Method for producing a power semiconductor module and power semiconductor module

Abstract

The invention relates to a method for producing a power semiconductor module and a power semiconductor module, the method having the following process steps: a) providing a power semiconductor arrangement having a base and power semiconductor components, b) providing an embossed film composite, wherein the embossed film composite is embossed such that, in the direction of the normal to a first film connection region of the film composite, the first film connection region is arranged at a first height level and a second film connection region is arranged at a second height level which is higher than the first height level, c) arranging an electrically conductive adhesive on the first and second film connection regions of the embossed film composite and / or on a first conductor track and a second power terminal, d) arranging the embossed film composite on the base such that a first portion of adhesive is in mechanical contact with the first film connection region and the first conductor track and a second portion of adhesive is in mechanical contact with the second film connection region and the second power terminal, e) hardening the adhesive.

Description

Technical Field

[0001] This invention relates to a method for producing power semiconductor modules and a power semiconductor module. Background Technology

[0002] DE 10 2013 104 949 B3 discloses a power semiconductor module having a substrate, a power semiconductor component, and a film composite, wherein the film composite is electrically connected to the power semiconductor component and the substrate by pressure sintering.

[0003] The formation of pressure-bonded connections is technically complex because it requires applying pressure and temperature to the components to be connected. Furthermore, high pressure loads can damage power semiconductor components and, in the case of DCB or AMB substrates, damage the ceramic layer of the substrate. Summary of the Invention

[0004] The purpose of this invention is to create an efficient method for producing power semiconductor modules, and a power semiconductor module that can be produced efficiently.

[0005] This objective is achieved through a method for producing power semiconductor modules, which includes the following processing steps:

[0006] a) A power semiconductor assembly is provided, the power semiconductor assembly comprising: a substrate having a non-conductive insulating layer, on which a first conductor track and a second conductor track are disposed; and a power semiconductor component disposed on the second conductor track of the substrate, the power semiconductor component having a first power terminal on its first main side facing the second conductor track and a second power terminal on its second main side facing away from the second conductor track, the first power terminal being conductively connected to the second conductor track.

[0007] b) Provide an embossed film composite having a non-conductive first film and a conductive second structured film disposed on the first film, wherein the second film is structured such that it has a first film connection region and a second film connection region disposed separately from the first film connection region, wherein the embossed film composite is embossed such that, in the normal direction of the first film connection region, the first film connection region is disposed at a first height level, and the second film connection region is disposed at a second height level higher than the first height level.

[0008] c) Arrange conductive adhesive on the first and second film-connecting regions of the embossed film composite, and / or arrange it on the first conductor track and the second power terminal.

[0009] d) The embossed film composite is disposed on the substrate such that a first portion of the adhesive is in mechanical contact with the first film bonding region and the first conductor track, and a second portion of the adhesive is in mechanical contact with the second film bonding region and the second power terminal.

[0010] e) To harden the adhesive.

[0011] Furthermore, this objective is achieved by a power semiconductor module comprising: a substrate having a non-conductive insulating layer, on which a first conductor track and a second conductor track are disposed; and a power semiconductor component disposed on the second conductor track of the substrate, having a first power terminal on the first main side of the power semiconductor component facing the second conductor track, and a second power terminal on the second main side of the power semiconductor component facing away from the second conductor track, wherein the first power terminal is conductively connected to the second conductor track; and the power semiconductor module having an embossed film composite having a non-conductive insulating layer. The power semiconductor module comprises an electrical first film and a conductive structured second film disposed on the first film, wherein the second film is structured such that the film has a first film connection region and a second film connection region disposed separately from the first film connection region, wherein the embossed film composite is embossed such that, in the normal direction of the first film connection region, the first film connection region is disposed at a first height level, and the second film connection region is disposed at a second height level above the first height level; and the power semiconductor module has a conductive hardening adhesive, wherein a first portion of the adhesive conductively connects the first film connection region to a first conductor track, and a second portion of the adhesive conductively connects the film connection region to a second power terminal.

[0012] Advantageous designs of the method are derived in a manner similar to advantageous designs of power semiconductor modules, and vice versa.

[0013] It proves advantageous if, in a further processing step f), at least one cavity disposed between the film composite and the power semiconductor component is completely filled with a non-conductive potting compound. This provides very reliable electrical insulation between certain sections of the film composite and the power semiconductor component.

[0014] It is advantageous if the embossed film composite has a conductive third film structured to form conductor tracks, and the first film is disposed between the second and third films. This enables simple wiring of the conductors for the current flowing through the film composite.

