Power module and method for producing same, and converter having a power module

Abstract

The invention relates to a power module (100) comprising a cooler (102), an insulating layer (104) arranged on a surface of the cooler, a conductor layer structure (106A, 106B, 106C) arranged on the insulating layer, and a plurality of heat and current conducting elements (108A, 108B, 108C), each having an upper side and a lower side, wherein the upper side is configured to form an electrical connection for an electronic device (110, 112) and the lower side is configured to directly contact the conductor layer structure (106A, 106B, 106C). The invention further relates to a method for producing such a power module (100) and to a converter having such a power module.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics. In particular, the present invention relates to a power module and a method for producing the power module. The present invention also relates to a converter having a power module, in particular an inverter or a DC voltage converter. Background Art

[0002] US2017 / 154877 A1 describes a power module with multiple insulation layers between the cooler and the electronic components. This structure takes up a lot of space and can also be improved in terms of heat conduction and the cooling efficiency associated therewith. Summary of the invention

[0003] The object of the present invention is to provide a compact power module with improved cooling efficiency.

[0004] This object is achieved by the subject matter of the independent patent claims. Advantageous embodiments of the invention are described in the dependent claims.

[0005] According to a first aspect of the present invention, a power module is described, the power module comprising:

[0006] - a cooler having a surface,

[0007] - an electrically insulating (and thermally conductive) layer formed on the surface of the cooler,

[0008] an electrically conductive conductor layer structure formed on the side of the insulation layer facing away from the cooler, and

[0009] a plurality of heat- and current-conducting elements made of metal or a metal alloy or copper or a copper alloy, each having an upper side and an underside, wherein the respective heat- and current-conducting element is (directly) arranged on the conductor layer structure via its respective underside and is (directly or exclusively via a material-bonded electrically and thermally conductive connection) (electrically) and thermally connected to the conductor layer structure,

[0010] - Semiconductor components which are each arranged on the top side of the respective heat- and current-conducting element and are (directly or only via a cohesive electrically and thermally conductive connection) connected to the respective heat- and current-conducting element.

[0011] The described power module is based on the finding that direct contact between the underside of the heat and current conducting element, which also serves as a heat distributor, and the conductor layer structure arranged directly on the heat sink allows very efficient heat conduction and thus good cooling efficiency in a compact design.

[0012] According to an embodiment of the present invention, the insulating layer is made of an electrically insulating material, in particular, an organic electrically insulating material or a ceramic electrically insulating material.

[0013] According to a further embodiment of the invention, the conductor layer structure consists of an electrically and thermally conductive material or metal or copper.

[0014] For example, the insulating layer and the conductor layer structure or the electrical contact surfaces formed therefrom and, if necessary, also the printed conductors are part of the cooler. In particular, after the insulating layer and the conductor layer structure have been fastened to the cooler, the semiconductor device can be fastened to the conductor layer structure directly or via a carrier, which is equipped with the semiconductor device. A carrier that may be present between the semiconductor device and the cooler body is not part of the cooler; rather, such a carrier on the conductor layer structure of the cooler (or the semiconductor device itself) is an element arranged on the cooler, the conductor layer structure being carried by the insulating layer of the cooler. The cooler with the conductor layer structure and the insulating layer can be provided as its own component for heat dissipation and can be set up to carry the semiconductor device as mentioned above.

[0015] According to a further embodiment of the invention, the heat and current conducting element is welded, sintered, adhesively bonded or soldered to the conductor layer structure via the underside.

[0016] According to a further embodiment of the invention, the semiconductor components are respectively soldered or sintered or adhesively bonded or welded to the top side of the corresponding heat- and current-conducting element.

[0017] Thus, the insulating layer and the conductor layer structure can together provide a circuit board-like surface structure of the cooler, to which heat- and current-conducting elements can be directly mounted, for example soldered, sintered, adhesively bonded or welded.

