Power electronics component with cooling and a power converter

Abstract

The invention relates to a power electronics component (100, 118) for an electric power converter (4) for an industrial process assembly (1), designed to supply a load (2), preferably a plasma process or heating process, designed to supply a load (2), preferably a plasma process or heating process, wherein the component (100, 118) comprises: - an electrically insulating first substrate (6) which has a top-side metallisation layer (11) on its top side and a bottom-side metallisation layer (9) on its bottom side, the top-side metallisation layer (11) being divided into at least three electrically isolated regions of a conductor structure (11a, 11b, 11c), - a semiconductor assembly (28) which is mounted on the first substrate (6) and which has: o at least two semiconductor components (110a, 110b, 110c) connected in series, e.g. one or more transistors (S1, S2), in particular an IGBT (76), or one or more diodes (FD, SD1, SD2, SD3, SD4), in particular PIN diodes, at least one of which is a controllable power semiconductor component, e.g. a transistor (S1, S2) or a PIN diode, - a first heat sink (5), the first side of which facing the first substrate (6) is thermally connected to the bottom-side metallisation layer (9) of the first substrate (6), which bottom-side metallisation layer faces away from the semiconductor assembly (28), wherein the heat sink (5) is monolithically constructed and is fixedly connected to the bottom-side metallisation layer (9) and has a first cooling channel (35) for guiding a cooling flow (36).

Description

[0001] Power electronic unit with cooling and power converter

[0002] The invention relates to a power electronic component with cooling. Furthermore, the invention relates to a method for joining a power electronic component.

[0003] The invention also relates to an electrical power converter for an industrial process arrangement, preferably a plasma process arrangement or heating arrangement, comprising, in particular, a high-frequency amplifier arrangement. This RF amplifier arrangement has a previously mentioned power electronics unit and is designed to generate an RF output power, in particular for plasma excitation, such as plasma coating processes, preferably for the production of semiconductor structures.

[0004] There are particular challenges for cooling in the field of electrical power conversion for specific power-intensive and instabilities-prone industrial processes, such as plasma excitation, plasma coating processes, gas laser excitation, particle accelerators, charging and discharging devices for large batteries, such as flow batteries, melting of solids, heating and / or gasification of liquids using, for example, microwave energy or induction heating, or plasma torches. This can be a process for generating radiation, e.g.

[0005] Microwave radiation, X-rays or particle accelerators. What all these processes have in common is that they are designed to generate and accelerate charged atomic or subatomic particles in a gas and / or plasma environment or liquid. Another thing all these processes have in common is that they have a high power consumption in the range of 1 kW or more, in particular 10 kW or more, preferably 100 kW or more. For the mentioned power range, frequencies > 20 kHz, preferably > 200 kHz, in particular > 2 MHz, are generated internally or for external applications. Many of these processes also have very high requirements in terms of the stability of the power supply because the processes are highly complex, such as semiconductor production using plasma processes and / or heating by electromagnetic fields. Typically, power from a mains frequency in the range of approx.50 Hz to 60 Hz, to different frequencies, which can be in the above-mentioned range. Conversion to direct current power, also called DC power, is also conceivable. Even when converting to direct current power, a frequency in the above-mentioned range is often generated internally for the power signal, which is then rectified again according to the requirements for voltage, current and power. This conversion of electrical power into other frequencies requires a large number of electronic components and assemblies, in particular power semiconductor components, such as transistors or diodes, in particular PIN diodes, for example for switching RF power between different paths, or a combination of transistor and diode designed for currents > 10 A and voltages > 400 V. These electronic components and assemblies generate heat loss during operation. The heat loss is often generated in a very limited area of ​​just a few mm.2 , e.g. < 8 mm 2 Dissipating this waste heat to protect components and / or assemblies from damage due to overheating presents a particular challenge. Often, very large and material-intensive heat sinks are used for this purpose, and their production is very costly.

[0006] In the prior art, the heat is dissipated by cooling using a cold plate. When cooling with such a conventional cold plate, the heat transfer from the electrical component, which may have a copper layer, to the cooling medium is achieved by applying a material such as thermal paste to the thermal interface, which dissipates the generated heat. However, such thermal interface material proves to be disadvantageous. On the one hand, it represents an additional heat transfer with thermal resistance, and on the other hand, it is subject to wear, which gradually deteriorates its effectiveness during operation. The surface area of ​​the cold plate is also increased or the number and performance of the components is reduced in order to dissipate a greater amount of heat. Both options prove to be inadequate. Since the installation space in the housing of such a power supply is limited, expanding the cooling surface is not possible indefinitely.Reducing the performance of individual components is also not effective. Overall, inadequate cooling of electrical components results in costs.

[0007] A particularly demanding area is a process for plasma excitation, especially plasma processing, such as coating, e.g. PVD, CVD, or etching. Such processes are used in the manufacture of semiconductors such as microprocessor components and / or memory chips. Here, the requirements for reliability, longevity, and process repeatability are particularly high. At the same time, the required power levels are also very high. Furthermore, the required output modulations, e.g. in modern electrical power converters with an RF amplifier arrangement or pulsed high-voltage power supplies with pulse shaping, have recently increased steadily. One requirement for RF amplifier arrangements can, for example, be the ability to be pulsed with several different power levels, which is called multi-level pulsing (MLP). Another requirement for RF amplifier arrangements can, for example,the ability to adjust the frequency and thus, for example, to be able to react quickly to load changes, which is called auto-frequency tuning (AFT). A further requirement can be, for example, the ability to provide a very high DC voltage, e.g. greater than or equal to 2 kV, in particular greater than or equal to 7 kV, in pulsed form, with pulse frequencies greater than or equal to 1 kHz, in particular greater than or equal to 10 kHz, particularly preferably greater than or equal to 200 kHz. With all of these requirements, the demands on power semiconductor components that are installed in the RF amplifier arrangement and used to generate the RF power also increase. In particular, the requirement for these components to convert power that cannot be delivered to the load in certain conditions into heat also increases. These losses that are converted into heat can be > 500 W, in particular > 1 kW in some applications.This heat must be dissipated by the power semiconductor components, otherwise they will be destroyed by overheating.

[0008] The object of the invention is to provide a power electronics assembly and a method for joining a power electronics assembly that enable improved dissipation of the heat generated during operation of power components. It is also an object of the invention to provide an electrical power converter for an industrial process arrangement that enables improved dissipation of the heat generated during operation of power components.

[0009] The solution to the problem is achieved by a power electronic unit according to claim 1.

[0010] Possible embodiments are disclosed in the dependent claims or in the description.

[0011] The power electronics unit for an electrical power converter for an industrial process system is designed to supply a load, preferably a plasma process or heating process. The power electronics unit comprises:

[0012] - an electrically insulating first substrate having a top-side metallization layer on its top side and a bottom-side metallization layer on its bottom side, wherein the top-side metallization layer is divided into at least three electrically separated regions of a conductor structure,

[0013] - a semiconductor assembly mounted on the first substrate, comprising: o at least two series-connected semiconductor components, e.g., one or more transistors, in particular one or more IGBTs, or one or more diodes, in particular PIN diodes. Of the two series-connected semiconductor components, at least one is a controllable power semiconductor component, e.g., a transistor or a PIN diode. The two series-connected semiconductor components comprise:

[0014] ■ at least one first terminal, in particular designed as a collector terminal surface or source terminal surface, which is thermally and electrically connected to at least one first region of the conductor structure,

[0015] ■ at least one second connection, in particular designed as an emitter connection surface or drain connection surface, which is electrically connected to a second connection surface of another semiconductor component and / or to one of the regions of the conductor structure via a plurality of connecting lines, in particular designed as bonding wires,

[0016] - a first heat sink arranged on the first substrate, the first side of which facing the first substrate is thermally connected to the underside metallization layer of the first substrate facing away from the semiconductor assembly,

[0017] - wherein the heat sink o is monolithically constructed and o is firmly connected to the underside metallization layer and o has a first cooling channel for guiding a cooling flow.

[0018] This allows for a significant reduction in thermal resistance. Cooling of the semiconductor component can be achieved very effectively. The heat sink can be made many times smaller.

[0019] In one aspect of the development, the semiconductor components are designed as bare-die semiconductor components and are thermally and electrically connected directly to one of the areas of the conductor structure via their first connection.

[0020] This allows the thermal resistance to be further reduced, allowing the semiconductor component to be cooled even more effectively. In one aspect of the development, the three areas of the conductor structure are arranged side by side in series.

[0021] In one aspect of the development, two series-connected semiconductor devices are arranged on at least two of the three regions of the conductor structure.

[0022] In one aspect of the development, a third area of ​​the conductor structure is free of semiconductor components and, in particular, only has contacting of the connections.

[0023] In one aspect of the development, the third region of the conductor structure is arranged between the other two regions of the conductor structure.

[0024] In one aspect of the development, the power electronic unit, in particular the semiconductor assembly, comprises: an AC converter arrangement, comprising o two DC voltage connections and o two AC voltage connections, wherein the AC converter arrangement is designed to convert a DC voltage or a DC current into an AC voltage or an AC current.

[0025] The AC converter arrangement can be designed in particular to generate an RF output power in the range of 300 W or more, 1 kW or more, in particular 2 kW or more, at frequencies > 20 kHz, preferably > 200 kHz, in particular > 2 MHz

[0026] This can include a push-pull amplifier. It can include a bridge circuit, particularly a full-bridge circuit.

[0027] Several AC converter arrangements of this type can be provided in an electrical power converter and thus the electrical power converter can provide output powers in the range of 1 kW or more, in particular 10 kW or more, preferably 100 kW or more.

[0028] In one aspect of the development, the structural unit, in particular the semiconductor assembly, particularly preferably the AC converter arrangement, comprises: a semiconductor switching unit comprising two transistors, wherein the transistors are electrically connected to one another at at least one power terminal.

[0029] In one aspect of the development, the power electronics unit, in particular the semiconductor assembly, particularly preferably comprises the AC converter arrangement: one, in particular two identically constructed, particularly preferably four identically constructed semiconductor switching units, each having a control terminal and two power terminals. The power terminals are preferably designed as a positive terminal point and a negative terminal point.

[0030] In one aspect of the development, the power electronic unit, in particular the semiconductor assembly, particularly preferably the AC converter arrangement comprises: an intermediate circuit capacitor, which is arranged in particular very close to the semiconductor components, in particular very close to the power terminals of the transistors, preferably with connection lines with a length of < 20 mm, particularly preferably < 10 mm.

[0031] In one aspect of the development, the positive connection point is formed as one of the areas of the conductor structure.

[0032] In one aspect of the development, the negative connection point is formed as one of the areas of the conductor structure.

[0033] In one aspect of the development, the common connection point is formed as one of the regions of the conductor structure, in particular as one of the regions located between two other regions of the conductor structure.

[0034] In one aspect of the development, the power electronic unit, in particular the semiconductor assembly, particularly preferably comprises the AC converter arrangement:

[0035] A positive contact connection device and a negative contact connection device

[0036] - each designed to contact a connection point on a printed circuit board or a mechanical connecting line, e.g. a copper line,

[0037] In one aspect of the development, the positive contact connection device is directly electrically connected to one of the regions of the conductor structure, in particular to the positive connection point. This connection is preferably made by ultrasonic welding.

[0038] In one aspect of the development, the negative contact connection device is directly electrically connected to one of the regions of the conductor structure, in particular to the negative connection point. This connection is preferably made by ultrasonic welding.

[0039] In one aspect of the development, a plurality of transistors are electrically connected in parallel at their power terminals. In one aspect of the development, at least one transistor is connected in series with a series diode arrangement, in particular comprising a plurality of series diodes electrically connected in parallel, wherein one, several, or in particular all of the series diodes are designed as Schottky diodes.

[0040] In one aspect of the development, a freewheeling diode is electrically connected in parallel with the power terminals of at least one of the transistors.

[0041] In one aspect of the development, several of the semiconductor switching units are arranged on a heat sink.

[0042] In one aspect of the development, the power electronic assembly further comprises: an electrically insulating additional substrate having a metallization layer on its top and bottom sides, wherein the additional substrate is attached to the second side of the first heat sink opposite the first side, and wherein the second side of the first heat sink is thermally connected to the metallization layer of the additional substrate facing the first heat sink.

[0043] In one aspect of the development, one or more semiconductor switching units can be arranged on a top side of the heat sink and one or more further semiconductor switching units can be arranged on a bottom side of the heat sink.

[0044] A half-bridge or full-bridge can be cooled very effectively using a heat sink.

[0045] In one aspect, the power electronics unit comprises a semiconductor assembly and an electrically insulating first substrate on which the semiconductor assembly is mounted and which has a metallization layer on its top and bottom sides, wherein at least one terminal of the semiconductor assembly is thermally and electrically connected to at least a region of the metallization layer of the first substrate facing the semiconductor assembly. Furthermore, the power electronics unit comprises a first heat sink, the first side of which, facing the first substrate, is thermally and electrically connected to the metallization layer of the first substrate facing away from the semiconductor assembly.Furthermore, the power electronics assembly comprises an electrically insulating additional substrate having a metallization layer on its top and bottom sides. The additional substrate is attached to the second side of the first heat sink opposite the first side, and the second side of the first heat sink is thermally, and in particular also electrically, connected to the metallization layer of the additional substrate facing the first heat sink. In the following, the metallization layer is also referred to simply as "metallization."

