Electronic power assembly with simplified construction

Abstract

The power module (1) has a module upper side (3) and a module lower side (4). The power module (1) is pressed against the heat sink (9) by means of the module underside (4) via a fastening screw (11) which has been screwed into the heat sink (9). The printed circuit board (13) has a printed circuit board upper side (14) and a printed circuit board lower side (15) and a passage opening (16) for the passage of the fastening screw (11). The circuit board (13) is arranged on the module upper side (3) such that the circuit board lower side (15) faces the module upper side (3). The circuit board is mechanically and electrically connected to the power module (1). A bridge structure (17) made of an electrically insulating base material, in particular plastic, has sleeve-like guide elements (18) which are connected to one another via a connection region (19) of the bridge structure (17). The connection region (19) has a section (20) which is arranged above the circuit board upper side (14) at a distance (a) from the circuit board upper side (14) and which forms, on the side thereof facing away from the circuit board (13), a mounting surface (21) running parallel to the circuit board (13) such that the section (20) provides a mounting plane for other components (22) of the power assembly. The guide (18) extends through the through-opening (16) of the circuit board (13) to the power module (1) such that a fastening screw (11) screwed into the heat sink (9) presses the power module (1) against the heat sink (9) via the guide (18) of the bridge structure (17).

Description

Technical Field

[0001] This invention relates to an electronic power component.

[0002] -The power component includes a power module, and the power module has an upper side and a lower side.

[0003] -The power component has a heat sink, and the power module is pressed against the heat sink by the lower side of the module via a fixing screw that has been screwed into the heat sink.

[0004] -The power component includes a circuit board, which has an upper side and a lower side.

[0005] -The circuit board has a through-hole for the fixing screw to pass through.

[0006] -The circuit board is positioned on the upper side of the module, with the lower side of the circuit board facing the upper side of the module, and the lower side of the circuit board is mechanically and electrically connected to the power module.

[0007] The present invention also relates to a converter having such a power component. Background Technology

[0008] Such power components are commonly known. Power components are used, for example, as power supply devices for electric drives.

[0009] In existing technology, the fixing screws act directly on the power module. This leads to various drawbacks. First, the through-hole opening on the circuit board must have a considerable diameter so that both the neck and head of the fixing screw can pass through it. Furthermore, the area of ​​the circuit board surrounding the through-hole opening is typically unsuitable for printed conductors, as this would otherwise compromise the required air and creepage distances between the fixing screw and the printed conductors.

[0010] Furthermore, the electrical and mechanical connections between the circuit board and the power module must be designed to be stable and reliable. For this purpose, the circuit board typically has additional through-holes through which additional fixing screws can pass. In this configuration, the additional fixing screws are screwed into the power module, pressing the circuit board against it. The additional fixing screws, along with the air and creepage distances that may also need to be observed, further reduce the space available for printed conductors on the circuit board.

[0011] A converter assembly is known from US 2015 / 0 208 500 A1, which has a lower substrate and an upper substrate. The lower substrate can be an IMS (Insulated Metal Substrate), and the upper substrate can be a circuit board. Both substrates are screwed to a heat sink. Electrodes have through-holes through which fixing screws are guided. The electrodes also have curved cantilever arms that pass through the upper substrate. The upper substrate has through-openings for the electrode cantilever arms to pass through. At the ends of the respective cantilever arms, the electrodes have connection areas for connecting external connectors.

[0012] An electronic power assembly is known from US 2010 / 0 284 155 A1, comprising a power module having an upper and a lower side. The power assembly also includes a heat sink, with the power module pressed against the heat sink via a fixing screw screwed into the heat sink from the lower side. The power assembly has a circuit board having an upper and a lower side. The circuit board has a through-hole for the fixing screw to pass through. The circuit board is positioned on the upper side of the module such that the lower side of the circuit board faces the upper side of the module.

