Power module and method for producing a power module

Abstract

According to an embodiment, a power module (100) comprises a power semiconductor device (1) and a connecting element (2) for electrically connecting the power semiconductor device. Furthermore, the device comprises a sensing element (3) for measuring a measured quantity. An engagement portion (21) of the connecting element is engaged to the power semiconductor device (1) and electrically connected therewith. The sensing element is mounted on the connecting element and spaced apart from the engagement portion.

Description

Technical Field

[0001] This disclosure relates to power modules and methods for manufacturing power modules. Background Technology

[0002] There is a need for an improved power module, for example, one that enables faster and / or more reliable fault detection (e.g., overheating). Furthermore, there is a need for an improved method for manufacturing power modules. Summary of the Invention

[0003] Embodiments of this disclosure relate to an improved power module. Further embodiments of this disclosure relate to an improved method for manufacturing power modules.

[0004] First, the power module was specified.

[0005] According to an embodiment, the power module includes a power semiconductor device and a connection element for electrically connecting the power semiconductor device. Furthermore, the power module includes a sensing element for measuring the measured quantity. A bonding portion of the connection element is bonded to and electrically connected to the power semiconductor device. The sensing element is mounted on the connection element and spaced apart from the bonding portion.

[0006] Overheating of power semiconductor devices (also known as power semiconductor chips or simply chips) in a power module can be detected using temperature sensors implemented within the power module. Overheating can result from a combination of connectivity degradation, loss of cooling capacity, or power semiconductor device failure. 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. If one or more sensing elements are placed as close as possible to the power semiconductor device, the sensor readings will better reflect the temperature behavior of the power semiconductor device.

[0007] However, sensing elements are typically placed on a separate metallized pattern on a substrate adjacent to the power semiconductor device. Here, the sensing element is not directly correlated to the junction temperature of the power semiconductor device, therefore a fairly 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 readings. Furthermore, there is a time delay between the actual chip temperature and the sensor readings.

[0008] An alternative that yields direct and accurate data is to place the sensing element on top of the heat-generating semiconductor device. However, on the one hand, this alternative occupies space used for bonding connections, which can be particularly critical on SiC chips due to their small chip size and higher current density. On the other hand, considering mounting the sensing element on top of the bonding portion of the connector, installation can be very difficult or even impossible due to the geometric and / or mechanical characteristics of wire bonding, strips, or clips to the chip, as these often have curved shapes. Another alternative is a chip with an integrated sensor or sensing element. However, this is rarely the case.

[0009] The inventors of this invention recognized that mounting at least one sensing element on a connector element bonded to a chip provides good sensor readings and a short response time, at least compared to mounting the sensing element on a substrate metallized pattern. The area of ​​the connector element spaced apart from the bonding portion where the connector element is actually bonded to the chip typically provides sufficient space for mounting the sensing element, yet still results in sufficiently good and fast sensor readings. This is especially due to the proximity of the sensing element to the chip. In the case of temperature sensors, the short response time is particularly due to the good thermal conduction of the connector element and the relatively short thermal path. Furthermore, no additional space is required on the substrate for a sensing element in this location. Therefore, the location of the sensing element potentially allows for a smaller module size, or more space for power semiconductor devices, which relates to higher current capabilities. This location is suitable for both small and large chips. A location on the connector element but spaced apart from the bonding portion is particularly advantageous for small chips where space is limited or unavailable on the chip or the top surface of the bonding portion. Last but not least, by placing the sensing element on the connector element, information regarding interface degradation between the power semiconductor device and the substrate, and between the connector element and the power semiconductor device, can be obtained separately.

[0010] The connecting element is, for example, based on a metal. For example, the connecting element comprises or is composed of Cu, Al, Au, Ag, or any alloy of these metals. For example, the connecting element is configured to carry a current of at least 1A, at least 10A, or at least 100A.

