Patent Application
20210021179
The disclosure relates to a circuit arrangement having a circuit carrier board, a power semiconductor arranged on the underside of the circuit carrier board, and a wiring carrier board arranged underneath the power semiconductor. The disclosure also relates to a converter with such a circuit arrangement and to an aircraft, (e.g., an airplane), having a converter. The disclosure also relates to a method for measuring the current in a power semiconductor.
External monitoring devices are currently required for the monitoring and control of power semiconductors in converters. These have to be created separately in the design phase (e.g., electrical, mechanical) and consume space accordingly, causing additional weight and costs. In a specific case, a load current may be determined directly on the power semiconductor.
Such a monitoring is necessary to detect the failure of individual components, to synchronize subsystems, to compensate for drift (e.g., due to temperature, aging, etc.), and to compensate for component scatter.
As is known, this monitoring may be resolved through “binning” of the semiconductors to compensate for scatter effects, or through installation of current sensors, such as Hall sensors (e.g., contactless) or shunts (e.g., connected in series), with corresponding evaluation electronics. These sensors are required in every power path of a system (e.g., at least for every semiconductor chip). Alternatively, there may be no monitoring at all, with the disadvantage that the above-mentioned monitoring functions are not possible. The result is sudden (e.g., unexpected) failures, poorer electrical performance, drift (e.g., aging), etc.
A converter, also known as an inverter, refers to a power converter that converts an AC voltage or a DC voltage into an AC voltage with a modified frequency and amplitude. Converters may be configured as AC/DC-DC/AC converters or DC/AC converters, wherein an output AC voltage is generated from an input AC voltage or an input DC voltage via a DC link and clocked semiconductors.
It is an object of the disclosure to specify a solution for simple and space-saving current measurement for power semiconductors in converters.
According to the disclosure, the object addressed is achieved with the circuit arrangement, the converter, the aircraft, and the method disclosed herein. The scope of the present disclosure is defined solely by the appended claims and is not affected to any degree by the statements within this summary. The present embodiments may obviate one or more of the drawbacks or limitations in the related art.
In a design variant, the power semiconductors are prefabricated with a carrier ceramic (CKV) and then joined to a circuit carrier (e.g., soldering, sintering). In addition to the power semiconductor chip, which is contacted in this manner on its second side, further contacts are implemented.
This is achieved using so-called change-overs that act as spacers, e.g., conductive elements which roughly correspond in height to the power semiconductor chip and are also joined in addition to the chip (if necessary, simultaneously with the chip by soldering or sintering). In the simplest case, the change-overs are metallic formed parts (e.g., punched parts).
If a current path to be measured is routed through these change-overs, it may be used for current measurement by tapping the electrical potential directly above and directly below and then feeding it to a voltage measuring device. In this case, the change-over is used as a shunt at the same time, because it is required anyway and is arranged in the current path (e.g., series circuit).
A circuit arrangement is disclosed herein. The circuit arrangement has a circuit carrier board, a power semiconductor arranged on the underside of the circuit carrier board, and a wiring carrier board arranged underneath the power semiconductor. The circuit arrangement also includes a metallic first spacer element (=change-over) arranged between the circuit carrier board and the wiring carrier board and through which an electrical load current of the power semiconductor flows. The first spacer element acts as a shunt through which current flows. The circuit arrangement also includes a voltage measuring unit through which a voltage drop across the first spacer element, produced by the load current flow, may be determined.
The disclosure offers the advantage of measuring a load current in a simple and space-saving manner.
In an extension, the height of the first spacer element may be approximately the same as the height of the power semiconductor.
In another embodiment, the circuit carrier board may be a DCB-substrate board.
The circuit arrangement may also have electrical and/or electronic assemblies arranged on the top of the circuit carrier board.
In a further embodiment, a heat sink may be arranged on the top of the circuit carrier board.
In addition, a second metal spacer element (=change-over) may be arranged between the circuit carrier board and the wiring carrier board, via which the power semiconductor may be activated and/or the current measurement controlled.
A converter with a circuit arrangement is also disclosed herein.
In addition, an aircraft with a converter and an electric motor as an electric drive of the aircraft is also disclosed herein, wherein the electric motor may be supplied with electrical energy by the converter.
The aircraft may have a propeller driven by the electric motor.
Finally, a method is disclosed for measuring current in a power semiconductor having a circuit arrangement, wherein the load current of the power semiconductor is passed through the first spacer element and the voltage drop across the first spacer element due to the load current is determined.
Further special features and advantages of the disclosure are described in the following explanations of an exemplary embodiment using schematic drawings.
The load current of the power semiconductor 2 flows through the metallic first spacer element 4. The first spacer element 4 has a defined, known resistance and is used as a shunt for current measurement. To determine the load current, the voltage drop along the first spacer element 4 is determined using the voltage measuring unit 5, and the load current is determined from this. The first spacer element 4 is also referred to as a “change-over” because the current path “changes over” from the wiring carrier board 3 to the circuit carrier board 1.
Electrical or electronic assemblies 6, or simply heat sinks, are arranged on the side of the circuit carrier board 1 facing the power semiconductor 2.
The power semiconductor 2 may be activated and/or the current measurement may be controlled by the metallic second spacer element 7.
Although the disclosure has been illustrated and described in greater detail by the exemplary embodiments, the disclosure is not restricted by the examples disclosed, and other variations may be derived therefrom by the person skilled in the art without departing from the scope of protection of the disclosure.
It is to be understood that the elements and features recited in the appended claims may be combined in different ways to produce new claims that likewise fall within the scope of the present disclosure. Thus, whereas the dependent claims appended below depend from only a single independent or dependent claim, it is to be understood that these dependent claims may, alternatively, be made to depend in the alternative from any preceding or following claim, whether independent or dependent, and that such new combinations are to be understood as forming a part of the present specification.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2018 204 865.7 | Mar 2018 | DE | national |
The present patent document is a § 371 nationalization of PCT Application Serial No. PCT/EP2019/054943, filed Feb. 28, 2019, designating the United States, which is hereby incorporated by reference, and this patent document also claims the benefit of German Patent Application No. 10 2018 204 865.7, filed Mar. 29, 2018, which is also hereby incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2019/054943 | 2/28/2019 | WO | 00 |
