Half-bridge module of a traction inverter of a power electronics device of a vehicle

Abstract

A half-bridge module (1) of a traction inverter of a power electronics device of an electric or hybrid vehicle, having a base plate (3), semiconductor switching elements (4) arranged on a first side (3a) of the base plate (3), power terminals (9) to which power lines for the transmission of traction energy are connectable, signal terminals (10) to which signal lines are connectable for switching the semiconductor switching elements (4), a molding compound (12) which surrounds the base plate (3) and the semiconductor switching elements (4) on the first side (3a) of the base plate (3), wherein the power terminals (9) and the signal terminals (10) are both accessible from the first side (3a) of the base plate (3) such that the power terminals (9) and the signal terminals (10) extend through the molding compound (12) as seen from the first side (3a) of the base plate (3) and are arranged in a bottom surface extending from the base plate (3) as seen in a direction of passage through the molding compound (12).

Description

Technical Field

[0001] This invention relates to a half-bridge module of a traction inverter for a power electronics device in an electric or hybrid vehicle. Background Technology

[0002] Electric vehicles and hybrid vehicles use electric motors as their drive components. To supply traction energy to these electric motors, electric and hybrid vehicles also include an energy storage device called a traction battery. Here, the traction battery is designed as a DC voltage battery; however, the electric motor requires AC voltage. Therefore, a power electronic device with a traction inverter is connected between the traction battery and the electric motor in the electric or hybrid vehicle. The inverter is also called a converter.

[0003] Traction inverters in the power electronics of electric or hybrid vehicles typically include semiconductor switching elements composed of transistors. It is known to provide semiconductor switching elements with varying degrees of integration, particularly as discrete single switches with low integration but high scalability, or as bridge modules with high integration but low scalability, and as half-bridge modules that fall between single switches and bridge modules in terms of integration and scalability. A common feature of all known embodiments is that they have relatively high inductance in the tens of nH (nanohenries) range due to the leakage inductance of the commutation unit. This results in high overvoltages or higher switching losses when switching the power semiconductors. Furthermore, the long signal terminals with high inductance lead to poor switchability or gate control of the power semiconductors.

[0004] There is a need for a new type of half-bridge module for traction inverters of power electronics in electric or hybrid vehicles. This half-bridge module is highly scalable and requires low assembly costs due to its integration. Furthermore, the half-bridge module has low inductance in the commutation unit and signal terminals to keep electrical losses as low as possible during switching.

[0005] US 2018 / 0114740A1 discloses a low-integration inverter in the form of a single switch for power electronics in electric or hybrid vehicles. Bipolar transistors are arranged on a substrate, each at least partially surrounded by molding compound. The substrate is secured to a housing by a sintering layer. Summary of the Invention

[0006] Therefore, the basic objective of this invention is to provide a novel half-bridge module for the traction inverter of the power electronics device of an electric vehicle or a hybrid vehicle.

[0007] The half-bridge module according to the invention has a substrate. The half-bridge module according to the invention also has a semiconductor switching element disposed on a first side of the substrate. The half-bridge module according to the invention further has a molding compound surrounding the substrate and the semiconductor switching element on the first side of the substrate.

[0008] The half-bridge module according to the invention also has a power terminal, to which a power line for transmitting traction power can be connected. The half-bridge module according to the invention also has a signal terminal, to which a signal line can be connected to switch the semiconductor switching element.

[0009] According to the present invention, the power terminals and signal terminals of the half-bridge module are accessible from a first side of the substrate, such that the power terminals and the signal terminals extend through the molding compound when viewed from the first side of the substrate, and are arranged within the bottom surface extended by the substrate when viewed in the direction through which they pass through the molding compound.

[0010] The substrate can be a DBC (Direct Bonded Copper) substrate, an AMB (Active Metal Brazing) substrate, or an IM (Insulated Metal) substrate.