[0011] A connecting element (i.e., its bonding portion) is bonded to a power semiconductor device (e.g., a contact element bonded to a power semiconductor device). Thus, a strong bond is formed between the power semiconductor device and the connecting element. For example, the connecting element may be glued, soldered, sintered, or fused to the power semiconductor device. Therefore, at most, adhesive, solder, or sintered material is disposed between the connecting element and the power semiconductor device. The connecting element can be formed continuously. For example, the connecting element may be integrally formed.

[0012] A bonding portion of a connecting element is a portion configured to bond to another element. The bonding portion may be a pin, stitched portion, or stamped portion of the connecting element. A connecting element may include one or more such bonding portions. A bonding portion is defined, for example, as the area of ​​the connecting element where one or more connectors are formed between the connecting element and a power semiconductor device.

[0013] The sensing element is configured to measure a measurand (e.g., the physical characteristics of a power semiconductor device or the physical characteristics of the environment surrounding the power semiconductor device). The sensing element can be a sensor or part of a sensor, i.e., the first element of the measurement chain (i.e., the part of the sensor that directly responds to the measurand). Such a sensing element is also referred to as a transducer. In addition to this first element, the sensor itself may also include other components of the measurement chain.

[0014] The sensing element may be electrically connected to the connection element, or it may be electrically isolated from the connection element. The sensing element may, for example, be electrically connected to one or more additional elements of the power module via wire connection.

[0015] The sensing element is mounted on the connecting element (e.g., securely bonded to the connecting element). For example, the sensing element is bonded to the connecting element by welding, gluing, sintering, or any other suitable bonding / joining method. Thus, the sensing element is spaced apart from the joint portions. In cases where the connecting element comprises two or more joint portions, the sensing element is spaced apart from each of these joint portions.

[0016] The distance between the sensing element and the bonding portion or each bonding portion (i.e., the shortest connection) 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 connecting element connecting the sensing element and the bonding portion 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. Due to the optional connecting material therebetween, the distance between the sensing element and the connecting element is, for example, at most 200 μm or at most 50 μm or at most 10 μm or at most 5 μm.

[0017] In addition to the power semiconductor devices, connection elements, and sensing elements mentioned so far, the power module may also include one or more additional power semiconductor devices, one or more additional connection elements, and / or one or more additional sensing elements. For example, one or more additional connection elements may be coupled and electrically connected to the power semiconductor devices. One or more additional sensing elements may be mounted on the connection elements and / or the additional connection elements. All features disclosed so far and below with respect to a power semiconductor device, a connection element, and a sensing element are also disclosed with respect to all additional power semiconductor devices, connection elements, and sensing elements.

[0018] According to another embodiment, the sensing element is a temperature sensing element for measuring temperature. The temperature measured by means of the sensing element is a temperature and / or time-dependent characteristic of the power semiconductor device, since the sensing element is mounted nearby and the power semiconductor device is the primary heat source of the power module.

[0019] Alternatively, the sensing element can be configured to measure various measurands, such as moisture, humidity, current, voltage, pressure, magnetic field, vibration, etc. The sensing element can be, for example, a Hall sensor.

[0020] According to at least one embodiment, the connecting element is a strip, a wire, a clip, or a terminal.

[0021] A terminal is an element configured for external electrical connections to a power module (i.e., for electrical connections between the power module and external components of an application). A terminal is, for example, a sheet-like rigid element, such as a busbar or lead frame. A connecting element may include a body and at least one terminal pin. The terminal pin constitutes an engagement portion of the terminal for connecting the terminal. Between the body and the terminal pin, the terminal may include, for example, a 90° kink. Each terminal pin or the entire terminal may have a width of at least 1 mm and / or at most 15 mm. For example, the thickness of each terminal pin or the entire terminal may be at least 0.15 mm and / or at most 2.0 mm or at most 1.5 mm.

[0022] Clips are understood herein as rigid sheet-like structures, such as stamped, pre-bent structures. Clips are typically used to electrically connect two components of a power module. For example, a clip includes at least two clip leads or ends connected by a clip body. The clip leads or ends constitute the engaging portion of the clip for engaging the clips. A kink may be present between the body and each clip lead. The width and / or thickness may be the same as specified for the terminals.

