DE102015209352A1 - Power semiconductor module, power converter and vehicle - Google Patents

Abstract

The invention relates to a power semiconductor module (1) for a power converter (20), in particular for a power converter (20) of a drive train of a vehicle (21), wherein the power semiconductor module (1) comprises: - a housing (2), - an in housing ( 2) arranged circuit board (3) having an upper side (4) and a lower side (5), - at least one on the upper side (4) arranged semiconductor switch (6), which in each case in the housing (2) is arranged, - at least two on the Circuit board (3) arranged first terminal contacts (7), - at least one on the top (4) arranged capacitor (8), which in each case in the housing (2) is arranged, wherein the respective capacitor (8) with the respective semiconductor switch (6) and the respective first terminal contact (7) is electrically connected. Furthermore, the invention relates to a power converter (20) comprising at least one such power semiconductor module (1) and a vehicle (21), in particular hybrid or electric vehicle, comprising a drive train comprising at least one electric motor and such a power converter (20). In order to provide comparatively compact power semiconductor modules (1) or converters (20), in particular for vehicles (21), it is proposed that the respective capacitor (8) comprise a dielectric comprising a glass ceramic.

Description

• – ein Gehäuse,
• – eine im Gehäuse angeordnete Leiterplatte mit einer Oberseite und einer Unterseite,
• – zumindest einen auf der Oberseite angeordneten Halbleiterschalter, welcher jeweils im Gehäuse angeordnet ist,
• – zumindest zwei auf der Leiterplatte angeordnete erste Anschlusskontakte,
• – zumindest einen auf der Oberseite angeordneten Kondensator, welcher jeweils im Gehäuse angeordnet ist,

wobei der jeweilige Kondensator mit dem jeweiligen Halbleiterschalter und dem jeweiligen ersten Anschlusskontakt elektrisch verbunden ist.The invention relates to a power semiconductor module for a power converter, in particular for a power converter of a drive train of a vehicle,
wherein the power semiconductor module comprises:

• A housing,
• A printed circuit board arranged in the housing with an upper side and a lower side,
• At least one semiconductor switch arranged on the upper side, which is in each case arranged in the housing,
• At least two first terminal contacts arranged on the printed circuit board,
• At least one capacitor arranged on the upper side, which is in each case arranged in the housing,

wherein the respective capacitor is electrically connected to the respective semiconductor switch and the respective first terminal contact.

Furthermore, the invention relates to a power converter having at least one such power semiconductor module.

Finally, the invention relates to a vehicle, in particular a hybrid or electric vehicle or car, comprising a drive train comprising at least one electric motor and such a power converter.

Such power semiconductor modules and converters are used in many power electronics applications. In the inverters currently available on the market, e.g. In electric and hybrid vehicles to control the electric motor use, usually DC link capacitors are installed. These capacitors are usually wound film capacitors. The DC link capacitor on the one hand has the task of smoothing the voltage of the traction energy storage, usually a high-voltage battery, and on the other hand, the capacitor is a short-term, fast energy storage.

Due to the high switching frequencies of the inverter, the DC link capacitor is continuously charged and discharged. By the Umladungsvorgänge arise in the capacitor electrical losses in the form of heat. For effective and efficient operation of the inverter and to ensure the required life of the capacitor, the resulting heat loss must be removed from the condenser.

According to the state of the art, inverters in the automotive sector, i. H. used in particular for applications in electric and hybrid vehicles, film capacitors.

In general, the DC link capacitors, especially in applications such as those found in electric and hybrid vehicles, usually connected to a liquid cooling. Currently, the following technical solutions are used.

The electrical, mechanical and thermal design of the capacitor currently takes place in such a way that the temperatures occurring in the DC link capacitor during operation do not lead to damage or destruction within the desired service life. As a rule, capacitors designed in this way require a relatively large amount of installation space.

In a first alternative, the DC link capacitor is currently directly with thermally conductive, but electrically insulating material, eg. B. curable liquid grout, potted in a housing cavity. This solution requires a liquid process or casting in the production line.

