Half-bridge module with precise temperature detection

Abstract

The invention relates to a half-bridge module having two switching units, each comprising a plurality of transistors, in particular IGBTs or MOSFETs, connected in parallel and / or in series, wherein the transistors are arranged on a first substrate, the half-bridge module having a temperature sensor array having a plurality of temperature sensors, which are at least locally thermally connected to the transistors. Furthermore, the invention also relates to a temperature sensor array.

Description

TECHNICAL FIELD

[0001] The present application relates to a half-bridge module having two switching units, each comprising a plurality of transistors, in particular IGBTs or MOSFETs, connected in parallel and / or in series, and to a temperature sensor array. BACKGROUND

[0002] Currently manufactured electric vehicles have a drive inverter for driving an electric motor, which converts the direct current of a power battery into an alternating current or three-phase current suitable for the electric motor. Such a drive inverter mainly comprises an intermediate circuit capacitor, power semiconductors, a driver circuit board and a controller circuit board. Preferably, the drive inverter for electric vehicles is configured three-phase.

[0003] The power semiconductors are often configured as a bridge rectifier, for example a so-called B6 bridge rectifier, and have a plurality of transistors. Due to a low yield or a high reject rate in production, in particular silicon carbide MOSFET power modules are manufactured in a half-bridge configuration or as half-bridge modules. Thereby, the reject rate in production can be reduced. Thus, the power semiconductors can be configured from three half-bridge modules.

[0004] In order to ensure a safe operation of the power semiconductors, temperature sensors are used to monitor the temperature of the transistors. In transistors designed as IGBTs, the maximum junction temperature allowed is 165°C. In order to increase the efficiency of the drive inverter in the future, silicon carbide MOSFETs are used as transistors. These transistors achieve an efficiency advantage in the partial load range due to the smaller switching losses and the lower on-resistance. In addition, such transistors can be operated at a maximum junction temperature of 200°C.

[0005] However, a prerequisite for operating the transistors of the power semiconductors in the range of the temperature limit is that the temperature of the individual transistors is precisely measured. Usually, one temperature sensor is used per half-bridge module. By means of the temperature measurement at only one point inside the half-bridge module, the actual chip temperature of the individual transistors can be modeled or estimated on the basis of the point measurement. Such modeling of the temperature distribution usually has tolerances and errors.

[0006] However, in order to ensure a safe operation of the transistors in the power semiconductors, sufficient safety in terms of operating temperature has to be preset, which leads to an excessive size of the power semiconductors and the entire drive inverter at a cost. SUMMARY

[0007] It is an object of the present application to provide a half-bridge module with precise temperature measurement and a temperature sensor array for a half-bridge module, which can detect the temperature distribution within the half-bridge module.

[0008] According to the invention, this objective is achieved by a half-bridge module having the features of claim 1 and by a temperature sensor array having the features of claim 8. Advantageous designs and improvements are derived from the dependent claims.

[0009] The half-bridge module according to the invention has two switching units, each comprising a plurality of transistors, particularly IGBTs or MOSFETs, connected in parallel and / or series. The transistors are arranged on a first substrate. According to the invention, the half-bridge module has a temperature sensor array comprising a plurality of temperature sensors, wherein these temperature sensors are at least partially thermally connected to the transistors.

[0010] By using an array of temperature sensors, the temperature distribution within the half-bridge module and among the individual transistors can be accurately detected. Therefore, it is no longer necessary to estimate the temperature distribution based on software simulations. By accurately detecting the single-chip temperature of the transistors using measurement techniques, the design of power semiconductors comprising multiple half-bridge modules can be significantly optimized.

[0011] This measure can either reduce the number of transistors used and thus reduce costs, or increase power while keeping the configuration the same, because the transistors can operate closer to their temperature limits.

[0012] Furthermore, precise temperature monitoring allows transistors to operate in a controlled manner within the maximum permissible junction temperature range. This can significantly reduce the size of the vehicle's cooling system and improve efficiency or driving range.

[0013] According to one embodiment, the temperature sensors of the temperature sensor array can be read individually or sequentially via connection terminals. This allows for reading of each temperature sensor according to the desired measurement frequency. Simultaneous reading of these temperature sensors can be achieved by individually connecting the temperature sensors via connection terminals or connection lines.

[0014] When reading temperature sensors sequentially, multiple temperature sensors can share a single connection terminal, thereby reducing the number of connection terminals required. For example, two or three temperature sensors can share a common connection terminal so that the measurements from each temperature sensor can be read sequentially.

[0015] According to another embodiment, the connection terminal is electrically connected to at least one temperature sensor. Each temperature sensor requires two connection terminals as electrical connection lines. The flexible connection of temperature sensors allows them to share connection terminals, thereby reducing the manufacturing cost of the temperature sensor array.

[0016] According to another embodiment, the temperature sensor in the temperature sensor array is constructed as a thermistor, a positive temperature coefficient resistor, or a thermocouple. This allows for the measurement and monitoring of the transistor's junction temperature using temperature sensors of any construction. Consequently, the temperature sensor array can be manufactured cost-effectively.

