Semiconductor module, inverter and drivetrain for a vehicle comprising such a power semiconductor module

Abstract

The present invention relates to a (power) semiconductor module (10), comprising at least one substrate (14), on a first side of which at least one power semiconductor component (12) is mounted, wherein the power semiconductor component (12) is embedded together with the substrate (14) in a printed circuit board (16) comprising a plurality of layers (32, 34), and wherein the substrate (14) is configured as a metal-ceramic substrate (14). The invention further relates to a (power) inverter, comprising at least one (power) semiconductor module (10) as stated above. The present invention additionally relates to a drivetrain for an electrically drivable vehicle, comprising at least one (power) semiconductor module (10) as stated above.

Description

[0001] 202401146

[0002] 1

[0003] Description

[0004] Semiconductor module, inverter and powertrain for a vehicle comprising such a power semiconductor module

[0005] The present invention relates to a (power) semiconductor module. The present invention further relates to an inverter and a drive train for an electrically powered vehicle comprising the above (power) semiconductor module.

[0006] Furthermore, the present invention relates to a control unit for a powertrain for an electrically powered vehicle, comprising the above (power) semiconductor module. The present invention further relates to an electrically powered vehicle, wherein the electrically powered vehicle comprises at least one of the above (power) semiconductor module, the above powertrain, and the above control unit.

[0007] Power semiconductor devices are semiconductor components used in power electronics for controlling and switching high electrical currents and voltages. They are used, for example, to control electric drives in transportation systems and can be used to convert and / or adapt voltage, current, and / or frequency. Power semiconductor devices are used, for example, in traction inverters for electric vehicles.

[0008] It is well known that power semiconductor devices are used in control units for electrically powered vehicles. For example, power semiconductor devices are used in traction inverters for electric vehicles.

[0009] Printed circuit boards (PCBs) can be used as substrates for power semiconductor devices. These devices are mechanically mounted and electrically interconnected on the PCBs. More highly integrated applications utilize embedded technology. Embedded technology employs bare dies (also known as "naked chips"). These bare dies are not housed in a plastic or ceramic package but are processed without a package and integrated into the multi-layered PCB along with a substrate on which the power semiconductor device is applied. 202401146

[0010] 2

[0011] Typically, highly filled prepreg layers are used for electrical insulation in printed circuit boards (PCBs) in embedded technology. These layers account for approximately 20% of the total material costs of the PCB. Furthermore, due to the high filler content used to improve thermal conductivity, these highly filled prepreg layers are prone to delamination defects under significant temperature fluctuations.

[0012] Another disadvantage is the poor thermal conductivity of the prepreg layer used for electrical insulation. To compensate for this poor thermal conductivity, the heat produced by the power semiconductor components integrated into the circuit board must be dissipated significantly within the substrate. This necessitates a large substrate area, resulting in correspondingly large power semiconductor module sizes. This, in turn, leads to additional costs for large heat sinks and problems integrating the power semiconductor modules into existing installation spaces.

[0013] Accordingly, there is a need to further improve power semiconductor modules, especially with regard to cost efficiency, cycle stability and space requirements.

[0014] The object of the present invention is to provide a solution that is able to overcome at least one disadvantage of the prior art, at least partially. In particular, it is an object of the present invention to provide a power semiconductor module that has a small footprint and / or a high density of power semiconductor components and / or reduces the risk of delamination defects.

[0015] The present invention is achieved by the power semiconductor module with the features of claim 1. The problem is further solved by a drive train with the features of claim 13, by a control unit with the features of claim 14, and by an electrically powered vehicle with the features of claim 15.

[0016] Preferred embodiments of the invention are described in the dependent claims, in the description or the figures, wherein further features described or shown in the dependent claims or in the description or the figures, individually or in any combination, constitute an object 202401146

[0017] 3 of the invention may be represented unless the context clearly indicates otherwise.

[0018] The present invention relates to a semiconductor module or a power semiconductor module comprising at least one substrate on which at least one power semiconductor device is applied on a first side, wherein the power semiconductor device is embedded with the substrate in a multi-layered printed circuit board, and wherein the substrate is designed as a metal ceramic substrate.

[0019] Such a power semiconductor module can offer significant advantages over state-of-the-art solutions, particularly with regard to space requirements and the problem of delamination.

