Circuit device and method for manufacturing a circuit device for a vehicle

Abstract

Circuit device (100) for a vehicle (800), wherein the circuit device (100) has the following features: a rigid-flexible printed circuit board (102) with a rigid section (104) with a circuit contact (126), and with a flexible section (106) with a transistor contact (124) and a conductor track (120) connecting the circuit contact (126) and the transistor contact (124), and with a component arranged on a surface of the flexible section (106) of the rigid-flexible printed circuit board (102) and connected to the conductor track (120), wherein the component is designed as an electrical resistor or a capacitor; a transistor device (110) comprising a transistor (112) and a control terminal for the transistor (112), wherein the control terminal is connected to the transistor contact (124) of the flexible section (106) of the rigid-flexible printed circuit board (102), wherein the transistor contact (124) of the flexible section (106) of the rigid-flexible printed circuit board (102) directly contacts the control terminal of the transistor device (110); and a control circuit (108) with a signal terminal (126) for outputting a control signal for controlling the transistor (112), wherein the control circuit (108) is arranged on the rigid section (104) of the rigid-flexible printed circuit board (102) and the signal terminal (126) of the control circuit (108) is connected to the circuit contact (126) of the rigid-flexible printed circuit board (102).

Description

[0001] The present invention relates to a circuit device and to a method for manufacturing a circuit device for a vehicle.

[0002] To connect a driver board to a transistor, a bond wire and a signal pin can be used. However, this results in a high inductance, which in turn can lead to oscillation problems.

[0003] DE 11 2018 005 546 T5 discloses a semiconductor module unit comprising a semiconductor module, a main board, and a secondary board, which is separate from the main board and on which a driver circuit is mounted. A flexible circuit board connects the main board and the secondary board. The secondary board contains a fitting element that fits into a corresponding fitting element of the semiconductor module. DE 10 2007 038 676 A1 discloses an electronic circuit with power semiconductors, each individually connected to a circuit board via flexible sections. DE 10 2015 121 680 A1 discloses a power semiconductor module comprising a power semiconductor chip and a flexible circuit board mounted at a distance from the power semiconductor chip. EP 2 790 215 A1 discloses a circuit board.

[0004] Against this background, the present invention provides an improved circuit device and an improved method for manufacturing a circuit device for a vehicle according to the main claims. Advantageous embodiments are described in the dependent claims and the following description.

[0005] A rigid-flex printed circuit board (PCB) can be advantageously used for electrically contacting fast-switching elements. This allows for the creation of a connection with low inductance, resulting in a small inductance loop. Examples of such fast-switching elements for which the use of a rigid-flex PCB can be advantageous include GaN, SiC, or CaO elements.

[0006] A corresponding circuit device for a vehicle has the following features: a rigid-flexible printed circuit board with a rigid section containing a circuit contact and a flexible section containing a transistor contact and a conductor connecting the circuit contact and the transistor contact; a transistor device comprising a transistor and a control terminal for the transistor, wherein the control terminal is connected to the transistor contact of the flexible section of the rigid-flexible printed circuit board; and a control circuit comprising a signal terminal for outputting a control signal for driving the transistor, wherein the control circuit is arranged on the rigid section of the rigid-flexible printed circuit board and the signal terminal of the control circuit is connected to the circuit contact of the rigid-flexible printed circuit board.