In a second alternative, the DC link capacitor is currently attached to the housing by means of a thermally conductive but electrically insulating solid, e.g. Heat-conducting foil or heat-conducting pad, connected.

From the DE 10 2013 209 444 A1 is a power semiconductor module with a semiconductor circuit having a plurality of arranged in a common housing power semiconductors, wherein a arranged in the same housing and in the power semiconductor module acting as a DC link capacitor is provided, wherein the capacitor is applied over a large area on a thermally conductive carrier.

From the JP 2000-092 858 A a similar power semiconductor module is known.

An object of the invention is to provide comparatively compact power semiconductor modules or power converters, in particular for vehicles.

A solution of the problem results in a power semiconductor module or a power converter of the type mentioned in that the respective capacitor comprises a dielectric comprising a glass ceramic.

So far, film capacitors with polypropylene (PP) or similar plastics have been used as a dielectric in power semiconductor modules or power converters in the rule. These have a relative permittivity of 2.2 for PP to 3.25 for polyethylene terephthalate (PET). The capacitance of a capacitor is directly proportional to the relative permittivity of a material.

Since the dielectric constant of glass-ceramic is substantially greater than that of the plastics commonly used for film capacitors, a higher energy density can be achieved with the respective proposed capacitor. That is, compared with a film capacitor, a desired target capacity can be realized by the proposed respective glass-ceramic capacitor in a smaller space.

So far, film capacitors made of PP or other plastics are usually connected externally to the power semiconductor modules or arranged outside the power semiconductor modules. Due to the current load in the busbars on the capacitor and due to the Rippelstromverluste in the winding of the condenser for cooling must be actively connected to the cooling, which is complicated and expensive in film capacitors.

In contrast, the integration of the respective capacitor with the glass ceramic in the power semiconductor module allows a compact design of the power semiconductor module or power converter, so that more space can be kept free in the converter. Furthermore, this makes it possible to save costs in the converter development and in particular to ensure a particularly good heat dissipation. This is achieved by virtue of the fact that the respective capacitor is integrated directly in the power semiconductor module for the purpose of efficient cooling connection, whereby a reduction of the supply line inductance can additionally be achieved.

In addition, it is advantageous that the respective capacitor, thanks to the glass ceramic even at relatively high operating temperatures of up to 150 ° C, in particular up to 200 ° C, is operable. This property of the glass ceramic allows to integrate the respective capacitor in the power semiconductor module and thus to place the respective capacitor in this. About the power semiconductor module is an optimal cooling connection for the respective capacitor with the glass ceramic, whereas a comparably good cooling connection would be reached in a film capacitor only at an increased cost. A particularly good cooling connection is achieved, in particular, by the metallic base plate explained below.

As a semiconductor switch preferably transistors, in particular IGBTs, and as a printed circuit board, for example, a PCB (printed circuit board) or a DCB structure (direct copper bonded) are used. In particular, the semiconductor switch comprises a half-bridge with one or more IGBTs and diodes. The proposed converter can be designed, for example, as a rectifier, inverter or inverter. For rectification preferably rectifier diodes or, to enable a four-quadrant operation, further semiconductor switches are used, which are each connected between a feeding AC voltage and the respective capacitor.

In an advantageous embodiment of the invention, the power semiconductor module is designed for operation with an electrical power of at least 10 kW, in particular of at least 25 kW.

The proposed power semiconductor module or the proposed power converter are thus particularly suitable for use in a drive train in the proposed vehicle. In particular, the power semiconductor module is adapted to be operated with electrical powers of up to 100 kW. Accordingly, the circuit board, the semiconductor switches and the respective capacitor are designed for such services.

In a further advantageous embodiment of the invention, the relative dielectric constant of the glass ceramic is at least 180, in particular at least 200.

Due to the comparatively large dielectric constant of the glass ceramic, a particularly high energy density can be achieved with the respective capacitor, which allows a particularly compact construction. For this purpose, for example, special glass-ceramic dielectrics may be used whose relative dielectric constant is for example 198, 213 or even more.

