Power module and method for producing a power module - Patents.com

Abstract

According to one embodiment, a power module (100) comprises a power semiconductor device (1) and a connection element (2) for electrically connecting the power semiconductor device. Furthermore, the arrangement comprises a sensing element (3) for measuring a measurand. A coupling section (21) of the connection element is coupled to and electrically connected to the power semiconductor device. The sensing element is attached to the connection element and spaced apart from the coupling section.

Description

[Technical field]

[0001] The present disclosure relates to a power module and a method for producing a power module. [Background technology]

[0002] There is a need for improved power modules, e.g., power modules that allow for faster and / or more reliable detection of malfunctions, such as overheating. Additionally, there is a need for improved methods for producing such power modules. Summary of the Invention [Means for solving the problem]

[0003] SUMMARY OF THE DISCLOSURE An embodiment of the present disclosure relates to an improved power module. Further embodiments of the present disclosure relate to an improved method for producing a power module.

[0004] First, the power module will be described. According to one embodiment, a power module comprises a power semiconductor device and a connection element for electrically connecting the power semiconductor device. Furthermore, the power module comprises a sensing element for measuring a measurand. A coupling section of the connection element is coupled to and electrically connected with the power semiconductor device. The sensing element is attached to the connection element and spaced apart from the coupling section.

[0005] Overheating of the power semiconductor devices in the power module, also called power semiconductor chips or simply chips for short, can be detected by using temperature sensors mounted in the power module. Overheating can be the result of deterioration of the bonded connections or loss of cooling capacity or malfunction of the power semiconductor devices. For detection, simple temperature sensing elements such as NTC, PTC and / or platinum-based resistors such as PT100 or PT1000 resistors can be used. One or more of these sensors are typically placed in the immediate vicinity of the heat-generating power semiconductor device. The sensor readings follow the temperature behavior of the power semiconductor device better if the sensing element or elements are placed as close as possible to the power semiconductor device.

[0006] However, the sensing element is usually placed on a separate metallization pattern of the substrate adjacent to the power semiconductor device. Here, the sensing element is not directly linked to the junction temperature of the power semiconductor device, and as a result, a relatively long thermal path must be considered, and a transfer function with corresponding errors and uncertainties is required to determine the junction temperature from the sensor reading. Additionally, there is a time delay between the true chip temperature and the sensor reading.

[0007] An alternative that allows to obtain direct and accurate data is to place the sensing element on the heat-generating power semiconductor device. However, on the other hand, this alternative takes space from the area used for the bonding connection, which can be particularly important in SiC chips due to the small chip size and higher current density. On the other hand, when considering mounting the sensing element on top of the bonding section of the connection element, the mounting can be very difficult or even impossible due to the geometric and / or mechanical features of the bonding connection between the wire bonds, ribbons or clips and the chip. This is because they often have a curved shape. A further alternative is a chip with an integrated sensor or sensing element. However, this is rare.

[0008] The inventors of the present invention have realized that mounting at least one sensing element on a connection element coupled to the chip provides good sensor readings and short response times, at least compared to the situation where the sensing element is implemented on the substrate metallization pattern. The area of ​​the connection element that is spaced apart from the bonding section where the connection element is actually coupled to the chip usually provides enough space for mounting the sensing element, but still results in sufficiently good and fast sensor readings. This is due in particular to the proximity of the sensing element to the chip. In the case of a temperature sensor, the short response time is due, among other things, to the good thermal conduction of the connection element and the relatively short thermal path. Moreover, no additional space is required on the substrate for the sensing element with this location of the sensing element. Thus, the position of the sensing element potentially allows a reduction in module size or there is more space for power semiconductor devices associated with higher current capacity. This position is applicable to small and large chips. In particular for small chips where space on the chip or on the top surface of the bonding section is limited or unavailable, a position on the connection element but spaced apart from the bonding section is beneficial. Finally, by arranging the sensing element on the connection element, information can be achieved about the interface degradation of the coupling connections between the power semiconductor device and the substrate and between the connection element and the power semiconductor device, respectively.

