CN111987005A - Method for producing power semiconductor modules and power semiconductor modules - Google Patents

Abstract

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

Description

Method for producing power semiconductor modules and power semiconductor modules

technical field

The invention relates to a method for producing a power semiconductor module and a power semiconductor module.

Background technique

DE 10 2013 104 949 B3 discloses a power semiconductor module with a substrate, a power semiconductor component and a membrane composite, wherein the membrane composite is electrically conductively connected to the power semiconductor component and the substrate by means of a pressure sintered connection.

The creation of a pressure sintered connection is technically complex because it requires the application of pressure and temperature to the elements to be connected to each other. Furthermore, high compressive loads can damage power semiconductor components and, for example, in the case of DCB substrates or AMB substrates, damage to the ceramic layers of the substrates.

SUMMARY OF THE INVENTION

The object of the present invention is to create an efficient method for producing power semiconductor modules, and a power semiconductor module that can be produced efficiently.

This object is achieved by a method for producing a power semiconductor module, which method has the following processing steps:

a) Providing a power semiconductor assembly having: a substrate having a non-conductive insulating layer on which a first conductor track and a second conductor track are arranged; and a power semiconductor component, the power semiconductor component is arranged on the second conductor track of the substrate and has a first power terminal on its first main side facing the second conductor track and on its side facing away from the second conductor track There is a second power terminal on the second main side, the first power terminal is conductively connected to the second conductor track,

b) providing 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 all 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 a direction normal to the first film connection region, the first film the connection area is arranged at a first height level, the second membrane connection area is arranged at a second height level higher than the first height level,

c) arranging the conductive adhesive on the first and second film connection areas of the embossed film composite and/or on the first conductor tracks and the second power terminals,

d) Disposing the embossed film composite on the substrate such that a first portion of the adhesive is in mechanical contact with the first film attachment area and the first conductor track, and a second portion of the adhesive is in mechanical contact with the second film attachment area and the first conductor track; The two power terminals are in mechanical contact,

e) Hardening the adhesive.

Furthermore, the object is achieved by a power semiconductor module having a base with an electrically non-conductive insulating layer, on a first main side of the electrically non-conductive insulating layer a first conductor track and a second conductor are arranged a track; and a power semiconductor component arranged on a second conductor track of the substrate and having a first power terminal on a first main side of the power semiconductor component facing the second conductor track, on the power semiconductor The second main side of the component facing away from the second conductor track has a second power terminal, wherein the first power terminal is connected in an electrically conductive manner to the second conductor track; and the power semiconductor module has an embossed film compound, which is pressed The flower film composite has a non-conductive 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 is connected to the first film a second membrane attachment region spaced apart from the membrane attachment region, wherein the embossed film composite is embossed such that the first membrane attachment region is arranged at a first height level in the direction normal to the first membrane attachment region, The second film connection area is arranged at a second height level higher than the first height level; and the power semiconductor module has an electrically conductive hardening adhesive, wherein a first portion of the adhesive connects the first film connection area in an electrically conductive manner to the first conductor track, and a second portion of the adhesive conductively connects the membrane connection area to the second power terminal.

The advantageous design of the method results in a similar way to the advantageous design of the power semiconductor module, and vice versa.

It proves to be advantageous if, in a further processing step f), at least one cavity arranged between the membrane composite and the power semiconductor component is completely filled with a non-conductive potting compound. This provides very reliable electrical isolation between certain sections of the membrane composite and the power semiconductor components.

It proves to be advantageous if the embossed film composite has an electrically conductive third film structured to form film conductor tracks, and the first film is arranged between the second film and the third film. This enables simple routing of the conductors for the current flowing through the membrane composite.

In this case, if the embossed film composite has conductive vias through the first film, wherein the conductive vias conductively connect the first and second film connection regions to the third film, then proved to be beneficial. This enables simple routing of the conductors of the current flowing through the membrane composite.

Furthermore, if the embossed film composite is embossed such that when processing step d) is carried out, the embossed film composite aligned with the surrounding area of the edge of the power semiconductor component has an arched profile above said surrounding area, wherein the apexes of the arches formed by the arched profiles are arranged on the side of the membrane composite facing the substrate at a third height level higher than the second height level in the normal direction of the first membrane connection area , it turns out to be beneficial. This reliably prevents mechanical contact of the film composite with the mechanically sensitive edge regions of the power semiconductor component. Furthermore, this facilitates the arrangement of a potting compound, in particular a soft or hard potting compound, between the film composite and the edge region of the power semiconductor component.