[0017] According to another embodiment, the temperature sensors of the temperature sensor array are arranged substantially coincidentally with the transistors and / or transistor connection lines of the half-bridge module. This arrangement of the temperature sensors minimizes the heat transfer path between the transistors or connection lines and the temperature sensors. Therefore, temperature measurement with a particularly fast response along the temperature distribution of the half-bridge module can be achieved with minimal time delay.

[0018] According to another embodiment, the temperature sensor array is designed in the form of a grid consisting of connecting terminals and temperature sensors, or in the form of a second substrate, wherein the temperature sensor array is arranged in parallel with the first substrate. This approach allows for the rapid and compact fabrication of the temperature sensor array. Furthermore, the temperature sensor array can be oriented with particular precision relative to the first substrate.

[0019] According to another embodiment, the temperature sensor array is cast together with the transistors of the half-bridge module into a potting compound, wherein the connection terminals of the temperature sensor array extend out from the potting compound. To accurately detect the individual chip temperature or junction temperature of each transistor during vehicle operation, the transistors and the temperature sensor array are cast together in a single mold. The temperature sensor array is positioned directly above the semiconductor chip or transistor before potting. For this purpose, the connection terminals are guided outwards and can be electrically accessed outside the potting compound.

[0020] According to another aspect of the invention, a temperature sensor array is provided. The temperature sensor array is preferably used in a half-bridge module according to the invention. The temperature sensor array has a plurality of temperature sensors and a plurality of connection terminals. The connection terminals are electrically connected to the temperature sensors, wherein each connection terminal is connected to at least one temperature sensor.

[0021] By using temperature sensors to accurately measure the temperature of a single chip, the design of power semiconductors in the automotive industry can be optimized. This prevents components from being excessively large and thus reduces costs. Increased power can be achieved while keeping the configuration constant because transistors, especially silicon carbide MOSFETs, can operate closer to their temperature limits.

[0022] Furthermore, this measure optimally utilizes silicon carbide technology to enable the transistor semiconductor to operate at the maximum permissible chip temperature of 200°C. This results in less heat dissipation, thus reducing the size of the vehicle's cooling system. Consequently, the efficiency and driving range of electric vehicles can also be increased. Attached Figure Description

[0023] The present invention is schematically illustrated with reference to the accompanying drawings and further described with reference to the drawings. Wherein:

[0024] Figure 1 An embodiment of the temperature sensor array according to the present invention is shown.

[0025] Figure 2 The invention is shown to have Figure 1 The half-bridge module of the temperature sensor array in the middle.

[0026] List of reference numerals in the attached diagram:

[0027] 1 Temperature sensor array

[0028] 2. First row of temperature sensors

[0029] 3. Second row of temperature sensors

[0030] 4. Third row of temperature sensors

[0031] 6 Second substrate

[0032] 8-Half-Bridge Module

[0033] 10 First substrate

[0034] 12 First Switching Unit

[0035] 14 Second Switching Unit

[0036] 16 Transistors of the first switching unit

[0037] 17. Transistor of the second switching unit

[0038] 18. Additional transistors in the second switching unit

[0039] 20 Temperature sensors based on existing technology

[0040] 22 potting compound

[0041] 24 transistor connection lines

[0042] Connection terminals of AL temperature sensor array Detailed Implementation

[0043] Figure 1An embodiment of a temperature sensor array 1 according to the present invention is shown. The temperature sensor array 1 has a plurality of temperature sensors 2, 3, and 4. In the illustrated embodiment, fifteen temperature sensors 2, 3, and 4 are provided.

[0044] Temperature sensors 2, 3, and 4 are implemented, for example, as positive temperature coefficient resistors or PTC thermistors, and therefore have a positive temperature coefficient. Here, the resistance is directly related to temperature. Alternatively, temperature sensors 2, 3, and 4 of temperature sensor array 1 can also be implemented as thermistors, thermocouples, etc.

[0045] Temperature sensors 2, 3, and 4 are arranged in three rows and electrically connected via connecting terminals or connecting lines AL. Two connecting terminals AL are connected to each of the temperature sensors 2, 3, and 4 to measure their resistance.

[0046] To minimize the number of connection lines used with temperature sensors 2, 3, and 4, every two or three temperature sensors 2, 3, and 4 can share one connection line AE, HL. With this arrangement, temperature sensors 2, 3, and 4 are interconnected, partly in series and partly in parallel, via connection lines AE, HL.

[0047] The temperature sensor array 1 can be constructed on the second substrate 6 or as a lead frame formed by connection terminals AL. Thus, the temperature sensor array 1 can be used to measure temperature distribution. For accurate detection, for example, during the operation of an electric vehicle... Figure 2 The individual chip temperatures of transistors 16, 17, and 18 are shown in the diagram. Temperature sensor array 1 is arranged parallel to transistors 16, 17, and 18. In this embodiment, temperature sensor array 1 is directly mounted above the semiconductor chip or transistors 16, 17, and 18 and is cast together with them. Each connection terminal AL is led outwards for this purpose and can be measured outside the potting compound 22.

