DE102022212323A1 - Power electronics module, method for producing a power electronics module - Google Patents

Abstract

A power electronics module is disclosed, comprising a plurality of semiconductor switching elements (S, S11, S21, S12, S22, S1n, S2n), in particular SiC semiconductor switches or GaN semiconductor switches, a control circuit (GDU1, GDU2) for controlling the plurality of semiconductor switching elements (S, S11, S21, S12, S22, S1n, S2n) and a control line structure (LS1, LS2) formed on a flexible film (11) with a plurality of control lines (12, 121, 122), wherein the control lines (12, 121, 122) each form at least a part of respective direct electrical connections between the control circuit on the one hand (GDU1, GDU2) and the respective semiconductor switching elements (S, S11, S21, S12, S22, S1n, S2n) on the other hand. Furthermore, a method for producing a power electronics module is described.

Description

The present invention relates to the technical field of power electronics. The present invention relates in particular to a power electronics module and a method for producing a power electronics module. Furthermore, a connection arrangement for a power electronics module is provided.

In the area of power electronics modules with switchable power semiconductor components, Si-IGBT switching semiconductor elements are increasingly being replaced by significantly faster switching and thus more efficient WBG semiconductor technologies such as SiC and GaN field effect transistors. The maximum switching speed of these semiconductors is a factor of 10...100 higher than that of Si-IGBT. This allows losses to be reduced both at the semiconductor and product level and important passive components to be significantly reduced in size.

In order to fully exploit the potential of higher switching speeds of WBG semiconductors, in addition to minimizing disruptive parasitic inductances in the load circuit, adjustments to the control circuit and the control signal routing to the semiconductor are also required. Stronger gate feedback as a result of the higher switching speeds, in combination with the lower switching voltage thresholds of the WBG semiconductors at the gate, require control solutions with significantly lower parasitic inductances in the control circuit.

In conventional power electronics modules, parallel-connected semiconductor switching elements are often controlled by a control circuit (Gate Driver Unit - GDU) via a central control line, which distributes the control signal to the semiconductor switching elements. The signal routing thus corresponds to a bus structure.

It has proven difficult to meet the requirements regarding parasitic inductances in such a bus structure. While parasitic inductances in the gate control circuit of 20nH and more are still tolerable in Si-IGBT power electronic modules, the maximum value for SiC and GaN power semiconductors is typically < 5nH per semiconductor. To make matters worse, the requirements for the maximum permissible parasitic inductance in the control circuit increase even further with the level of the gate current. This means that the more semiconductors are connected in parallel to increase the switching power and the faster they are to be operated, the further the maximum value of 5nH must be undercut.

The present invention is based on the object of overcoming the above-mentioned problems in connection with the control of semiconductor switching elements.

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

According to a first aspect of the invention, a power electronics module is described which has (a) a plurality of semiconductor switching elements, in particular WBG semiconductor switching elements (WBG semiconductor: semiconductor with a wide band gap, in English “Wide-Bandgap Semiconductor”), such as SiC and GaN semiconductor switches (SiC: silicon carbide, GaN: gallium nitride) or SiC and GaN field effect transistors, (b) a control circuit for controlling the plurality of semiconductor switching elements and (c) a control line structure formed on a flexible film with a plurality of control lines, wherein (d) the control lines each form at least part of the respective direct electrical connections between the control circuit on the one hand and the respective semiconductor switching elements on the other hand.

The described power electronics module is based on the knowledge that the control line structure is designed in such a way that each individual semiconductor switching element is directly connected to the control circuit. In other words, each individual control line represents at least part of a direct connection between the control circuit and a semiconductor switching element. These direct connections via individual control lines have significantly lower parasitic inductances compared to central control lines (shared by several semiconductor switching elements).

In the context of the present application, the term "at least part of a direct electrical connection" means that the control line itself forms a direct connection between the control circuit and a semiconductor switching element, i.e. the direct connection consists of the control line, or that it forms only part of such a direct connection or an indirect connection. In other words, each control line can form a direct connection or only part of a direct connection between the control circuit and one of the semiconductor switching elements. In the latter case, the control line structure can be connected to another control line structure via a connector, for example, or a gate resistor can be integrated in or on the flexible film.

According to one embodiment, the control lines are designed or shaped (in comparison to one another) in such a way that the parasitic inductances of all control lines are essentially the same, and thus the parasitic inductances of all electrical connections between the control circuit on the one hand and the respective semiconductor switching elements on the other hand are also essentially the same. Here or in this text, the term "essentially" means that the parasitic inductances of all control lines from one another or the parasitic inductances of all electrical connections from one another have a maximum deviation of less than 10% or better less than 5%, even less than 2% or less than 1%.