[0018] According to another embodiment of the invention, the conductor layer structure has a plurality of surfaces which are physically and thus electrically separated from one another. In particular, the surfaces are rectangular, triangular, elliptical, circular or consist of one or more polygons.

[0019] Each face preferably has a shape and dimensions that correspond to the shape and dimensions of the underside of at least one of the heat- and current-conducting elements or that are only slightly larger in their respective corresponding extent.

[0020] According to a further embodiment of the invention, at least one heat and current conducting element is arranged on each of the surfaces, said heat and current conducting element being (conductively) and (thermally) connected to the corresponding surface.

[0021] According to another embodiment of the invention, the surfaces are arranged in triads. Here, the three surfaces of the respective triad respectively form (or provide) the negative current connection, the phase current connection and the positive current connection of the power module or the switching bridge.

[0022] Each surface triplet forms, for example, three electrical contact surfaces of a switching bridge for contacting a heat- and current-conducting element.

[0023] According to another embodiment of the invention, the heat and current conducting element is designed in the form of a plate or block. In particular, the heat and current conducting element is punched or stamped out of a copper sheet.

[0024] The choice between a relatively thin plate-like heat and current conducting element or a relatively thick block-like heat and current conducting element depends on the facts, in particular the required heat conduction and distribution.

[0025] According to another embodiment of the invention, the heat and current conducting elements are arranged in triads. Here, the three heat and current conducting elements of the respective triads respectively constitute (or provide) a negative current terminal, a phase current terminal or a positive current terminal of the power module.

[0026] According to a further embodiment, the power module further comprises an electrically (and thermally) conductive spacer, which is respectively welded or sintered or adhesively bonded or soldered to the upper side of the corresponding heat and current conducting element. The spacer is designed to establish an electrical connection between the heat and current conducting element on the one hand and an external electrical contact partner of the power module, such as a busbar (English: "busbar") on the other hand, and at the same time to produce or ensure a spatial separation between the heat and current conducting element on the one hand and the external electrical contact partner on the other hand. In this case, the spacer is designed, for example, in block-like or columnar form.

[0027] According to a further exemplary embodiment of the invention, the cooler has a cooling body and / or a liquid cooler, in particular an active liquid cooler.

[0028] According to a second aspect of the invention, a method for producing a power module as described previously is described.

[0029] According to the method, a cooler is provided (step (a)). An electrically insulating layer is formed on the surface of the cooler (step (b)). An electrically conductive conductor layer structure is formed on the side of the insulating layer facing away from the cooler (step (c)). A plurality of heat and current conducting elements (108A, 108B, 108C) are provided (step (d)), each of which has an upper side and a lower side. The heat and current conducting elements are arranged on the side of the conductor layer structure facing away from the cooler. Here, the heat and current conducting elements are placed on the conductor layer structure via their respective lower sides and are electrically and thermally connected to the conductor layer structure (step (e)). Subsequently, semiconductor devices are provided and arranged on the respective heat and current conducting elements. Here, the semiconductor devices are respectively arranged on the respective corresponding heat and current conducting elements and are electrically and thermally connected to the respective heat and current conducting elements (step (f)).

[0030] The method described is essentially based on the same concept as the above-mentioned power module according to the first aspect and in particular provides a method for manufacturing such a power module. Here, in particular steps (b) and (c) can be performed in different ways. For example, a material consisting of an insulating material and a conductor material can be applied to the surface of the cooler, and a conductor layer structure can be provided by targeted removal of the conductive material. Alternatively, an insulating layer can first be applied to the surface of the cooler and then a conductor layer structure can be created by applying a conductor material to the insulating layer.

[0031] According to a third aspect of the invention, a converter, in particular an inverter or a DC voltage converter, is described having a power module according to the first aspect. The converter according to this third aspect thus benefits from the above-mentioned advantages of the power module.

