Device and method for manufacturing a power semiconductor assembly and a power semiconductor assembly manufactured in this way

Abstract

The present invention relates to a device (52) for manufacturing a power semiconductor assembly (18) with a power semiconductor (24, 38a, 38b) contacted on both sides, comprising: a receiving unit (54) for receiving an assembly base (50) to be sintered, comprising a lower contacting module (42), a power semiconductor, and sintering paste (40a, 40b) introduced between the lower contacting module and the power semiconductor; a stamping unit (44) with a stamp (46a, 46b) for exerting a predefined contact pressure on the assembly base in order to create a sintered connection between the lower contacting module and the power semiconductor; and a measuring unit (56) for determining a height of an upper side of the power semiconductor above the lower contacting module after sintering.The invention further relates to a method for manufacturing a power semiconductor assembly (18) with a power semiconductor (24, 38a, 38b) contacted on both sides, and to a power semiconductor assembly (18).

Description

The present invention relates to a device for manufacturing a power semiconductor assembly with power semiconductor contacted on both sides. The present invention relates to a method and a power semiconductor package.The power electronics of electric and hybrid vehicles forwards the traction energy from the battery to the electric motor and thereby converts direct current into alternating current. For this purpose, an AC converter or else inverter or traction converter is provided. In particular, a plurality of transistors or other power semiconductors are usually used here, which are combined to form a power semiconductor module and switch at short and regular intervals. In particular, MOSFETs (metal oxide semiconductor field effect transistors) or also IGBTs (insulated gate bipolar transistors) are used as power semiconductors. In the switched-on state, the battery current is passed on to the motor (conducting phase). These high-frequency switching processes achieve a voltage profile of the alternating voltage, which can then be converted into traction energy in the electric motor. To increase the current-carrying capacity, a plurality of power semiconductors are usually connected in parallel.By means of such power semiconductor modules or power semiconductors, comparatively high currents are switched and the power semiconductors develop high temperatures. Active or passive cooling systems are often used for dissipating heat, in which the heat is dissipated from the power semiconductor via a heat sink to another medium. Corresponding assemblies for inverters therefore comprise, in addition to the power semiconductor itself, suitably designed contact modules for electrically and thermally contacting the power semiconductor and also usually corresponding cooler structures for dissipating the heat. In this respect, a heat conduction path from the power semiconductor into a cooling medium is established. The heat conduction path (thermal path) usually also has electrically insulating layers (for example. Ceramic layers) for electrically decoupling the cooler or the cooler structure.In previous approaches, assemblies have often been provided in which contactings for dissipating the heat are provided on one or both sides for individual power semiconductors.A current approach in this context lies in the use of both-sided cooling of a power semiconductor to improve the heat dissipation. In this connection, DE 10 2016 121 801 A1 discloses an assembly, a vehicle, a method for use and a method for producing the assembly. The package comprises at least one electronic chip. Furthermore, the assembly comprises at least one first heat dissipation body on which the at least one electronic chip is fastened by means of a first connection. Furthermore, the assembly comprises a second heat dissipation body attached on or above the at least one electronic chip by means of a second connection. Finally, the package comprises an encapsulant encapsulating at least a portion of the at least one electronic chip, a portion of the first heat removal body, and a portion of the second heat removal body. The first compound is configured to have a different melting temperature than the second compound.DE 10 2010 000 537 A1 considers the construction of assemblies with power conductors and spacer elements contacting two sides, wherein in WO 2017 / 222 010 A1 compounds, in particular those with sintering paste, are considered in detail within a power semiconductor assembly.A disadvantage of previous approaches in this environment is that the production of assemblies with contacting on both sides is often comparatively complicated. Multistage production processes in particular often lead to higher costs or to more complicated production. Differences in the dimensions of the power semiconductors due to manufacturing tolerances result in particular requirements.Proceeding from this, the object of the present invention is to provide an efficient approach for the production of power semiconductor assemblies