Semiconductor device assembly and power module

Abstract

The present invention relates to a semiconductor device assembly and a power module, wherein the semiconductor device assembly comprises: a plurality of semiconductor devices (10, 12, 14, 16) and a cooling device (20) with a coolant channel (25), wherein the semiconductor devices (10, 12, 14, 16) of the plurality of semiconductor devices (10, 12, 14, 16) are arranged sequentially on the cooling device (20) substantially along a path of the coolant channel (25) and each has a thermal coupling with the cooling device (20), wherein the semiconductor devices (10, 12, 14, 16) have different properties from one another, such that they each require different cooling capacities to be operated within their respective specification limits when controlled identically, and wherein an arrangement sequence of the semiconductor devices (10, 12, 14,16) on the cooling device (20) in accordance with an expected temperature gradient between a coolant inlet (26) and a coolant outlet (28) of the coolant channel (20) during active operation of the semiconductor device arrangement, such that the semiconductor devices (10, 12, 14, 16) are arranged closer to the coolant inlet (26) the higher their required cooling capacity.

Description

State of the art

[0001] The present invention relates to a semiconductor device arrangement and a power module with such a semiconductor device arrangement.

[0002] Power modules are known from the prior art, which are used, for example, as inverters in electric vehicles. These power modules are cooled by means of water cooling to dissipate the waste heat generated within them as efficiently as possible. Such inverters consist of a varying number of B2 bridges, with the respective B2 bridges typically being implemented using transistors with an identical chip area. The B2 bridges can be implemented by connecting individual transistors or by connecting transistors in parallel.

[0003] Heat generation occurs primarily due to power losses during acceleration, braking, and high-speed driving, during which correspondingly high currents flow from the battery, through the inverter, to the electric motor and back. These losses from individual transistors in the power modules are typically dissipated via a thermally conductive heat sink into a coolant, thus preventing the transistors from overheating and potentially being thermally damaged during operation.

[0004] Essentially, two different types of cooling devices are known: so-called pin-fin coolers and closed coolers.

[0005] In the case of the pin-fin cooler, the semiconductor components are mounted outside of a coolant flowing through the coolant channel on a cooling plate of the cooling device. The cooling plate has cooling fins on its underside that project into the coolant channel. The cooling plate is positioned on the cooling device such that the coolant flows around the fins in the coolant channel. A seal prevents the coolant from entering an area containing the electrical connections of the semiconductor components.

[0006] In the case of a closed cooler, the semiconductor components are mounted on a substrate plate that is thermally connected to the top of the cooler assembly. The cooler is called a closed cooler because it does not use a substrate plate with fins. Therefore, no additional sealing of the electrical components is necessary.

[0007] The cooler variants described above can be implemented as both single-sided and double-sided coolers, whereby in the case of double-sided cooling the semiconductors are cooled by means of a first coolant channel and by means of a second coolant channel on two opposite surfaces.

[0008] During operation, the coolant is circulated through a coolant channel of the water cooling system, causing it to heat up as it travels from the coolant inlet to the coolant outlet. This creates a temperature gradient between the coolant inlet and outlet. This temperature gradient affects the cooling capacity of the transistors. Specifically, transistors located closer to the coolant outlet receive more effective cooling than those located further away.

[0009] Accordingly, in the prior art, the transistors used are designed and / or selected in such a way that they all receive sufficient cooling from the water cooling system in the area of ​​the coolant outlet.

[0010] DE102015212721 A1 discloses a cooling device for cooling a conduction semiconductor, wherein the cooling device has a cavity for guiding a fluid flow and wherein the height of the cavity is designed to decrease along a flow axis of the fluid flow in order to provide a substantially uniform cooling performance along the flow axis.

[0011] DE102017207361 A1 discloses a cooler for cooling an electrical arrangement with a heat sink having a cooling surface for transferring heat to a cooling medium flowing on the cooling surface, wherein the heat sink has a cooling structure on the cooling surface to increase the cooling surface, wherein the cooling structure changes in the flow direction of the cooling medium in such a way that the thermal resistance of the heat sink also changes along the flow direction of the cooling medium.

[0012] DE102020109726 A1 discloses a power electronic system with a total cooling device comprising a plurality of power electronic devices arranged in series, each with a cooling device and with a plurality of power semiconductor components to be cooled.

[0013] DE102021202552 A1 discloses an inverter with a heat sink and at least two semiconductor modules. The heat sink has two thermal contact surfaces. At least one semiconductor module is thermally connected to each thermal contact surface, such that the semiconductor modules enclose the heat sink between them. Furthermore, the heat sink has two fluid channels arranged in different planes, each extending parallel to one of the thermal contact surfaces. Disclosure of the invention

[0014] According to a first aspect of the present invention, a semiconductor device arrangement is proposed which comprises a plurality of semiconductor devices and a cooling device with a coolant channel.