[0020] One aspect of the invention is that the substrate is designed as a metal-ceramic substrate. In other words, instead of a copper substrate on which the power semiconductor device is applied and which is embedded in the printed circuit board, a metal-ceramic substrate is used. The metal-ceramic substrate has a ceramic layer for electrical insulation, which has a very high thermal conductivity compared to a highly filled prepreg layer. Accordingly, it is possible to eliminate the expensive, highly filled prepreg layer in the printed circuit board, which is prone to delamination problems, or to replace it with a less densely filled prepreg layer, in which the risk of delamination is significantly reduced.

[0021] Due to the excellent thermal conductivity of the metal-ceramic substrate, the substrate can be made significantly smaller compared to copper, as there is no need to compensate for the poor thermal conductivity of the highly filled prepreg layer through significant heat spreading. This allows the power semiconductor module to be smaller or to have a higher density of power semiconductor components. The reduced material requirements also result in lower manufacturing costs for the power semiconductor module.

[0022] The power semiconductor module has a substrate on which the power semiconductor device is applied on the first side. The power semiconductor device can be an element of an electrical circuit formed with the printed circuit board. For this purpose, the printed circuit board has several layers, with conductive traces preferably located between two insulating layers.

[0023] 4

[0024] are arranged in a circuit. The specific positioning and interconnection of the power semiconductor component in the electrical circuit can be implemented in a manner readily known to a person skilled in the art, taking into account the desired application.

[0025] The at least one power semiconductor device is preferably selected according to the desired application. The power semiconductor device is, for example, a power IGFET (insulated-gate field-effect transistor), a power MISFET (metal insulator semiconductor field-effect transistor), a power MOSFET (metal oxide semiconductor field-effect transistor), a power bipolar transistor (power BJT bipolar junction transistor), or a power IGBT (insulated-gate bipolar transistor). Preferably, at least one power semiconductor device of the power semiconductor module is a MOSFET. Furthermore, other active or passive components, such as resistors, can be present as elements of the circuit.

[0026] According to a preferred embodiment of the invention, the metal-ceramic substrate comprises a ceramic layer arranged between two electrically conductive layers, and the power semiconductor device is arranged on one of the electrically conductive layers. The metal-ceramic substrate thus preferably has an electrically insulating base structure and an electrically conductive first side to which the power semiconductor device is connected. The power semiconductor device can be connected to the first side using conventional technologies, preferably via a sintered or soldered connection. Preferably, the metal-ceramic substrate has a thin ceramic layer, preferably 250 pm ± 100 pm, with a high thermal conductivity at the operating temperature of the power semiconductor device.Due to the very high thermal conductivity and small ceramic thicknesses, the need for large heat spread is reduced, which allows for low layer densities of the electrically conductive first side on the ceramic layer. Preferably, the electrically conductive first side is a copper layer. Compared to copper substrates, the metal-ceramic substrate can be made significantly smaller in both its footprint and height, enabling a considerable reduction in the size of the power semiconductor module and corresponding material savings. In terms of the reduced height, significantly thinner components are also possible compared to copper substrates.

[0027] 5

[0028] Core layers of the printed circuit board are used, resulting in material savings.

[0029] The ceramic layer of the metal-ceramic substrate is preferably designed as an aluminum nitride ceramic (AlN ceramic) or as a silicon nitride ceramic (SisN4 ceramic). More preferably, the ceramic layer is designed as an aluminum silicate ceramic or an aluminum oxide ceramic.

[0030] The multi-layered printed circuit board (PCB) is preferably designed with multiple layers, including insulating layers made of electrically insulating material and the adjacent conductive traces for electrical connection. Fiber-reinforced plastic, and especially resin-reinforced glass fiber fabric, is preferably used as the electrically insulating material. The insulating layer may contain further inorganic fillers, preferably ceramic particles, to improve thermal conductivity. The conductive traces are preferably made of copper. The resin is preferably an epoxy resin.

[0031] According to a preferred embodiment of the invention, the substrate has a second side opposite the first side, and this second side is connected to a first metal layer of the printed circuit board via thermal vias through an insulating layer for heat dissipation. Due to the insulating structure of the metal-ceramic substrate, it is not necessary to provide additional electrical insulation to the underside. The thermal connection of the substrate undersides is preferably achieved via thermal vias through the insulating layer of the printed circuit board. Preferably, the first metal layer can be thermally connected to a heat sink either directly or via further insulating layers through thermal vias and metal layers.