[0046] In the power electronics unit according to this solution, the underside of a semiconductor assembly is cooled. For this purpose, the semiconductor assembly is thermally and electrically connected to the metallization of a first substrate facing the semiconductor assembly. A thermal and electrical connection to the first heat sink is formed via the metallization of the first substrate facing away from the semiconductor assembly. The heat generated on the semiconductor assembly side can therefore efficiently reach the first heat sink via the metallization layers of the first substrate and be dissipated there. The side of the heat sink facing away from the semiconductor assembly is connected to an additional substrate. For this purpose, the first heat sink is thermally, and in particular also electrically, connected to the metallization of the additional substrate facing the heat sink.The first heat sink is therefore connected to the first substrate on its top side and to the additional substrate on its bottom side. This sandwich arrangement creates a mechanically stable structural unit. A further advantage is that additional assemblies and components can be accommodated on the additional substrate, the heat generated by these components during operation being dissipated via the first heat sink. In particular, this could include control circuits that generate the control signals required to operate power components, for example. However, the use of the additional substrate is not limited to control circuits; rather, the additional substrate can be used for any type of component or assemblies.

[0047] In a further aspect, a method for joining a power electronic component is disclosed, the method comprising the following steps:

[0048] - Arranging a top-side metallization layer on a top side of an electrically insulating first substrate, wherein the top-side metallization layer is divided into at least three electrically separated regions of a conductor structure,

[0049] - Arranging a bottom metallization layer on the bottom side of the first substrate

[0050] - Arranging a semiconductor assembly on the first substrate, the semiconductor assembly comprising: at least two series-connected semiconductor components, e.g. one or more transistors, in particular one or more IGBTs, or one or more diodes, in particular PIN diodes, of which at least one is a controllable power semiconductor component, e.g. a transistor or a PIN diode,

[0051] - Producing at least one thermal and electrical connection between at least one terminal of the semiconductor assembly, in particular the two semiconductor components connected in series, and at least a first region of the top-side metallization layer of the first substrate facing the semiconductor assembly,

[0052] - Producing at least one electrical connection line from a second terminal of the semiconductor assembly, in particular the two semiconductor components connected in series, in particular designed as bonding wires, to at least one second connection surface of another semiconductor component or to one of the regions of the conductor structure,

[0053] - Construction of a first monolithically constructed heat sink with a first cooling channel for guiding a cooling flow,

[0054] - Arranging the first monolithically constructed heat sink on the first substrate, and

[0055] - Producing a thermal and electrical connection between a first side of the first heat sink facing the first substrate and the underside metallization layer of the first substrate facing away from the semiconductor assembly.

[0056] This reduces thermal resistance, allowing for very effective heat dissipation of the semiconductor component.

[0057] In one aspect, the method comprises the following further method step:

[0058] - Arranging a positive contact connection device on a region of the conductor structure with a direct electrical connection to the region of the conductor structure, in particular by means of ultrasonic welding.

[0059] This allows the thermal resistance to be further reduced, allowing the semiconductor component to be cooled even more effectively.

[0060] In one aspect, the method comprises the following further method step:

[0061] - Arranging a negative contact connection device at a region of the conductor structure with a direct electrical connection to the region of the conductor structure, particularly by means of ultrasonic welding. This allows the thermal resistance to be further reduced. Cooling of the semiconductor assembly can thus be achieved even more effectively.

[0062] In one aspect, the method comprises the following further method step: arranging an electrically insulating additional substrate, which has a metallization layer on its top and bottom sides, on the second side of the first heat sink opposite the first side, and establishing a thermal and electrical connection between the second side of the first heat sink and the bottom metallization layer of the additional substrate facing the first heat sink.

[0063] In one aspect, the power electronics assembly comprises an electrically insulating first substrate, which has a metallization layer on its top and bottom sides, and a semiconductor assembly mounted on the first substrate, which has at least one first terminal that is thermally and electrically connected to at least one region of the top-side metallization layer of the first substrate facing the semiconductor assembly. Furthermore, the power electronics assembly comprises an electrically insulating second substrate, which is mounted on the semiconductor assembly and has a metallization layer on its top and bottom sides, wherein the semiconductor assembly has at least one second terminal that is thermally and electrically connected to at least one region of the metallization layer of the second substrate facing the semiconductor assembly, a first heat sink,which is thermally and electrically connected to the underside metallization layer of the first substrate facing away from the semiconductor assembly, wherein the first heat sink has at least one first cooling channel through which coolant can flow, and a second heat sink which is thermally, and in particular also electrically, connected to the metallization layer of the second substrate facing away from the semiconductor assembly, wherein the second heat sink has at least one second cooling channel through which coolant can flow.

[0064] In one aspect, the power electronics unit has a semiconductor assembly that can be cooled on both its top side and its bottom side. For this purpose, the semiconductor assembly is thermally and electrically connected on its bottom side to the metallization of the first substrate facing the semiconductor assembly, wherein the metallization of the first substrate facing away from the semiconductor assembly is thermally, and in particular also electrically, connected to the first heat sink. This arrangement enables improved heat dissipation on the bottom side of the semiconductor assembly. The top side of the semiconductor assembly is correspondingly thermally and electrically connected to the metallization of the second substrate facing the semiconductor assembly, wherein the metallization of the second substrate facing away from the semiconductor assembly is thermally, and in particular also electrically, connected to a second heat sink.In this way, efficient heat dissipation is also enabled on the top side of the semiconductor module. Heat dissipation is further improved by the fact that both the first heat sink and the second heat sink each have at least one cooling channel through which coolant can flow. Thanks to the power electronics unit described here, even large amounts of heat generated on the semiconductor module side can be efficiently dissipated. It is particularly advantageous that the thermal coupling of the heat sinks takes place via the metallizations of the first and second substrates, because coupling the heat sinks via metallization layers results in improved heat transfer. The solution described here provides a compact and mechanically stable unit that cools the semiconductor module on both sides and provides improved heat dissipation.

[0065] In a further aspect, a method for joining a power electronic component is disclosed. The method comprises arranging a semiconductor assembly on an electrically insulating first substrate, which has a metallization layer on each of its top and bottom sides, and establishing at least one thermal and electrical connection between at least one first terminal of the semiconductor assembly and at least one region of the top-side metallization layer of the first substrate facing the semiconductor assembly.Furthermore, the method comprises arranging an electrically insulating second substrate, which has a metallization layer on its top and bottom sides, on the semiconductor assembly and establishing at least one thermal and electrical connection between at least one second terminal of the semiconductor assembly and at least one region of the top metallization layer of the second substrate facing the semiconductor assembly.The method also comprises arranging a first heat sink on the first substrate, the first heat sink having at least one first cooling channel through which coolant can flow, establishing a thermal and electrical connection between the first heat sink and the metallization layer of the first substrate facing away from the semiconductor assembly, arranging a second heat sink on the second substrate, the second heat sink having at least one second cooling channel through which coolant can flow, and establishing a thermal and electrical connection between the second heat sink and the metallization layer of the second substrate facing away from the semiconductor assembly.

[0066] To describe the structure of the power electronics unit, terms such as "on," "top," and "bottom" are used in this application to describe the geometric arrangement of the components of the power electronics unit. These specifications refer to a power electronics unit placed on a horizontal surface. The use of these terms is not intended to be restrictive with regard to the spatial orientation of the power electronics unit. Rather, the power electronics unit can be used in any spatial orientation. In particular, the power electronics unit can be used in any installation position.

[0067] In one aspect, the semiconductor assembly comprises one or more semiconductor components, in particular power semiconductor components, e.g. designed for currents > 10 A and / or designed for voltages > 400 V.

[0068] The semiconductor assembly is preferably arranged in a “bare die layer.” A “bare die layer” here refers to a layer in which one or more semiconductor components are arranged as “bare dies.” The term “bare dies” is derived from English usage. The terms “bare chips,” “die,” or “chip” are often used synonymously. These refer to integrated electronic components that are not conventionally installed in a plastic or ceramic package, but are further processed without a package. They are applied directly to the conductor structure of the substrate and can be electrically connected to surrounding components or conductor structures by bonding, in particular by chip bonding. Bonding here refers to the connection of bare dies to other components or conductor structures.

[0069] The bare die layer may have regions where no semiconductor components are arranged. These regions may be filled with a filler material. This filler material may be designed to improve stability, reduce mechanical stresses, and / or improve electrical insulation, for example, by increasing air and / or creepage distances.

[0070] The term "connection" here refers to any type of connection that the semiconductor device may have, for example: collector connection, emitter connection, drain connection, source connection, control connection, test connection. In particular, it can be a power connection, e.g., collector connection, emitter connection, drain connection, source connection. Each connection can have a connection surface with which it can be contacted to one of the metallizations. A power connection can, in particular, have a relatively large area of ​​2 mm 2or more.

[0071] An electrical connection refers, in particular, to a high-quality, low-resistance, and low-inductance connection. It should preferably have a contact resistance of 0.2 Ω or less and, preferably, a contact inductance of 5 nH or less.

[0072] A “thermal connection” refers in particular to a high-quality thermal connection with low thermal resistance.

[0073] The requirement arises from predictable power dissipation, e.g. in a semiconductor component such as a transistor, a diode, in particular a PIN diode e.g. for switching RF power between different paths, or from or a combination of transistor with diode, and system thermal resistance from bare die to the coolant. The system thermal resistance is calculated as the sum of all thermal resistances. The first important thermal resistance, which cannot be influenced by the cooling arrangement, is the thermal resistance between bare die or chip and bare die cooling surface. It is specified by the manufacturer as RthJ / C (from English Junction / Case). It depends on the cooling surface of the semiconductor component and can be, for example, between 0.7 K / W and 0.8 K / W for currently common transistors.

[0074] As previously mentioned, modern plasma process applications, particularly in the manufacture of semiconductors such as computers or memory chips, place high demands on electrical power converters. These can often only be met if the semiconductor component(s) are designed to absorb significant power dissipation. This can, for example, be greater than or equal to 1 kW. To achieve this, a thermal resistance of less than or equal to 0.15 K / W, measured from bare die or chip to coolant, should preferably be achieved. After extensive simulations and tests, it was determined that this can be achieved with the present power electronics component. Further improvements are not excluded and are always welcome.

[0075] In one aspect, the first heat sink is at least partially realized in the form of a layered structure of thermally bonded metal foils, preferably copper foils. Such a production of a monolithic heat sink is disclosed, for example, in DE4315580A1, in which individual metal foils are at least partially structured by laser processing and / or punching and / or produced by electroplating processes and subsequently joined to one another. Such a method is referred to below as a "metal layer bonding method." Preferably, the first heat sink is at least partially produced by a metal layer bonding method. Preferably, the metal foils are bonded to one another by a bonding method under high pressure and at high temperature.

[0076] In one aspect, the first heat sink is made of copper. Copper exhibits very good thermal and electrical conductivity. For example, oxide layers can be formed on the surfaces of copper layers, which are then welded together. The temperature is preferably chosen to be high enough so that the oxide layers melt but the metal foils do not. The metal foils thus bond to form a monolithic heat sink. If the metal foils are made of copper, for example, this is also referred to as direct copper bonding, abbreviated to DCB.

[0077] In one aspect, the metal foils have a thickness of 0.4 mm or less, in particular 0.25 mm or less. This allows for very effective heat dissipation.

[0078] In one aspect, the first heat sink has at least one first cooling channel through which coolant can flow, wherein the at least one first cooling channel is implemented in the form of at least one recess provided in the metal foils. For example, the structuring or production of the metal foils can be carried out in such a way that, after the layers are joined together, closed channels are created through which a cooling medium can flow.

[0079] It is advantageous if the first heat sink is connected to the underside metallization layer of the first substrate facing away from the semiconductor assembly by at least one of the following: sintering, pressing, a metal layer connection method, in particular DCB, at least one solder connection.

[0080] In one aspect, the first heat sink is produced at least partially by means of an additive manufacturing process, preferably by means of selective laser melting. One such additive manufacturing process is disclosed, for example, in EP1672690B1 Micro heat sink. The now more common term "additive manufacturing process" is described there using the method of selective laser melting. However, "additive manufacturing process" can also include processes other than selective laser melting. An additive manufacturing process is characterized in that the structure is gradually applied from the same material. The material can be melted during application. Lasers are currently suitable for this purpose in order to achieve particularly fine structures. In one aspect, a plurality of cooling pins are arranged in the first cooling channel or in a partial region of the first cooling channel and extend into the first cooling channel.The cooling pins are surrounded by the coolant flowing in the cooling channel. This allows for improved thermal coupling.

[0081] It is advantageous if the first heat sink comprises a coolant supply and a coolant discharge, both of which are fluidically connected to the first cooling channel, wherein the first heat sink is configured such that the first heat sink can be detachably fastened to a cooling unit comprising a first fluid port and a second fluid port, and that when the first heat sink is fastened to the cooling unit, a first fluidic connection can be formed between the coolant supply of the first heat sink and the first fluid port of the cooling unit, and a second fluidic connection can be formed between the coolant discharge of the first heat sink and the second fluid port of the cooling unit. The cooling unit is configured to supply coolant to the first heat sink and to discharge the coolant again.The first heat sink can, for example, be designed such that, when the first heat sink is mounted in the cooling unit, fluid-tight fluidic connections can be formed between the first heat sink and the cooling unit. This makes it possible, for example, to remove the power electronics module from the cooling unit as needed. This enables, for example, a detachable mounting of the power electronics module in the cooling unit. This is advantageous, particularly from the point of view of maintenance and repair.

[0082] In one aspect, the first heat sink is a micro heat sink, and the semiconductor assembly is an electronic component. A micro heat sink is configured to cool a single electronic component. This allows for customized cooling that can be adapted to the heat generated by the electronic component.