In a further advantageous embodiment of the invention, a metallic bottom plate is arranged on the underside, which is arranged in the housing, wherein the bottom plate on its, the underside opposite side has at least one projection, wherein the respective projection projects into a cavity of the housing, wherein the respective projection and the cavity are configured such that the bottom plate can be cooled by means of a coolant flow flowing through the cavity.

Preferably, a thermally highly conductive material such as aluminum or copper is used for the bottom plate. On the cavity facing outside of the metallic bottom plate is a special structure in the form of pins or fins. The power semiconductor module is used with these pins / fins directly into the coolant flow and thus efficiently cooled. In particular, the cavity is a cavity of the converter housing or of the converter housing.

By means of the bottom plate, the heat generated during operation of the power semiconductor module waste heat can be easily removed, for which purpose the respective projection is configured, for example, as Kühlfinne or cooling dome. During operation, the respective projection can deliver the waste heat well to a coolant, which flows along the bottom plate and flows around the respective projection.

In a further advantageous embodiment of the invention, a sintered layer is arranged between the respective capacitor and the printed circuit board, wherein the respective capacitor is connected by sintering to the printed circuit board.

The sintered layer ensures good heat transfer from the respective condenser to the base plate and stable mechanical fastening of the respective capacitor to the base plate. For example, the sintered layer has a sintered paste layer, for example in the form of a silver paste, so that the sintering process can be carried out in particular as silver sintering at comparatively low temperatures. The advantage here is a comparatively low processing temperature.

In principle, it is alternatively conceivable to fasten the respective capacitor to the bottom plate by means of a solder connection.

In a further advantageous embodiment of the invention, the respective capacitor acts as an intermediate circuit capacitor, wherein the first connection contacts comprise a connection for the positive potential of the intermediate circuit and a connection for the negative potential of the intermediate circuit.

In particular, the respective capacitor is thus used as a DC link capacitor of the rectifier, inverter or converter converter are used. For this purpose, the respective capacitor preferably has a capacitance which is sufficient, in particular, to operate the power semiconductor module with an electrical power of at least 10 kW or at least 25 kW.

The first connection contacts can be used for example for the positive and negative busbars of the intermediate circuit of the power converter or be designed as such.

In a further advantageous embodiment of the invention, the power semiconductor module in this case has at least two, arranged on the circuit board second terminal contacts for connecting an AC voltage, wherein the respective power semiconductor is electrically connected to the respective capacitor and the respective second terminal contact.

Thus, the energy can be supplied to the respective capacitor, for example from an AC voltage network, in particular after the AC voltage has been rectified.

Conversely, it is also conceivable that the DC voltage of the respective capacitor is reversed by means of the respective power semiconductor in an AC voltage to be used subsequently, for example, to operate an electric motor of the vehicle. For this purpose, in particular three second connection contacts and, for example, six semiconductor switches for a three-phase alternating voltage can be provided, for which in particular two or more of the proposed capacitors can be used.

In a further advantageous embodiment of the invention, the respective capacitor is arranged on that region of the upper side which lies between the respective semiconductor switch and the respective first terminal contact.

Such an arrangement of the respective capacitor with respect to the respective semiconductor switch and the respective first connection contact allows a compact spatial structure of the power semiconductor module. In addition, long and cumbersome leads are avoided, which can reduce line inductances, ultimately allowing higher currents to be switched in less time without creating dangerous overvoltages on the respective semiconductor switch.

Preferably, the respective capacitor is arranged directly between the respective semiconductor switch and the respective first terminal contact. In particular, no further components or the like are thus arranged between the respective capacitor on the one hand and the respective semiconductor switch or the respective first connection contact on the other hand.

In a further advantageous embodiment of the invention, the respective capacitor is connected via a respective electrical connecting line with the respective semiconductor switch, wherein the inductance of the respective connecting line is at most 6 nH, in particular at most 2 nH.

The respective electrical connection line thus has a very low inductance of only at most 6 nH or at most 2nH, which brings several advantages. For example, this allows a higher DC link voltage than at comparable power semiconductor modules, in which the respective capacitor is connected outside the module housing via a longer connecting line. In addition, the cut-off overvoltage is reduced by the proposed connection line.