[0011] The half-bridge module according to the invention has both a certain degree of integration and good scalability. Therefore, it combines the advantages of a discrete structure based on a single switch with the advantages of a highly integrated power module. All power terminals and signal terminals extend through the molding compound and are arranged within the bottom surface extended from the substrate in their direction through the molding compound. Thus, the power terminals can be oriented relative to each other such that the half-bridge module ultimately has low leakage inductance of the commutation unit on the order of several nanohenries, and low leakage inductance of the signal terminals. Both serve to minimize switching losses.

[0012] Another advantage of this design for power and signal terminals is that they no longer extend laterally and are therefore positioned outside the bottom surface extended from the substrate. This provides an advantage in terms of structural space.

[0013] Another advantage is the potentially larger electrical insulation distance (leakage path) achieved due to the terminals being arranged on the top surface, without significantly increasing the leakage inductance of the commutation unit.

[0014] According to an advantageous improvement of the invention, the power terminal includes a positive terminal, a negative terminal, and a phase terminal. The phase terminal is arranged adjacent to a first edge of the substrate in the through-path direction, and the negative terminal is arranged adjacent to a second edge of the substrate opposite to the first edge in the through-path direction. The positive terminal is arranged between the phase terminal and the negative terminal at a certain interval in the through-path direction. The positive terminal contacts a first bus of a surface configuration, and the negative terminal contacts a second bus of a surface configuration, wherein the first bus and the second bus extend in a superimposed manner, and preferably, an insulator is arranged between the first bus and the second bus. This improvement further reduces the leakage inductance of the half-bridge module. The half-bridge module provides an ultra-low inductance commutation unit, minimizing power losses.

[0015] According to an advantageous improvement of the invention, a first signal terminal for a first semiconductor switching element is arranged between the phase terminal and the positive terminal at a certain distance from the phase terminal and the positive terminal when viewed in the through-path direction. A second signal terminal for a second semiconductor switching element is arranged between the positive terminal and the negative terminal at a certain distance from the positive terminal and the negative terminal when viewed in the through-path direction. This achieves further structural space advantages.

[0016] All power and signal terminals can be positioned close to the semiconductor switching element. This eliminates the need for long connection paths between the power or signal terminals and the semiconductor switching element.

[0017] According to an advantageous improvement of the invention, the cooling device is connected to the half-bridge module by means of a material-fit connection, wherein the material-fit connection is a sintered connection, a brazed connection, or a thermally conductive adhesive connection. This largely achieves optimized thermal conductivity from the half-bridge module to the cooling device.

[0018] The present invention also relates to a traction inverter for a power electronics device in an electric vehicle or a hybrid vehicle, the traction inverter comprising at least two half-bridge modules according to the present invention. Attached Figure Description

[0019] Embodiments of the invention are illustrated in detail with the aid of the accompanying drawings, but are not intended to be limiting. In the drawings:

[0020] Figure 1 An exploded view of the half-bridge module according to the invention without a busbar and an external cooling device is shown.

[0021] Figure 2 A top view of the half-bridge module according to the invention without molding material is shown;

[0022] Figure 3 It shows Figure 2 The section along section line III-III;

[0023] Figure 4 A side view of the half-bridge module according to the present invention, together with an external cooling device and an external circuit board, is shown.

[0024] Figure 5 Possible implementations of the traction inverter according to the present invention are illustrated exemplaryly and schematically. Detailed Implementation

[0025] Figures 1 to 4 Various views of the traction inverter of the power electronics of an electric vehicle or hybrid vehicle according to the invention, showing a half-bridge module 1, are illustrated, wherein... Figure 1 and Figure 4 The diagram shows a half-bridge module 1 and a cooling device 2, wherein the half-bridge module 1 according to the invention can be connected to the cooling device.

[0026] The half-bridge module 1 has a substrate 3 and a semiconductor switching element 4 disposed on a first side 3a of the substrate 3. The semiconductor switching element 4 is composed of a semiconductor assembly 5 provided as a transistor.

[0027] The substrate 3 is, for example, a DBC (Direct Bonded Copper) substrate, which has, for example, a ceramic carrier plate 6, on both sides coated with copper layers 7 and 8.

[0028] In the region of the first side 3a of the substrate 3, the copper layer 8 is structured into a plurality of segments 8a that are separated from each other. Semiconductor switching elements 4 are specifically positioned on these segments 8a.

