Power module

Abstract

The power module (9) according to the invention has a housing (100) which comprises a carrier plate (1), housing walls (11) and a housing cover (8). The power module (9) also has semiconductor elements (2) and a temperature sensor unit (3, 4, 6) with a temperature sensor (3), which temperature sensor unit is arranged on the carrier plate (1) inside the housing (100). The power module (9) is characterized by a partition wall (10) which separates the temperature sensor unit (3, 4, 6) from the semiconductor elements (2) inside the housing (100) and encloses the temperature sensor unit in a chamber (15).

Description

Technical Field

[0001] The present invention relates to a power module. Background Art

[0002] To control the flow of electrical energy, power electronic modules are used, which are also referred to as power modules. A power module contains, among other things, semiconductors that are used to appropriately influence the current flow and thus the energy flow. The current and voltage typically vary in the range of 1 to 2000 amperes and 40 to 1500 V.

[0003] Power modules are usually located in electrical devices having an input terminal and an output terminal through which electrical energy enters and leaves. Also typically present in such a device is a control unit that takes over the control of the semiconductors of the power module and other control and protection functions specific to the device. Examples of such electrical devices are electronic motor control devices that use thyristors as semiconductors, or converters for controlling motors, in which IGBTs (= Insulated-Gate Bipolar Transistors) and thyristors are typically used as semiconductors. The overall electrical components, semiconductors, and connections through which the electrical energy flow passes are referred to as the main circuit.

[0004] The semiconductors of the power module heat up during current control due to the electrical losses generated therein, and can reach temperature values that limit or even destroy their function, for example when the current value becomes too high or the cooling of the device is impaired. Therefore, to protect the semiconductors, temperature-sensitive components are introduced into the power module, and the temperature of the semiconductors can be approximately acquired using these temperature-sensitive components. The temperature-sensitive components are also referred to as temperature sensors hereinafter.

[0005] The temperature measured by the temperature sensor or the electrical parameter corresponding to the temperature is usually transmitted to the control unit, which sends appropriate control signals to the semiconductor elements to protect the semiconductor elements when a pre-given temperature limit value is exceeded.

[0006] Since the control unit is generally constructed to be electrically insulated from the main circuit, the temperature sensors connected to the control unit are also arranged in the power module to be electrically insulated from the semiconductors. This electrical insulation is achieved by the spatial distance between the temperature sensor and the semiconductor in combination with an electrically insulating potting compound.

[0007] Here, subject to the requirements of electrical insulation, the temperature sensor is sought to be arranged as close as possible spatially to the semiconductor for the following reasons. On the one hand, the smaller the spatial distance between the temperature sensor and the semiconductor, the more accurate the temperature measurement of the semiconductor. On the other hand, the overall trend towards high power density and thus towards small structural volumes requires the semiconductor element and the temperature sensor to be arranged as compactly as possible within the power module.

[0008] Due to a fault condition or external interference, such as a short circuit on the output side of the device, very high current flows may occur in the semiconductor, which are far higher than the permitted values of the parts of the semiconductor or other current-carrying parts of the power module. This very high current value usually causes the evaporation of the current-carrying parts within the power module.

[0009] The plasma generated here propagates explosively within the power module and causes severe damage within the power module. Due to the propagation of the plasma, in extreme cases, it may lead to a short or persistent, faulty electrical connection between parts of the main circuit and the temperature sensor and thus the control unit. Then the high voltage of the main circuit is transferred to the control unit. Since the control unit is usually at the same low voltage potential as the operating plane, which is normally not dangerous, this voltage transfer must be avoided by appropriate measures in any case.

[0010] In summary, it can thus be said that the semiconductor of the power module should be protected from excessive temperatures. For good protection, i.e., for as accurate a temperature measurement as possible, the temperature sensor must be arranged as close as possible spatially to the semiconductor, thereby simultaneously meeting the requirements for a compact structure. Contrary to spatial compactness, there are the following requirements: the temperature sensor at the voltage level of the operating plane must be electrically separated from the high voltage level of the semiconductor, and this separation must also be ensured for extreme cases of short circuits.