[0023] The strip is a flexible or bendable structure. The strip may have a width of at least 0.5 mm and / or at most 15 mm. The thickness of the strip may be at least 20 μm and / or at most 2 mm. For example, the width is greater than the thickness, for example, at least twice as much.

[0024] The aforementioned dimensions of the connector enable excellent thermal conductivity from the power semiconductor device to the sensing element. Simultaneously, these dimensions limit the surface area of ​​the connector itself, preventing excessive cooling. On the other hand, these dimensions are large enough to allow the transmission of high currents without overheating the connector due to the current flow. Therefore, the placement of the sensing element on the connector precisely reflects the actual temperature of the power semiconductor device.

[0025] According to another embodiment, a bonding portion of the connecting element is bonded to a contact side of a power semiconductor device. The bonding connection between the bonding portion and the contact side is established within a bonding region. For example, within the bonding region, one or more joints, such as solder joints, brazed joints, or adhesive joints, exist between the bonding portion and the contact side. The bonding region is defined, for example, and / or limited to the area where a joint between the connecting element and the power semiconductor device is formed. A joint is understood herein as an area where a strong bond or material bond is achieved between two elements, respectively. In the case of soldering, the joint is, for example, an area where material is melted.

[0026] The contact side may be formed, at least partially, by a contact element of the power semiconductor device or by the surface of such a contact element. The contact element may be formed of a metal, including, for example, aluminum, copper, silver, or a corresponding alloy. For example, the bonding connection between the bonding portion and the power semiconductor device is between the bonding portion and the contact element.

[0027] According to another embodiment, the sensing element is mounted on the connecting element such that, in a plan view on the contact side, the sensing element is spaced apart from the engagement area, i.e., the sensing element does not overlap with the engagement area in this plan view. However, in a plan view on the contact side, the sensing element is close to the engagement area. For example, in this plan view, the lateral distance between the engagement area and the sensing element is at least 1 mm or at least 100 μm. In the case where the connecting element has multiple engagement portions and each engagement portion engages with the element in the engagement area, in this plan view, the sensing element (e.g.) does not overlap with any of these engagement areas.

[0028] For example, in a plan view on the contact side, the sensing element is separated from the engagement area by at least the thickness of the connecting element, or at least two or three times the thickness of the connecting element.

[0029] According to another embodiment, in the plan view of the contact side, the sensing element is spaced apart from the power semiconductor device and / or its active region. Therefore, the sensing element does not overlap with the power semiconductor device and / or its active region. For example, in the plan view of the contact side, the sensing element is spaced apart from the power semiconductor device and / or its active region by at least 1 mm or at least 100 μm.

[0030] According to another embodiment, the power module further includes a substrate. The substrate may have a top metallization for mounting components and for electrical connection to components of the power module. Additionally, the substrate may have a bottom metallization. An electrically insulating layer may be present between the top and bottom metallizations. The substrate may be an insulating metal substrate (IMS) having an electrically insulating resin layer sandwiched between the top and bottom metallizations. Alternatively, the substrate may be an active metal support or a direct-bonded copper (DBC) or direct-bonded aluminum (DBA) substrate, with a ceramic spacer between the top and bottom metallizations.

[0031] According to another embodiment, the power semiconductor device is mounted on and electrically connected to the substrate. For example, the power semiconductor device is mounted on a top metallization of the substrate and electrically connected to the top metallization of the substrate by means of, for example, soldering, gluing or sintering.

[0032] According to another embodiment, the contact side of the power semiconductor device is a top contact side facing away from the substrate. Therefore, the bottom side of the power semiconductor device, opposite to the top contact side, can face the substrate and can be electrically connected to the substrate.

[0033] The surface of the mounting sensing element of the connecting element may face away from the substrate. Alternatively, the surface may face the substrate.