[0083] In one aspect, the first substrate is integrally connected to the first heat sink at a first cooling wall, wherein the power electronics component is designed such that, during operation, the coolant is guided through the first cooling channel at a predetermined operating pressure, wherein a distance between the first cooling channel and the first cooling wall is selected to be so small that the first heat sink cannot ensure sufficient dimensional stability and / or tightness at the predetermined operating pressure without the first substrate being integrally connected to it, and the first substrate and its integral connection to the first heat sink at the first cooling wall is designed such that the power electronics component can ensure this sufficient dimensional stability and tightness. A typical predetermined operating pressure can be, for example, 3 bar or more overpressure compared to ambient pressure.There are several ways to design the substrate and its integral connection to the heat sink on the cooling wall so that the cooling arrangement can ensure sufficient dimensional stability and tightness. For example, the substrate can have a certain minimum thickness throughout. The substrate can be thicker, for example, in places where the distance between the cooling channel and the substrate is particularly small, to ensure stability only there. However, the dimensional stability of the substrate is only one parameter. The strength of the integral connection between the substrate and the heat sink is also important. The more stable this can be designed, the thinner the substrate can be.

[0084] It is advantageous if the first cooling channel is characterized in that its cross section has, at least in sections, a geometric shape whose width, measured parallel to the first cooling wall, decreases in the direction of the first cooling wall, and wherein the geometric shape of the cross section at the first cooling wall has a distance from the substrate which is designed such that at the predetermined operating pressure of the coolant, the first heat sink cannot ensure sufficient dimensional stability and / or tightness without the first substrate being integrally connected to it.

[0085] It is advantageous if at least one control terminal and at least one first power terminal are arranged on a first side of the semiconductor module and at least one second power terminal is arranged on the second side of the semiconductor module. In this embodiment, the first power terminal can be electrically contacted from the first side and the second power terminal from the second side. This enables large-area electrical contact between the power terminals. This is advantageous in view of the high currents that flow via the power terminals. The following discusses some solutions for leading the control terminal, which generally carries less current than the power terminals, out of the power electronics unit.

[0086] In one aspect, the metallization layer facing the first side of the semiconductor assembly has at least one first metallization region for electrically contacting at least one control terminal of the semiconductor assembly and at least one second metallization region for electrically contacting at least one first power terminal of the semiconductor assembly, wherein the at least one first metallization region and the at least one second metallization region are electrically separated from one another, and wherein at least one first metallization region is led to the side of the assembly and can be electrically contacted from the side of the assembly. In this embodiment, at least one control terminal can be electrically contacted by at least one first metallization region and at least one first power terminal can be electrically contacted by at least one second metallization region.This allows the control connection to be routed to the side of the unit.

[0087] It is advantageous if the at least one first metallization region and the at least one second metallization region of the metallization layer are separated from one another by means of an etching process. The etching process can divide the metallization layer into different, electrically separated metallization regions.

[0088] In one aspect, a contacting structure is provided for electrically contacting the control terminal, which is arranged on the metallization facing the first side of the semiconductor assembly. The contacting structure comprises at least one insulating material layer and a conductive layer, and the conductive layer is electrically connected to the control terminal and led to the side of the assembly. It is particularly advantageous if the conductive layer, which serves to lead out the control terminal, is electrically separated from other metallization regions by means of insulating material layers.

[0089] In one aspect, electrical contacting of at least one control terminal of the semiconductor assembly is achieved via at least one through-hole plating, also called a via, running through the first heat sink. At least one of the control terminals can be contacted from the side facing away from the semiconductor assembly via the at least one via.

[0090] In the area of ​​one or both heat sinks, a via insulation can be provided for a via, which protects the via from electrical contact with the heat sink.

[0091] In one aspect, the second heat sink is manufactured at least partially using a metal layer bonding process, in particular a DCB process. It is advantageous if the metallization layers of the second substrate and the metal foils of the second heat sink are bonded in one process. This means that all metal foils forming the heat sink and the metallization layer of the substrate are bonded to one another in one process. In one aspect, the first heat sink is manufactured at least partially using a metal layer bonding process, in particular a DCB process. It is advantageous if the underside metallization layer(s) of the first substrate and the metal foils of the first heat sink are bonded in one process. This means that all metal foils forming the heat sink and the metallization layer(s) of the substrate are bonded to one another in one process.

[0092] In one aspect, the second heat sink is at least partially realized in the form of a layered structure of thermally bonded metal foils, preferably copper foils. For example, metal foils can be at least partially structured by laser processing and / or punching and / or manufactured by electroplating processes and subsequently joined together. Preferably, the second heat sink is manufactured at least partially by a metal layer bonding process.

[0093] Preferably, the metal foils are bonded together using a bonding process under high pressure and at high temperature.

[0094] In one aspect, the second heat sink is made of copper. Copper exhibits very good thermal and electrical conductivity. For example, oxide layers can be formed on the surfaces of copper layers, which are then welded together. The temperature is preferably chosen to be high enough so that the oxide layers melt but the metal foils do not. In this way, the metal foils bond to form a monolithic heat sink. If the metal foils are made of copper, for example, this is also referred to as direct copper bonding, abbreviated to DCB.

[0095] In one aspect, the metal foils have a thickness of 0.4 mm or less, in particular 0.25 mm or less. This allows for very effective heat dissipation.

[0096] In one aspect, the second heat sink is connected to the metallization layer of the second substrate facing away from the semiconductor assembly by at least one of the following: sintering, pressing, a metal layer connection method, in particular DCB, at least one solder connection.

[0097] In one aspect, the first substrate and / or the second substrate is one of the following: ceramic substrate, direct bonded copper (DBC), insulated metal substrate (IMB), active metal brazed (AMB), thick film substrate.

[0098] In one aspect, the first substrate is arranged substantially parallel to the second substrate. The semiconductor assembly is surrounded by the first substrate at the bottom and the second substrate at the top, each of which is thermally connected to the associated heat sinks. This enables efficient heat dissipation to both sides. The symmetrical arrangement of the substrates results in a space-saving design and a favorable geometry with regard to the assembly of the assembly.

[0099] In one aspect, the first heat sink and the second heat sink are each micro heat sinks and the semiconductor assembly is an electronic component. In this embodiment, the first and the second heat sink are each designed as micro heat sinks. A micro heat sink is configured to cool a single electronic component. In the present case, the electronic component is therefore cooled by both the first and the second heat sink, both of which are designed as micro heat sinks. The electronic component together with the two micro heat sinks can, for example, be removed from a larger assembly and reinserted into it, which is advantageous from the point of view of maintenance and repair. This enables individual cooling that can be adapted to the heat generated by the electronic component.

[0100] It is advantageous if the assembly comprises control electronics arranged on the side of the additional substrate facing away from the first heat sink, wherein at least one terminal of the control electronics is thermally and electrically connected to at least one region of the metallization layer facing the control electronics. Control electronics that generates the signals required to control the semiconductor assembly can preferably be accommodated on the additional substrate. In this way, it is possible to generate the control signals for the semiconductor assembly located on the first substrate in the immediate spatial environment of the semiconductor assembly. This makes it possible to reduce or avoid signal interference in the control signals, which can arise, for example, from the coupling of electromagnetic interference signals.The at least one via can be used to route the control signals generated by the control electronics directly to the semiconductor module, for example, to control power electronic components there. Via insulation can be provided in the area of ​​the heat sink to protect the via from electrical contact with the heat sink.

[0101] In one aspect, at least one terminal of the control electronics is electrically connected to a terminal of the semiconductor assembly via at least one via that extends through the first heat sink. In one aspect, the first heat sink has at least one first cooling channel through which coolant can flow. It is advantageous if the first heat sink is implemented in the form of a layered structure made of thermally bonded metal foils, preferably copper foils, and the first cooling channel is implemented in the form of at least one recess provided in the metal foils.

[0102] In one aspect, the first substrate and / or the additional substrate is one of the following: ceramic substrate, direct bonded copper (DBC), insulated metal substrate (IMB), active metal brazed (AMB), thick film substrate.

[0103] Further preferably, the first substrate is arranged substantially parallel to the additional substrate. The arrangement of the first substrate on the underside of the first heat sink and the second, parallel, additional substrate on the top of the heat sink creates a compact geometric structure in which the heat sink is stabilized by the two substrates. The coolant supply and coolant discharge lines of the heat sink can be accessible, for example, from the side of the heat sink or, alternatively, can be routed through the additional substrate.

[0104] The object is also achieved by an electrical power converter for an industrial process arrangement, preferably a plasma process arrangement or heating arrangement, comprising a power electronics component as described above or below. The electrical power converter can be designed in particular to generate an RF output power. RF output power here refers to an output power in the range of 1 kW or more, in particular 10 kW or more, preferably 100 kW or more, at frequencies > 20 kHz, preferably > 200 kHz, in particular > 2 MHz.

[0105] As mentioned at the beginning, such a power converter is particularly dependent on very powerful and reliable cooling, which can be achieved particularly well with such a power electronics unit.

[0106] EP3317966B1 describes an arrangement with a printed circuit board for cooling on a metallic cooling plate. The printed circuit board has a bottom layer, with the bottom layer being a metallic layer that serves as a reference ground. However, the heat transfer from the printed circuit board to the cooling plate is not optimal. The card often does not lie flat on the cooling plate. To counteract the lack of heat transfer caused by this disadvantage, thermal paste is used. However, this is disadvantageous in the manufacturing process and can age, which can further deteriorate the heat transfer.

[0107] In one aspect, the power electronic unit comprises two power semiconductor components, in particular transistors, each having a first and a second power terminal and a control terminal. Both power semiconductor components, in particular transistors, are connected to one of their power terminals in a series circuit, with a direct current or direct voltage being connected to the remaining power terminals. This can be done, for example, directly or via a filter or an inductor.Furthermore, control electronics can be provided, which are connected to the control terminals of the power semiconductor components. The control electronics are designed to control the power semiconductor components, in particular transistors, in such a way that they can generate RF power and switch from a first conducting state to a second conducting state, with the conductivity of the two states being different. Such an arrangement can be operated very efficiently, e.g., in Class D, Class E, Class F, or Class F'. 1Operation of this type generates less power loss than, for example, Class A or Class B operation. In combination with the excellent cooling provided by the described power electronics unit, an even better supply of power to industrial processes can be achieved, for example, by allowing them to be operated at higher power. Typical operating classes for generating RF power are described, for example, in EP 1 601 098 B1.

[0108] In one aspect, the two power semiconductor components, in particular transistors, can each be connected by their first power terminal to a common connection point, in particular a ground connection point, wherein the power semiconductor components, in particular transistors, are in particular of similar design and are arranged on the multilayer printed circuit board. This allows cooling to be further improved and the power yield to be further increased.

[0109] In one aspect, one of the two power semiconductor components, in particular transistors, can be connected by its first power terminal to the other power semiconductor component, in particular transistor, and by its second power terminal to a common connection point, wherein the power semiconductor components, in particular transistors, are in particular of similar design and are arranged on the multilayer printed circuit board. This allows cooling to be further improved and the power yield to be further increased. In one aspect, a power transformer having a primary winding and a secondary winding can be arranged on the printed circuit board, wherein the primary winding is connected to the at least one power terminal of the power semiconductor components, in particular transistors.The primary and secondary windings of the power transformer can each be designed as planar conductor tracks arranged in different layers of the circuit board. The circuit board can have a thermal connection to the cooling unit. This can further improve cooling and increase power output.

[0110] In one aspect, the thermal connection to the cooling unit may comprise a thermally conductive compensation layer, the first surface of which is firmly connected to the first surface of the circuit board. Furthermore, the thermal connection may alternatively or additionally comprise a connecting layer, the first surface of which is firmly connected to the second surface of the thermally conductive compensation layer, and the second surface of which is firmly connected to the cooling unit.

[0111] The cooling unit can have heat-distributing characteristics. It can be electrically conductive or insulating.

[0112] By firmly connected we mean that the connection is firm and permanent, such as gluing, welding, soldering or pressing and preferably can only be removed with high heat and / or mechanical pressure.

[0113] In particular, the connection can be made with a material bond. This prevents air pockets and ensures good heat conduction.

[0114] In particular, the underside metallization layer can form a monolithic unit with the heat sink. This can be achieved, for example, using a direct-bonded-copper (DBC) process. Alternatively, or additionally, this can be achieved using an additive manufacturing process on the underside metallization layer. In both processes, the underside metallization layer can be integrated into the process step.

[0115] The thermally conductive leveling layer is designed to conduct heat from the circuit board toward the cooling unit. It can compensate for unevenness caused, for example, by conductor tracks, windings, or contact pads on the underside of the circuit board and provide a homogeneous and flat surface toward the cooling unit.

[0116] The thermally conductive compensating layer can be made of a prepreg or unreinforced adhesive. The insulating circuit board and the heat spreader can be bonded by heating and pressing together a prepreg sandwiched between them. "Prepreg" is a common material name, short for "preimpregnated." This typically refers to pre-impregnated, usually flat, sheet-like textile semi-finished products with a thermoplastic or thermosetting matrix, such as unidirectional layers of threads, fabrics, or scrims, often with perpendicularly arranged threads.

[0117] Prepregs are cured under heat and pressure to produce components. They are prefabricated, for example, in sheet form, wound on rolls. The term prepreg encompasses not only unidirectionally reinforced or flat semi-finished products, but also other preforms of essentially any shape, consisting, in the broadest sense, of a fiber-filled, uncured thermoset matrix. The matrix is ​​in a partially cross-linked state and is pasty to solid, but can be liquefied again by heating.

