can be molded into other components, for example, overmolded. Due to manufacturing constraints, these stamped grids are often significantly over-dimensioned with regard to current carrying capacity; their conductor cross-section is therefore considerably larger than electrically necessary. Consequently, they are heavier and more expensive than required. Furthermore, stamped grids are inflexible in terms of their shape and arrangement within the multi-component electronic assembly, which also results in inflexible design and more installation space required for the assembly itself.

[0003] Electrical components often generate waste heat during operation; in particular, power electronic components generate so much waste heat that they must be cooled in a targeted manner.

[0004] The object of the invention is therefore to create a design of an electronic multi-component assembly that is optimized with regard to the electrotechnical, thermal and geometric requirements. Disclosure of the invention

[0005] The invention solves this problem with regard to an electronic multi-component assembly with the features of claim 1 and with regard to an electronic control unit with the features of claim 10.

[0006] The electronic multi-component assembly, particularly for use in an electronic control unit, preferably for use in an electronic control unit for operating an electric compressor, comprises at least one printed circuit board, a metallic heat sink, and an electronic module, in particular an electronic module which generates waste heat during operation and must be cooled, whereby this refers to targeted and preferably active cooling that exceeds the cooling capacity of the electronic module's surroundings. In this context, an electronic module can be understood to be, in particular, a structure consisting of an electrical component and a substrate; preferably, the substrate can be a copper-coated ceramic substrate. According to the invention, the electronic module is arranged directly on the heat sink in a mounting plane, with the printed circuit board being arranged in the same mounting plane.The circuit board has a cutout and is arranged so that the cutout surrounds the electronic module.

[0007] The electronic multi-component assembly according to the invention has the advantages that the electronic module is arranged directly on a heat sink, so that the waste heat generated during operation can be optimally dissipated. The electronic module is arranged in a common plane with the printed circuit board, which offers advantages with regard to the utilization of installation space.

[0008] Advantageous further developments of the electronic multi-component assembly according to the invention are listed in the dependent claims.

[0009] In a first preferred embodiment of the electronic multi-component assembly, connection pads can be arranged on the printed circuit board surrounding the cutout, with electrically conductive connections from the connection pads of the printed circuit board to the electronic module arranged in the cutout being formed by means of wire bonding and / or ribbon bonding. The average person skilled in the art also knows these connection technologies in the largely English-language technical vocabulary as wire bonding and ribbon bonding, respectively. These connection technologies advantageously allow for the formation of very precise electrically conductive connections between the connection pads of the printed circuit board and the electronic module. Ribbon bonding is preferably used for electrically conductive connections with high current loads because the conductor cross-section of the ribbons used is larger than that of the wires used in wire bonding.For electrically conductive connections with low current load, for example connections for signal transmission, wire bonding can be used preferentially because the conductors advantageously take up little installation space.

[0010] In a further preferred embodiment of the electronic multi-component assembly, the printed circuit board (PCB) for operating the electronic module can have conductor tracks for electrical signal transmission and electrical power transmission. Particularly preferably, all electrical conductors for electrical signal transmission and electrical power transmission to / from the electronic module can be implemented as conductor tracks on the PCB. By implementing the electrical conductors as conductor tracks, greater flexibility in the design of the electrical conductors can be achieved compared to the use of conventional stamped grids, both with regard to the design of an embodiment and with regard to subsequent modifications during series production.This is possible because conductive traces are easier to design than die-cut grids, and because changes to the conductive traces on a printed circuit board require fewer or even no adjustments to the tools used to assemble the multi-component electronic assembly. Furthermore, the electrical routing of signal-carrying conductors and power-carrying conductors can be achieved more easily and advantageously. The use of conductive traces instead of die-cut grids allows for a significantly simplified assembly of the multi-component electronic assembly. Moreover, the conductive traces can be optimized with regard to electrical requirements; in particular, their conductor cross-section can be minimized.