[0034] According to another embodiment, the connecting element includes a flat portion. A "flat portion" means that the surface of this portion is flat within manufacturing tolerances. The flat portion and / or its surface may extend obliquely or parallel to the contact side and / or obliquely or parallel to the top side of the mounting power semiconductor device on the substrate. Here, parallelism means substantially parallel, for example, with a maximum deviation from precise parallelism of no more than 10°.

[0035] According to another embodiment, the sensing element is mounted on a flat portion (i.e., its flat surface) of the connecting element. This makes sensor installation particularly easy.

[0036] According to another embodiment, the flat portion is at a different height relative to the top side of the substrate and / or relative to the contact side than the bonding portion. For example, the flat portion is arranged at a higher height than the bonding portion relative to the top side of the substrate or the contact side of the power semiconductor device. The height difference may be at least 50 μm, at least 100 μm, or at least 1 mm.

[0037] According to another embodiment, a connecting element electrically connects the power semiconductor device to one or more additional elements of the power module. For example, in a plan view of the contact side of the power semiconductor device, a sensing element is then arranged between the power semiconductor device and the additional elements.

[0038] According to another embodiment, the additional element is an additional power semiconductor device or a substrate. It can be the same substrate on which the power semiconductor device is mounted, or it can be an additional substrate different from the substrate on which the power semiconductor device is mounted. The additional element can be an additional power semiconductor device on an additional substrate. The additional element can also be a terminal.

[0039] According to another embodiment, the power semiconductor device is a switching element, such as a transistor, thyristor, or diode.

[0040] According to another embodiment, the power semiconductor device is a MOSFET, IGBT, MISFET, JFET, or HEMT.

[0041] According to at least one embodiment, the connection element is electrically connected to the main electrode of the power semiconductor device, such as the source / emitter electrode or the drain / collector electrode. Alternatively, the connection element may be electrically connected to the gate of the power semiconductor device.

[0042] According to another embodiment, the power semiconductor device is based on at least one of silicon, silicon carbide, and gallium nitride. That is, the semiconductor body of the power semiconductor device is based on one of these semiconductors.

[0043] According to another embodiment, the sensing element is a resistive element. The sensing element may have positive resistive behavior (positive temperature coefficient, abbreviated as PTC) or negative resistive behavior (negative temperature coefficient, abbreviated as NTC). For example, the sensing element is based on Pt. The sensing element may be, for example, PT100, PT500, or PT1000.

[0044] Alternatively, the sensing element can be a thermocouple.

[0045] According to another embodiment, the sensing element is a chip or surface mount device (SMD). In this case, the sensing element can be a complete sensor. For example, the sensing element includes circuitry for signal processing.

[0046] According to another embodiment, the power module is configured to transmit measurement signals obtained by means of sensing elements to an external device. For example, the sensing elements are electrically connected to auxiliary terminals, which can be externally electrically connected to external or internal devices within the power module. Connections to the auxiliary terminals can be made via wires. Alternatively, the power module may include a wireless communication device, such as a Bluetooth device, which can be used to wirelessly transmit the measurement signals obtained by means of the sensing elements.

[0047] The chip-shaped sensing element may include at least one top contact and a bottom contact. The bottom contact may engage and be electrically connected to a connection element, and the top contact may, for example, be electrically connected to different areas of the power module via wire engagement. Alternatively, the sensing element may include two or more contact elements, each of which is electrically connected, for example, to other areas of the power module via wire engagement.

[0048] According to another embodiment, the power semiconductor device has an edge length of up to 8 mm or up to 5 mm. Therefore, the contact side of the power semiconductor device has a maximum length of 25 mm. 2 The area is small. Especially for such small power semiconductor devices, it is advantageous to place the sensing element on a connection element spaced apart from the junction portion. For example, the area used for the connection of the connection element on a power semiconductor device is small.

[0049] According to at least one embodiment, the sensing element has a size of up to 5 mm.

[0050] According to another embodiment, the power module includes a housing surrounding a power semiconductor device. For example, the housing surrounds the power semiconductor device at least in the lateral direction (i.e., a direction parallel to the contact side of the power semiconductor device and / or parallel to the main extension plane of the power module).

