Electronic power assembly having improved design

Abstract

The invention relates to an electronic power assembly which in particular can be designed as a converter unit and which has a printed circuit board (1) having conductor tracks (2) for conducting power currents. The power assembly also has an additional unit (5) which is located above the printed circuit board (1) and has a lower face (6) facing the printed circuit board (1). The additional unit (5) has electronic components (7) which are electrically connected to the conductor tracks (2) of the printed circuit board (1) via connecting units (9). The connecting units (9) each have a plug-in contact (10) and a receptacle (11) for the relevant plug-in contact (10). The plug-in contacts (10) are located on the lower face (6) of the additional unit (5), and the receptacles (11) are secured directly or indirectly to the conductor tracks (2) of the printed circuit board (1). Alternatively, conversely, the receptacles (11) can be located on the lower face (6) of the additional unit (5), and the plug-in contacts (10) can be secured directly or indirectly to the conductor tracks (2) of the printed circuit board (1).

Description

[0001] Description

[0002] Electronic power module with improved design

[0003] The present invention is based on an electronic power module, in particular a converter unit,

[0004] - wherein the power module comprises a printed circuit board which has conductor tracks for carrying power currents of 10 A and more,

[0005] - wherein switching elements for switching the power currents are arranged directly on the printed circuit board or on a substrate arranged on the printed circuit board,

[0006] - whereby voltages of 100 V and more are switched by means of the switching elements and the potential which a certain conductor track has or carries varies to the same extent over time,

[0007] - wherein the power module has an additional unit arranged above the circuit board, which has a bottom side facing the circuit board,

[0008] - the additional unit has electronic components.

[0009] Such power modules are well known. They are used, for example, as power supply units for electric drives.

[0010] In state-of-the-art power assemblies, the connecting units comprise screws that are screwed into corresponding threads. This is disadvantageous because the screw head of each screw must be accessible. Thus, each point where a screw is to be screwed in blocks a large volume above the screw head, which must be kept clear and cannot be used for other purposes—particularly the arrangement of electronic components or conductor tracks.

[0011] An electronic power module in the form of a converter unit is known from US 2017 / 0 244 197 A1. The power module has a printed circuit board in a main unit. The power module also has an additional unit arranged laterally next to the converter unit, which additional unit has a side facing the printed circuit board. An electronic circuit can be arranged on the additional unit. The main unit and the additional unit have plug connectors via which the main unit and the additional unit are electrically connected to one another. The components of the plug contacts are arranged on sides of the main unit and the additional unit facing one another. Signals are exchanged between the printed circuit board of the main unit and the printed circuit board of the additional unit via the plug connectors.

[0012] The object of the present invention is to create possibilities by means of which the installation space available for the arrangement of mechanical and electrical elements (including conductor tracks) of the additional unit and also of the power module as a whole can be increased.

[0013] The problem is solved by an electronic power module having the features of claim 1. Advantageous embodiments of the electronic power module are the subject of dependent claims 2 to 6.

[0014] According to the invention, an electronic power module of the type mentioned at the outset is designed in such a way that

[0015] - that the electronic components are electrically connected to the conductor tracks of the printed circuit board via connecting units,

[0016] - that the connecting units each have a plug contact and a receptacle for the respective plug contact and

[0017] - that the plug contacts are arranged on the underside of the additional unit and the receptacles are attached directly or indirectly to the conductor tracks of the circuit board or, conversely, the receptacles are arranged on the underside of the additional unit and the plug contacts are attached directly or indirectly to the conductor tracks of the circuit board.

[0018] In particular, it was recognized that screw connections are not required to establish the electrical connections between the printed circuit board and the auxiliary unit. In particular, the electrical connections do not need to be able to absorb or transmit any mechanical forces—with the exception of the contact forces required to ensure the desired current-carrying capacity of the connecting units.

[0019] The power currents carried by the conductor tracks are 10 A and more. They are often 100 A or even several hundred A, and in extreme cases even more than 1 kA. Switching elements for switching the power currents are usually arranged either directly on the circuit board or on a substrate which is itself arranged on the circuit board. The switching elements are used to switch voltages of 100 V and more, usually voltages of several hundred V, in some cases even voltages above 1 kV, in extreme cases up to 3.0 kV or 3.3 kV. The potential that a particular conductor track of this type has or carries varies to the same extent over time.

[0020] Plug contacts suitable for conducting the required power currents are known. Purely as examples, reference can be made to DE 10 2021 119 087 A1 and DE 10 2021 119 088 A1.