[0015] In this case, it proves advantageous if the embossed film composite has conductive vias that pass through the first film, wherein the conductive vias conductively connect the first film connection region and the second film connection region to the third film. This enables simple wiring of the conductor through which the current flows through the film composite.

[0016] Furthermore, it is advantageous if the embossed film composite is embossed such that, when processing step d), the embossed film composite, aligned with the surrounding area of ​​the power semiconductor component's edge, has an arched profile above said surrounding area, wherein the apex of the arch formed by the arched profile is arranged on the substrate-facing side of the film composite at a third height level above the second height level, in the normal direction of the first film connection region. This reliably prevents mechanical contact between the film composite and the mechanically sensitive edge region of the power semiconductor component. Furthermore, this facilitates the placement of a potting compound, particularly a soft or hard casting, between the film composite and the edge region of the power semiconductor component.

[0017] Furthermore, it proves advantageous to produce the embossed film compound by performing a method having the following processing steps in step b) of the processing step for providing the embossed film compound:

[0018] b1) An unembossed film composite is arranged between the first and second dies of the press.

[0019] b2) Embossing is performed on the unembossed film composite by performing relative movement of the first and second dies toward each other, such that the first and second dies press onto the unembossed film composite, thereby forming an embossed film composite from the unembossed film composite, wherein the first and / or second dies have a geometry such that, after embossing, in the normal direction of the first film connection region, the first film connection region is arranged at a first height level, and the second film connection region is arranged at a second height level higher than the first height level.

[0020] b3) Remove the embossed film compound from the press.

[0021] In this case, it proves advantageous if, in processing step b2), the first and second dies have a geometry such that, when processing step d), the embossed film composite aligned with the peripheral region of the power semiconductor component's edge has an arched profile above said peripheral region, wherein the apex of the arch formed by the arched profile is arranged on the substrate-facing side of the film composite at a third height level above the second height level, in the normal direction of the first film connection region. This reliably prevents mechanical contact between the film composite and the mechanically sensitive edge region of the power semiconductor component in the power semiconductor module. Furthermore, this facilitates the placement of a potting compound, particularly a soft or hard casting, between the film composite and the edge region of the power semiconductor component.

[0022] Furthermore, it proves advantageous if the first die has a rigid geometry and the second die is formed of an elastic material, or if the second die has a rigid geometry and the first die is formed of an elastic material, or if both the first and second dies have rigid geometries, wherein the first and second dies have convex and concave geometries relative to each other. This leads to highly efficient embossing of the unembossed film composite. Attached Figure Description

[0023] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings listed below. In the drawings:

[0024] Figure 1 The power semiconductor component and the embossed film composite are shown.

[0025] Figure 2 A power semiconductor component and an embossed film composite are shown, wherein a conductive adhesive is disposed on the embossed film composite.

[0026] Figure 3 A power semiconductor module according to the present invention is shown, and

[0027] Figure 4 A press and an un-embossed membrane composite arranged in the press for embossing purposes are shown.

[0028] The same elements in the accompanying drawings are labeled with the same reference numerals. Specific Implementation

[0029] The following describes a method for producing power semiconductor module 1 (see Figure 3 ).

[0030] In processing step a) (an example of this processing step is shown in...) Figure 1As shown in the figure, a power semiconductor component 2 is provided. In an exemplary embodiment, the power semiconductor component 2 has a substrate 3 having a non-conductive insulating layer 4, on which a first conductive conductor track 5a, a second conductive conductor track 5b, and a conductive third conductor track 5c are arranged. The substrate 3 preferably has a conductive, preferably unstructured, metallization layer 6, and the insulating layer 4 is disposed between the metallization layer 6 and the conductor tracks 5a, 5b, and 5c. The insulating layer 4 is preferably designed as a ceramic plate. The substrate 3 can be implemented as, for example, a direct copper bond substrate (DCB substrate) or an active metal brazing substrate (AMB substrate). Alternatively, the substrate 3 can also be implemented as an insulating metal substrate (IMS substrate).

[0031] The power semiconductor component 2 also has a power semiconductor element 7 disposed on a second conductor track 5b of the substrate 3. This power semiconductor element has a first power terminal 9a on its first main side 8a facing the second conductor track 5b and a second power terminal 9b on its second main side 8b facing away from the second conductor track 5b. The first power terminal 9a is conductively connected to the second conductor track 5b, preferably via a soldered or sintered metal layer 21. The power semiconductor element 7 is preferably in the form of a transistor such as an IGBT (Insulated Gate Bipolar Transistor), a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), or a diode. In an exemplary embodiment, the power semiconductor element 7 is designed as an IGBT, wherein the first power terminal 9a forms the collector terminal of the IGBT, and the second power terminal 9b forms the emitter terminal of the IGBT. Alternatively, the second power terminal 9b may also form the gate terminal of the IGBT.