According to a further embodiment, each control line has a contact element on its section or end section facing the respective semiconductor switching element, which is (directly) physically and electrically connected to an upper-side electrical connection contact surface of the respective corresponding semiconductor switching element or is welded onto this connection contact surface.

In other words, each control line has an electrically conductive contact element on the respective section or end section that is coupled to the semiconductor switching element or faces this semiconductor switching element or is located on or above this semiconductor switching element or its corresponding connection contact surface, which is directly physically and electrically connected to the connection contact surface of the semiconductor switching element, in particular is welded onto the connection contact surface of the semiconductor switching element, for example by means of ultrasonic welding or alternatively by means of laser welding.

According to a further embodiment, the contact element has an electrically conductive pin extending through the section of the respective corresponding control line, which has, at its end facing the respective corresponding semiconductor switching element or its connection contact surface, a contact surface resting on the connection contact surface of the semiconductor switching element, in particular welded onto this connection contact surface.

In other words, the contact element has a pin that extends transversely (i.e. essentially perpendicular to the longitudinal direction of the corresponding control line) through the corresponding section or end section of the control line. At one end of the pin there is an electrical contact surface that is (directly) physically and electrically connected to the connection contact surface or is welded to the connection contact surface of the semiconductor switching element. The contact surface can consist in particular of aluminum or an aluminum alloy. The rest of the contact element can also consist of aluminum or an aluminum alloy or of another material, such as copper or another metal alloy, such as a copper alloy.

This direct physical and electrical connection via an electrically conductive pin, the end of which is welded to the semiconductor switching element, is simple and space-saving, and can be made without additional material build-up (such as in connection with solder or sintered connections).

According to a further embodiment, the pin has a centering element for positioning the pin relative to the respective corresponding semiconductor switching element at its other end facing away from the respective corresponding semiconductor switching element and thus from the aforementioned end.

The centering element facilitates the positioning, holding and welding of the contact element to the connection contact surface of the semiconductor switching element and can in particular be designed as a pin-shaped projection on the top side of the contact element, which can, for example, contribute to better contacting, fixing and energy transfer from an ultrasonic sonotrode during an ultrasonic welding process.

According to a further embodiment, the control line structure or its control lines are designed or shaped in such a way that the longer the conductor length of those control lines in their respective longitudinal direction (compared to the other control lines), the larger the cross-sectional area or the line width of those control lines transverse to their respective longitudinal direction (compared to the other control lines), so that the parasitic inductances and/or DC resistances of all control lines of the same control line structure are essentially the same. In other words: the longest control line of the control line structure has the largest cross-sectional area or the largest line width of all control lines of the control line structure. The second longest control line of the control line structure has the second largest cross-sectional area or the second largest line width of all control lines of the control line structure, etc. Accordingly, the shortest control line of the Control line structure has the smallest cross-sectional area or the smallest line width of all control lines in the control line structure.

The parasitic inductances of all control lines of the same control line structure thus have essentially the same value, which is preferably less than 5 nH. This enables synchronous and fast switching to be achieved.

According to a further embodiment, each semiconductor switching element has two top-side electrical connection contact areas, which are each electrically connected directly to the control circuit by a corresponding pair of control lines. The two connection contact areas can in particular be a gate connection contact area and a Kelvin-source connection contact area of the semiconductor switching element.

According to a further embodiment, the control lines of at least one pair of control lines are arranged flat one above the other and are physically connected to one another and at the same time electrically separated from one another by an electrically insulating layer lying between these two control lines.

In other words, the two control lines of a pair run flat in two different planes or layers and are separated by an insulating layer. This arrangement of the control lines saves space and allows a particularly compact design in which many pairs of control lines can run next to each other in a space-saving manner. This type of arrangement is also optimal in terms of reducing disruptive parasitic inductances in the electrical connections between the control circuit on the one hand and the semiconductor switching elements to be controlled on the other.

According to a further embodiment, the control lines of at least one pair of control lines are arranged flat next to each other.

This design of the control line structure is comparatively material-saving, as the control lines can be installed in a single plane without additional layers, and is therefore cost-effective.

