Electrical control unit, method for manufacturing an electrical control unit, retrofitting tool for manufacturing a control unit

Abstract

The invention relates to an electrical control unit, a manufacturing method for manufacturing an electrical control unit, a modification tool for manufacturing a control unit. The electrical control unit has a circuit board (20), a structural element (30) arranged on a first side (S1) of the circuit board (20) and a busbar (40) resting on a second side (S2) of the circuit board (20), wherein a contact projection (42) of the busbar (40) projects into a through-hole (22) of the circuit board (20) such that an end face (44) of the contact projection (42) is arranged flush with the first side (S1) of the circuit board (20) in the longitudinal direction of the contact projection (42), wherein the contact projection (42) has a predetermined maximum length (H1) in the original state and is mechanically modified to a final installation length (H2) in the final installation state.

Description

Technical Field

[0001] The present invention relates to an electrical control unit having a circuit board, a structural element disposed on a first side of the circuit board, and a bus disposed on a second side of the circuit board, wherein the bus has a contact protrusion, and the circuit board has a through hole corresponding to the contact protrusion, wherein the contact protrusion extends into the through hole of the circuit board such that the end face of the contact protrusion is disposed flush with the first side of the circuit board in the longitudinal direction of the contact protrusion and is in electrical contact with the structural element. Background Technology

[0002] Such electrical control units are known in the prior art, wherein the electrical control unit typically has a circuit board, a plurality of structural elements disposed on the circuit board and electrically in contact with the circuit board, and at least one bus electrically in contact with the structural elements and / or the circuit board. The bus can be mechanically and electrically connected to the circuit board and the structural elements, such that the bus has at least one contact protrusion that is fitted into a through-hole of the circuit board, wherein the contact protrusion is connected to the circuit board by connection with a structural element additionally connected to the circuit board. The connection between the structural element and the circuit board and the contact protrusion is achieved on a common first side of the circuit board, facing away from the bus. Here, the structural element is electrically and mechanically connected to the end face of the contact protrusion and to the circuit board, particularly to the electrical conductor layer, with one side facing the circuit board. To establish this connection, the end face of the contact protrusion and the first side of the circuit board must be flush with each other. Such an electrical control unit is disclosed, for example, in EP 2 043 412 A1.

[0003] The problem here is that, on the one hand, circuit boards can, in principle, be implemented with different thicknesses; on the other hand, manufacturing tolerances exist for both the bus and the circuit board, meaning that a flush connection is not always present between the end face of the contact protrusion and the first side of the circuit board. To achieve this flush connection, the circuit board and the bus are typically positioned relative to each other, thereby creating an undesirable gap between the second side of the circuit board and the bus. This gap makes assembly of the circuit board with structural components difficult, as solder can flow uncontrollably into the gap when soldering structural components. Furthermore, another gap may exist between the circumferential surface of the contact protrusion and the circumferential surface of the via, thus posing a risk of insufficient contact between the contact protrusion and the structural component, as solder may flow uncontrollably into the gap and thus out from the contact area between the contact protrusion and the structural component. Summary of the Invention

[0004] The purpose of this invention is to provide an electrical control unit in which a busbar can be simply and reliably fixed on a circuit board and can be electrically connected to structural elements and / or the circuit board.

[0005] This objective is achieved by the features of claim 1.

[0006] According to the invention, the contact protrusion has a predetermined maximum length in its original state and is mechanically modified to the final installation length in the final installation state.

[0007] Therefore, when installing the bus, the contact protrusions of the bus can be adapted to the thickness of the circuit board as needed, that is, specifically for the circuit board. The length of the contact protrusions is adapted to the circuit board through mechanical modification, particularly through stamping. Due to the adapted length of the contact protrusions, the bus rests against the second side of the circuit board, and the end face of the contact protrusions is flush with the first side of the circuit board.

[0008] This allows for a simple and reliable connection of the busbar to the circuit board, particularly to the mechanical and electrical grounds, while avoiding undesirable gaps between the busbar and the second side of the circuit board, and ensuring that the end faces of the contact protrusions remain flush with the first side of the circuit board. Specifically, this enables the busbar to be manufactured independently of the given circuit board and to be mounted on circuit boards of varying thicknesses, wherein, when the electrical control unit is mounted onto the corresponding circuit board, specifically for the circuit board ground, the contact protrusions are adapted by mechanically modifying them, particularly by stamping them.