[0021] In some cases, the additional unit can be arranged directly on the printed circuit board. However, the power module preferably has a bridge structure made of an electrically insulating material, in particular a plastic, which has a support surface on its upper side facing away from the printed circuit board and towards the additional unit. In this case, the bridge structure forms a mounting plane for the additional unit and the underside of the additional unit rests on the support surface of the bridge structure, either directly or via an intermediate element. This means that the installation space of the power module located beneath the bridge structure can also be used for arranging electronic components.

[0022] When using the bridge structure, the power module preferably has angled busbars, each having a circuit board end section, an additional unit end section and an intermediate section connecting the two respective end sections. In this case, the circuit board end sections run parallel to the circuit board and are fastened to the conductor tracks. The intermediate sections extend substantially orthogonally to the circuit board. The additional unit end sections run in the mounting plane. One of the receptacles or one of the plug-in contacts is fastened to the ends of the additional unit end sections facing away from the intermediate sections.

[0023] This design enables the circuit board-side elements of the connection units (i.e. the receptacles or plug contacts that are directly or indirectly electrically and mechanically connected to the conductor tracks of the circuit board) to be arranged in a simple and reliable manner in the mounting plane for the additional unit.

[0024] Preferably, the additional unit end sections project beyond the bridge structure in the mounting plane, so that the receptacles or plug contacts arranged at the ends of the additional unit end sections facing away from the intermediate sections can yield toward the circuit board when the additional unit is placed on the bridge structure. This allows for simple tolerance compensation.

[0025] Preferably, the receptacles or plug contacts are pressed into the end sections of the additional unit. This design offers manufacturing advantages when producing the busbars.

[0026] The plug contacts or receptacles can protrude over the underside of the additional unit towards the circuit board. However, the plug contacts or receptacles arranged on the underside of the additional unit are preferably set back from the underside of the additional unit, so that the plug contacts or receptacles are recessed relative to the underside of the additional unit. This design protects the corresponding plug contacts or receptacles from damage when handling the additional unit. Furthermore, it can increase air and creepage distances and thus the dielectric strength of the power module.

[0027] The above-described properties, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more readily understood in connection with the following description of the embodiments, which are explained in more detail in conjunction with the drawings. Herein, in schematic representation:

[0028] FIG 1 Components of an electronic power module from the side,

[0029] FIG 2 is a plan view of a printed circuit board,

[0030] FIG 3 a section through an additional part,

[0031] FIGS 4 to 6 are perspective views of components of an electronic power module,

[0032] FIG 7 a perspective view of an additional part,

[0033] FIG 8 is a perspective view of an electronic power module and

[0034] FIG 9 a section through the power module of

[0035] FIG 8 .

[0036] Figures 1 to 3 are clearly schematic. They depict only a fraction of the actual components, etc. Figures 4 to 9, on the other hand, are considerably more detailed and realistic.

[0037] 1 and 2, an electronic power module has a printed circuit board 1. The power module can be a converter unit, for example. The printed circuit board 1 has conductor tracks 2 and further conductor tracks 3. The conductor tracks 2 are used to carry power currents. The further conductor tracks 3 are used to transmit control signals and measured variables. According to FIG. 2, the conductor tracks 2 for the power currents are considerably larger than the further conductor tracks 3. Electronic components 4 are often placed on the conductor tracks 2 and sometimes also on the further conductor tracks 3, for example switching elements such as transistors or thyristors in the case of a converter unit. The exact design of the transistors or thyristors can be as required, for example in the case of transistors as bipolar transistors, as IGBTs or as FETs. Only a single such switching element is shown in FIG. 1.As a rule, however, several switching elements are present.

[0038] In the following, only conductor tracks 2 are relevant for the power currents. When the term "conductor track" is used below, this always refers to conductor tracks 2 for the power currents. The other conductor tracks 3 are not considered below.

[0039] The electronic power module also has an additional unit 5. The additional unit 5 is arranged above the printed circuit board 1. It has a bottom side 6 which faces the printed circuit board 1. The additional unit 5 also has electronic components 7. The electronic components 7 can, for example, be arranged on a separate printed circuit board 8 of the additional unit 5. The electronic components 7 can, for example, form a filter circuit which is customary in converter units. In the illustration in FIG. 1, the additional unit 5 is not yet connected to the printed circuit board 1 and the conductor tracks 2 arranged on the printed circuit board 1.

[0040] The circuit board 8 of the additional unit 5 is of secondary importance within the scope of the present invention. Therefore, when the term "circuit board" is used below, it always refers to the circuit board 1, not the circuit board 8.

[0041] The electronic components 7 of the additional unit 5 are electrically connected to the conductor tracks 2 of the printed circuit board 1. The electrical connection is made (at least) via connecting units 9. In FIGS. 1 and 2, only one connecting unit 9 or a part of a connecting unit 9 is shown. As a rule, several connecting units 9 are present, for example, three connecting units 9 as shown in FIG. 3.