[0011] In a further preferred embodiment of the electronic multi-component assembly, the electronic module can be thermally connected to the heat sink by means of a thermally conductive connection, preferably by means of a thermally conductive adhesive bond or a thermally conductive soldered connection. A thermally conductive connection between the electronic module and the heat sink advantageously enables particularly good dissipation of waste heat from the electronic module to the heat sink. A thermally conductive adhesive bond is advantageously easy to produce, while the alternative and equally advantageous thermally conductive soldered connection offers optimal heat conduction. Both the production of a thermally conductive adhesive bond and a thermally conductive soldered connection can be easily automated, which advantageously keeps manufacturing costs low and guarantees consistently high connection quality.

[0012] In a further preferred embodiment of the electronic multi-component assembly, the electronic module can include a power electronic component, in particular a power transistor, preferably a power MOSFET. This embodiment works particularly advantageously in conjunction with the optimized cooling performance achieved by the arrangement on the heat sink, because power electronic components, especially power transistors, generate a great deal of waste heat during operation and therefore require particularly effective cooling. The electronic module can most preferably include a power MOSFET. These components are particularly well-suited for switching higher voltages and exhibit a high current-carrying capacity, so that power MOSFETs consequently allow the switching of high electrical power.

[0013] In a further preferred embodiment of the electronic multi-component assembly, a frame can be arranged on the printed circuit board (PCB). The frame can surround the cutout in the PCB and form a fluid-tight connection with the PCB by means of a fluid-tight adhesive bond or a sealing lip molded into the frame. This creates an interior space open on one side, formed by the PCB and the frame, in which the cutout in the PCB can be located. This interior space can be filled with an electrically insulating gel, preferably an electrically insulating gel to comply with regulations and / or requirements for preventing electrical malfunctions and accidents. This advantageously and simply allows the area around the electronic module to be filled with an electrically insulating gel, which is required by regulations in many cases.Due to these regulations, the use of a gel with appropriate technical suitability and approval for the intended application of the electronic multi-component assembly is therefore particularly advantageous. The frame ensures that the electrically insulating gel remains within the defined area delimited by the frame. This prevents insufficient gel coverage in this area by preventing the gel volume from spreading over a larger surface.

[0014] In a further preferred embodiment of the electronic multi-component assembly, the printed circuit board (PCB) can be fluid-tightly connected to the heat sink surrounding the cutout, preventing the electrically insulating gel from escaping through the cutout from the interior above the cutout and thus fixing the PCB relative to the heat sink. This connection can be implemented, in particular, as a fluid-tight adhesive bond. Other fluid-tight connection options are also possible; for example, the PCB can be screwed to the heat sink, and a sealing lip as part of the PCB can be fluid-tightly in contact with the heat sink, in particular by being pressed against it.Advantageously, this ensures that the electrically insulating gel remains within the defined area bounded by the frame, thereby guaranteeing a sufficient layer thickness of the insulating gel in that area. Furthermore, the connection allows the relative position of the printed circuit board (PCB) to the heat sink to be determined, and consequently, the relative position of the PCB to the electronic module mounted on the heat sink. This determination of the relative position can advantageously simplify or even enable the electrically conductive connection of the electronic module to the PCB. Particularly for automated electrically conductive bonding of the electronic module to the PCB using wire bonding and / or tape bonding, it is especially advantageous if the components are always positioned in the same relative position.

[0015] In a further preferred embodiment of the electronic multi-component assembly, the printed circuit board can have three adjacent cutouts. An electronic module, preferably several electronic modules, can be arranged in each cutout and thermally connected to the heat sink. In this way, particularly good cooling performance can be advantageously achieved for several electronic modules by means of this arrangement on the heat sink.

[0016] In a further preferred embodiment of the electronic multi-component assembly, which works particularly advantageously in conjunction with the embodiment described above, the three electronic modules can be configured to generate a three-phase voltage for operating an electric motor. This embodiment is particularly advantageous in a control unit for operating an electric compressor because an electric machine preferably used for this purpose requires a three-phase voltage for operation, which is generated by the three electronic modules.