which are contacted on both sides. The intention is to make possible a manufacture of the assembly which is flexible with regard to the dimensioning and configuration of the power semiconductor assembly to be produced but nevertheless efficient. In addition, the susceptibility to errors is to be reduced.To achieve this object, the present invention relates, in a first aspect, to a device for manufacturing a power semiconductor assembly having power semiconductor which is contacted on both sides, having:a receiving unit for receiving a module base to be sintered, having a lower contact module, a power semiconductor and sintering paste introduced between the lower contact module and the power semiconductor;a stamp unit having a stamp for applying a predefined contact pressure to the assembly base in order to produce a sintered connection between the lower contact module and the power semiconductor; anda measuring unit for determining a height of an upper side of the power semiconductor above the lower contacting module after sintering.In a further aspect, the present invention relates to a method for manufacturing a power semiconductor assembly with power semiconductor contacted on both sides, having the steps:receiving a package base to be sintered, having a lower contacting module, a power semiconductor and between the lower contacting module, andPower Semiconductor-Introduced Sintering Paste in a Receiving Unit;applying a predefined contact pressure to the assembly base in order to produce a sintered connection between the lower contact module and the power semiconductor by means of a punch of a punch unit; anddetermining a height of an upper side of the power semiconductor above the lower contacting module after sintering with a measuring unit.Finally, in one aspect, the present invention relates to a power semiconductor assembly having a plurality of power semiconductors which are fastened via sintered connections between a lower contacting module and an upper contacting module, wherein, in order to compensate for height tolerances of the plurality of power semiconductors, at least one spacer is arranged between at least one power semiconductor and the upper contacting module; and the power semiconductor assembly is preferably produced by means of a device as described above and / or in a method as described above.Preferred embodiments of the invention are described in the dependent claims. It is understood that the features mentioned above and those still to be explained below can be used not only in the respectively specified combination, but also in other combinations or alone, without departing from the scope of the present invention. In particular, the device, the method and the power semiconductor assembly can be embodied in accordance with the configurations described for the device, the method and the power semiconductor assembly in the dependent claims.According to the invention, it is provided that, for the production of a power semiconductor assembly having at least one power semiconductor which is contacted on both sides, firstly a assembly base is accommodated in an accommodation unit. This assembly base comprises a lower contacting module on which the power semiconductor is arranged, wherein sinter paste is introduced between the lower contacting module and the power semiconductor. For the sintering process, the pressure required for this is exerted by means of a punch in order to produce a sintered compound between the lower contact module and the power semiconductor. The punch of the punch unit generates a predefined contact pressure, which is a process parameter of the sintering process. It is provided that after the sintering process is completed, a height of an upper side of the power semiconductor above the lower contacting module is measured by means of a measuring unit. Thus, a thickness of the power semiconductor and of the sintered compound is determined, so to speak.Power semiconductors (semiconductor chips) of planar configuration are used. These often have different heights or thicknesses due to manufacturing tolerances. In other words, the power semiconductors used are therefore often of different thicknesses. In the case of contacting on both sides, this different height can lead to challenges. In particular in the case of a use of a plurality of power semiconductors on the same lower contacting module or in the same power semiconductor assembly. If, for example, two power semiconductors of different thicknesses are used in the same assembly, a height compensation must be provided in order to be able to mount an upper contacting module. For this height compensation, a spacer (spacer) can be provided in order to compensate for a possible height difference. Also in the case of a use of a single power semiconductor, a height compensation may be necessary in order to achieve a predefined overall height or in order not to exceed / fall below predefined maximum or minimum values. This is achieved according to the invention by determining the height of the upper side of the power semiconductor above the lower contact-making module.In comparison with previous approaches, in