[0007] The circuitry can be part of the vehicle's electrical system. The vehicle could, for example, be an electric vehicle. For the rigid-flex printed circuit board (PCB), it is advantageous to use known designs. For example, such a PCB can consist of a rigid section made up of pressed rigid layers and a flexible section made up of pressed flexible layers. The rigid section can correspond to a conventional printed circuit board. The flexible section can be formed like a film and thus include flexible conductors. One or more electrical components, such as integrated circuits, can be contacted on a surface of the rigid section.The rigid section can comprise multiple contact surfaces to electrically connect such electrical components, for example, using solder joints. The circuit contact can be formed as such a contact surface. The flexible section, particularly at its edges, can also comprise multiple contact surfaces. Thus, the flexible section can be guided to a component to be contacted and electrically connected to it via a corresponding contact surface. Such a contact surface can also be a contact point, which, for example, can be formed by an exposed end of a conductor track running through the flexible section. The transistor contact of the flexible section can be formed by a corresponding contact surface of the flexible section.The conductor track can have one section within the rigid part and another within the flexible part. The transistor assembly can comprise one or more transistors. Thus, the transistor assembly can be a transistor with terminals or a transistor circuit comprising at least one transistor. A corresponding transistor can have a package. It can be a fast-switching transistor. It can be a power transistor. The control circuit can be a driver circuit for driving the transistor. For example, it can be a control circuit such as those used in power electronics, for instance, in inverters, rectifiers, or converters.

[0008] For example, the transistor contact of the flexible section of the rigid-flex printed circuit board can directly contact the control terminal of the transistor device. This allows for high signal quality of a control signal to control the transistor.

[0009] For example, the circuit device can incorporate an ultrasonic weld connection that links the transistor contact of the flexible section of the rigid-flex printed circuit board and the control terminal of the transistor device. A reliable electrical connection can be achieved using a suitable ultrasonic welding process.

[0010] For example, the control terminal of the transistor device can be implemented as a gate contact of the transistor or be connected to a gate contact of the transistor. The switching behavior of the transistor can be controlled via the gate contact.

[0011] For example, the transistor can be designed as a power transistor. This allows the transistor to be used to switch high currents flowing in the electrical system of an electric vehicle.

[0012] The transistor can be implemented as a GaN transistor, a SiC transistor, or a CaO transistor. Transistors based on these materials are advantageously suited for power electronics.

[0013] The circuit device can include at least one component arranged on a surface of the flexible section of the rigid-flex printed circuit board. The component can be connected to the conductor track. The component can be, for example, an electrical resistor or a capacitor. By arranging it on the flexible section, the component can be positioned very close to the transistor contact. This can improve the signal quality of a signal transmitted via the conductor track.

[0014] According to one embodiment, the transistor assembly can have a second control terminal for the transistor. Correspondingly, the control circuit can have a second signal terminal for outputting a further control signal to drive the transistor. The rigid section of the rigid-flex circuit board can have a second circuit contact connected to the second signal terminal. The flexible section of the rigid-flex circuit board can have a second transistor contact and a second conductor connecting the second circuit contact and the second transistor contact. The second control terminal can be connected to the second transistor contact. Thus, multiple conductors can be routed across the flexible section, carrying multiple electrical connections between the control circuit and the transistor assembly.

[0015] For example, the second control terminal can be implemented as a source contact of the transistor or connected to a source contact of the transistor. Thus, the gate and source contacts of the transistor can be controlled by electrical voltages applied by the control circuit via the flexible section of the rigid-flex printed circuit board.

[0016] According to one embodiment, the circuit device can include a further transistor assembly with another transistor and another control terminal for the further transistor. The control circuit can accordingly have another signal terminal for outputting another control signal to drive the further transistor. The rigid section of the rigid-flex circuit board can have another circuit contact that can be connected to the further signal terminal. The flexible section of the rigid-flex circuit board can have another transistor contact and another conductor connecting the further circuit contact and the further transistor contact. The further control terminal can be connected to the further transistor contact. Advantageously, the flexible section can be used in this way to electrically contact a plurality of transistor assemblies.

[0017] According to one embodiment, the circuit device can be configured as an inverter for the vehicle's electric drive. The control circuit can be designed according to known driver circuits of known inverters. Thus, the circuit device can be used very easily as a replacement for known inverters.

[0018] A method for manufacturing a circuit device for a vehicle comprises the following steps: Providing a rigid-flex printed circuit board with a rigid section containing a circuit contact and a flexible section containing a transistor contact and a conductor connecting the circuit contact and the transistor contact; Providing a transistor device with one transistor and a control terminal for the transistor Providing a control circuit with a signal connection for outputting a control signal to control the transistor; Mounting the control circuit onto the rigid section of the rigid-flex printed circuit board, wherein the signal terminal of the control circuit is connected to the circuit contact of the rigid-flex printed circuit board; and

[0019] Connecting the control terminal of the transistor device to the transistor contact of the flexible section of the rigid-flexible printed circuit board.