[0029] The copper layer 7 formed on the opposite second side 3b of the substrate 3 is structured and therefore not fully mounted onto the ceramic carrier 6.

[0030] In addition to the substrate 3 and the semiconductor switching element 4, the half-bridge module 1 according to the present invention also includes a power terminal 9 and a signal terminal 10.

[0031] Power terminal 9 is used to connect power lines designed as busbar 11, which are used to transmit traction power. Signal terminal 10 is used to connect signal lines to control the switching state of semiconductor switching elements 4 and thus switch these semiconductor switching elements.

[0032] exist Figure 4The diagram shows power lines designed as bus 11, which are connected to power terminals 9. Furthermore, Figure 4 Circuit board 19 is shown, which carries signal lines connected to the signal terminals 10 of the half-bridge module 1. Figure 1 , Figure 2 and Figure 3 The power line 11 and circuit board 19 are not shown in the diagram.

[0033] The half-bridge module 1 according to the invention also includes a molding compound 12, particularly made of plastic. The molding compound 12 surrounds the substrate 3 and the semiconductor switching element 4 on a first side 3a of the substrate 3.

[0034] Both the power terminal 9 and the signal terminal 10 are accessible on this first side 3a of the substrate 3, wherein the power terminal 9 and the signal terminal 10 extend through the molding compound 12 as viewed from the first side 3a of the substrate 3, and are arranged within the bottom surface of the substrate 3 extending from the substrate 3 in their through-mold direction. This bottom surface of the substrate 3 is particularly... Figure 2 It is visible in the middle and is defined by the edge 13 of the substrate 3.

[0035] Therefore in Figure 3 In cross-section, all power terminals 9 and signal terminals 10 extend upwards, but do not protrude from the side of the bottom surface of the substrate 3 defined by edge 13.

[0036] If best can be Figure 2 and Figure 3 As can be seen, power terminal 9 includes a positive terminal 9a, a negative terminal 9b, and a phase terminal 9c. The positive terminal 9a of power terminal 9 is... Figure 2 and Figure 3 The positive terminal 9b is represented by a positive sign, the negative terminal 9b by a negative sign, and the phase terminal 9c by the symbol P. Viewed in the direction through which the power terminal 9 passes through the molding compound 12, the phase terminal 9c is arranged adjacent to the first edge 13 of the substrate 3, and the negative terminal 9b is arranged adjacent to the second edge 13 of the substrate 3 opposite to the first edge 13. These two edges 13 form the narrow edges of the substrate 3. Edges 13 extending between these edges 13 form the long edges of the substrate 3. According to the invention, the power terminal 9, designed as the positive terminal 9a of the half-bridge module 1, is arranged between the phase terminals 9c and the negative terminals 9b at a certain distance from them, viewed in the direction through which it passes through the molding compound 12. Figure 2 and Figure 3 As can be seen, the distance between the positive terminal 9a and the phase terminal 9c is smaller than the distance between the positive terminal 9a and the negative terminal 9b.

[0037] As explained above, power terminal 9 is connected to the power line designed as bus 11. According to... Figure 4 The two positive terminals 9a are in contact with the first busbar 11a of the common surface, the negative terminal 9b is in contact with the second busbar 11b of the common surface, and the phase terminal 9c is in contact with the third busbar 11c of the common surface.

[0038] Here, the first busbar 11a for the two positive terminals 9a and the second busbar 11b for the two negative terminals 9b extend outward beyond the second edge 13 of the substrate 3, wherein the two buses 11a, 11b for the positive terminals 9a and the negative terminals 9b extend in a partially overlapping manner, especially when the insulator 14 is arranged in the middle.

[0039] The third bus 11c of the surface (with two phase terminals 9c in contact with it) extends outward beyond the first edge 13 of the substrate 3.

[0040] By employing the aforementioned design of power terminals 9 and signal terminals 10, and especially their arrangement, along with the design and arrangement of bus 11, leakage inductance can be minimized. This allows for a low-inductance half-bridge module with rectifier unit inductance on the order of a few nanohenries. Consequently, electrical losses are reduced to a minimum. Furthermore, a structural space advantage is achieved because all power terminals 9 and signal terminals 10 are arranged within the bottom surface of substrate 3.