[0011] One solution for separating the voltage levels is to make the spatial distance between the semiconductor and the temperature sensor large enough so that no electrical connection between the main circuit and the control unit can occur in the event of a short circuit. However, this makes the power module larger and more expensive, thus limiting the possibility of manufacturing compact devices with higher power density and reducing the accuracy of temperature measurement. Infineon Application Note AN2009 - 10 "Internal Design": "Using the NTC inside a power electronic module (using the NTC inside the power electronic module)" Chapter 2 "(V1.0, November 2009, Edition 2010 - 01 - 13, Infineon Technologies AG, 59568 Warstein, Germany) "NTC inside the EconoDUAL" TM3mounted on a separate DCB close to the IGBT (EconoDUAL mounted on a separate DCB close to the IGBT TM The left diagram of the "NTC inside 3" shows an example.

[0012] Another solution is to provide fuse elements that protect the main circuit from damage in the event of a short circuit. Fuse elements imply increased cost and overhead; moreover, they get very hot during operation, which leads to additional overhead for cooling, for example, in switchgear construction.

[0013] Another solution is to deprecate the temperature sensor integrated in the power module and, instead, implement the temperature sensor as a separate component with its own housing, i.e., as an external temperature sensor, such that a short circuit in the main circuit has no effect on the temperature sensor. As a result, a compact structure is only possible to a limited extent, the accuracy of temperature measurement is not optimal, and the external temperature sensor incurs additional costs due to its own housing, separate mounting, and connection. Such an external temperature sensor is described in EP1568978A1 (Siemens Aktiengesellschaft, August 31, 2005).

[0014] A solution that is also used is to additionally electrically isolate the temperature sensor from the control unit. In this case, it is assumed that, for example, due to a short circuit, the temperature sensor is at the same electrical potential as the main circuit. In this case, the necessary electrical isolation is usually carried out within the control unit, for example, using an optocoupler that converts the temperature analog signal of the temperature sensor to the voltage level of the control unit via an optical isolation path. In addition to the overhead of the electrical components for connecting the optocoupler, a spatial distance must also be maintained in the area of the electrically isolated optocoupler, which requires more space on the printed circuit board where the electronic components are arranged. In addition to the additional cost of the optocoupler and its electrical wiring, this also has a negative impact on the compactness of the control unit and may lead to a larger device. The right diagram of "NTC inside a module without baseplate, mounted close to the silicon (NTC inside a module without a baseplate, mounted close to the silicon)" in Chapter 2 of the above-mentioned Infineon Application Note AN2009-10 "Internal Design" shows the temperature sensor arranged close to the semiconductor. In this case, as just described, it may be necessary to electrically isolate the temperature sensor from the control unit. The corresponding considerations regarding insulation are mentioned in Section 2.1 "Isolation considerations" of the above-mentioned Infineon Application Note AN2009-10. Summary of the Invention

[0015] Accordingly, the technical problem to be solved by the present invention is to provide a power module in which a temperature sensor is thermally tightly coupled to one or more semiconductors and is still electrically isolated from the high voltage level of the semiconductors, even in the event of a fault.

[0016] According to the present invention, the above technical problem is solved by a power module according to the present invention. Advantageous design embodiments of the power module according to the present invention are also part of the present invention.

[0017] The power module has a housing. The housing has a carrier plate, housing walls and a housing cover. Here, the carrier plate acts as the bottom plate of the housing. The housing has an interior space surrounded by the carrier plate, the housing walls and the housing cover. The power module has semiconductor elements arranged on the carrier plate inside the housing. The power module has a temperature sensor unit arranged on the carrier plate inside the housing. Here, the temperature sensor unit has a temperature sensor. The power module also has partition walls that separate the temperature sensor unit from the semiconductor elements inside the housing and enclose it in a chamber. These partition walls form a chamber around the temperature sensor unit that largely isolates the temperature sensor unit connected to the voltage level of the control unit from the rest of the power module belonging to the voltage level of the main circuit.