[0020] Advantageously, a known pick-and-place machine suitable for rigid-flex printed circuit boards can be used for production.

[0021] The invention is explained in more detail by way of example with reference to the accompanying drawings. These show: Fig. 1 a schematic representation of a circuit device according to an exemplary embodiment; Fig. 2 a schematic representation of a manufacturing step of a circuit device according to an exemplary embodiment; Fig. 3 a schematic representation of a circuit device according to an exemplary embodiment; Fig. 4 a representation of a transistor device according to an exemplary embodiment; Fig. 5 a schematic representation of a rigid-flexible printed circuit board according to an exemplary embodiment; Fig. 6. A representation of a rigid-flexible printed circuit board according to an exemplary embodiment; Fig. 7. A flowchart of a method for manufacturing a circuit device for a vehicle; and Fig. 8 A schematic representation of a vehicle with a switching device according to an exemplary embodiment.

[0022] In the following description of preferred embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and having a similar effect, without repeating these elements.

[0023] Fig. Figure 1 shows a schematic representation of a circuit device 100 according to an exemplary embodiment. The circuit device 100 comprises a rigid-flex circuit board 102 with a rigid section 104 and a flexible section 106, as well as a control circuit 108 and a transistor assembly 110, which includes at least one transistor 112. The control circuit 108 is arranged on the rigid section 104 of the rigid-flex circuit board 102 and is connected to the transistor assembly 110 via the flexible section 106 of the rigid-flex circuit board 102.

[0024] The rigid-flexible circuit board 102 has a conductor track 120 which connects a circuit contact 122 arranged on the rigid section 104 to a transistor contact 124 arranged on the flexible section 106.

[0025] The control circuit 108 has a signal terminal 126, which is electrically connected to the circuit contact 122, for example by a solder connection. The signal terminal 126 is, for example, designed as a solderable pad or as a solderable pin. The transistor assembly 110 has a control terminal 128, which is electrically connected to the transistor contact 124, for example by soldering or welding. For example, the control terminal 128 and the transistor contact 124 are connected by an ultrasonic weld.

[0026] Thus, the operation of transistor 112 can be controlled via conductor track 120 by the control circuit 108. The control circuit 108 comprises, for example, one or more integrated circuits and is configured, for example, to receive a request signal from a higher-level control unit and convert it into at least one control signal for controlling transistor circuit 110.

[0027] For example, transistor 112 is implemented as a GaN transistor, a SiC transistor, or a CaO transistor. According to one embodiment, transistor 112 is implemented as a power transistor. Transistor 112 is also implemented, for example, as a metal-oxide-semiconductor field-effect transistor. In this case, the control terminal 128 is implemented as a gate contact of transistor 112 or is connected to the gate contact of transistor 112.

[0028] According to one embodiment, the rigid-flex circuit board 102 has a second conductor track 130 that connects a second circuit contact 132 located on the rigid section 104 to a second transistor contact 134 located on the flexible section 106. The control circuit 108 accordingly has, for example, a second signal connection 136 that is electrically connected to the second circuit contact 132. The transistor assembly 110 has a second control connection 138 that is electrically connected to the second transistor contact 134. Thus, the operation of the transistor 112 can be controlled by the control circuit 108 via the conductor tracks 120 and 130. For example, the second control connection 138 is a source contact of the transistor 112 or is connected to the source contact of the transistor 112.

[0029] Optionally, the control circuit has at least one further signal connection 146 for outputting a further control signal for controlling at least one further transistor. The further transistor can, for example, be encompassed by the transistor assembly 110 or by another transistor assembly. The further transistor can be contacted via a further conductor track routed over the flexible section 106 or another flexible section of the rigid-flexible printed circuit board 102, as shown, for example, below. Fig. 3 is shown.