[0009] Preferably, the contact protrusion is stamped such that the final mounting outer diameter of the contact protrusion is at least partially larger than the original outer diameter. In its original state, the contact protrusion is at least partially spaced from the inner circumferential surface when viewed circumferentially, and in its final mounting state, it is supported on the circuit board transversely to the longitudinal direction of the contact protrusion on the inner circumferential surface of the through-hole. During stamping, the contact protrusion is shortened, thereby radially outwardly compressing the material of the contact protrusion and increasing its diameter. Specifically, stamping creates an arched or raised circumferential surface of the contact protrusion, resulting in the final mounting outer diameter of the contact protrusion being largest at the center and decreasing towards the edge in the longitudinal direction. Here, viewed longitudinally, the contact protrusion circumferentially abuts the inner circumferential surface of the through-hole in the central region. Alternatively, the contact protrusion may be raised over its entire length or almost its entire length, thus having a substantially (cylindrical) longitudinal section and abutting the circumferential surface of the through-hole over its entire circumferential surface. Thus, the busbar is also positioned or supported on the circuit board laterally in the longitudinal direction. Additionally, there is a force-locking connection between the contact protrusion and the inner peripheral surface of the through hole along the longitudinal direction of the contact protrusion, thereby positioning and holding the contact protrusion and the circuit board relative to each other for the connection process between the structural elements and the contact protrusion and the circuit board.

[0010] In a preferred design, the contact protrusion has a U-shaped longitudinal section. In other words, the contact protrusion is implemented as hollow. During mechanical modification, that is, during modification, the sidewalls of the contact protrusion are subjected to pressure, wherein, from a specific load along the longitudinal direction of the contact protrusion, the sidewalls of the hollow contact protrusion arch radially outward, thereby increasing the outer diameter of the contact protrusion. By implementing the contact protrusion as hollow or having a U-shaped longitudinal section, a relatively small force or load is required to mechanically modify the contact protrusion. The end face of the contact protrusion is preferably implemented as circular. In a preferred design, the contact protrusion has a constant wall thickness. In particular, the busbar is implemented as a (metal) sheet metal component. To manufacture the busbar, the busbar is punched from a sheet metal blank and the contact protrusion is manufactured by mechanical modification, particularly deep drawing. Thus, the busbar with hollow contact protrusions can be manufactured simply and cost-effectively.

[0011] Alternatively, the contact protrusion is implemented using a solid material. Preferably, the busbar has a modification tooling recess on the side opposite to the contact protrusion. The modification tooling recess is arranged aligned with the contact protrusion and is used to mechanically modify only the contact protrusion during the modification process, minimizing mechanical modification of other areas of the busbar. Here, a component of the modification tool is fitted into the modification tooling recess, wherein the component provides a reaction force against the load that causes the mechanical modification of the contact protrusion. Furthermore, the modification tooling recess is used to optimize the formation of the contact protrusion during flow extrusion.

[0012] Preferably, the bus has multiple contact protrusions, allowing different structural components to be electrically connected to each other. Each contact protrusion extends into a through-hole of the circuit board, resulting in multiple through-holes. In a preferred design, multiple buses are arranged on the second side, each bus having at least one contact protrusion. This allows for different electrical connections to be achieved through different buses. Advantageously, the bus is provided with a plug tongue for connecting cables to conduct current. Alternatively, the bus may also have bolts, crimp connections, threaded holes, or welded geometry for connecting cables or busbars to conduct current. In both cases, reliable contact and ease of manufacture are ensured.

[0013] Preferably, the structural element is a power semiconductor structural element or an electrical connection element, such as a bus. Advantageously, the power semiconductor structural element is implemented as an SMD (Surface Mount Device) assembly. This allows the control unit to be manufactured particularly compactly. For example, two contact protrusions of different buses on the first side of the circuit board can be interconnected via electrical connection elements.

