POWER ELECTRONICS DEVICE AND POWER ELECTRONICS FUNCTIONAL SYSTEM

Abstract

A power electronics device comprises a power semiconductor, a first circuit board controllingly connected to the power semiconductor, a lead frame connecting the power semiconductor and the first circuit board. The power semiconductor is connected to at least one contacting region of the lead frame in such a way that heat can be transferred from the power semiconductor to the lead frame and can be conducted away from the lead frame by the power semiconductor The power electronics device further comprises a housing , which borders at least regions of a fluid reservoir accommodating a coolant fluid. The power semiconductor and the lead frame are arranged in the fluid reservoir and are configured to transfer heat to the coolant fluid.

Claims

1. A power electronics devices, comprising a power semiconductor; a first circuit board controllingly connected to the power semiconductor a lead frame connecting the power semiconductor and the first circuit board, wherein the power semiconductor is connected to at least one contacting region of the lead frame in such a way that heat can be transferred from the power semiconductor to the lead frame and can be conducted away from the lead frame by the power semiconductor; and a housing which borders at least regions of a fluid reservoir accommodating a coolant fluid; wherein the power semiconductor and the lead frame are arranged in the fluid reservoir and configured to transfer heat to the coolant fluid.

2. The power electronics device according to claim 1, further comprising: a further power semiconductor; and a further lead frame connecting further power semiconductor and the first circuit board; wherein the further power semiconductor is connected to at least one contacting region of the further lead frame in such a way that heat can be transferred from the further power semiconductor to the further lead frame and can be away from the further lead frame by the further power semiconductor wherein the further power semiconductor and the further lead frame are arranged on an opposite side of the first circuit board than the power semiconductor and the lead frame.

3. The power electronics device according to claim 1, wherein line elements of the lead frame form a total heat transfer surface for transferring heat to the coolant fluid, an area of the total heat transfer surface is greater than an area of a connection surface of the lead frame on which the lead frame contacts the power semiconductor.

4. The power electronics device according to claim 1, wherein a plane of attachment of the lead frame frame to the power semiconductor has a spacing from the first circuit board.

5. The power electronics device according to claim 2, wherein the first circuit board is electrically coupled to a second circuit board, and wherein the first circuit board with the power semiconductors and lead frames arranged thereon is positioned in such a way that the further lead frame has a spacing from the second circuit board.

6. The power electronics device according to claim 1, further comprising a condensing unit configured to cool and thus condense vaporized coolant fluid and in turn to provide the cooled and condensed coolant fluid for cooling at least one of the power semiconductor or the lead frame.

7. The power electronics device according to claim 6, 7. (Currently Amended) The power electronics device according to claim 6, wherein the condensing unit has a receiving space and a cooling medium accommodated in the receiving space, the condensing unit being configured to absorb heat from vaporized coolant fluid and transfer the absorbed heat to the cooling medium in the receiving space.

8. The power electronics device according to claim 7, 8. (Currently Amended) The power electronics device according to claim 7, the condensing unit has projections, .extending towards the fluid reservior, wherein the receiving space extends at least into the projections.

9. A power electronics functional system, comprising a plurality of power electronics devices according to claim 1, wherein the power electronics devices are connected to lines for different voltage phases.

10. A motor vehicle having an electric motor , comprising a power electronics device according to claim, and a cooling medium circuit which is fluidically coupled to the condensing unit of the power electronics device.

11. A power electronics device, comprising: a circuit board; a housing, at least partially, defining a fluid reservoir; a power semiconductor disposed in the fluid reservoir; a lead frame disposed in the fluid reservoir, the lead frame being connected to the power semiconductor and the circuit board; and a coolant fluid housed in the fluid reservoir, the coolant fluid surrounding the power semiconductor and the lead frame in the fluid reservoir.

12. The power electronics device of claim 11, wherein the power semiconductor is connected to the circuit board on an opposite side of the circuit board than the lead frame, the power semiconductor being configured to transfer heat directly to the circuit board.

13. The power electronics device of claim 11, wherein the circuit board, at least partially, defines the fluid reservoir.

14. The power electronics device of claim 11, wherein the circuit board is disposed in the fluid reservoir.

15. The power electronics device of claim 11, further comprising: a further power semiconductor disposed in the fluid reservoir; and a further lead frame disposed in the fluid reservoir, the further lead frame connecting the further semiconductor to the circuit board; wherein the coolant fluid surrounds the further power semiconductor and the further lead frame in the fluid reservoir.

