Electric mechanism provided with a positioning auxiliary part and manufacturing method

Abstract

A manufacturing method and an electrical arrangement (1) are proposed, which comprises a power board (2) with an electrical conductor path (3), an insulating structure (4) and a conductive structure (5) made of sheet metal, which has a first contact area (6), a terminal area (11) and a first coupling area (9) between the first contact area (6) and the terminal area (11), the contact area (6) being electrically, in particular materially, coupled to the electrical conductor path (3) in a cavity (12) in the insulating structure (4), transitioning at an angle to the coupling area (9) along an edge (7) running in the X-direction and having a flag-shaped portion (8) for positioning the conductive structure (5), which extends in the Y-direction beyond an imaginary extension of the edge (7).

Description

Technical Field

[0001] The present invention relates to an electric mechanism provided with a positioning aid and a manufacturing method therefor. The present invention relates, in particular, to an electric mechanism having an insulating structure raised on a power substrate.

Background Art

[0002] Today's power substrates are sometimes based on ceramic structures having upper and lower surfaces of metal. On this, power switches (such as IGBTs, MOSFETs, etc.) are arranged (mounted) and wired. Due to the substrate, branching is only possible in a two-dimensional space. As external contacts, bonding, also called "ribbon" and "wire", etc., is used. Stamped parts contacted by ultrasonic or laser welding are also used. In the case of this type of power substrate provided with a packaged, i.e., raised, insulating structure, it is also common to position the coupling elements together in the same way and project them beyond the packaging edge. The "packaging edge" refers to the insulating structure surrounding the edge of the power substrate. In this case, the protruding coupling elements are used for external electrical contact.

[0003] Contacting the packaging edge above the surface of the power substrate causes a reduction in the surface creepage distance of the current along the surface of the insulating structure between the upper and lower surfaces.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Furthermore, there is a need for an electric mechanism in which the inductance in the commutation circuit is as low as possible, which is suitable for manufacturing, is less affected by tolerances, and provides electronic components having a low inductance structure. At the same time, the robustness for the assembly steps on the factory side should be enabled and guaranteed.

Means for Solving the Problems

[0005] The present invention proposes an electrical mechanism, which is particularly suitable for use in a power circuit. Such a power circuit is necessary, for example, in the field of electromobility where an alternating voltage or a polyphase voltage required for the operation of a traction machine is to be generated from a DC voltage stored on board. This electrical mechanism includes a power board with electrical conductor paths and has an insulating structure. The insulating structure may be injection-molded onto the power board, for example, in the form of a foam material. Thereby, electrical insulation between, in particular, the upper and lower surfaces of the power board is provided at a predetermined creepage distance (current creepage distance). For this purpose, the insulating structure can expose several contact surfaces on the power board that are electrically coupled to the electrical conductor paths. In other words, the insulating structure can surround the contact surfaces, and in this case, an edge arranged at a predetermined position can be provided around the contact surface (such as a window or a frame). Furthermore, a sheet-metal conductive structure having a three-dimensional shape is provided. This conductive structure has a first contact region that is galvanically connected to the contact surface on the power board. The conductive structure further has a terminal region for external electrical contact and a first connection region that connects the first contact region and the terminal region. This connection region can, in particular, ensure current transmission between the contact region and the terminal region when the contact region and the terminal region do not extend in the same plane. The contact region can be electrically, in particular, materially bonded to the contact surface of the power board, i.e., the electrical conductor path. For this purpose, the insulating structure has a cavity (window / frame), and within the cavity, the contact region of the conductive structure lies flat on the power board. The contact region is bent at an angle along an edge or transitions to the connection region in another way. Such a deformation of the sheet-metal conductive structure sometimes involves an increase in tolerance, and in the region of the edge, since this edge usually has a similar radius / curve, it does not provide the possibility of clearly defining a form fit surrounding the edge. Sometimes, the angle of the connection region with respect to the plane of the first contact region cannot always be precise due to manufacturing constraints. Therefore, a flag-shaped part is provided for positioning the conductive structure, and this flag-shaped part extends in a direction perpendicular to the direction of the edge beyond the virtual extension of the edge.The edge causes the first contact region to shift into the bonding region. In other words, adjacent to the edge, the flag-shaped part remains within the plane of the first contact region and has a tip edge that is, in particular, cut or punched out, and this tip edge has a tolerance that is smaller than the spatial position of the bonding region. In particular, while the bonding region can emerge out of a window in the insulating structure without contacting the insulating structure, the flag-shaped part inserts, in particular fits, preferably presses, an edge opposite the first contact region into the window in the insulating structure, and the window in the insulating structure positions the first contact region, and thus the conductive structure, within the electrical mechanism. Thereby, a very precise positioning of the conductive structure on the power substrate or relative to the insulating structure can be ensured, while the creepage distance along the insulating structure is very small because the flag-shaped part is directly present on the power substrate and does not contact the "higher" position of the insulating structure.