[0014] Furthermore, this task is solved by a method for manufacturing a control unit for electricity, or a method for manufacturing a control unit for producing electricity, and by a modified tool for manufacturing a control unit for electricity.

[0015] In this manufacturing method, a circuit board, structural components, and a bus are first provided. The bus is then mounted on the circuit board, wherein contact protrusions are inserted into through-holes in the circuit board and mechanically modified from their maximum length to a predetermined length, such that the end faces of the contact protrusions are flush with a first side of the circuit board, and the bus rests against a second side of the circuit board. Finally, the structural components are electrically and mechanically connected, particularly by soldering, to at least the contact protrusions, preferably to the contact protrusions and the circuit board.

[0016] The modified tool includes: a receiving unit for accommodating a bus and a circuit board, wherein, during modification, the bus rests against the receiving unit, and the circuit board rests against the bus on a second side, such that contact protrusions of the bus are arranged in through-holes of the circuit board; a clamping device rests against a first side of the circuit board during modification; and a punch that is translatably movable, such that the punch acts on the end face of the contact protrusion during modification. During modification, the circuit board and the bus are positioned on the receiving unit such that the bus rests against the second side of the circuit board, and the contact protrusions protrude from the first side of the circuit board along the longitudinal direction of the contact protrusion. Then, the clamping device is placed on the circuit board, for example by translational movement, thereby pressing the bus and the circuit board together and thus holding them together along the longitudinal direction of the contact protrusion. Finally, in particular, the punch, which is translatably supported on the clamping device, is translated such that the punch loads the contact protrusion through the end face of the contact protrusion. Here, the contact protrusion is modified using a punch until the end face of the contact protrusion is flush with the first side of the circuit board. Subsequently, a structural element is mounted on the first side, and the structural element is connected to the contact protrusion and, if necessary, to the circuit board. Here, the structural element rests planarly against the end face of the contact protrusion and against the first side of the circuit board. The connection between the structural element and the contact protrusion, and to the circuit board, is achieved by soldering, particularly with solder paste.

[0017] Preferably, the punch has a flat, arched, or centrally protruding working surface. When the working surface is flat, the end face contacting the protrusion is uniformly loaded. When the working surface is arched or centrally protruding, particularly at a point, a greater force acts at the center of the end face contacting the protrusion than in the outer region, thereby causing the material contacting the protrusion to be selectively and uniformly extruded radially outward during stamping.

[0018] In a preferred design, a retaining element is arranged on the receiving unit, which abuts against the side of the busbar facing away from the circuit board in the area of ​​the contact protrusion. The retaining element is fixedly or translatably supported on the receiving unit with spring preload along the longitudinal direction of the contact protrusion. The retaining element is particularly fitted into a tooling recess in the busbar. The translatably translatably spring-preloaded retaining element reliably prevents overload of the contact protrusion or busbar during the modification process, i.e., during stamping. The reaction force on the punch can be set by selecting a spring element that provides spring preload and has a specific spring characteristic curve. Attached Figure Description

[0019] Different embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. As shown herein:

[0020] Figure 1 A portion of a first embodiment of the electrical control unit is shown in cross-section; and

[0021] Figure 2 A portion of a second embodiment of the electrical control unit is shown in cross-section;

[0022] Figure 3 The cross-section shows the materials used for manufacturing. Figure 1 and Figure 2 Modification tools for the electrical control unit in the middle;

[0023] Figure 4a Shown in cross-section Figure 3 The modified tool is a part of the first embodiment.

[0024] Figure 4b Shown in cross-section Figure 3 The modified tool in the second embodiment, and

[0025] Figure 4c Shown in cross-section Figure 3 The modified tool is partially described in the third embodiment. Detailed Implementation

[0026] Figure 1 and Figure 2 Two different embodiments of an electrical control unit 10 are shown, which is used, for example, in a vehicle, to control electrically operated vehicle equipment.

[0027] The electrical control unit 10 includes a circuit board 20, multiple structural elements 30, 32 and at least one busbar 40.

