METHOD FOR PRODUCING A POWER MODULE UNIT, POWER MODULE UNIT, NETWORK PART AND FREQUENCY CONVERTER

Abstract

A power module unit, in particular for a frequency converter, includes a base plate having a first side provided with a recess and a second side, a cooling fin fastened in the recess of the base plate at least in one region by a positive fit, a material fit, and/or a non-positive fit, and a substrate provided for a power semiconductor and disposed on the second side of the base plate.

Claims

1.-18. (canceled)

19. A power module unit, in particular for a frequency converter, said power module comprising: a base plate having a first side provided with a recess and a second side; a cooling fin fastened in the recess of the base plate at least in one region by at least one connection selected from the group consisting of a positive fit, a material fit, and a non-positive fit; and a substrate for a power semiconductor, said substrate being disposed on the second side of the base plate.

20. The power module unit of claim 19, wherein the connection of the cooling fin to the base plate is a pressed connection, an adhesive connection, or a soldered connection.

21. The power module unit of claim 19, wherein the base plate includes copper, aluminum or a layer of copper and a layer of aluminum and/or the cooling fin includes copper, aluminum or an alloy thereof.

22. The power module unit of claim 19, wherein the cooling fin includes an attachment such as to touch the first side of the base plate when the cooling fin is received in the recess.

23. The power module unit of claim 19, wherein one of the base plate and the cooling fin has a notch and another one of the base plate and the cooling fin has a protrusion to reinforce the connection of the cooling fin to the base plate.

24. The power module unit of claim 19, wherein the base plate is made of a material having a hardness which is different than a hardness of a material for the cooling fin.

25. The power module unit of claim 19, wherein the cooling fin has a U-shaped configuration, O-shaped configuration, or an 8-shaped configuration.

26. The power module unit of claim 19, wherein the recess has a cross-section which is tapered toward the second side, preferably is embodied in a trapezoid-shaped manner.

27. The power module unit of claim 19, further comprising a plurality of said cooling fin and a further cooling fin positioned between adjacent two of the plurality of said cooling fin such that the further cooling fin and the adjacent two of the plurality of said cooling fin have at least one region with overlapping sides,

28. A frequency converter or power supply, in particular for industrial use, comprising a power module unit, said power module unit comprising a base plate having a first side provided with a recess and a second side, a cooling fin fastened in the recess of the base plate at least in one region by at least one connection selected from the group consisting of a positive fit, a material fit, and a non-positive fit in regions, and a substrate for a power semiconductor, said substrate being disposed on the second side of the base plate.

29. A method for producing a power module unit, said method comprising: forming a recess on a first side of a base plate; positioning a substrate on a second side of the base plate in opposition to the first side; heating the base plate and the substrate sufficient to fasten the substrate to the second side of the base plate, in particular by way of a soldered or sintered connection; and introducing and fastening a cooling fin in the recess by a positive fit and/or non-positive fit.

30. The method of claim 29, wherein the base plate and the substrate are heated in a furnace and/or wherein the cooling fin is introduced into the recess after the base plate has cooled down.

31. The method of claim 29, wherein the cooling fin is introduced into the recess in a direction along the recess.

32. The method of claim 29, wherein a plurality of cooling fins are introduced in one step into a plurality of recesses in the first side of the base plate in one-to-one correspondence.

33. The method of claim 29, wherein the cooling fin is introduced into the recess tangentially in relation to the first side of the base plate, and further comprising shaping the recess in the first side of the base plate with a trapezoidal cross-section.

34. The method of claim 32, wherein the cooling fin is slid into the recess orthogonally in relation to the cross-section of the recess, as the cooling fin is introduced into the recess tangentially in relation to the first side of the base plate to cause minimal deformation of the base plate.

35. The method of claim 29, wherein the cooling fin is introduced into the recess, in particular slid in or drawn in, via a side area of the base plate in orthogonal orientation in relation to the side area.

36. The method of claim 29, further comprising: forming the cooling fin with an opening, and guiding a press into the opening of the coaling fin to press the cooling fin into the recess.

Description

[0109] In the figures:

[0110] FIG. 1 shows an exemplary power module unit,

[0111] FIG. 2 shows a cutout of an exemplary power module unit,

[0112] FIG. 3 shows an exemplary method,

[0113] FIG. 4 shows a possible cross-section of a recess,

[0114] FIG. 5 shows a further exemplary power module unit,

[0115] FIG. 6 shows a cutout of a power module unit,

[0116] FIG. 7 shows a cutout of a power module unit, and

[0117] FIG. 8 shows a connection between cooling fins and further cooling fins.