[0009] The connection element may be, for example, metal-based. For example, the connection element may comprise or consist of Cu, Al, Au, Ag, or any alloy of these metals. By way of example, the connection element may be configured to carry a current of at least 1 A, or at least 10 A, or at least 100 A.

[0010] The connection element, i.e. its coupling section, is coupled to a power semiconductor device, e.g. a contact element of the power semiconductor device. This results in a strong bond between the power semiconductor device and the connection element. For example, the connection element is glued or soldered or sintered or welded to the power semiconductor device. Thus, in most cases, an adhesive or solder material or a sintered material is arranged between the connection element and the power semiconductor device. The connection element may also be formed continuously. For example, the connection element is formed in one piece.

[0011] The bonding section of a connection element is the part that is bonded to another element. The bonding section may be a foot or a stitch section or a perforation section of the connection element. A connection element may include one or more such bonding sections. A bonding section is defined as, for example, an area of ​​a connection element where one or more joints between the connection element and a power semiconductor device are formed.

[0012] The sensing element is configured to measure a measurand, such as a physical property of the power semiconductor device or a physical property of the environment surrounding the power semiconductor device. The sensing element may be a sensor or part of a sensor, i.e. a first element of a measurement chain, i.e. a part of a sensor that responds directly to the measurand. Such a sensing element is also known as a transducer. The sensor itself may comprise further components of the measurement chain in addition to this first element.

[0013] The sensing element may be electrically connected to the connecting element or may be electrically isolated from the connecting element. The sensing element may be electrically connected to one or more further elements of the power module, for example by wire bonding.

[0014] The sensing element is attached to the connecting element, e.g., firmly bonded to the connecting element. For example, the sensing element is bonded to the connecting element by soldering, gluing, sintering, or any other applicable bonding / joining method. This results in the sensing element being spaced apart from the bonding section. If the connecting element includes more than one bonding section, the sensing element is, for example, spaced apart from each of these bonding sections.

[0015] The distance, i.e. the shortest connection, between the sensing element and the or each binding section is, for example, at least 50 μm or at least 100 μm and / or at most 15 mm or at most 5 mm or at most 1 mm. For example, the length of the shortest path along the connection element connecting the sensing element and the binding section is at least 50 μm or at least 100 μm and / or at most 15 mm or at most 5 mm or at most 1 mm. The distance between the sensing element and the connection element due to the optional connection material between them is, for example, at most 200 μm or at most 50 μm or at most 10 μm or at most 5 μm.

[0016] In addition to the power semiconductor device, the connection element and the sensing element described so far, the power module may comprise one or more further power semiconductor devices, one or more further connection elements and / or one or more further sensing elements. By way of example, the one or more further connection elements are coupled and electrically connected to the power semiconductor device. The one or more further sensing elements may be mounted on the connection element and / or the further connection element. All features disclosed hereinbefore and below for a power semiconductor device, a connection element and a sensing element are also disclosed for all further power semiconductor devices, connection elements and sensing elements, respectively.

[0017] According to a further embodiment, the sensing element is a temperature sensing element for measuring a temperature, the temperature measured by means of the sensing element being characteristic of the temperature and / or its time dependence of the power semiconductor device, in the vicinity of which the sensing element is mounted, since the power semiconductor device is the main heat source of the power module.

[0018] Alternatively, the sensing element may be configured to measure a different measurand such as moisture, humidity, current, voltage, pressure, magnetic field, vibration, etc. The sensing element may be, for example, a Hall sensor.

[0019] According to at least one embodiment, the connection element is a ribbon or a wire or a clip or a terminal.

[0020] The terminal is an element configured for the external electrical connection of the power module, i.e. for electrically connecting the power module to an external component of the application. The terminal is, for example, a sheet-like rigid element such as a busbar or a lead frame. The connection element may comprise a body and at least one terminal foot. The terminal foot constitutes a coupling section of the terminal for coupling the terminal. Between the body and the terminal foot, the terminal may include, for example, a 90° kink. Each terminal foot or the entire terminal may have a width of at least 1 mm and / or at most 15 mm. The thickness of each terminal foot or the entire terminal is, for example, at least 0.15 mm and / or at most 2.0 mm or at most 1.5 mm.