[0028] Circuit board 20, also known as PCB (Printed Circuit Board), is an electrical switching circuit whose components and conductors are mounted within a mechanical structure. Copper printed wires, pads, coolants, or conductive surfaces are conductive components. The mechanical structure consists of insulating material located between layers made of conductive material. Circuit board 20 has a plate-like shape, such that circuit board 20 includes a first side S1 and an opposite second side S2.

[0029] Structural elements 30 and 32 are implemented as semiconductor power structural elements, particularly SMD structural elements. Unlike THT structural elements, SMD structural elements do not include wire connectors but are directly soldered to the circuit board 20 via solderable connection surfaces or pins. The first structural element 30 is arranged on a first side S1 of the circuit board 20, and the second structural element 32 is arranged on a second side S2 of the circuit board 20. The electrical control unit 10 typically includes other structural elements and other buses, wherein the structural elements may also be electrical connection elements, such as connecting two separate buses to each other.

[0030] Bus 40 is implemented as a plate and is arranged on the second side S2 of circuit board 20. Bus 40 is a single piece and is made of conductive metal material.

[0031] Busbar 40 is used to allow different components to contact each other. Figure 1 and 2 The bus 40 shown is mechanically and electrically connected to the circuit board 20 and the structural element 30. The bus 40 is connected to the first side S1 of the circuit board 20 and the first structural element 30 via a first solder layer 50, and to the second side S2 of the circuit board 20 via a second solder layer 52. The second structural element 32 is connected to the second side S2 of the circuit board 20 via a third solder layer 54.

[0032] For contact with the first structural element 30, the busbar 40 has a contact protrusion 42 on the first side of the circuit board 20. The circuit board 20 has a through hole 22 corresponding to the contact protrusion, wherein, in the final installed state of the electrical control unit 10, the contact protrusion 42 is fitted into the through hole 22 such that the contact protrusion 42 extends from the second side S2 of the circuit board 20 to the first side S1. To allow the first structural element 30 to contact the circuit board 20 and the contact protrusion 42, the end face 44 of the contact protrusion 42 is arranged flush with the first side S1 of the circuit board 20. In other words, the end face 44 of the contact protrusion 42 is arranged in the plane E1 of the first side S1 of the circuit board 20.

[0033] The arrangement of the end face 44 of the contact protrusion 42 being flush with the first side S1 of the circuit board 20 is achieved in such a way that when the busbar 40 has been mounted on the circuit board 20, that is, when the contact protrusion 42 has been inserted into the through hole 22 and the busbar 40 is abutting against the second side S2 of the circuit board 20, the contact protrusion 42 is mechanically modified, that is, stamped, wherein these components have not yet been soldered to each other.

[0034] exist Figure 1 and Figure 2 The decisive difference between the two implementations shown is that... Figure 2 The contact protrusion 42 has a U-shaped longitudinal section and a constant wall thickness, while Figure 1 The contact protrusion 42 is implemented as a solid material. The contact protrusion 40 is stamped in both cases, wherein the deformation mode differs from each other in these different embodiments.

[0035] exist Figure 3 The image shows a modification tool 60, which can mechanically modify the contact protrusion 42. The modification tool 60 includes a receiving unit 62, a mating retainer 64 arranged at the receiving unit 62, a movable clamping device 66, and a punch 68 that can be translated at the clamping device 66.

[0036] The receiving unit 62 and the mating retainer 64 are configured such that, during installation or modification, the bus 40 and the circuit board 20 are received such that the bus 40 rests against the receiving unit 62, and the circuit board 20 rests against the bus 40 on its second side S2, wherein the contact protrusion 42 of the bus 40 extends into the through hole 22 of the circuit board 20. The mating retainer 64 extends into the modification tool fitting groove 48 of the bus 40, wherein the mating retainer is fixedly or translationally, spring-preloaded, i.e., supported by a punch 68 under a predetermined force at the receiving unit 62. The clamping device 66 rests against the first side S1 of the circuit board 20 and is applied a clamping force toward the circuit board 20, thereby clamping the circuit board 20 and the bus 40 between the receiving unit 62 and the mating retainer 64 and the clamping device 66. Thus, the bus 40 rests against the second side of the circuit board 20. During the modification process, the punch 68 applies a modification force to the end face 44 of the contact protrusion 42.