[0041] As from Figure 2 and Figure 3 As can be best seen, the sections 8a of the copper coating 8 formed on the first side 3a of the substrate 3 are electrically connected to each other by contact elements designed, for example, to join the connector 15.

[0042] according to Figure 2 Gate drivers 16 are arranged on circuit board 19. These gate drivers are used to control the semiconductor switching element 4 (i.e., gate control). The gate drivers 16 can control the semiconductor switching element 4 via signal line 10.

[0043] from Figure 2 It can be seen that the first signal terminal 10 for the first semiconductor switching element 4 is arranged between these phase terminals and these positive terminals in a manner that is a certain distance from the phase terminals 9c and the positive terminals 9a when viewed in the direction through which it passes through the molding material 12, while the second signal terminal 10 for the second semiconductor switching element 4 is arranged between these positive terminals and these negative terminals in a manner that is a certain distance from the positive terminals 9a and the negative terminals 9b when viewed in the direction through which it passes through the molding material 12.

[0044] As explained above, molding compound 12 is disposed on the first side 3a of substrate 3 and surrounds substrate 3 and semiconductor switching element 4 on the first side 3a. Power terminal 9 and signal terminal 10 extend outward through molding compound 12.

[0045] The molding material 12 exposes the copper layer 7 of the substrate 3 on the opposite side 3b. Thus, on this second side 3b, the half-bridge module 1 connects with... Figure 1 and Figure 4 The separate cooling device 2 shown is connected, particularly by means of material fitting, such as by means of sintered layer 17. The cooling device 2 is preferably a water cooler. Figure 4 The passage 18 through which water flows in the cooling device 2 is shown schematically.

[0046] The half-bridge module 1, for example, has two semiconductor switching elements 4, two positive terminals 9a, two negative terminals 9c, and two phase terminals 9c, that is, a total of six power terminals 9. All power terminals 9 and signal terminals 10 are arranged within the bottom surface of the substrate 3 when viewed through the molding material 12. Therefore, multiple half-bridge modules 1 can be positioned side by side with each other in a space-saving manner, without the need to provide free space between adjacent bridge modules 1 for arranging power terminals and signal terminals.

[0047] The key feature of the half-bridge module 1 according to the invention is its compact structure and very low inductance. This combines the advantages of discrete individual switches with the advantages of a highly integrated bridge module. The half-bridge module 1 according to the invention is scalable and maintains low power consumption when the half-bridge module is assembled into a power electronics device.

[0048] Figure 5 A possible implementation of a traction inverter 20 according to the invention for power electronics of an electric or hybrid vehicle is illustrated exemplary and schematically. According to the example, the traction inverter 20 includes six half-bridge modules 1 according to the invention, wherein the phase terminals 9c of every two half-bridge modules 1 are contacted via a common third bus 11c. In contrast, the positive terminals 9a and negative terminals 9b for all six half-bridge modules 1 are contacted via a common first bus 11a or a common second bus 11b, respectively. As can be seen, all terminals 9a, 9b, and 9c are located on the first side 3a of the substrate 3. (By means of...) Figure 5 (Not shown in the image) Sintered layer, half-bridge module 1 is arranged on cooling device 2 which is designed as a water cooler.