According to a further embodiment, the conductor width and/or the conductor length and/or the conductor thickness and/or the conductor spacing for each pair of control lines are adjusted such that the parasitic inductances and/or DC resistances of all control lines are substantially equal.

wobei l die Länge des (Doppel-)Leiters in mm, b die Breite des Leiters in mm und d den Abstand der Leiter zueinander in mm bezeichnen.The parasitic inductance L (in nH) of two flat conductors arranged one above the other can be approximately calculated using the following formula: $$\text{L}\approx \text{0}\text{,4*}|*\mathrm{\pi }*\text{d}/\text{b},$$

where l is the length of the (double) conductor in mm, b is the width of the conductor in mm and d is the distance between the conductors in mm.

This means, for example, that longer control lines can have the same parasitic inductance as shorter control lines if they are made somewhat wider, at least in sections.

According to a further embodiment, a further flexible (in particular electrically insulating and/or mechanically resistant) film is applied over the control line structure, which protects the control line structure from electrical and/or electromagnetic and/or mechanical interference.

The additional flexible film protects the control line structure and also represents an electrical insulating layer.

According to a further embodiment, the power electronics module further comprises a lower electrically conductive EMC shielding layer under the control line structure and/or an upper electrically conductive EMC shielding layer on the control line structure, which are physically connected to the control line structure and at the same time are electrically insulated from the control line structure or from its control lines and are configured to electromagnetically shield the control line structure or its control lines.

The lower and/or upper electrically conductive shielding layer additionally improves the EMC properties (EMC = electromagnetic compatibility) of the power electronics module.

According to a further embodiment, the power electronics module further comprises a lower electrical insulation layer which physically connects the control line structure to the lower shielding layer and at the same time electrically insulates it from the lower shielding layer, and/or an upper electrical insulation layer which physically connects the control line structure to the upper shielding layer and at the same time electrically insulates it from the upper shielding layer.

According to a further embodiment, the lower shielding layer is in the lower insulation layer embedded in or enclosed by the lower insulating layer, and/or the upper shielding layer embedded in or enclosed by the upper insulating layer.

The EMC shielding layers in the respective insulating layers protect the environment and the power electronics module from the electromagnetic interference generated by the currents flowing in the control line structure or through its control lines.

According to a further embodiment, the lower and/or upper shielding layer are coupled or electrically connected to electrical ground.

According to a second aspect of the invention, a method for producing a power electronics module is described. The described method comprises the following: (a) providing a plurality of semiconductor switching elements, in particular SiC semiconductor switches or GaN semiconductor switches, (b) providing a control circuit for controlling the plurality of semiconductor switching elements, (c) providing a control line structure formed on a flexible film with a plurality of control lines, (d) forming direct electrical connections between the control circuit on the one hand and the respective semiconductor switching elements on the other hand via the respective control lines, wherein the control lines each form at least part of the respective direct electrical connections between the control circuit on the one hand and the respective semiconductor switching elements on the other hand.

The described method is essentially based on the same idea as the power electronics module described above according to the first aspect and in particular provides a method for producing such a power electronics module by connecting each individual semiconductor switching element directly to the control circuit via a corresponding control line.

For example, the control lines will be designed or shaped in such a way that the parasitic inductances of all control lines will be essentially the same.

For example, the control lines are each provided with a contact element at their end facing the respective corresponding semiconductor switching element. The contact elements of the respective control lines are then physically and electrically connected to a top-side connection contact surface of the respective corresponding semiconductor switching elements or welded onto this connection contact surface.

According to a third aspect of the invention, a connection arrangement for a power electronics module is described, wherein the power electronics module has a plurality of semiconductor switching elements, in particular WBG semiconductor switching elements, and a control circuit for controlling the plurality of semiconductor switching elements. The connection arrangement described has (a) a control line structure formed on a flexible film with a plurality of control lines, wherein (b) each control line is designed to form at least part of a direct connection between the control circuit and an individual one of the semiconductor switching elements, and wherein (c) the parasitic inductances of all control lines are substantially the same.

The connection arrangement according to the third aspect can be used in particular in a power electronics module according to the first aspect.

It is noted that embodiments of the invention have been described with reference to different subject matters. In particular, some embodiments of the invention are described with method claims and other embodiments of the invention are described with apparatus claims. However, it will immediately become clear to those skilled in the art upon reading this application that, unless explicitly stated otherwise, in addition to a combination of features belonging to one type of subject matter, any combination of features belonging to different types of subject matter is also possible.