[0030] Fig. Figure 2 shows a schematic representation of a manufacturing step of a method for manufacturing a circuit device according to an exemplary embodiment. This is, for example, an exemplary embodiment of a circuit device as described in Fig. 1 is described.

[0031] A cross-section through the rigid section 104 and the flexible section 106 of the rigid-flexible printed circuit board 102 is shown.

[0032] The rigid-flex printed circuit board 102 has, for example, a layered structure in the rigid section 104 consisting of at least one copper foil and a rigid plate made of a composite material. In the case of a layered structure comprising several conductive layers, the rigid section 104 optionally includes at least one via 250 for electrically connecting conductive layers arranged on different levels.

[0033] In the flexible section 106, the rigid-flexible printed circuit board 102, for example, has a layer structure consisting of at least one copper foil and one plastic foil.

[0034] According to this embodiment, a free end of a conductor track 120 guided through the flexible section 106 is connected to the control terminal 128 of the transistor device 110, for example by ultrasonic welding.

[0035] According to one embodiment, the transistor device 110 is designed as a power chip which is contacted via the flexible section 106.

[0036] Fig. Figure 3 shows a schematic representation of a circuit device 100 according to an exemplary embodiment. This is, for example, an exemplary embodiment of a circuit device as described in Fig. 1 is described.

[0037] According to the illustrated embodiment, the rigid-flex circuit board 102 has, in addition to the flexible section 106, a further flexible section 306. The flexible sections 106 and 306 are connected to the rigid section 104.

[0038] According to the illustrated embodiment, the flexible section 106 of the rigid-flexible printed circuit board 102 is used to contact at least one second transistor assembly 310 in addition to the transistor assembly 110. The second transistor assembly 310 has at least one second transistor 312. The contacting of the at least one second transistor assembly 310 is, for example, according to the diagram shown below. Fig. 1 described contacting of the transistor device 110. Thus, the flexible section 106 has, for example, at least one further transistor contact 324, 334.

[0039] The flexible section 106 is designed, for example, to contact a total of six transistor devices 110, 310. Each of the six transistor devices 110, 310 is implemented as a SiC chip. The transistor contacts 124, 134 are suitable, for example, for contacting a gate of the transistor devices 110, 310.

[0040] According to one embodiment, at least one component 360 is arranged on a surface of the flexible section 106 of the rigid-flexible printed circuit board 102. The component 360 is located adjacent to the transistor contacts 124, 134 and is, for example, electrically connected to a conductor that leads to one of the transistor contacts 124, 134. The component 360 is, for example, designed as an electrical resistor or a capacitor to prevent vibrations.

[0041] According to one embodiment, each of the transistor devices 110, 310 connected to the flexible section 106 is assigned a corresponding component 360.

[0042] According to the illustrated embodiment, the additional flexible section 306 is used to connect further transistor devices 360 to the control circuit 108. For example, the flexible sections 106 and 306 are configured to be identical to each other. Accordingly, the further transistor devices 360 are configured and contacted, for example, in accordance with transistor device 110.

[0043] Fig. Figure 4 shows a representation of transistor devices 110, 310 according to an exemplary embodiment. By way of example, the transistor devices 110, 310 form a series circuit of two transistors 112, 312.

[0044] According to one embodiment, the control terminal 128 corresponds to the gate contact and the second control terminal 138 to the source contact of transistor 112. One control terminal 428 of the second transistor assembly 310 corresponds to the gate contact and a second control terminal 138 of the second transistor assembly 310 to the source contact of the second transistor 312.

[0045] If the control pins 128, 138, 428, 438 are contacted via a flexible section of a rigid-flex printed circuit board, as is the case, for example, with Fig. As shown in Figure 3, gate loop inductances can be avoided.

[0046] According to an alternative embodiment, the transistors 112, 312 are elements of a single transistor arrangement.