Assuming an inductance of the connecting line of 1.2 nH per millimeter cable length, the value of at most 6 nH can be achieved, for example, by a connecting line which is not longer than 5 mm.

The comparatively very low inductance of the respective connecting line makes it possible to switch higher currents in a shorter time, without generating dangerous overvoltages on the respective semiconductor switch. In particular, can be reliably prevented by such a low inductance of the respective connecting line that at fast switching of the semiconductor switches to high switching overvoltages occur on the semiconductor switch, which could lead to its destruction.

In a further advantageous embodiment of the invention, the respective capacitor has a capacity of the order of 100 μF.

The thus designed power semiconductor module is particularly well suited for use in a power converter of a vehicle drive train, since a sufficient electrical power can be provided.

For the drive train of a vehicle, for example, three modules may be provided, each of which has a capacitor with a capacity of one third of the target capacity of the intermediate circuit. Alternatively, it would also be conceivable to use in each case a capacitor with a somewhat smaller capacitance and to support the intermediate circuit by means of an external capacitor whose capacitance is approximately 40-60% of the target capacitance of the intermediate circuit. For a desired electrical power of the respective power semiconductor module of several 10 kW, said target capacity is, for example, 600 μF to 1 mF. The respective power semiconductor module is preferably designed for an electrical power of at least 10 kW, in particular at least 25 kW, and the corresponding power converter for an electrical power of several 10 kW, in particular up to 100 kW and possibly beyond.

In a further advantageous embodiment of the invention, the power semiconductor module is designed to switch at least temporarily a momentary current of at least 1350 A during a switching period of 100 ns to 200 ns of the respective semiconductor switch.

With the power semiconductor module configured in this way, the drive power for a power converter of a vehicle drive train can be provided particularly well. In particular, this can ensure operation with an electrical power of at least 10 kW, in particular of at least 25 kW, for the power semiconductor module and several 10 kW, in particular up to 100 kW and possibly beyond, for the power converter.

As described above, the respective capacitor is advantageously arranged on that region of the upper side which lies between the respective semiconductor switch and the respective first connection contact. In particular, the inductance of the respective connecting line is at most 6 nH, in particular at most 2 nH, explained above.

In the following the invention will be described and explained in more detail with reference to the embodiments illustrated in the figures. Show it:

1 a first embodiment of the proposed power semiconductor module,

2 - 3 A second embodiment of the proposed power semiconductor module,

4 - 5 a third embodiment of the proposed power semiconductor module, and

6 an embodiment of the proposed vehicle.

1 shows a first embodiment of the proposed power semiconductor module 1 , wherein a plan view is shown.

The power semiconductor module 1 has a housing 2 on, which is merely indicated for reasons of clarity. In the case 2 is a circuit board 3 with a top 4 and a bottom 5 , Which 1 not seen, arranged. On the top 4 the circuit board 3 are a semiconductor switch 6 , two first connection contacts 7 as well as a capacitor 8th inside the case 2 arranged. The capacitor 8th is with the respective first connection contact 7 and via an electrical connection line 14 with the semiconductor switch 6 electrically connected. The capacitor 8th has a dielectric, which has a glass ceramic on.

In particular, the semiconductor switch comprises 6 a half bridge with one or more IGBTs and diodes. Preferably, the power semiconductor module 1 for operation with an electric power of at least 10 kW, in particular of at least 25 kW, designed. In particular, the relative dielectric constant of the glass ceramic is at least 180, in particular at least 200. For example, the capacitor functions 8th as a DC link capacitor, wherein the two first connection contacts 7 a connection for the positive potential of the DC link and a connection for the negative potential of the DC link.

Advantageously, the capacitor 8th on that area of the top 4 arranged, which between the semiconductor switch 6 and the respective first connection contact 7 lies, as in 1 is indicated. In particular, the inductance of the connecting line 14 at most 6 nH, in particular at most 2 nH. For example, the capacitor has 8th a capacity of the order of 100 μF. Preferably, the power semiconductor module 1 designed for a switching period of 100 ns to 200 ns of the semiconductor switch 6 at least temporarily switching a momentary current of at least 1350 A.