• 1 zeigt ein Leistungselektronikmodul mit gemeinsamen Ansteuerleitungen gemäß dem Stand der Technik.
• 2 zeigt ein Leistungselektronikmodul mit individuellen Ansteuerleitungen gemäß einer Ausführungsform der vorliegenden Erfindung.
• 3 zeigt eine Verbindung zwischen Ansteuerleitung und Halbleiterschaltelement über ein Kontaktelement gemäß einer Ausführungsform der vorliegenden Erfindung.
• 4 zeigt drei verschiedene Ausführungen eines Kontaktelements gemäß Ausführungsformen der vorliegenden Erfindung.
• 5 zeigt eine Draufsicht und eine Seitenansicht eines Paares von Ansteuerleitungen mit Kontaktelementen gemäß einer Ausführungsform der vorliegenden Erfindung.
• 6 zeigt Ansteuerleitungen mit variierender Breite gemäß einer Ausführungsform der vorliegenden Erfindung.
• 7 zeigt verschiedene Anordnungen von Ansteuerleitungen gemäß Ausführungsformen der vorliegenden Erfindung.
• 8 zeigt ein beschichtetes Kontaktelement gemäß einer Ausführungsform der vorliegenden Erfindung.
• 9 zeigt verschiedene Ausführungen von Kontaktelementen gemäß Ausführungsformen der vorliegenden Erfindung.
• 10 zeigt eine Ansteuerleitungsstruktur mit EMV-Abschirmen gemäß einer Ausführungsform der vorliegenden Erfindung.

Further advantages and features of the present invention will become apparent from the following exemplary description of a preferred embodiment.

• 1 shows a power electronics module with common control lines according to the state of the art.
• 2 shows a power electronics module with individual control lines according to an embodiment of the present invention.
• 3 shows a connection between control line and semiconductor switching element via a contact element according to an embodiment of the present invention.
• 4 shows three different designs of a contact element according to embodiments of the present invention.
• 5 shows a top view and a side view of a pair of control lines with Contact elements according to an embodiment of the present invention.
• 6 shows drive lines with varying width according to an embodiment of the present invention.
• 7 shows various arrangements of drive lines according to embodiments of the present invention.
• 8th shows a coated contact element according to an embodiment of the present invention.
• 9 shows various designs of contact elements according to embodiments of the present invention.
• 10 shows a drive line structure with EMC shields according to an embodiment of the present invention.

It should be noted that the embodiments described below represent only a limited selection of possible embodiments of the invention.

The 1 shows a power electronics module with common control lines according to the state of the art. More specifically, the 1 a power electronics module with a half-bridge 1, which has a plurality of pairs of semiconductor switching elements S11, S21, S12, S22, ... S1n, S2n arranged in parallel in a known manner, which are controlled by two control modules GDU1, GDU2 via respective line pairs L1, L2 such that the output line Out is coupled either to the electrical potential HV+ or to the electrical potential HV-. As mentioned at the beginning, this configuration with split pairs of control lines L1, L2 is problematic due to parasitic inductances if the semiconductor switching elements S11, S21, S12, S22, ... S1n, S2n are to be switched quickly and precisely, as is required or desired, for example, in the case of WBG semiconductor switching elements.

The 2 shows a power electronics module with individual control lines according to an embodiment of the present invention. The difference to the 1 The advantage of the power electronics module shown is that the control line structure has two collections of control lines LS1, LS2, wherein each individual semiconductor switching element is connected to the respective control module GDU1, GDU2 via its own pair of control lines.

The control line arrangement LS1, LS2 with an individual connection between each control connection (or control connection contact surface) of the semiconductor switching elements S11, S21, S12, S22, ... S1n, S2n and the respective control module GDU1, GDU2 reduces the parasitic inductances considerably and thus enables faster and more precise switching of the semiconductor switching elements S11, S21, S12, S22, ... S1n, S2n. The embodiments of the present invention described below deal in particular with how the many control lines LS1, LS2 can be advantageously arranged on a flexible film (as a so-called flex film conductor) and connected directly to the semiconductor switching elements S11, S21, S12, S22, ... S1n, S2n via simple contact elements.

The 3 shows a connection between a control line 12 and a semiconductor switching element S via a contact element according to an embodiment of the present invention. The control line 12 is part of a control line structure formed on a flexible film 11 and preferably consists of a flat conductor made of copper or aluminum, which is covered at the top by another flexible film 13. The flexible films 11, 13 are electrically insulating layers and consist of polyimide, for example. The control line 12 protrudes to the right between the films 11, 13 and is connected at this end directly to a connection contact surface 14 of the semiconductor switching element S via a pin 15 as a contact element. In this embodiment, the pin 15 is welded to the connection contact surface 14 by means of ultrasonic welding (US), the pin 15 being exposed to ultrasonic energy on its upper surface 16. The pin 15 is made entirely or partially of aluminum. In the latter case, in particular the part of the pin 15 which is directly adjacent to the connection contact surface 14 is made of aluminium.