[0118] Prepregs are machine-processable and are therefore frequently used in automated processes. They produce consistent, high-quality products. Their advantages include their low undulation and high fiber volume fraction. Curing at high temperatures enables short cycle times in further processing. Processing requires significant investment, e.g., for autoclaves, placement robots, and refrigerated storage. Such prepregs are generally used to join several circuit boards together to form a multilayer circuit board. To ensure a secure and long-lasting joint, the materials to be joined should have very similar properties regarding their expansion under heat. However, this is not necessarily the case for the circuit board and the heat spreader, especially if the heat spreader is made of ceramic. This initially spoke against such a connection.However, ceramic exhibits very good thermal conductivity and, at the same time, very good electrical insulating properties, as well as low dielectric losses when isolating high-frequency signals at high voltages. Contrary to expectations, however, tests have shown that, even with small dimensions, a secure and long-lasting joining of materials with different properties, such as ceramic with FR-4 and / or ceramic with PTFE material, is possible. "Small dimensions" here means a bonding area of ​​less than 400 cm. 2 and / or with a maximum length of 20 cm.

[0119] The bonding layer may comprise a resin-based adhesive. It may be thinner than the thermally conductive compensating layer. The bonding layer may comprise an adhesive film.

[0120] Together, the two layers can form a solid connection with good heat conduction to the cooling unit.

[0121] In one aspect, such an electrical power converter will improve the properties of a power supply system that has LDMOS transistors as the element to be cooled, as disclosed, for example, in DE 102013226537 A1, EP 3 317 964 B1, EP3 317 965 B1. The load capacity of the LDMOS transistors in such power supply systems often reaches its limits because they become too hot, even though neither their maximum voltage nor their maximum current carrying capacity has been reached. This means that with a cooling improvement as described above and below, such power supply systems can be operated much more reliably.

[0122] In one aspect, such an electrical power converter will improve the properties of a power supply system which provides very high voltages at its output, in particular voltages greater than or equal to 1 kV, more preferably greater than or equal to 2 kV, in particular greater than or equal to 4 kV. This is particularly preferred if these are also provided in pulsed form, as described, for example, in EP 4235 737 A1 as a 'high power generator'. Since the switching elements described therein must switch on even when a voltage is applied to their power terminals, these switching operations are particularly lossy. EP 4235 737 A1 describes a very complex cooling process, which can be improved with the device and / or method described here.

[0123] In one aspect, such an electrical power converter will improve the properties of a power supply system having a coupler unit, in particular a phase-shifting coupler unit, preferably a 90° hybrid coupler, as described, for example, in DE 102013226537 A1 or WO 2020 / 025547 A1. This coupler unit described therein can be used independently of further features as described in DE 102013226537 A1 or WO 2020 / 025547 A1. The coupler unit can preferably have a first and a second planar inductance, as also described in DE 102013226537 A1.

[0124] In one aspect, such an electrical power converter will improve the properties of a power supply system that includes GaN transistors as the element to be cooled. Such power converters are described, for example, in WO 2010 / 091696 A1 or WO 2010 / 091697 A1.

[0125] In one aspect, such an electrical power converter will improve the properties of a power supply system that has SiC transistors as the element to be cooled. Such power converters are described, for example, in WO 2020 / 025547 A1.

[0126] The patent publications DE 102013 226 537 A1, EP 3 317 964 B1, EP3 317 965 B1 , WO 2010 / 091696 A1 , WO 2010 / 091697 A1 , WO 2020 / 025547 A1 and EP 4235 737 A1 are incorporated in their entirety by reference into this application.

[0127] Further advantageous embodiments are described in more detail below with reference to several exemplary embodiments shown in the drawings, to which the development described here is not, however, limited.

[0128] Not all claimed features are necessarily visible in the figures.

[0129] They show schematically:

[0130] Fig. 1 shows an industrial process arrangement with an electrical power converter with a first embodiment of a power electronic unit.

[0131] Fig. 1a shows a first embodiment of a power electronic unit.

[0132] Fig. 1b shows a circuit diagram of an embodiment of a semiconductor assembly designed as a semiconductor switching unit.

[0133] Fig. 1c shows a detailed area of ​​a power electronic unit from Fig. 1a

[0134] Fig. 1d shows a circuit diagram of an embodiment of a semiconductor assembly designed as an AC converter arrangement.

[0135] Fig. 2 shows an electronic assembly as part of a second embodiment of a power electronic unit.

[0136] Fig. 3 shows a further embodiment of an electronic assembly as part of a fourth embodiment of a power electronic unit.

[0137] Fig. 4 shows the connection surfaces of an IGBT.

[0138] Fig. 5 shows a further embodiment of a power electronic unit.

[0139] Fig. 6 shows an embodiment of a power electronic unit in an oblique view.

[0140] Fig. 6a shows an electrical power converter in an industrial process arrangement, preferably a plasma process arrangement or heating arrangement.

[0141] Fig. 7 shows a further embodiment of a power electronics unit. Fig. 8 shows a third embodiment of a power electronics unit. Fig. 9 shows a further embodiment of a power electronics unit.

[0142] Fig. 10 shows a first possibility for leading a control terminal of a semiconductor component out of the power electronics unit laterally.

[0143] Fig. 11 shows a second possibility for leading a control terminal of a semiconductor component out of the power electronics unit laterally.

[0144] Fig. 12 shows a third possibility for leading a control terminal of a semiconductor component out of the power electronic unit.

[0145] Fig. 12a shows an electrical power converter in an industrial process arrangement, preferably a plasma process arrangement or heating arrangement.

[0146] In the following description of preferred embodiments, the same reference numerals designate the same or comparable components.

[0147] The semiconductor assembly 28 described in the following figures comprises electronic components and assemblies for power applications, in particular power semiconductor components such as transistors or diodes, in particular PIN diodes, e.g., for switching RF power between different paths, or a combination of transistor and diode, which are designed, for example, for currents >10A and voltages >400V. These can generate high levels of heat loss during operation, which must be dissipated. The load capacity of such electronic components and assemblies often reaches its limits because they become too hot, even though neither their maximum voltage nor their maximum current carrying capacity has been reached.

[0148] Fig. 1 shows an industrial process arrangement 1 with an electrical power converter 4 in an industrial process arrangement, preferably a plasma process arrangement or heating arrangement with a first embodiment of a power electronic unit 100,

[0149] The industrial process arrangement 1 has:

[0150] - an electrical power converter 4,

[0151] - a load 2, preferably a plasma process or heating process, e.g. an induction or microwave heating process, wherein the load 2 is electrically connected to the electrical power converter 4 so that the electrical power converter 4 can supply the load 2 with the required electrical power,

[0152] - optionally an additional adjustment unit 3, which is connected between the power converter 4 and the load 2. The power converter 4 has:

[0153] - two of the first power electronic units 100, as described previously or subsequently, for example, in the description of Fig. 1a, b, c,

[0154] - a cooling unit 22 comprising, as described above and below, one or more distribution units 20 and a carrier unit 21,

[0155] - a circuit board 75,

[0156] - a unit 10 to be cooled, in particular an electrical unit, preferably a semiconductor device, preferably comprising a power semiconductor component,

[0157] - further electronic components 8a, 8b, 8c, wherein the further electronic components 8a, 8b, 8c and the unit 10 to be cooled are arranged on or at a printed circuit board 75 and are connected by electrical contacts, wherein the unit 10 to be cooled has a fixed, in particular material-locking, connection with the heat sink 5.

[0158] Two power semiconductor components, in particular transistors S1, S2, are arranged on or on the circuit board 75 as the unit 10 to be cooled. Each transistor has a first and a second power terminal and a control terminal G1, G2, 12B. Both transistors S1, S2 can be connected to one of their power terminals to form a series circuit. A direct current or direct voltage DC+, DC- can be connected to the remaining power terminals. Control electronics 114 can be connected to the control terminals of the power semiconductor components.

[0159] Also arranged on the circuit board 75 is a power transformer 197 comprising a primary winding 196 and a secondary winding 194. The primary winding 196 and the secondary winding 194 of the power transformer 197 are each designed as planar conductor tracks arranged in different layers of the circuit board 75. The circuit board has a thermal connection to the cooling unit 22.

[0160] The thermal connection to the cooling unit 22 can comprise a heat-conducting compensation layer which is firmly connected with its first surface to the first surface of the circuit board 75, and a connection layer which is firmly connected with its first surface to the second surface of the heat-conducting compensation layer and with its second surface to the heat spreader.

[0161] Figures 1a to 1d are described in context. Fig. 1a shows a detailed embodiment of a power electronics unit 100 for an industrial process arrangement 1, preferably a plasma process arrangement or heating arrangement, as already shown in Fig. 1. Fig. 1b shows a circuit diagram of an embodiment of a semiconductor assembly 28 designed as a semiconductor switching unit 150. In Fig. 1a, two such semiconductor switching units 150 are arranged side by side on a heat sink 50. In this way, a half-bridge can be constructed, for example, for a Class-D amplifier or a medium-frequency (MF) power converter. These are preferably used for induction heating processes and / or plasma processing processes.

[0162] With two such half-bridges, a full bridge can be constructed, as shown, for example, in Fig. 1d. For this purpose, the semiconductor assembly 28 with the top-side metallization 11 and the first substrate 6, which is arranged on the top side of the heat sink in Fig. 1a, can be arranged in an identical configuration on the bottom side.

[0163] Fig 1c shows a detailed area of ​​a power electronic unit from Fig. 1a.

[0164] Fig. 1d shows a circuit diagram of an embodiment of a semiconductor module designed as an AC converter arrangement, here in particular as a full bridge.

[0165] With three half-bridges, as shown in Fig 1a, a 3-phase AC converter can be constructed, for example for feeding power into a supply network, e.g. at 50 or 60 Hz, or a drive circuit for an electric motor.

[0166] The power electronic unit 100 comprises:

[0167] - an electrically insulating first substrate 6, o which has a top-side metallization layer 11 on its top side and o a bottom-side metallization layer 9 on its bottom side, o wherein the top-side metallization layer 11 is divided into at least three electrically separated regions of a conductor structure 11a, 11b, 11c.

[0168] The power electronic unit 100 further comprises:

[0169] - a semiconductor assembly 28 mounted on the first substrate 6, which in turn comprises: o at least two series-connected semiconductor components 110a, 110b, 110c, of which at least one is a controllable power semiconductor component, e.g. a transistor S1, S2 or a PIN diode not shown here, wherein the two series-connected semiconductor components 110a, 110b, 110c comprise:

[0170] ■ at least one first terminal 77, in particular designed as a collector terminal area 84 or a source terminal area not shown here. The first terminal 77 is thermally and electrically connected to at least a first region of the conductor structure 11a, 11b, 11c.

[0171] ■ at least one second terminal 79, in particular designed as an emitter terminal area 78 or a drain terminal area (not shown here), which is electrically connected via a plurality of connecting lines 112 to a second terminal area 79 of another semiconductor component 110a, 110b, 110c and / or to one of the regions of the conductor structure 11a, 11b, 11c. The connecting lines 112 can be designed, in particular, as bonding wires.

[0172] The power electronic unit 100 further comprises:

[0173] - a first heat sink 5 arranged on the first substrate 6, the first side of which facing the first substrate 6 is thermally connected to the underside metallization layer 9 of the first substrate 6 facing away from the semiconductor assembly 28,

[0174] - wherein the heat sink 5 o is monolithically constructed and o is firmly connected to the underside metallization layer 9 and o has a first cooling channel 35 for guiding a cooling flow 36.

[0175] A heat sink made of metal can dissipate heat very effectively. However, it may have the disadvantage of electrical conductivity. This electrical conductivity carries the risk of inducing currents within it. These could lead to additional unwanted losses. However, thanks to its particularly high heat dissipation efficiency, the dimensions of the heat sink have been reduced to such an extent that the induction of currents has also been significantly reduced.

[0176] The semiconductor components 110a, 110b, 110c are designed here as bare-die semiconductor components and are directly thermally and electrically connected with their first connection 77 to one of the regions of the conductor structure 11a, 11b, 11c.

[0177] This allows the thermal resistance to be further reduced, allowing the semiconductor component to be cooled even more effectively.

[0178] The three areas of the conductor structure 11a, 11b, 11c are arranged side by side in series in Fig. 1a and Fig. 1c.

[0179] In this way, the inductance in the connecting lines can be reduced. The two series-connected semiconductor components 110a, 110c are arranged here on two of the three areas of the conductor structure 11a, 11c.

[0180] This allows the inductance in the connecting lines to be reduced,

[0181] A third region of the conductor structure 11b is free of semiconductor components and has, in particular, only contacting of the connections 112, which are designed here as bonding wires.

[0182] This allows the inductance in the connecting lines to be reduced,

[0183] The third region of the conductor structure 11b is arranged here between the two other regions of the conductor structure 11a, 11c.

[0184] This allows the inductance in the connecting lines to be reduced,

[0185] Reducing the inductance in the connecting lines reduces unwanted and loss-causing oscillations in the semiconductor module. This further reduces heat generation, allowing the heat sink to be made smaller.

[0186] The assembly 100, 118, in particular the semiconductor assembly 28, may comprise: an AC converter arrangement 152, comprising two DC voltage terminals DC1, DC2 and two AC voltage terminals AC1, AC2, configured to convert a DC voltage or a DC current into an AC voltage or an AC current in the aforementioned power range and the aforementioned frequency range.

[0187] The AC converter arrangement 152 may include a push-pull amplifier. Such a push-pull amplifier can be particularly well cooled.

[0188] The AC converter arrangement 152 may comprise a bridge circuit, in particular a full-bridge circuit, as shown by way of example in Fig. 1d. Thus, such a bridge circuit can be particularly well cooled.

[0189] The assembly 100, 118, in particular the semiconductor module 28, in particular the AC converter arrangement 152, comprises here: a semiconductor switching unit 150, comprising two transistors S1, S2, wherein the transistors S1, S2 are electrically connected to one another at at least one power terminal.