[0118] FIG. 1 shows an exemplary power module unit 1. The power module unit 1 comprises a base plate 3, wherein the base plate 3 has recesses 9 on a first side. The recesses 9 serve to accommodate at least one cooling fin 7 in each case. The base plate has a substrate 4 on a second side 3b. The substrate 4 serves as a carrier for the power semiconductor 5. The substrate is preferably produced from a ceramic, wherein the substrate has a copper coating on both sides. The copper coating serves in particular as a basis for a soldered connection 11 for fastening the substrate 4 to the base plate 3. The power semiconductors 5 are preferably likewise connected to the substrate 4 by a soldered connection 11.

[0119] The base plate 3 is preferably embodied from a copper ahoy or an aluminum alloy. Particularly advantageously, the base plate 3 is produced from aluminum in the lower region adjoining the first side 3a, and is produced from copper in the upper region adjoining the second side 3b. The basis for such a base plate 3 is a layered material. One possible layered structure is indicated by the dashed line in the base plate 3.

[0120] The respective cooling fin is fastened into the respective recess 9 in the base plate 3 by way of a positive and/or non-positive connection using the base plate 3.

[0121] FIG. 2 shows a cutout of an exemplary power module unit 1. A base plate 3 is shown with a plurality of cooling fins 7. The cooling fins 7 are introduced in one of the recesses 9 of the base plate 3 in each case. The cooling fins 7 shown each have two openings 7a. The openings 8 are separated from one another by a border in the center of the cooling fin 7. An 8-shaped profile of the cooling fin is therefore embodied. Due to the 8-shaped profile, a flow of air is able to cool the cooling fins in a particularly efficient manner.

[0122] At the respective end 7b of the cooling fin 7, the cooling fin 7 is embodied in a reinforced manner. Such a reinforcement may be achieved by an increased wall thickness of the cooling fin 7 in the region of the respective end 7a thereof. By reinforcing the cooling fin 7 at its respective end 7a, a particularly stable connection of the respective cooling fin 7 to the base plate 3 is possible.

[0123] FIG. 3 shows an exemplary method. The method comprises a first step a, a second step b, a third, optional step c and a fourth step d.

[0124] In the first step a, the respective recess 9 is introduced into the base plate 3. The recess is imprinted into the base plate by a rolling process, a machining method such as milling or by a forging method.

[0125] In a second step b, a substrate 4 is positioned on the second side 3b of the base plate 3. To fasten the substrate 4 to the second side 3b of the base plate 3, the base plate with the substrate is heated in a furnace to a temperature of 200 degrees to 500 degrees Celsius. The substrate 4 is connected to the second side 3b of the base plate in a fixed manner in the second step b by way of a soldered connection or a sintered connection.

[0126] In a third, optional step c, the base plate with the substrate is cooled down to room temperature again. Depending on the type of connection of the substrate 4 to the base plate 3, the cooling down takes place rapidly or slowly.

[0127] In a fourth step d, the cooling fins 7 are introduced into the respective recess 9 of the base plate and fastened. The introduction of the cooling fins takes place either from the side, i.e. tangentially in relation to the first side 3a of the base plate 3, or perpendicularly in relation thereto. When introducing the cooling fins 7 into the base plate tangentially, the cooling fin 7 is slid into the recess orthogonally in relation to the cross-section 9a of the recess 9. Such an introduction advantageously only minimally deforms the base plate.

[0128] When introducing the respective cooling fin 7 into the recess 9 perpendicularly, care should be taken that the force that acts on the base plate 3 does not lead to a deformation of the base plate 3, as otherwise the substrate 4 could be damaged.

[0129] FIG. 4 shows a possible cross-section 9a of a recess 9. The recess 9 in the base plate 3 is inwardly tapered. For improved holding of the cooling fin 7, the recess 9 has protrusions 10 on its inner side 9b. The protrusions 10 advantageously serve to embody positive connections in regions between the base plate 3 (shown as a cutout here) and the cooling fin 7.

[0130] The trapezoid-shaped cross-section 9a of the recess 9, when introducing the cooling fin 7 into the recess 9 in a perpendicular manner, serves to reduce the force that acts perpendicularly in relation to the first side 3a or second side 3b of the base plate 3. Instead, the force is redirected in a direction running tangentially in relation to the respective side 3a,3b of the base plate 3. This is represented by the arrows that emerge from the recess.

[0131] Moreover, a pressing means 11 is indicated in the figure. The pressing means 11 serves to introduce the cooling fin 7 into the recess 9. Preferably, the pressing means 11 is designed as a rod, which is guided through the opening 7a of the cooling fin and is able to press the cooling fin 7 into the recess 9 of the base plate 3. Depending on the shape of the pressing means 11 and a cross-section of the cooling fin 7, the pressing means 11 may contribute to embodying a positive connection. The pressing means 11 preferably deforms the respective end 7a of the cooling fin 7, so that the material of the cooling fin 7 fills the recess 9, at least in regions.