[0032] It is pointed out that embodiments of the invention have been described with respect to different inventive subjects. In particular, some embodiments of the invention are described with the aid of method claims and other embodiments of the invention are described with the aid of device claims. However, it will be immediately clear to a person skilled in the art when reading this application that, in addition to combinations of features belonging to one type of inventive subject matter, any combination of features belonging to different types of inventive subject matter is also possible, unless explicitly stated otherwise. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Further advantages and features of the invention emerge from the following exemplary description of preferred embodiments.

[0034] Figure 1 A power module according to an exemplary embodiment is shown.

[0035] Figure 2Three heat and current conducting elements are shown according to an exemplary embodiment.

[0036] Figure 3 A switching bridge according to an exemplary embodiment is shown.

[0037] Figure 4 A flow chart of a method for manufacturing a power module according to an exemplary embodiment is shown.

[0038] It is pointed out that the embodiments described below represent only a limited selection of possible implementation variants of the invention. DETAILED DESCRIPTION

[0039] Figure 1 A power module 100 according to an exemplary embodiment is shown. The power module 100 has a cooler 102, an insulating layer 104 arranged on the surface of the cooler 102, a conductor layer structure 106A, 106B, 106C arranged on the insulating layer 104, and a plurality of heat and current conducting elements in the form of copper elements (i.e. made of copper or copper alloy) 108A, 108B, 108C. Each copper element 108A, 108B, 108C serves as a heat distributor and at the same time as an electrical conductor or current terminal and has an upper side and a lower side, respectively. The upper side is configured to form an electrical terminal for an electronic device, and the lower side is configured to directly contact the conductor layer structure. The insulating layer 104 is preferably composed of an electrically insulating material, such as an organic or ceramic material. The conductor layer structure 106A, 106B, 106C is preferably made of an electrically and thermally conductive material, in particular copper, and consists of a plurality of triplets of rectangular surfaces 106A, 106B, 106C on the insulating layer 104. For each triplet of rectangular surfaces 106A, 106B, 106C, a triplet 108 of copper elements or heat distributors 108A, 108B, 108C is provided. It should be noted that the surfaces 106A, 106B, 106C can also have a shape other than a rectangle, in particular, the surfaces can be triangular, oval or circular, or consist of one or more polygons.

[0040] Figure 2 The three copper elements 108A, 108B, 108C of such a triplet 108 are shown in more detail. More specifically, Figure 2A copper element 108A is shown as a heat distributor and a negative terminal for the switching bridge, a copper element 108B is shown as a heat distributor and a phase current terminal for the low-side semiconductor of the switching bridge, and a copper element 108C is shown as a heat distributor and a positive terminal for the high-side semiconductor of the switching bridge. The shape and size of the copper elements 108A, 108B, 108C are matched to the shape and size of the rectangular surfaces 106A, 106B, 106C, respectively. Each copper element 108A, 108B, 108C has two block-shaped elements as spacers 109, which are designed to be connected to one or more busbars.

[0041] Figure 3 A top view of a switching bridge 108 is shown according to an exemplary embodiment, which is also shown in FIG. Figure 1 The switching bridge has three copper elements 108A, 108B, 108C, which have just been combined Figure 1 and Figure 2 Semiconductor components 110 , 112 are placed on the copper elements 108B and 108C, which are at least partially surrounded by an insulating material 114 and are connected by means of bonding wires or bonding ribbons 111 .

[0042] Figure 4 A flow chart 120 of a method for manufacturing a power module 100 according to an exemplary embodiment is shown. The method begins at 122 with providing a cooler 102. At 124, an insulating layer 104 is formed on a surface of the cooler 102, and at 126, a conductor layer structure 106A, 106B, 106C is formed on the insulating layer 104. At 128, a plurality of copper elements 108A, 108B, 108C are provided, each having an upper side and a lower side, wherein the upper side is configured for forming an electrical terminal for the electronic device 110, 112, and the lower side is configured for directly contacting the conductor layer structure 106A, 106B, 106C.