[0048] The AL header can be used to sequentially drive each sensor segment or each temperature sensor 2, 3, 4 during operation, and thus acquire the temperature of the corresponding temperature sensor 2, 3, 4.

[0049] exist Figure 2 The figure shows a product according to the invention. Figure 1 The temperature sensor array 1 is a half-bridge module 8. To illustrate this arrangement, the temperature sensor array 1 is schematically placed on the first circuit board 10 of the half-bridge module 8, and the components of the first circuit board 10 can be seen. Figure 2 The internal chip configuration, including associated terminals, is also shown in a top view.

[0050] The half-bridge module 8 has two switching units 12 and 14, each comprising multiple transistors 16, 17, and 18 connected in parallel and / or series. In the illustrated embodiment, transistors 16, 17, and 18 are configured as silicon carbide MOSFETs and can operate at a maximum junction temperature of 200°C.

[0051] To illustrate the difference between the half-bridge module 8 according to the present invention and the half-bridge module according to the prior art, the temperature sensor array 1 according to the present invention is provided only on the second switching unit 14.

[0052] The first switching unit 12 corresponds to the prior art and includes a single temperature sensor 20, which is arranged on the first circuit board 10 next to the transistors 16 of the first switching unit 12. Therefore, it is not possible to accurately measure the temperature of each transistor 16.

[0053] By positioning or placing the temperature sensor array 1 on the transistors 17 and 18 of the second switching unit 14, the temperature and temperature distribution of the transistors 17 and 18 can be directly measured.

[0054] Temperature sensors 2, 3, and 4 of temperature sensor array 1 are at least partially thermally connected to transistors 17 and 18. For example, temperature sensors 2, 3, and 4 can be thermally coupled to transistors 17 and 18 via potting compound 22 or through direct body contact.

[0055] Temperature sensors 2, 3, and 4 are matched within temperature sensor array 1 in terms of position, number, and orientation to transistors 17 and 18. Temperature sensors 2, 3, and 4 of temperature sensor array 1 therefore substantially coincide with transistors 17 and 18 of half-bridge module 8 and / or the connection lines 24 of transistors 17 and 18.

[0056] To measure the temperature of transistor 17, the connection terminals H and I of the temperature sensor array 1 can be evaluated. Evaluation of the connection terminals D and I enables thermal monitoring of the connection lines 24 of transistor 17.

[0057] Other connections leading from the potting compound 22, including the drain, gate, and source, can drive transistors 16, 17, and 18. Connections DC+ and DC- are used to connect to a battery (not shown), which acts as a DC power source. The voltage supplied by the battery is converted to AC voltage, which is output at connection AC. Thus, when the B6 circuit is used, for example, by three half-bridge modules 8, a vehicle motor (not shown) can be operated by means of the half-bridge modules 8.

Claims

1. A half-bridge module (8) having two switching units (12, 14), each switching unit comprising a plurality of transistors (16, 17, 18) connected in parallel and / or in series, wherein, Transistors (16, 17, 18) are arranged on a first substrate (10). The half-bridge module (8) has a temperature sensor array (1) having multiple temperature sensors (2, 3, 4), wherein the temperature sensors (2, 3, 4) are at least partially thermally connected to the transistors (16, 17, 18). The temperature sensors (2, 3, 4) of the temperature sensor array (1) can be read individually or sequentially through the connection terminals (AL). The temperature sensor array (1) is directly placed above the transistors (16, 17, 18) and is poured into the potting compound (22) together with the transistors (16, 17, 18), so that each connection terminal (AL) is led out and can be measured outside the potting compound (22).

2. The half-bridge module according to claim 1, characterized in that, The plurality of transistors (16, 17, 18) are IGBTs or MOSFETs.

3. The half-bridge module according to claim 1, characterized in that, The connection terminal (AL) is electrically connected to at least one temperature sensor (2, 3, 4).

4. The half-bridge module according to any one of claims 1 to 3, characterized in that, The temperature sensors (2, 3, 4) of the temperature sensor array (1) are designed as thermistors, positive temperature coefficient resistors or thermocouples.

5. The half-bridge module according to any one of claims 1 to 3, characterized in that, The temperature sensors (2, 3, 4) of the temperature sensor array (1) are arranged to overlap with the transistors (16, 17, 18) and / or transistors (16, 17, 18) of the half-bridge module (8).

6. The half-bridge module according to any one of claims 1 to 3, characterized in that, The temperature sensor array (1) is constructed in the form of a grid consisting of connecting terminals (AL) and temperature sensors (2, 3, 4) or in the form of a second substrate (6), wherein the temperature sensor array (1) is arranged in parallel with the first substrate (10).

7. A temperature sensor array for use in a half-bridge module (8) according to any one of claims 1 to 6, the temperature sensor array having a plurality of temperature sensors (2, 3, 4) and a plurality of connection terminals (AL), the connection terminals being electrically connected to the temperature sensors (2, 3, 4), wherein, Each connection terminal (AL) is connected to at least one temperature sensor (2, 3, 4).

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