[0013] A device for encapsulating a power unit at least partially constructed within a heat sink and for centering a control unit relative to the power unit is known from EP 4 017 229 A1. The control unit has at least one electronic component. The power unit includes a semiconductor device and a substrate. The power unit has a frame that at least partially surrounds the substrate. The power unit includes a first type of protrusion and a second type of protrusion. The first type of protrusion engages in a recess or opening in the heat sink, and the second type of protrusion engages in a recess or opening in the control unit. Summary of the Invention

[0014] The purpose of this invention is to provide a feasible solution by which the required connections between the heat sink, power module and circuit board can be established in a simple and reliable manner and with low space requirements, and further simplifies the other structures of the power module.

[0015] This objective is achieved by an electronic power module having the features of claim 1. Advantageous designs of the power module are the subject of dependent claims 2 to 8.

[0016] According to the present invention, the type of electronic power component mentioned in the opening section is designed in the following manner:

[0017] - Power components have a bridge structure made of an electrically insulating base material, particularly plastic.

[0018] - The bridge structure has sleeve-shaped guides that are interconnected via connection areas of the bridge structure.

[0019] -The connection area has a section arranged at a certain distance from the upper side of the circuit board, which forms a mounting surface extending parallel to the circuit board on its side opposite to the circuit board, so that the section provides a mounting plane for other components of the power assembly.

[0020] - The guide extends through the through-hole in the circuit board to the power module, so that the fixing screws already screwed into the heat sink press the power module against the heat sink via the guide of the bridge structure.

[0021] Preferably, the guide is sized such that the screw heads of the fixing screws are positioned above the upper side of the circuit board. This automatically provides the air distance relative to the circuit board.

[0022] By incorporating a separation element in the bridge structure that completely or almost completely surrounds the screw head of the fixing screw, it is possible to further increase the air distance and creepage distance.

[0023] Preferably, the guide is also sized such that the screw head of the fixing screw is positioned below the mounting plane provided by the section. This provides an automatically obtained air distance from the mounting plane provided by the section. Furthermore, the mounting plane provided by the section can be designed to be continuous in a simple manner, ensuring that the screw head of the fixing screw does not interfere with the mounting.

[0024] It is feasible for the base material itself to have sufficient strength to transmit the force applied by the fixing screw to the power module. Alternatively, it is feasible for the guide to have a reinforcing sleeve made of additional material on its inner side facing the fixing screw, the reinforcing sleeve having a higher strength than the base material.

[0025] The additional material can also be electrically insulating. For example, it can be plastic. It can also be ceramic. Alternatively, the additional material can be conductive, particularly made of steel, brass, or other metals or metal alloys. The conductivity of the additional material is not important because the necessary air and creepage distances must be maintained between the fixing screws and the printed conductors on the circuit board (and, if necessary, the mounting planes for other components) through the design of the bridge structure. However, materials based on metals and metal alloys generally have higher structural strength than that achievable with plastics.

[0026] Preferably, the bridge structure has a resilient pressing element on its side facing the upper side of the circuit board, by means of which the circuit board is pressed against the power module. This eliminates the need for additional fixing elements and additional through-holes required in the prior art for pressing the circuit board against the power module.

[0027] This power component is particularly suitable for use as a power supply device for electric power systems.

[0028] Semiconductor switches and their interconnections preferably realize a certain number of bridge branches of the converter.

[0029] This objective is also achieved by a converter having at least one such power component. Attached Figure Description

[0030] The above-described features, characteristics, and advantages of the present invention, as well as the ways and methods of implementing them, become clearer and more apparent in conjunction with the following description of embodiments, which are described in more detail with reference to the accompanying drawings. These are illustrated schematically herein:

[0031] Figure 1 A cross-sectional view of the electronic power component is shown.

[0032] Figure 2 The diagram shows a plan view of the power module from above.

[0033] Figure 3 Showing through Figure 2 A cross-sectional view of the power module.

[0034] Figure 4 A cross-sectional view is shown through a portion of the electronic power assembly in the guide region.

[0035] Figure 5 A cross-sectional view of the electronic power component is shown.