[0032] In this context, according to a further preferred embodiment of the invention, a further insulating layer of the printed circuit board adjoins the first metal layer, wherein this further insulating layer is not a highly filled layer. Since, due to the better thermal conductivity of the metal-ceramic substrate, it is not necessary to use an insulating layer on the underside that has comparatively good thermal conductivity due to a high proportion of thermally conductive fillers, an insulating layer with a low filler content can be used. Since a high proportion of thermally conductive fillers in the insulating layer increases their adhesion to the adjacent surface, 202401146

[0033] 6

[0034] Since the metal layer deteriorates, the problem of delamination is significantly reduced by using a less densely filled insulation layer. A less densely filled insulation layer is particularly preferably one with a thermal conductivity greater than 5 W / (m K). Conversely, a less densely filled insulation layer is one with a thermal conductivity less than 5 W / (m K), preferably less than 3 W / (m K), and particularly preferably less than 1 W / (m K). Less densely filled insulation layers typically have thermal conductivities in the range of 0.51 W / (m K), while less densely filled insulation layers have thermal conductivities in the range of 5 W / (m K) to 10 W / (m K).

[0035] According to a further preferred embodiment of the invention, none of the insulating layers of the printed circuit board are highly filled layers. In particular, due to the improved thermal conductivity of the metal-ceramic substrate, it is possible to dispense with highly filled insulating layers in the power semiconductor module. Thus, the problem of delamination of highly filled layers is eliminated.

[0036] According to a preferred embodiment of the invention, the first side and / or the power semiconductor device is electrically connected to a conductor track of the printed circuit board (PCB) via vias through an insulating layer. Due to the electrically insulating ceramic layer of the metal-ceramic substrate, all electrical connections of the power semiconductor device must be made from the top surface of the substrate. This is preferably achieved via vias, which, for example, in the case of a MOSFET-designed power semiconductor device, facilitate the electrical connection of the drain terminal to the conductor track. Similarly, the control signals of the power semiconductor device—for example, the gate terminal in the case of a MOSFET—are preferably made from the top surface via vias.

[0037] According to a preferred embodiment of the invention, the substrate has a rectangular shape. Preferably, a rectangular shape is not meant to be a square shape, but rather a shape in which the two sides of the rectangle are of different lengths. Furthermore, the power semiconductor device is preferably arranged offset from the center of the substrate, so that an area of ​​the substrate not covered by the power semiconductor device is surrounded by the 202401146

[0038] 7

[0039] The substrate has a rectangular shape and / or an offset arrangement, which allows for a particularly simple realization of the additional area required for the vias for electrically contacting the terminals of the power semiconductor device.

[0040] According to a further preferred embodiment of the invention, the second side of the substrate, opposite the first side, is free of power semiconductor components. In other words, this provides a design-related separation between heat dissipation via the second side and electrical contacting via the first side, which simplifies the fabrication of the power semiconductor module.

[0041] According to a further preferred embodiment of the invention, the power semiconductor device is embedded in the printed circuit board (PCB) with the substrate by means of an encapsulation material. For improved electrical insulation, the ceramic layer of the metal-ceramic substrate is preferably made slightly larger than the electrically conductive layers of the substrate above and below it. During the manufacturing process of the power semiconductor module, which preferably involves a lamination process, undesirable air inclusions can occur in the edge region of the substrate, reducing the electrical insulation strength. To prevent such air inclusions, it is preferably provided that the encapsulation material, preferably a resin of the same type as that used in the insulating layer of the PCB, particularly preferably an epoxy resin, is additionally filled under the substrate before integration. This then fills the cavity around the substrate and the component mounted on the substrate.

[0042] The amount of additional encapsulation material is preferably adapted to the cavity to be filled and to the amount of resin already present in the insulating layers of the printed circuit board.