[0047] Fig. Figure 5 shows a schematic representation of a rigid-flex printed circuit board 102 according to an exemplary embodiment. This is, for example, a cross-sectional view of a part of the board, based on… Fig. 3 described circuit board. For example, the rigid section 104 is populated on both the top and bottom sides with components 560, for example in the form of resistors, capacitors, transistors or integrated circuits.

[0048] For example, it shows Fig. 5 a cross-sectional view of a driver board.

[0049] Fig. Figure 6 shows a representation of a rigid-flex printed circuit board 102 according to an exemplary embodiment. The rigid-flex printed circuit board 102 has a rigid section 104 and, by way of example, three flexible sections 106, 306, 606, each of which is connected at one end to the rigid section 104.

[0050] Optionally, one end of the rigid section 104 is shaped as a connector 670.

[0051] The rigid section 104 has a plurality of vias 250, conductor tracks 620, and contact pads 626, of which, for the sake of clarity, only one is labeled with a reference numeral. Contacts of, for example, the following can be connected to the contact pads 626: Fig. 1 control circuit shown and / or the one in Fig. The 5 components shown are soldered on.

[0052] Fig. Figure 7 shows a flowchart of a method for manufacturing a circuit device for a vehicle according to an exemplary embodiment. For example, a circuit device like the one shown in the preceding figures can be manufactured using this method.

[0053] In step 701, a rigid-flex printed circuit board is provided, in step 703 a transistor assembly, and in step 705 a control circuit, as demonstrated, for example, by Fig. The following steps are described in section 1. In step 707, the rigid section of the rigid-flex printed circuit board is populated with the control circuit. In step 709, the transistor assembly is connected to the flexible section of the rigid-flex printed circuit board. The sequence of steps 701, 703, 705, 707, and 709 is only an example.

[0054] Fig. Figure 8 shows a schematic representation of a vehicle 800 with a switching device 100 according to an exemplary embodiment. This can be an exemplary embodiment of the switching device 100 described with reference to the preceding figures.

[0055] For illustrative purposes only, vehicle 800 is an electric vehicle with a battery 880 and an electric machine 882 for driving at least one wheel of vehicle 800. The battery 880 is designed to provide a direct current voltage, which, for example, is converted into a three-phase alternating current voltage for driving the electric machine 882 using the circuit device 100.

[0056] For example, the circuit device 100 for providing the three-phase alternating voltage comprises six transistors, two of which are connected in series, as is the case, for example, in Fig. Figure 4 shows that the six transistors are contacted, for example, via a single flexible section of a rigid-flex printed circuit board, as shown in Figure 4. Fig. 3 is shown.

[0057] Thus, the circuit device 100 can be designed, for example, as an inverter for an electric drive of the vehicle 800. Reference sign 100 circuit device 102 rigid-flex printed circuit boards 104 rigid section 106 flexible section 108 Control circuit 110 transistor device 112 transistors 120 conductor tracks 122 Circuit contact 124 transistor contacts 126 Signal connection 128 Control connection 130 second conductor track 132 second circuit contact 134 second transistor contact 136 second signal connection 138 second control connection 146 additional signal connection 250 vias 306 further flexible section 310 second transistor device 312 second transistor 360 component 428 Control connection 438 second control connection 560 components 606 flexible section 670 plugs 620 conductor tracks 626 contact surfaces 701 Providing a rigid-flex printed circuit board 703 Providing a transistor device 705 Providing a control circuit 707 Assemble 709 Connect 800 vehicles 880 battery 882 electric machine