[0190] This allows such a circuit to be cooled particularly well.

[0191] The assembly 100, 118, in particular the semiconductor assembly 28, preferably the AC converter arrangement 152, comprises here: one, in particular two identical, particularly preferably four identical semiconductor switching units 150 having one or more control terminals G1, G2, 128 and two power terminals, designed as a positive terminal point P1 and a negative terminal point N1.

[0192] This allows such a circuit to be cooled particularly well.

[0193] The assembly 100, 118, in particular the semiconductor assembly 28, preferably the AC converter arrangement 152, has here: an intermediate circuit capacitor C1, which is arranged in particular very close to the semiconductor components, in particular power terminals of the transistors S1, S2, preferably with connection lines with a length of less than or equal to 20 mm, particularly preferably less than or equal to 10 mm.

[0194] This allows the inductance in the connecting lines to be reduced.

[0195] The positive connection point P1 is formed here as one of the areas of the conductor structure 11c. This allows the inductance in the connecting lines to be reduced.

[0196] The negative connection point N1 is formed here as one of the areas of the conductor structure 11a. This allows the inductance in the connecting lines to be reduced.

[0197] A common connection point L1 is formed here as one of the areas of the conductor structure 11b. This allows the inductance in the connecting lines to be reduced.

[0198] The assembly 100, 118, in particular the semiconductor module 28, preferably the AC converter arrangement 152, comprises a positive contact connection device PP1 and a negative contact connection device PN1, each configured to contact a connection point on a circuit board 75 or a mechanical connecting line, e.g., a copper line. This allows the inductance in the connecting lines to be reduced.

[0199] The positive contact connection device PP1 is directly electrically connected to one of the areas of the conductor structure 11c, in particular to the positive connection point P1. This connection is preferably made by ultrasonic welding. This allows the inductance in the connecting lines to be reduced.

[0200] The negative contact connection device PN1 is directly electrically connected to one of the regions of the conductor structure 11a, in particular to the negative connection point N1. This connection is preferably established by ultrasonic welding. This allows the inductance in the connecting lines to be reduced. Ultrasonic welding is a preferred technique for joining metals: on the one hand in the form of wire bonding, and on the other hand as ultrasonic welding for connecting connection devices to substrates, e.g., DCB substrates or stranded wires and cables in external circuits. Power levels from 500 W up to the kilowatt range are used for ultrasonic welding. For this purpose, piezoelectrically generated, low-frequency ultrasonic oscillations in the range of 15 to 50 kHz can be used. These can differ in terms of oscillation form and force impression.The following adverse properties are known for the different types when used:.

[0201] • Longitudinal vibrations tend to cause so-called hammering, which describes unwanted vibrations in the vertical direction and can have a negative effect on components or connections already on the substrate.

[0202] • Torsional vibrations have a radius-dependent vibration amplitude, which can lead to insufficient connection formation in the center.

[0203] In the present assembly, these disadvantages could be overcome and a reliable connection could be made by means of ultrasonic welding, regardless of the type of vibration, without negatively affecting other connections or components on the assembly.

[0204] Here, several transistors S1 and S2 are electrically connected in parallel at their power terminals. This reduces the inductance in the connecting lines.

[0205] At least one transistor S1, S2 is connected in series with a series diode arrangement SD, in particular comprising a plurality of series diodes SD1, SD2, SD3, SD4 connected electrically in parallel.

[0206] In this case, one, several or in particular all series diodes SD1, SD2, SD3, SD4 are designed as Schottky diodes.

[0207] A freewheeling diode FD is electrically connected in parallel to the power terminals of at least one of the transistors S1, S2.

[0208] In Fig. 1a it is shown that several of the semiconductor switching units 150 are arranged on a heat sink 50.

[0209] Not shown, but as a possible embodiment, one or more semiconductor switching units 150 can be arranged on a top side of the heat sink 5, and one or more further semiconductor switching units 150 can be arranged on a bottom side of the heat sink 50. For this purpose, a further substrate, such as the first substrate, can be arranged on the other side of the heat sink 5. This will be described in more detail below. Thus, a half-bridge or full-bridge can be cooled very effectively by a heat sink 50.

[0210] Fig. 2 shows an electronic assembly 24 with a cooling arrangement 7 and with an electrical unit 10 to be cooled, which is preferably a semiconductor arrangement. The electronic assembly 24 can be part of a power electronics unit 188, as described above and below. The cooling arrangement 7 has the first heat sink 5 and the first substrate 6 integrally connected to it. The first heat sink 5 has a first cooling channel 35 through which coolant can flow in a predetermined flow direction. The first heat sink 5 further has a cooling wall 50 on the side of the first cooling channel 35 facing the electrical unit 10 to be cooled. The first substrate 6 is integrally connected to the first heat sink 5 at the cooling wall 50. On the side facing away from the first substrate 6, the electrical unit 10 is mechanically firmly connected to the first substrate 6.The electrical unit 10 comprises:.

[0211] - a conductor structure 11a, 11b 11c, together referred to as metallization 11,

[0212] - a semiconductor assembly 28 comprising:

[0213] - a semiconductor component 12, which can be 3-pole, in particular a transistor, or a PIN diode, e.g. for switching RF power between different paths,

[0214] - other 2-pole semiconductor components 13a, 13b to be cooled, e.g. diodes.

[0215] The 3-terminal semiconductor component 12 can be designed as a bare-die layer 14. This allows for very direct thermal coupling. It can be firmly and firmly connected to the conductor structure 11c, e.g., by a solder joint. This results in a particularly low and stable thermal resistance.

[0216] One or more, in particular all, of the 2-terminal semiconductor components 13a, 13b to be cooled can be designed as a bare die layer 14. This allows for very direct thermal coupling. It can be firmly and firmly connected to the conductor structure 11c, e.g., by a solder joint. This results in a particularly low and stable thermal resistance.

[0217] The 3-terminal semiconductor component 12 and the 2-terminal semiconductor components 13a, 13b are also collectively referred to as semiconductor components.

[0218] On the side of the first substrate 6 facing away from the bare die layer 14, a metallization is also applied as underside metallization 9. The cooling arrangement 7 is designed such that, during operation, the coolant is guided through the first cooling channel 35 at a predetermined operating pressure that is higher than the ambient pressure applied to the first substrate 6 on the side of the electrical unit 10 to be cooled. A distance D between the first cooling channel 35 and the cooling wall 50 is selected to be so small that the first heat sink 5 cannot ensure sufficient dimensional stability and / or tightness at the predetermined operating pressure without the first substrate e being integrally connected to it. A typical predetermined operating pressure can be, for example, 3 bar, preferably 4 bar, or more excess pressure compared to ambient pressure.However, the first substrate 6 and its integral connection to the first heat sink 5 on the cooling wall 50 are designed such that the cooling arrangement 7 can ensure this sufficient dimensional stability and tightness. The first heat sink 5 has a monolithic construction. In particular, the distance D can be equal to or less than the thickness of the metallization 9 and / or less than or equal to 50 μm.

[0219] The first cooling channel 35 is characterized in that its cross section Q has, at least in sections, a geometric shape F whose width B, measured parallel to the cooling wall 50, decreases in the direction of the cooling wall 50. The geometric shape F of the cross section Q on the cooling wall 50 has, at least in sections, a distance D from the first substrate 6 which is designed so small that, at the predetermined operating pressure of the coolant, the first heat sink 5 cannot ensure sufficient dimensional stability and / or tightness without the first substrate e being integrally connected to it.

[0220] As an alternative or at least partially in addition to the production of the heat sinks 5, 26 by means of a metal layer bonding process as illustrated in Fig. 2, 5, 6, 7, 8, 9, at least one of the heat sinks 5, 26 can be produced by means of an additive process, for example by means of selective laser melting. Additive manufacturing processes are characterized in that the structure is gradually applied from the same material. The material can be melted during application. To produce such a heat sink, for example, the metallization applied to the side of the respective substrate facing away from the bare die layer 14 can be further built up by means of an additive manufacturing process.

[0221] Additive manufacturing processes enable the layer-by-layer construction of components directly from digital models by selectively applying material. In contrast to subtractive methods, which require material to be removed, additive processes offer high flexibility in the design of complex geometries and are particularly efficient in material consumption. Furthermore, additive manufacturing processes offer the possibility of producing monolithic components with cavities and complex internal structures. These technologies are widely used in prototype development, small-scale production, and increasingly also in industrial production.

[0222] A heat sink made of metal using an additive manufacturing process has a surface structure specific to this manufacturing process. This structure is characterized by a rough surface because the metal is first melted during the additive manufacturing process and then hardens upon cooling. This roughness is similar to a very fine crystal structure, such as that found in nature. This roughness can lead to a particularly large surface area between the coolant and the metal. This increased surface area can increase heat transfer between the heat sink and the coolant. In addition, turbulence can form particularly well on the rough surface, which can also be beneficial for heat transfer between the heat sink and the coolant.The heat sink therefore has this rough surface structure, which is typical of the additive manufacturing process, at least partially, preferably predominantly, on the wall facing the cooling liquid.

[0223] One or more outer surfaces of the heat sink can be ground or shaped after the additive manufacturing process step. This allows for favorable heat transfer from a winding or electrical conductor of the heat-generating component and / or from a core of the heat-generating component to the heat sink.

[0224] In one aspect, the heat sink is manufactured using selective laser melting (SLM). Selective laser melting is an additive manufacturing process used to produce metal components. The metal powder is applied layer by layer and precisely melted and solidified using a high-power laser to create a three-dimensional component. A heat sink made of metal using SLM exhibits a surface structure specific to this manufacturing process. This structure is characterized by a particularly rough surface.

[0225] SLM is frequently used in industries that place high demands on component quality and precision, such as aerospace, medical technology, automotive engineering, and tool manufacturing. Thanks to its ability to produce components with complex internal structures and high material utilization, the process is increasingly being used for demanding, customized applications. Advantages of SLM processes include the production of complex geometries. The process enables the production of highly complex and intricate structures that are difficult or impossible to realize using conventional manufacturing methods. Furthermore, the SLM process enables a wide variety of materials. SLM can be performed with various metals such as aluminum, titanium, stainless steel, and nickel, as well as numerous alloys with these materials, making it attractive for numerous industries. The SLM process is also very cost-effective for small series production.Especially for the production of prototypes and small series, SLM can be more cost-effective than conventional manufacturing processes, as no special tools or molds are required. The SLM process with copper was barely developed in the past and was considered particularly expensive.

[0226] The disadvantages of the SLM manufacturing process are the time and cost. For the same component size, a heat sink manufactured using an additive manufacturing process, particularly an SLM manufacturing process, would be many times more expensive than one produced by machining, pressing, or casting. In the past, this manufacturing process was therefore discouraged for larger series and cost-critical developments. However, since the size of the heat sink has been significantly reduced due to its significantly increased efficiency, costs and production time have also been reduced. This makes heat sinks manufactured using this additive manufacturing process, particularly the SLM manufacturing process, attractive again. Since the weight and dimensions of the heat-generating component can also be significantly reduced, this type of heat sink is even more attractive.Over the course of development, even more heat could be dissipated from a smaller area of ​​the heat-generating component. This allowed the conductors and / or core of the heat-generating component to be improved, in particular, further reduced in size, leading to a further reduction in the dimensions of a power converter. Components surrounding the heat-generating component could also be arranged in a more space-efficient manner. This also reduced the length of the supply lines to these components. This led to a reduction in electromagnetic interference and susceptibility to interference in the device and a further reduction in power loss. All of these positive effects combined justify the higher manufacturing costs of a heat sink manufactured using additive manufacturing, particularly the SLM manufacturing process.

[0227] In one aspect, the heat sink comprises a one-piece main body. This means that the heat sink is designed as a single, continuous component. This can enable increased mechanical stability and improved heat dissipation. By eliminating a multi-piece construction, potential weak points that could arise from connections or joints can be avoided. This can contribute to the longevity and reliability of the heat-generating component. This is particularly advantageous in the context of liquid cooling of the heat sink, as the one-piece main body eliminates the need for seals or the like, which would be necessary with multi-piece designs. This can reduce the risk of coolant leakage, which can further increase the operational reliability and efficiency of the cooling system.This design can also simplify the manufacture and assembly of the heat-generating component if fewer individual parts are required and the heat sink can be manufactured more efficiently as an integral part of the heat-generating component.

[0228] Fig. 8 shows an embodiment of the first power electronic unit 188 in which double-sided cooling is provided for cooling the components, i.e. cooling from both the top and bottom of the components.

[0229] Fig. 8 shows a semiconductor assembly 28 in a bare die layer 14, which may comprise one or more semiconductor components 110a-c. These semiconductor components 110a-c may represent power semiconductor devices, e.g. transistors S1, S2, and / or diodes SD1 - SD4, FD for switching and conducting very high power, a very high current and / or a very high voltage. The power may be, for example, 10 kW or more. The voltage may be, for example, 400 V or more, in particular 1 kV or more. The current may be, for example, 10 A or more, in particular 50 A or more. The switching frequency may be, for example, 10 kHz or more, preferably 100 kHz or more, in particular 1 MHz or more. The semiconductor components are firmly connected on their underside to the conductor structures 11a-c of the top-side metallization 11, which is applied to the top side of a first substrate 6.The bare-die semiconductor elements and the top-side metallization 11 can be connected to one another, for example, by means of at least one soldered connection, in particular a silver solder connection, at least one welded connection, by sintering, or a comparable process. Such a material-to-material connection exhibits very good and stable heat transfer.