[0043] The power semiconductor module is preferably manufactured by a process that includes a lamination process. An exemplary manufacturing process is as follows: In one step, the substrate with the power semiconductor component attached to the first side is preferably inserted into an opening in the core layer of the printed circuit board. The core layer preferably comprises an insulating layer that is covered on both sides with a metal layer. The core layer is preferably mounted on 202401146

[0044] 8. An insulating layer is provided, this insulating layer optionally bordering a metal layer on the side not adjacent to the core layer. After inserting the power semiconductor device into the opening of the core layer, the cavity is preferably filled with encapsulation material, and the opening is then preferably covered on the top side with an insulating layer and optionally a metal layer of the printed circuit board. This layer stack, consisting of optionally a metal layer - insulating layer - core layer - insulating layer - optionally a metal layer, is then preferably laminated. Subsequently, the metal layers are preferably structured to form the conductive tracks, preferably by etching. The electrical connection between the power semiconductor device and the conductive tracks in the metal layer and / or the thermal connection between the substrate and the metal layer is preferably achieved using vias.For this purpose, mechanical drilling and / or laser drilling is preferably carried out through the insulation layers, which are then filled with metal in a subsequent electroplating process, thus creating an electrical and / or thermal connection between the conductor tracks and the power semiconductor device or between the metal layer and the substrate.

[0045] Preferably, the number of insulation and metal layers can be adjusted by repeating the steps, thus building up the power semiconductor module layer by layer from the inside out. Pressures of approximately 20 bar to 30 bar and temperatures of approximately 200 °C are used in the lamination process. It is further preferred that the same number of metal and insulation layers are used above and below the substrate. This advantageously prevents the module from warping due to differing coefficients of thermal expansion of the metal and insulation layers when the temperature changes.

[0046] In this context, according to a preferred embodiment of the invention, the power semiconductor module comprises a semiconductor protection element arranged on the first side, in particular annular, which at least partially surrounds or encloses the power semiconductor device, wherein a vertical extension of the semiconductor protection element is such that an (exposed) top surface of the semiconductor protection element is at least equal to or higher than an (exposed) top surface of the power semiconductor device. If the first side of the substrate on which the power semiconductor device and the semiconductor protection element are arranged is largely flat, then 202401146

[0047] 9. The semiconductor protection element is taller or thicker than the power semiconductor device. To protect the power semiconductor device from excessive pressure during the manufacturing process, which preferably includes a lamination process, the power semiconductor device is preferably at least partially enclosed by the semiconductor protection element and is taller than it. The semiconductor protection element is preferably made of a plastic and particularly preferably of a thermoset. The semiconductor protection element preferably rests flat on the metal-ceramic substrate. It is possible for the semiconductor protection element to completely enclose the power semiconductor device as a continuous ring. Alternatively, the semiconductor protection element can also comprise one or more ring segments and / or only partially enclose the power semiconductor device.An advantage of ring segments that are spaced apart is that, when using the encapsulation material, it can distribute itself between the ring segments during the manufacturing process.

[0048] Regarding the placement of the semiconductor protection element on the substrate, a further preferred embodiment of the invention provides that the semiconductor protection element at least partially encloses a preferably chamfered edge region of the first side of the substrate. In other words, the semiconductor protection element preferably has a chamfer on its outer edge region that is adapted to an angle of an edge, or an etched edge, of the substrate. This allows for particularly easy placement of the semiconductor protection element on the substrate. Particularly preferably, the semiconductor protection element also covers at least a portion, and preferably the entire surface, of a contact area of ​​the vias for the electrical contacting of the power semiconductor device. This enables the use of uniform process parameters for the laser drilling in these areas.

[0049] Furthermore, the semiconductor protection element can have at least one projection that extends around the beveled edge region (at least partially and preferably completely) in a collar-like manner and is tapered towards the edge region. In addition, the projection extends towards the beveled edge region of the first side of the substrate and rests on this edge region, thus enclosing the edge region at least partially and preferably completely. 202401146

[0050] 10

[0051] The semiconductor protection element can be placed on the substrate after the substrate has already been inserted into the core layer of the printed circuit board. Alternatively, the semiconductor protection element can be placed on the substrate before the substrate has been inserted into the core layer of the printed circuit board. Preferably, the semiconductor protection element is positioned such that the distance between the semiconductor protection element and the power semiconductor device, which is at least partially enclosed by the semiconductor protection element, is dimensioned such that sufficient resin from the insulating layer or encapsulation material can penetrate the area between the semiconductor protection element and the power semiconductor device to ensure the electrical insulation of the power semiconductor device.

