POWER MODULE AND METHOD FOR MOUNTING A POWER MODULE

Abstract

A power module (20) is provided. The power module (20) comprises: a carrier (22); a driver board (40) arranged on the carrier (22), which includes at least one cavity (42), wherein the cavity (42) is open to the driver board (40) and is otherwise surrounded by the driver board (40); and at least one semiconductor chip (24, 26) which is arranged in the cavity (42) on the carrier (22) and is electrically coupled to the driver board (40).

Description

[0001] The invention relates to a power module and a method for assembling the power module.

[0002] A conventional power module can comprise a substrate, one or more semiconductor chips mounted on the substrate, and a driver board for electrically contacting and / or controlling the semiconductor chip(s). One or more of the semiconductor chips can be configured as switches, particularly high-speed switches. One or more of the semiconductor chips can be configured as high-power semiconductor chips. The substrate can be a DBC (direct bonded copper) substrate or an IMS (insulated metal substrate). The driver board can comprise one or more electronic components for driving the semiconductor chip(s). The electronic components can include one or more active electronic components and / or one or more passive electronic components. The passive electronic components can include one or more resistors, one or more capacitors, and / or one or more conductors.The active electronic components can include one or more chips and / or one or more transistors.

[0003] In a conventional power module architecture, the driver board can be mounted facing away from the substrate on the semiconductor chips. Therefore, a large distance can exist between the semiconductor chips and the electronic components used to drive them, especially if the semiconductor chips are located on a different side of the driver board than the electronic components. This large distance can create a large gate loop by using a control line to electrically couple a gate contact of the semiconductor chip to the corresponding electronic component. The large gate loop can contribute to a high inductance generated during power module operation. If a control pin is used to electrically couple the gate contact to the corresponding electronic component, the control pin may need to be relatively large, further contributing to the high inductance.The high inductance can negatively affect the electronic components and / or semiconductor chips, especially if the semiconductor chips are based on SiC or GaN and / or if the semiconductor chips form one or more switching devices, e.g., high-speed switching devices. This can contribute to low power module performance.

[0004] Furthermore, the distance between one or more power lines for the power module, which may be arranged to carry current from one or more power terminals of the power module to the semiconductor chips, can be relatively large. Therefore, the power lines may not be cooled by a heat sink provided, for example, by the substrate. And finally, the power module is relatively thick and therefore large.

[0005] Therefore, one object of the present invention is to provide a power module that can be compact, lightweight, and / or provide high power. A further object of the present invention is to provide a method for assembling the power module.

[0006] The problems are solved by the subject matter of the independent claims. Advantageous embodiments are described in the dependent claims.

[0007] One aspect concerns a power module. The power module comprises: a carrier; a driver board arranged on the carrier, which includes at least one cavity, the cavity being open to the carrier and otherwise surrounded by the driver board; and at least one semiconductor chip arranged in the cavity on the carrier and electrically coupled to the driver board.

[0008] Providing the cavity and arranging the semiconductor chip within it allows for a small power module size, enabling a very compact design. Furthermore, arranging the semiconductor chip within the cavity allows it to be positioned close to one or more electronic components on the driver board, thus reducing the inductance generated by a gate loop of the power module compared to a conventional power module. This can contribute to proper functioning and, consequently, high performance of the semiconductor chip and, therefore, the power module. The driver board can comprise a printed circuit board (PCB) and the electronic components, with the cavity being formed within the PCB.

[0009] The semiconductor chip can be SiC or GaN. The power module can comprise two or more semiconductor chips mounted on the substrate and arranged in corresponding cavities on the driver board. The electronic components can be active electronic components, such as a chip or transistor, or passive electronic components, such as a resistor, capacitor, or inductor. The power module can comprise two or more electronic components mounted on the substrate board.

[0010] In one embodiment, the cavity is sealed by the driver board and the carrier. For example, the cavity is completely sealed by the driver board and the carrier. For example, the cavity is sealed fluid-tight by the driver board and the carrier. This can help prevent dirt or other substances from entering the cavity.