[0032] In processing step b) (an example of this processing step is shown in...) Figure 1(As shown separately), an embossed film composite 10 is provided, having a non-conductive first film 11 and a conductive, structured second film 12 disposed on the first film 11. The second film 12 is structured such that it has a first film connection region 12a, a second film connection region 12b disposed separately from the first film connection region 12a, and preferably a third film connection region 12c disposed separately from the first film connection region 12a and the second film connection region 12b. The film connection regions 12a, 12b, and 12c may also exist in the form of film conductor track segments, which can be implemented by structuring the second film 12. The embossed film composite 10 preferably has a conductive third film 13, which is structured to form film conductor tracks 13a and 13b, with the first film 11 disposed between the second film 12 and the third film 13. The first film 11 is bonded to the second film 12 and the third film 13 by material bonding. The second film 12 and the third film 13 are preferably formed of metal films. The first film is preferably implemented as a plastic film. Of course, the membrane composite 10 may have one or more further structured or unstructured conductive films (e.g., metal films), with a non-conductive film (e.g., a plastic film) disposed between each conductive film. Each metal film may have a single layer or multiple metal layers stacked on top of each other. The embossed membrane composite 10 preferably has a conductive via 14 passing through the first membrane 11, which conductive via conductively connects the first membrane connection region 12a, the second membrane connection region 12b, and the third membrane connection region 12c to the third membrane 13, respectively.

[0033] In this invention, the embossed film composite 10 is embossed such that, along the normal direction N of the first film connection region 12a, the first film connection region 12a is arranged at a first height level H1, and the second film connection region 12b is arranged at a second height level H2, which is higher than the first height level H1. It should be noted that, for the purposes of this invention, the normal direction N of the first film connection region 12a is the normal direction N of the surface of the first film connection region 12a facing away from the first film 11, and this normal direction extends towards the first film 11.

[0034] In subsequent processing step c) (an example of this processing step is shown in...) Figure 2 As shown in the diagram, conductive adhesive 15 is disposed on the first film bonding region 12a, the second film bonding region 12b, and the third film bonding region 12c of the embossed film composite 10 and / or disposed on the first conductor track 5a, the second power terminal 9b, and the third conductor track 5c. The conductive adhesive is part of the general state of the prior art. The conductivity of the adhesive is preferably achieved by at least one conductive filler material (e.g., silver particles) added to the bonding matrix. The conductive adhesive may be present, for example, in the form of a sintered adhesive.

[0035] In the subsequent processing step d) (an example of this processing step is shown in...) Figure 3 As shown in the diagram, the embossed film composite 10 is disposed on the substrate 3 such that a first portion 15a of the adhesive 15 is in mechanical contact with the first film connection region 12a and the first conductor track 5a, a second portion 15b of the adhesive 15 is in mechanical contact with the second film connection region 12b and the second power terminal 9b, and a third portion 15c of the adhesive 15 is in mechanical contact with the third film connection region 12c and the third conductor track 5c. The embossed film composite 10 is preferably embossed such that, when processing step d) is performed, the embossed film composite 10, aligned with the surrounding region U of the edge 7' of the power semiconductor component 7, has an arched profile above said surrounding region U, wherein the apex SP of the arch formed by the arched profile B is disposed on the side 10a of the film composite 10 facing the substrate 3 at a third height level H3 above the second height level H2 in the normal direction N of the first film connection region 12a. The surrounding region U of the edge 7' of the power semiconductor component 7 extends slightly beyond the edge 7' of the power semiconductor component 7.

[0036] In the subsequent processing step e), such as Figure 3 As shown in the example, adhesive 15 is hardened, for example by applying temperature or ultraviolet radiation to adhesive 15.

[0037] In this invention, by forming a membrane composite into an embossed membrane composite 10, together with a conductive adhesive for electrically contacting the membrane composite 10 to the power semiconductor module 2, efficient production of the power semiconductor module 1 becomes possible.

[0038] In a preferred subsequent processing step f), at least one cavity 22 disposed between the film composite 10 and the power semiconductor component 2 is completely filled with a non-conductive potting compound, particularly a soft or hard casting. The potting compound may be formed, for example, a silicone potting compound or an epoxy potting compound.