[0017] The invention further comprises an electronic control unit, in particular an electronic control unit for operating a compressor, comprising at least a housing and an electronic multi-component assembly according to the invention. The use of the electronic multi-component assembly according to the invention advantageously enables a more compact and lighter design when used in an electronic control unit, with optimized cooling of the electronic modules. Furthermore, the use of the electronic multi-component assembly according to the invention allows for particularly cost-effective manufacturing. The more compact and lighter design offers advantages with regard to the required installation space for the control unit and with regard to fitting the control unit into a predetermined installation space, the so-called packaging, which is of central importance for obtaining a contract.Lower manufacturing costs can advantageously increase the revenue from the sale of the electronic control unit and / or make it possible to submit a more favorable offer, which is another crucial advantage for successfully marketing the electronic control unit.

[0018] Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments of the invention and from the drawings. Brief description of the drawings Fig. Figure 1 shows a state-of-the-art electronic multi-component assembly in a perspective view. Fig. 2: shows a section of an electronic multi-component assembly according to the invention in a perspective view, Fig. Figure 3 shows a section of an electronic multi-component assembly according to the invention in a schematic sectional view. Embodiments of the invention

[0019] Identical elements or elements with the same function are provided with the same reference numbers in the figures.

[0020] In the Fig. Figure 1 shows a perspective view of a prior art multi-component electronic assembly. The multi-component assembly comprises three electronic modules 3, a boundary frame 4, three die-cut grids 2, and a heat sink 6. The boundary frame 4 surrounds the three electronic modules 3, forming an open-topped interior filled with an electrically insulating gel (not shown). The three die-cut grids 2 provide the electrically conductive connection from the three electronic modules 3 to three connection terminals 21. The die-cut grids 2 are made of a copper-based alloy and are molded into the boundary frame 4. The electrically conductive connection from the three electronic modules 3 to the three die-cut grids 2 is established by means of several tape bond connections 5.

[0021] The Fig. Figure 2 shows a perspective view of a section of an electronic multi-component assembly 10 according to the invention. It comprises a printed circuit board 11 with three cutouts 12, a boundary frame 4, three electronic modules 3, and a heat sink 6. The electronic modules 3 are arranged directly on the heat sink 6. The printed circuit board 11 is arranged in the same mounting plane, positioned such that the three cutouts of the printed circuit board 11 surround the three electronic modules 3. Connection pads 13 are arranged at the edge of the three cutouts 12. The connection pads 13 are electrically connected to the electronic modules 3 by means of wire bonds 14 or tape bonds 5.The circuit board 11 contains conductor tracks (not shown) that supply the electronic modules 3 with voltage, receive signals, and transmit the electrical power provided by the electronic modules 3 to a load. No die-cut grids are used. The boundary frame 4 is fluid-tight and attached to the circuit board 11. It surrounds the three cutouts in the circuit board 12 containing the three electronic modules 3 and the connection pads 13, forming an open-topped interior filled with an electrically insulating gel (not shown).

[0022] The Fig. Figure 3 shows a schematic sectional view of a section of an electronic multi-component assembly 10 according to the invention. The section passes through a cutout 12 of the printed circuit board 11, and the section plane is perpendicular to the mounting plane and thus also to the plane of the printed circuit board. The heat sink 6 comprises a first cooling part 15 and a second cooling part 16, wherein the first cooling part 15 is made of aluminum, preferably high-purity aluminum, and is arranged as an insert in the second cooling part 16, which is made of an aluminum die-cast alloy. The printed circuit board 11 is firmly connected to the heat sink 6 by means of a fluid-tight adhesive bond 18. The adhesive bond runs mainly between the second cooling part 16 and the printed circuit board 11, and the view together with the Fig.2 It becomes clear that the circuit board in the area of ​​the webs between the cutouts 12 is also fluid-tightly bonded to the first cooler part 15. The boundary frame 4 is firmly connected to the circuit board with a fluid-tight bond 19.