[0230] The bare die layer 14 may have regions in which no semiconductor components are arranged. These regions may be filled with a filler material 141. This filler material 141 may be designed to improve stability, to reduce mechanical stresses, and / or to improve electrical insulation, for example by extending air and / or creepage distances. The semiconductor components of the semiconductor assembly 28 mounted on the first substrate 6 have at least one first terminal 77, which is thermally and electrically connected to at least a first region of the top-side metallization layer 11 of the first substrate 6 facing the semiconductor assembly 28.

[0231] An electrically insulating second substrate 18 is mounted on the semiconductor assembly 28 and has a metallization layer 17, 19 on its top and bottom sides.

[0232] The semiconductor components of the semiconductor assembly 28 have at least one second terminal 79 which is thermally and electrically connected to at least a second region of the metallization layer 17 of the second substrate 18 facing the semiconductor assembly 28.

[0233] The first substrate 6 can preferably be a ceramic substrate. Examples of suitable ceramic materials include aluminum oxide ceramic, beryllium oxide ceramic, aluminum nitride ceramic, and sapphire. The metallization 11 can be applied to the first substrate e using a previously mentioned bonding process, for example, using direct-bonded copper. In this process, a copper foil can be bonded to the substrate, for example, the ceramic substrate, under pressure and at high temperature. Alternatively, metallization processes such as IMB (Insulated Metal Substrate) or AMB (Active Metal Brazed) could be considered. Such a cohesive bond exhibits very good and stable heat transfer.

[0234] On the side of the first substrate 6 facing away from the bare die layer 14, a metallization 9 is also applied. The metallization 9 can also be applied to the first substrate 6 using a bonding process, for example, using direct-bonded copper. The first heat sink 5 is firmly connected to the metallization 9. Such a material-to-material connection exhibits very good and stable heat transfer.

[0235] In the example shown in Fig. 7, the first heat sink 5 is manufactured by means of a metal layer bonding process. In this process, individual metal foils 27a-m, preferably copper foils, are structured at least partially by laser processing and / or punching and / or produced by means of electroplating processes and then joined together. The structuring or production is carried out in such a way that after the layers have been joined together, closed first cooling channels 35 are created through which a cooling medium can flow. By means of a cooling channel structure, the coolant can be guided specifically to the areas of the first heat sink 5 that particularly require cooling. The metal foils are preferably bonded to one another by means of a bonding process under high pressure and at high temperature. For this purpose, for example,Oxide layers can be formed, which are then welded together, with the temperature preferably being selected so high that the oxide layers melt but the metal foils do not. The metal foils thus bond to form a monolithic heat sink. If the metal foils are made of copper, for example, this is also referred to as direct copper bonding, abbreviated to DCB. The metal foils 27a-m preferably have a thickness of 0.4 mm or less, in particular 0.25 mm or less.

[0236] There are different possibilities for producing the structure shown in Fig. 7. According to a first possibility, the first substrate 6 provided with metallizations 9 and 11 and the first heat sink 5 are each produced in separate steps. The first heat sink 5 is then firmly connected to the metallization 9, for example by means of a bonding process, in particular by means of direct copper bonding. In this way, the metallization 9 can be part of the heat sink 5, in particular of the monolithic heat sink. Other, less preferred, methods for connecting the heat sink 5 to the metallization can be, for example, soldering, welding, or sintering.According to a second, alternative manufacturing method, all layers, i.e. the first substrate 6, the metal foil 9 as well as the metal foils 27g - 27m from which the first heat sink 5 is formed, are bonded together in a bonding process under high pressure and at high temperature, preferably by means of direct copper bonding and direct bonded copper.

[0237] Further preferably, the metallization 11 is also applied to the top side of the substrate 6 in the same step.

[0238] The formation of the metallization 11 into the conductor structures 11a, 11b, 11c can then be carried out, for example, by an etching process.

[0239] In the first power electronics assembly 188 shown in Fig. 7, the top side of the bare die layer 14 is additionally cooled by means of a second heat sink 26. In this way, effective heat dissipation of the bare die layer 14 from both sides is enabled. For this purpose, a second substrate 18 is arranged on the top side of the bare die layer 14 and is provided with metallizations 17, 19 on both sides. The bare die layer 14 is firmly connected to conductor structures of the metallization 17 of the second substrate 18, and the second substrate 18 is firmly connected to the second heat sink 26 via the metallization 19. Just like the first heat sink 5, the second heat sink 26 can also be manufactured from a plurality of metal foils 27a-f using a metal layer bonding process. The second heat sink 26 has at least one second cooling channel 37 for cooling the first power electronic unit 188.

[0240] Since the layer structure on the top side of the bare die layer 14 corresponds to the layer structure on the bottom side of the bare die layer 14, reference is made to the description of the structure attached to the bottom side of the bare die layer 14 with regard to the various possibilities for connecting the layers.

[0241] Particularly efficient dissipation of the heat generated by the semiconductor components can be achieved in the first power electronics assembly 188 shown in Fig. 7 if the cooling channels 35 and 37 are arranged in the immediate vicinity of, and at a short distance from, the respective substrates 6 and 18, respectively. Such an embodiment for the first heat sink 5 is shown in Fig. 2. "Short distance" here means, for example, a distance of less than 50 m.

[0242] Fig. 8 shows an embodiment of the first power electronics assembly 188, in which the heat dissipation of the semiconductor components on the top side takes place by means of the second heat sink 26, which is manufactured using a metal layer bonding process. The first heat sink 5, provided for cooling the underside of the semiconductor components, is manufactured using an additive manufacturing process in the embodiment of Fig. 8. It can be seen that the first heat sink 5 has a first cooling channel 35 through which a cooling stream 36 flows. This cooling stream 36 cools the first cooling wall 50, which is firmly connected to the metallization 9 applied to the underside of the first substrate 6. It is particularly advantageous if the metallization 9 of the first substrate 6, which was applied to the first substrate 6, for example, using direct bonded copper, is built up to form the first heat sink 5 using the additive manufacturing process.Alternatively, the first heat sink 5 could also be manufactured separately using the additive manufacturing process and then firmly connected to the metallization 9, for example by soldering, welding or sintering.

[0243] The embodiment shown in Fig. 8 can be configured such that a flat, extended bare die layer 14, which comprises a plurality of semiconductor components, is cooled on both sides. Alternatively, the heat sink arrangement shown in Fig. 8 can also be configured in the form of a microcooler for cooling individual semiconductor components or groups of semiconductor components. Such a solution is shown in Fig. 5.

[0244] Fig. 3 shows a further embodiment of an electronic assembly 24 as part of a fourth embodiment of a power electronics unit 100, 188, 118. The electronic assembly 24 is shown in longitudinal section. The electronic assembly 24 comprises the first heat sink 5, which is designed to cool an electrical unit 10 attached to the first heat sink 5. The electrical unit 10 to be cooled can, in particular, be an electrical unit, preferably a semiconductor device.

[0245] The first heat sink 5 is detachably connected to a cooling unit 22. In the example shown in the figures, the cooling unit 22 comprises a distribution unit 20, which is designed here, for example, to supply the first heat sink 5 with coolant. The cooling unit 22 also comprises, for example, a carrier unit 21 into which the distribution unit 20 is inserted. The cooling unit 22 has a receptacle 23 into which the first heat sink 5 can be detachably inserted. The first heat sink 5 is then fastened to the cooling unit 22 by means of at least one fastening means 15, preferably by means of one or more screws. The cooling unit 22 has at least one receiving device 16 for the at least one fastening means 15. In order to separate the first heat sink 5 from the cooling unit 22 again, the at least one fastening means 15 is first released.The first heat sink 5 can then be removed from the receptacle 23 of the cooling unit 22 together with the electrical unit 10 to be cooled mounted thereon.

[0246] In one aspect, the electrical unit 10 is mechanically and thermally connected to the first heat sink 5. The electrical unit 10 can be connected to the first heat sink 5, for example, by means of one or more soldered connections. Another possibility is to connect the electrical unit 10 to the first heat sink 5, for example, by sintering. Alternatively, it is possible to weld the electrical unit 10 to the first heat sink 5. As a further, albeit less advantageous, alternative, the electrical unit 10 could also be connected to the first heat sink 5 by means of a layer of thermal paste. One aspect of the development described here, however, is to realize the connection between the electrical unit 10 to be cooled and the first heat sink 5 with as few additional materials and as thinly as possible.During the considerations, simulations, and tests for this development described here, it became clear that this is particularly possible when the fluid-flowing heat sink is firmly connected, in particular by a material bond, to the electrical unit 10 to be cooled. This can be achieved, for example, by soldering, sintering, pressing, or direct copper bonding (DCB). "Solidly" here can mean "can only be removed by destruction." That is, by means of a connection that cannot be removed even with tools without destroying either the electrical unit 10 to be cooled or the first heat sink 5, or both components. It was further recognized that such a solution will only be feasible if a new solution can be found for the interchangeability of the printed circuit board component with electronic components and, in particular, with the electrical unit 10 to be cooled attached to it. This has been achieved with the proposed first heat sink 5.

[0247] The first heat sink 5 and the electrical unit 10, which is mechanically firmly connected to the first heat sink 5, together form an electronic assembly 24. This electronic assembly 24 can be inserted into the receptacle 23 of the cooling unit 22 and removed again from this receptacle 23.

[0248] The cooling unit 22 is designed to supply coolant to the first heat sink 5 attached to the cooling unit 22 and to discharge the coolant again after the coolant has flowed through the first heat sink 5. Within the cooling unit 22, a first flow channel 25 can be seen, via which coolant can be supplied to the first heat sink 5. Within the cooling unit 22, a second flow channel 30 can be seen, via which the coolant can be discharged. The first heat sink 5 has a first cooling channel 35 through which the coolant can flow. A coolant supply 40 is provided at a first end of the first cooling channel 35, and a coolant discharge 45 is provided at the second end of the first cooling channel 35 opposite the first end. The coolant supply 40 and the coolant discharge 45 are fluidically connected to the first cooling channel 35.

[0249] The cooling unit 22 comprises a first fluid port 41, which is fluidically connected to the first flow channel 25, and a second fluid port 46, which is fluidically connected to the second flow channel 30. Upon insertion and subsequent fastening of the first heat sink 5 in the receptacle 23, a first fluid connection is formed between the first fluid port 41 and the coolant supply 40, and a second fluid connection is formed between the second fluid port 46 and the coolant discharge 45.

[0250] To seal the first fluidic connection, a first sealing ring 42 is arranged in a groove 43 between the cooling unit 22 and the first heat sink 5, wherein the sealing ring 42 completely surrounds the first fluid port 41. Likewise, a second sealing ring 44 is provided on the second fluid port 46, which completely surrounds the second fluid port 46 and is arranged in a groove 43 between the cooling unit 22 and the first heat sink 5. When the at least one fastening means 15 is attached, for example when tightening the at least one screw, the first heat sink 5 is pressed against the first fluid port 41 and the first sealing ring 42 as well as against the second fluid port 46 and the second sealing ring 44. As a result of this pressing, a liquid-tight first fluidic connection and a liquid-tight second fluidic connection are formed between the cooling unit 22 and the first heat sink 5.

[0251] As shown in Fig. 3, a cooling flow 36 can be formed within the cooling device. The coolant flows from the first flow channel 25 via the first fluid port 41 and the coolant supply 40 into the first cooling channel 35. The coolant flows through the first cooling channel 35 and is discharged again via the coolant discharge 45, the second fluid port 46, and the second flow channel 30.

[0252] The first heat sink 5 has a first cooling wall 50 on the side facing the electrical unit 10 to be cooled. On the side of the first heat sink 5 facing away from the electrical unit 10 to be cooled, the first cooling channel 35 is delimited by a second cooling wall 55, which is opposite the first cooling wall 50. Preferably, the second cooling wall 55 is formed parallel to the first cooling wall 50.

[0253] In the example shown in Fig. 3, the electrical unit 10 comprises a semiconductor assembly 28, which comprises, for example, an arrangement of transistors 60, which can in particular be designed as bare-die semiconductor components. The heat generated during operation of the transistors 60 is dissipated via the coolant flowing in the first cooling channel 35. In order to achieve cooling of the transistors 60 on both sides, a second heat sink can be applied to the top side of the transistors 60. This second heat sink could, for example, be a heat sink produced using a metal layer connection process or a heat sink produced using an additive manufacturing process. Such an arrangement is also conceivable for one or more PIN diodes, e.g. for switching RF power between different paths, or a combination of transistor and diode.

[0254] In order to improve the thermal exchange between the coolant flowing through the first cooling channel 35 and the first heat sink 5, a plurality of cooling pins 65 can be arranged inside the first cooling channel 35, which extend from the first cooling wall 50 and / or from the second cooling wall 55 into the first cooling channel 35. Coolant flows around the cooling pins 65 and ensures improved thermal coupling between the first heat sink 5 and the coolant. Fig. 3 also shows that the electrical unit 10, together with the first heat sink 5 arranged underneath it, can be arranged within a first recess 70 of a printed circuit board 75.

[0255] The arrangements shown in Fig. 7 to 11 can have an electrically insulating additional substrate 102, which has a metallization layer 104, 106 on its top and bottom sides, wherein the additional substrate 102 can be attached to the second side of the first heat sink 5 opposite the first side and / or to the second side of the second heat sink 26 opposite the first side. In this case, for example, the second side of the first heat sink 5 can be thermally connected to the metallization layer 104 of the additional substrate 102 facing the first heat sink 5. Alternatively or additionally, for example, the second side of the second heat sink 26 can be thermally connected to the metallization layer of the additional substrate facing the second heat sink 26. This is not shown in Fig. 7 to 12, but can be seen when viewed together with Fig. 6 and 9.