[0052] If the semiconductor protection element is attached to the metal-ceramic substrate before the latter is inserted into the core layer of the printed circuit board, it is advantageous to bond the semiconductor protection element to the substrate using an adhesive. In this context, a preferred embodiment of the invention provides that the semiconductor protection element is bonded to the first side with an adhesive. This is preferably done with an underfill adhesive. A further advantage of fixing the semiconductor protection element with adhesive is that the adhesive simultaneously provides reliable electrical insulation in the area around the power semiconductor component.

[0053] According to a further preferred embodiment of the invention, the power semiconductor module comprises several power semiconductor devices and preferably several substrates, wherein the several power semiconductor devices are embedded with the substrates in the multi-layered printed circuit board. Preferably, exactly one power semiconductor device is deposited on each substrate. The substrates are preferably arranged side by side in one or more rows. This arrangement has proven advantageous for a uniform current distribution within the power module. Preferably, several power semiconductor devices connected in parallel and deposited on their own substrates form a power switch. A power semiconductor module can have one or preferably several power switches. Furthermore, electrical power connections for the power switches are preferably provided at one or more edge regions of the power semiconductor module.202401146.

[0054] 11

[0055] Due to the significantly improved thermal conductivity of the metal-ceramic substrate, the rectangular shape of the substrate, and / or the arrangement of the substrates and power semiconductor components within the power semiconductor module, the required surface area of ​​the power module is reduced. The percentage reduction in the power module area increases with the number of power semiconductor components per circuit breaker. For example, with four power semiconductor components per circuit breaker, the reduction in the power module area compared to a design using copper substrates is more than 10%.

[0056] The object of the invention is also achieved by a drive train for an electrically powered vehicle, comprising a voltage source, at least one power semiconductor module, and an electric motor, wherein the power semiconductor module is configured as described above. In the configuration described above, the power semiconductor module is preferably usable in the drive train of the electrically powered vehicle. Thus, the described invention can, in particular, replace prior art solutions where alternative solutions, such as copper-based substrates, have been implemented. Therefore, the advantages of the present invention, especially the reduced module size, can be fully realized.

[0057] Furthermore, thermal management is of great importance, especially for power semiconductor modules, so improved solutions regarding heat dissipation, for example in the powertrain of an electrically powered vehicle, are significant.

[0058] The power semiconductor module can be used, for example, in an inverter. The inverter can invert the DC voltage into AC voltage and thereby supply the electric motor, such as a three-phase electric motor. This, in turn, can be used to propel the vehicle. Thus, the power semiconductor module can be described as a control unit for the electric motor or can form this function together with a microcontroller. The inverter is preferably a two-level inverter whose power semiconductor module comprises two power switches per phase. Depending on the power and / or current requirements, the power switch in turn comprises one or more power semiconductor components, preferably connected in parallel. 202401146

[0059] 12

[0060] Such a structure is known in itself, but by using the power semiconductor module according to the invention it offers the advantages described above with regard to reduced installation space requirements and efficient cooling at low cost.

[0061] With reference to further advantages and technical features of the powertrain, reference is made to the description of the control unit, the power semiconductor module, the vehicle, the figures, and the description of the figures, and vice versa.

[0062] A control unit for a powertrain of an electrically powered vehicle is also described, comprising at least one power semiconductor module, wherein the power semiconductor module is configured as described above. Preferably, such a control unit additionally comprises a microcontroller for controlling the power semiconductor module.

[0063] The advantages of such a control unit include reduced installation space requirements and efficient cooling, all while keeping costs down. Furthermore, an integrated control unit solution is possible, enabling use in harsh or rugged environments.

[0064] With regard to further advantages and technical features of the control unit, reference is made to the description of the power semiconductor module, the drive train, the vehicle, the figures, and the description of the figures, and vice versa.

[0065] Furthermore, an electrically powered vehicle is described, wherein the electrically powered vehicle comprises at least one of a power semiconductor module and a drive train and a control unit, as described in detail.

[0066] The vehicle can be, for example, a fully electric vehicle, a hybrid vehicle, or a mild hybrid vehicle. It can be a motor vehicle, such as a car, a truck, or a bus. In particular, it can be a commercial vehicle suitable for use in harsh environments. However, the vehicle can also be any type of vehicle. 202401146

[0067] 13. other land vehicle, water vehicle, in particular ship, or aircraft, such as an airplane or a space vehicle.