[0037] During the modification process, the circuit board 20 and bus 40 are positioned on the receiving unit 62 and the mating retainer 64, such that the bus 40 abuts against the second side S2 of the circuit board 20, and due to the maximum length H1, the contact protrusion 42 protrudes from the first side S1 of the circuit board 20 along its longitudinal direction. Then, the clamping device 66 is placed on the circuit board 20, for example by translational movement, thereby pressing the bus 40 and the circuit board 20 together and thus holding them together along the longitudinal direction of the contact protrusion 42. Finally, the punch 68 is moved and loaded such that the punch 68 loads the contact protrusion 42 through its end face 44. Here, the contact protrusion 42 is deformed by the punch 68 to the final installation length H2 until the end face 44 of the contact protrusion 42 is flush with the first side S1 of the circuit board 20. By stamping the contact protrusion 42, the original outer diameter D1 of the contact protrusion 42 is increased to the final mounting outer diameter D2. In its original state, the contact protrusion 42 is at least partially spaced from the inner circumferential surface 24 of the through hole 22 when viewed circumferentially, and in its final mounting state, it abuts against the inner circumferential surface 24 of the through hole 22 transversely to the longitudinal direction of the contact protrusion 42. Here, the contact protrusion 42 is shortened during stamping, thereby the material of the contact protrusion 42 is radially outwardly compressed, and thus the diameter of the contact protrusion increases. In particular, stamping the contact protrusion 42 causes an arched or raised circumferential surface of the contact protrusion 42, wherein the final mounting outer diameter D2 of the contact protrusion 42 is largest at the center in the longitudinal direction and decreases from the center towards the edge.

[0038] In order to specifically induce this modification of the contact protrusion 42, the punch 68 has a configuration according to... Figure 4c Arched or according to Figure 4b The working surface 69 has a pointed protrusion at the center. Alternatively, the punch 68 may have a... Figure 4a The flat working surface 69 shown in the figure indicates that, when the working surface 69 is flat, the end face of the contact protrusion 42 is uniformly loaded. When the working surface 69 is arched or has a protrusion at the center, especially a tip, a greater radial force acts at the center of the end face 44 of the contact protrusion 42 than in the outer region, thereby causing the material of the contact protrusion 42 to be radially extruded in a targeted and uniform manner during stamping.

[0039] After modifying the contact protrusion, the modification tool 60 is removed. A first structural element 30 is mounted on the first side S1, and the structural element 30 is connected to the contact protrusion 42 and the circuit board 20. Here, the structural element 30 is planarly attached to the end face 44 of the contact protrusion 42 and to the first side S1 of the circuit board 20, which is flush with the end face 44. The connection between the structural element 30 and the contact protrusion 42, and between the structural element 30 and the circuit board 20, is achieved by soldering. The second structural element 32 is soldered to the second side S2 of the circuit board 20.

[0040] List of reference numerals

[0041] 10-electric control unit

[0042] 20 circuit boards

[0043] 22 through holes

[0044] 24 inner circumferential surfaces

[0045] 30 First structural element

[0046] 32 Second structural element

[0047] 40 busbars

[0048] 42 contact protrusions

[0049] 44 end face

[0050] 50 First solder layer

[0051] 52 Second solder layer

[0052] 54 Third solder layer

[0053] 60 Modification Tools

[0054] 62 housing units

[0055] 64 mating retainer

[0056] 66 clamping device

[0057] 68 punch

[0058] 69 working surfaces

[0059] D1 Original Outer Diameter

[0060] D2 final installation outer diameter

[0061] E1 plane

[0062] H1 maximum length

[0063] H2 final installation length

Claims

1. An electrical control unit, having: Circuit board (20) Structural element (30), said structural element being arranged on the first side (S1) of the circuit board (20), Bus (40), the bus is arranged on the second side (S2) of the circuit board (20), wherein, The busbar (40) has a contact protrusion (42) and the circuit board (20) has a through hole (22) corresponding to the contact protrusion (42), wherein the contact protrusion (42) extends into the through hole (22) of the circuit board (20) such that the end face (44) of the contact protrusion (42) is flush with the first side (S1) of the circuit board (20) in the longitudinal direction of the contact protrusion (42) and makes electrical contact with the structural element (30). Its features are, The contact protrusion (42) has a predefined maximum length (H1) in its original state and is mechanically modified to the final installation length (H2) in its final installed state.