[0256] Fig. 4 shows how a bare-die component, for example configured as an IGBT 76, can be electrically contacted. The IGBT 76 has first connections 77 on its first side, in particular configured as four emitter connection surfaces 78, a control connection surface 80, and a test connection surface 82 required for testing purposes. On the rear side, the IGBT 76 has a second connection 79, in particular configured as a collector connection surface 84. These connection surfaces can be electrically contacted by the conductor structures 11a-c of the metallizations 11 and / or 17. In particular, the collector connection surface 84 is also electrically connected directly to the connection of the bare-die component to the conductor structure 11c. In particular, the emitter connection surfaces 78 are connected to a conductor structure of the opposite metallization 17.This can also be formed into ladder structures, as will be explained in more detail below and in further figures.

[0257] The arrangement can also be reversed, i.e. the collector connection surface 84 can be electrically connected directly to the connection of the bare die component of a conductor structure of the metallization 17 and the emitter connection surfaces 78 can be electrically connected to a conductor structure 11c of the opposite metallization 11.

[0258] When the semiconductor components are cooled from both sides, the question arises as to how a control terminal of a semiconductor component can be led to the outside. There are various possibilities for this, which are described previously or subsequently, e.g. in Figures 10, 11, and 5. Fig. 10 shows the metallization 11 applied to the first substrate 6. The metallization 11 can be made of copper, for example, and preferably of copper coated with NiAu. The coating can serve as a diffusion barrier. An insulating material layer 86 is first applied to the metallization 11 and extends laterally outwards from the location of the respective control terminal. A conductor track layer 88 made of conductive material is then applied to this insulating material layer 86 and is designed to electrically contact the control terminal of the respective semiconductor component.For this purpose, the insulating material layer 86 can have a recess at the location of the gate connection. A conductive track insulating material layer 90 is then applied to this conductive track layer 88, which also extends laterally outward from the location of the control connection. The conductive track layer 88 is thus insulated from the metallization 11 by the insulating material layer 86 and from the bare die layer 14 by the conductive track insulating material layer 90. The control connection can be electrically contacted via the conductive track layer 88 extending outward.

[0259] Fig. 11 shows a further possibility of how the control connection of the semiconductor component can be led laterally outwards in order to be able to make electrical contact with the control connection from the side of the power electronics unit. Fig. 11 shows the metallization 11 which is applied to the first substrate 6. In the first step, the metallization 11 within the trench-shaped region 92 as far as the first substrate 6 is recessed, e.g. etched away, leaving an inner region 94 of the metallization 11. This inner region 94 extends laterally outwards from the control connection of the semiconductor component and is insulated from the remaining metallization 11 by the trench-shaped region 92 running around the inner region 94. Subsequently, etching is carried out to a certain depth within a partial region 96 of the inner region 94, leaving part of the metal as a control connection conductor track.Subsequently, a conductor track insulation material layer 98 is deposited on this partially etched portion 96. This conductor track insulation material layer 98 insulates the control terminal of the semiconductor component, which is laterally led outward, from the bare die layer 14.

[0260] According to a further aspect of the development described here, an additional substrate is arranged on the side of the heat sink facing away from the bare die layer 14 in at least one of the heat sinks, so that the heat sink is arranged in a sandwich structure between two substrates. Fig. 5 shows a second power electronics assembly 100 according to the second aspect of the development described here. Fig. 5 shows that the first substrate 6 is arranged below the bare die layer 14, with the metallization 11 of the first substrate 6 being connected to the bare die layer 14 as previously described. The first heat sink 5 is attached to the side of the first substrate 6 facing away from the bare die layer 14, and an additional substrate 102 is arranged on the side of the first heat sink 5 facing away from the bare die layer 14. The additional substrate 102 has metallizations 104, 106 on both sides.The metallization 104 facing the first heat sink 5 is firmly connected to the first heat sink 5. The additional metallization 106 is arranged on the side of the substrate 6 facing away from the heat sink 5 and can be configured like a previously described conductor structure for accommodating electronic components, in particular semiconductor components. This additional substrate 102 can increase the stability of the heat sink 5. Furthermore, the additional metallization 106 on the side of the substrate 6 facing away from the heat sink 5 offers the possibility of arranging drivers and / or measurement electronics with very short electrical paths to the power components of the bare die layer 14.

[0261] The first heat sink 5 is thus arranged in a sandwich structure between the first substrate 6 and the additional substrate 102. The substrates 6 and 102 are preferably made of ceramic, and therefore, this sandwich structure results in additional mechanical stabilization of the first heat sink 5. A further advantage is that one or more semiconductor components, e.g., in a further bare die layer 108, can be arranged on the metallization 106, which is located on the side of the additional substrate 102 facing away from the first heat sink 5. The additional substrate 102 can therefore be used, for example, to accommodate driver and control circuits, e.g., control electronics 114 for the actual power electronics. With the aid of one or more vias 115, which extend through the first heat sink 5, electrical connections can be made between the semiconductor components, e.g.,the control electronics 114, which may be part of the further bare die layer 108, and the semiconductor components 110a-c of the bare die layer 14 arranged on the first substrate e. At least one terminal 117a of the control electronics 114 can be thermally and electrically connected to at least one region of the further metallization layer 106 facing the control electronics 114. At least one further terminal 117b of the control electronics 114 can be electrically connected to a terminal 119 of the semiconductor assembly 28 via at least one via 115, which runs through the first heat sink 5, in particular insulated therefrom.

[0262] The second power electronics assembly 100 shown in Fig. 5 is shown again in an oblique view in Fig. 6. Fig. 6 shows the first substrate 6 with the metallizations 9 and 11 on both sides, the additional substrate 102 with the two metallizations 104 and 106, and the first heat sink 5 arranged therebetween. Semiconductor components 110a, 110b, 110c, which are part of the bare die layer 14, are attached to the top side of the metallization 11. Also visible on the top side of the second power electronics assembly 100 are undulating connecting lines 112, in particular designed as bonding wires, which are provided for establishing electrical connections between the semiconductor components 110a, 110b, 110c and the conductor structures on the metallization 11 by means of wire bonding.

[0263] On the side of the additional substrate 102 facing away from the first heat sink 5, further semiconductor components such as, for example, control electronics 114 are arranged on the metallization 106, which can be connected, for example, via a through-contact, also called “via” 115, to the semiconductor components 110a, 110b, 110c on the top side of the second power electronics unit 100.

[0264] In the area of ​​the heat sink 5, a via insulation 116 can be provided, which protects the via from electrical contact with the heat sink 5.

[0265] The first cooling channels 35 run within the first heat sink 5.

[0266] The power electronics assembly 100 shown in Fig. 5 can optionally have a second heat sink 26, as shown, for example, in Fig. 7 or Fig. 9, but not shown in Fig. 5. This second heat sink 26 can be thermally connected to the metallization layer 19 of the second substrate 18 facing away from the semiconductor assembly 28. The second heat sink 26 can have at least one second cooling channel 37 through which coolant can flow.

[0267] Fig. 6a shows an industrial process arrangement 1, preferably a plasma process arrangement or heating arrangement.

[0268] The industrial process arrangement 1 has:

[0269] - an electrical power converter 4,

[0270] - a load 2, preferably a plasma process or heating process, e.g. an induction or microwave heating process, wherein the load 2 is electrically connected to the electrical power converter 4 so that the electrical power converter 4 can supply the load 2 with the required electrical power,

[0271] - optionally an additional adaptation unit 3, which is connected between the power converter 4 and the load 2.

[0272] The power converter 4 has:

[0273] - two of the second power electronic units 100, as previously described, for example, in the description of Fig. 6 and previously and subsequently, for example, in the description of Fig. 6,

[0274] - a cooling unit 22 comprising, as described above and below, one or more distribution units 20 and a carrier unit 21,

[0275] - a circuit board 75,

[0276] - a unit 10 to be cooled, in particular an electrical unit, preferably a semiconductor device, preferably comprising a power semiconductor component,

[0277] - further electronic components 8a, 8b, 8c, wherein the further electronic components 8a, 8b, 8c and the unit 10 to be cooled are arranged on or at a printed circuit board 75 and are connected to electrical contacts, wherein the unit 10 to be cooled has a fixed, in particular material-locking, connection with the heat sink 5, 85.

[0278] Two power semiconductor components, in particular transistors S1, S2, are arranged on or on the circuit board 75 as the unit 10 to be cooled. Each transistor has a first and a second power terminal and a control terminal. Both transistors S1, S2 can be connected to one of their power terminals in a series circuit. A direct current or direct voltage can be connected to the remaining power terminals. Control electronics 114 can be connected to the control terminals of the power semiconductor components.

[0279] Also arranged on the circuit board 75 is a power transformer 197 comprising a primary winding 196 and a secondary winding 194. The primary winding 196 and the secondary winding 194 of the power transformer 197 are each designed as planar conductor tracks arranged in different layers of the circuit board 75. The circuit board has a thermal connection to the cooling unit 22.

[0280] The thermal connection to the cooling unit 22 can comprise a heat-conducting compensation layer which is firmly connected with its first surface to the first surface of the circuit board 75, and a connection layer which is firmly connected with its first surface to the second surface of the heat-conducting compensation layer and with its second surface to the heat spreader.

[0281] Fig. 9 shows a third power electronics module 118, which has a power electronics module of the type shown in Fig. 5 on both the top and bottom sides of the bare die layer 14. The first substrate 6 with the two metallizations 9 and 11, the heat sink, and the additional substrate 102 with the two metallizations 104 and 106 are arranged on the bottom side of the bare die layer 14. The second substrate 18 with the metallizations 17 and 19, the second heat sink 26, and the additional substrate 120 with the metallizations 122 and 124 are arranged on the top side of the bare die layer 14. First cooling channels 35 are provided in the first heat sink 5, and second cooling channels 37 are provided in the second heat sink 26, through which coolant can flow.

[0282] Fig. 12a shows an industrial process arrangement 1, preferably a plasma process arrangement or heating arrangement.

[0283] The industrial process arrangement 1 has:

[0284] - an electrical power converter 4,

[0285] - a load 2, preferably a plasma process or heating process, e.g. an induction or microwave heating process, wherein the load 2 is electrically connected to the electrical power converter 4 so that the electrical power converter 4 can supply the load 2 with the required electrical power,

[0286] - optionally an additional adaptation unit 3, which is connected between the power converter 4 and the load 2.

[0287] The power converter 4 has:

[0288] - two of the first power electronic units 118, as described above or below, e.g. in the description of Fig. 9, 12,

[0289] - a cooling unit 22 comprising, as described above and below, one or more distribution units 20 and a carrier unit 21,

[0290] - a circuit board 75,

[0291] - a unit 10 to be cooled, in particular an electrical unit, preferably a semiconductor device, preferably comprising a power semiconductor component,

[0292] - further electronic components 8a, 8b, 8c, wherein the further electronic components 8a, 8b, 8c and the unit 10 to be cooled are arranged on or at a printed circuit board 75 and are connected by electrical contacts, wherein the unit 10 to be cooled has a fixed, in particular materially bonded, connection with the heat sink 5, 85. Two power semiconductor components, in particular transistors S1, S2, are arranged here as the unit 10 to be cooled on or at the printed circuit board 75, each having a first and a second power terminal and a control terminal, wherein both transistors S1, S2 can be connected by one of their power terminals to form a series circuit. A direct current or direct voltage can be connected to the remaining power terminals. Control electronics 114 can be connected to the control terminals of the power semiconductor components.

[0293] Also arranged on the circuit board 75 is a power transformer 197 comprising a primary winding 196 and a secondary winding 194. The primary winding 196 and the secondary winding 194 of the power transformer 197 are each designed as planar conductor tracks arranged in different layers of the circuit board 75. The circuit board has a thermal connection to the cooling unit 22.

[0294] The thermal connection to the cooling unit 22 can comprise a heat-conducting compensation layer which is firmly connected with its first surface to the first surface of the circuit board 75, and a connection layer which is firmly connected with its first surface to the second surface of the heat-conducting compensation layer and with its second surface to the heat spreader.

[0295] Fig. 12 shows a further possibility of how, in a third power electronics assembly 188, 118 with cooling of the semiconductor components on both sides, a control terminal 128 of a semiconductor component can be contacted from the outside. In the embodiment shown in Fig. 12, the control terminal 128 of the semiconductor component is electrically contacted from the top side of the third power electronics assembly 118. Fig. 12 shows the bare die layer 14. The first substrate 6 with its two metallizations 9 and 11 and the first heat sink 5 are arranged on the underside of the bare die layer 14. The second substrate 18 with its metallizations 17 and 19 and the second heat sink 26 are attached to the top side of the bare die layer 14. In Fig. 12, the additional substrate 102 is also attached to the underside of the first heat sink 5, which is provided with metallizations 104, 106 on both sides.The additional substrate 120, which has the metallizations 122 and 124, is arranged on the top side of the second heat sink 26.

[0296] For electrically contacting the control terminal 128, a hole 130 is provided, which extends from the top side of the third power electronics assembly 118 through the second heat sink 26 to the control terminal 128. A pin 132 made of conductive material, preferably copper or another metal, is inserted into the hole 130 such that the pin 130 electrically contacts the control terminal 128. In this way, a via is formed that leads the control terminal 128 outward through the second heat sink 26. Optionally, a connection pad 134 can be attached to the top side of the power electronics assembly above the additional substrate 120, wherein the connection pad 134 is electrically connected to the control terminal 128 via the pin 132.

[0297] In the area of ​​the second heat sink 26, a via insulation 116 may be provided, which protects the through-hole connection from electrical contact with the second heat sink 26. The features disclosed in the above description, the claims, and the drawings may be important both individually and in any combination for the realization of the development described here in its various embodiments.