[0051] The housing may include or be composed of an electrically insulating material. The housing may be at least partially formed of a framework of thermoplastic or thermosetting resin material, which may be filled with inorganic particles or fibers. For example, the housing includes a framework surrounding a cavity and a gel or potting resin filled into the cavity. For example, a power semiconductor device is embedded in and encapsulated by the housing. The housing may be at least partially formed by a molding process (e.g., transfer molding or injection molding).

[0052] According to another embodiment, the power module includes a base plate on which one or more substrates are mounted. The base plate may be configured as a heat sink. For example, the base plate includes cooling fins and / or heat sinks on a side opposite to the substrates.

[0053] A power module can be a device that incorporates multiple power semiconductor devices and electrically and mechanically interconnects these devices. A power module can be adapted to handle currents greater than 10A. A power module can be a low-voltage module adapted to handle voltages below 1kV, or a medium-voltage module adapted to handle voltages between 1kV and 10kV.

[0054] Power modules can be used in electrical converters that rectify AC voltage / current to DC voltage / current to supply a DC link or battery (e.g., a battery in an electric vehicle). Power modules can also be inverters that generate AC voltage / current from DC voltage / current to supply a motor (e.g., a motor in an electric vehicle). Inverters can also be used to change the frequency of AC voltage / current to another frequency. Power modules can be used in automotive applications, such as electric vehicles, motorcycles, buses, off-road construction vehicles, trucks, charging stations, power plants, or traction applications.

[0055] Next, a method for producing a power module is described in detail. This method can be configured to produce a power module according to any of the embodiments described herein. Therefore, all features disclosed for a power module are also disclosed for this method, and vice versa.

[0056] In at least one embodiment, the method includes the steps of providing a power semiconductor device and a connection element for electrically connecting the power semiconductor device. In another step, a bonding portion of the connection element is bonded to the power semiconductor device. In yet another step, a sensing element is mounted on the connection element in a region spaced apart from but sufficiently close to the bonding portion, such that, with the bonding portion bonded to the power semiconductor device, a measurand associated with the power semiconductor device can be measured by means of the sensing element.

[0057] The process of attaching the bonding portion to the power semiconductor device can be performed before or after mounting the sensing element. Mounting the sensing element may include bonding, soldering, or sintering the sensing element to the bonding element.

[0058] For example, a compromise can be made in selecting the area for mounting the sensing element, ensuring that, on the one hand, there is sufficient space on the connector for mounting the sensing element, and on the other hand, it maintains sufficient proximity to the power semiconductor device to provide reasonable or direct measurement results using the sensing element. For instance, if the sensing element is a temperature sensing element, the closer the sensing element is mounted to the junction, the better the measurement results will reflect the true temperature of the power semiconductor device. For example, the area for mounting the sensing element can be determined with the help of prior simulation. Attached Figure Description

[0059] In the following description, a power module and a method for manufacturing a power module will be explained in more detail with reference to the accompanying drawings, based on exemplary embodiments. The drawings are included to provide further understanding. In the drawings, elements having the same structure and / or function can be represented by the same reference numerals. It should be understood that the embodiments shown in the figures are illustrative and not necessarily drawn to scale. Descriptions of elements or components in the following figures will not be repeated as long as their functional aspects correspond to each other in different figures. For clarity, elements may not appear with corresponding reference numerals in all figures.

[0060] Figures 1 to 8 Different exemplary embodiments of the power module are shown in different views;

[0061] Figure 9 and Figure 10 A temperature graph is shown;

[0062] Figure 11 A flowchart illustrating an exemplary embodiment of a method for producing power modules is shown. Detailed Implementation

[0063] Figure 1 A first exemplary embodiment of the power module 100 is shown in cross-section. The power module 100 includes a substrate 4 having a top metallization 40, a bottom metallization 42, and an electrical insulating layer 41 between the top metallization 40 and the bottom metallization 42. The top metallization 40 is divided into different segments.