[0021] A clip is understood here to be a rigid sheet-like structure, for example a stamped pre-bent structure. The clip is usually used to electrically connect two elements of a power module. For example, the clip comprises at least two clip feet or ends connected by the body of the clip. The clip feet or ends constitute the coupling section of the clip for coupling the clip. There may be a kink between the body and each clip foot. The width and / or thickness may be the same as specified for the terminal.

[0022] A ribbon is a flexible or bendable structure. A ribbon can have a width of at least 0.5 mm and / or at most 15 mm. A ribbon can have a thickness of at least 20 μm and / or at most 2 mm. For example, the width is at least twice as large as the thickness.

[0023] The above dimensions of the connection element allow good heat conduction from the power semiconductor device to the sensing element. At the same time, the dimensions are such that the connection element itself does not have too large a surface, in order to provide for strong cooling of the connection element. On the other hand, the dimensions are large enough to be able to transport high currents without excessive heating of the connection element due to the passing currents. The position on the connection element at which the sensing element is attached therefore very well reflects the actual temperature of the power semiconductor device.

[0024] According to a further embodiment, the bonding section of the connection element is bonded to the contact surface of the power semiconductor device. The bonding connection between the bonding section and the contact surface is established in a bonding area. For example, in the bonding area there is one or more joints, such as welded joints, soldered joints or adhesive joints, between the bonding section and the contact surface. The bonding area is for example defined and / or limited to the area on which the joint between the connection element and the power semiconductor device is formed. A joint is understood here as the area on which a strong bond or material bond, respectively, between the two elements is realized. In case of welding the joint, this is for example the area on which the material melts.

[0025] The contact surface may be at least partially formed by a contact element of the power semiconductor device or by a surface of such a contact element, respectively. The contact element may be formed from a metal, including, for example, aluminum, copper, silver, or a corresponding alloy. For example, the coupling connection between the coupling section and the power semiconductor device is between the coupling section and the contact element.

[0026] According to a further embodiment, the sensing element is attached to the connection element such that in a plan view of the contact surface, the sensing element is spaced apart from the bonding area, i.e. the sensing element does not overlap the bonding area in this plan view. However, in a plan view of the contact surface, the sensing element is close to the bonding area. For example, in this plan view, the lateral distance between the bonding area and the sensing element is at least 1 mm or at least 100 μm. In the case of a connection element having several bonding sections each bonded to an element in the bonding area, the sensing element does not overlap, for example, any of these bonding areas in the plan view.

[0027] By way of example, in a plan view of the contact surface, the sensing element is spaced from the bonding region by at least the thickness of the connecting element, or by at least two or at least three times the thickness of the connecting element.

[0028] According to a further embodiment, in a plan view of the contact surface, the sensing element is spaced apart from the power semiconductor device and / or the active area of ​​the power semiconductor device. Thus, the sensing element does not overlap the power semiconductor device and / or its active area. For example, in a plan view of the contact surface, the sensing element is spaced apart from the power semiconductor device and / or its active area by at least 1 mm or at least 100 μm.

[0029] According to a further embodiment, the power module further comprises a substrate. The substrate may have an upper metallization for mounting of components and electrical connection to the components of the power module. Furthermore, the substrate may have a lower metallization. There may be an electrical insulation layer between the upper and lower metallizations. The substrate may be an insulated metal substrate (IMS) with an electrically insulating resin layer sandwiched between the upper and lower metallizations. Alternatively, the substrate may be an active metal brace or a direct bonded copper (DBC) or direct bonded aluminum (DBA) substrate with a ceramic insulation sheet between the upper and lower metallizations.

[0030] According to a further embodiment, the power semiconductor device is attached to the substrate and electrically connected to the substrate, for example, the power semiconductor device is attached to and electrically connected to a top metallization of the substrate, for example by soldering, gluing or sintering.