[0018] The present invention is based on the idea that by simple structural measures, namely by means of additional partition walls inside the existing housing of the power module, the temperature sensor of the temperature sensor unit remains thermally tightly coupled to one or more semiconductor elements, and the temperature sensor unit is still electrically isolated from the high voltage level of the semiconductor elements, even in the event of a fault. Thus, the temperature sensor can be arranged spatially close to the semiconductor, thereby simultaneously meeting the requirements for a compact structure. At the same time, the temperature sensor unit located at the potential of the operating plane is electrically isolated from the high voltage level of the semiconductor by the partition walls, and this separation is ensured even for the extreme case of a short circuit. Here, the wall thickness of the partition walls is selected such that sufficient shielding action or mechanical load capacity of the partition walls is ensured. Here, the wall thickness is matched to the performance or current intensity of the power module as well as to the short circuit requirements and destructive effects.

[0019] The present invention can be implemented without significant overhead: the overhead is basically limited to the structural measures in the housing of the power module, and these structural measures do not incur or only incur minimal additional costs in new developments. The compactness of the power module and thus the device in which the power module is installed is maintained, because the proposed solution enables a small distance between the semiconductor of the main circuit and the temperature sensor unit, and thus does not require any significant additional space requirements. Due to the small distance between the semiconductor and the temperature sensor, the accuracy of temperature measurement is very high. No additional time- and cost-related measures are required in the device firmware to improve the accuracy.

[0020] According to a preferred embodiment of the present invention, the partition wall is connected to the housing cover and forms a component together with the housing cover. This has the advantage that when the housing cover is placed on the housing wall, the partition wall is positioned inside the housing.

[0021] According to a preferred embodiment of the present invention, the partition wall is configured as a separate component, and this separate component is arranged on a carrier plate inside the housing. Here, before the housing cover is installed, the chamber-shaped component is placed above the temperature sensor. Since the external dimensions of the power module are not changed by the partition wall but remain the same, it is also considered to use a separate component implemented as a chamber for existing power modules, and this is a relatively simple retrofit possibility because no changes have to be made to the housing cover; thus, the performance of the already used power module in the case of a short circuit can be improved in a relatively simple manner.

[0022] According to a preferred embodiment of the present invention, the wall thickness of the partition wall is reduced at its lower edge pointing to the carrier plate. This has the advantage that the partition wall extending to or almost extending to the carrier plate only reduces the thickness of the potting compound in the area of the reduced wall thickness to such an extent that an electrically insulating potting compound can still be formed with sufficient thickness, and this electrically insulating potting compound is used to encapsulate the electrical components of the power module against the environment and for electrical insulation.

[0023] The reduced wall thickness of the partition wall at its lower edge pointing to the carrier plate can also have the following advantage: due to the relatively small bearing surface of the partition wall on the carrier plate in this regard, for example, the pressure on the partition wall from above by placing the housing cover results in a relatively high surface pressure and thus causes the lower edge of the partition wall pointing to the carrier plate to be pressed tightly against the carrier plate without gaps. Therefore, air entrapment between the lower edge of the partition wall and the carrier plate is avoided, and this air entrapment may cause the insulation effect of the partition wall to deteriorate.

[0024] According to a preferred embodiment of the present invention, the partition wall extends to the lower edge of the carrier plate until it reaches the carrier plate, or only a narrow through-gap is formed between the partition wall and the carrier plate. This has the advantage that the chamber formed by the partition wall is so stable that it cannot be damaged by the influence of a short circuit in the power module. Here, the gap height of the through-gap is selected such that the electrically insulating potting compound filled into the interior of the housing can still flow through the through-gap, but at the same time does not significantly weaken the shielding effect and mechanical load-bearing capacity of the partition wall.