[0039] In the simplest case, in processing step b), the embossed film compound 10 can be provided by making the embossed film compound 10 available in the form of a prefabricated part.

[0040] Alternatively, in processing step b) (an example of this processing step is shown in...), Figure 4 (as shown in the figure) provides an embossed film composite 10, and the method for producing the embossed film composite 10 can be carried out by the following processing steps.

[0041] In the first method step b1), the unembossed film composite 10' is arranged between the first die 16 and the second die 17 of the press 20. Except for the feature that the unembossed film composite is not yet embossed, the unembossed film composite 10' is the same as the embossed film composite 10.

[0042] In the subsequent processing step b2), the unembossed film composite 10' is embossed by performing relative movement of the first mold 16 and the second mold 17 toward each other, such that the first mold 16 and the second mold 17 press onto the unembossed film composite 10', thereby forming an embossed film composite 10 from the unembossed film composite 10'. The first mold 16 and / or the second mold 17 have a geometry such that, after embossing, in the normal direction N of the first film connection region 12a, the first film connection region 12a is arranged at a first height level H1, and the second film connection region 12b is arranged at a second height level H2 above the first height level H1. In an exemplary embodiment, the press 20 has a first pressing element 18 and a second pressing element 19, with the first mold 16 arranged on the first pressing element 18 and the second mold 17 arranged on the second pressing element 19. In order to perform relative movement of the first mold 16 and the second mold 17 toward each other, in an exemplary embodiment, the first pressing element 18 moves toward the second pressing element 19, the movement being... Figure 1 The arrow indicates this. Alternatively, the second pressing element 19 may also move toward the first pressing element 18.

[0043] In processing step b2), the first mold 16 and / or the second mold 17 preferably have a geometry such that when processing step d) is performed, the embossed film composite 10, aligned with the surrounding region U of the edge 7' of the power semiconductor component 7, has an arched profile above the surrounding region U, wherein the apex SP of the arch formed by the arched profile B is arranged on the side 10a of the film composite 10 facing the substrate 3 at a third height level H3 above the second height level H2 in the normal direction N of the first film connection region 12a.

[0044] The first mold 16 may have a rigid geometry, and the second mold 17 may be made of an elastic material. Alternatively, the second mold 17 may have a rigid geometry, and the first mold 16 may be made of an elastic material. For example, the elastic material may be formed of silicone resin. Alternatively, the first mold 16 and the second mold 17 may have rigid geometries, with convex and concave geometries relative to each other, which in... Figure 4 It is drawn with a dashed line.

[0045] In the subsequent processing step b3), the embossed film composite 10 is removed from the press 20.

[0046] It should be noted that the features of different exemplary embodiments of the present invention can of course be freely combined with each other, as long as the features are not mutually exclusive.

Claims

1. Method for manufacturing a power semiconductor module (1), comprising the following process steps: a) providing a power semiconductor assembly (2) having a substrate (3) with an electrically non-conductive insulation layer (4) on a first main side (4a) of which a first conductor track (5a) and a second conductor track (5b) are arranged, and a power semiconductor component (7) which is arranged on the second conductor track (5b) of the substrate (3) and has a first power terminal (9a) on a first main side (8a) of the power semiconductor component facing the second conductor track (5b) and a second power terminal (9b) on a second main side (8b) of the power semiconductor component facing away from the second conductor track (5b), wherein the first power terminal (9a) is connected to the second conductor track (5b) in an electrically conductive manner, b) providing an embossed film composite (10) having an electrically non-conductive first film (11) and an electrically conductive structured second film (12) arranged on the first film, wherein the second film (12) is structured such that the second film has a first film connection area (12a) and a second film connection area (12b) arranged separately from the first film connection area (12a), wherein the embossed film composite (10) is embossed such that in the direction of the normal (N) of the first film connection area (12a) the first film connection area (12a) is arranged at a first height level (H1) and the second film connection area (12b) is arranged at a second height level (H2) which is higher than the first height level (H1), c) arranging an electrically conductive adhesive (15) on the first film connection area (12a) and the second film connection area (12b) of the embossed film composite (10) and / or on the first conductor track (5a) and the second power terminal (9b), d) arranging the embossed film composite (10) on the substrate (2) such that a first portion (15a) of the adhesive (15) is in mechanical contact with the first film connection area (12a) and the first conductor track (5a) and a second portion (15b) of the adhesive (15) is in mechanical contact with the second film connection area (12b) and the second power terminal (9b), e) hardening the adhesive (15).