[0036] Figure 6 A cross-sectional view of the electronic power component is shown.

[0037] Figure 7 Show Figure 5 A partial 3D view of the electronic power components, and

[0038] Figure 8 A cross-sectional view of the electronic power component is shown. Detailed Implementation

[0039] according to Figure 1 The electronic power components include power module 1. According to... Figure 2 and Figure 3 In the view shown, power module 1 typically includes multiple semiconductor switches 2. However, Figure 2 and Figure 3 The number of the two semiconductor switches 2 shown should not be interpreted as limiting.

[0040] Semiconductor switch 2 typically switches voltages ranging from several hundred volts to, and sometimes slightly above, 1 kV, and in some cases even up to, for example, 3 kV or 3.3 kV. When switched on, semiconductor switch 2 can carry currents typically in the range of several amperes (typically 50 amps to several hundred amps). Power module 1 typically creates a number of bridge branches of the converter using its semiconductor switches 2 and their interconnections. Within these bridge branches, semiconductor switches 2 form series circuits, where the two ends of the series circuit can be connected to corresponding DC voltage potentials, and taps for AC voltage are present between two of the semiconductor switches 2 in the respective series circuits.

[0041] Power module 1 has an upper side 3 and a lower side 4. The direction from the upper side 3 to the lower side 4 (or vice versa) defines the height direction of power module 1. Power module 1 is based on Figure 2 and Figure 3 The view in the image is typically constructed in a rectangular shape, where the height of power module 1 is significantly smaller than its length and width.

[0042] according to Figure 3 In the view shown, the power module 1 typically has a support structure 5 in the region below the module 4, and the semiconductor switch 2 is arranged on the support structure 5. The support structure 5 can be, for example, a substrate. Furthermore, according to... Figure 2 and Figure 3 In the view shown, the power module 1 typically has a sidewall 6, such that the supporting structure 5 and the sidewall 6 together form a groove. The groove is typically cast with castable refractory 7 (see [reference]). Figure 3 In addition, the connector pin 8 typically extends upward from the upper edge of the side wall 6 (which corresponds to the upper side 3 of the module), that is, it extends from the upper side 3 of the module.

[0043] Although the above-described structure of power module 1 is generally quite common, it is ultimately secondary. The number and arrangement of connection pins 8 are also secondary. However, what is important is: according to Figure 1 The power module 1 is pressed against the heat sink 9 via its lower side 4, thereby thermally coupling the supporting structure 5 and the semiconductor switch 2 to the heat sink 9. Thermal paste or similar materials can be present between the lower side 4 of the module and the heat sink 9, but this is not mandatory.

[0044] To press the power module 1 against the heat sink 9, a thread 10 is introduced into the heat sink 9, and a fixing screw 11 is screwed into the thread 10. The power module 1 is pressed against the heat sink 9 by means of the fixing screw 11.

[0045] according to Figures 1 to 3 In the view shown, power module 1 has a connector 12 that extends laterally from the current power module 1. According to... Figures 1 to 3 In the design, the connector 12 is primarily pressed against the heat sink 9 by means of the fixing screw 11. The pressing of the power module 1 is indirectly achieved through the rigid connection between the connector 12 and the current power module 1. This design is common, but not mandatory. Alternatively, pressure can also be applied to the upper side 3 of the module by means of the fixing screw 11.

[0046] according to Figure 1 The power component also includes a circuit board 13, which has an upper side 14 and a lower side 15. The circuit board 13 is positioned on the upper side 3 of the module such that the lower side 15 faces the upper side 3 of the module. Typically, the circuit board 13 is located on the upper side 3 of the module. Figure 1 The small spacing shown is for illustrative purposes only.

[0047] Circuit board 13 is electrically and mechanically connected to power module 1. This mechanical and electrical connection between circuit board 13 and power module 1 can be achieved, for example, by mounting circuit board 13 onto power module 1 or onto connector pin 8. Figure 2 , Figure 3 The exact manner and method of electrical and mechanical connections are secondary. In any case, the circuit board 13 has a through-hole 16 through which the fixing screw 11 can pass.