[0064] The power semiconductor device 1 is mounted on and electrically connected to different segments of the top metallization portion 40. For example, the power semiconductor device 1 is bonded to the top metallization portion 40 by soldering, gluing, or sintering. For example, the power semiconductor device 1 is a MOSFET, an IGBT, or a diode.

[0065] The top contact side 10 of the power semiconductor device 1 faces away from the substrate 4. The top contact side 10 is at least partially formed by the top contact element 11 of the respective power semiconductor device 1. The connecting element 2 is engaged and electrically connected to each of these top contact elements 11, such that the connecting element 2 is electrically connected to the power semiconductor device 1.

[0066] exist Figure 1 In an exemplary embodiment, the connecting element 2 includes two engagement portions 21 located at opposite ends. Each engagement portion 21 engages with one of the power semiconductor devices 1. Thus, a strong engagement is established in the corresponding engagement region 12. The connecting element 2 is, for example, a clip of a pre-bent rigid metal sheet. The engagement portions 21 form pins of the clip 2.

[0067] The connecting element 2 also includes a flat portion 20, which extends parallel to either the top side 10 or the main extension plane of the substrate 4. A sensing element 3 is mounted on the flat surface of the flat portion 20. This flat surface faces away from the substrate 4. Therefore, the sensing element 3 is spaced apart from the engagement portion 21 of the connecting element 2.

[0068] The middle portion of the connecting element 2 is formed between the engaging portion 21 and the flat portion 20. The middle portion extends obliquely to the contact side 10, for example. Therefore, the flat portion 20 and the corresponding sensing element 3 are arranged at a higher height than the engaging portion 21.

[0069] Sensing element 3 is configured for temperature measurement. Due to its arrangement on connecting element 2, sensing element 3 is close to and thermally well coupled to power semiconductor device 1. This enables very accurate measurement of the temperature of power semiconductor device 1 without significant time delay.

[0070] The sensing element 3 is, for example, a PT100 element, an NTC / PTC, or a thermocouple. Alternatively, the sensing element 3 may be an entire temperature sensor 3 (e.g., a temperature sensor in the form of a chip or SMD).

[0071] Figure 2 The following plan view shows Figure 1 The power module 100, wherein the plan view is located on the contact side 10 or the top side of the substrate 4. As can be seen here, the sensing element 3 is completely arranged within the connecting element 2. Therefore, in the lateral direction parallel to the top side 10, the sensing element 3 does not protrude beyond the connecting element 2. Furthermore, the sensing element 3 is spaced apart from the junction area 12 and even 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.

[0072] Figure 3 and Figure 4 Again in the cross-sectional view ( Figure 3 ) and floor plan ( Figure 4 Another exemplary embodiment of the power module 100 is shown in Figure 100. In contrast to the previous exemplary embodiment, the connecting element 2 now electrically connects the top-side contact element 11 to a segment of the top metallized portion 40 of the substrate 4. For this purpose, the connecting element 2 (i.e., its engagement portion 21) engages with the contact element 11 in engagement region 12 on one side and with the substrate 4 in engagement region 14 on the other side. Contrary to what is shown in the figure, the opposing engagement portions 21 may also be located at different heights.

[0073] exist Figure 5 (Cross-section view) and Figure 6In the exemplary embodiment (plan view), the substrate 4 has a top metallization 40 comprising three segments. A first power semiconductor device 1 is mounted on the first segment, and a second power semiconductor device 1 is mounted on the second segment. The connecting element 2 has four engagement portions 21, each engaging to a different region. Pin-shaped engagement portions 21 engage and are electrically connected to the first power semiconductor device 1 and the third segment of the top metallization 40. Two stitched or stamped engagement portions 21 engage and are electrically connected to the second power semiconductor device 1. As in the preceding exemplary embodiment, the connecting element 2 is an integrally formed clip.

[0074] The connecting element 2 includes two flat portions 21, and a sensing element 3 (e.g., a temperature sensing element) is mounted on each flat portion 21. Figure 6 As shown, the sensing element 3 is again spaced apart from the junction portion 21 and does not overlap with the power semiconductor device 1 or the junction region 12, respectively.