The 2 and 3 show a second embodiment of the proposed power semiconductor module 1 , where in 2 a top view and in 3 a cross section are shown. Same reference numerals as in 1 denote the same objects. Since the second embodiment has similarities with the first embodiment, some differences will be explained below.

The second embodiment of the power semiconductor module 1 has three semiconductor switches 6 on, which via a respective electrical connection line 14 with the capacitor 8th are connected. Between the capacitor 8th and the circuit board 3 is a sintered layer 13 arranged, the capacitor 8th by sintering with the circuit board 3 connected is.

Furthermore, there are two second connection contacts 16 provided, which via not shown connections with the respective power semiconductor 6 are connected. For example, at the two connection contacts 16 connected an AC voltage, which is the power semiconductor module 1 fed.

In addition, there is a metallic bottom plate 9 on the bottom 5 the circuit board 3 and inside the case 2 arranged, with the bottom plate 9 at her, the bottom 5 opposite side several projections 10 and the respective projection 10 in a cavity 11 of the housing 2 protrudes. The respective lead 10 and the cavity 11 are designed such that the bottom plate 9 by means of a through the cavity 11 flowing coolant flow 12 is coolable.

The 4 and 5 show a third embodiment of the proposed power semiconductor module 1 , where in 4 a top view and in 5 a cross section are shown. Since the third embodiment is similar to the second embodiment, some differences will be explained below.

In addition, there are three semiconductor elements 15 provided, for example, electrically between the two second terminal contacts 16 , in particular the feeding AC voltage, and the capacitor 8th are arranged. The semiconductor elements 15 For example, they are used for rectifying the alternating voltage and are preferably designed as rectifier diodes or, in order to enable four-quadrant operation, as further semiconductor switches.

6 shows an embodiment of the proposed vehicle 21 , The vehicle 21 is designed for example as an electric or hybrid vehicle and has a drive train comprising a power converter 20 with a power semiconductor module 1 on.

• – ein Gehäuse,
• – eine im Gehäuse angeordnete Leiterplatte mit einer Oberseite und einer Unterseite,
• – zumindest einen auf der Oberseite angeordneten Halbleiterschalter, welcher jeweils im Gehäuse angeordnet ist,
• – zumindest zwei auf der Leiterplatte angeordnete erste Anschlusskontakte,
• – zumindest einen auf der Oberseite angeordneten Kondensator, welcher jeweils im Gehäuse angeordnet ist,

wobei der jeweilige Kondensator mit dem jeweiligen Halbleiterschalter und dem jeweiligen ersten Anschlusskontakt elektrisch verbunden ist. Weiterhin betrifft die Erfindung einen Stromrichter aufweisend zumindest ein derartiges Leistungshalbleitermodul sowie ein Fahrzeug, insbesondere Hybrid- oder Elektrofahrzeug, aufweisend einen Antriebsstrang umfassend zumindest einen Elektromotor und einen derartigen Stromrichter. In summary, the invention relates to a power semiconductor module for a power converter, in particular for a power converter of a drive train of a vehicle, wherein the power semiconductor module comprises:

• A housing,
• A printed circuit board arranged in the housing with an upper side and a lower side,
• At least one semiconductor switch arranged on the upper side, which is in each case arranged in the housing,
• At least two first terminal contacts arranged on the printed circuit board,
• At least one capacitor arranged on the upper side, which is in each case arranged in the housing,

wherein the respective capacitor is electrically connected to the respective semiconductor switch and the respective first terminal contact. Furthermore, the invention relates to a power converter having at least one such power semiconductor module and a vehicle, in particular hybrid or electric vehicle, comprising a drive train comprising at least one electric motor and such a power converter.