[0031] According to a further embodiment, the contact surface of the power semiconductor device is a top contact surface facing away from the substrate, such that a bottom surface of the power semiconductor device opposite the top contact surface faces the substrate and can be electrically connected to the substrate.

[0032] The surface of the connecting element to which the sensing element is attached may face away from the substrate. Alternatively, the surface may face the substrate.

[0033] According to a further embodiment, the connection element comprises a flat section. By "flat section" is meant that the surface of this section is flat within the limits of manufacturing tolerances. The flat section and / or its surface may extend obliquely or parallel to the contact surface and / or obliquely or parallel to the top surface of the substrate on which the power semiconductor device is mounted. Parallel in this context means essentially parallel, e.g. with a maximum deviation of up to 10° from exact parallelism.

[0034] According to a further embodiment, the sensing element is attached to a flat section of the connecting element, i.e. to its flat surface, which makes mounting of the sensor particularly easy.

[0035] According to further embodiments, the flat section is at a different height than the bonding section relative to the top surface and / or the contact surface of the substrate. For example, the flat section is arranged at a higher height than the bonding section relative to the top surface of the substrate or the contact surface of the power semiconductor device. The height difference may be at least 50 μm, or at least 100 μm, or at least 1 mm.

[0036] According to a further embodiment, the connection element electrically connects the power semiconductor device with one or more further elements of the power module, for example in a plan view of the contact surface of the power semiconductor device, the sensing element is then arranged between the power semiconductor device and the further element.

[0037] According to a further embodiment, the further element is a further power semiconductor device or a substrate. This may be the same substrate as the substrate on which the power semiconductor device is mounted or may be a further substrate different from the substrate on which the power semiconductor device is mounted. The further element may be a further power semiconductor device on a further substrate. The further element may also be a terminal.

[0038] According to a further embodiment, the power semiconductor device is a switching element such as a transistor or a thyristor or a diode.

[0039] According to a further embodiment, the power semiconductor device is a MOSFET or an IGBT or a MISFET or a JFET or a HEMT.

[0040] According to at least one embodiment, the connection element is electrically connected to a main electrode of the power semiconductor device, such as a source / emitter electrode or a drain / collector electrode. Alternatively, the connection element may be electrically connected to a gate electrode of the power semiconductor device.

[0041] According to further embodiments, the power semiconductor device is based on at least one of silicon, silicon carbide, gallium nitride, i.e. the semiconductor body of the power semiconductor device is based on one of these semiconductors.

[0042] According to a further embodiment, the sensing element is a resistive element. The sensing element can have a positive resistive behavior (Positive Temperature Coefficient, PTC for short) or a negative resistive behavior (Negative Temperature Coefficient, NTC for short). For example, the sensing element is based on Pt. The sensing element can be, for example, PT100 or PT500 or PT1000.

[0043] Alternatively, the sensing element may be a thermocouple. According to a further embodiment, the sensing element is a chip or a surface mounted device, SMD for short. In this case, the sensing element may be a complete sensor, for example comprising a processing circuit for signal processing.

[0044] According to a further embodiment, the power module is configured to transmit the measurement signal obtained by using the sensing element to an external device. For example, the sensing element is electrically connected to an auxiliary terminal in the power module that is electrically connectable externally to an external or internal device. The connection to the auxiliary terminal may be via wire bonding. Alternatively, the power module may comprise a wireless communication device, such as a Bluetooth device, by which the measurement signal obtained by using the sensing element is wirelessly transmitted.

[0045] The chip-like sensing element may comprise at least one upper contact and a lower contact. The lower contact may be bonded and electrically connected to a connecting element, and the upper contact element may be electrically connected to a different region of the power module, for example by wire bonding. Alternatively, the sensing element may comprise two or more contact elements, each of which is electrically connected to a further region of the power module, for example by wire bonding.