[0011] According to one embodiment, the driver board is arranged on the carrier such that it contacts the carrier. In other words, the driver board can be directly coupled to the carrier. The carrier can act as a heat sink for the power module. Arranging the driver board on the carrier allows the carrier to cool the driver board, and in particular its electronic components.

[0012] According to one embodiment, the driver board comprises at least one electronic component and a control line for transmitting a control signal from the electronic component to the semiconductor chip. The control line is electrically coupled to the electronic component and the semiconductor chip, and the control line is arranged on or within the driver board on a side of the driver board facing away from the substrate. For example, the electronic component may be arranged on a first side of the driver board facing away from the substrate, and the control line may be arranged between the semiconductor chip and the electronic component.Providing the cavity, arranging the semiconductor chip in the cavity, and placing the control line on or near the first side of the driver board can help to ensure that the inductance generated by a gate loop of the power module is low or at least reduced compared to a conventional power module.

[0013] Alternatively or additionally, the semiconductor chip can be coupled to the control line via a control pin, which can be coupled to the electronic component. The control pin can extend from the semiconductor chip to the first side of the driver board, for example, through a through-hole in the driver board. Providing the cavity and arranging the semiconductor chip within it can allow the pin to be relatively short compared to a corresponding pin in a conventional power module. This relatively short pin can contribute to generating relatively low inductance during operation of the power module.

[0014] The electronic component can be configured to control the semiconductor chip. The driver board can include two or more electronic components for controlling the semiconductor chip, or optionally, two or more semiconductor chips. The driver board can include two or more control lines for electrically coupling the electronic components to the semiconductor chips. Each control line can be coupled to the corresponding semiconductor chip via a gate contact of the corresponding semiconductor chip. The gate loop can be provided by the gate contact of the semiconductor chip, the electronic component for controlling the semiconductor chip, and the control line coupling the electronic component to the gate of the semiconductor chip.

[0015] According to one embodiment, the driver board comprises at least one power connector for electrically coupling the power module to an external device and a current line for transmitting current from the semiconductor chip to the power connector or vice versa. The current line is electrically coupled to the semiconductor chip and the power connector and is located on or within the driver board on a side facing the substrate. This substrate-facing side of the driver board can be referred to as a second side of the driver board. The current line can be configured to transmit high currents and / or withstand high voltages, where the high currents and / or voltages may be higher than those transmitted by the control line.Positioning the power supply on or near the second side of the driver board means that the power supply is located on or near the support structure. This allows for efficient cooling of the power supply by the support structure.

[0016] According to one embodiment, the semiconductor chip is a high-performance semiconductor chip.

[0017] According to one embodiment, the semiconductor chip, or at least one other semiconductor chip of the power module, is a high-power semiconductor chip. The high-power semiconductor chip can be configured to handle high voltages, for example, more than 100 V, and / or high currents, for example, more than 10 A.

[0018] Another aspect concerns a method for mounting the power module. The method comprises providing the driver board, which includes the at least one cavity; arranging the at least one semiconductor chip in the cavity; and arranging the driver board with the semiconductor chip on the carrier, such that the cavity is open to the carrier and otherwise surrounded by the driver board.

[0019] Features, embodiments and / or advantages relating to the above power module may also relate to features, embodiments or advantages of a method for assembling the power module.

[0020] According to one embodiment, the semiconductor chip is electrically coupled to the driver board during or after its placement in the cavity and before the driver board is placed on the substrate. The driver board can comprise one or more electronic components, with the semiconductor chip being coupled to the electronic component, for example, via the control line and / or the control pin, when the semiconductor chip is coupled to the driver board.

[0021] According to one embodiment, the driver board encompassing the cavity is provided by providing a printed circuit board, forming the cavity in the printed circuit board, and arranging at least one electronic component on the printed circuit board, wherein the printed circuit board with the cavity and the electronic component forms the driver board.

[0022] These and other aspects of the invention will become apparent and be explained with reference to the embodiments described below. Embodiments of the present invention are described in more detail below with reference to the attached drawings. Fig. Figure 1 shows a side section view of an exemplary embodiment of a power module. Fig. Figure 2 shows a cutaway side view of a driver board of the power module of Fig. 1 in a first state. Fig. Figure 3 shows a cutaway side view of the driver board of the power module of the Fig. 1 and Fig. 2 in a second state.