[0075] In the illustrated embodiment, the connecting element 2 is always implemented as a clip. However, a strip or wire can be used instead of a clip. The sensing element 3 does not need to be configured for temperature measurement. It can be additionally or alternatively configured for measuring other measurands, such as humidity or current.

[0076] Figure 7 and Figure 8 An exemplary embodiment of the power module 100 is shown, in which other components of the power module 100 are illustrated. The power module 100 includes a base plate 7 having a heat sink 70. A substrate having a power semiconductor device 1 is laterally surrounded by a housing frame 5. The frame 5 is formed, for example, of resin. The cavity formed by the frame is further filled with a gel or resin 6, such that the power semiconductor device 1, the connection element 2, and the sensing element 3 are embedded in the gel 6. The frame 5 and the gel or resin 6 together form the housings 5 ​​and 6 of the power module 100.

[0077] from Figure 8 As can be seen, the power module 100 further includes terminals 50 protruding from the housings 5 ​​and 6. The power module 100 can be electrically connected via the terminals 50.

[0078] Figure 9 and Figure 10 The diagram shows the initial temperature T of the power semiconductor device as a function of time t (solid line), and the resulting temperature measured by a sensing element near the power semiconductor device (dashed line). Figure 9As shown, the sensing element is mounted on a separate segment of the top metallized portion of the substrate adjacent to the power semiconductor device. It can be seen that the temperature measured by the sensing element rises with a considerable delay compared to the temperature of the power semiconductor device. Furthermore, the highest temperature measured is much lower than the highest temperature of the power semiconductor device. This is particularly due to the long thermal path along the substrate.

[0079] exist Figure 10 The image shows a sensing element such as... Figure 3 and Figure 4 In the exemplary embodiment, the mounting is as shown, i.e., mounted on a connection element that is bonded and electrically connected to the power semiconductor device. Due to the good thermal conductivity of the connection element and its proximity to the power semiconductor device (shorter thermal path), the temperature rise is delayed compared to... Figure 9 The values ​​are much smaller, and the highest temperature measured is closer to the highest temperature of power semiconductor devices.

[0080] Figure 11 A flowchart illustrating an exemplary embodiment of a method for manufacturing a power module is shown. In step S1, a power semiconductor device and a connection element for electrically connecting the power semiconductor device are provided. In step S2, a bonding portion of the connection element is bonded to the power semiconductor device. In step S3, a sensing element is mounted on the connection element in a region spaced apart from but sufficiently close to the bonding portion, such that, with the bonding portion bonded to the power semiconductor device, a measurand associated with the power semiconductor device can be measured by means of the sensing element. The order of steps S2 and S3 can be interchanged.

[0081] like Figures 1 to 8 and Figure 11 The embodiments shown represent exemplary embodiments of the improved power modules and improved methods; therefore, they do not constitute a complete list of all embodiments according to the improved power modules and improved methods. For example, actual power modules and methods may differ from the illustrated embodiments in terms of arrangement, devices, and components.