The 4 shows three different versions 15a, 15b, 15c of the above in connection with the 3 described pin-shaped contact element 15 according to embodiments of the present invention. In all three embodiments, the contact element 15a, 15b, 15c has a lower rounded section 17 and an upper section 19, which are separated by a groove 18, i.e. a section with a slightly smaller diameter than the sections 17 and 19. The groove 18 preferably fits in a hole running through the end of the control line 12. The rounded shape of the lower section 17 corresponds to the shape of a bonding ball. The upper section 19 of the contact element 15a has a flat surface 16 at the top and thus corresponds in this respect to the 3 The upper section 19 of the contact element 15b, on the other hand, has a centrally mounted and upwardly projecting pin 20 with a smaller diameter than the upper section 19 of the contact element 15b. The pin 20 functions as a centering element and facilitates ultrasonic welding for fastening the contact element 15b to the connection contact surface 14 of the semiconductor switching element S. The upper section 19 of the contact element 15c does not have a pin, but rather a small hemispherical projection 21. The projection 21 basically has the same function as the pin 20 of the contact element 15b.

The 5 shows a top view 25 and a side view 27 of a pair of control lines 121, 122 with contact elements 151, 152 in a control line structure according to an embodiment of the present invention. The control lines 121, 122 are attached flat one above the other on the flexible film 11, electrically separated by an insulating layer 123, and covered by another flexible film. The insulating layer 123 can be made significantly thinner than the upper and lower flexible films 11, 13, since the dielectric requirements are lower here. The end regions of the two control lines run in opposite directions and each have a contact element 151, 152, which, like the contact element 15c in the 4 The two flat conductors 121, 122 have a length l and a width b. The distance d between the two flat conductors 121, 122 is equal to the thickness of the insulating layer 123.

wobei l, b und d in mm anzugeben sind. Mit beispielhaften physikalischen Abmaßen, die in der Praxis üblich und auch problemlos zu realisieren sind, ergibt sich: I = 100mm, d = 50µm, b = 2 mm => L ≈ 3,1 nH, d.h. einen Wert der parasitären Induktivität deutlich unter 5nH. Wie nachfolgend erläutert wird, lassen sich der Gleichstromwiderstand und die parasitäre Induktivität über die Geometrie der Leiterbahnen anpassen. Im einfachsten Fall werden die längeren Leiter (für die entfernter liegenden Halbleiterschaltelemente) mit einer breiteren Struktur b ausgeführt. Hierdurch lässt sich, nach der obigen Gleichung, die Gesamtinduktivität L trotz größerer Länge l für alle Leiter symmetrieren. Dabei kann die Anpassung der Struktur über die ganze Länge des Leiters oder auch nur in Teilabschnitten erfolgen.The parasitic inductance L (in nH) of the flat conductors 121, 122 is approximately: $$\text{L}\approx \text{0}\text{,4}*|*\mathrm{\pi }*\text{d}/\text{b},$$

where l, b and d are in mm. Using example physical dimensions that are common in practice and easy to implement, the result is: I = 100mm, d = 50µm, b = 2 mm => L ≈ 3.1 nH, i.e. a parasitic inductance value well under 5nH. As explained below, the DC resistance and the parasitic inductance can be adjusted via the geometry of the conductor tracks. In the simplest case, the longer conductors (for the more distant semiconductor switching elements) are designed with a wider structure b. This allows, according to the above equation, the total inductance L to be symmetrical for all conductors despite the greater length l. The structure can be adjusted over the entire length of the conductor or just in partial sections.

The 6 shows control lines with varying widths according to an embodiment of the present invention. In the plan view shown, a control line structure is shown with a first pair of control lines 121, 122 running flat one above the other and a second pair of control lines 124, 125 running flat one above the other, which are attached to a flexible film 11 and covered by a further flexible film 13. The two pairs of control lines 121, 122 and 124, 125 are attached next to each other, run essentially parallel, and each have the same structure as the 5 shown pair of control lines 121, 122. The first pair 121, 122 is connected to connection contact areas KS (Kelvin source) and G (gate) on a first bare (die) semiconductor switching element S11 via corresponding contact elements 151, 152. Similarly, the second pair 124, 125 is connected to the connection contact areas KS and G on a second bare semiconductor switching element S12 via corresponding contact elements 154, 155. In order to compensate for the greater length of the control lines 124, 125 in comparison with the control lines 121, 122, the width of the control lines 124, 125 is larger from the point P, b2 > b1. In this way, an (at least substantially) identical parasitic inductance of all control lines 121, 122, 124, 125 is achieved.