[0048] according to Figure 1 The power module also has a bridge structure 17. The bridge structure 17 is made of an electrically insulating material, which is referred to below as the base material. The base material can be, in particular, plastic.

[0049] according to Figure 1 The bridge structure 17 has sleeve-shaped guides 18 and a connecting region 19. The guides 18 are interconnected via the connecting region 19. The connecting region 19 has a segment 20 that is arranged on the upper side 14 of the circuit board at a distance a from the upper side 14. The segment 20 forms a mounting surface 21 on its side facing away from the circuit board 13. The mounting surface 21 extends parallel to the circuit board 13. Thus, the segment 20 provides a mounting plane for other components 22 of the power module. Optionally, the mounting surface 21 may also include guide structures for other components 22. Other components 22 may be, for example, busbars arranged on the mounting surface 21.

[0050] according to Figure 1 Views in (see also) Figure 4The guide 18 extends through the through-hole 16 of the circuit board 13 to the power module 1. The fixing screw 11 (more precisely, its screw head 23) acts directly on the guide 18 (more precisely, the end of the guide 18 spaced apart from the power module 1). Furthermore, the guide 18 (more precisely, the end of the guide 18 positioned on the power module 1) acts on the power module 1. As a result, the fixing screw 11 thus presses the power module 1 against the heat sink 9 via the guide 18 of the bridge structure 17.

[0051] exist Figure 1 The paper also illustrates some advantageous design schemes for electronic power components.

[0052] Therefore, for example from Figure 1 (See also: Chinese) Figure 4 and Figure 5 It can be identified that the guide 18 is sized such that the screw head 23 of the fixing screw 11 is positioned on the upper side 14 of the circuit board. From Figure 1 It can also be identified that the guide 18 is sized such that the screw head 23 is positioned below the mounting plane 21 provided by the section 20. Finally, from Figure 1 It can be identified that the bridge structure 17 has a resilient pressing element 24. The pressing element 24 is arranged on the side of the bridge structure 17 facing the upper side 14 of the circuit board. The circuit board 13 is pressed against the power module 1 by means of the pressing element 24.

[0053] Figure 4 This illustrates another possible advantageous design scheme for electronic power components. According to... Figure 4 The guide 18 has a reinforcing sleeve 25 on its inner side facing the fixing screw 11. The reinforcing sleeve 25 is made of a different material than the bridge structure 17 (particularly the outer area of ​​the guide 18). The material used to make the reinforcing sleeve 25 has a higher material strength than the base material. This is referred to hereinafter as the additional material. For example, the additional material can be ceramic or metal (particularly steel or brass). The presence of the reinforcing sleeve 25 has the advantage that only the reinforcing sleeve 25 must have the mechanical stability required to transmit pressure.

[0054] The basic facts of this invention can also be found in Figures 5 to 8 This is derived from [the present invention]. Since the basic elements of the invention have already been explained, [further details are needed regarding...]. Figures 5 to 8 Detailed description not provided. Instead, refer to [reference needed]. Figures 5 to 8 The attached figures are labeled with reference to the figures.

[0055] Specifically, Figure 5 and Figure 6 Showing with Figure 1 A similar cross-sectional view through the power module. Figure 5 Design scheme and Figure 6The difference between the design schemes lies in: based on Figure 6 The design scheme includes a pressing element 24, while according to Figure 5 The design scheme does not include a pressing element.

[0056] Figure 7 Show in three dimensions Figure 5 A part of it. Figure 8 Show again with Figure 1 and Figure 5 Similar cross-sectional view.