[0046] According to further embodiments, the power semiconductor device has an edge length of up to 8 mm or up to 5 mm. Thus, the area of ​​the contact surface of the power semiconductor device is up to 25 mm 2 In particular for such small power semiconductor devices, the positioning of the sensing element on the connection element spaced apart from the bonding section is advantageous, for example the area on the power semiconductor device for bonding the connection element is small.

[0047] According to at least one embodiment, the sensing element has a maximum dimension of 5 mm. According to a further embodiment, the power module comprises a housing surrounding the power semiconductor device, for example the housing surrounding the power semiconductor device at least laterally, i.e. in a direction parallel to the contact surface of the power semiconductor device and / or parallel to a main extension surface of the power module.

[0048] The housing may include or consist of an electrically insulating material. The housing may be at least partially formed by a frame of a thermoplastic or thermosetting resin material, which may be filled with inorganic particles or fibers. For example, the housing comprises a frame surrounding a cavity and a gel or potting resin filled in the cavity. The power semiconductor device is, for example, embedded in and encapsulated by the housing. The housing may be at least partially formed by a molding process, such as transfer molding or injection molding.

[0049] According to a further embodiment, the power module comprises a base plate to which one or more substrates are attached. The base plate may be configured as a heat sink. For example, the base plate comprises cooling ribs and / or cooling fins on a surface facing away from the substrates.

[0050] A power module may be a device incorporating and electrically and mechanically interconnecting multiple power semiconductor devices. A power module may be adapted to handle currents in excess of 10 A. A power module may be a low voltage module adapted to handle voltages below 1 kV, or a medium voltage module adapted to handle voltages between 1 kV and 10 kV.

[0051] The power module can be utilized, for example, in an electric converter that rectifies an AC voltage / current to a DC voltage / current that is supplied to a DC link or a battery, such as the battery of an electric vehicle. It is also possible for the power module to be an inverter that generates an AC voltage / current from a DC voltage / current that is supplied to an electric motor, such as the motor of an electric vehicle. The inverter may also be used to change the frequency of the AC voltage / current to another frequency of AC voltage / current. The power module can be used in automotive applications such as electric cars, motorcycles, buses, off-road construction vehicles, trucks, charging stations or power plants or traction applications.

[0052] Next, a method for producing a power module is described. The method can be configured to produce a power module according to any one of the embodiments described herein. Thus, all features disclosed for the power module are also disclosed for the method and vice versa.

[0053] In at least one embodiment, the method includes providing a power semiconductor device and a connection element for electrically connecting the power semiconductor device. In a further step, a bonding section of the connection element is coupled to the power semiconductor device. In a still further step, a sensing element is attached to the connection element in a region spaced from the bonding section but sufficiently close to the bonding section such that a measurand associated with the power semiconductor device is measurable using the sensing element when the bonding section is coupled to the power semiconductor device.

[0054] Bonding the coupling section to the power semiconductor device can occur before or after attaching the sensing element. Attaching the sensing element can include gluing, soldering, or sintering the sensing element to the connecting element.

[0055] The area for mounting the sensing element is selected as a compromise, for example, such that on the one hand, sufficient space is available on the connection element for mounting the sensing element, and on the other hand, sufficient proximity to the power semiconductor device is maintained to provide a reasonable or direct measurement with the sensing element. For example, the sensing element is a temperature sensing element, so that the closer to the coupling section the sensing element is mounted, the better the measurements will reflect the true temperature of the power semiconductor device. For example, the area where the sensing element is mounted is determined in advance using a simulation.