[0025] The through-gap is correlated with the reduced wall thickness, and this correlation is formed due to the fact that the space for arranging the temperature sensor in the power module may be very small while simultaneously requiring electrical insulation and mechanical strength. If the distance between the conductor surface on which the semiconductor element is mounted and the conductor line on which the temperature sensor unit is mounted is only slightly larger than the thickness of the partition wall, and the partition wall is pulled down to the carrier plate with its full thickness, then although this is advantageous for the mechanical strength of the chamber, only a relatively narrow gap remains between the conductor surface and the partition wall, and the potting compound must flow into this gap in order to be able to fulfill its function as an electrical insulator. This also applies to the other side of the partition wall, which shows with respect to the chamber: Here, only a relatively narrow gap also remains between the partition wall and the conductor line on which the temperature sensor unit is mounted. Here, the two gaps formed by the partition wall can be so narrow that from a manufacturing technology perspective, it cannot be ensured that the potting compound is thick enough in these gaps and thus forms sufficient electrical insulation.

[0026] Additionally, the remaining through-gap between the lower edge of the partition plate and the carrier plate can be so narrow that no potting compound can flow into the through-gap, and thus air will remain there. However, air has significantly worse insulating properties compared to the potting compound. Therefore, it must be taken into account that the combination of a very narrow gap and air inclusions does not have sufficient insulating strength. For this reason, it is advantageous to reduce the thickness of the partition wall towards the carrier plate in the contact area. The remaining corner area thus becomes significantly wider, and the potting compound can reliably form on both sides of the partition wall with sufficient thickness for the insulating effect.

[0027] However, in order to avoid the risk of air inclusions between the lower edge of the partition wall and the carrier plate (which may lead to insulation failure), it must be ensured that the potting compound can flow in between the lower edge of the partition wall and the carrier plate, which requires that the through-gap h is also large enough. Therefore, the reduced thickness d of the partition wall is correlated with the required gap height h of the through-gap: the larger the reduced thickness d of the partition wall is selected, the larger the gap height h of the through-gap must also be selected.

[0028] According to a preferred embodiment of the present invention, the housing wall has at least one side wall and / or longitudinal wall, which has a smaller wall thickness compared to the remaining housing walls, such that the side wall and / or longitudinal wall can act as a designated fracture location in the case of an increase in pressure inside the housing. In this way, the stability of the chamber of the temperature sensor is increased compared to the stability of the remaining power modules. In the case of a short circuit occurring in the region of the semiconductor, the explosively generated gas diffuses in all directions in the first instance. The pressure wave then propagates in the direction of least mechanical resistance, such that at least one thinned side wall and / or at least one thinned longitudinal wall yields to the pressure and ruptures before the partition wall forming the chamber of the temperature sensor unit is attacked. By completely or partially maintaining the mechanical integrity of the chamber of the temperature sensor unit, voltage transfer from the main circuit side to the control unit can be avoided.

[0029] According to a preferred embodiment of the present invention, the power module has two or more semiconductor elements, and a temperature sensor unit is arranged between the two or more semiconductor elements. This has the advantage that, due to the small distance between the semiconductor and the temperature sensor, the accuracy of temperature measurement is relatively high.

[0030] According to a preferred embodiment of the present invention, the temperature sensor unit has electrical leads for supplying the temperature sensor. Here, it is advantageous that the components located at the potential of the operating plane are arranged together in the chamber and are separated from the potential of the main circuit.

[0031] According to a preferred embodiment of the present invention, the temperature sensor unit has conductor tracks located on a carrier plate, which form a feeder line to the temperature sensor. Here, it is advantageous that the components located at the potential of the operating plane are arranged together in the chamber and are separated from the potential of the main circuit.