16. The power electronics device of claim 15, wherein the further power semiconductor and the further lead frame are arranged on an opposite side of the circuit board than the power semiconductor and the lead frame.

17. The power electronics device of claim 11, further comprising a further circuit board supporting the housing, the further circuit board, at least partially, defining the fluid reservoir, wherein the power semiconductor, the circuit board, and the lead frame are spaced from the further circuit board.

18. The power electronics device of claim 11, wherein a plane of attachment of the lead frame to the power semiconductor has a spacing from the circuit board.

19. The power electronics device of claim 11, further comprising a condensing unit disposed within the housing, the condensing unit being configured to cool vaporized coolant fluid received from the fluid reservoir and to provide condensed coolant fluid to the fluid reservoir.

20. The power electronics device of claim 11, the power semiconductor is configured to transfer heat to at least one of the cooling fluid or the lead frame, and the lead frame is configured to transfer heat to the cooling fluid.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0069] The disclosure described above is explained in detail below based on the relevant technical background with reference to the associated drawings. The disclosure is in no way restricted by the purely schematic drawings, wherein it should be noted that the exemplary embodiments shown in the drawings are not limited to the dimensions shown. In the drawings:

[0070] FIG. 1: shows power electronics with a conventional structure,

[0071] FIG. 2: shows an enlarged view of the region of the electrical connection of the chip according to the embodiment according to FIG. 1,

[0072] FIG. 3: shows power electronics according to the disclosure in a sectional view,

[0073] FIG. 4: shows the region of the connection of high-current contacts of a high-current contact according to the embodiment shown in FIG. 3,

[0074] FIG. 5: shows a further embodiment of power electronics according to the disclosure in a sectional view, and

[0075] FIG. 6: shows a power electronics functional system according to the disclosure with several power electronics devices according to the disclosure.

DETAILED DESCRIPTION

[0076] FIGS. 1 and 2 have already been discussed in order to explain the prior art.

[0077] FIG. 3 shows a first embodiment of a power electronics device 1 according to the disclosure.

[0078] This includes a power semiconductor 16, which can also be referred to as a chip. The chip or the power semiconductor 16 is electrically conductively connected to a lead frame 20 via its underside 17, which is oriented upwards in the embodiment shown here. It can be seen that the contacting region 21 between the power semiconductor 16 and the lead frame 20 is significantly smaller than the total area formed by the lead frame 20, so that heat introduced into the lead frame 20 by the power semiconductor 16 can be distributed by the lead frame 20 over its large surface. The lead frame 20 is in turn electrically connected to a first circuit board 30. Correspondingly, heat is also transferred from the lead frame 20 to the first circuit board 30. The power semiconductor 16 and the lead frame 20 are arranged within a fluid reservoir 41 delimited by a housing 40. Coolant fluid 42 is present in this fluid reservoir 41 and completely surrounds the power semiconductor 16 and the lead frame 20. Correspondingly, heat can be transferred from the power semiconductor 16 to the coolant fluid 42 over the large area of the lead frame 20 and the power semiconductor 16 is correspondingly effectively cooled.

[0079] The first circuit board 30 is therefore designed to be multifunctional, since it is used for contacting the power semiconductor 16 and for electrical contacting to the outside, and at the same time also for delimiting the fluid reservoir 41 in regions.

[0080] The power electronics device 1 also comprises a condensing unit 100, which forms a receiving space 101 in which a cooling medium 103 is arranged. For the purpose of enlarging the surface of the condensing unit 100, projections 102 are provided in the direction of the first circuit board 30, which are part of the receiving space 101 and are correspondingly filled with cooling medium 103.

[0081] If the coolant fluid 42 vaporizes due to the temperature, it reaches the condensing unit 100 in vapor form. Due to the fact that this is kept at a low temperature by the cooling medium 103, the coolant fluid vapor 42 condenses, so that the liquefied coolant fluid 42 in turn drips off the projections 102 and is fed to the fluid reservoir 41 for the purpose of once again cooling the power semiconductor 16 or the lead frame 20. The cooling medium 103 of the condensing unit 100 can be fluidically connected to another circuit, such as a cooling system of a motor vehicle, so that it can also be cooled via a heat exchanger, not shown here, and can be fed back to the aforementioned condensation purpose.