[0056] Hereinafter, the power module and the method for producing the power module will be described in more detail based on an exemplary embodiment with reference to the drawings. The attached drawings are included to provide further understanding. In the drawings, elements of the same structure and / or function may be referred to by the same reference numerals. It should be understood that the embodiments shown in the drawings are exemplary representations and are not necessarily drawn to scale. Insofar as elements or components correspond to each other in terms of their functions in different figures, the description thereof will not be repeated for each of the following figures. For clarity, elements may not be labeled with corresponding reference numerals in all figures. [Brief description of the drawings]

[0057] [Figure 1] 1A-1C illustrate different exemplary embodiments of a power module in different views. [Diagram 2] 1A-1C illustrate different exemplary embodiments of a power module in different views. [Diagram 3] 1A-1C illustrate different exemplary embodiments of a power module in different views. [Figure 4] 1A-1C illustrate different exemplary embodiments of a power module in different views. [Diagram 5] 1A-1C illustrate different exemplary embodiments of a power module in different views. [Figure 6] 1A-1C illustrate different exemplary embodiments of a power module in different views. [Figure 7] 1A-1C illustrate different exemplary embodiments of a power module in different views. [Figure 8] 1A-1C illustrate different exemplary embodiments of a power module in different views. [Figure 9] Temperature diagram. [Figure 10] Temperature diagram. [Figure 11] 1 is a flow chart of an exemplary embodiment of a method for producing a power module. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0058] 1 illustrates in cross-section a first exemplary embodiment of a power module 100. The power module 100 comprises a substrate 4 having an upper metallization 40, a lower metallization 42, and an electrical insulation layer 41 therebetween. The upper metallization 40 is segmented into a number of different segments.

[0059] The power semiconductor devices 1 are attached and electrically connected to different segments of the upper metallization 40. For example, the power semiconductor devices 1 are bonded onto the upper metallization 40 by soldering, gluing or sintering. As an example, the power semiconductor devices 1 are MOSFETs or IGBTs or diodes.

[0060] Top contact surfaces 10 of the power semiconductor devices 1 face outwardly from the substrate 4. The top contact surfaces 10 are at least partially formed by top contact elements 11 of the respective power semiconductor devices 1. A connection element 2 is coupled to and electrically connected to each of these top contact elements 11, such that the connection element 2 is electrically connected to the power semiconductor devices 1.

[0061] 1, the connection element 2 comprises two coupling sections 21 at either end. Each coupling section 21 is coupled to a power semiconductor device 1. This establishes a strong bond at the respective coupling area 12. The connection element 2 is, for example, a clip, which is a pre-bent rigid metal sheet. The coupling sections 21 form the feet of the clip 2.

[0062] The connecting element 2 further comprises a flat section 20 extending parallel to the top surface 10 or parallel to the main extension plane of the substrate 4, respectively. On the flat surface of the flat section 20 the sensing element 3 is attached. The flat surface faces away from the substrate 4. The sensing element 3 is therefore spaced apart from the bonding section 21 of the connecting element 2.

[0063] Between the bonding section 21 and the flat section 20 an intermediate section of the connecting element 2 is formed. The intermediate section extends, for example, obliquely to the contact surface 10. As a result of this, the flat section 20, and thus the sensing element 3, is arranged at a higher height than the bonding section 21.

[0064] The sensing element 3 is configured, for example, for temperature measurement. Since the sensing element 3 is arranged on the connection element 2, the sensing element 3 is in close proximity to the power semiconductor device 1 and is well thermally coupled to the power semiconductor device 1. This makes it possible to measure the temperature of the power semiconductor device 1 very accurately without significant time delays.

[0065] The sensing element 3 is for example a PT100 element, an NTC / PTC or a thermocouple. Alternatively, the sensing element 3 may be the entire temperature sensor 3, for example in the form of a chip or SMD.

[0066] 2 shows the power module 100 of FIG. 1 in a plan view relative to the contact surface 10 or the top surface of the substrate 4, respectively. As can be seen, the sensing element 3 is arranged completely within the connection element 2. In a lateral direction parallel to the top surface 10, the sensing element 3 therefore does not protrude beyond the connection element 2. Furthermore, the sensing element 3 is spaced apart from the coupling region 12 and also from the power semiconductor device 1 itself. In particular, in this plan view, the sensing element 3 is arranged between two power semiconductor devices 1.