In order to provide comparatively compact power semiconductor modules or power converters, in particular for vehicles, it is proposed that the respective capacitor has a dielectric comprising a glass ceramic.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102013209444 A1 [0011]
• JP 2000-092858A [0012]

Claims (13)

Power semiconductor module ( 1 ) for a power converter ( 20 ), in particular for a power converter ( 20 ) of a drive train of a vehicle ( 21 ), wherein the power semiconductor module ( 1 ): - a housing ( 2 ), - one in the housing ( 2 ) arranged circuit board ( 3 ) with a top side ( 4 ) and a bottom ( 5 ), - at least one on the top ( 4 ) arranged semiconductor switch ( 6 ), which in each case in the housing ( 2 ), - at least two on the printed circuit board ( 3 ) arranged first connection contacts ( 7 ), - at least one on the top ( 4 ) arranged capacitor ( 8th ), which in each case in the housing ( 2 ), wherein the respective capacitor ( 8th ) with the respective semiconductor switch ( 6 ) and the respective first connection contact ( 7 ) is electrically connected, characterized in that the respective capacitor ( 8th ) comprises a dielectric comprising a glass ceramic. Power semiconductor module ( 1 ) according to claim 1, wherein the power semiconductor module ( 1 ) is designed for operation with an electrical power of at least 10 kW, in particular of at least 25 kW. Power semiconductor module ( 1 ) according to one of the preceding claims, wherein the relative dielectric constant of the glass ceramic is at least 180, in particular at least 200. Power semiconductor module ( 1 ) according to any one of the preceding claims, wherein at the bottom ( 5 ) a metallic base plate ( 9 ) is arranged, which in the housing ( 2 ) is arranged, wherein the bottom plate ( 9 ) at her, the underside ( 5 ) opposite side at least one projection ( 10 ), wherein the respective projection ( 10 ) into a cavity ( 11 ) of the housing ( 2 ), whereby the respective projection ( 10 ) and the cavity ( 11 ) are configured such that the bottom plate ( 9 ) by means of a through the cavity ( 11 ) flowing coolant flow ( 12 ) is coolable. Power semiconductor module ( 1 ) according to any one of the preceding claims, wherein between the respective capacitor ( 8th ) and the printed circuit board ( 3 ) a sintered layer ( 13 ), wherein the respective capacitor ( 8th ) by sintering with the printed circuit board ( 3 ) connected is. Power semiconductor module ( 1 ) according to one of the preceding claims, wherein the respective capacitor ( 8th ) acts as a DC link capacitor, wherein the first terminal contacts ( 7 ) comprise a connection for the positive potential of the intermediate circuit and a connection for the negative potential of the intermediate circuit. Power semiconductor module ( 1 ) according to claim 6, wherein the power semiconductor module ( 1 ) at least two, on the circuit board ( 3 ) arranged second connection contacts ( 16 ) for connecting an AC voltage, wherein the respective power semiconductor ( 6 ) with the respective capacitor ( 8th ) and the respective second connection contact ( 16 ) is electrically connected. Power semiconductor module ( 1 ) according to one of the preceding claims, wherein the respective capacitor ( 8th ) on that area of the top ( 4 ) is arranged, which between the respective semiconductor switch ( 6 ) and the respective first connection contact ( 7 ) lies. Power semiconductor module ( 1 ) according to one of the preceding claims, wherein the respective capacitor ( 8th ) via a respective electrical connection line ( 14 ) with the respective semiconductor switch ( 6 ), wherein the inductance of the respective connecting line ( 14 ) is at most 6 nH, in particular at most 2 nH. Power semiconductor module ( 1 ) according to one of the preceding claims, wherein the respective capacitor ( 8th ) has a capacity of the order of 100 μF. Power semiconductor module ( 1 ) according to one of the preceding claims, wherein the power semiconductor module ( 1 ) is designed, during a switching period of 100 ns to 200 ns of the respective semiconductor switch ( 6 ) at least temporarily switch a current of at least 1350 A current. Power converter ( 20 ) comprising at least one power semiconductor module ( 1 ) according to any one of the preceding claims. Vehicle ( 21 ), in particular hybrid or electric vehicle, comprising a drive train comprising at least one electric motor and a power converter ( 20 ) according to claim 12.

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