The 7 shows three different arrangements of control lines, in particular in the end region near the connections of the semiconductor switching elements, according to embodiments of the present invention. In the upper example a), the control lines of both pairs P1, P2 run flat on top of each other and directly towards the connection contact surfaces until one control line reaches its connection contact surface, after which the second control line continues in the same direction to its connection contact surface. In the middle example b), the control lines of both pairs P1, P2 run flat on top of each other and slightly offset relative to the connection surfaces until one control line reaches the level of its connection surface. At this point, one control line changes its direction by 90° and continues to the corresponding contact surface. The other control line continues in its original direction until it also reaches the level of its connection surface. Here it also changes its direction by 90° and continues to the corresponding contact surface. In the lower example c), the connection lines of the two pairs P1 and P2 run in the same way as in the 6 shown and explained above. A great deal of flexibility and adaptability to the arrangement of the semiconductor switching elements and their connection areas can be seen.

The 8th shows a coated contact element 15d according to an embodiment of the present invention. This embodiment is similar to that shown in 3 and differs from this in particular in that a contact element 15d is provided with a coating 28, in particular an aluminum or gold coating, wherein the coating 28 is bonded to the connection surface 14 of the semiconductor switching element S. Thus, both the conductor track 12 and the main part of the contact element 15d can advantageously consist of a different material, e.g. copper.

The 9 shows three different designs of contact elements according to embodiments of the present invention. In each of the three examples a), b) and c), two planar control lines 121, 122 are separated by an insulating layer 123 and between a lower flexible foil 11 and an upper flexible foil 13 as in the 5 attached. In the upper example, the contact element 151 a at the end of the lower control line 121 is the same as the contact element 152 a at the end of the upper control line 122. Consequently, the contact element 152 a is slightly higher than the contact element 151 a. The corresponding height difference can be compensated for before or during ultrasonic welding due to the flexibility of the control line structure by carefully pressing it down and, if necessary, gluing it in place. Alternatively, as in the middle example b), the contact element 152 b at the end of the upper control line 122 can be made slightly larger in the lower area so that the contact element 152 b is higher overall than the contact element 152 a and can be welded on without pressing it down and bending the flexible control line structure. Additionally or alternatively, as in the lower example c), the contact element 151 c at the end of the lower control line 121 can be made slightly larger in the upper area so that it is more easily accessible from above during ultrasonic welding.

The 10 shows a control line structure with EMC shields 31, 32 according to an embodiment of the present invention. More specifically, Figure 10 shows a control line structure similar to that shown in 9 a) shown drive line structure, wherein a lower EMC shielding layer 31 is embedded in the lower flexible film 11 and an upper EMC shielding layer 32 is embedded in the upper flexible film 13. The EMC shielding layers 31, 32 are formed from electrically conductive material and are preferably connected to ground.