[0067] 3 and 4 show a further exemplary embodiment of a power module 100, also in cross-section (FIG. 3) and in plan view (FIG. 4). In contrast to the previous exemplary embodiment, here the connection element 2 electrically connects the top contact element 11 with a segment of the upper metallization 40 of the substrate 4. For this purpose, the connection element 2, i.e. its bonding section 21, is bonded on the one hand to the contact element 11 in the bonding area 12 and on the other hand to the substrate 4 in the bonding area 14. In contrast to what is shown in the figures, the opposing bonding sections 21 may also be at different heights.

[0068] In the exemplary embodiment of FIG. 5 (cross-sectional view) and FIG. 6 (plan view), the substrate 4 has an upper metallization 40 with three segments. In the first segment, the first power semiconductor device 1 is attached, and in the second segment, the second power semiconductor device 1 is attached. The connection element 2 has four coupling sections 21, each coupled to a different area. The foot-like coupling section 21 is coupled and electrically connected to the first power semiconductor device 1 and to the third segment of the upper metallization 40. Two stitched or stamped coupling sections 21 are coupled and electrically connected to the second power semiconductor device 1. As in the previous exemplary embodiment, the connection element 2 is an integrally formed clip.

[0069] The connection element 2 comprises two flat sections 21, on each of which a sensing element 3, for example a temperature sensing element, is attached. As can be seen in Fig. 6, the sensing element 3 is again spaced apart from the bonding section 21 and does not overlap the power semiconductor device 1 or the bonding area 12, respectively.

[0070] In the illustrated exemplary embodiment, the connection element 2 is always realized as a clip. Instead of a clip, however, a ribbon or a wire may also be used. The sensing element 3 does not have to be configured for temperature measurement. Additionally or alternatively, it may be configured for measurement of other measurands, such as humidity or current.

[0071] 7 and 8 show an exemplary embodiment of a power module 100, further components of which are shown. The power module 100 comprises a base plate 7 with cooling fins 70. The substrate with the power semiconductor devices 1 is laterally surrounded by a frame 5 of a housing. The frame 5 is made, for example, from resin. The cavity formed by the frame is further filled with a gel or resin 6, so that the power semiconductor devices 1, the connection elements 2 and the sensing elements 3 are embedded in the gel 6. The frame 5 and the gel or resin 6 together form the housing 5, 6 of the power module 100.

[0072] 8, it can be seen that the power module 100 further comprises terminals 50 protruding from the housings 5, 6. The power module 100 is electrically connectable via the terminals 50.

[0073] 9 and 10 show the temperature T (solid line) as a function of time t of a power semiconductor device when it is put into operation, and the resulting temperature measured by a sensing element in the vicinity of the power semiconductor device (dashed line). The case is shown in FIG. 9 where the sensing element is attached to a separate segment of the top metallization of the substrate adjacent to the power semiconductor device. As can be seen, the temperature measured by the sensing element rises with a significant delay compared to the temperature of the power semiconductor device. Moreover, the maximum measured temperature is much lower than the maximum temperature of the power semiconductor device. This is due in particular to the long thermal path along the substrate.

[0074] In Fig. 10, the case is shown where the sensing element is mounted on a connection element coupled and electrically connected to the power semiconductor device, e.g., as in the exemplary embodiment of Fig. 3 and Fig. 4. Due to the proximity of the power semiconductor device (shorter thermal path) and the good thermal conductivity of the connection element, the delay in the temperature rise is much smaller than in Fig. 9 and the maximum measured temperature is much closer to the maximum temperature of the power semiconductor device.

[0075] 11 is a flow chart of an exemplary embodiment of a method for producing a power module. In step S1, a power semiconductor device and a connection element for electrically connecting the power semiconductor device are provided. In step S2, a coupling section of the connection element is coupled to the power semiconductor device. In step S3, a sensing element is attached to the connection element in an area spaced apart from the coupling section but sufficiently close to the coupling section such that a measurand associated with the power semiconductor device is measurable using the sensing element when the coupling section is coupled to the power semiconductor device. The order of steps S2 and S3 may be reversed.