[0042] The connection units 9 each have a plug contact 10 and a receptacle 11 for the respective plug contact 10. According to FIG 1, the plug contacts 10 are arranged on the underside 6 of the additional unit 5. In this case, the receptacles 11 are attached directly or indirectly to the conductor tracks 2 of the circuit board 1. Alternatively, the reverse assignment is also possible. In this case - not shown in the FIG - the receptacles 11 are arranged on the underside 6 of the additional unit 5 and the plug contacts 10 are also attached directly or indirectly to the conductor tracks 2 of the circuit board 1. Regardless of whether one or the other embodiment is adopted, the additional unit 5 and its electronic components 7 can therefore be electrically connected to the conductor tracks 2 of the circuit board 1 simply by placing the additional unit 5 on the receptacles 11 or the plug contacts 10. The landing is indicated in FIG 1 by an arrow PI .

[0043] By placing the additional unit 5 onto the receptacles 11 (or the plug contacts 10), essentially only the electrical contacting of the electronic components 7 of the additional unit 5 with the conductor tracks 2 is achieved. The mechanical mounting of the additional part 5 is realized in another way. For example, a bracket can be provided or a screw connection can be used. Other configurations are also possible. This is of secondary importance within the scope of the present invention.

[0044] In many cases, the power module has a bridge structure 12 (with regard to FIGS. 1 to 3, only shown in FIG. 1). The bridge structure 12, if present, consists of an electrically insulating material, in particular a plastic. The bridge structure 12 is fastened to the circuit board 1. The fastening can be carried out as required, for example via schematically indicated screw connections 13. The bridge structure 12 has a support surface 15 on its upper side 14 - that is the side which faces away from the circuit board 1 and thus at the same time faces the additional unit 5. The bridge structure 12 therefore forms a mounting plane for the additional unit 5. In the simplest case (see FIG. 1), the additional unit 5 lies directly on the support surface 15 of the bridge structure 12.

[0045] In the case of the bridge structure 12, the power module often also includes busbars 16. The busbars 16 are angled. They each have a circuit board end section 17, an auxiliary unit end section 18, and an intermediate section 19.

[0046] The circuit board end sections 17 run parallel to the circuit board 1 and are attached to the conductor tracks 2. The connection can be as required, for example via schematically indicated screw connections 20, via solder connections, via plug connections, and others. The exact type of attachment is of secondary importance within the scope of the present invention. The intermediate sections 19 connect the two end sections

[0047] 17, 18 of the respective busbar 16. They extend essentially orthogonally to the circuit board 1.

[0048] The additional unit end sections 18 extend in the mounting plane formed by the bridge structure 12. At each end of the additional unit end sections 18 facing away from the intermediate sections 19, one of the plug contacts 10 (alternatively: one of the receptacles 11) is attached.

[0049] According to FIG. 1, the additional unit end sections 18 project beyond the bridge structure 12 as seen in the mounting plane. This applies in particular to the areas of the additional unit end sections 18 in which the plug contacts 10 (alternatively: the receptacles 11) are fastened. As a result, the corresponding areas of the additional unit end sections 18 can yield—even if only slightly—in the direction of the printed circuit board 1 when the additional unit 5 is placed on the bridge structure 12. This is indicated in FIG. 1 by an arrow P2.

[0050] As can be seen in particular from FIG. 1, the plug contacts 10 arranged on the underside 6 of the additional unit 5 (alternatively: the receptacles 11 arranged at the same location) are set back from the underside 6 of the additional unit 5. As a result, the plug contacts 10 (alternatively: the receptacles 11) are arranged countersunk with respect to the underside 6 of the additional unit 5.

[0051] FIGS 4 to 9 show - as far as relevant here - the same facts that were explained above in connection with FIGS 1 to 3, using a real electronic power module.

[0052] FIGS. 4 and 5 show an electronic power module before the additional unit 5 is attached. Specifically, FIGS. 4 and 5 show the circuit board 1, some of the electronic components 4, the bridge structure 12 and its design, the busbars 16 and their design, and the receptacles 11. In FIGS. 4 and 5, only one of the busbars 16 has its additional unit end section 18 provided with its reference symbol, and only one of the receptacles 11 has its reference symbol. Furthermore, FIGS. 4 and 5 show a typically present heat sink 21.

[0053] FIG. 6 also shows the electronic power module of FIGS. 4 and 5 before the additional unit 5 is placed on the bridge structure 12. In FIG. 6, however, cover elements 22, 23 are applied to the circuit board 1. The cover element 23 forms an intermediate element which is arranged between the upper side 14 of the bridge structure 12 and the additional unit 5. As a result, the underside 6 of the additional unit 5 does not rest directly on the support surface 15 of the bridge structure 12, but only indirectly via the cover element 23.