the device proposed according to the invention for manufacturing a power semiconductor assembly, a measuring unit is provided for automatically determining the height of the upper side of the power semiconductor above the lower contacting module. The automated and integrated height determination during production ensures that compensation can be carried out, for example by means of a corresponding spacer. The determination of the necessary dimensioning of a spacer is made possible without problems. In comparison with previous approaches with a separate determination of the dimensioning of a spacer, an efficiency gain is made possible. Costs can be saved and the process can be accelerated. Compared to previous approaches when using a single power semiconductor in a power semiconductor assembly, a predefined height can be realized, which simplifies the further processing or the further processing of the power semiconductor assembly.In a preferred embodiment, the measuring unit comprises a laser for interferometrically measuring a distance between the measuring unit and the upper side of the power semiconductor. A laser enables a highly accurate distance determination at reasonable costs. In addition, a robust measurement and also imaging of different installation situations can be made possible. This results in an accurate and cost-effective measurement of the distance that can be realized.In a preferred embodiment, the laser is designed to measure a penetration depth of the punch. Preferably, the laser is oriented parallel to a stamping direction of the stamp on a measuring surface on the stamp. In particular, an alignment to a measurement surface can be provided on an upper side of the punch. If it is assumed that a length of the punch or a dimensioning of the punch is known, a measurement of the insertion depth of the punch is sufficient. Due to the predefined contact pressure, this is directly connected to the height of the upper side of the power semiconductor above the lower contacting module. This applies in particular if a lower contacting module with a constant and known thickness is assumed. By using a measuring surface on the punch with parallel alignment of the laser direction to a punch direction, a simple and efficiently realizable configuration with low susceptibility to errors results.In a preferred embodiment, the stamp unit is designed to preset the predefined contact pressure on the stamp via a medium under pressure, preferably air. In particular, the stamp unit can be designed to introduce a pressure onto a medium. This pressure is then passed on to the punch and is thereby exerted as a predefined contact pressure on the assembly base to be sintered. The use of air additionally allows measurement by means of the laser through the air-filled space. In other words, the laser can thus be arranged in such a way that the interferometric measurement is carried out within the pressure chamber. This results in an efficient measurement with simple mechanical implementability.In a preferred embodiment, the stamp unit comprises a pressure chamber arranged above the stamp for receiving the medium. The measuring unit is designed to carry out a measurement inside the pressure chamber and is preferably arranged above the pressure chamber. In other words, it can be provided insofar that a measurement is carried out within the pressure chamber. In particular, it is advantageous if a laser is arranged within the pressure chamber and is aligned with a measurement surface on the punch, in particular at the top of the punch. By the measurement in the pressure chamber, an efficient and accurate measurement of the height of the top side of the power semiconductor can be implemented. In addition, there is a low risk of contamination and a possible measurement imprecision caused by this.In a preferred embodiment, the measuring unit comprises an optical detection unit for recording an optical coding on the punch and is designed for determining the height on the basis of the recorded optical coding. Additionally or alternatively, the measuring unit comprises an ultrasonic unit for carrying out an ultrasonic distance measurement and is designed for determining the height based on the ultrasonic distance measurement. Alternatively or additionally to the use of a laser, an optical detection unit can also be provided. In particular, an optical coding can be recorded by means of a camera. The recording of the optical coding can then be used as a basis for determining the height. For example, a line or other pattern can be recorded and evaluated by means of corresponding image processing algorithms. Alternatively or in addition to this, an ultrasonic distance measurement can also be carried out. By means of ultrasonic distance measurement, it is likewise possible to allow precise measurement of a distance at comparatively low costs.In a preferred embodiment, the receiving unit is configured to receive a module base to be sintered, having a lower contacting module, two or more power semiconductors and sintering paste introduced between the lower contacting module and the two or more power semiconductors. The