2. The electrical control unit according to claim 1, characterized in that, The contact protrusion (42) is mechanically stamped so that the busbar (40) abuts against the second side (S2) of the circuit board (20) and the end face (44) of the contact protrusion (42) is flush with the first side (S1) of the circuit board (20).

3. The electrical control unit according to claim 2, characterized in that, The contact protrusion (42) is stamped such that the final mounting outer diameter (D2) of the contact protrusion (42) is at least partially larger than the original outer diameter (D1), wherein the contact protrusion (42) is at least partially spaced from the inner circumferential surface (24) of the through hole (22) when viewed in the circumferential direction in the original state, and in the final mounting state, the contact protrusion (42) is supported on the circuit board (20) transversely to the longitudinal direction of the contact protrusion (42) by abutting against the inner circumferential surface (24) of the through hole (22).

4. The electrical control unit according to any one of the preceding claims, characterized in that, The contact protrusion (42) has a U-shaped longitudinal section.

5. The electrical control unit according to any one of claims 1 to 3, characterized in that, The contact protrusion (42) is implemented in a solid material manner.

6. The electrical control unit according to any one of the preceding claims, characterized in that, The busbar (40) has a modified tooling groove (48) on the side opposite to the contact protrusion (42).

7. The electrical control unit according to any one of the preceding claims, characterized in that, The busbar (40) has multiple contact protrusions (42).

8. The electrical control unit according to any one of the preceding claims, characterized in that, Structural elements (30, 32) are power semiconductor structural elements or electrical connection elements.

9. A method for manufacturing an electrical control unit according to any one of claims 1 to 8, the method comprising the following steps: Circuit board (20) is provided. Provide structural components (30). Provide bus (40). The busbar (40) is mounted on the circuit board (20), wherein a contact protrusion (42) is inserted into a through hole (22) of the circuit board (20), and the contact protrusion is mechanically modified from its maximum length (H1) to a final mounting length (H2) such that the end face (44) of the contact protrusion (42) is flush with the first side (S1) of the circuit board (20), and the busbar (40) rests against the second side (S2) of the circuit board (20). The first side (S1) of the circuit board (20) is assembled with the structural element (30) such that the structural element (30) at least rests against the end face (44) of the contact protrusion (42). The structural element (30) is connected to at least the contact protrusion (42).

10. The manufacturing method according to claim 9, Its features are, The structural element (30) is welded to the contact protrusion (42).

11. The manufacturing method according to claim 9 or 10, Its features are, The structural element (30) is connected to the first side (S1) of the circuit board (20) and to the busbar (40).

12. A modified tool for manufacturing an electrical control unit according to any one of claims 1 to 8, the modified tool comprising: Receiving unit (62), said receiving unit being implemented for receiving bus (40) and circuit board (20), wherein, During the modification process, the bus (40) is attached to the receiving unit (62), and the circuit board (20) is attached to the bus (40) on the second side (S2), such that the contact protrusion (42) of the bus (40) is arranged in the through hole (22) of the circuit board (20); A clamping device (66) is attached to the first side (S1) of the circuit board (20) during the modification process; and A punch (68) is translatably movable so that it acts on the end face (44) of the contact protrusion (42) during the modification process.

13. The modified tool according to claim 12, characterized in that, The punch (68) has a flat, arched or centrally raised working surface (69).

14. The modified tool according to claim 12 or 13, characterized in that, The punch (68) can be translatably supported on the clamping device.

15. The modified tool according to any one of claims 12 to 14, characterized in that, A mating retainer (64) is arranged on the receiving unit (62), which abuts against the side of the busbar (40) away from the circuit board (20) in the area of ​​the contact protrusion (42), wherein the mating retainer (64) is fixedly or translatably movable along the longitudinal direction of the contact protrusion (42) and spring-preloaded on the receiving unit (62).

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