Furthermore, it proves to be advantageous if, in the process step b) for providing the embossed film composite, a process for producing an embossed film composite is carried out with the following process steps:

b1) arranging the unembossed film composite between the first die and the second die of the press,

b2) performing embossing on the unembossed film composite by performing relative movement of the first and second stamps towards each other so that the first and second stamps are pressed against the unembossed film composite to form an embossed film composite from an unembossed film composite, wherein the first stamp and/or the second stamp have a geometry such that, after embossing, in the normal direction of the first film connection area , the first membrane connection area is arranged at a first height level, the second membrane connection area is arranged at a second height level higher than the first height level,

b3) Remove the embossed film composite from the press.

In this case, if, in process step b2), the first and second stampers have a geometry such that when process step d) is performed, the embossings are aligned with the surrounding area of the edge of the power semiconductor component The membrane composite has an arched profile above the surrounding area, wherein the apex of the arch formed by the arched profile is at a third height level higher than the second height level in the normal direction of the first membrane connection area It has proven to be advantageous to be arranged on the side of the membrane composite facing the substrate. This reliably prevents mechanical contact of the film composite with mechanically sensitive edge regions of the power semiconductor components in the power semiconductor module. Furthermore, this facilitates the arrangement of a potting compound, in particular a soft or hard potting compound, between the film composite and the edge region of the power semiconductor component.

Additionally, if the first die has a rigid geometry and the second die is formed of an elastomeric material, or if the second die has a rigid geometry and the first die is formed of an elastomeric material, or if the first die and The second die has a rigid geometry, wherein the first die and the second die have convex and concave geometries relative to each other, it proves to be advantageous. This results in efficient embossing of the unembossed film composite.

Description of drawings

Exemplary embodiments of the present invention are described below with reference to the drawings listed below. In the attached image:

Figure 1 shows a power semiconductor assembly and an embossed film composite,

Figure 2 shows a power semiconductor assembly and an embossed film composite with a conductive adhesive disposed on the embossed film composite,

Figure 3 shows a power semiconductor module according to the present invention, and

Figure 4 shows a press and an unembossed film composite arranged in the press for embossing purposes.

Identical elements in the figures are marked with the same reference numerals.

specific embodiment

The method for producing the power semiconductor module 1 is described below (see FIG. 3 ).

In processing step a), an example of which is shown in FIG. 1 , a power semiconductor assembly 2 is provided. In the exemplary embodiment, the power semiconductor component 2 has a substrate 3 with a non-conductive insulating layer 4, on a first main side 4a of the non-conductive insulating layer 4 a first conductive conductor track 5a and a second conductive conductor track 5a are arranged conductor track 5b, and a conductive third conductor track 5c. The substrate 3 preferably has an electrically conductive, preferably unstructured, metallization layer 6, between which an insulating layer 4 is arranged and the conductor tracks 5a, 5b and 5c. The insulating layer 4 is preferably designed as a ceramic plate. The substrate 3 may be implemented, for example, as a direct copper bonding 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).

The power semiconductor assembly 2 also has a power semiconductor component 7 arranged on the second conductor track 5b of the substrate 3, which power semiconductor component has a first power terminal 9a on its first main side 8a facing the second conductor track 5b, and On its second main side 8b facing away from the second conductor track 5b there is a second power terminal 9b, wherein the first power terminal 9a is connected to the second conductor track 5b in an electrically conductive manner, preferably via soldered or sintered metal Layer 21. The power semiconductor component 7 is preferably in the form of a transistor, eg an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) or a diode. In the exemplary embodiment, the power semiconductor component 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 can also form the gate terminal of the IGBT.

In processing step b) (an example of this processing step is additionally shown in FIG. 1 ), an embossed film composite 10 is provided, which has a non-conductive first film 11 and is arranged on the first A conductively structured second film 12 on the film 11, wherein the second film 12 is structured such that it has a first film connection region 12a, a second film connection region 12b arranged separately from the first film connection region 12a, and It is preferably a third membrane connecting region 12c arranged separately from the first membrane connecting region 12a and the second membrane connecting region 12b. The membrane connection regions 12 a , 12 b and 12 c can also be present in the form of membrane conductor track sections, which can be implemented by structuring the second membrane 12 . The embossed film composite 10 preferably has an electrically conductive third film 13 structured to form film conductor tracks 13a and 13b, the first film 11 being arranged between the second film 12 and the third film 13 between. The first film 11 is connected to the second film 12 and the third film 13 in a material-bonded manner. The second film 12 and the third film 13 are preferably formed of metal films. The first film is preferably embodied as a plastic film. Of course, the film composite 10 may have one or more further structured or unstructured conductive films (eg metal films), with a non-conductive film (eg plastic film) arranged between each conductive film. Each metal film may have a single layer or multiple metal layers stacked on top of each other. The embossed film composite 10 preferably has conductive vias 14 through the first film 11 that electrically connect the first, second, and third film connection regions 12a, 12b, and 12c, respectively to the third membrane 13 .