stamp unit comprises a stamp for each power semiconductor and is configured to exert the predefined contact pressure on each power semiconductor of the two or more power semiconductors in order to produce a sintered compound in each case. The measuring unit is configured to determine heights of the upper sides of the two or more power semiconductors above the lower contacting module after sintering. In particular, in an advantageous configuration of the device according to the invention, a use of a plurality of power semiconductors on a common lower contacting module can be provided. A punch and a corresponding height determination are preferably provided separately for each power semiconductor. Manufacturing tolerances and thus different thicknesses occur between the different power semiconductors of the two or more power semiconductors. In order to compensate for these or to initially detect them, the measuring unit is designed to determine the different heights of the upper sides accordingly. This results in efficient processing in power semiconductor assemblies having a plurality of power semiconductors contacted on both sides.In a preferred embodiment, the measuring unit for measuring entry depths of the plurality of punches comprises a plurality of lasers assigned to the plurality of punches. Alternatively, the measuring unit for measuring entry depths of the multiple punches comprises a common laser with variable alignment, in particular a variable alignment converted by a movability of the common laser. For the different height measurements, on the one hand, a plurality of lasers can be provided, wherein in each case one laser is assigned to a respective punch. Alternatively, however, it is also possible for a common laser with a corresponding movability to be provided and for the measurement of the different heights to be carried out sequentially by means of said common laser. It may also be possible here for different light paths to be made possible by a corresponding mirror construction and the movability in this respect relates only to a changeover of a mirror. This results in an efficient and cost-effectively implementable measurement of the various heights. In addition, an accurate height detection is obtained.In a preferred embodiment of the method according to the invention, it comprises a step of attaching a spacer on the assembly base after sintering by a further sintering step. A thickness of the spacer was determined based on the determined height of the upper side of the power semiconductor, such that a defined total thickness of the assembly base with the spacer mounted thereon can be achieved. In particular, provision can be made for attaching a spacer within the production method. This spacer is selected depending on the determined height of the upper side of the power semiconductor or the thickness of the spacer is defined based thereon. For example, spacers from a predefined selection set may be used. Alternatively, however, it is also possible for a corresponding spacer to be produced separately in each case, for example by applying a corresponding layer with a corresponding thickness by a suitable plastics application method. By attaching the spacer, a defined total thickness is made possible. This results in efficient further processing. In addition, a cost reduction results due to a later re-measurement made possible by this.In a preferred embodiment, the method comprises a step of attaching an upper contacting module on the assembly base and in the spacer attached thereto by a further sintering step. In particular, the upper contacting module can be provided for the termination, wherein the defined height has already been reached and, insofar, no further tolerance compensation is necessary. This results in efficient production of a power semiconductor assembly with power semiconductor contacted on both sides.Herein, a power semiconductor assembly is understood in particular to mean a power semiconductor module or an assembly for use in an inverter or in an inverter structure. Usually, a plurality of power semiconductors are combined to form a power semiconductor module, wherein the power semiconductor module itself can in turn comprise a plurality of power semiconductor assemblies. A power semiconductor corresponds in particular to an electronic chip (semiconductor chip) which has one or more integrated circuit components. For example, MOSFETs or IGBTs can be used as power semiconductors. A power semiconductor is in particular a semiconductor switch. The terms "lower" and "upper" in connection with components or modules are used merely for clarification and differentiation. It goes without saying that the power semiconductor assembly can also be arranged elsewhere or upside down. The same applies to the distinction between "first" and "second". A first side and a second side or a first module and a second module are thus understood to mean in particular two different sides or two different modules. The power semiconductor assembly according to the invention is suitable in particular for use in a vehicle. Here, a determination of a height is understood in