[0043] In the above embodiments, the function of the conductor layer structure as a heat conductor has been particularly emphasized. However, it should be noted that the conductor layer structures 106A, 106B, 106C can also be used as a wiring layer for signals, electrical components or other functions (such as placing a temperature sensor). In other words, the conductor layer structures 106A, 106B, 106C can be used for both heat conduction and electrical conduction.

Claims

1. A power module (100), comprising: - a cooler (102), - an electrically insulating layer (104) on the surface of the cooler, - an electrical conductor layer structure (106A, 106B, 106C) on the side of the insulation layer facing away from the cooler, and - a plurality of heat and current conducting elements (108A, 108B, 108C) made of metal or metal alloy or copper or copper alloy, each having an upper side and a lower side, wherein the heat- and current-conducting elements are arranged via their respective undersides on the side of the conductor layer structure facing away from the cooler and are electrically and thermally connected to the conductor layer structure, - semiconductor components (110, 112) which are each arranged on the upper side of the respective heat and current conducting element and are electrically and thermally connected to the respective heat and current conducting element. 2 . The power module according to claim 1 , wherein the insulating layer is composed of an organic electrically insulating material or a ceramic electrically insulating material. 3 . The power module according to claim 1 , wherein the heat and current conducting element is welded or sintered or adhesively bonded or soldered to the conductor layer structure via the underside. 4 . The power module according to claim 1 , wherein the semiconductor components are respectively soldered or sintered or adhesively bonded or welded to the upper side of the corresponding heat- and current-conducting element. 5 . 5 . The power module according to claim 1 , wherein the conductor layer structure has a plurality of conducting surfaces which are physically and electrically separated from one another. 6 . The power module according to claim 5 , wherein at least one heat and current conducting element is arranged on each of the surfaces, the heat and current conducting element being electrically and thermally connected to the respective corresponding surface. 7 . The power module according to claim 1 , wherein the faces are arranged in triads, wherein the three faces of a respective triad respectively constitute a negative current terminal, a phase current terminal and a positive current terminal of the power module. 8 . The power module according to claim 1 , wherein the heat and current conducting element is designed in the form of a plate or block.

9. The power module according to any of the preceding claims, wherein the heat and current conducting elements are arranged in triads (108), wherein the three heat and current conducting elements of a respective triad respectively constitute a negative current terminal, a phase current terminal and a positive current terminal of the power module.

10. A power module according to any of the preceding claims, further comprising an electrically conductive spacer (109), which is respectively welded or sintered or adhesively bonded or soldered to the upper side of the corresponding heat and current conducting element and is provided for establishing an electrical connection between the heat and current conducting element on the one hand and an external electrical contact partner of the power module on the other hand, and at the same time for creating a spatial separation between the heat and current conducting element on the one hand and the external electrical contact partner on the other hand. 11 . The power module according to claim 10 , wherein the spacer is configured in a block shape or a column shape.

12. A method for producing a power module according to any one of the preceding claims, the method comprising the following steps: - providing (122) a cooler (102), - forming (124) an electrically insulating layer (104) on the surface of the cooler, - forming (126) a conductor layer structure (106A, 106B, 106C) on the side of the insulating layer facing away from the cooler, - providing (128) a plurality of heat and current conducting elements (108A, 108B, 108C) made of metal or metal alloy or copper or copper alloy, each having an upper side and a lower side, - arranging the heat- and current-conducting element on the side of the conductor layer structure facing away from the cooler, wherein the heat- and current-conducting element is placed on the conductor layer structure via its respective underside and is electrically and thermally connected to the conductor layer structure, - arranging semiconductor devices (110, 112) onto respective corresponding heat and current conducting elements and electrically and thermally connecting said semiconductor devices to respective corresponding heat and current conducting elements.

13. A converter having a power module according to any one of claims 1 to 11.

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