[0015] The semiconductor components are designed, for example, as transistors (e.g., MOSFETs, IGBTs, etc.) and, in particular, as power transistors, which can alternatively or additionally also be designed, for example, as (power) diodes, thyristors, or in other configurations. Preferably, the respective semiconductor components are functionally related semiconductor components that fulfill a common function, such as semiconductor components of a bridge circuit, etc.

[0016] Furthermore, it is possible that the respective semiconductor element is composed of a large number of semiconductor elements connected in parallel.

[0017] The cooling device can be designed, for example, as a pin-fin cooler, a closed cooler, or a cooler with a different design. Furthermore, the cooling can be implemented on one or both sides, as described above.

[0018] The course and / or cross-sectional shape of the coolant channel within the cooling device are not fundamentally restricted. For example, the coolant channel can be straight, loop-shaped, U-shaped, meandering, or have a shape deviating from these. Preferably, the coolant channel has a substantially uniform cross-sectional area and shape along its entire length.

[0019] The semiconductor components of the multitude of semiconductor components are essentially arranged in series along the course of the coolant channel on the cooling device and each has a thermal coupling with the cooling device.

[0020] Furthermore, the semiconductor components have different properties (i.e., different specifications or specification limits), so that with identical control (e.g., by applying identical gate voltages to gate-controlled transistors) they require different cooling capacities to be operated within their respective specification limits.

[0021] The arrangement of the semiconductor components on the cooling device is determined in accordance with an expected temperature gradient between a coolant inlet and a coolant outlet of the coolant channel during active operation of the semiconductor component arrangement, such that the semiconductor components are arranged closer to the coolant inlet the higher their required cooling capacity.

[0022] The expected temperature gradient results from the fact that the coolant is additionally heated by each semiconductor component as it passes through the series-arranged semiconductor components, so that the temperature of the coolant increases from the coolant inlet towards the coolant outlet.

[0023] The semiconductor device arrangement according to the invention offers in particular the advantage that not all semiconductor devices used in the semiconductor device arrangement have to be designed with regard to the lowest possible cooling power in the vicinity of the coolant outlet, but that costs and / or weight and / or volume of the semiconductor device arrangement can be saved by adapting their respective properties to the expected temperature gradient.

[0024] It should be noted that not all semiconductor components used in the semiconductor device assembly need to have different properties. For example, it is conceivable that two, three, or more semiconductor components arranged consecutively along the coolant channel might have identical properties. Furthermore, it is conceivable that several semiconductor components are arranged parallel to each other, essentially perpendicular to the direction of the coolant channel, and may also have identical properties. Such an arrangement of identical semiconductor components is particularly advantageous when several semiconductor components are connected in parallel.

[0025] It should also be noted that, particularly in the case where the different properties of the semiconductor components used are insufficient to operate within their respective specification limits with regard to the cooling capacity that can be provided at their respective arrangement positions on the cooling device, an increase in cooling capacity can be achieved by additionally adjusting the number and / or shape and / or size of cooling fins at the respective positions of the semiconductor components in the coolant channel.

[0026] The dependent claims describe preferred embodiments of the invention.

[0027] In an advantageous embodiment of the present invention, the respective distances between the series-arranged semiconductor devices are determined in accordance with the expected temperature gradient between the coolant inlet and the coolant outlet of the coolant channel. In this way, with a suitable design of the respective semiconductor devices, it is possible to minimize the distances between them, thereby, for example, reducing the overall volume of the semiconductor device arrangement.

[0028] Preferably, the semiconductor components are each made up of an identical number of cells (e.g. transistor cells) so that they are suitable for switching identical power levels and can be used, for example, as semiconductor components of an inverter, etc.

[0029] In a further advantageous embodiment of the present invention, the different required cooling capacities of the semiconductor components are achieved by using different chip areas of the semiconductor components. The chip area is understood to be the area that, in the installed state of the chip, is in contact with the cooling device. Since the required cooling capacity for the respective semiconductor components generally increases with decreasing chip area (due to the higher density of individual cells), it is advantageous to design those semiconductor components located closer to the more intensely cooled area of ​​the coolant inlet with a smaller chip area than those semiconductor components located closer to the less intensely cooled coolant outlet of the cooling device.In this way it is possible to reduce the size of the semiconductor device arrangement, since the total area of ​​the individual chip areas can be reduced and thus also the total area or volume of the semiconductor device arrangement according to the invention can be reduced.