[0023] The reference symbols used in the drawings and their meanings are summarized in the following list of reference symbols. Generally, identical parts in the figures are designated with the same reference symbols.

[0024] Fig. Figure 1 shows a cutaway side view of an embodiment of a power module 20. The power module 20 comprises a carrier 22, at least one semiconductor chip, e.g., a first semiconductor chip 24 and a second semiconductor chip 26, arranged on the carrier 22, and a driver board 40 coupled to the carrier 22. The power module 20 can provide one or more half-bridges that can be used in an inverter and / or a rectifier.

[0025] The power module 20 may comprise one or more than two of the semiconductor chips 24, 26 on the carrier 22. At least one of the semiconductor chips 24, 26 of the power module 20 may be a high-power semiconductor chip. The high-power semiconductor chip may be configured to handle high voltages, for example, more than 100 V, and / or high currents, for example, more than 10 A. The semiconductor chip may comprise SiC or GaN.

[0026] The support 22 can comprise one or more columns 34 on which the semiconductor chips 24, 26 are arranged, and a heat sink 30 on which the columns 34 are arranged. The columns 34 can be coupled to the heat sink 30 by an insulating layer 36. The insulating layer 36 can have high thermal conductivity. The thermal conductivity of the insulating layer 36 can be greater than 10 kW / m. The breakdown voltage of the insulating layer can be greater than 4 kV DC. The heat sink 30 can comprise or be made of copper or aluminum. The support 22 can be or comprise a DBC substrate (direct bonded copper) or an IMS substrate (insulated metal substrate), wherein the columns 34 can be formed, for example, by etching, from an upper layer of the corresponding DBC or IMS.

[0027] The driver board 40 can comprise a printed circuit board (PCB) 38. The driver board 40 can include at least one electronic component, e.g., one or more first electronic components 44 and one or more second electronic components 46, which are coupled to the semiconductor chips 24, 26. The electronic components 44, 46 of the driver board 40 can be arranged on a side of the driver board 40 facing away from the carrier 22, i.e., a first side of the driver board 40. The electronic components 44, 46 can each comprise one or more active electronic components, e.g., one or more chips or transistors, or one or more passive electronic components, e.g., one or more resistors, one or more capacitors, or one or more inductors. The driver board 40 can include one or more power lines 50, 54, 58 and / or control lines 60, 62, etc. B.The vias are embedded in or printed on the PCB 38. The driver board 40 can include one or more electrical connections, such as a first DC connection 48, a second DC connection 52, and an AC connection 56. For example, the first DC connection 48 can be a DC+ connection and / or the second DC connection 52 can be a DC- connection. The connections 48, 52, and 56 can be provided for coupling the power module 22 to one or more external devices (not shown), such as a load powered by the power module 20, e.g., an electric motor or actuator, and / or to a power source, e.g., the mains power supply or a generator.

[0028] The power lines 50, 54, 58 can be arranged to couple the source and / or drain contacts (not shown) of the semiconductor chips 24, 26 with the power terminals 48, 52, 56. The power lines 50, 54, 58 can be configured to carry high currents, in particular high DC or AC currents. The power lines 50, 54, 58 can be configured to transmit currents from the semiconductor chips 24, 26 to the corresponding power terminals 48, 52, 56 or vice versa. The power lines 50, 54, 58 can be electrically coupled to the corresponding semiconductor chips 24, 26 and the corresponding power terminals 48, 52, 56. The power lines 50, 54, 58 can be arranged on or in the driver board 40 on a side of the driver board 40 facing the carrier 22. The side of the driver board 40 facing the carrier 22 can be referred to as a second side of the driver board 40.The second side of the driver board 40 can be opposite the first side of the driver board 40. The power lines 50, 54, 58 can be configured to transmit high currents and / or withstand high voltages, whereby the high currents and / or voltages can be higher than the currents or voltages transmitted by the control lines 60, 62.