particular to mean a direct or indirect measurement of a thickness of a power semiconductor. This thickness is often different between different power semiconductors due to manufacturing tolerances. This thickness is measured directly or indirectly in order to be able to bring about a thickness compensation. This is important in particular if a plurality of power semiconductors are to be contacted on both sides. However, advantages also arise in the further processing in the case of a single power semiconductor.The invention will be described and explained in more detail below with reference to some selected exemplary embodiments in conjunction with the accompanying drawings. The following are shown: FIG. 1 is a schematic illustration of a vehicle having an inverter and an assembly in accordance with the present invention; FIG. 2 shows a schematic illustration of a thermal path from a semiconductor to the cooling medium in a subassembly of the prior art; FIG. 3 shows a schematic illustration of the problem of differently thick power semiconductors; FIG. 4 shows a schematic illustration of a device for producing a power semiconductor assembly with power semiconductor which is contacted on both sides without a measurement unit; FIG. 5 shows a schematic illustration of a device according to the invention for producing a power semiconductor assembly with power semiconductor contacted on both sides; FIG. 6 shows a schematic illustration of a power semiconductor assembly according to the invention with power semiconductor bonded on both sides and with spacers; FIG. 7 shows a schematic illustration of an alternative embodiment of a device according to the invention for producing a power semiconductor assembly; and FIG. 8 shows a schematic illustration of a method according to the invention.FIG. 1 schematically illustrates a vehicle 10 having an inverter 12 according to the invention. The inverter 12 is disposed between a battery 14 and an electric machine 16 of the vehicle 10 to convert the direct current of the battery 14 into the alternating current required by the electric machine 16. The inverter 12 usually comprises a plurality of power semiconductor assemblies 18, wherein, for example, a plurality of power semiconductor assemblies 18 can be combined to form a power semiconductor module and a plurality of power semiconductor modules can in turn be provided. The power semiconductor assemblies 18 each comprise the power semiconductors or semiconductor switches, which can be embodied in particular as MOSFETs. It is understood that the illustration is schematic and components are not illustrated in order not to impair the clarity.Current inverters are characterized in that the switching semiconductors (power semiconductors) must be actively cooled in order to dissipate the switching and power losses. In order to conduct away the losses, a heat conduction path is built up from the semiconductor into a cooling medium. In assemblies of the prior art, this thermal path comprises, for example, the components illustrated in FIG. 2.For dissipating the heat, the power semiconductor 24 is arranged on an upper copper layer 26, which in turn is arranged on a ceramic layer 28 and a lower copper layer 30. The construction of upper copper layer 26, lower copper layer 30 and ceramic layer 28 is also referred to as direct bonded copper (DBC) structure. The DBC structure is disposed on a cooling plate 32 (cooling member) that is in contact with the cooling medium 34. The thermal path from the power semiconductor 24 to the cooling medium 34 builds up across the various components, wherein the DBC structure represents an electrically insulating layer.The thermal resistance, i.e. the sum of the different thermal resistances of the individual components in FIG. 2, has a strong influence on the performance of the semiconductor. As an alternative to the meander structure for the cooling plate 32 shown in FIG. 2, pin-fin structures are also customary in use.To optimize the heat path, the thermal resistance must be minimized. At this point, there are electrically necessary resistors, such as ceramic layer 28 for insulation, as well as the resistors necessary from the manufacturing standpoint. Resistors which are necessary from the manufacturing standpoint are, in particular, the resistors of the copper layers 26, 30 which are required for the construction and connection technology and whose thickness can be optimized for the heat conduction. Furthermore, the resistance of the cooling plate 32 that is necessary from the manufacturing standpoint is obtained, which cannot be freely optimized for the heat conduction because of manufacturing and assembly-related restrictions. Finally, the resistance necessary for manufacturing purposes is the transition between cooling plate 32 and cooling medium 34, which is likewise greater than technically necessary on account of manufacturing and assembly-related restrictions.The connection between the various components, for example between cooling plate and copper, and also between copper and power semiconductor, is increasingly produced by sintered connections. Sintered connections are