[0006] The cited claims show preferred variants of the invention. After cutting out the conductive structure from the sheet metal, by the flag-shaped part not being deformed relative to the first contact region, the flag-shaped part may be in the same plane as the contact region. The flag-shaped part is so to speak a flat tongue attached to the first contact region of the conductive structure, protruding with respect to the bonding region beside the edge, that is, protruding beyond the edge with respect to the bonding region. By doing so, it can be ensured that the bonding region has a predefined spacing with respect to the insulating structure and that the bonding region does not reduce the creepage distance of the current along the insulating structure.

[0007] Particularly inexpensive possibilities for manufacturing a conductive structure from sheet metal can lead to laser cutting or punching of the outer shape of a flat conductive structure, whereupon a bending process results in an edge running in the X direction between a first contact region and a first bonding region. Optionally, an edge can also be provided between a terminal region for external contact and the first bonding region, whereby the conductive structure is coupled to external electrical peripherals in a direction parallel to the surface of the power substrate. Due to process constraints, in the present case, in the region of the edge, a radius can occur on the convex side of the conductive structure, specifically a radius that is not suitable for positioning near the power substrate, caused by an insulating structure. In this case, a flag-shaped portion that is excluded during the bending process is useful. That is, the cutting edge of the flag-shaped portion is provided as a positioning aid on the other side of the edge between the bonding region and the first contact region, that is, adjacent.

[0008] Preferably, the electric mechanism has a further contact region and optionally also a further bonding region. That is, a second contact region and a second bonding region between the second contact region and the terminal region (already described above) can be provided. The second contact region can also transition to the second bonding region at an angle along a second edge running in the X direction. In particular, the edge between the second contact region and the second bonding region is formed on the same line as the edge between the first contact region and the first bonding region. The second contact region can be formed corresponding to, or identical to, or mirror-inverted to the first contact region. Thus, the second contact region is in the same direction as the first contact region when viewed from the terminal region, but is parallel. Basically, it is also possible to contact these contact regions with the terminal region via one and the same bonding region. In any case, the flags of both contact regions can bring about a predetermined linear abutment to the respective regions of the insulating structure, thus ensuring a particularly reliable positioning of the conductive structure. The first and second contact regions can be arranged on the power substrate within a common cavity of the insulating structure, i.e., within a common window / frame. However, it is preferably possible to provide an insulating structure between both contact regions, and this insulating structure can also be used as a positioning aid in the X direction. In other words, this insulating structure forms a bridge portion between the first contact region and the second contact region, and this bridge portion prevents misalignment in the direction of the first and second edges. This bridge portion may have a thickness that increases in the direction of the surface of the power substrate, whereby easy positioning of the conductive structure is possible due to the tolerance gradually decreasing as the conductive structure approaches the insulating structure.

[0009] The flag can preferably be designed in relation to the remaining contact areas such that the tip of the flag fits precisely into the cavity of the insulating structure together with the opposite edge of the contact area. If another second contact area with a second flag is present, the above applies correspondingly to the second flag. In particular, if there are at least two contact areas with a certain extent in the X direction, a precise positioning of the conductive structure in the X and Y directions can be ensured and thus a rotation of the conductive structure relative to the power substrate about the Z axis can also be prevented.

[0010] A bay may be provided between the flag and an edge provided between the coupling area and the first contact area or the second coupling area and the second contact area. The bay may have a width (i.e. an extension in the X-direction) of, for example, 0.2 mm, preferably 0.5 mm, particularly preferably 1 mm, very particularly preferably 2 mm. In this way, it can be prevented that the folding process that follows the cutting of the sheet metal does not inadvertently cause a deformation of the flag relative to the respective contact area. Thus, a precise positioning of the conductive structure in the window of the insulating structure is always guaranteed close to the substrate.

[0011] In other words, and without any limiting nature to the appended claims, the invention is based on the idea of ​​enabling direct coupling between modules on a board-based power switch. This is done via exposures / voids in the packaging housing (insulating structure) of the module. The exposures / voids can be shaped to be placed directly against the housing shape of the packaging (insulating) without additional delicate geometries that are difficult to make. This reduces rejects during the manufacture of the electrical system (module). Furthermore, the sometimes subsequent surface exposure process of the power board (which sometimes in the state of the art involves subsequent burning off of the insulating components that remain with a laser) can be eliminated. Due to the flat structure of the contact area according to the invention with the positioning flags, the clearance and creepage distance requirements can be better respected.