Claims

CLAIMS 1. Power electronic unit (100, 118) for an electrical power converter (4) for an industrial process arrangement (1), designed to supply a load (2), preferably a plasma process or heating process, the assembly (100, 118) comprising: - an electrically insulating first substrate (6), o which has a top-side metallization layer (11) on its top side and o a bottom-side metallization layer (9) on its bottom side, o wherein the top-side metallization layer (11) is divided into at least three electrically separated regions of a conductor structure (11a, 11b, 11c), - a semiconductor assembly (28) mounted on the first substrate (6), comprising: o at least two series-connected semiconductor components (110a, 110b, 110c), at least one of which is a controllable power semiconductor component, the two series-connected semiconductor components (110a, 110b, 110c) comprising: ■ at least one first connection (77), in particular designed as a collector connection surface (84) or source connection surface, which is thermally and electrically connected to at least one first region of the conductor structure (11a, 11b, 11c), ■ at least one second connection (79), in particular designed as an emitter connection surface (78) or drain connection surface, which is electrically connected via a plurality of connecting lines (112) to a second connection surface (79) of another semiconductor component (110a, 110b, 110c) and / or to one of the regions of the conductor structure (11a, 11b, 11c), - a first heat sink (5) arranged on the first substrate (6), the first side of which facing the first substrate (6) is thermally connected to the underside metallization layer (9) of the first substrate (6) facing away from the semiconductor assembly (28), - wherein the heat sink (5) o is monolithically constructed and o is firmly connected to the underside metallization layer (9) and o has a first cooling channel (35) for guiding a cooling flow (36).

2. Assembly according to claim 1, characterized in that the semiconductor components (110a, 110b, 110c) are designed as bare-die semiconductor components and are thermally and electrically connected directly with their first connection (77) to one of the regions of the conductor structure (11a, 11b, 11c).

3. A structural unit according to any one of the preceding claims, characterized in that two series-connected semiconductor components (110a, 110c) are arranged on two of the three regions of the conductor structure (11a, 11c) and a third region of the conductor structure (11b) is free of semiconductor components and, in particular, only has contacting of the connections (112).

4. The assembly according to any one of the preceding claims, characterized in that the assembly (100, 118), in particular the semiconductor assembly (28), in particular the AC converter arrangement (152), comprises: a semiconductor switching unit (150) comprising two transistors (S1, S2), wherein the transistors (S1, S2) are electrically connected to one another at at least one power terminal.

5. The assembly according to any one of the preceding claims, characterized in that the assembly, in particular the semiconductor assembly (28), preferably the AC converter arrangement (152), comprises: an intermediate circuit capacitor C1, which is arranged in particular very close to the semiconductor components, in particular power terminals of the transistors (S1, S2), preferably with connection leads having a length of less than or equal to 20 mm, particularly preferably less than or equal to 10 mm.

6. Assembly according to one of the preceding claims, characterized in that the assembly, in particular the semiconductor assembly (28), preferably the AC converter arrangement (152) has: a positive contact connection device (PP1) and a negative contact connection device (PN1), each designed to contact a connection point on a printed circuit board (75) or a mechanical connecting line, e.g. a copper line, wherein the positive contact connection device (PP1) is directly electrically connected to one of the regions of the conductor structure (11c), in particular to the positive connection point (P1).

7. A structural unit according to any one of the preceding claims, characterized in that several of the semiconductor switching units (150) are arranged on a heat sink (50).

8. The assembly according to any one of the preceding claims, characterized in that it further comprises: an electrically insulating additional substrate (102) having a metallization layer (104, 106) on its top and bottom sides, wherein the additional substrate (102) is attached to the second side of the first heat sink (5) opposite the first side, and wherein the second side of the first heat sink (5) is thermally connected to the metallization layer (104) of the additional substrate (102) facing the first heat sink (5).

9. A structural unit according to any one of the preceding claims, characterized in that the structural unit (100, 118) comprises control electronics (114) which are arranged on the side of the additional substrate (102) facing away from the first heat sink (5), wherein at least one terminal (117a) of the control electronics (114) is thermally and electrically connected to at least one region of the metallization layer (106) facing the control electronics (114).

10. The assembly according to claim 9, characterized in that at least one further terminal (117b) of the control electronics (114) is electrically connected to a terminal (119) of the semiconductor assembly (28) via at least one via (115) which extends through the first heat sink (5).

11. Assembly according to one of the preceding claims, characterized in that the first substrate (6) and / or the additional substrate (102) is one of the following: ceramic substrate, direct bonded copper (DBG), insulated metal substrate (IMB), active metal brazed (AMB), thick film substrate.

12. Assembly according to one of the preceding claims, further comprising: - an electrically insulating second substrate (18) which is mounted on the semiconductor assembly (28) and has a metallization layer (17, 19) on its top and bottom sides, wherein the semiconductor assembly (28) has at least one second terminal (79) which is thermally and electrically connected to at least a second region of the metallization layer (17) of the second substrate (18) facing the semiconductor assembly (28), - a second heat sink (26) which is thermally connected to the metallization layer (19) of the second substrate (18) facing away from the semiconductor assembly (28), wherein the second heat sink (26) has at least one second cooling channel (37) through which coolant can flow.

13. A structural unit according to claim 12, characterized in that the second heat sink (26) is at least partially realized in the form of a layer structure of thermally bonded metal foils, preferably copper foils.

14. Assembly according to one of the preceding claims, characterized in that the first substrate (6) and / or the second substrate (18) is one of the following: Ceramic substrate, Direct Bonded Copper (DBG), Insulated Metal Substrate (IMB), Active Metal Brazed (AMB), thick film substrate.

15. Assembly according to one of the preceding claims, characterized in that the semiconductor assembly (28) has a bare die layer (14), wherein the bare die layer (14) comprises one or more semiconductor components (12, 13a, 13b, 60, 110a, 110b, 110c).

16. A structural unit according to one of the preceding claims, characterized in that the first heat sink (5) is at least partially realized in the form of a layer structure of thermally bonded metal foils (27g - 27m), preferably copper foils.

17. The assembly according to claim 16, characterized in that the first cooling body (5) has at least one first cooling channel (35) through which coolant can flow, wherein the at least one first cooling channel (35) is realized in the form of at least one recess provided in the metal foils (27g - 27m).

18. Assembly according to one of the preceding claims, characterized in that the first heat sink (5) is at least partially manufactured by means of an additive manufacturing process, preferably by means of selective laser melting.

19. A structural unit according to one of the preceding claims, characterized in that the first heat sink (5) comprises a coolant supply (40) and a coolant discharge (45), both of which are fluidically connected to the first cooling channel (35), wherein the first heat sink (5) is designed such that the first heat sink (5) can be detachably fastened to a cooling unit (22) comprising a first fluid port (41) and a second fluid port (46), and that when the first heat sink (5) is fastened to the cooling unit (22), a first fluidic connection can be formed between the coolant supply (40) of the first heat sink (5) and the first fluid port (41) of the cooling unit (22), and a second fluidic connection can be formed between the coolant discharge (45) of the first heat sink (5) and the second fluid port (46) of the cooling unit (22).

20. A structural unit according to any one of the preceding claims, characterized in that the first substrate (6) is integrally connected to the first heat sink (5) at a first cooling wall (50), wherein the power electronics structural unit (188, 100, 118) is designed such that, during operation, the coolant is guided through the first cooling channel (35) at a predetermined operating pressure, wherein a distance between the first cooling channel (35) and the first cooling wall (50) is selected to be so small that the first heat sink (5) cannot ensure sufficient dimensional stability and / or tightness at the predetermined operating pressure, in particular at 3 bar or more overpressure compared to ambient pressure, without the first substrate (6) being integrally connected to it, and the first substrate (6) and its integral connection to the first heat sink (5) on the first cooling wall (50) is designed such that the power electronics unit (188, 100, 118) can ensure this sufficient dimensional stability and tightness.

21. A structural unit according to any one of the preceding claims, characterized in that at least one control terminal (80) and at least one first power terminal (78) are arranged on a first side of the semiconductor assembly (28) and at least one second power terminal (84) are arranged on the second side of the semiconductor assembly (28).

22. The assembly according to claim 1, wherein the top-side metallization layer (11) facing the first side of the semiconductor assembly (28) has at least one first metallization region for electrically contacting at least one control terminal (80) of the semiconductor assembly (28) and at least one second metallization region for electrically contacting at least one first power terminal (78) of the semiconductor assembly (28), wherein the at least one first metallization region and the at least one second metallization region are electrically separated from one another, and wherein at least one first metallization region is led to the side of the assembly (188, 100, 118) and can be electrically contacted from the side of the assembly (188, 100, 118).

23. A structural unit according to one of the preceding claims, characterized in that electrical contacting of at least one control terminal (78) of the semiconductor assembly (28) is effected via at least one via running through the first heat sink (5).

24. A method for joining a power electronic component (100, 118), the method comprising the following steps: - Arranging a top-side metallization layer (11) on a top side of an electrically insulating first substrate (6), wherein the top-side metallization layer (11) is divided into at least three electrically separated regions of a conductor structure (11a, 11b, 11c), - Arranging a bottom metallization layer (9) on the bottom of the first substrate (6) - Arranging a semiconductor assembly (28) on the first substrate (6), the semiconductor assembly (28) comprising: at least two series-connected semiconductor components (110a, 110b, 110c), - Producing at least one thermal and electrical connection between at least one terminal (77) of the semiconductor assembly (28), in particular the two series-connected semiconductor components (110a, 110b, 110c), and at least a first region of the top-side metallization layer (11) of the first substrate (6) facing the semiconductor assembly (28), - producing at least one electrical connection line from a second terminal (79) of the semiconductor assembly (28), in particular the two series-connected semiconductor components (110a, 110b, 110c), to at least one second connection surface (79) of another semiconductor component (110a, 110b, 110c) or to one of the regions of the conductor structure (11a, 11b, 11c), - construction of a first monolithically constructed heat sink (5) with a first cooling channel (35) for guiding a cooling flow (36), - Arranging the first monolithically constructed heat sink (5) on the first substrate (6), and thereby - Producing a thermal and electrical connection between a first side of the first heat sink (5) facing the first substrate (6) and the underside metallization layer (9) of the first substrate (6) facing away from the semiconductor assembly (28).

25. Method according to claim 24, characterized in that the method comprises the following further method steps: - Arranging a positive contact connection device (PP1) on a region of the conductor structure (11c) with a direct electrical connection to the region of the conductor structure (11c), in particular by means of ultrasonic welding - Arranging a negative contact connection device (PN1) on a region of the conductor structure (11a) with a direct electrical connection to the region of the conductor structure (11a), in particular by means of ultrasonic welding.

26. Method according to one of the preceding claims 24 - 25, characterized in that the method comprises the further method step: - arranging an electrically insulating additional substrate (102), which has a metallization layer (104, 106) on its top and bottom sides, on the second side of the first heat sink (5) opposite the first side, - Producing a thermal and electrical connection between the second side of the first heat sink (5) and the metallization layer (104) of the additional substrate (102) facing the first heat sink (5).

27. Method according to one of the preceding claims 24 -26, characterized in that the first heat sink (5) is produced at least partially by means of a metal layer bonding method, in particular a DCB method.

28. Method according to one of the preceding claims 24 - 27, characterized in that the underside metallization layer (9) of the first substrate (6) and the metal foils (27g - 27m) of the first heat sink (5) are connected in one process.

29. Method according to one of the preceding claims 24 - 28, wherein the method comprises the following further steps: - Arranging an electrically insulating second substrate (18), which has a metallization layer (17, 19) on its top and bottom sides, on the semiconductor assembly (28), - establishing at least one thermal and electrical connection between at least one second terminal of the semiconductor assembly (28) and at least one second region of the metallization layer (17) of the second substrate (18) facing the semiconductor assembly (28), - When arranging the first heat sink (5) on the first substrate (6): providing at least one first cooling channel (35) through which coolant can flow, - arranging a second heat sink (26) on the second substrate (18), wherein the second heat sink (26) has at least one second cooling channel (37) through which coolant can flow, - Producing a thermal and electrical connection between the second heat sink (26) and the metallization layer (19) of the second substrate (18) facing away from the semiconductor assembly (28).

30. Electrical power converter (4) for an industrial process arrangement (1), preferably a plasma process arrangement or heating arrangement, comprising a power electronic unit (188, 118) according to one of the preceding claims 1 to 22, in particular designed to generate an RF output power.

31. Electrical power converter (4) according to claim 30, characterized in that the power electronic unit (188, 118) comprises: - two power semiconductor components, in particular transistors (S1, S2), each having a first and a second power terminal and a control terminal, wherein both power semiconductor components, in particular transistors (S1, S2), are connected by one of their power terminals to form a series circuit, wherein a direct current or direct voltage is connected to the remaining power terminals, wherein control electronics (114) is further provided which is connected to the control terminals of the power semiconductor components, in particular of the two transistors (S1, S2), and the control electronics (114) is designed to control the power semiconductor components, in particular transistors (S1, S2), in such a way that they can generate an RF power from a first conducting state to a second conducting state, wherein the conductivity of the two states is different.

32. Electrical power converter (4) according to one of the preceding claims 30 to 31, characterized in that a power transformer (197) with a primary winding (196) and a secondary winding (194) is arranged on the printed circuit board (75), wherein the primary winding (196) is connected to the at least one power connection of the power semiconductor components, in particular transistors (S1, S2), wherein the primary winding (196) and the secondary winding (194) of the power transformer (197) are each designed as planar conductor tracks which are arranged in different layers of the printed circuit board (75) and the printed circuit board has a thermal connection to the cooling unit (22).

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