[0068] The vehicle can in particular exhibit the aforementioned advantages, namely that the design of the power semiconductor module or the drive train comprising the semiconductor module or the control unit offers advantages with regard to thermal management and installation space requirements, while simultaneously keeping costs low.

[0069] With regard to further advantages and technical features of the vehicle, reference is made to the description of the power semiconductor module, the drive train, the control unit, the figures, and the description of the figures, and vice versa.

[0070] Another object of the present invention is an inverter or a power inverter, comprising at least one previously described (power) semiconductor module and a cooler with a cooling surface, wherein the (power) semiconductor module is arranged on the cooling surface and is thermally connected to the cooler.

[0071] A further object of the present invention is a drive train for an electrically propelled vehicle, comprising at least one previously described (power) semiconductor module, which further comprises at least one phase current connection that is electrically connected to the power semiconductor component of the power semiconductor module. The drive train further comprises an electric motor with at least one winding connection, wherein the (power) semiconductor module is electrically connected to the winding connection of the electric motor via its phase current connection.

[0072] The invention is further explained below with reference to the figures, whereby one or more features of the figures, individually or in combination, can constitute a feature of the invention. Furthermore, the figures are to be considered merely exemplary and in no way limiting.

[0073] Fig. 1 schematically shows a top view of a power semiconductor module according to a preferred embodiment of the invention; 202401146

[0074] 14

[0075] Fig. 2 schematically shows a top view of a power semiconductor device applied to a substrate according to a further preferred embodiment of the invention;

[0076] Fig. 3 schematically shows a sectional view through a power semiconductor device mounted on a substrate according to a further preferred embodiment in a) the X direction and in b) the Y direction; and

[0077] Fig. 4 schematically shows a sectional view of a power semiconductor module according to a further preferred embodiment of the invention;

[0078] Figure 1 schematically shows a top view of a power semiconductor module 10 according to a preferred embodiment of the invention. The power semiconductor module 10 shown comprises several power semiconductor devices 12 and several substrates 14, with each power semiconductor device 12 being applied to exactly one substrate 14. The substrates 14 with their respective power semiconductor devices 12 are embedded in a multi-layered printed circuit board 16. As can be seen, the substrates 14 with their power semiconductor devices are arranged side by side in two rows. Several power semiconductor devices 12 arranged in a row are connected in parallel and form a power switch 18. The power semiconductor module 10 shown in Figure 1 comprises two power switches 18 and is designed for one phase.Electrical power connections 20 for the circuit breakers 18 are provided at three edge areas of the power semiconductor module 10.

[0079] The substrate 14 has a rectangular shape, wherein the power semiconductor device 12 is arranged offset from a center of the substrate 14, such that an area of ​​the substrate 14 not covered by the power semiconductor device 12 around the power semiconductor device 12 has a different width on at least two opposite sides of the power semiconductor device 12.

[0080] Figure 2 schematically shows a top view of a power semiconductor device 12 applied to a substrate 14, according to a further preferred embodiment of the invention, while Figure 3 schematically shows a sectional view through a 202401146 applied to a substrate

[0081] 15

[0082] The power semiconductor device is shown in two views. In Figure 2 – and even more clearly in Figure 3 – it can be seen that the substrate 14 is designed as a metal-ceramic substrate 14 with a ceramic layer 24 arranged between two electrically conductive layers 22. The electrically conductive layers 22 are, in this case, copper layers 22.

[0083] The power semiconductor device 12 is connected to the electrically conductive layer 22, in this case the top side, via a sintered connection 26 shown in Figure 3. As is also clearly visible in Figure 3 and indicated in Figure 2, the edge of the electrically conductive layer 22 is chamfered due to the etching process.

[0084] As can also be seen in Figure 3, in this embodiment the power semiconductor module 10 also includes an annular semiconductor protection element 28. The semiconductor protection element 28 surrounds the power semiconductor device 12, at least partially, and has such a vertical extent that one upper surface of the semiconductor protection element 28 is higher than one upper surface of the power semiconductor device 12. The semiconductor protection element 28 is bonded to the substrate 14, and in particular to the electrically conductive layer 22, by means of an underfill adhesive 30.

[0085] The semiconductor protection element 28 has a chamfer at its outer edge region, which is adapted to the angle of the etched edge of the electrical layer 22 of the substrate 14. The semiconductor protection element 28 thus at least partially encloses the chamfered etched edge.