2. Method according to claim 1, having the following process step: f) filling at least one cavity (22) arranged between the film composite (10) and the power semiconductor assembly (2) with an electrically non-conductive potting compound. The embossed film composite (10) has an electrically conductive third film (13) which is structured to form film conductor tracks (13a, 13b) and the first film (11) is arranged between the second film (12) and the third film (13). ​ ​ ​ ​ ​ 3. The method according to any of the preceding claims, characterized in that, ​ 4. The method of claim 3, wherein, The embossed film composite (10) has an electrically conductive via (14) through the first film (11) which electrically conductively connects the first film connection area (12a) and the second film connection area (12b) to the third film (13).

5. The method of any one of claims 1 to 2, wherein, The embossed film composite (10) is embossed in such a way that, when performing the process step d), the embossed film composite (10) aligned with the surrounding area (U) of the edge (7') of the power semiconductor component (7) has an arch-shaped profile over the surrounding area (U), wherein an apex (SP) of an arch formed by the arch-shaped profile (B) is arranged on the side (10a) of the film composite (10) facing the base (3) in the normal direction (N) of the first film connection area (12a) at a third height level (H3) which is higher than the second height level (H2).

6. The method of claim 5, wherein, In the process step b) for providing the embossed film composite (10), a method for producing the embossed film composite (10) is carried out, which method has the following process steps: b1) arranging an unembossed film composite (10') between a first press mold (16) and a second press mold (17) of a press (20), b2) carrying out embossing of the unembossed film composite (10') by performing a relative movement of the first press mold (16) and the second press mold (17) towards one another, so that the first press mold (16) and the second press mold (17) press on the unembossed film composite (10'), thereby forming the embossed film composite (10) from the unembossed film composite (10'), wherein the first press mold (16) and / or the second press mold (17) have a geometry so that, after the embossing, in the normal direction (N) of the first film connection area (12a), the first film connection area (12a) is arranged at a first height level (H1) and the second film connection area (12b) is arranged at a second height level (H2) which is higher than the first height level (H1), b3) removing the embossed film composite (10) from the press (20).

7. The method of claim 6, wherein, In the process step b2), the first press mold (16) and / or the second press mold (17) have a geometry so that, when performing the process step d), the embossed film composite (10) aligned with the surrounding area (U) of the edge (7') of the power semiconductor component (7) has an arch-shaped profile over the surrounding area (U), wherein an apex (SP) of an arch formed by the arch-shaped profile (B) is arranged on the side (10a) of the film composite (10) facing the base (3) in the normal direction (N) of the first film connection area (12a) at a third height level (H3) which is higher than the second height level (H2).

8. The method of claim 6, wherein, The first die (16) has a rigid geometry and the second die (17) is formed of an elastic material, or the second die (17) has a rigid geometry and the first die (16) is formed of an elastic material, or the first die (16) and the second die (17) have a rigid geometry, wherein the first die (16) and the second die (17) have convex and concave geometries with respect to each other.

9. A power semiconductor module having a base (3) with an electrically non-conductive insulation layer (4) on a first main side (4a) of which a first conductor track (5a) and a second conductor track (5b) are arranged, and a power semiconductor component (7) which is arranged on the second conductor track (5b) of the base (3) and has a first power terminal (9a) on a first main side (8a) of the power semiconductor component facing the second conductor track (5b) and a second power terminal (9b) on a second main side (8b) of the power semiconductor component facing away from the second conductor track (5b), wherein the first power terminal (9a) is connected to the second conductor track (5b) in an electrically conductive manner; and having an embossed film composite (10) with an electrically non-conductive first film (11) and an electrically conductive structured second film (12) arranged on the first film, wherein the second film (12) is structured such that the second film has a first film connection region (12a) and a second film connection region (12b) arranged separately from the first film connection region (12a), wherein the embossed film composite (10) is embossed such that in the direction of the normal (N) of the first film connection region (12a) the first film connection region (12a) is arranged at a first height level (HI) and the second film connection region (12b) is arranged at a second height level (H2) which is higher than the first height level (HI); and having an electrically conductive hardening adhesive (15), wherein a first portion (15a) of the adhesive (15) connects the first film connection region (12a) to the first conductor track (5a) in an electrically conductive manner and a second portion (15b) of the adhesive (15) connects the film connection region (12b) to the second power terminal (9b) in an electrically conductive manner.

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