[0032] According to a preferred embodiment of the present invention, the partition wall has at least one opening, which forms a connection channel between the chamber and the remaining internal space of the housing, through which an electrically insulating potting compound can flow into the chamber. This has the advantage that the temperature sensor can be protected from the environment by the electrically insulating potting compound and is encapsulated for electrical insulation.

[0033] According to a preferred embodiment of the present invention, at least one of the partition walls is constructed as two-layer or multi-layer. This has the advantage that the mechanical stability of the multi-layer wall can be increased compared to a single-layer wall of the same thickness. Description of the Drawings

[0034] The features, characteristics and advantages of the present invention described above and the manner of their implementation are more clearly and distinctly understood from the following description of the drawings. Here, in a schematic and non-scaled illustration:

[0035] Figure 1 Shows an oblique view of the carrier plate of the power module;

[0036] Figure 2 Shows Figure 1 longitudinal section II-II of the power module of;

[0037] Figure 3 Shows Figure 1 cross-section III-III of the power module of;

[0038] Figure 4 Shows Figure 1 oblique view of horizontal section IV-IV of the power module of;

[0039] Figure 5 Shows Figure 1 top view of horizontal section IV-IV of the power module of;

[0040] Figures 6 to 9 Shows the cross-section of the partition wall according to four different design schemes;

[0041] Figure 10 and Figure 11 Shows two implementations of the partition wall of the multi-shell; and

[0042] Figures 12 to 14 Shows another design scheme of the power module with a separate chamber member. Detailed Description

[0043] Figure 1 Shows the carrier plate 1 of the power module, on which two semiconductor elements 2 and a temperature sensor 3 are arranged. Also shown are the electrical conductors 4, 5 configured as cylindrical connecting pins, which contact the conductor tracks 6, 7 located on the carrier plate 1. The conductor tracks 6, 7, preferably configured as copper rails, form the feed lines to the two semiconductor elements 2 and the temperature sensor 3. Here, the semiconductor element 2 is arranged on the conductor surface 18, which is located on the carrier plate 1 and is configured as a copper surface.

[0044] There are two regions on the carrier plate 1, which belong to different voltage levels. On the one hand, the two semiconductor elements 2, the conductor tracks 7 contacting them, and the electrical conductors 5 (connecting pins) contacting these conductor tracks 7 are part of the voltage level of the main circuit. On the other hand, the temperature sensor 3 together with its conductor track 6 and the associated electrical conductor 4 (connecting pin) belong to the voltage level of the control unit, in which there is a significantly lower voltage than in the main circuit.

[0045] The temperature sensor 3 is located between two semiconductor elements 2 and has only a small distance from these two semiconductor elements. By placing the temperature sensor 3 between the two semiconductor elements 2, the space requirement on the carrier plate 1 is not increased, so that the power module can be very compact. In addition, the small distance between the temperature sensor and the two semiconductor elements is advantageous for the accuracy of temperature measurement.

[0046] The spatial proximity between the two semiconductor elements 2 and the temperature sensor 3 requires measures to protect the temperature sensor 3 from short circuits at least to the extent that a short circuit in the main circuit, which can lead to an explosive evaporation process and thus to damage in the area of the semiconductor element 2, is prevented from causing a transient or even continuous voltage transfer from the voltage level of the main circuit to the voltage level of the temperature sensor 3 and thus to the control unit.