[0057] In summary, the present invention relates to the following facts:

[0058] Power module 1 has an upper side 3 and a lower side 4. Power module 1 is pressed against heat sink 9 via a fixing screw 11 screwed into heat sink 9 using the lower side 4. Circuit board 13 has an upper side 14 and a lower side 15, as well as a through opening 16 for the fixing screw 11 to pass through. Circuit board 13 is arranged on the upper side 3 such that the lower side 15 faces the upper side 3. Circuit board 1 is mechanically and electrically connected to power module 1. Bridge structure 17, made of an electrically insulating base material, particularly plastic, has sleeve-shaped guides 18, which are interconnected via connection areas 19 of bridge structure 17. Connection area 19 has a section 20 arranged above the upper side 14 at a distance a from the upper side 4, the section forming a mounting surface 21 parallel to the extension of circuit board 13 on its side opposite to the circuit board 13, such that section 20 provides a mounting plane for other components 22 of the power assembly. The guide 18 extends through the through opening 16 of the circuit board 13 to the power module 1, such that the fixing screw 11 screwed into the heat sink 9 presses the power module 1 against the heat sink 9 via the guide 18 of the bridge structure 17.

[0059] This invention offers numerous advantages. In particular, the structure is simple and compact, requiring fewer recesses to be incorporated into the circuit board 13 compared to existing technologies, and allowing even printed conductors to extend within the area surrounding the through-hole 16. This reduces development and manufacturing costs. The overall stability of electronic power components can also generally be improved.

[0060] Although the invention has been described and illustrated in detail with reference to preferred embodiments, the invention is not limited to the disclosed examples, and those skilled in the art can derive other variations therefrom without departing from the scope of the invention.

Claims

1. An electronic power component, -in, The power component has a power module (1), which has an upper side (3) and a lower side (4). -The power assembly has a heat sink (9), and the power module (1) is pressed against the heat sink by the lower side (4) of the module via a fixing screw (11) screwed into the heat sink (9). -The power component has a circuit board (13), which has an upper side (14) and a lower side (15). -The circuit board (13) has a through opening (16) for the fixing screw (11) to pass through. -The circuit board (13) is arranged on the upper side (3) of the module, such that the lower side (15) of the circuit board faces the upper side (3) of the module and the lower side of the circuit board is mechanically and electrically connected to the power module (1). Its features are, - The power component has a bridge structure (17) made of an electrically insulating base material, particularly plastic. - The bridge structure (17) has sleeve-shaped guides (18), which are interconnected via connection areas (19) of the bridge structure (17). -The connection area (19) has a segment (20) arranged above the upper side (14) of the circuit board at a certain distance (a) from the upper side (14). The segment forms a mounting surface (21) extending parallel to the circuit board (13) on the side of the segment facing away from the circuit board (13), such that the segment (20) provides a mounting plane for other components (22) of the power assembly. - The guide (18) extends through the through opening (16) of the circuit board (13) to the power module (1), such that the fixing screw (11) screwed into the heat sink (9) presses the power module (1) against the heat sink (9) via the guide (18) of the bridge structure (17).

2. The power component according to claim 1, characterized in that, The guide (18) is sized such that the screw head (23) of the fixing screw (11) is positioned on the upper side (14) of the circuit board.

3. The power component according to claim 2, characterized in that, The bridge structure (17) has a separation element that completely or almost completely surrounds the screw head (23) of the fixing screw (11).

4. The power component according to claim 2 or 3, characterized in that, The guide (18) is sized such that the screw head (23) of the fixing screw (11) is positioned below the mounting plane provided by the section (20).

5. The power component according to any one of the preceding claims, characterized in that, The guide (18) has a reinforcing sleeve (25) made of an additional material on the inner side of the guide facing the fixing screw (11), the additional material having a higher material strength than the base material.

6. The power component according to any one of the preceding claims, characterized in that, The bridge structure (17) has an elastic pressing element (24) on the side of the bridge structure facing the upper side (14) of the circuit board, by means of the pressing element pressing the circuit board (13) against the power module (1).

7. The power component according to any one of the preceding claims, characterized in that, The power component is used as a power supply device for an electric power system.

8. The power component according to any one of the preceding claims, characterized in that, The interconnection of the semiconductor switch (2) and the semiconductor switch enables a certain number of bridge branches of the converter.

9. A converter having at least one power component according to claim 8.

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