• 1) Direkte Anbindung von Flex-Leitern an die Gate- und Kelvin-Source-Anschlüsse von Leistungshalbleiterschaltelemente. Die Verbindung erfolgt ohne zusätzliche Löt- oder Sinterschichten direkt über eine Ultraschall-Verschweißung oder Laser-Schweißung des Anschlusspins, der sich am Flex-Leiter befindet, mit dem Halbleiter. Es lassen sich so zusätzliche Löt- und Sinterprozesse am Gate-Anschluss vermeiden und damit Kosten sparen.
• 2) Durch die direkte Verbindung der Flex-Folie mit dem Halbleiter lässt sich auch die parasitäre Induktivität im Anschlussbereich auf ein Minimum reduzieren. Damit lassen sich die Vorteile von Flex-Leitern (der niedrige Induktivitätsbelag) erst voll nutzen und die für sehr schnell schaltende Halbleiter notwendige geringe parasitäre Induktivität im Ansteuerkreis erreichen.
• 3) Ein weiterer Vorteil ist der sehr geringe Bauraumbedarf für die Signalführung über den Flex-Leiter und die Kontaktierung am Gate. Auf dem (teuren) Substrat werden keine Bond-Landeflächen oder ähnliches benötigt. Selbst bei Leistungselektronikmodulen mit zehn oder mehr parallel geschalteten Halbleitern pro Schalter ist es möglich, alle Gate- und Kelvin-Source-Anschlüsse einzeln und getrennt über nur eine Flex-Folie zur Gate-Ansteuerschaltung zu führen. Diese führt zu einer Erhöhung der Leistungsdichte im Leistungselektronikmodul.
• 4) Durch die getrennte Gate-Signalführung zu den Halbleitern und den geringen Induktivitätsbelag der Flex-Folie kann die Gate-Ansteuerschaltung räumlich weiter entfernt platziert werden. Eine räumlich dichte Integration von Halbleitern und Ansteuerschaltung ist nicht notwendig. Hierdurch ergeben sich Package-Vorteile sowohl beim Leistungselektronikmodul als auch im Gesamtaufbau des Produktes.
• 5) Durch Anpassung der Leiter-Geometrien in der Flex-Folie lassen sich die elektrischen Eigenschaften (Widerstand und parasitäre Induktivitäten) aller Ansteuerleitungen symmetrieren und so die Voraussetzungen für eine zeitgleiches Schalten der Halbleiter gewährleisten.
• 6) Alle Signale, welche vom Leistungselektronikmodul benötigt werden, lassen sich mit dieser Verbindungstechnik erfassen und nach außen führen, somit fallen weitere Verbindungstechniken direkt am Leistungselektronikmodul weg.
• 7) Die notwendigen Spannungsabstände zwischen verschiedenen Potentialen sind im Flexleiter geringer als außerhalb davon. Somit lassen sich kompaktere Module aufbauen.

The above-described embodiments of the present invention have a number of distributions:

• 1) Direct connection of flexible conductors to the gate and Kelvin source connections of power semiconductor switching elements. The connection is made directly to the semiconductor via ultrasonic welding or laser welding of the connection pin on the flexible conductor without additional soldering or sintering layers. This avoids additional soldering and sintering processes on the gate connection and thus saves costs.
• 2) The direct connection of the flexible foil to the semiconductor also allows the parasitic inductance in the connection area to be reduced to a minimum. This allows the advantages of flexible conductors (the low inductance per unit area) to be fully exploited and the low parasitic inductance in the control circuit required for very fast switching semiconductors to be achieved.
• 3) Another advantage is the very small installation space required for signal routing via the flexible conductor and contacting at the gate. No bonding pads or similar are required on the (expensive) substrate. Even with power electronics modules with ten or more semiconductors connected in parallel per switch, it is possible to route all gate and Kelvin source connections individually and separately to the gate control circuit via just one flexible foil. This leads to an increase in the power density in the power electronics module.
• 4) Due to the separate gate signal routing to the semiconductors and the low inductance of the flex film, the gate control circuit can be placed further away. A spatially dense integration of semiconductors and control circuit is not necessary. This results in packaging advantages both in the power electronics module and in the overall structure of the product.
• 5) By adapting the conductor geometries in the flex foil, the electrical properties (resistance and parasitic inductances) of all control lines can be symmetrical and thus the conditions for simultaneous switching of the semiconductors can be ensured.
• 6) All signals required by the power electronics module can be captured and routed to the outside using this connection technology, thus eliminating the need for additional connection technologies directly on the power electronics module.
• 7) The necessary voltage gaps between different potentials are smaller in the flexible conductor than outside of it. This allows more compact modules to be constructed.

Claims (17)