[0047] Figures 2 to 5 It is illustrated how, to solve the technical problem, the temperature sensor 3 is spatially separated from the area of the main circuit by structural measures according to the invention. For this purpose, a wall is mounted on the housing cover 8 of the housing 100 of the power module 9, which wall acts as a partition wall 10 inside the housing 100 and is formed by the carrier plate 1 forming the housing bottom, the housing cover 8 and the housing wall 11 extending between the carrier plate 1 and the housing cover 8. By means of these partition walls 10, a chamber 15 is established around the temperature sensor unit 3, 4, 6, which temperature sensor unit 3, 4, 6 consists of the temperature sensor 3, the conductor track 6 in contact therewith and the associated electrical conductor 4, and this chamber largely isolates the temperature sensor unit (which is connected to the voltage level of the control unit) from the rest of the power module 9 (which belongs to the voltage level of the main circuit). The partition walls 10 are implemented so deep that when the housing cover 8 is placed on the housing wall 11, the partition walls reach up to the carrier plate 1, as shown in Figure 6 and Figure 8 or as shown in Figure 7 and Figure 9 at least only leaving a through-gap 24 with a gap height h from the carrier plate 1. Here, the gap height h is selected such that the potting compound can still flow through the through-gap 24, but at the same time the shielding effect and the mechanical load-bearing capacity of the partition wall 10 are not significantly reduced. Typical gap heights can be in the range of 0.1 to 3 mm; these values should only be understood by way of example and in no way construed as limiting; the through-gap 24 can also have any other gap height h that proves suitable for the respective application case.

[0048] The housing cover 8 has a filling opening 12 for filling potting compound and a through hole 22 which extends vertically through a post 23 arranged at the center of the power module 9. The through hole 22 serves the purpose of enabling a screw to pass through, whereby the power module 9 can be pressed onto the cooling body.

[0049] As Figures 6 to 9 shown, the partition wall 10 has a wall thickness D thick enough for its function as explosion protection and is connected to the existing housing wall 11 and the housing cover 8 such that a stable chamber 15 is formed around the temperature sensor units 3, 4, 6. A typical wall thickness can be in the range of 0.5 to 5 mm; these values should only be understood exemplarily and should in no way be construed as restrictive; the partition wall 10 can also have any other wall thickness D which proves suitable for the respective application case. The stability of the chamber 15 is large enough such that the chamber is not destroyed by a short - circuit effect or is only destroyed to the extent that it can prevent voltage transfer from the voltage level of the main circuit to the voltage level of the temperature sensor units 3, 4, 6.

[0050] To prevent environmental influences and for electrical insulation, the electrical components of the power module are encapsulated with an electrically insulating potting compound. This is filled through one of the two filling openings 12 in the housing cover 8 shown in Figure 2 until a predetermined filling height 16 is reached, which ensures that all conductive parts inside the power module 9 are encapsulated, thus achieving electrical insulation and protection against environmental influences.

[0051] To enable the potting compound to also enter the chamber of the temperature sensor unit, a connection channel 13 shown in Figure 3 and Figure 5 is introduced into the partition wall 10. For cost reasons and for technical reasons, the potting compound is not filled up to the lower edge of the housing cover 8. In the case of complete filling, due to the thermal expansion of the potting compound in the case of temperature changes, pressure may act on the housing cover 8 and the carrier plate 1, and this pressure may cause the housing cover 8 to lift from the carrier plate 1 and thus may damage the electrical insulation characteristics of the power module 9.

[0052] To prevent, in the case of a short - circuit, conductive gas that can enter through the connection channel 13 of the chamber 15 from reaching the electrical wire 4 of the temperature sensor 3 and thus causing voltage transfer from the main current side to the voltage level of the control unit, the electrical wire 4 is separated by an additional wall 14 which separates the chamber 15 into a main chamber 15a in which the temperature sensor 3 is arranged and a semi - open sub - chamber 15b in which the electrical wire 4 is arranged. As Figure 3As shown, the additional wall 14 is implemented only so deep that the remaining opening between the lower edge 14a of the additional wall 14 and the carrier plate 1 is large enough so that the potting compound can also flow into the sub-chamber 15b and thus cover all areas of the carrier plate 1 within the chamber 15. In this way, in the sub-chamber 15b, the conductor tracks 6 are also completely encapsulated and the electrical conductors 4 are partially encapsulated and thus electrically insulated. In order for the potting compound to also be able to rise to a preset filling height 16 (which is shown as a dashed line in Figure 3 ), an exhaust opening 17 is introduced in the housing cover 8.