distinguished by low thermal resistance and high cycle stability. In order to ensure a high quality of the sintered connection, special tools are necessary which enable height compensation. In current power semiconductor assemblies with power semiconductor contacted on both sides, it is often necessary to use soldered connections because of the tolerance compensation.FIG. 3 schematically shows two power semiconductors 24 of different thicknesses (power semiconductors with different heights). Often, due to manufacturing tolerances, power semiconductors or semiconductor chips are of different thicknesses. In the case of a sintered connection, tolerance compensation of the piece to be sintered must take place. Despite different thicknesses, the most constant possible pressure must be exerted on the tool in order to produce a good sintered connection.There are several possibilities for implementation. A tool is required which can compensate for this difference in height or thickness. A possible realization of the prior art is shown in FIG. 4. In particular, a device 36 for manufacturing a power semiconductor assembly with power semiconductor contacted on both sides is shown. In the exemplary embodiment shown, a power semiconductor assembly having two power semiconductors 38 a, 38 bis produced. The device 36 comprises a stamp unit 44 with two stamps 46 a, 46 bwhich are movable in the Y direction. The actual contact pressure takes place via a liquid or gaseous medium which is introduced on one side of the device 36. In particular, in the exemplary embodiment shown, a pressure chamber 48 is provided for this purpose. Sinter paste 40 a, 40 bis applied to a lower contact module 42 at two points. In the exemplary embodiment shown, the assembly base 50 to be sintered comprises the lower contacting module 42, the two power semiconductors 38 a, 38 band the applied sintering paste 40 a, 40 b. A receiving unit 54 serves to receive the package base 50.In order to realize a two-sided sintered connection for two-sided cooling in such a sintering process, the difference in height or thickness must be compensated, preferably by a spacer (spacer). This requires the most accurate possible measurement of this height difference. According to the invention, for this purpose, a determination of a height of an upper side of the power semiconductor 38 a, 38 bover the lower contacting module 42 after sintering is proposed. In this context, FIG. 5 schematically shows an embodiment of a device 52 according to the invention for producing a power semiconductor assembly with power semiconductor contacted on both sides. Again, an embodiment is shown in which a power semiconductor assembly is fabricated with two power semiconductors 38a, 38b. The device 52 can be designed in particular as a sintering press or as part of such a press. The device 52 comprises a receiving unit 54 for receiving a module base 50 to be sintered. The module base 50 comprises a lower contacting module 42 and, in the exemplary embodiment shown, two power semiconductors 38 a, 38 bwith respectively associated sintering paste 40 a, 40 b. In addition, the device 52 comprises a punch unit 44 with two punches 46 a, 46 b, which are designed to exert a predefined contact pressure on the assembly base 50 in order to produce sintered connections. In the exemplary embodiment shown, the stamp unit 44 comprises a pressure chamber 48, in which a medium, in particular compressed air, is accommodated in order to apply the contact pressure to the stamps 46 a, 46 b.Furthermore, a measuring unit 56 is provided, which is designed to determine a height of an upper side of the two power semiconductors 38 a, 38 bover the lower contacting module 42 after sintering. In the exemplary embodiment shown, the measuring unit 56 comprises two lasers 58 a, 58 b, which are designed for interferometrically measuring a distance between the measuring unit 56 and the top side of the power semiconductors 38 a, 38 b. It is shown that it is possible in particular for the lasers to be designed for emitting a laser beam into the pressure chamber 48 onto a measurement surface attached to the upper side of the punch 46 a, 46 b. In this respect, the measuring unit 56 is thus designed to carry out a measurement within the pressure chamber 48. By means of the two lasers 58 a, 58 b, a retraction depth of the punches 46 a, 46 bis measured.According to the invention, it is thus possible to determine a height or a difference in height very accurately. In a subsequent further sintering step for contacting the power semiconductors 38 a, 38 bwith an upper contacting module (not shown), this difference can then be compensated. Since the two punches 46 a, 46 bare guided in the tool, non-parallelism can also be compensated for in this respect. The measurement is preferably carried out during the sintering process. The second sintering for contacting the upper contacting module can then take place directly subsequently.It goes without saying that, as an alternative to the embodiment shown in FIG. 5, power semiconductor assemblies with a single power semiconductor or else with a relatively large number of power