[0082] Figure Labels

[0083] 1 Power Semiconductor Devices

[0084] 2 connecting elements

[0085] 3 sensing elements

[0086] 4 bases

[0087] 5-framework

[0088] 6. Gel or resin

[0089] 7 base plate

[0090] 10 Contact side

[0091] 11 Contact Elements

[0092] 12 joint areas

[0093] 14 junction areas

[0094] 20 flat sections

[0095] 21 Joint parts

[0096] 40 Top Metallization Section

[0097] 41 Electrical insulation layer

[0098] 42 Bottom Metallization Section

[0099] 50 terminal

[0100] 70 heatsink

[0101] 100 power module

[0102] Si method steps

Claims

1. A power module (100), comprising: - Base (4) - A power semiconductor device (1), which is mounted on the substrate (4) and electrically connected to the substrate (4). - Connecting element (2) for electrically connecting the power semiconductor device (1). - Sensing element (3), used to measure the measurand, wherein - The bonding portion (21) of the connecting element (2) is bonded to the power semiconductor device (1) and electrically connected to the power semiconductor device. - The sensing element (3) is mounted on the connecting element (2) and spaced apart from the engaging portion (21). - The bonding portion (21) of the connecting element (2) is bonded to the contact side (10) of the power semiconductor device (1) in the bonding region (12), wherein the contact side (10) is the top contact side facing away from the substrate (4). - The sensing element (3) is mounted on the connecting element (2) such that, in the plan view of the contact side (10), the sensing element (3) is spaced apart from the engagement area (12). - The connecting element (2) includes a flat portion (20) extending parallel to the contact side (10). - The sensing element (3) is mounted on the flat portion (20), characterized in that - The flat portion (20) is positioned at a higher height than the joining portion (21) relative to the top side of the base (4). The sensing element (3) is a temperature sensing element used to measure temperature. The power semiconductor device (1) includes a top contact element (11), the contact side (10) is at least partially formed by the top contact element (11), and the engagement portion (21) of the connecting element (2) is engaged and electrically connected to the top contact element (11), such that the connecting element (2) is electrically connected to the power semiconductor device (1).

2. The power module (100) according to claim 1, wherein - The connecting element (2) is one of the following: a strip, a wire, a terminal, or a clip.

3. The power module (100) according to claim 1 or 2, wherein - In the plan view of the contact side (10), the sensing element (3) is separated from the power semiconductor device (1) and / or the active region of the power semiconductor device.

4. The power module (100) according to claim 1 or 2, wherein - The connecting element (2) electrically connects the power semiconductor device (1) to one or more additional elements (1, 4) of the power module (100).

5. The power module (100) according to claim 4, wherein - The additional elements (1, 4) are additional power semiconductor devices (1) or substrates (4) or terminals.

6. The power module (100) according to claim 1 or 2, wherein - The power semiconductor device (1) is a transistor, thyristor, or diode.

7. The power module (100) according to claim 1 or 2, wherein - The power semiconductor device (1) is based on at least one of silicon, silicon carbide, and gallium nitride.

8. The power module (100) according to claim 1 or any one of claims 2 to 7 dependent on claim 1, wherein - The sensing element (3) is a resistive element.

9. The power module (100) according to claim 1 or 2, wherein - The sensing element (3) is a chip or SMD.

10. The power module (100) according to claim 1 or 2, wherein - The power semiconductor device (1) has an edge length of up to 8 mm. - The distance between the sensing element (3) and the joint portion (21) is at most 15 mm.

11. A method for manufacturing power modules, comprising: - Provide a power semiconductor device (1) and a connection element (2) for electrically connecting the power semiconductor device; - Connect the bonding portion (21) of the connecting element (2) to the power semiconductor device (1); - In a region spaced apart from but sufficiently close to the junction portion (21), a sensing element (3) is mounted on the connecting element (2) such that, when the junction portion (21) is joined to the power semiconductor device (1), the sensing element (3) can be used to measure the measurand associated with the power semiconductor device (1), wherein - The power semiconductor device (1) is mounted on the substrate (4) and electrically connected to the substrate (4). - The bonding portion (21) of the connecting element (2) is bonded to the contact side (10) of the power semiconductor device (1) in the bonding region (12), wherein the contact side (10) is the top contact side facing away from the substrate (4). - The sensing element (3) is mounted on the connecting element (2) such that, in the plan view of the contact side (10), the sensing element (3) is spaced apart from the engagement area (12). - The connecting element (2) includes a flat portion (20) extending parallel to the contact side (10). - The sensing element (3) is mounted on the flat portion (20), characterized in that, - The flat portion (20) is positioned at a higher height than the joining portion (21) relative to the top side of the base (4). The sensing element (3) is a temperature sensing element used to measure temperature. The power semiconductor device (1) includes a top contact element (11), the contact side (10) is at least partially formed by the top contact element (11), and the engagement portion (21) of the connecting element (2) is engaged and electrically connected to the top contact element (11), such that the connecting element (2) is electrically connected to the power semiconductor device (1).

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