[0132] FIG. 5 shows a further exemplary power module unit 1. The power module unit 1 has a similar structure to the power module unit that is shown in FIG. 1. Unlike in FIG. 1, the power module unit 1 shown here comprises cooling fins 7 that are connected to one another. The connection of the cooling fins takes place by way of connecting elements 17. The connecting elements 17 and the cooling fins 7 form a fixed unit here. The unit consisting of cooling fins 7 and connecting elements 17 is introduced into the recesses 9 in the base plate 3, where it is connected to the base plate with a positive fit and/or a non-positive fit, at least in regions.

[0133] FIG. 6 shows a cutout of a power module unit 1. A cutout of the base plate 3 with the recess 9 is shown, wherein a cooling fin 7 has been introduced into the recess 9. The cooling fin 7 comprises an attachment 25, wherein the attachment 25 is positioned on the respective side of the cooling fin 7 such that, once the cooling fin 7 has been introduced into the recess 9, a cavity 23 is embodied in the recess. The cavity 23 is arranged between the side of the cooling fin 7 and the bottom side of the recess 9. The cavity 23 is embodied because the cooling fin is not fully introduced into the recess 9. In order to embody the cavity 23, the respective attachment 25 is positioned on the sides of the cooling fin 7 in such a manner that, once the cooling fin 7 has been introduced into the recess 9, the attachment 25 touches the first side 31 or is fastened thereto.

[0134] Advantageously, the attachment 25 of the cooling fin 7 is in contact with the first side 3a of the base plate 3. Advantageously, the attachment 25 being in contact with the first side 3a increases a planar connection 21 between cooling fin 7 and the base plate. The planar connection serves to transfer heat from the base plate 3 to the cooling fin.

[0135] The height of the cavity 23 may also be embodied as being small enough for the bottom side of the recess 9 to touch the cooling fin 7 at points.

[0136] FIG. 7 shows a cutout of a power module unit 1. In a similar way to the cutout that is shown in FIG. 6, the cooling fin 7 likewise has an attachment 26. The attachment 25 is embodied such that it has an oblique contact area, wherein the oblique contact area is in contact with a corresponding oblique area in the recess 9. When introducing the cooling fin 7 into the recess 9, the forces that occur are marked by arrows. The forces (symbolized by the arrows) have, as a function of the orientation of the oblique contact area, a force component in the parallel direction to the first side of the base plate 3.

[0137] Due to the oblique orientation of the contact area, when introducing the cooling fin 7, less force is impressed onto the base plate 3 to embody a bending stress and therefore to impose strain on the substrate 4. Moreover, the area between the cooling fin 7 and the base plate 3 is enlarged. Due to the enlarged area, heat can be emitted from the base plate 3 to the cooling fin.

[0138] For the improved connection of the cooling fin 7 to the base plate, the inner side 9a of the recess 9 and/or the cooling fin 7 have a protrusion 10 on their side. The protrusion preferably protrudes into a notch, wherein the notch is introduced in each case on the side that touches the protrusion. Preferably, such a protrusion 10 contributes to the improved stability of the connection between the base plate 3 and the cooling fin 7.

[0139] FIG. 8 shows a connection 21 between cooling fins 7 and further cooling fins 7′. The connection 21 between the cooling fins 87 and the further cooling fins 7′ may be embodied by a damped connection or a non-positive connection. For improved cohesion, the cooling fins 7 and/or the further cooling fins 7′ have a corrugated structure in the region of the connection 21. Preferably, cooling fins 7 and/or further cooling fins 7′ have protrusions with a triangle cross-section that extend in parallel in regions on their respective side. These protrusions may also protrude into notches, wherein the notches have a triangular cross-section and are positioned in the cooling fin 7 and/or the further cooling fin 7′ between the protrusions. One such connection 21 is shown in the enlarged view. The corrugated structure serves to connect the cooling fins 7 to the respective further cooling fin 7′ in a more stable manner.

[0140] A connecting element 17 is shown, wherein the connecting element 17 reveals the possibility of connecting the cooling fins 7 (similarly to the embodiment shown in FIG. 5).

[0141] The further cooling fins 7′, which are introduced into the intermediate spaces of the cooling fins 7 which are oriented in parallel in each case, serve to further improve the cooling of cooling fins 7 embodied in parallel in each case and thus serve to cool the substrate 4 on the base plate 3 in an improved manner

[0142] In summary, the invention relates to a method for producing a power module unit 1 and to a power module unit 1. Moreover, the invention relates to a power supply and to a frequency converter. In order to produce the power module unit 1, a base plate 3 is provided with recesses 9. The base plate is connected to a substrate 4, which carries the power semiconductor 5. After fastening the substrate 4 to the base plate, the cooling fins 7 are guided into the recesses 9 in the base plate 3 and are fastened with a positive and/or non-positive fit. Due to the embodiment, a power module unit 1 may be embodied with cooling fins 7 as required, and at the same time the production of the power module unit 1 may be simplified.