[0086] Figure 4 schematically shows a sectional view of a power semiconductor module 10 according to a further preferred embodiment of the invention. In particular, Figure 4 shows how the power semiconductor device 12 is embedded with the substrate 14 in the multi-layered printed circuit board 16.

[0087] The multi-layered printed circuit board 16 is designed with insulating layers 32 – in this case made of glass fiber reinforced epoxy resin – and adjacent copper layers 34, into which the conductive traces are embedded. As can be seen in Figure 4, in this embodiment the underside of the substrate 14 is free of power semiconductor components, and the power semiconductor component 12 is applied to the top side of the substrate 14. The underside of the substrate 14 is designed for heat dissipation via 202401146

[0088] Sixteen thermal vias 36 are connected through a first insulating layer 32a of the printed circuit board 16 to a first copper layer 34a of the printed circuit board 16. In this embodiment, a further insulating layer 32b adjoins this first copper layer 34a, wherein this insulating layer 32b is not a highly filled insulating layer with a high proportion of thermally conductive fillers. The copper layer 34a is also connected to a final copper layer 34b via thermal vias 36 through the further insulating layer 32b for heat dissipation. The copper layer 34b is suitable for being connected to a heat sink.

[0089] With regard to the top side, Figure 4 further shows that the top side of the substrate 14 and the power semiconductor device 12 is electrically connected via vias 38 through an insulating layer 32c of the printed circuit board 16 to a conductor 34c, 34c', 34c" of the printed circuit board 16 for electrical contact purposes. The power semiconductor device 12 is a power MOSFET 12, whose source terminal is connected to conductor 34c and whose drain terminal is connected to conductor 34c' via the substrate 14. The gate terminal of the power MOSFET 12 is connected to conductor 34c". As can be seen in Figure 4, a further insulation layer 32d and a further copper layer with conductors 34d are connected to the conductor layer 34c, with the gate connection of the power MOSFET 12 being connected to the conductor layer 34d via the via 38'.Inside the circuit board 16 is the so-called core layer, which consists of the insulation layer 32e and two copper layers 34e.

[0090] Figure 4 also shows the semiconductor protection element 28. In this case, the semiconductor protection element 28 completely covers the contact area of ​​the vias 38 on the substrate 14 for the electrical contacting of the drain terminal of the power semiconductor device 12. Furthermore, the power semiconductor device 12 and the substrate 14 are embedded in the printed circuit board 16 by an encapsulation material 40.

[0091] In the present exemplary embodiment, the power semiconductor module 10 is manufactured from the inside out, with the copper layers 34e being structured in a first step. An opening for the substrate 14 is then created in the core layer. Subsequently, the insulation layer 32a and copper layer 34a located beneath the core layers 32e and 34e are integrated. In a further step, the substrate 14 is coated with the applied 202401146

[0092] 17

[0093] The power semiconductor device 12 is inserted into the opening of the core layer 32e, 34e. To prevent air inclusions, the encapsulation material 40 is also added to the opening. The semiconductor protection element 28, made of a thermoset plastic, is then placed on the substrate 14. The opening is then covered on both sides with an insulating layer 32a, 32c and a copper layer 34a, 34c of the printed circuit board 16, and subsequently laminated. The copper layers 34c and 34a are then structured to form further conductor tracks. The vias 38 provide the electrical connection between the power semiconductor device 12 and the conductor tracks 34c, 34c', 34c" and the thermal vias 36 provide the thermal connection between the

[0094] Substrate 14 and copper layer 34a are produced by mechanical drilling and / or laser drilling through the insulating layers 32a and 32c, followed by an electroplating process. If necessary, the copper thickness can also be increased in the same electroplating process to improve current-carrying capacity or reduce ohmic losses. The remaining layers 32d, 34d, 32b, and 34c of the printed circuit board 16 can be built up by repeating these steps.