The embossed film composite 10 in the present invention is embossed such that, 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. It should be noted that, for the purposes of the present 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, which normal The direction extends toward the first film 11 .

In a subsequent processing step c) (an example of this processing step is shown in FIG. 2 ), an electrically conductive adhesive 15 is arranged in the first 12a, second 12b film connection areas of the embossed film composite 10 and the third film connection region 12c and/or are arranged on the first conductor track 5a, on the second power terminal 9b and on the third conductor track 5c. Conductive adhesives are part of the general state of the art. The electrical conductivity of the adhesive is preferably achieved by at least one conductive filler material, such as silver particles, which is added to the bonding matrix. The conductive binder can be present, for example, in the form of a sintered binder.

In a subsequent processing step d) (an example of this processing step is shown in FIG. 3 ), the embossed film composite 10 is arranged on the substrate 3 such that the first portion 15a of the adhesive 15 is connected to the first film area 12a is in mechanical contact with the first conductor track 5a, the second part 15b of the adhesive 15 is in mechanical contact with the second film connection area 12b and the second power terminal 9b, and the third part 15c of the adhesive 15 is in mechanical contact with the third film connection area 12c is in mechanical contact with the third conductor track 5c. The embossed film composite 10 is preferably embossed such that when processing step d) is carried out, the embossed film composite 10 aligned with the surrounding area U of the edge 7' of the power semiconductor component 7 has above said surrounding area U. An arched profile in which the apex SP of the arch formed by the arched profile B is arranged on the membrane at a third height level H3 higher than the second height level H2 in the normal direction N of the first membrane connecting region 12a. On the side 10a of the composite 10 facing the substrate 3 . The surrounding area U of the edge 7' of the power semiconductor component 7 extends slightly beyond the edge 7' of the power semiconductor component 7 .

In a subsequent processing step e), as shown by way of example in FIG. 3 , the adhesive 15 is hardened, for example by applying temperature or UV radiation to the adhesive 15 .

In the present invention, efficient production of power semiconductor modules 1 is enabled by forming the film composite into an embossed film composite 10 , in conjunction with forming a conductive adhesive for electrically contacting the film composite 10 to the power semiconductor assembly 2 . become possible.

In a processing step f), which is preferably carried out subsequently, at least one cavity 22 arranged between the membrane composite 10 and the power semiconductor component 2 is completely filled with a non-conductive potting compound, in particular a soft or hard potting compound. The potting compound can be formed, for example, as a silicone potting compound or an epoxy potting compound.

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

Alternatively, in order to provide the embossed film composite 10 in process step b) (an example of which is shown in FIG. 4 ), the method for producing the embossed film composite 10 can be carried out by the following process steps .

In a first method step b1), the unembossed film composite 10' The unembossed film composite 10' is identical to the embossed film composite 10 except for the feature that the unembossed film composite has not been embossed.

In a subsequent process step b2), the unembossed film composite 10' is embossed by performing a relative movement of the first stamp 16 and the second stamp 17 towards each other, so that the first stamp 16 and the second stamp 17 are embossed The second stamper 17 is pressed onto the unembossed film composite 10', thereby forming the embossed film composite 10 from the unembossed film composite 10'. The first stamp 16 and/or the second stamp 17 have a geometry such that after embossing, in the normal direction N of the first film connecting region 12a, the first film connecting region 12a is arranged at a first height level At H1, the second membrane connection region 12b is arranged at a second height level H2 higher than the first height level H1. In the exemplary embodiment, the press 20 has a first pressing element 18 on which the first pressing die 16 is arranged and a second pressing element 19 on which the second pressing element 19 is arranged Modulo 17. In order to carry out the relative movement of the first pressing die 16 and the second pressing die 17 towards each other, in the exemplary embodiment, the first pressing element 18 is moved towards the second pressing element 19 , this movement being shown by arrows in FIG. 1 . Alternatively, the second pressing element 19 can also be moved towards the first pressing element 18 .

In process step b2), the first stamper 16 and/or the second stamper 17 preferably have a geometry such that when process step d) is carried out, an area U aligned with the surrounding area U of the edge 7' of the power semiconductor component 7 The embossed film composite 10 has an arched profile above said surrounding area U, wherein the apex SP of the arch formed by the arched profile B is in the normal direction N of the first film connection area 12a, above the second A third height level H3 of the height level H2 is arranged on that side 10a of the membrane composite 10 facing the substrate 3 .