[0030] In a particularly advantageous embodiment of the present invention, the semiconductor devices in the plurality of semiconductor devices are all of the same type, with their differing cooling requirements resulting from manufacturing tolerances. In other words, this makes it advantageously possible to use lower-grade (binned) semiconductor devices of the same type, i.e., semiconductor devices whose parameters do not meet the highest specification requirements, together with semiconductor devices of the same type that do meet these specification requirements due to lower manufacturing tolerances. This reduces manufacturing rejects and thus makes it possible to produce the semiconductor device assembly more cost-effectively using semiconductor devices with greater variation.

[0031] Furthermore, it is advantageous that the different cooling capacities required by the semiconductor components may result from the different semiconductor materials used in the manufacture of the semiconductor components.

[0032] Referring to the embodiment described above, it is possible, for example, for a first part of the semiconductor components, which is located closer to the coolant inlet than a second part, to be based on a silicon semiconductor, and for the second part to be based on a silicon carbide semiconductor. In this way, the partial use of less expensive silicon semiconductors makes it possible to reduce the costs of the semiconductor component arrangement. It should be noted that the use of different semiconductor materials is not limited to those mentioned above; alternative or additional materials can also be used.

[0033] In a further advantageous embodiment of the present invention, the different cooling capacities required for the semiconductor devices are achieved through different arrangement geometries of the cells and / or chips (e.g., when the semiconductor devices are configured as multi-chip modules). By adapting the arrangement geometries to the expected cooling capacity at the respective arrangement position of the semiconductor devices, the cooling of the respective semiconductor devices can be optimized. This can be achieved in particular by selecting the arrangement geometries such that, with increasing proximity to the coolant outlet, there is an increasing parallel cooling of the cells and / or chips of the respective semiconductor device.

[0034] Referring to the embodiment described above, it is possible, for example, to arrange more cells and / or chips of the respective semiconductor components transversely to the course of the coolant channel the closer the respective semiconductor component is to the coolant outlet, while the total number of cells and / or chips of the respective semiconductor components is preferably identical.

[0035] According to a second aspect of the present invention, a power module is proposed which comprises a semiconductor device arrangement according to the first aspect of the invention. The power module is configured, for example, as an inverter, and in particular as an inverter for a battery-electric vehicle, without being limited to an inverter configuration. The features, combinations of features, and the advantages arising therefrom correspond to those described in connection with the first aspect of the invention, such that reference is made to the above descriptions to avoid repetition. Brief description of the drawings

[0036] Exemplary embodiments of the invention are described in detail below with reference to the accompanying drawings. The drawing shows: Fig. 1 a schematic cross-sectional view of an embodiment of a semiconductor device arrangement according to the invention for the case of one-sided cooling; and Fig. 2 a schematic top view of a power module according to the invention for the case of one-sided cooling in conjunction with a drive train of a battery electric vehicle. Embodiments of the invention

[0037] Fig. Figure 1 shows a schematic cross-sectional view of an embodiment of a semiconductor device arrangement according to the invention comprising a plurality of semiconductor devices 10, 12, 14, 16, which are each designed as power MOSFETs and a cooling device 20 with a coolant channel 25, which here provides one-sided cooling of the semiconductor devices 10, 12, 14, 16.

[0038] The semiconductor components 10, 12, 14, 16 are arranged in a row along a path of the coolant channel 25 on a carrier plate 22 of the cooling device 20 and thus each have a thermal coupling with the cooling device 20.

[0039] The semiconductor components 10, 12, 14, 16 have different chip area sizes, so that with identical control by one or more gate drivers they each require different cooling capacities in order to be operated within their respective specification limits.

[0040] The respective distances between successive semiconductor devices 10, 12, 14, 16 are essentially uniform, so that the overall space requirement for the arrangement of the semiconductor devices 10, 12, 14, 16 is reduced compared to a conventional use of identically designed semiconductor devices, thereby enabling a reduction in size of the semiconductor device arrangement according to the invention compared to an arrangement known from the prior art.

[0041] An arrangement sequence of the semiconductor components 10, 12, 14, 16 on the cooling device 20 is determined in accordance with an expected temperature gradient between a coolant inlet 26 and a coolant outlet 28 of the coolant channel 20 during active operation of the semiconductor component arrangement, such that the semiconductor components 10, 12, 14, 16 are arranged closer to the coolant inlet 26 the higher their required cooling capacity is or the smaller their chip area is.

[0042] It is understood that the semiconductor device arrangement according to the invention includes further semiconductor devices 17, 18 (see Fig. 2) can have, for example, to form a three-phase inverter or similar.