[0029] The control lines 60, 62 can comprise a first control line 60 and a second control line 62. The control lines 60, 62 can be arranged to couple gate contacts (not shown) of the semiconductor chips 24, 26 with the electronic components 44, 46. The control lines 60, 62 can be configured to carry only low-voltage control signals. The control lines 60, 62 can be configured to transmit the control signals from one or more of the electronic components 44, 46 to the corresponding semiconductor chip 24, 26. The control lines 60, 62 can be arranged on or in the driver board 40, e.g., on the first side of the driver board 40 facing away from the carrier 22. For example, the control lines 60, 62 can be arranged between the semiconductor chips 24, 26 and the electronic components 44, 46.

[0030] Alternatively or additionally, the semiconductor chips 24, 26 can be coupled to the electronic components 44, 46 by one or more control pins, e.g., a first control pin 64 coupled to the first semiconductor chip 24 and a second control pin 66 coupled to the second semiconductor chip 26. The control pins 64, 66 can be coupled to the corresponding control lines 60, 62. The control pins 64, 66 can each extend from the corresponding semiconductor chip 24, 26 to the first side of the driver board 40, e.g., through a through-hole in the driver board 40. Each control line 60, 62 and / or control pin 64, 66 can be coupled to the corresponding semiconductor chip 24, 26 via a gate contact (not shown) of the corresponding semiconductor chip 24, 26.

[0031] The driver board 40 can be arranged on the carrier 22 such that it contacts the carrier 22. In other words, the driver board 40 can be directly coupled to the carrier 22. Outside the columns 34, the driver board 40 can be coupled to the carrier 22, in particular to the insulating layer 36. Optionally, the driver board 40 can be coupled to the carrier 22 by one or more thin layers of thermal interface material (TIM). The TIM can be an adhesive or a lubricant with very high thermal conductivity. The thermal conductivity of the TIM can be greater than 10 kW / m. Alternatively, the insulating layer 36 can be formed by the thermal interface material (TIM).

[0032] The driver board 40 comprises at least one cavity, e.g., two cavities 42. Each cavity is open to the carrier 22 and otherwise surrounded by the driver board 40. The semiconductor chips 24, 26 are arranged in the respective cavity 42. Each cavity can accommodate one or more of the semiconductor chips 24, 26. The cavities can be configured such that they are sealed by the driver board 40 and the carrier 22. For example, the cavities 42 can be completely sealed by the driver board 40 and the carrier 22. Alternatively, the cavities 42 can be fluid-tightly sealed by the driver board 40 and the carrier 22.

[0033] Fig. Figure 1 can show a final state of the power module 20. A method for assembling the power module 20, and thus a method for achieving the final state of Fig. 1 is explained below.

[0034] Fig. Figure 2 shows a cutaway side view of a driver board of the power module of Fig. 1 in a first state. The first state can be a first state of the method for mounting the power module 20. In the first state, the driver board 40, comprising at least one cavity, e.g., two cavities 42, is provided. The driver board 40, comprising the cavity 42, can be provided by providing the PCB 38, by forming the cavity 42 in the PCB 38, and by arranging at least one of the electronic components 44, 46 on the PCB 38. The power and / or control lines 50, 54, 58, 60, 62 can be formed before or after the cavity 42 is formed on or in the PCB 38.

[0035] Fig. Figure 3 shows a cutaway side view of the driver board of the power module of the Fig. 1 and Fig. 2 in a second state. The second state can be a second state of the method for mounting the power module 20. In the second state, the at least one, e.g., two, semiconductor chips 24, 26 can be arranged in the corresponding cavity 42. Furthermore, the semiconductor chip 24, 26 can be electrically coupled to the driver board 40 during or after its placement in the cavity 42 and before the driver board 40 is placed on the carrier 22. The semiconductor chip 24, 26 can be coupled to the electronic component 44, 46, e.g., via the control line 60, 62 and / or the control pin 64, 66, when the semiconductor chip 24, 26 is coupled to the driver board 40.

[0036] Finally, as in Fig.As shown in Figure 1, the driver board 40 with the semiconductor chip 24, 26 is arranged in the cavity 42 on the carrier 22 such that the cavity 42 is open to the carrier 22 and is otherwise surrounded by the driver board 40.