[0082] In the embodiment shown here, the power electronics device 1 also comprises what is termed a DC link capacitor 104 for connecting it to a DC network.

[0083] In an alternative embodiment, the DC link capacitor 104 can also be mounted on the housing 40 via a press connection when the power electronics device 1 is mounted.

[0084] What is termed a snubber capacitor 95 is also arranged in an electrically conductive manner on the first circuit board 30 for the purpose of damping voltage peaks.

[0085] There is a spacing 80 between the lead frame 20 and the first circuit board 30. In the embodiment shown here, the spacing 80 is arranged in such a way that the power semiconductor 16 rests with its side facing away from the lead frame 20 and consequently with its upper side on the first circuit board 30 and makes electrically conductive contact therewith. In this way, heat can be transferred directly from the power semiconductor 16 to the first circuit board 30.

[0086] A seal 70 is arranged between the housing 40 and the circuit board 30. The electrical signals or the electrical power supply are transmitted or implemented by high-current contacts 92 which are coupled to the first circuit board 30.

[0087] This connection can be seen in an enlarged view in FIG. 4.

[0088] It can also be seen here that a respective high-current contact 92 is electrically conductively connected to the first circuit board 30 by means of what is termed a respective via 94. The via 94 also ensures a fluid seal against the coolant fluid 42 at the same time that it is passed through the circuit board 30.

[0089] FIG. 5 shows a further embodiment of the power electronics device 1 according to the disclosure.

[0090] This differs from the embodiment shown in FIG. 3 essentially in that a further power semiconductor 50 and a further lead frame 60 are arranged on the side of the first circuit board 30 opposite the power semiconductor 16 and the lead frame 20. Similarly to the power semiconductor 16 and the lead frame 20, and thus likewise the further power semiconductor 50 and the further lead frame 60 are completely surrounded by the coolant fluid 42. This is ensured by a spacing 91 between the first circuit board 30 and a second circuit board 90 which, together with the housing 40, borders the fluid reservoir 41.

[0091] The connection between the first circuit board 30 and the second circuit board 90 is implemented here via additional high-current contacts 93. As in the first embodiment shown in FIG. 3, the power electronics device 1 is electrically connected via high-current contacts 92, however, these are connected to the second circuit board 90 in the embodiment shown here.

[0092] The embodiment shown in FIG. 5 thus has the advantage that two power semiconductors 16, 50 can be cooled at the same time in a very space-efficient manner by a coolant fluid 42 that condenses on a common condensing unit 100.

[0093] FIG. 6 shows a power electronics functional system according to the disclosure, which comprises several power electronics devices 1 according to the disclosure. The power electronics devices 1 are connected via the high-current contacts 92 to current-carrying lines 200, which can in particular be copper sheet layers, via which heat can also be dissipated. For example, one phase of a three-phase motor is connected to the output of the power electronics functional unit, here at the AC connection. Power electronics functional units are therefore connected to a three-phase motor of the type usual in an electric drive system.

[0094] The power electronics device and the power electronics functional system enable a power semiconductor to be cooled in a thermally optimized and energy-optimized manner, so that it can be designed for high performance.

LIST OF REFERENCE SYMBOLS

[0095] 1 Power electronics device [0096] 2 Control circuit board [0097] 3 Power module [0098] 4 Busbar [0099] 5 Intermediate circuit capacitor [0100] 6 Cooling element [0101] 7 Cooling medium [0102] 8 Chip [0103] 9 Bonding wire [0104] 10 Solder layer [0105] 11 DCB [0106] 12 Base plate [0107] 13 Thermal paste [0108] 16 Power semiconductor [0109] 17 Underside of the chip [0110] 20 Lead frame [0111] 21 Contacting region [0112] 30 First circuit board [0113] 40 Housing [0114] 41 Fluid reservoir [0115] 42 Coolant [0116] 50 Further power semiconductors [0117] 60 Further lead frames [0118] 70 Seal [0119] 80 Spacing [0120] 90 Second circuit board [0121] 91 Spacing between the first circuit board and the second circuit board [0122] 92 High-current contact [0123] 93 Further high-current contact [0124] 94 Via [0125] 95 Snubber capacitor [0126] 100 Condensing unit [0127] 101 Receiving space [0128] 102 Projection [0129] 103 Cooling medium [0130] 104 DC link capacitor [0131] 200 Current-carrying lines/layers [0132] 201 AC phase output