[0095] 202401146

[0096] 18

[0097] Reference symbol list

[0098] 10 Power semiconductor module

[0099] 12 power semiconductor devices

[0100] 14 Substrat

[0101] 16 circuit board

[0102] 18 circuit breakers

[0103] 20 power connection

[0104] 22 Electrically conductive layer of the substrate, copper layer

[0105] 24 ceramic layers

[0106] 26 Sintered compound

[0107] 28 Semiconductor protection element

[0108] 30 Underfill adhesive

[0109] 32 Insulation layer

[0110] 34 metal layers, copper layers, conductor tracks

[0111] 36 thermal via

[0112] 38 Via

[0113] 40 Encapsulation material

Claims

202401146 19 Patent claims 1. (Power) semiconductor module (10) comprising at least one substrate (14) on which at least one power semiconductor device (12) is applied on a first side, wherein the power semiconductor device (12) is embedded with the substrate (14) in a printed circuit board (16) comprising several layers (32, 34), characterized in that the substrate (14) is designed as a metal ceramic substrate (14).

2. (Power) semiconductor module (10) according to claim 1, wherein the metal ceramic substrate (14) has a ceramic layer (24) arranged between two electrically conductive layers (22) and wherein the power semiconductor device (12) is arranged on one of the electrically conductive layers (22).

3. (Power) semiconductor module (10) according to one of the preceding claims, wherein the substrate (14) has a second side opposite the first side, and wherein the second side of the substrate (14) is connected to a first metal layer (34a) of the printed circuit board (16) via thermal vias (36) through an insulating layer (32a) of the printed circuit board (16) for the purpose of heat dissipation.

4. (Power) semiconductor module (10) according to the preceding claim, wherein a further insulating layer (32b) of the printed circuit board (16) is connected to the first metal layer (34a), and wherein this further insulating layer (32b) is not a highly filled layer.

5. (Power) semiconductor module (10) according to one of the preceding claims, wherein none of the insulation layers (32) of the printed circuit board (16) is a highly filled layer.

6. (Power) semiconductor module (10) according to one of the preceding claims, wherein the first side of the substrate (14) and / or the power semiconductor device (12) is electrically connected via vias (38) through an insulating layer (32c) of the printed circuit board (16) to a conductor (34c, 34c', 34c“) of the printed circuit board (16) for electrical contacting purposes.

7. (Power) semiconductor module (10) according to one of the preceding claims, wherein the second side of the substrate (14) is free of power semiconductor components (12). 202401146 20 8. (Power) semiconductor module (10) according to one of the preceding claims, wherein the power semiconductor device (12) is embedded with the substrate (14) in the printed circuit board (16) by means of an encapsulation material (40).

9. (Power) semiconductor module (10) according to one of the preceding claims, comprising a semiconductor protection element (28) arranged on the first side of the substrate (14), which at least partially surrounds the power semiconductor device (12), wherein a vertical extent of the semiconductor protection element (28) is such that a top side of the semiconductor protection element (28) is at least as high as or higher than a top side of the power semiconductor device (12).

10. (Power) semiconductor module (10) according to claim 9, wherein the semiconductor protection element (28) is made of a plastic or a thermoset.

11. (Power) semiconductor module (10) according to claim 9 or 10, wherein the semiconductor protection element (28) at least partially encloses a preferably beveled edge region of the first side of the substrate (14).

12. (Power) semiconductor module (10) according to one of claims 9 to 11, wherein the semiconductor protection element (28) has at least one projection which projects towards the chamfered edge region of the first side of the substrate (14) and rests on the edge region.

13. (Power) semiconductor module (10) according to any one of the preceding claims 9 to 12, wherein the semiconductor protection element (28) is connected to the first side of the substrate (14) by means of an adhesive (30).

14. (Power) semiconductor module (10) according to one of the preceding claims, comprising several power semiconductor devices (12) and preferably several substrates (14), wherein the several power semiconductor devices (12) are embedded with the substrates (14) in the circuit board (16) comprising several layers (32, 34).

15. Inverter, comprising: 202401146 21 - at least one (power) semiconductor module (10) according to one of claims 1 to 14, and - a cooler with a cooling surface, wherein the (power) semiconductor module (10) is arranged on the cooling surface and is thermally connected to the cooler.

16. Powertrain for an electrically powered vehicle, comprising: - at least one (power) semiconductor module (10) according to one of claims 1 to 14, which further comprises at least one phase current connection that is electrically connected to the power semiconductor component (12) of the power semiconductor module (10), and - an electric motor with at least one winding connection, - wherein the (power) semiconductor module (10) is electrically connected to the winding connection of the electric motor via the phase current connection.

Images