[0023] An electronic module 3 is arranged in the cutout 12 of the circuit board and is mounted directly onto the first cooling element 15 by means of a thermally conductive adhesive bond 17 and thermally connected to it. Tape bonds 5 and wire bonds 14 connect the electronic module 3 to connection pads 13 of the circuit board 11. An interior space is formed by means of the boundary frame 4 and the fluid-tight adhesive bonds 18, 19, which is filled with an insulating gel 20.

[0024] The conductor tracks of the circuit board 11, which are used instead of stamped grids, are not shown.

Claims

[1] Electronic multi-component assembly (10), in particular for use in an electronic control unit, preferably for use in an electronic control unit for operating an electric compressor, comprising at least a printed circuit board (11), a metallic heat sink (6, 15, 16) and an electronic module (3), in particular an electronic module which generates waste heat during operation and must be cooled, characterized by , that the electronic module (3) is arranged directly on the heat sink (6, 15, 16) in a mounting plane, wherein the printed circuit board (11) is arranged in the same mounting plane, wherein the printed circuit board has a cutout (12) and is arranged such that the cutout (12) surrounds the electronic module (3). [2] Electronic multi-component assembly according to claim 1, characterized by, that connection pads (13) are arranged on the circuit board (11) surrounding the cutout (12), wherein electrically conductive connections from the connection pads of the circuit board (11) to the electronic module (3) arranged in the cutout are formed by means of wire bonding (14) and / or ribbon bonding (5). [3] Electronic multi-component assembly according to one of the preceding claims, characterized by , that the printed circuit board (11) for operating the electronic module (3) has conductor tracks for electrical signal transmission and electrical power transmission, wherein preferably all electrical conductors for electrical signal transmission and electrical power transmission to / from the electronic module are designed as conductor tracks of the printed circuit board (11). [4] Electronic multi-component assembly according to one of the preceding claims, characterized by, that the electronic module (3) is thermally connected to the heat sink (6) by means of a thermally conductive connection, preferably by means of a thermally conductive adhesive connection (17) or by means of a thermally conductive soldered connection. [5] Electronic multi-component assembly according to any one of the preceding claims, characterized by , that the electronic module (3) comprises a power electronic component, in particular a power transistor, preferably a power MOSFET. [6] Electronic multi-component assembly according to any one of the preceding claims, characterized by, that a frame (4) is arranged on the printed circuit board (11), wherein the frame surrounds the cutout (12) in the printed circuit board and wherein the frame forms a fluid-tight connection with the printed circuit board (11) by means of a fluid-tight adhesive bond (18) or by means of a sealing lip molded into the frame, wherein an interior space open on one side, which is formed by the printed circuit board (11) and the frame (4) and in which the cutout (12) in the printed circuit board is arranged, is filled with an electrically insulating gel (20), preferably an electrically insulating gel to meet rules and / or specifications for preventing electrical malfunctions and accidents. [7] Electronic multi-component assembly according to one of the preceding claims, characterized by, that the circuit board (11) is fluid-tightly connected to the heat sink (6) surrounding the cutout, so that the electrically insulating gel cannot escape through the cutout (12) from the interior above the cutout and thereby fixes the circuit board (11) relative to the heat sink (6). [8] Electronic multi-component assembly according to any one of the preceding claims, characterized by , that the circuit board (11) has three adjacent cutouts (12) and in each cutout an electronic module (3), preferably several electronic modules (3), is arranged and thermally connected to the heat sink (6). [9] Electronic multi-component assembly according to claim 8, characterized by , that the three electronic modules (3) are designed to generate a three-phase voltage for operating an electric motor. [10] Electronic control unit, in particular an electronic control unit for operating a compressor, comprising at least a housing and an electronic multi-component assembly (10) according to any one of claims 1 to 9.

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