semiconductors can also be used. In a corresponding manner, it may be possible that a different number of punches and / or lasers can be provided in each case. In addition, it is also possible for a plurality of punches to be measured by means of a single laser.FIG. 6 shows in this context a power semiconductor assembly 18 according to the invention, which is manufactured, for example, by means of the device described above. In the exemplary embodiment shown, the power semiconductor assembly 18 comprises a lower contacting module 42, two power semiconductors 38 a, 38 b, an upper contacting module 62 and a spacer 64.With the aid of the height measurement made possible according to the invention, a spacer can therefore be inserted, for example onto the upper side of the power semiconductor, and connected / connected by sintering. This thus makes it possible to produce a predefined maximum height.In FIG. 7, an alternative embodiment of a device 52 according to the invention is schematically shown. In other sintering presses, the tolerance compensation in the Y direction is effected by springs (e.g. disk springs) which form the punches of a punch unit 44. Here too, a corresponding height measurement can be carried out, for example by means of lasers, through the springs. For the reference numerals in FIG. 7, reference is made to the previously used reference numerals with reference to FIG. 5. The lasers 58 a, 58 bof the measuring unit 56 are oriented such that the distance measurement takes place through the springs 68 a, 68 b.In further alternative embodiments, it can be provided that instead of using a separate laser for each die, the use of a common laser is provided. This common laser can be moved, for example, between the punches by means of a corresponding device. Instead of a laser, it is also possible to use other methods for distance measurement, such as ultrasound or optical measurement methods. The method proposed according to the invention can also be applied to larger assemblies, such as, for example, the sintering of entire modules.FIG. 8 schematically illustrates a method according to the invention for producing a power semiconductor assembly with power semiconductor contacted on both sides. The method comprises a step of receiving S 10 a package base to be sintered. The method further comprises a step of applying S 12 a predefined contact pressure to the assembly base. In addition, the method comprises a step of ascertaining S 14 a height of an upper side of the power semiconductor above the lower contacting module. In the exemplary embodiment shown, the method further comprises optional steps of attaching S 16 a spacer on the assembly base and attaching S 18 an upper contacting module on the assembly base. The method can be implemented in software, for example, as a control method for a corresponding production device. In particular, the method may be a manufacturing method for a power semiconductor assembly.The invention has been fully described and explained with reference to the drawings and the specification. The description and explanation are to be taken by way of example and not limitation. The invention is not limited to the disclosed embodiments. Other embodiments or variations will become apparent to those skilled in the art upon use of the present invention, as well as upon a detailed analysis of the drawings, disclosure and appended claims.In the claims, the words "comprise" and "with" do not exclude the presence of further elements or steps. The undefined article "a" or "an" does not exclude the presence of a plurality. A single element or unit may perform the functions of several of the units recited in the claims. An element, a unit, an interface, a device and a system can be partially or completely implemented in hardware and / or in software. The mere naming of some measures in several different dependent claims is not to be understood as meaning that a combination of these measures cannot likewise be used advantageously. A computer program can be stored / distributed on a non-volatile data carrier, for example on an optical memory or on a solid state drive (SSD). A computer program can be distributed together with hardware and / or as part of hardware, for example by means of the Internet or by means of wired or wireless communication systems. Reference signs in the patent claims should be understood to be non-limiting.Reference numerals denote reference numerals10 Vehicle 12 Inverter 14 Battery 16 E-machine 18 Power semiconductor assembly 24 Power semiconductor 26 Upper copper layer 28 Ceramic layer 30 Lower copper layer 32 Cooling plate 34 Cooling medium 36 Prior art device 38 a, 38 b Power semiconductor 40 a, 40 b Sinter paste 42 Lower contacting module 44 Stamp unit 46 a, 46 b Stempel 48 Pressure chamber 50 Assembly base 52 Device 54 Receiving unit 56 Measuring unit 58 a, 58 bLaser 62 Upper contacting module 64 Spacer 66 Sintered layer 68 a, 68 b Federn

Claims