[0012] The form according to the invention enables simple and reliable contact in the contact area by means of insertion / placement onto a power substrate or contact surface / electrical conductor path for the purpose of welding. Based on a second aspect of the invention, a method for manufacturing the electrical mechanism described in detail above is proposed. This method includes applying an insulating structure onto a power substrate. The insulating structure is raised and is provided, inter alia, for extending the current creepage distance between the upper and lower surfaces of the power substrate. The insulating structure has a cavity where the conductive structure is to be electrically contacted. In a further step, the conductive structure is cut out and bent from sheet metal. At this time, flag portions for positioning within the insulating structure also occur. Subsequently, the contact area is placed into the cavity within the insulating structure and finally is joined to the electrical conductor path of the power substrate in a material-bonding manner. Incorrect alignment of the conductive structure with respect to the power substrate is prevented by precisely aligning the cavity with respect to the structure of the contact area and the flag portions. The steep walls in the form of inclined paths within the insulating structure can be utilized when inserting the contact area and reduce the requirement for precise positioning using handling tools during mounting of the power substrate.

[0013] The assembly process of the contact area or the conductive structure with respect to the power substrate requires perfect positioning of these mating materials. This thereby also enables overall surface placement for subsequent joining processes. This is done by the coordination of the shaping and profiling of the bonding sheet metal (conductive structure) and the power substrate (power switch). Setting the punching direction prevents snagging during assembly. In other words, a punch having the shape of the conductive structure can be placed onto the sheet metal from the direction where the power substrate will later be present. Thereby, sharp edges or burrs formed on the sheet metal on the die side are behind in the assembly direction and there is no risk of snagging on the insulating structure. The geometric shapes that are shape-bonded for these above-mentioned mating materials guarantee the mounting position without requiring additional tooling costs.

[0014] Exemplary embodiments of the invention will be described in detail below with reference to the accompanying drawings.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0016] FIG. 1 shows a side view of one exemplary embodiment of an electric mechanism 1 according to the present invention. In this electric mechanism 1, a power substrate 2 provided with an electric conductor path 3 supports an insulating structure 4 and a conductive structure 5. The contact region 6 of the conductive structure 5 is bonded to the electric conductor path 3 in a material bonding manner. The region of the edge in the X direction transitions to a first bonding region 9 with a radius R so that electrical contact can be made above the insulating structure 4. The bonding region 9 transitions to a terminal region 11 by an edge 10 running parallel to the edge 7. Two edges of the insulator 4 facing each other in the Y direction define a cavity 12 within the insulating structure 4. The flag 8 protrudes in the Y direction beyond the edge running in the X direction as an extension of the first contact region 6, thereby providing precise and (provisional) fixation of the conductive structure 5 within the cavity 12 and on the electric conductor path 3. Moreover, the flag 8 ensures the spacing b between the bonding region 9 and the insulating structure 4, thereby avoiding incorrect contact of the bonding region 9 with the insulating structure 4, and thus continuously maintaining the length of the creepage distance 14.

[0017] Figure 2 shows a perspective view of the electrical mechanism 1, in which the conductive structure 5 is locked in the X direction by the bridge portion 15. A curved portion 13 is provided between the flag-shaped portion 8 and the edge 7, and the curved portion 13 prevents the flag-shaped portion 8 from being deformed with respect to the contact region 6 during bending. The second contact region 16 is arranged and formed symmetrically with respect to the first contact region 6 in a mirror image manner. The flag-shaped portions 8, 18 prevent play in the contact regions 6, 16 within the voids of the insulating structure 4. The additional contact regions without flag-shaped portions and curved portions are connected to a common terminal region 11 via additional connection regions, and external electrical contact of the electrical mechanism 1 is made via this terminal region 11.

[0018] Figure 3 shows a plan view of the underside of the electrical mechanism 1 according to the present invention. In this figure, the positions of the flag-shaped portions 8, 18 and the curved portion 13 arranged between these flag-shaped portions and their respective edges 7, 17 can be clearly recognized.