[0049] List of reference numerals

[0050] 1 Half-bridge module

[0051] 2. Cooling device

[0052] 3 substrate

[0053] 3a First side

[0054] 3b Second side

[0055] 4 Semiconductor switching elements

[0056] 5 Semiconductor Components

[0057] 6. Carrier plate

[0058] 7 Copper Layer

[0059] 8 copper layers

[0060] Section 8a

[0061] 9 Power terminals

[0062] 9a Positive extreme

[0063] 9b Negative extreme sub-particle

[0064] 9c phase terminal

[0065] 10 signal terminal

[0066] 11 Busbar

[0067] 11a First Bus

[0068] 11b Second Busbar

[0069] 11c Third Bus

[0070] 12 Molding materials

[0071] 13 Edge

[0072] 14 Insulators

[0073] 15 Connecting connectors

[0074] 16-Gate Driver

[0075] 17 Sintered Layer

[0076] 18 channels

[0077] 19 Circuit Boards

[0078] 20 Traction Inverters

Claims

1. A half-bridge module (1) of a traction inverter of a power electronics device of an electric or hybrid vehicle, having a base plate (3), a semiconductor switching element (4) arranged on a first side (3a) of the base plate (3), power terminals (9) to which power lines for the transmission of traction electric power can be connected, signal terminals (10) to which signal lines can be connected in order to switch the semiconductor switching element (4), a molding compound (12) which surrounds the base plate (3) and the semiconductor switching element (4) on the first side (3a) of the base plate (3), wherein the power terminals (9) and the signal terminals (10) are both accessible from the first side (3a) of the base plate (3) such that the power terminals (9) and the signal terminals (10) extend through the molding compound (12) as seen from the first side (3a) of the base plate (3) and are arranged within a floor surface extending from the base plate (3) as seen in a direction of passage through the molding compound (12), the power terminals (9) comprise a positive terminal (9a), a negative terminal (9b) and a phase terminal (9c), wherein a first signal terminal (10) for a first semiconductor switching element (4) is arranged between the phase terminal and the positive terminal at a distance from the phase terminal (9c) and the positive terminal (9a) as seen in the direction of passage, a second signal terminal (10) for a second semiconductor switching element (4) is arranged between the positive terminal and the negative terminal at a distance from the positive terminal (9a) and the negative terminal (9b) as seen in the direction of passage.

2. The half-bridge module according to claim 1, characterized in that the power terminals (9) comprise a positive terminal (9a), a negative terminal (9b) and a phase terminal (9c), wherein the phase terminal (9c) is arranged adjacent to a first edge (13) of the base plate (3) as seen in the direction of passage and the negative terminal (9b) is arranged adjacent to a second edge (13) of the base plate (3) opposite the first edge as seen in the direction of passage, wherein the positive terminal (9a) is arranged between the phase terminal and the negative terminal at a distance from the phase terminal (9c) and the negative terminal (9b) as seen in the direction of passage.

3. The half-bridge module according to claim 2, characterized in that the positive terminal (9a) is in contact with a first busbar (11a) and the negative terminal (9b) is in contact with a second busbar (11b), the first busbar extending in a superposed manner with the second busbar.

4. The half-bridge module according to claim 3, characterized in that the first busbar (11a) and the second busbar (11b) are directed outward beyond the second edge (13) of the base plate (3).

5. The half-bridge module according to claim 3, characterized in that ​ ​ wherein ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ An insulator (14) is arranged between the first busbar (11a) and the second busbar (11b).

6. The half-bridge module according to claim 3, characterized in that The first busbar (11a) and / or the second busbar (11b) have a plastic overmolding.

7. The half-bridge module according to claim 1, characterized in that The power terminals (9) comprise a positive terminal (9a), a negative terminal (9b) and a phase terminal (9c), wherein the phase terminal (9c) is in contact with a third busbar (11v) which is directed outward beyond a first edge (13) of the base plate (3).

8. The half-bridge module of claim 1, wherein, The first signal terminal (10) and the second signal terminal (10c) are in contact with a circuit board (19).

9. The half-bridge module according to one of claims 1 to 8, characterized in that A molding compound (12) which surrounds the base plate (3) and the semiconductor switching elements (4) on a first side (3a) of the base plate (3) at least partially exposes the base plate on an opposite second side (3b) of the base plate, wherein on the second side (3b) of the base plate (3) the half-bridge module is connected to a separate cooling device (2).

10. The half-bridge module according to claim 9, characterized in that The cooling device is connected to the half-bridge module by means of a material-fit connection, wherein the material-fit connection is a sintering connection, a soldering connection or a thermally conductive adhesive connection.

11. A traction inverter (20) for a power electronics device of an electric or hybrid vehicle, comprising at least three half-bridge modules according to any one of claims 1 to 10.

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