The first stamp 16 may have a rigid geometry and the second stamp 17 may be made of an elastic material. Alternatively, the second stamp 17 may have a rigid geometry and the first stamp 16 may be made of an elastic material. For example, the elastic material may be formed of silicone. Alternatively, the first dies 16 and the second dies 17 may have rigid geometries, the first 16 and the second dies 17 having convex and concave geometries relative to each other, which are used in FIG. 4 . Dotted lines are drawn.

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

It should be noted here that the features of the different exemplary embodiments of the invention may of course be freely combined with each other, as long as the features are not mutually exclusive.

Claims (9)

1. Method for manufacturing a power semiconductor module (1), comprising the following process steps:

a) providing a power semiconductor component (2), the power semiconductor component (2) having: a substrate (3) having a non-conductive insulating layer (4) on a first main side (4a) of which a first and a second conductor track (5a, 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), the embossed film composite (10) having a first film (11) which is electrically non-conductive and a second structured film (12) which is electrically conductive and which is arranged on the first film, wherein the second film (12) is structured such that the film has a first film connection region (12a) and a second film connection region (12b) which is arranged separately from the first film connection region (12a), wherein the embossed film composite (10) is embossed such that, in a 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),

c) arranging a conductive adhesive (15) on the first and second film connection areas (12a, 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 region (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 region (12b) and the second power terminal (9b),

e) hardening the adhesive (15).

2. Method according to claim 1, having the following process steps:

f) at least one cavity (22) arranged between the membrane composite (10) and the power semiconductor component (2) is filled with a non-conductive potting compound.

3. The method according to any one of the preceding claims, characterized in that the embossed film composite (10) has a third film (13) which is electrically conductive, which is structured to form film conductor tracks (13a, 13b), and the first film (11) is arranged between the second and third films (12, 13).

4. The method according to claim 3, characterized in that the embossed film composite (10) has conductive vias (14) through the first film (11) which connect the first and second film connection regions (12a, 12b) to the third film (13) in a conductive manner.

5. Method according to any one of claims 1 to 2, characterized in that the embossed film composite (10) is embossed such that, when carrying out the processing step d), the embossed film composite (10) aligned with a surrounding area (U) of an edge (7') of the power semiconductor component (7) has an arched profile above the surrounding area (U), wherein an apex (SP) of an arch formed by the arched profile (B) is arranged on that side (10a) of the film composite (10) facing the substrate (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 according to claim 5, characterized in that in the processing 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 processing steps:

b1) arranging an unembossed film composite (10') between a first and a second die (16, 17) of a press (20),

b2) -embossing the unembossed film composite (10 ') by performing a relative movement of the first and second stamps (16, 17) towards each other such that the first and second stamps (16, 17) are pressed against the unembossed film composite (10 ') thereby forming the embossed film composite (10) from the unembossed film composite (10 '), wherein the first and/or second stamp (16, 17) has a geometry such that after the embossing 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) higher than the first height level (H1) in a normal direction (N) of the first film connection region (12a),

b3) removing the embossed film composite (10) from the press (20).

7. Method according to claim 6, characterized in that in process step B2), the first and/or the second stamp (16, 17) has a geometry such that, when process step d) is performed, the embossed film composite (10) aligned with a surrounding area (U) of the edge (7') of the power semiconductor component (7) has an arched profile above the surrounding area (U), wherein an apex (SP) of an arch formed by the arched profile (B) is arranged on that side (10a) of the film composite (10) facing the substrate (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. Method according to claim 6, characterized in that the first stamp (16) has a rigid geometry and the second stamp (17) is formed of an elastic material, or the second stamp (17) has a rigid geometry and the first stamp (16) is formed of an elastic material, or the first and second stamps (16, 17) have a rigid geometry, wherein the first and second stamps (16, 17) have a convex and concave geometry with respect to each other.

9. A power semiconductor module having: a substrate (3) having a non-conductive insulating layer (4) on a first main side (4a) of which a first and a second conductor track (5a, 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; and the power semiconductor module has an embossed film composite (10), the embossed film composite (10) having a first film (11) which is electrically non-conductive and a second, electrically conductive, structured film (12) which is arranged on the first film, wherein the second film (12) is structured such that the film has a first film connection region (12a) and a second film connection region (12b) which is arranged separately from the first film connection region (12a), wherein the embossed film composite (10) is embossed such that, in a 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); and having an electrically conductive hardened 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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