Power electronics module comprising a plurality of semiconductor switching elements (S, S11, S21, S12, S22, S1n, S2n), in particular SiC semiconductor switches or GaN semiconductor switches, a control circuit (GDU1, GDU2) for controlling the plurality of semiconductor switching elements (S, S11, S21, S12, S22, S1n, S2n) and a control line structure (LS1, LS2) formed on a flexible film (11) with a plurality of control lines (12, 121, 122), wherein the control lines (12, 121, 122) each form at least a part of respective direct electrical connections between the control circuit on the one hand (GDU1, GDU2) and the respective semiconductor switching elements (S, S11, S21, S12, S22, S1n, S2n) on the other hand. Power electronics module according to Claim 1 , wherein the control lines (12, 121, 122) are designed or shaped such that the parasitic inductances of all control lines (12, 121, 122) are substantially equal, or the parasitic inductances of all electrical connections between the control circuit on the one hand and the respective semiconductor switching elements on the other hand are substantially equal. Power electronics module according to Claim 1 or 2 , wherein the control lines (12, 121, 122) each have a contact element (15, 15a, 15b, 15c) on their section facing the respective semiconductor switching element, which is physically and electrically connected to an upper-side connection contact surface (14) of the respective corresponding semiconductor switching element or is welded onto this connection contact surface. Power electronics module according to Claim 3 , wherein the contact element has an electrically conductive pin extending through the section of the respective corresponding control line, which has at its end facing the respective corresponding semiconductor switching element a contact surface (17) resting on the connection contact surface (14) of the semiconductor switching element, in particular welded thereon. Power electronics module according to Claim 4 , wherein the pin has a centering element (20, 21) at its end facing away from the respective corresponding semiconductor switching element for positioning the pin relative to the respective corresponding semiconductor switching element. Power electronics module according to one of the preceding claims, wherein the control lines are designed such that the longer the conductor length (l) of those control lines in their respective longitudinal direction, the larger the cross-sectional area of those control lines transverse to their respective longitudinal direction, so that the parasitic inductances and/or DC resistances of all control lines are substantially equal. Power electronics module according to one of the preceding claims, wherein each semiconductor switching element has two connection contact surfaces (KS, G) which are each connected to the control circuit by a corresponding pair of control lines. Power electronics module according to Claim 7 , wherein the control lines of at least one pair of control lines (121, 122) are arranged flat one above the other and are physically connected to one another and at the same time electrically separated from one another by an electrically insulating insulating layer (123) lying therebetween. Power electronics module according to one of the Claims 7 until 8th , wherein the conductor width (b) and/or the conductor length (l) and/or the conductor thickness (d) and/or the conductor spacing for each pair of control lines are adjusted such that the parasitic inductances and/or DC resistances of all control lines are substantially equal. Power electronics module according to one of the preceding claims, wherein a further flexible film (13) is attached over the control line structure, which protects the control line structure from electrical and/or electromagnetic and/or mechanical interference. Power electronics module according to one of the preceding claims, further comprising a lower electrically conductive shielding layer (31) under the control line structure and/or an upper electrically conductive shielding layer (32) on the control line structure, which are physically connected to the control line structure and at the same time electrically insulated from the control line structure and are configured to electromagnetically shield the control line structure. Power electronics module according to Claim 11 , further comprising a lower electrical insulation layer (11) which physically connects the control line structure to the lower shielding layer and at the same time electrically insulates it from the lower shielding layer, and/or an upper electrical insulation layer (13) which physically connects the control line structure to the upper shielding layer and at the same time electrically insulates it from the upper shielding layer. Power electronics module according to Claim 12 , wherein the lower shielding layer of the lower insulating layer (11) is embedded or enclosed by that of the lower insulating layer, and/or wherein the upper shielding layer of the upper insulating layer (13) is embedded or enclosed by that of the upper insulating layer. Power electronics module according to one of the Claims 11 until 13 , wherein the lower and/or upper shielding layer are electrically connected to electrical ground. Method for producing a power electronics module, the method comprising providing a plurality of semiconductor switching elements (S, S11, S21, S12, S22, S1n, S2n), in particular SiC semiconductor switches or GaN semiconductor switches, providing a control circuit (GDU1, GDU2) for controlling the plurality of semiconductor switching elements (S, S11, S21, S12, S22, S1n, S2n), providing a control line structure formed on a flexible film (11) with a plurality of control lines (12, 121, 122), forming direct electrical connections between the control circuit (GDU1, GDU2) on the one hand and the respective semiconductor switching elements (S, S11, S21, S12, S22, S1n, S2n) on the other hand via the respective control lines (12, 121, 122), wherein the Control lines (12, 121, 122) each form at least a part of the respective direct electrical connections between the control circuit (GDU1, GDU2) and an individual one of the semiconductor switching elements (S, S11, S21, S12, S22, S1n, S2n). Procedure according to Claim 15 wherein the step of providing the drive line structure further provides that the drive lines (12, 121, 122) are designed or shaped such that the parasitic inductances of all drive lines (12, 121, 122) will be substantially equal. Procedure according to Claim 16 , wherein the step of providing the control line structure further provides that the control lines are each provided with a contact element (15, 15a, 15b, 15c) at their end facing the respective semiconductor switching element (S, S11, S21, S12, S22, S1n, S2n), wherein the step of forming the direct electrical connections further provides that the contact element of the respective control lines is physically and electrically connected to a top-side connection contact surface (14) of the respective corresponding semiconductor switching elements or is welded onto this connection contact surface.

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