[0037] The invention is not limited to the embodiments described above. For example, there may be more or fewer semiconductor chips 24, 26, electronic components 44, 46, corresponding control lines 60, 62, columns 34, and / or control pins 64, 66. Although the invention has been illustrated and described in detail in the drawings and the preceding description, such illustration and description are to be considered illustrative or exemplary and not limiting; the invention is not limited to the disclosed embodiments. A person skilled in the art, when carrying out the claimed invention, will be able to identify and implement further variations of the disclosed embodiments by careful examination of the drawings, the disclosure, and the appended claims. In the claims, the term "comprise" does not exclude any other elements or steps, and the indefinite article "a" does not exclude a plural.A single processor, controller, or other unit can perform the functions of several elements listed in the claims. The mere fact that certain measures are listed in different interdependent claims does not preclude the possibility of combining these measures to one's advantage. Any reference numerals in the claims should not be interpreted as limiting the scope of protection. List of reference symbols 20 Power module 22 carriers 24 first semiconductor chip 26 second semiconductor chip 30 Heat sink 34th pillar 36 Insulation layer 38 PCB 40 driver boards 42 Cavity 44 first electronic component 46 second electronic component 48 first DC connection 50 first power line 52 second DC connector 54 second power line 56 AC connection 58 third power line 60 first control line 62 second control line 64 first control pin 66 second control pin

Claims

[1] Power module (20), comprising: a carrier (22); a driver board (40) arranged on the carrier (22) and comprising at least one cavity (42), the cavity (42) being open to the carrier (22) and otherwise surrounded by the driver board (40); and at least one semiconductor chip (24, 26) arranged in the cavity (42) on the carrier (22) and electrically coupled to the driver board (40). [2] Power module (20) according to claim 1, wherein the cavity (42) is closed by the driver board (40) and the carrier (22). [3] Power module (20) according to one of the preceding claims, wherein the driver board (40) is arranged on the carrier (22) such that the driver board (40) touches the carrier (22). [4] Power module (20) according to one of the preceding claims, wherein the driver board (40) comprises at least one electronic component (44, 46) and a control line (60, 62) for transmitting a control signal from the electronic component (44, 46) to the semiconductor chip (24, 26), the control line (60, 62) is electrically coupled to the electronic component (44, 46) and the semiconductor chip (24, 26), and the control line (60, 62) is arranged on or in the driver board (40) on a side of the driver board (40) facing away from the carrier (22). [5] Power module (20) according to one of the preceding claims, wherein the driver board (40) comprises at least one power terminal (48, 52, 56) for electrically coupling the power module (20) to an external device and a power line (50, 54, 58) for transmitting a current from the semiconductor chip (24, 26) to the power terminal (48, 52, 56) or vice versa, the power line (50, 54, 58) is electrically coupled to the corresponding semiconductor chip (24, 26) and the corresponding power terminal (48, 52, 56), and the power line (50, 54, 58) is arranged on or in the driver board (40) on a side of the driver board (40) facing the carrier (22). [6] Power module (20) according to one of the preceding claims, wherein the semiconductor chip (24, 26) is a high-performance semiconductor chip. [7] A method of assembling a power module (20), the method comprising: Providing a driver board (40) comprising at least one cavity (42); Arranging the at least one semiconductor chip (24, 26) in the cavity (42); and Arranging the driver board (40) with the semiconductor chip (24, 26) on a carrier (22) such that the cavity (42) is open to the carrier (22) and is otherwise surrounded by the driver board (40). [8] The method of claim 7, wherein the semiconductor chip (24, 26) is electrically coupled to the driver board (40) during or after arranging the semiconductor chip (24, 26) in the cavity (42) and before arranging the driver board (40) on the carrier (22). [9] Method according to one of claims 7 or 8, wherein the driver board (40) comprising the cavity (42) is provided by providing a printed circuit board (38), forming the cavity (42) in the printed circuit board (38) and arranging at least one electronic component (44, 46) on the printed circuit board (38), the printed circuit board (38) with the cavity (42) and the electronic component (44, 46) forming the driver board (40).

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