Claims

[1] Circuit device (100) for a vehicle (800), wherein the circuit device (100) has the following features: a rigid-flexible printed circuit board (102) with a rigid section (104) with a circuit contact (126), and with a flexible section (106) with a transistor contact (124) and a conductor track (120) connecting the circuit contact (126) and the transistor contact (124), and with a component arranged on a surface of the flexible section (106) of the rigid-flexible printed circuit board (102) and connected to the conductor track (120), wherein the component is designed as an electrical resistor or a capacitor; a transistor device (110) comprising a transistor (112) and a control terminal for the transistor (112), wherein the control terminal is connected to the transistor contact (124) of the flexible section (106) of the rigid-flexible printed circuit board (102), wherein the transistor contact (124) of the flexible section (106) of the rigid-flexible printed circuit board (102) directly contacts the control terminal of the transistor device (110); and a control circuit (108) with a signal terminal (126) for outputting a control signal for controlling the transistor (112), wherein the control circuit (108) is arranged on the rigid section (104) of the rigid-flexible printed circuit board (102) and the signal terminal (126) of the control circuit (108) is connected to the circuit contact (126) of the rigid-flexible printed circuit board (102). [2] Circuit device (100) according to claim 1, comprising an ultrasonic welding connection that connects the transistor contact (124) of the flexible section (106) of the rigid-flexible printed circuit board (102) and the control terminal of the transistor device (110). [3] Circuit device (100) according to one of the preceding claims, wherein the control terminal is configured as a gate contact of the transistor (112) or is connected to a gate contact of the transistor (112). [4] Circuit device (100) according to one of the preceding claims, wherein the transistor (112) is designed as a power transistor. [5] Circuit device (100) according to one of the preceding claims, wherein the transistor (112) is configured as a GaN transistor, a SiC transistor or a CaO transistor. [6] Circuit device (100) according to one of the preceding claims, wherein the transistor device (110) has a second control terminal (138) for the transistor (112), wherein the control circuit (108) has a second signal terminal (136) for outputting a further control signal for controlling the transistor (112), wherein the rigid section (104) of the rigid-flexible printed circuit board (102) has a second circuit contact (136) which is connected to the second signal terminal (136), wherein the flexible section (106) of the rigid-flexible printed circuit board (102) has a second transistor contact (134) and a second conductor track (130) connecting the second circuit contact (136) and the second transistor contact (134), wherein the second control terminal (138) is connected to the second transistor contact (134). [7] Circuit device (100) according to claim 6, wherein the second control terminal is configured as a source contact of the transistor (112) or is connected to a source contact of the transistor (112). [8] Circuit device (100) according to one of the preceding claims, with a further transistor arrangement (310, 360) with a further transistor (312) and a further control connection for the further transistor (312), wherein the control circuit (108) has a further signal connection (146) for outputting a further control signal for controlling the further transistor (312), wherein the rigid section (104) of the rigid-flexible printed circuit board (102) has a further circuit contact which is connected to the further signal connection (146), wherein the flexible section (106) of the rigid-flexible printed circuit board (102) or a further flexible section (306) of the rigid-flexible printed circuit board (102) has a further transistor contact (324) and a further conductor connecting the further circuit contact (146) and the further transistor contact (324), wherein the further control connection is connected to the further transistor contact (324). [9] Circuit device (100) according to one of the preceding claims, which is designed as an inverter for an electric machine (882) of the vehicle (800). [10] Method for manufacturing a circuit device (100) for a vehicle (800), the method comprising the following steps: Providing (701) a rigid-flexible printed circuit board (102) with a rigid section (104) having a circuit contact (126), and with a flexible section (106) having a transistor contact (124) and a conductor track (120) connecting the circuit contact (126) and the transistor contact (124), and with a component arranged on a surface of the flexible section (106) of the rigid-flexible printed circuit board (102) and connected to the conductor track (120), wherein the component is designed as an electrical resistor or a capacitor; Providing (703) a transistor device comprising a transistor (112) and a control terminal for the transistor (112) Providing (705) a control circuit (108) with a signal terminal (126) for outputting a control signal to control the transistor (112); Mounting (707) the rigid section (104) of the rigid-flex printed circuit board (102) with the control circuit (108), wherein the signal terminal (126) of the control circuit (108) is connected to the circuit contact (126) of the rigid-flex printed circuit board (102); and Connecting (709) the control terminal of the transistor device to the transistor contact (124) of the flexible section (106) of the rigid-flexible printed circuit board (102), wherein the transistor contact (124) of the flexible section (106) of the rigid-flexible printed circuit board (102) directly contacts the control terminal of the transistor device (110).

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