[0076] The embodiments shown in Figures 1-8 and 11 above represent exemplary embodiments of the improved power module and improved method. Therefore, they do not constitute an exhaustive list of all embodiments of the improved power module and improved method. The actual power module and method may differ from the illustrated embodiments, for example, in terms of arrangement, devices, and components.

[0077] Reference sign [Explanation of symbols]

[0078] 1. Power Semiconductor Devices 2 Connection elements 3. Detection elements 4. Board 5 Frames 6 Gel or Resin 7 Base plate 10 Contact surface 11 Contact Elements 12 Combined area 14 Combined area 20 Flat Section 21 Combined Section 40 Upper Metallization 41 Electrical insulation layer 42 Lower Metallization 50 Terminals 70 Cooling fins 100 Power Module Si method steps

Claims

1. A power module (100), A power semiconductor device (1); a connection element (2) for electrically connecting the power semiconductor device (1); A sensing element (3) for measuring a measurand; Equipped with a coupling section (21) of the connection element (2) coupled to and electrically connected to the power semiconductor device (1); The power module (100), wherein the sensing element (3) is attached to the connection element (2) and spaced apart from the coupling section (21).

2. the coupling section (21) of the connection element (2) is coupled to a contact surface (10) of the power semiconductor device (1) in a coupling region (12), 2. The power module (100) of claim 1, wherein the sensing element (3) is attached to the connection element (2) such that, in a plan view of the contact surface (10), the sensing element (3) is spaced from the bonding region (12).

3. The power module (100) according to claim 1 or 2, wherein the sensing element (3) is a temperature sensing element for measuring a temperature.

4. The power module (100) according to any one of the preceding claims, wherein the connection element (2) is one of a ribbon, a wire, a terminal, a clip.

5. A power module (100) according to claim 2 or any of claims 3 and 4 dependent on claim 2, wherein in a plan view of the contact surface (10), the sensing element (3) is spaced apart from the power semiconductor device (1) and / or an active area of ​​the power semiconductor device.

6. Further comprising a substrate (4), The power semiconductor device (1) is attached to and electrically connected to the substrate (4); A power module (100) according to claim 2 or any one of claims 3 to 5 dependent thereon, wherein the contact surface (10) is an upper contact surface facing away from the substrate (4).

7. The connecting element (2) comprises a flat section (20) extending parallel to the contact surface (10), 10. The power module (100) according to any one of the preceding claims, wherein the sensing element (3) is attached to the flat section (20).

8. 10. The power module (100) according to any one of the preceding claims, wherein the connection element (2) electrically connects the power semiconductor device (1) with one or more further elements (1, 4) of the power module (100).

9. 8. A power module (100) according to claim 7, wherein the further element (1, 4) is a further power semiconductor device (1) or a substrate (4) or a terminal.

10. 10. The power module (100) according to any one of the preceding claims, wherein the power semiconductor device (1) is a transistor or a thyristor or a diode.

11. 10. The power module (100) according to any one of the preceding claims, wherein the power semiconductor devices (1) are based on at least one of the following: silicon, silicon carbide, gallium nitride.

12. A power module (100) according to claim 3 or any one of claims 4 to 11 depending on claim 3, wherein the sensing element (3) is a resistive element.

13. The power module (100) according to any one of the preceding claims, wherein the sensing element (3) is a chip or an SMD.

14. The edge length of the power semiconductor device (1) is a maximum of 8 mm; 10. The power module (100) according to any one of the preceding claims, wherein the distance between the sensing element (3) and the coupling section (21) is at most 15 mm.

15. 1. A method for producing a power module, comprising: Providing a power semiconductor device (1) and a connection element (2) for electrically connecting said power semiconductor device (1); coupling a coupling section (21) of the connection element (2) to the power semiconductor device (1); attaching the sensing element (3) to the connection element (2) in a region spaced apart from the coupling section (21) but sufficiently close to the coupling section (21) such that a measurand associated with the power semiconductor device (1) is measurable using the sensing element (3) when the coupling section (21) is coupled to the power semiconductor device (1); A method comprising:

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