Device (52) for manufacturing a power semiconductor assembly (18) with power semiconductor (24, 38a, 38b) contacted on both sides, comprising: a receiving unit (54) for receiving a assembly base (50) to be sintered, comprising a lower contacting module (42), a power semiconductor and sintering paste (40a, 40b) introduced between the lower contacting module and the power semiconductor; a stamp unit (44) with a stamp (46a, 46b) for exerting a predefined contact pressure on the assembly base in order to produce a sinter connection between the lower contacting module and the power semiconductor; and a measuring unit (56) for determining a height of an upper side of the power semiconductor above the lower contacting module after sintering.The device (52) according to claim 1, wherein the measuring unit (56) comprises a laser (58a, 58b) for interferometrically measuring a distance between the measuring unit and the upper side of the power semiconductor (24, 38a, 38b).The device (52) according to claim 2, wherein the laser (58a, 58b) is configured to measure a retraction depth of the punch (46a, 46b); and preferably is aligned parallel to a punch direction of the punch on a measurement surface on the punch, in particular a measurement surface on an upper side of the punch.The device (52) according to any one of the preceding claims, wherein the stamp unit (44) is configured to preset the predefined contact pressure on the stamp (46a, 46b) via a medium under pressure, preferably air.The apparatus (52) according to claim 4, wherein the punch unit (44) comprises a pressure chamber (48) arranged above the punch (46a, 46b) for receiving the medium; and the measuring unit (56) is configured to perform a measurement inside the pressure chamber and preferably arranged above the pressure chamber.The device (52) according to any one of the preceding claims, wherein the measuring unit (56) comprises an optical detection unit for recording an optical coding on the punch (46a, 46b) and is configured to determine the height based on the recorded optical coding; and / or comprises an ultrasound unit for carrying out an ultrasound distance measurement and is configured to determine the height based on the ultrasound distance measurement.The device (52) according to any one of the preceding claims, wherein the receiving unit (54) is configured to receive a module base (50) to be sintered, having a lower contacting module (42), two or more power semiconductors (24, 38a, 38b) and sintering paste (40a, 40b) introduced between the lower contacting module and the two or more power semiconductors; the stamp unit (44) comprises a stamp (46a, 46b) for each power semiconductor and is configured to exert the predefined contact pressure on each power semiconductor of the two or more power semiconductors in order to generate a sinter connection in each case; and the measuring unit (56) is configured to determine heights of the upper sides of the two or more power semiconductors above the lower contacting module after the sintering.The apparatus (52) according to claim 7, wherein the measuring unit (56) for measuring retraction depths of the plurality of punches (46a, 46b) comprises a plurality of lasers (58a, 58b) associated with the plurality of punches; or comprises a common laser with variable alignment, in particular a variable alignment implemented by a movability of the common laser.Method for manufacturing a power semiconductor assembly (18) with power semiconductor (24, 38a, 38b) contacted on both sides, comprising the steps: receiving (S10) a assembly base (50) to be sintered with a lower contacting module (42), a power semiconductor and sintering paste (40a, 40b) introduced between the lower contacting module and power semiconductor in a receiving unit (54); applying (S12) a predefined contact pressure to the assembly base in order to generate a sinter connection between the lower contacting module and power semiconductor by means of a punch (46a, 46b) of a punch unit (44); and determining (S14) a height of an upper side of the power semiconductor above the lower contacting module after sintering with a measuring unit (56).Method according to claim 9, comprising a step of attaching (S16) a spacer (64) to the package base (50) after sintering by a further sintering step, wherein a thickness of the spacer has been determined based on the determined height of the top side of the power semiconductor (24, 38a, 38b), such that a defined total thickness of the package base with spacer attached thereon is achievable.Method according to one of Claims 9 to 10, having a step of attaching (S18) an upper contacting module on the assembly base (50) and the spacer (64) attached thereto by a further sintering step.Power semiconductor assembly (18) having a plurality of power semiconductors (24, 38a, 38b) which are fastened via sintered connections between a lower contacting module (42) and an upper contacting module (62), wherein, in order to compensate for height tolerances of the plurality of power semiconductors, at least one spacer (64) is arranged between at least one power semiconductor and upper contacting module; and the power semiconductor assembly is produced by means of a device according to one of Claims 1 to 8 and / or in a method according to one of Claims 9 to 11.

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