[0053] As a further measure for avoiding a voltage transfer from the voltage level of the main circuit to the voltage level of the control unit, for example, the side walls 20 of the housing wall 11 and the longitudinal walls 21 of the housing wall 11 can be implemented thinner in specific regions, as shown in Figure 4 and Figure 5 . In this way, compared to the stability of the remaining power module 9, the stability of the chambers 15 of the temperature sensor units 3, 4, 6 is increased. In the event of a short circuit occurring in the region of the semiconductor element 2, the gas generated explosively spreads in all directions in the first instance. Then, the pressure wave propagates in the direction of least mechanical resistance such that the thinner side walls 20 and the thinner longitudinal walls 21 yield to the pressure and rupture first before the partition walls 10 of the temperature sensor units 3, 4, 6 are attacked. By maintaining the mechanical integrity of the chambers 15 of the temperature sensor units 3, 4, 6 completely or partially, a voltage transfer from the main circuit to the control unit can be avoided.

[0054] Figures 6 to 9 shows cross-sections of partition walls according to four different design variants. Due to the spatial compactness of the power module 9, the distance a between the conductor surface 18 on which the semiconductor element 2 is mounted and the conductor tracks 6 of the temperature sensor units 3, 4, 6 can be relatively small, as can be seen in Figure 2 . The electrical insulation between the conductor surface 18 of the semiconductor element 2 (which belongs to the voltage level of the main circuit) and the conductor tracks 6 of the temperature sensor units 3, 4, 6 (which belong to the voltage level of the control unit) is achieved by the potting compound which covers the conductor tracks 6 and the conductor surface 18. In order for the potting compound to be able to fulfill its electrical insulation function, the layer thickness of the potting compound must have a minimum thickness. A typical layer thickness of the potting compound can be in the range from 0.5 to 5 mm; this value should only be understood by way of example and should in no way be understood as being restrictive; the potting compound can also have any other layer thickness which proves suitable for the respective application case. In order for the partition walls 10 which extend to or almost extend to the carrier plate 1 not to reduce the thickness of the potting compound in the vertical edge regions of the conductor tracks 6 and the conductor surface 18 in an impermissible manner, as in Figure 6 and Figure 7As shown, the dividing wall 10 can be thinned to a thickness d at its lower edge 19 such that potting compound can still be formed with sufficient thickness in the corner region of the carrier plate 1 and the dividing wall 10 defined by the conductor track 6 or the conductor surface 18. Herein, Figure 6 shows an embodiment in which the thinned edge 19 abuts against the carrier plate 1; while Figure 7 shows an embodiment in which a through-gap 24 with a gap height h is formed between the thinned edge 19 and the carrier plate 1, and the potting compound can flow into the through-gap.

[0055] Typical reduced wall thicknesses d can range from 0.2 to 3 mm; these values should only be understood exemplarily and in no way construed as limiting; the dividing wall 10 can also have any other reduced wall thickness d that proves suitable for the respective application case.

[0056] If the distance a between the conductor surface 18 on which the semiconductor element 2 is mounted and the conductor tracks 6 of the temperature sensor units 3, 4, 6 is large enough, it is not necessary to reduce the wall thickness of the dividing wall 10 at its lower edge 19; alternatively, the dividing wall 10 can have a uniform thickness D over its entire height, as Figure 8 and Figure 9 shown. Herein, Figure 8 shows an embodiment in which the edge 19 of the dividing wall 10 abuts against the carrier plate 1; while Figure 7 shows an embodiment in which a through-gap 24 with a gap height h is formed between the thinned edge 19 and the carrier plate 1, and the potting compound can flow into the through-gap.

[0057] Figure 10 and Figure 11 show two embodiments of a multi-shell dividing wall.

[0058] Figure 10 shows a three-shell structure of the dividing wall 10, which consists of a first outer shell 10a arranged on the side of the dividing wall 10 facing away from the chamber 15, a second outer shell 10c arranged on the side of the dividing wall 10 facing the chamber 15, and an intermediate shell 10b configured as an air layer.