[0054] FIG. 7 shows the additional unit 5. It is particularly clearly visible in FIG. 7 that the plug contacts 10 are recessed relative to the underside 6 of the additional unit 5.

[0055] FIG. 8 shows the electronic power module after the additional unit 5 has been placed on the bridge structure 12. One can particularly see the absence of recesses that are required in the prior art to be able to operate connecting screws that are arranged under the additional unit 5 in the prior art.

[0056] FIG 9 shows a section through the electronic power module of FIG 8 after the additional attachment of a housing 24. FIG 9 shows in particular the printed circuit board 1, some of the electronic components 4, the additional unit 5, one of the connection units 9 and its structure, the bridge structure 12 and its design, part of a busbar 16 and its design and the heat sink 21. Of the busbar 16, only its additional unit end section 18 is provided with its reference numeral. Furthermore, a further advantageous embodiment can be seen from FIG 9, namely that the receptacles 11 (alternatively: the plug contacts 10) are pressed into the additional unit end sections 18.

[0057] A significant advantage of the present invention can also be seen in FIG. 9. Specifically, the area 25 of the additional unit 5 according to the invention is available as usable space for the arrangement of components of the additional unit 5. In the prior art, however, the area 25 would have to be left free.

[0058] The present invention offers many advantages. In particular, while maintaining the same overall volume of the electronic power module, a larger usable volume is available for the arrangement of conductor tracks 2, additional conductor tracks 3, and electronic components 4, or even mechanical components and structures. Furthermore, the assembly of the electronic power module is simplified.

[0059] Although the invention has been illustrated and described in detail by the preferred embodiment, the invention is not limited to the disclosed examples and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Claims

Patent claims 1. Electronic power module, in particular converter unit, - wherein the power module comprises a printed circuit board (1) having conductor tracks (2) for carrying power currents of 10 A and more, - wherein switching elements (4) for switching the power currents are arranged directly on the printed circuit board (1) or on a substrate which in turn is arranged on the printed circuit board (1), - wherein voltages of 100 V and more are switched by means of the switching elements (4) and the potential which a specific conductor track (2) has or carries varies to the same extent over time, - wherein the power module has an additional unit (5) arranged above the circuit board (1), which has a bottom side (6) facing the circuit board (1), - wherein the additional unit (5) comprises electronic components (7), characterized in that - that the electronic components (7) are electrically connected to the conductor tracks (2) of the printed circuit board (1) via connecting units (9), - that the connecting units (9) each have a plug contact (10) and a receptacle (11) for the respective plug contact (10) and - that the plug contacts (10) are arranged on the underside (6) of the additional unit (5) and the receptacles (11) are fastened directly or indirectly to the conductor tracks (2) of the printed circuit board (1) or conversely the receptacles (11) are arranged on the underside (6) of the additional unit (5) and the plug contacts (10) are fastened directly or indirectly to the conductor tracks (2) of the printed circuit board (1).

2. Power module according to claim 1, characterized in that the power module is made of an electrically insulating material, in particular a plastic, which has a support surface (15) on its upper side (14) facing away from the printed circuit board (1) and towards the additional unit (5), so that the bridge structure (12) forms a mounting plane for the additional unit (5), and that the additional unit (5) rests with its underside (6) directly or via an intermediate element (23) on the support surface (15) of the bridge structure (12).

3. Power module according to claim 2, characterized in that - that the power module has angled busbars (16), each having a circuit board end section (17), an additional unit end section (18) and an intermediate section (19) connecting the two respective end sections (17, 18), - that the circuit board end sections (17) run parallel to the circuit board (1) and are attached to the conductor tracks (2), - that the intermediate sections (19) extend substantially orthogonally to the printed circuit board (1), - that the additional unit end sections (18) run in the mounting plane and - that one of the receptacles (11) or one of the plug contacts (10) is fastened to the ends of the additional unit end sections (18) facing away from the intermediate sections (19).

4. Power module according to claim 3, characterized in that the additional unit end sections (18) project beyond the bridge structure (12) as seen in the mounting plane, so that the receptacles (11) or plug contacts (10) arranged at the ends of the additional unit end sections (18) facing away from the intermediate sections (19) can yield in the direction of the printed circuit board (1) when the additional unit (5) is placed on the bridge structure (12).

5. Power module according to claim 3 or 4, characterized in that the receptacles (11) or the plug contacts (10) are pressed into the additional unit end sections (18).

6. Power module according to one of the above claims, characterized in that the plug contacts (10) or receptacles (11) arranged on the underside (6) of the additional unit (5) are set back relative to the underside (6) of the additional unit (5), so that the plug contacts (10) or receptacles (11) are arranged countersunk relative to the underside (6) of the additional unit (5).

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