[0043] Fig.Figure 2 shows a schematic top view of a power module 30 according to the invention in conjunction with a drive train of a (not shown) battery electric vehicle, wherein the power module 30 is designed here as a three-phase inverter, which is configured to convert electrical energy stored in a traction battery 40 of the vehicle into a three-phase alternating voltage for operating an electric motor 50 of the vehicle.

[0044] The power module 30 has a semiconductor device arrangement according to the invention, which, in addition to a cooling device 20 with a coolant channel 25, has six semiconductor devices 10, 12, 14, 16, 17, 18, wherein two semiconductor devices 10, 12, 14, 16, 17, 18 each form a half-bridge of the power module 30.

[0045] The cooling device also provides one-sided cooling of the semiconductor components 10, 12, 14, 16, 17, 18.

[0046] The semiconductor components 10, 12, 14, 16, 17, 18 have identical chip areas but differing power ratings, which result from manufacturing tolerances of the semiconductor components 10, 12, 14, 16, 17, 18 of the same type. The lower the respective power rating of the semiconductor components 10, 12, 14, 16, 17, 18, the closer they are positioned to a coolant inlet 26 of the cooling device 20 to benefit from improved cooling.

[0047] The coolant inlet 26 is connected via the coolant channel 25 to a coolant outlet 28 of the cooling device 20.

[0048] Based on the configuration described above, it is therefore possible to use semiconductor components 10, 12, 14, 16, 17, 18 of the same type, but with different power classifications, within the same power module 30, thereby saving manufacturing costs. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 102015212721 A1

[0010] DE 102017207361 A1

[0011] DE 102020109726 A1

[0012] DE 102021202552 A1

[0013]

Claims

[1] Semiconductor device arrangement comprising: - a plurality of semiconductor components (10, 12, 14, 16), and - a cooling device (20) having a coolant channel (25), where - the semiconductor components (10, 12, 14, 16) of the plurality of semiconductor components (10, 12, 14, 16) are arranged in sequence on the cooling device (20) substantially along a course of the coolant channel (25) and each have a thermal coupling with the cooling device (20), - the semiconductor components (10, 12, 14, 16) have different properties, so that with identical control they each require different cooling capacities in order to be operated within their respective specification limits, and - an arrangement sequence of the semiconductor components (10, 12, 14, 16) on the cooling device (20) is determined in accordance with an expected temperature gradient between a coolant inlet (26) and a coolant outlet (28) of the coolant channel (20) during active operation of the semiconductor component arrangement, so that the semiconductor components (10, 12, 14, 16) are arranged closer to the coolant inlet (26), the higher their required cooling power is. [2] Semiconductor device arrangement according to claim 1, wherein respective distances between the semiconductor devices (10, 12, 14, 16) arranged in series are determined in accordance with the expected temperature gradient between the coolant inlet (26) and the coolant outlet (28) of the coolant channel (20). [3] Semiconductor component arrangement according to one of the preceding claims, wherein the semiconductor components (10, 12, 14, 16) are each formed from an identical number of cells. [4] Semiconductor component arrangement according to one of the preceding claims, wherein the respectively different required cooling capacities of the semiconductor components (10, 12, 14, 16) result from different chip areas of the semiconductor components (10, 12, 14, 16). [5] Semiconductor device arrangement according to one of the preceding claims, wherein - the semiconductor components (10, 12, 14, 16) of the plurality of semiconductor components (10, 12, 14, 16) are each semiconductor components (10, 12, 14, 16) of the same type, and - their respective different required cooling capacities result from tolerances in the manufacture of the semiconductor components (10, 12, 14, 16). [6] Semiconductor component arrangement according to one of the preceding claims, wherein the respectively different required cooling capacities of the semiconductor components (10, 12, 14, 16) result from different semiconductor materials of the semiconductor components (10, 12, 14, 16). [7] Semiconductor component arrangement according to claim 6, wherein a first part of the semiconductor components (10, 12, 14, 16), which is arranged closer to the coolant inlet (26) than a second part of the semiconductor components (10, 12, 14, 16), is formed on the basis of a Si semiconductor and wherein the second part (14, 16) of the semiconductor components (10, 12, 14, 16) is formed on the basis of a SiC semiconductor. [8] Semiconductor component arrangement according to one of the preceding claims, wherein the respectively different required cooling capacities of the semiconductor components (10, 12, 14, 16) result from different arrangement geometries of cells and / or chips of the semiconductor components (10, 12, 14, 16). [9] Semiconductor component arrangement according to claim 8, wherein the more cells and / or the more chips of the respective semiconductor components (10, 12, 14, 16) are arranged transversely to the course of the coolant channel (20), the closer the respective semiconductor component (10, 12, 14, 16) is arranged to the coolant outlet (28). [10] Power module (30) comprising a semiconductor device arrangement according to one of the preceding claims.

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