[0059] Figure 11 shows a five-shell structure of the dividing wall 10, which has a first outer shell 10a arranged on the side of the dividing wall 10 facing away from the chamber 15, a second outer shell 10e arranged on the side of the dividing wall 10 facing the chamber 15, and an intermediate shell 10c arranged between the two outer shells 10a and 10e. Connecting layers 10b or 10d are respectively arranged between the outer shells 10a, 10e and the intermediate shell 10c, which can be designed as adhesive layers, for example.

[0060] Figures 12 to 14Another embodiment is shown, in which its own mechanical component 30 is used, which is configured as a chamber 15. Before installing the housing cover 8 (see Figure 14 ), this chamber-shaped component 30 is placed on the temperature sensor units 3, 4, 6, see Figure 12 and Figure 13 . The features described previously, such as the filling opening 12 for the potting compound, the additional partition wall 14 of the sub-chamber 15b for the electrical conductors 4 of the temperature sensor units 3, 4, and 6, which are configured as connecting pins, and the tapering of the partition wall 10 at its edges to the carrier plate 1 can also be applied to this separate chamber component. An existing power module can also be retrofitted with the separate chamber component 30, since no changes have to be made to the housing cover 8.

Claims

1. A power module (9), comprising: - A housing (100), which includes a carrier plate (1), a housing wall (11), and a housing cover (8), - A semiconductor element (2) and a temperature sensor unit (3, 4, 6) having a temperature sensor (3), the temperature sensor unit being arranged on the carrier plate (1) inside the housing (100), characterized in that A partition wall (10), which separates the temperature sensor unit (3, 4, 6) from the semiconductor element (2) inside the housing (100) and encloses the temperature sensor unit (3, 4, 6) in a chamber (15), wherein the wall thickness of the partition wall (10) decreases at its lower edge (19) pointing to the carrier plate (1).

2. The power module (9) according to claim 1, Among them, The partition wall (10) is connected to the housing cover (8) and forms a component together with the housing cover (8).

3. The power module (9) according to claim 1, Among them, The partition wall (10) is configured as a separate component (30), and the separate component is arranged on the carrier plate (1) inside the housing (100).

4. The power module (9) according to any one of claims 1 to 3, Among them, The partition wall (10) reaches the carrier plate (1) with its lower edge (19) pointing to the carrier plate (1), or only a narrow through-gap (24) is formed between the partition wall (10) and the carrier plate (1).

5. The power module (9) according to any one of claims 1 to 3, Among them, The housing wall (11) has at least one side wall (20) and / or a longitudinal wall (21), and the side wall and / or the longitudinal wall have a smaller wall thickness compared to the remaining housing wall (11), such that the side wall and / or the longitudinal wall can act as a designated fracture location when the pressure inside the housing (100) increases.

6. The power module (9) according to any one of claims 1 to 3, Among them, The power module (9) has two or more semiconductor elements (2), and the temperature sensor unit (3, 4, 6) is arranged between the two or more semiconductor elements.

7. The power module (9) according to any one of claims 1 to 3, Among them, The temperature sensor unit (3, 4, 6) has an electrical wire (4) for supplying power to the temperature sensor (3).

8. The power module (9) according to any one of claims 1 to 3, Among them, The temperature sensor unit (3, 4, 6) has a conductor track (6) located on the carrier plate (1), and the conductor track forms a feeder line to the temperature sensor (3).

9. The power module (9) according to any one of claims 1 to 3, Among them, The partition wall (10) has at least one through-opening (13), and the through-opening forms a connection channel between the chamber (15) and the remaining internal space of the housing (100), and an electrically insulating potting compound can flow into the chamber (15) through the connection channel.

10. The power module (9) according to any one of claims 1 to 3, Among them, at least one of the partition walls (10) is configured to be two-layered or multi-layered.

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