[0019] In Figure 4, a cross-sectional view of the electrical mechanism 1 shown in Figures 2 and 3 is shown. The insulator 4 surrounds the edge of the power substrate 2, and the power substrate 2 has a first electrical conductor path 3a on its upper surface and a second electrical conductor path 3b on its lower surface. The creepage distance 14 is drawn as a line that winds around between the lower electrical conductor path 3b and the upper electrical conductor path 3a. Since the first contact region 6 is overall flat and lies flat on the electrical conductor path 3a, the creepage distance 14 is not reduced by the first contact region 6, and a predetermined sufficient electrical insulation between the electrical conductor paths 3a, 3b is always ensured.

[0020] FIG. 5 shows the steps of one exemplary embodiment of a manufacturing method according to the invention of an electric mechanism based on the above exemplary embodiment. In step 100, an insulating structure is applied onto the power substrate. For this purpose, the power substrate is placed in a mold and the surface of the power substrate is injection molded around it in a corresponding ratio. Due to the contact of the electrical conductor paths arranged on the power substrate, only voids at predetermined locations remain blank. In step 200, the conductive structure is manufactured from a flat sheet metal. For this purpose, the conductive structure is cut out from the sheet metal and subsequently bent (folded and edged) as described above. In step 300, the first contact region is placed into the void in the insulating structure 4. In this case, the sharp burrs generated during the punching process are present on the upper surface and are not directed towards the power substrate. By doing so, there is no possibility that the burrs will create a break in the insulating structure and no possibility of making the positioning process difficult / frustrating. Finally, by welding the first contact region to the electrical conductor path, the first contact region is joined to the electrical conductor path of the power substrate in a material-bonded manner. This electric mechanism can subsequently be potted and / or mounted within a housing. The plug may include a terminal structure for external electrical contact.

Claims

1. - A power substrate (2) comprising an electrical conductor path (3), - An insulating structure (4) supported by the power substrate (2), - And a sheet metal conductive structure (5), wherein the conductive structure (5) - Has a first contact region (6), - A terminal region (11), - And a first coupling region (9) between the first contact region (6) and the terminal region (11), and the first contact region (6) - Is electrically coupled within a cavity (12) in the insulating structure (4) to the electrical conductor path (3), - Runs along an edge (7) in the X direction at an angle and transitions to the first coupling region (9), - Has a flag portion (8) for positioning the conductive structure (5), the flag portion (8) extends in a Y direction perpendicular to the X direction and protrudes in the Y direction beyond the edge (7) running in the X direction, An electrical mechanism (1).

2. The electrical mechanism (1) according to claim 1, characterized in that the first contact region (6) is materially coupled within a cavity (12) in the electrical conductor path (3) and the insulating structure (4).

3. The electrical mechanism (1) according to claim 1, wherein the flag portion (8) is in a common plane with the first contact region (6).

4. The electrical mechanism (1) according to claim 1, wherein the first contact region (6) transitions to the first coupling region (9) with a finite radius (R).

5. The electrical mechanism (1) according to claim 1, wherein the flag portion (8) has a tip region that protrudes at least partially in the Y direction beyond the first coupling region (9).

6. The electrical mechanism (1) according to claim 1, wherein the conductive structure (5) comprises sheet metal that is punched and / or cut using a laser.

7. The conductive structure (5) further - Has a second contact region (16) and - A second coupling region (19) between the second contact region (16) and the terminal region (11), - And the second contact region (16) also runs along a second edge (17) in the X direction that is collinear with the edge (7) between the first contact region (6) and the first coupling region (9), at an angle and transitions to the second coupling region (19), The electrical mechanism (1) according to claim 1.

8. The electric mechanism (1) according to claim 1, wherein the first contact region (6) is positioned on the power substrate (2) within a cavity (12) in the insulation structure (4) by the flag-shaped portion (8).

9. The electric mechanism (1) according to claim 8, wherein the first contact region (6) is surrounded on a plurality of sides.

10. The electric mechanism (1) according to claim 1, wherein a predetermined interval (d) exists between the first coupling region (9) and the insulation structure (4).

11. The electric mechanism (1) according to claim 10, wherein the interval (d) is 2 mm or more.

12. The electric mechanism (1) according to claim 1, wherein a curved portion (13) is provided between the flag-shaped portion (8) and the edge (7).

13. A manufacturing method of the electric mechanism (1) according to claim 1, comprising: - a step (100) of applying an insulation structure (4) onto the power substrate (2); - a step (200) of manufacturing the conductive structure (5) from a flat sheet metal; - a step (300) of inserting the first contact region (6) into a cavity in the insulation structure (4); - a step (400) of coupling the first contact region (6) to the electrical conductor path (3) of the power substrate (2) in a material-bonding manner. A manufacturing method including the above steps.

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